| | 1 | /* |
| | 2 | * drivers/uio/uio.c |
| | 3 | * |
| | 4 | * Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de> |
| | 5 | * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de> |
| | 6 | * Copyright(C) 2006, Hans J. Koch <hjk@hansjkoch.de> |
| | 7 | * Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com> |
| | 8 | * |
| | 9 | * Userspace IO |
| | 10 | * |
| | 11 | * Base Functions |
| | 12 | * |
| | 13 | * Licensed under the GPLv2 only. |
| | 14 | */ |
| | 15 | |
| | 16 | #include <linux/module.h> |
| | 17 | #include <linux/init.h> |
| | 18 | #include <linux/poll.h> |
| | 19 | #include <linux/device.h> |
| | 20 | #include <linux/slab.h> |
| | 21 | #include <linux/mm.h> |
| | 22 | #include <linux/idr.h> |
| | 23 | #include <linux/sched/signal.h> |
| | 24 | #include <linux/string.h> |
| | 25 | #include <linux/kobject.h> |
| | 26 | #include <linux/cdev.h> |
| | 27 | #include <linux/uio_driver.h> |
| | 28 | |
| | 29 | #define UIO_MAX_DEVICES (1U << MINORBITS) |
| | 30 | |
| | 31 | static int uio_major; |
| | 32 | static struct cdev *uio_cdev; |
| | 33 | static DEFINE_IDR(uio_idr); |
| | 34 | static const struct file_operations uio_fops; |
| | 35 | |
| | 36 | /* Protect idr accesses */ |
| | 37 | static DEFINE_MUTEX(minor_lock); |
| | 38 | |
| | 39 | /* |
| | 40 | * attributes |
| | 41 | */ |
| | 42 | |
| | 43 | struct uio_map { |
| | 44 | struct kobject kobj; |
| | 45 | struct uio_mem *mem; |
| | 46 | }; |
| | 47 | #define to_map(map) container_of(map, struct uio_map, kobj) |
| | 48 | |
| | 49 | static ssize_t map_name_show(struct uio_mem *mem, char *buf) |
| | 50 | { |
| | 51 | if (unlikely(!mem->name)) |
| | 52 | mem->name = ""; |
| | 53 | |
| | 54 | return sprintf(buf, "%s\n", mem->name); |
| | 55 | } |
| | 56 | |
| | 57 | static ssize_t map_addr_show(struct uio_mem *mem, char *buf) |
| | 58 | { |
| | 59 | return sprintf(buf, "%pa\n", &mem->addr); |
| | 60 | } |
| | 61 | |
| | 62 | static ssize_t map_size_show(struct uio_mem *mem, char *buf) |
| | 63 | { |
| | 64 | return sprintf(buf, "%pa\n", &mem->size); |
| | 65 | } |
| | 66 | |
| | 67 | static ssize_t map_offset_show(struct uio_mem *mem, char *buf) |
| | 68 | { |
| | 69 | return sprintf(buf, "0x%llx\n", (unsigned long long)mem->offs); |
| | 70 | } |
| | 71 | |
| | 72 | struct map_sysfs_entry { |
| | 73 | struct attribute attr; |
| | 74 | ssize_t (*show)(struct uio_mem *, char *); |
| | 75 | ssize_t (*store)(struct uio_mem *, const char *, size_t); |
| | 76 | }; |
| | 77 | |
| | 78 | static struct map_sysfs_entry name_attribute = |
| | 79 | __ATTR(name, S_IRUGO, map_name_show, NULL); |
| | 80 | static struct map_sysfs_entry addr_attribute = |
| | 81 | __ATTR(addr, S_IRUGO, map_addr_show, NULL); |
| | 82 | static struct map_sysfs_entry size_attribute = |
| | 83 | __ATTR(size, S_IRUGO, map_size_show, NULL); |
| | 84 | static struct map_sysfs_entry offset_attribute = |
| | 85 | __ATTR(offset, S_IRUGO, map_offset_show, NULL); |
| | 86 | |
| | 87 | static struct attribute *attrs[] = { |
| | 88 | &name_attribute.attr, |
| | 89 | &addr_attribute.attr, |
| | 90 | &size_attribute.attr, |
| | 91 | &offset_attribute.attr, |
| | 92 | NULL, /* need to NULL terminate the list of attributes */ |
| | 93 | }; |
| | 94 | |
| | 95 | static void map_release(struct kobject *kobj) |
| | 96 | { |
| | 97 | struct uio_map *map = to_map(kobj); |
| | 98 | kfree(map); |
| | 99 | } |
| | 100 | |
| | 101 | static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr, |
| | 102 | char *buf) |
| | 103 | { |
| | 104 | struct uio_map *map = to_map(kobj); |
| | 105 | struct uio_mem *mem = map->mem; |
| | 106 | struct map_sysfs_entry *entry; |
| | 107 | |
| | 108 | entry = container_of(attr, struct map_sysfs_entry, attr); |
| | 109 | |
| | 110 | if (!entry->show) |
