blob: 10f1ef5826595ae53e927243bcdfa5f66c4121c6 [file] [log] [blame]
Ian Campbellf7116282009-02-06 19:21:19 -08001/******************************************************************************
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
Joe Perches283c0972013-06-28 03:21:41 -070034#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
35
Ian Campbellf7116282009-02-06 19:21:19 -080036#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>
Ian Campbellf7116282009-02-06 19:21:19 -080043#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>
Ian Campbellf7116282009-02-06 19:21:19 -080050#include <linux/mutex.h>
51#include <linux/cpu.h>
David Vrabel86200152015-11-26 16:14:35 +000052#include <linux/mm.h>
53#include <linux/vmalloc.h>
Jeremy Fitzhardinge1ccbf532009-10-06 15:11:14 -070054
55#include <xen/xen.h>
Ian Campbellf7116282009-02-06 19:21:19 -080056#include <xen/events.h>
57#include <xen/evtchn.h>
Vitaly Kuznetsovcbbb4682016-06-30 17:56:42 +020058#include <xen/xen-ops.h>
Ian Campbellf7116282009-02-06 19:21:19 -080059#include <asm/xen/hypervisor.h>
60
61struct per_user_data {
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -080062 struct mutex bind_mutex; /* serialize bind/unbind operations */
David Vrabel73cc4bb2013-07-19 15:52:00 +010063 struct rb_root evtchns;
David Vrabel86200152015-11-26 16:14:35 +000064 unsigned int nr_evtchns;
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -080065
Ian Campbellf7116282009-02-06 19:21:19 -080066 /* Notification ring, accessed via /dev/xen/evtchn. */
David Vrabel86200152015-11-26 16:14:35 +000067 unsigned int ring_size;
Ian Campbellf7116282009-02-06 19:21:19 -080068 evtchn_port_t *ring;
69 unsigned int ring_cons, ring_prod, ring_overflow;
70 struct mutex ring_cons_mutex; /* protect against concurrent readers */
David Vrabel73cc4bb2013-07-19 15:52:00 +010071 spinlock_t ring_prod_lock; /* product against concurrent interrupts */
Ian Campbellf7116282009-02-06 19:21:19 -080072
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;
David Vrabelfbc872c2016-07-11 15:45:51 +010077
78 domid_t restrict_domid;
Ian Campbellf7116282009-02-06 19:21:19 -080079};
80
David Vrabelfbc872c2016-07-11 15:45:51 +010081#define UNRESTRICTED_DOMID ((domid_t)-1)
82
David Vrabel73cc4bb2013-07-19 15:52:00 +010083struct user_evtchn {
84 struct rb_node node;
85 struct per_user_data *user;
86 unsigned port;
87 bool enabled;
88};
Ian Campbellf7116282009-02-06 19:21:19 -080089
David Vrabel86200152015-11-26 16:14:35 +000090static void evtchn_free_ring(evtchn_port_t *ring)
91{
92 kvfree(ring);
93}
94
95static unsigned int evtchn_ring_offset(struct per_user_data *u,
96 unsigned int idx)
97{
98 return idx & (u->ring_size - 1);
99}
100
101static 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
David Vrabel73cc4bb2013-07-19 15:52:00 +0100107static int add_evtchn(struct per_user_data *u, struct user_evtchn *evtchn)
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700108{
David Vrabel73cc4bb2013-07-19 15:52:00 +0100109 struct rb_node **new = &(u->evtchns.rb_node), *parent = NULL;
110
David Vrabel86200152015-11-26 16:14:35 +0000111 u->nr_evtchns++;
112
David Vrabel73cc4bb2013-07-19 15:52:00 +0100113 while (*new) {
114 struct user_evtchn *this;
115
Geliang Tang2f60b282016-12-20 22:02:20 +0800116 this = rb_entry(*new, struct user_evtchn, node);
David Vrabel73cc4bb2013-07-19 15:52:00 +0100117
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;
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700132}
133
