IRQ: Use the new typedef for interrupt handler function pointers
[linux-2.6.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/kernel.h"
9 #include "linux/module.h"
10 #include "linux/smp.h"
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"
28 #include "user_util.h"
29 #include "kern_util.h"
30 #include "irq_user.h"
31 #include "irq_kern.h"
32 #include "os.h"
33 #include "sigio.h"
34 #include "misc_constants.h"
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;
56                 if (!action) 
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
65                 seq_printf(p, " %14s", irq_desc[i].chip->typename);
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
81 struct irq_fd *active_fds = NULL;
82 static struct irq_fd **last_irq_ptr = &active_fds;
83
84 extern void free_irqs(void);
85
86 void sigio_handler(int sig, union uml_pt_regs *regs)
87 {
88         struct irq_fd *irq_fd;
89         int n;
90
91         if (smp_sigio_handler())
92                 return;
93
94         while (1) {
95                 n = os_waiting_for_events(active_fds);
96                 if (n <= 0) {
97                         if(n == -EINTR) continue;
98                         else break;
99                 }
100
101                 for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
102                         if (irq_fd->current_events != 0) {
103                                 irq_fd->current_events = 0;
104                                 do_IRQ(irq_fd->irq, regs);
105                         }
106                 }
107         }
108
109         free_irqs();
110 }
111
112 static DEFINE_SPINLOCK(irq_lock);
113
114 int activate_fd(int irq, int fd, int type, void *dev_id)
115 {
116         struct pollfd *tmp_pfd;
117         struct irq_fd *new_fd, *irq_fd;
118         unsigned long flags;
119         int pid, events, err, n;
120
121         pid = os_getpid();
122         err = os_set_fd_async(fd, pid);
123         if (err < 0)
124                 goto out;
125
126         new_fd = um_kmalloc(sizeof(*new_fd));
127         err = -ENOMEM;
128         if (new_fd == NULL)
129                 goto out;
130
131         if (type == IRQ_READ)
132                 events = UM_POLLIN | UM_POLLPRI;
133         else
134                 events = UM_POLLOUT;
135         *new_fd = ((struct irq_fd) { .next              = NULL,
136                                      .id                = dev_id,
137                                      .fd                = fd,
138                                      .type              = type,
139                                      .irq               = irq,
140                                      .pid               = pid,
141                                      .events            = events,
142                                      .current_events    = 0 } );
143
144         spin_lock_irqsave(&irq_lock, flags);
145         for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
146                 if ((irq_fd->fd == fd) && (irq_fd->type == type)) {
147                         printk("Registering fd %d twice\n", fd);
148                         printk("Irqs : %d, %d\n", irq_fd->irq, irq);
149                         printk("Ids : 0x%p, 0x%p\n", irq_fd->id, dev_id);
150                         goto out_unlock;
151                 }
152         }
153
154         if (type == IRQ_WRITE)
155                 fd = -1;
156
157         tmp_pfd = NULL;
158         n = 0;
159
160         while (1) {
161                 n = os_create_pollfd(fd, events, tmp_pfd, n);
162                 if (n == 0)
163                         break;
164
165                 /* n > 0
166                  * It means we couldn't put new pollfd to current pollfds
167                  * and tmp_fds is NULL or too small for new pollfds array.
168                  * Needed size is equal to n as minimum.
169                  *
170                  * Here we have to drop the lock in order to call
171                  * kmalloc, which might sleep.
172                  * If something else came in and changed the pollfds array
173                  * so we will not be able to put new pollfd struct to pollfds
174                  * then we free the buffer tmp_fds and try again.
