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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; | |
fbc872c3 DV |
76 | |
77 | domid_t restrict_domid; | |
f7116284 IC |
78 | }; |
79 | ||
fbc872c3 DV |
80 | #define UNRESTRICTED_DOMID ((domid_t)-1) |
81 | ||
73cc4bb0 DV |
82 | struct user_evtchn { |
83 | struct rb_node node; | |
84 | struct per_user_data *user; | |
85 | unsigned port; | |
86 | bool enabled; | |
87 | }; | |
f7116284 | 88 | |
86200154 DV |
89 | static evtchn_port_t *evtchn_alloc_ring(unsigned int size) |
90 | { | |
91 | evtchn_port_t *ring; | |
92 | size_t s = size * sizeof(*ring); | |
93 | ||
94 | ring = kmalloc(s, GFP_KERNEL); | |
95 | if (!ring) | |
96 | ring = vmalloc(s); | |
97 | ||
98 | return ring; | |
99 | } | |
100 | ||
101 | static void evtchn_free_ring(evtchn_port_t *ring) | |
102 | { | |
103 | kvfree(ring); | |
104 | } | |
105 | ||
106 | static unsigned int evtchn_ring_offset(struct per_user_data *u, | |
107 | unsigned int idx) | |
108 | { | |
109 | return idx & (u->ring_size - 1); | |
110 | } | |
111 | ||
112 | static evtchn_port_t *evtchn_ring_entry(struct per_user_data *u, | |
113 | unsigned int idx) | |
114 | { | |
115 | return u->ring + evtchn_ring_offset(u, idx); | |
116 | } | |
117 | ||
73cc4bb0 | 118 | static int add_evtchn(struct per_user_data *u, struct user_evtchn *evtchn) |
e3cc067b | 119 | { |
73cc4bb0 | 120 | struct rb_node **new = &(u->evtchns.rb_node), *parent = NULL; |
e3cc067b | 121 | |
86200154 DV |
122 | u->nr_evtchns++; |
123 | ||
73cc4bb0 DV |
124 | while (*new) { |
125 | struct user_evtchn *this; | |
126 | ||
127 | this = container_of(*new, struct user_evtchn, node); | |
128 | ||
129 | parent = *new; | |
130 | if (this->port < evtchn->port) | |
131 | new = &((*new)->rb_left); | |
132 | else if (this->port > evtchn->port) | |
133 | new = &((*new)->rb_right); | |
134 | else | |
135 | return -EEXIST; | |
136 | } | |
137 | ||
138 | /* Add new node and rebalance tree. */ | |
139 | rb_link_node(&evtchn->node, parent, new); | |
140 | rb_insert_color(&evtchn->node, &u->evtchns); | |
141 | ||
142 | return 0; | |
e3cc067b JF |
143 | } |
144 | ||
73cc4bb0 | 145 | static void del_evtchn(struct per_user_data *u, struct user_evtchn *evtchn) |
e3cc067b | 146 | { |
86200154 | 147 | u->nr_evtchns--; |
73cc4bb0 DV |
148 | rb_erase(&evtchn->node, &u->evtchns); |
149 | kfree(evtchn); | |
e3cc067b JF |
150 | } |
151 | ||
73cc4bb0 | 152 | static struct user_evtchn *find_evtchn(struct per_user_data *u, unsigned port) |
e3cc067b | 153 | { |
73cc4bb0 DV |
154 | struct rb_node *node = u->evtchns.rb_node; |
155 | ||
156 | while (node) { | |
157 | struct user_evtchn *evtchn; | |
158 | ||
159 | evtchn = container_of(node, struct user_evtchn, node); | |
160 | ||
161 | if (evtchn->port < port) | |
162 | node = node->rb_left; | |
163 | else if (evtchn->port > port) | |
164 | node = node->rb_right; | |
165 | else | |
166 | return evtchn; | |
167 | } | |
168 | return NULL; | |
