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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; | |
0102e4ef | 86 | evtchn_port_t port; |
73cc4bb0 DV |
87 | bool enabled; |
88 | }; | |
f7116284 | 89 | |
86200154 DV |
90 | static void evtchn_free_ring(evtchn_port_t *ring) |
91 | { | |
92 | kvfree(ring); | |
93 | } | |
94 | ||
95 | static unsigned int evtchn_ring_offset(struct per_user_data *u, | |
96 | unsigned int idx) | |
97 | { | |
98 | return idx & (u->ring_size - 1); | |
99 | } | |
100 | ||
101 | static evtchn_port_t *evtchn_ring_entry(struct per_user_data *u, | |
102 | unsigned int idx) | |
103 | { | |
104 | return u->ring + evtchn_ring_offset(u, idx); | |
105 | } | |
106 | ||
73cc4bb0 | 107 | static int add_evtchn(struct per_user_data *u, struct user_evtchn *evtchn) |
e3cc067b | 108 | { |
73cc4bb0 | 109 | struct rb_node **new = &(u->evtchns.rb_node), *parent = NULL; |
e3cc067b | 110 | |
86200154 DV |
111 | u->nr_evtchns++; |
112 | ||
73cc4bb0 DV |
113 | while (*new) { |
114 | struct user_evtchn *this; | |
115 | ||
2f60b288 | 116 | this = rb_entry(*new, struct user_evtchn, node); |
73cc4bb0 DV |
117 | |
118 | parent = *new; | |
119 | if (this->port < evtchn->port) | |
120 | new = &((*new)->rb_left); | |
121 | else if (this->port > evtchn->port) | |
122 | new = &((*new)->rb_right); | |
123 | else | |
124 | return -EEXIST; | |
125 | } | |
126 | ||
127 | /* Add new node and rebalance tree. */ | |
128 | rb_link_node(&evtchn->node, parent, new); | |
129 | rb_insert_color(&evtchn->node, &u->evtchns); | |
130 | ||
131 | return 0; | |
e3cc067b JF |
132 | } |
133 | ||
73cc4bb0 | 134 | static void del_evtchn(struct per_user_data *u, struct user_evtchn *evtchn) |
e3cc067b | 135 | { |
86200154 | 136 | u->nr_evtchns--; |
73cc4bb0 DV |
137 | rb_erase(&evtchn->node, &u->evtchns); |
138 | kfree(evtchn); | |
e3cc067b JF |
139 | } |
140 | ||
0102e4ef YY |
141 | static struct user_evtchn *find_evtchn(struct per_user_data *u, |
142 | evtchn_port_t port) | |
e3cc067b | 143 | { |
73cc4bb0 DV |
144 | struct rb_node *node = u->evtchns.rb_node; |
145 | ||
146 | while (node) { | |
147 | struct user_evtchn *evtchn; | |
148 | ||
2f60b288 | 149 | evtchn = rb_entry(node, struct user_evtchn, node); |
73cc4bb0 DV |
150 | |
151 | if (evtchn->port < port) | |
152 | node = node->rb_left; | |
153 | else if (evtchn->port > port) | |
154 | node = node->rb_right; | |
155 | else | |
156 | return evtchn; | |
157 | } | |
158 | return NULL; | |
e3cc067b JF |
159 | } |
160 | ||
70697d54 | 161 | static irqreturn_t evtchn_interrupt(int irq, void *data) |
f7116284 | 162 | { |
73cc4bb0 DV |
163 | struct user_evtchn *evtchn = data; |
164 | struct per_user_data *u = evtchn->user; | |
6977c0b5 | 165 | unsigned int prod, cons; |
e3cc067b | 166 | |
73cc4bb0 | 167 | WARN(!evtchn->enabled, |
0102e4ef | 168 | "Interrupt for port %u, but apparently not enabled; per-user %p\n", |
73cc4bb0 | 169 | evtchn->port, u); |
