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
->host_connected
)
535 spin_lock_irq(&port
->outvq_lock
);
537 * Check if the Host has consumed any buffers since we last
538 * sent data (this is only applicable for nonblocking ports).
540 reclaim_consumed_buffers(port
);
541 ret
= port
->outvq_full
;
542 spin_unlock_irq(&port
->outvq_lock
);
547 static ssize_t
port_fops_read(struct file
*filp
, char __user
*ubuf
,
548 size_t count
, loff_t
*offp
)
553 port
= filp
->private_data
;
555 if (!port_has_data(port
)) {
557 * If nothing's connected on the host just return 0 in
558 * case of list_empty; this tells the userspace app
559 * that there's no connection
561 if (!port
->host_connected
)
563 if (filp
->f_flags
& O_NONBLOCK
)
566 ret
= wait_event_interruptible(port
->waitqueue
,
567 !will_read_block(port
));
572 * We could've received a disconnection message while we were
573 * waiting for more data.
575 * This check is not clubbed in the if() statement above as we
576 * might receive some data as well as the host could get
577 * disconnected after we got woken up from our wait. So we
578 * really want to give off whatever data we have and only then
579 * check for host_connected.
581 if (!port_has_data(port
) && !port
->host_connected
)
584 return fill_readbuf(port
, ubuf
, count
, true);
587 static ssize_t
port_fops_write(struct file
*filp
, const char __user
*ubuf
,
588 size_t count
, loff_t
*offp
)
595 port
= filp
->private_data
;
597 nonblock
= filp
->f_flags
& O_NONBLOCK
;
599 if (will_write_block(port
)) {
603 ret
= wait_event_interruptible(port
->waitqueue
,
604 !will_write_block(port
));
609 count
= min((size_t)(32 * 1024), count
);
611 buf
= kmalloc(count
, GFP_KERNEL
);
615 ret
= copy_from_user(buf
, ubuf
, count
);
621 ret
= send_buf(port
, buf
, count
, nonblock
);
623 if (nonblock
&& ret
> 0)
632 static unsigned int port_fops_poll(struct file
*filp
, poll_table
*wait
)
637 port
= filp
->private_data
;
638 poll_wait(filp
, &port
->waitqueue
, wait
);
642 ret
|= POLLIN
| POLLRDNORM
;
643 if (!will_write_block(port
))
645 if (!port
->host_connected
)
651 static int port_fops_release(struct inode
*inode
, struct file
*filp
)
655 port
= filp
->private_data
;
657 /* Notify host of port being closed */
658 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
660 spin_lock_irq(&port
->inbuf_lock
);
661 port
->guest_connected
= false;
663 discard_port_data(port
);
665 spin_unlock_irq(&port
->inbuf_lock
);
667 spin_lock_irq(&port
->outvq_lock
);
668 reclaim_consumed_buffers(port
);
669 spin_unlock_irq(&port
->outvq_lock
);
674 static int port_fops_open(struct inode
*inode
, struct file
*filp
)
676 struct cdev
*cdev
= inode
->i_cdev
;
679 port
= container_of(cdev
, struct port
, cdev
);
680 filp
->private_data
= port
;
683 * Don't allow opening of console port devices -- that's done
686 if (is_console_port(port
))
689 /* Allow only one process to open a particular port at a time */
690 spin_lock_irq(&port
->inbuf_lock
);
691 if (port
->guest_connected
) {
692 spin_unlock_irq(&port
->inbuf_lock
);
696 port
->guest_connected
= true;
697 spin_unlock_irq(&port
->inbuf_lock
);
699 spin_lock_irq(&port
->outvq_lock
);
701 * There might be a chance that we missed reclaiming a few
702 * buffers in the window of the port getting previously closed
705 reclaim_consumed_buffers(port
);
706 spin_unlock_irq(&port
->outvq_lock
);
708 /* Notify host of port being opened */
709 send_control_msg(filp
->private_data
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
715 * The file operations that we support: programs in the guest can open
716 * a console device, read from it, write to it, poll for data and
717 * close it. The devices are at
718 * /dev/vport<device number>p<port number>
720 static const struct file_operations port_fops
= {
721 .owner
= THIS_MODULE
,
722 .open
= port_fops_open
,
723 .read
= port_fops_read
,
724 .write
= port_fops_write
,
725 .poll
= port_fops_poll
,
726 .release
= port_fops_release
,
730 * The put_chars() callback is pretty straightforward.
