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Rusty Russella23ea922010-01-18 19:14:55 +05301/*
2 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
Amit Shah5084f892011-01-31 13:06:37 +05303 * Copyright (C) 2009, 2010, 2011 Red Hat, Inc.
4 * Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com>
Rusty Russell31610432007-10-22 11:03:39 +10005 *
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 */
Amit Shahfb08bd22009-12-21 21:36:04 +053020#include <linux/cdev.h>
Amit Shahd99393e2009-12-21 22:36:21 +053021#include <linux/debugfs.h>
Christian Borntraeger5e384832011-09-22 23:44:23 +053022#include <linux/completion.h>
Amit Shahfb08bd22009-12-21 21:36:04 +053023#include <linux/device.h>
Rusty Russell31610432007-10-22 11:03:39 +100024#include <linux/err.h>
Amit Shaha08fa922011-09-14 13:06:41 +053025#include <linux/freezer.h>
Amit Shah2030fa42009-12-21 21:49:30 +053026#include <linux/fs.h>
Rusty Russell31610432007-10-22 11:03:39 +100027#include <linux/init.h>
Amit Shah38edf582010-01-18 19:15:05 +053028#include <linux/list.h>
Amit Shah2030fa42009-12-21 21:49:30 +053029#include <linux/poll.h>
30#include <linux/sched.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090031#include <linux/slab.h>
Amit Shah38edf582010-01-18 19:15:05 +053032#include <linux/spinlock.h>
Rusty Russell31610432007-10-22 11:03:39 +100033#include <linux/virtio.h>
34#include <linux/virtio_console.h>
Amit Shah2030fa42009-12-21 21:49:30 +053035#include <linux/wait.h>
Amit Shah17634ba2009-12-21 21:03:25 +053036#include <linux/workqueue.h>
Paul Gortmakerc22405c2011-07-03 13:35:48 -040037#include <linux/module.h>
Amit Shah51df0ac2011-02-01 09:31:25 +053038#include "../tty/hvc/hvc_console.h"
Rusty Russell31610432007-10-22 11:03:39 +100039
Amit Shah38edf582010-01-18 19:15:05 +053040/*
41 * This is a global struct for storing common data for all the devices
42 * this driver handles.
43 *
44 * Mainly, it has a linked list for all the consoles in one place so
45 * that callbacks from hvc for get_chars(), put_chars() work properly
46 * across multiple devices and multiple ports per device.
47 */
48struct ports_driver_data {
Amit Shahfb08bd22009-12-21 21:36:04 +053049 /* Used for registering chardevs */
50 struct class *class;
51
Amit Shahd99393e2009-12-21 22:36:21 +053052 /* Used for exporting per-port information to debugfs */
53 struct dentry *debugfs_dir;
54
Amit Shah6bdf2af2010-09-02 18:11:49 +053055 /* List of all the devices we're handling */
56 struct list_head portdevs;
57
Amit Shahfb08bd22009-12-21 21:36:04 +053058 /* Number of devices this driver is handling */
59 unsigned int index;
60
Rusty Russelld8a02bd2010-01-18 19:15:06 +053061 /*
62 * This is used to keep track of the number of hvc consoles
63 * spawned by this driver. This number is given as the first
64 * argument to hvc_alloc(). To correctly map an initial
65 * console spawned via hvc_instantiate to the console being
66 * hooked up via hvc_alloc, we need to pass the same vtermno.
67 *
68 * We also just assume the first console being initialised was
69 * the first one that got used as the initial console.
70 */
71 unsigned int next_vtermno;
72
Amit Shah38edf582010-01-18 19:15:05 +053073 /* All the console devices handled by this driver */
74 struct list_head consoles;
75};
76static struct ports_driver_data pdrvdata;
77
78DEFINE_SPINLOCK(pdrvdata_lock);
Christian Borntraeger5e384832011-09-22 23:44:23 +053079DECLARE_COMPLETION(early_console_added);
Amit Shah38edf582010-01-18 19:15:05 +053080
Amit Shah4f23c572010-01-18 19:15:09 +053081/* This struct holds information that's relevant only for console ports */
82struct console {
83 /* We'll place all consoles in a list in the pdrvdata struct */
84 struct list_head list;
85
86 /* The hvc device associated with this console port */
87 struct hvc_struct *hvc;
88
Amit Shah97788292010-05-06 02:05:08 +053089 /* The size of the console */
90 struct winsize ws;
91
Amit Shah4f23c572010-01-18 19:15:09 +053092 /*
93 * This number identifies the number that we used to register
94 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
95 * number passed on by the hvc callbacks to us to
96 * differentiate between the other console ports handled by
97 * this driver
98 */
99 u32 vtermno;
100};
101
Amit Shahfdb9a052010-01-18 19:15:01 +0530102struct port_buffer {
103 char *buf;
104
105 /* size of the buffer in *buf above */
106 size_t size;
107
108 /* used length of the buffer */
109 size_t len;
110 /* offset in the buf from which to consume data */
111 size_t offset;
112};
113
Amit Shah17634ba2009-12-21 21:03:25 +0530114/*
115 * This is a per-device struct that stores data common to all the
116 * ports for that device (vdev->priv).
117 */
118struct ports_device {
Amit Shah6bdf2af2010-09-02 18:11:49 +0530119 /* Next portdev in the list, head is in the pdrvdata struct */
120 struct list_head list;
121
Amit Shah17634ba2009-12-21 21:03:25 +0530122 /*
123 * Workqueue handlers where we process deferred work after
124 * notification
125 */
126 struct work_struct control_work;
127
128 struct list_head ports;
129
130 /* To protect the list of ports */
131 spinlock_t ports_lock;
132
133 /* To protect the vq operations for the control channel */
134 spinlock_t cvq_lock;
135
136 /* The current config space is stored here */
Amit Shahb99fa812010-05-19 22:15:46 -0600137 struct virtio_console_config config;
Amit Shah17634ba2009-12-21 21:03:25 +0530138
139 /* The virtio device we're associated with */
140 struct virtio_device *vdev;
141
142 /*
143 * A couple of virtqueues for the control channel: one for
144 * guest->host transfers, one for host->guest transfers
145 */
146 struct virtqueue *c_ivq, *c_ovq;
147
148 /* Array of per-port IO virtqueues */
149 struct virtqueue **in_vqs, **out_vqs;
Amit Shahfb08bd22009-12-21 21:36:04 +0530150
151 /* Used for numbering devices for sysfs and debugfs */
152 unsigned int drv_index;
153
154 /* Major number for this device. Ports will be created as minors. */
155 int chr_major;
Amit Shah17634ba2009-12-21 21:03:25 +0530156};
157
Amit Shah17e5b4f2011-09-14 13:06:46 +0530158struct port_stats {
159 unsigned long bytes_sent, bytes_received, bytes_discarded;
160};
161
Amit Shah1c85bf32010-01-18 19:15:07 +0530162/* This struct holds the per-port data */
Rusty Russell21206ed2010-01-18 19:15:00 +0530163struct port {
Amit Shah17634ba2009-12-21 21:03:25 +0530164 /* Next port in the list, head is in the ports_device */
165 struct list_head list;
166
Amit Shah1c85bf32010-01-18 19:15:07 +0530167 /* Pointer to the parent virtio_console device */
168 struct ports_device *portdev;
Amit Shahfdb9a052010-01-18 19:15:01 +0530169
170 /* The current buffer from which data has to be fed to readers */
171 struct port_buffer *inbuf;
Rusty Russell31610432007-10-22 11:03:39 +1000172
Amit Shah203baab2010-01-18 19:15:12 +0530173 /*
174 * To protect the operations on the in_vq associated with this
175 * port. Has to be a spinlock because it can be called from
176 * interrupt context (get_char()).
177 */
178 spinlock_t inbuf_lock;
179
Amit Shahcdfadfc2010-05-19 22:15:50 -0600180 /* Protect the operations on the out_vq. */
181 spinlock_t outvq_lock;
182
Amit Shah1c85bf32010-01-18 19:15:07 +0530183 /* The IO vqs for this port */
184 struct virtqueue *in_vq, *out_vq;
185
Amit Shahd99393e2009-12-21 22:36:21 +0530186 /* File in the debugfs directory that exposes this port's information */
187 struct dentry *debugfs_file;
188
Amit Shah4f23c572010-01-18 19:15:09 +0530189 /*
Amit Shah17e5b4f2011-09-14 13:06:46 +0530190 * Keep count of the bytes sent, received and discarded for
191 * this port for accounting and debugging purposes. These
192 * counts are not reset across port open / close events.
