]>
Commit | Line | Data |
---|---|---|
2ea5bc5e | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) |
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 | ||
1da177e4 LT |
8 | #include "linux/kernel.h" |
9 | #include "linux/module.h" | |
10 | #include "linux/smp.h" | |
1da177e4 LT |
11 | #include "linux/kernel_stat.h" |
12 | #include "linux/interrupt.h" | |
13 | #include "linux/random.h" | |
14 | #include "linux/slab.h" | |
15 | #include "linux/file.h" | |
16 | #include "linux/proc_fs.h" | |
17 | #include "linux/init.h" | |
18 | #include "linux/seq_file.h" | |
19 | #include "linux/profile.h" | |
20 | #include "linux/hardirq.h" | |
21 | #include "asm/irq.h" | |
22 | #include "asm/hw_irq.h" | |
23 | #include "asm/atomic.h" | |
24 | #include "asm/signal.h" | |
25 | #include "asm/system.h" | |
26 | #include "asm/errno.h" | |
27 | #include "asm/uaccess.h" | |
1da177e4 LT |
28 | #include "kern_util.h" |
29 | #include "irq_user.h" | |
30 | #include "irq_kern.h" | |
75e5584c | 31 | #include "os.h" |
9b4f018d JD |
32 | #include "sigio.h" |
33 | #include "misc_constants.h" | |
c14b8494 | 34 | #include "as-layout.h" |
1da177e4 LT |
35 | |
36 | /* | |
37 | * Generic, controller-independent functions: | |
38 | */ | |
39 | ||
40 | int show_interrupts(struct seq_file *p, void *v) | |
41 | { | |
42 | int i = *(loff_t *) v, j; | |
43 | struct irqaction * action; | |
44 | unsigned long flags; | |
45 | ||
46 | if (i == 0) { | |
47 | seq_printf(p, " "); | |
48 | for_each_online_cpu(j) | |
49 | seq_printf(p, "CPU%d ",j); | |
50 | seq_putc(p, '\n'); | |
51 | } | |
52 | ||
53 | if (i < NR_IRQS) { | |
54 | spin_lock_irqsave(&irq_desc[i].lock, flags); | |
55 | action = irq_desc[i].action; | |
2ea5bc5e | 56 | if (!action) |
1da177e4 LT |
57 | goto skip; |
58 | seq_printf(p, "%3d: ",i); | |
59 | #ifndef CONFIG_SMP | |
60 | seq_printf(p, "%10u ", kstat_irqs(i)); | |
61 | #else | |
62 | for_each_online_cpu(j) | |
63 | seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]); | |
64 | #endif | |
d1bef4ed | 65 | seq_printf(p, " %14s", irq_desc[i].chip->typename); |
1da177e4 LT |
66 | seq_printf(p, " %s", action->name); |
67 | ||
68 | for (action=action->next; action; action = action->next) | |
69 | seq_printf(p, ", %s", action->name); | |
70 | ||
71 | seq_putc(p, '\n'); | |
72 | skip: | |
73 | spin_unlock_irqrestore(&irq_desc[i].lock, flags); | |
74 | } else if (i == NR_IRQS) { | |
75 | seq_putc(p, '\n'); | |
76 | } | |
77 | ||
78 | return 0; | |
79 | } | |
80 | ||
d973a77b JD |
81 | /* |
82 | * This list is accessed under irq_lock, except in sigio_handler, | |
83 | * where it is safe from being modified. IRQ handlers won't change it - | |
84 | * if an IRQ source has vanished, it will be freed by free_irqs just | |
85 | * before returning from sigio_handler. That will process a separate | |
86 | * list of irqs to free, with its own locking, coming back here to | |
87 | * remove list elements, taking the irq_lock to do so. | |
88 | */ | |
f2e62992 | 89 | static struct irq_fd *active_fds = NULL; |
9b4f018d JD |
90 | static struct irq_fd **last_irq_ptr = &active_fds; |
91 | ||
92 | extern void free_irqs(void); | |
93 | ||
94 | void sigio_handler(int sig, union uml_pt_regs *regs) | |
95 | { | |
