Jeff Dike | 2ea5bc5 | 2007-05-10 22:22:32 -0700 | [diff] [blame] | 1 | /* |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 2 | * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * Licensed under the GPL |
| 4 | * Derived (i.e. mostly copied) from arch/i386/kernel/irq.c: |
| 5 | * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar |
| 6 | */ |
| 7 | |
Al Viro | 37185b3 | 2012-10-08 03:27:32 +0100 | [diff] [blame] | 8 | #include <linux/cpumask.h> |
| 9 | #include <linux/hardirq.h> |
| 10 | #include <linux/interrupt.h> |
| 11 | #include <linux/kernel_stat.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/sched.h> |
| 14 | #include <linux/seq_file.h> |
| 15 | #include <linux/slab.h> |
| 16 | #include <as-layout.h> |
| 17 | #include <kern_util.h> |
| 18 | #include <os.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | |
| 20 | /* |
Jeff Dike | d973a77 | 2007-05-06 14:51:27 -0700 | [diff] [blame] | 21 | * This list is accessed under irq_lock, except in sigio_handler, |
| 22 | * where it is safe from being modified. IRQ handlers won't change it - |
| 23 | * if an IRQ source has vanished, it will be freed by free_irqs just |
| 24 | * before returning from sigio_handler. That will process a separate |
| 25 | * list of irqs to free, with its own locking, coming back here to |
| 26 | * remove list elements, taking the irq_lock to do so. |
| 27 | */ |
Jeff Dike | f2e6299 | 2007-02-10 01:44:23 -0800 | [diff] [blame] | 28 | static struct irq_fd *active_fds = NULL; |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 29 | static struct irq_fd **last_irq_ptr = &active_fds; |
| 30 | |
| 31 | extern void free_irqs(void); |
| 32 | |
Martin Pärtel | d3c1cfc | 2012-08-02 00:49:17 +0200 | [diff] [blame] | 33 | void sigio_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs) |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 34 | { |
| 35 | struct irq_fd *irq_fd; |
| 36 | int n; |
| 37 | |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 38 | if (smp_sigio_handler()) |
| 39 | return; |
| 40 | |
| 41 | while (1) { |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 42 | n = os_waiting_for_events(active_fds); |
| 43 | if (n <= 0) { |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 44 | if (n == -EINTR) |
| 45 | continue; |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 46 | else break; |
| 47 | } |
| 48 | |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 49 | for (irq_fd = active_fds; irq_fd != NULL; |
| 50 | irq_fd = irq_fd->next) { |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 51 | if (irq_fd->current_events != 0) { |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 52 | irq_fd->current_events = 0; |
| 53 | do_IRQ(irq_fd->irq, regs); |
| 54 | } |
| 55 | } |
| 56 | } |
| 57 | |
| 58 | free_irqs(); |
| 59 | } |
| 60 | |
Jeff Dike | bfaafd7 | 2006-07-10 04:45:10 -0700 | [diff] [blame] | 61 | static DEFINE_SPINLOCK(irq_lock); |
| 62 | |
WANG Cong | 4c182ae | 2008-07-23 21:28:47 -0700 | [diff] [blame] | 63 | static int activate_fd(int irq, int fd, int type, void *dev_id) |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 64 | { |
| 65 | struct pollfd *tmp_pfd; |
| 66 | struct irq_fd *new_fd, *irq_fd; |
| 67 | unsigned long flags; |
Jeff Dike | bf8fde7 | 2008-02-04 22:31:04 -0800 | [diff] [blame] | 68 | int events, err, n; |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 69 | |
Jeff Dike | bf8fde7 | 2008-02-04 22:31:04 -0800 | [diff] [blame] | 70 | err = os_set_fd_async(fd); |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 71 | if (err < 0) |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 72 | goto out; |
