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f7116284 IC |
1 | /****************************************************************************** |
2 | * evtchn.c | |
3 | * | |
4 | * Driver for receiving and demuxing event-channel signals. | |
5 | * | |
6 | * Copyright (c) 2004-2005, K A Fraser | |
7 | * Multi-process extensions Copyright (c) 2004, Steven Smith | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License version 2 | |
11 | * as published by the Free Software Foundation; or, when distributed | |
12 | * separately from the Linux kernel or incorporated into other | |
13 | * software packages, subject to the following license: | |
14 | * | |
15 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
16 | * of this source file (the "Software"), to deal in the Software without | |
17 | * restriction, including without limitation the rights to use, copy, modify, | |
18 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, | |
19 | * and to permit persons to whom the Software is furnished to do so, subject to | |
20 | * the following conditions: | |
21 | * | |
22 | * The above copyright notice and this permission notice shall be included in | |
23 | * all copies or substantial portions of the Software. | |
24 | * | |
25 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
26 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
27 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
28 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
29 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
30 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
31 | * IN THE SOFTWARE. | |
32 | */ | |
33 | ||
283c0972 JP |
34 | #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt |
35 | ||
f7116284 IC |
36 | #include <linux/module.h> |
37 | #include <linux/kernel.h> | |
38 | #include <linux/sched.h> | |
39 | #include <linux/slab.h> | |
40 | #include <linux/string.h> | |
41 | #include <linux/errno.h> | |
42 | #include <linux/fs.h> | |
f7116284 IC |
43 | #include <linux/miscdevice.h> |
44 | #include <linux/major.h> | |
45 | #include <linux/proc_fs.h> | |
46 | #include <linux/stat.h> | |
47 | #include <linux/poll.h> | |
48 | #include <linux/irq.h> | |
49 | #include <linux/init.h> | |
f7116284 IC |
50 | #include <linux/mutex.h> |
51 | #include <linux/cpu.h> | |
86200154 DV |
52 | #include <linux/mm.h> |
53 | #include <linux/vmalloc.h> | |
1ccbf534 JF |
54 | |
55 | #include <xen/xen.h> | |
f7116284 IC |
56 | #include <xen/events.h> |
57 | #include <xen/evtchn.h> | |
58 | #include <asm/xen/hypervisor.h> | |
59 | ||
60 | struct per_user_data { | |
0a4666b5 | 61 | struct mutex bind_mutex; /* serialize bind/unbind operations */ |
73cc4bb0 | 62 | struct rb_root evtchns; |
86200154 | 63 | unsigned int nr_evtchns; |
0a4666b5 | 64 | |
f7116284 | 65 | /* Notification ring, accessed via /dev/xen/evtchn. */ |
86200154 | 66 | unsigned int ring_size; |
f7116284 IC |
67 | evtchn_port_t *ring; |
68 | unsigned int ring_cons, ring_prod, ring_overflow; | |
69 | struct mutex ring_cons_mutex; /* protect against concurrent readers */ | |
73cc4bb0 | 70 | spinlock_t ring_prod_lock; /* product against concurrent interrupts */ |
f7116284 IC |
71 | |
72 | /* Processes wait on this queue when ring is empty. */ | |
