1 /* 2 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation 3 * Copyright (C) 2009, 2010, 2011 Red Hat, Inc. 4 * Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19 */ 20 #include <linux/cdev.h> 21 #include <linux/debugfs.h> 22 #include <linux/completion.h> 23 #include <linux/device.h> 24 #include <linux/err.h> 25 #include <linux/freezer.h> 26 #include <linux/fs.h> 27 #include <linux/splice.h> 28 #include <linux/pagemap.h> 29 #include <linux/init.h> 30 #include <linux/list.h> 31 #include <linux/poll.h> 32 #include <linux/sched.h> 33 #include <linux/slab.h> 34 #include <linux/spinlock.h> 35 #include <linux/virtio.h> 36 #include <linux/virtio_console.h> 37 #include <linux/wait.h> 38 #include <linux/workqueue.h> 39 #include <linux/module.h> 40 #include <linux/dma-mapping.h> 41 #include <linux/kconfig.h> 42 #include "../tty/hvc/hvc_console.h" 43 44 #define is_rproc_enabled IS_ENABLED(CONFIG_REMOTEPROC) 45 46 /* 47 * This is a global struct for storing common data for all the devices 48 * this driver handles. 49 * 50 * Mainly, it has a linked list for all the consoles in one place so 51 * that callbacks from hvc for get_chars(), put_chars() work properly 52 * across multiple devices and multiple ports per device. 53 */ 54 struct ports_driver_data { 55 /* Used for registering chardevs */ 56 struct class *class; 57 58 /* Used for exporting per-port information to debugfs */ 59 struct dentry *debugfs_dir; 60 61 /* List of all the devices we're handling */ 62 struct list_head portdevs; 63 64 /* 65 * This is used to keep track of the number of hvc consoles 66 * spawned by this driver. This number is given as the first 67 * argument to hvc_alloc(). To correctly map an initial 68 * console spawned via hvc_instantiate to the console being 69 * hooked up via hvc_alloc, we need to pass the same vtermno. 70 * 71 * We also just assume the first console being initialised was 72 * the first one that got used as the initial console. 73 */ 74 unsigned int next_vtermno; 75 76 /* All the console devices handled by this driver */ 77 struct list_head consoles; 78 }; 79 static struct ports_driver_data pdrvdata; 80 81 static DEFINE_SPINLOCK(pdrvdata_lock); 82 static DECLARE_COMPLETION(early_console_added); 83 84 /* This struct holds information that's relevant only for console ports */ 85 struct console { 86 /* We'll place all consoles in a list in the pdrvdata struct */ 87 struct list_head list; 88 89 /* The hvc device associated with this console port */ 90 struct hvc_struct *hvc; 91 92 /* The size of the console */ 93 struct winsize ws; 94 95 /* 96 * This number identifies the number that we used to register 97 * with hvc in hvc_instantiate() and hvc_alloc(); this is the 98 * number passed on by the hvc callbacks to us to 99 * differentiate between the other console ports handled by 100 * this driver 101 */ 102 u32 vtermno; 103 }; 104 105 struct port_buffer { 106 char *buf; 107 108 /* size of the buffer in *buf above */ 109 size_t size; 110 111 /* used length of the buffer */ 112 size_t len; 113 /* offset in the buf from which to consume data */ 114 size_t offset; 115 116 /* DMA address of buffer */ 117 dma_addr_t dma; 118 119 /* Device we got DMA memory from */ 120 struct device *dev; 121 122 /* List of pending dma buffers to free */ 123 struct list_head list; 124 125 /* If sgpages == 0 then buf is used */ 126 unsigned int sgpages; 127 128 /* sg is used if spages > 0. sg must be the last in is struct */ 129 struct scatterlist sg[0]; 130 }; 131 132 /* 133 * This is a per-device struct that stores data common to all the 134 * ports for that device (vdev->priv). 135 */ 136 struct ports_device { 137 /* Next portdev in the list, head is in the pdrvdata struct */ 138 struct list_head list; 139 140 /* 141 * Workqueue handlers where we process deferred work after 142 * notification 143 */ 144 struct work_struct control_work; 145 146 struct list_head ports; 147 148 /* To protect the list of ports */ 149 spinlock_t ports_lock; 150 151 /* To protect the vq operations for the control channel */ 152 spinlock_t c_ivq_lock; 153 spinlock_t c_ovq_lock; 154 155 /* The current config space is stored here */ 156 struct virtio_console_config config; 157 158 /* The virtio device we're associated with */ 159 struct virtio_device *vdev; 160 161 /* 162 * A couple of virtqueues for the control channel: one for 163 * guest->host transfers, one for host->guest transfers 164 */ 165 struct virtqueue *c_ivq, *c_ovq; 166 167 /* Array of per-port IO virtqueues */ 168 struct virtqueue **in_vqs, **out_vqs; 169 170 /* Major number for this device. Ports will be created as minors. */ 171 int chr_major; 172 }; 173 174 struct port_stats { 175 unsigned long bytes_sent, bytes_received, bytes_discarded; 176 }; 177 178 /* This struct holds the per-port data */ 179 struct port { 180 /* Next port in the list, head is in the ports_device */ 181 struct list_head list; 182 183 /* Pointer to the parent virtio_console device */ 184 struct ports_device *portdev; 185 186 /* The current buffer from which data has to be fed to readers */ 187 struct port_buffer *inbuf; 188 189 /* 190 * To protect the operations on the in_vq associated with this 191 * port. Has to be a spinlock because it can be called from 192 * interrupt context (get_char()). 193 */ 194 spinlock_t inbuf_lock; 195 196 /* Protect the operations on the out_vq. */ 197 spinlock_t outvq_lock; 198 199 /* The IO vqs for this port */ 200 struct virtqueue *in_vq, *out_vq; 201 202 /* File in the debugfs directory that exposes this port's information */ 203 struct dentry *debugfs_file; 204 205 /* 206 * Keep count of the bytes sent, received and discarded for 207 * this port for accounting and debugging purposes. These 208 * counts are not reset across port open / close events. 209 */ 210 struct port_stats stats; 211 212 /* 213 * The entries in this struct will be valid if this port is 214 * hooked up to an hvc console 215 */ 216 struct console cons; 217 218 /* Each port associates with a separate char device */ 219 struct cdev *cdev; 220 struct device *dev; 221 222 /* Reference-counting to handle port hot-unplugs and file operations */ 223 struct kref kref; 224 225 /* A waitqueue for poll() or blocking read operations */ 226 wait_queue_head_t waitqueue; 227 228 /* The 'name' of the port that we expose via sysfs properties */ 229 char *name; 230 231 /* We can notify apps of host connect / disconnect events via SIGIO */ 232 struct fasync_struct *async_queue; 233 234 /* The 'id' to identify the port with the Host */ 235 u32 id; 236 237 bool outvq_full; 238 239 /* Is the host device open */ 240 bool host_connected; 241 242 /* We should allow only one process to open a port */ 243 bool guest_connected; 244 }; 245 246 /* This is the very early arch-specified put chars function. */ 247 static int (*early_put_chars)(u32, const char *, int); 248 249 static struct port *find_port_by_vtermno(u32 vtermno) 250 { 251 struct port *port; 252 struct console *cons; 253 unsigned long flags; 254 255 spin_lock_irqsave(&pdrvdata_lock, flags); 256 list_for_each_entry(cons, &pdrvdata.consoles, list) { 257 if (cons->vtermno == vtermno) { 258 port = container_of(cons, struct port, cons); 259 goto out; 260 } 261 } 262 port = NULL; 263 out: 264 spin_unlock_irqrestore(&pdrvdata_lock, flags); 265 return port; 266 } 267 268 static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev, 269 dev_t dev) 270 { 271 struct port *port; 272 unsigned long flags; 273 274 spin_lock_irqsave(&portdev->ports_lock, flags); 275 list_for_each_entry(port, &portdev->ports, list) { 276 if (port->cdev->dev == dev) { 277 kref_get(&port->kref); 278 goto out; 279 } 280 } 281 port = NULL; 282 out: 283 spin_unlock_irqrestore(&portdev->ports_lock, flags); 284 285 return port; 286 } 287 288 static struct port *find_port_by_devt(dev_t dev) 289 { 