1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (c) 2016, Linaro Ltd. 4 * Copyright (c) 2012, Michal Simek <monstr@monstr.eu> 5 * Copyright (c) 2012, PetaLogix 6 * Copyright (c) 2011, Texas Instruments, Inc. 7 * Copyright (c) 2011, Google, Inc. 8 * 9 * Based on rpmsg performance statistics driver by Michal Simek, which in turn 10 * was based on TI & Google OMX rpmsg driver. 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/cdev.h> 16 #include <linux/device.h> 17 #include <linux/fs.h> 18 #include <linux/idr.h> 19 #include <linux/kernel.h> 20 #include <linux/module.h> 21 #include <linux/poll.h> 22 #include <linux/rpmsg.h> 23 #include <linux/skbuff.h> 24 #include <linux/slab.h> 25 #include <linux/uaccess.h> 26 #include <uapi/linux/rpmsg.h> 27 28 #define RPMSG_DEV_MAX (MINORMASK + 1) 29 30 static dev_t rpmsg_major; 31 static struct class *rpmsg_class; 32 33 static DEFINE_IDA(rpmsg_ctrl_ida); 34 static DEFINE_IDA(rpmsg_ept_ida); 35 static DEFINE_IDA(rpmsg_minor_ida); 36 37 #define dev_to_eptdev(dev) container_of(dev, struct rpmsg_eptdev, dev) 38 #define cdev_to_eptdev(i_cdev) container_of(i_cdev, struct rpmsg_eptdev, cdev) 39 40 #define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev) 41 #define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev) 42 43 /** 44 * struct rpmsg_ctrldev - control device for instantiating endpoint devices 45 * @rpdev: underlaying rpmsg device 46 * @cdev: cdev for the ctrl device 47 * @dev: device for the ctrl device 48 */ 49 struct rpmsg_ctrldev { 50 struct rpmsg_device *rpdev; 51 struct cdev cdev; 52 struct device dev; 53 }; 54 55 /** 56 * struct rpmsg_eptdev - endpoint device context 57 * @dev: endpoint device 58 * @cdev: cdev for the endpoint device 59 * @rpdev: underlaying rpmsg device 60 * @chinfo: info used to open the endpoint 61 * @ept_lock: synchronization of @ept modifications 62 * @ept: rpmsg endpoint reference, when open 63 * @queue_lock: synchronization of @queue operations 64 * @queue: incoming message queue 65 * @readq: wait object for incoming queue 66 */ 67 struct rpmsg_eptdev { 68 struct device dev; 69 struct cdev cdev; 70 71 struct rpmsg_device *rpdev; 72 struct rpmsg_channel_info chinfo; 73 74 struct mutex ept_lock; 75 struct rpmsg_endpoint *ept; 76 77 spinlock_t queue_lock; 78 struct sk_buff_head queue; 79 wait_queue_head_t readq; 80 }; 81 82 static int rpmsg_eptdev_destroy(struct device *dev, void *data) 83 { 84 struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev); 85 86 mutex_lock(&eptdev->ept_lock); 87 if (eptdev->ept) { 88 rpmsg_destroy_ept(eptdev->ept); 89 eptdev->ept = NULL; 90 } 91 mutex_unlock(&eptdev->ept_lock); 92 93 /* wake up any blocked readers */ 94 wake_up_interruptible(&eptdev->readq); 95 96 cdev_device_del(&eptdev->cdev, &eptdev->dev); 97 put_device(&eptdev->dev); 98 99 return 0; 100 } 101 102 static int rpmsg_ept_cb(struct rpmsg_device *rpdev, void *buf, int len, 103 void *priv, u32 addr) 104 { 105 struct rpmsg_eptdev *eptdev = priv; 106 struct sk_buff *skb; 107 108 skb = alloc_skb(len, GFP_ATOMIC); 109 if (!skb) 110 return -ENOMEM; 111 112 skb_put_data(skb, buf, len); 113 114 spin_lock(&eptdev->queue_lock); 115 skb_queue_tail(&eptdev->queue, skb); 116 spin_unlock(&eptdev->queue_lock); 117 118 /* wake up any blocking processes, waiting for new data */ 119 wake_up_interruptible(&eptdev->readq); 120 121 return 0; 122 } 123 124 static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) 125 { 126 struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev); 127 struct rpmsg_endpoint *ept; 128 struct rpmsg_device *rpdev = eptdev->rpdev; 129 struct device *dev = &eptdev->dev; 130 131 if (eptdev->ept) 132 return -EBUSY; 133 134 get_device(dev); 135 136 ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo); 137 if (!ept) { 138 dev_err(dev, "failed to open %s\n", eptdev->chinfo.name); 139 put_device(dev); 140 return -EINVAL; 141 } 142 143 eptdev->ept = ept; 144 filp->private_data = eptdev; 145 146 return 0; 147 } 148 149 static int rpmsg_eptdev_release(struct inode *inode, struct file *filp) 150 { 151 struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev); 152 struct device *dev = &eptdev->dev; 153 154 /* Close the endpoint, if it's not already destroyed by the parent */ 155 mutex_lock(&eptdev->ept_lock); 156 if (eptdev->ept) { 157 rpmsg_destroy_ept(eptdev->ept); 158 eptdev->ept = NULL; 159 } 160 mutex_unlock(&eptdev->ept_lock); 161 162 /* Discard all SKBs */ 163 skb_queue_purge(&eptdev->queue); 164 165 put_device(dev); 166 167 return 0; 168 } 169 170 static ssize_t rpmsg_eptdev_read_iter(struct kiocb *iocb, struct iov_iter *to) 171 { 172 struct file *filp = iocb->ki_filp; 173 struct rpmsg_eptdev *eptdev = filp->private_data; 174 unsigned long flags; 175 struct sk_buff *skb; 176 int use; 177 178 if (!eptdev->ept) 179 return -EPIPE; 180 181 spin_lock_irqsave(&eptdev->queue_lock, flags); 182 183 /* Wait for data in the queue */ 184 if (skb_queue_empty(&eptdev->queue)) { 185 spin_unlock_irqrestore(&eptdev->queue_lock, flags); 186 187 if (filp->f_flags & O_NONBLOCK) 188 return -EAGAIN; 189 190 /* Wait until we get data or the endpoint goes away */ 191 if (wait_event_interruptible(eptdev->readq, 192 !skb_queue_empty(&eptdev->queue) || 193 !eptdev->ept)) 194 return -ERESTARTSYS; 195 196 /* We lost the endpoint while waiting */ 197 if (!eptdev->ept) 198 return -EPIPE; 199 200 spin_lock_irqsave(&eptdev->queue_lock, flags); 201 } 202 203 skb = skb_dequeue(&eptdev->queue); 204 spin_unlock_irqrestore(&eptdev->queue_lock, flags); 205 if (!skb) 206 return -EFAULT; 207 208 use = min_t(size_t, iov_iter_count(to), skb->len); 209 if (copy_to_iter(skb->data, use, to) != use) 210 use = -EFAULT; 211 212 kfree_skb(skb); 213 214 return use; 215 } 216 217 static ssize_t rpmsg_eptdev_write_iter(struct kiocb *iocb, 218 struct iov_iter *from) 219 { 220 struct file *filp = iocb->ki_filp; 221 struct rpmsg_eptdev *eptdev = filp->private_data; 222 size_t len = iov_iter_count(from); 223 void *kbuf; 224 int ret; 225 226 kbuf = kzalloc(len, GFP_KERNEL); 227 if (!kbuf) 228 return -ENOMEM; 229 230 if (!copy_from_iter_full(kbuf, len, from)) { 231 ret = -EFAULT; 232 goto free_kbuf; 233 } 234 235 if (mutex_lock_interruptible(&eptdev->ept_lock)) { 236 ret = -ERESTARTSYS; 237 goto free_kbuf; 238 } 239 240 if (!eptdev->ept) { 241 ret = -EPIPE; 242 goto unlock_eptdev; 243 } 244 245 if (filp->f_flags & O_NONBLOCK) 246 ret = rpmsg_trysendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst); 247 else 248 ret = rpmsg_sendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst); 249 250 unlock_eptdev: 251 mutex_unlock(&eptdev->ept_lock); 252 253 free_kbuf: 254 kfree(kbuf); 255 return ret < 0 ? ret : len; 256 } 257 258 static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait) 259 { 260 struct rpmsg_eptdev *eptdev = filp->private_data; 261 __poll_t mask = 0; 262 263 if (!eptdev->ept) 264 return EPOLLERR; 265 266 poll_wait(filp, &eptdev->readq, wait); 267 268 if (!skb_queue_empty(&eptdev->queue)) 269 mask |= EPOLLIN | EPOLLRDNORM; 270 271 mask |= rpmsg_poll(eptdev->ept, filp, wait); 272 273 return mask; 274 } 275 276 static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd, 277 unsigned long arg) 278 { 279 struct rpmsg_eptdev *eptdev = fp->private_data; 280 281 if (cmd != RPMSG_DESTROY_EPT_IOCTL) 282 return -EINVAL; 283 284 return rpmsg_eptdev_destroy(&eptdev->dev, NULL); 285 } 286 287 static const struct file_operations rpmsg_eptdev_fops = { 288 .owner = THIS_MODULE, 289 .open = rpmsg_eptdev_open, 290 .release = rpmsg_eptdev_release, 291 .read_iter = rpmsg_eptdev_read_iter, 292 .write_iter = rpmsg_eptdev_write_iter, 293 .poll = rpmsg_eptdev_poll, 