^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * XArray implementation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * Copyright (c) 2017-2018 Microsoft Corporation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (c) 2018-2020 Oracle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Author: Matthew Wilcox <willy@infradead.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/bitmap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/list.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/xarray.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * Coding conventions in this file:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * @xa is used to refer to the entire xarray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * @xas is the 'xarray operation state'. It may be either a pointer to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * an xa_state, or an xa_state stored on the stack. This is an unfortunate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * ambiguity.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * @index is the index of the entry being operated on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) * @mark is an xa_mark_t; a small number indicating one of the mark bits.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * @node refers to an xa_node; usually the primary one being operated on by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * this function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * @offset is the index into the slots array inside an xa_node.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * @parent refers to the @xa_node closer to the head than @node.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * @entry refers to something stored in a slot in the xarray
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) static inline unsigned int xa_lock_type(const struct xarray *xa)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) return (__force unsigned int)xa->xa_flags & 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) static inline void xas_lock_type(struct xa_state *xas, unsigned int lock_type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) if (lock_type == XA_LOCK_IRQ)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) xas_lock_irq(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) else if (lock_type == XA_LOCK_BH)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) xas_lock_bh(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) xas_lock(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) static inline void xas_unlock_type(struct xa_state *xas, unsigned int lock_type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) if (lock_type == XA_LOCK_IRQ)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) xas_unlock_irq(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) else if (lock_type == XA_LOCK_BH)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) xas_unlock_bh(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) xas_unlock(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) static inline bool xa_track_free(const struct xarray *xa)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) return xa->xa_flags & XA_FLAGS_TRACK_FREE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) static inline bool xa_zero_busy(const struct xarray *xa)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) return xa->xa_flags & XA_FLAGS_ZERO_BUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) static inline void xa_mark_set(struct xarray *xa, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) if (!(xa->xa_flags & XA_FLAGS_MARK(mark)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) xa->xa_flags |= XA_FLAGS_MARK(mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) static inline void xa_mark_clear(struct xarray *xa, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) if (xa->xa_flags & XA_FLAGS_MARK(mark))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) xa->xa_flags &= ~(XA_FLAGS_MARK(mark));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) static inline unsigned long *node_marks(struct xa_node *node, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) return node->marks[(__force unsigned)mark];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) static inline bool node_get_mark(struct xa_node *node,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) unsigned int offset, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) return test_bit(offset, node_marks(node, mark));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) /* returns true if the bit was set */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) static inline bool node_set_mark(struct xa_node *node, unsigned int offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) return __test_and_set_bit(offset, node_marks(node, mark));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) /* returns true if the bit was set */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) static inline bool node_clear_mark(struct xa_node *node, unsigned int offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) return __test_and_clear_bit(offset, node_marks(node, mark));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) static inline bool node_any_mark(struct xa_node *node, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) return !bitmap_empty(node_marks(node, mark), XA_CHUNK_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) static inline void node_mark_all(struct xa_node *node, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) bitmap_fill(node_marks(node, mark), XA_CHUNK_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) #define mark_inc(mark) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) mark = (__force xa_mark_t)((__force unsigned)(mark) + 1); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) * xas_squash_marks() - Merge all marks to the first entry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) * @xas: Array operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) * Set a mark on the first entry if any entry has it set. Clear marks on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) * all sibling entries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) static void xas_squash_marks(const struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) unsigned int mark = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) unsigned int limit = xas->xa_offset + xas->xa_sibs + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) if (!xas->xa_sibs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) unsigned long *marks = xas->xa_node->marks[mark];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) if (find_next_bit(marks, limit, xas->xa_offset + 1) == limit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) __set_bit(xas->xa_offset, marks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) bitmap_clear(marks, xas->xa_offset + 1, xas->xa_sibs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) } while (mark++ != (__force unsigned)XA_MARK_MAX);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) /* extracts the offset within this node from the index */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) static unsigned int get_offset(unsigned long index, struct xa_node *node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) return (index >> node->shift) & XA_CHUNK_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) static void xas_set_offset(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) xas->xa_offset = get_offset(xas->xa_index, xas->xa_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) /* move the index either forwards (find) or backwards (sibling slot) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) static void xas_move_index(struct xa_state *xas, unsigned long offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) unsigned int shift = xas->xa_node->shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) xas->xa_index &= ~XA_CHUNK_MASK << shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) xas->xa_index += offset << shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) static void xas_advance(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) xas->xa_offset++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) xas_move_index(xas, xas->xa_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) static void *set_bounds(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) xas->xa_node = XAS_BOUNDS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) * Starts a walk. If the @xas is already valid, we assume that it's on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) * the right path and just return where we've got to. If we're in an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) * error state, return NULL. If the index is outside the current scope
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) * of the xarray, return NULL without changing @xas->xa_node. Otherwise
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) * set @xas->xa_node to NULL and return the current head of the array.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) static void *xas_start(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) if (xas_valid(xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) return xas_reload(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) if (xas_error(xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) entry = xa_head(xas->xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) if (!xa_is_node(entry)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) if (xas->xa_index)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) return set_bounds(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) if ((xas->xa_index >> xa_to_node(entry)->shift) > XA_CHUNK_MASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) return set_bounds(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) xas->xa_node = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) static void *xas_descend(struct xa_state *xas, struct xa_node *node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) unsigned int offset = get_offset(xas->xa_index, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) void *entry = xa_entry(xas->xa, node, offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) xas->xa_node = node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) if (xa_is_sibling(entry)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) offset = xa_to_sibling(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) entry = xa_entry(xas->xa, node, offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) xas->xa_offset = offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) * xas_load() - Load an entry from the XArray (advanced).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) * Usually walks the @xas to the appropriate state to load the entry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) * stored at xa_index. However, it will do nothing and return %NULL if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) * @xas is in an error state. xas_load() will never expand the tree.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) * If the xa_state is set up to operate on a multi-index entry, xas_load()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) * may return %NULL or an internal entry, even if there are entries
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) * present within the range specified by @xas.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) * Context: Any context. The caller should hold the xa_lock or the RCU lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) * Return: Usually an entry in the XArray, but see description for exceptions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) void *xas_load(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) void *entry = xas_start(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) while (xa_is_node(entry)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) struct xa_node *node = xa_to_node(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) if (xas->xa_shift > node->shift)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) entry = xas_descend(xas, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) if (node->shift == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) EXPORT_SYMBOL_GPL(xas_load);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) /* Move the radix tree node cache here */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) extern struct kmem_cache *radix_tree_node_cachep;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) extern void radix_tree_node_rcu_free(struct rcu_head *head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) #define XA_RCU_FREE ((struct xarray *)1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) static void xa_node_free(struct xa_node *node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) XA_NODE_BUG_ON(node, !list_empty(&node->private_list));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) node->array = XA_RCU_FREE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) call_rcu(&node->rcu_head, radix_tree_node_rcu_free);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) * xas_destroy() - Free any resources allocated during the XArray operation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) * This function is now internal-only.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) static void xas_destroy(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) struct xa_node *next, *node = xas->xa_alloc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) while (node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) XA_NODE_BUG_ON(node, !list_empty(&node->private_list));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) next = rcu_dereference_raw(node->parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) radix_tree_node_rcu_free(&node->rcu_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) xas->xa_alloc = node = next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) * xas_nomem() - Allocate memory if needed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) * @gfp: Memory allocation flags.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) * If we need to add new nodes to the XArray, we try to allocate memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) * with GFP_NOWAIT while holding the lock, which will usually succeed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) * If it fails, @xas is flagged as needing memory to continue. The caller
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) * should drop the lock and call xas_nomem(). If xas_nomem() succeeds,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) * the caller should retry the operation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) * Forward progress is guaranteed as one node is allocated here and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) * stored in the xa_state where it will be found by xas_alloc(). More
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) * nodes will likely be found in the slab allocator, but we do not tie
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) * them up here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) * Return: true if memory was needed, and was successfully allocated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) bool xas_nomem(struct xa_state *xas, gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) if (xas->xa_node != XA_ERROR(-ENOMEM)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) xas_destroy(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) if (xas->xa->xa_flags & XA_FLAGS_ACCOUNT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) gfp |= __GFP_ACCOUNT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) if (!xas->xa_alloc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) xas->xa_alloc->parent = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) XA_NODE_BUG_ON(xas->xa_alloc, !list_empty(&xas->xa_alloc->private_list));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) xas->xa_node = XAS_RESTART;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) EXPORT_SYMBOL_GPL(xas_nomem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) * __xas_nomem() - Drop locks and allocate memory if needed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) * @gfp: Memory allocation flags.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) * Internal variant of xas_nomem().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) * Return: true if memory was needed, and was successfully allocated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) static bool __xas_nomem(struct xa_state *xas, gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) __must_hold(xas->xa->xa_lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) unsigned int lock_type = xa_lock_type(xas->xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) if (xas->xa_node != XA_ERROR(-ENOMEM)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) xas_destroy(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) if (xas->xa->xa_flags & XA_FLAGS_ACCOUNT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) gfp |= __GFP_ACCOUNT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) if (gfpflags_allow_blocking(gfp)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) xas_unlock_type(xas, lock_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) xas_lock_type(xas, lock_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) if (!xas->xa_alloc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) xas->xa_alloc->parent = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) XA_NODE_BUG_ON(xas->xa_alloc, !list_empty(&xas->xa_alloc->private_list));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) xas->xa_node = XAS_RESTART;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) static void xas_update(struct xa_state *xas, struct xa_node *node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) if (xas->xa_update)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) xas->xa_update(node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) XA_NODE_BUG_ON(node, !list_empty(&node->private_list));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) static void *xas_alloc(struct xa_state *xas, unsigned int shift)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) struct xa_node *parent = xas->xa_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) struct xa_node *node = xas->xa_alloc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) if (xas_invalid(xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) if (node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) xas->xa_alloc = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) gfp_t gfp = GFP_NOWAIT | __GFP_NOWARN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) if (xas->xa->xa_flags & XA_FLAGS_ACCOUNT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) gfp |= __GFP_ACCOUNT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) node = kmem_cache_alloc(radix_tree_node_cachep, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) if (!node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) xas_set_err(xas, -ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) if (parent) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) node->offset = xas->xa_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) parent->count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) XA_NODE_BUG_ON(node, parent->count > XA_CHUNK_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) xas_update(xas, parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) XA_NODE_BUG_ON(node, shift > BITS_PER_LONG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) XA_NODE_BUG_ON(node, !list_empty(&node->private_list));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) node->shift = shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) node->count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) node->nr_values = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) RCU_INIT_POINTER(node->parent, xas->xa_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) node->array = xas->xa;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) return node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) #ifdef CONFIG_XARRAY_MULTI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) /* Returns the number of indices covered by a given xa_state */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) static unsigned long xas_size(const struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) return (xas->xa_sibs + 1UL) << xas->xa_shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) * Use this to calculate the maximum index that will need to be created