290 struct ports_device *portdev; 291 struct port *port; 292 unsigned long flags; 293 294 spin_lock_irqsave(&pdrvdata_lock, flags); 295 list_for_each_entry(portdev, &pdrvdata.portdevs, list) { 296 port = find_port_by_devt_in_portdev(portdev, dev); 297 if (port) 298 goto out; 299 } 300 port = NULL; 301 out: 302 spin_unlock_irqrestore(&pdrvdata_lock, flags); 303 return port; 304 } 305 306 static struct port *find_port_by_id(struct ports_device *portdev, u32 id) 307 { 308 struct port *port; 309 unsigned long flags; 310 311 spin_lock_irqsave(&portdev->ports_lock, flags); 312 list_for_each_entry(port, &portdev->ports, list) 313 if (port->id == id) 314 goto out; 315 port = NULL; 316 out: 317 spin_unlock_irqrestore(&portdev->ports_lock, flags); 318 319 return port; 320 } 321 322 static struct port *find_port_by_vq(struct ports_device *portdev, 323 struct virtqueue *vq) 324 { 325 struct port *port; 326 unsigned long flags; 327 328 spin_lock_irqsave(&portdev->ports_lock, flags); 329 list_for_each_entry(port, &portdev->ports, list) 330 if (port->in_vq == vq || port->out_vq == vq) 331 goto out; 332 port = NULL; 333 out: 334 spin_unlock_irqrestore(&portdev->ports_lock, flags); 335 return port; 336 } 337 338 static bool is_console_port(struct port *port) 339 { 340 if (port->cons.hvc) 341 return true; 342 return false; 343 } 344 345 static bool is_rproc_serial(const struct virtio_device *vdev) 346 { 347 return is_rproc_enabled && vdev->id.device == VIRTIO_ID_RPROC_SERIAL; 348 } 349 350 static inline bool use_multiport(struct ports_device *portdev) 351 { 352 /* 353 * This condition can be true when put_chars is called from 354 * early_init 355 */ 356 if (!portdev->vdev) 357 return 0; 358 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT); 359 } 360 361 static DEFINE_SPINLOCK(dma_bufs_lock); 362 static LIST_HEAD(pending_free_dma_bufs); 363 364 static void free_buf(struct port_buffer *buf, bool can_sleep) 365 { 366 unsigned int i; 367 368 for (i = 0; i < buf->sgpages; i++) { 369 struct page *page = sg_page(&buf->sg[i]); 370 if (!page) 371 break; 372 put_page(page); 373 } 374 375 if (!buf->dev) { 376 kfree(buf->buf); 377 } else if (is_rproc_enabled) { 378 unsigned long flags; 379 380 /* dma_free_coherent requires interrupts to be enabled. */ 381 if (!can_sleep) { 382 /* queue up dma-buffers to be freed later */ 383 spin_lock_irqsave(&dma_bufs_lock, flags); 384 list_add_tail(&buf->list, &pending_free_dma_bufs); 385 spin_unlock_irqrestore(&dma_bufs_lock, flags); 386 return; 387 } 388 dma_free_coherent(buf->dev, buf->size, buf->buf, buf->dma); 389 390 /* Release device refcnt and allow it to be freed */ 391 put_device(buf->dev); 392 } 393 394 kfree(buf); 395 } 396 397 static void reclaim_dma_bufs(void) 398 { 399 unsigned long flags; 400 struct port_buffer *buf, *tmp; 401 LIST_HEAD(tmp_list); 402 403 if (list_empty(&pending_free_dma_bufs)) 404 return; 405 406 /* Create a copy of the pending_free_dma_bufs while holding the lock */ 407 spin_lock_irqsave(&dma_bufs_lock, flags); 408 list_cut_position(&tmp_list, &pending_free_dma_bufs, 409 pending_free_dma_bufs.prev); 410 spin_unlock_irqrestore(&dma_bufs_lock, flags); 411 412 /* Release the dma buffers, without irqs enabled */ 413 list_for_each_entry_safe(buf, tmp, &tmp_list, list) { 414 list_del(&buf->list); 415 free_buf(buf, true); 416 } 417 } 418 419 static struct port_buffer *alloc_buf(struct virtqueue *vq, size_t buf_size, 420 int pages) 421 { 422 struct port_buffer *buf; 423 424 reclaim_dma_bufs(); 425 426 /* 427 * Allocate buffer and the sg list. The sg list array is allocated 428 * directly after the port_buffer struct. 429 */ 430 buf = kmalloc(sizeof(*buf) + sizeof(struct scatterlist) * pages, 431 GFP_KERNEL); 432 if (!buf) 433 goto fail; 434 435 buf->sgpages = pages; 436 if (pages > 0) { 437 buf->dev = NULL; 438 buf->buf = NULL; 439 return buf; 440 } 441 442 if (is_rproc_serial(vq->vdev)) { 443 /* 444 * Allocate DMA memory from ancestor. When a virtio 445 * device is created by remoteproc, the DMA memory is 446 * associated with the grandparent device: 447 * vdev => rproc => platform-dev. 448 * The code here would have been less quirky if 449 * DMA_MEMORY_INCLUDES_CHILDREN had been supported 450 * in dma-coherent.c 451 */ 452 if (!vq->vdev->dev.parent || !vq->vdev->dev.parent->parent) 453 goto free_buf; 454 buf->dev = vq->vdev->dev.parent->parent; 455 456 /* Increase device refcnt to avoid freeing it */ 457 get_device(buf->dev); 458 buf->buf = dma_alloc_coherent(buf->dev, buf_size, &buf->dma, 459 GFP_KERNEL); 460 } else { 461 buf->dev = NULL; 462 buf->buf = kmalloc(buf_size, GFP_KERNEL); 463 } 464 465 if (!buf->buf) 466 goto free_buf; 467 buf->len = 0; 468 buf->offset = 0; 469 buf->size = buf_size; 470 return buf; 471 472 free_buf: 473 kfree(buf); 474 fail: 475 return NULL; 476 } 477 478 /* Callers should take appropriate locks */ 479 static struct port_buffer *get_inbuf(struct port *port) 480 { 481 struct port_buffer *buf; 482 unsigned int len; 483 484 if (port->inbuf) 485 return port->inbuf; 486 487 buf = virtqueue_get_buf(port->in_vq, &len); 488 if (buf) { 489 buf->len = len; 490 buf->offset = 0; 491 port->stats.bytes_received += len; 492 } 493 return buf; 494 } 495 496 /* 497 * Create a scatter-gather list representing our input buffer and put 498 * it in the queue. 499 * 500 * Callers should take appropriate locks. 501 */ 502 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf) 503 { 504 struct scatterlist sg[1]; 505 int ret; 506 507 sg_init_one(sg, buf->buf, buf->size); 508 509 ret = virtqueue_add_inbuf(vq, sg, 1, buf, GFP_ATOMIC); 510 virtqueue_kick(vq); 511 if (!ret) 512 ret = vq->num_free; 513 return ret; 514 } 515 516 /* Discard any unread data this port has. Callers lockers. */ 517 static void discard_port_data(struct port *port) 518 { 519 struct port_buffer *buf; 520 unsigned int err; 521 522 if (!port->portdev) { 523 /* Device has been unplugged. vqs are already gone. */ 524 return; 525 } 526 buf = get_inbuf(port); 527 528 err = 0; 529 while (buf) { 530 port->stats.bytes_discarded += buf->len - buf->offset; 531 if (add_inbuf(port->in_vq, buf) < 0) { 532 err++; 533 free_buf(buf, false); 534 } 535 port->inbuf = NULL; 536 buf = get_inbuf(port); 537 } 538 if (err) 539 dev_warn(port->dev, "Errors adding %d buffers back to vq\n", 540 err); 541 } 542 543 static bool port_has_data(struct port *port) 544 { 545 unsigned long flags; 546 bool ret; 547 548 ret = false; 549 spin_lock_irqsave(&port->inbuf_lock, flags); 550 port->inbuf = get_inbuf(port); 551 if (port->inbuf) 552 ret = true; 553 554 spin_unlock_irqrestore(&port->inbuf_lock, flags); 555 return ret; 556 } 557 558 static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id, 559 unsigned int event, unsigned int value) 560 { 561 struct scatterlist sg[1]; 562 struct virtio_console_control cpkt; 563 struct virtqueue *vq; 564 unsigned int len; 565 566 if (!use_multiport(portdev)) 567 return 0; 568 569 cpkt.id = port_id; 570 cpkt.event = event; 571 cpkt.value = value; 572 573 vq = portdev->c_ovq; 574 575 sg_init_one(sg, &cpkt, sizeof(cpkt)); 576 577 spin_lock(&portdev->c_ovq_lock); 578 if (virtqueue_add_outbuf(vq, sg, 1, &cpkt, GFP_ATOMIC) == 0) { 579 virtqueue_kick(vq); 580 while (!virtqueue_get_buf(vq, &len) 581 && !virtqueue_is_broken(vq)) 582 cpu_relax(); 583 } 584 spin_unlock(&portdev->c_ovq_lock); 585 return 0; 586 } 587 588 static ssize_t send_control_msg(struct port *port, unsigned int event, 589 unsigned int value) 590 { 591 /* Did the port get unplugged before userspace closed it? */ 592 if (port->portdev) 593 return __send_control_msg(port->portdev, port->id, event, value); 594 return 0; 595 } 596 597 598 /* Callers must take the port->outvq_lock */ 599 static void reclaim_consumed_buffers(struct port *port) 600 { 601 struct port_buffer *buf; 602 unsigned int len; 603 