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 ports in blocking mode or for data
463 * from the hvc_console; the tty operations are performed with
464 * spinlocks held so we can't sleep here.
466 while (!virtqueue_get_buf(out_vq
, &len
))
469 spin_unlock_irqrestore(&port
->outvq_lock
, flags
);
471 * We're expected to return the amount of data we wrote -- all
478 * Give out the data that's requested from the buffer that we have
481 static ssize_t
fill_readbuf(struct port
*port
, char *out_buf
, size_t out_count
,
484 struct port_buffer
*buf
;
487 if (!out_count
|| !port_has_data(port
))
491 out_count
= min(out_count
, buf
->len
- buf
->offset
);
496 ret
= copy_to_user(out_buf
, buf
->buf
+ buf
->offset
, out_count
);
500 memcpy(out_buf
, buf
->buf
+ buf
->offset
, out_count
);
503 buf
->offset
+= out_count
;
505 if (buf
->offset
== buf
->len
) {
507 * We're done using all the data in this buffer.
508 * Re-queue so that the Host can send us more data.
510 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
513 if (add_inbuf(port
->in_vq
, buf
) < 0)
514 dev_warn(port
->dev
, "failed add_buf\n");
516 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
518 /* Return the number of bytes actually copied */
522 /* The condition that must be true for polling to end */
523 static bool will_read_block(struct port
*port
)
525 return !port_has_data(port
) && port
->host_connected
;
528 static bool will_write_block(struct port
*port
)
532 if (!port
->guest_connected
) {
533 /* Port got hot-unplugged. Let's exit. */
536 if (!port
->host_connected
)
539 spin_lock_irq(&port
->outvq_lock
);
541 * Check if the Host has consumed any buffers since we last
542 * sent data (this is only applicable for nonblocking ports).
544 reclaim_consumed_buffers(port
);
545 ret
= port
->outvq_full
;
546 spin_unlock_irq(&port
->outvq_lock
);
551 static ssize_t
port_fops_read(struct file
*filp
, char __user
*ubuf
,
552 size_t count
, loff_t
*offp
)
557 port
= filp
->private_data
;
559 if (!port_has_data(port
)) {
561 * If nothing's connected on the host just return 0 in
562 * case of list_empty; this tells the userspace app
563 * that there's no connection
565 if (!port
->host_connected
)
567 if (filp
->f_flags
& O_NONBLOCK
)
570 ret
= wait_event_interruptible(port
->waitqueue
,
571 !will_read_block(port
));
576 * We could've received a disconnection message while we were
577 * waiting for more data.
579 * This check is not clubbed in the if() statement above as we
580 * might receive some data as well as the host could get
581 * disconnected after we got woken up from our wait. So we
582 * really want to give off whatever data we have and only then
583 * check for host_connected.
585 if (!port_has_data(port
) && !port
->host_connected
)
588 return fill_readbuf(port
, ubuf
, count
, true);
591 static ssize_t
port_fops_write(struct file
*filp
, const char __user
*ubuf
,
592 size_t count
, loff_t
*offp
)
599 /* Userspace could be out to fool us */
603 port
= filp
->private_data
;
605 nonblock
= filp
->f_flags
& O_NONBLOCK
;
607 if (will_write_block(port
)) {
611 ret
= wait_event_interruptible(port
->waitqueue
,
612 !will_write_block(port
));
617 count
= min((size_t)(32 * 1024), count
);
619 buf
= kmalloc(count
, GFP_KERNEL
);
623 ret
= copy_from_user(buf
, ubuf
, count
);
629 ret
= send_buf(port
, buf
, count
, nonblock
);
631 if (nonblock
&& ret
> 0)
640 static unsigned int port_fops_poll(struct file
*filp
, poll_table
*wait
)
645 port
= filp
->private_data
;
646 poll_wait(filp
, &port
->waitqueue
, wait
);
649 if (!will_read_block(port
))
650 ret
|= POLLIN
| POLLRDNORM
;
651 if (!will_write_block(port
))
653 if (!port
->host_connected
)
659 static int port_fops_release(struct inode
*inode
, struct file
*filp
)
663 port
= filp
->private_data
;
665 /* Notify host of port being closed */
666 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
668 spin_lock_irq(&port
->inbuf_lock