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) * in order to add the entry described by @xas. Because we cannot store a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) * multi-index entry at index 0, the calculation is a little more complex
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) * than you might expect.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) static unsigned long xas_max(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) unsigned long max = xas->xa_index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) #ifdef CONFIG_XARRAY_MULTI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) if (xas->xa_shift || xas->xa_sibs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) unsigned long mask = xas_size(xas) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) max |= mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) if (mask == max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) max++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) return max;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) /* The maximum index that can be contained in the array without expanding it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) static unsigned long max_index(void *entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) if (!xa_is_node(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) return (XA_CHUNK_SIZE << xa_to_node(entry)->shift) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) static void xas_shrink(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) struct xarray *xa = xas->xa;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) struct xa_node *node = xas->xa_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) XA_NODE_BUG_ON(node, node->count > XA_CHUNK_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) if (node->count != 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) entry = xa_entry_locked(xa, node, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) if (!entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) if (!xa_is_node(entry) && node->shift)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) if (xa_is_zero(entry) && xa_zero_busy(xa))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) entry = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) xas->xa_node = XAS_BOUNDS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) RCU_INIT_POINTER(xa->xa_head, entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) if (xa_track_free(xa) && !node_get_mark(node, 0, XA_FREE_MARK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) xa_mark_clear(xa, XA_FREE_MARK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) node->count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) node->nr_values = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) if (!xa_is_node(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) RCU_INIT_POINTER(node->slots[0], XA_RETRY_ENTRY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) xas_update(xas, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) xa_node_free(node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) if (!xa_is_node(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) node = xa_to_node(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) node->parent = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) * xas_delete_node() - Attempt to delete an xa_node
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) * @xas: Array operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) * Attempts to delete the @xas->xa_node. This will fail if xa->node has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) * a non-zero reference count.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) static void xas_delete_node(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) struct xa_node *node = xas->xa_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) struct xa_node *parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) XA_NODE_BUG_ON(node, node->count > XA_CHUNK_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) if (node->count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) parent = xa_parent_locked(xas->xa, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) xas->xa_node = parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) xas->xa_offset = node->offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) xa_node_free(node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) if (!parent) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) xas->xa->xa_head = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) xas->xa_node = XAS_BOUNDS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) parent->slots[xas->xa_offset] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) parent->count--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) XA_NODE_BUG_ON(parent, parent->count > XA_CHUNK_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) node = parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) xas_update(xas, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) if (!node->parent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) xas_shrink(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) * xas_free_nodes() - Free this node and all nodes that it references
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) * @xas: Array operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) * @top: Node to free
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) * This node has been removed from the tree. We must now free it and all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) * of its subnodes. There may be RCU walkers with references into the tree,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) * so we must replace all entries with retry markers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) static void xas_free_nodes(struct xa_state *xas, struct xa_node *top)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) unsigned int offset = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) struct xa_node *node = top;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) void *entry = xa_entry_locked(xas->xa, node, offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) if (node->shift && xa_is_node(entry)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) node = xa_to_node(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) offset = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) if (entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) RCU_INIT_POINTER(node->slots[offset], XA_RETRY_ENTRY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) offset++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) while (offset == XA_CHUNK_SIZE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) struct xa_node *parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) parent = xa_parent_locked(xas->xa, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) offset = node->offset + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) node->count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) node->nr_values = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) xas_update(xas, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) xa_node_free(node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) if (node == top)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) node = parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) * xas_expand adds nodes to the head of the tree until it has reached
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) * sufficient height to be able to contain @xas->xa_index
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) static int xas_expand(struct xa_state *xas, void *head)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) struct xarray *xa = xas->xa;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) struct xa_node *node = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) unsigned int shift = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) unsigned long max = xas_max(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) if (!head) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) if (max == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) while ((max >> shift) >= XA_CHUNK_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) shift += XA_CHUNK_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) return shift + XA_CHUNK_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) } else if (xa_is_node(head)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) node = xa_to_node(head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) shift = node->shift + XA_CHUNK_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) xas->xa_node = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) while (max > max_index(head)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) xa_mark_t mark = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) XA_NODE_BUG_ON(node, shift > BITS_PER_LONG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) node = xas_alloc(xas, shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) if (!node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) node->count = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) if (xa_is_value(head))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) node->nr_values = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) RCU_INIT_POINTER(node->slots[0], head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) /* Propagate the aggregated mark info to the new child */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) if (xa_track_free(xa) && mark == XA_FREE_MARK) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) node_mark_all(node, XA_FREE_MARK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) if (!xa_marked(xa, XA_FREE_MARK)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) node_clear_mark(node, 0, XA_FREE_MARK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) xa_mark_set(xa, XA_FREE_MARK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) } else if (xa_marked(xa, mark)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) node_set_mark(node, 0, mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) if (mark == XA_MARK_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) mark_inc(mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) * Now that the new node is fully initialised, we can add
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) * it to the tree
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) if (xa_is_node(head)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) xa_to_node(head)->offset = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) rcu_assign_pointer(xa_to_node(head)->parent, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) head = xa_mk_node(node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) rcu_assign_pointer(xa->xa_head, head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) xas_update(xas, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) shift += XA_CHUNK_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) xas->xa_node = node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) return shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) * xas_create() - Create a slot to store an entry in.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) * @allow_root: %true if we can store the entry in the root directly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) * Most users will not need to call this function directly, as it is called
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) * by xas_store(). It is useful for doing conditional store operations
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) * (see the xa_cmpxchg() implementation for an example).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) * Return: If the slot already existed, returns the contents of this slot.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) * If the slot was newly created, returns %NULL. If it failed to create the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) * slot, returns %NULL and indicates the error in @xas.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) static void *xas_create(struct xa_state *xas, bool allow_root)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) struct xarray *xa = xas->xa;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) void __rcu **slot;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) struct xa_node *node = xas->xa_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) int shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) unsigned int order = xas->xa_shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) if (xas_top(node)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) entry = xa_head_locked(xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) xas->xa_node = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) if (!entry && xa_zero_busy(xa))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) entry = XA_ZERO_ENTRY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) shift = xas_expand(xas, entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) if (shift < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) if (!shift && !allow_root)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) shift = XA_CHUNK_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) entry = xa_head_locked(xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) slot = &xa->xa_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) } else if (xas_error(xas)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) } else if (node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) unsigned int offset = xas->xa_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) shift = node->shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) entry = xa_entry_locked(xa, node, offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) slot = &node->slots[offset];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) shift = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) entry = xa_head_locked(xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) slot = &xa->xa_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) while (shift > order) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) shift -= XA_CHUNK_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) if (!entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) node = xas_alloc(xas, shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) if (!node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) if (xa_track_free(xa))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) node_mark_all(node, XA_FREE_MARK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) rcu_assign_pointer(*slot, xa_mk_node(node));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) } else if (xa_is_node(entry)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) node = xa_to_node(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) entry = xas_descend(xas, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) slot = &node->slots[xas->xa_offset];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) * xas_create_range() - Ensure that stores to this range will succeed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) * Creates all of the slots in the range covered by @xas. Sets @xas to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) * create single-index entries and positions it at the beginning of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) * range. This is for the benefit of users which have not yet been
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) * converted to use multi-index entries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) void xas_create_range(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) unsigned long index = xas->xa_index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) unsigned char shift = xas->xa_shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) unsigned char sibs = xas->xa_sibs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) xas->xa_index |= ((sibs + 1UL) << shift) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) if (xas_is_node(xas) && xas->xa_node->shift == xas->xa_shift)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) xas->xa_offset |= sibs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) xas->xa_shift = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) xas->xa_sibs = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) xas_create(xas, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) if (xas_error(xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) goto restore;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) if (xas->xa_index <= (index | XA_CHUNK_MASK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) goto success;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) xas->xa_index -= XA_CHUNK_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) struct xa_node *node = xas->xa_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) if (node->shift >= shift)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) xas->xa_node = xa_parent_locked(xas->xa, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) xas->xa_offset = node->offset - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) if (node->offset != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) restore:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) xas->xa_shift = shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) xas->xa_sibs = sibs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) xas->xa_index = index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) success:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) xas->xa_index = index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) if (xas->xa_node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) xas_set_offset(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) EXPORT_SYMBOL_GPL(xas_create_range);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) static void update_node(struct xa_state *xas, struct xa_node *node,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) int count, int values)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) if (!node || (!count && !values))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) node->count += count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) node->nr_values += values;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) XA_NODE_BUG_ON(node, node->count > XA_CHUNK_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) XA_NODE_BUG_ON(node, node->nr_values > XA_CHUNK_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) xas_update(xas, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) if (count < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) xas_delete_node(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) * xas_store() - Store this entry in the XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) * @entry: New entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) * If @xas is operating on a multi-index entry, the entry returned by this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) * function is essentially meaningless (it may be an internal entry or it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) * may be %NULL, even if there are non-NULL entries at some of the indices