73 | wait_queue_head_t evtchn_wait; | |
74 | struct fasync_struct *evtchn_async_queue; | |
75 | const char *name; | |
76 | }; | |
77 | ||
73cc4bb0 DV |
78 | struct user_evtchn { |
79 | struct rb_node node; | |
80 | struct per_user_data *user; | |
81 | unsigned port; | |
82 | bool enabled; | |
83 | }; | |
f7116284 | 84 | |
86200154 DV |
85 | static evtchn_port_t *evtchn_alloc_ring(unsigned int size) |
86 | { | |
87 | evtchn_port_t *ring; | |
88 | size_t s = size * sizeof(*ring); | |
89 | ||
90 | ring = kmalloc(s, GFP_KERNEL); | |
91 | if (!ring) | |
92 | ring = vmalloc(s); | |
93 | ||
94 | return ring; | |
95 | } | |
96 | ||
97 | static void evtchn_free_ring(evtchn_port_t *ring) | |
98 | { | |
99 | kvfree(ring); | |
100 | } | |
101 | ||
102 | static unsigned int evtchn_ring_offset(struct per_user_data *u, | |
103 | unsigned int idx) | |
104 | { | |
105 | return idx & (u->ring_size - 1); | |
106 | } | |
107 | ||
108 | static evtchn_port_t *evtchn_ring_entry(struct per_user_data *u, | |
109 | unsigned int idx) | |
110 | { | |
111 | return u->ring + evtchn_ring_offset(u, idx); | |
112 | } | |
113 | ||
73cc4bb0 | 114 | static int add_evtchn(struct per_user_data *u, struct user_evtchn *evtchn) |
e3cc067b | 115 | { |
73cc4bb0 | 116 | struct rb_node **new = &(u->evtchns.rb_node), *parent = NULL; |
e3cc067b | 117 | |
86200154 DV |
118 | u->nr_evtchns++; |
119 | ||
73cc4bb0 DV |
120 | while (*new) { |
121 | struct user_evtchn *this; | |
122 | ||
123 | this = container_of(*new, struct user_evtchn, node); | |
124 | ||
125 | parent = *new; | |
126 | if (this->port < evtchn->port) | |
127 | new = &((*new)->rb_left); | |
128 | else if (this->port > evtchn->port) | |
129 | new = &((*new)->rb_right); | |
130 | else | |
131 | return -EEXIST; | |
132 | } | |
133 | ||
134 | /* Add new node and rebalance tree. */ | |
135 | rb_link_node(&evtchn->node, parent, new); | |
136 | rb_insert_color(&evtchn->node, &u->evtchns); | |
137 | ||
138 | return 0; | |
e3cc067b JF |
139 | } |
140 | ||
73cc4bb0 | 141 | static void del_evtchn(struct per_user_data *u, struct user_evtchn *evtchn) |
e3cc067b | 142 | { |
86200154 | 143 | u->nr_evtchns--; |
73cc4bb0 DV |
144 | rb_erase(&evtchn->node, &u->evtchns); |
145 | kfree(evtchn); | |
e3cc067b JF |
146 | } |
147 | ||
73cc4bb0 | 148 | static struct user_evtchn *find_evtchn(struct per_user_data *u, unsigned port) |
e3cc067b | 149 | { |
73cc4bb0 DV |
150 | struct rb_node *node = u->evtchns.rb_node; |
151 | ||
152 | while (node) { | |
153 | struct user_evtchn *evtchn; | |
154 | ||
155 | evtchn = container_of(node, struct user_evtchn, node); | |
156 | ||
157 | if (evtchn->port < port) | |
158 | node = node->rb_left; | |
159 | else if (evtchn->port > port) | |
160 | node = node->rb_right; | |
161 | else | |
162 | return evtchn; | |
163 | } | |
164 | return NULL; | |
e3cc067b JF |
165 | } |
166 | ||
70697d54 | 167 | static irqreturn_t evtchn_interrupt(int irq, void *data) |
f7116284 | 168 | { |
73cc4bb0 DV |
169 | struct user_evtchn *evtchn = data; |
170 | struct per_user_data *u = evtchn->user; | |
e3cc067b | 171 | |
73cc4bb0 | 172 | WARN(!evtchn->enabled, |
0edce91d | 173 | "Interrupt for port %d, but apparently not enabled; per-user %p\n", |