| 73 | |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 74 | err = -ENOMEM; |
Jeff Dike | f2e6299 | 2007-02-10 01:44:23 -0800 | [diff] [blame] | 75 | new_fd = kmalloc(sizeof(struct irq_fd), GFP_KERNEL); |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 76 | if (new_fd == NULL) |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 77 | goto out; |
| 78 | |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 79 | if (type == IRQ_READ) |
| 80 | events = UM_POLLIN | UM_POLLPRI; |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 81 | else events = UM_POLLOUT; |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 82 | *new_fd = ((struct irq_fd) { .next = NULL, |
| 83 | .id = dev_id, |
| 84 | .fd = fd, |
| 85 | .type = type, |
| 86 | .irq = irq, |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 87 | .events = events, |
| 88 | .current_events = 0 } ); |
| 89 | |
Paolo 'Blaisorblade' Giarrusso | 0f97869 | 2007-03-07 20:41:13 -0800 | [diff] [blame] | 90 | err = -EBUSY; |
Jeff Dike | bfaafd7 | 2006-07-10 04:45:10 -0700 | [diff] [blame] | 91 | spin_lock_irqsave(&irq_lock, flags); |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 92 | for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) { |
| 93 | if ((irq_fd->fd == fd) && (irq_fd->type == type)) { |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 94 | printk(KERN_ERR "Registering fd %d twice\n", fd); |
| 95 | printk(KERN_ERR "Irqs : %d, %d\n", irq_fd->irq, irq); |
| 96 | printk(KERN_ERR "Ids : 0x%p, 0x%p\n", irq_fd->id, |
| 97 | dev_id); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 98 | goto out_unlock; |
| 99 | } |
| 100 | } |
| 101 | |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 102 | if (type == IRQ_WRITE) |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 103 | fd = -1; |
| 104 | |
| 105 | tmp_pfd = NULL; |
| 106 | n = 0; |
| 107 | |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 108 | while (1) { |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 109 | n = os_create_pollfd(fd, events, tmp_pfd, n); |
| 110 | if (n == 0) |
| 111 | break; |
| 112 | |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 113 | /* |
| 114 | * n > 0 |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 115 | * It means we couldn't put new pollfd to current pollfds |
| 116 | * and tmp_fds is NULL or too small for new pollfds array. |
| 117 | * Needed size is equal to n as minimum. |
| 118 | * |
| 119 | * Here we have to drop the lock in order to call |
| 120 | * kmalloc, which might sleep. |
| 121 | * If something else came in and changed the pollfds array |
| 122 | * so we will not be able to put new pollfd struct to pollfds |
| 123 | * then we free the buffer tmp_fds and try again. |
| 124 | */ |
Jeff Dike | bfaafd7 | 2006-07-10 04:45:10 -0700 | [diff] [blame] | 125 | spin_unlock_irqrestore(&irq_lock, flags); |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 126 | kfree(tmp_pfd); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 127 | |
Jeff Dike | f2e6299 | 2007-02-10 01:44:23 -0800 | [diff] [blame] | 128 | tmp_pfd = kmalloc(n, GFP_KERNEL); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 129 | if (tmp_pfd == NULL) |
| 130 | goto out_kfree; |
| 131 | |
Jeff Dike | bfaafd7 | 2006-07-10 04:45:10 -0700 | [diff] [blame] | 132 | spin_lock_irqsave(&irq_lock, flags); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 133 | } |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 134 | |
