1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
   4 * Copyright (C) 2009, 2010, 2011 Red Hat, Inc.
   5 * Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com>
   6 */
   7#include <linux/cdev.h>
   8#include <linux/debugfs.h>
   9#include <linux/completion.h>
  10#include <linux/device.h>
  11#include <linux/err.h>
  12#include <linux/freezer.h>
  13#include <linux/fs.h>
  14#include <linux/splice.h>
  15#include <linux/pagemap.h>
  16#include <linux/idr.h>
  17#include <linux/init.h>
  18#include <linux/list.h>
  19#include <linux/poll.h>
  20#include <linux/sched.h>
  21#include <linux/slab.h>
  22#include <linux/spinlock.h>
  23#include <linux/virtio.h>
  24#include <linux/virtio_console.h>
  25#include <linux/wait.h>
  26#include <linux/workqueue.h>
  27#include <linux/module.h>
  28#include <linux/dma-mapping.h>
  29#include "../tty/hvc/hvc_console.h"
  30
  31#define is_rproc_enabled IS_ENABLED(CONFIG_REMOTEPROC)
  32#define VIRTCONS_MAX_PORTS 0x8000
  33
  34/*
  35 * This is a global struct for storing common data for all the devices
  36 * this driver handles.
  37 *
  38 * Mainly, it has a linked list for all the consoles in one place so
  39 * that callbacks from hvc for get_chars(), put_chars() work properly
  40 * across multiple devices and multiple ports per device.
  41 */
  42struct ports_driver_data {
  43	/* Used for registering chardevs */
  44	struct class *class;
  45
  46	/* Used for exporting per-port information to debugfs */
  47	struct dentry *debugfs_dir;
  48
  49	/* List of all the devices we're handling */
  50	struct list_head portdevs;
  51
 
 
 
 
 
 
 
 
 
 
 
 
  52	/* All the console devices handled by this driver */
  53	struct list_head consoles;
  54};
  55
  56static struct ports_driver_data pdrvdata;
  57
  58static DEFINE_SPINLOCK(pdrvdata_lock);
  59static DECLARE_COMPLETION(early_console_added);
  60
  61/* This struct holds information that's relevant only for console ports */
  62struct console {
  63	/* We'll place all consoles in a list in the pdrvdata struct */
  64	struct list_head list;
  65
  66	/* The hvc device associated with this console port */
  67	struct hvc_struct *hvc;
  68
  69	/* The size of the console */
  70	struct winsize ws;
  71
  72	/*
  73	 * This number identifies the number that we used to register
  74	 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
  75	 * number passed on by the hvc callbacks to us to
  76	 * differentiate between the other console ports handled by
  77	 * this driver
  78	 */
  79	u32 vtermno;
  80};
  81
  82static DEFINE_IDA(vtermno_ida);
  83
  84struct port_buffer {
  85	char *buf;
  86
  87	/* size of the buffer in *buf above */
  88	size_t size;
  89
  90	/* used length of the buffer */
  91	size_t len;
  92	/* offset in the buf from which to consume data */
  93	size_t offset;
  94
  95	/* DMA address of buffer */
  96	dma_addr_t dma;
  97
  98	/* Device we got DMA memory from */
  99	struct device *dev;
 100
 101	/* List of pending dma buffers to free */
 102	struct list_head list;
 103
 104	/* If sgpages == 0 then buf is used */
 105	unsigned int sgpages;
 106
 107	/* sg is used if spages > 0. sg must be the last in is struct */
 108	struct scatterlist sg[];
 109};
 110
 111/*
 112 * This is a per-device struct that stores data common to all the
 113 * ports for that device (vdev->priv).
 114 */
 115struct ports_device {
 116	/* Next portdev in the list, head is in the pdrvdata struct */
 117	struct list_head list;
 118
 119	/*
 120	 * Workqueue handlers where we process deferred work after
 121	 * notification
 122	 */
 123	struct work_struct control_work;
 124	struct work_struct config_work;
 125
 126	struct list_head ports;
 127
 128	/* To protect the list of ports */
 129	spinlock_t ports_lock;
 130
 131	/* To protect the vq operations for the control channel */
 132	spinlock_t c_ivq_lock;
 133	spinlock_t c_ovq_lock;
 134
 135	/* max. number of ports this device can hold */
 136	u32 max_nr_ports;
 137
 138	/* The virtio device we're associated with */
 139	struct virtio_device *vdev;
 140
 141	/*
 142	 * A couple of virtqueues for the control channel: one for
 143	 * guest->host transfers, one for host->guest transfers
 144	 */
 145	struct virtqueue *c_ivq, *c_ovq;
 146
 147	/*
 148	 * A control packet buffer for guest->host requests, protected
 149	 * by c_ovq_lock.
 150	 */
 151	struct virtio_console_control cpkt;
 152
 153	/* Array of per-port IO virtqueues */
 154	struct virtqueue **in_vqs, **out_vqs;
 155
 156	/* Major number for this device.  Ports will be created as minors. */
 157	int chr_major;
 158};
 159
 160struct port_stats {
 161	unsigned long bytes_sent, bytes_received, bytes_discarded;
 162};
 163
 164/* This struct holds the per-port data */
 165struct port {
 166	/* Next port in the list, head is in the ports_device */
 167	struct list_head list;
 168
 169	/* Pointer to the parent virtio_console device */
 170	struct ports_device *portdev;
 171
 172	/* The current buffer from which data has to be fed to readers */
 173	struct port_buffer *inbuf;
 174
 175	/*
 176	 * To protect the operations on the in_vq associated with this
 177	 * port.  Has to be a spinlock because it can be called from
 178	 * interrupt context (get_char()).
 179	 */
 180	spinlock_t inbuf_lock;
 181
 182	/* Protect the operations on the out_vq. */
 183	spinlock_t outvq_lock;
 184
 185	/* The IO vqs for this port */
 186	struct virtqueue *in_vq, *out_vq;
 187
 188	/* File in the debugfs directory that exposes this port's information */
 189	struct dentry *debugfs_file;
 190
 191	/*
 192	 * Keep count of the bytes sent, received and discarded for
 193	 * this port for accounting and debugging purposes.  These
 194	 * counts are not reset across port open / close events.
 195	 */
 196	struct port_stats stats;
 197
 198	/*
 199	 * The entries in this struct will be valid if this port is
 200	 * hooked up to an hvc console
 201	 */
 202	struct console cons;
 203
 204	/* Each port associates with a separate char device */
 205	struct cdev *cdev;
 206	struct device *dev;
 207
 208	/* Reference-counting to handle port hot-unplugs and file operations */
 209	struct kref kref;
 210
 211	/* A waitqueue for poll() or blocking read operations */
 212	wait_queue_head_t waitqueue;
 213
 214	/* The 'name' of the port that we expose via sysfs properties */
 215	char *name;
 216
 217	/* We can notify apps of host connect / disconnect events via SIGIO */
 218	struct fasync_struct *async_queue;
 219
 220	/* The 'id' to identify the port with the Host */
 221	u32 id;
 222
 223	bool outvq_full;
 224
 225	/* Is the host device open */
 226	bool host_connected;
 227
 228	/* We should allow only one process to open a port */
 229	bool guest_connected;
 230};
 231
 232/* This is the very early arch-specified put chars function. */
 233static int (*early_put_chars)(u32, const char *, int);
 234
 235static struct port *find_port_by_vtermno(u32 vtermno)
 236{
 237	struct port *port;
 238	struct console *cons;
 239	unsigned long flags;
 240
 241	spin_lock_irqsave(&pdrvdata_lock, flags);
 242	list_for_each_entry(cons, &pdrvdata.consoles, list) {
 243		if (cons->vtermno == vtermno) {
 244			port = container_of(cons, struct port, cons);
 245			goto out;
 246		}
 247	}
 248	port = NULL;
 249out:
 250	spin_unlock_irqrestore(&pdrvdata_lock, flags);
 251	return port;
 252}
 253
 254static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
 255						 dev_t dev)
 256{
 257	struct port *port;
 258	unsigned long flags;
 259
 260	spin_lock_irqsave(&portdev->ports_lock, flags);
 261	list_for_each_entry(port, &portdev->ports, list) {
 262		if (port->cdev->dev == dev) {
 263			kref_get(&port->kref);
 264			goto out;
 265		}
 266	}
 267	port = NULL;
 268out:
 269	spin_unlock_irqrestore(&portdev->ports_lock, flags);
 270
 271	return port;
 272}
 273
 274static struct port *find_port_by_devt(dev_t dev)
 275{
 276	struct ports_device *portdev;
 277	struct port *port;
 278	unsigned long flags;
 279
 280	spin_lock_irqsave(&pdrvdata_lock, flags);
 281	list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
 282		port = find_port_by_devt_in_portdev(portdev, dev);
 283		if (port)
 284			goto out;
 285	}
 286	port = NULL;
 287out:
 288	spin_unlock_irqrestore(&pdrvdata_lock, flags);
 289	return port;
 290}
 291
 292static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
 293{
 294	struct port *port;
 295	unsigned long flags;
 296
 297	spin_lock_irqsave(&portdev->ports_lock, flags);
 298	list_for_each_entry(port, &portdev->ports, list)
 299		if (port->id == id)
 300			goto out;
 301	port = NULL;
 302out:
 303	spin_unlock_irqrestore(&portdev->ports_lock, flags);
 304
 305	return port;
 306}
 307
