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 /* List of all the devices we're handling */
52 struct list_head portdevs
;
54 /* Number of devices this driver is handling */
58 * This is used to keep track of the number of hvc consoles
59 * spawned by this driver. This number is given as the first
60 * argument to hvc_alloc(). To correctly map an initial
61 * console spawned via hvc_instantiate to the console being
62 * hooked up via hvc_alloc, we need to pass the same vtermno.
64 * We also just assume the first console being initialised was
65 * the first one that got used as the initial console.
67 unsigned int next_vtermno
;
69 /* All the console devices handled by this driver */
70 struct list_head consoles
;
72 static struct ports_driver_data pdrvdata
;
74 DEFINE_SPINLOCK(pdrvdata_lock
);
76 /* This struct holds information that's relevant only for console ports */
78 /* We'll place all consoles in a list in the pdrvdata struct */
79 struct list_head list
;
81 /* The hvc device associated with this console port */
82 struct hvc_struct
*hvc
;
84 /* The size of the console */
88 * This number identifies the number that we used to register
89 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
90 * number passed on by the hvc callbacks to us to
91 * differentiate between the other console ports handled by
100 /* size of the buffer in *buf above */
103 /* used length of the buffer */
105 /* offset in the buf from which to consume data */
110 * This is a per-device struct that stores data common to all the
111 * ports for that device (vdev->priv).
113 struct ports_device
{
114 /* Next portdev in the list, head is in the pdrvdata struct */
115 struct list_head list
;
118 * Workqueue handlers where we process deferred work after
121 struct work_struct control_work
;
123 struct list_head ports
;
125 /* To protect the list of ports */
126 spinlock_t ports_lock
;
128 /* To protect the vq operations for the control channel */
131 /* The current config space is stored here */
132 struct virtio_console_config config
;
134 /* The virtio device we're associated with */
135 struct virtio_device
*vdev
;
138 * A couple of virtqueues for the control channel: one for
139 * guest->host transfers, one for host->guest transfers
141 struct virtqueue
*c_ivq
, *c_ovq
;
143 /* Array of per-port IO virtqueues */
144 struct virtqueue
**in_vqs
, **out_vqs
;
146 /* Used for numbering devices for sysfs and debugfs */
147 unsigned int drv_index
;
149 /* Major number for this device. Ports will be created as minors. */
153 /* This struct holds the per-port data */
155 /* Next port in the list, head is in the ports_device */
156 struct list_head list
;
158 /* Pointer to the parent virtio_console device */
159 struct ports_device
*portdev
;
161 /* The current buffer from which data has to be fed to readers */
162 struct port_buffer
*inbuf
;
165 * To protect the operations on the in_vq associated with this
166 * port. Has to be a spinlock because it can be called from
167 * interrupt context (get_char()).
169 spinlock_t inbuf_lock
;
171 /* Protect the operations on the out_vq. */
172 spinlock_t outvq_lock
;
174 /* The IO vqs for this port */
175 struct virtqueue
*in_vq
, *out_vq
;
177 /* File in the debugfs directory that exposes this port's information */
178 struct dentry
*debugfs_file
;
181 * The entries in this struct will be valid if this port is
182 * hooked up to an hvc console
186 /* Each port associates with a separate char device */
190 /* A waitqueue for poll() or blocking read operations */
191 wait_queue_head_t waitqueue
;
193 /* The 'name' of the port that we expose via sysfs properties */
196 /* The 'id' to identify the port with the Host */
201 /* Is the host device open */
204 /* We should allow only one process to open a port */
205 bool guest_connected
;
208 /* This is the very early arch-specified put chars function. */
209 static int (*early_put_chars
)(u32
, const char *, int);
211 static struct port
*find_port_by_vtermno(u32 vtermno
)
214 struct console
*cons
;
217 spin_lock_irqsave(&pdrvdata_lock
, flags
);
218 list_for_each_entry(cons
, &pdrvdata
.consoles
, list
) {
219 if (cons
->vtermno
== vtermno
) {
220 port
= container_of(cons
, struct port
, cons
);
226 spin_unlock_irqrestore(&pdrvdata_lock
, flags
);
230 static struct port
*find_port_by_id(struct ports_device
*portdev
, u32 id
)
235 spin_lock_irqsave(&portdev
->ports_lock
, flags
);
236 list_for_each_entry(port
, &portdev
->ports
, list
)
241 spin_unlock_irqrestore(&portdev
->ports_lock
, flags
);
246 static struct port
*find_port_by_vq(struct ports_device
*portdev
,
247 struct virtqueue
*vq
)
252 spin_lock_irqsave(&portdev
->ports_lock
, flags
);
253 list_for_each_entry(port
, &portdev
->ports
, list
)
254 if (port
->in_vq
== vq
|| port
->out_vq
== vq
)
258 spin_unlock_irqrestore(&portdev
->ports_lock
, flags
);
262 static bool is_console_port(struct port
*port
)
269 static inline bool use_multiport(struct ports_device
*portdev
)
272 * This condition can be true when put_chars is called from
277 return portdev
->vdev
->features
[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT
);
280 static void free_buf(struct port_buffer
*buf
)
286 static struct port_buffer
*alloc_buf(size_t buf_size
)
288 struct port_buffer
*buf
;
290 buf
= kmalloc(sizeof(*buf
), GFP_KERNEL
);
293 buf
->buf
= kzalloc(buf_size
, GFP_KERNEL
);
298 buf
->size
= buf_size
;
307 /* Callers should take appropriate locks */
308 static void *get_inbuf(struct port
*port
)
310 struct port_buffer
*buf
;
311 struct virtqueue
*vq
;
315 buf
= virtqueue_get_buf(vq
, &len
);
324 * Create a scatter-gather list representing our input buffer and put
327 * Callers should take appropriate locks.