732 * We turn the characters into a scatter-gather list, add it to the
733 * output queue and then kick the Host. Then we sit here waiting for
734 * it to finish: inefficient in theory, but in practice
735 * implementations will do it immediately (lguest's Launcher does).
737 static int put_chars(u32 vtermno
, const char *buf
, int count
)
741 if (unlikely(early_put_chars
))
742 return early_put_chars(vtermno
, buf
, count
);
744 port
= find_port_by_vtermno(vtermno
);
748 return send_buf(port
, (void *)buf
, count
, false);
752 * get_chars() is the callback from the hvc_console infrastructure
753 * when an interrupt is received.
755 * We call out to fill_readbuf that gets us the required data from the
756 * buffers that are queued up.
758 static int get_chars(u32 vtermno
, char *buf
, int count
)
762 /* If we've not set up the port yet, we have no input to give. */
763 if (unlikely(early_put_chars
))
766 port
= find_port_by_vtermno(vtermno
);
770 /* If we don't have an input queue yet, we can't get input. */
771 BUG_ON(!port
->in_vq
);
773 return fill_readbuf(port
, buf
, count
, false);
776 static void resize_console(struct port
*port
)
778 struct virtio_device
*vdev
;
780 /* The port could have been hot-unplugged */
781 if (!port
|| !is_console_port(port
))
784 vdev
= port
->portdev
->vdev
;
785 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_SIZE
))
786 hvc_resize(port
->cons
.hvc
, port
->cons
.ws
);
789 /* We set the configuration at this point, since we now have a tty */
790 static int notifier_add_vio(struct hvc_struct
*hp
, int data
)
794 port
= find_port_by_vtermno(hp
->vtermno
);
798 hp
->irq_requested
= 1;
799 resize_console(port
);
804 static void notifier_del_vio(struct hvc_struct
*hp
, int data
)
806 hp
->irq_requested
= 0;
809 /* The operations for console ports. */
810 static const struct hv_ops hv_ops
= {
811 .get_chars
= get_chars
,
812 .put_chars
= put_chars
,
813 .notifier_add
= notifier_add_vio
,
814 .notifier_del
= notifier_del_vio
,
815 .notifier_hangup
= notifier_del_vio
,
819 * Console drivers are initialized very early so boot messages can go
820 * out, so we do things slightly differently from the generic virtio
821 * initialization of the net and block drivers.
823 * At this stage, the console is output-only. It's too early to set
824 * up a virtqueue, so we let the drivers do some boutique early-output
827 int __init
virtio_cons_early_init(int (*put_chars
)(u32
, const char *, int))
829 early_put_chars
= put_chars
;
830 return hvc_instantiate(0, 0, &hv_ops
);
833 int init_port_console(struct port
*port
)
838 * The Host's telling us this port is a console port. Hook it
839 * up with an hvc console.
841 * To set up and manage our virtual console, we call
844 * The first argument of hvc_alloc() is the virtual console
845 * number. The second argument is the parameter for the
846 * notification mechanism (like irq number). We currently
847 * leave this as zero, virtqueues have implicit notifications.
849 * The third argument is a "struct hv_ops" containing the
850 * put_chars() get_chars(), notifier_add() and notifier_del()
851 * pointers. The final argument is the output buffer size: we
852 * can do any size, so we put PAGE_SIZE here.
854 port
->cons
.vtermno
= pdrvdata
.next_vtermno
;
856 port
->cons
.hvc
= hvc_alloc(port
->cons
.vtermno
, 0, &hv_ops
, PAGE_SIZE
);
857 if (IS_ERR(port
->cons
.hvc
)) {
858 ret
= PTR_ERR(port
->cons
.hvc
);
860 "error %d allocating hvc for port\n", ret
);
861 port
->cons
.hvc
= NULL
;
864 spin_lock_irq(&pdrvdata_lock
);
865 pdrvdata
.next_vtermno
++;
866 list_add_tail(&port
->cons
.list
, &pdrvdata
.consoles
);
867 spin_unlock_irq(&pdrvdata_lock
);
868 port
->guest_connected
= true;
871 * Start using the new console output if this is the first
872 * console to come up.