 308static struct port *find_port_by_vq(struct ports_device *portdev,
 309				    struct virtqueue *vq)
 310{
 311	struct port *port;
 312	unsigned long flags;
 313
 314	spin_lock_irqsave(&portdev->ports_lock, flags);
 315	list_for_each_entry(port, &portdev->ports, list)
 316		if (port->in_vq == vq || port->out_vq == vq)
 317			goto out;
 318	port = NULL;
 319out:
 320	spin_unlock_irqrestore(&portdev->ports_lock, flags);
 321	return port;
 322}
 323
 324static bool is_console_port(struct port *port)
 325{
 326	if (port->cons.hvc)
 327		return true;
 328	return false;
 329}
 330
 331static bool is_rproc_serial(const struct virtio_device *vdev)
 332{
 333	return is_rproc_enabled && vdev->id.device == VIRTIO_ID_RPROC_SERIAL;
 334}
 335
 336static inline bool use_multiport(struct ports_device *portdev)
 337{
 338	/*
 339	 * This condition can be true when put_chars is called from
 340	 * early_init
 341	 */
 342	if (!portdev->vdev)
 343		return false;
 344	return __virtio_test_bit(portdev->vdev, VIRTIO_CONSOLE_F_MULTIPORT);
 345}
 346
 347static DEFINE_SPINLOCK(dma_bufs_lock);
 348static LIST_HEAD(pending_free_dma_bufs);
 349
 350static void free_buf(struct port_buffer *buf, bool can_sleep)
 351{
 352	unsigned int i;
 353
 354	for (i = 0; i < buf->sgpages; i++) {
 355		struct page *page = sg_page(&buf->sg[i]);
 356		if (!page)
 357			break;
 358		put_page(page);
 359	}
 360
 361	if (!buf->dev) {
 362		kfree(buf->buf);
 363	} else if (is_rproc_enabled) {
 364		unsigned long flags;
 365
 366		/* dma_free_coherent requires interrupts to be enabled. */
 367		if (!can_sleep) {
 368			/* queue up dma-buffers to be freed later */
 369			spin_lock_irqsave(&dma_bufs_lock, flags);
 370			list_add_tail(&buf->list, &pending_free_dma_bufs);
 371			spin_unlock_irqrestore(&dma_bufs_lock, flags);
 372			return;
 373		}
 374		dma_free_coherent(buf->dev, buf->size, buf->buf, buf->dma);
 375
 376		/* Release device refcnt and allow it to be freed */
 377		put_device(buf->dev);
 378	}
 379
 380	kfree(buf);
 381}
 382
 383static void reclaim_dma_bufs(void)
 384{
 385	unsigned long flags;
 386	struct port_buffer *buf, *tmp;
 387	LIST_HEAD(tmp_list);
 388
 389	if (list_empty(&pending_free_dma_bufs))
 390		return;
 391
 392	/* Create a copy of the pending_free_dma_bufs while holding the lock */
 393	spin_lock_irqsave(&dma_bufs_lock, flags);
 394	list_cut_position(&tmp_list, &pending_free_dma_bufs,
 395			  pending_free_dma_bufs.prev);
 396	spin_unlock_irqrestore(&dma_bufs_lock, flags);
 397
 398	/* Release the dma buffers, without irqs enabled */
 399	list_for_each_entry_safe(buf, tmp, &tmp_list, list) {
 400		list_del(&buf->list);
 401		free_buf(buf, true);
 402	}
 403}
 404
 405static struct port_buffer *alloc_buf(struct virtio_device *vdev, size_t buf_size,
 406				     int pages)
 407{
 408	struct port_buffer *buf;
 409
 410	reclaim_dma_bufs();
 411
 412	/*
 413	 * Allocate buffer and the sg list. The sg list array is allocated
 414	 * directly after the port_buffer struct.
 415	 */
 416	buf = kmalloc(struct_size(buf, sg, pages), GFP_KERNEL);
 417	if (!buf)
 418		goto fail;
 419
 420	buf->sgpages = pages;
 421	if (pages > 0) {
 422		buf->dev = NULL;
 423		buf->buf = NULL;
 424		return buf;
 425	}
 426
 427	if (is_rproc_serial(vdev)) {
 428		/*
 429		 * Allocate DMA memory from ancestor. When a virtio
 430		 * device is created by remoteproc, the DMA memory is
 431		 * associated with the parent device:
 432		 * virtioY => remoteprocX#vdevYbuffer.
 433		 */
 434		buf->dev = vdev->dev.parent;
 435		if (!buf->dev)
 436			goto free_buf;
 437
 438		/* Increase device refcnt to avoid freeing it */
 439		get_device(buf->dev);
 440		buf->buf = dma_alloc_coherent(buf->dev, buf_size, &buf->dma,
 441					      GFP_KERNEL);
 442	} else {
 443		buf->dev = NULL;
 444		buf->buf = kmalloc(buf_size, GFP_KERNEL);
 445	}
 446
 447	if (!buf->buf)
 448		goto free_buf;
 449	buf->len = 0;
 450	buf->offset = 0;
 451	buf->size = buf_size;
 452	return buf;
 453
 454free_buf:
 455	kfree(buf);
 456fail:
 457	return NULL;
 458}
 459
 460/* Callers should take appropriate locks */
 461static struct port_buffer *get_inbuf(struct port *port)
 462{
 463	struct port_buffer *buf;
 464	unsigned int len;
 465
 466	if (port->inbuf)
 467		return port->inbuf;
 468
 469	buf = virtqueue_get_buf(port->in_vq, &len);
 470	if (buf) {
 471		buf->len = min_t(size_t, len, buf->size);
 472		buf->offset = 0;
 473		port->stats.bytes_received += len;
 474	}
 475	return buf;
 476}
 477
 478/*
 479 * Create a scatter-gather list representing our input buffer and put
 480 * it in the queue.
 481 *
 482 * Callers should take appropriate locks.
 483 */
 484static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
 485{
 486	struct scatterlist sg[1];
 487	int ret;
 488
 489	sg_init_one(sg, buf->buf, buf->size);
 490
 491	ret = virtqueue_add_inbuf(vq, sg, 1, buf, GFP_ATOMIC);
 492	virtqueue_kick(vq);
 493	if (!ret)
 494		ret = vq->num_free;
 495	return ret;
 496}
 497
 498/* Discard any unread data this port has. Callers lockers. */
 499static void discard_port_data(struct port *port)
 500{
 501	struct port_buffer *buf;
 502	unsigned int err;
 503
 504	if (!port->portdev) {
 505		/* Device has been unplugged.  vqs are already gone. */
 506		return;
 507	}
 508	buf = get_inbuf(port);
 509
 510	err = 0;
 511	while (buf) {
 512		port->stats.bytes_discarded += buf->len - buf->offset;
 513		if (add_inbuf(port->in_vq, buf) < 0) {
 514			err++;
 515			free_buf(buf, false);
 516		}
 517		port->inbuf = NULL;
 518		buf = get_inbuf(port);
 519	}
 520	if (err)
 521		dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
 522			 err);
 523}
 524
 525static bool port_has_data(struct port *port)
 526{
 527	unsigned long flags;
 528	bool ret;
 529
 530	ret = false;
 531	spin_lock_irqsave(&port->inbuf_lock, flags);
 532	port->inbuf = get_inbuf(port);
 533	if (port->inbuf)
 534		ret = true;
 535
 536	spin_unlock_irqrestore(&port->inbuf_lock, flags);
 537	return ret;
 538}
 539
 540static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
 541				  unsigned int event, unsigned int value)
 542{
 543	struct scatterlist sg[1];
 544	struct virtqueue *vq;
 545	unsigned int len;
 546
 547	if (!use_multiport(portdev))
 548		return 0;
 549
 550	vq = portdev->c_ovq;
 551
 552	spin_lock(&portdev->c_ovq_lock);
 553
 554	portdev->cpkt.id = cpu_to_virtio32(portdev->vdev, port_id);
 555	portdev->cpkt.event = cpu_to_virtio16(portdev->vdev, event);
 556	portdev->cpkt.value = cpu_to_virtio16(portdev->vdev, value);
 557
 558	sg_init_one(sg, &portdev->cpkt, sizeof(struct virtio_console_control));
 559
 560	if (virtqueue_add_outbuf(vq, sg, 1, &portdev->cpkt, GFP_ATOMIC) == 0) {
 561		virtqueue_kick(vq);
 562		while (!virtqueue_get_buf(vq, &len)
 563			&& !virtqueue_is_broken(vq))
 564			cpu_relax();
 565	}
 566
 567	spin_unlock(&portdev->c_ovq_lock);
 568	return 0;
 569}
 570
 571static ssize_t send_control_msg(struct port *port, unsigned int event,
 572				unsigned int value)
 573{
 574	/* Did the port get unplugged before userspace closed it? */
 575	if (port->portdev)
 576		return __send_control_msg(port->portdev, port->id, event, value);
 577	return 0;
 578}
 579
 580
 581/* Callers must take the port->outvq_lock */
 582static void reclaim_consumed_buffers(struct port *port)
 583{
 584	struct port_buffer *buf;
 585	unsigned int len;
 586
 587	if (!port->portdev) {
 588		/* Device has been unplugged.  vqs are already gone. */
 589		return;
 590	}
 591	while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
 592		free_buf(buf, false);
 593		port->outvq_full = false;
 594	}
 595}
 596
 597static ssize_t __send_to_port(struct port *port, struct scatterlist *sg,
 598			      int nents, size_t in_count,
 599			      void *data, bool nonblock)
 600{
 601	struct virtqueue *out_vq;
 602	int err;
 603	unsigned long flags;
 604	unsigned int len;
 605
 606	out_vq = port->out_vq;
 607
 608	spin_lock_irqsave(&port->outvq_lock, flags);
 609
 610	reclaim_consumed_buffers(port);
 611
 612	err = virtqueue_add_outbuf(out_vq, sg, nents, data, GFP_ATOMIC);
 613
 614	/* Tell Host to go! */
 615	virtqueue_kick(out_vq);
 616
 617	if (err) {
 618		in_count = 0;
 619		goto done;
 620	}
 621
 622	if (out_vq->num_free == 0)
 623		port->outvq_full = true;
 624
 625	if (nonblock)
 626		goto done;
 627
 628	/*
 629	 * Wait till the host acknowledges it pushed out the data we
 630	 * sent.  This is done for data from the hvc_console; the tty
 631	 * operations are performed with spinlocks held so we can't
 632	 * sleep here.  An alternative would be to copy the data to a
 633	 * buffer and relax the spinning requirement.  The downside is
 634	 * we need to kmalloc a GFP_ATOMIC buffer each time the
 635	 * console driver writes something out.
