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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> | |
cbbb4682 | 58 | #include <xen/xen-ops.h> |
f7116284 IC |
59 | #include <asm/xen/hypervisor.h> |
60 | ||
61 | struct per_user_data { | |
0a4666b5 | 62 | struct mutex bind_mutex; /* serialize bind/unbind operations */ |
73cc4bb0 | 63 | struct rb_root evtchns; |
86200154 | 64 | unsigned int nr_evtchns; |
0a4666b5 | 65 | |
f7116284 | 66 | /* Notification ring, accessed via /dev/xen/evtchn. */ |
86200154 | 67 | unsigned int ring_size; |
f7116284 IC |
68 | evtchn_port_t *ring; |
69 | unsigned int ring_cons, ring_prod, ring_overflow; | |
70 | struct mutex ring_cons_mutex; /* protect against concurrent readers */ | |
73cc4bb0 | 71 | spinlock_t ring_prod_lock; /* product against concurrent interrupts */ |
f7116284 IC |
72 | |
73 | /* Processes wait on this queue when ring is empty. */ | |
74 | wait_queue_head_t evtchn_wait; | |
75 | struct fasync_struct *evtchn_async_queue; | |
76 | const char *name; | |
fbc872c3 DV |
77 | |
78 | domid_t restrict_domid; | |
f7116284 IC |
79 | }; |
80 | ||
fbc872c3 DV |
81 | #define UNRESTRICTED_DOMID ((domid_t)-1) |
82 | ||
73cc4bb0 DV |
83 | struct user_evtchn { |
84 | struct rb_node node; | |
85 | struct per_user_data *user; | |
86 | unsigned port; | |
87 | bool enabled; | |
88 | }; | |
f7116284 | 89 | |
86200154 DV |
90 | static evtchn_port_t *evtchn_alloc_ring(unsigned int size) |
91 | { | |
92 | evtchn_port_t *ring; | |
93 | size_t s = size * sizeof(*ring); | |
94 | ||
95 | ring = kmalloc(s, GFP_KERNEL); | |
96 | if (!ring) | |
97 | ring = vmalloc(s); | |
98 | ||
99 | return ring; | |
100 | } | |
101 | ||
102 | static void evtchn_free_ring(evtchn_port_t *ring) | |
103 | { | |
104 | kvfree(ring); | |
105 | } | |
106 | ||
107 | static unsigned int evtchn_ring_offset(struct per_user_data *u, | |
108 | unsigned int idx) | |
109 | { | |
110 | return idx & (u->ring_size - 1); | |
111 | } | |
112 | ||
113 | static evtchn_port_t *evtchn_ring_entry(struct per_user_data *u, | |
114 | unsigned int idx) | |
115 | { | |
116 | return u->ring + evtchn_ring_offset(u, idx); | |
117 | } | |
118 | ||
73cc4bb0 | 119 | static int add_evtchn(struct per_user_data *u, struct user_evtchn *evtchn) |
e3cc067b | 120 | { |
73cc4bb0 | 121 | struct rb_node **new = &(u->evtchns.rb_node), *parent = NULL; |
e3cc067b | 122 | |
86200154 DV |
123 | u->nr_evtchns++; |
124 | ||
73cc4bb0 DV |
125 | while (*new) { |
126 | struct user_evtchn *this; | |
127 | ||
2f60b288 | 128 | this = rb_entry(*new, struct user_evtchn, node); |
73cc4bb0 DV |
129 | |
130 | parent = *new; | |
131 | if (this->port < evtchn->port) | |
132 | new = &((*new)->rb_left); | |
133 | else if (this->port > evtchn->port) | |
134 | new = &((*new)->rb_right); | |
135 | else | |
136 | return -EEXIST; | |
137 | } | |
138 | ||
139 | /* Add new node and rebalance tree. */ | |
140 | rb_link_node(&evtchn->node, parent, new); | |
141 | rb_insert_color(&evtchn->node, &u->evtchns); | |
142 | ||
143 | return 0; | |
e3cc067b JF |
144 | } |
145 | ||
