2 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
3 * Copyright (C) 2009, 2010 Red Hat, Inc.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 #include <linux/cdev.h>
20 #include <linux/debugfs.h>
21 #include <linux/device.h>
22 #include <linux/err.h>
24 #include <linux/init.h>
25 #include <linux/list.h>
26 #include <linux/poll.h>
27 #include <linux/sched.h>
28 #include <linux/slab.h>
29 #include <linux/spinlock.h>
30 #include <linux/virtio.h>
31 #include <linux/virtio_console.h>
32 #include <linux/wait.h>
33 #include <linux/workqueue.h>
34 #include "hvc_console.h"
37 * This is a global struct for storing common data for all the devices
38 * this driver handles.
40 * Mainly, it has a linked list for all the consoles in one place so
41 * that callbacks from hvc for get_chars(), put_chars() work properly
42 * across multiple devices and multiple ports per device.
44 struct ports_driver_data
{
45 /* Used for registering chardevs */
48 /* Used for exporting per-port information to debugfs */
49 struct dentry
*debugfs_dir
;
51 /* Number of devices this driver is handling */
55 * This is used to keep track of the number of hvc consoles
56 * spawned by this driver. This number is given as the first
57 * argument to hvc_alloc(). To correctly map an initial
58 * console spawned via hvc_instantiate to the console being
59 * hooked up via hvc_alloc, we need to pass the same vtermno.
61 * We also just assume the first console being initialised was
62 * the first one that got used as the initial console.
64 unsigned int next_vtermno
;
66 /* All the console devices handled by this driver */
67 struct list_head consoles
;
69 static struct ports_driver_data pdrvdata
;
71 DEFINE_SPINLOCK(pdrvdata_lock
);
73 /* This struct holds information that's relevant only for console ports */
75 /* We'll place all consoles in a list in the pdrvdata struct */
76 struct list_head list
;
78 /* The hvc device associated with this console port */
79 struct hvc_struct
*hvc
;
81 /* The size of the console */
85 * This number identifies the number that we used to register
86 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
87 * number passed on by the hvc callbacks to us to
88 * differentiate between the other console ports handled by
97 /* size of the buffer in *buf above */
100 /* used length of the buffer */
102 /* offset in the buf from which to consume data */
107 * This is a per-device struct that stores data common to all the
108 * ports for that device (vdev->priv).
110 struct ports_device
{
112 * Workqueue handlers where we process deferred work after
115 struct work_struct control_work
;
117 struct list_head ports
;
119 /* To protect the list of ports */
120 spinlock_t ports_lock
;
122 /* To protect the vq operations for the control channel */
125 /* The current config space is stored here */
126 struct virtio_console_config config
;
128 /* The virtio device we're associated with */
129 struct virtio_device
*vdev
;
132 * A couple of virtqueues for the control channel: one for
133 * guest->host transfers, one for host->guest transfers
135 struct virtqueue
*c_ivq
, *c_ovq
;
137 /* Array of per-port IO virtqueues */
138 struct virtqueue
**in_vqs
, **out_vqs
;
140 /* Used for numbering devices for sysfs and debugfs */
141 unsigned int drv_index
;
143 /* Major number for this device. Ports will be created as minors. */
147 /* This struct holds the per-port data */
149 /* Next port in the list, head is in the ports_device */
150 struct list_head list
;
152 /* Pointer to the parent virtio_console device */
153 struct ports_device
*portdev
;
155 /* The current buffer from which data has to be fed to readers */
156 struct port_buffer
*inbuf
;
159 * To protect the operations on the in_vq associated with this
160 * port. Has to be a spinlock because it can be called from
161 * interrupt context (get_char()).
163 spinlock_t inbuf_lock
;
165 /* Protect the operations on the out_vq. */
166 spinlock_t outvq_lock
;
168 /* The IO vqs for this port */
169 struct virtqueue
*in_vq
, *out_vq
;
171 /* File in the debugfs directory that exposes this port's information */
172 struct dentry
*debugfs_file
;
175 * The entries in this struct will be valid if this port is
176 * hooked up to an hvc console
180 /* Each port associates with a separate char device */
184 /* A waitqueue for poll() or blocking read operations */
185 wait_queue_head_t waitqueue
;
187 /* The 'name' of the port that we expose via sysfs properties */
190 /* The 'id' to identify the port with the Host */
195 /* Is the host device open */
198 /* We should allow only one process to open a port */
199 bool guest_connected
;
202 /* This is the very early arch-specified put chars function. */
203 static int (*early_put_chars
)(u32
, const char *, int);
205 static struct port
*find_port_by_vtermno(u32 vtermno
)
208 struct console
*cons
;
211 spin_lock_irqsave(&pdrvdata_lock
, flags
);
212 list_for_each_entry(cons
, &pdrvdata
.consoles
, list
) {
213 if (cons
->vtermno
== vtermno
) {
214 port
= container_of(cons
, struct port
, cons
);
220 spin_unlock_irqrestore(&pdrvdata_lock
, flags
);
224 static struct port
*find_port_by_id(struct ports_device
*portdev
, u32 id
)
229 spin_lock_irqsave(&portdev
->ports_lock
, flags
);
230 list_for_each_entry(port
, &portdev
->ports
, list
)
235 spin_unlock_irqrestore(&portdev
->ports_lock
, flags
);
240 static struct port
*find_port_by_vq(struct ports_device
*portdev
,
241 struct virtqueue
*vq
)
246 spin_lock_irqsave(&portdev
->ports_lock
, flags
);
247 list_for_each_entry(port
, &portdev
->ports
, list
)
248 if (port
->in_vq
== vq
|| port
->out_vq
== vq
)
252 spin_unlock_irqrestore(&portdev
->ports_lock
, flags
);
256 static bool is_console_port(struct port
*port
)
263 static inline bool use_multiport(struct ports_device
*portdev
)
266 * This condition can be true when put_chars is called from
271 return portdev
->vdev
->features
[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT
);
274 static void free_buf(struct port_buffer
*buf
)
280 static struct port_buffer
*alloc_buf(size_t buf_size
)
282 struct port_buffer
*buf
;
284 buf
= kmalloc(sizeof(*buf
), GFP_KERNEL
);
287 buf
->buf
= kzalloc(buf_size
, GFP_KERNEL
);
292 buf
->size
= buf_size
;
301 /* Callers should take appropriate locks */
302 static void *get_inbuf(struct port
*port
)
304 struct port_buffer
*buf
;
305 struct virtqueue
*vq
;
309 buf
= virtqueue_get_buf(vq
, &len
);
318 * Create a scatter-gather list representing our input buffer and put
321 * Callers should take appropriate locks.