193 */
194 struct port_stats stats;
195
196 /*
Amit Shah4f23c572010-01-18 19:15:09 +0530197 * The entries in this struct will be valid if this port is
198 * hooked up to an hvc console
199 */
200 struct console cons;
Amit Shah17634ba2009-12-21 21:03:25 +0530201
Amit Shahfb08bd22009-12-21 21:36:04 +0530202 /* Each port associates with a separate char device */
Amit Shahd22a6982010-09-02 18:20:59 +0530203 struct cdev *cdev;
Amit Shahfb08bd22009-12-21 21:36:04 +0530204 struct device *dev;
205
Amit Shahb353a6b2010-09-02 18:38:29 +0530206 /* Reference-counting to handle port hot-unplugs and file operations */
207 struct kref kref;
208
Amit Shah2030fa42009-12-21 21:49:30 +0530209 /* A waitqueue for poll() or blocking read operations */
210 wait_queue_head_t waitqueue;
211
Amit Shah431edb82009-12-21 21:57:40 +0530212 /* The 'name' of the port that we expose via sysfs properties */
213 char *name;
214
Amit Shah3eae0ad2010-09-02 18:47:52 +0530215 /* We can notify apps of host connect / disconnect events via SIGIO */
216 struct fasync_struct *async_queue;
217
Amit Shah17634ba2009-12-21 21:03:25 +0530218 /* The 'id' to identify the port with the Host */
219 u32 id;
Amit Shah2030fa42009-12-21 21:49:30 +0530220
Amit Shahcdfadfc2010-05-19 22:15:50 -0600221 bool outvq_full;
222
Amit Shah2030fa42009-12-21 21:49:30 +0530223 /* Is the host device open */
224 bool host_connected;
Amit Shah3c7969c2009-11-26 11:25:38 +0530225
226 /* We should allow only one process to open a port */
227 bool guest_connected;
Rusty Russell21206ed2010-01-18 19:15:00 +0530228};
Rusty Russell31610432007-10-22 11:03:39 +1000229
Rusty Russell971f3392010-01-18 19:14:56 +0530230/* This is the very early arch-specified put chars function. */
231static int (*early_put_chars)(u32, const char *, int);
232
Amit Shah38edf582010-01-18 19:15:05 +0530233static struct port *find_port_by_vtermno(u32 vtermno)
234{
235 struct port *port;
Amit Shah4f23c572010-01-18 19:15:09 +0530236 struct console *cons;
Amit Shah38edf582010-01-18 19:15:05 +0530237 unsigned long flags;
238
239 spin_lock_irqsave(&pdrvdata_lock, flags);
Amit Shah4f23c572010-01-18 19:15:09 +0530240 list_for_each_entry(cons, &pdrvdata.consoles, list) {
241 if (cons->vtermno == vtermno) {
242 port = container_of(cons, struct port, cons);
Amit Shah38edf582010-01-18 19:15:05 +0530243 goto out;
Amit Shah4f23c572010-01-18 19:15:09 +0530244 }
Amit Shah38edf582010-01-18 19:15:05 +0530245 }
246 port = NULL;
247out:
248 spin_unlock_irqrestore(&pdrvdata_lock, flags);
249 return port;
250}
251
Amit Shah04950cd2010-09-02 18:20:58 +0530252static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
253 dev_t dev)
254{
255 struct port *port;
256 unsigned long flags;
257
258 spin_lock_irqsave(&portdev->ports_lock, flags);
259 list_for_each_entry(port, &portdev->ports, list)
Amit Shahd22a6982010-09-02 18:20:59 +0530260 if (port->cdev->dev == dev)
Amit Shah04950cd2010-09-02 18:20:58 +0530261 goto out;
262 port = NULL;
263out:
264 spin_unlock_irqrestore(&portdev->ports_lock, flags);
265
266 return port;
267}
268
269static struct port *find_port_by_devt(dev_t dev)
270{
271 struct ports_device *portdev;
272 struct port *port;
273 unsigned long flags;
274
275 spin_lock_irqsave(&pdrvdata_lock, flags);
276 list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
277 port = find_port_by_devt_in_portdev(portdev, dev);
278 if (port)
279 goto out;
280 }
281 port = NULL;
282out:
283 spin_unlock_irqrestore(&pdrvdata_lock, flags);
284 return port;
285}
286
Amit Shah17634ba2009-12-21 21:03:25 +0530287static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
288{
289 struct port *port;
290 unsigned long flags;
291
292 spin_lock_irqsave(&portdev->ports_lock, flags);
293 list_for_each_entry(port, &portdev->ports, list)
294 if (port->id == id)
295 goto out;
296 port = NULL;
297out:
298 spin_unlock_irqrestore(&portdev->ports_lock, flags);
299
300 return port;
301}
302
Amit Shah203baab2010-01-18 19:15:12 +0530303static struct port *find_port_by_vq(struct ports_device *portdev,
304 struct virtqueue *vq)
305{
306 struct port *port;
Amit Shah203baab2010-01-18 19:15:12 +0530307 unsigned long flags;
308
Amit Shah17634ba2009-12-21 21:03:25 +0530309 spin_lock_irqsave(&portdev->ports_lock, flags);
310 list_for_each_entry(port, &portdev->ports, list)
Amit Shah203baab2010-01-18 19:15:12 +0530311 if (port->in_vq == vq || port->out_vq == vq)
312 goto out;
Amit Shah203baab2010-01-18 19:15:12 +0530313 port = NULL;
314out:
Amit Shah17634ba2009-12-21 21:03:25 +0530315 spin_unlock_irqrestore(&portdev->ports_lock, flags);
Amit Shah203baab2010-01-18 19:15:12 +0530316 return port;
317}
318
Amit Shah17634ba2009-12-21 21:03:25 +0530319static bool is_console_port(struct port *port)
320{
321 if (port->cons.hvc)
322 return true;
323 return false;
324}
325
326static inline bool use_multiport(struct ports_device *portdev)
327{
328 /*
329 * This condition can be true when put_chars is called from
330 * early_init
331 */
332 if (!portdev->vdev)
333 return 0;
334 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
335}
336
Amit Shahfdb9a052010-01-18 19:15:01 +0530337static void free_buf(struct port_buffer *buf)
338{
339 kfree(buf->buf);
340 kfree(buf);
341}
342
343static struct port_buffer *alloc_buf(size_t buf_size)
344{
345 struct port_buffer *buf;
346
347 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
348 if (!buf)
349 goto fail;
350 buf->buf = kzalloc(buf_size, GFP_KERNEL);
351 if (!buf->buf)
352 goto free_buf;
353 buf->len = 0;
354 buf->offset = 0;
355 buf->size = buf_size;
356 return buf;
357
358free_buf:
359 kfree(buf);
360fail:
361 return NULL;
362}
363
Amit Shaha3cde442010-01-18 19:15:03 +0530364/* Callers should take appropriate locks */
Amit Shahdefde662011-09-14 13:06:42 +0530365static struct port_buffer *get_inbuf(struct port *port)
Amit Shaha3cde442010-01-18 19:15:03 +0530366{
367 struct port_buffer *buf;
Amit Shaha3cde442010-01-18 19:15:03 +0530368 unsigned int len;
369
Amit Shahd25a9dd2011-09-14 13:06:43 +0530370 if (port->inbuf)
371 return port->inbuf;
372
373 buf = virtqueue_get_buf(port->in_vq, &len);
Amit Shaha3cde442010-01-18 19:15:03 +0530374 if (buf) {
375 buf->len = len;
376 buf->offset = 0;
Amit Shah17e5b4f2011-09-14 13:06:46 +0530377 port->stats.bytes_received += len;
Amit Shaha3cde442010-01-18 19:15:03 +0530378 }
379 return buf;
380}
381
Rusty Russella23ea922010-01-18 19:14:55 +0530382/*
Amit Shahe27b5192010-01-18 19:15:02 +0530383 * Create a scatter-gather list representing our input buffer and put
384 * it in the queue.
385 *
386 * Callers should take appropriate locks.
387 */
Amit Shah203baab2010-01-18 19:15:12 +0530388static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
Amit Shahe27b5192010-01-18 19:15:02 +0530389{
390 struct scatterlist sg[1];
Amit Shah203baab2010-01-18 19:15:12 +0530391 int ret;
Amit Shah1c85bf32010-01-18 19:15:07 +0530392
Amit Shahe27b5192010-01-18 19:15:02 +0530393 sg_init_one(sg, buf->buf, buf->size);
394
Rusty Russellf96fde42012-01-12 15:44:42 +1030395 ret = virtqueue_add_buf(vq, sg, 0, 1, buf, GFP_ATOMIC);
Michael S. Tsirkin505b0452010-04-12 16:18:32 +0300396 virtqueue_kick(vq);
Amit Shah203baab2010-01-18 19:15:12 +0530397 return ret;
398}
399
Amit Shah88f251a2009-12-21 22:15:30 +0530400/* Discard any unread data this port has. Callers lockers. */
401static void discard_port_data(struct port *port)
402{
403 struct port_buffer *buf;
Amit Shah2d24cda2011-09-14 13:06:45 +0530404 unsigned int err;
Amit Shah88f251a2009-12-21 22:15:30 +0530405
Amit Shahd7a62cd2011-03-04 14:04:33 +1030406 if (!port->portdev) {
407 /* Device has been unplugged. vqs are already gone. */
408 return;
409 }
Amit Shah2d24cda2011-09-14 13:06:45 +0530410 buf = get_inbuf(port);
Amit Shah88f251a2009-12-21 22:15:30 +0530411
Amit Shahce072a02011-09-14 13:06:44 +0530412 err = 0;
Amit Shahd6933562010-02-12 10:32:18 +0530413 while (buf) {
Amit Shah17e5b4f2011-09-14 13:06:46 +0530414 port->stats.bytes_discarded += buf->len - buf->offset;
Amit Shah2d24cda2011-09-14 13:06:45 +0530415 if (add_inbuf(port->in_vq, buf) < 0) {
Amit Shahce072a02011-09-14 13:06:44 +0530416 err++;
Amit Shahd6933562010-02-12 10:32:18 +0530417 free_buf(buf);
418 }
Amit Shah2d24cda2011-09-14 13:06:45 +0530419 port->inbuf = NULL;
420 buf = get_inbuf(port);
Amit Shah88f251a2009-12-21 22:15:30 +0530421 }
Amit Shahce072a02011-09-14 13:06:44 +0530422 if (err)
Amit Shahd6933562010-02-12 10:32:18 +0530423 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
Amit Shahce072a02011-09-14 13:06:44 +0530424 err);
Amit Shah88f251a2009-12-21 22:15:30 +0530425}
426
Amit Shah203baab2010-01-18 19:15:12 +0530427static bool port_has_data(struct port *port)
428{
429 unsigned long flags;
430 bool ret;
431
Amit Shahd6933562010-02-12 10:32:18 +0530432 ret = false;
Amit Shahd25a9dd2011-09-14 13:06:43 +0530433 spin_lock_irqsave(&port->inbuf_lock, flags);
434 port->inbuf = get_inbuf(port);
435 if (port->inbuf)
436 ret = true;
437
Amit Shah203baab2010-01-18 19:15:12 +0530438 spin_unlock_irqrestore(&port->inbuf_lock, flags);
Amit Shah203baab2010-01-18 19:15:12 +0530439 return ret;
440}
441
Amit Shah3425e702010-05-19 22:15:46 -0600442static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
443 unsigned int event, unsigned int value)
Amit Shah17634ba2009-12-21 21:03:25 +0530444{
445 struct scatterlist sg[1];
446 struct virtio_console_control cpkt;
447 struct virtqueue *vq;
Amit Shah604b2ad2010-02-24 10:36:51 +0530448 unsigned int len;
Amit Shah17634ba2009-12-21 21:03:25 +0530449
Amit Shah3425e702010-05-19 22:15:46 -0600450 if (!use_multiport(portdev))
Amit Shah17634ba2009-12-21 21:03:25 +0530451 return 0;
452
Amit Shah3425e702010-05-19 22:15:46 -0600453 cpkt.id = port_id;
Amit Shah17634ba2009-12-21 21:03:25 +0530454 cpkt.event = event;
455 cpkt.value = value;
456
Amit Shah3425e702010-05-19 22:15:46 -0600457 vq = portdev->c_ovq;
Amit Shah17634ba2009-12-21 21:03:25 +0530458
459 sg_init_one(sg, &cpkt, sizeof(cpkt));
Rusty Russellf96fde42012-01-12 15:44:42 +1030460 if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt, GFP_ATOMIC) >= 0) {
Michael S. Tsirkin505b0452010-04-12 16:18:32 +0300461 virtqueue_kick(vq);
462 while (!virtqueue_get_buf(vq, &len))
Amit Shah17634ba2009-12-21 21:03:25 +0530463 cpu_relax();
464 }
465 return 0;
466}
467
Amit Shah3425e702010-05-19 22:15:46 -0600468static ssize_t send_control_msg(struct port *port, unsigned int event,
469 unsigned int value)
470{
Amit Shah84ec06c2010-09-02 18:11:42 +0530471 /* Did the port get unplugged before userspace closed it? */
472 if (port->portdev)
473 return __send_control_msg(port->portdev, port->id, event, value);
474 return 0;
Amit Shah3425e702010-05-19 22:15:46 -0600475}
476
Amit Shahcdfadfc2010-05-19 22:15:50 -0600477/* Callers must take the port->outvq_lock */
478static void reclaim_consumed_buffers(struct port *port)
479{
480 void *buf;
481 unsigned int len;
482
Amit Shahd7a62cd2011-03-04 14:04:33 +1030483 if (!port->portdev) {
484 /* Device has been unplugged. vqs are already gone. */
485 return;
486 }
Amit Shahcdfadfc2010-05-19 22:15:50 -0600487 while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
488 kfree(buf);
489 port->outvq_full = false;
490 }
491}
492
493static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count,
494 bool nonblock)
Amit Shahf997f00b2009-12-21 17:28:51 +0530495{
496 struct scatterlist sg[1];
497 struct virtqueue *out_vq;
498 ssize_t ret;
Amit Shahcdfadfc2010-05-19 22:15:50 -0600499 unsigned long flags;
Amit Shahf997f00b2009-12-21 17:28:51 +0530500 unsigned int len;
501
502 out_vq = port->out_vq;
503
Amit Shahcdfadfc2010-05-19 22:15:50 -0600504 spin_lock_irqsave(&port->outvq_lock, flags);
505
506 reclaim_consumed_buffers(port);
507
Amit Shahf997f00b2009-12-21 17:28:51 +0530508 sg_init_one(sg, in_buf, in_count);
Rusty Russellf96fde42012-01-12 15:44:42 +1030509 ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf, GFP_ATOMIC);
Amit Shahf997f00b2009-12-21 17:28:51 +0530510
511 /* Tell Host to go! */
Michael S. Tsirkin505b0452010-04-12 16:18:32 +0300512 virtqueue_kick(out_vq);
Amit Shahf997f00b2009-12-21 17:28:51 +0530513
514 if (ret < 0) {
Rusty Russell9ff4cfa2010-04-08 09:46:16 -0600515 in_count = 0;
Amit Shahcdfadfc2010-05-19 22:15:50 -0600516 goto done;
Amit Shahf997f00b2009-12-21 17:28:51 +0530517 }
518
Amit Shahcdfadfc2010-05-19 22:15:50 -0600519 if (ret == 0)
520 port->outvq_full = true;
521
522 if (nonblock)
523 goto done;
524
525 /*
526 * Wait till the host acknowledges it pushed out the data we
Amit Shah531295e2010-10-20 13:45:43 +1030527 * sent. This is done for data from the hvc_console; the tty
528 * operations are performed with spinlocks held so we can't
529 * sleep here. An alternative would be to copy the data to a
530 * buffer and relax the spinning requirement. The downside is
531 * we need to kmalloc a GFP_ATOMIC buffer each time the
532 * console driver writes something out.