329 static int add_inbuf(struct virtqueue
*vq
, struct port_buffer
*buf
)
331 struct scatterlist sg
[1];
334 sg_init_one(sg
, buf
->buf
, buf
->size
);
336 ret
= virtqueue_add_buf(vq
, sg
, 0, 1, buf
);
341 /* Discard any unread data this port has. Callers lockers. */
342 static void discard_port_data(struct port
*port
)
344 struct port_buffer
*buf
;
345 struct virtqueue
*vq
;
353 buf
= virtqueue_get_buf(vq
, &len
);
357 if (add_inbuf(vq
, buf
) < 0) {
361 buf
= virtqueue_get_buf(vq
, &len
);
365 dev_warn(port
->dev
, "Errors adding %d buffers back to vq\n",
369 static bool port_has_data(struct port
*port
)
374 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
379 port
->inbuf
= get_inbuf(port
);
386 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
390 static ssize_t
__send_control_msg(struct ports_device
*portdev
, u32 port_id
,
391 unsigned int event
, unsigned int value
)
393 struct scatterlist sg
[1];
394 struct virtio_console_control cpkt
;
395 struct virtqueue
*vq
;
398 if (!use_multiport(portdev
))
407 sg_init_one(sg
, &cpkt
, sizeof(cpkt
));
408 if (virtqueue_add_buf(vq
, sg
, 1, 0, &cpkt
) >= 0) {
410 while (!virtqueue_get_buf(vq
, &len
))
416 static ssize_t
send_control_msg(struct port
*port
, unsigned int event
,
419 /* Did the port get unplugged before userspace closed it? */
421 return __send_control_msg(port
->portdev
, port
->id
, event
, value
);
425 /* Callers must take the port->outvq_lock */
426 static void reclaim_consumed_buffers(struct port
*port
)
431 while ((buf
= virtqueue_get_buf(port
->out_vq
, &len
))) {
433 port
->outvq_full
= false;
437 static ssize_t
send_buf(struct port
*port
, void *in_buf
, size_t in_count
,
440 struct scatterlist sg
[1];
441 struct virtqueue
*out_vq
;
446 out_vq
= port
->out_vq
;
448 spin_lock_irqsave(&port
->outvq_lock
, flags
);
450 reclaim_consumed_buffers(port
);
452 sg_init_one(sg
, in_buf
, in_count
);
453 ret
= virtqueue_add_buf(out_vq
, sg
, 1, 0, in_buf
);
455 /* Tell Host to go! */
456 virtqueue_kick(out_vq
);
464 port
->outvq_full
= true;
470 * Wait till the host acknowledges it pushed out the data we
471 * sent. This is done for data from the hvc_console; the tty
472 * operations are performed with spinlocks held so we can't
473 * sleep here. An alternative would be to copy the data to a
474 * buffer and relax the spinning requirement. The downside is
475 * we need to kmalloc a GFP_ATOMIC buffer each time the
476 * console driver writes something out.
478 while (!virtqueue_get_buf(out_vq
, &len
))
481 spin_unlock_irqrestore(&port
->outvq_lock
, flags
);
483 * We're expected to return the amount of data we wrote -- all
490 * Give out the data that's requested from the buffer that we have
493 static ssize_t
fill_readbuf(struct port
*port
, char *out_buf
, size_t out_count
,
496 struct port_buffer
*buf
;
499 if (!out_count
|| !port_has_data(port
))
503 out_count
= min(out_count
, buf
->len
- buf
->offset
);
508 ret
= copy_to_user(out_buf
, buf
->buf
+ buf
->offset
, out_count
);
512 memcpy(out_buf
, buf
->buf
+ buf
->offset
, out_count
);
515 buf
->offset
+= out_count
;
517 if (buf
->offset
== buf
->len
) {
519 * We're done using all the data in this buffer.
520 * Re-queue so that the Host can send us more data.
522 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
525 if (add_inbuf(port
->in_vq
, buf
) < 0)
526 dev_warn(port
->dev
, "failed add_buf\n");
528 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
530 /* Return the number of bytes actually copied */
534 /* The condition that must be true for polling to end */
535 static bool will_read_block(struct port
*port
)
537 if (!port
->guest_connected
) {
538 /* Port got hot-unplugged. Let's exit. */
541 return !port_has_data(port
) && port
->host_connected
;
544 static bool will_write_block(struct port
*port
)
548 if (!port
->guest_connected
) {
549 /* Port got hot-unplugged. Let's exit. */
552 if (!port
->host_connected
)
555 spin_lock_irq(&port
->outvq_lock
);
557 * Check if the Host has consumed any buffers since we last
558 * sent data (this is only applicable for nonblocking ports).