David Vrabel73cc4bb2013-07-19 15:52:00 +0100134static void del_evtchn(struct per_user_data *u, struct user_evtchn *evtchn)
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700135{
David Vrabel86200152015-11-26 16:14:35 +0000136 u->nr_evtchns--;
David Vrabel73cc4bb2013-07-19 15:52:00 +0100137 rb_erase(&evtchn->node, &u->evtchns);
138 kfree(evtchn);
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700139}
140
David Vrabel73cc4bb2013-07-19 15:52:00 +0100141static struct user_evtchn *find_evtchn(struct per_user_data *u, unsigned port)
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700142{
David Vrabel73cc4bb2013-07-19 15:52:00 +0100143 struct rb_node *node = u->evtchns.rb_node;
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700144
David Vrabel73cc4bb2013-07-19 15:52:00 +0100145 while (node) {
146 struct user_evtchn *evtchn;
147
Geliang Tang2f60b282016-12-20 22:02:20 +0800148 evtchn = rb_entry(node, struct user_evtchn, node);
David Vrabel73cc4bb2013-07-19 15:52:00 +0100149
150 if (evtchn->port < port)
151 node = node->rb_left;
152 else if (evtchn->port > port)
153 node = node->rb_right;
154 else
155 return evtchn;
156 }
157 return NULL;
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700158}
159
Jeremy Fitzhardinge70697d542010-10-05 11:13:44 -0700160static irqreturn_t evtchn_interrupt(int irq, void *data)
Ian Campbellf7116282009-02-06 19:21:19 -0800161{
David Vrabel73cc4bb2013-07-19 15:52:00 +0100162 struct user_evtchn *evtchn = data;
163 struct per_user_data *u = evtchn->user;
Ian Campbellf7116282009-02-06 19:21:19 -0800164
David Vrabel73cc4bb2013-07-19 15:52:00 +0100165 WARN(!evtchn->enabled,
Jeremy Fitzhardinge0edce912009-09-18 16:55:29 -0700166 "Interrupt for port %d, but apparently not enabled; per-user %p\n",
David Vrabel73cc4bb2013-07-19 15:52:00 +0100167 evtchn->port, u);
Ian Campbellf7116282009-02-06 19:21:19 -0800168
169 disable_irq_nosync(irq);
David Vrabel73cc4bb2013-07-19 15:52:00 +0100170 evtchn->enabled = false;
171
172 spin_lock(&u->ring_prod_lock);
Ian Campbellf7116282009-02-06 19:21:19 -0800173
David Vrabel86200152015-11-26 16:14:35 +0000174 if ((u->ring_prod - u->ring_cons) < u->ring_size) {
175 *evtchn_ring_entry(u, u->ring_prod) = evtchn->port;
Ian Campbellf7116282009-02-06 19:21:19 -0800176 wmb(); /* Ensure ring contents visible */
177 if (u->ring_cons == u->ring_prod++) {
178 wake_up_interruptible(&u->evtchn_wait);
179 kill_fasync(&u->evtchn_async_queue,
180 SIGIO, POLL_IN);
181 }
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700182 } else
Ian Campbellf7116282009-02-06 19:21:19 -0800183 u->ring_overflow = 1;
Ian Campbellf7116282009-02-06 19:21:19 -0800184
David Vrabel73cc4bb2013-07-19 15:52:00 +0100185 spin_unlock(&u->ring_prod_lock);
Ian Campbellf7116282009-02-06 19:21:19 -0800186
187 return IRQ_HANDLED;
188}
189
190static ssize_t evtchn_read(struct file *file, char __user *buf,
191 size_t count, loff_t *ppos)
192{
193 int rc;
194 unsigned int c, p, bytes1 = 0, bytes2 = 0;
195 struct per_user_data *u = file->private_data;
196
197 /* Whole number of ports. */
198 count &= ~(sizeof(evtchn_port_t)-1);
199
200 if (count == 0)
201 return 0;
202
203 if (count > PAGE_SIZE)
204 count = PAGE_SIZE;
205
206 for (;;) {
207 mutex_lock(&u->ring_cons_mutex);
208
209 rc = -EFBIG;
210 if (u->ring_overflow)
211 goto unlock_out;
212
213 c = u->ring_cons;
214 p = u->ring_prod;
215 if (c != p)
216 break;
217
218 mutex_unlock(&u->ring_cons_mutex);
219
220 if (file->f_flags & O_NONBLOCK)
221 return -EAGAIN;
222
223 rc = wait_event_interruptible(u->evtchn_wait,
224 u->ring_cons != u->ring_prod);