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) * covered by the range). This is not a problem for any current users,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) * and can be changed if needed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) * Return: The old entry at this index.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) void *xas_store(struct xa_state *xas, void *entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) struct xa_node *node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777) void __rcu **slot = &xas->xa->xa_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) unsigned int offset, max;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) int count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) int values = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) void *first, *next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) bool value = xa_is_value(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) if (entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) bool allow_root = !xa_is_node(entry) && !xa_is_zero(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) first = xas_create(xas, allow_root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) first = xas_load(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791) if (xas_invalid(xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) return first;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793) node = xas->xa_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) if (node && (xas->xa_shift < node->shift))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) xas->xa_sibs = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) if ((first == entry) && !xas->xa_sibs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) return first;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) next = first;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) offset = xas->xa_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) max = xas->xa_offset + xas->xa_sibs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) if (node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803) slot = &node->slots[offset];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) if (xas->xa_sibs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805) xas_squash_marks(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) if (!entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808) xas_init_marks(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) * Must clear the marks before setting the entry to NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) * otherwise xas_for_each_marked may find a NULL entry and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) * stop early. rcu_assign_pointer contains a release barrier
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815) * so the mark clearing will appear to happen before the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) * entry is set to NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818) rcu_assign_pointer(*slot, entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) if (xa_is_node(next) && (!node || node->shift))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) xas_free_nodes(xas, xa_to_node(next));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) if (!node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823) count += !next - !entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) values += !xa_is_value(first) - !value;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825) if (entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826) if (offset == max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) if (!xa_is_sibling(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829) entry = xa_mk_sibling(xas->xa_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831) if (offset == XA_CHUNK_MASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) next = xa_entry_locked(xas->xa, node, ++offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835) if (!xa_is_sibling(next)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) if (!entry && (offset > max))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838) first = next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) slot++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843) update_node(xas, node, count, values);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) return first;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846) EXPORT_SYMBOL_GPL(xas_store);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849) * xas_get_mark() - Returns the state of this mark.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851) * @mark: Mark number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853) * Return: true if the mark is set, false if the mark is clear or @xas
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) * is in an error state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) bool xas_get_mark(const struct xa_state *xas, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) if (xas_invalid(xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) if (!xas->xa_node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) return xa_marked(xas->xa, mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862) return node_get_mark(xas->xa_node, xas->xa_offset, mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) EXPORT_SYMBOL_GPL(xas_get_mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867) * xas_set_mark() - Sets the mark on this entry and its parents.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869) * @mark: Mark number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871) * Sets the specified mark on this entry, and walks up the tree setting it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872) * on all the ancestor entries. Does nothing if @xas has not been walked to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873) * an entry, or is in an error state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) void xas_set_mark(const struct xa_state *xas, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877) struct xa_node *node = xas->xa_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) unsigned int offset = xas->xa_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880) if (xas_invalid(xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 881) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 882)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 883) while (node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 884) if (node_set_mark(node, offset, mark))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886) offset = node->offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887) node = xa_parent_locked(xas->xa, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890) if (!xa_marked(xas->xa, mark))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) xa_mark_set(xas->xa, mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893) EXPORT_SYMBOL_GPL(xas_set_mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896) * xas_clear_mark() - Clears the mark on this entry and its parents.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898) * @mark: Mark number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900) * Clears the specified mark on this entry, and walks back to the head
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901) * attempting to clear it on all the ancestor entries. Does nothing if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902) * @xas has not been walked to an entry, or is in an error state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904) void xas_clear_mark(const struct xa_state *xas, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906) struct xa_node *node = xas->xa_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907) unsigned int offset = xas->xa_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909) if (xas_invalid(xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912) while (node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913) if (!node_clear_mark(node, offset, mark))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915) if (node_any_mark(node, mark))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918) offset = node->offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919) node = xa_parent_locked(xas->xa, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922) if (xa_marked(xas->xa, mark))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923) xa_mark_clear(xas->xa, mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925) EXPORT_SYMBOL_GPL(xas_clear_mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928) * xas_init_marks() - Initialise all marks for the entry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929) * @xas: Array operations state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931) * Initialise all marks for the entry specified by @xas. If we're tracking
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932) * free entries with a mark, we need to set it on all entries. All other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933) * marks are cleared.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935) * This implementation is not as efficient as it could be; we may walk
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936) * up the tree multiple times.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938) void xas_init_marks(const struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) xa_mark_t mark = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943) if (xa_track_free(xas->xa) && mark == XA_FREE_MARK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944) xas_set_mark(xas, mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946) xas_clear_mark(xas, mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947) if (mark == XA_MARK_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949) mark_inc(mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952) EXPORT_SYMBOL_GPL(xas_init_marks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954) #ifdef CONFIG_XARRAY_MULTI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955) static unsigned int node_get_marks(struct xa_node *node, unsigned int offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 957) unsigned int marks = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 958) xa_mark_t mark = XA_MARK_0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 959)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) if (node_get_mark(node, offset, mark))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962) marks |= 1 << (__force unsigned int)mark;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) if (mark == XA_MARK_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965) mark_inc(mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968) return marks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971) static void node_set_marks(struct xa_node *node, unsigned int offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972) struct xa_node *child, unsigned int marks)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974) xa_mark_t mark = XA_MARK_0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) if (marks & (1 << (__force unsigned int)mark)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978) node_set_mark(node, offset, mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979) if (child)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) node_mark_all(child, mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982) if (mark == XA_MARK_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984) mark_inc(mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 987)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 988) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 989) * xas_split_alloc() - Allocate memory for splitting an entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991) * @entry: New entry which will be stored in the array.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992) * @order: New entry order.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) * @gfp: Memory allocation flags.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) * This function should be called before calling xas_split().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996) * If necessary, it will allocate new nodes (and fill them with @entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997) * to prepare for the upcoming split of an entry of @order size into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998) * entries of the order stored in the @xas.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000) * Context: May sleep if @gfp flags permit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002) void xas_split_alloc(struct xa_state *xas, void *entry, unsigned int order,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003) gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) unsigned int sibs = (1 << (order % XA_CHUNK_SHIFT)) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006) unsigned int mask = xas->xa_sibs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008) /* XXX: no support for splitting really large entries yet */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009) if (WARN_ON(xas->xa_shift + 2 * XA_CHUNK_SHIFT < order))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010) goto nomem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) if (xas->xa_shift + XA_CHUNK_SHIFT > order)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1014) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1015) unsigned int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1016) void *sibling = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1017) struct xa_node *node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1018)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1019) node = kmem_cache_alloc(radix_tree_node_cachep, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1020) if (!node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1021) goto nomem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1022) node->array = xas->xa;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1023) for (i = 0; i < XA_CHUNK_SIZE; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1024) if ((i & mask) == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1025) RCU_INIT_POINTER(node->slots[i], entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1026) sibling = xa_mk_sibling(i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1027) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1028) RCU_INIT_POINTER(node->slots[i], sibling);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1029) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1030) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1031) RCU_INIT_POINTER(node->parent, xas->xa_alloc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1032) xas->xa_alloc = node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1033) } while (sibs-- > 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1034)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1035) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1036) nomem:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1037) xas_destroy(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1038) xas_set_err(xas, -ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1039) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1040) EXPORT_SYMBOL_GPL(xas_split_alloc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1041)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1042) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1043) * xas_split() - Split a multi-index entry into smaller entries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1044) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1045) * @entry: New entry to store in the array.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1046) * @order: New entry order.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1047) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1048) * The value in the entry is copied to all the replacement entries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1049) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1050) * Context: Any context. The caller should hold the xa_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1051) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1052) void xas_split(struct xa_state *xas, void *entry, unsigned int order)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1053) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1054) unsigned int sibs = (1 << (order % XA_CHUNK_SHIFT)) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1055) unsigned int offset, marks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1056) struct xa_node *node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1057) void *curr = xas_load(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1058) int values = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1059)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1060) node = xas->xa_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1061) if (xas_top(node))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1062) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1063)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1064) marks = node_get_marks(node, xas->xa_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1065)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1066) offset = xas->xa_offset + sibs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1067) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1068) if (xas->xa_shift < node->shift) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1069) struct xa_node *child = xas->xa_alloc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1070)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1071) xas->xa_alloc = rcu_dereference_raw(child->parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1072) child->shift = node->shift - XA_CHUNK_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1073) child->offset = offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1074) child->count = XA_CHUNK_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1075) child->nr_values = xa_is_value(entry) ?