);
669 port
->guest_connected
= false;
671 discard_port_data(port
);
673 spin_unlock_irq(&port
->inbuf_lock
);
675 spin_lock_irq(&port
->outvq_lock
);
676 reclaim_consumed_buffers(port
);
677 spin_unlock_irq(&port
->outvq_lock
);
682 static int port_fops_open(struct inode
*inode
, struct file
*filp
)
684 struct cdev
*cdev
= inode
->i_cdev
;
687 port
= container_of(cdev
, struct port
, cdev
);
688 filp
->private_data
= port
;
691 * Don't allow opening of console port devices -- that's done
694 if (is_console_port(port
))
697 /* Allow only one process to open a particular port at a time */
698 spin_lock_irq(&port
->inbuf_lock
);
699 if (port
->guest_connected
) {
700 spin_unlock_irq(&port
->inbuf_lock
);
704 port
->guest_connected
= true;
705 spin_unlock_irq(&port
->inbuf_lock
);
707 spin_lock_irq(&port
->outvq_lock
);
709 * There might be a chance that we missed reclaiming a few
710 * buffers in the window of the port getting previously closed
713 reclaim_consumed_buffers(port
);
714 spin_unlock_irq(&port
->outvq_lock
);
716 /* Notify host of port being opened */
717 send_control_msg(filp
->private_data
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
723 * The file operations that we support: programs in the guest can open
724 * a console device, read from it, write to it, poll for data and
725 * close it. The devices are at
726 * /dev/vport<device number>p<port number>
728 static const struct file_operations port_fops
= {
729 .owner
= THIS_MODULE
,
730 .open
= port_fops_open
,
731 .read
= port_fops_read
,
732 .write
= port_fops_write
,
733 .poll
= port_fops_poll
,
734 .release
= port_fops_release
,
738 * The put_chars() callback is pretty straightforward.
740 * We turn the characters into a scatter-gather list, add it to the
741 * output queue and then kick the Host. Then we sit here waiting for
742 * it to finish: inefficient in theory, but in practice
743 * implementations will do it immediately (lguest's Launcher does).
745 static int put_chars(u32 vtermno
, const char *buf
, int count
)
749 if (unlikely(early_put_chars
))
750 return early_put_chars(vtermno
, buf
, count
);
752 port
= find_port_by_vtermno(vtermno
);
756 return send_buf(port
, (void *)buf
, count
, false);
760 * get_chars() is the callback from the hvc_console infrastructure
761 * when an interrupt is received.
763 * We call out to fill_readbuf that gets us the required data from the
764 * buffers that are queued up.
766 static int get_chars(u32 vtermno
, char *buf
, int count
)
770 /* If we've not set up the port yet, we have no input to give. */
771 if (unlikely(early_put_chars
))
774 port
= find_port_by_vtermno(vtermno
);
778 /* If we don't have an input queue yet, we can't get input. */
779 BUG_ON(!port
->in_vq
);
781 return fill_readbuf(port
, buf
, count
, false);
784 static void resize_console(struct port
*port
)
786 struct virtio_device
*vdev
;
788 /* The port could have been hot-unplugged */
789 if (!port
|| !is_console_port(port
))
792 vdev
= port
->portdev
->vdev
;
793 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_SIZE
))
794 hvc_resize(port
->cons
.hvc
, port
->cons
.ws
);
797 /* We set the configuration at this point, since we now have a tty */
798 static int notifier_add_vio(struct hvc_struct
*hp
, int data
)
802 port
= find_port_by_vtermno(hp
->vtermno
);
806 hp
->irq_requested
= 1;
807 resize_console(port
);
812 static void notifier_del_vio(struct hvc_struct
*hp
, int data
)
814 hp
->irq_requested
= 0;
817 /* The operations for console ports. */
818 static const struct hv_ops hv_ops
= {
819 .get_chars
= get_chars
,
820 .put_chars
= put_chars
,
821 .notifier_add
= notifier_add_vio
,
822 .notifier_del
= notifier_del_vio
,
823 .notifier_hangup
= notifier_del_vio
,
827 * Console drivers are initialized very early so boot messages can go
828 * out, so we do things slightly differently from the generic virtio
829 * initialization of the net and block drivers.