e3cc067b JF |
169 | } |
170 | ||
70697d54 | 171 | static irqreturn_t evtchn_interrupt(int irq, void *data) |
f7116284 | 172 | { |
73cc4bb0 DV |
173 | struct user_evtchn *evtchn = data; |
174 | struct per_user_data *u = evtchn->user; | |
e3cc067b | 175 | |
73cc4bb0 | 176 | WARN(!evtchn->enabled, |
0edce91d | 177 | "Interrupt for port %d, but apparently not enabled; per-user %p\n", |
73cc4bb0 | 178 | evtchn->port, u); |
f7116284 IC |
179 | |
180 | disable_irq_nosync(irq); | |
73cc4bb0 DV |
181 | evtchn->enabled = false; |
182 | ||
183 | spin_lock(&u->ring_prod_lock); | |
f7116284 | 184 | |
86200154 DV |
185 | if ((u->ring_prod - u->ring_cons) < u->ring_size) { |
186 | *evtchn_ring_entry(u, u->ring_prod) = evtchn->port; | |
f7116284 IC |
187 | wmb(); /* Ensure ring contents visible */ |
188 | if (u->ring_cons == u->ring_prod++) { | |
189 | wake_up_interruptible(&u->evtchn_wait); | |
190 | kill_fasync(&u->evtchn_async_queue, | |
191 | SIGIO, POLL_IN); | |
192 | } | |
e3cc067b | 193 | } else |
f7116284 | 194 | u->ring_overflow = 1; |
f7116284 | 195 | |
73cc4bb0 | 196 | spin_unlock(&u->ring_prod_lock); |
f7116284 IC |
197 | |
198 | return IRQ_HANDLED; | |
199 | } | |
200 | ||
201 | static ssize_t evtchn_read(struct file *file, char __user *buf, | |
202 | size_t count, loff_t *ppos) | |
203 | { | |
204 | int rc; | |
205 | unsigned int c, p, bytes1 = 0, bytes2 = 0; | |
206 | struct per_user_data *u = file->private_data; | |
207 | ||
208 | /* Whole number of ports. */ | |
209 | count &= ~(sizeof(evtchn_port_t)-1); | |
210 | ||
211 | if (count == 0) | |
212 | return 0; | |
213 | ||
214 | if (count > PAGE_SIZE) | |
215 | count = PAGE_SIZE; | |
216 | ||
217 | for (;;) { | |
218 | mutex_lock(&u->ring_cons_mutex); | |
219 | ||
220 | rc = -EFBIG; | |
221 | if (u->ring_overflow) | |
222 | goto unlock_out; | |
223 | ||
224 | c = u->ring_cons; | |
225 | p = u->ring_prod; | |
226 | if (c != p) | |
227 | break; | |
228 | ||
229 | mutex_unlock(&u->ring_cons_mutex); | |
230 | ||
231 | if (file->f_flags & O_NONBLOCK) | |
232 | return -EAGAIN; | |
233 | ||
234 | rc = wait_event_interruptible(u->evtchn_wait, | |
235 | u->ring_cons != u->ring_prod); | |
236 | if (rc) | |
237 | return rc; | |
238 | } | |
239 | ||
240 | /* Byte lengths of two chunks. Chunk split (if any) is at ring wrap. */ | |
86200154 DV |
241 | if (((c ^ p) & u->ring_size) != 0) { |
242 | bytes1 = (u->ring_size - evtchn_ring_offset(u, c)) * | |
f7116284 | 243 | sizeof(evtchn_port_t); |
86200154 | 244 | bytes2 = evtchn_ring_offset(u, p) * sizeof(evtchn_port_t); |
f7116284 IC |
245 | } else { |
246 | bytes1 = (p - c) * sizeof(evtchn_port_t); | |
247 | bytes2 = 0; | |
248 | } | |
249 | ||
250 | /* Truncate chunks according to caller's maximum byte count. */ | |
251 | if (bytes1 > count) { | |
252 | bytes1 = count; | |
253 | bytes2 = 0; | |
254 | } else if ((bytes1 + bytes2) > count) { | |
255 | bytes2 = count - bytes1; | |
256 | } | |
257 | ||
258 | rc = -EFAULT; | |