Amit Shahcdfadfc2010-05-19 22:15:50 -0600533 */
Michael S. Tsirkin505b0452010-04-12 16:18:32 +0300534 while (!virtqueue_get_buf(out_vq, &len))
Amit Shahf997f00b2009-12-21 17:28:51 +0530535 cpu_relax();
Amit Shahcdfadfc2010-05-19 22:15:50 -0600536done:
537 spin_unlock_irqrestore(&port->outvq_lock, flags);
Amit Shah17e5b4f2011-09-14 13:06:46 +0530538
539 port->stats.bytes_sent += in_count;
Amit Shahcdfadfc2010-05-19 22:15:50 -0600540 /*
541 * We're expected to return the amount of data we wrote -- all
542 * of it
543 */
Rusty Russell9ff4cfa2010-04-08 09:46:16 -0600544 return in_count;
Amit Shahf997f00b2009-12-21 17:28:51 +0530545}
546
Amit Shah203baab2010-01-18 19:15:12 +0530547/*
548 * Give out the data that's requested from the buffer that we have
549 * queued up.
550 */
Amit Shahb766cee2009-12-21 21:26:45 +0530551static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
552 bool to_user)
Amit Shah203baab2010-01-18 19:15:12 +0530553{
554 struct port_buffer *buf;
555 unsigned long flags;
556
557 if (!out_count || !port_has_data(port))
558 return 0;
559
560 buf = port->inbuf;
Amit Shahb766cee2009-12-21 21:26:45 +0530561 out_count = min(out_count, buf->len - buf->offset);
Amit Shah203baab2010-01-18 19:15:12 +0530562
Amit Shahb766cee2009-12-21 21:26:45 +0530563 if (to_user) {
564 ssize_t ret;
Amit Shah203baab2010-01-18 19:15:12 +0530565
Amit Shahb766cee2009-12-21 21:26:45 +0530566 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
567 if (ret)
568 return -EFAULT;
569 } else {
570 memcpy(out_buf, buf->buf + buf->offset, out_count);
571 }
572
Amit Shah203baab2010-01-18 19:15:12 +0530573 buf->offset += out_count;
574
575 if (buf->offset == buf->len) {
576 /*
577 * We're done using all the data in this buffer.
578 * Re-queue so that the Host can send us more data.
579 */
580 spin_lock_irqsave(&port->inbuf_lock, flags);
581 port->inbuf = NULL;
582
583 if (add_inbuf(port->in_vq, buf) < 0)
Amit Shahfb08bd22009-12-21 21:36:04 +0530584 dev_warn(port->dev, "failed add_buf\n");
Amit Shah203baab2010-01-18 19:15:12 +0530585
586 spin_unlock_irqrestore(&port->inbuf_lock, flags);
587 }
Amit Shahb766cee2009-12-21 21:26:45 +0530588 /* Return the number of bytes actually copied */
Amit Shah203baab2010-01-18 19:15:12 +0530589 return out_count;
Amit Shahe27b5192010-01-18 19:15:02 +0530590}
591
Amit Shah2030fa42009-12-21 21:49:30 +0530592/* The condition that must be true for polling to end */
Amit Shah60caacd2010-05-19 22:15:49 -0600593static bool will_read_block(struct port *port)
Amit Shah2030fa42009-12-21 21:49:30 +0530594{
Amit Shah3709ea72010-09-02 18:11:43 +0530595 if (!port->guest_connected) {
596 /* Port got hot-unplugged. Let's exit. */
597 return false;
598 }
Amit Shah60caacd2010-05-19 22:15:49 -0600599 return !port_has_data(port) && port->host_connected;
Amit Shah2030fa42009-12-21 21:49:30 +0530600}
601
Amit Shahcdfadfc2010-05-19 22:15:50 -0600602static bool will_write_block(struct port *port)
603{
604 bool ret;
605
Amit Shah60e5e0b2010-05-27 13:24:40 +0530606 if (!port->guest_connected) {
607 /* Port got hot-unplugged. Let's exit. */
608 return false;
609 }
Amit Shahcdfadfc2010-05-19 22:15:50 -0600610 if (!port->host_connected)
611 return true;
612
613 spin_lock_irq(&port->outvq_lock);
614 /*
615 * Check if the Host has consumed any buffers since we last
616 * sent data (this is only applicable for nonblocking ports).
617 */
618 reclaim_consumed_buffers(port);
619 ret = port->outvq_full;
620 spin_unlock_irq(&port->outvq_lock);
621
622 return ret;
623}
624
Amit Shah2030fa42009-12-21 21:49:30 +0530625static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
626 size_t count, loff_t *offp)
627{
628 struct port *port;
629 ssize_t ret;
630
631 port = filp->private_data;
632
633 if (!port_has_data(port)) {
634 /*
635 * If nothing's connected on the host just return 0 in
636 * case of list_empty; this tells the userspace app
637 * that there's no connection
638 */
639 if (!port->host_connected)
640 return 0;
641 if (filp->f_flags & O_NONBLOCK)
642 return -EAGAIN;
643
Amit Shaha08fa922011-09-14 13:06:41 +0530644 ret = wait_event_freezable(port->waitqueue,
645 !will_read_block(port));
Amit Shah2030fa42009-12-21 21:49:30 +0530646 if (ret < 0)
647 return ret;
648 }
Amit Shahb3dddb92010-09-02 18:11:45 +0530649 /* Port got hot-unplugged. */
650 if (!port->guest_connected)
651 return -ENODEV;
Amit Shah2030fa42009-12-21 21:49:30 +0530652 /*
653 * We could've received a disconnection message while we were
654 * waiting for more data.
655 *
656 * This check is not clubbed in the if() statement above as we
657 * might receive some data as well as the host could get
658 * disconnected after we got woken up from our wait. So we
659 * really want to give off whatever data we have and only then
660 * check for host_connected.
661 */
662 if (!port_has_data(port) && !port->host_connected)
663 return 0;
664
665 return fill_readbuf(port, ubuf, count, true);
666}
667
668static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
669 size_t count, loff_t *offp)
670{
671 struct port *port;
672 char *buf;
673 ssize_t ret;
Amit Shahcdfadfc2010-05-19 22:15:50 -0600674 bool nonblock;
Amit Shah2030fa42009-12-21 21:49:30 +0530675
Amit Shah65745422010-09-14 13:26:16 +0530676 /* Userspace could be out to fool us */
677 if (!count)
678 return 0;
679
Amit Shah2030fa42009-12-21 21:49:30 +0530680 port = filp->private_data;
681
Amit Shahcdfadfc2010-05-19 22:15:50 -0600682 nonblock = filp->f_flags & O_NONBLOCK;
683
684 if (will_write_block(port)) {
685 if (nonblock)
686 return -EAGAIN;
687
Amit Shaha08fa922011-09-14 13:06:41 +0530688 ret = wait_event_freezable(port->waitqueue,
689 !will_write_block(port));
Amit Shahcdfadfc2010-05-19 22:15:50 -0600690 if (ret < 0)
691 return ret;
692 }
Amit Shahf4028112010-09-02 18:11:46 +0530693 /* Port got hot-unplugged. */
694 if (!port->guest_connected)
695 return -ENODEV;
Amit Shahcdfadfc2010-05-19 22:15:50 -0600696
Amit Shah2030fa42009-12-21 21:49:30 +0530697 count = min((size_t)(32 * 1024), count);
698
699 buf = kmalloc(count, GFP_KERNEL);
700 if (!buf)
701 return -ENOMEM;
702
703 ret = copy_from_user(buf, ubuf, count);
704 if (ret) {
705 ret = -EFAULT;
706 goto free_buf;
707 }
708
Amit Shah531295e2010-10-20 13:45:43 +1030709 /*
710 * We now ask send_buf() to not spin for generic ports -- we
711 * can re-use the same code path that non-blocking file
712 * descriptors take for blocking file descriptors since the
713 * wait is already done and we're certain the write will go
714 * through to the host.