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1076) XA_CHUNK_SIZE : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1077) RCU_INIT_POINTER(child->parent, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1078) node_set_marks(node, offset, child, marks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1079) rcu_assign_pointer(node->slots[offset],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1080) xa_mk_node(child));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1081) if (xa_is_value(curr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1082) values--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1083) xas_update(xas, child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1084) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1085) unsigned int canon = offset - xas->xa_sibs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1086)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1087) node_set_marks(node, canon, NULL, marks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1088) rcu_assign_pointer(node->slots[canon], entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1089) while (offset > canon)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1090) rcu_assign_pointer(node->slots[offset--],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1091) xa_mk_sibling(canon));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1092) values += (xa_is_value(entry) - xa_is_value(curr)) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1093) (xas->xa_sibs + 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1094) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1095) } while (offset-- > xas->xa_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1096)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1097) node->nr_values += values;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1098) xas_update(xas, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1099) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1100) EXPORT_SYMBOL_GPL(xas_split);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1101) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1103) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1104) * xas_pause() - Pause a walk to drop a lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1105) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1106) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1107) * Some users need to pause a walk and drop the lock they're holding in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1108) * order to yield to a higher priority thread or carry out an operation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1109) * on an entry. Those users should call this function before they drop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1110) * the lock. It resets the @xas to be suitable for the next iteration
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1111) * of the loop after the user has reacquired the lock. If most entries
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1112) * found during a walk require you to call xas_pause(), the xa_for_each()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1113) * iterator may be more appropriate.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1114) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1115) * Note that xas_pause() only works for forward iteration. If a user needs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1116) * to pause a reverse iteration, we will need a xas_pause_rev().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1117) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1118) void xas_pause(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1119) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1120) struct xa_node *node = xas->xa_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1122) if (xas_invalid(xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1123) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1125) xas->xa_node = XAS_RESTART;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1126) if (node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1127) unsigned long offset = xas->xa_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1128) while (++offset < XA_CHUNK_SIZE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1129) if (!xa_is_sibling(xa_entry(xas->xa, node, offset)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1130) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1131) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1132) xas->xa_index += (offset - xas->xa_offset) << node->shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1133) if (xas->xa_index == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1134) xas->xa_node = XAS_BOUNDS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1135) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1136) xas->xa_index++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1137) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1138) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1139) EXPORT_SYMBOL_GPL(xas_pause);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1141) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1142) * __xas_prev() - Find the previous entry in the XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1143) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1144) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1145) * Helper function for xas_prev() which handles all the complex cases
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1146) * out of line.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1147) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1148) void *__xas_prev(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1149) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1150) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1152) if (!xas_frozen(xas->xa_node))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1153) xas->xa_index--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1154) if (!xas->xa_node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1155) return set_bounds(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1156) if (xas_not_node(xas->xa_node))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1157) return xas_load(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1159) if (xas->xa_offset != get_offset(xas->xa_index, xas->xa_node))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1160) xas->xa_offset--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1162) while (xas->xa_offset == 255) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1163) xas->xa_offset = xas->xa_node->offset - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1164) xas->xa_node = xa_parent(xas->xa, xas->xa_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1165) if (!xas->xa_node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1166) return set_bounds(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1167) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1169) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1170) entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1171) if (!xa_is_node(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1172) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1174) xas->xa_node = xa_to_node(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1175) xas_set_offset(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1176) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1177) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1178) EXPORT_SYMBOL_GPL(__xas_prev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1180) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1181) * __xas_next() - Find the next entry in the XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1182) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1183) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1184) * Helper function for xas_next() which handles all the complex cases
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1185) * out of line.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1186) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1187) void *__xas_next(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1188) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1189) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1190)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1191) if (!xas_frozen(xas->xa_node))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1192) xas->xa_index++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1193) if (!xas->xa_node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1194) return set_bounds(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1195) if (xas_not_node(xas->xa_node))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1196) return xas_load(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1197)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1198) if (xas->xa_offset != get_offset(xas->xa_index, xas->xa_node))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1199) xas->xa_offset++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1200)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1201) while (xas->xa_offset == XA_CHUNK_SIZE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1202) xas->xa_offset = xas->xa_node->offset + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1203) xas->xa_node = xa_parent(xas->xa, xas->xa_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1204) if (!xas->xa_node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1205) return set_bounds(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1206) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1207)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1208) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1209) entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1210) if (!xa_is_node(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1211) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1212)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1213) xas->xa_node = xa_to_node(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1214) xas_set_offset(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1215) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1216) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1217) EXPORT_SYMBOL_GPL(__xas_next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1219) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1220) * xas_find() - Find the next present entry in the XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1221) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1222) * @max: Highest index to return.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1223) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1224) * If the @xas has not yet been walked to an entry, return the entry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1225) * which has an index >= xas.xa_index. If it has been walked, the entry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1226) * currently being pointed at has been processed, and so we move to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1227) * next entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1228) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1229) * If no entry is found and the array is smaller than @max, the iterator
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1230) * is set to the smallest index not yet in the array. This allows @xas
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1231) * to be immediately passed to xas_store().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1232) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1233) * Return: The entry, if found, otherwise %NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1234) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1235) void *xas_find(struct xa_state *xas, unsigned long max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1236) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1237) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1239) if (xas_error(xas) || xas->xa_node == XAS_BOUNDS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1240) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1241) if (xas->xa_index > max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1242) return set_bounds(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1243)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1244) if (!xas->xa_node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1245) xas->xa_index = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1246) return set_bounds(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1247) } else if (xas->xa_node == XAS_RESTART) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1248) entry = xas_load(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1249) if (entry || xas_not_node(xas->xa_node))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1250) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1251) } else if (!xas->xa_node->shift &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1252) xas->xa_offset != (xas->xa_index & XA_CHUNK_MASK)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1253) xas->xa_offset = ((xas->xa_index - 1) & XA_CHUNK_MASK) + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1254) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1256) xas_advance(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1257)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1258) while (xas->xa_node && (xas->xa_index <= max)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1259) if (unlikely(xas->xa_offset == XA_CHUNK_SIZE)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1260) xas->xa_offset = xas->xa_node->offset + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1261) xas->xa_node = xa_parent(xas->xa, xas->xa_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1262) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1263) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1264)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1265) entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1266) if (xa_is_node(entry)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1267) xas->xa_node = xa_to_node(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1268) xas->xa_offset = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1269) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1270) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1271) if (entry && !xa_is_sibling(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1272) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1273)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1274) xas_advance(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1275) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1276)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1277) if (!xas->xa_node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1278) xas->xa_node = XAS_BOUNDS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1279) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1280) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1281) EXPORT_SYMBOL_GPL(xas_find);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1282)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1283) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1284) * xas_find_marked() - Find the next marked entry in the XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1285) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1286) * @max: Highest index to return.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1287) * @mark: Mark number to search for.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1288) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1289) * If the @xas has not yet been walked to an entry, return the marked entry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1290) * which has an index >= xas.xa_index. If it has been walked, the entry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1291) * currently being pointed at has been processed, and so we return the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1292) * first marked entry with an index > xas.xa_index.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1293) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1294) * If no marked entry is found and the array is smaller than @max, @xas is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1295) * set to the bounds state and xas->xa_index is set to the smallest index
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1296) * not yet in the array. This allows @xas to be immediately passed to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1297) * xas_store().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1298) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1299) * If no entry is found before @max is reached, @xas is set to the restart