225 if (rc)
226 return rc;
227 }
228
229 /* Byte lengths of two chunks. Chunk split (if any) is at ring wrap. */
David Vrabel86200152015-11-26 16:14:35 +0000230 if (((c ^ p) & u->ring_size) != 0) {
231 bytes1 = (u->ring_size - evtchn_ring_offset(u, c)) *
Ian Campbellf7116282009-02-06 19:21:19 -0800232 sizeof(evtchn_port_t);
David Vrabel86200152015-11-26 16:14:35 +0000233 bytes2 = evtchn_ring_offset(u, p) * sizeof(evtchn_port_t);
Ian Campbellf7116282009-02-06 19:21:19 -0800234 } else {
235 bytes1 = (p - c) * sizeof(evtchn_port_t);
236 bytes2 = 0;
237 }
238
239 /* Truncate chunks according to caller's maximum byte count. */
240 if (bytes1 > count) {
241 bytes1 = count;
242 bytes2 = 0;
243 } else if ((bytes1 + bytes2) > count) {
244 bytes2 = count - bytes1;
245 }
246
247 rc = -EFAULT;
248 rmb(); /* Ensure that we see the port before we copy it. */
David Vrabel86200152015-11-26 16:14:35 +0000249 if (copy_to_user(buf, evtchn_ring_entry(u, c), bytes1) ||
Ian Campbellf7116282009-02-06 19:21:19 -0800250 ((bytes2 != 0) &&
251 copy_to_user(&buf[bytes1], &u->ring[0], bytes2)))
252 goto unlock_out;
253
254 u->ring_cons += (bytes1 + bytes2) / sizeof(evtchn_port_t);
255 rc = bytes1 + bytes2;
256
257 unlock_out:
258 mutex_unlock(&u->ring_cons_mutex);
259 return rc;
260}
261
262static ssize_t evtchn_write(struct file *file, const char __user *buf,
263 size_t count, loff_t *ppos)
264{
265 int rc, i;
266 evtchn_port_t *kbuf = (evtchn_port_t *)__get_free_page(GFP_KERNEL);
267 struct per_user_data *u = file->private_data;
268
269 if (kbuf == NULL)
270 return -ENOMEM;
271
272 /* Whole number of ports. */
273 count &= ~(sizeof(evtchn_port_t)-1);
274
275 rc = 0;
276 if (count == 0)
277 goto out;
278
279 if (count > PAGE_SIZE)
280 count = PAGE_SIZE;
281
282 rc = -EFAULT;
283 if (copy_from_user(kbuf, buf, count) != 0)
284 goto out;
285
David Vrabel73cc4bb2013-07-19 15:52:00 +0100286 mutex_lock(&u->bind_mutex);
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700287
288 for (i = 0; i < (count/sizeof(evtchn_port_t)); i++) {
289 unsigned port = kbuf[i];
David Vrabel73cc4bb2013-07-19 15:52:00 +0100290 struct user_evtchn *evtchn;
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700291
David Vrabel73cc4bb2013-07-19 15:52:00 +0100292 evtchn = find_evtchn(u, port);
293 if (evtchn && !evtchn->enabled) {
294 evtchn->enabled = true;
Jeremy Fitzhardingee3cc0672009-09-18 16:31:22 -0700295 enable_irq(irq_from_evtchn(port));
296 }
297 }
298
David Vrabel73cc4bb2013-07-19 15:52:00 +0100299 mutex_unlock(&u->bind_mutex);
Ian Campbellf7116282009-02-06 19:21:19 -0800300
301 rc = count;
302
303 out:
304 free_page((unsigned long)kbuf);
305 return rc;
306}
307
David Vrabel86200152015-11-26 16:14:35 +0000308static int evtchn_resize_ring(struct per_user_data *u)
309{
310 unsigned int new_size;
311 evtchn_port_t *new_ring, *old_ring;
David Vrabel86200152015-11-26 16:14:35 +0000312
313 /*
314 * Ensure the ring is large enough to capture all possible
315 * events. i.e., one free slot for each bound event.
316 */
317 if (u->nr_evtchns <= u->ring_size)
318 return 0;
319
320 if (u->ring_size == 0)
321 new_size = 64;
322 else
323 new_size = 2 * u->ring_size;
324
Michal Hocko752ade62017-05-08 15:57:27 -0700325 new_ring = kvmalloc(new_size * sizeof(*new_ring), GFP_KERNEL);
David Vrabel86200152015-11-26 16:14:35 +0000326 if (!new_ring)
327 return -ENOMEM;
328
329 old_ring = u->ring;
330
331 /*
332 * Access to the ring contents is serialized by either the
333 * prod /or/ cons lock so take both when resizing.
