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 */
  54struct 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};
  79static struct ports_driver_data pdrvdata;
  80
  81static DEFINE_SPINLOCK(pdrvdata_lock);
  82static DECLARE_COMPLETION(early_console_added);
  83
  84/* This struct holds information that's relevant only for console ports */
  85struct 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
 105struct 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 */
 136struct 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	struct work_struct config_work;
 146
 147	struct list_head ports;
 148
 149	/* To protect the list of ports */
 150	spinlock_t ports_lock;
 151
 152	/* To protect the vq operations for the control channel */
 153	spinlock_t c_ivq_lock;
 154	spinlock_t c_ovq_lock;
 155
 156	/* The current config space is stored here */
 157	struct virtio_console_config config;
 158
 159	/* The virtio device we're associated with */
 160	struct virtio_device *vdev;
 161
 162	/*
 163	 * A couple of virtqueues for the control channel: one for
 164	 * guest->host transfers, one for host->guest transfers
 165	 */
 166	struct virtqueue *c_ivq, *c_ovq;
 167
 
 
 
 
 
 
 168	/* Array of per-port IO virtqueues */
 169	struct virtqueue **in_vqs, **out_vqs;
 170
 171	/* Major number for this device.  Ports will be created as minors. */
 172	int chr_major;
 173};
 174
 175struct port_stats {
 176	unsigned long bytes_sent, bytes_received, bytes_discarded;
 177};
 178
 179/* This struct holds the per-port data */
 180struct port {
 181	/* Next port in the list, head is in the ports_device */
 182	struct list_head list;
 183
 184	/* Pointer to the parent virtio_console device */
 185	struct ports_device *portdev;
 186
 187	/* The current buffer from which data has to be fed to readers */
 188	struct port_buffer *inbuf;
 189
 190	/*
 191	 * To protect the operations on the in_vq associated with this
 192	 * port.  Has to be a spinlock because it can be called from
 193	 * interrupt context (get_char()).
 194	 */
 195	spinlock_t inbuf_lock;
 196
 197	/* Protect the operations on the out_vq. */
 198	spinlock_t outvq_lock;
 199
 200	/* The IO vqs for this port */
 201	struct virtqueue *in_vq, *out_vq;
 202
 203	/* File in the debugfs directory that exposes this port's information */
 204	struct dentry *debugfs_file;
 205
 206	/*
 207	 * Keep count of the bytes sent, received and discarded for
 208	 * this port for accounting and debugging purposes.  These
 209	 * counts are not reset across port open / close events.
 210	 */
 211	struct port_stats stats;
 212
 213	/*
 214	 * The entries in this struct will be valid if this port is
 215	 * hooked up to an hvc console
 216	 */
 217	struct console cons;
 218
 219	/* Each port associates with a separate char device */
 220	struct cdev *cdev;
 221	struct device *dev;
 222
 223	/* Reference-counting to handle port hot-unplugs and file operations */
 224	struct kref kref;
 225
 226	/* A waitqueue for poll() or blocking read operations */
 227	wait_queue_head_t waitqueue;
 228
 229	/* The 'name' of the port that we expose via sysfs properties */
 230	char *name;
 231
 232	/* We can notify apps of host connect / disconnect events via SIGIO */
 233	struct fasync_struct *async_queue;
 234
 235	/* The 'id' to identify the port with the Host */
 236	u32 id;
 237
 238	bool outvq_full;
 239
 240	/* Is the host device open */
 241	bool host_connected;
 242
 243	/* We should allow only one process to open a port */
 244	bool guest_connected;
 245};
 246
 247/* This is the very early arch-specified put chars function. */
 248static int (*early_put_chars)(u32, const char *, int);
 249
 250static struct port *find_port_by_vtermno(u32 vtermno)
 251{
 252	struct port *port;
 253	struct console *cons;
 254	unsigned long flags;
 255
 256	spin_lock_irqsave(&pdrvdata_lock, flags);
 257	list_for_each_entry(cons, &pdrvdata.consoles, list) {
 258		if (cons->vtermno == vtermno) {
 259			port = container_of(cons, struct port, cons);
 260			goto out;
 261		}
 262	}
 263	port = NULL;
 264out:
 265	spin_unlock_irqrestore(&pdrvdata_lock, flags);
 266	return port;
 267}
 268
 269static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
 270						 dev_t dev)
 271{
 272	struct port *port;
 273	unsigned long flags;
 274
 275	spin_lock_irqsave(&portdev->ports_lock, flags);
 276	list_for_each_entry(port, &portdev->ports, list) {
 277		if (port->cdev->dev == dev) {
 278			kref_get(&port->kref);
 279			goto out;
 280		}
 281	}
 282	port = NULL;
 283out:
 284	spin_unlock_irqrestore(&portdev->ports_lock, flags);
 285
 286	return port;
 287}
 288
 289static struct port *find_port_by_devt(dev_t dev)
 290{
 291	struct ports_device *portdev;
 292	struct port *port;
 293	unsigned long flags;
 294
 295	spin_lock_irqsave(&pdrvdata_lock, flags);
 296	list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
 297		port = find_port_by_devt_in_portdev(portdev, dev);
 298		if (port)
 299			goto out;
 300	}
 301	port = NULL;
 302out:
 303	spin_unlock_irqrestore(&pdrvdata_lock, flags);
 304	return port;
 305}
 306
 307static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
 308{
 309	struct port *port;
 310	unsigned long flags;
 311
 312	spin_lock_irqsave(&portdev->ports_lock, flags);
 313	list_for_each_entry(port, &portdev->ports, list)
 314		if (port->id == id)
 315			goto out;
 316	port = NULL;
 317out:
 318	spin_unlock_irqrestore(&portdev->ports_lock, flags);
 319
 320	return port;
 321}
 322
 323static struct port *find_port_by_vq(struct ports_device *portdev,
 324				    struct virtqueue *vq)
 325{
 326	struct port *port;
 327	unsigned long flags;
 328
 329	spin_lock_irqsave(&portdev->ports_lock, flags);
 330	list_for_each_entry(port, &portdev->ports, list)
 331		if (port->in_vq == vq || port->out_vq == vq)
 332			goto out;
 333	port = NULL;
 334out:
 335	spin_unlock_irqrestore(&portdev->ports_lock, flags);
 336	return port;
 337}
 338
 339static bool is_console_port(struct port *port)
 340{
 341	if (port->cons.hvc)
 342		return true;
 343	return false;
 344}
 345
 346static bool is_rproc_serial(const struct virtio_device *vdev)
 347{