| | 111 | return -EIO; |
| | 112 | |
| | 113 | return entry->show(mem, buf); |
| | 114 | } |
| | 115 | |
| | 116 | static const struct sysfs_ops map_sysfs_ops = { |
| | 117 | .show = map_type_show, |
| | 118 | }; |
| | 119 | |
| | 120 | static struct kobj_type map_attr_type = { |
| | 121 | .release = map_release, |
| | 122 | .sysfs_ops = &map_sysfs_ops, |
| | 123 | .default_attrs = attrs, |
| | 124 | }; |
| | 125 | |
| | 126 | struct uio_portio { |
| | 127 | struct kobject kobj; |
| | 128 | struct uio_port *port; |
| | 129 | }; |
| | 130 | #define to_portio(portio) container_of(portio, struct uio_portio, kobj) |
| | 131 | |
| | 132 | static ssize_t portio_name_show(struct uio_port *port, char *buf) |
| | 133 | { |
| | 134 | if (unlikely(!port->name)) |
| | 135 | port->name = ""; |
| | 136 | |
| | 137 | return sprintf(buf, "%s\n", port->name); |
| | 138 | } |
| | 139 | |
| | 140 | static ssize_t portio_start_show(struct uio_port *port, char *buf) |
| | 141 | { |
| | 142 | return sprintf(buf, "0x%lx\n", port->start); |
| | 143 | } |
| | 144 | |
| | 145 | static ssize_t portio_size_show(struct uio_port *port, char *buf) |
| | 146 | { |
| | 147 | return sprintf(buf, "0x%lx\n", port->size); |
| | 148 | } |
| | 149 | |
| | 150 | static ssize_t portio_porttype_show(struct uio_port *port, char *buf) |
| | 151 | { |
| | 152 | const char *porttypes[] = {"none", "x86", "gpio", "other"}; |
| | 153 | |
| | 154 | if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER)) |
| | 155 | return -EINVAL; |
| | 156 | |
| | 157 | return sprintf(buf, "port_%s\n", porttypes[port->porttype]); |
| | 158 | } |
| | 159 | |
| | 160 | struct portio_sysfs_entry { |
| | 161 | struct attribute attr; |
| | 162 | ssize_t (*show)(struct uio_port *, char *); |
| | 163 | ssize_t (*store)(struct uio_port *, const char *, size_t); |
| | 164 | }; |
| | 165 | |
| | 166 | static struct portio_sysfs_entry portio_name_attribute = |
| | 167 | __ATTR(name, S_IRUGO, portio_name_show, NULL); |
| | 168 | static struct portio_sysfs_entry portio_start_attribute = |
| | 169 | __ATTR(start, S_IRUGO, portio_start_show, NULL); |
| | 170 | static struct portio_sysfs_entry portio_size_attribute = |
| | 171 | __ATTR(size, S_IRUGO, portio_size_show, NULL); |
| | 172 | static struct portio_sysfs_entry portio_porttype_attribute = |
| | 173 | __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL); |
| | 174 | |
| | 175 | static struct attribute *portio_attrs[] = { |
| | 176 | &portio_name_attribute.attr, |
| | 177 | &portio_start_attribute.attr, |
| | 178 | &portio_size_attribute.attr, |
| | 179 | &portio_porttype_attribute.attr, |
| | 180 | NULL, |
| | 181 | }; |
| | 182 | |
| | 183 | static void portio_release(struct kobject *kobj) |
| | 184 | { |
| | 185 | struct uio_portio *portio = to_portio(kobj); |
| | 186 | kfree(portio); |
| | 187 | } |
| | 188 | |
| | 189 | static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr, |
| | 190 | char *buf) |
| | 191 | { |
| | 192 | struct uio_portio *portio = to_portio(kobj); |
| | 193 | struct uio_port *port = portio->port; |
| | 194 | struct portio_sysfs_entry *entry; |
| | 195 | |
| | 196 | entry = container_of(attr, struct portio_sysfs_entry, attr); |
| | 197 | |
| | 198 | if (!entry->show) |
| | 199 | return -EIO; |
| | 200 | |
| | 201 | return entry->show(port, buf); |
| | 202 | } |
| | 203 | |
| | 204 | static const struct sysfs_ops portio_sysfs_ops = { |
| | 205 | .show = portio_type_show, |
| | 206 | }; |
| | 207 | |
| | 208 | static struct kobj_type portio_attr_type = { |
| | 209 | .release = portio_release, |
| | 210 | .sysfs_ops = &portio_sysfs_ops, |
| | 211 | .default_attrs = portio_attrs, |
| | 212 | }; |
| | 213 | |
| | 214 | static ssize_t name_show(struct device *dev, |
| | 215 | struct device_attribute *attr, char *buf) |