334 */
335 mutex_lock(&u->ring_cons_mutex);
336 spin_lock_irq(&u->ring_prod_lock);
337
338 /*
339 * Copy the old ring contents to the new ring.
340 *
Jan Beulich27e0e632016-05-04 07:02:36 -0600341 * To take care of wrapping, a full ring, and the new index
342 * pointing into the second half, simply copy the old contents
343 * twice.
David Vrabel86200152015-11-26 16:14:35 +0000344 *
345 * +---------+ +------------------+
Jan Beulich27e0e632016-05-04 07:02:36 -0600346 * |34567 12| -> |34567 1234567 12|
347 * +-----p-c-+ +-------c------p---+
David Vrabel86200152015-11-26 16:14:35 +0000348 */
Jan Beulich27e0e632016-05-04 07:02:36 -0600349 memcpy(new_ring, old_ring, u->ring_size * sizeof(*u->ring));
350 memcpy(new_ring + u->ring_size, old_ring,
351 u->ring_size * sizeof(*u->ring));
David Vrabel86200152015-11-26 16:14:35 +0000352
353 u->ring = new_ring;
354 u->ring_size = new_size;
355
356 spin_unlock_irq(&u->ring_prod_lock);
357 mutex_unlock(&u->ring_cons_mutex);
358
359 evtchn_free_ring(old_ring);
360
361 return 0;
362}
363
Ian Campbellf7116282009-02-06 19:21:19 -0800364static int evtchn_bind_to_user(struct per_user_data *u, int port)
365{
David Vrabel73cc4bb2013-07-19 15:52:00 +0100366 struct user_evtchn *evtchn;
367 struct evtchn_close close;
Ian Campbellf7116282009-02-06 19:21:19 -0800368 int rc = 0;
369
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -0800370 /*
371 * Ports are never reused, so every caller should pass in a
372 * unique port.
373 *
374 * (Locking not necessary because we haven't registered the
375 * interrupt handler yet, and our caller has already
376 * serialized bind operations.)
377 */
David Vrabel73cc4bb2013-07-19 15:52:00 +0100378
379 evtchn = kzalloc(sizeof(*evtchn), GFP_KERNEL);
380 if (!evtchn)
381 return -ENOMEM;
382
383 evtchn->user = u;
384 evtchn->port = port;
385 evtchn->enabled = true; /* start enabled */
386
387 rc = add_evtchn(u, evtchn);
388 if (rc < 0)
389 goto err;
Ian Campbellf7116282009-02-06 19:21:19 -0800390
David Vrabel86200152015-11-26 16:14:35 +0000391 rc = evtchn_resize_ring(u);
392 if (rc < 0)
393 goto err;
394
Michael Opdenackeraf09d1a2013-09-09 05:09:47 +0200395 rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, 0,
David Vrabel73cc4bb2013-07-19 15:52:00 +0100396 u->name, evtchn);
397 if (rc < 0)
398 goto err;
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -0800399
David Vrabel73cc4bb2013-07-19 15:52:00 +0100400 rc = evtchn_make_refcounted(port);
401 return rc;
402
403err:
404 /* bind failed, should close the port now */
405 close.port = port;
406 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
407 BUG();
408 del_evtchn(u, evtchn);
Ian Campbellf7116282009-02-06 19:21:19 -0800409 return rc;
410}
411
David Vrabel73cc4bb2013-07-19 15:52:00 +0100412static void evtchn_unbind_from_user(struct per_user_data *u,
413 struct user_evtchn *evtchn)
Ian Campbellf7116282009-02-06 19:21:19 -0800414{
David Vrabel73cc4bb2013-07-19 15:52:00 +0100415 int irq = irq_from_evtchn(evtchn->port);
Ian Campbellf7116282009-02-06 19:21:19 -0800416
Wei Liue7e44e42013-02-18 14:57:58 +0000417 BUG_ON(irq < 0);
418
David Vrabel73cc4bb2013-07-19 15:52:00 +0100419 unbind_from_irqhandler(irq, evtchn);