 636	 */
 637	while (!virtqueue_get_buf(out_vq, &len)
 638		&& !virtqueue_is_broken(out_vq))
 639		cpu_relax();
 640done:
 641	spin_unlock_irqrestore(&port->outvq_lock, flags);
 642
 643	port->stats.bytes_sent += in_count;
 644	/*
 645	 * We're expected to return the amount of data we wrote -- all
 646	 * of it
 647	 */
 648	return in_count;
 649}
 650
 651/*
 652 * Give out the data that's requested from the buffer that we have
 653 * queued up.
 654 */
 655static ssize_t fill_readbuf(struct port *port, char __user *out_buf,
 656			    size_t out_count, bool to_user)
 657{
 658	struct port_buffer *buf;
 659	unsigned long flags;
 660
 661	if (!out_count || !port_has_data(port))
 662		return 0;
 663
 664	buf = port->inbuf;
 665	out_count = min(out_count, buf->len - buf->offset);
 666
 667	if (to_user) {
 668		ssize_t ret;
 669
 670		ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
 671		if (ret)
 672			return -EFAULT;
 673	} else {
 674		memcpy((__force char *)out_buf, buf->buf + buf->offset,
 675		       out_count);
 676	}
 677
 678	buf->offset += out_count;
 679
 680	if (buf->offset == buf->len) {
 681		/*
 682		 * We're done using all the data in this buffer.
 683		 * Re-queue so that the Host can send us more data.
 684		 */
 685		spin_lock_irqsave(&port->inbuf_lock, flags);
 686		port->inbuf = NULL;
 687
 688		if (add_inbuf(port->in_vq, buf) < 0)
 689			dev_warn(port->dev, "failed add_buf\n");
 690
 691		spin_unlock_irqrestore(&port->inbuf_lock, flags);
 692	}
 693	/* Return the number of bytes actually copied */
 694	return out_count;
 695}
 696
 697/* The condition that must be true for polling to end */
 698static bool will_read_block(struct port *port)
 699{
 700	if (!port->guest_connected) {
 701		/* Port got hot-unplugged. Let's exit. */
 702		return false;
 703	}
 704	return !port_has_data(port) && port->host_connected;
 705}
 706
 707static bool will_write_block(struct port *port)
 708{
 709	bool ret;
 710
 711	if (!port->guest_connected) {
 712		/* Port got hot-unplugged. Let's exit. */
 713		return false;
 714	}
 715	if (!port->host_connected)
 716		return true;
 717
 718	spin_lock_irq(&port->outvq_lock);
 719	/*
 720	 * Check if the Host has consumed any buffers since we last
 721	 * sent data (this is only applicable for nonblocking ports).
 722	 */
 723	reclaim_consumed_buffers(port);
 724	ret = port->outvq_full;
 725	spin_unlock_irq(&port->outvq_lock);
 726
 727	return ret;
 728}
 729
 730static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
 731			      size_t count, loff_t *offp)
 732{
 733	struct port *port;
 734	ssize_t ret;
 735
 736	port = filp->private_data;
 737
 738	/* Port is hot-unplugged. */
 739	if (!port->guest_connected)
 740		return -ENODEV;
 741
 742	if (!port_has_data(port)) {
 743		/*
 744		 * If nothing's connected on the host just return 0 in
 745		 * case of list_empty; this tells the userspace app
 746		 * that there's no connection
 747		 */
 748		if (!port->host_connected)
 749			return 0;
 750		if (filp->f_flags & O_NONBLOCK)
 751			return -EAGAIN;
 752
 753		ret = wait_event_freezable(port->waitqueue,
 754					   !will_read_block(port));
 755		if (ret < 0)
 756			return ret;
 757	}
 758	/* Port got hot-unplugged while we were waiting above. */
 759	if (!port->guest_connected)
 760		return -ENODEV;
 761	/*
 762	 * We could've received a disconnection message while we were
 763	 * waiting for more data.
 764	 *
 765	 * This check is not clubbed in the if() statement above as we
 766	 * might receive some data as well as the host could get
 767	 * disconnected after we got woken up from our wait.  So we
 768	 * really want to give off whatever data we have and only then
 769	 * check for host_connected.
 770	 */
 771	if (!port_has_data(port) && !port->host_connected)
 772		return 0;
 773
 774	return fill_readbuf(port, ubuf, count, true);
 775}
 776
 777static int wait_port_writable(struct port *port, bool nonblock)
 778{
 779	int ret;
 780
 781	if (will_write_block(port)) {
 782		if (nonblock)
 783			return -EAGAIN;
 784
 785		ret = wait_event_freezable(port->waitqueue,
 786					   !will_write_block(port));
 787		if (ret < 0)
 788			return ret;
 789	}
 790	/* Port got hot-unplugged. */
 791	if (!port->guest_connected)
 792		return -ENODEV;
 793
 794	return 0;
 795}
 796
 797static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
 798			       size_t count, loff_t *offp)
 799{
 800	struct port *port;
 801	struct port_buffer *buf;
 802	ssize_t ret;
 803	bool nonblock;
 804	struct scatterlist sg[1];
 805
 806	/* Userspace could be out to fool us */
 807	if (!count)
 808		return 0;
 809
 810	port = filp->private_data;
 811
 812	nonblock = filp->f_flags & O_NONBLOCK;
 813
 814	ret = wait_port_writable(port, nonblock);
 815	if (ret < 0)
 816		return ret;
 817
 818	count = min((size_t)(32 * 1024), count);
 819
 820	buf = alloc_buf(port->portdev->vdev, count, 0);
 821	if (!buf)
 822		return -ENOMEM;
 823
 824	ret = copy_from_user(buf->buf, ubuf, count);
 825	if (ret) {
 826		ret = -EFAULT;
 827		goto free_buf;
 828	}
 829
 830	/*
 831	 * We now ask send_buf() to not spin for generic ports -- we
 832	 * can re-use the same code path that non-blocking file
 833	 * descriptors take for blocking file descriptors since the
 834	 * wait is already done and we're certain the write will go
 835	 * through to the host.
 836	 */
 837	nonblock = true;
 838	sg_init_one(sg, buf->buf, count);
 839	ret = __send_to_port(port, sg, 1, count, buf, nonblock);
 840
 841	if (nonblock && ret > 0)
 842		goto out;
 843
 844free_buf:
 845	free_buf(buf, true);
 846out:
 847	return ret;
 848}
 849
 850struct sg_list {
 851	unsigned int n;
 852	unsigned int size;
 853	size_t len;
 854	struct scatterlist *sg;
 855};
 856
 857static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
 858			struct splice_desc *sd)
 859{
 860	struct sg_list *sgl = sd->u.data;
 861	unsigned int offset, len;
 862
 863	if (sgl->n == sgl->size)
 864		return 0;
 865
 866	/* Try lock this page */
 867	if (pipe_buf_try_steal(pipe, buf)) {
 868		/* Get reference and unlock page for moving */
 869		get_page(buf->page);
 870		unlock_page(buf->page);
 871
 872		len = min(buf->len, sd->len);
 873		sg_set_page(&(sgl->sg[sgl->n]), buf->page, len, buf->offset);
 874	} else {
 875		/* Failback to copying a page */
 876		struct page *page = alloc_page(GFP_KERNEL);
 877		char *src;
 878
 879		if (!page)
 880			return -ENOMEM;
 881
 882		offset = sd->pos & ~PAGE_MASK;
 883
 884		len = sd->len;
 885		if (len + offset > PAGE_SIZE)
 886			len = PAGE_SIZE - offset;
 887
 888		src = kmap_atomic(buf->page);
 889		memcpy(page_address(page) + offset, src + buf->offset, len);
 890		kunmap_atomic(src);
 891
 892		sg_set_page(&(sgl->sg[sgl->n]), page, len, offset);
 893	}
 894	sgl->n++;
 895	sgl->len += len;
 896
 897	return len;
 898}
 899
 900/* Faster zero-copy write by splicing */
 901static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
 902				      struct file *filp, loff_t *ppos,
 903				      size_t len, unsigned int flags)
 904{
 905	struct port *port = filp->private_data;
 906	struct sg_list sgl;
 907	ssize_t ret;
 908	struct port_buffer *buf;
 909	struct splice_desc sd = {
 910		.total_len = len,
 911		.flags = flags,
 912		.pos = *ppos,
 913		.u.data = &sgl,
 914	};
 915	unsigned int occupancy;
 916
 917	/*
 918	 * Rproc_serial does not yet support splice. To support splice
 919	 * pipe_to_sg() must allocate dma-buffers and copy content from
 920	 * regular pages to dma pages. And alloc_buf and free_buf must
 921	 * support allocating and freeing such a list of dma-buffers.