604 if (!port->portdev) { 605 /* Device has been unplugged. vqs are already gone. */ 606 return; 607 } 608 while ((buf = virtqueue_get_buf(port->out_vq, &len))) { 609 free_buf(buf, false); 610 port->outvq_full = false; 611 } 612 } 613 614 static ssize_t __send_to_port(struct port *port, struct scatterlist *sg, 615 int nents, size_t in_count, 616 void *data, bool nonblock) 617 { 618 struct virtqueue *out_vq; 619 int err; 620 unsigned long flags; 621 unsigned int len; 622 623 out_vq = port->out_vq; 624 625 spin_lock_irqsave(&port->outvq_lock, flags); 626 627 reclaim_consumed_buffers(port); 628 629 err = virtqueue_add_outbuf(out_vq, sg, nents, data, GFP_ATOMIC); 630 631 /* Tell Host to go! */ 632 virtqueue_kick(out_vq); 633 634 if (err) { 635 in_count = 0; 636 goto done; 637 } 638 639 if (out_vq->num_free == 0) 640 port->outvq_full = true; 641 642 if (nonblock) 643 goto done; 644 645 /* 646 * Wait till the host acknowledges it pushed out the data we 647 * sent. This is done for data from the hvc_console; the tty 648 * operations are performed with spinlocks held so we can't 649 * sleep here. An alternative would be to copy the data to a 650 * buffer and relax the spinning requirement. The downside is 651 * we need to kmalloc a GFP_ATOMIC buffer each time the 652 * console driver writes something out. 653 */ 654 while (!virtqueue_get_buf(out_vq, &len) 655 && !virtqueue_is_broken(out_vq)) 656 cpu_relax(); 657 done: 658 spin_unlock_irqrestore(&port->outvq_lock, flags); 659 660 port->stats.bytes_sent += in_count; 661 /* 662 * We're expected to return the amount of data we wrote -- all 663 * of it 664 */ 665 return in_count; 666 } 667 668 /* 669 * Give out the data that's requested from the buffer that we have 670 * queued up. 671 */ 672 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count, 673 bool to_user) 674 { 675 struct port_buffer *buf; 676 unsigned long flags; 677 678 if (!out_count || !port_has_data(port)) 679 return 0; 680 681 buf = port->inbuf; 682 out_count = min(out_count, buf->len - buf->offset); 683 684 if (to_user) { 685 ssize_t ret; 686 687 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count); 688 if (ret) 689 return -EFAULT; 690 } else { 691 memcpy(out_buf, buf->buf + buf->offset, out_count); 692 } 693 694 buf->offset += out_count; 695 696 if (buf->offset == buf->len) { 697 /* 698 * We're done using all the data in this buffer. 699 * Re-queue so that the Host can send us more data. 700 */ 701 spin_lock_irqsave(&port->inbuf_lock, flags); 702 port->inbuf = NULL; 703 704 if (add_inbuf(port->in_vq, buf) < 0) 705 dev_warn(port->dev, "failed add_buf\n"); 706 707 spin_unlock_irqrestore(&port->inbuf_lock, flags); 708 } 709 /* Return the number of bytes actually copied */ 710 return out_count; 711 } 712 713 /* The condition that must be true for polling to end */ 714 static bool will_read_block(struct port *port) 715 { 716 if (!port->guest_connected) { 717 /* Port got hot-unplugged. Let's exit. */ 718 return false; 719 } 720 return !port_has_data(port) && port->host_connected; 721 } 722 723 static bool will_write_block(struct port *port) 724 { 725 bool ret; 726 727 if (!port->guest_connected) { 728 /* Port got hot-unplugged. Let's exit. */ 729 return false; 730 } 731 if (!port->host_connected) 732 return true; 733 734 spin_lock_irq(&port->outvq_lock); 735 /* 736 * Check if the Host has consumed any buffers since we last 737 * sent data (this is only applicable for nonblocking ports). 738 */ 739 reclaim_consumed_buffers(port); 740 ret = port->outvq_full; 741 spin_unlock_irq(&port->outvq_lock); 742 743 return ret; 744 } 745 746 static ssize_t port_fops_read(struct file *filp, char __user *ubuf, 747 size_t count, loff_t *offp) 748 { 749 struct port *port; 750 ssize_t ret; 751 752 port = filp->private_data; 753 754 /* Port is hot-unplugged. */ 755 if (!port->guest_connected) 756 return -ENODEV; 757 758 if (!port_has_data(port)) { 759 /* 760 * If nothing's connected on the host just return 0 in 761 * case of list_empty; this tells the userspace app 762 * that there's no connection 763 */ 764 if (!port->host_connected) 765 return 0; 766 if (filp->f_flags & O_NONBLOCK) 767 return -EAGAIN; 768 769 ret = wait_event_freezable(port->waitqueue, 770 !will_read_block(port)); 771 if (ret < 0) 772 return ret; 773 } 774 /* Port got hot-unplugged while we were waiting above. */ 775 if (!port->guest_connected) 776 return -ENODEV; 777 /* 778 * We could've received a disconnection message while we were 779 * waiting for more data. 780 * 781 * This check is not clubbed in the if() statement above as we 782 * might receive some data as well as the host could get 783 * disconnected after we got woken up from our wait. So we 784 * really want to give off whatever data we have and only then 785 * check for host_connected. 786 */ 787 if (!port_has_data(port) && !port->host_connected) 788 return 0; 789 790 return fill_readbuf(port, ubuf, count, true); 791 } 792 793 static int wait_port_writable(struct port *port, bool nonblock) 794 { 795 int ret; 796 797 if (will_write_block(port)) { 798 if (nonblock) 799 return -EAGAIN; 800 801 ret = wait_event_freezable(port->waitqueue, 802 !will_write_block(port)); 803 if (ret < 0) 804 return ret; 805 } 806 /* Port got hot-unplugged. */ 807 if (!port->guest_connected) 808 return -ENODEV; 809 810 return 0; 811 } 812 813 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf, 814 size_t count, loff_t *offp) 815 { 816 struct port *port; 817 struct port_buffer *buf; 818 ssize_t ret; 819 bool nonblock; 820 struct scatterlist sg[1]; 821 822 /* Userspace could be out to fool us */ 823 if (!count) 824 return 0; 825 826 port = filp->private_data; 827 828 nonblock = filp->f_flags & O_NONBLOCK; 829 830 ret = wait_port_writable(port, nonblock); 831 if (ret < 0) 832 return ret; 833 834 count = min((size_t)(32 * 1024), count); 835 836 buf = alloc_buf(port->out_vq, count, 0); 837 if (!buf) 838 return -ENOMEM; 839 840 ret = copy_from_user(buf->buf, ubuf, count); 841 if (ret) { 842 ret = -EFAULT; 843 goto free_buf; 844 } 845 846 /* 847 * We now ask send_buf() to not spin for generic ports -- we 848 * can re-use the same code path that non-blocking file 849 * descriptors take for blocking file descriptors since the 850 * wait is already done and we're certain the write will go 851 * through to the host. 852 */ 853 nonblock = true; 854 sg_init_one(sg, buf->buf, count); 855 ret = __send_to_port(port, sg, 1, count, buf, nonblock); 856 857 if (nonblock && ret > 0) 858 goto out; 859 860 free_buf: 861 free_buf(buf, true); 862 out: 863 return ret; 864 } 865 866 struct sg_list { 867 unsigned int n; 868 unsigned int size; 869 size_t len; 870 struct scatterlist *sg; 871 }; 872 873 static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf, 874 struct splice_desc *sd) 875 { 876 struct sg_list *sgl = sd->u.data; 877 unsigned int offset, len; 878 879 if (sgl->n == sgl->size) 880 return 0; 881 882 /* Try lock this page */ 883 if (buf->ops->steal(pipe, buf) == 0) { 884 /* Get reference and unlock page for moving */ 885 get_page(buf->page); 886 unlock_page(buf->page); 887 888 len = min(buf->len, sd->len); 889 sg_set_page(&(sgl->sg[sgl->n]), buf->page, len, buf->offset); 890 } else { 891 /* Failback to copying a page */ 892 struct page *page = alloc_page(GFP_KERNEL); 893 char *src; 894 895 if (!page) 896 return -ENOMEM; 897 898 offset = sd->pos & ~PAGE_MASK; 899 900 len = sd->len; 901 if (len + offset > PAGE_SIZE) 902 len = PAGE_SIZE - offset; 903 904 src = kmap_atomic(buf->page); 905 memcpy(page_address(page) + offset, src + buf->offset, len); 906 kunmap_atomic(src); 907 908 sg_set_page(&(sgl->sg[sgl->n]), page, len, offset); 909 } 910 sgl->n++; 911 sgl->len += len; 912 913 return len; 914 } 915 916 /* Faster zero-copy write by splicing */ 917 static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe, 918 struct file *filp, loff_t *ppos, 919 size_t len, unsigned int flags) 920 { 921 struct port *port = filp->private_data; 922 struct sg_list sgl; 923 ssize_t ret; 924 struct port_buffer *buf; 925 struct splice_desc sd = { 926 .total_len = len, 927 .flags = flags, 928 .pos = *ppos, 929 .u.data = &sgl, 930 }; 931 932 /* 933 * Rproc_serial does not yet support splice. To support splice 934 * pipe_to_sg() must allocate dma-buffers and copy content from 935 * regular pages to dma pages. And alloc_buf and free_buf must 936 * support allocating and freeing such a list of dma-buffers. 