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -0800420
David Vrabel73cc4bb2013-07-19 15:52:00 +0100421 del_evtchn(u, evtchn);
Ian Campbellf7116282009-02-06 19:21:19 -0800422}
423
424static long evtchn_ioctl(struct file *file,
425 unsigned int cmd, unsigned long arg)
426{
427 int rc;
428 struct per_user_data *u = file->private_data;
429 void __user *uarg = (void __user *) arg;
430
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -0800431 /* Prevent bind from racing with unbind */
432 mutex_lock(&u->bind_mutex);
433
Ian Campbellf7116282009-02-06 19:21:19 -0800434 switch (cmd) {
435 case IOCTL_EVTCHN_BIND_VIRQ: {
436 struct ioctl_evtchn_bind_virq bind;
437 struct evtchn_bind_virq bind_virq;
438
David Vrabelfbc872c2016-07-11 15:45:51 +0100439 rc = -EACCES;
440 if (u->restrict_domid != UNRESTRICTED_DOMID)
441 break;
442
Ian Campbellf7116282009-02-06 19:21:19 -0800443 rc = -EFAULT;
444 if (copy_from_user(&bind, uarg, sizeof(bind)))
445 break;
446
447 bind_virq.virq = bind.virq;
Vitaly Kuznetsovcbbb4682016-06-30 17:56:42 +0200448 bind_virq.vcpu = xen_vcpu_nr(0);
Ian Campbellf7116282009-02-06 19:21:19 -0800449 rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
450 &bind_virq);
451 if (rc != 0)
452 break;
453
454 rc = evtchn_bind_to_user(u, bind_virq.port);
455 if (rc == 0)
456 rc = bind_virq.port;
457 break;
458 }
459
460 case IOCTL_EVTCHN_BIND_INTERDOMAIN: {
461 struct ioctl_evtchn_bind_interdomain bind;
462 struct evtchn_bind_interdomain bind_interdomain;
463
464 rc = -EFAULT;
465 if (copy_from_user(&bind, uarg, sizeof(bind)))
466 break;
467
David Vrabelfbc872c2016-07-11 15:45:51 +0100468 rc = -EACCES;
469 if (u->restrict_domid != UNRESTRICTED_DOMID &&
470 u->restrict_domid != bind.remote_domain)
471 break;
472
Ian Campbellf7116282009-02-06 19:21:19 -0800473 bind_interdomain.remote_dom = bind.remote_domain;
474 bind_interdomain.remote_port = bind.remote_port;
475 rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
476 &bind_interdomain);
477 if (rc != 0)
478 break;
479
480 rc = evtchn_bind_to_user(u, bind_interdomain.local_port);
481 if (rc == 0)
482 rc = bind_interdomain.local_port;
483 break;
484 }
485
486 case IOCTL_EVTCHN_BIND_UNBOUND_PORT: {
487 struct ioctl_evtchn_bind_unbound_port bind;
488 struct evtchn_alloc_unbound alloc_unbound;
489
David Vrabelfbc872c2016-07-11 15:45:51 +0100490 rc = -EACCES;
491 if (u->restrict_domid != UNRESTRICTED_DOMID)
492 break;
493
Ian Campbellf7116282009-02-06 19:21:19 -0800494 rc = -EFAULT;
495 if (copy_from_user(&bind, uarg, sizeof(bind)))
496 break;
497
498 alloc_unbound.dom = DOMID_SELF;
499 alloc_unbound.remote_dom = bind.remote_domain;
500 rc = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound,
501 &alloc_unbound);
502 if (rc != 0)
503 break;
504
505 rc = evtchn_bind_to_user(u, alloc_unbound.port);
506 if (rc == 0)
507 rc = alloc_unbound.port;
508 break;
509 }
510
511 case IOCTL_EVTCHN_UNBIND: {
512 struct ioctl_evtchn_unbind unbind;
David Vrabel73cc4bb2013-07-19 15:52:00 +0100513 struct user_evtchn *evtchn;
Ian Campbellf7116282009-02-06 19:21:19 -0800514
515 rc = -EFAULT;
516 if (copy_from_user(&unbind, uarg, sizeof(unbind)))
517 break;
518
