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 get_device(dev); 131 132 ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo); 133 if (!ept) { 134 dev_err(dev, "failed to open %s\n", eptdev->chinfo.name); 135 put_device(dev); 136 return -EINVAL; 137 } 138 139 eptdev->ept = ept; 140 filp->private_data = eptdev; 141 142 return 0; 143 } 144 145 static int rpmsg_eptdev_release(struct inode *inode, struct file *filp) 146 { 147 struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev); 148 struct device *dev = &eptdev->dev; 149 struct sk_buff *skb; 150 151 /* Close the endpoint, if it's not already destroyed by the parent */ 152 mutex_lock(&eptdev->ept_lock); 153 if (eptdev->ept) { 154 rpmsg_destroy_ept(eptdev->ept); 155 eptdev->ept = NULL; 156 } 157 mutex_unlock(&eptdev->ept_lock); 158 159 /* Discard all SKBs */ 160 while (!skb_queue_empty(&eptdev->queue)) { 161 skb = skb_dequeue(&eptdev->queue); 162 kfree_skb(skb); 163 } 164 165 put_device(dev); 166 167 return 0; 168 } 169 170 static ssize_t rpmsg_eptdev_read(struct file *filp, char __user *buf, 171 size_t len, loff_t *f_pos) 172 { 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, len, skb->len); 209 if (copy_to_user(buf, skb->data, use)) 210 use = -EFAULT; 211 212 kfree_skb(skb); 213 214 return use; 215 } 216 217 static ssize_t rpmsg_eptdev_write(struct file *filp, const char __user *buf, 218 size_t len, loff_t *f_pos) 219 { 220 struct rpmsg_eptdev *eptdev = filp->private_data; 221 void *kbuf; 222 int ret; 223 224 kbuf = memdup_user(buf, len); 225 if (IS_ERR(kbuf)) 226 return PTR_ERR(kbuf); 227 228 if (mutex_lock_interruptible(&eptdev->ept_lock)) { 229 ret = -ERESTARTSYS; 230 goto free_kbuf; 231 } 232 233 if (!eptdev->ept) { 234 ret = -EPIPE; 235 goto unlock_eptdev; 236 } 237 238 if (filp->f_flags & O_NONBLOCK) 239 ret = rpmsg_trysend(eptdev->ept, kbuf, len); 240 else 241 ret = rpmsg_send(eptdev->ept, kbuf, len); 242 243 unlock_eptdev: 244 mutex_unlock(&eptdev->ept_lock); 245 246 free_kbuf: 247 kfree(kbuf); 248 return ret < 0 ? ret : len; 249 } 250 251 static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait) 252 { 253 struct rpmsg_eptdev *eptdev = filp->private_data; 254 __poll_t mask = 0; 255 256 if (!eptdev->ept) 257 return EPOLLERR; 258 259 poll_wait(filp, &eptdev->readq, wait); 260 261 if (!skb_queue_empty(&eptdev->queue)) 262 mask |= EPOLLIN | EPOLLRDNORM; 263 264 mask |= rpmsg_poll(eptdev->ept, filp, wait); 265 266 return mask; 267 } 268 269 static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd, 270 unsigned long arg) 271 { 272 struct rpmsg_eptdev *eptdev = fp->private_data; 273 274 if (cmd != RPMSG_DESTROY_EPT_IOCTL) 275 return -EINVAL; 276 277 return rpmsg_eptdev_destroy(&eptdev->dev, NULL); 278 } 279 280 static const struct file_operations rpmsg_eptdev_fops = { 281 .owner = THIS_MODULE, 282 .open = rpmsg_eptdev_open, 283 .release = rpmsg_eptdev_release, 284 .read = rpmsg_eptdev_read, 285 .write = rpmsg_eptdev_write, 286 .poll = rpmsg_eptdev_poll, 287 .unlocked_ioctl = rpmsg_eptdev_ioctl, 288 }; 289 290 static ssize_t name_show(struct device *dev, struct device_attribute *attr, 291 char *buf) 292 { 293 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev); 294 295 return sprintf(buf, "%s\n", eptdev->chinfo.name); 296 } 297 static DEVICE_ATTR_RO(name); 298 299 static ssize_t src_show(struct device *dev, struct device_attribute *attr, 300 char *buf) 301 { 302 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev); 303 304 return sprintf(buf, "%d\n", eptdev->chinfo.src); 305 } 306 static DEVICE_ATTR_RO(src); 307 308 static ssize_t dst_show(struct device *dev, struct device_attribute *attr, 309 char *buf) 310 { 311 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev); 312 313 return sprintf(buf, "%d\n", eptdev->chinfo.dst); 314 } 315 static DEVICE_ATTR_RO(dst); 316 317 static struct attribute *rpmsg_eptdev_attrs[] = { 318 &dev_attr_name.attr, 319 &dev_attr_src.attr, 320 &dev_attr_dst.attr, 321 NULL 322 }; 323 ATTRIBUTE_GROUPS(rpmsg_eptdev); 324 325 static void rpmsg_eptdev_release_device(struct device *dev) 326 { 327 struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev); 328 329 ida_simple_remove(&rpmsg_ept_ida, dev->id); 330 ida_simple_remove(&rpmsg_minor_ida, MINOR(eptdev->dev.devt)); 331 cdev_del(&eptdev->cdev); 332 kfree(eptdev); 333 } 334 335 static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev, 336 struct rpmsg_channel_info chinfo) 337 { 338 struct rpmsg_device *rpdev = ctrldev->rpdev; 339 struct rpmsg_eptdev *eptdev; 340 struct device *dev; 341 int ret; 342 343 eptdev = kzalloc(sizeof(*eptdev), GFP_KERNEL); 344 if (!eptdev) 345 return -ENOMEM; 346 347 dev = &eptdev->dev; 348 eptdev->rpdev = rpdev; 349 eptdev->chinfo = chinfo; 350 351 mutex_init(&eptdev->ept_lock); 352 spin_lock_init(&eptdev->queue_lock); 353 skb_queue_head_init(&eptdev->queue); 354 init_waitqueue_head(&eptdev->readq); 355 356 device_initialize(dev); 357 dev->class = rpmsg_class; 358 dev->parent = &ctrldev->dev; 359 dev->groups = rpmsg_eptdev_groups; 360 dev_set_drvdata(dev, eptdev); 361 362 cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops); 363 eptdev->cdev.owner = THIS_MODULE; 364 365 ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL); 366 if (ret < 0) 367 goto free_eptdev; 368 dev->devt = MKDEV(MAJOR(rpmsg_major), ret); 369 370 ret = ida_simple_get(&rpmsg_ept_ida, 0, 0, GFP_KERNEL); 371 if (ret < 0) 372 goto free_minor_ida; 373 dev->id = ret; 374 dev_set_name(dev, "rpmsg%d", ret); 375 376 ret = cdev_add(&eptdev->cdev, dev->devt, 1); 377 if (ret) 378 goto free_ept_ida; 379 380 /* We can now rely on the release function for cleanup */ 381 dev->release = rpmsg_eptdev_release_device; 382 383 ret = device_add(dev); 384 if (ret) { 385 dev_err(dev, "device_add failed: %d\n", ret); 386 put_device(dev); 387 } 388 389 return ret; 390 391 free_ept_ida: 392 ida_simple_remove(&rpmsg_ept_ida, dev->id); 393 free_minor_ida: 394 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); 395 free_eptdev: 396 put_device(dev); 397 kfree(eptdev); 398 399 return ret; 400 } 401 402 static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp) 403 { 404 struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev); 405 406 get_device(&ctrldev->dev); 407 filp->private_data = ctrldev; 408 409 return 0; 410 } 411 412 static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp) 413 { 414 struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev); 415 416 put_device(&ctrldev->dev); 417 418 return 0; 419 } 420 421 static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, 422 unsigned long arg) 423 { 424 struct rpmsg_ctrldev *ctrldev = fp->private_data; 425 void __user *argp = (void __user *)arg; 426 struct rpmsg_endpoint_info eptinfo; 427 struct rpmsg_channel_info chinfo; 428 429 if (cmd != RPMSG_CREATE_EPT_IOCTL) 430 return -EINVAL; 431 432 if (copy_from_user(&eptinfo, argp, sizeof(eptinfo))) 433 return -EFAULT; 434 435 memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE); 436 chinfo.name[RPMSG_NAME_SIZE-1] = '\0'; 437 chinfo.src = eptinfo.src; 438 chinfo.dst = eptinfo.dst; 439 440 return rpmsg_eptdev_create(ctrldev, chinfo); 441 }; 442 443 static const struct file_operations rpmsg_ctrldev_fops = { 444 .owner = THIS_MODULE, 445 .open = rpmsg_ctrldev_open, 446 .release = rpmsg_ctrldev_release, 447 .unlocked_ioctl = rpmsg_ctrldev_ioctl, 448 }; 449 450 static void rpmsg_ctrldev_release_device(struct device *dev) 451 { 452 struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev); 453 454 ida_simple_remove(&rpmsg_ctrl_ida, dev->id); 455 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); 456 cdev_del(&ctrldev->cdev); 457 kfree(ctrldev); 458 } 459 460 static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev) 461 { 462 struct rpmsg_ctrldev *ctrldev; 463 struct device *dev; 464 int ret; 465 466 ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL); 467 if (!ctrldev) 468 return -ENOMEM; 469 470 ctrldev->rpdev = rpdev; 471 472 dev = &ctrldev->dev; 473 device_initialize(dev); 474 dev->parent = &rpdev->dev; 475 dev->class = rpmsg_class; 476 477 cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops); 478 ctrldev->cdev.owner = THIS_MODULE; 479 480 ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL); 481 if (ret < 0) 482 goto free_ctrldev; 483 dev->devt = MKDEV(MAJOR(rpmsg_major), ret); 484 485 ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL); 486 if (ret < 0) 487 goto free_minor_ida; 488 dev->id = ret; 489 dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret); 490 491 ret = cdev_add(&ctrldev->cdev, dev->devt, 1); 492 if (ret) 493 goto free_ctrl_ida; 494 495 /* We can now rely on the release function for cleanup */ 496 dev->release = rpmsg_ctrldev_release_device; 497 498 ret = device_add(dev); 499 if (ret) { 500 dev_err(&rpdev->dev, "device_add failed: %d\n", ret); 501 put_device(dev); 502 } 503 504 dev_set_drvdata(&rpdev->dev, ctrldev); 505 506 return ret; 507 508 free_ctrl_ida: 509 ida_simple_remove(&rpmsg_ctrl_ida, dev->id); 510 free_minor_ida: 511 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); 512 free_ctrldev: 513 put_device(dev); 514 kfree(ctrldev); 515 516 return ret; 517 } 518 519 static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev) 520 { 521 struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev); 522 int ret; 523 524 /* Destroy all endpoints */ 525 ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_eptdev_destroy); 526 if (ret) 527 dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret); 528 529 device_del(&ctrldev->dev); 530 put_device(&ctrldev->dev); 531 } 532 533 static struct rpmsg_driver rpmsg_chrdev_driver = { 534 .probe = rpmsg_chrdev_probe, 535 .remove = rpmsg_chrdev_remove, 536 .drv = { 537 .name = "rpmsg_chrdev", 538 }, 539 }; 540 541 static int rpmsg_char_init(void) 542 { 543 int ret; 544 545 ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg"); 546 if (ret < 0) { 547 pr_err("rpmsg: failed to allocate char dev region\n"); 548 return ret; 549 } 550 551 rpmsg_class = class_create(THIS_MODULE, "rpmsg"); 552 if (IS_ERR(rpmsg_class)) { 553 pr_err("failed to create rpmsg class\n"); 554 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); 555 return PTR_ERR(rpmsg_class); 556 } 557 558 ret = register_rpmsg_driver(&rpmsg_chrdev_driver); 559 if (ret < 0) { 560 pr_err("rpmsgchr: failed to register rpmsg driver\n"); 561 class_destroy(rpmsg_class); 562 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); 563 } 564 565 return ret; 566 } 567 postcore_initcall(rpmsg_char_init); 568 569 static void rpmsg_chrdev_exit(void) 570 { 571 unregister_rpmsg_driver(&rpmsg_chrdev_driver); 572 class_destroy(rpmsg_class); 573 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); 574 } 575 module_exit(rpmsg_chrdev_exit); 576 577 MODULE_ALIAS("rpmsg:rpmsg_chrdev"); 578 MODULE_LICENSE("GPL v2"); 579