 922	 */
 923	if (is_rproc_serial(port->out_vq->vdev))
 924		return -EINVAL;
 925
 926	pipe_lock(pipe);
 927	ret = 0;
 928	if (pipe_empty(pipe->head, pipe->tail))
 929		goto error_out;
 930
 931	ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK);
 932	if (ret < 0)
 933		goto error_out;
 934
 935	occupancy = pipe_occupancy(pipe->head, pipe->tail);
 936	buf = alloc_buf(port->portdev->vdev, 0, occupancy);
 937
 938	if (!buf) {
 939		ret = -ENOMEM;
 940		goto error_out;
 941	}
 942
 943	sgl.n = 0;
 944	sgl.len = 0;
 945	sgl.size = occupancy;
 946	sgl.sg = buf->sg;
 947	sg_init_table(sgl.sg, sgl.size);
 948	ret = __splice_from_pipe(pipe, &sd, pipe_to_sg);
 949	pipe_unlock(pipe);
 950	if (likely(ret > 0))
 951		ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true);
 952
 953	if (unlikely(ret <= 0))
 954		free_buf(buf, true);
 955	return ret;
 956
 957error_out:
 958	pipe_unlock(pipe);
 959	return ret;
 960}
 961
 962static __poll_t port_fops_poll(struct file *filp, poll_table *wait)
 963{
 964	struct port *port;
 965	__poll_t ret;
 966
 967	port = filp->private_data;
 968	poll_wait(filp, &port->waitqueue, wait);
 969
 970	if (!port->guest_connected) {
 971		/* Port got unplugged */
 972		return EPOLLHUP;
 973	}
 974	ret = 0;
 975	if (!will_read_block(port))
 976		ret |= EPOLLIN | EPOLLRDNORM;
 977	if (!will_write_block(port))
 978		ret |= EPOLLOUT;
 979	if (!port->host_connected)
 980		ret |= EPOLLHUP;
 981
 982	return ret;
 983}
 984
 985static void remove_port(struct kref *kref);
 986
 987static int port_fops_release(struct inode *inode, struct file *filp)
 988{
 989	struct port *port;
 990
 991	port = filp->private_data;
 992
 993	/* Notify host of port being closed */
 994	send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
 995
 996	spin_lock_irq(&port->inbuf_lock);
 997	port->guest_connected = false;
 998
 999	discard_port_data(port);
1000
1001	spin_unlock_irq(&port->inbuf_lock);
1002
1003	spin_lock_irq(&port->outvq_lock);
1004	reclaim_consumed_buffers(port);
1005	spin_unlock_irq(&port->outvq_lock);
1006
1007	reclaim_dma_bufs();
1008	/*
1009	 * Locks aren't necessary here as a port can't be opened after
1010	 * unplug, and if a port isn't unplugged, a kref would already
1011	 * exist for the port.  Plus, taking ports_lock here would
1012	 * create a dependency on other locks taken by functions
1013	 * inside remove_port if we're the last holder of the port,
1014	 * creating many problems.
1015	 */
1016	kref_put(&port->kref, remove_port);
1017
1018	return 0;
1019}
1020
1021static int port_fops_open(struct inode *inode, struct file *filp)
1022{
1023	struct cdev *cdev = inode->i_cdev;
1024	struct port *port;
1025	int ret;
1026
1027	/* We get the port with a kref here */
1028	port = find_port_by_devt(cdev->dev);
1029	if (!port) {
1030		/* Port was unplugged before we could proceed */
1031		return -ENXIO;
1032	}
1033	filp->private_data = port;
1034
1035	/*
1036	 * Don't allow opening of console port devices -- that's done
1037	 * via /dev/hvc
1038	 */
1039	if (is_console_port(port)) {
1040		ret = -ENXIO;
1041		goto out;
1042	}
1043
1044	/* Allow only one process to open a particular port at a time */
1045	spin_lock_irq(&port->inbuf_lock);
1046	if (port->guest_connected) {
1047		spin_unlock_irq(&port->inbuf_lock);
1048		ret = -EBUSY;
1049		goto out;
1050	}
1051
1052	port->guest_connected = true;
1053	spin_unlock_irq(&port->inbuf_lock);
1054
1055	spin_lock_irq(&port->outvq_lock);
1056	/*
1057	 * There might be a chance that we missed reclaiming a few
1058	 * buffers in the window of the port getting previously closed
1059	 * and opening now.
1060	 */
1061	reclaim_consumed_buffers(port);
1062	spin_unlock_irq(&port->outvq_lock);
1063
1064	nonseekable_open(inode, filp);
1065
1066	/* Notify host of port being opened */
1067	send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
1068
1069	return 0;
1070out:
1071	kref_put(&port->kref, remove_port);
1072	return ret;
1073}
1074
1075static int port_fops_fasync(int fd, struct file *filp, int mode)
1076{
1077	struct port *port;
1078
1079	port = filp->private_data;
1080	return fasync_helper(fd, filp, mode, &port->async_queue);
1081}
1082
1083/*
1084 * The file operations that we support: programs in the guest can open
1085 * a console device, read from it, write to it, poll for data and
1086 * close it.  The devices are at
1087 *   /dev/vport<device number>p<port number>
1088 */
1089static const struct file_operations port_fops = {
1090	.owner = THIS_MODULE,
1091	.open  = port_fops_open,
1092	.read  = port_fops_read,
1093	.write = port_fops_write,
1094	.splice_write = port_fops_splice_write,
1095	.poll  = port_fops_poll,
1096	.release = port_fops_release,
1097	.fasync = port_fops_fasync,
1098	.llseek = no_llseek,
1099};
1100
1101/*
1102 * The put_chars() callback is pretty straightforward.
1103 *
1104 * We turn the characters into a scatter-gather list, add it to the
1105 * output queue and then kick the Host.  Then we sit here waiting for
1106 * it to finish: inefficient in theory, but in practice
1107 * implementations will do it immediately.
1108 */
1109static int put_chars(u32 vtermno, const char *buf, int count)
1110{
1111	struct port *port;
1112	struct scatterlist sg[1];
1113	void *data;
1114	int ret;
1115
1116	if (unlikely(early_put_chars))
1117		return early_put_chars(vtermno, buf, count);
1118
1119	port = find_port_by_vtermno(vtermno);
1120	if (!port)
1121		return -EPIPE;
1122
1123	data = kmemdup(buf, count, GFP_ATOMIC);
1124	if (!data)
1125		return -ENOMEM;
1126
1127	sg_init_one(sg, data, count);
1128	ret = __send_to_port(port, sg, 1, count, data, false);
1129	kfree(data);
1130	return ret;
1131}
1132
1133/*
1134 * get_chars() is the callback from the hvc_console infrastructure
1135 * when an interrupt is received.
1136 *
1137 * We call out to fill_readbuf that gets us the required data from the
1138 * buffers that are queued up.
1139 */
1140static int get_chars(u32 vtermno, char *buf, int count)
1141{
1142	struct port *port;
1143
1144	/* If we've not set up the port yet, we have no input to give. */
1145	if (unlikely(early_put_chars))
1146		return 0;
1147
1148	port = find_port_by_vtermno(vtermno);
1149	if (!port)
1150		return -EPIPE;
1151
1152	/* If we don't have an input queue yet, we can't get input. */
1153	BUG_ON(!port->in_vq);
1154
1155	return fill_readbuf(port, (__force char __user *)buf, count, false);
1156}
1157
1158static void resize_console(struct port *port)
1159{
1160	struct virtio_device *vdev;
1161
1162	/* The port could have been hot-unplugged */
1163	if (!port || !is_console_port(port))
1164		return;
1165
1166	vdev = port->portdev->vdev;
1167
1168	/* Don't test F_SIZE at all if we're rproc: not a valid feature! */
1169	if (!is_rproc_serial(vdev) &&
1170	    virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
1171		hvc_resize(port->cons.hvc, port->cons.ws);
1172}
1173
1174/* We set the configuration at this point, since we now have a tty */
1175static int notifier_add_vio(struct hvc_struct *hp, int data)
1176{
1177	struct port *port;
1178
1179	port = find_port_by_vtermno(hp->vtermno);
1180	if (!port)
1181		return -EINVAL;
1182
1183	hp->irq_requested = 1;
1184	resize_console(port);
1185
1186	return 0;
1187}
1188
1189static void notifier_del_vio(struct hvc_struct *hp, int data)
1190{
1191	hp->irq_requested = 0;
1192}
1193
1194/* The operations for console ports. */
1195static const struct hv_ops hv_ops = {
1196	.get_chars = get_chars,
1197	.put_chars = put_chars,
1198	.notifier_add = notifier_add_vio,
1199	.notifier_del = notifier_del_vio,
1200	.notifier_hangup = notifier_del_vio,
1201};
1202
1203/*
1204 * Console drivers are initialized very early so boot messages can go
1205 * out, so we do things slightly differently from the generic virtio
1206 * initialization of the net and block drivers.