| 135 | *last_irq_ptr = new_fd; |
| 136 | last_irq_ptr = &new_fd->next; |
| 137 | |
Jeff Dike | bfaafd7 | 2006-07-10 04:45:10 -0700 | [diff] [blame] | 138 | spin_unlock_irqrestore(&irq_lock, flags); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 139 | |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 140 | /* |
| 141 | * This calls activate_fd, so it has to be outside the critical |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 142 | * section. |
| 143 | */ |
Jeff Dike | 8e64d96a | 2006-07-10 04:45:11 -0700 | [diff] [blame] | 144 | maybe_sigio_broken(fd, (type == IRQ_READ)); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 145 | |
Jeff Dike | 19bdf04 | 2006-09-25 23:33:04 -0700 | [diff] [blame] | 146 | return 0; |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 147 | |
| 148 | out_unlock: |
Jeff Dike | bfaafd7 | 2006-07-10 04:45:10 -0700 | [diff] [blame] | 149 | spin_unlock_irqrestore(&irq_lock, flags); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 150 | out_kfree: |
| 151 | kfree(new_fd); |
| 152 | out: |
Jeff Dike | 19bdf04 | 2006-09-25 23:33:04 -0700 | [diff] [blame] | 153 | return err; |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 154 | } |
| 155 | |
| 156 | static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg) |
| 157 | { |
| 158 | unsigned long flags; |
| 159 | |
Jeff Dike | bfaafd7 | 2006-07-10 04:45:10 -0700 | [diff] [blame] | 160 | spin_lock_irqsave(&irq_lock, flags); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 161 | os_free_irq_by_cb(test, arg, active_fds, &last_irq_ptr); |
Jeff Dike | bfaafd7 | 2006-07-10 04:45:10 -0700 | [diff] [blame] | 162 | spin_unlock_irqrestore(&irq_lock, flags); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 163 | } |
| 164 | |
| 165 | struct irq_and_dev { |
| 166 | int irq; |
| 167 | void *dev; |
| 168 | }; |
| 169 | |
| 170 | static int same_irq_and_dev(struct irq_fd *irq, void *d) |
| 171 | { |
| 172 | struct irq_and_dev *data = d; |
| 173 | |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 174 | return ((irq->irq == data->irq) && (irq->id == data->dev)); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 175 | } |
| 176 | |
WANG Cong | 4c182ae | 2008-07-23 21:28:47 -0700 | [diff] [blame] | 177 | static void free_irq_by_irq_and_dev(unsigned int irq, void *dev) |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 178 | { |
| 179 | struct irq_and_dev data = ((struct irq_and_dev) { .irq = irq, |
| 180 | .dev = dev }); |
| 181 | |
| 182 | free_irq_by_cb(same_irq_and_dev, &data); |
| 183 | } |
| 184 | |
| 185 | static int same_fd(struct irq_fd *irq, void *fd) |
| 186 | { |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 187 | return (irq->fd == *((int *)fd)); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 188 | } |
| 189 | |
| 190 | void free_irq_by_fd(int fd) |
| 191 | { |
| 192 | free_irq_by_cb(same_fd, &fd); |
| 193 | } |
| 194 | |
Jeff Dike | d973a77 | 2007-05-06 14:51:27 -0700 | [diff] [blame] | 195 | /* Must be called with irq_lock held */ |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 196 | static struct irq_fd *find_irq_by_fd(int fd, int irqnum, int *index_out) |
| 197 | { |
| 198 | struct irq_fd *irq; |
| 199 | int i = 0; |
| 200 | int fdi; |
| 201 | |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 202 | for (irq = active_fds; irq != NULL; irq = irq->next) { |
| 203 | if ((irq->fd == fd) && (irq->irq == irqnum)) |
| 204 | break; |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 205 | i++; |