323 static int add_inbuf(struct virtqueue
*vq
, struct port_buffer
*buf
)
325 struct scatterlist sg
[1];
328 sg_init_one(sg
, buf
->buf
, buf
->size
);
330 ret
= virtqueue_add_buf(vq
, sg
, 0, 1, buf
);
335 /* Discard any unread data this port has. Callers lockers. */
336 static void discard_port_data(struct port
*port
)
338 struct port_buffer
*buf
;
339 struct virtqueue
*vq
;
347 buf
= virtqueue_get_buf(vq
, &len
);
351 if (add_inbuf(vq
, buf
) < 0) {
355 buf
= virtqueue_get_buf(vq
, &len
);
359 dev_warn(port
->dev
, "Errors adding %d buffers back to vq\n",
363 static bool port_has_data(struct port
*port
)
368 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
373 port
->inbuf
= get_inbuf(port
);
380 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
384 static ssize_t
__send_control_msg(struct ports_device
*portdev
, u32 port_id
,
385 unsigned int event
, unsigned int value
)
387 struct scatterlist sg
[1];
388 struct virtio_console_control cpkt
;
389 struct virtqueue
*vq
;
392 if (!use_multiport(portdev
))
401 sg_init_one(sg
, &cpkt
, sizeof(cpkt
));
402 if (virtqueue_add_buf(vq
, sg
, 1, 0, &cpkt
) >= 0) {
404 while (!virtqueue_get_buf(vq
, &len
))
410 static ssize_t
send_control_msg(struct port
*port
, unsigned int event
,
413 return __send_control_msg(port
->portdev
, port
->id
, event
, value
);
416 /* Callers must take the port->outvq_lock */
417 static void reclaim_consumed_buffers(struct port
*port
)
422 while ((buf
= virtqueue_get_buf(port
->out_vq
, &len
))) {
424 port
->outvq_full
= false;
428 static ssize_t
send_buf(struct port
*port
, void *in_buf
, size_t in_count
,
431 struct scatterlist sg
[1];
432 struct virtqueue
*out_vq
;
437 out_vq
= port
->out_vq
;
439 spin_lock_irqsave(&port
->outvq_lock
, flags
);
441 reclaim_consumed_buffers(port
);
443 sg_init_one(sg
, in_buf
, in_count
);
444 ret
= virtqueue_add_buf(out_vq
, sg
, 1, 0, in_buf
);
446 /* Tell Host to go! */
447 virtqueue_kick(out_vq
);
455 port
->outvq_full
= true;
461 * Wait till the host acknowledges it pushed out the data we
462 * sent. This is done for data from the hvc_console; the tty
463 * operations are performed with spinlocks held so we can't
464 * sleep here. An alternative would be to copy the data to a
465 * buffer and relax the spinning requirement. The downside is
466 * we need to kmalloc a GFP_ATOMIC buffer each time the
467 * console driver writes something out.
469 while (!virtqueue_get_buf(out_vq
, &len
))
472 spin_unlock_irqrestore(&port
->outvq_lock
, flags
);
474 * We're expected to return the amount of data we wrote -- all
481 * Give out the data that's requested from the buffer that we have
484 static ssize_t
fill_readbuf(struct port
*port
, char *out_buf
, size_t out_count
,
487 struct port_buffer
*buf
;
490 if (!out_count
|| !port_has_data(port
))
494 out_count
= min(out_count
, buf
->len
- buf
->offset
);
499 ret
= copy_to_user(out_buf
, buf
->buf
+ buf
->offset
, out_count
);
503 memcpy(out_buf
, buf
->buf
+ buf
->offset
, out_count
);
506 buf
->offset
+= out_count
;
508 if (buf
->offset
== buf
->len
) {
510 * We're done using all the data in this buffer.