875 early_put_chars
= NULL
;
877 /* Notify host of port being opened */
878 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
883 static ssize_t
show_port_name(struct device
*dev
,
884 struct device_attribute
*attr
, char *buffer
)
888 port
= dev_get_drvdata(dev
);
890 return sprintf(buffer
, "%s\n", port
->name
);
893 static DEVICE_ATTR(name
, S_IRUGO
, show_port_name
, NULL
);
895 static struct attribute
*port_sysfs_entries
[] = {
900 static struct attribute_group port_attribute_group
= {
901 .name
= NULL
, /* put in device directory */
902 .attrs
= port_sysfs_entries
,
905 static int debugfs_open(struct inode
*inode
, struct file
*filp
)
907 filp
->private_data
= inode
->i_private
;
911 static ssize_t
debugfs_read(struct file
*filp
, char __user
*ubuf
,
912 size_t count
, loff_t
*offp
)
916 ssize_t ret
, out_offset
, out_count
;
919 buf
= kmalloc(out_count
, GFP_KERNEL
);
923 port
= filp
->private_data
;
925 out_offset
+= snprintf(buf
+ out_offset
, out_count
,
926 "name: %s\n", port
->name
? port
->name
: "");
927 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
928 "guest_connected: %d\n", port
->guest_connected
);
929 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
930 "host_connected: %d\n", port
->host_connected
);
931 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
932 "outvq_full: %d\n", port
->outvq_full
);
933 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
935 is_console_port(port
) ? "yes" : "no");
936 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
937 "console_vtermno: %u\n", port
->cons
.vtermno
);
939 ret
= simple_read_from_buffer(ubuf
, count
, offp
, buf
, out_offset
);
944 static const struct file_operations port_debugfs_ops
= {
945 .owner
= THIS_MODULE
,
946 .open
= debugfs_open
,
947 .read
= debugfs_read
,
950 static void set_console_size(struct port
*port
, u16 rows
, u16 cols
)
952 if (!port
|| !is_console_port(port
))
955 port
->cons
.ws
.ws_row
= rows
;
956 port
->cons
.ws
.ws_col
= cols
;
959 static unsigned int fill_queue(struct virtqueue
*vq
, spinlock_t
*lock
)
961 struct port_buffer
*buf
;
962 unsigned int nr_added_bufs
;
967 buf
= alloc_buf(PAGE_SIZE
);
972 ret
= add_inbuf(vq
, buf
);
974 spin_unlock_irq(lock
);
979 spin_unlock_irq(lock
);
982 return nr_added_bufs
;
985 static int add_port(struct ports_device
*portdev
, u32 id
)
987 char debugfs_name
[16];
989 struct port_buffer
*buf
;
991 unsigned int nr_added_bufs
;
994 port
= kmalloc(sizeof(*port
), GFP_KERNEL
);
1000 port
->portdev
= portdev
;
1005 port
->cons
.hvc
= NULL
;
1007 port
->cons
.ws
.ws_row
= port
->cons
.ws
.ws_col
= 0;
1009 port
->host_connected
= port
->guest_connected
= false;
1011 port
->outvq_full
= false;
1013 port
->in_vq
= portdev
->in_vqs
[port
->id
];
1014 port
->out_vq
= portdev
->out_vqs
[port
->id
];
1016 cdev_init(&port
->cdev
, &port_fops
);
1018 devt
= MKDEV(portdev
->chr_major
, id
);
1019 err
= cdev_add(&port
->cdev
, devt
, 1);
1021 dev_err(&port
->portdev
->vdev
->dev
,
1022 "Error %d adding cdev for port %u\n", err
, id
);
1025 port
->dev
= device_create(pdrvdata
.class, &port
->portdev
->vdev
->dev
,
1026 devt
, port
, "vport%up%u",
1027 port
->portdev
->drv_index
, id
);
1028 if (IS_ERR(port
->dev
)) {
1029 err
= PTR_ERR(port
->dev
);
1030 dev_err(&port
->portdev
->vdev
->dev
,
1031 "Error %d creating device for port %u\n",
1036 spin_lock_init(&port
->inbuf_lock
);
1037 spin_lock_init(&port
->outvq_lock
);
1038 init_waitqueue_head(&port
->waitqueue
);
1040 /* Fill the in_vq with buffers so the host can send us data. */
1041 nr_added_bufs
= fill_queue(port
->in_vq
, &port
->inbuf_lock
);
1042 if (!nr_added_bufs
) {
1043 dev_err(port
->dev
, "Error allocating inbufs\n");
1049 * If we're not using multiport support, this has to be a console port
1051 if (!use_multiport(port
->portdev
)) {
1052 err
= init_port_console(port
);
1057 spin_lock_irq(&portdev
->ports_lock
);
1058 list_add_tail(&port
->list
, &port
->portdev
->ports
);
1059 spin_unlock_irq(&portdev
->ports_lock
);
1062 * Tell the Host we're set so that it can send us various
1063 * configuration parameters for this port (eg, port name,
1064 * caching, whether this is a console port, etc.)