| 206 | } |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 207 | if (irq == NULL) { |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 208 | printk(KERN_ERR "find_irq_by_fd doesn't have descriptor %d\n", |
| 209 | fd); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 210 | goto out; |
| 211 | } |
| 212 | fdi = os_get_pollfd(i); |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 213 | if ((fdi != -1) && (fdi != fd)) { |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 214 | printk(KERN_ERR "find_irq_by_fd - mismatch between active_fds " |
| 215 | "and pollfds, fd %d vs %d, need %d\n", irq->fd, |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 216 | fdi, fd); |
| 217 | irq = NULL; |
| 218 | goto out; |
| 219 | } |
| 220 | *index_out = i; |
| 221 | out: |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 222 | return irq; |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 223 | } |
| 224 | |
| 225 | void reactivate_fd(int fd, int irqnum) |
| 226 | { |
| 227 | struct irq_fd *irq; |
| 228 | unsigned long flags; |
| 229 | int i; |
| 230 | |
Jeff Dike | bfaafd7 | 2006-07-10 04:45:10 -0700 | [diff] [blame] | 231 | spin_lock_irqsave(&irq_lock, flags); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 232 | irq = find_irq_by_fd(fd, irqnum, &i); |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 233 | if (irq == NULL) { |
Jeff Dike | bfaafd7 | 2006-07-10 04:45:10 -0700 | [diff] [blame] | 234 | spin_unlock_irqrestore(&irq_lock, flags); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 235 | return; |
| 236 | } |
| 237 | os_set_pollfd(i, irq->fd); |
Jeff Dike | bfaafd7 | 2006-07-10 04:45:10 -0700 | [diff] [blame] | 238 | spin_unlock_irqrestore(&irq_lock, flags); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 239 | |
Jeff Dike | 19bdf04 | 2006-09-25 23:33:04 -0700 | [diff] [blame] | 240 | add_sigio_fd(fd); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 241 | } |
| 242 | |
| 243 | void deactivate_fd(int fd, int irqnum) |
| 244 | { |
| 245 | struct irq_fd *irq; |
| 246 | unsigned long flags; |
| 247 | int i; |
| 248 | |
Jeff Dike | bfaafd7 | 2006-07-10 04:45:10 -0700 | [diff] [blame] | 249 | spin_lock_irqsave(&irq_lock, flags); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 250 | irq = find_irq_by_fd(fd, irqnum, &i); |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 251 | if (irq == NULL) { |
Jeff Dike | 19bdf04 | 2006-09-25 23:33:04 -0700 | [diff] [blame] | 252 | spin_unlock_irqrestore(&irq_lock, flags); |
| 253 | return; |
| 254 | } |
| 255 | |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 256 | os_set_pollfd(i, -1); |
Jeff Dike | bfaafd7 | 2006-07-10 04:45:10 -0700 | [diff] [blame] | 257 | spin_unlock_irqrestore(&irq_lock, flags); |
Jeff Dike | 19bdf04 | 2006-09-25 23:33:04 -0700 | [diff] [blame] | 258 | |
| 259 | ignore_sigio_fd(fd); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 260 | } |
Al Viro | 73395a0 | 2011-08-18 20:14:10 +0100 | [diff] [blame] | 261 | EXPORT_SYMBOL(deactivate_fd); |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 262 | |
Jeff Dike | d973a77 | 2007-05-06 14:51:27 -0700 | [diff] [blame] | 263 | /* |
| 264 | * Called just before shutdown in order to provide a clean exec |
| 265 | * environment in case the system is rebooting. No locking because |
| 266 | * that would cause a pointless shutdown hang if something hadn't |
| 267 | * released the lock. |
| 268 | */ |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 269 | int deactivate_all_fds(void) |
| 270 | { |
| 271 | struct irq_fd *irq; |
| 272 | int err; |