519 rc = -EINVAL;
David Vrabel0dc00642013-09-23 21:03:38 +0100520 if (unbind.port >= xen_evtchn_nr_channels())
Ian Campbellf7116282009-02-06 19:21:19 -0800521 break;
522
Ian Campbellf7116282009-02-06 19:21:19 -0800523 rc = -ENOTCONN;
David Vrabel73cc4bb2013-07-19 15:52:00 +0100524 evtchn = find_evtchn(u, unbind.port);
525 if (!evtchn)
Ian Campbellf7116282009-02-06 19:21:19 -0800526 break;
Ian Campbellf7116282009-02-06 19:21:19 -0800527
Jeremy Fitzhardinge3f5e5542010-05-28 15:28:27 -0700528 disable_irq(irq_from_evtchn(unbind.port));
David Vrabel73cc4bb2013-07-19 15:52:00 +0100529 evtchn_unbind_from_user(u, evtchn);
Ian Campbellf7116282009-02-06 19:21:19 -0800530 rc = 0;
531 break;
532 }
533
534 case IOCTL_EVTCHN_NOTIFY: {
535 struct ioctl_evtchn_notify notify;
David Vrabel73cc4bb2013-07-19 15:52:00 +0100536 struct user_evtchn *evtchn;
Ian Campbellf7116282009-02-06 19:21:19 -0800537
538 rc = -EFAULT;
539 if (copy_from_user(&notify, uarg, sizeof(notify)))
540 break;
541
David Vrabel73cc4bb2013-07-19 15:52:00 +0100542 rc = -ENOTCONN;
543 evtchn = find_evtchn(u, notify.port);
544 if (evtchn) {
Ian Campbellf7116282009-02-06 19:21:19 -0800545 notify_remote_via_evtchn(notify.port);
546 rc = 0;
547 }
548 break;
549 }
550
551 case IOCTL_EVTCHN_RESET: {
552 /* Initialise the ring to empty. Clear errors. */
553 mutex_lock(&u->ring_cons_mutex);
David Vrabel73cc4bb2013-07-19 15:52:00 +0100554 spin_lock_irq(&u->ring_prod_lock);
Ian Campbellf7116282009-02-06 19:21:19 -0800555 u->ring_cons = u->ring_prod = u->ring_overflow = 0;
David Vrabel73cc4bb2013-07-19 15:52:00 +0100556 spin_unlock_irq(&u->ring_prod_lock);
Ian Campbellf7116282009-02-06 19:21:19 -0800557 mutex_unlock(&u->ring_cons_mutex);
558 rc = 0;
559 break;
560 }
561
David Vrabelfbc872c2016-07-11 15:45:51 +0100562 case IOCTL_EVTCHN_RESTRICT_DOMID: {
563 struct ioctl_evtchn_restrict_domid ierd;
564
565 rc = -EACCES;
566 if (u->restrict_domid != UNRESTRICTED_DOMID)
567 break;
568
569 rc = -EFAULT;
570 if (copy_from_user(&ierd, uarg, sizeof(ierd)))
571 break;
572
573 rc = -EINVAL;
574 if (ierd.domid == 0 || ierd.domid >= DOMID_FIRST_RESERVED)
575 break;
576
577 u->restrict_domid = ierd.domid;
578 rc = 0;
579
580 break;
581 }
582
Ian Campbellf7116282009-02-06 19:21:19 -0800583 default:
584 rc = -ENOSYS;
585 break;
586 }
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -0800587 mutex_unlock(&u->bind_mutex);
Ian Campbellf7116282009-02-06 19:21:19 -0800588
589 return rc;
590}
591
592static unsigned int evtchn_poll(struct file *file, poll_table *wait)
593{
594 unsigned int mask = POLLOUT | POLLWRNORM;
595 struct per_user_data *u = file->private_data;
596
597 poll_wait(file, &u->evtchn_wait, wait);
598 if (u->ring_cons != u->ring_prod)
599 mask |= POLLIN | POLLRDNORM;
600 if (u->ring_overflow)
601 mask = POLLERR;
602 return mask;
603}
604
605static int evtchn_fasync(int fd, struct file *filp, int on)
606{
607 struct per_user_data *u = filp->private_data;
608 return fasync_helper(fd, filp, on, &u->evtchn_async_queue);
609}
610
611static int evtchn_open(struct inode *inode, struct file *filp)
612{
613 struct per_user_data *u;
614
615 u = kzalloc(sizeof(*u), GFP_KERNEL);
616 if (u == NULL)