73cc4bb0 | 146 | static void del_evtchn(struct per_user_data *u, struct user_evtchn *evtchn) |
e3cc067b | 147 | { |
86200154 | 148 | u->nr_evtchns--; |
73cc4bb0 DV |
149 | rb_erase(&evtchn->node, &u->evtchns); |
150 | kfree(evtchn); | |
e3cc067b JF |
151 | } |
152 | ||
73cc4bb0 | 153 | static struct user_evtchn *find_evtchn(struct per_user_data *u, unsigned port) |
e3cc067b | 154 | { |
73cc4bb0 DV |
155 | struct rb_node *node = u->evtchns.rb_node; |
156 | ||
157 | while (node) { | |
158 | struct user_evtchn *evtchn; | |
159 | ||
2f60b288 | 160 | evtchn = rb_entry(node, struct user_evtchn, node); |
73cc4bb0 DV |
161 | |
162 | if (evtchn->port < port) | |
163 | node = node->rb_left; | |
164 | else if (evtchn->port > port) | |
165 | node = node->rb_right; | |
166 | else | |
167 | return evtchn; | |
168 | } | |
169 | return NULL; | |
e3cc067b JF |
170 | } |
171 | ||
70697d54 | 172 | static irqreturn_t evtchn_interrupt(int irq, void *data) |
f7116284 | 173 | { |
73cc4bb0 DV |
174 | struct user_evtchn *evtchn = data; |
175 | struct per_user_data *u = evtchn->user; | |
e3cc067b | 176 | |
73cc4bb0 | 177 | WARN(!evtchn->enabled, |
0edce91d | 178 | "Interrupt for port %d, but apparently not enabled; per-user %p\n", |
73cc4bb0 | 179 | evtchn->port, u); |
f7116284 IC |
180 | |
181 | disable_irq_nosync(irq); | |
73cc4bb0 DV |
182 | evtchn->enabled = false; |
183 | ||
184 | spin_lock(&u->ring_prod_lock); | |
f7116284 | 185 | |
86200154 DV |
186 | if ((u->ring_prod - u->ring_cons) < u->ring_size) { |
187 | *evtchn_ring_entry(u, u->ring_prod) = evtchn->port; | |
f7116284 IC |
188 | wmb(); /* Ensure ring contents visible */ |
189 | if (u->ring_cons == u->ring_prod++) { | |
190 | wake_up_interruptible(&u->evtchn_wait); | |
191 | kill_fasync(&u->evtchn_async_queue, | |
192 | SIGIO, POLL_IN); | |
193 | } | |
e3cc067b | 194 | } else |
f7116284 | 195 | u->ring_overflow = 1; |
f7116284 | 196 | |
73cc4bb0 | 197 | spin_unlock(&u->ring_prod_lock); |
f7116284 IC |
198 | |
199 | return IRQ_HANDLED; | |
200 | } | |
201 | ||
202 | static ssize_t evtchn_read(struct file *file, char __user *buf, | |
203 | size_t count, loff_t *ppos) | |
204 | { | |
205 | int rc; | |
206 | unsigned int c, p, bytes1 = 0, bytes2 = 0; | |
207 | struct per_user_data *u = file->private_data; | |
208 | ||
209 | /* Whole number of ports. */ | |
210 | count &= ~(sizeof(evtchn_port_t)-1); | |
211 | ||
212 | if (count == 0) | |
213 | return 0; | |
214 | ||
215 | if (count > PAGE_SIZE) | |
216 | count = PAGE_SIZE; | |
217 | ||
218 | for (;;) { | |
219 | mutex_lock(&u->ring_cons_mutex); | |
220 | ||
221 | rc = -EFBIG; | |
222 | if (u->ring_overflow) | |
223 | goto unlock_out; | |
224 | ||
225 | c = u->ring_cons; | |
226 | p = u->ring_prod; | |
227 | if (c != p) | |
228 | break; | |
229 | ||
230 | mutex_unlock(&u->ring_cons_mutex); | |
231 | ||
232 | if (file->f_flags & O_NONBLOCK) | |
233 | return -EAGAIN; | |
234 | ||
235 | rc = wait_event_interruptible(u->evtchn_wait, | |
236 | u->ring_cons != u->ring_prod); | |
237 | if (rc) | |
238 | return rc; | |
239 | } | |