f7116284 | 170 | |
73cc4bb0 DV |
171 | evtchn->enabled = false; |
172 | ||
173 | spin_lock(&u->ring_prod_lock); | |
f7116284 | 174 | |
6977c0b5 JG |
175 | prod = READ_ONCE(u->ring_prod); |
176 | cons = READ_ONCE(u->ring_cons); | |
177 | ||
178 | if ((prod - cons) < u->ring_size) { | |
179 | *evtchn_ring_entry(u, prod) = evtchn->port; | |
d5669959 | 180 | smp_wmb(); /* Ensure ring contents visible */ |
6977c0b5 JG |
181 | WRITE_ONCE(u->ring_prod, prod + 1); |
182 | if (cons == prod) { | |
f7116284 IC |
183 | wake_up_interruptible(&u->evtchn_wait); |
184 | kill_fasync(&u->evtchn_async_queue, | |
185 | SIGIO, POLL_IN); | |
186 | } | |
e3cc067b | 187 | } else |
f7116284 | 188 | u->ring_overflow = 1; |
f7116284 | 189 | |
73cc4bb0 | 190 | spin_unlock(&u->ring_prod_lock); |
f7116284 IC |
191 | |
192 | return IRQ_HANDLED; | |
193 | } | |
194 | ||
195 | static ssize_t evtchn_read(struct file *file, char __user *buf, | |
196 | size_t count, loff_t *ppos) | |
197 | { | |
198 | int rc; | |
199 | unsigned int c, p, bytes1 = 0, bytes2 = 0; | |
200 | struct per_user_data *u = file->private_data; | |
201 | ||
202 | /* Whole number of ports. */ | |
203 | count &= ~(sizeof(evtchn_port_t)-1); | |
204 | ||
205 | if (count == 0) | |
206 | return 0; | |
207 | ||
208 | if (count > PAGE_SIZE) | |
209 | count = PAGE_SIZE; | |
210 | ||
211 | for (;;) { | |
212 | mutex_lock(&u->ring_cons_mutex); | |
213 | ||
214 | rc = -EFBIG; | |
215 | if (u->ring_overflow) | |
216 | goto unlock_out; | |
217 | ||
6977c0b5 JG |
218 | c = READ_ONCE(u->ring_cons); |
219 | p = READ_ONCE(u->ring_prod); | |
f7116284 IC |
220 | if (c != p) |
221 | break; | |
222 | ||
223 | mutex_unlock(&u->ring_cons_mutex); | |
224 | ||
225 | if (file->f_flags & O_NONBLOCK) | |
226 | return -EAGAIN; | |
227 | ||
228 | rc = wait_event_interruptible(u->evtchn_wait, | |
6977c0b5 | 229 | READ_ONCE(u->ring_cons) != READ_ONCE(u->ring_prod)); |
f7116284 IC |
230 | if (rc) |
231 | return rc; | |
232 | } | |
233 | ||
234 | /* Byte lengths of two chunks. Chunk split (if any) is at ring wrap. */ | |
86200154 DV |
235 | if (((c ^ p) & u->ring_size) != 0) { |
236 | bytes1 = (u->ring_size - evtchn_ring_offset(u, c)) * | |
f7116284 | 237 | sizeof(evtchn_port_t); |
86200154 | 238 | bytes2 = evtchn_ring_offset(u, p) * sizeof(evtchn_port_t); |
f7116284 IC |
239 | } else { |
240 | bytes1 = (p - c) * sizeof(evtchn_port_t); | |
241 | bytes2 = 0; | |
242 | } | |
243 | ||
244 | /* Truncate chunks according to caller's maximum byte count. */ | |
245 | if (bytes1 > count) { | |
246 | bytes1 = count; | |
247 | bytes2 = 0; | |
248 | } else if ((bytes1 + bytes2) > count) { | |
249 | bytes2 = count - bytes1; | |
250 | } | |
251 | ||
252 | rc = -EFAULT; | |
d5669959 | 253 | smp_rmb(); /* Ensure that we see the port before we copy it. */ |
86200154 | 254 | if (copy_to_user(buf, evtchn_ring_entry(u, c), bytes1) || |
f7116284 IC |
255 | ((bytes2 != 0) && |