1207 *
1208 * At this stage, the console is output-only.  It's too early to set
1209 * up a virtqueue, so we let the drivers do some boutique early-output
1210 * thing.
1211 */
1212int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
1213{
1214	early_put_chars = put_chars;
1215	return hvc_instantiate(0, 0, &hv_ops);
1216}
1217
1218static int init_port_console(struct port *port)
1219{
1220	int ret;
1221
1222	/*
1223	 * The Host's telling us this port is a console port.  Hook it
1224	 * up with an hvc console.
1225	 *
1226	 * To set up and manage our virtual console, we call
1227	 * hvc_alloc().
1228	 *
1229	 * The first argument of hvc_alloc() is the virtual console
1230	 * number.  The second argument is the parameter for the
1231	 * notification mechanism (like irq number).  We currently
1232	 * leave this as zero, virtqueues have implicit notifications.
1233	 *
1234	 * The third argument is a "struct hv_ops" containing the
1235	 * put_chars() get_chars(), notifier_add() and notifier_del()
1236	 * pointers.  The final argument is the output buffer size: we
1237	 * can do any size, so we put PAGE_SIZE here.
1238	 */
1239	ret = ida_alloc_min(&vtermno_ida, 1, GFP_KERNEL);
1240	if (ret < 0)
1241		return ret;
1242
1243	port->cons.vtermno = ret;
1244	port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
1245	if (IS_ERR(port->cons.hvc)) {
1246		ret = PTR_ERR(port->cons.hvc);
1247		dev_err(port->dev,
1248			"error %d allocating hvc for port\n", ret);
1249		port->cons.hvc = NULL;
1250		ida_free(&vtermno_ida, port->cons.vtermno);
1251		return ret;
1252	}
1253	spin_lock_irq(&pdrvdata_lock);
 
1254	list_add_tail(&port->cons.list, &pdrvdata.consoles);
1255	spin_unlock_irq(&pdrvdata_lock);
1256	port->guest_connected = true;
1257
1258	/*
1259	 * Start using the new console output if this is the first
1260	 * console to come up.
1261	 */
1262	if (early_put_chars)
1263		early_put_chars = NULL;
1264
1265	/* Notify host of port being opened */
1266	send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1267
1268	return 0;
1269}
1270
1271static ssize_t show_port_name(struct device *dev,
1272			      struct device_attribute *attr, char *buffer)
1273{
1274	struct port *port;
1275
1276	port = dev_get_drvdata(dev);
1277
1278	return sprintf(buffer, "%s\n", port->name);
1279}
1280
1281static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1282
1283static struct attribute *port_sysfs_entries[] = {
1284	&dev_attr_name.attr,
1285	NULL
1286};
1287
1288static const struct attribute_group port_attribute_group = {
1289	.name = NULL,		/* put in device directory */
1290	.attrs = port_sysfs_entries,
1291};
1292
1293static int port_debugfs_show(struct seq_file *s, void *data)
1294{
1295	struct port *port = s->private;
1296
1297	seq_printf(s, "name: %s\n", port->name ? port->name : "");
1298	seq_printf(s, "guest_connected: %d\n", port->guest_connected);
1299	seq_printf(s, "host_connected: %d\n", port->host_connected);
1300	seq_printf(s, "outvq_full: %d\n", port->outvq_full);
1301	seq_printf(s, "bytes_sent: %lu\n", port->stats.bytes_sent);
1302	seq_printf(s, "bytes_received: %lu\n", port->stats.bytes_received);
1303	seq_printf(s, "bytes_discarded: %lu\n", port->stats.bytes_discarded);
1304	seq_printf(s, "is_console: %s\n",
1305		   is_console_port(port) ? "yes" : "no");
1306	seq_printf(s, "console_vtermno: %u\n", port->cons.vtermno);
1307
1308	return 0;
1309}
1310
1311DEFINE_SHOW_ATTRIBUTE(port_debugfs);
1312
1313static void set_console_size(struct port *port, u16 rows, u16 cols)
1314{
1315	if (!port || !is_console_port(port))
1316		return;
1317
1318	port->cons.ws.ws_row = rows;
1319	port->cons.ws.ws_col = cols;
1320}
1321
1322static int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1323{
1324	struct port_buffer *buf;
1325	int nr_added_bufs;
1326	int ret;
1327
1328	nr_added_bufs = 0;
1329	do {
1330		buf = alloc_buf(vq->vdev, PAGE_SIZE, 0);
1331		if (!buf)
1332			return -ENOMEM;
1333
1334		spin_lock_irq(lock);
1335		ret = add_inbuf(vq, buf);
1336		if (ret < 0) {
1337			spin_unlock_irq(lock);
1338			free_buf(buf, true);
1339			return ret;
1340		}
1341		nr_added_bufs++;
1342		spin_unlock_irq(lock);
1343	} while (ret > 0);
1344
1345	return nr_added_bufs;
1346}
1347
1348static void send_sigio_to_port(struct port *port)
1349{
1350	if (port->async_queue && port->guest_connected)
1351		kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1352}
1353
1354static int add_port(struct ports_device *portdev, u32 id)
1355{
1356	char debugfs_name[16];
1357	struct port *port;
1358	dev_t devt;
1359	int err;
1360
1361	port = kmalloc(sizeof(*port), GFP_KERNEL);
1362	if (!port) {
1363		err = -ENOMEM;
1364		goto fail;
1365	}
1366	kref_init(&port->kref);
1367
1368	port->portdev = portdev;
1369	port->id = id;
1370
1371	port->name = NULL;
1372	port->inbuf = NULL;
1373	port->cons.hvc = NULL;
1374	port->async_queue = NULL;
1375
1376	port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1377	port->cons.vtermno = 0;
1378
1379	port->host_connected = port->guest_connected = false;
1380	port->stats = (struct port_stats) { 0 };
1381
1382	port->outvq_full = false;
1383
1384	port->in_vq = portdev->in_vqs[port->id];
1385	port->out_vq = portdev->out_vqs[port->id];
1386
1387	port->cdev = cdev_alloc();
1388	if (!port->cdev) {
1389		dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1390		err = -ENOMEM;
1391		goto free_port;
1392	}
1393	port->cdev->ops = &port_fops;
1394
1395	devt = MKDEV(portdev->chr_major, id);
1396	err = cdev_add(port->cdev, devt, 1);
1397	if (err < 0) {
1398		dev_err(&port->portdev->vdev->dev,
1399			"Error %d adding cdev for port %u\n", err, id);
1400		goto free_cdev;
1401	}
1402	port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1403				  devt, port, "vport%up%u",
1404				  port->portdev->vdev->index, id);
1405	if (IS_ERR(port->dev)) {
1406		err = PTR_ERR(port->dev);
1407		dev_err(&port->portdev->vdev->dev,
1408			"Error %d creating device for port %u\n",
1409			err, id);
1410		goto free_cdev;
1411	}
1412
1413	spin_lock_init(&port->inbuf_lock);
1414	spin_lock_init(&port->outvq_lock);
1415	init_waitqueue_head(&port->waitqueue);
1416
1417	/* We can safely ignore ENOSPC because it means
1418	 * the queue already has buffers. Buffers are removed
1419	 * only by virtcons_remove(), not by unplug_port()
1420	 */
1421	err = fill_queue(port->in_vq, &port->inbuf_lock);
1422	if (err < 0 && err != -ENOSPC) {
1423		dev_err(port->dev, "Error allocating inbufs\n");
1424		goto free_device;
1425	}
1426
1427	if (is_rproc_serial(port->portdev->vdev))
1428		/*
1429		 * For rproc_serial assume remote processor is connected.
1430		 * rproc_serial does not want the console port, only
1431		 * the generic port implementation.
1432		 */
1433		port->host_connected = true;
1434	else if (!use_multiport(port->portdev)) {
1435		/*
1436		 * If we're not using multiport support,
1437		 * this has to be a console port.
1438		 */
1439		err = init_port_console(port);
1440		if (err)
1441			goto free_inbufs;
1442	}
1443
1444	spin_lock_irq(&portdev->ports_lock);
1445	list_add_tail(&port->list, &port->portdev->ports);
1446	spin_unlock_irq(&portdev->ports_lock);
1447
1448	/*
1449	 * Tell the Host we're set so that it can send us various
1450	 * configuration parameters for this port (eg, port name,
1451	 * caching, whether this is a console port, etc.)