| | 216 | { |
| | 217 | struct uio_device *idev = dev_get_drvdata(dev); |
| | 218 | return sprintf(buf, "%s\n", idev->info->name); |
| | 219 | } |
| | 220 | static DEVICE_ATTR_RO(name); |
| | 221 | |
| | 222 | static ssize_t version_show(struct device *dev, |
| | 223 | struct device_attribute *attr, char *buf) |
| | 224 | { |
| | 225 | struct uio_device *idev = dev_get_drvdata(dev); |
| | 226 | return sprintf(buf, "%s\n", idev->info->version); |
| | 227 | } |
| | 228 | static DEVICE_ATTR_RO(version); |
| | 229 | |
| | 230 | static ssize_t event_show(struct device *dev, |
| | 231 | struct device_attribute *attr, char *buf) |
| | 232 | { |
| | 233 | struct uio_device *idev = dev_get_drvdata(dev); |
| | 234 | return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event)); |
| | 235 | } |
| | 236 | static DEVICE_ATTR_RO(event); |
| | 237 | |
| | 238 | static struct attribute *uio_attrs[] = { |
| | 239 | &dev_attr_name.attr, |
| | 240 | &dev_attr_version.attr, |
| | 241 | &dev_attr_event.attr, |
| | 242 | NULL, |
| | 243 | }; |
| | 244 | ATTRIBUTE_GROUPS(uio); |
| | 245 | |
| | 246 | /* UIO class infrastructure */ |
| | 247 | static struct class uio_class = { |
| | 248 | .name = "uio", |
| | 249 | .dev_groups = uio_groups, |
| | 250 | }; |
| | 251 | |
| | 252 | /* |
| | 253 | * device functions |
| | 254 | */ |
| | 255 | static int uio_dev_add_attributes(struct uio_device *idev) |
| | 256 | { |
| | 257 | int ret; |
| | 258 | int mi, pi; |
| | 259 | int map_found = 0; |
| | 260 | int portio_found = 0; |
| | 261 | struct uio_mem *mem; |
| | 262 | struct uio_map *map; |
| | 263 | struct uio_port *port; |
| | 264 | struct uio_portio *portio; |
| | 265 | |
| | 266 | for (mi = 0; mi < MAX_UIO_MAPS; mi++) { |
| | 267 | mem = &idev->info->mem[mi]; |
| | 268 | if (mem->size == 0) |
| | 269 | break; |
| | 270 | if (!map_found) { |
| | 271 | map_found = 1; |
| | 272 | idev->map_dir = kobject_create_and_add("maps", |
| | 273 | &idev->dev->kobj); |
| | 274 | if (!idev->map_dir) { |
| | 275 | ret = -ENOMEM; |
| | 276 | goto err_map; |
| | 277 | } |
| | 278 | } |
| | 279 | map = kzalloc(sizeof(*map), GFP_KERNEL); |
| | 280 | if (!map) { |
| | 281 | ret = -ENOMEM; |
| | 282 | goto err_map; |
| | 283 | } |
| | 284 | kobject_init(&map->kobj, &map_attr_type); |
| | 285 | map->mem = mem; |
| | 286 | mem->map = map; |
| | 287 | ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi); |
| | 288 | if (ret) |
| | 289 | goto err_map_kobj; |
| | 290 | ret = kobject_uevent(&map->kobj, KOBJ_ADD); |
| | 291 | if (ret) |
| | 292 | goto err_map_kobj; |
| | 293 | } |
| | 294 | |
| | 295 | for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) { |
| | 296 | port = &idev->info->port[pi]; |
| | 297 | if (port->size == 0) |
| | 298 | break; |
| | 299 | if (!portio_found) { |
| | 300 | portio_found = 1; |
| | 301 | idev->portio_dir = kobject_create_and_add("portio", |
| | 302 | &idev->dev->kobj); |
| | 303 | if (!idev->portio_dir) { |
| | 304 | ret = -ENOMEM; |
| | 305 | goto err_portio; |
| | 306 | } |
| | 307 | } |
| | 308 | portio = kzalloc(sizeof(*portio), GFP_KERNEL); |
| | 309 | if (!portio) { |
| | 310 | ret = -ENOMEM; |
| | 311 | goto err_portio; |
| | 312 | } |
| | 313 | kobject_init(&portio->kobj, &portio_attr_type); |
| | 314 | portio->port = port; |
| | 315 | port->portio = portio; |
| | 316 | ret = kobject_add(&portio->kobj, idev->portio_dir, |
| | 317 | "port%d", pi); |
| | 318 | if (ret) |
| | 319 | goto err_portio_kobj; |
| | 320 | ret = kobject_uevent(&portio->kobj, KOBJ_ADD); |
| | 321 | if (ret) |
| | 322 | goto err_portio_kobj; |
| | 323 | } |
| | 324 | |
| | 325 | return 0; |
| | 326 | |
| | 327 | err_portio: |
| | 328 | pi--; |
| | 329 | err_portio_kobj: |
| | 330 | for (; pi >= 0; pi--) { |
