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 #include <linux/cdev.h> 13 #include <linux/device.h> 14 #include <linux/fs.h> 15 #include <linux/idr.h> 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include <linux/poll.h> 19 #include <linux/rpmsg.h> 20 #include <linux/skbuff.h> 21 #include <linux/slab.h> 22 #include <linux/uaccess.h> 23 #include <uapi/linux/rpmsg.h> 24 25 #include "rpmsg_internal.h" 26 27 #define RPMSG_DEV_MAX (MINORMASK + 1) 28 29 static dev_t rpmsg_major; 30 static struct class *rpmsg_class; 31 32 static DEFINE_IDA(rpmsg_ctrl_ida); 33 static DEFINE_IDA(rpmsg_ept_ida); 34 static DEFINE_IDA(rpmsg_minor_ida); 35 36 #define dev_to_eptdev(dev) container_of(dev, struct rpmsg_eptdev, dev) 37 #define cdev_to_eptdev(i_cdev) container_of(i_cdev, struct rpmsg_eptdev, cdev) 38 39 #define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev) 40 #define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev) 41 42 /** 43 * struct rpmsg_ctrldev - control device for instantiating endpoint devices 44 * @rpdev: underlaying rpmsg device 45 * @cdev: cdev for the ctrl device 46 * @dev: device for the ctrl device 47 */ 48 struct rpmsg_ctrldev { 49 struct rpmsg_device *rpdev; 50 struct cdev cdev; 51 struct device dev; 52 }; 53 54 /** 55 * struct rpmsg_eptdev - endpoint device context 56 * @dev: endpoint device 57 * @cdev: cdev for the endpoint device 58 * @rpdev: underlaying rpmsg device 59 * @chinfo: info used to open the endpoint 60 * @ept_lock: synchronization of @ept modifications 61 * @ept: rpmsg endpoint reference, when open 62 * @queue_lock: synchronization of @queue operations 63 * @queue: incoming message queue 64 * @readq: wait object for incoming queue 65 */ 66 struct rpmsg_eptdev { 67 struct device dev; 68 struct cdev cdev; 69 70 struct rpmsg_device *rpdev; 71 struct rpmsg_channel_info chinfo; 72 73 struct mutex ept_lock; 74 struct rpmsg_endpoint *ept; 75 76 spinlock_t queue_lock; 77 struct sk_buff_head queue; 78 wait_queue_head_t readq; 79 }; 80 81 static int rpmsg_eptdev_destroy(struct device *dev, void *data) 82 { 83 struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev); 84 85 mutex_lock(&eptdev->ept_lock); 86 if (eptdev->ept) { 87 rpmsg_destroy_ept(eptdev->ept); 88 eptdev->ept = NULL; 89 } 90 mutex_unlock(&eptdev->ept_lock); 91 92 /* wake up any blocked readers */ 93 wake_up_interruptible(&eptdev->readq); 94 95 device_del(&eptdev->dev); 96 put_device(&eptdev->dev); 97 98 return 0; 99 } 100 101 static int rpmsg_ept_cb(struct rpmsg_device *rpdev, void *buf, int len, 102 void *priv, u32 addr) 103 { 104 struct rpmsg_eptdev *eptdev = priv; 105 struct sk_buff *skb; 106 107 skb = alloc_skb(len, GFP_ATOMIC); 108 if (!skb) 109 return -ENOMEM; 110 111 skb_put_data(skb, buf, len); 112 113 spin_lock(&eptdev->queue_lock); 114 skb_queue_tail(&eptdev->queue, skb); 115 spin_unlock(&eptdev->queue_lock); 116 117 /* wake up any blocking processes, waiting for new data */ 118 wake_up_interruptible(&eptdev->readq); 119 120 return 0; 121 } 122 123 static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) 124 { 125 struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev); 126 struct rpmsg_endpoint *ept; 127 struct rpmsg_device *rpdev = eptdev->rpdev; 128 struct device *dev = &eptdev->dev; 129 130 if (eptdev->ept) 131 return -EBUSY; 132 133 get_device(dev); 134 135 ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo); 136 if (!ept) { 137 dev_err(dev, "failed to open %s\n", eptdev->chinfo.name); 138 