831 * At this stage, the console is output-only. It's too early to set
832 * up a virtqueue, so we let the drivers do some boutique early-output
835 int __init
virtio_cons_early_init(int (*put_chars
)(u32
, const char *, int))
837 early_put_chars
= put_chars
;
838 return hvc_instantiate(0, 0, &hv_ops
);
841 int init_port_console(struct port
*port
)
846 * The Host's telling us this port is a console port. Hook it
847 * up with an hvc console.
849 * To set up and manage our virtual console, we call
852 * The first argument of hvc_alloc() is the virtual console
853 * number. The second argument is the parameter for the
854 * notification mechanism (like irq number). We currently
855 * leave this as zero, virtqueues have implicit notifications.
857 * The third argument is a "struct hv_ops" containing the
858 * put_chars() get_chars(), notifier_add() and notifier_del()
859 * pointers. The final argument is the output buffer size: we
860 * can do any size, so we put PAGE_SIZE here.
862 port
->cons
.vtermno
= pdrvdata
.next_vtermno
;
864 port
->cons
.hvc
= hvc_alloc(port
->cons
.vtermno
, 0, &hv_ops
, PAGE_SIZE
);
865 if (IS_ERR(port
->cons
.hvc
)) {
866 ret
= PTR_ERR(port
->cons
.hvc
);
868 "error %d allocating hvc for port\n", ret
);
869 port
->cons
.hvc
= NULL
;
872 spin_lock_irq(&pdrvdata_lock
);
873 pdrvdata
.next_vtermno
++;
874 list_add_tail(&port
->cons
.list
, &pdrvdata
.consoles
);
875 spin_unlock_irq(&pdrvdata_lock
);
876 port
->guest_connected
= true;
879 * Start using the new console output if this is the first
880 * console to come up.
883 early_put_chars
= NULL
;
885 /* Notify host of port being opened */
886 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
891 static ssize_t
show_port_name(struct device
*dev
,
892 struct device_attribute
*attr
, char *buffer
)
896 port
= dev_get_drvdata(dev
);
898 return sprintf(buffer
, "%s\n", port
->name
);
901 static DEVICE_ATTR(name
, S_IRUGO
, show_port_name
, NULL
);
903 static struct attribute
*port_sysfs_entries
[] = {
908 static struct attribute_group port_attribute_group
= {
909 .name
= NULL
, /* put in device directory */
910 .attrs
= port_sysfs_entries
,
913 static int debugfs_open(struct inode
*inode
, struct file
*filp
)
915 filp
->private_data
= inode
->i_private
;
919 static ssize_t
debugfs_read(struct file
*filp
, char __user
*ubuf
,
920 size_t count
, loff_t
*offp
)
924 ssize_t ret
, out_offset
, out_count
;
927 buf
= kmalloc(out_count
, GFP_KERNEL
);
931 port
= filp
->private_data
;
933 out_offset
+= snprintf(buf
+ out_offset
, out_count
,
934 "name: %s\n", port
->name
? port
->name
: "");
935 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
936 "guest_connected: %d\n", port
->guest_connected
);
937 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
938 "host_connected: %d\n", port
->host_connected
);
939 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
940 "outvq_full: %d\n", port
->outvq_full
);
941 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
943 is_console_port(port
) ? "yes" : "no");
944 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
945 "console_vtermno: %u\n", port
->cons
.vtermno
);
947 ret
= simple_read_from_buffer(ubuf
, count
, offp
, buf
, out_offset
);
952 static const struct file_operations port_debugfs_ops
= {
953 .owner
= THIS_MODULE
,
954 .open
= debugfs_open
,
955 .read
= debugfs_read
,
958 static void set_console_size(struct port
*port
, u16 rows
, u16 cols
)
960 if (!port
|| !is_console_port(port
))
963 port
->cons
.ws
.ws_row
= rows
;
964 port
->cons
.ws
.ws_col
= cols
;