240 | ||
241 | /* Byte lengths of two chunks. Chunk split (if any) is at ring wrap. */ | |
86200154 DV |
242 | if (((c ^ p) & u->ring_size) != 0) { |
243 | bytes1 = (u->ring_size - evtchn_ring_offset(u, c)) * | |
f7116284 | 244 | sizeof(evtchn_port_t); |
86200154 | 245 | bytes2 = evtchn_ring_offset(u, p) * sizeof(evtchn_port_t); |
f7116284 IC |
246 | } else { |
247 | bytes1 = (p - c) * sizeof(evtchn_port_t); | |
248 | bytes2 = 0; | |
249 | } | |
250 | ||
251 | /* Truncate chunks according to caller's maximum byte count. */ | |
252 | if (bytes1 > count) { | |
253 | bytes1 = count; | |
254 | bytes2 = 0; | |
255 | } else if ((bytes1 + bytes2) > count) { | |
256 | bytes2 = count - bytes1; | |
257 | } | |
258 | ||
259 | rc = -EFAULT; | |
260 | rmb(); /* Ensure that we see the port before we copy it. */ | |
86200154 | 261 | if (copy_to_user(buf, evtchn_ring_entry(u, c), bytes1) || |
f7116284 IC |
262 | ((bytes2 != 0) && |
263 | copy_to_user(&buf[bytes1], &u->ring[0], bytes2))) | |
264 | goto unlock_out; | |
265 | ||
266 | u->ring_cons += (bytes1 + bytes2) / sizeof(evtchn_port_t); | |
267 | rc = bytes1 + bytes2; | |
268 | ||
269 | unlock_out: | |
270 | mutex_unlock(&u->ring_cons_mutex); | |
271 | return rc; | |
272 | } | |
273 | ||
274 | static ssize_t evtchn_write(struct file *file, const char __user *buf, | |
275 | size_t count, loff_t *ppos) | |
276 | { | |
277 | int rc, i; | |
278 | evtchn_port_t *kbuf = (evtchn_port_t *)__get_free_page(GFP_KERNEL); | |
279 | struct per_user_data *u = file->private_data; | |
280 | ||
281 | if (kbuf == NULL) | |
282 | return -ENOMEM; | |
283 | ||
284 | /* Whole number of ports. */ | |
285 | count &= ~(sizeof(evtchn_port_t)-1); | |
286 | ||
287 | rc = 0; | |
288 | if (count == 0) | |
289 | goto out; | |
290 | ||
291 | if (count > PAGE_SIZE) | |
292 | count = PAGE_SIZE; | |
293 | ||
294 | rc = -EFAULT; | |
295 | if (copy_from_user(kbuf, buf, count) != 0) | |
296 | goto out; | |
297 | ||
73cc4bb0 | 298 | mutex_lock(&u->bind_mutex); |
e3cc067b JF |
299 | |
300 | for (i = 0; i < (count/sizeof(evtchn_port_t)); i++) { | |
301 | unsigned port = kbuf[i]; | |
73cc4bb0 | 302 | struct user_evtchn *evtchn; |
e3cc067b | 303 | |
73cc4bb0 DV |
304 | evtchn = find_evtchn(u, port); |
305 | if (evtchn && !evtchn->enabled) { | |
306 | evtchn->enabled = true; | |
e3cc067b JF |
307 | enable_irq(irq_from_evtchn(port)); |
308 | } | |
309 | } | |
310 | ||
73cc4bb0 | 311 | mutex_unlock(&u->bind_mutex); |
f7116284 IC |
312 | |
313 | rc = count; | |
314 | ||
315 | out: | |
316 | free_page((unsigned long)kbuf); | |
317 | return rc; | |
318 | } | |
319 | ||
86200154 DV |
320 | static int evtchn_resize_ring(struct per_user_data *u) |
321 | { | |
322 | unsigned int new_size; | |
323 | evtchn_port_t *new_ring, *old_ring; | |
86200154 DV |
324 | |
325 | /* | |
326 | * Ensure the ring is large enough to capture all possible | |
327 | * events. i.e., one free slot for each bound event. | |
328 | */ | |
329 | if (u->nr_evtchns <= u->ring_size) | |
330 | return 0; | |
331 | ||
332 | if (u->ring_size == 0) | |