294 .unlocked_ioctl = rpmsg_eptdev_ioctl, 295 .compat_ioctl = compat_ptr_ioctl, 296 }; 297 298 static ssize_t name_show(struct device *dev, struct device_attribute *attr, 299 char *buf) 300 { 301 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev); 302 303 return sprintf(buf, "%s\n", eptdev->chinfo.name); 304 } 305 static DEVICE_ATTR_RO(name); 306 307 static ssize_t src_show(struct device *dev, struct device_attribute *attr, 308 char *buf) 309 { 310 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev); 311 312 return sprintf(buf, "%d\n", eptdev->chinfo.src); 313 } 314 static DEVICE_ATTR_RO(src); 315 316 static ssize_t dst_show(struct device *dev, struct device_attribute *attr, 317 char *buf) 318 { 319 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev); 320 321 return sprintf(buf, "%d\n", eptdev->chinfo.dst); 322 } 323 static DEVICE_ATTR_RO(dst); 324 325 static struct attribute *rpmsg_eptdev_attrs[] = { 326 &dev_attr_name.attr, 327 &dev_attr_src.attr, 328 &dev_attr_dst.attr, 329 NULL 330 }; 331 ATTRIBUTE_GROUPS(rpmsg_eptdev); 332 333 static void rpmsg_eptdev_release_device(struct device *dev) 334 { 335 struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev); 336 337 ida_simple_remove(&rpmsg_ept_ida, dev->id); 338 ida_simple_remove(&rpmsg_minor_ida, MINOR(eptdev->dev.devt)); 339 kfree(eptdev); 340 } 341 342 static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev, 343 struct rpmsg_channel_info chinfo) 344 { 345 struct rpmsg_device *rpdev = ctrldev->rpdev; 346 struct rpmsg_eptdev *eptdev; 347 struct device *dev; 348 int ret; 349 350 eptdev = kzalloc(sizeof(*eptdev), GFP_KERNEL); 351 if (!eptdev) 352 return -ENOMEM; 353 354 dev = &eptdev->dev; 355 eptdev->rpdev = rpdev; 356 eptdev->chinfo = chinfo; 357 358 mutex_init(&eptdev->ept_lock); 359 spin_lock_init(&eptdev->queue_lock); 360 skb_queue_head_init(&eptdev->queue); 361 init_waitqueue_head(&eptdev->readq); 362 363 device_initialize(dev); 364 dev->class = rpmsg_class; 365 dev->parent = &ctrldev->dev; 366 dev->groups = rpmsg_eptdev_groups; 367 dev_set_drvdata(dev, eptdev); 368 369 cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops); 370 eptdev->cdev.owner = THIS_MODULE; 371 372 ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL); 373 if (ret < 0) 374 goto free_eptdev; 375 dev->devt = MKDEV(MAJOR(rpmsg_major), ret); 376 377 ret = ida_simple_get(&rpmsg_ept_ida, 0, 0, GFP_KERNEL); 378 if (ret < 0) 379 goto free_minor_ida; 380 dev->id = ret; 381 dev_set_name(dev, "rpmsg%d", ret); 382 383 ret = cdev_device_add(&eptdev->cdev, &eptdev->dev); 384 if (ret) 385 goto free_ept_ida; 386 387 /* We can now rely on the release function for cleanup */ 388 dev->release = rpmsg_eptdev_release_device; 389 390 return ret; 391 392 free_ept_ida: 393 ida_simple_remove(&rpmsg_ept_ida, dev->id); 394 free_minor_ida: 395 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); 396 free_eptdev: 397 put_device(dev); 398 kfree(eptdev); 399 400 return ret; 401 } 402 403 static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp) 404 { 405 struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev); 406 407 get_device(&ctrldev->dev); 408 filp->private_data = ctrldev; 409 410 return 0; 411 } 412 413 static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp) 414 { 415 struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev); 416 417 put_device(&ctrldev->dev); 418 419 return 0; 420 } 421 422 static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, 423 unsigned long arg) 424 { 425 struct rpmsg_ctrldev *ctrldev = fp->private_data; 426 void __user *argp = (void __user *)arg; 427 struct rpmsg_endpoint_info eptinfo; 428 struct rpmsg_channel_info chinfo; 429 430 if (cmd != RPMSG_CREATE_EPT_IOCTL) 431 return -EINVAL; 432 433 if (copy_from_user(&eptinfo, argp, sizeof(eptinfo))) 434 return -EFAULT; 435 436 memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE); 437 chinfo.name[RPMSG_NAME_SIZE-1] = '\0'; 438 chinfo.src = eptinfo.src; 439 chinfo.dst = eptinfo.dst; 440 441 return rpmsg_eptdev_create(ctrldev, chinfo); 442 }; 443 444 static const struct file_operations rpmsg_ctrldev_fops = { 445 .owner = THIS_MODULE, 446 .open = rpmsg_ctrldev_open, 447 .release = rpmsg_ctrldev_release, 448 .unlocked_ioctl = rpmsg_ctrldev_ioctl, 449 .compat_ioctl = compat_ptr_ioctl, 450 }; 451 452 static void rpmsg_ctrldev_release_device(struct device *dev) 453 { 454 struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev); 455 456 ida_simple_remove(&rpmsg_ctrl_ida, dev->id); 457 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); 458 kfree(ctrldev); 459 } 460 461 static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev) 462 { 463 struct rpmsg_ctrldev *ctrldev; 464 struct device *dev; 465 int ret; 466 467 ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL); 468 if (!ctrldev) 469 return -ENOMEM; 470 471 ctrldev->rpdev = rpdev; 472 473 dev = &ctrldev->dev; 474 device_initialize(dev); 475 dev->parent = &rpdev->dev; 476 dev->class = rpmsg_class; 477 478 cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops); 479 ctrldev->cdev.owner = THIS_MODULE; 480 481 ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL); 482 if (ret < 0) 483 goto free_ctrldev; 484 dev->devt = MKDEV(MAJOR(rpmsg_major), ret); 485 486 ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL); 487 if (ret < 0) 488 goto free_minor_ida; 489 dev->id = ret; 490 dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret); 491 492 ret = cdev_device_add(&ctrldev->cdev, &ctrldev->dev); 493 if (ret) 494 goto free_ctrl_ida; 495 496 /* We can now rely on the release function for cleanup */ 497 dev->release = rpmsg_ctrldev_release_device; 498 499 dev_set_drvdata(&rpdev->dev, ctrldev); 500 501 return ret; 502 503 free_ctrl_ida: 504 ida_simple_remove(&rpmsg_ctrl_ida, dev->id); 505 free_minor_ida: 506 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); 507 free_ctrldev: 508 put_device(dev); 509 kfree(ctrldev); 510 511 return ret; 512 } 513 514 static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev) 515 { 516 struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev); 517 int ret; 518 519 /* Destroy all endpoints */ 520 ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_eptdev_destroy); 521 if (ret) 522 dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret); 523 524 cdev_device_del(&ctrldev->cdev, &ctrldev->dev); 525 put_device(&ctrldev->dev); 526 } 527 528 static struct rpmsg_driver rpmsg_chrdev_driver = { 529 .probe = rpmsg_chrdev_probe, 530 .remove = rpmsg_chrdev_remove, 531 .drv = { 532 .name = "rpmsg_chrdev", 533 }, 534 }; 535 536 static int rpmsg_chrdev_init(void) 537 { 538 int ret; 539 540 ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg"); 541 if (ret < 0) { 542 pr_err("failed to allocate char dev region\n"); 543 return ret; 544 } 545 546 rpmsg_class = class_create(THIS_MODULE, "rpmsg"); 547 if (IS_ERR(rpmsg_class)) { 548 pr_err("failed to create rpmsg class\n"); 549 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); 550 return PTR_ERR(rpmsg_class); 551 } 552 553 ret = register_rpmsg_driver(&rpmsg_chrdev_driver); 554 if (ret < 0) { 555 pr_err("failed to register rpmsg driver\n"); 556 class_destroy(rpmsg_class); 557 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); 558 } 559 560 return ret; 561 } 562 postcore_initcall(rpmsg_chrdev_init); 563 564 static void rpmsg_chrdev_exit(void) 565 { 566 unregister_rpmsg_driver(&rpmsg_chrdev_driver); 567 class_destroy(rpmsg_class); 568 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); 569 } 570 module_exit(rpmsg_chrdev_exit); 571 572 MODULE_ALIAS("rpmsg:rpmsg_chrdev"); 573 MODULE_LICENSE("GPL v2"); 574