1066 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1068 if (pdrvdata
.debugfs_dir
) {
1070 * Finally, create the debugfs file that we can use to
1071 * inspect a port's state at any time
1073 sprintf(debugfs_name
, "vport%up%u",
1074 port
->portdev
->drv_index
, id
);
1075 port
->debugfs_file
= debugfs_create_file(debugfs_name
, 0444,
1076 pdrvdata
.debugfs_dir
,
1083 while ((buf
= virtqueue_detach_unused_buf(port
->in_vq
)))
1086 device_destroy(pdrvdata
.class, port
->dev
->devt
);
1088 cdev_del(&port
->cdev
);
1092 /* The host might want to notify management sw about port add failure */
1093 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 0);
1097 /* Remove all port-specific data. */
1098 static int remove_port(struct port
*port
)
1100 struct port_buffer
*buf
;
1102 spin_lock_irq(&port
->portdev
->ports_lock
);
1103 list_del(&port
->list
);
1104 spin_unlock_irq(&port
->portdev
->ports_lock
);
1106 if (is_console_port(port
)) {
1107 spin_lock_irq(&pdrvdata_lock
);
1108 list_del(&port
->cons
.list
);
1109 spin_unlock_irq(&pdrvdata_lock
);
1112 * hvc_remove() not called as removing one hvc port
1113 * results in other hvc ports getting frozen.
1115 * Once this is resolved in hvc, this functionality
1116 * will be enabled. Till that is done, the -EPIPE
1117 * return from get_chars() above will help
1118 * hvc_console.c to clean up on ports we remove here.
1120 hvc_remove(port
->cons
.hvc
);
1123 if (port
->guest_connected
)
1124 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
1126 sysfs_remove_group(&port
->dev
->kobj
, &port_attribute_group
);
1127 device_destroy(pdrvdata
.class, port
->dev
->devt
);
1128 cdev_del(&port
->cdev
);
1130 /* Remove unused data this port might have received. */
1131 discard_port_data(port
);
1133 reclaim_consumed_buffers(port
);
1135 /* Remove buffers we queued up for the Host to send us data in. */
1136 while ((buf
= virtqueue_detach_unused_buf(port
->in_vq
)))
1141 debugfs_remove(port
->debugfs_file
);
1147 /* Any private messages that the Host and Guest want to share */
1148 static void handle_control_message(struct ports_device
*portdev
,
1149 struct port_buffer
*buf
)
1151 struct virtio_console_control
*cpkt
;
1156 cpkt
= (struct virtio_console_control
*)(buf
->buf
+ buf
->offset
);
1158 port
= find_port_by_id(portdev
, cpkt
->id
);
1159 if (!port
&& cpkt
->event
!= VIRTIO_CONSOLE_PORT_ADD
) {
1160 /* No valid header at start of buffer. Drop it. */
1161 dev_dbg(&portdev
->vdev
->dev
,
1162 "Invalid index %u in control packet\n", cpkt
->id
);
1166 switch (cpkt
->event
) {
1167 case VIRTIO_CONSOLE_PORT_ADD
:
1169 dev_dbg(&portdev
->vdev
->dev
,
1170 "Port %u already added\n", port
->id
);
1171 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1174 if (cpkt
->id
>= portdev
->config
.max_nr_ports
) {
1175 dev_warn(&portdev
->vdev
->dev
,
1176 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1177 cpkt
->id
, portdev
->config
.max_nr_ports
- 1);
1180 add_port(portdev
, cpkt
->id
);
1182 case VIRTIO_CONSOLE_PORT_REMOVE
:
1185 case VIRTIO_CONSOLE_CONSOLE_PORT
:
1188 if (is_console_port(port
))
1191 init_port_console(port
);
1193 * Could remove the port here in case init fails - but
1194 * have to notify the host first.