put_device(dev); 139 return -EINVAL; 140 } 141 142 eptdev->ept = ept; 143 filp->private_data = eptdev; 144 145 return 0; 146 } 147 148 static int rpmsg_eptdev_release(struct inode *inode, struct file *filp) 149 { 150 struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev); 151 struct device *dev = &eptdev->dev; 152 153 /* Close the endpoint, if it's not already destroyed by the parent */ 154 mutex_lock(&eptdev->ept_lock); 155 if (eptdev->ept) { 156 rpmsg_destroy_ept(eptdev->ept); 157 eptdev->ept = NULL; 158 } 159 mutex_unlock(&eptdev->ept_lock); 160 161 /* Discard all SKBs */ 162 skb_queue_purge(&eptdev->queue); 163 164 put_device(dev); 165 166 return 0; 167 } 168 169 static ssize_t rpmsg_eptdev_read_iter(struct kiocb *iocb, struct iov_iter *to) 170 { 171 struct file *filp = iocb->ki_filp; 172 struct rpmsg_eptdev *eptdev = filp->private_data; 173 unsigned long flags; 174 struct sk_buff *skb; 175 int use; 176 177 if (!eptdev->ept) 178 return -EPIPE; 179 180 spin_lock_irqsave(&eptdev->queue_lock, flags); 181 182 /* Wait for data in the queue */ 183 if (skb_queue_empty(&eptdev->queue)) { 184 spin_unlock_irqrestore(&eptdev->queue_lock, flags); 185 186 if (filp->f_flags & O_NONBLOCK) 187 return -EAGAIN; 188 189 /* Wait until we get data or the endpoint goes away */ 190 if (wait_event_interruptible(eptdev->readq, 191 !skb_queue_empty(&eptdev->queue) || 192 !eptdev->ept)) 193 return -ERESTARTSYS; 194 195 /* We lost the endpoint while waiting */ 196 if (!eptdev->ept) 197 return -EPIPE; 198 199 spin_lock_irqsave(&eptdev->queue_lock, flags); 200 } 201 202 skb = skb_dequeue(&eptdev->queue); 203 spin_unlock_irqrestore(&eptdev->queue_lock, flags); 204 if (!skb) 205 return -EFAULT; 206 207 use = min_t(size_t, iov_iter_count(to), skb->len); 208 if (copy_to_iter(skb->data, use, to) != use) 209 use = -EFAULT; 210 211 kfree_skb(skb); 212 213 return use; 214 } 215 216 static ssize_t rpmsg_eptdev_write_iter(struct kiocb *iocb, 217 struct iov_iter *from) 218 { 219 struct file *filp = iocb->ki_filp; 220 struct rpmsg_eptdev *eptdev = filp->private_data; 221 size_t len = iov_iter_count(from); 222 void *kbuf; 223 int ret; 224 225 kbuf = kzalloc(len, GFP_KERNEL); 226 if (!kbuf) 227 return -ENOMEM; 228 229 if (!copy_from_iter_full(kbuf, len, from)) { 230 ret = -EFAULT; 231 goto free_kbuf; 232 } 233 234 if (mutex_lock_interruptible(&eptdev->ept_lock)) { 235 ret = -ERESTARTSYS; 236 goto free_kbuf; 237 } 238 239 if (!eptdev->ept) { 240 ret = -EPIPE; 241 goto unlock_eptdev; 242 } 243 244 if (filp->f_flags & O_NONBLOCK) 245 ret = rpmsg_trysendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst); 246 else 247 ret = rpmsg_sendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst); 248 249 unlock_eptdev: 250 mutex_unlock(&eptdev->ept_lock); 251 252 free_kbuf: 253 kfree(kbuf); 254 return ret < 0 ? ret : len; 255 } 256 257 static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait) 258 { 259 struct rpmsg_eptdev *eptdev = filp->private_data; 260 __poll_t mask = 0; 261 262 if (!eptdev->ept) 263 return EPOLLERR; 264 265 poll_wait(filp, &eptdev->readq, wait); 266 267 if (!skb_queue_empty(&eptdev->queue)) 268 mask |= EPOLLIN | EPOLLRDNORM; 269 270 mask |= rpmsg_poll(eptdev->ept, filp, wait); 271 272 return mask; 273 } 274 275 static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd, 276 unsigned long arg) 277 { 278 struct rpmsg_eptdev *eptdev = fp->private_data; 279 280 if (cmd != RPMSG_DESTROY_EPT_IOCTL) 281 return -EINVAL; 282 283 return