 348	return is_rproc_enabled && vdev->id.device == VIRTIO_ID_RPROC_SERIAL;
 349}
 350
 351static inline bool use_multiport(struct ports_device *portdev)
 352{
 353	/*
 354	 * This condition can be true when put_chars is called from
 355	 * early_init
 356	 */
 357	if (!portdev->vdev)
 358		return false;
 359	return __virtio_test_bit(portdev->vdev, VIRTIO_CONSOLE_F_MULTIPORT);
 360}
 361
 362static DEFINE_SPINLOCK(dma_bufs_lock);
 363static LIST_HEAD(pending_free_dma_bufs);
 364
 365static void free_buf(struct port_buffer *buf, bool can_sleep)
 366{
 367	unsigned int i;
 368
 369	for (i = 0; i < buf->sgpages; i++) {
 370		struct page *page = sg_page(&buf->sg[i]);
 371		if (!page)
 372			break;
 373		put_page(page);
 374	}
 375
 376	if (!buf->dev) {
 377		kfree(buf->buf);
 378	} else if (is_rproc_enabled) {
 379		unsigned long flags;
 380
 381		/* dma_free_coherent requires interrupts to be enabled. */
 382		if (!can_sleep) {
 383			/* queue up dma-buffers to be freed later */
 384			spin_lock_irqsave(&dma_bufs_lock, flags);
 385			list_add_tail(&buf->list, &pending_free_dma_bufs);
 386			spin_unlock_irqrestore(&dma_bufs_lock, flags);
 387			return;
 388		}
 389		dma_free_coherent(buf->dev, buf->size, buf->buf, buf->dma);
 390
 391		/* Release device refcnt and allow it to be freed */
 392		put_device(buf->dev);
 393	}
 394
 395	kfree(buf);
 396}
 397
 398static void reclaim_dma_bufs(void)
 399{
 400	unsigned long flags;
 401	struct port_buffer *buf, *tmp;
 402	LIST_HEAD(tmp_list);
 403
 404	if (list_empty(&pending_free_dma_bufs))
 405		return;
 406
 407	/* Create a copy of the pending_free_dma_bufs while holding the lock */
 408	spin_lock_irqsave(&dma_bufs_lock, flags);
 409	list_cut_position(&tmp_list, &pending_free_dma_bufs,
 410			  pending_free_dma_bufs.prev);
 411	spin_unlock_irqrestore(&dma_bufs_lock, flags);
 412
 413	/* Release the dma buffers, without irqs enabled */
 414	list_for_each_entry_safe(buf, tmp, &tmp_list, list) {
 415		list_del(&buf->list);
 416		free_buf(buf, true);
 417	}
 418}
 419
 420static struct port_buffer *alloc_buf(struct virtqueue *vq, size_t buf_size,
 421				     int pages)
 422{
 423	struct port_buffer *buf;
 424
 425	reclaim_dma_bufs();
 426
 427	/*
 428	 * Allocate buffer and the sg list. The sg list array is allocated
 429	 * directly after the port_buffer struct.
 430	 */
 431	buf = kmalloc(sizeof(*buf) + sizeof(struct scatterlist) * pages,
 432		      GFP_KERNEL);
 433	if (!buf)
 434		goto fail;
 435
 436	buf->sgpages = pages;
 437	if (pages > 0) {
 438		buf->dev = NULL;
 439		buf->buf = NULL;
 440		return buf;
 441	}
 442
 443	if (is_rproc_serial(vq->vdev)) {
 444		/*
 445		 * Allocate DMA memory from ancestor. When a virtio
 446		 * device is created by remoteproc, the DMA memory is
 447		 * associated with the grandparent device:
 448		 * vdev => rproc => platform-dev.
 449		 * The code here would have been less quirky if
 450		 * DMA_MEMORY_INCLUDES_CHILDREN had been supported
 451		 * in dma-coherent.c
 452		 */
 453		if (!vq->vdev->dev.parent || !vq->vdev->dev.parent->parent)
 454			goto free_buf;
 455		buf->dev = vq->vdev->dev.parent->parent;
 456
 457		/* Increase device refcnt to avoid freeing it */
 458		get_device(buf->dev);
 459		buf->buf = dma_alloc_coherent(buf->dev, buf_size, &buf->dma,
 460					      GFP_KERNEL);
 461	} else {
 462		buf->dev = NULL;
 463		buf->buf = kmalloc(buf_size, GFP_KERNEL);
 464	}
 465
 466	if (!buf->buf)
 467		goto free_buf;
 468	buf->len = 0;
 469	buf->offset = 0;
 470	buf->size = buf_size;
 471	return buf;
 472
 473free_buf:
 474	kfree(buf);
 475fail:
 476	return NULL;
 477}
 478
 479/* Callers should take appropriate locks */
 480static struct port_buffer *get_inbuf(struct port *port)
 481{
 482	struct port_buffer *buf;
 483	unsigned int len;
 484
 485	if (port->inbuf)
 486		return port->inbuf;
 487
 488	buf = virtqueue_get_buf(port->in_vq, &len);
 489	if (buf) {
 490		buf->len = len;
 491		buf->offset = 0;
 492		port->stats.bytes_received += len;
 493	}
 494	return buf;
 495}
 496
 497/*
 498 * Create a scatter-gather list representing our input buffer and put
 499 * it in the queue.
 500 *
 501 * Callers should take appropriate locks.
 502 */
 503static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
 504{
 505	struct scatterlist sg[1];
 506	int ret;
 507
 508	sg_init_one(sg, buf->buf, buf->size);
 509
 510	ret = virtqueue_add_inbuf(vq, sg, 1, buf, GFP_ATOMIC);
 511	virtqueue_kick(vq);
 512	if (!ret)
 513		ret = vq->num_free;
 514	return ret;
 515}
 516
 517/* Discard any unread data this port has. Callers lockers. */
 518static void discard_port_data(struct port *port)
 519{
 520	struct port_buffer *buf;
 521	unsigned int err;
 522
 523	if (!port->portdev) {
 524		/* Device has been unplugged.  vqs are already gone. */
 525		return;
 526	}
 527	buf = get_inbuf(port);
 528
 529	err = 0;
 530	while (buf) {
 531		port->stats.bytes_discarded += buf->len - buf->offset;
 532		if (add_inbuf(port->in_vq, buf) < 0) {
 533			err++;
 534			free_buf(buf, false);
 535		}
 536		port->inbuf = NULL;
 537		buf = get_inbuf(port);
 538	}
 539	if (err)
 540		dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
 541			 err);
 542}
 543
 544static bool port_has_data(struct port *port)
 545{
 546	unsigned long flags;
 547	bool ret;
 548
 549	ret = false;
 550	spin_lock_irqsave(&port->inbuf_lock, flags);
 551	port->inbuf = get_inbuf(port);
 552	if (port->inbuf)
 553		ret = true;
 554
 555	spin_unlock_irqrestore(&port->inbuf_lock, flags);
 556	return ret;
 557}
 558
 559static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
 560				  unsigned int event, unsigned int value)
 561{
 562	struct scatterlist sg[1];
 563	struct virtio_console_control cpkt;
 564	struct virtqueue *vq;
 565	unsigned int len;
 566
 567	if (!use_multiport(portdev))
 568		return 0;
 569
 570	cpkt.id = cpu_to_virtio32(portdev->vdev, port_id);
 571	cpkt.event = cpu_to_virtio16(portdev->vdev, event);
 572	cpkt.value = cpu_to_virtio16(portdev->vdev, value);
 573
 574	vq = portdev->c_ovq;
 575
 576	sg_init_one(sg, &cpkt, sizeof(cpkt));
 577
 578	spin_lock(&portdev->c_ovq_lock);
 579	if (virtqueue_add_outbuf(vq, sg, 1, &cpkt, GFP_ATOMIC) == 0) {
 
