1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2022, STMicroelectronics 4 * Copyright (c) 2016, Linaro Ltd. 5 * Copyright (c) 2012, Michal Simek <monstr@monstr.eu> 6 * Copyright (c) 2012, PetaLogix 7 * Copyright (c) 2011, Texas Instruments, Inc. 8 * Copyright (c) 2011, Google, Inc. 9 * 10 * Based on rpmsg performance statistics driver by Michal Simek, which in turn 11 * was based on TI & Google OMX rpmsg driver. 12 */ 13 14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 15 16 #include <linux/cdev.h> 17 #include <linux/device.h> 18 #include <linux/fs.h> 19 #include <linux/idr.h> 20 #include <linux/kernel.h> 21 #include <linux/module.h> 22 #include <linux/poll.h> 23 #include <linux/rpmsg.h> 24 #include <linux/skbuff.h> 25 #include <linux/slab.h> 26 #include <linux/uaccess.h> 27 #include <uapi/linux/rpmsg.h> 28 29 #include "rpmsg_char.h" 30 #include "rpmsg_internal.h" 31 32 #define RPMSG_DEV_MAX (MINORMASK + 1) 33 34 static dev_t rpmsg_major; 35 36 static DEFINE_IDA(rpmsg_ctrl_ida); 37 static DEFINE_IDA(rpmsg_ept_ida); 38 static DEFINE_IDA(rpmsg_minor_ida); 39 40 #define dev_to_eptdev(dev) container_of(dev, struct rpmsg_eptdev, dev) 41 #define cdev_to_eptdev(i_cdev) container_of(i_cdev, struct rpmsg_eptdev, cdev) 42 43 #define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev) 44 #define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev) 45 46 /** 47 * struct rpmsg_ctrldev - control device for instantiating endpoint devices 48 * @rpdev: underlaying rpmsg device 49 * @cdev: cdev for the ctrl device 50 * @dev: device for the ctrl device 51 */ 52 struct rpmsg_ctrldev { 53 struct rpmsg_device *rpdev; 54 struct cdev cdev; 55 struct device dev; 56 }; 57 58 /** 59 * struct rpmsg_eptdev - endpoint device context 60 * @dev: endpoint device 61 * @cdev: cdev for the endpoint device 62 * @rpdev: underlaying rpmsg device 63 * @chinfo: info used to open the endpoint 64 * @ept_lock: synchronization of @ept modifications 65 * @ept: rpmsg endpoint reference, when open 66 * @queue_lock: synchronization of @queue operations 67 * @queue: incoming message queue 68 * @readq: wait object for incoming queue 69 */ 70 struct rpmsg_eptdev { 71 struct device dev; 72 struct cdev cdev; 73 74 struct rpmsg_device *rpdev; 75 struct rpmsg_channel_info chinfo; 76 77 struct mutex ept_lock; 78 struct rpmsg_endpoint *ept; 79 80 spinlock_t queue_lock; 81 struct sk_buff_head queue; 82 wait_queue_head_t readq; 83 }; 84 85 int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *data) 86 { 87 struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev); 88 89 mutex_lock(&eptdev->ept_lock); 90 if (eptdev->ept) { 91 rpmsg_destroy_ept(eptdev->ept); 92 eptdev->ept = NULL; 93 } 94 mutex_unlock(&eptdev->ept_lock); 95 96 /* wake up any blocked readers */ 97 wake_up_interruptible(&eptdev->readq); 98 99 cdev_device_del(&eptdev->cdev, &eptdev->dev); 100 put_device(&eptdev->dev); 101 102 return 0; 103 } 104 EXPORT_SYMBOL(rpmsg_chrdev_eptdev_destroy); 105 106 static int rpmsg_ept_cb(struct rpmsg_device *rpdev, void *buf, int len, 107 void *priv, u32 addr) 108 { 109 struct rpmsg_eptdev *eptdev = priv; 110 struct sk_buff *skb; 111 112 skb = alloc_skb(len, GFP_ATOMIC); 113 if (!skb) 114 return -ENOMEM; 115 116 skb_put_data(skb, buf, len); 117 118 spin_lock(&eptdev->queue_lock); 119 skb_queue_tail(&eptdev->queue, skb); 120 spin_unlock(&eptdev->queue_lock); 121 122 /* wake up any blocking processes, waiting for new data */ 123 wake_up_interruptible(&eptdev->readq); 124 125 return 0; 126 } 127 128 static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) 129 { 130 struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev); 131 struct rpmsg_endpoint *ept; 132 struct rpmsg_device *rpdev = eptdev->rpdev; 133 struct device *dev = &eptdev->dev; 134 135 if (eptdev->ept) 136 return -EBUSY; 137 138 get_device(dev); 139 140 ept = rpmsg_create_ept(rpdev, rpmsg_ept_cb, eptdev, eptdev->chinfo); 141 if (!ept) { 142 dev_err(dev, "failed to open %s\n", eptdev->chinfo.name); 143 put_device(dev); 144 return -EINVAL; 145 } 146 147 eptdev->ept = ept; 148 filp->private_data = eptdev; 149 150 return 0; 151 } 152 153 static int rpmsg_eptdev_release(struct inode *inode, struct file *filp) 154 { 155 struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev); 156 struct device *dev = &eptdev->dev; 157 158 /* Close the endpoint, if it's not already destroyed by the parent */ 159 mutex_lock(&eptdev->ept_lock); 160 if (eptdev->ept) { 161 rpmsg_destroy_ept(eptdev->ept); 162 eptdev->ept = NULL; 163 } 164 mutex_unlock(&eptdev->ept_lock); 165 166 /* Discard all SKBs */ 167 skb_queue_purge(&eptdev->queue); 168 169 put_device(dev); 170 171 return 0; 172 } 173 174 static ssize_t rpmsg_eptdev_read_iter(struct kiocb *iocb, struct iov_iter *to) 175 { 176 struct file *filp = iocb->ki_filp; 177 struct rpmsg_eptdev *eptdev = filp->private_data; 178 unsigned long flags; 179 struct sk_buff *skb; 180 int use; 181 182 if (!eptdev->ept) 183 return -EPIPE; 184 185 spin_lock_irqsave(&eptdev->queue_lock, flags); 186 187 /* Wait for data in the queue */ 188 if (skb_queue_empty(&eptdev->queue)) { 189 spin_unlock_irqrestore(&eptdev->queue_lock, flags); 190 191 if (filp->f_flags & O_NONBLOCK) 192 return -EAGAIN; 193 194 /* Wait until we get data or the endpoint goes away */ 195 if (wait_event_interruptible(eptdev->readq, 196 !skb_queue_empty(&eptdev->queue) || 197 !eptdev->ept)) 198 return -ERESTARTSYS; 199 200 /* We lost the endpoint while waiting */ 201 if (!eptdev->ept) 202 return -EPIPE; 203 204 spin_lock_irqsave(&eptdev->queue_lock, flags); 205 } 206 207 skb = skb_dequeue(&eptdev->queue); 208 spin_unlock_irqrestore(&eptdev->queue_lock, flags); 209 if (!skb) 210 return -EFAULT; 211 212 use = min_t(size_t, iov_iter_count(to), skb->len); 213 if (copy_to_iter(skb->data, use, to) != use) 214 use = -EFAULT; 215 216 kfree_skb(skb); 217 218 return use; 219 } 220 221 static ssize_t rpmsg_eptdev_write_iter(struct kiocb *iocb, 222 struct iov_iter *from) 223 { 224 struct file *filp = iocb->ki_filp; 225 struct rpmsg_eptdev *eptdev = filp->private_data; 226 size_t len = iov_iter_count(from); 227 void *kbuf; 228 int ret; 229 230 kbuf = kzalloc(len, GFP_KERNEL); 231 if (!kbuf) 232 return -ENOMEM; 233 234 if (!copy_from_iter_full(kbuf, len, from)) { 235 ret = -EFAULT; 236 goto free_kbuf; 237 } 238 239 if (mutex_lock_interruptible(&eptdev->ept_lock)) { 240 ret = -ERESTARTSYS; 241 goto free_kbuf; 242 } 243 244 if (!eptdev->ept) { 245 ret = -EPIPE; 246 goto unlock_eptdev; 247 } 248 249 if (filp->f_flags & O_NONBLOCK) { 250 ret = rpmsg_trysendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst); 251 if (ret == -ENOMEM) 252 ret = -EAGAIN; 253 } else { 254 ret = rpmsg_sendto(eptdev->ept, kbuf, len, eptdev->chinfo.dst); 255 } 256 257 unlock_eptdev: 258 mutex_unlock(&eptdev->ept_lock); 259 260 free_kbuf: 261 kfree(kbuf); 262 return ret < 0 ? ret : len; 263 } 264 265 static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait) 266 { 267 struct rpmsg_eptdev *eptdev = filp->private_data; 268 __poll_t mask = 0; 269 270 if (!eptdev->ept) 271 return EPOLLERR; 272 273 poll_wait(filp, &eptdev->readq, wait); 274 275 if (!skb_queue_empty(&eptdev->queue)) 276 mask |= EPOLLIN | EPOLLRDNORM; 277 278 mask |= rpmsg_poll(eptdev->ept, filp, wait); 279 280 return mask; 281 } 282 283 static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd, 284 unsigned long arg) 285 { 286 struct rpmsg_eptdev *eptdev = fp->private_data; 287 288 if (cmd != RPMSG_DESTROY_EPT_IOCTL) 289 return -EINVAL; 290 291 return rpmsg_chrdev_eptdev_destroy(&eptdev->dev, NULL); 292 } 293 294 static const struct file_operations rpmsg_eptdev_fops = { 295 .owner = THIS_MODULE, 296 .open = rpmsg_eptdev_open, 297 .release = rpmsg_eptdev_release, 298 .read_iter = rpmsg_eptdev_read_iter, 299 .write_iter = rpmsg_eptdev_write_iter, 300 .poll = rpmsg_eptdev_poll, 301 .unlocked_ioctl = rpmsg_eptdev_ioctl, 302 .compat_ioctl = compat_ptr_ioctl, 303 }; 304 305 static ssize_t name_show(struct device *dev, struct device_attribute *attr, 306 char *buf) 307 { 308 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev); 309 310 return sprintf(buf, "%s\n", eptdev->chinfo.name); 311 } 312 static DEVICE_ATTR_RO(name); 313 314 static ssize_t src_show(struct device *dev, struct device_attribute *attr, 315 char *buf) 316 { 317 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev); 318 319 return sprintf(buf, "%d\n", eptdev->chinfo.src); 320 } 321 static DEVICE_ATTR_RO(src); 322 323 static ssize_t dst_show(struct device *dev, struct device_attribute *attr, 324 char *buf) 325 { 326 struct rpmsg_eptdev *eptdev = dev_get_drvdata(dev); 327 328 return sprintf(buf, "%d\n", eptdev->chinfo.dst); 329 } 330 static DEVICE_ATTR_RO(dst); 331 332 static struct attribute *rpmsg_eptdev_attrs[] = { 333 &dev_attr_name.attr, 334 &dev_attr_src.attr, 335 &dev_attr_dst.attr, 336 NULL 337 }; 338 ATTRIBUTE_GROUPS(rpmsg_eptdev); 339 340 static void rpmsg_eptdev_release_device(struct device *dev) 341 { 342 struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev); 343 344 ida_simple_remove(&rpmsg_ept_ida, dev->id); 345 ida_simple_remove(&rpmsg_minor_ida, MINOR(eptdev->dev.devt)); 346 kfree(eptdev); 347 } 348 349 int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *parent, 350 struct rpmsg_channel_info chinfo) 351 { 352 struct rpmsg_eptdev *eptdev; 353 struct device *dev; 354 int ret; 355 356 eptdev = kzalloc(sizeof(*eptdev), GFP_KERNEL); 357 if (!eptdev) 358 return -ENOMEM; 359 360 dev = &eptdev->dev; 361 eptdev->rpdev = rpdev; 362 eptdev->chinfo = chinfo; 363 364 mutex_init(&eptdev->ept_lock); 365 spin_lock_init(&eptdev->queue_lock); 366 skb_queue_head_init(&eptdev->queue); 367 init_waitqueue_head(&eptdev->readq); 368 369 device_initialize(dev); 370 dev->class = rpmsg_class; 371 dev->parent = parent; 372 dev->groups = rpmsg_eptdev_groups; 373 dev_set_drvdata(dev, eptdev); 374 375 cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops); 376 eptdev->cdev.owner = THIS_MODULE; 377 378 ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL); 379 if (ret < 0) 380 goto free_eptdev; 381 dev->devt = MKDEV(MAJOR(rpmsg_major), ret); 382 383 ret = ida_simple_get(&rpmsg_ept_ida, 0, 0, GFP_KERNEL); 384 if (ret < 0) 385 goto free_minor_ida; 386 dev->id = ret; 387 dev_set_name(dev, "rpmsg%d", ret); 388 389 ret = cdev_device_add(&eptdev->cdev, &eptdev->dev); 390 if (ret) 391 goto free_ept_ida; 392 393 /* We can now rely on the release function for cleanup */ 394 dev->release = rpmsg_eptdev_release_device; 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 