| | 331 | port = &idev->info->port[pi]; |
| | 332 | portio = port->portio; |
| | 333 | kobject_put(&portio->kobj); |
| | 334 | } |
| | 335 | kobject_put(idev->portio_dir); |
| | 336 | err_map: |
| | 337 | mi--; |
| | 338 | err_map_kobj: |
| | 339 | for (; mi >= 0; mi--) { |
| | 340 | mem = &idev->info->mem[mi]; |
| | 341 | map = mem->map; |
| | 342 | kobject_put(&map->kobj); |
| | 343 | } |
| | 344 | kobject_put(idev->map_dir); |
| | 345 | dev_err(idev->dev, "error creating sysfs files (%d)\n", ret); |
| | 346 | return ret; |
| | 347 | } |
| | 348 | |
| | 349 | static void uio_dev_del_attributes(struct uio_device *idev) |
| | 350 | { |
| | 351 | int i; |
| | 352 | struct uio_mem *mem; |
| | 353 | struct uio_port *port; |
| | 354 | |
| | 355 | for (i = 0; i < MAX_UIO_MAPS; i++) { |
| | 356 | mem = &idev->info->mem[i]; |
| | 357 | if (mem->size == 0) |
| | 358 | break; |
| | 359 | kobject_put(&mem->map->kobj); |
| | 360 | } |
| | 361 | kobject_put(idev->map_dir); |
| | 362 | |
| | 363 | for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) { |
| | 364 | port = &idev->info->port[i]; |
| | 365 | if (port->size == 0) |
| | 366 | break; |
| | 367 | kobject_put(&port->portio->kobj); |
| | 368 | } |
| | 369 | kobject_put(idev->portio_dir); |
| | 370 | } |
| | 371 | |
| | 372 | static int uio_get_minor(struct uio_device *idev) |
| | 373 | { |
| | 374 | int retval = -ENOMEM; |
| | 375 | |
| | 376 | mutex_lock(&minor_lock); |
| | 377 | retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL); |
| | 378 | if (retval >= 0) { |
| | 379 | idev->minor = retval; |
| | 380 | retval = 0; |
| | 381 | } else if (retval == -ENOSPC) { |
| | 382 | dev_err(idev->dev, "too many uio devices\n"); |
| | 383 | retval = -EINVAL; |
| | 384 | } |
| | 385 | mutex_unlock(&minor_lock); |
| | 386 | return retval; |
| | 387 | } |
| | 388 | |
| | 389 | static void uio_free_minor(struct uio_device *idev) |
| | 390 | { |
| | 391 | mutex_lock(&minor_lock); |
| | 392 | idr_remove(&uio_idr, idev->minor); |
| | 393 | mutex_unlock(&minor_lock); |
| | 394 | } |
| | 395 | |
| | 396 | /** |
| | 397 | * uio_event_notify - trigger an interrupt event |
| | 398 | * @info: UIO device capabilities |
| | 399 | */ |
| | 400 | void uio_event_notify(struct uio_info *info) |
| | 401 | { |
| | 402 | struct uio_device *idev = info->uio_dev; |
| | 403 | |
| | 404 | atomic_inc(&idev->event); |
| | 405 | wake_up_interruptible(&idev->wait); |
| | 406 | kill_fasync(&idev->async_queue, SIGIO, POLL_IN); |
| | 407 | } |
| | 408 | EXPORT_SYMBOL_GPL(uio_event_notify); |
| | 409 | |
| | 410 | /** |
| | 411 | * uio_interrupt - hardware interrupt handler |
| | 412 | * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer |
| | 413 | * @dev_id: Pointer to the devices uio_device structure |
| | 414 | */ |
| | 415 | static irqreturn_t uio_interrupt(int irq, void *dev_id) |
| | 416 | { |
| | 417 | struct uio_device *idev = (struct uio_device *)dev_id; |
| | 418 | irqreturn_t ret = idev->info->handler(irq, idev->info); |
| | 419 | |
| | 420 | if (ret == IRQ_HANDLED) |
| | 421 | uio_event_notify(idev->info); |
| | 422 | |
| | 423 | return ret; |
| | 424 | } |
| | 425 | |
| | 426 | struct uio_listener { |
| | 427 | struct uio_device *dev; |
| | 428 | s32 event_count; |
| | 429 | }; |
| | 430 | |
| | 431 | static int uio_open(struct inode *inode, struct file *filep) |
| | 432 | { |
| | 433 | struct uio_device *idev; |
| | 434 | struct uio_listener *listener; |
| | 435 | int ret = 0; |
| | 436 | |
| | 437 | mutex_lock(&minor_lock); |
| | 438 | idev = idr_find(&uio_idr, iminor(inode)); |
| | 439 | mutex_unlock(&minor_lock); |
| | 440 | if (!idev) { |
| | 441 | ret = -ENODEV; |
| | 442 | goto out; |
| | 443 | } |
| | 444 | |
| | 445 | if (!try_module_get(idev->owner)) { |