333 | new_size = 64; | |
334 | else | |
335 | new_size = 2 * u->ring_size; | |
336 | ||
337 | new_ring = evtchn_alloc_ring(new_size); | |
338 | if (!new_ring) | |
339 | return -ENOMEM; | |
340 | ||
341 | old_ring = u->ring; | |
342 | ||
343 | /* | |
344 | * Access to the ring contents is serialized by either the | |
345 | * prod /or/ cons lock so take both when resizing. | |
346 | */ | |
347 | mutex_lock(&u->ring_cons_mutex); | |
348 | spin_lock_irq(&u->ring_prod_lock); | |
349 | ||
350 | /* | |
351 | * Copy the old ring contents to the new ring. | |
352 | * | |
27e0e638 JB |
353 | * To take care of wrapping, a full ring, and the new index |
354 | * pointing into the second half, simply copy the old contents | |
355 | * twice. | |
86200154 DV |
356 | * |
357 | * +---------+ +------------------+ | |
27e0e638 JB |
358 | * |34567 12| -> |34567 1234567 12| |
359 | * +-----p-c-+ +-------c------p---+ | |
86200154 | 360 | */ |
27e0e638 JB |
361 | memcpy(new_ring, old_ring, u->ring_size * sizeof(*u->ring)); |
362 | memcpy(new_ring + u->ring_size, old_ring, | |
363 | u->ring_size * sizeof(*u->ring)); | |
86200154 DV |
364 | |
365 | u->ring = new_ring; | |
366 | u->ring_size = new_size; | |
367 | ||
368 | spin_unlock_irq(&u->ring_prod_lock); | |
369 | mutex_unlock(&u->ring_cons_mutex); | |
370 | ||
371 | evtchn_free_ring(old_ring); | |
372 | ||
373 | return 0; | |
374 | } | |
375 | ||
f7116284 IC |
376 | static int evtchn_bind_to_user(struct per_user_data *u, int port) |
377 | { | |
73cc4bb0 DV |
378 | struct user_evtchn *evtchn; |
379 | struct evtchn_close close; | |
f7116284 IC |
380 | int rc = 0; |
381 | ||
0a4666b5 JF |
382 | /* |
383 | * Ports are never reused, so every caller should pass in a | |
384 | * unique port. | |
385 | * | |
386 | * (Locking not necessary because we haven't registered the | |
387 | * interrupt handler yet, and our caller has already | |
388 | * serialized bind operations.) | |
389 | */ | |
73cc4bb0 DV |
390 | |
391 | evtchn = kzalloc(sizeof(*evtchn), GFP_KERNEL); | |
392 | if (!evtchn) | |
393 | return -ENOMEM; | |
394 | ||
395 | evtchn->user = u; | |
396 | evtchn->port = port; | |
397 | evtchn->enabled = true; /* start enabled */ | |
398 | ||
399 | rc = add_evtchn(u, evtchn); | |
400 | if (rc < 0) | |
401 | goto err; | |
f7116284 | 402 | |
86200154 DV |
403 | rc = evtchn_resize_ring(u); |
404 | if (rc < 0) | |
405 | goto err; | |
406 | ||
af09d1a7 | 407 | rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, 0, |
73cc4bb0 DV |
408 | u->name, evtchn); |
409 | if (rc < 0) | |
410 | goto err; | |
0a4666b5 | 411 | |
73cc4bb0 DV |
412 | rc = evtchn_make_refcounted(port); |
413 | return rc; | |
414 | ||
415 | err: | |
416 | /* bind failed, should close the port now */ | |
417 | close.port = port; | |
418 | if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0) | |
419 | BUG(); | |
420 | del_evtchn(u, evtchn); | |
f7116284 IC |
421 | return rc; |
422 | } | |
423 | ||
73cc4bb0 DV |
424 | static void evtchn_unbind_from_user(struct per_user_data *u, |
425 | struct user_evtchn *evtchn) | |