256 | copy_to_user(&buf[bytes1], &u->ring[0], bytes2))) | |
257 | goto unlock_out; | |
258 | ||
6977c0b5 | 259 | WRITE_ONCE(u->ring_cons, c + (bytes1 + bytes2) / sizeof(evtchn_port_t)); |
f7116284 IC |
260 | rc = bytes1 + bytes2; |
261 | ||
262 | unlock_out: | |
263 | mutex_unlock(&u->ring_cons_mutex); | |
264 | return rc; | |
265 | } | |
266 | ||
267 | static ssize_t evtchn_write(struct file *file, const char __user *buf, | |
268 | size_t count, loff_t *ppos) | |
269 | { | |
270 | int rc, i; | |
271 | evtchn_port_t *kbuf = (evtchn_port_t *)__get_free_page(GFP_KERNEL); | |
272 | struct per_user_data *u = file->private_data; | |
273 | ||
274 | if (kbuf == NULL) | |
275 | return -ENOMEM; | |
276 | ||
277 | /* Whole number of ports. */ | |
278 | count &= ~(sizeof(evtchn_port_t)-1); | |
279 | ||
280 | rc = 0; | |
281 | if (count == 0) | |
282 | goto out; | |
283 | ||
284 | if (count > PAGE_SIZE) | |
285 | count = PAGE_SIZE; | |
286 | ||
287 | rc = -EFAULT; | |
288 | if (copy_from_user(kbuf, buf, count) != 0) | |
289 | goto out; | |
290 | ||
73cc4bb0 | 291 | mutex_lock(&u->bind_mutex); |
e3cc067b JF |
292 | |
293 | for (i = 0; i < (count/sizeof(evtchn_port_t)); i++) { | |
0102e4ef | 294 | evtchn_port_t port = kbuf[i]; |
73cc4bb0 | 295 | struct user_evtchn *evtchn; |
e3cc067b | 296 | |
73cc4bb0 DV |
297 | evtchn = find_evtchn(u, port); |
298 | if (evtchn && !evtchn->enabled) { | |
299 | evtchn->enabled = true; | |
c44b849c | 300 | xen_irq_lateeoi(irq_from_evtchn(port), 0); |
e3cc067b JF |
301 | } |
302 | } | |
303 | ||
73cc4bb0 | 304 | mutex_unlock(&u->bind_mutex); |
f7116284 IC |
305 | |
306 | rc = count; | |
307 | ||
308 | out: | |
309 | free_page((unsigned long)kbuf); | |
310 | return rc; | |
311 | } | |
312 | ||
86200154 DV |
313 | static int evtchn_resize_ring(struct per_user_data *u) |
314 | { | |
315 | unsigned int new_size; | |
316 | evtchn_port_t *new_ring, *old_ring; | |
86200154 DV |
317 | |
318 | /* | |
319 | * Ensure the ring is large enough to capture all possible | |
320 | * events. i.e., one free slot for each bound event. | |
321 | */ | |
322 | if (u->nr_evtchns <= u->ring_size) | |
323 | return 0; | |
324 | ||
325 | if (u->ring_size == 0) | |
326 | new_size = 64; | |
327 | else | |
328 | new_size = 2 * u->ring_size; | |
329 | ||
344476e1 | 330 | new_ring = kvmalloc_array(new_size, sizeof(*new_ring), GFP_KERNEL); |
86200154 DV |
331 | if (!new_ring) |
332 | return -ENOMEM; | |
333 | ||
334 | old_ring = u->ring; | |
335 | ||
336 | /* | |
337 | * Access to the ring contents is serialized by either the | |
338 | * prod /or/ cons lock so take both when resizing. | |
339 | */ | |
340 | mutex_lock(&u->ring_cons_mutex); | |
341 | spin_lock_irq(&u->ring_prod_lock); | |
342 | ||
343 | /* | |
344 | * Copy the old ring contents to the new ring. | |
345 | * | |
27e0e638 JB |
346 | * To take care of wrapping, a full ring, and the new index |
347 | * pointing into the second half, simply copy the old contents | |