1197 case VIRTIO_CONSOLE_RESIZE
: {
1203 if (!is_console_port(port
))
1206 memcpy(&size
, buf
->buf
+ buf
->offset
+ sizeof(*cpkt
),
1208 set_console_size(port
, size
.rows
, size
.cols
);
1210 port
->cons
.hvc
->irq_requested
= 1;
1211 resize_console(port
);
1214 case VIRTIO_CONSOLE_PORT_OPEN
:
1215 port
->host_connected
= cpkt
->value
;
1216 wake_up_interruptible(&port
->waitqueue
);
1218 * If the host port got closed and the host had any
1219 * unconsumed buffers, we'll be able to reclaim them
1222 spin_lock_irq(&port
->outvq_lock
);
1223 reclaim_consumed_buffers(port
);
1224 spin_unlock_irq(&port
->outvq_lock
);
1226 case VIRTIO_CONSOLE_PORT_NAME
:
1228 * Skip the size of the header and the cpkt to get the size
1229 * of the name that was sent
1231 name_size
= buf
->len
- buf
->offset
- sizeof(*cpkt
) + 1;
1233 port
->name
= kmalloc(name_size
, GFP_KERNEL
);
1236 "Not enough space to store port name\n");
1239 strncpy(port
->name
, buf
->buf
+ buf
->offset
+ sizeof(*cpkt
),
1241 port
->name
[name_size
- 1] = 0;
1244 * Since we only have one sysfs attribute, 'name',
1245 * create it only if we have a name for the port.
1247 err
= sysfs_create_group(&port
->dev
->kobj
,
1248 &port_attribute_group
);
1251 "Error %d creating sysfs device attributes\n",
1255 * Generate a udev event so that appropriate
1256 * symlinks can be created based on udev
1259 kobject_uevent(&port
->dev
->kobj
, KOBJ_CHANGE
);
1265 static void control_work_handler(struct work_struct
*work
)
1267 struct ports_device
*portdev
;
1268 struct virtqueue
*vq
;
1269 struct port_buffer
*buf
;
1272 portdev
= container_of(work
, struct ports_device
, control_work
);
1273 vq
= portdev
->c_ivq
;
1275 spin_lock(&portdev
->cvq_lock
);
1276 while ((buf
= virtqueue_get_buf(vq
, &len
))) {
1277 spin_unlock(&portdev
->cvq_lock
);
1282 handle_control_message(portdev
, buf
);
1284 spin_lock(&portdev
->cvq_lock
);
1285 if (add_inbuf(portdev
->c_ivq
, buf
) < 0) {
1286 dev_warn(&portdev
->vdev
->dev
,
1287 "Error adding buffer to queue\n");
1291 spin_unlock(&portdev
->cvq_lock
);
1294 static void in_intr(struct virtqueue
*vq
)
1297 unsigned long flags
;
1299 port
= find_port_by_vq(vq
->vdev
->priv
, vq
);
1303 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
1305 port
->inbuf
= get_inbuf(port
);
1308 * Don't queue up data when port is closed. This condition
1309 * can be reached when a console port is not yet connected (no
1310 * tty is spawned) and the host sends out data to console
1311 * ports. For generic serial ports, the host won't
1312 * (shouldn't) send data till the guest is connected.