| 273 | |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 274 | for (irq = active_fds; irq != NULL; irq = irq->next) { |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 275 | err = os_clear_fd_async(irq->fd); |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 276 | if (err) |
| 277 | return err; |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 278 | } |
| 279 | /* If there is a signal already queued, after unblocking ignore it */ |
| 280 | os_set_ioignore(); |
| 281 | |
Jesper Juhl | 191ef96 | 2006-05-01 12:15:57 -0700 | [diff] [blame] | 282 | return 0; |
Jeff Dike | 9b4f018 | 2006-03-27 01:14:31 -0800 | [diff] [blame] | 283 | } |
| 284 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | /* |
Simon Arlott | b60745b | 2007-10-20 01:23:03 +0200 | [diff] [blame] | 286 | * do_IRQ handles all normal device IRQs (the special |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | * SMP cross-CPU interrupts have their own specific |
| 288 | * handlers). |
| 289 | */ |
Jeff Dike | 77bf440 | 2007-10-16 01:26:58 -0700 | [diff] [blame] | 290 | unsigned int do_IRQ(int irq, struct uml_pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | { |
Al Viro | 7bea96f | 2006-10-08 22:49:34 +0100 | [diff] [blame] | 292 | struct pt_regs *old_regs = set_irq_regs((struct pt_regs *)regs); |
| 293 | irq_enter(); |
Richard Weinberger | be76d81 | 2010-10-26 14:22:20 -0700 | [diff] [blame] | 294 | generic_handle_irq(irq); |
Al Viro | 7bea96f | 2006-10-08 22:49:34 +0100 | [diff] [blame] | 295 | irq_exit(); |
| 296 | set_irq_regs(old_regs); |
| 297 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | } |
| 299 | |
Richard Weinberger | fa7a044 | 2012-04-17 22:37:13 +0200 | [diff] [blame] | 300 | void um_free_irq(unsigned int irq, void *dev) |
| 301 | { |
| 302 | free_irq_by_irq_and_dev(irq, dev); |
| 303 | free_irq(irq, dev); |
| 304 | } |
| 305 | EXPORT_SYMBOL(um_free_irq); |
| 306 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | int um_request_irq(unsigned int irq, int fd, int type, |
David Howells | 40220c1 | 2006-10-09 12:19:47 +0100 | [diff] [blame] | 308 | irq_handler_t handler, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | unsigned long irqflags, const char * devname, |
| 310 | void *dev_id) |
| 311 | { |
| 312 | int err; |
| 313 | |
Jeff Dike | 9ac625a | 2007-11-14 17:00:23 -0800 | [diff] [blame] | 314 | if (fd != -1) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | err = activate_fd(irq, fd, type, dev_id); |
Jeff Dike | 9ac625a | 2007-11-14 17:00:23 -0800 | [diff] [blame] | 316 | if (err) |
| 317 | return err; |
| 318 | } |
| 319 | |
| 320 | return request_irq(irq, handler, irqflags, devname, dev_id); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 321 | } |
Jeff Dike | 9ac625a | 2007-11-14 17:00:23 -0800 | [diff] [blame] | 322 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | EXPORT_SYMBOL(um_request_irq); |
| 324 | EXPORT_SYMBOL(reactivate_fd); |
| 325 | |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 326 | /* |
Thomas Gleixner | 1d119aa | 2011-02-06 22:45:34 +0000 | [diff] [blame] | 327 | * irq_chip must define at least enable/disable and ack when |
| 328 | * the edge handler is used. |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 329 | */ |
Thomas Gleixner | 1d119aa | 2011-02-06 22:45:34 +0000 | [diff] [blame] | 330 | static void dummy(struct irq_data *d) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | { |
| 332 | } |
| 333 | |
Paolo 'Blaisorblade' Giarrusso | dbce706 | 2005-06-21 17:16:19 -0700 | [diff] [blame] | 334 | /* This is used for everything else than the timer. */ |