937 */ 938 if (is_rproc_serial(port->out_vq->vdev)) 939 return -EINVAL; 940 941 /* 942 * pipe->nrbufs == 0 means there are no data to transfer, 943 * so this returns just 0 for no data. 944 */ 945 pipe_lock(pipe); 946 if (!pipe->nrbufs) { 947 ret = 0; 948 goto error_out; 949 } 950 951 ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK); 952 if (ret < 0) 953 goto error_out; 954 955 buf = alloc_buf(port->out_vq, 0, pipe->nrbufs); 956 if (!buf) { 957 ret = -ENOMEM; 958 goto error_out; 959 } 960 961 sgl.n = 0; 962 sgl.len = 0; 963 sgl.size = pipe->nrbufs; 964 sgl.sg = buf->sg; 965 sg_init_table(sgl.sg, sgl.size); 966 ret = __splice_from_pipe(pipe, &sd, pipe_to_sg); 967 pipe_unlock(pipe); 968 if (likely(ret > 0)) 969 ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true); 970 971 if (unlikely(ret <= 0)) 972 free_buf(buf, true); 973 return ret; 974 975 error_out: 976 pipe_unlock(pipe); 977 return ret; 978 } 979 980 static unsigned int port_fops_poll(struct file *filp, poll_table *wait) 981 { 982 struct port *port; 983 unsigned int ret; 984 985 port = filp->private_data; 986 poll_wait(filp, &port->waitqueue, wait); 987 988 if (!port->guest_connected) { 989 /* Port got unplugged */ 990 return POLLHUP; 991 } 992 ret = 0; 993 if (!will_read_block(port)) 994 ret |= POLLIN | POLLRDNORM; 995 if (!will_write_block(port)) 996 ret |= POLLOUT; 997 if (!port->host_connected) 998 ret |= POLLHUP; 999 1000 return ret; 1001 } 1002 1003 static void remove_port(struct kref *kref); 1004 1005 static int port_fops_release(struct inode *inode, struct file *filp) 1006 { 1007 struct port *port; 1008 1009 port = filp->private_data; 1010 1011 /* Notify host of port being closed */ 1012 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0); 1013 1014 spin_lock_irq(&port->inbuf_lock); 1015 port->guest_connected = false; 1016 1017 discard_port_data(port); 1018 1019 spin_unlock_irq(&port->inbuf_lock); 1020 1021 spin_lock_irq(&port->outvq_lock); 1022 reclaim_consumed_buffers(port); 1023 spin_unlock_irq(&port->outvq_lock); 1024 1025 reclaim_dma_bufs(); 1026 /* 1027 * Locks aren't necessary here as a port can't be opened after 1028 * unplug, and if a port isn't unplugged, a kref would already 1029 * exist for the port. Plus, taking ports_lock here would 1030 * create a dependency on other locks taken by functions 1031 * inside remove_port if we're the last holder of the port, 1032 * creating many problems. 1033 */ 1034 kref_put(&port->kref, remove_port); 1035 1036 return 0; 1037 } 1038 1039 static int port_fops_open(struct inode *inode, struct file *filp) 1040 { 1041 struct cdev *cdev = inode->i_cdev; 1042 struct port *port; 1043 int ret; 1044 1045 /* We get the port with a kref here */ 1046 port = find_port_by_devt(cdev->dev); 1047 if (!port) { 1048 /* Port was unplugged before we could proceed */ 1049 return -ENXIO; 1050 } 1051 filp->private_data = port; 1052 1053 /* 1054 * Don't allow opening of console port devices -- that's done 1055 * via /dev/hvc 1056 */ 1057 if (is_console_port(port)) { 1058 ret = -ENXIO; 1059 goto out; 1060 } 1061 1062 /* Allow only one process to open a particular port at a time */ 1063 spin_lock_irq(&port->inbuf_lock); 1064 if (port->guest_connected) { 1065 spin_unlock_irq(&port->inbuf_lock); 1066 ret = -EBUSY; 1067 goto out; 1068 } 1069 1070 port->guest_connected = true; 1071 spin_unlock_irq(&port->inbuf_lock); 1072 1073 spin_lock_irq(&port->outvq_lock); 1074 /* 1075 * There might be a chance that we missed reclaiming a few 1076 * buffers in the window of the port getting previously closed 1077 * and opening now. 1078 */ 1079 reclaim_consumed_buffers(port); 1080 spin_unlock_irq(&port->outvq_lock); 1081 1082 nonseekable_open(inode, filp); 1083 1084 /* Notify host of port being opened */ 1085 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1); 1086 1087 return 0; 1088 out: 1089 kref_put(&port->kref, remove_port); 1090 return ret; 1091 } 1092 1093 static int port_fops_fasync(int fd, struct file *filp, int mode) 1094 { 1095 struct port *port; 1096 1097 port = filp->private_data; 1098 return fasync_helper(fd, filp, mode, &port->async_queue); 1099 } 1100 1101 /* 1102 * The file operations that we support: programs in the guest can open 1103 * a console device, read from it, write to it, poll for data and 1104 * close it. The devices are at 1105 * /dev/vport<device number>p<port number> 1106 */ 1107 static const struct file_operations port_fops = { 1108 .owner = THIS_MODULE, 1109 .open = port_fops_open, 1110 .read = port_fops_read, 1111 .write = port_fops_write, 1112 .splice_write = port_fops_splice_write, 1113 .poll = port_fops_poll, 1114 .release = port_fops_release, 1115 .fasync = port_fops_fasync, 1116 .llseek = no_llseek, 1117 }; 1118 1119 /* 1120 * The put_chars() callback is pretty straightforward. 1121 * 1122 * We turn the characters into a scatter-gather list, add it to the 1123 * output queue and then kick the Host. Then we sit here waiting for 1124 * it to finish: inefficient in theory, but in practice 1125 * implementations will do it immediately (lguest's Launcher does). 1126 */ 1127 static int put_chars(u32 vtermno, const char *buf, int count) 1128 { 1129 struct port *port; 1130 struct scatterlist sg[1]; 1131 1132 if (unlikely(early_put_chars)) 1133 return early_put_chars(vtermno, buf, count); 1134 1135 port = find_port_by_vtermno(vtermno); 1136 if (!port) 1137 return -EPIPE; 1138 1139 sg_init_one(sg, buf, count); 1140 return __send_to_port(port, sg, 1, count, (void *)buf, false); 1141 } 1142 1143 /* 1144 * get_chars() is the callback from the hvc_console infrastructure 1145 * when an interrupt is received. 1146 * 1147 * We call out to fill_readbuf that gets us the required data from the 1148 * buffers that are queued up. 1149 */ 1150 static int get_chars(u32 vtermno, char *buf, int count) 1151 { 1152 struct port *port; 1153 1154 /* If we've not set up the port yet, we have no input to give. */ 1155 if (unlikely(early_put_chars)) 1156 return 0; 1157 1158 port = find_port_by_vtermno(vtermno); 1159 if (!port) 1160 return -EPIPE; 1161 1162 /* If we don't have an input queue yet, we can't get input. */ 1163 BUG_ON(!port->in_vq); 1164 1165 return fill_readbuf(port, buf, count, false); 1166 } 1167 1168 static void resize_console(struct port *port) 1169 { 1170 struct virtio_device *vdev; 1171 1172 /* The port could have been hot-unplugged */ 1173 if (!port || !is_console_port(port)) 1174 return; 1175 1176 vdev = port->portdev->vdev; 1177 1178 /* Don't test F_SIZE at all if we're rproc: not a valid feature! */ 1179 if (!is_rproc_serial(vdev) && 1180 virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)) 1181 hvc_resize(port->cons.hvc, port->cons.ws); 1182 } 1183 1184 /* We set the configuration at this point, since we now have a tty */ 1185 static int notifier_add_vio(struct hvc_struct *hp, int data) 1186 { 1187 struct port *port; 1188 1189 port = find_port_by_vtermno(hp->vtermno); 1190 if (!port) 1191 return -EINVAL; 1192 1193 hp->irq_requested = 1; 1194 resize_console(port); 1195 1196 return 0; 1197 } 1198 1199 static void notifier_del_vio(struct hvc_struct *hp, int data) 1200 { 1201 hp->irq_requested = 0; 1202 } 1203 1204 /* The operations for console ports. */ 1205 static const struct hv_ops hv_ops = { 1206 .get_chars = get_chars, 1207 .put_chars = put_chars, 1208 .notifier_add = notifier_add_vio, 1209 .notifier_del = notifier_del_vio, 1210 .notifier_hangup = notifier_del_vio, 1211 }; 1212 1213 /* 1214 * Console drivers are initialized very early so boot messages can go 1215 * out, so we do things slightly differently from the generic virtio 1216 * initialization of the net and block drivers. 