96 | struct irq_fd *irq_fd; | |
97 | int n; | |
98 | ||
191ef966 JJ |
99 | if (smp_sigio_handler()) |
100 | return; | |
101 | ||
102 | while (1) { | |
9b4f018d JD |
103 | n = os_waiting_for_events(active_fds); |
104 | if (n <= 0) { | |
105 | if(n == -EINTR) continue; | |
106 | else break; | |
107 | } | |
108 | ||
191ef966 JJ |
109 | for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) { |
110 | if (irq_fd->current_events != 0) { | |
9b4f018d JD |
111 | irq_fd->current_events = 0; |
112 | do_IRQ(irq_fd->irq, regs); | |
113 | } | |
114 | } | |
115 | } | |
116 | ||
117 | free_irqs(); | |
118 | } | |
119 | ||
bfaafd71 JD |
120 | static DEFINE_SPINLOCK(irq_lock); |
121 | ||
9b4f018d JD |
122 | int activate_fd(int irq, int fd, int type, void *dev_id) |
123 | { | |
124 | struct pollfd *tmp_pfd; | |
125 | struct irq_fd *new_fd, *irq_fd; | |
126 | unsigned long flags; | |
127 | int pid, events, err, n; | |
128 | ||
129 | pid = os_getpid(); | |
130 | err = os_set_fd_async(fd, pid); | |
191ef966 | 131 | if (err < 0) |
9b4f018d JD |
132 | goto out; |
133 | ||
9b4f018d | 134 | err = -ENOMEM; |
f2e62992 | 135 | new_fd = kmalloc(sizeof(struct irq_fd), GFP_KERNEL); |
191ef966 | 136 | if (new_fd == NULL) |
9b4f018d JD |
137 | goto out; |
138 | ||
191ef966 JJ |
139 | if (type == IRQ_READ) |
140 | events = UM_POLLIN | UM_POLLPRI; | |
141 | else | |
142 | events = UM_POLLOUT; | |
9b4f018d JD |
143 | *new_fd = ((struct irq_fd) { .next = NULL, |
144 | .id = dev_id, | |
145 | .fd = fd, | |
146 | .type = type, | |
147 | .irq = irq, | |
148 | .pid = pid, | |
149 | .events = events, | |
150 | .current_events = 0 } ); | |
151 | ||
0f97869d | 152 | err = -EBUSY; |
bfaafd71 | 153 | spin_lock_irqsave(&irq_lock, flags); |
191ef966 JJ |
154 | for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) { |
155 | if ((irq_fd->fd == fd) && (irq_fd->type == type)) { | |
9b4f018d JD |
156 | printk("Registering fd %d twice\n", fd); |
157 | printk("Irqs : %d, %d\n", irq_fd->irq, irq); | |
158 | printk("Ids : 0x%p, 0x%p\n", irq_fd->id, dev_id); | |
159 | goto out_unlock; | |
160 | } | |
161 | } | |
162 | ||
191ef966 | 163 | if (type == IRQ_WRITE) |
9b4f018d JD |
164 | fd = -1; |
165 | ||
166 | tmp_pfd = NULL; | |
167 | n = 0; | |
168 | ||
191ef966 | 169 | while (1) { |
9b4f018d JD |
170 | n = os_create_pollfd(fd, events, tmp_pfd, n); |
171 | if (n == 0) | |
172 | break; | |
173 | ||
174 | /* n > 0 | |
175 | * It means we couldn't put new pollfd to current pollfds | |
176 | * and tmp_fds is NULL or too small for new pollfds array. | |
177 | * Needed size is equal to n as minimum. | |
178 | * | |
179 | * Here we have to drop the lock in order to call | |
180 | * kmalloc, which might sleep. | |
181 | * If something else came in and changed the pollfds array | |
182 | * so we will not be able to put new pollfd struct to pollfds | |
183 | * then we free the buffer tmp_fds and try again. | |
184 | */ | |
bfaafd71 | 185 | spin_unlock_irqrestore(&irq_lock, flags); |
191ef966 | 186 | kfree(tmp_pfd); |
9b4f018d | 187 | |
f2e62992 | 188 | tmp_pfd = kmalloc(n, GFP_KERNEL); |
9b4f018d JD |
189 | if (tmp_pfd == NULL) |
190 | goto out_kfree; | |
191 | ||
bfaafd71 | 192 | spin_lock_irqsave(&irq_lock, flags); |
