Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 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 | |
Joe Perches | 283c097 | 2013-06-28 03:21:41 -0700 | [diff] [blame] | 34 | #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt |
| 35 | |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 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> |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 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> |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 50 | #include <linux/mutex.h> |
| 51 | #include <linux/cpu.h> |
David Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 52 | #include <linux/mm.h> |
| 53 | #include <linux/vmalloc.h> |
Jeremy Fitzhardinge | 1ccbf53 | 2009-10-06 15:11:14 -0700 | [diff] [blame] | 54 | |
| 55 | #include <xen/xen.h> |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 56 | #include <xen/events.h> |
| 57 | #include <xen/evtchn.h> |
Vitaly Kuznetsov | cbbb468 | 2016-06-30 17:56:42 +0200 | [diff] [blame] | 58 | #include <xen/xen-ops.h> |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 59 | #include <asm/xen/hypervisor.h> |
| 60 | |
| 61 | struct per_user_data { |
Jeremy Fitzhardinge | 0a4666b | 2009-02-12 13:03:24 -0800 | [diff] [blame] | 62 | struct mutex bind_mutex; /* serialize bind/unbind operations */ |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 63 | struct rb_root evtchns; |
David Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 64 | unsigned int nr_evtchns; |
Jeremy Fitzhardinge | 0a4666b | 2009-02-12 13:03:24 -0800 | [diff] [blame] | 65 | |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 66 | /* Notification ring, accessed via /dev/xen/evtchn. */ |
David Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 67 | unsigned int ring_size; |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 68 | evtchn_port_t *ring; |
| 69 | unsigned int ring_cons, ring_prod, ring_overflow; |
| 70 | struct mutex ring_cons_mutex; /* protect against concurrent readers */ |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 71 | spinlock_t ring_prod_lock; /* product against concurrent interrupts */ |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 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; |
David Vrabel | fbc872c | 2016-07-11 15:45:51 +0100 | [diff] [blame] | 77 | |
| 78 | domid_t restrict_domid; |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 79 | }; |
| 80 | |
David Vrabel | fbc872c | 2016-07-11 15:45:51 +0100 | [diff] [blame] | 81 | #define UNRESTRICTED_DOMID ((domid_t)-1) |
| 82 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 83 | struct user_evtchn { |
| 84 | struct rb_node node; |
| 85 | struct per_user_data *user; |
| 86 | unsigned port; |
| 87 | bool enabled; |
| 88 | }; |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 89 | |
David Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 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 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 107 | static int add_evtchn(struct per_user_data *u, struct user_evtchn *evtchn) |
Jeremy Fitzhardinge | e3cc067 | 2009-09-18 16:31:22 -0700 | [diff] [blame] | 108 | { |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 109 | struct rb_node **new = &(u->evtchns.rb_node), *parent = NULL; |
| 110 | |
David Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 111 | u->nr_evtchns++; |
| 112 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 113 | while (*new) { |
| 114 | struct user_evtchn *this; |
| 115 | |
Geliang Tang | 2f60b28 | 2016-12-20 22:02:20 +0800 | [diff] [blame] | 116 | this = rb_entry(*new, struct user_evtchn, node); |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 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; |
Jeremy Fitzhardinge | e3cc067 | 2009-09-18 16:31:22 -0700 | [diff] [blame] | 132 | } |
| 133 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 134 | static void del_evtchn(struct per_user_data *u, struct user_evtchn *evtchn) |
Jeremy Fitzhardinge | e3cc067 | 2009-09-18 16:31:22 -0700 | [diff] [blame] | 135 | { |
David Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 136 | u->nr_evtchns--; |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 137 | rb_erase(&evtchn->node, &u->evtchns); |
| 138 | kfree(evtchn); |
Jeremy Fitzhardinge | e3cc067 | 2009-09-18 16:31:22 -0700 | [diff] [blame] | 139 | } |
| 140 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 141 | static struct user_evtchn *find_evtchn(struct per_user_data *u, unsigned port) |
Jeremy Fitzhardinge | e3cc067 | 2009-09-18 16:31:22 -0700 | [diff] [blame] | 142 | { |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 143 | struct rb_node *node = u->evtchns.rb_node; |
Jeremy Fitzhardinge | e3cc067 | 2009-09-18 16:31:22 -0700 | [diff] [blame] | 144 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 145 | while (node) { |
| 146 | struct user_evtchn *evtchn; |
| 147 | |
Geliang Tang | 2f60b28 | 2016-12-20 22:02:20 +0800 | [diff] [blame] | 148 | evtchn = rb_entry(node, struct user_evtchn, node); |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 149 | |