259 | rmb(); /* Ensure that we see the port before we copy it. */ | |
86200154 | 260 | if (copy_to_user(buf, evtchn_ring_entry(u, c), bytes1) || |
f7116284 IC |
261 | ((bytes2 != 0) && |
262 | copy_to_user(&buf[bytes1], &u->ring[0], bytes2))) | |
263 | goto unlock_out; | |
264 | ||
265 | u->ring_cons += (bytes1 + bytes2) / sizeof(evtchn_port_t); | |
266 | rc = bytes1 + bytes2; | |
267 | ||
268 | unlock_out: | |
269 | mutex_unlock(&u->ring_cons_mutex); | |
270 | return rc; | |
271 | } | |
272 | ||
273 | static ssize_t evtchn_write(struct file *file, const char __user *buf, | |
274 | size_t count, loff_t *ppos) | |
275 | { | |
276 | int rc, i; | |
277 | evtchn_port_t *kbuf = (evtchn_port_t *)__get_free_page(GFP_KERNEL); | |
278 | struct per_user_data *u = file->private_data; | |
279 | ||
280 | if (kbuf == NULL) | |
281 | return -ENOMEM; | |
282 | ||
283 | /* Whole number of ports. */ | |
284 | count &= ~(sizeof(evtchn_port_t)-1); | |
285 | ||
286 | rc = 0; | |
287 | if (count == 0) | |
288 | goto out; | |
289 | ||
290 | if (count > PAGE_SIZE) | |
291 | count = PAGE_SIZE; | |
292 | ||
293 | rc = -EFAULT; | |
294 | if (copy_from_user(kbuf, buf, count) != 0) | |
295 | goto out; | |
296 | ||
73cc4bb0 | 297 | mutex_lock(&u->bind_mutex); |
e3cc067b JF |
298 | |
299 | for (i = 0; i < (count/sizeof(evtchn_port_t)); i++) { | |
300 | unsigned port = kbuf[i]; | |
73cc4bb0 | 301 | struct user_evtchn *evtchn; |
e3cc067b | 302 | |
73cc4bb0 DV |
303 | evtchn = find_evtchn(u, port); |
304 | if (evtchn && !evtchn->enabled) { | |
305 | evtchn->enabled = true; | |
e3cc067b JF |
306 | enable_irq(irq_from_evtchn(port)); |
307 | } | |
308 | } | |
309 | ||
73cc4bb0 | 310 | mutex_unlock(&u->bind_mutex); |
f7116284 IC |
311 | |
312 | rc = count; | |
313 | ||
314 | out: | |
315 | free_page((unsigned long)kbuf); | |
316 | return rc; | |
317 | } | |
318 | ||
86200154 DV |
319 | static int evtchn_resize_ring(struct per_user_data *u) |
320 | { | |
321 | unsigned int new_size; | |
322 | evtchn_port_t *new_ring, *old_ring; | |
86200154 DV |
323 | |
324 | /* | |
325 | * Ensure the ring is large enough to capture all possible | |
326 | * events. i.e., one free slot for each bound event. | |
327 | */ | |
328 | if (u->nr_evtchns <= u->ring_size) | |
329 | return 0; | |
330 | ||
331 | if (u->ring_size == 0) | |
332 | new_size = 64; | |
333 | else | |
334 | new_size = 2 * u->ring_size; | |
335 | ||
336 | new_ring = evtchn_alloc_ring(new_size); | |
337 | if (!new_ring) | |
338 | return -ENOMEM; | |
339 | ||
340 | old_ring = u->ring; | |
341 | ||
342 | /* | |
343 | * Access to the ring contents is serialized by either the | |
344 | * prod /or/ cons lock so take both when resizing. | |
345 | */ | |
346 | mutex_lock(&u->ring_cons_mutex); | |
347 | spin_lock_irq(&u->ring_prod_lock); | |
348 | ||
349 | /* | |
350 | * Copy the old ring contents to the new ring. | |
351 | * | |
27e0e638 JB |
352 | * To take care of wrapping, a full ring, and the new index |