511 * Re-queue so that the Host can send us more data.
513 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
516 if (add_inbuf(port
->in_vq
, buf
) < 0)
517 dev_warn(port
->dev
, "failed add_buf\n");
519 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
521 /* Return the number of bytes actually copied */
525 /* The condition that must be true for polling to end */
526 static bool will_read_block(struct port
*port
)
528 return !port_has_data(port
) && port
->host_connected
;
531 static bool will_write_block(struct port
*port
)
535 if (!port
->guest_connected
) {
536 /* Port got hot-unplugged. Let's exit. */
539 if (!port
->host_connected
)
542 spin_lock_irq(&port
->outvq_lock
);
544 * Check if the Host has consumed any buffers since we last
545 * sent data (this is only applicable for nonblocking ports).
547 reclaim_consumed_buffers(port
);
548 ret
= port
->outvq_full
;
549 spin_unlock_irq(&port
->outvq_lock
);
554 static ssize_t
port_fops_read(struct file
*filp
, char __user
*ubuf
,
555 size_t count
, loff_t
*offp
)
560 port
= filp
->private_data
;
562 if (!port_has_data(port
)) {
564 * If nothing's connected on the host just return 0 in
565 * case of list_empty; this tells the userspace app
566 * that there's no connection
568 if (!port
->host_connected
)
570 if (filp
->f_flags
& O_NONBLOCK
)
573 ret
= wait_event_interruptible(port
->waitqueue
,
574 !will_read_block(port
));
579 * We could've received a disconnection message while we were
580 * waiting for more data.
582 * This check is not clubbed in the if() statement above as we
583 * might receive some data as well as the host could get
584 * disconnected after we got woken up from our wait. So we
585 * really want to give off whatever data we have and only then
586 * check for host_connected.
588 if (!port_has_data(port
) && !port
->host_connected
)
591 return fill_readbuf(port
, ubuf
, count
, true);
594 static ssize_t
port_fops_write(struct file
*filp
, const char __user
*ubuf
,
595 size_t count
, loff_t
*offp
)
602 /* Userspace could be out to fool us */
606 port
= filp
->private_data
;
608 nonblock
= filp
->f_flags
& O_NONBLOCK
;
610 if (will_write_block(port
)) {
614 ret
= wait_event_interruptible(port
->waitqueue
,
615 !will_write_block(port
));
620 count
= min((size_t)(32 * 1024), count
);
622 buf
= kmalloc(count
, GFP_KERNEL
);
626 ret
= copy_from_user(buf
, ubuf
, count
);
633 * We now ask send_buf() to not spin for generic ports -- we
634 * can re-use the same code path that non-blocking file
635 * descriptors take for blocking file descriptors since the
636 * wait is already done and we're certain the write will go
637 * through to the host.
640 ret
= send_buf(port
, buf
, count
, nonblock
);
642 if (nonblock
&& ret
> 0)
651 static unsigned int port_fops_poll(struct file
*filp
, poll_table
*wait
)
656 port
= filp
->private_data
;
657 poll_wait(filp
, &port
->waitqueue
, wait
);
660 if (!will_read_block(port
))
661 ret
|= POLLIN
| POLLRDNORM
;
662 if (!will_write_block(port
))
664 if (!port
->host_connected
)
670 static int port_fops_release(struct inode
*inode
, struct file
*filp
)
674 port
= filp
->private_data
;
676 /* Notify host of port being closed */
677 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
679 spin_lock_irq(&port
->inbuf_lock
);
680 port
->guest_connected
= false;
682 discard_port_data(port
);
684 spin_unlock_irq(&port
->inbuf_lock
);
686 spin_lock_irq(&port
->outvq_lock
);
687 reclaim_consumed_buffers(port
);
688 spin_unlock_irq(&port
->outvq_lock
);
693 static int port_fops_open(struct inode
*inode
, struct file
*filp
)
695 struct cdev
*cdev
= inode
->i_cdev
;
698 port
= container_of(cdev
, struct port
, cdev
);
699 filp
->private_data
= port
;
702 * Don't allow opening of console port devices -- that's done
705 if (is_console_port(port
))
708 /* Allow only one process to open a particular port at a time */
709 spin_lock_irq(&port
->inbuf_lock
);
710 if (port
->guest_connected
) {
711 spin_unlock_irq(&port
->inbuf_lock
);
715 port
->guest_connected
= true;
716 spin_unlock_irq(&port
->inbuf_lock
);
718 spin_lock_irq(&port
->outvq_lock
);
720 * There might be a chance that we missed reclaiming a few
721 * buffers in the window of the port getting previously closed
724 reclaim_consumed_buffers(port
);
725 spin_unlock_irq(&port
->outvq_lock
);
727 /* Notify host of port being opened */
728 send_control_msg(filp
->private_data
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
734 * The file operations that we support: programs in the guest can open
735 * a console device, read from it, write to it, poll for data and
736 * close it. The devices are at
737 * /dev/vport<device number>p<port number>
739 static const struct file_operations port_fops
= {
740 .owner
= THIS_MODULE
,
741 .open
= port_fops_open
,
742 .read
= port_fops_read
,
743 .write
= port_fops_write
,
744 .poll
= port_fops_poll
,
745 .release
= port_fops_release
,
749 * The put_chars() callback is pretty straightforward.
