ce7f233fc490d1cb03cc30a6d77dcd511a112cb5
[linux-3.10.git] / arch / um / kernel / irq.c
1 /* 
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
8 #include "linux/config.h"
9 #include "linux/kernel.h"
10 #include "linux/module.h"
11 #include "linux/smp.h"
12 #include "linux/kernel_stat.h"
13 #include "linux/interrupt.h"
14 #include "linux/random.h"
15 #include "linux/slab.h"
16 #include "linux/file.h"
17 #include "linux/proc_fs.h"
18 #include "linux/init.h"
19 #include "linux/seq_file.h"
20 #include "linux/profile.h"
21 #include "linux/hardirq.h"
22 #include "asm/irq.h"
23 #include "asm/hw_irq.h"
24 #include "asm/atomic.h"
25 #include "asm/signal.h"
26 #include "asm/system.h"
27 #include "asm/errno.h"
28 #include "asm/uaccess.h"
29 #include "user_util.h"
30 #include "kern_util.h"
31 #include "irq_user.h"
32 #include "irq_kern.h"
33 #include "os.h"
34 #include "sigio.h"
35 #include "misc_constants.h"
36
37 /*
38  * Generic, controller-independent functions:
39  */
40
41 int show_interrupts(struct seq_file *p, void *v)
42 {
43         int i = *(loff_t *) v, j;
44         struct irqaction * action;
45         unsigned long flags;
46
47         if (i == 0) {
48                 seq_printf(p, "           ");
49                 for_each_online_cpu(j)
50                         seq_printf(p, "CPU%d       ",j);
51                 seq_putc(p, '\n');
52         }
53
54         if (i < NR_IRQS) {
55                 spin_lock_irqsave(&irq_desc[i].lock, flags);
56                 action = irq_desc[i].action;
57                 if (!action) 
58                         goto skip;
59                 seq_printf(p, "%3d: ",i);
60 #ifndef CONFIG_SMP
61                 seq_printf(p, "%10u ", kstat_irqs(i));
62 #else
63                 for_each_online_cpu(j)
64                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
65 #endif
66                 seq_printf(p, " %14s", irq_desc[i].chip->typename);
67                 seq_printf(p, "  %s", action->name);
68
69                 for (action=action->next; action; action = action->next)
70                         seq_printf(p, ", %s", action->name);
71
72                 seq_putc(p, '\n');
73 skip:
74                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
75         } else if (i == NR_IRQS) {
76                 seq_putc(p, '\n');
77         }
78
79         return 0;
80 }
81
82 struct irq_fd *active_fds = NULL;
83 static struct irq_fd **last_irq_ptr = &active_fds;
84
85 extern void free_irqs(void);
86
87 void sigio_handler(int sig, union uml_pt_regs *regs)
88 {
89         struct irq_fd *irq_fd;
90         int n;
91
92         if (smp_sigio_handler())
93                 return;
94
95         while (1) {
96                 n = os_waiting_for_events(active_fds);
97                 if (n <= 0) {
98                         if(n == -EINTR) continue;
99                         else break;
100                 }
101
102                 for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
103                         if (irq_fd->current_events != 0) {
104                                 irq_fd->current_events = 0;
105                                 do_IRQ(irq_fd->irq, regs);
106                         }
107                 }
108         }
109
110         free_irqs();
111 }
112
113 static DEFINE_SPINLOCK(irq_lock);
114
115 int activate_fd(int irq, int fd, int type, void *dev_id)
116 {
117         struct pollfd *tmp_pfd;
118         struct irq_fd *new_fd, *irq_fd;
119         unsigned long flags;
120         int pid, events, err, n;
121
122         pid = os_getpid();
123         err = os_set_fd_async(fd, pid);
124         if (err < 0)
125                 goto out;
126
127         new_fd = um_kmalloc(sizeof(*new_fd));
128         err = -ENOMEM;
129         if (new_fd == NULL)
130                 goto out;
131
132         if (type == IRQ_READ)
133                 events = UM_POLLIN | UM_POLLPRI;
134         else
135                 events = UM_POLLOUT;
136         *new_fd = ((struct irq_fd) { .next              = NULL,
137                                      .id                = dev_id,
138                                      .fd                = fd,
139                                      .type              = type,
140                                      .irq               = irq,
141                                      .pid               = pid,
142                                      .events            = events,
143                                      .current_events    = 0 } );
144
145         spin_lock_irqsave(&irq_lock, flags);
146         for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
147                 if ((irq_fd->fd == fd) && (irq_fd->type == type)) {
148                         printk("Registering fd %d twice\n", fd);
149                         printk("Irqs : %d, %d\n", irq_fd->irq, irq);
150                         printk("Ids : 0x%p, 0x%p\n", irq_fd->id, dev_id);
151                         goto out_unlock;
152                 }
153         }
154
155         if (type == IRQ_WRITE)
156                 fd = -1;
157
158         tmp_pfd = NULL;
159         n = 0;
160
161         while (1) {
162                 n = os_create_pollfd(fd, events, tmp_pfd, n);
163                 if (n == 0)
164                         break;
165
166                 /* n > 0
167                  * It means we couldn't put new pollfd to current pollfds
168                  * and tmp_fds is NULL or too small for new pollfds array.