| 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 Fitzhardinge | e3cc067 | 2009-09-18 16:31:22 -0700 | [diff] [blame] | 158 | } |
| 159 | |
Jeremy Fitzhardinge | 70697d54 | 2010-10-05 11:13:44 -0700 | [diff] [blame] | 160 | static irqreturn_t evtchn_interrupt(int irq, void *data) |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 161 | { |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 162 | struct user_evtchn *evtchn = data; |
| 163 | struct per_user_data *u = evtchn->user; |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 164 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 165 | WARN(!evtchn->enabled, |
Jeremy Fitzhardinge | 0edce91 | 2009-09-18 16:55:29 -0700 | [diff] [blame] | 166 | "Interrupt for port %d, but apparently not enabled; per-user %p\n", |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 167 | evtchn->port, u); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 168 | |
| 169 | disable_irq_nosync(irq); |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 170 | evtchn->enabled = false; |
| 171 | |
| 172 | spin_lock(&u->ring_prod_lock); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 173 | |
David Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 174 | if ((u->ring_prod - u->ring_cons) < u->ring_size) { |
| 175 | *evtchn_ring_entry(u, u->ring_prod) = evtchn->port; |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 176 | 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 Fitzhardinge | e3cc067 | 2009-09-18 16:31:22 -0700 | [diff] [blame] | 182 | } else |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 183 | u->ring_overflow = 1; |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 184 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 185 | spin_unlock(&u->ring_prod_lock); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 186 | |
| 187 | return IRQ_HANDLED; |
| 188 | } |
| 189 | |
| 190 | static 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 Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 230 | if (((c ^ p) & u->ring_size) != 0) { |
| 231 | bytes1 = (u->ring_size - evtchn_ring_offset(u, c)) * |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 232 | sizeof(evtchn_port_t); |
David Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 233 | bytes2 = evtchn_ring_offset(u, p) * sizeof(evtchn_port_t); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 234 | } 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 Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 249 | if (copy_to_user(buf, evtchn_ring_entry(u, c), bytes1) || |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 250 | ((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 | |
| 262 | static 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 Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 286 | mutex_lock(&u->bind_mutex); |
Jeremy Fitzhardinge | e3cc067 | 2009-09-18 16:31:22 -0700 | [diff] [blame] | 287 | |
| 288 | for (i = 0; i < (count/sizeof(evtchn_port_t)); i++) { |
| 289 | unsigned port = kbuf[i]; |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 290 | struct user_evtchn *evtchn; |
Jeremy Fitzhardinge | e3cc067 | 2009-09-18 16:31:22 -0700 | [diff] [blame] | 291 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 292 | evtchn = find_evtchn(u, port); |
| 293 | if (evtchn && !evtchn->enabled) { |
| 294 | evtchn->enabled = true; |
Jeremy Fitzhardinge | e3cc067 | 2009-09-18 16:31:22 -0700 | [diff] [blame] | 295 | enable_irq(irq_from_evtchn(port)); |
| 296 | } |
| 297 | } |
| 298 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 299 | mutex_unlock(&u->bind_mutex); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 300 | |
| 301 | rc = count; |
| 302 | |
| 303 | out: |
| 304 | free_page((unsigned long)kbuf); |
| 305 | return rc; |
| 306 | } |
| 307 | |
David Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 308 | static int evtchn_resize_ring(struct per_user_data *u) |
| 309 | { |
| 310 | unsigned int new_size; |
| 311 | evtchn_port_t *new_ring, *old_ring; |
David Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 312 | |
| 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 Hocko | 752ade6 | 2017-05-08 15:57:27 -0700 | [diff] [blame] | 325 | new_ring = kvmalloc(new_size * sizeof(*new_ring), GFP_KERNEL); |
David Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 326 | 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 Beulich | 27e0e63 | 2016-05-04 07:02:36 -0600 | [diff] [blame] | 341 | * 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 Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 344 | * |
| 345 | * +---------+ +------------------+ |
Jan Beulich | 27e0e63 | 2016-05-04 07:02:36 -0600 | [diff] [blame] | 346 | * |34567 12| -> |34567 1234567 12| |
| 347 | * +-----p-c-+ +-------c------p---+ |
David Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 348 | */ |
Jan Beulich | 27e0e63 | 2016-05-04 07:02:36 -0600 | [diff] [blame] | 349 | 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 Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 352 | |
| 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 Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 364 | static int evtchn_bind_to_user(struct per_user_data *u, int port) |