560 reclaim_consumed_buffers(port
);
561 ret
= port
->outvq_full
;
562 spin_unlock_irq(&port
->outvq_lock
);
567 static ssize_t
port_fops_read(struct file
*filp
, char __user
*ubuf
,
568 size_t count
, loff_t
*offp
)
573 port
= filp
->private_data
;
575 if (!port_has_data(port
)) {
577 * If nothing's connected on the host just return 0 in
578 * case of list_empty; this tells the userspace app
579 * that there's no connection
581 if (!port
->host_connected
)
583 if (filp
->f_flags
& O_NONBLOCK
)
586 ret
= wait_event_interruptible(port
->waitqueue
,
587 !will_read_block(port
));
591 /* Port got hot-unplugged. */
592 if (!port
->guest_connected
)
595 * We could've received a disconnection message while we were
596 * waiting for more data.
598 * This check is not clubbed in the if() statement above as we
599 * might receive some data as well as the host could get
600 * disconnected after we got woken up from our wait. So we
601 * really want to give off whatever data we have and only then
602 * check for host_connected.
604 if (!port_has_data(port
) && !port
->host_connected
)
607 return fill_readbuf(port
, ubuf
, count
, true);
610 static ssize_t
port_fops_write(struct file
*filp
, const char __user
*ubuf
,
611 size_t count
, loff_t
*offp
)
618 /* Userspace could be out to fool us */
622 port
= filp
->private_data
;
624 nonblock
= filp
->f_flags
& O_NONBLOCK
;
626 if (will_write_block(port
)) {
630 ret
= wait_event_interruptible(port
->waitqueue
,
631 !will_write_block(port
));
635 /* Port got hot-unplugged. */
636 if (!port
->guest_connected
)
639 count
= min((size_t)(32 * 1024), count
);
641 buf
= kmalloc(count
, GFP_KERNEL
);
645 ret
= copy_from_user(buf
, ubuf
, count
);
652 * We now ask send_buf() to not spin for generic ports -- we
653 * can re-use the same code path that non-blocking file
654 * descriptors take for blocking file descriptors since the
655 * wait is already done and we're certain the write will go
656 * through to the host.
659 ret
= send_buf(port
, buf
, count
, nonblock
);
661 if (nonblock
&& ret
> 0)
670 static unsigned int port_fops_poll(struct file
*filp
, poll_table
*wait
)
675 port
= filp
->private_data
;
676 poll_wait(filp
, &port
->waitqueue
, wait
);
678 if (!port
->guest_connected
) {
679 /* Port got unplugged */
683 if (!will_read_block(port
))
684 ret
|= POLLIN
| POLLRDNORM
;
685 if (!will_write_block(port
))
687 if (!port
->host_connected
)
693 static int port_fops_release(struct inode
*inode
, struct file
*filp
)
697 port
= filp
->private_data
;
699 /* Notify host of port being closed */
700 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
702 spin_lock_irq(&port
->inbuf_lock
);
703 port
->guest_connected
= false;
705 discard_port_data(port
);
707 spin_unlock_irq(&port
->inbuf_lock
);
709 spin_lock_irq(&port
->outvq_lock
);
710 reclaim_consumed_buffers(port
);
711 spin_unlock_irq(&port
->outvq_lock
);
716 static int port_fops_open(struct inode
*inode
, struct file
*filp
)
718 struct cdev
*cdev
= inode
->i_cdev
;
722 port
= container_of(cdev
, struct port
, cdev
);
723 filp
->private_data
= port
;
726 * Don't allow opening of console port devices -- that's done
729 if (is_console_port(port
)) {
734 /* Allow only one process to open a particular port at a time */
735 spin_lock_irq(&port
->inbuf_lock
);
736 if (port
->guest_connected
) {
737 spin_unlock_irq(&port
->inbuf_lock
);
742 port
->guest_connected
= true;
743 spin_unlock_irq(&port
->inbuf_lock
);
745 spin_lock_irq(&port
->outvq_lock
);
747 * There might be a chance that we missed reclaiming a few
748 * buffers in the window of the port getting previously closed
751 reclaim_consumed_buffers(port
);
752 spin_unlock_irq(&port
->outvq_lock
);
754 /* Notify host of port being opened */
755 send_control_msg(filp
->private_data
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
763 * The file operations that we support: programs in the guest can open
764 * a console device, read from it, write to it, poll for data and
765 * close it. The devices are at
766 * /dev/vport<device number>p<port number>
768 static const struct file_operations port_fops
= {
769 .owner
= THIS_MODULE
,
770 .open
= port_fops_open
,
771 .read
= port_fops_read
,
772 .write
= port_fops_write
,
773 .poll
= port_fops_poll
,
774 .release
= port_fops_release
,
778 * The put_chars() callback is pretty straightforward.
780 * We turn the characters into a scatter-gather list, add it to the
781 * output queue and then kick the Host. Then we sit here waiting for
782 * it to finish: inefficient in theory, but in practice
783 * implementations will do it immediately (lguest's Launcher does).
785 static int put_chars(u32 vtermno
, const char *buf
, int count
)
789 if (unlikely(early_put_chars
))
790 return early_put_chars(vtermno
, buf
, count
);
792 port
= find_port_by_vtermno(vtermno
);
796 return send_buf(port
, (void *)buf
, count
, false);
800 * get_chars() is the callback from the hvc_console infrastructure
801 * when an interrupt is received.