 
 
 
 
 
 
 580		virtqueue_kick(vq);
 581		while (!virtqueue_get_buf(vq, &len)
 582			&& !virtqueue_is_broken(vq))
 583			cpu_relax();
 584	}
 
 585	spin_unlock(&portdev->c_ovq_lock);
 586	return 0;
 587}
 588
 589static ssize_t send_control_msg(struct port *port, unsigned int event,
 590				unsigned int value)
 591{
 592	/* Did the port get unplugged before userspace closed it? */
 593	if (port->portdev)
 594		return __send_control_msg(port->portdev, port->id, event, value);
 595	return 0;
 596}
 597
 598
 599/* Callers must take the port->outvq_lock */
 600static void reclaim_consumed_buffers(struct port *port)
 601{
 602	struct port_buffer *buf;
 603	unsigned int len;
 604
 605	if (!port->portdev) {
 606		/* Device has been unplugged.  vqs are already gone. */
 607		return;
 608	}
 609	while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
 610		free_buf(buf, false);
 611		port->outvq_full = false;
 612	}
 613}
 614
 615static ssize_t __send_to_port(struct port *port, struct scatterlist *sg,
 616			      int nents, size_t in_count,
 617			      void *data, bool nonblock)
 618{
 619	struct virtqueue *out_vq;
 620	int err;
 621	unsigned long flags;
 622	unsigned int len;
 623
 624	out_vq = port->out_vq;
 625
 626	spin_lock_irqsave(&port->outvq_lock, flags);
 627
 628	reclaim_consumed_buffers(port);
 629
 630	err = virtqueue_add_outbuf(out_vq, sg, nents, data, GFP_ATOMIC);
 631
 632	/* Tell Host to go! */
 633	virtqueue_kick(out_vq);
 634
 635	if (err) {
 636		in_count = 0;
 637		goto done;
 638	}
 639
 640	if (out_vq->num_free == 0)
 641		port->outvq_full = true;
 642
 643	if (nonblock)
 644		goto done;
 645
 646	/*
 647	 * Wait till the host acknowledges it pushed out the data we
 648	 * sent.  This is done for data from the hvc_console; the tty
 649	 * operations are performed with spinlocks held so we can't
 650	 * sleep here.  An alternative would be to copy the data to a
 651	 * buffer and relax the spinning requirement.  The downside is
 652	 * we need to kmalloc a GFP_ATOMIC buffer each time the
 653	 * console driver writes something out.
 654	 */
 655	while (!virtqueue_get_buf(out_vq, &len)
 656		&& !virtqueue_is_broken(out_vq))
 657		cpu_relax();
 658done:
 659	spin_unlock_irqrestore(&port->outvq_lock, flags);
 660
 661	port->stats.bytes_sent += in_count;
 662	/*
 663	 * We're expected to return the amount of data we wrote -- all
 664	 * of it
 665	 */
 666	return in_count;
 667}
 668
 669/*
 670 * Give out the data that's requested from the buffer that we have
 671 * queued up.
 672 */
 673static ssize_t fill_readbuf(struct port *port, char __user *out_buf,
 674			    size_t out_count, bool to_user)
 675{
 676	struct port_buffer *buf;
 677	unsigned long flags;
 678
 679	if (!out_count || !port_has_data(port))
 680		return 0;
 681
 682	buf = port->inbuf;
 683	out_count = min(out_count, buf->len - buf->offset);
 684
 685	if (to_user) {
 686		ssize_t ret;
 687
 688		ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
 689		if (ret)
 690			return -EFAULT;
 691	} else {
 692		memcpy((__force char *)out_buf, buf->buf + buf->offset,
 693		       out_count);
 694	}
 695
 696	buf->offset += out_count;
 697
 698	if (buf->offset == buf->len) {
 699		/*
 700		 * We're done using all the data in this buffer.
 701		 * Re-queue so that the Host can send us more data.
 702		 */
 703		spin_lock_irqsave(&port->inbuf_lock, flags);
 704		port->inbuf = NULL;
 705
 706		if (add_inbuf(port->in_vq, buf) < 0)
 707			dev_warn(port->dev, "failed add_buf\n");
 708
 709		spin_unlock_irqrestore(&port->inbuf_lock, flags);
 710	}
 711	/* Return the number of bytes actually copied */
 712	return out_count;
 713}
 714
 715/* The condition that must be true for polling to end */
 716static bool will_read_block(struct port *port)
 717{
 718	if (!port->guest_connected) {
 719		/* Port got hot-unplugged. Let's exit. */
 720		return false;
 721	}
 722	return !port_has_data(port) && port->host_connected;
 723}
 724
 725static bool will_write_block(struct port *port)
 726{
 727	bool ret;
 728
 729	if (!port->guest_connected) {
 730		/* Port got hot-unplugged. Let's exit. */
 731		return false;
 732	}
 733	if (!port->host_connected)
 734		return true;
 735
 736	spin_lock_irq(&port->outvq_lock);
 737	/*
 738	 * Check if the Host has consumed any buffers since we last
 739	 * sent data (this is only applicable for nonblocking ports).
 740	 */
 741	reclaim_consumed_buffers(port);
 742	ret = port->outvq_full;
 743	spin_unlock_irq(&port->outvq_lock);
 744
 745	return ret;
 746}
 747
 748static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
 749			      size_t count, loff_t *offp)
 750{
 751	struct port *port;
 752	ssize_t ret;
 753
 754	port = filp->private_data;
 755
 756	/* Port is hot-unplugged. */
 757	if (!port->guest_connected)
 758		return -ENODEV;
 759
 760	if (!port_has_data(port)) {
 761		/*
 762		 * If nothing's connected on the host just return 0 in
 763		 * case of list_empty; this tells the userspace app
 764		 * that there's no connection
 765		 */
 766		if (!port->host_connected)
 767			return 0;
 768		if (filp->f_flags & O_NONBLOCK)
 769			return -EAGAIN;
 770
 771		ret = wait_event_freezable(port->waitqueue,
 772					   !will_read_block(port));
 773		if (ret < 0)
 774			return ret;
 775	}
 776	/* Port got hot-unplugged while we were waiting above. */
 777	if (!port->guest_connected)
 778		return -ENODEV;
 779	/*
 780	 * We could've received a disconnection message while we were
 781	 * waiting for more data.
 782	 *
 783	 * This check is not clubbed in the if() statement above as we
 784	 * might receive some data as well as the host could get
 785	 * disconnected after we got woken up from our wait.  So we
 786	 * really want to give off whatever data we have and only then
 787	 * check for host_connected.
 788	 */
 789	if (!port_has_data(port) && !port->host_connected)
 790		return 0;
 791
 792	return fill_readbuf(port, ubuf, count, true);
 793}
 794
 795static int wait_port_writable(struct port *port, bool nonblock)
 796{
 797	int ret;
 798
 799	if (will_write_block(port)) {
 800		if (nonblock)
 801			return -EAGAIN;
 802
 803		ret = wait_event_freezable(port->waitqueue,
 804					   !will_write_block(port));
 805		if (ret < 0)
 806			return ret;
 807	}
 808	/* Port got hot-unplugged. */
 809	if (!port->guest_connected)
 810		return -ENODEV;
 811
 812	return 0;
 813}
 814
 815static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
 816			       size_t count, loff_t *offp)
 817{
 818	struct port *port;
 819	struct port_buffer *buf;
 820	ssize_t ret;
 821	bool nonblock;
 822	struct scatterlist sg[1];
 823
 824	/* Userspace could be out to fool us */
 825	if (!count)
 826		return 0;
 827
 828	port = filp->private_data;
 829
 830	nonblock = filp->f_flags & O_NONBLOCK;
 831
 832	ret = wait_port_writable(port, nonblock);
 833	if (ret < 0)
 834		return ret;
 835
 836	count = min((size_t)(32 * 1024), count);
 837
 838	buf = alloc_buf(port->out_vq, count, 0);
 839	if (!buf)
 840		return -ENOMEM;
 841
 842	ret = copy_from_user(buf->buf, ubuf, count);
 843	if (ret) {
 844		ret = -EFAULT;
 845		goto free_buf;
 846	}
 847
 848	/*
 849	 * We now ask send_buf() to not spin for generic ports -- we
 850	 * can re-use the same code path that non-blocking file
 851	 * descriptors take for blocking file descriptors since the
 852	 * wait is already done and we're certain the write will go
 853	 * through to the host.
 854	 */
 855	nonblock = true;
 856	sg_init_one(sg, buf->buf, count);
 857	ret = __send_to_port(port, sg, 1, count, buf, nonblock);
 858
 859	if (nonblock && ret > 0)
 860		goto out;
 861
 862free_buf:
 863	free_buf(buf, true);
 864out:
 865	return ret;
 866}
 867
 868struct sg_list {
 869	unsigned int n;
 870	unsigned int size;
 871	size_t len;
 872	struct scatterlist *sg;
 873};
 874
 875static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
 876			struct splice_desc *sd)
 877{
 878	struct sg_list *sgl = sd->u.data;
 879	unsigned int offset, len;
 880
 881	if (sgl->n == sgl->size)
 882		return 0;
 883
 884	/* Try lock this page */
 885	if (buf->ops->steal(pipe, buf) == 0) {
 886		/* Get reference and unlock page for moving */
 887		get_page(buf->page);
 888		unlock_page(buf->page);
 889
 890		len = min(buf->len, sd->len);
 891		sg_set_page(&(sgl->sg[sgl->n]), buf->page, len, buf->offset);
 892	} else {
 893		/* Failback to copying a page */
 894		struct page *page = alloc_page(GFP_KERNEL);
 895		char *src;
 896
 897		if (!page)
 898			return -ENOMEM;
 899
 900		offset = sd->pos & ~PAGE_MASK;
 901
 902		len = sd->len;
 903		if (len + offset > PAGE_SIZE)
 904			len = PAGE_SIZE - offset;
 905
 906		src = kmap_atomic(buf->page);
 907		memcpy(page_address(page) + offset, src + buf->offset, len);
 908		kunmap_atomic(src);
 909
 910		sg_set_page(&(sgl->sg[sgl->n]), page, len, offset);
 911	}
 912	sgl->n++;
 913	sgl->len += len;
 914
 915	return len;
 916}
 917
 918/* Faster zero-copy write by splicing */
 919static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
 920				      struct file *filp, loff_t *ppos,
 921				      size_t len, unsigned int flags)
 922{
 923	struct port *port = filp->private_data;
 924	struct sg_list sgl;
 925	ssize_t ret;
 926	struct port_buffer *buf;
 927	struct splice_desc sd = {
 928		.total_len = len,
 929		.flags = flags,
 930		.pos = *ppos,
 931		.u.data = &sgl,
 932	};
 
 933
 934	/*
 935	 * Rproc_serial does not yet support splice. To support splice
 936	 * pipe_to_sg() must allocate dma-buffers and copy content from
 937	 * regular pages to dma pages. And alloc_buf and free_buf must
 938	 * support allocating and freeing such a list of dma-buffers.
 939	 */
 940	if (is_rproc_serial(port->out_vq->vdev))
 941		return -EINVAL;
 942
 943	/*
 944	 * pipe->nrbufs == 0 means there are no data to transfer,
 945	 * so this returns just 0 for no data.
 946	 */
 947	pipe_lock(pipe);
 948	if (!pipe->nrbufs) {
 949		ret = 0;
 950		goto error_out;
 951	}
 952
 953	ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK);
 954	if (ret < 0)
 955		goto error_out;
 956
 957	buf = alloc_buf(port->out_vq, 0, pipe->nrbufs);
 
