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
;
82 * This number identifies the number that we used to register
83 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
84 * number passed on by the hvc callbacks to us to
85 * differentiate between the other console ports handled by
94 /* size of the buffer in *buf above */
97 /* used length of the buffer */
99 /* offset in the buf from which to consume data */
104 * This is a per-device struct that stores data common to all the
105 * ports for that device (vdev->priv).
107 struct ports_device
{
109 * Workqueue handlers where we process deferred work after
112 struct work_struct control_work
;
113 struct work_struct config_work
;
115 struct list_head ports
;
117 /* To protect the list of ports */
118 spinlock_t ports_lock
;
120 /* To protect the vq operations for the control channel */
123 /* The current config space is stored here */
124 struct virtio_console_config config
;
126 /* The virtio device we're associated with */
127 struct virtio_device
*vdev
;
130 * A couple of virtqueues for the control channel: one for
131 * guest->host transfers, one for host->guest transfers
133 struct virtqueue
*c_ivq
, *c_ovq
;
135 /* Array of per-port IO virtqueues */
136 struct virtqueue
**in_vqs
, **out_vqs
;
138 /* Used for numbering devices for sysfs and debugfs */
139 unsigned int drv_index
;
141 /* Major number for this device. Ports will be created as minors. */
145 /* This struct holds the per-port data */
147 /* Next port in the list, head is in the ports_device */
148 struct list_head list
;
150 /* Pointer to the parent virtio_console device */
151 struct ports_device
*portdev
;
153 /* The current buffer from which data has to be fed to readers */
154 struct port_buffer
*inbuf
;
157 * To protect the operations on the in_vq associated with this
158 * port. Has to be a spinlock because it can be called from
159 * interrupt context (get_char()).
161 spinlock_t inbuf_lock
;
163 /* The IO vqs for this port */
164 struct virtqueue
*in_vq
, *out_vq
;
166 /* File in the debugfs directory that exposes this port's information */
167 struct dentry
*debugfs_file
;
170 * The entries in this struct will be valid if this port is
171 * hooked up to an hvc console
175 /* Each port associates with a separate char device */
179 /* A waitqueue for poll() or blocking read operations */
180 wait_queue_head_t waitqueue
;
182 /* The 'name' of the port that we expose via sysfs properties */
185 /* The 'id' to identify the port with the Host */
188 /* Is the host device open */
191 /* We should allow only one process to open a port */
192 bool guest_connected
;
195 /* This is the very early arch-specified put chars function. */
196 static int (*early_put_chars
)(u32
, const char *, int);
198 static struct port
*find_port_by_vtermno(u32 vtermno
)
201 struct console
*cons
;
204 spin_lock_irqsave(&pdrvdata_lock
, flags
);
205 list_for_each_entry(cons
, &pdrvdata
.consoles
, list
) {
206 if (cons
->vtermno
== vtermno
) {
207 port
= container_of(cons
, struct port
, cons
);
213 spin_unlock_irqrestore(&pdrvdata_lock
, flags
);
217 static struct port
*find_port_by_id(struct ports_device
*portdev
, u32 id
)
222 spin_lock_irqsave(&portdev
->ports_lock
, flags
);
223 list_for_each_entry(port
, &portdev
->ports
, list
)
228 spin_unlock_irqrestore(&portdev
->ports_lock
, flags
);
233 static struct port
*find_port_by_vq(struct ports_device
*portdev
,
234 struct virtqueue
*vq
)
239 spin_lock_irqsave(&portdev
->ports_lock
, flags
);
240 list_for_each_entry(port
, &portdev
->ports
, list
)
241 if (port
->in_vq
== vq
|| port
->out_vq
== vq
)
245 spin_unlock_irqrestore(&portdev
->ports_lock
, flags
);
249 static bool is_console_port(struct port
*port
)
256 static inline bool use_multiport(struct ports_device
*portdev
)
259 * This condition can be true when put_chars is called from
264 return portdev
->vdev
->features
[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT
);
267 static void free_buf(struct port_buffer
*buf
)
273 static struct port_buffer
*alloc_buf(size_t buf_size
)
275 struct port_buffer
*buf
;
277 buf
= kmalloc(sizeof(*buf
), GFP_KERNEL
);
280 buf
->buf
= kzalloc(buf_size
, GFP_KERNEL
);
285 buf
->size
= buf_size
;
294 /* Callers should take appropriate locks */
295 static void *get_inbuf(struct port
*port
)
297 struct port_buffer
*buf
;
298 struct virtqueue
*vq
;
302 buf
= virtqueue_get_buf(vq
, &len
);
311 * Create a scatter-gather list representing our input buffer and put
314 * Callers should take appropriate locks.