751 * We turn the characters into a scatter-gather list, add it to the
752 * output queue and then kick the Host. Then we sit here waiting for
753 * it to finish: inefficient in theory, but in practice
754 * implementations will do it immediately (lguest's Launcher does).
756 static int put_chars(u32 vtermno
, const char *buf
, int count
)
760 if (unlikely(early_put_chars
))
761 return early_put_chars(vtermno
, buf
, count
);
763 port
= find_port_by_vtermno(vtermno
);
767 return send_buf(port
, (void *)buf
, count
, false);
771 * get_chars() is the callback from the hvc_console infrastructure
772 * when an interrupt is received.
774 * We call out to fill_readbuf that gets us the required data from the
775 * buffers that are queued up.
777 static int get_chars(u32 vtermno
, char *buf
, int count
)
781 /* If we've not set up the port yet, we have no input to give. */
782 if (unlikely(early_put_chars
))
785 port
= find_port_by_vtermno(vtermno
);
789 /* If we don't have an input queue yet, we can't get input. */
790 BUG_ON(!port
->in_vq
);
792 return fill_readbuf(port
, buf
, count
, false);
795 static void resize_console(struct port
*port
)
797 struct virtio_device
*vdev
;
799 /* The port could have been hot-unplugged */
800 if (!port
|| !is_console_port(port
))
803 vdev
= port
->portdev
->vdev
;
804 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_SIZE
))
805 hvc_resize(port
->cons
.hvc
, port
->cons
.ws
);
808 /* We set the configuration at this point, since we now have a tty */
809 static int notifier_add_vio(struct hvc_struct
*hp
, int data
)
813 port
= find_port_by_vtermno(hp
->vtermno
);
817 hp
->irq_requested
= 1;
818 resize_console(port
);
823 static void notifier_del_vio(struct hvc_struct
*hp
, int data
)
825 hp
->irq_requested
= 0;
828 /* The operations for console ports. */
829 static const struct hv_ops hv_ops
= {
830 .get_chars
= get_chars
,
831 .put_chars
= put_chars
,
832 .notifier_add
= notifier_add_vio
,
833 .notifier_del
= notifier_del_vio
,
834 .notifier_hangup
= notifier_del_vio
,
838 * Console drivers are initialized very early so boot messages can go
839 * out, so we do things slightly differently from the generic virtio
840 * initialization of the net and block drivers.
842 * At this stage, the console is output-only. It's too early to set
843 * up a virtqueue, so we let the drivers do some boutique early-output
846 int __init
virtio_cons_early_init(int (*put_chars
)(u32
, const char *, int))
848 early_put_chars
= put_chars
;
849 return hvc_instantiate(0, 0, &hv_ops
);
852 int init_port_console(struct port
*port
)
857 * The Host's telling us this port is a console port. Hook it
858 * up with an hvc console.
860 * To set up and manage our virtual console, we call
863 * The first argument of hvc_alloc() is the virtual console
864 * number. The second argument is the parameter for the
865 * notification mechanism (like irq number). We currently
866 * leave this as zero, virtqueues have implicit notifications.
868 * The third argument is a "struct hv_ops" containing the
869 * put_chars() get_chars(), notifier_add() and notifier_del()
870 * pointers. The final argument is the output buffer size: we
871 * can do any size, so we put PAGE_SIZE here.
873 port
->cons
.vtermno
= pdrvdata
.next_vtermno
;
875 port
->cons
.hvc
= hvc_alloc(port
->cons
.vtermno
, 0, &hv_ops
, PAGE_SIZE
);
876 if (IS_ERR(port
->cons
.hvc
)) {
877 ret
= PTR_ERR(port
->cons
.hvc
);
879 "error %d allocating hvc for port\n", ret
);
880 port
->cons
.hvc
= NULL
;
883 spin_lock_irq(&pdrvdata_lock
);
884 pdrvdata
.next_vtermno
++;
885 list_add_tail(&port
->cons
.list
, &pdrvdata
.consoles
);
886 spin_unlock_irq(&pdrvdata_lock
);
887 port
->guest_connected
= true;
890 * Start using the new console output if this is the first
891 * console to come up.