348 | * twice. | |
86200154 DV |
349 | * |
350 | * +---------+ +------------------+ | |
27e0e638 JB |
351 | * |34567 12| -> |34567 1234567 12| |
352 | * +-----p-c-+ +-------c------p---+ | |
86200154 | 353 | */ |
27e0e638 JB |
354 | memcpy(new_ring, old_ring, u->ring_size * sizeof(*u->ring)); |
355 | memcpy(new_ring + u->ring_size, old_ring, | |
356 | u->ring_size * sizeof(*u->ring)); | |
86200154 DV |
357 | |
358 | u->ring = new_ring; | |
359 | u->ring_size = new_size; | |
360 | ||
361 | spin_unlock_irq(&u->ring_prod_lock); | |
362 | mutex_unlock(&u->ring_cons_mutex); | |
363 | ||
364 | evtchn_free_ring(old_ring); | |
365 | ||
366 | return 0; | |
367 | } | |
368 | ||
0102e4ef | 369 | static int evtchn_bind_to_user(struct per_user_data *u, evtchn_port_t port) |
f7116284 | 370 | { |
73cc4bb0 DV |
371 | struct user_evtchn *evtchn; |
372 | struct evtchn_close close; | |
f7116284 IC |
373 | int rc = 0; |
374 | ||
0a4666b5 JF |
375 | /* |
376 | * Ports are never reused, so every caller should pass in a | |
377 | * unique port. | |
378 | * | |
379 | * (Locking not necessary because we haven't registered the | |
380 | * interrupt handler yet, and our caller has already | |
381 | * serialized bind operations.) | |
382 | */ | |
73cc4bb0 DV |
383 | |
384 | evtchn = kzalloc(sizeof(*evtchn), GFP_KERNEL); | |
385 | if (!evtchn) | |
386 | return -ENOMEM; | |
387 | ||
388 | evtchn->user = u; | |
389 | evtchn->port = port; | |
390 | evtchn->enabled = true; /* start enabled */ | |
391 | ||
392 | rc = add_evtchn(u, evtchn); | |
393 | if (rc < 0) | |
394 | goto err; | |
f7116284 | 395 | |
86200154 DV |
396 | rc = evtchn_resize_ring(u); |
397 | if (rc < 0) | |
398 | goto err; | |
399 | ||
c44b849c JG |
400 | rc = bind_evtchn_to_irqhandler_lateeoi(port, evtchn_interrupt, 0, |
401 | u->name, evtchn); | |
73cc4bb0 DV |
402 | if (rc < 0) |
403 | goto err; | |
0a4666b5 | 404 | |
73cc4bb0 DV |
405 | rc = evtchn_make_refcounted(port); |
406 | return rc; | |
407 | ||
408 | err: | |
409 | /* bind failed, should close the port now */ | |
410 | close.port = port; | |
411 | if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0) | |
412 | BUG(); | |
413 | del_evtchn(u, evtchn); | |
f7116284 IC |
414 | return rc; |
415 | } | |
416 | ||
73cc4bb0 DV |
417 | static void evtchn_unbind_from_user(struct per_user_data *u, |
418 | struct user_evtchn *evtchn) | |
f7116284 | 419 | { |
73cc4bb0 | 420 | int irq = irq_from_evtchn(evtchn->port); |
f7116284 | 421 | |
e7e44e44 WL |
422 | BUG_ON(irq < 0); |
423 | ||
73cc4bb0 | 424 | unbind_from_irqhandler(irq, evtchn); |
0a4666b5 | 425 | |
73cc4bb0 | 426 | del_evtchn(u, evtchn); |
f7116284 IC |
427 | } |
428 | ||
429 | static long evtchn_ioctl(struct file *file, | |
430 | unsigned int cmd, unsigned long arg) | |
431 | { | |
432 | int rc; | |
433 | struct per_user_data *u = file->private_data; | |
434 | void __user *uarg = (void __user *) arg; | |
435 | ||
0a4666b5 JF |