rpmsg_eptdev_destroy(&eptdev->dev, NULL); 284 } 285 286 static const struct file_operations rpmsg_eptdev_fops = { 287 .owner = THIS_MODULE, 288 .open = rpmsg_eptdev_open, 289 .release = rpmsg_eptdev_release, 290 .read_iter = rpmsg_eptdev_read_iter, 291 .write_iter = rpmsg_eptdev_write_iter, 292 .poll = rpmsg_eptdev_poll, 293 .unlocked_ioctl = rpmsg_eptdev_ioctl, 294 .compat_ioctl = compat_ptr_ioctl, 295 }; 296 297 static ssize_t name_show(struct device *dev, struct device_attribute *attr, 298 char *buf) 299 { 300 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev); 301 302 return sprintf(buf, "%s\n", eptdev->chinfo.name); 303 } 304 static DEVICE_ATTR_RO(name); 305 306 static ssize_t src_show(struct device *dev, struct device_attribute *attr, 307 char *buf) 308 { 309 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev); 310 311 return sprintf(buf, "%d\n", eptdev->chinfo.src); 312 } 313 static DEVICE_ATTR_RO(src); 314 315 static ssize_t dst_show(struct device *dev, struct device_attribute *attr, 316 char *buf) 317 { 318 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev); 319 320 return sprintf(buf, "%d\n", eptdev->chinfo.dst); 321 } 322 static DEVICE_ATTR_RO(dst); 323 324 static struct attribute *rpmsg_eptdev_attrs[] = { 325 &dev_attr_name.attr, 326 &dev_attr_src.attr, 327 &dev_attr_dst.attr, 328 NULL 329 }; 330 ATTRIBUTE_GROUPS(rpmsg_eptdev); 331 332 static void rpmsg_eptdev_release_device(struct device *dev) 333 { 334 struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev); 335 336 ida_simple_remove(&rpmsg_ept_ida, dev->id); 337 ida_simple_remove(&rpmsg_minor_ida, MINOR(eptdev->dev.devt)); 338 cdev_del(&eptdev->cdev); 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_add(&eptdev->cdev, dev->devt, 1); 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 ret = device_add(dev); 391 if (ret) { 392 dev_err(dev, "device_add failed: %d\n", ret); 393 put_device(dev); 394 } 395 396 return ret; 397 398 free_ept_ida: 399 ida_simple_remove(&rpmsg_ept_ida, dev->id); 400 free_minor_ida: 401 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); 402 free_eptdev: 403 put_device(dev); 404 kfree(eptdev); 405 406 return ret; 407 } 408 409 static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp) 410 { 411 struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev); 412 413 get_device(&ctrldev->dev); 414 filp->private_data = ctrldev; 415 416 return 0; 417 } 418 419 static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp) 420 { 421 struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev); 422 423 put_device(&ctrldev->dev); 424 425 return 0; 426 } 427 428 static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, 429 unsigned long arg) 430 { 431 struct rpmsg_ctrldev *ctrldev = fp->private_data; 432 void __user *argp = (void __user *)arg; 433 struct rpmsg_endpoint_info eptinfo; 434 struct rpmsg_channel_info chinfo; 435 436 if (cmd != RPMSG_CREATE_EPT_IOCTL) 437 return -EINVAL; 438 439 if (copy_from_user(&eptinfo, argp, sizeof(eptinfo))) 440 return -EFAULT; 441 442 memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE); 443 chinfo.name[RPMSG_NAME_SIZE-1] = '\0'; 444 chinfo.src = eptinfo.src; 445 chinfo.dst = eptinfo.dst; 446 447 return rpmsg_eptdev_create(ctrldev, chinfo); 448 }; 449 450 static const struct file_operations rpmsg_ctrldev_fops = { 451 .owner = THIS_MODULE, 452 .open = rpmsg_ctrldev_open, 453 .release = rpmsg_ctrldev_release, 454 .unlocked_ioctl = rpmsg_ctrldev_ioctl, 455 .compat_ioctl = compat_ptr_ioctl, 