894 early_put_chars
= NULL
;
896 /* Notify host of port being opened */
897 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
902 static ssize_t
show_port_name(struct device
*dev
,
903 struct device_attribute
*attr
, char *buffer
)
907 port
= dev_get_drvdata(dev
);
909 return sprintf(buffer
, "%s\n", port
->name
);
912 static DEVICE_ATTR(name
, S_IRUGO
, show_port_name
, NULL
);
914 static struct attribute
*port_sysfs_entries
[] = {
919 static struct attribute_group port_attribute_group
= {
920 .name
= NULL
, /* put in device directory */
921 .attrs
= port_sysfs_entries
,
924 static int debugfs_open(struct inode
*inode
, struct file
*filp
)
926 filp
->private_data
= inode
->i_private
;
930 static ssize_t
debugfs_read(struct file
*filp
, char __user
*ubuf
,
931 size_t count
, loff_t
*offp
)
935 ssize_t ret
, out_offset
, out_count
;
938 buf
= kmalloc(out_count
, GFP_KERNEL
);
942 port
= filp
->private_data
;
944 out_offset
+= snprintf(buf
+ out_offset
, out_count
,
945 "name: %s\n", port
->name
? port
->name
: "");
946 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
947 "guest_connected: %d\n", port
->guest_connected
);
948 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
949 "host_connected: %d\n", port
->host_connected
);
950 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
951 "outvq_full: %d\n", port
->outvq_full
);
952 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
954 is_console_port(port
) ? "yes" : "no");
955 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
956 "console_vtermno: %u\n", port
->cons
.vtermno
);
958 ret
= simple_read_from_buffer(ubuf
, count
, offp
, buf
, out_offset
);
963 static const struct file_operations port_debugfs_ops
= {
964 .owner
= THIS_MODULE
,
965 .open
= debugfs_open
,
966 .read
= debugfs_read
,
969 static void set_console_size(struct port
*port
, u16 rows
, u16 cols
)
971 if (!port
|| !is_console_port(port
))
974 port
->cons
.ws
.ws_row
= rows
;
975 port
->cons
.ws
.ws_col
= cols
;
978 static unsigned int fill_queue(struct virtqueue
*vq
, spinlock_t
*lock
)
980 struct port_buffer
*buf
;
981 unsigned int nr_added_bufs
;
986 buf
= alloc_buf(PAGE_SIZE
);
991 ret
= add_inbuf(vq
, buf
);
993 spin_unlock_irq(lock
);
998 spin_unlock_irq(lock
);
1001 return nr_added_bufs
;
1004 static int add_port(struct ports_device
*portdev
, u32 id
)
1006 char debugfs_name
[16];
1008 struct port_buffer
*buf
;
1010 unsigned int nr_added_bufs
;
1013 port
= kmalloc(sizeof(*port
), GFP_KERNEL
);
1019 port
->portdev
= portdev
;
1024 port
->cons
.hvc
= NULL
;
1026 port
->cons
.ws
.ws_row
= port
->cons
.ws
.ws_col
= 0;
1028 port
->host_connected
= port
->guest_connected
= false;
1030 port
->outvq_full
= false;
1032 port
->in_vq
= portdev
->in_vqs
[port
->id
];
1033 port
->out_vq
= portdev
->out_vqs
[port
->id
];
1035 cdev_init(&port
->cdev
, &port_fops
);
1037 devt
= MKDEV(portdev
->chr_major
, id
);
1038 err
= cdev_add(&port
->cdev
, devt
, 1);
1040 dev_err(&port
->portdev
->vdev
->dev
,
1041 "Error %d adding cdev for port %u\n", err
, id
);
1044 port
->dev
= device_create(pdrvdata
.class, &port
->portdev
->vdev
->dev
,
1045 devt
, port
, "vport%up%u",
1046 port
->portdev
->drv_index
, id
);
1047 if (IS_ERR(port
->dev
)) {
1048 err
= PTR_ERR(port
->dev
);
1049 dev_err(&port
->portdev
->vdev
->dev
,
1050 "Error %d creating device for port %u\n",
1055 spin_lock_init(&port
->inbuf_lock
);
1056 spin_lock_init(&port
->outvq_lock
);
1057 init_waitqueue_head(&port
->waitqueue
);
1059 /* Fill the in_vq with buffers so the host can send us data. */
1060 nr_added_bufs
= fill_queue(port
->in_vq
, &port
->inbuf_lock
);
1061 if (!nr_added_bufs
) {
1062 dev_err(port
->dev
, "Error allocating inbufs\n");
1068 * If we're not using multiport support, this has to be a console port
1070 if (!use_multiport(port
->portdev
)) {
1071 err
= init_port_console(port
);
1076 spin_lock_irq(&portdev
->ports_lock
);
1077 list_add_tail(&port
->list
, &port
->portdev
->ports
);
1078 spin_unlock_irq(&portdev
->ports_lock
);
1081 * Tell the Host we're set so that it can send us various
1082 * configuration parameters for this port (eg, port name,
1083 * caching, whether this is a console port, etc.)