1452	 */
1453	send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1454
1455	/*
1456	 * Finally, create the debugfs file that we can use to
1457	 * inspect a port's state at any time
1458	 */
1459	snprintf(debugfs_name, sizeof(debugfs_name), "vport%up%u",
1460		 port->portdev->vdev->index, id);
1461	port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1462						 pdrvdata.debugfs_dir,
1463						 port, &port_debugfs_fops);
1464	return 0;
1465
1466free_inbufs:
1467free_device:
1468	device_destroy(pdrvdata.class, port->dev->devt);
1469free_cdev:
1470	cdev_del(port->cdev);
1471free_port:
1472	kfree(port);
1473fail:
1474	/* The host might want to notify management sw about port add failure */
1475	__send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1476	return err;
1477}
1478
1479/* No users remain, remove all port-specific data. */
1480static void remove_port(struct kref *kref)
1481{
1482	struct port *port;
1483
1484	port = container_of(kref, struct port, kref);
1485
1486	kfree(port);
1487}
1488
1489static void remove_port_data(struct port *port)
1490{
1491	spin_lock_irq(&port->inbuf_lock);
1492	/* Remove unused data this port might have received. */
1493	discard_port_data(port);
1494	spin_unlock_irq(&port->inbuf_lock);
1495
1496	spin_lock_irq(&port->outvq_lock);
1497	reclaim_consumed_buffers(port);
1498	spin_unlock_irq(&port->outvq_lock);
1499}
1500
1501/*
1502 * Port got unplugged.  Remove port from portdev's list and drop the
1503 * kref reference.  If no userspace has this port opened, it will
1504 * result in immediate removal the port.
1505 */
1506static void unplug_port(struct port *port)
1507{
1508	spin_lock_irq(&port->portdev->ports_lock);
1509	list_del(&port->list);
1510	spin_unlock_irq(&port->portdev->ports_lock);
1511
1512	spin_lock_irq(&port->inbuf_lock);
1513	if (port->guest_connected) {
1514		/* Let the app know the port is going down. */
1515		send_sigio_to_port(port);
1516
1517		/* Do this after sigio is actually sent */
1518		port->guest_connected = false;
1519		port->host_connected = false;
1520
1521		wake_up_interruptible(&port->waitqueue);
1522	}
1523	spin_unlock_irq(&port->inbuf_lock);
1524
1525	if (is_console_port(port)) {
1526		spin_lock_irq(&pdrvdata_lock);
1527		list_del(&port->cons.list);
1528		spin_unlock_irq(&pdrvdata_lock);
1529		hvc_remove(port->cons.hvc);
1530		ida_free(&vtermno_ida, port->cons.vtermno);
1531	}
1532
1533	remove_port_data(port);
1534
1535	/*
1536	 * We should just assume the device itself has gone off --
1537	 * else a close on an open port later will try to send out a
1538	 * control message.
1539	 */
1540	port->portdev = NULL;
1541
1542	sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1543	device_destroy(pdrvdata.class, port->dev->devt);
1544	cdev_del(port->cdev);
1545
1546	debugfs_remove(port->debugfs_file);
1547	kfree(port->name);
1548
1549	/*
1550	 * Locks around here are not necessary - a port can't be
1551	 * opened after we removed the port struct from ports_list
1552	 * above.
1553	 */
1554	kref_put(&port->kref, remove_port);
1555}
1556
1557/* Any private messages that the Host and Guest want to share */
1558static void handle_control_message(struct virtio_device *vdev,
1559				   struct ports_device *portdev,
1560				   struct port_buffer *buf)
1561{
1562	struct virtio_console_control *cpkt;
1563	struct port *port;
1564	size_t name_size;
1565	int err;
1566
1567	cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1568
1569	port = find_port_by_id(portdev, virtio32_to_cpu(vdev, cpkt->id));
1570	if (!port &&
1571	    cpkt->event != cpu_to_virtio16(vdev, VIRTIO_CONSOLE_PORT_ADD)) {
1572		/* No valid header at start of buffer.  Drop it. */
1573		dev_dbg(&portdev->vdev->dev,
1574			"Invalid index %u in control packet\n", cpkt->id);
1575		return;
1576	}
1577
1578	switch (virtio16_to_cpu(vdev, cpkt->event)) {
1579	case VIRTIO_CONSOLE_PORT_ADD:
1580		if (port) {
1581			dev_dbg(&portdev->vdev->dev,
1582				"Port %u already added\n", port->id);
1583			send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1584			break;
1585		}
1586		if (virtio32_to_cpu(vdev, cpkt->id) >=
1587		    portdev->max_nr_ports) {
1588			dev_warn(&portdev->vdev->dev,
1589				"Request for adding port with "
1590				"out-of-bound id %u, max. supported id: %u\n",
1591				cpkt->id, portdev->max_nr_ports - 1);
1592			break;
1593		}
1594		add_port(portdev, virtio32_to_cpu(vdev, cpkt->id));
1595		break;
1596	case VIRTIO_CONSOLE_PORT_REMOVE:
1597		unplug_port(port);
1598		break;
1599	case VIRTIO_CONSOLE_CONSOLE_PORT:
1600		if (!cpkt->value)
1601			break;
1602		if (is_console_port(port))
1603			break;
1604
1605		init_port_console(port);
1606		complete(&early_console_added);
1607		/*
1608		 * Could remove the port here in case init fails - but
1609		 * have to notify the host first.
1610		 */
1611		break;
1612	case VIRTIO_CONSOLE_RESIZE: {
1613		struct {
1614			__u16 rows;
1615			__u16 cols;
1616		} size;
1617
1618		if (!is_console_port(port))
1619			break;
1620
1621		memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1622		       sizeof(size));
1623		set_console_size(port, size.rows, size.cols);
1624
1625		port->cons.hvc->irq_requested = 1;
1626		resize_console(port);
1627		break;
1628	}
1629	case VIRTIO_CONSOLE_PORT_OPEN:
1630		port->host_connected = virtio16_to_cpu(vdev, cpkt->value);
1631		wake_up_interruptible(&port->waitqueue);
1632		/*
1633		 * If the host port got closed and the host had any
1634		 * unconsumed buffers, we'll be able to reclaim them
1635		 * now.
1636		 */
1637		spin_lock_irq(&port->outvq_lock);
1638		reclaim_consumed_buffers(port);
1639		spin_unlock_irq(&port->outvq_lock);
1640
1641		/*
1642		 * If the guest is connected, it'll be interested in
1643		 * knowing the host connection state changed.
1644		 */
1645		spin_lock_irq(&port->inbuf_lock);
1646		send_sigio_to_port(port);
1647		spin_unlock_irq(&port->inbuf_lock);
1648		break;
1649	case VIRTIO_CONSOLE_PORT_NAME:
1650		/*
1651		 * If we woke up after hibernation, we can get this
1652		 * again.  Skip it in that case.
1653		 */
1654		if (port->name)
1655			break;
1656
1657		/*
1658		 * Skip the size of the header and the cpkt to get the size
1659		 * of the name that was sent
1660		 */
1661		name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1662
1663		port->name = kmalloc(name_size, GFP_KERNEL);
1664		if (!port->name) {
1665			dev_err(port->dev,
1666				"Not enough space to store port name\n");
1667			break;
1668		}
1669		strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1670			name_size - 1);
1671		port->name[name_size - 1] = 0;
1672
1673		/*
1674		 * Since we only have one sysfs attribute, 'name',
1675		 * create it only if we have a name for the port.
1676		 */
1677		err = sysfs_create_group(&port->dev->kobj,
1678					 &port_attribute_group);
1679		if (err) {
1680			dev_err(port->dev,
1681				"Error %d creating sysfs device attributes\n",
1682				err);
1683		} else {
1684			/*
1685			 * Generate a udev event so that appropriate
1686			 * symlinks can be created based on udev
1687			 * rules.
1688			 */
1689			kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1690		}
1691		break;
1692	}
1693}
1694
1695static void control_work_handler(struct work_struct *work)
1696{
1697	struct ports_device *portdev;
1698	struct virtqueue *vq;
1699	struct port_buffer *buf;
1700	unsigned int len;
1701
1702	portdev = container_of(work, struct ports_device, control_work);
1703	vq = portdev->c_ivq;
1704
1705	spin_lock(&portdev->c_ivq_lock);
1706	while ((buf = virtqueue_get_buf(vq, &len))) {
1707		spin_unlock(&portdev->c_ivq_lock);
1708
1709		buf->len = min_t(size_t, len, buf->size);
1710		buf->offset = 0;
1711
1712		handle_control_message(vq->vdev, portdev, buf);
1713
1714		spin_lock(&portdev->c_ivq_lock);
1715		if (add_inbuf(portdev->c_ivq, buf) < 0) {
1716			dev_warn(&portdev->vdev->dev,
1717				 "Error adding buffer to queue\n");
1718			free_buf(buf, false);
1719		}
1720	}
1721	spin_unlock(&portdev->c_ivq_lock);
1722}
1723
1724static void flush_bufs(struct virtqueue *vq, bool can_sleep)
1725{
1726	struct port_buffer *buf;
1727	unsigned int len;
1728
1729	while ((buf = virtqueue_get_buf(vq, &len)))
1730		free_buf(buf, can_sleep);
1731}
1732
1733static void out_intr(struct virtqueue *vq)
1734{
1735	struct port *port;
1736
1737	port = find_port_by_vq(vq->vdev->priv, vq);
1738	if (!port) {
1739		flush_bufs(vq, false);
1740		return;
1741	}
1742
1743	wake_up_interruptible(&port->waitqueue);
1744}
1745
1746static void in_intr(struct virtqueue *vq)
1747{
1748	struct port *port;
1749	unsigned long flags;
1750
1751	port = find_port_by_vq(vq->vdev->priv, vq);
1752	if (!port) {
1753		flush_bufs(vq, false);
1754		return;
1755	}
1756
1757	spin_lock_irqsave(&port->inbuf_lock, flags);
1758	port->inbuf = get_inbuf(port);
1759
1760	/*
1761	 * Normally the port should not accept data when the port is
1762	 * closed. For generic serial ports, the host won't (shouldn't)
1763	 * send data till the guest is connected. But this condition
1764	 * can be reached when a console port is not yet connected (no
1765	 * tty is spawned) and the other side sends out data over the
1766	 * vring, or when a remote devices start sending data before
1767	 * the ports are opened.