| 365 | { |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 366 | struct user_evtchn *evtchn; |
| 367 | struct evtchn_close close; |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 368 | int rc = 0; |
| 369 | |
Jeremy Fitzhardinge | 0a4666b | 2009-02-12 13:03:24 -0800 | [diff] [blame] | 370 | /* |
| 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 Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 378 | |
| 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 Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 390 | |
David Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 391 | rc = evtchn_resize_ring(u); |
| 392 | if (rc < 0) |
| 393 | goto err; |
| 394 | |
Michael Opdenacker | af09d1a | 2013-09-09 05:09:47 +0200 | [diff] [blame] | 395 | rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, 0, |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 396 | u->name, evtchn); |
| 397 | if (rc < 0) |
| 398 | goto err; |
Jeremy Fitzhardinge | 0a4666b | 2009-02-12 13:03:24 -0800 | [diff] [blame] | 399 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 400 | rc = evtchn_make_refcounted(port); |
| 401 | return rc; |
| 402 | |
| 403 | err: |
| 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 Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 409 | return rc; |
| 410 | } |
| 411 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 412 | static void evtchn_unbind_from_user(struct per_user_data *u, |
| 413 | struct user_evtchn *evtchn) |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 414 | { |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 415 | int irq = irq_from_evtchn(evtchn->port); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 416 | |
Wei Liu | e7e44e4 | 2013-02-18 14:57:58 +0000 | [diff] [blame] | 417 | BUG_ON(irq < 0); |
| 418 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 419 | unbind_from_irqhandler(irq, evtchn); |
Jeremy Fitzhardinge | 0a4666b | 2009-02-12 13:03:24 -0800 | [diff] [blame] | 420 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 421 | del_evtchn(u, evtchn); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 422 | } |
| 423 | |
| 424 | static 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 Fitzhardinge | 0a4666b | 2009-02-12 13:03:24 -0800 | [diff] [blame] | 431 | /* Prevent bind from racing with unbind */ |
| 432 | mutex_lock(&u->bind_mutex); |
| 433 | |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 434 | switch (cmd) { |
| 435 | case IOCTL_EVTCHN_BIND_VIRQ: { |
| 436 | struct ioctl_evtchn_bind_virq bind; |
| 437 | struct evtchn_bind_virq bind_virq; |
| 438 | |
David Vrabel | fbc872c | 2016-07-11 15:45:51 +0100 | [diff] [blame] | 439 | rc = -EACCES; |
| 440 | if (u->restrict_domid != UNRESTRICTED_DOMID) |
| 441 | break; |
| 442 | |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 443 | rc = -EFAULT; |
| 444 | if (copy_from_user(&bind, uarg, sizeof(bind))) |
| 445 | break; |
| 446 | |
| 447 | bind_virq.virq = bind.virq; |
Vitaly Kuznetsov | cbbb468 | 2016-06-30 17:56:42 +0200 | [diff] [blame] | 448 | bind_virq.vcpu = xen_vcpu_nr(0); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 449 | 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 Vrabel | fbc872c | 2016-07-11 15:45:51 +0100 | [diff] [blame] | 468 | rc = -EACCES; |
| 469 | if (u->restrict_domid != UNRESTRICTED_DOMID && |
| 470 | u->restrict_domid != bind.remote_domain) |
| 471 | break; |
| 472 | |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 473 | 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 Vrabel | fbc872c | 2016-07-11 15:45:51 +0100 | [diff] [blame] | 490 | rc = -EACCES; |
| 491 | if (u->restrict_domid != UNRESTRICTED_DOMID) |
| 492 | break; |
| 493 | |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 494 | 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 Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 513 | struct user_evtchn *evtchn; |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 514 | |
| 515 | rc = -EFAULT; |
| 516 | if (copy_from_user(&unbind, uarg, sizeof(unbind))) |
| 517 | break; |
| 518 | |
| 519 | rc = -EINVAL; |
David Vrabel | 0dc0064 | 2013-09-23 21:03:38 +0100 | [diff] [blame] | 520 | if (unbind.port >= xen_evtchn_nr_channels()) |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 521 | break; |
| 522 | |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 523 | rc = -ENOTCONN; |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 524 | evtchn = find_evtchn(u, unbind.port); |
| 525 | if (!evtchn) |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 526 | break; |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 527 | |
Jeremy Fitzhardinge | 3f5e554 | 2010-05-28 15:28:27 -0700 | [diff] [blame] | 528 | disable_irq(irq_from_evtchn(unbind.port)); |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 529 | evtchn_unbind_from_user(u, evtchn); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 530 | rc = 0; |
| 531 | break; |
| 532 | } |
| 533 | |
| 534 | case IOCTL_EVTCHN_NOTIFY: { |
| 535 | struct ioctl_evtchn_notify notify; |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 536 | struct user_evtchn *evtchn; |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 537 | |
