1 /* 2 * Copyright (c) 2016, Linaro Ltd. 3 * Copyright (c) 2012, Michal Simek <monstr@monstr.eu> 4 * Copyright (c) 2012, PetaLogix 5 * Copyright (c) 2011, Texas Instruments, Inc. 6 * Copyright (c) 2011, Google, Inc. 7 * 8 * Based on rpmsg performance statistics driver by Michal Simek, which in turn 9 * was based on TI & Google OMX rpmsg driver. 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 and 13 * only version 2 as published by the Free Software Foundation. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 */ 20 #include <linux/cdev.h> 21 #include <linux/device.h> 22 #include <linux/fs.h> 23 #include <linux/idr.h> 24 #include <linux/kernel.h> 25 #include <linux/module.h> 26 #include <linux/poll.h> 27 #include <linux/rpmsg.h> 28 #include <linux/skbuff.h> 29 #include <linux/slab.h> 30 #include <linux/uaccess.h> 31 #include <uapi/linux/rpmsg.h> 32 33 #include "rpmsg_internal.h" 34 35 #define RPMSG_DEV_MAX (MINORMASK + 1) 36 37 static dev_t rpmsg_major; 38 static struct class *rpmsg_class; 39 40 static DEFINE_IDA(rpmsg_ctrl_ida); 41 static DEFINE_IDA(rpmsg_ept_ida); 42 static DEFINE_IDA(rpmsg_minor_ida); 43 44 #define dev_to_eptdev(dev) container_of(dev, struct rpmsg_eptdev, dev) 45 #define cdev_to_eptdev(i_cdev) container_of(i_cdev, struct rpmsg_eptdev, cdev) 46 47 #define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev) 48 #define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev) 49 50 /** 51 * struct rpmsg_ctrldev - control device for instantiating endpoint devices 52 * @rpdev: underlaying rpmsg device 53 * @cdev: cdev for the ctrl device 54 * @dev: device for the ctrl device 55 */ 56 struct rpmsg_ctrldev { 57 struct rpmsg_device *rpdev; 58 struct cdev cdev; 59 struct device dev; 60 }; 61 62 /** 63 * struct rpmsg_eptdev - endpoint device context 64 * @dev: endpoint device 65 * @cdev: cdev for the endpoint device 66 * @rpdev: underlaying rpmsg device 67 * @chinfo: info used to open the endpoint 68 * @ept_lock: synchronization of @ept modifications 69 * @ept: rpmsg endpoint reference, when open 70 * @queue_lock: synchronization of @queue operations 71 * @queue: incoming message queue 72 * @readq: wait object for incoming queue 73 */ 74 struct rpmsg_eptdev { 75 struct device dev; 76 struct cdev cdev; 77 78 struct rpmsg_device *rpdev; 79 struct rpmsg_channel_info chinfo; 80 81 struct mutex ept_lock; 82 struct rpmsg_endpoint *ept; 83 84 spinlock_t queue_lock; 85 struct sk_buff_head queue; 86 wait_queue_head_t readq; 87 }; 88 89 static int rpmsg_eptdev_destroy(struct device *dev, void *data) 90 { 91 struct rpmsg_eptdev *eptdev = dev_to_eptdev(dev); 92 93 mutex_lock(&eptdev->ept_lock); 94 if (eptdev->ept) { 95 rpmsg_destroy_ept(eptdev->ept); 96 eptdev->ept = NULL; 97 } 98 mutex_unlock(&eptdev->ept_lock); 99 100 /* wake up any blocked readers */ 101 wake_up_interruptible(&eptdev->readq); 102 103 device_del(&eptdev->dev); 104 put_device(&eptdev->dev); 105 106 return 0; 107 } 108 109 static int rpmsg_ept_cb(struct rpmsg_device *rpdev, void *buf, int len, 110 void *priv, u32 addr) 111 { 112 struct rpmsg_eptdev *eptdev = priv; 113 struct sk_buff *skb; 114 115 skb = alloc_skb(len, GFP_ATOMIC); 116 if (!skb) 117 return -ENOMEM; 118 119 skb_put_data(skb, buf, len); 120 121 spin_lock(&eptdev->queue_lock); 122 skb_queue_tail(&eptdev->queue, skb); 123 spin_unlock(&eptdev->queue_lock); 124 125 /* wake up any blocking processes, waiting for new data */ 126 wake_up_interruptible(&eptdev->readq); 127 128 return 0; 129 } 130 131 static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) 132 { 133 struct rpmsg_eptdev *eptdev = cdev_to_eptdev(inode->i_cdev); 134 struct rpmsg_endpoint *ept; 135 struct rpmsg_device *rpdev = eptdev->rpdev; 136 struct device *dev = &eptdev->dev; 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 struct sk_buff *skb; 158 159 /* Close the endpoint, if it's not already destroyed by the parent */ 160 mutex_lock(&eptdev->ept_lock); 161 if (eptdev->ept) { 162 rpmsg_destroy_ept(eptdev->ept); 163 eptdev->ept = NULL; 164 } 165 mutex_unlock(&eptdev->ept_lock); 166 167 /* Discard all SKBs */ 168 while (!skb_queue_empty(&eptdev->queue)) { 169 skb = skb_dequeue(&eptdev->queue); 170 kfree_skb(skb); 171 } 172 173 put_device(dev); 174 175 return 0; 176 } 177 178 static ssize_t rpmsg_eptdev_read(struct file *filp, char __user *buf, 179 size_t len, loff_t *f_pos) 180 { 181 struct rpmsg_eptdev *eptdev = filp->private_data; 182 unsigned long flags; 183 struct sk_buff *skb; 184 int use; 185 186 if (!eptdev->ept) 187 return -EPIPE; 188 189 spin_lock_irqsave(&eptdev->queue_lock, flags); 190 191 /* Wait for data in the queue */ 192 if (skb_queue_empty(&eptdev->queue)) { 193 spin_unlock_irqrestore(&eptdev->queue_lock, flags); 194 195 if (filp->f_flags & O_NONBLOCK) 196 return -EAGAIN; 197 198 /* Wait until we get data or the endpoint goes away */ 199 if (wait_event_interruptible(eptdev->readq, 200 !skb_queue_empty(&eptdev->queue) || 201 !eptdev->ept)) 202 return -ERESTARTSYS; 203 204 /* We lost the endpoint while waiting */ 205 if (!eptdev->ept) 206 return -EPIPE; 207 208 spin_lock_irqsave(&eptdev->queue_lock, flags); 209 } 210 211 skb = skb_dequeue(&eptdev->queue); 212 spin_unlock_irqrestore(&eptdev->queue_lock, flags); 213 if (!skb) 214 return -EFAULT; 215 216 use = min_t(size_t, len, skb->len); 217 if (copy_to_user(buf, skb->data, use)) 218 use = -EFAULT; 219 220 kfree_skb(skb); 221 222 return use; 223 } 224 225 static ssize_t rpmsg_eptdev_write(struct file *filp, const char __user *buf, 226 size_t len, loff_t *f_pos) 227 { 228 struct rpmsg_eptdev *eptdev = filp->private_data; 229 void *kbuf; 230 int ret; 231 232 kbuf = memdup_user(buf, len); 233 if (IS_ERR(kbuf)) 234 return PTR_ERR(kbuf); 235 236 if (mutex_lock_interruptible(&eptdev->ept_lock)) { 237 ret = -ERESTARTSYS; 238 goto free_kbuf; 239 } 240 241 if (!eptdev->ept) { 242 ret = -EPIPE; 243 goto unlock_eptdev; 244 } 245 246 if (filp->f_flags & O_NONBLOCK) 247 ret = rpmsg_trysend(eptdev->ept, kbuf, len); 248 else 249 ret = rpmsg_send(eptdev->ept, kbuf, len); 250 251 unlock_eptdev: 252 mutex_unlock(&eptdev->ept_lock); 253 254 free_kbuf: 255 kfree(kbuf); 256 return ret < 0 ? ret : len; 257 } 258 259 static __poll_t rpmsg_eptdev_poll(struct file *filp, poll_table *wait) 260 { 261 struct rpmsg_eptdev *eptdev = filp->private_data; 262 __poll_t mask = 0; 263 264 if (!eptdev->ept) 265 return EPOLLERR; 266 267 poll_wait(filp, &eptdev->readq, wait); 268 269 if (!skb_queue_empty(&eptdev->queue)) 270 mask |= EPOLLIN | EPOLLRDNORM; 271 272 mask |= rpmsg_poll(eptdev->ept, filp, wait); 273 274 return mask; 275 } 276 277 static long rpmsg_eptdev_ioctl(struct file *fp, unsigned int cmd, 278 unsigned long arg) 279 { 280 struct rpmsg_eptdev *eptdev = fp->private_data; 281 282 if (cmd != RPMSG_DESTROY_EPT_IOCTL) 283 return -EINVAL; 284 285 return rpmsg_eptdev_destroy(&eptdev->dev, NULL); 286 } 287 288 static const struct file_operations rpmsg_eptdev_fops = { 289 .owner = THIS_MODULE, 290 .open = rpmsg_eptdev_open, 291 .release = rpmsg_eptdev_release, 292 .read = rpmsg_eptdev_read, 293 .write = rpmsg_eptdev_write, 294 .poll = rpmsg_eptdev_poll, 295 .unlocked_ioctl = rpmsg_eptdev_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 cdev_del(&eptdev->cdev); 340 kfree(eptdev); 341 } 342 343 static int rpmsg_eptdev_create(struct rpmsg_ctrldev *ctrldev, 344 struct rpmsg_channel_info chinfo) 345 { 346 struct rpmsg_device *rpdev = ctrldev->rpdev; 347 struct rpmsg_eptdev *eptdev; 348 struct device *dev; 349 int ret; 350 351 eptdev = kzalloc(sizeof(*eptdev), GFP_KERNEL); 352 if (!eptdev) 353 return -ENOMEM; 354 355 dev = &eptdev->dev; 356 eptdev->rpdev = rpdev; 357 eptdev->chinfo = chinfo; 358 359 mutex_init(&eptdev->ept_lock); 360 spin_lock_init(&eptdev->queue_lock); 361 skb_queue_head_init(&eptdev->queue); 362 init_waitqueue_head(&eptdev->readq); 363 364 device_initialize(dev); 365 dev->class = rpmsg_class; 366 dev->parent = &ctrldev->dev; 367 dev->groups = rpmsg_eptdev_groups; 368 dev_set_drvdata(dev, eptdev); 369 370 cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops); 371 eptdev->cdev.owner = THIS_MODULE; 372 373 ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL); 374 if (ret < 0) 375 goto free_eptdev; 376 dev->devt = MKDEV(MAJOR(rpmsg_major), ret); 377 378 ret = ida_simple_get(&rpmsg_ept_ida, 0, 0, GFP_KERNEL); 379 if (ret < 0) 380 goto free_minor_ida; 381 dev->id = ret; 382 dev_set_name(dev, "rpmsg%d", ret); 383 384 ret = cdev_add(&eptdev->cdev, dev->devt, 1); 385 if (ret) 386 goto free_ept_ida; 387 388 /* We can now rely on the release function for cleanup */ 389 dev->release = rpmsg_eptdev_release_device; 390 391 ret = device_add(dev); 392 if (ret) { 393 dev_err(dev, "device_add failed: %d\n", ret); 394 put_device(dev); 395 } 396 397 return ret; 398 399 free_ept_ida: 400 ida_simple_remove(&rpmsg_ept_ida, dev->id); 401 free_minor_ida: 402 ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt)); 403 free_eptdev: 404 put_device(dev); 405 kfree(eptdev); 406 407 return ret; 408 } 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_eptdev_create(ctrldev, 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 }; 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_char_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_char_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 MODULE_LICENSE("GPL v2"); 585