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1300) * state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1301) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1302) * Return: The entry, if found, otherwise %NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1303) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1304) void *xas_find_marked(struct xa_state *xas, unsigned long max, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1305) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1306) bool advance = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1307) unsigned int offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1308) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1309)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1310) if (xas_error(xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1311) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1312) if (xas->xa_index > max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1313) goto max;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1314)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1315) if (!xas->xa_node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1316) xas->xa_index = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1317) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1318) } else if (xas_top(xas->xa_node)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1319) advance = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1320) entry = xa_head(xas->xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1321) xas->xa_node = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1322) if (xas->xa_index > max_index(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1323) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1324) if (!xa_is_node(entry)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1325) if (xa_marked(xas->xa, mark))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1326) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1327) xas->xa_index = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1328) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1329) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1330) xas->xa_node = xa_to_node(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1331) xas->xa_offset = xas->xa_index >> xas->xa_node->shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1332) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1333)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1334) while (xas->xa_index <= max) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1335) if (unlikely(xas->xa_offset == XA_CHUNK_SIZE)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1336) xas->xa_offset = xas->xa_node->offset + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1337) xas->xa_node = xa_parent(xas->xa, xas->xa_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1338) if (!xas->xa_node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1339) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1340) advance = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1341) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1342) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1343)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1344) if (!advance) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1345) entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1346) if (xa_is_sibling(entry)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1347) xas->xa_offset = xa_to_sibling(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1348) xas_move_index(xas, xas->xa_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1349) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1350) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1352) offset = xas_find_chunk(xas, advance, mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1353) if (offset > xas->xa_offset) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1354) advance = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1355) xas_move_index(xas, offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1356) /* Mind the wrap */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1357) if ((xas->xa_index - 1) >= max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1358) goto max;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1359) xas->xa_offset = offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1360) if (offset == XA_CHUNK_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1361) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1362) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1363)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1364) entry = xa_entry(xas->xa, xas->xa_node, xas->xa_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1365) if (!entry && !(xa_track_free(xas->xa) && mark == XA_FREE_MARK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1366) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1367) if (!xa_is_node(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1368) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1369) xas->xa_node = xa_to_node(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1370) xas_set_offset(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1371) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1372)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1373) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1374) if (xas->xa_index > max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1375) goto max;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1376) return set_bounds(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1377) max:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1378) xas->xa_node = XAS_RESTART;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1379) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1380) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1381) EXPORT_SYMBOL_GPL(xas_find_marked);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1382)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1383) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1384) * xas_find_conflict() - Find the next present entry in a range.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1385) * @xas: XArray operation state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1386) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1387) * The @xas describes both a range and a position within that range.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1388) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1389) * Context: Any context. Expects xa_lock to be held.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1390) * Return: The next entry in the range covered by @xas or %NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1391) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1392) void *xas_find_conflict(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1393) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1394) void *curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1396) if (xas_error(xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1397) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1398)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1399) if (!xas->xa_node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1400) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1401)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1402) if (xas_top(xas->xa_node)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1403) curr = xas_start(xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1404) if (!curr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1405) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1406) while (xa_is_node(curr)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1407) struct xa_node *node = xa_to_node(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1408) curr = xas_descend(xas, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1409) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1410) if (curr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1411) return curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1412) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1413)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1414) if (xas->xa_node->shift > xas->xa_shift)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1415) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1416)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1417) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1418) if (xas->xa_node->shift == xas->xa_shift) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1419) if ((xas->xa_offset & xas->xa_sibs) == xas->xa_sibs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1420) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1421) } else if (xas->xa_offset == XA_CHUNK_MASK) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1422) xas->xa_offset = xas->xa_node->offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1423) xas->xa_node = xa_parent_locked(xas->xa, xas->xa_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1424) if (!xas->xa_node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1425) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1426) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1427) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1428) curr = xa_entry_locked(xas->xa, xas->xa_node, ++xas->xa_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1429) if (xa_is_sibling(curr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1430) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1431) while (xa_is_node(curr)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1432) xas->xa_node = xa_to_node(curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1433) xas->xa_offset = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1434) curr = xa_entry_locked(xas->xa, xas->xa_node, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1435) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1436) if (curr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1437) return curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1438) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1439) xas->xa_offset -= xas->xa_sibs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1440) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1441) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1442) EXPORT_SYMBOL_GPL(xas_find_conflict);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1443)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1444) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1445) * xa_load() - Load an entry from an XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1446) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1447) * @index: index into array.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1448) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1449) * Context: Any context. Takes and releases the RCU lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1450) * Return: The entry at @index in @xa.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1451) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1452) void *xa_load(struct xarray *xa, unsigned long index)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1453) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1454) XA_STATE(xas, xa, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1455) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1456)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1457) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1458) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1459) entry = xas_load(&xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1460) if (xa_is_zero(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1461) entry = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1462) } while (xas_retry(&xas, entry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1463) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1464)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1465) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1466) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1467) EXPORT_SYMBOL(xa_load);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1468)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1469) static void *xas_result(struct xa_state *xas, void *curr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1470) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1471) if (xa_is_zero(curr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1472) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1473) if (xas_error(xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1474) curr = xas->xa_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1475) return curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1476) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1477)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1478) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1479) * __xa_erase() - Erase this entry from the XArray while locked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1480) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1481) * @index: Index into array.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1482) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1483) * After this function returns, loading from @index will return %NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1484) * If the index is part of a multi-index entry, all indices will be erased
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1485) * and none of the entries will be part of a multi-index entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1486) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1487) * Context: Any context. Expects xa_lock to be held on entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1488) * Return: The entry which used to be at this index.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1489) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1490) void *__xa_erase(struct xarray *xa, unsigned long index)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1491) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1492) XA_STATE(xas, xa, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1493) return xas_result(&xas, xas_store(&xas, NULL));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1494) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1495) EXPORT_SYMBOL(__xa_erase);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1496)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1497) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1498) * xa_erase() - Erase this entry from the XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1499) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1500) * @index: Index of entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1501) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1502) * After this function returns, loading from @index will return %NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1503) * If the index is part of a multi-index entry, all indices will be erased
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1504) * and none of the entries will be part of a multi-index entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1505) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1506) * Context: Any context. Takes and releases the xa_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1507) * Return: The entry which used to be at this index.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1508) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1509) void *xa_erase(struct xarray *xa, unsigned long index)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1510) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1511) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1512)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1513) xa_lock(xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1514) entry = __xa_erase(xa, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1515) xa_unlock(xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1516)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1517) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1518) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1519) EXPORT_SYMBOL(xa_erase);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1520)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1521) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1522) * __xa_store() - Store this entry in the XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1523) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1524) * @index: Index into array.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1525) * @entry: New entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1526) * @gfp: Memory allocation flags.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1527) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1528) * You must already be holding the xa_lock when calling this function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1529) * It will drop the lock if needed to allocate memory, and then reacquire
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1530) * it afterwards.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1531) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1532) * Context: Any context. Expects xa_lock to be held on entry. May
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1533) * release and reacquire xa_lock if @gfp flags permit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1534) * Return: The old entry at this index or xa_err() if an error happened.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1535) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1536) void *__xa_store(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1537) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1538) XA_STATE(xas, xa, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1539) void *curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1540)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1541) if (WARN_ON_ONCE(xa_is_advanced(entry)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1542) return XA_ERROR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1543) if (xa_track_free(xa) && !entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1544) entry = XA_ZERO_ENTRY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1545)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1546) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1547) curr = xas_store(&xas, entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1548) if (xa_track_free(xa))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1549) xas_clear_mark(&xas, XA_FREE_MARK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1550) } while (__xas_nomem(&xas, gfp));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1551)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1552) return xas_result(&xas, curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1553) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1554) EXPORT_SYMBOL(__xa_store);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1555)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1556) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1557) * xa_store() - Store this entry in the XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1558) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1559) * @index: Index into array.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1560) * @entry: New entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1561) * @gfp: Memory allocation flags.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1562) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1563) * After this function returns, loads from this index will return @entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1564) * Storing into an existing multi-index entry updates the entry of every index.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1565) * The marks associated with @index are unaffected unless @entry is %NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1566) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1567) * Context: Any context. Takes and releases the xa_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1568) * May sleep if the @gfp flags permit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1569) * Return: The old entry at this index on success, xa_err(-EINVAL) if @entry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1570) * cannot be stored in an XArray, or xa_err(-ENOMEM) if memory allocation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1571) * failed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1572) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1573) void *xa_store(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1574) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1575) void *curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1576)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1577) xa_lock(xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1578) curr = __xa_store(xa, index, entry, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1579) xa_unlock(xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1580)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1581) return curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1582) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1583) EXPORT_SYMBOL(xa_store);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1584)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1585) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1586) * __xa_cmpxchg() - Store this entry in the XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1587) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1588) * @index: Index into array.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1589) * @old: Old value to test against.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1590) * @entry: New entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1591) * @gfp: Memory allocation flags.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1592) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1593) * You must already be holding the xa_lock when calling this function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1594) * It will drop the lock if needed to allocate memory, and then reacquire
