^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) * Copyright (C) 2017 - Cambridge Greys Ltd
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * Copyright (C) 2011 - 2014 Cisco Systems Inc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Derived (i.e. mostly copied) from arch/i386/kernel/irq.c:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/cpumask.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/hardirq.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/interrupt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/kernel_stat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/seq_file.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <as-layout.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <kern_util.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <os.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <irq_user.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) extern void free_irqs(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) /* When epoll triggers we do not know why it did so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * we can also have different IRQs for read and write.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * This is why we keep a small irq_fd array for each fd -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) * one entry per IRQ type
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) struct irq_entry {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) struct irq_entry *next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) int fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) struct irq_fd *irq_array[MAX_IRQ_TYPE + 1];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) static struct irq_entry *active_fds;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) static DEFINE_SPINLOCK(irq_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) static void irq_io_loop(struct irq_fd *irq, struct uml_pt_regs *regs)
^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) * irq->active guards against reentry
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) * irq->pending accumulates pending requests
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) * if pending is raised the irq_handler is re-run
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) * until pending is cleared
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) if (irq->active) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) irq->active = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) irq->pending = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) do_IRQ(irq->irq, regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) } while (irq->pending && (!irq->purge));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) if (!irq->purge)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) irq->active = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) irq->pending = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) struct irq_entry *irq_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) struct irq_fd *irq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) int n, i, j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) while (1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) /* This is now lockless - epoll keeps back-referencesto the irqs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) * which have trigger it so there is no need to walk the irq
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) * list and lock it every time. We avoid locking by turning off
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) * IO for a specific fd by executing os_del_epoll_fd(fd) before
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) * we do any changes to the actual data structures
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) n = os_waiting_for_events_epoll();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) if (n <= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) if (n == -EINTR)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) for (i = 0; i < n ; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) /* Epoll back reference is the entry with 3 irq_fd
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) * leaves - one for each irq type.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) irq_entry = (struct irq_entry *)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) os_epoll_get_data_pointer(i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) for (j = 0; j < MAX_IRQ_TYPE ; j++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) irq = irq_entry->irq_array[j];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) if (irq == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) if (os_epoll_triggered(i, irq->events) > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) irq_io_loop(irq, regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) if (irq->purge) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) irq_entry->irq_array[j] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) kfree(irq);
^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) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) free_irqs();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) static int assign_epoll_events_to_irq(struct irq_entry *irq_entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) int events = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) struct irq_fd *irq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) for (i = 0; i < MAX_IRQ_TYPE ; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) irq = irq_entry->irq_array[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) if (irq != NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) events = irq->events | events;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) if (events > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) /* os_add_epoll will call os_mod_epoll if this already exists */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) return os_add_epoll_fd(events, irq_entry->fd, irq_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) /* No events - delete */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) return os_del_epoll_fd(irq_entry->fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) static int activate_fd(int irq, int fd, int type, void *dev_id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) struct irq_fd *new_fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) struct irq_entry *irq_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) int i, err, events;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) err = os_set_fd_async(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) if (err < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) spin_lock_irqsave(&irq_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) /* Check if we have an entry for this fd */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) err = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) for (irq_entry = active_fds;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) irq_entry != NULL; irq_entry = irq_entry->next) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) if (irq_entry->fd == fd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) break;
^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) if (irq_entry == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) /* This needs to be atomic as it may be called from an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) * IRQ context.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) irq_entry = kmalloc(sizeof(struct irq_entry), GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) if (irq_entry == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) printk(KERN_ERR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) "Failed to allocate new IRQ entry\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) goto out_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) irq_entry->fd = fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) for (i = 0; i < MAX_IRQ_TYPE; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) irq_entry->irq_array[i] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) irq_entry->next = active_fds;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) active_fds = irq_entry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) /* Check if we are trying to re-register an interrupt for a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) * particular fd
^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) if (irq_entry->irq_array[type] != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) printk(KERN_ERR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) "Trying to reregister IRQ %d FD %d TYPE %d ID %p\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) irq, fd, type, dev_id
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) goto out_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) /* New entry for this fd */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) err = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) new_fd = kmalloc(sizeof(struct irq_fd), GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) if (new_fd == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) goto out_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) events = os_event_mask(type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) *new_fd = ((struct irq_fd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) .id = dev_id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) .irq = irq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) .type = type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) .events = events,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) .active = true,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) .pending = false,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) .purge = false
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) });
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) /* Turn off any IO on this fd - allows us to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) * avoid locking the IRQ loop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) os_del_epoll_fd(irq_entry->fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) irq_entry->irq_array[type] = new_fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) /* Turn back IO on with the correct (new) IO event mask */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) assign_epoll_events_to_irq(irq_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) spin_unlock_irqrestore(&irq_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) maybe_sigio_broken(fd, (type != IRQ_NONE));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) out_unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) spin_unlock_irqrestore(&irq_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) return err;
^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) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) * Walk the IRQ list and dispose of any unused entries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) * Should be done under irq_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) static void garbage_collect_irq_entries(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) bool reap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) struct irq_entry *walk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) struct irq_entry *previous = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) struct irq_entry *to_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) if (active_fds == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) walk = active_fds;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) while (walk != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) reap = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) for (i = 0; i < MAX_IRQ_TYPE ; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) if (walk->irq_array[i] != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) reap = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) if (reap) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) if (previous == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) active_fds = walk->next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) previous->next = walk->next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) to_free = walk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) to_free = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) walk = walk->next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) kfree(to_free);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) * Walk the IRQ list and get the descriptor for our FD
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) static struct irq_entry *get_irq_entry_by_fd(int fd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) struct irq_entry *walk = active_fds;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) while (walk != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) if (walk->fd == fd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) return walk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) walk = walk->next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) * Walk the IRQ list and dispose of an entry for a specific
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) * device, fd and number. Note - if sharing an IRQ for read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) * and writefor the same FD it will be disposed in either case.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) * If this behaviour is undesirable use different IRQ ids.