967 static unsigned int fill_queue(struct virtqueue
*vq
, spinlock_t
*lock
)
969 struct port_buffer
*buf
;
970 unsigned int nr_added_bufs
;
975 buf
= alloc_buf(PAGE_SIZE
);
980 ret
= add_inbuf(vq
, buf
);
982 spin_unlock_irq(lock
);
987 spin_unlock_irq(lock
);
990 return nr_added_bufs
;
993 static int add_port(struct ports_device
*portdev
, u32 id
)
995 char debugfs_name
[16];
997 struct port_buffer
*buf
;
999 unsigned int nr_added_bufs
;
1002 port
= kmalloc(sizeof(*port
), GFP_KERNEL
);
1008 port
->portdev
= portdev
;
1013 port
->cons
.hvc
= NULL
;
1015 port
->cons
.ws
.ws_row
= port
->cons
.ws
.ws_col
= 0;
1017 port
->host_connected
= port
->guest_connected
= false;
1019 port
->outvq_full
= false;
1021 port
->in_vq
= portdev
->in_vqs
[port
->id
];
1022 port
->out_vq
= portdev
->out_vqs
[port
->id
];
1024 cdev_init(&port
->cdev
, &port_fops
);
1026 devt
= MKDEV(portdev
->chr_major
, id
);
1027 err
= cdev_add(&port
->cdev
, devt
, 1);
1029 dev_err(&port
->portdev
->vdev
->dev
,
1030 "Error %d adding cdev for port %u\n", err
, id
);
1033 port
->dev
= device_create(pdrvdata
.class, &port
->portdev
->vdev
->dev
,
1034 devt
, port
, "vport%up%u",
1035 port
->portdev
->drv_index
, id
);
1036 if (IS_ERR(port
->dev
)) {
1037 err
= PTR_ERR(port
->dev
);
1038 dev_err(&port
->portdev
->vdev
->dev
,
1039 "Error %d creating device for port %u\n",
1044 spin_lock_init(&port
->inbuf_lock
);
1045 spin_lock_init(&port
->outvq_lock
);
1046 init_waitqueue_head(&port
->waitqueue
);
1048 /* Fill the in_vq with buffers so the host can send us data. */
1049 nr_added_bufs
= fill_queue(port
->in_vq
, &port
->inbuf_lock
);
1050 if (!nr_added_bufs
) {
1051 dev_err(port
->dev
, "Error allocating inbufs\n");
1057 * If we're not using multiport support, this has to be a console port
1059 if (!use_multiport(port
->portdev
)) {
1060 err
= init_port_console(port
);
1065 spin_lock_irq(&portdev
->ports_lock
);
1066 list_add_tail(&port
->list
, &port
->portdev
->ports
);
1067 spin_unlock_irq(&portdev
->ports_lock
);
1070 * Tell the Host we're set so that it can send us various
1071 * configuration parameters for this port (eg, port name,
1072 * caching, whether this is a console port, etc.)
1074 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1076 if (pdrvdata
.debugfs_dir
) {
1078 * Finally, create the debugfs file that we can use to
1079 * inspect a port's state at any time
1081 sprintf(debugfs_name
, "vport%up%u",
1082 port
->portdev
->drv_index
, id
);
1083 port
->debugfs_file
= debugfs_create_file(debugfs_name
, 0444,
1084 pdrvdata
.debugfs_dir
,
1091 while ((buf
= virtqueue_detach_unused_buf(port
->in_vq
)))
1094 device_destroy(pdrvdata
.class, port
->dev
->devt
);
1096 cdev_del(&port
->cdev
);
1100 /* The host might want to notify management sw about port add failure */
1101 __send_control_msg(portdev
, id
, VIRTIO_CONSOLE_PORT_READY
, 0);
1105 /* Remove all port-specific data. */
1106 static int remove_port(struct port
*port
)
1108 struct port_buffer
*buf
;
1110 if (port
->guest_connected
) {
1111 port
->guest_connected
= false;
1112 port
->host_connected
= false;
1113 wake_up_interruptible(&port
->waitqueue
);
1114 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
1117 spin_lock_irq(&port
->portdev
->ports_lock
);
1118 list_del(&port
->list
);
1119 spin_unlock_irq(&port
->portdev
->ports_lock
);
1121 if (is_console_port(port
)) {
1122 spin_lock_irq(&pdrvdata_lock
);
1123 list_del(&port
->cons
.list
);
1124 spin_unlock_irq(&pdrvdata_lock
);
1127 * hvc_remove() not called as removing one hvc port
1128 * results in other hvc ports getting frozen.