| 538 | rc = -EFAULT; |
| 539 | if (copy_from_user(¬ify, uarg, sizeof(notify))) |
| 540 | break; |
| 541 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 542 | rc = -ENOTCONN; |
| 543 | evtchn = find_evtchn(u, notify.port); |
| 544 | if (evtchn) { |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 545 | 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 Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 554 | spin_lock_irq(&u->ring_prod_lock); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 555 | u->ring_cons = u->ring_prod = u->ring_overflow = 0; |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 556 | spin_unlock_irq(&u->ring_prod_lock); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 557 | mutex_unlock(&u->ring_cons_mutex); |
| 558 | rc = 0; |
| 559 | break; |
| 560 | } |
| 561 | |
David Vrabel | fbc872c | 2016-07-11 15:45:51 +0100 | [diff] [blame] | 562 | 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 Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 583 | default: |
| 584 | rc = -ENOSYS; |
| 585 | break; |
| 586 | } |
Jeremy Fitzhardinge | 0a4666b | 2009-02-12 13:03:24 -0800 | [diff] [blame] | 587 | mutex_unlock(&u->bind_mutex); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 588 | |
| 589 | return rc; |
| 590 | } |
| 591 | |
| 592 | static 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 | |
| 605 | static 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 | |
| 611 | static 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 Fitzhardinge | 0a4666b | 2009-02-12 13:03:24 -0800 | [diff] [blame] | 627 | mutex_init(&u->bind_mutex); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 628 | mutex_init(&u->ring_cons_mutex); |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 629 | spin_lock_init(&u->ring_prod_lock); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 630 | |
David Vrabel | fbc872c | 2016-07-11 15:45:51 +0100 | [diff] [blame] | 631 | u->restrict_domid = UNRESTRICTED_DOMID; |
| 632 | |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 633 | filp->private_data = u; |
| 634 | |
Justin P. Mattock | 6eab04a | 2011-04-08 19:49:08 -0700 | [diff] [blame] | 635 | return nonseekable_open(inode, filp); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 636 | } |
| 637 | |
| 638 | static int evtchn_release(struct inode *inode, struct file *filp) |
| 639 | { |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 640 | struct per_user_data *u = filp->private_data; |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 641 | struct rb_node *node; |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 642 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 643 | while ((node = u->evtchns.rb_node)) { |
| 644 | struct user_evtchn *evtchn; |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 645 | |
David Vrabel | 73cc4bb | 2013-07-19 15:52:00 +0100 | [diff] [blame] | 646 | evtchn = rb_entry(node, struct user_evtchn, node); |
| 647 | disable_irq(irq_from_evtchn(evtchn->port)); |
| 648 | evtchn_unbind_from_user(u, evtchn); |
Jeremy Fitzhardinge | 3f5e554 | 2010-05-28 15:28:27 -0700 | [diff] [blame] | 649 | } |
| 650 | |
David Vrabel | 8620015 | 2015-11-26 16:14:35 +0000 | [diff] [blame] | 651 | evtchn_free_ring(u->ring); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 652 | kfree(u->name); |
| 653 | kfree(u); |
| 654 | |
| 655 | return 0; |
| 656 | } |
| 657 | |
| 658 | static 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 Fitzhardinge | bc7fc5e | 2010-11-18 22:32:17 -0800 | [diff] [blame] | 667 | .llseek = no_llseek, |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 668 | }; |
| 669 | |
| 670 | static struct miscdevice evtchn_miscdev = { |
| 671 | .minor = MISC_DYNAMIC_MINOR, |
Bastian Blank | 376d908 | 2010-05-28 15:43:49 -0700 | [diff] [blame] | 672 | .name = "xen/evtchn", |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 673 | .fops = &evtchn_fops, |
| 674 | }; |
| 675 | static int __init evtchn_init(void) |
| 676 | { |
| 677 | int err; |
| 678 | |
| 679 | if (!xen_domain()) |
| 680 | return -ENODEV; |
| 681 | |
Wei Liu | 18283ea | 2013-02-18 14:57:59 +0000 | [diff] [blame] | 682 | /* Create '/dev/xen/evtchn'. */ |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 683 | err = misc_register(&evtchn_miscdev); |
| 684 | if (err != 0) { |
Joe Perches | 283c097 | 2013-06-28 03:21:41 -0700 | [diff] [blame] | 685 | pr_err("Could not register /dev/xen/evtchn\n"); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 686 | return err; |
| 687 | } |
| 688 | |
Joe Perches | 283c097 | 2013-06-28 03:21:41 -0700 | [diff] [blame] | 689 | pr_info("Event-channel device installed\n"); |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 690 | |
| 691 | return 0; |
| 692 | } |
| 693 | |
| 694 | static void __exit evtchn_cleanup(void) |
| 695 | { |
Ian Campbell | f711628 | 2009-02-06 19:21:19 -0800 | [diff] [blame] | 696 | misc_deregister(&evtchn_miscdev); |
| 697 | } |
| 698 | |
| 699 | module_init(evtchn_init); |
| 700 | module_exit(evtchn_cleanup); |
| 701 | |
| 702 | MODULE_LICENSE("GPL"); |