f7116284 | 426 | { |
73cc4bb0 | 427 | int irq = irq_from_evtchn(evtchn->port); |
f7116284 | 428 | |
e7e44e44 WL |
429 | BUG_ON(irq < 0); |
430 | ||
73cc4bb0 | 431 | unbind_from_irqhandler(irq, evtchn); |
0a4666b5 | 432 | |
73cc4bb0 | 433 | del_evtchn(u, evtchn); |
f7116284 IC |
434 | } |
435 | ||
436 | static long evtchn_ioctl(struct file *file, | |
437 | unsigned int cmd, unsigned long arg) | |
438 | { | |
439 | int rc; | |
440 | struct per_user_data *u = file->private_data; | |
441 | void __user *uarg = (void __user *) arg; | |
442 | ||
0a4666b5 JF |
443 | /* Prevent bind from racing with unbind */ |
444 | mutex_lock(&u->bind_mutex); | |
445 | ||
f7116284 IC |
446 | switch (cmd) { |
447 | case IOCTL_EVTCHN_BIND_VIRQ: { | |
448 | struct ioctl_evtchn_bind_virq bind; | |
449 | struct evtchn_bind_virq bind_virq; | |
450 | ||
fbc872c3 DV |
451 | rc = -EACCES; |
452 | if (u->restrict_domid != UNRESTRICTED_DOMID) | |
453 | break; | |
454 | ||
f7116284 IC |
455 | rc = -EFAULT; |
456 | if (copy_from_user(&bind, uarg, sizeof(bind))) | |
457 | break; | |
458 | ||
459 | bind_virq.virq = bind.virq; | |
cbbb4682 | 460 | bind_virq.vcpu = xen_vcpu_nr(0); |
f7116284 IC |
461 | rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq, |
462 | &bind_virq); | |
463 | if (rc != 0) | |
464 | break; | |
465 | ||
466 | rc = evtchn_bind_to_user(u, bind_virq.port); | |
467 | if (rc == 0) | |
468 | rc = bind_virq.port; | |
469 | break; | |
470 | } | |
471 | ||
472 | case IOCTL_EVTCHN_BIND_INTERDOMAIN: { | |
473 | struct ioctl_evtchn_bind_interdomain bind; | |
474 | struct evtchn_bind_interdomain bind_interdomain; | |
475 | ||
476 | rc = -EFAULT; | |
477 | if (copy_from_user(&bind, uarg, sizeof(bind))) | |
478 | break; | |
479 | ||
fbc872c3 DV |
480 | rc = -EACCES; |
481 | if (u->restrict_domid != UNRESTRICTED_DOMID && | |
482 | u->restrict_domid != bind.remote_domain) | |
483 | break; | |
484 | ||
f7116284 IC |
485 | bind_interdomain.remote_dom = bind.remote_domain; |
486 | bind_interdomain.remote_port = bind.remote_port; | |
487 | rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain, | |
488 | &bind_interdomain); | |
489 | if (rc != 0) | |
490 | break; | |
491 | ||
492 | rc = evtchn_bind_to_user(u, bind_interdomain.local_port); | |
493 | if (rc == 0) | |
494 | rc = bind_interdomain.local_port; | |
495 | break; | |
496 | } | |
497 | ||
498 | case IOCTL_EVTCHN_BIND_UNBOUND_PORT: { | |
499 | struct ioctl_evtchn_bind_unbound_port bind; | |
500 | struct evtchn_alloc_unbound alloc_unbound; | |
501 | ||
fbc872c3 DV |
502 | rc = -EACCES; |
503 | if (u->restrict_domid != UNRESTRICTED_DOMID) | |
504 | break; | |
505 | ||
f7116284 IC |
506 | rc = -EFAULT; |
507 | if (copy_from_user(&bind, uarg, sizeof(bind))) | |
508 | break; | |
509 | ||
510 | alloc_unbound.dom = DOMID_SELF; | |
511 | alloc_unbound.remote_dom = bind.remote_domain; | |
512 | rc = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, | |
513 | &alloc_unbound); | |
514 | if (rc != 0) | |
515 | break; | |
516 | ||
517 | rc = evtchn_bind_to_user(u, alloc_unbound.port); | |