353 | * pointing into the second half, simply copy the old contents | |
354 | * twice. | |
86200154 DV |
355 | * |
356 | * +---------+ +------------------+ | |
27e0e638 JB |
357 | * |34567 12| -> |34567 1234567 12| |
358 | * +-----p-c-+ +-------c------p---+ | |
86200154 | 359 | */ |
27e0e638 JB |
360 | memcpy(new_ring, old_ring, u->ring_size * sizeof(*u->ring)); |
361 | memcpy(new_ring + u->ring_size, old_ring, | |
362 | u->ring_size * sizeof(*u->ring)); | |
86200154 DV |
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 | ||
fbc872c3 DV |
450 | rc = -EACCES; |
451 | if (u->restrict_domid != UNRESTRICTED_DOMID) | |
452 | break; | |
453 | ||
f7116284 IC |
454 | rc = -EFAULT; |
455 | if (copy_from_user(&bind, uarg, sizeof(bind))) | |
456 | break; | |
457 | ||
458 | bind_virq.virq = bind.virq; | |
459 | bind_virq.vcpu = 0; | |
460 | rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq, | |
461 | &bind_virq); | |
462 | if (rc != 0) | |
463 | break; | |
464 | ||
465 | rc = evtchn_bind_to_user(u, bind_virq.port); | |
466 | if (rc == 0) | |
467 | rc = bind_virq.port; | |
468 | break; | |
469 | } | |
470 | ||
471 | case IOCTL_EVTCHN_BIND_INTERDOMAIN: { | |
472 | struct ioctl_evtchn_bind_interdomain bind; | |
473 | struct evtchn_bind_interdomain bind_interdomain; | |
474 | ||
475 | rc = -EFAULT; | |
476 | if (copy_from_user(&bind, uarg, sizeof(bind))) | |
477 | break; | |
478 | ||
fbc872c3 DV |
479 | rc = -EACCES; |
480 | if (u->restrict_domid != UNRESTRICTED_DOMID && | |
481 | u->restrict_domid != bind.remote_domain) | |
482 | break; | |
483 | ||
f7116284 IC |
484 | bind_interdomain.remote_dom = bind.remote_domain; |
485 | bind_interdomain.remote_port = bind.remote_port; | |
486 | rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain, | |
487 | &bind_interdomain); | |
488 | if (rc != 0) | |
489 | break; | |
490 | ||
491 | rc = evtchn_bind_to_user(u, bind_interdomain.local_port); | |
492 | if (rc == 0) | |
493 | rc = bind_interdomain.local_port; | |
494 | break; | |
495 | } | |
496 | ||
497 | case IOCTL_EVTCHN_BIND_UNBOUND_PORT: { | |
498 | struct ioctl_evtchn_bind_unbound_port bind; | |
499 | struct evtchn_alloc_unbound alloc_unbound; | |
500 | ||
fbc872c3 DV |
501 | rc = -EACCES; |
502 | if (u->restrict_domid != UNRESTRICTED_DOMID) | |
503 | break; | |
504 | ||
f7116284 IC |
505 | rc = -EFAULT; |
506 | if (copy_from_user(&bind, uarg, sizeof(bind))) | |
507 | break; | |
508 | ||
509 | alloc_unbound.dom = DOMID_SELF; | |
510 | alloc_unbound.remote_dom = bind.remote_domain; | |
511 | rc = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, | |
512 | &alloc_unbound); | |
513 | if (rc != 0) | |
514 | break; | |
515 | ||
516 | rc = evtchn_bind_to_user(u, alloc_unbound.port); | |
517 | if (rc == 0) | |
518 | rc = alloc_unbound.port; | |
519 | break; | |
520 | } | |
521 | ||
522 | case IOCTL_EVTCHN_UNBIND: { | |
523 | struct ioctl_evtchn_unbind unbind; | |
73cc4bb0 | 524 | struct user_evtchn *evtchn; |