| | 446 | ret = -ENODEV; |
| | 447 | goto out; |
| | 448 | } |
| | 449 | |
| | 450 | listener = kmalloc(sizeof(*listener), GFP_KERNEL); |
| | 451 | if (!listener) { |
| | 452 | ret = -ENOMEM; |
| | 453 | goto err_alloc_listener; |
| | 454 | } |
| | 455 | |
| | 456 | listener->dev = idev; |
| | 457 | listener->event_count = atomic_read(&idev->event); |
| | 458 | filep->private_data = listener; |
| | 459 | |
| | 460 | if (idev->info->open) { |
| | 461 | ret = idev->info->open(idev->info, inode); |
| | 462 | if (ret) |
| | 463 | goto err_infoopen; |
| | 464 | } |
| | 465 | return 0; |
| | 466 | |
| | 467 | err_infoopen: |
| | 468 | kfree(listener); |
| | 469 | |
| | 470 | err_alloc_listener: |
| | 471 | module_put(idev->owner); |
| | 472 | |
| | 473 | out: |
| | 474 | return ret; |
| | 475 | } |
| | 476 | |
| | 477 | static int uio_fasync(int fd, struct file *filep, int on) |
| | 478 | { |
| | 479 | struct uio_listener *listener = filep->private_data; |
| | 480 | struct uio_device *idev = listener->dev; |
| | 481 | |
| | 482 | return fasync_helper(fd, filep, on, &idev->async_queue); |
| | 483 | } |
| | 484 | |
| | 485 | static int uio_release(struct inode *inode, struct file *filep) |
| | 486 | { |
| | 487 | int ret = 0; |
| | 488 | struct uio_listener *listener = filep->private_data; |
| | 489 | struct uio_device *idev = listener->dev; |
| | 490 | |
| | 491 | if (idev->info->release) |
| | 492 | ret = idev->info->release(idev->info, inode); |
| | 493 | |
| | 494 | module_put(idev->owner); |
| | 495 | kfree(listener); |
| | 496 | return ret; |
| | 497 | } |
| | 498 | |
| | 499 | static unsigned int uio_poll(struct file *filep, poll_table *wait) |
| | 500 | { |
| | 501 | struct uio_listener *listener = filep->private_data; |
| | 502 | struct uio_device *idev = listener->dev; |
| | 503 | |
| | 504 | if (!idev->info->irq) |
| | 505 | return -EIO; |
| | 506 | |
| | 507 | poll_wait(filep, &idev->wait, wait); |
| | 508 | if (listener->event_count != atomic_read(&idev->event)) |
| | 509 | return POLLIN | POLLRDNORM; |
| | 510 | return 0; |
| | 511 | } |
| | 512 | |
| | 513 | static ssize_t uio_read(struct file *filep, char __user *buf, |
| | 514 | size_t count, loff_t *ppos) |
| | 515 | { |
| | 516 | struct uio_listener *listener = filep->private_data; |
| | 517 | struct uio_device *idev = listener->dev; |
| | 518 | DECLARE_WAITQUEUE(wait, current); |
| | 519 | ssize_t retval; |
| | 520 | s32 event_count; |
| | 521 | |
| | 522 | if (!idev->info->irq) |
| | 523 | return -EIO; |
| | 524 | |
| | 525 | if (count != sizeof(s32)) |
| | 526 | return -EINVAL; |
| | 527 | |
| | 528 | add_wait_queue(&idev->wait, &wait); |
| | 529 | |
| | 530 | do { |
| | 531 | set_current_state(TASK_INTERRUPTIBLE); |
| | 532 | |
| | 533 | event_count = atomic_read(&idev->event); |
| | 534 | if (event_count != listener->event_count) { |
| | 535 | __set_current_state(TASK_RUNNING); |
| | 536 | if (copy_to_user(buf, &event_count, count)) |
| | 537 | retval = -EFAULT; |
| | 538 | else { |
| | 539 | listener->event_count = event_count; |
| | 540 | retval = count; |
| | 541 | } |
| | 542 | break; |
| | 543 | } |
| | 544 | |
| | 545 | if (filep->f_flags & O_NONBLOCK) { |
| | 546 | retval = -EAGAIN; |
| | 547 | break; |
| | 548 | } |
| | 549 | |
| | 550 | if (signal_pending(current)) { |
| | 551 | retval = -ERESTARTSYS; |
| | 552 | break; |
| | 553 | } |
| | 554 | schedule(); |
| | 555 | } while (1); |
| | 556 | |
| | 557 | __set_current_state(TASK_RUNNING); |
| | 558 | remove_wait_queue(&idev->wait, &wait); |
| | 559 | |
| | 560 | return retval; |
| | 561 | } |
| | 562 | |
| | 563 | static ssize_t uio_write(struct file *filep, const char __user *buf, |
| | 564 | size_t count, loff_t *ppos) |
| | 565 | { |
| | 566 | struct uio_listener *listener = filep->private_data; |