518 | if (rc == 0) | |
519 | rc = alloc_unbound.port; | |
520 | break; | |
521 | } | |
522 | ||
523 | case IOCTL_EVTCHN_UNBIND: { | |
524 | struct ioctl_evtchn_unbind unbind; | |
73cc4bb0 | 525 | struct user_evtchn *evtchn; |
f7116284 IC |
526 | |
527 | rc = -EFAULT; | |
528 | if (copy_from_user(&unbind, uarg, sizeof(unbind))) | |
529 | break; | |
530 | ||
531 | rc = -EINVAL; | |
0dc0064a | 532 | if (unbind.port >= xen_evtchn_nr_channels()) |
f7116284 IC |
533 | break; |
534 | ||
f7116284 | 535 | rc = -ENOTCONN; |
73cc4bb0 DV |
536 | evtchn = find_evtchn(u, unbind.port); |
537 | if (!evtchn) | |
f7116284 | 538 | break; |
f7116284 | 539 | |
3f5e554f | 540 | disable_irq(irq_from_evtchn(unbind.port)); |
73cc4bb0 | 541 | evtchn_unbind_from_user(u, evtchn); |
f7116284 IC |
542 | rc = 0; |
543 | break; | |
544 | } | |
545 | ||
546 | case IOCTL_EVTCHN_NOTIFY: { | |
547 | struct ioctl_evtchn_notify notify; | |
73cc4bb0 | 548 | struct user_evtchn *evtchn; |
f7116284 IC |
549 | |
550 | rc = -EFAULT; | |
551 | if (copy_from_user(¬ify, uarg, sizeof(notify))) | |
552 | break; | |
553 | ||
73cc4bb0 DV |
554 | rc = -ENOTCONN; |
555 | evtchn = find_evtchn(u, notify.port); | |
556 | if (evtchn) { | |
f7116284 IC |
557 | notify_remote_via_evtchn(notify.port); |
558 | rc = 0; | |
559 | } | |
560 | break; | |
561 | } | |
562 | ||
563 | case IOCTL_EVTCHN_RESET: { | |
564 | /* Initialise the ring to empty. Clear errors. */ | |
565 | mutex_lock(&u->ring_cons_mutex); | |
73cc4bb0 | 566 | spin_lock_irq(&u->ring_prod_lock); |
f7116284 | 567 | u->ring_cons = u->ring_prod = u->ring_overflow = 0; |
73cc4bb0 | 568 | spin_unlock_irq(&u->ring_prod_lock); |
f7116284 IC |
569 | mutex_unlock(&u->ring_cons_mutex); |
570 | rc = 0; | |
571 | break; | |
572 | } | |
573 | ||
fbc872c3 DV |
574 | case IOCTL_EVTCHN_RESTRICT_DOMID: { |
575 | struct ioctl_evtchn_restrict_domid ierd; | |
576 | ||
577 | rc = -EACCES; | |
578 | if (u->restrict_domid != UNRESTRICTED_DOMID) | |
579 | break; | |
580 | ||
581 | rc = -EFAULT; | |
582 | if (copy_from_user(&ierd, uarg, sizeof(ierd))) | |
583 | break; | |
584 | ||
585 | rc = -EINVAL; | |
586 | if (ierd.domid == 0 || ierd.domid >= DOMID_FIRST_RESERVED) | |
587 | break; | |
588 | ||
589 | u->restrict_domid = ierd.domid; | |
590 | rc = 0; | |
591 | ||
592 | break; | |
593 | } | |
594 | ||
f7116284 IC |
595 | default: |
596 | rc = -ENOSYS; | |
597 | break; | |
598 | } | |
0a4666b5 | 599 | mutex_unlock(&u->bind_mutex); |
f7116284 IC |
600 | |
601 | return rc; | |
602 | } | |
603 | ||
604 | static unsigned int evtchn_poll(struct file *file, poll_table *wait) | |
605 | { | |
606 | unsigned int mask = POLLOUT | POLLWRNORM; | |
607 | struct per_user_data *u = file->private_data; | |
608 | ||
609 | poll_wait(file, &u->evtchn_wait, wait); | |
610 | if (u->ring_cons != u->ring_prod) | |
611 | mask |= POLLIN | POLLRDNORM; | |
612 | if (u->ring_overflow) | |
613 | mask = POLLERR; | |
614 | return mask; | |
615 | } | |
616 | ||
617 | static int evtchn_fasync(int fd, struct file *filp, int on) | |
618 | { | |