1085 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1087 if (pdrvdata
.debugfs_dir
) {
1089 * Finally, create the debugfs file that we can use to
1090 * inspect a port's state at any time
1092 sprintf(debugfs_name
, "vport%up%u",
1093 port
->portdev
->drv_index
, id
);
1094 port
->debugfs_file
= debugfs_create_file(debugfs_name
, 0444,
1095 pdrvdata
.debugfs_dir
,
1102 while ((buf
= virtqueue_detach_unused_buf(port
->in_vq
)))
1105 device_destroy(pdrvdata
.class, port
->dev
->devt
);
1107 cdev_del(&port
->cdev
);
1111 /* The host might want to notify management sw about port add failure */
1112 __send_control_msg(portdev
, id
, VIRTIO_CONSOLE_PORT_READY
, 0);
1116 /* Remove all port-specific data. */
1117 static int remove_port(struct port
*port
)
1119 struct port_buffer
*buf
;
1121 if (port
->guest_connected
) {
1122 port
->guest_connected
= false;
1123 port
->host_connected
= false;
1124 wake_up_interruptible(&port
->waitqueue
);
1125 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
1128 spin_lock_irq(&port
->portdev
->ports_lock
);
1129 list_del(&port
->list
);
1130 spin_unlock_irq(&port
->portdev
->ports_lock
);
1132 if (is_console_port(port
)) {
1133 spin_lock_irq(&pdrvdata_lock
);
1134 list_del(&port
->cons
.list
);
1135 spin_unlock_irq(&pdrvdata_lock
);
1137 sysfs_remove_group(&port
->dev
->kobj
, &port_attribute_group
);
1138 device_destroy(pdrvdata
.class, port
->dev
->devt
);
1139 cdev_del(&port
->cdev
);
1141 /* Remove unused data this port might have received. */
1142 discard_port_data(port
);
1144 reclaim_consumed_buffers(port
);
1146 /* Remove buffers we queued up for the Host to send us data in. */
1147 while ((buf
= virtqueue_detach_unused_buf(port
->in_vq
)))
1152 debugfs_remove(port
->debugfs_file
);
1158 /* Any private messages that the Host and Guest want to share */
1159 static void handle_control_message(struct ports_device
*portdev
,
1160 struct port_buffer
*buf
)
1162 struct virtio_console_control
*cpkt
;
1167 cpkt
= (struct virtio_console_control
*)(buf
->buf
+ buf
->offset
);
1169 port
= find_port_by_id(portdev
, cpkt
->id
);
1170 if (!port
&& cpkt
->event
!= VIRTIO_CONSOLE_PORT_ADD
) {
1171 /* No valid header at start of buffer. Drop it. */
1172 dev_dbg(&portdev
->vdev
->dev
,
1173 "Invalid index %u in control packet\n", cpkt
->id
);
1177 switch (cpkt
->event
) {
1178 case VIRTIO_CONSOLE_PORT_ADD
:
1180 dev_dbg(&portdev
->vdev
->dev
,
1181 "Port %u already added\n", port
->id
);
1182 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1185 if (cpkt
->id
>= portdev
->config
.max_nr_ports
) {
1186 dev_warn(&portdev
->vdev
->dev
,
1187 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1188 cpkt
->id
, portdev
->config
.max_nr_ports
- 1);
1191 add_port(portdev
, cpkt
->id
);
1193 case VIRTIO_CONSOLE_PORT_REMOVE
:
1196 case VIRTIO_CONSOLE_CONSOLE_PORT
:
1199 if (is_console_port(port
))
1202 init_port_console(port
);
1204 * Could remove the port here in case init fails - but
1205 * have to notify the host first.
1208 case VIRTIO_CONSOLE_RESIZE
: {
1214 if (!is_console_port(port
))
1217 memcpy(&size
, buf
->buf
+ buf
->offset
+ sizeof(*cpkt
),
1219 set_console_size(port
, size
.rows
, size
.cols
);
1221 port
->cons
.hvc
->irq_requested
= 1;
1222 resize_console(port
);
1225 case VIRTIO_CONSOLE_PORT_OPEN
:
1226 port
->host_connected
= cpkt
->value
;
1227 wake_up_interruptible(&port
->waitqueue
);
1229 * If the host port got closed and the host had any
1230 * unconsumed buffers, we'll be able to reclaim them
1233 spin_lock_irq(&port
->outvq_lock
);
1234 reclaim_consumed_buffers(port
);
1235 spin_unlock_irq(&port
->outvq_lock
);
1237 case VIRTIO_CONSOLE_PORT_NAME
:
1239 * Skip the size of the header and the cpkt to get the size
1240 * of the name that was sent
1242 name_size
= buf
->len
- buf
->offset
- sizeof(*cpkt
) + 1;
1244 port
->name
= kmalloc(name_size
, GFP_KERNEL
);
1247 "Not enough space to store port name\n");
1250 strncpy(port
->name
, buf
->buf
+ buf
->offset
+ sizeof(*cpkt
),
1252 port
->name
[name_size
- 1] = 0;
1255 * Since we only have one sysfs attribute, 'name',
1256 * create it only if we have a name for the port.
1258 err
= sysfs_create_group(&port
->dev
->kobj
,
1259 &port_attribute_group
);
1262 "Error %d creating sysfs device attributes\n",
1266 * Generate a udev event so that appropriate
1267 * symlinks can be created based on udev
1270 kobject_uevent(&port
->dev
->kobj
, KOBJ_CHANGE
);
1276 static void control_work_handler(struct work_struct
*work
)
1278 struct ports_device
*portdev
;
1279 struct virtqueue
*vq
;
1280 struct port_buffer
*buf
;
1283 portdev
= container_of(work
, struct ports_device
, control_work
);
1284 vq
= portdev
->c_ivq
;
1286 spin_lock(&portdev
->cvq_lock
);
1287 while ((buf
= virtqueue_get_buf(vq
, &len
))) {
1288 spin_unlock(&portdev
->cvq_lock
);
1293 handle_control_message(portdev
, buf
);
1295 spin_lock(&portdev
->cvq_lock
);
1296 if (add_inbuf(portdev
->c_ivq
, buf
) < 0) {
1297 dev_warn(&portdev
->vdev
->dev
,
1298 "Error adding buffer to queue\n");
1302 spin_unlock(&portdev
->cvq_lock
);
1305 static void out_intr(struct virtqueue
*vq
)
1309 port
= find_port_by_vq(vq
->vdev
->priv
, vq
);
1313 wake_up_interruptible(&port
->waitqueue
);
1316 static void in_intr(struct virtqueue
*vq
)
1319 unsigned long flags
;
1321 port
= find_port_by_vq(vq
->vdev
->priv
, vq
);
1325 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
1327 port
->inbuf
= get_inbuf(port
);
1330 * Don't queue up data when port is closed. This condition
1331 * can be reached when a console port is not yet connected (no
1332 * tty is spawned) and the host sends out data to console
1333 * ports. For generic serial ports, the host won't
1334 * (shouldn't) send data till the guest is connected.