Thomas Gleixner | 6fa851c | 2009-06-16 15:33:29 -0700 | [diff] [blame] | 335 | static struct irq_chip normal_irq_type = { |
Thomas Gleixner | d1ea13c | 2010-09-23 18:40:07 +0200 | [diff] [blame] | 336 | .name = "SIGIO", |
Thomas Gleixner | 1d119aa | 2011-02-06 22:45:34 +0000 | [diff] [blame] | 337 | .irq_disable = dummy, |
| 338 | .irq_enable = dummy, |
| 339 | .irq_ack = dummy, |
Richard Weinberger | 81bab4c | 2013-09-02 22:49:22 +0200 | [diff] [blame] | 340 | .irq_mask = dummy, |
| 341 | .irq_unmask = dummy, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | }; |
| 343 | |
Thomas Gleixner | 6fa851c | 2009-06-16 15:33:29 -0700 | [diff] [blame] | 344 | static struct irq_chip SIGVTALRM_irq_type = { |
Thomas Gleixner | d1ea13c | 2010-09-23 18:40:07 +0200 | [diff] [blame] | 345 | .name = "SIGVTALRM", |
Thomas Gleixner | 1d119aa | 2011-02-06 22:45:34 +0000 | [diff] [blame] | 346 | .irq_disable = dummy, |
| 347 | .irq_enable = dummy, |
| 348 | .irq_ack = dummy, |
Richard Weinberger | 81bab4c | 2013-09-02 22:49:22 +0200 | [diff] [blame] | 349 | .irq_mask = dummy, |
| 350 | .irq_unmask = dummy, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | }; |
| 352 | |
| 353 | void __init init_IRQ(void) |
| 354 | { |
| 355 | int i; |
| 356 | |
Thomas Gleixner | 0ebec35 | 2011-03-24 18:24:42 +0100 | [diff] [blame] | 357 | irq_set_chip_and_handler(TIMER_IRQ, &SIGVTALRM_irq_type, handle_edge_irq); |
Richard Weinberger | be76d81 | 2010-10-26 14:22:20 -0700 | [diff] [blame] | 358 | |
Thomas Gleixner | 0ebec35 | 2011-03-24 18:24:42 +0100 | [diff] [blame] | 359 | for (i = 1; i < NR_IRQS; i++) |
| 360 | irq_set_chip_and_handler(i, &normal_irq_type, handle_edge_irq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | } |
| 362 | |
Jeff Dike | c14b849 | 2007-05-10 22:22:34 -0700 | [diff] [blame] | 363 | /* |
| 364 | * IRQ stack entry and exit: |
| 365 | * |
| 366 | * Unlike i386, UML doesn't receive IRQs on the normal kernel stack |
| 367 | * and switch over to the IRQ stack after some preparation. We use |
| 368 | * sigaltstack to receive signals on a separate stack from the start. |
| 369 | * These two functions make sure the rest of the kernel won't be too |
| 370 | * upset by being on a different stack. The IRQ stack has a |
| 371 | * thread_info structure at the bottom so that current et al continue |
| 372 | * to work. |
| 373 | * |
| 374 | * to_irq_stack copies the current task's thread_info to the IRQ stack |
| 375 | * thread_info and sets the tasks's stack to point to the IRQ stack. |
| 376 | * |
| 377 | * from_irq_stack copies the thread_info struct back (flags may have |
| 378 | * been modified) and resets the task's stack pointer. |
| 379 | * |
| 380 | * Tricky bits - |
| 381 | * |
| 382 | * What happens when two signals race each other? UML doesn't block |
| 383 | * signals with sigprocmask, SA_DEFER, or sa_mask, so a second signal |
| 384 | * could arrive while a previous one is still setting up the |
| 385 | * thread_info. |
| 386 | * |
| 387 | * There are three cases - |
| 388 | * The first interrupt on the stack - sets up the thread_info and |
| 389 | * handles the interrupt |
| 390 | * A nested interrupt interrupting the copying of the thread_info - |
| 391 | * can't handle the interrupt, as the stack is in an unknown state |
| 392 | * A nested interrupt not interrupting the copying of the |
| 393 | * thread_info - doesn't do any setup, just handles the interrupt |
| 394 | * |
| 395 | * The first job is to figure out whether we interrupted stack setup. |