 
 958	if (!buf) {
 959		ret = -ENOMEM;
 960		goto error_out;
 961	}
 962
 963	sgl.n = 0;
 964	sgl.len = 0;
 965	sgl.size = pipe->nrbufs;
 966	sgl.sg = buf->sg;
 967	sg_init_table(sgl.sg, sgl.size);
 968	ret = __splice_from_pipe(pipe, &sd, pipe_to_sg);
 969	pipe_unlock(pipe);
 970	if (likely(ret > 0))
 971		ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true);
 972
 973	if (unlikely(ret <= 0))
 974		free_buf(buf, true);
 975	return ret;
 976
 977error_out:
 978	pipe_unlock(pipe);
 979	return ret;
 980}
 981
 982static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
 983{
 984	struct port *port;
 985	unsigned int ret;
 986
 987	port = filp->private_data;
 988	poll_wait(filp, &port->waitqueue, wait);
 989
 990	if (!port->guest_connected) {
 991		/* Port got unplugged */
 992		return POLLHUP;
 993	}
 994	ret = 0;
 995	if (!will_read_block(port))
 996		ret |= POLLIN | POLLRDNORM;
 997	if (!will_write_block(port))
 998		ret |= POLLOUT;
 999	if (!port->host_connected)
1000		ret |= POLLHUP;
1001
1002	return ret;
1003}
1004
1005static void remove_port(struct kref *kref);
1006
1007static int port_fops_release(struct inode *inode, struct file *filp)
1008{
1009	struct port *port;
1010
1011	port = filp->private_data;
1012
1013	/* Notify host of port being closed */
1014	send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
1015
1016	spin_lock_irq(&port->inbuf_lock);
1017	port->guest_connected = false;
1018
1019	discard_port_data(port);
1020
1021	spin_unlock_irq(&port->inbuf_lock);
1022
1023	spin_lock_irq(&port->outvq_lock);
1024	reclaim_consumed_buffers(port);
1025	spin_unlock_irq(&port->outvq_lock);
1026
1027	reclaim_dma_bufs();
1028	/*
1029	 * Locks aren't necessary here as a port can't be opened after
1030	 * unplug, and if a port isn't unplugged, a kref would already
1031	 * exist for the port.  Plus, taking ports_lock here would
1032	 * create a dependency on other locks taken by functions
1033	 * inside remove_port if we're the last holder of the port,
1034	 * creating many problems.
1035	 */
1036	kref_put(&port->kref, remove_port);
1037
1038	return 0;
1039}
1040
1041static int port_fops_open(struct inode *inode, struct file *filp)
1042{
1043	struct cdev *cdev = inode->i_cdev;
1044	struct port *port;
1045	int ret;
1046
1047	/* We get the port with a kref here */
1048	port = find_port_by_devt(cdev->dev);
1049	if (!port) {
1050		/* Port was unplugged before we could proceed */
1051		return -ENXIO;
1052	}
1053	filp->private_data = port;
1054
1055	/*
1056	 * Don't allow opening of console port devices -- that's done
1057	 * via /dev/hvc
1058	 */
1059	if (is_console_port(port)) {
1060		ret = -ENXIO;
1061		goto out;
1062	}
1063
1064	/* Allow only one process to open a particular port at a time */
1065	spin_lock_irq(&port->inbuf_lock);
1066	if (port->guest_connected) {
1067		spin_unlock_irq(&port->inbuf_lock);
1068		ret = -EBUSY;
1069		goto out;
1070	}
1071
1072	port->guest_connected = true;
1073	spin_unlock_irq(&port->inbuf_lock);
1074
1075	spin_lock_irq(&port->outvq_lock);
1076	/*
1077	 * There might be a chance that we missed reclaiming a few
1078	 * buffers in the window of the port getting previously closed
1079	 * and opening now.
1080	 */
1081	reclaim_consumed_buffers(port);
1082	spin_unlock_irq(&port->outvq_lock);
1083
1084	nonseekable_open(inode, filp);
1085
1086	/* Notify host of port being opened */
1087	send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
1088
1089	return 0;
1090out:
1091	kref_put(&port->kref, remove_port);
1092	return ret;
1093}
1094
1095static int port_fops_fasync(int fd, struct file *filp, int mode)
1096{
1097	struct port *port;
1098
1099	port = filp->private_data;
1100	return fasync_helper(fd, filp, mode, &port->async_queue);
1101}
1102
1103/*
1104 * The file operations that we support: programs in the guest can open
1105 * a console device, read from it, write to it, poll for data and
1106 * close it.  The devices are at
1107 *   /dev/vport<device number>p<port number>
1108 */
1109static const struct file_operations port_fops = {
1110	.owner = THIS_MODULE,
1111	.open  = port_fops_open,
1112	.read  = port_fops_read,
1113	.write = port_fops_write,
1114	.splice_write = port_fops_splice_write,
1115	.poll  = port_fops_poll,
1116	.release = port_fops_release,
1117	.fasync = port_fops_fasync,
1118	.llseek = no_llseek,
1119};
1120
1121/*
1122 * The put_chars() callback is pretty straightforward.
1123 *
1124 * We turn the characters into a scatter-gather list, add it to the
1125 * output queue and then kick the Host.  Then we sit here waiting for
1126 * it to finish: inefficient in theory, but in practice
1127 * implementations will do it immediately (lguest's Launcher does).
1128 */
1129static int put_chars(u32 vtermno, const char *buf, int count)
1130{
1131	struct port *port;
1132	struct scatterlist sg[1];
 
 
1133
1134	if (unlikely(early_put_chars))
1135		return early_put_chars(vtermno, buf, count);
1136
1137	port = find_port_by_vtermno(vtermno);
1138	if (!port)
1139		return -EPIPE;
1140
1141	sg_init_one(sg, buf, count);
1142	return __send_to_port(port, sg, 1, count, (void *)buf, false);
 
 
 
 
 