f7116284 IC |
525 | |
526 | rc = -EFAULT; | |
527 | if (copy_from_user(&unbind, uarg, sizeof(unbind))) | |
528 | break; | |
529 | ||
530 | rc = -EINVAL; | |
0dc0064a | 531 | if (unbind.port >= xen_evtchn_nr_channels()) |
f7116284 IC |
532 | break; |
533 | ||
f7116284 | 534 | rc = -ENOTCONN; |
73cc4bb0 DV |
535 | evtchn = find_evtchn(u, unbind.port); |
536 | if (!evtchn) | |
f7116284 | 537 | break; |
f7116284 | 538 | |
3f5e554f | 539 | disable_irq(irq_from_evtchn(unbind.port)); |
73cc4bb0 | 540 | evtchn_unbind_from_user(u, evtchn); |
f7116284 IC |
541 | rc = 0; |
542 | break; | |
543 | } | |
544 | ||
545 | case IOCTL_EVTCHN_NOTIFY: { | |
546 | struct ioctl_evtchn_notify notify; | |
73cc4bb0 | 547 | struct user_evtchn *evtchn; |
f7116284 IC |
548 | |
549 | rc = -EFAULT; | |
550 | if (copy_from_user(¬ify, uarg, sizeof(notify))) | |
551 | break; | |
552 | ||
73cc4bb0 DV |
553 | rc = -ENOTCONN; |
554 | evtchn = find_evtchn(u, notify.port); | |
555 | if (evtchn) { | |
f7116284 IC |
556 | notify_remote_via_evtchn(notify.port); |
557 | rc = 0; | |
558 | } | |
559 | break; | |
560 | } | |
561 | ||
562 | case IOCTL_EVTCHN_RESET: { | |
563 | /* Initialise the ring to empty. Clear errors. */ | |
564 | mutex_lock(&u->ring_cons_mutex); | |
73cc4bb0 | 565 | spin_lock_irq(&u->ring_prod_lock); |
f7116284 | 566 | u->ring_cons = u->ring_prod = u->ring_overflow = 0; |
73cc4bb0 | 567 | spin_unlock_irq(&u->ring_prod_lock); |
f7116284 IC |
568 | mutex_unlock(&u->ring_cons_mutex); |
569 | rc = 0; | |
570 | break; | |
571 | } | |
572 | ||
fbc872c3 DV |
573 | case IOCTL_EVTCHN_RESTRICT_DOMID: { |
574 | struct ioctl_evtchn_restrict_domid ierd; | |
575 | ||
576 | rc = -EACCES; | |
577 | if (u->restrict_domid != UNRESTRICTED_DOMID) | |
578 | break; | |
579 | ||
580 | rc = -EFAULT; | |
581 | if (copy_from_user(&ierd, uarg, sizeof(ierd))) | |
582 | break; | |
583 | ||
584 | rc = -EINVAL; | |
585 | if (ierd.domid == 0 || ierd.domid >= DOMID_FIRST_RESERVED) | |
586 | break; | |
587 | ||
588 | u->restrict_domid = ierd.domid; | |
589 | rc = 0; | |
590 | ||
591 | break; | |
592 | } | |
593 | ||
f7116284 IC |
594 | default: |
595 | rc = -ENOSYS; | |
596 | break; | |
597 | } | |
0a4666b5 | 598 | mutex_unlock(&u->bind_mutex); |
f7116284 IC |
599 | |
600 | return rc; | |
601 | } | |
602 | ||
603 | static unsigned int evtchn_poll(struct file *file, poll_table *wait) | |
604 | { | |
605 | unsigned int mask = POLLOUT | POLLWRNORM; | |
606 | struct per_user_data *u = file->private_data; | |
607 | ||
608 | poll_wait(file, &u->evtchn_wait, wait); | |
609 | if (u->ring_cons != u->ring_prod) | |
610 | mask |= POLLIN | POLLRDNORM; | |
611 | if (u->ring_overflow) | |
612 | mask = POLLERR; | |
613 | return mask; | |
614 | } | |
615 | ||
616 | static int evtchn_fasync(int fd, struct file *filp, int on) | |
617 | { | |
618 | struct per_user_data *u = filp->private_data; | |
619 | return fasync_helper(fd, filp, on, &u->evtchn_async_queue); | |