803 * We call out to fill_readbuf that gets us the required data from the
804 * buffers that are queued up.
806 static int get_chars(u32 vtermno
, char *buf
, int count
)
810 /* If we've not set up the port yet, we have no input to give. */
811 if (unlikely(early_put_chars
))
814 port
= find_port_by_vtermno(vtermno
);
818 /* If we don't have an input queue yet, we can't get input. */
819 BUG_ON(!port
->in_vq
);
821 return fill_readbuf(port
, buf
, count
, false);
824 static void resize_console(struct port
*port
)
826 struct virtio_device
*vdev
;
828 /* The port could have been hot-unplugged */
829 if (!port
|| !is_console_port(port
))
832 vdev
= port
->portdev
->vdev
;
833 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_SIZE
))
834 hvc_resize(port
->cons
.hvc
, port
->cons
.ws
);
837 /* We set the configuration at this point, since we now have a tty */
838 static int notifier_add_vio(struct hvc_struct
*hp
, int data
)
842 port
= find_port_by_vtermno(hp
->vtermno
);
846 hp
->irq_requested
= 1;
847 resize_console(port
);
852 static void notifier_del_vio(struct hvc_struct
*hp
, int data
)
854 hp
->irq_requested
= 0;
857 /* The operations for console ports. */
858 static const struct hv_ops hv_ops
= {
859 .get_chars
= get_chars
,
860 .put_chars
= put_chars
,
861 .notifier_add
= notifier_add_vio
,
862 .notifier_del
= notifier_del_vio
,
863 .notifier_hangup
= notifier_del_vio
,
867 * Console drivers are initialized very early so boot messages can go
868 * out, so we do things slightly differently from the generic virtio
869 * initialization of the net and block drivers.
871 * At this stage, the console is output-only. It's too early to set
872 * up a virtqueue, so we let the drivers do some boutique early-output
875 int __init
virtio_cons_early_init(int (*put_chars
)(u32
, const char *, int))
877 early_put_chars
= put_chars
;
878 return hvc_instantiate(0, 0, &hv_ops
);
881 int init_port_console(struct port
*port
)
886 * The Host's telling us this port is a console port. Hook it
887 * up with an hvc console.
889 * To set up and manage our virtual console, we call
892 * The first argument of hvc_alloc() is the virtual console
893 * number. The second argument is the parameter for the
894 * notification mechanism (like irq number). We currently
895 * leave this as zero, virtqueues have implicit notifications.
897 * The third argument is a "struct hv_ops" containing the
898 * put_chars() get_chars(), notifier_add() and notifier_del()
899 * pointers. The final argument is the output buffer size: we
900 * can do any size, so we put PAGE_SIZE here.
902 port
->cons
.vtermno
= pdrvdata
.next_vtermno
;
904 port
->cons
.hvc
= hvc_alloc(port
->cons
.vtermno
, 0, &hv_ops
, PAGE_SIZE
);
905 if (IS_ERR(port
->cons
.hvc
)) {
906 ret
= PTR_ERR(port
->cons
.hvc
);
908 "error %d allocating hvc for port\n", ret
);
909 port
->cons
.hvc
= NULL
;
912 spin_lock_irq(&pdrvdata_lock
);
913 pdrvdata
.next_vtermno
++;
914 list_add_tail(&port
->cons
.list
, &pdrvdata
.consoles
);
915 spin_unlock_irq(&pdrvdata_lock
);
916 port
->guest_connected
= true;
919 * Start using the new console output if this is the first
920 * console to come up.
923 early_put_chars
= NULL
;
925 /* Notify host of port being opened */
926 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
931 static ssize_t
show_port_name(struct device
*dev
,
932 struct device_attribute
*attr
, char *buffer
)
936 port
= dev_get_drvdata(dev
);
938 return sprintf(buffer
, "%s\n", port
->name
);
941 static DEVICE_ATTR(name
, S_IRUGO
, show_port_name
, NULL
);
943 static struct attribute
*port_sysfs_entries
[] = {
948 static struct attribute_group port_attribute_group
= {
949 .name
= NULL
, /* put in device directory */
950 .attrs
= port_sysfs_entries
,
953 static int debugfs_open(struct inode
*inode
, struct file
*filp
)
955 filp
->private_data
= inode
->i_private
;
959 static ssize_t
debugfs_read(struct file
*filp
, char __user
*ubuf
,
960 size_t count
, loff_t
*offp
)
964 ssize_t ret
, out_offset
, out_count
;
967 buf
= kmalloc(out_count
, GFP_KERNEL
);
971 port
= filp
->private_data
;
973 out_offset
+= snprintf(buf
+ out_offset
, out_count
,
974 "name: %s\n", port
->name
? port
->name
: "");
975 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
976 "guest_connected: %d\n", port
->guest_connected
);
977 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
978 "host_connected: %d\n", port
->host_connected
);
979 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
980 "outvq_full: %d\n", port