9b4f018d | 193 | } |
9b4f018d JD |
194 | |
195 | *last_irq_ptr = new_fd; | |
196 | last_irq_ptr = &new_fd->next; | |
197 | ||
bfaafd71 | 198 | spin_unlock_irqrestore(&irq_lock, flags); |
9b4f018d JD |
199 | |
200 | /* This calls activate_fd, so it has to be outside the critical | |
201 | * section. | |
202 | */ | |
8e64d96a | 203 | maybe_sigio_broken(fd, (type == IRQ_READ)); |
9b4f018d | 204 | |
19bdf040 | 205 | return 0; |
9b4f018d JD |
206 | |
207 | out_unlock: | |
bfaafd71 | 208 | spin_unlock_irqrestore(&irq_lock, flags); |
9b4f018d JD |
209 | out_kfree: |
210 | kfree(new_fd); | |
211 | out: | |
19bdf040 | 212 | return err; |
9b4f018d JD |
213 | } |
214 | ||
215 | static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg) | |
216 | { | |
217 | unsigned long flags; | |
218 | ||
bfaafd71 | 219 | spin_lock_irqsave(&irq_lock, flags); |
9b4f018d | 220 | os_free_irq_by_cb(test, arg, active_fds, &last_irq_ptr); |
bfaafd71 | 221 | spin_unlock_irqrestore(&irq_lock, flags); |
9b4f018d JD |
222 | } |
223 | ||
224 | struct irq_and_dev { | |
225 | int irq; | |
226 | void *dev; | |
227 | }; | |
228 | ||
229 | static int same_irq_and_dev(struct irq_fd *irq, void *d) | |
230 | { | |
231 | struct irq_and_dev *data = d; | |
232 | ||
191ef966 | 233 | return ((irq->irq == data->irq) && (irq->id == data->dev)); |
9b4f018d JD |
234 | } |
235 | ||
236 | void free_irq_by_irq_and_dev(unsigned int irq, void *dev) | |
237 | { | |
238 | struct irq_and_dev data = ((struct irq_and_dev) { .irq = irq, | |
239 | .dev = dev }); | |
240 | ||
241 | free_irq_by_cb(same_irq_and_dev, &data); | |
242 | } | |
243 | ||
244 | static int same_fd(struct irq_fd *irq, void *fd) | |
245 | { | |
191ef966 | 246 | return (irq->fd == *((int *)fd)); |
9b4f018d JD |
247 | } |
248 | ||
249 | void free_irq_by_fd(int fd) | |
250 | { | |
251 | free_irq_by_cb(same_fd, &fd); | |
252 | } | |
253 | ||
d973a77b | 254 | /* Must be called with irq_lock held */ |
9b4f018d JD |
255 | static struct irq_fd *find_irq_by_fd(int fd, int irqnum, int *index_out) |
256 | { | |
257 | struct irq_fd *irq; | |
258 | int i = 0; | |
259 | int fdi; | |
260 | ||
191ef966 JJ |
261 | for (irq = active_fds; irq != NULL; irq = irq->next) { |
262 | if ((irq->fd == fd) && (irq->irq == irqnum)) | |
263 | break; | |
9b4f018d JD |
264 | i++; |
265 | } | |
191ef966 | 266 | if (irq == NULL) { |
9b4f018d JD |
267 | printk("find_irq_by_fd doesn't have descriptor %d\n", fd); |
268 | goto out; | |
269 | } | |
270 | fdi = os_get_pollfd(i); | |
191ef966 | 271 | if ((fdi != -1) && (fdi != fd)) { |
9b4f018d JD |
272 | printk("find_irq_by_fd - mismatch between active_fds and " |
273 | "pollfds, fd %d vs %d, need %d\n", irq->fd, | |
274 | fdi, fd); | |
275 | irq = NULL; | |
276 | goto out; | |
277 | } | |
278 | *index_out = i; | |
279 | out: | |
191ef966 | 280 | return irq; |
9b4f018d JD |
281 | } |
282 | ||
283 | void reactivate_fd(int fd, int irqnum) | |
284 | { | |
285 | struct irq_fd *irq; | |
286 | unsigned long flags; | |
287 | int i; | |
288 | ||
bfaafd71 | 289 | spin_lock_irqsave(&irq_lock, flags); |
9b4f018d | 290 | irq = find_irq_by_fd(fd, irqnum, &i); |
191ef966 | 291 | if (irq == NULL) { |
bfaafd71 | 292 | spin_unlock_irqrestore(&irq_lock, flags); |