73cc4bb0 | 174 | evtchn->port, u); |
f7116284 IC |
175 | |
176 | disable_irq_nosync(irq); | |
73cc4bb0 DV |
177 | evtchn->enabled = false; |
178 | ||
179 | spin_lock(&u->ring_prod_lock); | |
f7116284 | 180 | |
86200154 DV |
181 | if ((u->ring_prod - u->ring_cons) < u->ring_size) { |
182 | *evtchn_ring_entry(u, u->ring_prod) = evtchn->port; | |
f7116284 IC |
183 | wmb(); /* Ensure ring contents visible */ |
184 | if (u->ring_cons == u->ring_prod++) { | |
185 | wake_up_interruptible(&u->evtchn_wait); | |
186 | kill_fasync(&u->evtchn_async_queue, | |
187 | SIGIO, POLL_IN); | |
188 | } | |
e3cc067b | 189 | } else |
f7116284 | 190 | u->ring_overflow = 1; |
f7116284 | 191 | |
73cc4bb0 | 192 | spin_unlock(&u->ring_prod_lock); |
f7116284 IC |
193 | |
194 | return IRQ_HANDLED; | |
195 | } | |
196 | ||
197 | static ssize_t evtchn_read(struct file *file, char __user *buf, | |
198 | size_t count, loff_t *ppos) | |
199 | { | |
200 | int rc; | |
201 | unsigned int c, p, bytes1 = 0, bytes2 = 0; | |
202 | struct per_user_data *u = file->private_data; | |
203 | ||
204 | /* Whole number of ports. */ | |
205 | count &= ~(sizeof(evtchn_port_t)-1); | |
206 | ||
207 | if (count == 0) | |
208 | return 0; | |
209 | ||
210 | if (count > PAGE_SIZE) | |
211 | count = PAGE_SIZE; | |
212 | ||
213 | for (;;) { | |
214 | mutex_lock(&u->ring_cons_mutex); | |
215 | ||
216 | rc = -EFBIG; | |
217 | if (u->ring_overflow) | |
218 | goto unlock_out; | |
219 | ||
220 | c = u->ring_cons; | |
221 | p = u->ring_prod; | |
222 | if (c != p) | |
223 | break; | |
224 | ||
225 | mutex_unlock(&u->ring_cons_mutex); | |
226 | ||
227 | if (file->f_flags & O_NONBLOCK) | |
228 | return -EAGAIN; | |
229 | ||
230 | rc = wait_event_interruptible(u->evtchn_wait, | |
231 | u->ring_cons != u->ring_prod); | |
232 | if (rc) | |
233 | return rc; | |
234 | } | |
235 | ||
236 | /* Byte lengths of two chunks. Chunk split (if any) is at ring wrap. */ | |
86200154 DV |
237 | if (((c ^ p) & u->ring_size) != 0) { |
238 | bytes1 = (u->ring_size - evtchn_ring_offset(u, c)) * | |
f7116284 | 239 | sizeof(evtchn_port_t); |
86200154 | 240 | bytes2 = evtchn_ring_offset(u, p) * sizeof(evtchn_port_t); |
f7116284 IC |
241 | } else { |
242 | bytes1 = (p - c) * sizeof(evtchn_port_t); | |
243 | bytes2 = 0; | |
244 | } | |
245 | ||
246 | /* Truncate chunks according to caller's maximum byte count. */ | |
247 | if (bytes1 > count) { | |
248 | bytes1 = count; | |
249 | bytes2 = 0; | |
250 | } else if ((bytes1 + bytes2) > count) { | |
251 | bytes2 = count - bytes1; | |
252 | } | |
253 | ||
254 | rc = -EFAULT; | |
255 | rmb(); /* Ensure that we see the port before we copy it. */ | |
86200154 | 256 | if (copy_to_user(buf, evtchn_ring_entry(u, c), bytes1) || |
f7116284 IC |
257 | ((bytes2 != 0) && |
258 | copy_to_user(&buf[bytes1], &u->ring[0], bytes2))) | |
259 | goto unlock_out; | |
260 | ||
261 | u->ring_cons += (bytes1 + bytes2) / sizeof(evtchn_port_t); | |
262 | rc = bytes1 + bytes2; | |
263 | ||
264 | unlock_out: | |
265 | mutex_unlock(&u->ring_cons_mutex); | |
266 | return rc; | |
267 | } | |
268 | ||
269 | static ssize_t evtchn_write(struct file *file, const char __user *buf, | |
270 | size_t count, loff_t *ppos) | |
271 | { | |