| | 567 | struct uio_device *idev = listener->dev; |
| | 568 | ssize_t retval; |
| | 569 | s32 irq_on; |
| | 570 | |
| | 571 | if (!idev->info->irq) |
| | 572 | return -EIO; |
| | 573 | |
| | 574 | if (count != sizeof(s32)) |
| | 575 | return -EINVAL; |
| | 576 | |
| | 577 | if (!idev->info->irqcontrol) |
| | 578 | return -ENOSYS; |
| | 579 | |
| | 580 | if (copy_from_user(&irq_on, buf, count)) |
| | 581 | return -EFAULT; |
| | 582 | |
| | 583 | retval = idev->info->irqcontrol(idev->info, irq_on); |
| | 584 | |
| | 585 | return retval ? retval : sizeof(s32); |
| | 586 | } |
| | 587 | |
| | 588 | static int uio_find_mem_index(struct vm_area_struct *vma) |
| | 589 | { |
| | 590 | struct uio_device *idev = vma->vm_private_data; |
| | 591 | |
| | 592 | if (vma->vm_pgoff < MAX_UIO_MAPS) { |
| | 593 | if (idev->info->mem[vma->vm_pgoff].size == 0) |
| | 594 | return -1; |
| | 595 | return (int)vma->vm_pgoff; |
| | 596 | } |
| | 597 | return -1; |
| | 598 | } |
| | 599 | |
| | 600 | static int uio_vma_fault(struct vm_fault *vmf) |
| | 601 | { |
| | 602 | struct uio_device *idev = vmf->vma->vm_private_data; |
| | 603 | struct page *page; |
| | 604 | unsigned long offset; |
| | 605 | void *addr; |
| | 606 | |
| | 607 | int mi = uio_find_mem_index(vmf->vma); |
| | 608 | if (mi < 0) |
| | 609 | return VM_FAULT_SIGBUS; |
| | 610 | |
| | 611 | /* |
| | 612 | * We need to subtract mi because userspace uses offset = N*PAGE_SIZE |
| | 613 | * to use mem[N]. |
| | 614 | */ |
| | 615 | offset = (vmf->pgoff - mi) << PAGE_SHIFT; |
| | 616 | |
| | 617 | addr = (void *)(unsigned long)idev->info->mem[mi].addr + offset; |
| | 618 | if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL) |
| | 619 | page = virt_to_page(addr); |
| | 620 | else |
| | 621 | page = vmalloc_to_page(addr); |
| | 622 | get_page(page); |
| | 623 | vmf->page = page; |
| | 624 | return 0; |
| | 625 | } |
| | 626 | |
| | 627 | static const struct vm_operations_struct uio_logical_vm_ops = { |
| | 628 | .fault = uio_vma_fault, |
| | 629 | }; |
| | 630 | |
| | 631 | static int uio_mmap_logical(struct vm_area_struct *vma) |
| | 632 | { |
| | 633 | vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; |
| | 634 | vma->vm_ops = &uio_logical_vm_ops; |
| | 635 | return 0; |
| | 636 | } |
| | 637 | |
| | 638 | static const struct vm_operations_struct uio_physical_vm_ops = { |
| | 639 | #ifdef CONFIG_HAVE_IOREMAP_PROT |
| | 640 | .access = generic_access_phys, |
| | 641 | #endif |
| | 642 | }; |
| | 643 | |
| | 644 | static int uio_mmap_physical(struct vm_area_struct *vma) |
| | 645 | { |
| | 646 | struct uio_device *idev = vma->vm_private_data; |
| | 647 | int mi = uio_find_mem_index(vma); |
| | 648 | struct uio_mem *mem; |
| | 649 | if (mi < 0) |
| | 650 | return -EINVAL; |
| | 651 | mem = idev->info->mem + mi; |
| | 652 | |
| | 653 | if (mem->addr & ~PAGE_MASK) |
| | 654 | return -ENODEV; |
| | 655 | if (vma->vm_end - vma->vm_start > mem->size) |
| | 656 | return -EINVAL; |
| | 657 | |
| | 658 | vma->vm_ops = &uio_physical_vm_ops; |
| | 659 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
| | 660 | |
| | 661 | /* |
| | 662 | * We cannot use the vm_iomap_memory() helper here, |
| | 663 | * because vma->vm_pgoff is the map index we looked |
| | 664 | * up above in uio_find_mem_index(), rather than an |
| | 665 | * actual page offset into the mmap. |
| | 666 | * |
| | 667 | * So we just do the physical mmap without a page |
| | 668 | * offset. |
| | 669 | */ |
| | 670 | return remap_pfn_range(vma, |
| | 671 | vma->vm_start, |
| | 672 | mem->addr >> PAGE_SHIFT, |
| | 673 | vma->vm_end - vma->vm_start, |
| | 674 | vma->vm_page_prot); |
| | 675 | } |
| | 676 | |
| | 677 | static int uio_mmap(struct file *filep, struct vm_area_struct *vma) |