 
1143}
1144
1145/*
1146 * get_chars() is the callback from the hvc_console infrastructure
1147 * when an interrupt is received.
1148 *
1149 * We call out to fill_readbuf that gets us the required data from the
1150 * buffers that are queued up.
1151 */
1152static int get_chars(u32 vtermno, char *buf, int count)
1153{
1154	struct port *port;
1155
1156	/* If we've not set up the port yet, we have no input to give. */
1157	if (unlikely(early_put_chars))
1158		return 0;
1159
1160	port = find_port_by_vtermno(vtermno);
1161	if (!port)
1162		return -EPIPE;
1163
1164	/* If we don't have an input queue yet, we can't get input. */
1165	BUG_ON(!port->in_vq);
1166
1167	return fill_readbuf(port, (__force char __user *)buf, count, false);
1168}
1169
1170static void resize_console(struct port *port)
1171{
1172	struct virtio_device *vdev;
1173
1174	/* The port could have been hot-unplugged */
1175	if (!port || !is_console_port(port))
1176		return;
1177
1178	vdev = port->portdev->vdev;
1179
1180	/* Don't test F_SIZE at all if we're rproc: not a valid feature! */
1181	if (!is_rproc_serial(vdev) &&
1182	    virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
1183		hvc_resize(port->cons.hvc, port->cons.ws);
1184}
1185
1186/* We set the configuration at this point, since we now have a tty */
1187static int notifier_add_vio(struct hvc_struct *hp, int data)
1188{
1189	struct port *port;
1190
1191	port = find_port_by_vtermno(hp->vtermno);
1192	if (!port)
1193		return -EINVAL;
1194
1195	hp->irq_requested = 1;
1196	resize_console(port);
1197
1198	return 0;
1199}
1200
1201static void notifier_del_vio(struct hvc_struct *hp, int data)
1202{
1203	hp->irq_requested = 0;
1204}
1205
1206/* The operations for console ports. */
1207static const struct hv_ops hv_ops = {
1208	.get_chars = get_chars,
1209	.put_chars = put_chars,
1210	.notifier_add = notifier_add_vio,
1211	.notifier_del = notifier_del_vio,
1212	.notifier_hangup = notifier_del_vio,
1213};
1214
1215/*
1216 * Console drivers are initialized very early so boot messages can go
1217 * out, so we do things slightly differently from the generic virtio
1218 * initialization of the net and block drivers.
1219 *
1220 * At this stage, the console is output-only.  It's too early to set
1221 * up a virtqueue, so we let the drivers do some boutique early-output
1222 * thing.
1223 */
1224int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
1225{
1226	early_put_chars = put_chars;
1227	return hvc_instantiate(0, 0, &hv_ops);
1228}
1229
1230static int init_port_console(struct port *port)
1231{
1232	int ret;
1233
1234	/*
1235	 * The Host's telling us this port is a console port.  Hook it
1236	 * up with an hvc console.
1237	 *
1238	 * To set up and manage our virtual console, we call
1239	 * hvc_alloc().
1240	 *
1241	 * The first argument of hvc_alloc() is the virtual console
1242	 * number.  The second argument is the parameter for the
1243	 * notification mechanism (like irq number).  We currently
1244	 * leave this as zero, virtqueues have implicit notifications.
1245	 *
1246	 * The third argument is a "struct hv_ops" containing the
1247	 * put_chars() get_chars(), notifier_add() and notifier_del()
1248	 * pointers.  The final argument is the output buffer size: we
1249	 * can do any size, so we put PAGE_SIZE here.
1250	 */
1251	port->cons.vtermno = pdrvdata.next_vtermno;
1252
1253	port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
1254	if (IS_ERR(port->cons.hvc)) {
1255		ret = PTR_ERR(port->cons.hvc);
1256		dev_err(port->dev,
1257			"error %d allocating hvc for port\n", ret);
1258		port->cons.hvc = NULL;
1259		return ret;
1260	}
1261	spin_lock_irq(&pdrvdata_lock);
1262	pdrvdata.next_vtermno++;
1263	list_add_tail(&port->cons.list, &pdrvdata.consoles);
1264	spin_unlock_irq(&pdrvdata_lock);
1265	port->guest_connected = true;
1266
1267	/*
1268	 * Start using the new console output if this is the first
1269	 * console to come up.
1270	 */
1271	if (early_put_chars)
1272		early_put_chars = NULL;
1273
1274	/* Notify host of port being opened */
1275	send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1276
1277	return 0;
1278}
1279
1280static ssize_t show_port_name(struct device *dev,
1281			      struct device_attribute *attr, char *buffer)
1282{
1283	struct port *port;
1284
1285	port = dev_get_drvdata(dev);
1286
1287	return sprintf(buffer, "%s\n", port->name);
1288}
1289
1290static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1291
1292static struct attribute *port_sysfs_entries[] = {
1293	&dev_attr_name.attr,
1294	NULL
1295};
1296
1297static struct attribute_group port_attribute_group = {
1298	.name = NULL,		/* put in device directory */
1299	.attrs = port_sysfs_entries,
1300};
1301
1302static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
1303			    size_t count, loff_t *offp)
1304{
1305	struct port *port;
1306	char *buf;
1307	ssize_t ret, out_offset, out_count;
1308
1309	out_count = 1024;
1310	buf = kmalloc(out_count, GFP_KERNEL);
1311	if (!buf)
1312		return -ENOMEM;
1313
1314	port = filp->private_data;
1315	out_offset = 0;
1316	out_offset += snprintf(buf + out_offset, out_count,
1317			       "name: %s\n", port->name ? port->name : "");
1318	out_offset += snprintf(buf + out_offset, out_count - out_offset,
1319			       "guest_connected: %d\n", port->guest_connected);
1320	out_offset += snprintf(buf + out_offset, out_count - out_offset,
1321			       "host_connected: %d\n", port->host_connected);
1322	out_offset += snprintf(buf + out_offset, out_count - out_offset,
1323			       "outvq_full: %d\n", port->outvq_full);
1324	out_offset += snprintf(buf + out_offset, out_count - out_offset,
1325			       "bytes_sent: %lu\n", port->stats.bytes_sent);
1326	out_offset += snprintf(buf + out_offset, out_count - out_offset,
1327			       "bytes_received: %lu\n",
1328			       port->stats.bytes_received);
1329	out_offset += snprintf(buf + out_offset, out_count - out_offset,
1330			       "bytes_discarded: %lu\n",
1331			       port->stats.bytes_discarded);
1332	out_offset += snprintf(buf + out_offset, out_count - out_offset,
1333			       "is_console: %s\n",
1334			       is_console_port(port) ? "yes" : "no");
1335	out_offset += snprintf(buf + out_offset, out_count - out_offset,
1336			       "console_vtermno: %u\n", port->cons.vtermno);
1337
1338	ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
1339	kfree(buf);
1340	return ret;
1341}
1342
1343static const struct file_operations port_debugfs_ops = {
1344	.owner = THIS_MODULE,
1345	.open  = simple_open,
1346	.read  = debugfs_read,
1347};
1348
1349static void set_console_size(struct port *port, u16 rows, u16 cols)
1350{
1351	if (!port || !is_console_port(port))
1352		return;
1353
1354	port->cons.ws.ws_row = rows;
1355	port->cons.ws.ws_col = cols;
1356}
1357
1358static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1359{
1360	struct port_buffer *buf;
1361	unsigned int nr_added_bufs;
1362	int ret;
1363
1364	nr_added_bufs = 0;
1365	do {
1366		buf = alloc_buf(vq, PAGE_SIZE, 0);
1367		if (!buf)
1368			break;
1369
1370		spin_lock_irq(lock);
1371		ret = add_inbuf(vq, buf);
1372		if (ret < 0) {
1373			spin_unlock_irq(lock);
1374			free_buf(buf, true);
1375			break;
1376		}
1377		nr_added_bufs++;
1378		spin_unlock_irq(lock);
1379	} while (ret > 0);
1380
1381	return nr_added_bufs;
1382}
1383
1384static void send_sigio_to_port(struct port *port)
1385{
1386	if (port->async_queue && port->guest_connected)
1387		kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1388}
1389
1390static int add_port(struct ports_device *portdev, u32 id)
1391{
1392	char debugfs_name[16];
1393	struct port *port;
1394	struct port_buffer *buf;
1395	dev_t devt;
1396	unsigned int nr_added_bufs;
1397	int err;
1398
1399	port = kmalloc(sizeof(*port), GFP_KERNEL);
1400	if (!port) {
1401		err = -ENOMEM;
1402		goto fail;
1403	}
1404	kref_init(&port->kref);
1405
1406	port->portdev = portdev;
1407	port->id = id;
1408
1409	port->name = NULL;
1410	port->inbuf = NULL;
1411	port->cons.hvc = NULL;
1412	port->async_queue = NULL;
1413
1414	port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
 
1415
1416	port->host_connected = port->guest_connected = false;
1417	port->stats = (struct port_stats) { 0 };
1418
1419	port->outvq_full = false;
1420
1421	port->in_vq = portdev->in_vqs[port->id];
1422	port->out_vq = portdev->out_vqs[port->id];
1423
1424	port->cdev = cdev_alloc();
1425	if (!port->cdev) {
1426		dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1427		err = -ENOMEM;
1428		goto free_port;
1429	}
1430	port->cdev->ops = &port_fops;
1431
1432	devt = MKDEV(portdev->chr_major, id);
1433	err = cdev_add(port->cdev, devt, 1);
1434	if (err < 0) {
1435		dev_err(&port->portdev->vdev->dev,
1436			"Error %d adding cdev for port %u\n", err, id);
1437		goto free_cdev;
1438	}
1439	port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1440				  devt, port, "vport%up%u",
1441				  port->portdev->vdev->index, id);
1442	if (IS_ERR(port->dev)) {
1443		err = PTR_ERR(port->dev);
1444		dev_err(&port->portdev->vdev->dev,
1445			"Error %d creating device for port %u\n",
1446			err, id);
1447		goto free_cdev;
1448	}
1449
1450	spin_lock_init(&port->inbuf_lock);
1451	spin_lock_init(&port->outvq_lock);
1452	init_waitqueue_head(&port->waitqueue);
1453
1454	/* Fill the in_vq with buffers so the host can send us data. */
1455	nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1456	if (!nr_added_bufs) {
 
 
 