619 | struct per_user_data *u = filp->private_data; | |
620 | return fasync_helper(fd, filp, on, &u->evtchn_async_queue); | |
621 | } | |
622 | ||
623 | static int evtchn_open(struct inode *inode, struct file *filp) | |
624 | { | |
625 | struct per_user_data *u; | |
626 | ||
627 | u = kzalloc(sizeof(*u), GFP_KERNEL); | |
628 | if (u == NULL) | |
629 | return -ENOMEM; | |
630 | ||
631 | u->name = kasprintf(GFP_KERNEL, "evtchn:%s", current->comm); | |
632 | if (u->name == NULL) { | |
633 | kfree(u); | |
634 | return -ENOMEM; | |
635 | } | |
636 | ||
637 | init_waitqueue_head(&u->evtchn_wait); | |
638 | ||
0a4666b5 | 639 | mutex_init(&u->bind_mutex); |
f7116284 | 640 | mutex_init(&u->ring_cons_mutex); |
73cc4bb0 | 641 | spin_lock_init(&u->ring_prod_lock); |
f7116284 | 642 | |
fbc872c3 DV |
643 | u->restrict_domid = UNRESTRICTED_DOMID; |
644 | ||
f7116284 IC |
645 | filp->private_data = u; |
646 | ||
6eab04a8 | 647 | return nonseekable_open(inode, filp); |
f7116284 IC |
648 | } |
649 | ||
650 | static int evtchn_release(struct inode *inode, struct file *filp) | |
651 | { | |
f7116284 | 652 | struct per_user_data *u = filp->private_data; |
73cc4bb0 | 653 | struct rb_node *node; |
f7116284 | 654 | |
73cc4bb0 DV |
655 | while ((node = u->evtchns.rb_node)) { |
656 | struct user_evtchn *evtchn; | |
f7116284 | 657 | |
73cc4bb0 DV |
658 | evtchn = rb_entry(node, struct user_evtchn, node); |
659 | disable_irq(irq_from_evtchn(evtchn->port)); | |
660 | evtchn_unbind_from_user(u, evtchn); | |
3f5e554f JF |
661 | } |
662 | ||
86200154 | 663 | evtchn_free_ring(u->ring); |
f7116284 IC |
664 | kfree(u->name); |
665 | kfree(u); | |
666 | ||
667 | return 0; | |
668 | } | |
669 | ||
670 | static const struct file_operations evtchn_fops = { | |
671 | .owner = THIS_MODULE, | |
672 | .read = evtchn_read, | |
673 | .write = evtchn_write, | |
674 | .unlocked_ioctl = evtchn_ioctl, | |
675 | .poll = evtchn_poll, | |
676 | .fasync = evtchn_fasync, | |
677 | .open = evtchn_open, | |
678 | .release = evtchn_release, | |
bc7fc5e3 | 679 | .llseek = no_llseek, |
f7116284 IC |
680 | }; |
681 | ||
682 | static struct miscdevice evtchn_miscdev = { | |
683 | .minor = MISC_DYNAMIC_MINOR, | |
376d908f | 684 | .name = "xen/evtchn", |
f7116284 IC |
685 | .fops = &evtchn_fops, |
686 | }; | |
687 | static int __init evtchn_init(void) | |
688 | { | |
689 | int err; | |
690 | ||
691 | if (!xen_domain()) | |
692 | return -ENODEV; | |
693 | ||
18283ea7 | 694 | /* Create '/dev/xen/evtchn'. */ |
f7116284 IC |
695 | err = misc_register(&evtchn_miscdev); |
696 | if (err != 0) { | |
283c0972 | 697 | pr_err("Could not register /dev/xen/evtchn\n"); |
f7116284 IC |
698 | return err; |
699 | } | |
700 | ||
283c0972 | 701 | pr_info("Event-channel device installed\n"); |
f7116284 IC |
702 | |
703 | return 0; | |
704 | } | |
705 | ||
706 | static void __exit evtchn_cleanup(void) | |
707 | { | |
708 | misc_deregister(&evtchn_miscdev); | |
709 | } | |
710 | ||
711 | module_init(evtchn_init); | |
712 | module_exit(evtchn_cleanup); | |
713 | ||
714 | MODULE_LICENSE("GPL"); |