436 | /* Prevent bind from racing with unbind */ |
437 | mutex_lock(&u->bind_mutex); | |
438 | ||
f7116284 IC |
439 | switch (cmd) { |
440 | case IOCTL_EVTCHN_BIND_VIRQ: { | |
441 | struct ioctl_evtchn_bind_virq bind; | |
442 | struct evtchn_bind_virq bind_virq; | |
443 | ||
fbc872c3 DV |
444 | rc = -EACCES; |
445 | if (u->restrict_domid != UNRESTRICTED_DOMID) | |
446 | break; | |
447 | ||
f7116284 IC |
448 | rc = -EFAULT; |
449 | if (copy_from_user(&bind, uarg, sizeof(bind))) | |
450 | break; | |
451 | ||
452 | bind_virq.virq = bind.virq; | |
cbbb4682 | 453 | bind_virq.vcpu = xen_vcpu_nr(0); |
f7116284 IC |
454 | rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq, |
455 | &bind_virq); | |
456 | if (rc != 0) | |
457 | break; | |
458 | ||
459 | rc = evtchn_bind_to_user(u, bind_virq.port); | |
460 | if (rc == 0) | |
461 | rc = bind_virq.port; | |
462 | break; | |
463 | } | |
464 | ||
465 | case IOCTL_EVTCHN_BIND_INTERDOMAIN: { | |
466 | struct ioctl_evtchn_bind_interdomain bind; | |
467 | struct evtchn_bind_interdomain bind_interdomain; | |
468 | ||
469 | rc = -EFAULT; | |
470 | if (copy_from_user(&bind, uarg, sizeof(bind))) | |
471 | break; | |
472 | ||
fbc872c3 DV |
473 | rc = -EACCES; |
474 | if (u->restrict_domid != UNRESTRICTED_DOMID && | |
475 | u->restrict_domid != bind.remote_domain) | |
476 | break; | |
477 | ||
f7116284 IC |
478 | bind_interdomain.remote_dom = bind.remote_domain; |
479 | bind_interdomain.remote_port = bind.remote_port; | |
480 | rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain, | |
481 | &bind_interdomain); | |
482 | if (rc != 0) | |
483 | break; | |
484 | ||
485 | rc = evtchn_bind_to_user(u, bind_interdomain.local_port); | |
67473b81 | 486 | if (rc == 0) |
f7116284 IC |
487 | rc = bind_interdomain.local_port; |
488 | break; | |
489 | } | |
490 | ||
491 | case IOCTL_EVTCHN_BIND_UNBOUND_PORT: { | |
492 | struct ioctl_evtchn_bind_unbound_port bind; | |
493 | struct evtchn_alloc_unbound alloc_unbound; | |
494 | ||
fbc872c3 DV |
495 | rc = -EACCES; |
496 | if (u->restrict_domid != UNRESTRICTED_DOMID) | |
497 | break; | |
498 | ||
f7116284 IC |
499 | rc = -EFAULT; |
500 | if (copy_from_user(&bind, uarg, sizeof(bind))) | |
501 | break; | |
502 | ||
503 | alloc_unbound.dom = DOMID_SELF; | |
504 | alloc_unbound.remote_dom = bind.remote_domain; | |
505 | rc = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, | |
506 | &alloc_unbound); | |
507 | if (rc != 0) | |
508 | break; | |
509 | ||
510 | rc = evtchn_bind_to_user(u, alloc_unbound.port); | |
511 | if (rc == 0) | |
512 | rc = alloc_unbound.port; | |
513 | break; | |
514 | } | |
515 | ||
516 | case IOCTL_EVTCHN_UNBIND: { | |
517 | struct ioctl_evtchn_unbind unbind; | |
73cc4bb0 | 518 | struct user_evtchn *evtchn; |
f7116284 IC |
519 | |
520 | rc = -EFAULT; | |
521 | if (copy_from_user(&unbind, uarg, sizeof(unbind))) | |
522 | break; | |
523 | ||
524 | rc = -EINVAL; | |