175                  */
176                 spin_unlock_irqrestore(&irq_lock, flags);
177                 kfree(tmp_pfd);
178                 tmp_pfd = NULL;
179
180                 tmp_pfd = um_kmalloc(n);
181                 if (tmp_pfd == NULL)
182                         goto out_kfree;
183
184                 spin_lock_irqsave(&irq_lock, flags);
185         }
186
187         *last_irq_ptr = new_fd;
188         last_irq_ptr = &new_fd->next;
189
190         spin_unlock_irqrestore(&irq_lock, flags);
191
192         /* This calls activate_fd, so it has to be outside the critical
193          * section.
194          */
195         maybe_sigio_broken(fd, (type == IRQ_READ));
196
197         return 0;
198
199  out_unlock:
200         spin_unlock_irqrestore(&irq_lock, flags);
201  out_kfree:
202         kfree(new_fd);
203  out:
204         return err;
205 }
206
207 static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg)
208 {
209         unsigned long flags;
210
211         spin_lock_irqsave(&irq_lock, flags);
212         os_free_irq_by_cb(test, arg, active_fds, &last_irq_ptr);
213         spin_unlock_irqrestore(&irq_lock, flags);
214 }
215
216 struct irq_and_dev {
217         int irq;
218         void *dev;
219 };
220
221 static int same_irq_and_dev(struct irq_fd *irq, void *d)
222 {
223         struct irq_and_dev *data = d;
224
225         return ((irq->irq == data->irq) && (irq->id == data->dev));
226 }
227
228 void free_irq_by_irq_and_dev(unsigned int irq, void *dev)
229 {
230         struct irq_and_dev data = ((struct irq_and_dev) { .irq  = irq,
231                                                           .dev  = dev });
232
233         free_irq_by_cb(same_irq_and_dev, &data);
234 }
235
236 static int same_fd(struct irq_fd *irq, void *fd)
237 {
238         return (irq->fd == *((int *)fd));
239 }
240
241 void free_irq_by_fd(int fd)
242 {
243         free_irq_by_cb(same_fd, &fd);
244 }
245
246 static struct irq_fd *find_irq_by_fd(int fd, int irqnum, int *index_out)
247 {
248         struct irq_fd *irq;
249         int i = 0;
250         int fdi;
251
252         for (irq = active_fds; irq != NULL; irq = irq->next) {
253                 if ((irq->fd == fd) && (irq->irq == irqnum))
254                         break;
255                 i++;
256         }
257         if (irq == NULL) {
258                 printk("find_irq_by_fd doesn't have descriptor %d\n", fd);
259                 goto out;
260         }
261         fdi = os_get_pollfd(i);
262         if ((fdi != -1) && (fdi != fd)) {
263                 printk("find_irq_by_fd - mismatch between active_fds and "
264                        "pollfds, fd %d vs %d, need %d\n", irq->fd,
265                        fdi, fd);
266                 irq = NULL;
267                 goto out;
268         }
269         *index_out = i;
270  out:
271         return irq;
272 }
273
274 void reactivate_fd(int fd, int irqnum)
275 {
276         struct irq_fd *irq;
277         unsigned long flags;
278         int i;
279
280         spin_lock_irqsave(&irq_lock, flags);
281         irq = find_irq_by_fd(fd, irqnum, &i);
282         if (irq == NULL) {
283                 spin_unlock_irqrestore(&irq_lock, flags);
284                 return;
285         }
286         os_set_pollfd(i, irq->fd);
287         spin_unlock_irqrestore(&irq_lock, flags);
288
289         add_sigio_fd(fd);
290 }
291
292 void deactivate_fd(int fd, int irqnum)
293 {
294         struct irq_fd *irq;
295         unsigned long flags;
296         int i;
297
298         spin_lock_irqsave(&irq_lock, flags);
299         irq = find_irq_by_fd(fd, irqnum, &i);
300         if(irq == NULL){
301                 spin_unlock_irqrestore(&irq_lock, flags);
302                 return;
303         }
304
305         os_set_pollfd(i, -1);
306         spin_unlock_irqrestore(&irq_lock, flags);