1457		dev_err(port->dev, "Error allocating inbufs\n");
1458		err = -ENOMEM;
1459		goto free_device;
1460	}
1461
1462	if (is_rproc_serial(port->portdev->vdev))
1463		/*
1464		 * For rproc_serial assume remote processor is connected.
1465		 * rproc_serial does not want the console port, only
1466		 * the generic port implementation.
1467		 */
1468		port->host_connected = true;
1469	else if (!use_multiport(port->portdev)) {
1470		/*
1471		 * If we're not using multiport support,
1472		 * this has to be a console port.
1473		 */
1474		err = init_port_console(port);
1475		if (err)
1476			goto free_inbufs;
1477	}
1478
1479	spin_lock_irq(&portdev->ports_lock);
1480	list_add_tail(&port->list, &port->portdev->ports);
1481	spin_unlock_irq(&portdev->ports_lock);
1482
1483	/*
1484	 * Tell the Host we're set so that it can send us various
1485	 * configuration parameters for this port (eg, port name,
1486	 * caching, whether this is a console port, etc.)
1487	 */
1488	send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1489
1490	if (pdrvdata.debugfs_dir) {
1491		/*
1492		 * Finally, create the debugfs file that we can use to
1493		 * inspect a port's state at any time
1494		 */
1495		snprintf(debugfs_name, sizeof(debugfs_name), "vport%up%u",
1496			 port->portdev->vdev->index, id);
1497		port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1498							 pdrvdata.debugfs_dir,
1499							 port,
1500							 &port_debugfs_ops);
1501	}
1502	return 0;
1503
1504free_inbufs:
1505	while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1506		free_buf(buf, true);
1507free_device:
1508	device_destroy(pdrvdata.class, port->dev->devt);
1509free_cdev:
1510	cdev_del(port->cdev);
1511free_port:
1512	kfree(port);
1513fail:
1514	/* The host might want to notify management sw about port add failure */
1515	__send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1516	return err;
1517}
1518
1519/* No users remain, remove all port-specific data. */
1520static void remove_port(struct kref *kref)
1521{
1522	struct port *port;
1523
1524	port = container_of(kref, struct port, kref);
1525
1526	kfree(port);
1527}
1528
1529static void remove_port_data(struct port *port)
1530{
1531	struct port_buffer *buf;
1532
1533	spin_lock_irq(&port->inbuf_lock);
1534	/* Remove unused data this port might have received. */
1535	discard_port_data(port);
1536
1537	/* Remove buffers we queued up for the Host to send us data in. */
1538	while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1539		free_buf(buf, true);
1540	spin_unlock_irq(&port->inbuf_lock);
1541
1542	spin_lock_irq(&port->outvq_lock);
1543	reclaim_consumed_buffers(port);
1544
1545	/* Free pending buffers from the out-queue. */
1546	while ((buf = virtqueue_detach_unused_buf(port->out_vq)))
1547		free_buf(buf, true);
1548	spin_unlock_irq(&port->outvq_lock);
1549}
1550
1551/*
1552 * Port got unplugged.  Remove port from portdev's list and drop the
1553 * kref reference.  If no userspace has this port opened, it will
1554 * result in immediate removal the port.
1555 */
1556static void unplug_port(struct port *port)
1557{
1558	spin_lock_irq(&port->portdev->ports_lock);
1559	list_del(&port->list);
1560	spin_unlock_irq(&port->portdev->ports_lock);
1561
1562	spin_lock_irq(&port->inbuf_lock);
1563	if (port->guest_connected) {
1564		/* Let the app know the port is going down. */
1565		send_sigio_to_port(port);
1566
1567		/* Do this after sigio is actually sent */
1568		port->guest_connected = false;
1569		port->host_connected = false;
1570
1571		wake_up_interruptible(&port->waitqueue);
1572	}
1573	spin_unlock_irq(&port->inbuf_lock);
1574
1575	if (is_console_port(port)) {
1576		spin_lock_irq(&pdrvdata_lock);
1577		list_del(&port->cons.list);
1578		spin_unlock_irq(&pdrvdata_lock);
1579		hvc_remove(port->cons.hvc);
1580	}
1581
1582	remove_port_data(port);
1583
1584	/*
1585	 * We should just assume the device itself has gone off --
1586	 * else a close on an open port later will try to send out a
1587	 * control message.
1588	 */
1589	port->portdev = NULL;
1590
1591	sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1592	device_destroy(pdrvdata.class, port->dev->devt);
1593	cdev_del(port->cdev);
1594
1595	debugfs_remove(port->debugfs_file);
1596	kfree(port->name);
1597
1598	/*
1599	 * Locks around here are not necessary - a port can't be
1600	 * opened after we removed the port struct from ports_list
1601	 * above.
1602	 */
1603	kref_put(&port->kref, remove_port);
1604}
1605
1606/* Any private messages that the Host and Guest want to share */
1607static void handle_control_message(struct virtio_device *vdev,
1608				   struct ports_device *portdev,
1609				   struct port_buffer *buf)
1610{
1611	struct virtio_console_control *cpkt;
1612	struct port *port;
1613	size_t name_size;
1614	int err;
1615
1616	cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1617
1618	port = find_port_by_id(portdev, virtio32_to_cpu(vdev, cpkt->id));
1619	if (!port &&
1620	    cpkt->event != cpu_to_virtio16(vdev, VIRTIO_CONSOLE_PORT_ADD)) {
1621		/* No valid header at start of buffer.  Drop it. */
1622		dev_dbg(&portdev->vdev->dev,
1623			"Invalid index %u in control packet\n", cpkt->id);
1624		return;
1625	}
1626
1627	switch (virtio16_to_cpu(vdev, cpkt->event)) {
1628	case VIRTIO_CONSOLE_PORT_ADD:
1629		if (port) {
1630			dev_dbg(&portdev->vdev->dev,
1631				"Port %u already added\n", port->id);
1632			send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1633			break;
1634		}
1635		if (virtio32_to_cpu(vdev, cpkt->id) >=
1636		    portdev->config.max_nr_ports) {
1637			dev_warn(&portdev->vdev->dev,
1638				"Request for adding port with "
1639				"out-of-bound id %u, max. supported id: %u\n",
1640				cpkt->id, portdev->config.max_nr_ports - 1);
1641			break;
1642		}
1643		add_port(portdev, virtio32_to_cpu(vdev, cpkt->id));
1644		break;
1645	case VIRTIO_CONSOLE_PORT_REMOVE:
1646		unplug_port(port);
1647		break;
1648	case VIRTIO_CONSOLE_CONSOLE_PORT:
1649		if (!cpkt->value)
1650			break;
1651		if (is_console_port(port))
1652			break;
1653
1654		init_port_console(port);
1655		complete(&early_console_added);
1656		/*
1657		 * Could remove the port here in case init fails - but
1658		 * have to notify the host first.
1659		 */
1660		break;
1661	case VIRTIO_CONSOLE_RESIZE: {
1662		struct {
1663			__u16 rows;
1664			__u16 cols;
1665		} size;
1666
1667		if (!is_console_port(port))
1668			break;
1669
1670		memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1671		       sizeof(size));
1672		set_console_size(port, size.rows, size.cols);
1673
1674		port->cons.hvc->irq_requested = 1;
1675		resize_console(port);
1676		break;
1677	}
1678	case VIRTIO_CONSOLE_PORT_OPEN:
1679		port->host_connected = virtio16_to_cpu(vdev, cpkt->value);
1680		wake_up_interruptible(&port->waitqueue);
1681		/*
1682		 * If the host port got closed and the host had any
1683		 * unconsumed buffers, we'll be able to reclaim them
1684		 * now.
1685		 */
1686		spin_lock_irq(&port->outvq_lock);
1687		reclaim_consumed_buffers(port);
1688		spin_unlock_irq(&port->outvq_lock);
1689
1690		/*
1691		 * If the guest is connected, it'll be interested in
1692		 * knowing the host connection state changed.
1693		 */
1694		spin_lock_irq(&port->inbuf_lock);
1695		send_sigio_to_port(port);
1696		spin_unlock_irq(&port->inbuf_lock);
1697		break;
1698	case VIRTIO_CONSOLE_PORT_NAME:
1699		/*
1700		 * If we woke up after hibernation, we can get this
1701		 * again.  Skip it in that case.
1702		 */
1703		if (port->name)
1704			break;
1705
1706		/*
1707		 * Skip the size of the header and the cpkt to get the size
1708		 * of the name that was sent
1709		 */
1710		name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1711
1712		port->name = kmalloc(name_size, GFP_KERNEL);
1713		if (!port->name) {
1714			dev_err(port->dev,
1715				"Not enough space to store port name\n");
1716			break;
1717		}
1718		strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1719			name_size - 1);
1720		port->name[name_size - 1] = 0;
1721
1722		/*
1723		 * Since we only have one sysfs attribute, 'name',
1724		 * create it only if we have a name for the port.
1725		 */
1726		err = sysfs_create_group(&port->dev->kobj,
1727					 &port_attribute_group);
1728		if (err) {
1729			dev_err(port->dev,
1730				"Error %d creating sysfs device attributes\n",
1731				err);
1732		} else {
1733			/*
1734			 * Generate a udev event so that appropriate
1735			 * symlinks can be created based on udev
1736			 * rules.
1737			 */
1738			kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1739		}
1740		break;
1741	}
1742}
1743
1744static void control_work_handler(struct work_struct *work)
1745{
1746	struct ports_device *portdev;
1747	struct virtqueue *vq;
1748	struct port_buffer *buf;
1749	unsigned int len;
1750
1751	portdev = container_of(work, struct ports_device, control_work);
1752	vq = portdev->c_ivq;
1753
1754	spin_lock(&portdev->c_ivq_lock);
1755	while ((buf = virtqueue_get_buf(vq, &len))) {
1756		spin_unlock(&portdev->c_ivq_lock);
1757
1758		buf->len = len;
1759		buf->offset = 0;
1760
1761		handle_control_message(vq->vdev, portdev, buf);
1762
1763		spin_lock(&portdev->c_ivq_lock);
1764		if (add_inbuf(portdev->c_ivq, buf) < 0) {
1765			dev_warn(&portdev->vdev->dev,
1766				 "Error adding buffer to queue\n");
1767			free_buf(buf, false);
1768		}
1769	}
1770	spin_unlock(&portdev->c_ivq_lock);
1771}
1772
 
 
 
 
 
 
 
 
 
1773static void out_intr(struct virtqueue *vq)
1774{
1775	struct port *port;
1776
1777	port = find_port_by_vq(vq->vdev->priv, vq);
1778	if (!port)
 
1779		return;
 