^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) #define IGNORE_IRQ 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) #define IGNORE_DEV (1<<1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) static void do_free_by_irq_and_dev(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) struct irq_entry *irq_entry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) unsigned int irq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) void *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) int flags
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) struct irq_fd *to_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) for (i = 0; i < MAX_IRQ_TYPE ; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) if (irq_entry->irq_array[i] != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) if (
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) ((flags & IGNORE_IRQ) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) (irq_entry->irq_array[i]->irq == irq)) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) ((flags & IGNORE_DEV) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) (irq_entry->irq_array[i]->id == dev))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) ) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) /* Turn off any IO on this fd - allows us to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) * avoid locking the IRQ loop
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) os_del_epoll_fd(irq_entry->fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) to_free = irq_entry->irq_array[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) irq_entry->irq_array[i] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) assign_epoll_events_to_irq(irq_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) if (to_free->active)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) to_free->purge = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) kfree(to_free);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) }
^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) void free_irq_by_fd(int fd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) struct irq_entry *to_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) spin_lock_irqsave(&irq_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) to_free = get_irq_entry_by_fd(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) if (to_free != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) do_free_by_irq_and_dev(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) to_free,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) -1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) IGNORE_IRQ | IGNORE_DEV
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) garbage_collect_irq_entries();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) spin_unlock_irqrestore(&irq_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) EXPORT_SYMBOL(free_irq_by_fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) static void free_irq_by_irq_and_dev(unsigned int irq, void *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) struct irq_entry *to_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) spin_lock_irqsave(&irq_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) to_free = active_fds;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) while (to_free != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) do_free_by_irq_and_dev(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) to_free,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) irq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) to_free = to_free->next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) garbage_collect_irq_entries();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) spin_unlock_irqrestore(&irq_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) void deactivate_fd(int fd, int irqnum)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) struct irq_entry *to_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) os_del_epoll_fd(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) spin_lock_irqsave(&irq_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) to_free = get_irq_entry_by_fd(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) if (to_free != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) do_free_by_irq_and_dev(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) to_free,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) irqnum,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) IGNORE_DEV
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) garbage_collect_irq_entries();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) spin_unlock_irqrestore(&irq_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) ignore_sigio_fd(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) EXPORT_SYMBOL(deactivate_fd);
^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) * Called just before shutdown in order to provide a clean exec
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) * environment in case the system is rebooting. No locking because
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) * that would cause a pointless shutdown hang if something hadn't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) * released the lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) int deactivate_all_fds(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) struct irq_entry *to_free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) /* Stop IO. The IRQ loop has no lock so this is our
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) * only way of making sure we are safe to dispose
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) * of all IRQ handlers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) os_set_ioignore();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) to_free = active_fds;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) while (to_free != NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) do_free_by_irq_and_dev(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) to_free,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) -1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) IGNORE_IRQ | IGNORE_DEV
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) );
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) to_free = to_free->next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) /* don't garbage collect - we can no longer call kfree() here */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) os_close_epoll_fd();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) * do_IRQ handles all normal device IRQs (the special
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) * SMP cross-CPU interrupts have their own specific
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) * handlers).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) unsigned int do_IRQ(int irq, struct uml_pt_regs *regs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) struct pt_regs *old_regs = set_irq_regs((struct pt_regs *)regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) irq_enter();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) generic_handle_irq(irq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) irq_exit();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) set_irq_regs(old_regs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) void um_free_irq(unsigned int irq, void *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) free_irq_by_irq_and_dev(irq, dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) free_irq(irq, dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) EXPORT_SYMBOL(um_free_irq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) int um_request_irq(unsigned int irq, int fd, int type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) irq_handler_t handler,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) unsigned long irqflags, const char * devname,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) void *dev_id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) if (fd != -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) err = activate_fd(irq, fd, type, dev_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) return request_irq(irq, handler, irqflags, devname, dev_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) EXPORT_SYMBOL(um_request_irq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) * irq_chip must define at least enable/disable and ack when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) * the edge handler is used.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) static void dummy(struct irq_data *d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) /* This is used for everything else than the timer. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) static struct irq_chip normal_irq_type = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) .name = "SIGIO",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) .irq_disable = dummy,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) .irq_enable = dummy,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) .irq_ack = dummy,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) .irq_mask = dummy,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) .irq_unmask = dummy,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) static struct irq_chip SIGVTALRM_irq_type = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) .name = "SIGVTALRM",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) .irq_disable = dummy,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) .irq_enable = dummy,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) .irq_ack = dummy,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) .irq_mask = dummy,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) .irq_unmask = dummy,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) void __init init_IRQ(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) irq_set_chip_and_handler(TIMER_IRQ, &SIGVTALRM_irq_type, handle_edge_irq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) for (i = 1; i < NR_IRQS; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) irq_set_chip_and_handler(i, &normal_irq_type, handle_edge_irq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) /* Initialize EPOLL Loop */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) os_setup_epoll();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) * IRQ stack entry and exit:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) * Unlike i386, UML doesn't receive IRQs on the normal kernel stack
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) * and switch over to the IRQ stack after some preparation. We use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) * sigaltstack to receive signals on a separate stack from the start.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) * These two functions make sure the rest of the kernel won't be too
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) * upset by being on a different stack. The IRQ stack has a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) * thread_info structure at the bottom so that current et al continue
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) * to work.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) * to_irq_stack copies the current task's thread_info to the IRQ stack
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) * thread_info and sets the tasks's stack to point to the IRQ stack.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) * from_irq_stack copies the thread_info struct back (flags may have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) * been modified) and resets the task's stack pointer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) * Tricky bits -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) * What happens when two signals race each other? UML doesn't block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) * signals with sigprocmask, SA_DEFER, or sa_mask, so a second signal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) * could arrive while a previous one is still setting up the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) * thread_info.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) * There are three cases -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) * The first interrupt on the stack - sets up the thread_info and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) * handles the interrupt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) * A nested interrupt interrupting the copying of the thread_info -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) * can't handle the interrupt, as the stack is in an unknown state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) * A nested interrupt not interrupting the copying of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) * thread_info - doesn't do any setup, just handles the interrupt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) * The first job is to figure out whether we interrupted stack setup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) * This is done by xchging the signal mask with thread_info->pending.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) * If the value that comes back is zero, then there is no setup in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) * progress, and the interrupt can be handled. If the value is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) * non-zero, then there is stack setup in progress. In order to have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) * the interrupt handled, we leave our signal in the mask, and it will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) * be handled by the upper handler after it has set up the stack.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) * Next is to figure out whether we are the outer handler or a nested
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) * one. As part of setting up the stack, thread_info->real_thread is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) * set to non-NULL (and is reset to NULL on exit). This is the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) * nesting indicator. If it is non-NULL, then the stack is already
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) * set up and the handler can run.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) static unsigned long pending_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) unsigned long to_irq_stack(unsigned long *mask_out)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) struct thread_info *ti;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) unsigned long mask, old;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) int nested;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) mask = xchg(&pending_mask, *mask_out);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) if (mask != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) * If any interrupts come in at this point, we want to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) * make sure that their bits aren't lost by our
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) * putting our bit in. So, this loop accumulates bits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) * until xchg returns the same value that we put in.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) * When that happens, there were no new interrupts,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) * and pending_mask contains a bit for each interrupt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) * that came in.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) old = *mask_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) old |= mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) mask = xchg(&pending_mask, old);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) } while (mask != old);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) ti = current_thread_info();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) nested = (ti->real_thread != NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) if (!nested) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) struct task_struct *task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) struct thread_info *tti;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) task = cpu_tasks[ti->cpu].task;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) tti = task_thread_info(task);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) *ti = *tti;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) ti->real_thread = tti;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) task->stack = ti;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) mask = xchg(&pending_mask, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) *mask_out |= mask | nested;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) unsigned long from_irq_stack(int nested)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) struct thread_info *ti, *to;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) unsigned long mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) ti = current_thread_info();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) pending_mask = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) to = ti->real_thread;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) current->stack = to;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) ti->real_thread = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) *to = *ti;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) mask = xchg(&pending_mask, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) return mask & ~1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599)
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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