1217 * 1218 * At this stage, the console is output-only. It's too early to set 1219 * up a virtqueue, so we let the drivers do some boutique early-output 1220 * thing. 1221 */ 1222 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int)) 1223 { 1224 early_put_chars = put_chars; 1225 return hvc_instantiate(0, 0, &hv_ops); 1226 } 1227 1228 static int init_port_console(struct port *port) 1229 { 1230 int ret; 1231 1232 /* 1233 * The Host's telling us this port is a console port. Hook it 1234 * up with an hvc console. 1235 * 1236 * To set up and manage our virtual console, we call 1237 * hvc_alloc(). 1238 * 1239 * The first argument of hvc_alloc() is the virtual console 1240 * number. The second argument is the parameter for the 1241 * notification mechanism (like irq number). We currently 1242 * leave this as zero, virtqueues have implicit notifications. 1243 * 1244 * The third argument is a "struct hv_ops" containing the 1245 * put_chars() get_chars(), notifier_add() and notifier_del() 1246 * pointers. The final argument is the output buffer size: we 1247 * can do any size, so we put PAGE_SIZE here. 1248 */ 1249 port->cons.vtermno = pdrvdata.next_vtermno; 1250 1251 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE); 1252 if (IS_ERR(port->cons.hvc)) { 1253 ret = PTR_ERR(port->cons.hvc); 1254 dev_err(port->dev, 1255 "error %d allocating hvc for port\n", ret); 1256 port->cons.hvc = NULL; 1257 return ret; 1258 } 1259 spin_lock_irq(&pdrvdata_lock); 1260 pdrvdata.next_vtermno++; 1261 list_add_tail(&port->cons.list, &pdrvdata.consoles); 1262 spin_unlock_irq(&pdrvdata_lock); 1263 port->guest_connected = true; 1264 1265 /* 1266 * Start using the new console output if this is the first 1267 * console to come up. 1268 */ 1269 if (early_put_chars) 1270 early_put_chars = NULL; 1271 1272 /* Notify host of port being opened */ 1273 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1); 1274 1275 return 0; 1276 } 1277 1278 static ssize_t show_port_name(struct device *dev, 1279 struct device_attribute *attr, char *buffer) 1280 { 1281 struct port *port; 1282 1283 port = dev_get_drvdata(dev); 1284 1285 return sprintf(buffer, "%s\n", port->name); 1286 } 1287 1288 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL); 1289 1290 static struct attribute *port_sysfs_entries[] = { 1291 &dev_attr_name.attr, 1292 NULL 1293 }; 1294 1295 static struct attribute_group port_attribute_group = { 1296 .name = NULL, /* put in device directory */ 1297 .attrs = port_sysfs_entries, 1298 }; 1299 1300 static ssize_t debugfs_read(struct file *filp, char __user *ubuf, 1301 size_t count, loff_t *offp) 1302 { 1303 struct port *port; 1304 char *buf; 1305 ssize_t ret, out_offset, out_count; 1306 1307 out_count = 1024; 1308 buf = kmalloc(out_count, GFP_KERNEL); 1309 if (!buf) 1310 return -ENOMEM; 1311 1312 port = filp->private_data; 1313 out_offset = 0; 1314 out_offset += snprintf(buf + out_offset, out_count, 1315 "name: %s\n", port->name ? port->name : ""); 1316 out_offset += snprintf(buf + out_offset, out_count - out_offset, 1317 "guest_connected: %d\n", port->guest_connected); 1318 out_offset += snprintf(buf + out_offset, out_count - out_offset, 1319 "host_connected: %d\n", port->host_connected); 1320 out_offset += snprintf(buf + out_offset, out_count - out_offset, 1321 "outvq_full: %d\n", port->outvq_full); 1322 out_offset += snprintf(buf + out_offset, out_count - out_offset, 1323 "bytes_sent: %lu\n", port->stats.bytes_sent); 1324 out_offset += snprintf(buf + out_offset, out_count - out_offset, 1325 "bytes_received: %lu\n", 1326 port->stats.bytes_received); 1327 out_offset += snprintf(buf + out_offset, out_count - out_offset, 1328 "bytes_discarded: %lu\n", 1329 port->stats.bytes_discarded); 1330 out_offset += snprintf(buf + out_offset, out_count - out_offset, 1331 "is_console: %s\n", 1332 is_console_port(port) ? "yes" : "no"); 1333 out_offset += snprintf(buf + out_offset, out_count - out_offset, 1334 "console_vtermno: %u\n", port->cons.vtermno); 1335 1336 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset); 1337 kfree(buf); 1338 return ret; 1339 } 1340 1341 static const struct file_operations port_debugfs_ops = { 1342 .owner = THIS_MODULE, 1343 .open = simple_open, 1344 .read = debugfs_read, 1345 }; 1346 1347 static void set_console_size(struct port *port, u16 rows, u16 cols) 1348 { 1349 if (!port || !is_console_port(port)) 1350 return; 1351 1352 port->cons.ws.ws_row = rows; 1353 port->cons.ws.ws_col = cols; 1354 } 1355 1356 static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock) 1357 { 1358 struct port_buffer *buf; 1359 unsigned int nr_added_bufs; 1360 int ret; 1361 1362 nr_added_bufs = 0; 1363 do { 1364 buf = alloc_buf(vq, PAGE_SIZE, 0); 1365 if (!buf) 1366 break; 1367 1368 spin_lock_irq(lock); 1369 ret = add_inbuf(vq, buf); 1370 if (ret < 0) { 1371 spin_unlock_irq(lock); 1372 free_buf(buf, true); 1373 break; 1374 } 1375 nr_added_bufs++; 1376 spin_unlock_irq(lock); 1377 } while (ret > 0); 1378 1379 return nr_added_bufs; 1380 } 1381 1382 static void send_sigio_to_port(struct port *port) 1383 { 1384 if (port->async_queue && port->guest_connected) 1385 kill_fasync(&port->async_queue, SIGIO, POLL_OUT); 1386 } 1387 1388 static int add_port(struct ports_device *portdev, u32 id) 1389 { 1390 char debugfs_name[16]; 1391 struct port *port; 1392 struct port_buffer *buf; 1393 dev_t devt; 1394 unsigned int nr_added_bufs; 1395 int err; 1396 1397 port = kmalloc(sizeof(*port), GFP_KERNEL); 1398 if (!port) { 1399 err = -ENOMEM; 1400 goto fail; 1401 } 1402 kref_init(&port->kref); 1403 1404 port->portdev = portdev; 1405 port->id = id; 1406 1407 port->name = NULL; 1408 port->inbuf = NULL; 1409 port->cons.hvc = NULL; 1410 port->async_queue = NULL; 1411 1412 port->cons.ws.ws_row = port->cons.ws.ws_col = 0; 1413 1414 port->host_connected = port->guest_connected = false; 1415 port->stats = (struct port_stats) { 0 }; 1416 1417 port->outvq_full = false; 1418 1419 port->in_vq = portdev->in_vqs[port->id]; 1420 port->out_vq = portdev->out_vqs[port->id]; 1421 1422 port->cdev = cdev_alloc(); 1423 if (!port->cdev) { 1424 dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n"); 1425 err = -ENOMEM; 1426 goto free_port; 1427 } 1428 port->cdev->ops = &port_fops; 1429 1430 devt = MKDEV(portdev->chr_major, id); 1431 err = cdev_add(port->cdev, devt, 1); 1432 if (err < 0) { 1433 dev_err(&port->portdev->vdev->dev, 1434 "Error %d adding cdev for port %u\n", err, id); 1435 goto free_cdev; 1436 } 1437 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev, 1438 devt, port, "vport%up%u", 1439 port->portdev->vdev->index, id); 1440 if (IS_ERR(port->dev)) { 1441 err = PTR_ERR(port->dev); 1442 dev_err(&port->portdev->vdev->dev, 1443 "Error %d creating device for port %u\n", 1444 err, id); 1445 goto free_cdev; 1446 } 1447 1448 spin_lock_init(&port->inbuf_lock); 1449 spin_lock_init(&port->outvq_lock); 1450 init_waitqueue_head(&port->waitqueue); 1451 1452 /* Fill the in_vq with buffers so the host can send us data. */ 1453 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock); 1454 if (!nr_added_bufs) { 1455 dev_err(port->dev, "Error allocating inbufs\n"); 1456 err = -ENOMEM; 1457 goto free_device; 1458 } 1459 1460 if (is_rproc_serial(port->portdev->vdev)) 1461 /* 1462 * For rproc_serial assume remote processor is connected. 1463 * rproc_serial does not want the console port, only 1464 * the generic port implementation. 