EXPORT_SYMBOL(rpmsg_chrdev_eptdev_create); 409 410 static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp) 411 { 412 struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev); 413 414 get_device(&ctrldev->dev); 415 filp->private_data = ctrldev; 416 417 return 0; 418 } 419 420 static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp) 421 { 422 struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev); 423 424 put_device(&ctrldev->dev); 425 426 return 0; 427 } 428 429 static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd, 430 unsigned long arg) 431 { 432 struct rpmsg_ctrldev *ctrldev = fp->private_data; 433 void __user *argp = (void __user *)arg; 434 struct rpmsg_endpoint_info eptinfo; 435 struct rpmsg_channel_info chinfo; 436 437 if (cmd != RPMSG_CREATE_EPT_IOCTL) 438 return -EINVAL; 439 440 if (copy_from_user(&eptinfo, argp, sizeof(eptinfo))) 441 return -EFAULT; 442 443 memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE); 444 chinfo.name[RPMSG_NAME_SIZE-1] = '\0'; 445 chinfo.src = eptinfo.src; 446 chinfo.dst = eptinfo.dst; 447 448 return rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo); 449 }; 450 451 static const struct file_operations rpmsg_ctrldev_fops = { 452 .owner = THIS_MODULE, 453 .open = rpmsg_ctrldev_open, 454 .release = rpmsg_ctrldev_release, 455 .unlocked_ioctl = rpmsg_ctrldev_ioctl, 456 .compat_ioctl = compat_ptr_ioctl, 457 }; 458 459 static void rpmsg_ctrldev_release_device(struct device *dev) 460 { 461 struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev); 462 463 ida_simple_remove(&rpmsg_ctrl_ida, dev->id); 464 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); 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_device_add(&ctrldev->cdev, &ctrldev->dev); 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 dev_set_drvdata(&rpdev->dev, ctrldev); 507 508 return ret; 509 510 free_ctrl_ida: 511 ida_simple_remove(&rpmsg_ctrl_ida, dev->id); 512 free_minor_ida: 513 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); 514 free_ctrldev: 515 put_device(dev); 516 kfree(ctrldev); 517 518 return ret; 519 } 520 521 static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev) 522 { 523 struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev); 524 int ret; 525 526 /* Destroy all endpoints */ 527 ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_chrdev_eptdev_destroy); 528 if (ret) 529 dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret); 530 531 cdev_device_del(&ctrldev->cdev, &ctrldev->dev); 532 put_device(&ctrldev->dev); 533 } 534 535 static struct rpmsg_driver rpmsg_chrdev_driver = { 536 .probe = rpmsg_chrdev_probe, 537 .remove = rpmsg_chrdev_remove, 538 .drv = { 539 .name = "rpmsg_chrdev", 540 }, 541 }; 542 543 static int rpmsg_chrdev_init(void) 544 { 545 int ret; 546 547 ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg"); 548 if (ret < 0) { 549 pr_err("failed to allocate char dev region\n"); 550 return ret; 551 } 552 553 ret = register_rpmsg_driver(&rpmsg_chrdev_driver); 554 if (ret < 0) { 555 pr_err("failed to register rpmsg driver\n"); 556 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); 557 } 558 559 return ret; 560 } 561 postcore_initcall(rpmsg_chrdev_init); 562 563 static void rpmsg_chrdev_exit(void) 564 { 565 unregister_rpmsg_driver(&rpmsg_chrdev_driver); 566 unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX); 567 } 568 module_exit(rpmsg_chrdev_exit); 569 570 MODULE_ALIAS("rpmsg:rpmsg_chrdev"); 571 MODULE_LICENSE("GPL v2"); 572