1780
1781	wake_up_interruptible(&port->waitqueue);
1782}
1783
1784static void in_intr(struct virtqueue *vq)
1785{
1786	struct port *port;
1787	unsigned long flags;
1788
1789	port = find_port_by_vq(vq->vdev->priv, vq);
1790	if (!port)
 
1791		return;
 
1792
1793	spin_lock_irqsave(&port->inbuf_lock, flags);
1794	port->inbuf = get_inbuf(port);
1795
1796	/*
1797	 * Normally the port should not accept data when the port is
1798	 * closed. For generic serial ports, the host won't (shouldn't)
1799	 * send data till the guest is connected. But this condition
1800	 * can be reached when a console port is not yet connected (no
1801	 * tty is spawned) and the other side sends out data over the
1802	 * vring, or when a remote devices start sending data before
1803	 * the ports are opened.
1804	 *
1805	 * A generic serial port will discard data if not connected,
1806	 * while console ports and rproc-serial ports accepts data at
1807	 * any time. rproc-serial is initiated with guest_connected to
1808	 * false because port_fops_open expects this. Console ports are
1809	 * hooked up with an HVC console and is initialized with
1810	 * guest_connected to true.
1811	 */
1812
1813	if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev))
1814		discard_port_data(port);
1815
1816	/* Send a SIGIO indicating new data in case the process asked for it */
1817	send_sigio_to_port(port);
1818
1819	spin_unlock_irqrestore(&port->inbuf_lock, flags);
1820
1821	wake_up_interruptible(&port->waitqueue);
1822
1823	if (is_console_port(port) && hvc_poll(port->cons.hvc))
1824		hvc_kick();
1825}
1826
1827static void control_intr(struct virtqueue *vq)
1828{
1829	struct ports_device *portdev;
1830
1831	portdev = vq->vdev->priv;
1832	schedule_work(&portdev->control_work);
1833}
1834
1835static void config_intr(struct virtio_device *vdev)
1836{
1837	struct ports_device *portdev;
1838
1839	portdev = vdev->priv;
1840
1841	if (!use_multiport(portdev))
1842		schedule_work(&portdev->config_work);
1843}
1844
1845static void config_work_handler(struct work_struct *work)
1846{
1847	struct ports_device *portdev;
1848
1849	portdev = container_of(work, struct ports_device, control_work);
1850	if (!use_multiport(portdev)) {
1851		struct virtio_device *vdev;
1852		struct port *port;
1853		u16 rows, cols;
1854
1855		vdev = portdev->vdev;
1856		virtio_cread(vdev, struct virtio_console_config, cols, &cols);
1857		virtio_cread(vdev, struct virtio_console_config, rows, &rows);
1858
1859		port = find_port_by_id(portdev, 0);
1860		set_console_size(port, rows, cols);
1861
1862		/*
1863		 * We'll use this way of resizing only for legacy
1864		 * support.  For newer userspace
1865		 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1866		 * to indicate console size changes so that it can be
1867		 * done per-port.
1868		 */
1869		resize_console(port);
1870	}
1871}
1872
1873static int init_vqs(struct ports_device *portdev)
1874{
1875	vq_callback_t **io_callbacks;
1876	char **io_names;
1877	struct virtqueue **vqs;
1878	u32 i, j, nr_ports, nr_queues;
1879	int err;
1880
1881	nr_ports = portdev->config.max_nr_ports;
1882	nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1883
1884	vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1885	io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1886	io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1887	portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1888				  GFP_KERNEL);
1889	portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1890				   GFP_KERNEL);
 
1891	if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1892	    !portdev->out_vqs) {
1893		err = -ENOMEM;
1894		goto free;
1895	}
1896
1897	/*
1898	 * For backward compat (newer host but older guest), the host
1899	 * spawns a console port first and also inits the vqs for port
1900	 * 0 before others.
1901	 */
1902	j = 0;
1903	io_callbacks[j] = in_intr;
1904	io_callbacks[j + 1] = out_intr;
1905	io_names[j] = "input";
1906	io_names[j + 1] = "output";
1907	j += 2;
1908
1909	if (use_multiport(portdev)) {
1910		io_callbacks[j] = control_intr;
1911		io_callbacks[j + 1] = NULL;
1912		io_names[j] = "control-i";
1913		io_names[j + 1] = "control-o";
1914
1915		for (i = 1; i < nr_ports; i++) {
1916			j += 2;
1917			io_callbacks[j] = in_intr;
1918			io_callbacks[j + 1] = out_intr;
1919			io_names[j] = "input";
1920			io_names[j + 1] = "output";
1921		}
1922	}
1923	/* Find the queues. */
1924	err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1925					      io_callbacks,
1926					      (const char **)io_names);
1927	if (err)
1928		goto free;
1929
1930	j = 0;
1931	portdev->in_vqs[0] = vqs[0];
1932	portdev->out_vqs[0] = vqs[1];
1933	j += 2;
1934	if (use_multiport(portdev)) {
1935		portdev->c_ivq = vqs[j];
1936		portdev->c_ovq = vqs[j + 1];
1937
1938		for (i = 1; i < nr_ports; i++) {
1939			j += 2;
1940			portdev->in_vqs[i] = vqs[j];
1941			portdev->out_vqs[i] = vqs[j + 1];
1942		}
1943	}
1944	kfree(io_names);
1945	kfree(io_callbacks);
1946	kfree(vqs);
1947
1948	return 0;
1949
1950free:
1951	kfree(portdev->out_vqs);
1952	kfree(portdev->in_vqs);
1953	kfree(io_names);
1954	kfree(io_callbacks);
1955	kfree(vqs);
1956
1957	return err;
1958}
1959
1960static const struct file_operations portdev_fops = {
1961	.owner = THIS_MODULE,
1962};
1963
1964static void remove_vqs(struct ports_device *portdev)
1965{
 
 
 
 
 
 
 
 
 
1966	portdev->vdev->config->del_vqs(portdev->vdev);
1967	kfree(portdev->in_vqs);
1968	kfree(portdev->out_vqs);
1969}
1970
1971static void remove_controlq_data(struct ports_device *portdev)
1972{
1973	struct port_buffer *buf;
1974	unsigned int len;
1975
1976	if (!use_multiport(portdev))
1977		return;
1978
1979	while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1980		free_buf(buf, true);
 
1981
1982	while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1983		free_buf(buf, true);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1984}
1985
1986/*
1987 * Once we're further in boot, we get probed like any other virtio
1988 * device.
1989 *
1990 * If the host also supports multiple console ports, we check the
1991 * config space to see how many ports the host has spawned.  We
1992 * initialize each port found.
1993 */
1994static int virtcons_probe(struct virtio_device *vdev)
1995{
1996	struct ports_device *portdev;
1997	int err;
1998	bool multiport;
1999	bool early = early_put_chars != NULL;
2000
2001	/* We only need a config space if features are offered */
2002	if (!vdev->config->get &&
2003	    (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)
2004	     || virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT))) {
2005		dev_err(&vdev->dev, "%s failure: config access disabled\n",
2006			__func__);
2007		return -EINVAL;
2008	}
2009
2010	/* Ensure to read early_put_chars now */
2011	barrier();
2012
2013	portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
2014	if (!portdev) {
2015		err = -ENOMEM;
2016		goto fail;
2017	}
2018
2019	/* Attach this portdev to this virtio_device, and vice-versa. */
2020	portdev->vdev = vdev;
2021	vdev->priv = portdev;
2022
2023	portdev->chr_major = register_chrdev(0, "virtio-portsdev",
2024					     &portdev_fops);
2025	if (portdev->chr_major < 0) {
2026		dev_err(&vdev->dev,
2027			"Error %d registering chrdev for device %u\n",
2028			portdev->chr_major, vdev->index);
2029		err = portdev->chr_major;
2030		goto free;
2031	}
2032
2033	multiport = false;
2034	portdev->config.max_nr_ports = 1;
2035
2036	/* Don't test MULTIPORT at all if we're rproc: not a valid feature! */
2037	if (!is_rproc_serial(vdev) &&
2038	    virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
2039				 struct virtio_console_config, max_nr_ports,
2040				 &portdev->config.max_nr_ports) == 0) {
2041		multiport = true;
2042	}
2043
2044	err = init_vqs(portdev);
2045	if (err < 0) {
2046		dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
2047		goto free_chrdev;
2048	}
2049
2050	spin_lock_init(&portdev->ports_lock);
2051	INIT_LIST_HEAD(&portdev->ports);
 
2052
2053	virtio_device_ready(portdev->vdev);
2054
2055	INIT_WORK(&portdev->config_work, &config_work_handler);
2056	INIT_WORK(&portdev->control_work, &control_work_handler);
2057
2058	if (multiport) {
2059		unsigned int nr_added_bufs;
2060
2061		spin_lock_init(&portdev->c_ivq_lock);
2062		spin_lock_init(&portdev->c_ovq_lock);
2063
2064		nr_added_bufs = fill_queue(portdev->c_ivq,
2065					   &portdev->c_ivq_lock);
2066		if (!nr_added_bufs) {
2067			dev_err(&vdev->dev,
2068				"Error allocating buffers for control queue\n");
2069			err = -ENOMEM;
2070			goto free_vqs;
 