9b4f018d JD |
293 | return; |
294 | } | |
295 | os_set_pollfd(i, irq->fd); | |
bfaafd71 | 296 | spin_unlock_irqrestore(&irq_lock, flags); |
9b4f018d | 297 | |
19bdf040 | 298 | add_sigio_fd(fd); |
9b4f018d JD |
299 | } |
300 | ||
301 | void deactivate_fd(int fd, int irqnum) | |
302 | { | |
303 | struct irq_fd *irq; | |
304 | unsigned long flags; | |
305 | int i; | |
306 | ||
bfaafd71 | 307 | spin_lock_irqsave(&irq_lock, flags); |
9b4f018d | 308 | irq = find_irq_by_fd(fd, irqnum, &i); |
19bdf040 JD |
309 | if(irq == NULL){ |
310 | spin_unlock_irqrestore(&irq_lock, flags); | |
311 | return; | |
312 | } | |
313 | ||
9b4f018d | 314 | os_set_pollfd(i, -1); |
bfaafd71 | 315 | spin_unlock_irqrestore(&irq_lock, flags); |
19bdf040 JD |
316 | |
317 | ignore_sigio_fd(fd); | |
9b4f018d JD |
318 | } |
319 | ||
d973a77b JD |
320 | /* |
321 | * Called just before shutdown in order to provide a clean exec | |
322 | * environment in case the system is rebooting. No locking because | |
323 | * that would cause a pointless shutdown hang if something hadn't | |
324 | * released the lock. | |
325 | */ | |
9b4f018d JD |
326 | int deactivate_all_fds(void) |
327 | { | |
328 | struct irq_fd *irq; | |
329 | int err; | |
330 | ||
191ef966 | 331 | for (irq = active_fds; irq != NULL; irq = irq->next) { |
9b4f018d | 332 | err = os_clear_fd_async(irq->fd); |
191ef966 JJ |
333 | if (err) |
334 | return err; | |
9b4f018d JD |
335 | } |
336 | /* If there is a signal already queued, after unblocking ignore it */ | |
337 | os_set_ioignore(); | |
338 | ||
191ef966 | 339 | return 0; |
9b4f018d JD |
340 | } |
341 | ||
1da177e4 LT |
342 | /* |
343 | * do_IRQ handles all normal device IRQ's (the special | |
344 | * SMP cross-CPU interrupts have their own specific | |
345 | * handlers). | |
346 | */ | |
347 | unsigned int do_IRQ(int irq, union uml_pt_regs *regs) | |
348 | { | |
7bea96fd AV |
349 | struct pt_regs *old_regs = set_irq_regs((struct pt_regs *)regs); |
350 | irq_enter(); | |
351 | __do_IRQ(irq); | |
352 | irq_exit(); | |
353 | set_irq_regs(old_regs); | |
354 | return 1; | |
1da177e4 LT |
355 | } |
356 | ||
357 | int um_request_irq(unsigned int irq, int fd, int type, | |
40220c1a | 358 | irq_handler_t handler, |
1da177e4 LT |
359 | unsigned long irqflags, const char * devname, |
360 | void *dev_id) | |
361 | { | |
362 | int err; | |
363 | ||
364 | err = request_irq(irq, handler, irqflags, devname, dev_id); | |
191ef966 JJ |
365 | if (err) |
366 | return err; | |
1da177e4 | 367 | |
191ef966 | 368 | if (fd != -1) |
1da177e4 | 369 | err = activate_fd(irq, fd, type, dev_id); |
191ef966 | 370 | return err; |
1da177e4 LT |
371 | } |
372 | EXPORT_SYMBOL(um_request_irq); | |
373 | EXPORT_SYMBOL(reactivate_fd); | |
374 | ||
dbce706e PBG |
375 | /* hw_interrupt_type must define (startup || enable) && |
376 | * (shutdown || disable) && end */ | |
1da177e4 LT |
377 | static void dummy(unsigned int irq) |
378 | { | |
379 | } | |
380 | ||
dbce706e PBG |
381 | /* This is used for everything else than the timer. */ |
382 | static struct hw_interrupt_type normal_irq_type = { | |
1da177e4 | 383 | .typename = "SIGIO", |
dbce706e | 384 | .release = free_irq_by_irq_and_dev, |
1da177e4 LT |
385 | .disable = dummy, |
