^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * cb710/sgbuf2.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright by Michał Mirosław, 2008-2009
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/cb710.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) static bool sg_dwiter_next(struct sg_mapping_iter *miter)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) if (sg_miter_next(miter)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) miter->consumed = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) static bool sg_dwiter_is_at_end(struct sg_mapping_iter *miter)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) return miter->length == miter->consumed && !sg_dwiter_next(miter);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) static uint32_t sg_dwiter_read_buffer(struct sg_mapping_iter *miter)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) size_t len, left = 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) uint32_t data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) void *addr = &data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) len = min(miter->length - miter->consumed, left);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) memcpy(addr, miter->addr + miter->consumed, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) miter->consumed += len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) left -= len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) if (!left)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) return data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) addr += len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) } while (sg_dwiter_next(miter));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) memset(addr, 0, left);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) return data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) static inline bool needs_unaligned_copy(const void *ptr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) return ((uintptr_t)ptr & 3) != 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) static bool sg_dwiter_get_next_block(struct sg_mapping_iter *miter, uint32_t **ptr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) size_t len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) if (sg_dwiter_is_at_end(miter))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) len = miter->length - miter->consumed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) if (likely(len >= 4 && !needs_unaligned_copy(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) miter->addr + miter->consumed))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) *ptr = miter->addr + miter->consumed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) miter->consumed += 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) * cb710_sg_dwiter_read_next_block() - get next 32-bit word from sg buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) * @miter: sg mapping iterator used for reading
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) * Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) * Returns 32-bit word starting at byte pointed to by @miter@
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) * handling any alignment issues. Bytes past the buffer's end
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) * are not accessed (read) but are returned as zeroes. @miter@
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * is advanced by 4 bytes or to the end of buffer whichever is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) * closer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) * Context:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * Same requirements as in sg_miter_next().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) * Returns:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) * 32-bit word just read.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) uint32_t cb710_sg_dwiter_read_next_block(struct sg_mapping_iter *miter)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) uint32_t *ptr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) if (likely(sg_dwiter_get_next_block(miter, &ptr)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) return ptr ? *ptr : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) return sg_dwiter_read_buffer(miter);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) EXPORT_SYMBOL_GPL(cb710_sg_dwiter_read_next_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) static void sg_dwiter_write_slow(struct sg_mapping_iter *miter, uint32_t data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) size_t len, left = 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) void *addr = &data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) len = min(miter->length - miter->consumed, left);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) memcpy(miter->addr, addr, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) miter->consumed += len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) left -= len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) if (!left)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) addr += len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) } while (sg_dwiter_next(miter));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) }
^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) * cb710_sg_dwiter_write_next_block() - write next 32-bit word to sg buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) * @miter: sg mapping iterator used for writing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) * @data: data to write to sg buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) * Description:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) * Writes 32-bit word starting at byte pointed to by @miter@
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) * handling any alignment issues. Bytes which would be written
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) * past the buffer's end are silently discarded. @miter@ is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) * advanced by 4 bytes or to the end of buffer whichever is closer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) * Context:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) * Same requirements as in sg_miter_next().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) void cb710_sg_dwiter_write_next_block(struct sg_mapping_iter *miter, uint32_t data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) uint32_t *ptr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) if (likely(sg_dwiter_get_next_block(miter, &ptr))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) if (ptr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) *ptr = data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) sg_dwiter_write_slow(miter, data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) EXPORT_SYMBOL_GPL(cb710_sg_dwiter_write_next_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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