620 | } | |
621 | ||
622 | static int evtchn_open(struct inode *inode, struct file *filp) | |
623 | { | |
624 | struct per_user_data *u; | |
625 | ||
626 | u = kzalloc(sizeof(*u), GFP_KERNEL); | |
627 | if (u == NULL) | |
628 | return -ENOMEM; | |
629 | ||
630 | u->name = kasprintf(GFP_KERNEL, "evtchn:%s", current->comm); | |
631 | if (u->name == NULL) { | |
632 | kfree(u); | |
633 | return -ENOMEM; | |
634 | } | |
635 | ||
636 | init_waitqueue_head(&u->evtchn_wait); | |
637 | ||
0a4666b5 | 638 | mutex_init(&u->bind_mutex); |
f7116284 | 639 | mutex_init(&u->ring_cons_mutex); |
73cc4bb0 | 640 | spin_lock_init(&u->ring_prod_lock); |
f7116284 | 641 | |
fbc872c3 DV |
642 | u->restrict_domid = UNRESTRICTED_DOMID; |
643 | ||
f7116284 IC |
644 | filp->private_data = u; |
645 | ||
6eab04a8 | 646 | return nonseekable_open(inode, filp); |
f7116284 IC |
647 | } |
648 | ||
649 | static int evtchn_release(struct inode *inode, struct file *filp) | |
650 | { | |
f7116284 | 651 | struct per_user_data *u = filp->private_data; |
73cc4bb0 | 652 | struct rb_node *node; |
f7116284 | 653 | |
73cc4bb0 DV |
654 | while ((node = u->evtchns.rb_node)) { |
655 | struct user_evtchn *evtchn; | |
f7116284 | 656 | |
73cc4bb0 DV |
657 | evtchn = rb_entry(node, struct user_evtchn, node); |
658 | disable_irq(irq_from_evtchn(evtchn->port)); | |
659 | evtchn_unbind_from_user(u, evtchn); | |
3f5e554f JF |
660 | } |
661 | ||
86200154 | 662 | evtchn_free_ring(u->ring); |
f7116284 IC |
663 | kfree(u->name); |
664 | kfree(u); | |
665 | ||
666 | return 0; | |
667 | } | |
668 | ||
669 | static const struct file_operations evtchn_fops = { | |
670 | .owner = THIS_MODULE, | |
671 | .read = evtchn_read, | |
672 | .write = evtchn_write, | |
673 | .unlocked_ioctl = evtchn_ioctl, | |
674 | .poll = evtchn_poll, | |
675 | .fasync = evtchn_fasync, | |
676 | .open = evtchn_open, | |
677 | .release = evtchn_release, | |
bc7fc5e3 | 678 | .llseek = no_llseek, |
f7116284 IC |
679 | }; |
680 | ||
681 | static struct miscdevice evtchn_miscdev = { | |
682 | .minor = MISC_DYNAMIC_MINOR, | |
376d908f | 683 | .name = "xen/evtchn", |
f7116284 IC |
684 | .fops = &evtchn_fops, |
685 | }; | |
686 | static int __init evtchn_init(void) | |
687 | { | |
688 | int err; | |
689 | ||
690 | if (!xen_domain()) | |
691 | return -ENODEV; | |
692 | ||
18283ea7 | 693 | /* Create '/dev/xen/evtchn'. */ |
f7116284 IC |
694 | err = misc_register(&evtchn_miscdev); |
695 | if (err != 0) { | |
283c0972 | 696 | pr_err("Could not register /dev/xen/evtchn\n"); |
f7116284 IC |
697 | return err; |
698 | } | |
699 | ||
283c0972 | 700 | pr_info("Event-channel device installed\n"); |
f7116284 IC |
701 | |
702 | return 0; | |
703 | } | |
704 | ||
705 | static void __exit evtchn_cleanup(void) | |
706 | { | |
707 | misc_deregister(&evtchn_miscdev); | |
708 | } | |
709 | ||
710 | module_init(evtchn_init); | |
711 | module_exit(evtchn_cleanup); | |
712 | ||
713 | MODULE_LICENSE("GPL"); |