169                  * Needed size is equal to n as minimum.
170                  *
171                  * Here we have to drop the lock in order to call
172                  * kmalloc, which might sleep.
173                  * If something else came in and changed the pollfds array
174                  * so we will not be able to put new pollfd struct to pollfds
175                  * then we free the buffer tmp_fds and try again.
176                  */
177                 spin_unlock_irqrestore(&irq_lock, flags);
178                 kfree(tmp_pfd);
179                 tmp_pfd = NULL;
180
181                 tmp_pfd = um_kmalloc(n);
182                 if (tmp_pfd == NULL)
183                         goto out_kfree;
184
185                 spin_lock_irqsave(&irq_lock, flags);
186         }
187
188         *last_irq_ptr = new_fd;
189         last_irq_ptr = &new_fd->next;
190
191         spin_unlock_irqrestore(&irq_lock, flags);
192
193         /* This calls activate_fd, so it has to be outside the critical
194          * section.
195          */
196         maybe_sigio_broken(fd, (type == IRQ_READ));
197
198         return 0;
199
200  out_unlock:
201         spin_unlock_irqrestore(&irq_lock, flags);
202  out_kfree:
203         kfree(new_fd);
204  out:
205         return err;
206 }
207
208 static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg)
209 {
210         unsigned long flags;
211
212         spin_lock_irqsave(&irq_lock, flags);
213         os_free_irq_by_cb(test, arg, active_fds, &last_irq_ptr);
214         spin_unlock_irqrestore(&irq_lock, flags);
215 }
216
217 struct irq_and_dev {
218         int irq;
219         void *dev;
220 };
221
222 static int same_irq_and_dev(struct irq_fd *irq, void *d)
223 {
224         struct irq_and_dev *data = d;
225
226         return ((irq->irq == data->irq) && (irq->id == data->dev));
227 }
228
229 void free_irq_by_irq_and_dev(unsigned int irq, void *dev)
230 {
231         struct irq_and_dev data = ((struct irq_and_dev) { .irq  = irq,
232                                                           .dev  = dev });
233
234         free_irq_by_cb(same_irq_and_dev, &data);
235 }
236
237 static int same_fd(struct irq_fd *irq, void *fd)
238 {
239         return (irq->fd == *((int *)fd));
240 }
241
242 void free_irq_by_fd(int fd)
243 {
244         free_irq_by_cb(same_fd, &fd);
245 }
246
247 static struct irq_fd *find_irq_by_fd(int fd, int irqnum, int *index_out)
248 {
249         struct irq_fd *irq;
250         int i = 0;
251         int fdi;
252
253         for (irq = active_fds; irq != NULL; irq = irq->next) {
254                 if ((irq->fd == fd) && (irq->irq == irqnum))
255                         break;
256                 i++;
257         }
258         if (irq == NULL) {
259                 printk("find_irq_by_fd doesn't have descriptor %d\n", fd);
260                 goto out;
261         }
262         fdi = os_get_pollfd(i);
263         if ((fdi != -1) && (fdi != fd)) {
264                 printk("find_irq_by_fd - mismatch between active_fds and "
265                        "pollfds, fd %d vs %d, need %d\n", irq->fd,
266                        fdi, fd);
267                 irq = NULL;
268                 goto out;
269         }
270         *index_out = i;
271  out:
272         return irq;
273 }
274
275 void reactivate_fd(int fd, int irqnum)
276 {
277         struct irq_fd *irq;
278         unsigned long flags;
279         int i;
280
281         spin_lock_irqsave(&irq_lock, flags);
282         irq = find_irq_by_fd(fd, irqnum, &i);
283         if (irq == NULL) {
284                 spin_unlock_irqrestore(&irq_lock, flags);
285                 return;
286         }
287         os_set_pollfd(i, irq->fd);
288         spin_unlock_irqrestore(&irq_lock, flags);
289
290         add_sigio_fd(fd);
291 }
292
293 void deactivate_fd(int fd, int irqnum)
294 {
295         struct irq_fd *irq;
296         unsigned long flags;
297         int i;
298
299         spin_lock_irqsave(&irq_lock, flags);
300         irq = find_irq_by_fd(fd, irqnum, &i);
301         if(irq == NULL){
302                 spin_unlock_irqrestore(&irq_lock, flags);
303                 return;
304         }
305
306         os_set_pollfd(i, -1);
307         spin_unlock_irqrestore(&irq_lock, flags);
308
309         ignore_sigio_fd(fd);
310 }
311
312 int deactivate_all_fds(void)
313 {
314         struct irq_fd *irq;
315         int err;
316