1465 */ 1466 port->host_connected = true; 1467 else if (!use_multiport(port->portdev)) { 1468 /* 1469 * If we're not using multiport support, 1470 * this has to be a console port. 1471 */ 1472 err = init_port_console(port); 1473 if (err) 1474 goto free_inbufs; 1475 } 1476 1477 spin_lock_irq(&portdev->ports_lock); 1478 list_add_tail(&port->list, &port->portdev->ports); 1479 spin_unlock_irq(&portdev->ports_lock); 1480 1481 /* 1482 * Tell the Host we're set so that it can send us various 1483 * configuration parameters for this port (eg, port name, 1484 * caching, whether this is a console port, etc.) 1485 */ 1486 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); 1487 1488 if (pdrvdata.debugfs_dir) { 1489 /* 1490 * Finally, create the debugfs file that we can use to 1491 * inspect a port's state at any time 1492 */ 1493 sprintf(debugfs_name, "vport%up%u", 1494 port->portdev->vdev->index, id); 1495 port->debugfs_file = debugfs_create_file(debugfs_name, 0444, 1496 pdrvdata.debugfs_dir, 1497 port, 1498 &port_debugfs_ops); 1499 } 1500 return 0; 1501 1502 free_inbufs: 1503 while ((buf = virtqueue_detach_unused_buf(port->in_vq))) 1504 free_buf(buf, true); 1505 free_device: 1506 device_destroy(pdrvdata.class, port->dev->devt); 1507 free_cdev: 1508 cdev_del(port->cdev); 1509 free_port: 1510 kfree(port); 1511 fail: 1512 /* The host might want to notify management sw about port add failure */ 1513 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0); 1514 return err; 1515 } 1516 1517 /* No users remain, remove all port-specific data. */ 1518 static void remove_port(struct kref *kref) 1519 { 1520 struct port *port; 1521 1522 port = container_of(kref, struct port, kref); 1523 1524 kfree(port); 1525 } 1526 1527 static void remove_port_data(struct port *port) 1528 { 1529 struct port_buffer *buf; 1530 1531 spin_lock_irq(&port->inbuf_lock); 1532 /* Remove unused data this port might have received. */ 1533 discard_port_data(port); 1534 1535 /* Remove buffers we queued up for the Host to send us data in. */ 1536 while ((buf = virtqueue_detach_unused_buf(port->in_vq))) 1537 free_buf(buf, true); 1538 spin_unlock_irq(&port->inbuf_lock); 1539 1540 spin_lock_irq(&port->outvq_lock); 1541 reclaim_consumed_buffers(port); 1542 1543 /* Free pending buffers from the out-queue. */ 1544 while ((buf = virtqueue_detach_unused_buf(port->out_vq))) 1545 free_buf(buf, true); 1546 spin_unlock_irq(&port->outvq_lock); 1547 } 1548 1549 /* 1550 * Port got unplugged. Remove port from portdev's list and drop the 1551 * kref reference. If no userspace has this port opened, it will 1552 * result in immediate removal the port. 1553 */ 1554 static void unplug_port(struct port *port) 1555 { 1556 spin_lock_irq(&port->portdev->ports_lock); 1557 list_del(&port->list); 1558 spin_unlock_irq(&port->portdev->ports_lock); 1559 1560 spin_lock_irq(&port->inbuf_lock); 1561 if (port->guest_connected) { 1562 /* Let the app know the port is going down. */ 1563 send_sigio_to_port(port); 1564 1565 /* Do this after sigio is actually sent */ 1566 port->guest_connected = false; 1567 port->host_connected = false; 1568 1569 wake_up_interruptible(&port->waitqueue); 1570 } 1571 spin_unlock_irq(&port->inbuf_lock); 1572 1573 if (is_console_port(port)) { 1574 spin_lock_irq(&pdrvdata_lock); 1575 list_del(&port->cons.list); 1576 spin_unlock_irq(&pdrvdata_lock); 1577 hvc_remove(port->cons.hvc); 1578 } 1579 1580 remove_port_data(port); 1581 1582 /* 1583 * We should just assume the device itself has gone off -- 1584 * else a close on an open port later will try to send out a 1585 * control message. 1586 */ 1587 port->portdev = NULL; 1588 1589 sysfs_remove_group(&port->dev->kobj, &port_attribute_group); 1590 device_destroy(pdrvdata.class, port->dev->devt); 1591 cdev_del(port->cdev); 1592 1593 debugfs_remove(port->debugfs_file); 1594 kfree(port->name); 1595 1596 /* 1597 * Locks around here are not necessary - a port can't be 1598 * opened after we removed the port struct from ports_list 1599 * above. 1600 */ 1601 kref_put(&port->kref, remove_port); 1602 } 1603 1604 /* Any private messages that the Host and Guest want to share */ 1605 static void handle_control_message(struct ports_device *portdev, 1606 struct port_buffer *buf) 1607 { 1608 struct virtio_console_control *cpkt; 1609 struct port *port; 1610 size_t name_size; 1611 int err; 1612 1613 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset); 1614 1615 port = find_port_by_id(portdev, cpkt->id); 1616 if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) { 1617 /* No valid header at start of buffer. Drop it. */ 1618 dev_dbg(&portdev->vdev->dev, 1619 "Invalid index %u in control packet\n", cpkt->id); 1620 return; 1621 } 1622 1623 switch (cpkt->event) { 1624 case VIRTIO_CONSOLE_PORT_ADD: 1625 if (port) { 1626 dev_dbg(&portdev->vdev->dev, 1627 "Port %u already added\n", port->id); 1628 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); 1629 break; 1630 } 1631 if (cpkt->id >= portdev->config.max_nr_ports) { 1632 dev_warn(&portdev->vdev->dev, 1633 "Request for adding port with out-of-bound id %u, max. supported id: %u\n", 1634 cpkt->id, portdev->config.max_nr_ports - 1); 1635 break; 1636 } 1637 add_port(portdev, cpkt->id); 1638 break; 1639 case VIRTIO_CONSOLE_PORT_REMOVE: 1640 unplug_port(port); 1641 break; 1642 case VIRTIO_CONSOLE_CONSOLE_PORT: 1643 if (!cpkt->value) 1644 break; 1645 if (is_console_port(port)) 1646 break; 1647 1648 init_port_console(port); 1649 complete(&early_console_added); 1650 /* 1651 * Could remove the port here in case init fails - but 1652 * have to notify the host first. 1653 */ 1654 break; 1655 case VIRTIO_CONSOLE_RESIZE: { 1656 struct { 1657 __u16 rows; 1658 __u16 cols; 1659 } size; 1660 1661 if (!is_console_port(port)) 1662 break; 1663 1664 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt), 1665 sizeof(size)); 1666 set_console_size(port, size.rows, size.cols); 1667 1668 port->cons.hvc->irq_requested = 1; 1669 resize_console(port); 1670 break; 1671 } 1672 case VIRTIO_CONSOLE_PORT_OPEN: 1673 port->host_connected = cpkt->value; 1674 wake_up_interruptible(&port->waitqueue); 1675 /* 1676 * If the host port got closed and the host had any 1677 * unconsumed buffers, we'll be able to reclaim them 1678 * now. 1679 */ 1680 spin_lock_irq(&port->outvq_lock); 1681 reclaim_consumed_buffers(port); 1682 spin_unlock_irq(&port->outvq_lock); 1683 1684 /* 1685 * If the guest is connected, it'll be interested in 1686 * knowing the host connection state changed. 1687 */ 1688 spin_lock_irq(&port->inbuf_lock); 1689 send_sigio_to_port(port); 1690 spin_unlock_irq(&port->inbuf_lock); 1691 break; 1692 case VIRTIO_CONSOLE_PORT_NAME: 1693 /* 1694 * If we woke up after hibernation, we can get this 1695 * again. Skip it in that case. 1696 */ 1697 if (port->name) 1698 break; 1699 1700 /* 1701 * Skip the size of the header and the cpkt to get the size 1702 * of the name that was sent 1703 */ 1704 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1; 1705 1706 port->name = kmalloc(name_size, GFP_KERNEL); 1707 if (!port->name) { 1708 dev_err(port->dev, 1709 "Not enough space to store port name\n"); 1710 break; 1711 } 1712 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt), 1713 name_size - 1); 1714 port->name[name_size - 1] = 0; 1715 1716 /* 1717 * Since we only have one sysfs attribute, 'name', 1718 * create it only if we have a name for the port. 1719 */ 1720 err = sysfs_create_group(&port->dev->kobj, 1721 &port_attribute_group); 1722 if (err) { 1723 dev_err(port->dev, 1724 "Error %d creating sysfs device attributes\n", 1725 err); 1726 } else { 1727 /* 1728 * Generate a udev event so that appropriate 1729 * symlinks can be created based on udev 1730 * rules. 