1130 * Once this is resolved in hvc, this functionality
1131 * will be enabled. Till that is done, the -EPIPE
1132 * return from get_chars() above will help
1133 * hvc_console.c to clean up on ports we remove here.
1135 hvc_remove(port
->cons
.hvc
);
1138 sysfs_remove_group(&port
->dev
->kobj
, &port_attribute_group
);
1139 device_destroy(pdrvdata
.class, port
->dev
->devt
);
1140 cdev_del(&port
->cdev
);
1142 /* Remove unused data this port might have received. */
1143 discard_port_data(port
);
1145 reclaim_consumed_buffers(port
);
1147 /* Remove buffers we queued up for the Host to send us data in. */
1148 while ((buf
= virtqueue_detach_unused_buf(port
->in_vq
)))
1153 debugfs_remove(port
->debugfs_file
);
1159 /* Any private messages that the Host and Guest want to share */
1160 static void handle_control_message(struct ports_device
*portdev
,
1161 struct port_buffer
*buf
)
1163 struct virtio_console_control
*cpkt
;
1168 cpkt
= (struct virtio_console_control
*)(buf
->buf
+ buf
->offset
);
1170 port
= find_port_by_id(portdev
, cpkt
->id
);
1171 if (!port
&& cpkt
->event
!= VIRTIO_CONSOLE_PORT_ADD
) {
1172 /* No valid header at start of buffer. Drop it. */
1173 dev_dbg(&portdev
->vdev
->dev
,
1174 "Invalid index %u in control packet\n", cpkt
->id
);
1178 switch (cpkt
->event
) {
1179 case VIRTIO_CONSOLE_PORT_ADD
:
1181 dev_dbg(&portdev
->vdev
->dev
,
1182 "Port %u already added\n", port
->id
);
1183 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1186 if (cpkt
->id
>= portdev
->config
.max_nr_ports
) {
1187 dev_warn(&portdev
->vdev
->dev
,
1188 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1189 cpkt
->id
, portdev
->config
.max_nr_ports
- 1);
1192 add_port(portdev
, cpkt
->id
);
1194 case VIRTIO_CONSOLE_PORT_REMOVE
:
1197 case VIRTIO_CONSOLE_CONSOLE_PORT
:
1200 if (is_console_port(port
))
1203 init_port_console(port
);
1205 * Could remove the port here in case init fails - but
1206 * have to notify the host first.
1209 case VIRTIO_CONSOLE_RESIZE
: {
1215 if (!is_console_port(port
))
1218 memcpy(&size
, buf
->buf
+ buf
->offset
+ sizeof(*cpkt
),
1220 set_console_size(port
, size
.rows
, size
.cols
);
1222 port
->cons
.hvc
->irq_requested
= 1;
1223 resize_console(port
);
1226 case VIRTIO_CONSOLE_PORT_OPEN
:
1227 port
->host_connected
= cpkt
->value
;
1228 wake_up_interruptible(&port
->waitqueue
);
1230 * If the host port got closed and the host had any
1231 * unconsumed buffers, we'll be able to reclaim them
1234 spin_lock_irq(&port
->outvq_lock
);
1235 reclaim_consumed_buffers(port
);
1236 spin_unlock_irq(&port
->outvq_lock
);
1238 case VIRTIO_CONSOLE_PORT_NAME
:
1240 * Skip the size of the header and the cpkt to get the size
1241 * of the name that was sent
1243 name_size
= buf
->len
- buf
->offset
- sizeof(*cpkt
) + 1;
1245 port
->name
= kmalloc(name_size
, GFP_KERNEL
);
1248 "Not enough space to store port name\n");
1251 strncpy(port
->name
, buf
->buf
+ buf
->offset
+ sizeof(*cpkt
),
1253 port
->name
[name_size
- 1] = 0;
1256 * Since we only have one sysfs attribute, 'name',
1257 * create it only if we have a name for the port.