->outvq_full
);
981 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
983 is_console_port(port
) ? "yes" : "no");
984 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
985 "console_vtermno: %u\n", port
->cons
.vtermno
);
987 ret
= simple_read_from_buffer(ubuf
, count
, offp
, buf
, out_offset
);
992 static const struct file_operations port_debugfs_ops
= {
993 .owner
= THIS_MODULE
,
994 .open
= debugfs_open
,
995 .read
= debugfs_read
,
998 static void set_console_size(struct port
*port
, u16 rows
, u16 cols
)
1000 if (!port
|| !is_console_port(port
))
1003 port
->cons
.ws
.ws_row
= rows
;
1004 port
->cons
.ws
.ws_col
= cols
;
1007 static unsigned int fill_queue(struct virtqueue
*vq
, spinlock_t
*lock
)
1009 struct port_buffer
*buf
;
1010 unsigned int nr_added_bufs
;
1015 buf
= alloc_buf(PAGE_SIZE
);
1019 spin_lock_irq(lock
);
1020 ret
= add_inbuf(vq
, buf
);
1022 spin_unlock_irq(lock
);
1027 spin_unlock_irq(lock
);
1030 return nr_added_bufs
;
1033 static int add_port(struct ports_device
*portdev
, u32 id
)
1035 char debugfs_name
[16];
1037 struct port_buffer
*buf
;
1039 unsigned int nr_added_bufs
;
1042 port
= kmalloc(sizeof(*port
), GFP_KERNEL
);
1048 port
->portdev
= portdev
;
1053 port
->cons
.hvc
= NULL
;
1055 port
->cons
.ws
.ws_row
= port
->cons
.ws
.ws_col
= 0;
1057 port
->host_connected
= port
->guest_connected
= false;
1059 port
->outvq_full
= false;
1061 port
->in_vq
= portdev
->in_vqs
[port
->id
];
1062 port
->out_vq
= portdev
->out_vqs
[port
->id
];
1064 cdev_init(&port
->cdev
, &port_fops
);
1066 devt
= MKDEV(portdev
->chr_major
, id
);
1067 err
= cdev_add(&port
->cdev
, devt
, 1);
1069 dev_err(&port
->portdev
->vdev
->dev
,
1070 "Error %d adding cdev for port %u\n", err
, id
);
1073 port
->dev
= device_create(pdrvdata
.class, &port
->portdev
->vdev
->dev
,
1074 devt
, port
, "vport%up%u",
1075 port
->portdev
->drv_index
, id
);
1076 if (IS_ERR(port
->dev
)) {
1077 err
= PTR_ERR(port
->dev
);
1078 dev_err(&port
->portdev
->vdev
->dev
,
1079 "Error %d creating device for port %u\n",
1084 spin_lock_init(&port
->inbuf_lock
);
1085 spin_lock_init(&port
->outvq_lock
);
1086 init_waitqueue_head(&port
->waitqueue
);
1088 /* Fill the in_vq with buffers so the host can send us data. */
1089 nr_added_bufs
= fill_queue(port
->in_vq
, &port
->inbuf_lock
);
1090 if (!nr_added_bufs
) {
1091 dev_err(port
->dev
, "Error allocating inbufs\n");
1097 * If we're not using multiport support, this has to be a console port
1099 if (!use_multiport(port
->portdev
)) {
1100 err
= init_port_console(port
);
1105 spin_lock_irq(&portdev
->ports_lock
);
1106 list_add_tail(&port
->list
, &port
->portdev
->ports
);
1107 spin_unlock_irq(&portdev
->ports_lock
);
1110 * Tell the Host we're set so that it can send us various
1111 * configuration parameters for this port (eg, port name,
1112 * caching, whether this is a console port, etc.)
1114 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1116 if (pdrvdata
.debugfs_dir
) {
1118 * Finally, create the debugfs file that we can use to
1119 * inspect a port's state at any time
1121 sprintf(debugfs_name
, "vport%up%u",
1122 port
->portdev
->drv_index
, id
);
1123 port
->debugfs_file
= debugfs_create_file(debugfs_name
, 0444,
1124 pdrvdata
.debugfs_dir
,
1131 while ((buf
= virtqueue_detach_unused_buf(port
->in_vq
)))
1134 device_destroy(pdrvdata
.class, port
->dev
->devt
);
1136 cdev_del(&port
->cdev
);
1140 /* The host might want to notify management sw about port add failure */
1141 __send_control_msg(portdev
, id
, VIRTIO_CONSOLE_PORT_READY
, 0);
1145 /* Remove all port-specific data. */
1146 static void remove_port(struct port
*port
)
1148 struct port_buffer
*buf
;
1150 if (port
->guest_connected
) {
1151 port
->guest_connected
= false;
1152 port
->host_connected
= false;
1153 wake_up_interruptible(&port
->waitqueue
);
1154 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
1157 spin_lock_irq(&port
->portdev
->ports_lock
);
1158 list_del(&port
->list
);
1159 spin_unlock_irq(&port
->portdev
->ports_lock
);
1161 if (is_console_port(port
)) {
1162 spin_lock_irq(&pdrvdata_lock
);
1163 list_del(&port
->cons
.list
);
1164 spin_unlock_irq(&pdrvdata_lock
);
1167 * hvc_remove() not called as removing one hvc port
1168 * results in other hvc ports getting frozen.
1170 * Once this is resolved in hvc, this functionality
1171 * will be enabled. Till that is done, the -EPIPE
1172 * return from get_chars() above will help
1173 * hvc_console.c to clean up on ports we remove here.