1731 */ 1732 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE); 1733 } 1734 break; 1735 } 1736 } 1737 1738 static void control_work_handler(struct work_struct *work) 1739 { 1740 struct ports_device *portdev; 1741 struct virtqueue *vq; 1742 struct port_buffer *buf; 1743 unsigned int len; 1744 1745 portdev = container_of(work, struct ports_device, control_work); 1746 vq = portdev->c_ivq; 1747 1748 spin_lock(&portdev->c_ivq_lock); 1749 while ((buf = virtqueue_get_buf(vq, &len))) { 1750 spin_unlock(&portdev->c_ivq_lock); 1751 1752 buf->len = len; 1753 buf->offset = 0; 1754 1755 handle_control_message(portdev, buf); 1756 1757 spin_lock(&portdev->c_ivq_lock); 1758 if (add_inbuf(portdev->c_ivq, buf) < 0) { 1759 dev_warn(&portdev->vdev->dev, 1760 "Error adding buffer to queue\n"); 1761 free_buf(buf, false); 1762 } 1763 } 1764 spin_unlock(&portdev->c_ivq_lock); 1765 } 1766 1767 static void out_intr(struct virtqueue *vq) 1768 { 1769 struct port *port; 1770 1771 port = find_port_by_vq(vq->vdev->priv, vq); 1772 if (!port) 1773 return; 1774 1775 wake_up_interruptible(&port->waitqueue); 1776 } 1777 1778 static void in_intr(struct virtqueue *vq) 1779 { 1780 struct port *port; 1781 unsigned long flags; 1782 1783 port = find_port_by_vq(vq->vdev->priv, vq); 1784 if (!port) 1785 return; 1786 1787 spin_lock_irqsave(&port->inbuf_lock, flags); 1788 port->inbuf = get_inbuf(port); 1789 1790 /* 1791 * Normally the port should not accept data when the port is 1792 * closed. For generic serial ports, the host won't (shouldn't) 1793 * send data till the guest is connected. But this condition 1794 * can be reached when a console port is not yet connected (no 1795 * tty is spawned) and the other side sends out data over the 1796 * vring, or when a remote devices start sending data before 1797 * the ports are opened. 1798 * 1799 * A generic serial port will discard data if not connected, 1800 * while console ports and rproc-serial ports accepts data at 1801 * any time. rproc-serial is initiated with guest_connected to 1802 * false because port_fops_open expects this. Console ports are 1803 * hooked up with an HVC console and is initialized with 1804 * guest_connected to true. 1805 */ 1806 1807 if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev)) 1808 discard_port_data(port); 1809 1810 /* Send a SIGIO indicating new data in case the process asked for it */ 1811 send_sigio_to_port(port); 1812 1813 spin_unlock_irqrestore(&port->inbuf_lock, flags); 1814 1815 wake_up_interruptible(&port->waitqueue); 1816 1817 if (is_console_port(port) && hvc_poll(port->cons.hvc)) 1818 hvc_kick(); 1819 } 1820 1821 static void control_intr(struct virtqueue *vq) 1822 { 1823 struct ports_device *portdev; 1824 1825 portdev = vq->vdev->priv; 1826 schedule_work(&portdev->control_work); 1827 } 1828 1829 static void config_intr(struct virtio_device *vdev) 1830 { 1831 struct ports_device *portdev; 1832 1833 portdev = vdev->priv; 1834 1835 if (!use_multiport(portdev)) { 1836 struct port *port; 1837 u16 rows, cols; 1838 1839 virtio_cread(vdev, struct virtio_console_config, cols, &cols); 1840 virtio_cread(vdev, struct virtio_console_config, rows, &rows); 1841 1842 port = find_port_by_id(portdev, 0); 1843 set_console_size(port, rows, cols); 1844 1845 /* 1846 * We'll use this way of resizing only for legacy 1847 * support. For newer userspace 1848 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages 1849 * to indicate console size changes so that it can be 1850 * done per-port. 1851 */ 1852 resize_console(port); 1853 } 1854 } 1855 1856 static int init_vqs(struct ports_device *portdev) 1857 { 1858 vq_callback_t **io_callbacks; 1859 char **io_names; 1860 struct virtqueue **vqs; 1861 u32 i, j, nr_ports, nr_queues; 1862 int err; 1863 1864 nr_ports = portdev->config.max_nr_ports; 1865 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2; 1866 1867 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL); 1868 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL); 1869 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL); 1870 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *), 1871 GFP_KERNEL); 1872 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *), 1873 GFP_KERNEL); 1874 if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs || 1875 !portdev->out_vqs) { 1876 err = -ENOMEM; 1877 goto free; 1878 } 1879 1880 /* 1881 * For backward compat (newer host but older guest), the host 1882 * spawns a console port first and also inits the vqs for port 1883 * 0 before others. 1884 */ 1885 j = 0; 1886 io_callbacks[j] = in_intr; 1887 io_callbacks[j + 1] = out_intr; 1888 io_names[j] = "input"; 1889 io_names[j + 1] = "output"; 1890 j += 2; 1891 1892 if (use_multiport(portdev)) { 1893 io_callbacks[j] = control_intr; 1894 io_callbacks[j + 1] = NULL; 1895 io_names[j] = "control-i"; 1896 io_names[j + 1] = "control-o"; 1897 1898 for (i = 1; i < nr_ports; i++) { 1899 j += 2; 1900 io_callbacks[j] = in_intr; 1901 io_callbacks[j + 1] = out_intr; 1902 io_names[j] = "input"; 1903 io_names[j + 1] = "output"; 1904 } 1905 } 1906 /* Find the queues. */ 1907 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs, 1908 io_callbacks, 1909 (const char **)io_names); 1910 if (err) 1911 goto free; 1912 1913 j = 0; 1914 portdev->in_vqs[0] = vqs[0]; 1915 portdev->out_vqs[0] = vqs[1]; 1916 j += 2; 1917 if (use_multiport(portdev)) { 1918 portdev->c_ivq = vqs[j]; 1919 portdev->c_ovq = vqs[j + 1]; 1920 1921 for (i = 1; i < nr_ports; i++) { 1922 j += 2; 1923 portdev->in_vqs[i] = vqs[j]; 1924 portdev->out_vqs[i] = vqs[j + 1]; 1925 } 1926 } 1927 kfree(io_names); 1928 kfree(io_callbacks); 1929 kfree(vqs); 1930 1931 return 0; 1932 1933 free: 1934 kfree(portdev->out_vqs); 1935 kfree(portdev->in_vqs); 1936 kfree(io_names); 1937 kfree(io_callbacks); 1938 kfree(vqs); 1939 1940 return err; 1941 } 1942 1943 static const struct file_operations portdev_fops = { 1944 .owner = THIS_MODULE, 1945 }; 1946 1947 static void remove_vqs(struct ports_device *portdev) 1948 { 1949 portdev->vdev->config->del_vqs(portdev->vdev); 1950 kfree(portdev->in_vqs); 1951 kfree(portdev->out_vqs); 1952 } 1953 1954 static void remove_controlq_data(struct ports_device *portdev) 1955 { 1956 struct port_buffer *buf; 1957 unsigned int len; 1958 1959 if (!use_multiport(portdev)) 1960 return; 1961 1962 while ((buf = virtqueue_get_buf(portdev->c_ivq, &len))) 1963 free_buf(buf, true); 1964 1965 while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq))) 1966 free_buf(buf, true); 1967 } 1968 1969 /* 1970 * Once we're further in boot, we get probed like any other virtio 1971 * device. 1972 * 1973 * If the host also supports multiple console ports, we check the 1974 * config space to see how many ports the host has spawned. We 1975 * initialize each port found. 1976 */ 1977 static int virtcons_probe(struct virtio_device *vdev) 1978 { 1979 struct ports_device *portdev; 1980 int err; 1981 bool multiport; 1982 bool early = early_put_chars != NULL; 1983 1984 /* Ensure to read early_put_chars now */ 1985 barrier(); 1986 1987 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL); 1988 if (!portdev) { 1989 err = -ENOMEM; 1990 goto fail; 1991 } 1992 1993 /* Attach this portdev to this virtio_device, and vice-versa. */ 1994 portdev->vdev = vdev; 1995 vdev->priv = portdev; 1996 1997 portdev->chr_major = register_chrdev(0, "virtio-portsdev", 1998 &portdev_fops); 1999 if (portdev->chr_major < 0) { 2000 dev_err(&vdev->dev, 2001 "Error %d registering chrdev for device %u\n", 2002 portdev->chr_major, vdev->index); 2003 err = portdev->chr_major; 2004 goto free; 2005 } 2006 2007 multiport = false; 2008 portdev->config.max_nr_ports = 1; 2009 2010 /* Don't test MULTIPORT at all if we're rproc: not a valid feature! */ 2011 if (!is_rproc_serial(vdev) && 2012 virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT, 2013 struct virtio_console_config, max_nr_ports, 2014 &portdev->config.max_nr_ports) == 0) { 2015 multiport = true; 2016 } 2017 2018 err = init_vqs(portdev); 2019 if (err < 0) { 2020 dev_err(&vdev->dev, "Error %d initializing vqs\n", err); 2021 goto free_chrdev; 2022 } 2023 2024 spin_lock_init(&portdev->ports_lock); 2025 INIT_LIST_HEAD(&portdev->ports); 2026 2027 if (multiport) { 2028 unsigned int nr_added_bufs; 2029 2030 spin_lock_init(&portdev->c_ivq_lock); 2031 spin_lock_init(&portdev->c_ovq_lock); 2032 INIT_WORK(&portdev->control_work, &control_work_handler); 2033 2034 nr_added_bufs = fill_queue(portdev->c_ivq, 2035 &portdev->c_ivq_lock); 2036 if (!nr_added_bufs) { 2037 dev_err(&vdev->dev, 2038 "Error allocating buffers for control queue\n"); 2039 err = -ENOMEM; 2040 goto free_vqs; 2041 } 2042 } else { 2043 /* 2044 * For backward compatibility: Create a console port 2045 * if we're running on older host. 2046 */ 2047 add_port(portdev, 0); 2048 } 2049 2050 spin_lock_irq(&pdrvdata_lock); 2051 list_add_tail(&portdev->list, &pdrvdata.portdevs); 2052 spin_unlock_irq(&pdrvdata_lock); 2053 2054 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID, 2055 VIRTIO_CONSOLE_DEVICE_READY, 1); 2056 2057 /* 2058 * If there was an early virtio console, assume that there are no 2059 * other consoles. We need to wait until the hvc_alloc matches the 2060 * hvc_instantiate, otherwise tty_open will complain, resulting in 2061 * a "Warning: unable to open an initial console" boot failure. 2062 * Without multiport this is done in add_port above. With multiport 2063 * this might take some host<->guest communication - thus we have to 2064 * wait. 2065 */ 2066 if (multiport && early) 2067 wait_for_completion(&early_console_added); 2068 2069 return 0; 2070 2071 free_vqs: 2072 /* The host might want to notify mgmt sw about device add failure */ 2073 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID, 2074 VIRTIO_CONSOLE_DEVICE_READY, 0); 2075 remove_vqs(portdev); 2076 free_chrdev: 2077 unregister_chrdev(portdev->chr_major, "virtio-portsdev"); 2078 free: 2079 kfree(portdev); 2080 fail: 2081 return err; 2082 } 2083 2084 static void virtcons_remove(struct virtio_device *vdev) 2085 { 2086 struct ports_device *portdev; 2087 struct port *port, *port2; 2088 2089 portdev = vdev->priv; 2090 2091 spin_lock_irq(&pdrvdata_lock); 2092 list_del(&portdev->list); 2093 spin_unlock_irq(&pdrvdata_lock); 2094 2095 /* Disable interrupts for vqs */ 2096 vdev->config->reset(vdev); 2097 /* Finish up work that's lined up */ 2098 if (use_multiport(portdev)) 2099 cancel_work_sync(&portdev->control_work); 2100 2101 list_for_each_entry_safe(port, port2, &portdev->ports, list) 2102 unplug_port(port); 2103 2104 unregister_chrdev(portdev->chr_major, "virtio-portsdev"); 2105 2106 /* 2107 * When yanking out a device, we immediately lose the 2108 * (device-side) queues. So there's no point in keeping the 2109 * guest side around till we drop our final reference. This 2110 * also means that any ports which are in an open state will 2111 * have to just stop using the port, as the vqs are going 2112 * away. 2113 */ 2114 remove_controlq_data(portdev); 2115 remove_vqs(portdev); 2116 kfree(portdev); 2117 } 2118 2119 static struct virtio_device_id id_table[] = { 2120 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID }, 2121 { 0 }, 2122 }; 2123 2124 static unsigned int features[] = { 2125 VIRTIO_CONSOLE_F_SIZE, 2126 VIRTIO_CONSOLE_F_MULTIPORT, 2127 }; 2128 2129 static struct virtio_device_id rproc_serial_id_table[] = { 2130 #if IS_ENABLED(CONFIG_REMOTEPROC) 2131 { VIRTIO_ID_RPROC_SERIAL, VIRTIO_DEV_ANY_ID }, 2132 #endif 2133 { 0 }, 2134 }; 2135 2136 static unsigned int rproc_serial_features[] = { 2137 }; 2138 2139 #ifdef CONFIG_PM_SLEEP 2140 static int virtcons_freeze(struct virtio_device *vdev) 2141 { 2142 struct ports_device *portdev; 2143 struct port *port; 2144 2145 portdev = vdev->priv; 2146 2147 vdev->config->reset(vdev); 2148 2149 virtqueue_disable_cb(portdev->c_ivq); 2150 cancel_work_sync(&portdev->control_work); 2151 /* 2152 * Once more: if control_work_handler() was running, it would 2153 * enable the cb as the last step. 2154 */ 2155 virtqueue_disable_cb(portdev->c_ivq); 2156 remove_controlq_data(portdev); 2157 2158 list_for_each_entry(port, &portdev->ports, list) { 2159 virtqueue_disable_cb(port->in_vq); 2160 virtqueue_disable_cb(port->out_vq); 2161 /* 2162 * We'll ask the host later if the new invocation has 2163 * the port opened or closed. 2164 */ 2165 port->host_connected = false; 2166 remove_port_data(port); 2167 } 2168 remove_vqs(portdev); 2169 2170 return 0; 2171 } 2172 2173 static int virtcons_restore(struct virtio_device *vdev) 2174 { 2175 struct ports_device *portdev; 2176 struct port *port; 2177 int ret; 2178 2179 portdev = vdev->priv; 2180 2181 ret = init_vqs(portdev); 2182 if (ret) 2183 return ret; 2184 2185 if (use_multiport(portdev)) 2186 fill_queue(portdev->c_ivq, &portdev->c_ivq_lock); 2187 2188 list_for_each_entry(port, &portdev->ports, list) { 2189 port->in_vq = portdev->in_vqs[port->id]; 2190 port->out_vq = portdev->out_vqs[port->id]; 2191 2192 fill_queue(port->in_vq, &port->inbuf_lock); 2193 2194 /* Get port open/close status on the host */ 2195 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); 2196 2197 /* 2198 * If a port was open at the time of suspending, we 2199 * have to let the host know that it's still open. 2200 */ 2201 if (port->guest_connected) 2202 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1); 2203 } 2204 return 0; 2205 } 2206 #endif 2207 2208 static struct virtio_driver virtio_console = { 2209 .feature_table = features, 2210 .feature_table_size = ARRAY_SIZE(features), 2211 .driver.name = KBUILD_MODNAME, 2212 .driver.owner = THIS_MODULE, 2213 .id_table = id_table, 2214 .probe = virtcons_probe, 2215 .remove = virtcons_remove, 2216 .config_changed = config_intr, 2217 #ifdef CONFIG_PM_SLEEP 2218 .freeze = virtcons_freeze, 2219 .restore = virtcons_restore, 2220 #endif 2221 }; 2222 2223 static struct virtio_driver virtio_rproc_serial = { 2224 .feature_table = rproc_serial_features, 2225 .feature_table_size = ARRAY_SIZE(rproc_serial_features), 2226 .driver.name = "virtio_rproc_serial", 2227 .driver.owner = THIS_MODULE, 2228 .id_table = rproc_serial_id_table, 2229 .probe = virtcons_probe, 2230 .remove = virtcons_remove, 2231 }; 2232 2233 static int __init init(void) 2234 { 2235 int err; 2236 2237 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports"); 2238 if (IS_ERR(pdrvdata.class)) { 2239 err = PTR_ERR(pdrvdata.class); 2240 pr_err("Error %d creating virtio-ports class\n", err); 2241 return err; 2242 } 2243 2244 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL); 2245 if (!pdrvdata.debugfs_dir) 2246 pr_warning("Error creating debugfs dir for virtio-ports\n"); 2247 INIT_LIST_HEAD(&pdrvdata.consoles); 2248 INIT_LIST_HEAD(&pdrvdata.portdevs); 2249 2250 err = register_virtio_driver(&virtio_console); 2251 if (err < 0) { 2252 pr_err("Error %d registering virtio driver\n", err); 2253 goto free; 2254 } 2255 err = register_virtio_driver(&virtio_rproc_serial); 2256 if (err < 0) { 2257 pr_err("Error %d registering virtio rproc serial driver\n", 2258 err); 2259 goto unregister; 2260 } 2261 return 0; 2262 unregister: 2263 unregister_virtio_driver(&virtio_console); 2264 free: 2265 if (pdrvdata.debugfs_dir) 2266 debugfs_remove_recursive(pdrvdata.debugfs_dir); 2267 class_destroy(pdrvdata.class); 2268 return err; 2269 } 2270 2271 static void __exit fini(void) 2272 { 2273 reclaim_dma_bufs(); 2274 2275 unregister_virtio_driver(&virtio_console); 2276 unregister_virtio_driver(&virtio_rproc_serial); 2277 2278 class_destroy(pdrvdata.class); 2279 if (pdrvdata.debugfs_dir) 2280 debugfs_remove_recursive(pdrvdata.debugfs_dir); 2281 } 2282 module_init(init); 2283 module_exit(fini); 2284 2285 MODULE_DEVICE_TABLE(virtio, id_table); 2286 MODULE_DESCRIPTION("Virtio console driver"); 2287 MODULE_LICENSE("GPL"); 2288