1336 if (!port
->guest_connected
)
1337 discard_port_data(port
);
1339 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
1341 wake_up_interruptible(&port
->waitqueue
);
1343 if (is_console_port(port
) && hvc_poll(port
->cons
.hvc
))
1347 static void control_intr(struct virtqueue
*vq
)
1349 struct ports_device
*portdev
;
1351 portdev
= vq
->vdev
->priv
;
1352 schedule_work(&portdev
->control_work
);
1355 static void config_intr(struct virtio_device
*vdev
)
1357 struct ports_device
*portdev
;
1359 portdev
= vdev
->priv
;
1361 if (!use_multiport(portdev
)) {
1365 vdev
->config
->get(vdev
,
1366 offsetof(struct virtio_console_config
, cols
),
1367 &cols
, sizeof(u16
));
1368 vdev
->config
->get(vdev
,
1369 offsetof(struct virtio_console_config
, rows
),
1370 &rows
, sizeof(u16
));
1372 port
= find_port_by_id(portdev
, 0);
1373 set_console_size(port
, rows
, cols
);
1376 * We'll use this way of resizing only for legacy
1377 * support. For newer userspace
1378 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1379 * to indicate console size changes so that it can be
1382 resize_console(port
);
1386 static int init_vqs(struct ports_device
*portdev
)
1388 vq_callback_t
**io_callbacks
;
1390 struct virtqueue
**vqs
;
1391 u32 i
, j
, nr_ports
, nr_queues
;
1394 nr_ports
= portdev
->config
.max_nr_ports
;
1395 nr_queues
= use_multiport(portdev
) ? (nr_ports
+ 1) * 2 : 2;
1397 vqs
= kmalloc(nr_queues
* sizeof(struct virtqueue
*), GFP_KERNEL
);
1402 io_callbacks
= kmalloc(nr_queues
* sizeof(vq_callback_t
*), GFP_KERNEL
);
1403 if (!io_callbacks
) {
1407 io_names
= kmalloc(nr_queues
* sizeof(char *), GFP_KERNEL
);
1410 goto free_callbacks
;
1412 portdev
->in_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1414 if (!portdev
->in_vqs
) {
1418 portdev
->out_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1420 if (!portdev
->out_vqs
) {
1426 * For backward compat (newer host but older guest), the host
1427 * spawns a console port first and also inits the vqs for port
1431 io_callbacks
[j
] = in_intr
;
1432 io_callbacks
[j
+ 1] = out_intr
;
1433 io_names
[j
] = "input";
1434 io_names
[j
+ 1] = "output";
1437 if (use_multiport(portdev
)) {
1438 io_callbacks
[j
] = control_intr
;
1439 io_callbacks
[j
+ 1] = NULL
;
1440 io_names
[j
] = "control-i";
1441 io_names
[j
+ 1] = "control-o";
1443 for (i
= 1; i
< nr_ports
; i
++) {
1445 io_callbacks
[j
] = in_intr
;
1446 io_callbacks
[j
+ 1] = out_intr
;
1447 io_names
[j
] = "input";
1448 io_names
[j
+ 1] = "output";
1451 /* Find the queues. */
1452 err
= portdev
->vdev
->config
->find_vqs(portdev
->vdev
, nr_queues
, vqs
,
1454 (const char **)io_names
);
1459 portdev
->in_vqs
[0] = vqs
[0];
1460 portdev
->out_vqs
[0] = vqs
[1];
1462 if (use_multiport(portdev
)) {
1463 portdev
->c_ivq
= vqs
[j
];
1464 portdev
->c_ovq
= vqs
[j
+ 1];
1466 for (i
= 1; i
< nr_ports
; i
++) {
1468 portdev
->in_vqs
[i
] = vqs
[j
];
1469 portdev
->out_vqs
[i
] = vqs
[j
+ 1];
1472 kfree(io_callbacks
);
1481 kfree(io_callbacks
);
1483 kfree(portdev
->out_vqs
);
1485 kfree(portdev
->in_vqs
);
1492 static const struct file_operations portdev_fops
= {
1493 .owner
= THIS_MODULE
,
1497 * Once we're further in boot, we get probed like any other virtio
1500 * If the host also supports multiple console ports, we check the
1501 * config space to see how many ports the host has spawned. We
1502 * initialize each port found.