456 }; 457 458 static void rpmsg_ctrldev_release_device(struct device *dev) 459 { 460 struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev); 461 462 ida_simple_remove(&rpmsg_ctrl_ida, dev->id); 463 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); 464 cdev_del(&ctrldev->cdev); 465 kfree(ctrldev); 466 } 467 468 static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev) 469 { 470 struct rpmsg_ctrldev *ctrldev; 471 struct device *dev; 472 int ret; 473 474 ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL); 475 if (!ctrldev) 476 return -ENOMEM; 477 478 ctrldev->rpdev = rpdev; 479 480 dev = &ctrldev->dev; 481 device_initialize(dev); 482 dev->parent = &rpdev->dev; 483 dev->class = rpmsg_class; 484 485 cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops); 486 ctrldev->cdev.owner = THIS_MODULE; 487 488 ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL); 489 if (ret < 0) 490 goto free_ctrldev; 491 dev->devt = MKDEV(MAJOR(rpmsg_major), ret); 492 493 ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL); 494 if (ret < 0) 495 goto free_minor_ida; 496 dev->id = ret; 497 dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret); 498 499 ret = cdev_add(&ctrldev->cdev, dev->devt, 1); 500 if (ret) 501 goto free_ctrl_ida; 502 503 /* We can now rely on the release function for cleanup */ 504 dev->release = rpmsg_ctrldev_release_device; 505 506 ret = device_add(dev); 507 if (ret) { 508 dev_err(&rpdev->dev, "device_add failed: %d\n", ret); 509 put_device(dev); 510 } 511 512 dev_set_drvdata(&rpdev->dev, ctrldev); 513 514 return ret; 515 516 free_ctrl_ida: 517 ida_simple_remove(&rpmsg_ctrl_ida, dev->id); 518 free_minor_ida: 519 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); 520 free_ctrldev: 521 put_device(dev); 522 kfree(ctrldev); 523 524 return ret; 525 } 526 527 static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev) 528 { 529 struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev); 530 int ret; 531 532 /* Destroy all endpoints */ 533 ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_eptdev_destroy); 534 if (ret) 535 dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret); 536 537 device_del(&ctrldev->dev); 538 put_device(&ctrldev->dev); 539 } 540 541 static struct rpmsg_driver rpmsg_chrdev_driver = { 542 .probe = rpmsg_chrdev_probe, 543 .remove = rpmsg_chrdev_remove, 544 .drv = { 545 .name = "rpmsg_chrdev", 546 }, 547 }; 548 549 static int rpmsg_chrdev_init(void) 550 { 551 int ret; 552 553 ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg"); 554 if (ret < 0) { 555 pr_err("rpmsg: failed to allocate char dev region\n"); 556 return ret; 557 } 558 559 rpmsg_class = class_create(THIS_MODULE, "rpmsg"); 560 if (IS_ERR(rpmsg_class)) { 561 pr_err("failed to create rpmsg class\n"); 562 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); 563 return PTR_ERR(rpmsg_class); 564 } 565 566 ret = register_rpmsg_driver(&rpmsg_chrdev_driver); 567 if (ret < 0) { 568 pr_err("rpmsgchr: failed to register rpmsg driver\n"); 569 class_destroy(rpmsg_class); 570 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); 571 } 572 573 return ret; 574 } 575 postcore_initcall(rpmsg_chrdev_init); 576 577 static void rpmsg_chrdev_exit(void) 578 { 579 unregister_rpmsg_driver(&rpmsg_chrdev_driver); 580 class_destroy(rpmsg_class); 581 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); 582 } 583 module_exit(rpmsg_chrdev_exit); 584 585 MODULE_ALIAS("rpmsg:rpmsg_chrdev"); 586 MODULE_LICENSE("GPL v2"); 587