0dc0064a | 525 | if (unbind.port >= xen_evtchn_nr_channels()) |
f7116284 IC |
526 | break; |
527 | ||
f7116284 | 528 | rc = -ENOTCONN; |
73cc4bb0 DV |
529 | evtchn = find_evtchn(u, unbind.port); |
530 | if (!evtchn) | |
f7116284 | 531 | break; |
f7116284 | 532 | |
3f5e554f | 533 | disable_irq(irq_from_evtchn(unbind.port)); |
73cc4bb0 | 534 | evtchn_unbind_from_user(u, evtchn); |
f7116284 IC |
535 | rc = 0; |
536 | break; | |
537 | } | |
538 | ||
539 | case IOCTL_EVTCHN_NOTIFY: { | |
540 | struct ioctl_evtchn_notify notify; | |
73cc4bb0 | 541 | struct user_evtchn *evtchn; |
f7116284 IC |
542 | |
543 | rc = -EFAULT; | |
544 | if (copy_from_user(¬ify, uarg, sizeof(notify))) | |
545 | break; | |
546 | ||
73cc4bb0 DV |
547 | rc = -ENOTCONN; |
548 | evtchn = find_evtchn(u, notify.port); | |
549 | if (evtchn) { | |
f7116284 IC |
550 | notify_remote_via_evtchn(notify.port); |
551 | rc = 0; | |
552 | } | |
553 | break; | |
554 | } | |
555 | ||
556 | case IOCTL_EVTCHN_RESET: { | |
557 | /* Initialise the ring to empty. Clear errors. */ | |
558 | mutex_lock(&u->ring_cons_mutex); | |
73cc4bb0 | 559 | spin_lock_irq(&u->ring_prod_lock); |
6977c0b5 JG |
560 | WRITE_ONCE(u->ring_cons, 0); |
561 | WRITE_ONCE(u->ring_prod, 0); | |
562 | u->ring_overflow = 0; | |
73cc4bb0 | 563 | spin_unlock_irq(&u->ring_prod_lock); |
f7116284 IC |
564 | mutex_unlock(&u->ring_cons_mutex); |
565 | rc = 0; | |
566 | break; | |
567 | } | |
568 | ||
fbc872c3 DV |
569 | case IOCTL_EVTCHN_RESTRICT_DOMID: { |
570 | struct ioctl_evtchn_restrict_domid ierd; | |
571 | ||
572 | rc = -EACCES; | |
573 | if (u->restrict_domid != UNRESTRICTED_DOMID) | |
574 | break; | |
575 | ||
576 | rc = -EFAULT; | |
577 | if (copy_from_user(&ierd, uarg, sizeof(ierd))) | |
578 | break; | |
579 | ||
580 | rc = -EINVAL; | |
581 | if (ierd.domid == 0 || ierd.domid >= DOMID_FIRST_RESERVED) | |
582 | break; | |
583 | ||
584 | u->restrict_domid = ierd.domid; | |
585 | rc = 0; | |
586 | ||
587 | break; | |
588 | } | |
589 | ||
f7116284 IC |
590 | default: |
591 | rc = -ENOSYS; | |
592 | break; | |
593 | } | |
0a4666b5 | 594 | mutex_unlock(&u->bind_mutex); |
f7116284 IC |
595 | |
596 | return rc; | |
597 | } | |
598 | ||
afc9a42b | 599 | static __poll_t evtchn_poll(struct file *file, poll_table *wait) |
f7116284 | 600 | { |
a9a08845 | 601 | __poll_t mask = EPOLLOUT | EPOLLWRNORM; |
f7116284 IC |
602 | struct per_user_data *u = file->private_data; |
603 | ||
604 | poll_wait(file, &u->evtchn_wait, wait); | |
6977c0b5 | 605 | if (READ_ONCE(u->ring_cons) != READ_ONCE(u->ring_prod)) |
a9a08845 | 606 | mask |= EPOLLIN | EPOLLRDNORM; |
f7116284 | 607 | if (u->ring_overflow) |
a9a08845 | 608 | mask = EPOLLERR; |
f7116284 IC |
609 | return mask; |
610 | } | |
611 | ||
612 | static int evtchn_fasync(int fd, struct file *filp, int on) | |
613 | { | |
614 | struct per_user_data *u = filp->private_data; | |
615 | return fasync_helper(fd, filp, on, &u->evtchn_async_queue); | |