715 */
716 nonblock = true;
Amit Shahcdfadfc2010-05-19 22:15:50 -0600717 ret = send_buf(port, buf, count, nonblock);
718
719 if (nonblock && ret > 0)
720 goto out;
721
Amit Shah2030fa42009-12-21 21:49:30 +0530722free_buf:
723 kfree(buf);
Amit Shahcdfadfc2010-05-19 22:15:50 -0600724out:
Amit Shah2030fa42009-12-21 21:49:30 +0530725 return ret;
726}
727
728static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
729{
730 struct port *port;
731 unsigned int ret;
732
733 port = filp->private_data;
734 poll_wait(filp, &port->waitqueue, wait);
735
Amit Shah8529a502010-09-02 18:11:44 +0530736 if (!port->guest_connected) {
737 /* Port got unplugged */
738 return POLLHUP;
739 }
Amit Shah2030fa42009-12-21 21:49:30 +0530740 ret = 0;
Hans de Goede6df7aad2010-09-16 14:43:08 +0530741 if (!will_read_block(port))
Amit Shah2030fa42009-12-21 21:49:30 +0530742 ret |= POLLIN | POLLRDNORM;
Amit Shahcdfadfc2010-05-19 22:15:50 -0600743 if (!will_write_block(port))
Amit Shah2030fa42009-12-21 21:49:30 +0530744 ret |= POLLOUT;
745 if (!port->host_connected)
746 ret |= POLLHUP;
747
748 return ret;
749}
750
Amit Shahb353a6b2010-09-02 18:38:29 +0530751static void remove_port(struct kref *kref);
752
Amit Shah2030fa42009-12-21 21:49:30 +0530753static int port_fops_release(struct inode *inode, struct file *filp)
754{
755 struct port *port;
756
757 port = filp->private_data;
758
759 /* Notify host of port being closed */
760 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
761
Amit Shah88f251a2009-12-21 22:15:30 +0530762 spin_lock_irq(&port->inbuf_lock);
Amit Shah3c7969c2009-11-26 11:25:38 +0530763 port->guest_connected = false;
764
Amit Shah88f251a2009-12-21 22:15:30 +0530765 discard_port_data(port);
766
767 spin_unlock_irq(&port->inbuf_lock);
768
Amit Shahcdfadfc2010-05-19 22:15:50 -0600769 spin_lock_irq(&port->outvq_lock);
770 reclaim_consumed_buffers(port);
771 spin_unlock_irq(&port->outvq_lock);
772
Amit Shahb353a6b2010-09-02 18:38:29 +0530773 /*
774 * Locks aren't necessary here as a port can't be opened after
775 * unplug, and if a port isn't unplugged, a kref would already
776 * exist for the port. Plus, taking ports_lock here would
777 * create a dependency on other locks taken by functions
778 * inside remove_port if we're the last holder of the port,
779 * creating many problems.
780 */
781 kref_put(&port->kref, remove_port);
782
Amit Shah2030fa42009-12-21 21:49:30 +0530783 return 0;
784}
785
786static int port_fops_open(struct inode *inode, struct file *filp)
787{
788 struct cdev *cdev = inode->i_cdev;
789 struct port *port;
Amit Shah8ad37e82010-09-02 18:11:48 +0530790 int ret;
Amit Shah2030fa42009-12-21 21:49:30 +0530791
Amit Shah04950cd2010-09-02 18:20:58 +0530792 port = find_port_by_devt(cdev->dev);
Amit Shah2030fa42009-12-21 21:49:30 +0530793 filp->private_data = port;
794
Amit Shahb353a6b2010-09-02 18:38:29 +0530795 /* Prevent against a port getting hot-unplugged at the same time */
796 spin_lock_irq(&port->portdev->ports_lock);
797 kref_get(&port->kref);
798 spin_unlock_irq(&port->portdev->ports_lock);
799
Amit Shah2030fa42009-12-21 21:49:30 +0530800 /*
801 * Don't allow opening of console port devices -- that's done
802 * via /dev/hvc
803 */
Amit Shah8ad37e82010-09-02 18:11:48 +0530804 if (is_console_port(port)) {
805 ret = -ENXIO;
806 goto out;
807 }
Amit Shah2030fa42009-12-21 21:49:30 +0530808
Amit Shah3c7969c2009-11-26 11:25:38 +0530809 /* Allow only one process to open a particular port at a time */
810 spin_lock_irq(&port->inbuf_lock);
811 if (port->guest_connected) {
812 spin_unlock_irq(&port->inbuf_lock);
Amit Shah8ad37e82010-09-02 18:11:48 +0530813 ret = -EMFILE;
814 goto out;
Amit Shah3c7969c2009-11-26 11:25:38 +0530815 }
816
817 port->guest_connected = true;
818 spin_unlock_irq(&port->inbuf_lock);
819
Amit Shahcdfadfc2010-05-19 22:15:50 -0600820 spin_lock_irq(&port->outvq_lock);
821 /*
822 * There might be a chance that we missed reclaiming a few
823 * buffers in the window of the port getting previously closed
824 * and opening now.
825 */
826 reclaim_consumed_buffers(port);
827 spin_unlock_irq(&port->outvq_lock);
828
Amit Shah299fb612010-09-16 14:43:09 +0530829 nonseekable_open(inode, filp);
830
Amit Shah2030fa42009-12-21 21:49:30 +0530831 /* Notify host of port being opened */
832 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
833
834 return 0;
Amit Shah8ad37e82010-09-02 18:11:48 +0530835out:
Amit Shahb353a6b2010-09-02 18:38:29 +0530836 kref_put(&port->kref, remove_port);
Amit Shah8ad37e82010-09-02 18:11:48 +0530837 return ret;
Amit Shah2030fa42009-12-21 21:49:30 +0530838}
839
Amit Shah3eae0ad2010-09-02 18:47:52 +0530840static int port_fops_fasync(int fd, struct file *filp, int mode)
841{
842 struct port *port;
843
844 port = filp->private_data;
845 return fasync_helper(fd, filp, mode, &port->async_queue);
846}
847
Amit Shah2030fa42009-12-21 21:49:30 +0530848/*
849 * The file operations that we support: programs in the guest can open
850 * a console device, read from it, write to it, poll for data and
851 * close it. The devices are at
852 * /dev/vport<device number>p<port number>
853 */
854static const struct file_operations port_fops = {
855 .owner = THIS_MODULE,
856 .open = port_fops_open,
857 .read = port_fops_read,
858 .write = port_fops_write,
859 .poll = port_fops_poll,
860 .release = port_fops_release,
Amit Shah3eae0ad2010-09-02 18:47:52 +0530861 .fasync = port_fops_fasync,
Amit Shah299fb612010-09-16 14:43:09 +0530862 .llseek = no_llseek,
Amit Shah2030fa42009-12-21 21:49:30 +0530863};
864
Amit Shahe27b5192010-01-18 19:15:02 +0530865/*
Rusty Russella23ea922010-01-18 19:14:55 +0530866 * The put_chars() callback is pretty straightforward.
Rusty Russell31610432007-10-22 11:03:39 +1000867 *
Rusty Russella23ea922010-01-18 19:14:55 +0530868 * We turn the characters into a scatter-gather list, add it to the
869 * output queue and then kick the Host. Then we sit here waiting for
870 * it to finish: inefficient in theory, but in practice
871 * implementations will do it immediately (lguest's Launcher does).
872 */
Rusty Russell31610432007-10-22 11:03:39 +1000873static int put_chars(u32 vtermno, const char *buf, int count)
874{
Rusty Russell21206ed2010-01-18 19:15:00 +0530875 struct port *port;
Amit Shah38edf582010-01-18 19:15:05 +0530876
François Diakhaté162a6892010-03-23 18:23:15 +0530877 if (unlikely(early_put_chars))
878 return early_put_chars(vtermno, buf, count);
879
Amit Shah38edf582010-01-18 19:15:05 +0530880 port = find_port_by_vtermno(vtermno);
881 if (!port)
Amit Shah6dc69f92010-05-19 22:15:47 -0600882 return -EPIPE;
Rusty Russell31610432007-10-22 11:03:39 +1000883
Amit Shahcdfadfc2010-05-19 22:15:50 -0600884 return send_buf(port, (void *)buf, count, false);
Rusty Russell31610432007-10-22 11:03:39 +1000885}
886
Rusty Russella23ea922010-01-18 19:14:55 +0530887/*
Rusty Russella23ea922010-01-18 19:14:55 +0530888 * get_chars() is the callback from the hvc_console infrastructure
889 * when an interrupt is received.
Rusty Russell31610432007-10-22 11:03:39 +1000890 *
Amit Shah203baab2010-01-18 19:15:12 +0530891 * We call out to fill_readbuf that gets us the required data from the
892 * buffers that are queued up.
Rusty Russella23ea922010-01-18 19:14:55 +0530893 */
Rusty Russell31610432007-10-22 11:03:39 +1000894static int get_chars(u32 vtermno, char *buf, int count)
895{
Rusty Russell21206ed2010-01-18 19:15:00 +0530896 struct port *port;
Rusty Russell31610432007-10-22 11:03:39 +1000897
Amit Shah6dc69f92010-05-19 22:15:47 -0600898 /* If we've not set up the port yet, we have no input to give. */
899 if (unlikely(early_put_chars))
900 return 0;
901
Amit Shah38edf582010-01-18 19:15:05 +0530902 port = find_port_by_vtermno(vtermno);
903 if (!port)
Amit Shah6dc69f92010-05-19 22:15:47 -0600904 return -EPIPE;
Rusty Russell21206ed2010-01-18 19:15:00 +0530905
906 /* If we don't have an input queue yet, we can't get input. */
907 BUG_ON(!port->in_vq);
908
Amit Shahb766cee2009-12-21 21:26:45 +0530909 return fill_readbuf(port, buf, count, false);
Rusty Russell31610432007-10-22 11:03:39 +1000910}
Rusty Russell31610432007-10-22 11:03:39 +1000911
Amit Shahcb06e362010-01-18 19:15:08 +0530912static void resize_console(struct port *port)
Christian Borntraegerc2983452008-11-25 13:36:26 +0100913{
Amit Shahcb06e362010-01-18 19:15:08 +0530914 struct virtio_device *vdev;
Christian Borntraegerc2983452008-11-25 13:36:26 +0100915
Amit Shah2de16a42010-03-19 17:36:44 +0530916 /* The port could have been hot-unplugged */
Amit Shah97788292010-05-06 02:05:08 +0530917 if (!port || !is_console_port(port))
Amit Shah2de16a42010-03-19 17:36:44 +0530918 return;
919
Amit Shahcb06e362010-01-18 19:15:08 +0530920 vdev = port->portdev->vdev;
Amit Shah97788292010-05-06 02:05:08 +0530921 if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
922 hvc_resize(port->cons.hvc, port->cons.ws);
Christian Borntraegerc2983452008-11-25 13:36:26 +0100923}
924
Amit Shah38edf582010-01-18 19:15:05 +0530925/* We set the configuration at this point, since we now have a tty */
Christian Borntraeger91fcad12008-06-20 15:24:15 +0200926static int notifier_add_vio(struct hvc_struct *hp, int data)
927{
Amit Shah38edf582010-01-18 19:15:05 +0530928 struct port *port;
929
930 port = find_port_by_vtermno(hp->vtermno);
931 if (!port)
932 return -EINVAL;
933
Christian Borntraeger91fcad12008-06-20 15:24:15 +0200934 hp->irq_requested = 1;
Amit Shahcb06e362010-01-18 19:15:08 +0530935 resize_console(port);
Christian Borntraegerc2983452008-11-25 13:36:26 +0100936
Christian Borntraeger91fcad12008-06-20 15:24:15 +0200937 return 0;
938}
939
940static void notifier_del_vio(struct hvc_struct *hp, int data)
941{
942 hp->irq_requested = 0;
943}
944
Amit Shah17634ba2009-12-21 21:03:25 +0530945/* The operations for console ports. */
Rusty Russell1dff3992009-11-28 12:20:26 +0530946static const struct hv_ops hv_ops = {
Rusty Russell971f3392010-01-18 19:14:56 +0530947 .get_chars = get_chars,
948 .put_chars = put_chars,
949 .notifier_add = notifier_add_vio,
950 .notifier_del = notifier_del_vio,
951 .notifier_hangup = notifier_del_vio,
952};
953
954/*
955 * Console drivers are initialized very early so boot messages can go
956 * out, so we do things slightly differently from the generic virtio
957 * initialization of the net and block drivers.