307
308         ignore_sigio_fd(fd);
309 }
310
311 int deactivate_all_fds(void)
312 {
313         struct irq_fd *irq;
314         int err;
315
316         for (irq = active_fds; irq != NULL; irq = irq->next) {
317                 err = os_clear_fd_async(irq->fd);
318                 if (err)
319                         return err;
320         }
321         /* If there is a signal already queued, after unblocking ignore it */
322         os_set_ioignore();
323
324         return 0;
325 }
326
327 #ifdef CONFIG_MODE_TT
328 void forward_interrupts(int pid)
329 {
330         struct irq_fd *irq;
331         unsigned long flags;
332         int err;
333
334         spin_lock_irqsave(&irq_lock, flags);
335         for (irq = active_fds; irq != NULL; irq = irq->next) {
336                 err = os_set_owner(irq->fd, pid);
337                 if (err < 0) {
338                         /* XXX Just remove the irq rather than
339                          * print out an infinite stream of these
340                          */
341                         printk("Failed to forward %d to pid %d, err = %d\n",
342                                irq->fd, pid, -err);
343                 }
344
345                 irq->pid = pid;
346         }
347         spin_unlock_irqrestore(&irq_lock, flags);
348 }
349 #endif
350
351 /*
352  * do_IRQ handles all normal device IRQ's (the special
353  * SMP cross-CPU interrupts have their own specific
354  * handlers).
355  */
356 unsigned int do_IRQ(int irq, union uml_pt_regs *regs)
357 {
358         struct pt_regs *old_regs = set_irq_regs((struct pt_regs *)regs);
359         irq_enter();
360         __do_IRQ(irq);
361         irq_exit();
362         set_irq_regs(old_regs);
363         return 1;
364 }
365
366 int um_request_irq(unsigned int irq, int fd, int type,
367                    irq_handler_t handler,
368                    unsigned long irqflags, const char * devname,
369                    void *dev_id)
370 {
371         int err;
372
373         err = request_irq(irq, handler, irqflags, devname, dev_id);
374         if (err)
375                 return err;
376
377         if (fd != -1)
378                 err = activate_fd(irq, fd, type, dev_id);
379         return err;
380 }
381 EXPORT_SYMBOL(um_request_irq);
382 EXPORT_SYMBOL(reactivate_fd);
383
384 /* hw_interrupt_type must define (startup || enable) &&
385  * (shutdown || disable) && end */
386 static void dummy(unsigned int irq)
387 {
388 }
389
390 /* This is used for everything else than the timer. */
391 static struct hw_interrupt_type normal_irq_type = {
392         .typename = "SIGIO",
393         .release = free_irq_by_irq_and_dev,
394         .disable = dummy,
395         .enable = dummy,
396         .ack = dummy,
397         .end = dummy
398 };
399
400 static struct hw_interrupt_type SIGVTALRM_irq_type = {
401         .typename = "SIGVTALRM",
402         .release = free_irq_by_irq_and_dev,
403         .shutdown = dummy, /* never called */
404         .disable = dummy,
405         .enable = dummy,
406         .ack = dummy,
407         .end = dummy
408 };
409
410 void __init init_IRQ(void)
411 {
412         int i;
413
414         irq_desc[TIMER_IRQ].status = IRQ_DISABLED;
415         irq_desc[TIMER_IRQ].action = NULL;
416         irq_desc[TIMER_IRQ].depth = 1;
417         irq_desc[TIMER_IRQ].chip = &SIGVTALRM_irq_type;
418         enable_irq(TIMER_IRQ);
419         for (i = 1; i < NR_IRQS; i++) {
420                 irq_desc[i].status = IRQ_DISABLED;
421                 irq_desc[i].action = NULL;
422                 irq_desc[i].depth = 1;
423                 irq_desc[i].chip = &normal_irq_type;
424                 enable_irq(i);
425         }
426 }
427
428 int init_aio_irq(int irq, char *name, irq_handler_t handler)
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 }