1768	 *
1769	 * A generic serial port will discard data if not connected,
1770	 * while console ports and rproc-serial ports accepts data at
1771	 * any time. rproc-serial is initiated with guest_connected to
1772	 * false because port_fops_open expects this. Console ports are
1773	 * hooked up with an HVC console and is initialized with
1774	 * guest_connected to true.
1775	 */
1776
1777	if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev))
1778		discard_port_data(port);
1779
1780	/* Send a SIGIO indicating new data in case the process asked for it */
1781	send_sigio_to_port(port);
1782
1783	spin_unlock_irqrestore(&port->inbuf_lock, flags);
1784
1785	wake_up_interruptible(&port->waitqueue);
1786
1787	if (is_console_port(port) && hvc_poll(port->cons.hvc))
1788		hvc_kick();
1789}
1790
1791static void control_intr(struct virtqueue *vq)
1792{
1793	struct ports_device *portdev;
1794
1795	portdev = vq->vdev->priv;
1796	schedule_work(&portdev->control_work);
1797}
1798
1799static void config_intr(struct virtio_device *vdev)
1800{
1801	struct ports_device *portdev;
1802
1803	portdev = vdev->priv;
1804
1805	if (!use_multiport(portdev))
1806		schedule_work(&portdev->config_work);
1807}
1808
1809static void config_work_handler(struct work_struct *work)
1810{
1811	struct ports_device *portdev;
1812
1813	portdev = container_of(work, struct ports_device, config_work);
1814	if (!use_multiport(portdev)) {
1815		struct virtio_device *vdev;
1816		struct port *port;
1817		u16 rows, cols;
1818
1819		vdev = portdev->vdev;
1820		virtio_cread(vdev, struct virtio_console_config, cols, &cols);
1821		virtio_cread(vdev, struct virtio_console_config, rows, &rows);
1822
1823		port = find_port_by_id(portdev, 0);
1824		set_console_size(port, rows, cols);
1825
1826		/*
1827		 * We'll use this way of resizing only for legacy
1828		 * support.  For newer userspace
1829		 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1830		 * to indicate console size changes so that it can be
1831		 * done per-port.
1832		 */
1833		resize_console(port);
1834	}
1835}
1836
1837static int init_vqs(struct ports_device *portdev)
1838{
1839	vq_callback_t **io_callbacks;
1840	char **io_names;
1841	struct virtqueue **vqs;
1842	u32 i, j, nr_ports, nr_queues;
1843	int err;
1844
1845	nr_ports = portdev->max_nr_ports;
1846	nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1847
1848	vqs = kmalloc_array(nr_queues, sizeof(struct virtqueue *), GFP_KERNEL);
1849	io_callbacks = kmalloc_array(nr_queues, sizeof(vq_callback_t *),
1850				     GFP_KERNEL);
1851	io_names = kmalloc_array(nr_queues, sizeof(char *), GFP_KERNEL);
1852	portdev->in_vqs = kmalloc_array(nr_ports, sizeof(struct virtqueue *),
1853					GFP_KERNEL);
1854	portdev->out_vqs = kmalloc_array(nr_ports, sizeof(struct virtqueue *),
1855					 GFP_KERNEL);
1856	if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1857	    !portdev->out_vqs) {
1858		err = -ENOMEM;
1859		goto free;
1860	}
1861
1862	/*
1863	 * For backward compat (newer host but older guest), the host
1864	 * spawns a console port first and also inits the vqs for port
1865	 * 0 before others.
1866	 */
1867	j = 0;
1868	io_callbacks[j] = in_intr;
1869	io_callbacks[j + 1] = out_intr;
1870	io_names[j] = "input";
1871	io_names[j + 1] = "output";
1872	j += 2;
1873
1874	if (use_multiport(portdev)) {
1875		io_callbacks[j] = control_intr;
1876		io_callbacks[j + 1] = NULL;
1877		io_names[j] = "control-i";
1878		io_names[j + 1] = "control-o";
1879
1880		for (i = 1; i < nr_ports; i++) {
1881			j += 2;
1882			io_callbacks[j] = in_intr;
1883			io_callbacks[j + 1] = out_intr;
1884			io_names[j] = "input";
1885			io_names[j + 1] = "output";
1886		}
1887	}
1888	/* Find the queues. */
1889	err = virtio_find_vqs(portdev->vdev, nr_queues, vqs,
1890			      io_callbacks,
1891			      (const char **)io_names, NULL);
1892	if (err)
1893		goto free;
1894
1895	j = 0;
1896	portdev->in_vqs[0] = vqs[0];
1897	portdev->out_vqs[0] = vqs[1];
1898	j += 2;
1899	if (use_multiport(portdev)) {
1900		portdev->c_ivq = vqs[j];
1901		portdev->c_ovq = vqs[j + 1];
1902
1903		for (i = 1; i < nr_ports; i++) {
1904			j += 2;
1905			portdev->in_vqs[i] = vqs[j];
1906			portdev->out_vqs[i] = vqs[j + 1];
1907		}
1908	}
1909	kfree(io_names);
1910	kfree(io_callbacks);
1911	kfree(vqs);
1912
1913	return 0;
1914
1915free:
1916	kfree(portdev->out_vqs);
1917	kfree(portdev->in_vqs);
1918	kfree(io_names);
1919	kfree(io_callbacks);
1920	kfree(vqs);
1921
1922	return err;
1923}
1924
1925static const struct file_operations portdev_fops = {
1926	.owner = THIS_MODULE,
1927};
1928
1929static void remove_vqs(struct ports_device *portdev)
1930{
1931	struct virtqueue *vq;
1932
1933	virtio_device_for_each_vq(portdev->vdev, vq) {
1934		struct port_buffer *buf;
1935
1936		flush_bufs(vq, true);
1937		while ((buf = virtqueue_detach_unused_buf(vq)))
1938			free_buf(buf, true);
1939	}
1940	portdev->vdev->config->del_vqs(portdev->vdev);
1941	kfree(portdev->in_vqs);
1942	kfree(portdev->out_vqs);
1943}
1944
1945static void virtcons_remove(struct virtio_device *vdev)
1946{
1947	struct ports_device *portdev;
1948	struct port *port, *port2;
1949
1950	portdev = vdev->priv;
1951
1952	spin_lock_irq(&pdrvdata_lock);
1953	list_del(&portdev->list);
1954	spin_unlock_irq(&pdrvdata_lock);
1955
1956	/* Device is going away, exit any polling for buffers */
1957	virtio_break_device(vdev);
1958	if (use_multiport(portdev))
1959		flush_work(&portdev->control_work);
1960	else
1961		flush_work(&portdev->config_work);
1962
1963	/* Disable interrupts for vqs */
1964	virtio_reset_device(vdev);
1965	/* Finish up work that's lined up */
1966	if (use_multiport(portdev))
1967		cancel_work_sync(&portdev->control_work);
1968	else
1969		cancel_work_sync(&portdev->config_work);
1970
1971	list_for_each_entry_safe(port, port2, &portdev->ports, list)
1972		unplug_port(port);
1973
1974	unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1975
1976	/*
1977	 * When yanking out a device, we immediately lose the
1978	 * (device-side) queues.  So there's no point in keeping the
1979	 * guest side around till we drop our final reference.  This
1980	 * also means that any ports which are in an open state will
1981	 * have to just stop using the port, as the vqs are going
1982	 * away.
1983	 */
1984	remove_vqs(portdev);
1985	kfree(portdev);
1986}
1987
1988/*
1989 * Once we're further in boot, we get probed like any other virtio
1990 * device.
1991 *
1992 * If the host also supports multiple console ports, we check the
1993 * config space to see how many ports the host has spawned.  We
1994 * initialize each port found.