958 *
959 * At this stage, the console is output-only. It's too early to set
960 * up a virtqueue, so we let the drivers do some boutique early-output
961 * thing.
962 */
963int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
964{
965 early_put_chars = put_chars;
966 return hvc_instantiate(0, 0, &hv_ops);
967}
968
Amit Shah17634ba2009-12-21 21:03:25 +0530969int init_port_console(struct port *port)
Amit Shahcfa6d372010-01-18 19:15:10 +0530970{
971 int ret;
972
973 /*
974 * The Host's telling us this port is a console port. Hook it
975 * up with an hvc console.
976 *
977 * To set up and manage our virtual console, we call
978 * hvc_alloc().
979 *
980 * The first argument of hvc_alloc() is the virtual console
981 * number. The second argument is the parameter for the
982 * notification mechanism (like irq number). We currently
983 * leave this as zero, virtqueues have implicit notifications.
984 *
985 * The third argument is a "struct hv_ops" containing the
986 * put_chars() get_chars(), notifier_add() and notifier_del()
987 * pointers. The final argument is the output buffer size: we
988 * can do any size, so we put PAGE_SIZE here.
989 */
990 port->cons.vtermno = pdrvdata.next_vtermno;
991
992 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
993 if (IS_ERR(port->cons.hvc)) {
994 ret = PTR_ERR(port->cons.hvc);
Amit Shah298add72010-01-18 16:35:23 +0530995 dev_err(port->dev,
996 "error %d allocating hvc for port\n", ret);
Amit Shahcfa6d372010-01-18 19:15:10 +0530997 port->cons.hvc = NULL;
998 return ret;
999 }
1000 spin_lock_irq(&pdrvdata_lock);
1001 pdrvdata.next_vtermno++;
1002 list_add_tail(&port->cons.list, &pdrvdata.consoles);
1003 spin_unlock_irq(&pdrvdata_lock);
Amit Shah3c7969c2009-11-26 11:25:38 +05301004 port->guest_connected = true;
Amit Shahcfa6d372010-01-18 19:15:10 +05301005
Amit Shah1d051602010-05-19 22:15:49 -06001006 /*
1007 * Start using the new console output if this is the first
1008 * console to come up.
1009 */
1010 if (early_put_chars)
1011 early_put_chars = NULL;
1012
Amit Shah2030fa42009-12-21 21:49:30 +05301013 /* Notify host of port being opened */
1014 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1015
Amit Shahcfa6d372010-01-18 19:15:10 +05301016 return 0;
1017}
1018
Amit Shah431edb82009-12-21 21:57:40 +05301019static ssize_t show_port_name(struct device *dev,
1020 struct device_attribute *attr, char *buffer)
1021{
1022 struct port *port;
1023
1024 port = dev_get_drvdata(dev);
1025
1026 return sprintf(buffer, "%s\n", port->name);
1027}
1028
1029static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1030
1031static struct attribute *port_sysfs_entries[] = {
1032 &dev_attr_name.attr,
1033 NULL
1034};
1035
1036static struct attribute_group port_attribute_group = {
1037 .name = NULL, /* put in device directory */
1038 .attrs = port_sysfs_entries,
1039};
1040
Amit Shahd99393e2009-12-21 22:36:21 +05301041static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
1042 size_t count, loff_t *offp)
1043{
1044 struct port *port;
1045 char *buf;
1046 ssize_t ret, out_offset, out_count;
1047
1048 out_count = 1024;
1049 buf = kmalloc(out_count, GFP_KERNEL);
1050 if (!buf)
1051 return -ENOMEM;
1052
1053 port = filp->private_data;
1054 out_offset = 0;
1055 out_offset += snprintf(buf + out_offset, out_count,
1056 "name: %s\n", port->name ? port->name : "");
1057 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1058 "guest_connected: %d\n", port->guest_connected);
1059 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1060 "host_connected: %d\n", port->host_connected);
1061 out_offset += snprintf(buf + out_offset, out_count - out_offset,
Amit Shahcdfadfc2010-05-19 22:15:50 -06001062 "outvq_full: %d\n", port->outvq_full);
1063 out_offset += snprintf(buf + out_offset, out_count - out_offset,
Amit Shah17e5b4f2011-09-14 13:06:46 +05301064 "bytes_sent: %lu\n", port->stats.bytes_sent);
1065 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1066 "bytes_received: %lu\n",
1067 port->stats.bytes_received);
1068 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1069 "bytes_discarded: %lu\n",
1070 port->stats.bytes_discarded);
1071 out_offset += snprintf(buf + out_offset, out_count - out_offset,
Amit Shahd99393e2009-12-21 22:36:21 +05301072 "is_console: %s\n",
1073 is_console_port(port) ? "yes" : "no");
1074 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1075 "console_vtermno: %u\n", port->cons.vtermno);
1076
1077 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
1078 kfree(buf);
1079 return ret;
1080}
1081
1082static const struct file_operations port_debugfs_ops = {
1083 .owner = THIS_MODULE,
Stephen Boyd234e3402012-04-05 14:25:11 -07001084 .open = simple_open,
Amit Shahd99393e2009-12-21 22:36:21 +05301085 .read = debugfs_read,
1086};
1087
Amit Shah97788292010-05-06 02:05:08 +05301088static void set_console_size(struct port *port, u16 rows, u16 cols)
1089{
1090 if (!port || !is_console_port(port))
1091 return;
1092
1093 port->cons.ws.ws_row = rows;
1094 port->cons.ws.ws_col = cols;
1095}
1096
Amit Shahc446f8f2010-05-19 22:15:48 -06001097static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1098{
1099 struct port_buffer *buf;
1100 unsigned int nr_added_bufs;
1101 int ret;
1102
1103 nr_added_bufs = 0;
1104 do {
1105 buf = alloc_buf(PAGE_SIZE);
1106 if (!buf)
1107 break;
1108
1109 spin_lock_irq(lock);
1110 ret = add_inbuf(vq, buf);
1111 if (ret < 0) {
1112 spin_unlock_irq(lock);
1113 free_buf(buf);
1114 break;
1115 }
1116 nr_added_bufs++;
1117 spin_unlock_irq(lock);
1118 } while (ret > 0);
1119
1120 return nr_added_bufs;
1121}
1122
Amit Shah3eae0ad2010-09-02 18:47:52 +05301123static void send_sigio_to_port(struct port *port)
1124{
1125 if (port->async_queue && port->guest_connected)
1126 kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1127}
1128
Amit Shahc446f8f2010-05-19 22:15:48 -06001129static int add_port(struct ports_device *portdev, u32 id)
1130{
1131 char debugfs_name[16];
1132 struct port *port;
1133 struct port_buffer *buf;
1134 dev_t devt;
1135 unsigned int nr_added_bufs;
1136 int err;
1137
1138 port = kmalloc(sizeof(*port), GFP_KERNEL);
1139 if (!port) {
1140 err = -ENOMEM;
1141 goto fail;
1142 }
Amit Shahb353a6b2010-09-02 18:38:29 +05301143 kref_init(&port->kref);
Amit Shahc446f8f2010-05-19 22:15:48 -06001144
1145 port->portdev = portdev;
1146 port->id = id;
1147
1148 port->name = NULL;
1149 port->inbuf = NULL;
1150 port->cons.hvc = NULL;
Amit Shah3eae0ad2010-09-02 18:47:52 +05301151 port->async_queue = NULL;
Amit Shahc446f8f2010-05-19 22:15:48 -06001152
Amit Shah97788292010-05-06 02:05:08 +05301153 port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1154
Amit Shahc446f8f2010-05-19 22:15:48 -06001155 port->host_connected = port->guest_connected = false;
Amit Shah17e5b4f2011-09-14 13:06:46 +05301156 port->stats = (struct port_stats) { 0 };
Amit Shahc446f8f2010-05-19 22:15:48 -06001157
Amit Shahcdfadfc2010-05-19 22:15:50 -06001158 port->outvq_full = false;
1159
Amit Shahc446f8f2010-05-19 22:15:48 -06001160 port->in_vq = portdev->in_vqs[port->id];
1161 port->out_vq = portdev->out_vqs[port->id];
1162
Amit Shahd22a6982010-09-02 18:20:59 +05301163 port->cdev = cdev_alloc();
1164 if (!port->cdev) {
1165 dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1166 err = -ENOMEM;
1167 goto free_port;
1168 }
1169 port->cdev->ops = &port_fops;
Amit Shahc446f8f2010-05-19 22:15:48 -06001170
1171 devt = MKDEV(portdev->chr_major, id);
Amit Shahd22a6982010-09-02 18:20:59 +05301172 err = cdev_add(port->cdev, devt, 1);
Amit Shahc446f8f2010-05-19 22:15:48 -06001173 if (err < 0) {
1174 dev_err(&port->portdev->vdev->dev,
1175 "Error %d adding cdev for port %u\n", err, id);
Amit Shahd22a6982010-09-02 18:20:59 +05301176 goto free_cdev;
Amit Shahc446f8f2010-05-19 22:15:48 -06001177 }
1178 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1179 devt, port, "vport%up%u",
1180 port->portdev->drv_index, id);
1181 if (IS_ERR(port->dev)) {
1182 err = PTR_ERR(port->dev);
1183 dev_err(&port->portdev->vdev->dev,
1184 "Error %d creating device for port %u\n",
1185 err, id);
1186 goto free_cdev;
1187 }
1188
1189 spin_lock_init(&port->inbuf_lock);
Amit Shahcdfadfc2010-05-19 22:15:50 -06001190 spin_lock_init(&port->outvq_lock);
Amit Shahc446f8f2010-05-19 22:15:48 -06001191 init_waitqueue_head(&port->waitqueue);
1192
1193 /* Fill the in_vq with buffers so the host can send us data. */
1194 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1195 if (!nr_added_bufs) {
1196 dev_err(port->dev, "Error allocating inbufs\n");
1197 err = -ENOMEM;
1198 goto free_device;
1199 }
1200
1201 /*
1202 * If we're not using multiport support, this has to be a console port
1203 */
1204 if (!use_multiport(port->portdev)) {
1205 err = init_port_console(port);
1206 if (err)
1207 goto free_inbufs;
1208 }
1209
1210 spin_lock_irq(&portdev->ports_lock);
1211 list_add_tail(&port->list, &port->portdev->ports);
1212 spin_unlock_irq(&portdev->ports_lock);
1213
1214 /*
1215 * Tell the Host we're set so that it can send us various
1216 * configuration parameters for this port (eg, port name,
1217 * caching, whether this is a console port, etc.)