 
 
 
 
 
 
2071		}
2072	} else {
2073		/*
2074		 * For backward compatibility: Create a console port
2075		 * if we're running on older host.
2076		 */
2077		add_port(portdev, 0);
2078	}
2079
2080	spin_lock_irq(&pdrvdata_lock);
2081	list_add_tail(&portdev->list, &pdrvdata.portdevs);
2082	spin_unlock_irq(&pdrvdata_lock);
2083
2084	__send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2085			   VIRTIO_CONSOLE_DEVICE_READY, 1);
2086
2087	/*
2088	 * If there was an early virtio console, assume that there are no
2089	 * other consoles. We need to wait until the hvc_alloc matches the
2090	 * hvc_instantiate, otherwise tty_open will complain, resulting in
2091	 * a "Warning: unable to open an initial console" boot failure.
2092	 * Without multiport this is done in add_port above. With multiport
2093	 * this might take some host<->guest communication - thus we have to
2094	 * wait.
2095	 */
2096	if (multiport && early)
2097		wait_for_completion(&early_console_added);
2098
2099	return 0;
2100
2101free_vqs:
2102	/* The host might want to notify mgmt sw about device add failure */
2103	__send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2104			   VIRTIO_CONSOLE_DEVICE_READY, 0);
2105	remove_vqs(portdev);
2106free_chrdev:
2107	unregister_chrdev(portdev->chr_major, "virtio-portsdev");
2108free:
2109	kfree(portdev);
2110fail:
2111	return err;
2112}
2113
2114static void virtcons_remove(struct virtio_device *vdev)
2115{
2116	struct ports_device *portdev;
2117	struct port *port, *port2;
2118
2119	portdev = vdev->priv;
2120
2121	spin_lock_irq(&pdrvdata_lock);
2122	list_del(&portdev->list);
2123	spin_unlock_irq(&pdrvdata_lock);
2124
2125	/* Disable interrupts for vqs */
2126	vdev->config->reset(vdev);
2127	/* Finish up work that's lined up */
2128	if (use_multiport(portdev))
2129		cancel_work_sync(&portdev->control_work);
2130	else
2131		cancel_work_sync(&portdev->config_work);
2132
2133	list_for_each_entry_safe(port, port2, &portdev->ports, list)
2134		unplug_port(port);
2135
2136	unregister_chrdev(portdev->chr_major, "virtio-portsdev");
2137
2138	/*
2139	 * When yanking out a device, we immediately lose the
2140	 * (device-side) queues.  So there's no point in keeping the
2141	 * guest side around till we drop our final reference.  This
2142	 * also means that any ports which are in an open state will
2143	 * have to just stop using the port, as the vqs are going
2144	 * away.
2145	 */
2146	remove_controlq_data(portdev);
2147	remove_vqs(portdev);
2148	kfree(portdev);
2149}
2150
2151static struct virtio_device_id id_table[] = {
2152	{ VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
2153	{ 0 },
2154};
 
2155
2156static unsigned int features[] = {
2157	VIRTIO_CONSOLE_F_SIZE,
2158	VIRTIO_CONSOLE_F_MULTIPORT,
2159};
2160
2161static struct virtio_device_id rproc_serial_id_table[] = {
2162#if IS_ENABLED(CONFIG_REMOTEPROC)
2163	{ VIRTIO_ID_RPROC_SERIAL, VIRTIO_DEV_ANY_ID },
2164#endif
2165	{ 0 },
2166};
 
2167
2168static unsigned int rproc_serial_features[] = {
2169};
2170
2171#ifdef CONFIG_PM_SLEEP
2172static int virtcons_freeze(struct virtio_device *vdev)
2173{
2174	struct ports_device *portdev;
2175	struct port *port;
2176
2177	portdev = vdev->priv;
2178
2179	vdev->config->reset(vdev);
2180
2181	virtqueue_disable_cb(portdev->c_ivq);
 
2182	cancel_work_sync(&portdev->control_work);
2183	cancel_work_sync(&portdev->config_work);
2184	/*
2185	 * Once more: if control_work_handler() was running, it would
2186	 * enable the cb as the last step.
2187	 */
2188	virtqueue_disable_cb(portdev->c_ivq);
2189	remove_controlq_data(portdev);
2190
2191	list_for_each_entry(port, &portdev->ports, list) {
2192		virtqueue_disable_cb(port->in_vq);
2193		virtqueue_disable_cb(port->out_vq);
2194		/*
2195		 * We'll ask the host later if the new invocation has
2196		 * the port opened or closed.
2197		 */
2198		port->host_connected = false;
2199		remove_port_data(port);
2200	}
2201	remove_vqs(portdev);
2202
2203	return 0;
2204}
2205
2206static int virtcons_restore(struct virtio_device *vdev)
2207{
2208	struct ports_device *portdev;
2209	struct port *port;
2210	int ret;
2211
2212	portdev = vdev->priv;
2213
2214	ret = init_vqs(portdev);
2215	if (ret)
2216		return ret;
2217
2218	virtio_device_ready(portdev->vdev);
2219
2220	if (use_multiport(portdev))
2221		fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
2222
2223	list_for_each_entry(port, &portdev->ports, list) {
2224		port->in_vq = portdev->in_vqs[port->id];
2225		port->out_vq = portdev->out_vqs[port->id];
2226
2227		fill_queue(port->in_vq, &port->inbuf_lock);
2228
2229		/* Get port open/close status on the host */
2230		send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
2231
2232		/*
2233		 * If a port was open at the time of suspending, we
2234		 * have to let the host know that it's still open.
2235		 */
2236		if (port->guest_connected)
2237			send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
2238	}
2239	return 0;
2240}
2241#endif
2242
2243static struct virtio_driver virtio_console = {
2244	.feature_table = features,
2245	.feature_table_size = ARRAY_SIZE(features),
2246	.driver.name =	KBUILD_MODNAME,
2247	.driver.owner =	THIS_MODULE,
2248	.id_table =	id_table,
2249	.probe =	virtcons_probe,
2250	.remove =	virtcons_remove,
2251	.config_changed = config_intr,
2252#ifdef CONFIG_PM_SLEEP
2253	.freeze =	virtcons_freeze,
2254	.restore =	virtcons_restore,
2255#endif
2256};
2257
2258static struct virtio_driver virtio_rproc_serial = {
2259	.feature_table = rproc_serial_features,
2260	.feature_table_size = ARRAY_SIZE(rproc_serial_features),
2261	.driver.name =	"virtio_rproc_serial",
2262	.driver.owner =	THIS_MODULE,
2263	.id_table =	rproc_serial_id_table,
2264	.probe =	virtcons_probe,
2265	.remove =	virtcons_remove,
2266};
2267
2268static int __init init(void)
2269{
2270	int err;
2271
2272	pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
2273	if (IS_ERR(pdrvdata.class)) {
2274		err = PTR_ERR(pdrvdata.class);
2275		pr_err("Error %d creating virtio-ports class\n", err);
2276		return err;
2277	}
2278
2279	pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
2280	if (!pdrvdata.debugfs_dir)
2281		pr_warning("Error creating debugfs dir for virtio-ports\n");
2282	INIT_LIST_HEAD(&pdrvdata.consoles);
2283	INIT_LIST_HEAD(&pdrvdata.portdevs);
2284
2285	err = register_virtio_driver(&virtio_console);
2286	if (err < 0) {
2287		pr_err("Error %d registering virtio driver\n", err);
2288		goto free;
2289	}
2290	err = register_virtio_driver(&virtio_rproc_serial);
2291	if (err < 0) {
2292		pr_err("Error %d registering virtio rproc serial driver\n",
2293		       err);
2294		goto unregister;
2295	}
2296	return 0;
2297unregister:
2298	unregister_virtio_driver(&virtio_console);
2299free:
2300	debugfs_remove_recursive(pdrvdata.debugfs_dir);
2301	class_destroy(pdrvdata.class);
2302	return err;
2303}
2304
2305static void __exit fini(void)
2306{
2307	reclaim_dma_bufs();
2308
2309	unregister_virtio_driver(&virtio_console);
2310	unregister_virtio_driver(&virtio_rproc_serial);
2311
2312	class_destroy(pdrvdata.class);
2313	debugfs_remove_recursive(pdrvdata.debugfs_dir);
2314}
2315module_init(init);
2316module_exit(fini);
2317
2318MODULE_DEVICE_TABLE(virtio, id_table);
2319MODULE_DESCRIPTION("Virtio console driver");
2320MODULE_LICENSE("GPL");