1504 static int __devinit
virtcons_probe(struct virtio_device
*vdev
)
1506 struct ports_device
*portdev
;
1510 portdev
= kmalloc(sizeof(*portdev
), GFP_KERNEL
);
1516 /* Attach this portdev to this virtio_device, and vice-versa. */
1517 portdev
->vdev
= vdev
;
1518 vdev
->priv
= portdev
;
1520 spin_lock_irq(&pdrvdata_lock
);
1521 portdev
->drv_index
= pdrvdata
.index
++;
1522 spin_unlock_irq(&pdrvdata_lock
);
1524 portdev
->chr_major
= register_chrdev(0, "virtio-portsdev",
1526 if (portdev
->chr_major
< 0) {
1528 "Error %d registering chrdev for device %u\n",
1529 portdev
->chr_major
, portdev
->drv_index
);
1530 err
= portdev
->chr_major
;
1535 portdev
->config
.max_nr_ports
= 1;
1536 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_MULTIPORT
)) {
1538 vdev
->features
[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT
;
1540 vdev
->config
->get(vdev
, offsetof(struct virtio_console_config
,
1542 &portdev
->config
.max_nr_ports
,
1543 sizeof(portdev
->config
.max_nr_ports
));
1546 /* Let the Host know we support multiple ports.*/
1547 vdev
->config
->finalize_features(vdev
);
1549 err
= init_vqs(portdev
);
1551 dev_err(&vdev
->dev
, "Error %d initializing vqs\n", err
);
1555 spin_lock_init(&portdev
->ports_lock
);
1556 INIT_LIST_HEAD(&portdev
->ports
);
1559 unsigned int nr_added_bufs
;
1561 spin_lock_init(&portdev
->cvq_lock
);
1562 INIT_WORK(&portdev
->control_work
, &control_work_handler
);
1564 nr_added_bufs
= fill_queue(portdev
->c_ivq
, &portdev
->cvq_lock
);
1565 if (!nr_added_bufs
) {
1567 "Error allocating buffers for control queue\n");
1573 * For backward compatibility: Create a console port
1574 * if we're running on older host.
1576 add_port(portdev
, 0);
1579 __send_control_msg(portdev
, VIRTIO_CONSOLE_BAD_ID
,
1580 VIRTIO_CONSOLE_DEVICE_READY
, 1);
1584 /* The host might want to notify mgmt sw about device add failure */
1585 __send_control_msg(portdev
, VIRTIO_CONSOLE_BAD_ID
,
1586 VIRTIO_CONSOLE_DEVICE_READY
, 0);
1587 vdev
->config
->del_vqs(vdev
);
1588 kfree(portdev
->in_vqs
);
1589 kfree(portdev
->out_vqs
);
1591 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1598 static void virtcons_remove(struct virtio_device
*vdev
)
1600 struct ports_device
*portdev
;
1601 struct port
*port
, *port2
;
1602 struct port_buffer
*buf
;
1605 portdev
= vdev
->priv
;
1607 cancel_work_sync(&portdev
->control_work
);
1609 list_for_each_entry_safe(port
, port2
, &portdev
->ports
, list
)
1612 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1614 while ((buf
= virtqueue_get_buf(portdev
->c_ivq
, &len
)))
1617 while ((buf
= virtqueue_detach_unused_buf(portdev
->c_ivq
)))
1620 vdev
->config
->del_vqs(vdev
);
1621 kfree(portdev
->in_vqs
);
1622 kfree(portdev
->out_vqs
);
1627 static struct virtio_device_id id_table
[] = {
1628 { VIRTIO_ID_CONSOLE
, VIRTIO_DEV_ANY_ID
},
1632 static unsigned int features
[] = {
1633 VIRTIO_CONSOLE_F_SIZE
,
1634 VIRTIO_CONSOLE_F_MULTIPORT
,
1637 static struct virtio_driver virtio_console
= {
1638 .feature_table
= features
,
1639 .feature_table_size
= ARRAY_SIZE(features
),
1640 .driver
.name
= KBUILD_MODNAME
,
1641 .driver
.owner
= THIS_MODULE
,
1642 .id_table
= id_table
,
1643 .probe
= virtcons_probe
,
1644 .remove
= virtcons_remove
,
1645 .config_changed
= config_intr
,
1648 static int __init
init(void)
1652 pdrvdata
.class = class_create(THIS_MODULE
, "virtio-ports");
1653 if (IS_ERR(pdrvdata
.class)) {
1654 err
= PTR_ERR(pdrvdata
.class);
1655 pr_err("Error %d creating virtio-ports class\n", err
);
1659 pdrvdata
.debugfs_dir
= debugfs_create_dir("virtio-ports", NULL
);
1660 if (!pdrvdata
.debugfs_dir
) {
1661 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1662 PTR_ERR(pdrvdata
.debugfs_dir
));
1664 INIT_LIST_HEAD(&pdrvdata
.consoles
);
1666 return register_virtio_driver(&virtio_console
);
1669 static void __exit
fini(void)
1671 unregister_virtio_driver(&virtio_console
);
1673 class_destroy(pdrvdata
.class);
1674 if (pdrvdata
.debugfs_dir
)
1675 debugfs_remove_recursive(pdrvdata
.debugfs_dir
);
1680 MODULE_DEVICE_TABLE(virtio
, id_table
);
1681 MODULE_DESCRIPTION("Virtio console driver");
1682 MODULE_LICENSE("GPL");