| | 678 | { |
| | 679 | struct uio_listener *listener = filep->private_data; |
| | 680 | struct uio_device *idev = listener->dev; |
| | 681 | int mi; |
| | 682 | unsigned long requested_pages, actual_pages; |
| | 683 | int ret = 0; |
| | 684 | |
| | 685 | if (vma->vm_end < vma->vm_start) |
| | 686 | return -EINVAL; |
| | 687 | |
| | 688 | vma->vm_private_data = idev; |
| | 689 | |
| | 690 | mi = uio_find_mem_index(vma); |
| | 691 | if (mi < 0) |
| | 692 | return -EINVAL; |
| | 693 | |
| | 694 | requested_pages = vma_pages(vma); |
| | 695 | actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) |
| | 696 | + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; |
| | 697 | if (requested_pages > actual_pages) |
| | 698 | return -EINVAL; |
| | 699 | |
| | 700 | if (idev->info->mmap) { |
| | 701 | ret = idev->info->mmap(idev->info, vma); |
| | 702 | return ret; |
| | 703 | } |
| | 704 | |
| | 705 | switch (idev->info->mem[mi].memtype) { |
| | 706 | case UIO_MEM_PHYS: |
| | 707 | return uio_mmap_physical(vma); |
| | 708 | case UIO_MEM_LOGICAL: |
| | 709 | case UIO_MEM_VIRTUAL: |
| | 710 | return uio_mmap_logical(vma); |
| | 711 | default: |
| | 712 | return -EINVAL; |
| | 713 | } |
| | 714 | } |
| | 715 | |
| | 716 | static const struct file_operations uio_fops = { |
| | 717 | .owner = THIS_MODULE, |
| | 718 | .open = uio_open, |
| | 719 | .release = uio_release, |
| | 720 | .read = uio_read, |
| | 721 | .write = uio_write, |
| | 722 | .mmap = uio_mmap, |
| | 723 | .poll = uio_poll, |
| | 724 | .fasync = uio_fasync, |
| | 725 | .llseek = noop_llseek, |
| | 726 | }; |
| | 727 | |
| | 728 | static int uio_major_init(void) |
| | 729 | { |
| | 730 | static const char name[] = "uio"; |
| | 731 | struct cdev *cdev = NULL; |
| | 732 | dev_t uio_dev = 0; |
| | 733 | int result; |
| | 734 | |
| | 735 | result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name); |
| | 736 | if (result) |
| | 737 | goto out; |
| | 738 | |
| | 739 | result = -ENOMEM; |
| | 740 | cdev = cdev_alloc(); |
| | 741 | if (!cdev) |
| | 742 | goto out_unregister; |
| | 743 | |
| | 744 | cdev->owner = THIS_MODULE; |
| | 745 | cdev->ops = &uio_fops; |
| | 746 | kobject_set_name(&cdev->kobj, "%s", name); |
| | 747 | |
| | 748 | result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES); |
| | 749 | if (result) |
| | 750 | goto out_put; |
| | 751 | |
| | 752 | uio_major = MAJOR(uio_dev); |
| | 753 | uio_cdev = cdev; |
| | 754 | return 0; |
| | 755 | out_put: |
| | 756 | kobject_put(&cdev->kobj); |
| | 757 | out_unregister: |
| | 758 | unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES); |
| | 759 | out: |
| | 760 | return result; |
| | 761 | } |
| | 762 | |
| | 763 | static void uio_major_cleanup(void) |
| | 764 | { |
| | 765 | unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES); |
| | 766 | cdev_del(uio_cdev); |
| | 767 | } |
| | 768 | |
| | 769 | static int init_uio_class(void) |
| | 770 | { |
| | 771 | int ret; |
| | 772 | |
| | 773 | /* This is the first time in here, set everything up properly */ |
| | 774 | ret = uio_major_init(); |
| | 775 | if (ret) |
| | 776 | goto exit; |
| | 777 | |
| | 778 | ret = class_register(&uio_class); |
| | 779 | if (ret) { |
| | 780 | printk(KERN_ERR "class_register failed for uio\n"); |
| | 781 | goto err_class_register; |
| | 782 | } |
| | 783 | return 0; |
| | 784 | |
| | 785 | err_class_register: |
| | 786 | uio_major_cleanup(); |
| | 787 | exit: |
| | 788 | return ret; |
| | 789 | } |
| | 790 | |
| | 791 | static void release_uio_class(void) |
| | 792 | { |
| | 793 | class_unregister(&uio_class); |
| | 794 | uio_major_cleanup(); |
| | 795 | } |
| | 796 | |
| | 797 | /** |
| | 798 | * uio_register_device - register a new userspace IO device |
| | 799 | * @owner: module that creates the new device |