1218 */
1219 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1220
1221 if (pdrvdata.debugfs_dir) {
1222 /*
1223 * Finally, create the debugfs file that we can use to
1224 * inspect a port's state at any time
1225 */
1226 sprintf(debugfs_name, "vport%up%u",
1227 port->portdev->drv_index, id);
1228 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1229 pdrvdata.debugfs_dir,
1230 port,
1231 &port_debugfs_ops);
1232 }
1233 return 0;
1234
1235free_inbufs:
1236 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1237 free_buf(buf);
1238free_device:
1239 device_destroy(pdrvdata.class, port->dev->devt);
1240free_cdev:
Amit Shahd22a6982010-09-02 18:20:59 +05301241 cdev_del(port->cdev);
Amit Shahc446f8f2010-05-19 22:15:48 -06001242free_port:
1243 kfree(port);
1244fail:
1245 /* The host might want to notify management sw about port add failure */
Julia Lawall0643e4c2010-05-15 11:45:53 +02001246 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
Amit Shahc446f8f2010-05-19 22:15:48 -06001247 return err;
1248}
1249
Amit Shahb353a6b2010-09-02 18:38:29 +05301250/* No users remain, remove all port-specific data. */
1251static void remove_port(struct kref *kref)
1252{
1253 struct port *port;
1254
1255 port = container_of(kref, struct port, kref);
1256
1257 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1258 device_destroy(pdrvdata.class, port->dev->devt);
1259 cdev_del(port->cdev);
1260
1261 kfree(port->name);
1262
1263 debugfs_remove(port->debugfs_file);
1264
1265 kfree(port);
1266}
1267
Amit Shaha0e2dbf2011-12-22 16:58:27 +05301268static void remove_port_data(struct port *port)
1269{
1270 struct port_buffer *buf;
1271
1272 /* Remove unused data this port might have received. */
1273 discard_port_data(port);
1274
1275 reclaim_consumed_buffers(port);
1276
1277 /* Remove buffers we queued up for the Host to send us data in. */
1278 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1279 free_buf(buf);
1280}
1281
Amit Shahb353a6b2010-09-02 18:38:29 +05301282/*
1283 * Port got unplugged. Remove port from portdev's list and drop the
1284 * kref reference. If no userspace has this port opened, it will
1285 * result in immediate removal the port.
1286 */
1287static void unplug_port(struct port *port)
Amit Shah1f7aa422009-12-21 22:27:31 +05301288{
Amit Shahb353a6b2010-09-02 18:38:29 +05301289 spin_lock_irq(&port->portdev->ports_lock);
1290 list_del(&port->list);
1291 spin_unlock_irq(&port->portdev->ports_lock);
1292
Amit Shah00476342010-05-27 13:24:39 +05301293 if (port->guest_connected) {
1294 port->guest_connected = false;
1295 port->host_connected = false;
1296 wake_up_interruptible(&port->waitqueue);
Amit Shaha461e112010-09-02 18:47:54 +05301297
1298 /* Let the app know the port is going down. */
1299 send_sigio_to_port(port);
Amit Shah00476342010-05-27 13:24:39 +05301300 }
1301
Amit Shah1f7aa422009-12-21 22:27:31 +05301302 if (is_console_port(port)) {
1303 spin_lock_irq(&pdrvdata_lock);
1304 list_del(&port->cons.list);
1305 spin_unlock_irq(&pdrvdata_lock);
1306 hvc_remove(port->cons.hvc);
1307 }
Amit Shah1f7aa422009-12-21 22:27:31 +05301308
Amit Shaha0e2dbf2011-12-22 16:58:27 +05301309 remove_port_data(port);
Amit Shaha9cdd482010-02-12 10:32:15 +05301310
Amit Shahb353a6b2010-09-02 18:38:29 +05301311 /*
1312 * We should just assume the device itself has gone off --
1313 * else a close on an open port later will try to send out a
1314 * control message.
1315 */
1316 port->portdev = NULL;
Amit Shah1f7aa422009-12-21 22:27:31 +05301317
Amit Shahb353a6b2010-09-02 18:38:29 +05301318 /*
1319 * Locks around here are not necessary - a port can't be
1320 * opened after we removed the port struct from ports_list
1321 * above.
1322 */
1323 kref_put(&port->kref, remove_port);
Amit Shah1f7aa422009-12-21 22:27:31 +05301324}
1325
Amit Shah17634ba2009-12-21 21:03:25 +05301326/* Any private messages that the Host and Guest want to share */
1327static void handle_control_message(struct ports_device *portdev,
1328 struct port_buffer *buf)
1329{
1330 struct virtio_console_control *cpkt;
1331 struct port *port;
Amit Shah431edb82009-12-21 21:57:40 +05301332 size_t name_size;
1333 int err;
Amit Shah17634ba2009-12-21 21:03:25 +05301334
1335 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1336
1337 port = find_port_by_id(portdev, cpkt->id);
Amit Shahf909f852010-05-19 22:15:48 -06001338 if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) {
Amit Shah17634ba2009-12-21 21:03:25 +05301339 /* No valid header at start of buffer. Drop it. */
1340 dev_dbg(&portdev->vdev->dev,
1341 "Invalid index %u in control packet\n", cpkt->id);
1342 return;
1343 }
1344
1345 switch (cpkt->event) {
Amit Shahf909f852010-05-19 22:15:48 -06001346 case VIRTIO_CONSOLE_PORT_ADD:
1347 if (port) {
Amit Shah1d051602010-05-19 22:15:49 -06001348 dev_dbg(&portdev->vdev->dev,
1349 "Port %u already added\n", port->id);
Amit Shahf909f852010-05-19 22:15:48 -06001350 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1351 break;
1352 }
1353 if (cpkt->id >= portdev->config.max_nr_ports) {
1354 dev_warn(&portdev->vdev->dev,
1355 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1356 cpkt->id, portdev->config.max_nr_ports - 1);
1357 break;
1358 }
1359 add_port(portdev, cpkt->id);
1360 break;
1361 case VIRTIO_CONSOLE_PORT_REMOVE:
Amit Shahb353a6b2010-09-02 18:38:29 +05301362 unplug_port(port);
Amit Shahf909f852010-05-19 22:15:48 -06001363 break;
Amit Shah17634ba2009-12-21 21:03:25 +05301364 case VIRTIO_CONSOLE_CONSOLE_PORT:
1365 if (!cpkt->value)
1366 break;
1367 if (is_console_port(port))
1368 break;
1369
1370 init_port_console(port);
Christian Borntraeger5e384832011-09-22 23:44:23 +05301371 complete(&early_console_added);
Amit Shah17634ba2009-12-21 21:03:25 +05301372 /*
1373 * Could remove the port here in case init fails - but
1374 * have to notify the host first.
1375 */
1376 break;
Amit Shah8345adb2010-05-06 02:05:09 +05301377 case VIRTIO_CONSOLE_RESIZE: {
1378 struct {
1379 __u16 rows;
1380 __u16 cols;
1381 } size;
1382
Amit Shah17634ba2009-12-21 21:03:25 +05301383 if (!is_console_port(port))
1384 break;
Amit Shah8345adb2010-05-06 02:05:09 +05301385
1386 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1387 sizeof(size));
1388 set_console_size(port, size.rows, size.cols);
1389
Amit Shah17634ba2009-12-21 21:03:25 +05301390 port->cons.hvc->irq_requested = 1;
1391 resize_console(port);
1392 break;
Amit Shah8345adb2010-05-06 02:05:09 +05301393 }
Amit Shah2030fa42009-12-21 21:49:30 +05301394 case VIRTIO_CONSOLE_PORT_OPEN:
1395 port->host_connected = cpkt->value;
1396 wake_up_interruptible(&port->waitqueue);
Amit Shahcdfadfc2010-05-19 22:15:50 -06001397 /*
1398 * If the host port got closed and the host had any
1399 * unconsumed buffers, we'll be able to reclaim them
1400 * now.
1401 */
1402 spin_lock_irq(&port->outvq_lock);
1403 reclaim_consumed_buffers(port);
1404 spin_unlock_irq(&port->outvq_lock);
Amit Shah3eae0ad2010-09-02 18:47:52 +05301405
1406 /*
1407 * If the guest is connected, it'll be interested in
1408 * knowing the host connection state changed.
1409 */
1410 send_sigio_to_port(port);
Amit Shah2030fa42009-12-21 21:49:30 +05301411 break;
Amit Shah431edb82009-12-21 21:57:40 +05301412 case VIRTIO_CONSOLE_PORT_NAME:
1413 /*
Amit Shah291024e2011-09-14 13:06:40 +05301414 * If we woke up after hibernation, we can get this
1415 * again. Skip it in that case.
1416 */
1417 if (port->name)
1418 break;
1419
1420 /*
Amit Shah431edb82009-12-21 21:57:40 +05301421 * Skip the size of the header and the cpkt to get the size
1422 * of the name that was sent
1423 */
1424 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1425
1426 port->name = kmalloc(name_size, GFP_KERNEL);
1427 if (!port->name) {
1428 dev_err(port->dev,
1429 "Not enough space to store port name\n");
1430 break;
1431 }
1432 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1433 name_size - 1);
1434 port->name[name_size - 1] = 0;
1435
1436 /*
1437 * Since we only have one sysfs attribute, 'name',
1438 * create it only if we have a name for the port.
1439 */
1440 err = sysfs_create_group(&port->dev->kobj,
1441 &port_attribute_group);
Amit Shahec642132010-03-19 17:36:43 +05301442 if (err) {
Amit Shah431edb82009-12-21 21:57:40 +05301443 dev_err(port->dev,
1444 "Error %d creating sysfs device attributes\n",
1445 err);
Amit Shahec642132010-03-19 17:36:43 +05301446 } else {
1447 /*
1448 * Generate a udev event so that appropriate
1449 * symlinks can be created based on udev
1450 * rules.
1451 */
1452 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1453 }
Amit Shah431edb82009-12-21 21:57:40 +05301454 break;
Amit Shah17634ba2009-12-21 21:03:25 +05301455 }
1456}
1457
1458static void control_work_handler(struct work_struct *work)
1459{
1460 struct ports_device *portdev;
1461 struct virtqueue *vq;
1462 struct port_buffer *buf;
1463 unsigned int len;
1464
1465 portdev = container_of(work, struct ports_device, control_work);
1466 vq = portdev->c_ivq;
1467
1468 spin_lock(&portdev->cvq_lock);
Michael S. Tsirkin505b0452010-04-12 16:18:32 +03001469 while ((buf = virtqueue_get_buf(vq, &len))) {
Amit Shah17634ba2009-12-21 21:03:25 +05301470 spin_unlock(&portdev->cvq_lock);
1471
1472 buf->len = len;
1473 buf->offset = 0;
1474
1475 handle_control_message(portdev, buf);
1476
1477 spin_lock(&portdev->cvq_lock);
1478 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1479 dev_warn(&portdev->vdev->dev,
1480 "Error adding buffer to queue\n");
1481 free_buf(buf);
1482 }
1483 }
1484 spin_unlock(&portdev->cvq_lock);
1485}
1486
Amit Shah2770c5e2011-01-31 13:06:36 +05301487static void out_intr(struct virtqueue *vq)
1488{
1489 struct port *port;
1490
1491 port = find_port_by_vq(vq->vdev->priv, vq);
1492 if (!port)
1493 return;
1494
1495 wake_up_interruptible(&port->waitqueue);
1496}
1497
Amit Shah17634ba2009-12-21 21:03:25 +05301498static void in_intr(struct virtqueue *vq)
1499{
1500 struct port *port;
1501 unsigned long flags;
1502
1503 port = find_port_by_vq(vq->vdev->priv, vq);
1504 if (!port)
1505 return;
1506
1507 spin_lock_irqsave(&port->inbuf_lock, flags);
Amit Shahd25a9dd2011-09-14 13:06:43 +05301508 port->inbuf = get_inbuf(port);
Amit Shah17634ba2009-12-21 21:03:25 +05301509
Amit Shah88f251a2009-12-21 22:15:30 +05301510 /*
1511 * Don't queue up data when port is closed. This condition
1512 * can be reached when a console port is not yet connected (no
1513 * tty is spawned) and the host sends out data to console
1514 * ports. For generic serial ports, the host won't
1515 * (shouldn't) send data till the guest is connected.