1175 hvc_remove(port
->cons
.hvc
);
1178 sysfs_remove_group(&port
->dev
->kobj
, &port_attribute_group
);
1179 device_destroy(pdrvdata
.class, port
->dev
->devt
);
1180 cdev_del(&port
->cdev
);
1182 /* Remove unused data this port might have received. */
1183 discard_port_data(port
);
1185 reclaim_consumed_buffers(port
);
1187 /* Remove buffers we queued up for the Host to send us data in. */
1188 while ((buf
= virtqueue_detach_unused_buf(port
->in_vq
)))
1193 debugfs_remove(port
->debugfs_file
);
1198 /* Any private messages that the Host and Guest want to share */
1199 static void handle_control_message(struct ports_device
*portdev
,
1200 struct port_buffer
*buf
)
1202 struct virtio_console_control
*cpkt
;
1207 cpkt
= (struct virtio_console_control
*)(buf
->buf
+ buf
->offset
);
1209 port
= find_port_by_id(portdev
, cpkt
->id
);
1210 if (!port
&& cpkt
->event
!= VIRTIO_CONSOLE_PORT_ADD
) {
1211 /* No valid header at start of buffer. Drop it. */
1212 dev_dbg(&portdev
->vdev
->dev
,
1213 "Invalid index %u in control packet\n", cpkt
->id
);
1217 switch (cpkt
->event
) {
1218 case VIRTIO_CONSOLE_PORT_ADD
:
1220 dev_dbg(&portdev
->vdev
->dev
,
1221 "Port %u already added\n", port
->id
);
1222 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1225 if (cpkt
->id
>= portdev
->config
.max_nr_ports
) {
1226 dev_warn(&portdev
->vdev
->dev
,
1227 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1228 cpkt
->id
, portdev
->config
.max_nr_ports
- 1);
1231 add_port(portdev
, cpkt
->id
);
1233 case VIRTIO_CONSOLE_PORT_REMOVE
:
1236 case VIRTIO_CONSOLE_CONSOLE_PORT
:
1239 if (is_console_port(port
))
1242 init_port_console(port
);
1244 * Could remove the port here in case init fails - but
1245 * have to notify the host first.
1248 case VIRTIO_CONSOLE_RESIZE
: {
1254 if (!is_console_port(port
))
1257 memcpy(&size
, buf
->buf
+ buf
->offset
+ sizeof(*cpkt
),
1259 set_console_size(port
, size
.rows
, size
.cols
);
1261 port
->cons
.hvc
->irq_requested
= 1;
1262 resize_console(port
);
1265 case VIRTIO_CONSOLE_PORT_OPEN
:
1266 port
->host_connected
= cpkt
->value
;
1267 wake_up_interruptible(&port
->waitqueue
);
1269 * If the host port got closed and the host had any
1270 * unconsumed buffers, we'll be able to reclaim them
1273 spin_lock_irq(&port
->outvq_lock
);
1274 reclaim_consumed_buffers(port
);
1275 spin_unlock_irq(&port
->outvq_lock
);
1277 case VIRTIO_CONSOLE_PORT_NAME
:
1279 * Skip the size of the header and the cpkt to get the size
1280 * of the name that was sent
1282 name_size
= buf
->len
- buf
->offset
- sizeof(*cpkt
) + 1;
1284 port
->name
= kmalloc(name_size
, GFP_KERNEL
);
1287 "Not enough space to store port name\n");
1290 strncpy(port
->name
, buf
->buf
+ buf
->offset
+ sizeof(*cpkt
),
1292 port
->name
[name_size
- 1] = 0;
1295 * Since we only have one sysfs attribute, 'name',
1296 * create it only if we have a name for the port.
1298 err
= sysfs_create_group(&port
->dev
->kobj
,
1299 &port_attribute_group
);
1302 "Error %d creating sysfs device attributes\n",
1306 * Generate a udev event so that appropriate
1307 * symlinks can be created based on udev
1310 kobject_uevent(&port
->dev
->kobj
, KOBJ_CHANGE
);
1316 static void control_work_handler(struct work_struct
*work
)
1318 struct ports_device
*portdev
;
1319 struct virtqueue
*vq
;
1320 struct port_buffer
*buf
;
1323 portdev
= container_of(work
, struct ports_device
, control_work
);
1324 vq
= portdev
->c_ivq
;
1326 spin_lock(&portdev
->cvq_lock
);
1327 while ((buf
= virtqueue_get_buf(vq
, &len
))) {
1328 spin_unlock(&portdev
->cvq_lock
);
1333 handle_control_message(portdev
, buf
);
1335 spin_lock(&portdev
->cvq_lock
);
1336 if (add_inbuf(portdev
->c_ivq
, buf
) < 0) {
1337 dev_warn(&portdev
->vdev
->dev
,
1338 "Error adding buffer to queue\n");
1342 spin_unlock(&portdev
->cvq_lock
);
1345 static void in_intr(struct virtqueue
*vq
)
1348 unsigned long flags
;
1350 port
= find_port_by_vq(vq
->vdev
->priv
, vq
);
1354 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
1356 port
->inbuf
= get_inbuf(port
);
1359 * Don't queue up data when port is closed. This condition
1360 * can be reached when a console port is not yet connected (no
1361 * tty is spawned) and the host sends out data to console
1362 * ports. For generic serial ports, the host won't
1363 * (shouldn't) send data till the guest is connected.