617 return -ENOMEM;
618
619 u->name = kasprintf(GFP_KERNEL, "evtchn:%s", current->comm);
620 if (u->name == NULL) {
621 kfree(u);
622 return -ENOMEM;
623 }
624
625 init_waitqueue_head(&u->evtchn_wait);
626
Jeremy Fitzhardinge0a4666b2009-02-12 13:03:24 -0800627 mutex_init(&u->bind_mutex);
Ian Campbellf7116282009-02-06 19:21:19 -0800628 mutex_init(&u->ring_cons_mutex);
David Vrabel73cc4bb2013-07-19 15:52:00 +0100629 spin_lock_init(&u->ring_prod_lock);
Ian Campbellf7116282009-02-06 19:21:19 -0800630
David Vrabelfbc872c2016-07-11 15:45:51 +0100631 u->restrict_domid = UNRESTRICTED_DOMID;
632
Ian Campbellf7116282009-02-06 19:21:19 -0800633 filp->private_data = u;
634
Justin P. Mattock6eab04a2011-04-08 19:49:08 -0700635 return nonseekable_open(inode, filp);
Ian Campbellf7116282009-02-06 19:21:19 -0800636}
637
638static int evtchn_release(struct inode *inode, struct file *filp)
639{
Ian Campbellf7116282009-02-06 19:21:19 -0800640 struct per_user_data *u = filp->private_data;
David Vrabel73cc4bb2013-07-19 15:52:00 +0100641 struct rb_node *node;
Ian Campbellf7116282009-02-06 19:21:19 -0800642
David Vrabel73cc4bb2013-07-19 15:52:00 +0100643 while ((node = u->evtchns.rb_node)) {
644 struct user_evtchn *evtchn;
Ian Campbellf7116282009-02-06 19:21:19 -0800645
David Vrabel73cc4bb2013-07-19 15:52:00 +0100646 evtchn = rb_entry(node, struct user_evtchn, node);
647 disable_irq(irq_from_evtchn(evtchn->port));
648 evtchn_unbind_from_user(u, evtchn);
Jeremy Fitzhardinge3f5e5542010-05-28 15:28:27 -0700649 }
650
David Vrabel86200152015-11-26 16:14:35 +0000651 evtchn_free_ring(u->ring);
Ian Campbellf7116282009-02-06 19:21:19 -0800652 kfree(u->name);
653 kfree(u);
654
655 return 0;
656}
657
658static const struct file_operations evtchn_fops = {
659 .owner = THIS_MODULE,
660 .read = evtchn_read,
661 .write = evtchn_write,
662 .unlocked_ioctl = evtchn_ioctl,
663 .poll = evtchn_poll,
664 .fasync = evtchn_fasync,
665 .open = evtchn_open,
666 .release = evtchn_release,
Jeremy Fitzhardingebc7fc5e2010-11-18 22:32:17 -0800667 .llseek = no_llseek,
Ian Campbellf7116282009-02-06 19:21:19 -0800668};
669
670static struct miscdevice evtchn_miscdev = {
671 .minor = MISC_DYNAMIC_MINOR,
Bastian Blank376d9082010-05-28 15:43:49 -0700672 .name = "xen/evtchn",
Ian Campbellf7116282009-02-06 19:21:19 -0800673 .fops = &evtchn_fops,
674};
675static int __init evtchn_init(void)
676{
677 int err;
678
679 if (!xen_domain())
680 return -ENODEV;
681
Wei Liu18283ea2013-02-18 14:57:59 +0000682 /* Create '/dev/xen/evtchn'. */
Ian Campbellf7116282009-02-06 19:21:19 -0800683 err = misc_register(&evtchn_miscdev);
684 if (err != 0) {
Joe Perches283c0972013-06-28 03:21:41 -0700685 pr_err("Could not register /dev/xen/evtchn\n");
Ian Campbellf7116282009-02-06 19:21:19 -0800686 return err;
687 }
688
Joe Perches283c0972013-06-28 03:21:41 -0700689 pr_info("Event-channel device installed\n");
Ian Campbellf7116282009-02-06 19:21:19 -0800690
691 return 0;
692}
693
694static void __exit evtchn_cleanup(void)
695{
Ian Campbellf7116282009-02-06 19:21:19 -0800696 misc_deregister(&evtchn_miscdev);
697}
698
699module_init(evtchn_init);
700module_exit(evtchn_cleanup);
701
702MODULE_LICENSE("GPL");