386 | .enable = dummy, | |
387 | .ack = dummy, | |
388 | .end = dummy | |
389 | }; | |
390 | ||
391 | static struct hw_interrupt_type SIGVTALRM_irq_type = { | |
392 | .typename = "SIGVTALRM", | |
dbce706e | 393 | .release = free_irq_by_irq_and_dev, |
1da177e4 LT |
394 | .shutdown = dummy, /* never called */ |
395 | .disable = dummy, | |
396 | .enable = dummy, | |
397 | .ack = dummy, | |
398 | .end = dummy | |
399 | }; | |
400 | ||
401 | void __init init_IRQ(void) | |
402 | { | |
403 | int i; | |
404 | ||
405 | irq_desc[TIMER_IRQ].status = IRQ_DISABLED; | |
406 | irq_desc[TIMER_IRQ].action = NULL; | |
407 | irq_desc[TIMER_IRQ].depth = 1; | |
d1bef4ed | 408 | irq_desc[TIMER_IRQ].chip = &SIGVTALRM_irq_type; |
1da177e4 | 409 | enable_irq(TIMER_IRQ); |
191ef966 | 410 | for (i = 1; i < NR_IRQS; i++) { |
1da177e4 LT |
411 | irq_desc[i].status = IRQ_DISABLED; |
412 | irq_desc[i].action = NULL; | |
413 | irq_desc[i].depth = 1; | |
d1bef4ed | 414 | irq_desc[i].chip = &normal_irq_type; |
1da177e4 LT |
415 | enable_irq(i); |
416 | } | |
1da177e4 LT |
417 | } |
418 | ||
40220c1a | 419 | int init_aio_irq(int irq, char *name, irq_handler_t handler) |
75e5584c JD |
420 | { |
421 | int fds[2], err; | |
422 | ||
423 | err = os_pipe(fds, 1, 1); | |
191ef966 | 424 | if (err) { |
75e5584c JD |
425 | printk("init_aio_irq - os_pipe failed, err = %d\n", -err); |
426 | goto out; | |
427 | } | |
428 | ||
429 | err = um_request_irq(irq, fds[0], IRQ_READ, handler, | |
bd6aa650 | 430 | IRQF_DISABLED | IRQF_SAMPLE_RANDOM, name, |
75e5584c | 431 | (void *) (long) fds[0]); |
191ef966 | 432 | if (err) { |
75e5584c JD |
433 | printk("init_aio_irq - : um_request_irq failed, err = %d\n", |
434 | err); | |
435 | goto out_close; | |
436 | } | |
437 | ||
438 | err = fds[1]; | |
439 | goto out; | |
440 | ||
441 | out_close: | |
442 | os_close_file(fds[0]); | |
443 | os_close_file(fds[1]); | |
444 | out: | |
191ef966 | 445 | return err; |
75e5584c | 446 | } |
c14b8494 JD |
447 | |
448 | /* | |
449 | * IRQ stack entry and exit: | |
450 | * | |
451 | * Unlike i386, UML doesn't receive IRQs on the normal kernel stack | |
452 | * and switch over to the IRQ stack after some preparation. We use | |
453 | * sigaltstack to receive signals on a separate stack from the start. | |
454 | * These two functions make sure the rest of the kernel won't be too | |
455 | * upset by being on a different stack. The IRQ stack has a | |
456 | * thread_info structure at the bottom so that current et al continue | |
457 | * to work. | |
458 | * | |
459 | * to_irq_stack copies the current task's thread_info to the IRQ stack | |
460 | * thread_info and sets the tasks's stack to point to the IRQ stack. | |
461 | * | |
462 | * from_irq_stack copies the thread_info struct back (flags may have | |
463 | * been modified) and resets the task's stack pointer. | |
464 | * | |
465 | * Tricky bits - | |
466 | * | |
467 | * What happens when two signals race each other? UML doesn't block | |
468 | * signals with sigprocmask, SA_DEFER, or sa_mask, so a second signal | |
469 | * could arrive while a previous one is still setting up the | |
470 | * thread_info. | |
471 | * | |
472 | * There are three cases - | |