1365 if (!port
->guest_connected
)
1366 discard_port_data(port
);
1368 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
1370 wake_up_interruptible(&port
->waitqueue
);
1372 if (is_console_port(port
) && hvc_poll(port
->cons
.hvc
))
1376 static void control_intr(struct virtqueue
*vq
)
1378 struct ports_device
*portdev
;
1380 portdev
= vq
->vdev
->priv
;
1381 schedule_work(&portdev
->control_work
);
1384 static void config_intr(struct virtio_device
*vdev
)
1386 struct ports_device
*portdev
;
1388 portdev
= vdev
->priv
;
1390 if (!use_multiport(portdev
)) {
1394 vdev
->config
->get(vdev
,
1395 offsetof(struct virtio_console_config
, cols
),
1396 &cols
, sizeof(u16
));
1397 vdev
->config
->get(vdev
,
1398 offsetof(struct virtio_console_config
, rows
),
1399 &rows
, sizeof(u16
));
1401 port
= find_port_by_id(portdev
, 0);
1402 set_console_size(port
, rows
, cols
);
1405 * We'll use this way of resizing only for legacy
1406 * support. For newer userspace
1407 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1408 * to indicate console size changes so that it can be
1411 resize_console(port
);
1415 static int init_vqs(struct ports_device
*portdev
)
1417 vq_callback_t
**io_callbacks
;
1419 struct virtqueue
**vqs
;
1420 u32 i
, j
, nr_ports
, nr_queues
;
1423 nr_ports
= portdev
->config
.max_nr_ports
;
1424 nr_queues
= use_multiport(portdev
) ? (nr_ports
+ 1) * 2 : 2;
1426 vqs
= kmalloc(nr_queues
* sizeof(struct virtqueue
*), GFP_KERNEL
);
1431 io_callbacks
= kmalloc(nr_queues
* sizeof(vq_callback_t
*), GFP_KERNEL
);
1432 if (!io_callbacks
) {
1436 io_names
= kmalloc(nr_queues
* sizeof(char *), GFP_KERNEL
);
1439 goto free_callbacks
;
1441 portdev
->in_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1443 if (!portdev
->in_vqs
) {
1447 portdev
->out_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1449 if (!portdev
->out_vqs
) {
1455 * For backward compat (newer host but older guest), the host
1456 * spawns a console port first and also inits the vqs for port
1460 io_callbacks
[j
] = in_intr
;
1461 io_callbacks
[j
+ 1] = NULL
;
1462 io_names
[j
] = "input";
1463 io_names
[j
+ 1] = "output";
1466 if (use_multiport(portdev
)) {
1467 io_callbacks
[j
] = control_intr
;
1468 io_callbacks
[j
+ 1] = NULL
;
1469 io_names
[j
] = "control-i";
1470 io_names
[j
+ 1] = "control-o";
1472 for (i
= 1; i
< nr_ports
; i
++) {
1474 io_callbacks
[j
] = in_intr
;
1475 io_callbacks
[j
+ 1] = NULL
;
1476 io_names
[j
] = "input";
1477 io_names
[j
+ 1] = "output";
1480 /* Find the queues. */
1481 err
= portdev
->vdev
->config
->find_vqs(portdev
->vdev
, nr_queues
, vqs
,
1483 (const char **)io_names
);
1488 portdev
->in_vqs
[0] = vqs
[0];
1489 portdev
->out_vqs
[0] = vqs
[1];
1491 if (use_multiport(portdev
)) {
1492 portdev
->c_ivq
= vqs
[j
];
1493 portdev
->c_ovq
= vqs
[j
+ 1];
1495 for (i
= 1; i
< nr_ports
; i
++) {
1497 portdev
->in_vqs
[i
] = vqs
[j
];
1498 portdev
->out_vqs
[i
] = vqs
[j
+ 1];
1501 kfree(io_callbacks
);
1510 kfree(io_callbacks
);
1512 kfree(portdev
->out_vqs
);
1514 kfree(portdev
->in_vqs
);
1521 static const struct file_operations portdev_fops
= {
1522 .owner
= THIS_MODULE
,
1526 * Once we're further in boot, we get probed like any other virtio
1529 * If the host also supports multiple console ports, we check the
1530 * config space to see how many ports the host has spawned. We
1531 * initialize each port found.