616 | } | |
617 | ||
618 | static int evtchn_open(struct inode *inode, struct file *filp) | |
619 | { | |
620 | struct per_user_data *u; | |
621 | ||
622 | u = kzalloc(sizeof(*u), GFP_KERNEL); | |
623 | if (u == NULL) | |
624 | return -ENOMEM; | |
625 | ||
626 | u->name = kasprintf(GFP_KERNEL, "evtchn:%s", current->comm); | |
627 | if (u->name == NULL) { | |
628 | kfree(u); | |
629 | return -ENOMEM; | |
630 | } | |
631 | ||
632 | init_waitqueue_head(&u->evtchn_wait); | |
633 | ||
0a4666b5 | 634 | mutex_init(&u->bind_mutex); |
f7116284 | 635 | mutex_init(&u->ring_cons_mutex); |
73cc4bb0 | 636 | spin_lock_init(&u->ring_prod_lock); |
f7116284 | 637 | |
fbc872c3 DV |
638 | u->restrict_domid = UNRESTRICTED_DOMID; |
639 | ||
f7116284 IC |
640 | filp->private_data = u; |
641 | ||
c5bf68fe | 642 | return stream_open(inode, filp); |
f7116284 IC |
643 | } |
644 | ||
645 | static int evtchn_release(struct inode *inode, struct file *filp) | |
646 | { | |
f7116284 | 647 | struct per_user_data *u = filp->private_data; |
73cc4bb0 | 648 | struct rb_node *node; |
f7116284 | 649 | |
73cc4bb0 DV |
650 | while ((node = u->evtchns.rb_node)) { |
651 | struct user_evtchn *evtchn; | |
f7116284 | 652 | |
73cc4bb0 DV |
653 | evtchn = rb_entry(node, struct user_evtchn, node); |
654 | disable_irq(irq_from_evtchn(evtchn->port)); | |
655 | evtchn_unbind_from_user(u, evtchn); | |
3f5e554f JF |
656 | } |
657 | ||
86200154 | 658 | evtchn_free_ring(u->ring); |
f7116284 IC |
659 | kfree(u->name); |
660 | kfree(u); | |
661 | ||
662 | return 0; | |
663 | } | |
664 | ||
665 | static const struct file_operations evtchn_fops = { | |
666 | .owner = THIS_MODULE, | |
667 | .read = evtchn_read, | |
668 | .write = evtchn_write, | |
669 | .unlocked_ioctl = evtchn_ioctl, | |
670 | .poll = evtchn_poll, | |
671 | .fasync = evtchn_fasync, | |
672 | .open = evtchn_open, | |
673 | .release = evtchn_release, | |
bc7fc5e3 | 674 | .llseek = no_llseek, |
f7116284 IC |
675 | }; |
676 | ||
677 | static struct miscdevice evtchn_miscdev = { | |
678 | .minor = MISC_DYNAMIC_MINOR, | |
376d908f | 679 | .name = "xen/evtchn", |
f7116284 IC |
680 | .fops = &evtchn_fops, |
681 | }; | |
682 | static int __init evtchn_init(void) | |
683 | { | |
684 | int err; | |
685 | ||
686 | if (!xen_domain()) | |
687 | return -ENODEV; | |
688 | ||
18283ea7 | 689 | /* Create '/dev/xen/evtchn'. */ |
f7116284 IC |
690 | err = misc_register(&evtchn_miscdev); |
691 | if (err != 0) { | |
283c0972 | 692 | pr_err("Could not register /dev/xen/evtchn\n"); |
f7116284 IC |
693 | return err; |
694 | } | |
695 | ||
283c0972 | 696 | pr_info("Event-channel device installed\n"); |
f7116284 IC |
697 | |
698 | return 0; | |
699 | } | |
700 | ||
701 | static void __exit evtchn_cleanup(void) | |
702 | { | |
703 | misc_deregister(&evtchn_miscdev); | |
704 | } | |
705 | ||
706 | module_init(evtchn_init); | |
707 | module_exit(evtchn_cleanup); | |
708 | ||
709 | MODULE_LICENSE("GPL"); |