272 | int rc, i; | |
273 | evtchn_port_t *kbuf = (evtchn_port_t *)__get_free_page(GFP_KERNEL); | |
274 | struct per_user_data *u = file->private_data; | |
275 | ||
276 | if (kbuf == NULL) | |
277 | return -ENOMEM; | |
278 | ||
279 | /* Whole number of ports. */ | |
280 | count &= ~(sizeof(evtchn_port_t)-1); | |
281 | ||
282 | rc = 0; | |
283 | if (count == 0) | |
284 | goto out; | |
285 | ||
286 | if (count > PAGE_SIZE) | |
287 | count = PAGE_SIZE; | |
288 | ||
289 | rc = -EFAULT; | |
290 | if (copy_from_user(kbuf, buf, count) != 0) | |
291 | goto out; | |
292 | ||
73cc4bb0 | 293 | mutex_lock(&u->bind_mutex); |
e3cc067b JF |
294 | |
295 | for (i = 0; i < (count/sizeof(evtchn_port_t)); i++) { | |
296 | unsigned port = kbuf[i]; | |
73cc4bb0 | 297 | struct user_evtchn *evtchn; |
e3cc067b | 298 | |
73cc4bb0 DV |
299 | evtchn = find_evtchn(u, port); |
300 | if (evtchn && !evtchn->enabled) { | |
301 | evtchn->enabled = true; | |
e3cc067b JF |
302 | enable_irq(irq_from_evtchn(port)); |
303 | } | |
304 | } | |
305 | ||
73cc4bb0 | 306 | mutex_unlock(&u->bind_mutex); |
f7116284 IC |
307 | |
308 | rc = count; | |
309 | ||
310 | out: | |
311 | free_page((unsigned long)kbuf); | |
312 | return rc; | |
313 | } | |
314 | ||
86200154 DV |
315 | static int evtchn_resize_ring(struct per_user_data *u) |
316 | { | |
317 | unsigned int new_size; | |
318 | evtchn_port_t *new_ring, *old_ring; | |
319 | unsigned int p, c; | |
320 | ||
321 | /* | |
322 | * Ensure the ring is large enough to capture all possible | |
323 | * events. i.e., one free slot for each bound event. | |
324 | */ | |
325 | if (u->nr_evtchns <= u->ring_size) | |
326 | return 0; | |
327 | ||
328 | if (u->ring_size == 0) | |
329 | new_size = 64; | |
330 | else | |
331 | new_size = 2 * u->ring_size; | |
332 | ||
333 | new_ring = evtchn_alloc_ring(new_size); | |
334 | if (!new_ring) | |
335 | return -ENOMEM; | |
336 | ||
337 | old_ring = u->ring; | |
338 | ||
339 | /* | |
340 | * Access to the ring contents is serialized by either the | |
341 | * prod /or/ cons lock so take both when resizing. | |
342 | */ | |
343 | mutex_lock(&u->ring_cons_mutex); | |
344 | spin_lock_irq(&u->ring_prod_lock); | |
345 | ||
346 | /* | |
347 | * Copy the old ring contents to the new ring. | |
348 | * | |
349 | * If the ring contents crosses the end of the current ring, | |
350 | * it needs to be copied in two chunks. | |
351 | * | |
352 | * +---------+ +------------------+ | |
353 | * |34567 12| -> | 1234567 | | |
354 | * +-----p-c-+ +------------------+ | |
355 | */ | |
356 | p = evtchn_ring_offset(u, u->ring_prod); | |
357 | c = evtchn_ring_offset(u, u->ring_cons); | |
358 | if (p < c) { | |
359 | memcpy(new_ring + c, u->ring + c, (u->ring_size - c) * sizeof(*u->ring)); | |
360 | memcpy(new_ring + u->ring_size, u->ring, p * sizeof(*u->ring)); | |
361 | } else | |
362 | memcpy(new_ring + c, u->ring + c, (p - c) * sizeof(*u->ring)); | |
363 | ||
364 | u->ring = new_ring; | |
365 | u->ring_size = new_size; | |
366 | ||
367 | spin_unlock_irq(&u->ring_prod_lock); | |
368 | mutex_unlock(&u->ring_cons_mutex); | |
369 | ||
370 | evtchn_free_ring(old_ring); | |
371 | ||
372 | return 0; | |
373 | } | |
374 | ||
f7116284 IC |