1259 err
= sysfs_create_group(&port
->dev
->kobj
,
1260 &port_attribute_group
);
1263 "Error %d creating sysfs device attributes\n",
1267 * Generate a udev event so that appropriate
1268 * symlinks can be created based on udev
1271 kobject_uevent(&port
->dev
->kobj
, KOBJ_CHANGE
);
1277 static void control_work_handler(struct work_struct
*work
)
1279 struct ports_device
*portdev
;
1280 struct virtqueue
*vq
;
1281 struct port_buffer
*buf
;
1284 portdev
= container_of(work
, struct ports_device
, control_work
);
1285 vq
= portdev
->c_ivq
;
1287 spin_lock(&portdev
->cvq_lock
);
1288 while ((buf
= virtqueue_get_buf(vq
, &len
))) {
1289 spin_unlock(&portdev
->cvq_lock
);
1294 handle_control_message(portdev
, buf
);
1296 spin_lock(&portdev
->cvq_lock
);
1297 if (add_inbuf(portdev
->c_ivq
, buf
) < 0) {
1298 dev_warn(&portdev
->vdev
->dev
,
1299 "Error adding buffer to queue\n");
1303 spin_unlock(&portdev
->cvq_lock
);
1306 static void in_intr(struct virtqueue
*vq
)
1309 unsigned long flags
;
1311 port
= find_port_by_vq(vq
->vdev
->priv
, vq
);
1315 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
1317 port
->inbuf
= get_inbuf(port
);
1320 * Don't queue up data when port is closed. This condition
1321 * can be reached when a console port is not yet connected (no
1322 * tty is spawned) and the host sends out data to console
1323 * ports. For generic serial ports, the host won't
1324 * (shouldn't) send data till the guest is connected.
1326 if (!port
->guest_connected
)
1327 discard_port_data(port
);
1329 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
1331 wake_up_interruptible(&port
->waitqueue
);
1333 if (is_console_port(port
) && hvc_poll(port
->cons
.hvc
))
1337 static void control_intr(struct virtqueue
*vq
)
1339 struct ports_device
*portdev
;
1341 portdev
= vq
->vdev
->priv
;
1342 schedule_work(&portdev
->control_work
);
1345 static void config_intr(struct virtio_device
*vdev
)
1347 struct ports_device
*portdev
;
1349 portdev
= vdev
->priv
;
1351 if (!use_multiport(portdev
)) {
1355 vdev
->config
->get(vdev
,
1356 offsetof(struct virtio_console_config
, cols
),
1357 &cols
, sizeof(u16
));
1358 vdev
->config
->get(vdev
,
1359 offsetof(struct virtio_console_config
, rows
),
1360 &rows
, sizeof(u16
));
1362 port
= find_port_by_id(portdev
, 0);
1363 set_console_size(port
, rows
, cols
);
1366 * We'll use this way of resizing only for legacy
1367 * support. For newer userspace
1368 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1369 * to indicate console size changes so that it can be
1372 resize_console(port
);
1376 static int init_vqs(struct ports_device
*portdev
)
1378 vq_callback_t
**io_callbacks
;
1380 struct virtqueue
**vqs
;
1381 u32 i
, j
, nr_ports
, nr_queues
;
1384 nr_ports
= portdev
->config
.max_nr_ports
;
1385 nr_queues
= use_multiport(portdev
) ? (nr_ports
+ 1) * 2 : 2;
1387 vqs
= kmalloc(nr_queues
* sizeof(struct virtqueue
*), GFP_KERNEL
);
1392 io_callbacks
= kmalloc(nr_queues
* sizeof(vq_callback_t
*), GFP_KERNEL
);
1393 if (!io_callbacks
) {
1397 io_names
= kmalloc(nr_queues
* sizeof(char *), GFP_KERNEL
);
1400 goto free_callbacks
;
1402 portdev
->in_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1404 if (!portdev
->in_vqs
) {
1408 portdev