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1595) * it afterwards.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1596) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1597) * Context: Any context. Expects xa_lock to be held on entry. May
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1598) * release and reacquire xa_lock if @gfp flags permit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1599) * Return: The old entry at this index or xa_err() if an error happened.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1600) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1601) void *__xa_cmpxchg(struct xarray *xa, unsigned long index,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1602) void *old, void *entry, gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1603) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1604) XA_STATE(xas, xa, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1605) void *curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1606)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1607) if (WARN_ON_ONCE(xa_is_advanced(entry)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1608) return XA_ERROR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1609)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1610) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1611) curr = xas_load(&xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1612) if (curr == old) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1613) xas_store(&xas, entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1614) if (xa_track_free(xa) && entry && !curr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1615) xas_clear_mark(&xas, XA_FREE_MARK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1616) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1617) } while (__xas_nomem(&xas, gfp));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1618)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1619) return xas_result(&xas, curr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1620) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1621) EXPORT_SYMBOL(__xa_cmpxchg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1622)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1623) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1624) * __xa_insert() - Store this entry in the XArray if no entry is present.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1625) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1626) * @index: Index into array.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1627) * @entry: New entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1628) * @gfp: Memory allocation flags.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1629) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1630) * Inserting a NULL entry will store a reserved entry (like xa_reserve())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1631) * if no entry is present. Inserting will fail if a reserved entry is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1632) * present, even though loading from this index will return NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1633) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1634) * Context: Any context. Expects xa_lock to be held on entry. May
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1635) * release and reacquire xa_lock if @gfp flags permit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1636) * Return: 0 if the store succeeded. -EBUSY if another entry was present.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1637) * -ENOMEM if memory could not be allocated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1638) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1639) int __xa_insert(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1640) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1641) XA_STATE(xas, xa, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1642) void *curr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1643)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1644) if (WARN_ON_ONCE(xa_is_advanced(entry)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1645) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1646) if (!entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1647) entry = XA_ZERO_ENTRY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1648)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1649) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1650) curr = xas_load(&xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1651) if (!curr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1652) xas_store(&xas, entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1653) if (xa_track_free(xa))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1654) xas_clear_mark(&xas, XA_FREE_MARK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1655) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1656) xas_set_err(&xas, -EBUSY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1657) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1658) } while (__xas_nomem(&xas, gfp));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1659)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1660) return xas_error(&xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1661) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1662) EXPORT_SYMBOL(__xa_insert);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1663)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1664) #ifdef CONFIG_XARRAY_MULTI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1665) static void xas_set_range(struct xa_state *xas, unsigned long first,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1666) unsigned long last)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1667) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1668) unsigned int shift = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1669) unsigned long sibs = last - first;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1670) unsigned int offset = XA_CHUNK_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1671)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1672) xas_set(xas, first);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1673)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1674) while ((first & XA_CHUNK_MASK) == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1675) if (sibs < XA_CHUNK_MASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1676) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1677) if ((sibs == XA_CHUNK_MASK) && (offset < XA_CHUNK_MASK))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1678) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1679) shift += XA_CHUNK_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1680) if (offset == XA_CHUNK_MASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1681) offset = sibs & XA_CHUNK_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1682) sibs >>= XA_CHUNK_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1683) first >>= XA_CHUNK_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1684) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1685)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1686) offset = first & XA_CHUNK_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1687) if (offset + sibs > XA_CHUNK_MASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1688) sibs = XA_CHUNK_MASK - offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1689) if ((((first + sibs + 1) << shift) - 1) > last)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1690) sibs -= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1691)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1692) xas->xa_shift = shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1693) xas->xa_sibs = sibs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1694) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1695)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1696) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1697) * xa_store_range() - Store this entry at a range of indices in the XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1698) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1699) * @first: First index to affect.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1700) * @last: Last index to affect.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1701) * @entry: New entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1702) * @gfp: Memory allocation flags.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1703) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1704) * After this function returns, loads from any index between @first and @last,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1705) * inclusive will return @entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1706) * Storing into an existing multi-index entry updates the entry of every index.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1707) * The marks associated with @index are unaffected unless @entry is %NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1708) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1709) * Context: Process context. Takes and releases the xa_lock. May sleep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1710) * if the @gfp flags permit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1711) * Return: %NULL on success, xa_err(-EINVAL) if @entry cannot be stored in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1712) * an XArray, or xa_err(-ENOMEM) if memory allocation failed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1713) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1714) void *xa_store_range(struct xarray *xa, unsigned long first,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1715) unsigned long last, void *entry, gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1716) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1717) XA_STATE(xas, xa, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1718)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1719) if (WARN_ON_ONCE(xa_is_internal(entry)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1720) return XA_ERROR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1721) if (last < first)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1722) return XA_ERROR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1723)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1724) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1725) xas_lock(&xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1726) if (entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1727) unsigned int order = BITS_PER_LONG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1728) if (last + 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1729) order = __ffs(last + 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1730) xas_set_order(&xas, last, order);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1731) xas_create(&xas, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1732) if (xas_error(&xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1733) goto unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1734) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1735) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1736) xas_set_range(&xas, first, last);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1737) xas_store(&xas, entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1738) if (xas_error(&xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1739) goto unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1740) first += xas_size(&xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1741) } while (first <= last);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1742) unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1743) xas_unlock(&xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1744) } while (xas_nomem(&xas, gfp));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1745)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1746) return xas_result(&xas, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1747) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1748) EXPORT_SYMBOL(xa_store_range);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1749)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1750) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1751) * xa_get_order() - Get the order of an entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1752) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1753) * @index: Index of the entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1754) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1755) * Return: A number between 0 and 63 indicating the order of the entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1756) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1757) int xa_get_order(struct xarray *xa, unsigned long index)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1758) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1759) XA_STATE(xas, xa, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1760) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1761) int order = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1762)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1763) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1764) entry = xas_load(&xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1765)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1766) if (!entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1767) goto unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1768)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1769) if (!xas.xa_node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1770) goto unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1771)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1772) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1773) unsigned int slot = xas.xa_offset + (1 << order);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1774)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1775) if (slot >= XA_CHUNK_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1776) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1777) if (!xa_is_sibling(xas.xa_node->slots[slot]))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1778) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1779) order++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1780) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1781)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1782) order += xas.xa_node->shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1783) unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1784) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1785)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1786) return order;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1787) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1788) EXPORT_SYMBOL(xa_get_order);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1789) #endif /* CONFIG_XARRAY_MULTI */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1790)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1791) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1792) * __xa_alloc() - Find somewhere to store this entry in the XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1793) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1794) * @id: Pointer to ID.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1795) * @limit: Range for allocated ID.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1796) * @entry: New entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1797) * @gfp: Memory allocation flags.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1798) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1799) * Finds an empty entry in @xa between @limit.min and @limit.max,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1800) * stores the index into the @id pointer, then stores the entry at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1801) * that index. A concurrent lookup will not see an uninitialised @id.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1802) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1803) * Context: Any context. Expects xa_lock to be held on entry. May