375 | static int evtchn_bind_to_user(struct per_user_data *u, int port) |
376 | { | |
73cc4bb0 DV |
377 | struct user_evtchn *evtchn; |
378 | struct evtchn_close close; | |
f7116284 IC |
379 | int rc = 0; |
380 | ||
0a4666b5 JF |
381 | /* |
382 | * Ports are never reused, so every caller should pass in a | |
383 | * unique port. | |
384 | * | |
385 | * (Locking not necessary because we haven't registered the | |
386 | * interrupt handler yet, and our caller has already | |
387 | * serialized bind operations.) | |
388 | */ | |
73cc4bb0 DV |
389 | |
390 | evtchn = kzalloc(sizeof(*evtchn), GFP_KERNEL); | |
391 | if (!evtchn) | |
392 | return -ENOMEM; | |
393 | ||
394 | evtchn->user = u; | |
395 | evtchn->port = port; | |
396 | evtchn->enabled = true; /* start enabled */ | |
397 | ||
398 | rc = add_evtchn(u, evtchn); | |
399 | if (rc < 0) | |
400 | goto err; | |
f7116284 | 401 | |
86200154 DV |
402 | rc = evtchn_resize_ring(u); |
403 | if (rc < 0) | |
404 | goto err; | |
405 | ||
af09d1a7 | 406 | rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, 0, |
73cc4bb0 DV |
407 | u->name, evtchn); |
408 | if (rc < 0) | |
409 | goto err; | |
0a4666b5 | 410 | |
73cc4bb0 DV |
411 | rc = evtchn_make_refcounted(port); |
412 | return rc; | |
413 | ||
414 | err: | |
415 | /* bind failed, should close the port now */ | |
416 | close.port = port; | |
417 | if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0) | |
418 | BUG(); | |
419 | del_evtchn(u, evtchn); | |
f7116284 IC |
420 | return rc; |
421 | } | |
422 | ||
73cc4bb0 DV |
423 | static void evtchn_unbind_from_user(struct per_user_data *u, |
424 | struct user_evtchn *evtchn) | |
f7116284 | 425 | { |
73cc4bb0 | 426 | int irq = irq_from_evtchn(evtchn->port); |
f7116284 | 427 | |
e7e44e44 WL |
428 | BUG_ON(irq < 0); |
429 | ||
73cc4bb0 | 430 | unbind_from_irqhandler(irq, evtchn); |
0a4666b5 | 431 | |
73cc4bb0 | 432 | del_evtchn(u, evtchn); |
f7116284 IC |
433 | } |
434 | ||
435 | static long evtchn_ioctl(struct file *file, | |
436 | unsigned int cmd, unsigned long arg) | |
437 | { | |
438 | int rc; | |
439 | struct per_user_data *u = file->private_data; | |
440 | void __user *uarg = (void __user *) arg; | |
441 | ||
0a4666b5 JF |
442 | /* Prevent bind from racing with unbind */ |
443 | mutex_lock(&u->bind_mutex); | |
444 | ||
f7116284 IC |
445 | switch (cmd) { |
446 | case IOCTL_EVTCHN_BIND_VIRQ: { | |
447 | struct ioctl_evtchn_bind_virq bind; | |
448 | struct evtchn_bind_virq bind_virq; | |
449 | ||
450 | rc = -EFAULT; | |
451 | if (copy_from_user(&bind, uarg, sizeof(bind))) | |
452 | break; | |
453 | ||
454 | bind_virq.virq = bind.virq; | |
455 | bind_virq.vcpu = 0; | |
456 | rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq, | |
457 | &bind_virq); | |
458 | if (rc != 0) | |
459 | break; | |
460 | ||
461 | rc = evtchn_bind_to_user(u, bind_virq.port); | |
462 | if (rc == 0) | |
463 | rc = bind_virq.port; | |
464 | break; | |
465 | } | |
466 | ||
467 | case IOCTL_EVTCHN_BIND_INTERDOMAIN: { | |
468 | struct ioctl_evtchn_bind_interdomain bind; | |
469 | struct evtchn_bind_interdomain bind_interdomain; | |
470 | ||
471 | rc = -EFAULT; | |
472 | if (copy_from_user(&bind, uarg, sizeof(bind))) | |
473 | break; | |
474 | ||
475 | bind_interdomain.remote_dom = bind.remote_domain; | |