1516 */
1517 if (!port->guest_connected)
1518 discard_port_data(port);
1519
Amit Shah17634ba2009-12-21 21:03:25 +05301520 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1521
Amit Shah2030fa42009-12-21 21:49:30 +05301522 wake_up_interruptible(&port->waitqueue);
1523
Amit Shah55f6bcc2010-09-02 18:47:53 +05301524 /* Send a SIGIO indicating new data in case the process asked for it */
1525 send_sigio_to_port(port);
1526
Amit Shah17634ba2009-12-21 21:03:25 +05301527 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1528 hvc_kick();
1529}
1530
1531static void control_intr(struct virtqueue *vq)
1532{
1533 struct ports_device *portdev;
1534
1535 portdev = vq->vdev->priv;
1536 schedule_work(&portdev->control_work);
1537}
1538
Amit Shah7f5d8102009-12-21 22:22:08 +05301539static void config_intr(struct virtio_device *vdev)
1540{
1541 struct ports_device *portdev;
1542
1543 portdev = vdev->priv;
Amit Shah99f905f2010-05-19 22:15:48 -06001544
Amit Shah4038f5b72010-05-06 02:05:07 +05301545 if (!use_multiport(portdev)) {
Amit Shah97788292010-05-06 02:05:08 +05301546 struct port *port;
1547 u16 rows, cols;
1548
1549 vdev->config->get(vdev,
1550 offsetof(struct virtio_console_config, cols),
1551 &cols, sizeof(u16));
1552 vdev->config->get(vdev,
1553 offsetof(struct virtio_console_config, rows),
1554 &rows, sizeof(u16));
1555
1556 port = find_port_by_id(portdev, 0);
1557 set_console_size(port, rows, cols);
1558
Amit Shah4038f5b72010-05-06 02:05:07 +05301559 /*
1560 * We'll use this way of resizing only for legacy
1561 * support. For newer userspace
1562 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1563 * to indicate console size changes so that it can be
1564 * done per-port.
1565 */
Amit Shah97788292010-05-06 02:05:08 +05301566 resize_console(port);
Amit Shah4038f5b72010-05-06 02:05:07 +05301567 }
Amit Shah7f5d8102009-12-21 22:22:08 +05301568}
1569
Amit Shah2658a792010-01-18 19:15:11 +05301570static int init_vqs(struct ports_device *portdev)
1571{
1572 vq_callback_t **io_callbacks;
1573 char **io_names;
1574 struct virtqueue **vqs;
Amit Shah17634ba2009-12-21 21:03:25 +05301575 u32 i, j, nr_ports, nr_queues;
Amit Shah2658a792010-01-18 19:15:11 +05301576 int err;
1577
Amit Shah17634ba2009-12-21 21:03:25 +05301578 nr_ports = portdev->config.max_nr_ports;
1579 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
Amit Shah2658a792010-01-18 19:15:11 +05301580
1581 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
Amit Shah2658a792010-01-18 19:15:11 +05301582 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
Amit Shah2658a792010-01-18 19:15:11 +05301583 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
Amit Shah2658a792010-01-18 19:15:11 +05301584 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1585 GFP_KERNEL);
Amit Shah2658a792010-01-18 19:15:11 +05301586 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1587 GFP_KERNEL);
Jiri Slaby22e132f2010-11-06 10:06:50 +01001588 if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
Amit Shah286f9a22011-09-14 13:06:39 +05301589 !portdev->out_vqs) {
Amit Shah2658a792010-01-18 19:15:11 +05301590 err = -ENOMEM;
Jiri Slaby22e132f2010-11-06 10:06:50 +01001591 goto free;
Amit Shah2658a792010-01-18 19:15:11 +05301592 }
1593
Amit Shah17634ba2009-12-21 21:03:25 +05301594 /*
1595 * For backward compat (newer host but older guest), the host
1596 * spawns a console port first and also inits the vqs for port
1597 * 0 before others.
1598 */
1599 j = 0;
1600 io_callbacks[j] = in_intr;
Amit Shah2770c5e2011-01-31 13:06:36 +05301601 io_callbacks[j + 1] = out_intr;
Amit Shah17634ba2009-12-21 21:03:25 +05301602 io_names[j] = "input";
1603 io_names[j + 1] = "output";
1604 j += 2;
Amit Shah2658a792010-01-18 19:15:11 +05301605
Amit Shah17634ba2009-12-21 21:03:25 +05301606 if (use_multiport(portdev)) {
1607 io_callbacks[j] = control_intr;
1608 io_callbacks[j + 1] = NULL;
1609 io_names[j] = "control-i";
1610 io_names[j + 1] = "control-o";
1611
1612 for (i = 1; i < nr_ports; i++) {
1613 j += 2;
1614 io_callbacks[j] = in_intr;
Amit Shah2770c5e2011-01-31 13:06:36 +05301615 io_callbacks[j + 1] = out_intr;
Amit Shah17634ba2009-12-21 21:03:25 +05301616 io_names[j] = "input";
1617 io_names[j + 1] = "output";
1618 }
1619 }
Amit Shah2658a792010-01-18 19:15:11 +05301620 /* Find the queues. */
1621 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1622 io_callbacks,
1623 (const char **)io_names);
1624 if (err)
Jiri Slaby22e132f2010-11-06 10:06:50 +01001625 goto free;
Amit Shah2658a792010-01-18 19:15:11 +05301626
Amit Shah17634ba2009-12-21 21:03:25 +05301627 j = 0;
Amit Shah2658a792010-01-18 19:15:11 +05301628 portdev->in_vqs[0] = vqs[0];
1629 portdev->out_vqs[0] = vqs[1];
Amit Shah17634ba2009-12-21 21:03:25 +05301630 j += 2;
1631 if (use_multiport(portdev)) {
1632 portdev->c_ivq = vqs[j];
1633 portdev->c_ovq = vqs[j + 1];
Amit Shah2658a792010-01-18 19:15:11 +05301634
Amit Shah17634ba2009-12-21 21:03:25 +05301635 for (i = 1; i < nr_ports; i++) {
1636 j += 2;
1637 portdev->in_vqs[i] = vqs[j];
1638 portdev->out_vqs[i] = vqs[j + 1];
1639 }
1640 }
Amit Shah2658a792010-01-18 19:15:11 +05301641 kfree(io_names);
Jiri Slaby22e132f2010-11-06 10:06:50 +01001642 kfree(io_callbacks);
Amit Shah2658a792010-01-18 19:15:11 +05301643 kfree(vqs);
1644
1645 return 0;
1646
Jiri Slaby22e132f2010-11-06 10:06:50 +01001647free:
Amit Shah2658a792010-01-18 19:15:11 +05301648 kfree(portdev->out_vqs);
Amit Shah2658a792010-01-18 19:15:11 +05301649 kfree(portdev->in_vqs);
Jiri Slaby22e132f2010-11-06 10:06:50 +01001650 kfree(io_names);
1651 kfree(io_callbacks);
Amit Shah2658a792010-01-18 19:15:11 +05301652 kfree(vqs);
Jiri Slaby22e132f2010-11-06 10:06:50 +01001653
Amit Shah2658a792010-01-18 19:15:11 +05301654 return err;
1655}
1656
Amit Shahfb08bd22009-12-21 21:36:04 +05301657static const struct file_operations portdev_fops = {
1658 .owner = THIS_MODULE,
1659};
1660
Amit Shaha0e2dbf2011-12-22 16:58:27 +05301661static void remove_vqs(struct ports_device *portdev)
1662{
1663 portdev->vdev->config->del_vqs(portdev->vdev);
1664 kfree(portdev->in_vqs);
1665 kfree(portdev->out_vqs);
1666}
1667
1668static void remove_controlq_data(struct ports_device *portdev)
1669{
1670 struct port_buffer *buf;
1671 unsigned int len;
1672
1673 if (!use_multiport(portdev))
1674 return;
1675
1676 while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1677 free_buf(buf);
1678
1679 while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1680 free_buf(buf);
1681}
1682
Amit Shah1c85bf32010-01-18 19:15:07 +05301683/*
1684 * Once we're further in boot, we get probed like any other virtio
1685 * device.
Amit Shah17634ba2009-12-21 21:03:25 +05301686 *
1687 * If the host also supports multiple console ports, we check the
1688 * config space to see how many ports the host has spawned. We
1689 * initialize each port found.
Amit Shah1c85bf32010-01-18 19:15:07 +05301690 */
1691static int __devinit virtcons_probe(struct virtio_device *vdev)
1692{
Amit Shah1c85bf32010-01-18 19:15:07 +05301693 struct ports_device *portdev;
1694 int err;
Amit Shah17634ba2009-12-21 21:03:25 +05301695 bool multiport;
Christian Borntraeger5e384832011-09-22 23:44:23 +05301696 bool early = early_put_chars != NULL;
1697
1698 /* Ensure to read early_put_chars now */
1699 barrier();
Amit Shah1c85bf32010-01-18 19:15:07 +05301700
1701 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1702 if (!portdev) {
1703 err = -ENOMEM;
1704 goto fail;
1705 }
1706
1707 /* Attach this portdev to this virtio_device, and vice-versa. */
1708 portdev->vdev = vdev;
1709 vdev->priv = portdev;
1710
Amit Shahfb08bd22009-12-21 21:36:04 +05301711 spin_lock_irq(&pdrvdata_lock);
1712 portdev->drv_index = pdrvdata.index++;
1713 spin_unlock_irq(&pdrvdata_lock);
1714
1715 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
1716 &portdev_fops);
1717 if (portdev->chr_major < 0) {
1718 dev_err(&vdev->dev,
1719 "Error %d registering chrdev for device %u\n",
1720 portdev->chr_major, portdev->drv_index);
1721 err = portdev->chr_major;
1722 goto free;
1723 }
1724
Amit Shah17634ba2009-12-21 21:03:25 +05301725 multiport = false;
Amit Shah17634ba2009-12-21 21:03:25 +05301726 portdev->config.max_nr_ports = 1;
Sasha Levin51c6d612011-08-14 17:52:31 +03001727 if (virtio_config_val(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
1728 offsetof(struct virtio_console_config,
1729 max_nr_ports),
1730 &portdev->config.max_nr_ports) == 0)
Amit Shah17634ba2009-12-21 21:03:25 +05301731 multiport = true;
Amit Shah17634ba2009-12-21 21:03:25 +05301732
Amit Shah2658a792010-01-18 19:15:11 +05301733 err = init_vqs(portdev);
1734 if (err < 0) {
1735 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
Amit Shahfb08bd22009-12-21 21:36:04 +05301736 goto free_chrdev;
Amit Shah2658a792010-01-18 19:15:11 +05301737 }
Amit Shah1c85bf32010-01-18 19:15:07 +05301738
Amit Shah17634ba2009-12-21 21:03:25 +05301739 spin_lock_init(&portdev->ports_lock);
1740 INIT_LIST_HEAD(&portdev->ports);
1741
1742 if (multiport) {
Amit Shah335a64a5c2010-02-24 10:37:44 +05301743 unsigned int nr_added_bufs;
1744
Amit Shah17634ba2009-12-21 21:03:25 +05301745 spin_lock_init(&portdev->cvq_lock);
1746 INIT_WORK(&portdev->control_work, &control_work_handler);
1747
Amit Shah335a64a5c2010-02-24 10:37:44 +05301748 nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1749 if (!nr_added_bufs) {
Amit Shah22a29ea2010-02-12 10:32:17 +05301750 dev_err(&vdev->dev,
1751 "Error allocating buffers for control queue\n");
1752 err = -ENOMEM;
1753 goto free_vqs;
1754 }
Amit Shah1d051602010-05-19 22:15:49 -06001755 } else {
1756 /*
1757 * For backward compatibility: Create a console port
1758 * if we're running on older host.