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1804) * release and reacquire xa_lock if @gfp flags permit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1805) * Return: 0 on success, -ENOMEM if memory could not be allocated or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1806) * -EBUSY if there are no free entries in @limit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1807) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1808) int __xa_alloc(struct xarray *xa, u32 *id, void *entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1809) struct xa_limit limit, gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1810) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1811) XA_STATE(xas, xa, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1812)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1813) if (WARN_ON_ONCE(xa_is_advanced(entry)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1814) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1815) if (WARN_ON_ONCE(!xa_track_free(xa)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1816) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1817)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1818) if (!entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1819) entry = XA_ZERO_ENTRY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1820)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1821) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1822) xas.xa_index = limit.min;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1823) xas_find_marked(&xas, limit.max, XA_FREE_MARK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1824) if (xas.xa_node == XAS_RESTART)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1825) xas_set_err(&xas, -EBUSY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1826) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1827) *id = xas.xa_index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1828) xas_store(&xas, entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1829) xas_clear_mark(&xas, XA_FREE_MARK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1830) } while (__xas_nomem(&xas, gfp));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1831)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1832) return xas_error(&xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1833) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1834) EXPORT_SYMBOL(__xa_alloc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1835)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1836) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1837) * __xa_alloc_cyclic() - Find somewhere to store this entry in the XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1838) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1839) * @id: Pointer to ID.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1840) * @entry: New entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1841) * @limit: Range of allocated ID.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1842) * @next: Pointer to next ID to allocate.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1843) * @gfp: Memory allocation flags.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1844) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1845) * Finds an empty entry in @xa between @limit.min and @limit.max,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1846) * stores the index into the @id pointer, then stores the entry at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1847) * that index. A concurrent lookup will not see an uninitialised @id.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1848) * The search for an empty entry will start at @next and will wrap
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1849) * around if necessary.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1850) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1851) * Context: Any context. Expects xa_lock to be held on entry. May
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1852) * release and reacquire xa_lock if @gfp flags permit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1853) * Return: 0 if the allocation succeeded without wrapping. 1 if the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1854) * allocation succeeded after wrapping, -ENOMEM if memory could not be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1855) * allocated or -EBUSY if there are no free entries in @limit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1856) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1857) int __xa_alloc_cyclic(struct xarray *xa, u32 *id, void *entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1858) struct xa_limit limit, u32 *next, gfp_t gfp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1859) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1860) u32 min = limit.min;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1861) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1862)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1863) limit.min = max(min, *next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1864) ret = __xa_alloc(xa, id, entry, limit, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1865) if ((xa->xa_flags & XA_FLAGS_ALLOC_WRAPPED) && ret == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1866) xa->xa_flags &= ~XA_FLAGS_ALLOC_WRAPPED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1867) ret = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1868) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1869)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1870) if (ret < 0 && limit.min > min) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1871) limit.min = min;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1872) ret = __xa_alloc(xa, id, entry, limit, gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1873) if (ret == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1874) ret = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1875) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1876)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1877) if (ret >= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1878) *next = *id + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1879) if (*next == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1880) xa->xa_flags |= XA_FLAGS_ALLOC_WRAPPED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1881) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1882) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1883) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1884) EXPORT_SYMBOL(__xa_alloc_cyclic);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1885)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1886) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1887) * __xa_set_mark() - Set this mark on this entry while locked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1888) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1889) * @index: Index of entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1890) * @mark: Mark number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1891) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1892) * Attempting to set a mark on a %NULL entry does not succeed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1893) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1894) * Context: Any context. Expects xa_lock to be held on entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1895) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1896) void __xa_set_mark(struct xarray *xa, unsigned long index, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1897) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1898) XA_STATE(xas, xa, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1899) void *entry = xas_load(&xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1900)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1901) if (entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1902) xas_set_mark(&xas, mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1903) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1904) EXPORT_SYMBOL(__xa_set_mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1905)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1906) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1907) * __xa_clear_mark() - Clear this mark on this entry while locked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1908) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1909) * @index: Index of entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1910) * @mark: Mark number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1911) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1912) * Context: Any context. Expects xa_lock to be held on entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1913) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1914) void __xa_clear_mark(struct xarray *xa, unsigned long index, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1915) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1916) XA_STATE(xas, xa, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1917) void *entry = xas_load(&xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1918)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1919) if (entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1920) xas_clear_mark(&xas, mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1921) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1922) EXPORT_SYMBOL(__xa_clear_mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1923)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1924) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1925) * xa_get_mark() - Inquire whether this mark is set on this entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1926) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1927) * @index: Index of entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1928) * @mark: Mark number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1929) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1930) * This function uses the RCU read lock, so the result may be out of date
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1931) * by the time it returns. If you need the result to be stable, use a lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1932) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1933) * Context: Any context. Takes and releases the RCU lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1934) * Return: True if the entry at @index has this mark set, false if it doesn't.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1935) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1936) bool xa_get_mark(struct xarray *xa, unsigned long index, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1937) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1938) XA_STATE(xas, xa, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1939) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1940)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1941) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1942) entry = xas_start(&xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1943) while (xas_get_mark(&xas, mark)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1944) if (!xa_is_node(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1945) goto found;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1946) entry = xas_descend(&xas, xa_to_node(entry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1947) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1948) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1949) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1950) found:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1951) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1952) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1953) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1954) EXPORT_SYMBOL(xa_get_mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1955)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1956) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1957) * xa_set_mark() - Set this mark on this entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1958) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1959) * @index: Index of entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1960) * @mark: Mark number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1961) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1962) * Attempting to set a mark on a %NULL entry does not succeed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1963) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1964) * Context: Process context. Takes and releases the xa_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1965) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1966) void xa_set_mark(struct xarray *xa, unsigned long index, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1967) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1968) xa_lock(xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1969) __xa_set_mark(xa, index, mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1970) xa_unlock(xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1971) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1972) EXPORT_SYMBOL(xa_set_mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1973)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1974) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1975) * xa_clear_mark() - Clear this mark on this entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1976) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1977) * @index: Index of entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1978) * @mark: Mark number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1979) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1980) * Clearing a mark always succeeds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1981) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1982) * Context: Process context. Takes and releases the xa_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1983) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1984) void xa_clear_mark(struct xarray *xa, unsigned long index, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1985) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1986) xa_lock(xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1987) __xa_clear_mark(xa, index, mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1988) xa_unlock(xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1989) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1990) EXPORT_SYMBOL(xa_clear_mark);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1991)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1992) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1993) * xa_find() - Search the XArray for an entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1994) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1995) * @indexp: Pointer to an index.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1996) * @max: Maximum index to search to.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1997) * @filter: Selection criterion.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1998) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1999) * Finds the entry in @xa which matches the @filter, and has the lowest
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2000) * index that is at least @indexp and no more than @max.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2001) * If an entry is found, @indexp is updated to be the index of the entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2002) * This function is protected by the RCU read lock, so it may not find
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2003) * entries which are being simultaneously added. It will not return an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2004) * %XA_RETRY_ENTRY; if you need to see retry entries, use xas_find().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2005) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2006) * Context: Any context. Takes and releases the RCU lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2007) * Return: The entry, if found, otherwise %NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2008) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2009) void *xa_find(struct xarray *xa, unsigned long *indexp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2010) unsigned long max, xa_mark_t filter)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2011) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2012) XA_STATE(xas, xa, *indexp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2013) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2014)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2015) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2016) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2017) if ((__force unsigned int)filter < XA_MAX_MARKS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2018) entry = xas_find_marked(&xas, max, filter);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2019) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2020) entry = xas_find(&xas, max);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2021) } while (xas_retry(&xas, entry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2022) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2023)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2024) if (entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2025) *indexp = xas.xa_index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2026) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2027) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2028) EXPORT_SYMBOL(xa_find);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2029)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2030) static bool xas_sibling(struct xa_state *xas)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2031) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2032) struct xa_node *node = xas->xa_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2033) unsigned long mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2034)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2035) if (!IS_ENABLED(CONFIG_XARRAY_MULTI) || !node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2036) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2037) mask = (XA_CHUNK_SIZE << node->shift) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2038) return (xas->xa_index & mask) >
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2039) ((unsigned long)xas->xa_offset << node->shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2040) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2041)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2042) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2043) * xa_find_after() - Search the XArray for a present entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2044) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2045) * @indexp: Pointer to an index.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2046) * @max: Maximum index to search to.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2047) * @filter: Selection criterion.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2048) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2049) * Finds the entry in @xa which matches the @filter and has the lowest
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2050) * index that is above @indexp and no more than @max.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2051) * If an entry is found, @indexp is updated to be the index of the entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2052) * This function is protected by the RCU read lock, so it may miss entries