1533 static int __devinit
virtcons_probe(struct virtio_device
*vdev
)
1535 struct ports_device
*portdev
;
1539 portdev
= kmalloc(sizeof(*portdev
), GFP_KERNEL
);
1545 /* Attach this portdev to this virtio_device, and vice-versa. */
1546 portdev
->vdev
= vdev
;
1547 vdev
->priv
= portdev
;
1549 spin_lock_irq(&pdrvdata_lock
);
1550 portdev
->drv_index
= pdrvdata
.index
++;
1551 spin_unlock_irq(&pdrvdata_lock
);
1553 portdev
->chr_major
= register_chrdev(0, "virtio-portsdev",
1555 if (portdev
->chr_major
< 0) {
1557 "Error %d registering chrdev for device %u\n",
1558 portdev
->chr_major
, portdev
->drv_index
);
1559 err
= portdev
->chr_major
;
1564 portdev
->config
.max_nr_ports
= 1;
1565 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_MULTIPORT
)) {
1567 vdev
->features
[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT
;
1569 vdev
->config
->get(vdev
, offsetof(struct virtio_console_config
,
1571 &portdev
->config
.max_nr_ports
,
1572 sizeof(portdev
->config
.max_nr_ports
));
1575 /* Let the Host know we support multiple ports.*/
1576 vdev
->config
->finalize_features(vdev
);
1578 err
= init_vqs(portdev
);
1580 dev_err(&vdev
->dev
, "Error %d initializing vqs\n", err
);
1584 spin_lock_init(&portdev
->ports_lock
);
1585 INIT_LIST_HEAD(&portdev
->ports
);
1588 unsigned int nr_added_bufs
;
1590 spin_lock_init(&portdev
->cvq_lock
);
1591 INIT_WORK(&portdev
->control_work
, &control_work_handler
);
1593 nr_added_bufs
= fill_queue(portdev
->c_ivq
, &portdev
->cvq_lock
);
1594 if (!nr_added_bufs
) {
1596 "Error allocating buffers for control queue\n");
1602 * For backward compatibility: Create a console port
1603 * if we're running on older host.
1605 add_port(portdev
, 0);
1608 spin_lock_irq(&pdrvdata_lock
);
1609 list_add_tail(&portdev
->list
, &pdrvdata
.portdevs
);
1610 spin_unlock_irq(&pdrvdata_lock
);
1612 __send_control_msg(portdev
, VIRTIO_CONSOLE_BAD_ID
,
1613 VIRTIO_CONSOLE_DEVICE_READY
, 1);
1617 /* The host might want to notify mgmt sw about device add failure */
1618 __send_control_msg(portdev
, VIRTIO_CONSOLE_BAD_ID
,
1619 VIRTIO_CONSOLE_DEVICE_READY
, 0);
1620 vdev
->config
->del_vqs(vdev
);
1621 kfree(portdev
->in_vqs
);
1622 kfree(portdev
->out_vqs
);
1624 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1631 static void virtcons_remove(struct virtio_device
*vdev
)
1633 struct ports_device
*portdev
;
1634 struct port
*port
, *port2
;
1636 portdev
= vdev
->priv
;
1638 spin_lock_irq(&pdrvdata_lock
);
1639 list_del(&portdev
->list
);
1640 spin_unlock_irq(&pdrvdata_lock
);
1642 /* Disable interrupts for vqs */
1643 vdev
->config
->reset(vdev
);
1644 /* Finish up work that's lined up */
1645 cancel_work_sync(&portdev
->control_work
);
1647 list_for_each_entry_safe(port
, port2
, &portdev
->ports
, list
)
1650 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1652 if (use_multiport(portdev
)) {
1653 struct port_buffer
*buf
;
1656 while ((buf
= virtqueue_get_buf(portdev
->c_ivq
, &len
)))
1659 while ((buf
= virtqueue_detach_unused_buf(portdev
->c_ivq
)))
1663 vdev
->config
->del_vqs(vdev
);
1664 kfree(portdev
->in_vqs
);
1665 kfree(portdev
->out_vqs
);
1670 static struct virtio_device_id id_table
[] = {
1671 { VIRTIO_ID_CONSOLE
, VIRTIO_DEV_ANY_ID
},
1675 static unsigned int features
[] = {
1676 VIRTIO_CONSOLE_F_SIZE
,
1677 VIRTIO_CONSOLE_F_MULTIPORT
,
1680 static struct virtio_driver virtio_console
= {
1681 .feature_table
= features
,
1682 .feature_table_size
= ARRAY_SIZE(features
),
1683 .driver
.name
= KBUILD_MODNAME
,
1684 .driver
.owner
= THIS_MODULE
,
1685 .id_table
= id_table
,
1686 .probe
= virtcons_probe
,
1687 .remove
= virtcons_remove
,
1688 .config_changed
= config_intr
,
1691 static int __init
init(void)
1695 pdrvdata
.class = class_create(THIS_MODULE
, "virtio-ports");
1696 if (IS_ERR(pdrvdata
.class)) {
1697 err
= PTR_ERR(pdrvdata
.class);
1698 pr_err("Error %d creating virtio-ports class\n", err
);
1702 pdrvdata
.debugfs_dir
= debugfs_create_dir("virtio-ports", NULL
);
1703 if (!pdrvdata
.debugfs_dir
) {
1704 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1705 PTR_ERR(pdrvdata
.debugfs_dir
));
1707 INIT_LIST_HEAD(&pdrvdata
.consoles
);
1708 INIT_LIST_HEAD(&pdrvdata
.portdevs
);
1710 return register_virtio_driver(&virtio_console
);
1713 static void __exit
fini(void)
1715 unregister_virtio_driver(&virtio_console
);
1717 class_destroy(pdrvdata
.class);
1718 if (pdrvdata
.debugfs_dir
)
1719 debugfs_remove_recursive(pdrvdata
.debugfs_dir
);
1724 MODULE_DEVICE_TABLE(virtio
, id_table
);
1725 MODULE_DESCRIPTION("Virtio console driver");
1726 MODULE_LICENSE("GPL");