476 | bind_interdomain.remote_port = bind.remote_port; | |
477 | rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain, | |
478 | &bind_interdomain); | |
479 | if (rc != 0) | |
480 | break; | |
481 | ||
482 | rc = evtchn_bind_to_user(u, bind_interdomain.local_port); | |
483 | if (rc == 0) | |
484 | rc = bind_interdomain.local_port; | |
485 | break; | |
486 | } | |
487 | ||
488 | case IOCTL_EVTCHN_BIND_UNBOUND_PORT: { | |
489 | struct ioctl_evtchn_bind_unbound_port bind; | |
490 | struct evtchn_alloc_unbound alloc_unbound; | |
491 | ||
492 | rc = -EFAULT; | |
493 | if (copy_from_user(&bind, uarg, sizeof(bind))) | |
494 | break; | |
495 | ||
496 | alloc_unbound.dom = DOMID_SELF; | |
497 | alloc_unbound.remote_dom = bind.remote_domain; | |
498 | rc = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, | |
499 | &alloc_unbound); | |
500 | if (rc != 0) | |
501 | break; | |
502 | ||
503 | rc = evtchn_bind_to_user(u, alloc_unbound.port); | |
504 | if (rc == 0) | |
505 | rc = alloc_unbound.port; | |
506 | break; | |
507 | } | |
508 | ||
509 | case IOCTL_EVTCHN_UNBIND: { | |
510 | struct ioctl_evtchn_unbind unbind; | |
73cc4bb0 | 511 | struct user_evtchn *evtchn; |
f7116284 IC |
512 | |
513 | rc = -EFAULT; | |
514 | if (copy_from_user(&unbind, uarg, sizeof(unbind))) | |
515 | break; | |
516 | ||
517 | rc = -EINVAL; | |
0dc0064a | 518 | if (unbind.port >= xen_evtchn_nr_channels()) |
f7116284 IC |
519 | break; |
520 | ||
f7116284 | 521 | rc = -ENOTCONN; |
73cc4bb0 DV |
522 | evtchn = find_evtchn(u, unbind.port); |
523 | if (!evtchn) | |
f7116284 | 524 | break; |
f7116284 | 525 | |
3f5e554f | 526 | disable_irq(irq_from_evtchn(unbind.port)); |
73cc4bb0 | 527 | evtchn_unbind_from_user(u, evtchn); |
f7116284 IC |
528 | rc = 0; |
529 | break; | |
530 | } | |
531 | ||
532 | case IOCTL_EVTCHN_NOTIFY: { | |
533 | struct ioctl_evtchn_notify notify; | |
73cc4bb0 | 534 | struct user_evtchn *evtchn; |
f7116284 IC |
535 | |
536 | rc = -EFAULT; | |
537 | if (copy_from_user(¬ify, uarg, sizeof(notify))) | |
538 | break; | |
539 | ||
73cc4bb0 DV |
540 | rc = -ENOTCONN; |
541 | evtchn = find_evtchn(u, notify.port); | |
542 | if (evtchn) { | |
f7116284 IC |
543 | notify_remote_via_evtchn(notify.port); |
544 | rc = 0; | |
545 | } | |
546 | break; | |
547 | } | |
548 | ||
549 | case IOCTL_EVTCHN_RESET: { | |
550 | /* Initialise the ring to empty. Clear errors. */ | |
551 | mutex_lock(&u->ring_cons_mutex); | |
73cc4bb0 | 552 | spin_lock_irq(&u->ring_prod_lock); |
f7116284 | 553 | u->ring_cons = u->ring_prod = u->ring_overflow = 0; |
73cc4bb0 | 554 | spin_unlock_irq(&u->ring_prod_lock); |
f7116284 IC |
555 | mutex_unlock(&u->ring_cons_mutex); |
556 | rc = 0; | |
557 | break; | |
558 | } | |
559 | ||
560 | default: | |
561 | rc = -ENOSYS; | |
562 | break; | |
563 | } | |
0a4666b5 | 564 | mutex_unlock(&u->bind_mutex); |
f7116284 IC |
565 | |
566 | return rc; | |
567 | } | |
568 | ||
569 | static unsigned int evtchn_poll(struct file *file, poll_table *wait) | |
570 | { | |
571 | unsigned int mask = POLLOUT | POLLWRNORM; | |
572 | struct per_user_data *u = file->private_data; | |
573 | ||
574 | poll_wait(file, &u->evtchn_wait, wait); | |
575 | if (u->ring_cons != u->ring_prod) | |