1314 if (!port
->guest_connected
)
1315 discard_port_data(port
);
1317 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
1319 wake_up_interruptible(&port
->waitqueue
);
1321 if (is_console_port(port
) && hvc_poll(port
->cons
.hvc
))
1325 static void control_intr(struct virtqueue
*vq
)
1327 struct ports_device
*portdev
;
1329 portdev
= vq
->vdev
->priv
;
1330 schedule_work(&portdev
->control_work
);
1333 static void config_intr(struct virtio_device
*vdev
)
1335 struct ports_device
*portdev
;
1337 portdev
= vdev
->priv
;
1339 if (!use_multiport(portdev
)) {
1343 vdev
->config
->get(vdev
,
1344 offsetof(struct virtio_console_config
, cols
),
1345 &cols
, sizeof(u16
));
1346 vdev
->config
->get(vdev
,
1347 offsetof(struct virtio_console_config
, rows
),
1348 &rows
, sizeof(u16
));
1350 port
= find_port_by_id(portdev
, 0);
1351 set_console_size(port
, rows
, cols
);
1354 * We'll use this way of resizing only for legacy
1355 * support. For newer userspace
1356 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1357 * to indicate console size changes so that it can be
1360 resize_console(port
);
1364 static int init_vqs(struct ports_device
*portdev
)
1366 vq_callback_t
**io_callbacks
;
1368 struct virtqueue
**vqs
;
1369 u32 i
, j
, nr_ports
, nr_queues
;
1372 nr_ports
= portdev
->config
.max_nr_ports
;
1373 nr_queues
= use_multiport(portdev
) ? (nr_ports
+ 1) * 2 : 2;
1375 vqs
= kmalloc(nr_queues
* sizeof(struct virtqueue
*), GFP_KERNEL
);
1380 io_callbacks
= kmalloc(nr_queues
* sizeof(vq_callback_t
*), GFP_KERNEL
);
1381 if (!io_callbacks
) {
1385 io_names
= kmalloc(nr_queues
* sizeof(char *), GFP_KERNEL
);
1388 goto free_callbacks
;
1390 portdev
->in_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1392 if (!portdev
->in_vqs
) {
1396 portdev
->out_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1398 if (!portdev
->out_vqs
) {
1404 * For backward compat (newer host but older guest), the host
1405 * spawns a console port first and also inits the vqs for port
1409 io_callbacks
[j
] = in_intr
;
1410 io_callbacks
[j
+ 1] = NULL
;
1411 io_names
[j
] = "input";
1412 io_names
[j
+ 1] = "output";
1415 if (use_multiport(portdev
)) {
1416 io_callbacks
[j
] = control_intr
;
1417 io_callbacks
[j
+ 1] = NULL
;
1418 io_names
[j
] = "control-i";
1419 io_names
[j
+ 1] = "control-o";
1421 for (i
= 1; i
< nr_ports
; i
++) {
1423 io_callbacks
[j
] = in_intr
;
1424 io_callbacks
[j
+ 1] = NULL
;
1425 io_names
[j
] = "input";
1426 io_names
[j
+ 1] = "output";
1429 /* Find the queues. */
1430 err
= portdev
->vdev
->config
->find_vqs(portdev
->vdev
, nr_queues
, vqs
,
1432 (const char **)io_names
);
1437 portdev
->in_vqs
[0] = vqs
[0];
1438 portdev
->out_vqs
[0] = vqs
[1];
1440 if (use_multiport(portdev
)) {
1441 portdev
->c_ivq
= vqs
[j
];
1442 portdev
->c_ovq
= vqs
[j
+ 1];
1444 for (i
= 1; i
< nr_ports
; i
++) {
1446 portdev
->in_vqs
[i
] = vqs
[j
];
1447 portdev
->out_vqs
[i
] = vqs
[j
+ 1];
1450 kfree(io_callbacks
);
1459 kfree(io_callbacks
);
1461 kfree(portdev
->out_vqs
);
1463 kfree(portdev
->in_vqs
);
1470 static const struct file_operations portdev_fops
= {
1471 .owner
= THIS_MODULE
,
1475 * Once we're further in boot, we get probed like any other virtio
1478 * If the host also supports multiple console ports, we check the
1479 * config space to see how many ports the host has spawned. We
1480 * initialize each port found.
1482 static int __devinit
virtcons_probe(struct virtio_device
*vdev
)
1484 struct ports_device
*portdev
;
1488 portdev
= kmalloc(sizeof(*portdev
), GFP_KERNEL
);
1494 /* Attach this portdev to this virtio_device, and vice-versa. */
1495 portdev
->vdev
= vdev
;
1496 vdev
->priv
= portdev
;
1498 spin_lock_irq(&pdrvdata_lock
);
1499 portdev
->drv_index
= pdrvdata
.index
++;
1500 spin_unlock_irq(&pdrvdata_lock
);
1502 portdev
->chr_major
= register_chrdev(0, "virtio-portsdev",
1504 if (portdev
->chr_major
< 0) {
1506 "Error %d registering chrdev for device %u\n",
1507 portdev
->chr_major
, portdev
->drv_index
);
1508 err
= portdev
->chr_major
;
1513 portdev
->config
.max_nr_ports
= 1;
1514 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_MULTIPORT
)) {
1516 vdev
->features
[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT
;
1518 vdev
->config
->get(vdev
, offsetof(struct virtio_console_config
,
1520 &portdev
->config
.max_nr_ports
,
1521 sizeof(portdev
->config
.max_nr_ports
));
1524 /* Let the Host know we support multiple ports.*/
1525 vdev
->config
->finalize_features(vdev
);
1527 err
= init_vqs(portdev
);
1529 dev_err(&vdev
->dev
, "Error %d initializing vqs\n", err
);
1533 spin_lock_init(&portdev
->ports_lock
);
1534 INIT_LIST_HEAD(&portdev
->ports
);
1537 unsigned int nr_added_bufs
;
1539 spin_lock_init(&portdev
->cvq_lock
);
1540 INIT_WORK(&portdev
->control_work
, &control_work_handler
);
1542 nr_added_bufs
= fill_queue(portdev
->c_ivq
, &portdev
->cvq_lock
);
1543 if (!nr_added_bufs
) {
1545 "Error allocating buffers for control queue\n");
1551 * For backward compatibility: Create a console port
1552 * if we're running on older host.