473 | * The first interrupt on the stack - sets up the thread_info and | |
474 | * handles the interrupt | |
475 | * A nested interrupt interrupting the copying of the thread_info - | |
476 | * can't handle the interrupt, as the stack is in an unknown state | |
477 | * A nested interrupt not interrupting the copying of the | |
478 | * thread_info - doesn't do any setup, just handles the interrupt | |
479 | * | |
480 | * The first job is to figure out whether we interrupted stack setup. | |
481 | * This is done by xchging the signal mask with thread_info->pending. | |
482 | * If the value that comes back is zero, then there is no setup in | |
483 | * progress, and the interrupt can be handled. If the value is | |
484 | * non-zero, then there is stack setup in progress. In order to have | |
485 | * the interrupt handled, we leave our signal in the mask, and it will | |
486 | * be handled by the upper handler after it has set up the stack. | |
487 | * | |
488 | * Next is to figure out whether we are the outer handler or a nested | |
489 | * one. As part of setting up the stack, thread_info->real_thread is | |
490 | * set to non-NULL (and is reset to NULL on exit). This is the | |
491 | * nesting indicator. If it is non-NULL, then the stack is already | |
492 | * set up and the handler can run. | |
493 | */ | |
494 | ||
495 | static unsigned long pending_mask; | |
496 | ||
508a9274 | 497 | unsigned long to_irq_stack(unsigned long *mask_out) |
c14b8494 JD |
498 | { |
499 | struct thread_info *ti; | |
500 | unsigned long mask, old; | |
501 | int nested; | |
502 | ||
508a9274 | 503 | mask = xchg(&pending_mask, *mask_out); |
c14b8494 JD |
504 | if(mask != 0){ |
505 | /* If any interrupts come in at this point, we want to | |
506 | * make sure that their bits aren't lost by our | |
507 | * putting our bit in. So, this loop accumulates bits | |
508 | * until xchg returns the same value that we put in. | |
509 | * When that happens, there were no new interrupts, | |
510 | * and pending_mask contains a bit for each interrupt | |
511 | * that came in. | |
512 | */ | |
508a9274 | 513 | old = *mask_out; |
c14b8494 JD |
514 | do { |
515 | old |= mask; | |
516 | mask = xchg(&pending_mask, old); | |
517 | } while(mask != old); | |
518 | return 1; | |
519 | } | |
520 | ||
521 | ti = current_thread_info(); | |
522 | nested = (ti->real_thread != NULL); | |
523 | if(!nested){ | |
524 | struct task_struct *task; | |
525 | struct thread_info *tti; | |
526 | ||
527 | task = cpu_tasks[ti->cpu].task; | |
528 | tti = task_thread_info(task); | |
508a9274 | 529 | |
c14b8494 JD |
530 | *ti = *tti; |
531 | ti->real_thread = tti; | |
532 | task->stack = ti; | |
533 | } | |
534 | ||
535 | mask = xchg(&pending_mask, 0); | |
536 | *mask_out |= mask | nested; | |
537 | return 0; | |
538 | } | |
539 | ||
540 | unsigned long from_irq_stack(int nested) | |
541 | { | |
542 | struct thread_info *ti, *to; | |
543 | unsigned long mask; | |
544 | ||
545 | ti = current_thread_info(); | |
546 | ||
547 | pending_mask = 1; | |
548 | ||
549 | to = ti->real_thread; | |
550 | current->stack = to; | |
551 | ti->real_thread = NULL; | |
552 | *to = *ti; | |
553 | ||
554 | mask = xchg(&pending_mask, 0); | |
555 | return mask & ~1; | |
556 | } | |
557 |