576 | mask |= POLLIN | POLLRDNORM; | |
577 | if (u->ring_overflow) | |
578 | mask = POLLERR; | |
579 | return mask; | |
580 | } | |
581 | ||
582 | static int evtchn_fasync(int fd, struct file *filp, int on) | |
583 | { | |
584 | struct per_user_data *u = filp->private_data; | |
585 | return fasync_helper(fd, filp, on, &u->evtchn_async_queue); | |
586 | } | |
587 | ||
588 | static int evtchn_open(struct inode *inode, struct file *filp) | |
589 | { | |
590 | struct per_user_data *u; | |
591 | ||
592 | u = kzalloc(sizeof(*u), GFP_KERNEL); | |
593 | if (u == NULL) | |
594 | return -ENOMEM; | |
595 | ||
596 | u->name = kasprintf(GFP_KERNEL, "evtchn:%s", current->comm); | |
597 | if (u->name == NULL) { | |
598 | kfree(u); | |
599 | return -ENOMEM; | |
600 | } | |
601 | ||
602 | init_waitqueue_head(&u->evtchn_wait); | |
603 | ||
0a4666b5 | 604 | mutex_init(&u->bind_mutex); |
f7116284 | 605 | mutex_init(&u->ring_cons_mutex); |
73cc4bb0 | 606 | spin_lock_init(&u->ring_prod_lock); |
f7116284 IC |
607 | |
608 | filp->private_data = u; | |
609 | ||
6eab04a8 | 610 | return nonseekable_open(inode, filp); |
f7116284 IC |
611 | } |
612 | ||
613 | static int evtchn_release(struct inode *inode, struct file *filp) | |
614 | { | |
f7116284 | 615 | struct per_user_data *u = filp->private_data; |
73cc4bb0 | 616 | struct rb_node *node; |
f7116284 | 617 | |
73cc4bb0 DV |
618 | while ((node = u->evtchns.rb_node)) { |
619 | struct user_evtchn *evtchn; | |
f7116284 | 620 | |
73cc4bb0 DV |
621 | evtchn = rb_entry(node, struct user_evtchn, node); |
622 | disable_irq(irq_from_evtchn(evtchn->port)); | |
623 | evtchn_unbind_from_user(u, evtchn); | |
3f5e554f JF |
624 | } |
625 | ||
86200154 | 626 | evtchn_free_ring(u->ring); |
f7116284 IC |
627 | kfree(u->name); |
628 | kfree(u); | |
629 | ||
630 | return 0; | |
631 | } | |
632 | ||
633 | static const struct file_operations evtchn_fops = { | |
634 | .owner = THIS_MODULE, | |
635 | .read = evtchn_read, | |
636 | .write = evtchn_write, | |
637 | .unlocked_ioctl = evtchn_ioctl, | |
638 | .poll = evtchn_poll, | |
639 | .fasync = evtchn_fasync, | |
640 | .open = evtchn_open, | |
641 | .release = evtchn_release, | |
bc7fc5e3 | 642 | .llseek = no_llseek, |
f7116284 IC |
643 | }; |
644 | ||
645 | static struct miscdevice evtchn_miscdev = { | |
646 | .minor = MISC_DYNAMIC_MINOR, | |
376d908f | 647 | .name = "xen/evtchn", |
f7116284 IC |
648 | .fops = &evtchn_fops, |
649 | }; | |
650 | static int __init evtchn_init(void) | |
651 | { | |
652 | int err; | |
653 | ||
654 | if (!xen_domain()) | |
655 | return -ENODEV; | |
656 | ||
18283ea7 | 657 | /* Create '/dev/xen/evtchn'. */ |
f7116284 IC |
658 | err = misc_register(&evtchn_miscdev); |
659 | if (err != 0) { | |
283c0972 | 660 | pr_err("Could not register /dev/xen/evtchn\n"); |
f7116284 IC |
661 | return err; |
662 | } | |
663 | ||
283c0972 | 664 | pr_info("Event-channel device installed\n"); |
f7116284 IC |
665 | |
666 | return 0; | |
667 | } | |
668 | ||
669 | static void __exit evtchn_cleanup(void) | |
670 | { | |
671 | misc_deregister(&evtchn_miscdev); | |
672 | } | |
673 | ||
674 | module_init(evtchn_init); | |
675 | module_exit(evtchn_cleanup); | |
676 | ||
677 | MODULE_LICENSE("GPL"); |