1554 add_port(portdev
, 0);
1557 __send_control_msg(portdev
, VIRTIO_CONSOLE_BAD_ID
,
1558 VIRTIO_CONSOLE_DEVICE_READY
, 1);
1562 vdev
->config
->del_vqs(vdev
);
1563 kfree(portdev
->in_vqs
);
1564 kfree(portdev
->out_vqs
);
1566 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1570 /* The host might want to notify mgmt sw about device add failure */
1571 __send_control_msg(portdev
, VIRTIO_CONSOLE_BAD_ID
,
1572 VIRTIO_CONSOLE_DEVICE_READY
, 0);
1576 static void virtcons_remove(struct virtio_device
*vdev
)
1578 struct ports_device
*portdev
;
1579 struct port
*port
, *port2
;
1580 struct port_buffer
*buf
;
1583 portdev
= vdev
->priv
;
1585 cancel_work_sync(&portdev
->control_work
);
1587 list_for_each_entry_safe(port
, port2
, &portdev
->ports
, list
)
1590 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1592 while ((buf
= virtqueue_get_buf(portdev
->c_ivq
, &len
)))
1595 while ((buf
= virtqueue_detach_unused_buf(portdev
->c_ivq
)))
1598 vdev
->config
->del_vqs(vdev
);
1599 kfree(portdev
->in_vqs
);
1600 kfree(portdev
->out_vqs
);
1605 static struct virtio_device_id id_table
[] = {
1606 { VIRTIO_ID_CONSOLE
, VIRTIO_DEV_ANY_ID
},
1610 static unsigned int features
[] = {
1611 VIRTIO_CONSOLE_F_SIZE
,
1612 VIRTIO_CONSOLE_F_MULTIPORT
,
1615 static struct virtio_driver virtio_console
= {
1616 .feature_table
= features
,
1617 .feature_table_size
= ARRAY_SIZE(features
),
1618 .driver
.name
= KBUILD_MODNAME
,
1619 .driver
.owner
= THIS_MODULE
,
1620 .id_table
= id_table
,
1621 .probe
= virtcons_probe
,
1622 .remove
= virtcons_remove
,
1623 .config_changed
= config_intr
,
1626 static int __init
init(void)
1630 pdrvdata
.class = class_create(THIS_MODULE
, "virtio-ports");
1631 if (IS_ERR(pdrvdata
.class)) {
1632 err
= PTR_ERR(pdrvdata
.class);
1633 pr_err("Error %d creating virtio-ports class\n", err
);
1637 pdrvdata
.debugfs_dir
= debugfs_create_dir("virtio-ports", NULL
);
1638 if (!pdrvdata
.debugfs_dir
) {
1639 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1640 PTR_ERR(pdrvdata
.debugfs_dir
));
1642 INIT_LIST_HEAD(&pdrvdata
.consoles
);
1644 return register_virtio_driver(&virtio_console
);
1647 static void __exit
fini(void)
1649 unregister_virtio_driver(&virtio_console
);
1651 class_destroy(pdrvdata
.class);
1652 if (pdrvdata
.debugfs_dir
)
1653 debugfs_remove_recursive(pdrvdata
.debugfs_dir
);
1658 MODULE_DEVICE_TABLE(virtio
, id_table
);
1659 MODULE_DESCRIPTION("Virtio console driver");
1660 MODULE_LICENSE("GPL");