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2053) * which are being simultaneously added. It will not return an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2054) * %XA_RETRY_ENTRY; if you need to see retry entries, use xas_find().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2055) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2056) * Context: Any context. Takes and releases the RCU lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2057) * Return: The pointer, if found, otherwise %NULL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2058) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2059) void *xa_find_after(struct xarray *xa, unsigned long *indexp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2060) unsigned long max, xa_mark_t filter)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2061) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2062) XA_STATE(xas, xa, *indexp + 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2063) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2064)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2065) if (xas.xa_index == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2066) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2067)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2068) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2069) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2070) if ((__force unsigned int)filter < XA_MAX_MARKS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2071) entry = xas_find_marked(&xas, max, filter);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2072) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2073) entry = xas_find(&xas, max);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2074)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2075) if (xas_invalid(&xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2076) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2077) if (xas_sibling(&xas))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2078) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2079) if (!xas_retry(&xas, entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2080) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2081) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2082) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2083)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2084) if (entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2085) *indexp = xas.xa_index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2086) return entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2087) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2088) EXPORT_SYMBOL(xa_find_after);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2089)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2090) static unsigned int xas_extract_present(struct xa_state *xas, void **dst,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2091) unsigned long max, unsigned int n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2092) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2093) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2094) unsigned int i = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2095)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2096) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2097) xas_for_each(xas, entry, max) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2098) if (xas_retry(xas, entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2099) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2100) dst[i++] = entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2101) if (i == n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2102) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2103) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2104) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2106) return i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2107) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2109) static unsigned int xas_extract_marked(struct xa_state *xas, void **dst,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2110) unsigned long max, unsigned int n, xa_mark_t mark)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2111) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2112) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2113) unsigned int i = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2115) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2116) xas_for_each_marked(xas, entry, max, mark) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2117) if (xas_retry(xas, entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2118) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2119) dst[i++] = entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2120) if (i == n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2121) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2122) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2123) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2125) return i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2126) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2128) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2129) * xa_extract() - Copy selected entries from the XArray into a normal array.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2130) * @xa: The source XArray to copy from.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2131) * @dst: The buffer to copy entries into.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2132) * @start: The first index in the XArray eligible to be selected.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2133) * @max: The last index in the XArray eligible to be selected.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2134) * @n: The maximum number of entries to copy.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2135) * @filter: Selection criterion.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2136) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2137) * Copies up to @n entries that match @filter from the XArray. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2138) * copied entries will have indices between @start and @max, inclusive.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2139) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2140) * The @filter may be an XArray mark value, in which case entries which are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2141) * marked with that mark will be copied. It may also be %XA_PRESENT, in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2142) * which case all entries which are not %NULL will be copied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2143) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2144) * The entries returned may not represent a snapshot of the XArray at a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2145) * moment in time. For example, if another thread stores to index 5, then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2146) * index 10, calling xa_extract() may return the old contents of index 5
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2147) * and the new contents of index 10. Indices not modified while this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2148) * function is running will not be skipped.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2149) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2150) * If you need stronger guarantees, holding the xa_lock across calls to this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2151) * function will prevent concurrent modification.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2152) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2153) * Context: Any context. Takes and releases the RCU lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2154) * Return: The number of entries copied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2155) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2156) unsigned int xa_extract(struct xarray *xa, void **dst, unsigned long start,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2157) unsigned long max, unsigned int n, xa_mark_t filter)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2158) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2159) XA_STATE(xas, xa, start);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2160)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2161) if (!n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2162) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2164) if ((__force unsigned int)filter < XA_MAX_MARKS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2165) return xas_extract_marked(&xas, dst, max, n, filter);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2166) return xas_extract_present(&xas, dst, max, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2167) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2168) EXPORT_SYMBOL(xa_extract);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2170) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2171) * xa_delete_node() - Private interface for workingset code.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2172) * @node: Node to be removed from the tree.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2173) * @update: Function to call to update ancestor nodes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2174) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2175) * Context: xa_lock must be held on entry and will not be released.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2176) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2177) void xa_delete_node(struct xa_node *node, xa_update_node_t update)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2178) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2179) struct xa_state xas = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2180) .xa = node->array,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2181) .xa_index = (unsigned long)node->offset <<
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2182) (node->shift + XA_CHUNK_SHIFT),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2183) .xa_shift = node->shift + XA_CHUNK_SHIFT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2184) .xa_offset = node->offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2185) .xa_node = xa_parent_locked(node->array, node),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2186) .xa_update = update,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2187) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2189) xas_store(&xas, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2190) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2191) EXPORT_SYMBOL_GPL(xa_delete_node); /* For the benefit of the test suite */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2192)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2193) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2194) * xa_destroy() - Free all internal data structures.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2195) * @xa: XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2196) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2197) * After calling this function, the XArray is empty and has freed all memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2198) * allocated for its internal data structures. You are responsible for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2199) * freeing the objects referenced by the XArray.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2200) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2201) * Context: Any context. Takes and releases the xa_lock, interrupt-safe.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2202) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2203) void xa_destroy(struct xarray *xa)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2204) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2205) XA_STATE(xas, xa, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2206) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2207) void *entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2209) xas.xa_node = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2210) xas_lock_irqsave(&xas, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2211) entry = xa_head_locked(xa);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2212) RCU_INIT_POINTER(xa->xa_head, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2213) xas_init_marks(&xas);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2214) if (xa_zero_busy(xa))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2215) xa_mark_clear(xa, XA_FREE_MARK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2216) /* lockdep checks we're still holding the lock in xas_free_nodes() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2217) if (xa_is_node(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2218) xas_free_nodes(&xas, xa_to_node(entry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2219) xas_unlock_irqrestore(&xas, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2220) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2221) EXPORT_SYMBOL(xa_destroy);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2222)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2223) #ifdef XA_DEBUG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2224) void xa_dump_node(const struct xa_node *node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2225) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2226) unsigned i, j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2228) if (!node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2229) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2230) if ((unsigned long)node & 3) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2231) pr_cont("node %px\n", node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2232) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2233) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2234)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2235) pr_cont("node %px %s %d parent %px shift %d count %d values %d "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2236) "array %px list %px %px marks",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2237) node, node->parent ? "offset" : "max", node->offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2238) node->parent, node->shift, node->count, node->nr_values,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2239) node->array, node->private_list.prev, node->private_list.next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2240) for (i = 0; i < XA_MAX_MARKS; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2241) for (j = 0; j < XA_MARK_LONGS; j++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2242) pr_cont(" %lx", node->marks[i][j]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2243) pr_cont("\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2244) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2245)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2246) void xa_dump_index(unsigned long index, unsigned int shift)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2247) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2248) if (!shift)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2249) pr_info("%lu: ", index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2250) else if (shift >= BITS_PER_LONG)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2251) pr_info("0-%lu: ", ~0UL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2252) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2253) pr_info("%lu-%lu: ", index, index | ((1UL << shift) - 1));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2254) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2256) void xa_dump_entry(const void *entry, unsigned long index, unsigned long shift)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2257) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2258) if (!entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2259) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2260)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2261) xa_dump_index(index, shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2262)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2263) if (xa_is_node(entry)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2264) if (shift == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2265) pr_cont("%px\n", entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2266) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2267) unsigned long i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2268) struct xa_node *node = xa_to_node(entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2269) xa_dump_node(node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2270) for (i = 0; i < XA_CHUNK_SIZE; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2271) xa_dump_entry(node->slots[i],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2272) index + (i << node->shift), node->shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2273) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2274) } else if (xa_is_value(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2275) pr_cont("value %ld (0x%lx) [%px]\n", xa_to_value(entry),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2276) xa_to_value(entry), entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2277) else if (!xa_is_internal(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2278) pr_cont("%px\n", entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2279) else if (xa_is_retry(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2280) pr_cont("retry (%ld)\n", xa_to_internal(entry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2281) else if (xa_is_sibling(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2282) pr_cont("sibling (slot %ld)\n", xa_to_sibling(entry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2283) else if (xa_is_zero(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2284) pr_cont("zero (%ld)\n", xa_to_internal(entry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2285) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2286) pr_cont("UNKNOWN ENTRY (%px)\n", entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2287) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2288)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2289) void xa_dump(const struct xarray *xa)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2290) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2291) void *entry = xa->xa_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2292) unsigned int shift = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2293)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2294) pr_info("xarray: %px head %px flags %x marks %d %d %d\n", xa, entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2295) xa->xa_flags, xa_marked(xa, XA_MARK_0),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2296) xa_marked(xa, XA_MARK_1), xa_marked(xa, XA_MARK_2));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2297) if (xa_is_node(entry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2298) shift = xa_to_node(entry)->shift + XA_CHUNK_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2299) xa_dump_entry(entry, 0, shift);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2300) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2301) #endif
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
3 Commits
0 Branches
0 Tags