->out_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1410 if (!portdev
->out_vqs
) {
1416 * For backward compat (newer host but older guest), the host
1417 * spawns a console port first and also inits the vqs for port
1421 io_callbacks
[j
] = in_intr
;
1422 io_callbacks
[j
+ 1] = NULL
;
1423 io_names
[j
] = "input";
1424 io_names
[j
+ 1] = "output";
1427 if (use_multiport(portdev
)) {
1428 io_callbacks
[j
] = control_intr
;
1429 io_callbacks
[j
+ 1] = NULL
;
1430 io_names
[j
] = "control-i";
1431 io_names
[j
+ 1] = "control-o";
1433 for (i
= 1; i
< nr_ports
; i
++) {
1435 io_callbacks
[j
] = in_intr
;
1436 io_callbacks
[j
+ 1] = NULL
;
1437 io_names
[j
] = "input";
1438 io_names
[j
+ 1] = "output";
1441 /* Find the queues. */
1442 err
= portdev
->vdev
->config
->find_vqs(portdev
->vdev
, nr_queues
, vqs
,
1444 (const char **)io_names
);
1449 portdev
->in_vqs
[0] = vqs
[0];
1450 portdev
->out_vqs
[0] = vqs
[1];
1452 if (use_multiport(portdev
)) {
1453 portdev
->c_ivq
= vqs
[j
];
1454 portdev
->c_ovq
= vqs
[j
+ 1];
1456 for (i
= 1; i
< nr_ports
; i
++) {
1458 portdev
->in_vqs
[i
] = vqs
[j
];
1459 portdev
->out_vqs
[i
] = vqs
[j
+ 1];
1462 kfree(io_callbacks
);
1471 kfree(io_callbacks
);
1473 kfree(portdev
->out_vqs
);
1475 kfree(portdev
->in_vqs
);
1482 static const struct file_operations portdev_fops
= {
1483 .owner
= THIS_MODULE
,
1487 * Once we're further in boot, we get probed like any other virtio
1490 * If the host also supports multiple console ports, we check the
1491 * config space to see how many ports the host has spawned. We
1492 * initialize each port found.
1494 static int __devinit
virtcons_probe(struct virtio_device
*vdev
)
1496 struct ports_device
*portdev
;
1500 portdev
= kmalloc(sizeof(*portdev
), GFP_KERNEL
);
1506 /* Attach this portdev to this virtio_device, and vice-versa. */
1507 portdev
->vdev
= vdev
;
1508 vdev
->priv
= portdev
;
1510 spin_lock_irq(&pdrvdata_lock
);
1511 portdev
->drv_index
= pdrvdata
.index
++;
1512 spin_unlock_irq(&pdrvdata_lock
);
1514 portdev
->chr_major
= register_chrdev(0, "virtio-portsdev",
1516 if (portdev
->chr_major
< 0) {
1518 "Error %d registering chrdev for device %u\n",
1519 portdev
->chr_major
, portdev
->drv_index
);
1520 err
= portdev
->chr_major
;
1525 portdev
->config
.max_nr_ports
= 1;
1526 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_MULTIPORT
)) {
1528 vdev
->features
[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT
;
1530 vdev
->config
->get(vdev
, offsetof(struct virtio_console_config
,
1532 &portdev
->config
.max_nr_ports
,
1533 sizeof(portdev
->config
.max_nr_ports
));
1536 /* Let the Host know we support multiple ports.*/
1537 vdev
->config
->finalize_features(vdev
);
1539 err
= init_vqs(portdev
);
1541 dev_err(&vdev
->dev
, "Error %d initializing vqs\n", err
);
1545 spin_lock_init(&portdev
->ports_lock
);
1546 INIT_LIST_HEAD(&portdev
->ports
);
1549 unsigned int nr_added_bufs
;
1551 spin_lock_init(&portdev
->cvq_lock
);
1552 INIT_WORK(&portdev
->control_work
, &control_work_handler
);
1554 nr_added_bufs
= fill_queue(portdev
->c_ivq
, &portdev
->cvq_lock
);
1555 if (!nr_added_bufs
) {
1557 "Error allocating buffers for control queue\n");
1563 * For backward compatibility: Create a console port
1564 * if we're running on older host.