316 static int add_inbuf(struct virtqueue
*vq
, struct port_buffer
*buf
)
318 struct scatterlist sg
[1];
321 sg_init_one(sg
, buf
->buf
, buf
->size
);
323 ret
= virtqueue_add_buf(vq
, sg
, 0, 1, buf
);
328 /* Discard any unread data this port has. Callers lockers. */
329 static void discard_port_data(struct port
*port
)
331 struct port_buffer
*buf
;
332 struct virtqueue
*vq
;
340 buf
= virtqueue_get_buf(vq
, &len
);
344 if (add_inbuf(vq
, buf
) < 0) {
348 buf
= virtqueue_get_buf(vq
, &len
);
352 dev_warn(port
->dev
, "Errors adding %d buffers back to vq\n",
356 static bool port_has_data(struct port
*port
)
361 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
366 port
->inbuf
= get_inbuf(port
);
373 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
377 static ssize_t
__send_control_msg(struct ports_device
*portdev
, u32 port_id
,
378 unsigned int event
, unsigned int value
)
380 struct scatterlist sg
[1];
381 struct virtio_console_control cpkt
;
382 struct virtqueue
*vq
;
385 if (!use_multiport(portdev
))
394 sg_init_one(sg
, &cpkt
, sizeof(cpkt
));
395 if (virtqueue_add_buf(vq
, sg
, 1, 0, &cpkt
) >= 0) {
397 while (!virtqueue_get_buf(vq
, &len
))
403 static ssize_t
send_control_msg(struct port
*port
, unsigned int event
,
406 return __send_control_msg(port
->portdev
, port
->id
, event
, value
);
409 static ssize_t
send_buf(struct port
*port
, void *in_buf
, size_t in_count
)
411 struct scatterlist sg
[1];
412 struct virtqueue
*out_vq
;
416 out_vq
= port
->out_vq
;
418 sg_init_one(sg
, in_buf
, in_count
);
419 ret
= virtqueue_add_buf(out_vq
, sg
, 1, 0, in_buf
);
421 /* Tell Host to go! */
422 virtqueue_kick(out_vq
);
429 /* Wait till the host acknowledges it pushed out the data we sent. */
430 while (!virtqueue_get_buf(out_vq
, &len
))
433 /* We're expected to return the amount of data we wrote */
438 * Give out the data that's requested from the buffer that we have
441 static ssize_t
fill_readbuf(struct port
*port
, char *out_buf
, size_t out_count
,
444 struct port_buffer
*buf
;
447 if (!out_count
|| !port_has_data(port
))
451 out_count
= min(out_count
, buf
->len
- buf
->offset
);
456 ret
= copy_to_user(out_buf
, buf
->buf
+ buf
->offset
, out_count
);
460 memcpy(out_buf
, buf
->buf
+ buf
->offset
, out_count
);
463 buf
->offset
+= out_count
;
465 if (buf
->offset
== buf
->len
) {
467 * We're done using all the data in this buffer.
468 * Re-queue so that the Host can send us more data.
470 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
473 if (add_inbuf(port
->in_vq
, buf
) < 0)
474 dev_warn(port
->dev
, "failed add_buf\n");
476 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
478 /* Return the number of bytes actually copied */
482 /* The condition that must be true for polling to end */
483 static bool wait_is_over(struct port
*port
)
485 return port_has_data(port
) || !port
->host_connected
;
488 static ssize_t
port_fops_read(struct file
*filp
, char __user
*ubuf
,
489 size_t count
, loff_t
*offp
)
494 port
= filp
->private_data
;
496 if (!port_has_data(port
)) {
498 * If nothing's connected on the host just return 0 in
499 * case of list_empty; this tells the userspace app
500 * that there's no connection
502 if (!port
->host_connected
)
504 if (filp
->f_flags
& O_NONBLOCK
)
507 ret
= wait_event_interruptible(port
->waitqueue
,
513 * We could've received a disconnection message while we were
514 * waiting for more data.
516 * This check is not clubbed in the if() statement above as we
517 * might receive some data as well as the host could get
518 * disconnected after we got woken up from our wait. So we
519 * really want to give off whatever data we have and only then
520 * check for host_connected.