| 396 | * This is done by xchging the signal mask with thread_info->pending. |
| 397 | * If the value that comes back is zero, then there is no setup in |
| 398 | * progress, and the interrupt can be handled. If the value is |
| 399 | * non-zero, then there is stack setup in progress. In order to have |
| 400 | * the interrupt handled, we leave our signal in the mask, and it will |
| 401 | * be handled by the upper handler after it has set up the stack. |
| 402 | * |
| 403 | * Next is to figure out whether we are the outer handler or a nested |
| 404 | * one. As part of setting up the stack, thread_info->real_thread is |
| 405 | * set to non-NULL (and is reset to NULL on exit). This is the |
| 406 | * nesting indicator. If it is non-NULL, then the stack is already |
| 407 | * set up and the handler can run. |
| 408 | */ |
| 409 | |
| 410 | static unsigned long pending_mask; |
| 411 | |
Jeff Dike | 508a927 | 2007-09-18 22:46:49 -0700 | [diff] [blame] | 412 | unsigned long to_irq_stack(unsigned long *mask_out) |
Jeff Dike | c14b849 | 2007-05-10 22:22:34 -0700 | [diff] [blame] | 413 | { |
| 414 | struct thread_info *ti; |
| 415 | unsigned long mask, old; |
| 416 | int nested; |
| 417 | |
Jeff Dike | 508a927 | 2007-09-18 22:46:49 -0700 | [diff] [blame] | 418 | mask = xchg(&pending_mask, *mask_out); |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 419 | if (mask != 0) { |
| 420 | /* |
| 421 | * If any interrupts come in at this point, we want to |
Jeff Dike | c14b849 | 2007-05-10 22:22:34 -0700 | [diff] [blame] | 422 | * make sure that their bits aren't lost by our |
| 423 | * putting our bit in. So, this loop accumulates bits |
| 424 | * until xchg returns the same value that we put in. |
| 425 | * When that happens, there were no new interrupts, |
| 426 | * and pending_mask contains a bit for each interrupt |
| 427 | * that came in. |
| 428 | */ |
Jeff Dike | 508a927 | 2007-09-18 22:46:49 -0700 | [diff] [blame] | 429 | old = *mask_out; |
Jeff Dike | c14b849 | 2007-05-10 22:22:34 -0700 | [diff] [blame] | 430 | do { |
| 431 | old |= mask; |
| 432 | mask = xchg(&pending_mask, old); |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 433 | } while (mask != old); |
Jeff Dike | c14b849 | 2007-05-10 22:22:34 -0700 | [diff] [blame] | 434 | return 1; |
| 435 | } |
| 436 | |
| 437 | ti = current_thread_info(); |
| 438 | nested = (ti->real_thread != NULL); |
Jeff Dike | ba180fd | 2007-10-16 01:27:00 -0700 | [diff] [blame] | 439 | if (!nested) { |
Jeff Dike | c14b849 | 2007-05-10 22:22:34 -0700 | [diff] [blame] | 440 | struct task_struct *task; |
| 441 | struct thread_info *tti; |
| 442 | |
| 443 | task = cpu_tasks[ti->cpu].task; |
| 444 | tti = task_thread_info(task); |
Jeff Dike | 508a927 | 2007-09-18 22:46:49 -0700 | [diff] [blame] | 445 | |
Jeff Dike | c14b849 | 2007-05-10 22:22:34 -0700 | [diff] [blame] | 446 | *ti = *tti; |
| 447 | ti->real_thread = tti; |
| 448 | task->stack = ti; |
| 449 | } |
| 450 | |
| 451 | mask = xchg(&pending_mask, 0); |
| 452 | *mask_out |= mask | nested; |
| 453 | return 0; |
| 454 | } |
| 455 | |
| 456 | unsigned long from_irq_stack(int nested) |
| 457 | { |
| 458 | struct thread_info *ti, *to; |
| 459 | unsigned long mask; |
| 460 | |
| 461 | ti = current_thread_info(); |
| 462 | |
| 463 | pending_mask = 1; |
| 464 | |
| 465 | to = ti->real_thread; |
| 466 | current->stack = to; |
| 467 | ti->real_thread = NULL; |
| 468 | *to = *ti; |
| 469 | |
| 470 | mask = xchg(&pending_mask, 0); |
| 471 | return mask & ~1; |
| 472 | } |
| 473 | |