| | 800 | * @parent: parent device |
| | 801 | * @info: UIO device capabilities |
| | 802 | * |
| | 803 | * returns zero on success or a negative error code. |
| | 804 | */ |
| | 805 | int __uio_register_device(struct module *owner, |
| | 806 | struct device *parent, |
| | 807 | struct uio_info *info) |
| | 808 | { |
| | 809 | struct uio_device *idev; |
| | 810 | int ret = 0; |
| | 811 | |
| | 812 | if (!parent || !info || !info->name || !info->version) |
| | 813 | return -EINVAL; |
| | 814 | |
| | 815 | info->uio_dev = NULL; |
| | 816 | |
| | 817 | idev = devm_kzalloc(parent, sizeof(*idev), GFP_KERNEL); |
| | 818 | if (!idev) { |
| | 819 | return -ENOMEM; |
| | 820 | } |
| | 821 | |
| | 822 | idev->owner = owner; |
| | 823 | idev->info = info; |
| | 824 | init_waitqueue_head(&idev->wait); |
| | 825 | atomic_set(&idev->event, 0); |
| | 826 | |
| | 827 | ret = uio_get_minor(idev); |
| | 828 | if (ret) |
| | 829 | return ret; |
| | 830 | |
| | 831 | idev->dev = device_create(&uio_class, parent, |
| | 832 | MKDEV(uio_major, idev->minor), idev, |
| | 833 | "uio%d", idev->minor); |
| | 834 | if (IS_ERR(idev->dev)) { |
| | 835 | printk(KERN_ERR "UIO: device register failed\n"); |
| | 836 | ret = PTR_ERR(idev->dev); |
| | 837 | goto err_device_create; |
| | 838 | } |
| | 839 | |
| | 840 | ret = uio_dev_add_attributes(idev); |
| | 841 | if (ret) |
| | 842 | goto err_uio_dev_add_attributes; |
| | 843 | |
| | 844 | info->uio_dev = idev; |
| | 845 | |
| | 846 | if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { |
| | 847 | /* |
| | 848 | * Note that we deliberately don't use devm_request_irq |
| | 849 | * here. The parent module can unregister the UIO device |
| | 850 | * and call pci_disable_msi, which requires that this |
| | 851 | * irq has been freed. However, the device may have open |
| | 852 | * FDs at the time of unregister and therefore may not be |
| | 853 | * freed until they are released. |
| | 854 | */ |
| | 855 | ret = request_irq(info->irq, uio_interrupt, |
| | 856 | info->irq_flags, info->name, idev); |
| | 857 | if (ret) |
| | 858 | goto err_request_irq; |
| | 859 | } |
| | 860 | |
| | 861 | return 0; |
| | 862 | |
| | 863 | err_request_irq: |
| | 864 | uio_dev_del_attributes(idev); |
| | 865 | err_uio_dev_add_attributes: |
| | 866 | device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); |
| | 867 | err_device_create: |
| | 868 | uio_free_minor(idev); |
| | 869 | return ret; |
| | 870 | } |
| | 871 | EXPORT_SYMBOL_GPL(__uio_register_device); |
| | 872 | |
| | 873 | /** |
| | 874 | * uio_unregister_device - unregister a industrial IO device |
| | 875 | * @info: UIO device capabilities |
| | 876 | * |
| | 877 | */ |
| | 878 | void uio_unregister_device(struct uio_info *info) |
| | 879 | { |
| | 880 | struct uio_device *idev; |
| | 881 | |
| | 882 | if (!info || !info->uio_dev) |
| | 883 | return; |
| | 884 | |
| | 885 | idev = info->uio_dev; |
| | 886 | |
| | 887 | uio_free_minor(idev); |
| | 888 | |
| | 889 | uio_dev_del_attributes(idev); |
| | 890 | |
| | 891 | if (info->irq && info->irq != UIO_IRQ_CUSTOM) |
| | 892 | free_irq(info->irq, idev); |
| | 893 | |
| | 894 | device_destroy(&uio_class, MKDEV(uio_major, idev->minor)); |
| | 895 | |
| | 896 | return; |
| | 897 | } |
| | 898 | EXPORT_SYMBOL_GPL(uio_unregister_device); |
| | 899 | |
| | 900 | static int __init uio_init(void) |
| | 901 | { |
| | 902 | return init_uio_class(); |
| | 903 | } |
| | 904 | |
| | 905 | static void __exit uio_exit(void) |
| | 906 | { |
| | 907 | release_uio_class(); |
| | 908 | idr_destroy(&uio_idr); |
| | 909 | } |
| | 910 | |
| | 911 | module_init(uio_init) |
| | 912 | module_exit(uio_exit) |
| | 913 | MODULE_LICENSE("GPL v2"); |
projects / mirror_ubuntu-artful-kernel.git / blame_incremental