1995 */
1996static int virtcons_probe(struct virtio_device *vdev)
1997{
1998	struct ports_device *portdev;
1999	int err;
2000	bool multiport;
2001	bool early = early_put_chars != NULL;
2002
2003	/* We only need a config space if features are offered */
2004	if (!vdev->config->get &&
2005	    (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)
2006	     || virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT))) {
2007		dev_err(&vdev->dev, "%s failure: config access disabled\n",
2008			__func__);
2009		return -EINVAL;
2010	}
2011
2012	/* Ensure to read early_put_chars now */
2013	barrier();
2014
2015	portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
2016	if (!portdev) {
2017		err = -ENOMEM;
2018		goto fail;
2019	}
2020
2021	/* Attach this portdev to this virtio_device, and vice-versa. */
2022	portdev->vdev = vdev;
2023	vdev->priv = portdev;
2024
2025	portdev->chr_major = register_chrdev(0, "virtio-portsdev",
2026					     &portdev_fops);
2027	if (portdev->chr_major < 0) {
2028		dev_err(&vdev->dev,
2029			"Error %d registering chrdev for device %u\n",
2030			portdev->chr_major, vdev->index);
2031		err = portdev->chr_major;
2032		goto free;
2033	}
2034
2035	multiport = false;
2036	portdev->max_nr_ports = 1;
2037
2038	/* Don't test MULTIPORT at all if we're rproc: not a valid feature! */
2039	if (!is_rproc_serial(vdev) &&
2040	    virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
2041				 struct virtio_console_config, max_nr_ports,
2042				 &portdev->max_nr_ports) == 0) {
2043		if (portdev->max_nr_ports == 0 ||
2044		    portdev->max_nr_ports > VIRTCONS_MAX_PORTS) {
2045			dev_err(&vdev->dev,
2046				"Invalidate max_nr_ports %d",
2047				portdev->max_nr_ports);
2048			err = -EINVAL;
2049			goto free;
2050		}
2051		multiport = true;
2052	}
2053
2054	err = init_vqs(portdev);
2055	if (err < 0) {
2056		dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
2057		goto free_chrdev;
2058	}
2059
2060	spin_lock_init(&portdev->ports_lock);
2061	INIT_LIST_HEAD(&portdev->ports);
2062	INIT_LIST_HEAD(&portdev->list);
2063
2064	virtio_device_ready(portdev->vdev);
2065
2066	INIT_WORK(&portdev->config_work, &config_work_handler);
2067	INIT_WORK(&portdev->control_work, &control_work_handler);
2068
2069	if (multiport) {
2070		spin_lock_init(&portdev->c_ivq_lock);
2071		spin_lock_init(&portdev->c_ovq_lock);
2072
2073		err = fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
2074		if (err < 0) {
2075			dev_err(&vdev->dev,
2076				"Error allocating buffers for control queue\n");
2077			/*
2078			 * The host might want to notify mgmt sw about device
2079			 * add failure.
2080			 */
2081			__send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2082					   VIRTIO_CONSOLE_DEVICE_READY, 0);
2083			/* Device was functional: we need full cleanup. */
2084			virtcons_remove(vdev);
2085			return err;
2086		}
2087	} else {
2088		/*
2089		 * For backward compatibility: Create a console port
2090		 * if we're running on older host.
2091		 */
2092		add_port(portdev, 0);
2093	}
2094
2095	spin_lock_irq(&pdrvdata_lock);
2096	list_add_tail(&portdev->list, &pdrvdata.portdevs);
2097	spin_unlock_irq(&pdrvdata_lock);
2098
2099	__send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2100			   VIRTIO_CONSOLE_DEVICE_READY, 1);
2101
2102	/*
2103	 * If there was an early virtio console, assume that there are no
2104	 * other consoles. We need to wait until the hvc_alloc matches the
2105	 * hvc_instantiate, otherwise tty_open will complain, resulting in
2106	 * a "Warning: unable to open an initial console" boot failure.
2107	 * Without multiport this is done in add_port above. With multiport
2108	 * this might take some host<->guest communication - thus we have to
2109	 * wait.
2110	 */
2111	if (multiport && early)
2112		wait_for_completion(&early_console_added);
2113
2114	return 0;
2115
2116free_chrdev:
2117	unregister_chrdev(portdev->chr_major, "virtio-portsdev");
2118free:
2119	kfree(portdev);
2120fail:
2121	return err;
2122}
2123
2124static const struct virtio_device_id id_table[] = {
2125	{ VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
2126	{ 0 },
2127};
2128MODULE_DEVICE_TABLE(virtio, id_table);
2129
2130static const unsigned int features[] = {
2131	VIRTIO_CONSOLE_F_SIZE,
2132	VIRTIO_CONSOLE_F_MULTIPORT,
2133};
2134
2135static const struct virtio_device_id rproc_serial_id_table[] = {
2136#if IS_ENABLED(CONFIG_REMOTEPROC)
2137	{ VIRTIO_ID_RPROC_SERIAL, VIRTIO_DEV_ANY_ID },
2138#endif
2139	{ 0 },
2140};
2141MODULE_DEVICE_TABLE(virtio, rproc_serial_id_table);
2142
2143static const unsigned int rproc_serial_features[] = {
2144};
2145
2146#ifdef CONFIG_PM_SLEEP
2147static int virtcons_freeze(struct virtio_device *vdev)
2148{
2149	struct ports_device *portdev;
2150	struct port *port;
2151
2152	portdev = vdev->priv;
2153
2154	virtio_reset_device(vdev);
2155
2156	if (use_multiport(portdev))
2157		virtqueue_disable_cb(portdev->c_ivq);
2158	cancel_work_sync(&portdev->control_work);
2159	cancel_work_sync(&portdev->config_work);
2160	/*
2161	 * Once more: if control_work_handler() was running, it would
2162	 * enable the cb as the last step.
2163	 */
2164	if (use_multiport(portdev))
2165		virtqueue_disable_cb(portdev->c_ivq);
2166
2167	list_for_each_entry(port, &portdev->ports, list) {
2168		virtqueue_disable_cb(port->in_vq);
2169		virtqueue_disable_cb(port->out_vq);
2170		/*
2171		 * We'll ask the host later if the new invocation has
2172		 * the port opened or closed.
2173		 */
2174		port->host_connected = false;
2175		remove_port_data(port);
2176	}
2177	remove_vqs(portdev);
2178
2179	return 0;
2180}
2181
2182static int virtcons_restore(struct virtio_device *vdev)
2183{
2184	struct ports_device *portdev;
2185	struct port *port;
2186	int ret;
2187
2188	portdev = vdev->priv;
2189
2190	ret = init_vqs(portdev);
2191	if (ret)
2192		return ret;
2193
2194	virtio_device_ready(portdev->vdev);
2195
2196	if (use_multiport(portdev))
2197		fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
2198
2199	list_for_each_entry(port, &portdev->ports, list) {
2200		port->in_vq = portdev->in_vqs[port->id];
2201		port->out_vq = portdev->out_vqs[port->id];
2202
2203		fill_queue(port->in_vq, &port->inbuf_lock);
2204
2205		/* Get port open/close status on the host */
2206		send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
2207
2208		/*
2209		 * If a port was open at the time of suspending, we
2210		 * have to let the host know that it's still open.
2211		 */
2212		if (port->guest_connected)
2213			send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
2214	}
2215	return 0;
2216}
2217#endif
2218
2219static struct virtio_driver virtio_console = {
2220	.feature_table = features,
2221	.feature_table_size = ARRAY_SIZE(features),
2222	.driver.name =	KBUILD_MODNAME,
2223	.driver.owner =	THIS_MODULE,
2224	.id_table =	id_table,
2225	.probe =	virtcons_probe,
2226	.remove =	virtcons_remove,
2227	.config_changed = config_intr,
2228#ifdef CONFIG_PM_SLEEP
2229	.freeze =	virtcons_freeze,
2230	.restore =	virtcons_restore,
2231#endif
2232};
2233
2234static struct virtio_driver virtio_rproc_serial = {
2235	.feature_table = rproc_serial_features,
2236	.feature_table_size = ARRAY_SIZE(rproc_serial_features),
2237	.driver.name =	"virtio_rproc_serial",
2238	.driver.owner =	THIS_MODULE,
2239	.id_table =	rproc_serial_id_table,
2240	.probe =	virtcons_probe,
2241	.remove =	virtcons_remove,
2242};
2243
2244static int __init virtio_console_init(void)
2245{
2246	int err;
2247
2248	pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
2249	if (IS_ERR(pdrvdata.class)) {
2250		err = PTR_ERR(pdrvdata.class);
2251		pr_err("Error %d creating virtio-ports class\n", err);
2252		return err;
2253	}
2254
2255	pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
2256	INIT_LIST_HEAD(&pdrvdata.consoles);
2257	INIT_LIST_HEAD(&pdrvdata.portdevs);
2258
2259	err = register_virtio_driver(&virtio_console);
2260	if (err < 0) {
2261		pr_err("Error %d registering virtio driver\n", err);
2262		goto free;
2263	}
2264	err = register_virtio_driver(&virtio_rproc_serial);
2265	if (err < 0) {
2266		pr_err("Error %d registering virtio rproc serial driver\n",
2267		       err);
2268		goto unregister;
2269	}
2270	return 0;
2271unregister:
2272	unregister_virtio_driver(&virtio_console);
2273free:
2274	debugfs_remove_recursive(pdrvdata.debugfs_dir);
2275	class_destroy(pdrvdata.class);
2276	return err;
2277}
2278
2279static void __exit virtio_console_fini(void)
2280{
2281	reclaim_dma_bufs();
2282
2283	unregister_virtio_driver(&virtio_console);
2284	unregister_virtio_driver(&virtio_rproc_serial);
2285
2286	class_destroy(pdrvdata.class);
2287	debugfs_remove_recursive(pdrvdata.debugfs_dir);
2288}
2289module_init(virtio_console_init);
2290module_exit(virtio_console_fini);
2291
2292MODULE_DESCRIPTION("Virtio console driver");
2293MODULE_LICENSE("GPL");