1759 */
1760 add_port(portdev, 0);
Amit Shah17634ba2009-12-21 21:03:25 +05301761 }
1762
Amit Shah6bdf2af2010-09-02 18:11:49 +05301763 spin_lock_irq(&pdrvdata_lock);
1764 list_add_tail(&portdev->list, &pdrvdata.portdevs);
1765 spin_unlock_irq(&pdrvdata_lock);
1766
Amit Shahf909f852010-05-19 22:15:48 -06001767 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1768 VIRTIO_CONSOLE_DEVICE_READY, 1);
Christian Borntraeger5e384832011-09-22 23:44:23 +05301769
1770 /*
1771 * If there was an early virtio console, assume that there are no
1772 * other consoles. We need to wait until the hvc_alloc matches the
1773 * hvc_instantiate, otherwise tty_open will complain, resulting in
1774 * a "Warning: unable to open an initial console" boot failure.
1775 * Without multiport this is done in add_port above. With multiport
1776 * this might take some host<->guest communication - thus we have to
1777 * wait.
1778 */
1779 if (multiport && early)
1780 wait_for_completion(&early_console_added);
1781
Rusty Russell31610432007-10-22 11:03:39 +10001782 return 0;
1783
Amit Shah22a29ea2010-02-12 10:32:17 +05301784free_vqs:
Julia Lawall0643e4c2010-05-15 11:45:53 +02001785 /* The host might want to notify mgmt sw about device add failure */
1786 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
1787 VIRTIO_CONSOLE_DEVICE_READY, 0);
Amit Shaha0e2dbf2011-12-22 16:58:27 +05301788 remove_vqs(portdev);
Amit Shahfb08bd22009-12-21 21:36:04 +05301789free_chrdev:
1790 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
Rusty Russell31610432007-10-22 11:03:39 +10001791free:
Amit Shah1c85bf32010-01-18 19:15:07 +05301792 kfree(portdev);
Rusty Russell31610432007-10-22 11:03:39 +10001793fail:
1794 return err;
1795}
1796
Amit Shah71778762010-02-12 10:32:16 +05301797static void virtcons_remove(struct virtio_device *vdev)
1798{
1799 struct ports_device *portdev;
1800 struct port *port, *port2;
Amit Shah71778762010-02-12 10:32:16 +05301801
1802 portdev = vdev->priv;
1803
Amit Shah6bdf2af2010-09-02 18:11:49 +05301804 spin_lock_irq(&pdrvdata_lock);
1805 list_del(&portdev->list);
1806 spin_unlock_irq(&pdrvdata_lock);
1807
Amit Shah02238952010-09-02 18:11:40 +05301808 /* Disable interrupts for vqs */
1809 vdev->config->reset(vdev);
1810 /* Finish up work that's lined up */
Amit Shah71778762010-02-12 10:32:16 +05301811 cancel_work_sync(&portdev->control_work);
Amit Shah71778762010-02-12 10:32:16 +05301812
1813 list_for_each_entry_safe(port, port2, &portdev->ports, list)
Amit Shahb353a6b2010-09-02 18:38:29 +05301814 unplug_port(port);
Amit Shah71778762010-02-12 10:32:16 +05301815
1816 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
1817
Amit Shahe0620132010-09-02 18:38:30 +05301818 /*
1819 * When yanking out a device, we immediately lose the
1820 * (device-side) queues. So there's no point in keeping the
1821 * guest side around till we drop our final reference. This
1822 * also means that any ports which are in an open state will
1823 * have to just stop using the port, as the vqs are going
1824 * away.
1825 */
Amit Shaha0e2dbf2011-12-22 16:58:27 +05301826 remove_controlq_data(portdev);
1827 remove_vqs(portdev);
Amit Shah71778762010-02-12 10:32:16 +05301828 kfree(portdev);
1829}
1830
Rusty Russell31610432007-10-22 11:03:39 +10001831static struct virtio_device_id id_table[] = {
1832 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
1833 { 0 },
1834};
1835
Christian Borntraegerc2983452008-11-25 13:36:26 +01001836static unsigned int features[] = {
1837 VIRTIO_CONSOLE_F_SIZE,
Amit Shahb99fa812010-05-19 22:15:46 -06001838 VIRTIO_CONSOLE_F_MULTIPORT,
Christian Borntraegerc2983452008-11-25 13:36:26 +01001839};
1840
Amit Shah2b8f41d2011-12-22 16:58:28 +05301841#ifdef CONFIG_PM
1842static int virtcons_freeze(struct virtio_device *vdev)
1843{
1844 struct ports_device *portdev;
1845 struct port *port;
1846
1847 portdev = vdev->priv;
1848
1849 vdev->config->reset(vdev);
1850
Amit Shahc743d092012-01-06 16:19:08 +05301851 virtqueue_disable_cb(portdev->c_ivq);
Amit Shah2b8f41d2011-12-22 16:58:28 +05301852 cancel_work_sync(&portdev->control_work);
Amit Shahc743d092012-01-06 16:19:08 +05301853 /*
1854 * Once more: if control_work_handler() was running, it would
1855 * enable the cb as the last step.
1856 */
1857 virtqueue_disable_cb(portdev->c_ivq);
Amit Shah2b8f41d2011-12-22 16:58:28 +05301858 remove_controlq_data(portdev);
1859
1860 list_for_each_entry(port, &portdev->ports, list) {
Amit Shahc743d092012-01-06 16:19:08 +05301861 virtqueue_disable_cb(port->in_vq);
1862 virtqueue_disable_cb(port->out_vq);
Amit Shah2b8f41d2011-12-22 16:58:28 +05301863 /*
1864 * We'll ask the host later if the new invocation has
1865 * the port opened or closed.
1866 */
1867 port->host_connected = false;
1868 remove_port_data(port);
1869 }
1870 remove_vqs(portdev);
1871
1872 return 0;
1873}
1874
1875static int virtcons_restore(struct virtio_device *vdev)
1876{
1877 struct ports_device *portdev;
1878 struct port *port;
1879 int ret;
1880
1881 portdev = vdev->priv;
1882
1883 ret = init_vqs(portdev);
1884 if (ret)
1885 return ret;
1886
1887 if (use_multiport(portdev))
1888 fill_queue(portdev->c_ivq, &portdev->cvq_lock);
1889
1890 list_for_each_entry(port, &portdev->ports, list) {
1891 port->in_vq = portdev->in_vqs[port->id];
1892 port->out_vq = portdev->out_vqs[port->id];
1893
1894 fill_queue(port->in_vq, &port->inbuf_lock);
1895
1896 /* Get port open/close status on the host */
1897 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
Amit Shahfa8b66c2012-04-25 14:40:39 +05301898
1899 /*
1900 * If a port was open at the time of suspending, we
1901 * have to let the host know that it's still open.
1902 */
1903 if (port->guest_connected)
1904 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
Amit Shah2b8f41d2011-12-22 16:58:28 +05301905 }
1906 return 0;
1907}
1908#endif
1909
Rusty Russell31610432007-10-22 11:03:39 +10001910static struct virtio_driver virtio_console = {
Christian Borntraegerc2983452008-11-25 13:36:26 +01001911 .feature_table = features,
1912 .feature_table_size = ARRAY_SIZE(features),
Rusty Russell31610432007-10-22 11:03:39 +10001913 .driver.name = KBUILD_MODNAME,
1914 .driver.owner = THIS_MODULE,
1915 .id_table = id_table,
1916 .probe = virtcons_probe,
Amit Shah71778762010-02-12 10:32:16 +05301917 .remove = virtcons_remove,
Amit Shah7f5d8102009-12-21 22:22:08 +05301918 .config_changed = config_intr,
Amit Shah2b8f41d2011-12-22 16:58:28 +05301919#ifdef CONFIG_PM
1920 .freeze = virtcons_freeze,
1921 .restore = virtcons_restore,
1922#endif
Rusty Russell31610432007-10-22 11:03:39 +10001923};
1924
1925static int __init init(void)
1926{
Amit Shahfb08bd22009-12-21 21:36:04 +05301927 int err;
1928
1929 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
1930 if (IS_ERR(pdrvdata.class)) {
1931 err = PTR_ERR(pdrvdata.class);
1932 pr_err("Error %d creating virtio-ports class\n", err);
1933 return err;
1934 }
Amit Shahd99393e2009-12-21 22:36:21 +05301935
1936 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
1937 if (!pdrvdata.debugfs_dir) {
1938 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1939 PTR_ERR(pdrvdata.debugfs_dir));
1940 }
Amit Shah38edf582010-01-18 19:15:05 +05301941 INIT_LIST_HEAD(&pdrvdata.consoles);
Amit Shah6bdf2af2010-09-02 18:11:49 +05301942 INIT_LIST_HEAD(&pdrvdata.portdevs);
Amit Shah38edf582010-01-18 19:15:05 +05301943
Rusty Russell31610432007-10-22 11:03:39 +10001944 return register_virtio_driver(&virtio_console);
1945}
Amit Shah71778762010-02-12 10:32:16 +05301946
1947static void __exit fini(void)
1948{
1949 unregister_virtio_driver(&virtio_console);
1950
1951 class_destroy(pdrvdata.class);
1952 if (pdrvdata.debugfs_dir)
1953 debugfs_remove_recursive(pdrvdata.debugfs_dir);
1954}
Rusty Russell31610432007-10-22 11:03:39 +10001955module_init(init);
Amit Shah71778762010-02-12 10:32:16 +05301956module_exit(fini);
Rusty Russell31610432007-10-22 11:03:39 +10001957
1958MODULE_DEVICE_TABLE(virtio, id_table);
1959MODULE_DESCRIPTION("Virtio console driver");
1960MODULE_LICENSE("GPL");