1566 add_port(portdev
, 0);
1569 __send_control_msg(portdev
, VIRTIO_CONSOLE_BAD_ID
,
1570 VIRTIO_CONSOLE_DEVICE_READY
, 1);
1574 /* The host might want to notify mgmt sw about device add failure */
1575 __send_control_msg(portdev
, VIRTIO_CONSOLE_BAD_ID
,
1576 VIRTIO_CONSOLE_DEVICE_READY
, 0);
1577 vdev
->config
->del_vqs(vdev
);
1578 kfree(portdev
->in_vqs
);
1579 kfree(portdev
->out_vqs
);
1581 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1588 static void virtcons_remove(struct virtio_device
*vdev
)
1590 struct ports_device
*portdev
;
1591 struct port
*port
, *port2
;
1592 struct port_buffer
*buf
;
1595 portdev
= vdev
->priv
;
1597 cancel_work_sync(&portdev
->control_work
);
1599 list_for_each_entry_safe(port
, port2
, &portdev
->ports
, list
)
1602 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1604 while ((buf
= virtqueue_get_buf(portdev
->c_ivq
, &len
)))
1607 while ((buf
= virtqueue_detach_unused_buf(portdev
->c_ivq
)))
1610 vdev
->config
->del_vqs(vdev
);
1611 kfree(portdev
->in_vqs
);
1612 kfree(portdev
->out_vqs
);
1617 static struct virtio_device_id id_table
[] = {
1618 { VIRTIO_ID_CONSOLE
, VIRTIO_DEV_ANY_ID
},
1622 static unsigned int features
[] = {
1623 VIRTIO_CONSOLE_F_SIZE
,
1624 VIRTIO_CONSOLE_F_MULTIPORT
,
1627 static struct virtio_driver virtio_console
= {
1628 .feature_table
= features
,
1629 .feature_table_size
= ARRAY_SIZE(features
),
1630 .driver
.name
= KBUILD_MODNAME
,
1631 .driver
.owner
= THIS_MODULE
,
1632 .id_table
= id_table
,
1633 .probe
= virtcons_probe
,
1634 .remove
= virtcons_remove
,
1635 .config_changed
= config_intr
,
1638 static int __init
init(void)
1642 pdrvdata
.class = class_create(THIS_MODULE
, "virtio-ports");
1643 if (IS_ERR(pdrvdata
.class)) {
1644 err
= PTR_ERR(pdrvdata
.class);
1645 pr_err("Error %d creating virtio-ports class\n", err
);
1649 pdrvdata
.debugfs_dir
= debugfs_create_dir("virtio-ports", NULL
);
1650 if (!pdrvdata
.debugfs_dir
) {
1651 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1652 PTR_ERR(pdrvdata
.debugfs_dir
));
1654 INIT_LIST_HEAD(&pdrvdata
.consoles
);
1656 return register_virtio_driver(&virtio_console
);
1659 static void __exit
fini(void)
1661 unregister_virtio_driver(&virtio_console
);
1663 class_destroy(pdrvdata
.class);
1664 if (pdrvdata
.debugfs_dir
)
1665 debugfs_remove_recursive(pdrvdata
.debugfs_dir
);
1670 MODULE_DEVICE_TABLE(virtio
, id_table
);
1671 MODULE_DESCRIPTION("Virtio console driver");
1672 MODULE_LICENSE("GPL");