317         for (irq = active_fds; irq != NULL; irq = irq->next) {
318                 err = os_clear_fd_async(irq->fd);
319                 if (err)
320                         return err;
321         }
322         /* If there is a signal already queued, after unblocking ignore it */
323         os_set_ioignore();
324
325         return 0;
326 }
327
328 #ifdef CONFIG_MODE_TT
329 void forward_interrupts(int pid)
330 {
331         struct irq_fd *irq;
332         unsigned long flags;
333         int err;
334
335         spin_lock_irqsave(&irq_lock, flags);
336         for (irq = active_fds; irq != NULL; irq = irq->next) {
337                 err = os_set_owner(irq->fd, pid);
338                 if (err < 0) {
339                         /* XXX Just remove the irq rather than
340                          * print out an infinite stream of these
341                          */
342                         printk("Failed to forward %d to pid %d, err = %d\n",
343                                irq->fd, pid, -err);
344                 }
345
346                 irq->pid = pid;
347         }
348         spin_unlock_irqrestore(&irq_lock, flags);
349 }
350 #endif
351
352 /*
353  * do_IRQ handles all normal device IRQ's (the special
354  * SMP cross-CPU interrupts have their own specific
355  * handlers).
356  */
357 unsigned int do_IRQ(int irq, union uml_pt_regs *regs)
358 {
359        irq_enter();
360        __do_IRQ(irq, (struct pt_regs *)regs);
361        irq_exit();
362        return 1;
363 }
364
365 int um_request_irq(unsigned int irq, int fd, int type,
366                    irqreturn_t (*handler)(int, void *, struct pt_regs *),
367                    unsigned long irqflags, const char * devname,
368                    void *dev_id)
369 {
370         int err;
371
372         err = request_irq(irq, handler, irqflags, devname, dev_id);
373         if (err)
374                 return err;
375
376         if (fd != -1)
377                 err = activate_fd(irq, fd, type, dev_id);
378         return err;
379 }
380 EXPORT_SYMBOL(um_request_irq);
381 EXPORT_SYMBOL(reactivate_fd);
382
383 /* hw_interrupt_type must define (startup || enable) &&
384  * (shutdown || disable) && end */
385 static void dummy(unsigned int irq)
386 {
387 }
388
389 /* This is used for everything else than the timer. */
390 static struct hw_interrupt_type normal_irq_type = {
391         .typename = "SIGIO",
392         .release = free_irq_by_irq_and_dev,
393         .disable = dummy,
394         .enable = dummy,
395         .ack = dummy,
396         .end = dummy
397 };
398
399 static struct hw_interrupt_type SIGVTALRM_irq_type = {
400         .typename = "SIGVTALRM",
401         .release = free_irq_by_irq_and_dev,
402         .shutdown = dummy, /* never called */
403         .disable = dummy,
404         .enable = dummy,
405         .ack = dummy,
406         .end = dummy
407 };
408
409 void __init init_IRQ(void)
410 {
411         int i;
412
413         irq_desc[TIMER_IRQ].status = IRQ_DISABLED;
414         irq_desc[TIMER_IRQ].action = NULL;
415         irq_desc[TIMER_IRQ].depth = 1;
416         irq_desc[TIMER_IRQ].chip = &SIGVTALRM_irq_type;
417         enable_irq(TIMER_IRQ);
418         for (i = 1; i < NR_IRQS; i++) {
419                 irq_desc[i].status = IRQ_DISABLED;
420                 irq_desc[i].action = NULL;
421                 irq_desc[i].depth = 1;
422                 irq_desc[i].chip = &normal_irq_type;
423                 enable_irq(i);
424         }
425 }
426
427 int init_aio_irq(int irq, char *name, irqreturn_t (*handler)(int, void *,
428                                                              struct pt_regs *))
429 {
430         int fds[2], err;
431
432         err = os_pipe(fds, 1, 1);
433         if (err) {
434                 printk("init_aio_irq - os_pipe failed, err = %d\n", -err);
435                 goto out;
436         }
437
438         err = um_request_irq(irq, fds[0], IRQ_READ, handler,
439                              IRQF_DISABLED | IRQF_SAMPLE_RANDOM, name,
440                              (void *) (long) fds[0]);
441         if (err) {
442                 printk("init_aio_irq - : um_request_irq failed, err = %d\n",
443                        err);
444                 goto out_close;
445         }
446
447         err = fds[1];
448         goto out;
449
450  out_close:
451         os_close_file(fds[0]);
452         os_close_file(fds[1]);
453  out:
454         return err;
455 }