522 if (!port_has_data(port
) && !port
->host_connected
)
525 return fill_readbuf(port
, ubuf
, count
, true);
528 static ssize_t
port_fops_write(struct file
*filp
, const char __user
*ubuf
,
529 size_t count
, loff_t
*offp
)
535 port
= filp
->private_data
;
537 count
= min((size_t)(32 * 1024), count
);
539 buf
= kmalloc(count
, GFP_KERNEL
);
543 ret
= copy_from_user(buf
, ubuf
, count
);
549 ret
= send_buf(port
, buf
, count
);
555 static unsigned int port_fops_poll(struct file
*filp
, poll_table
*wait
)
560 port
= filp
->private_data
;
561 poll_wait(filp
, &port
->waitqueue
, wait
);
565 ret
|= POLLIN
| POLLRDNORM
;
566 if (port
->host_connected
)
568 if (!port
->host_connected
)
574 static int port_fops_release(struct inode
*inode
, struct file
*filp
)
578 port
= filp
->private_data
;
580 /* Notify host of port being closed */
581 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
583 spin_lock_irq(&port
->inbuf_lock
);
584 port
->guest_connected
= false;
586 discard_port_data(port
);
588 spin_unlock_irq(&port
->inbuf_lock
);
593 static int port_fops_open(struct inode
*inode
, struct file
*filp
)
595 struct cdev
*cdev
= inode
->i_cdev
;
598 port
= container_of(cdev
, struct port
, cdev
);
599 filp
->private_data
= port
;
602 * Don't allow opening of console port devices -- that's done
605 if (is_console_port(port
))
608 /* Allow only one process to open a particular port at a time */
609 spin_lock_irq(&port
->inbuf_lock
);
610 if (port
->guest_connected
) {
611 spin_unlock_irq(&port
->inbuf_lock
);
615 port
->guest_connected
= true;
616 spin_unlock_irq(&port
->inbuf_lock
);
618 /* Notify host of port being opened */
619 send_control_msg(filp
->private_data
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
625 * The file operations that we support: programs in the guest can open
626 * a console device, read from it, write to it, poll for data and
627 * close it. The devices are at
628 * /dev/vport<device number>p<port number>
630 static const struct file_operations port_fops
= {
631 .owner
= THIS_MODULE
,
632 .open
= port_fops_open
,
633 .read
= port_fops_read
,
634 .write
= port_fops_write
,
635 .poll
= port_fops_poll
,
636 .release
= port_fops_release
,
640 * The put_chars() callback is pretty straightforward.
642 * We turn the characters into a scatter-gather list, add it to the
643 * output queue and then kick the Host. Then we sit here waiting for
644 * it to finish: inefficient in theory, but in practice
645 * implementations will do it immediately (lguest's Launcher does).
647 static int put_chars(u32 vtermno
, const char *buf
, int count
)
651 if (unlikely(early_put_chars
))
652 return early_put_chars(vtermno
, buf
, count
);
654 port
= find_port_by_vtermno(vtermno
);
658 return send_buf(port
, (void *)buf
, count
);
662 * get_chars() is the callback from the hvc_console infrastructure
663 * when an interrupt is received.
665 * We call out to fill_readbuf that gets us the required data from the
666 * buffers that are queued up.
668 static int get_chars(u32 vtermno
, char *buf
, int count
)
672 /* If we've not set up the port yet, we have no input to give. */
673 if (unlikely(early_put_chars
))
676 port
= find_port_by_vtermno(vtermno
);
680 /* If we don't have an input queue yet, we can't get input. */
681 BUG_ON(!port
->in_vq
);
683 return fill_readbuf(port
, buf
, count
, false);
686 static void resize_console(struct port
*port
)
688 struct virtio_device
*vdev
;
691 /* The port could have been hot-unplugged */
695 vdev
= port
->portdev
->vdev
;
696 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_SIZE
)) {
697 vdev
->config
->get(vdev
,
698 offsetof(struct virtio_console_config
, cols
),
699 &ws
.ws_col
, sizeof(u16
));
700 vdev
->config
->get(vdev
,
701 offsetof(struct virtio_console_config
, rows
),
702 &ws
.ws_row
, sizeof(u16
));
703 hvc_resize(port
->cons
.hvc
, ws
);
707 /* We set the configuration at this point, since we now have a tty */
708 static int notifier_add_vio(struct hvc_struct
*hp
, int data
)
712 port
= find_port_by_vtermno(hp
->vtermno
);
716 hp
->irq_requested
= 1;
717 resize_console(port
);
722 static void notifier_del_vio(struct hvc_struct
*hp
, int data
)
724 hp
->irq_requested
= 0;
727 /* The operations for console ports. */
728 static const struct hv_ops hv_ops
= {
729 .get_chars
= get_chars
,
730 .put_chars
= put_chars
,
731 .notifier_add
= notifier_add_vio
,
732 .notifier_del
= notifier_del_vio
,
733 .notifier_hangup
= notifier_del_vio
,
737 * Console drivers are initialized very early so boot messages can go
738 * out, so we do things slightly differently from the generic virtio
739 * initialization of the net and block drivers.
741 * At this stage, the console is output-only. It's too early to set
742 * up a virtqueue, so we let the drivers do some boutique early-output
745 int __init
virtio_cons_early_init(int (*put_chars
)(u32
, const char *, int))
747 early_put_chars
= put_chars
;
748 return hvc_instantiate(0, 0, &hv_ops
);
751 int init_port_console(struct port
*port
)
756 * The Host's telling us this port is a console port. Hook it
757 * up with an hvc console.
759 * To set up and manage our virtual console, we call
762 * The first argument of hvc_alloc() is the virtual console
763 * number. The second argument is the parameter for the
764 * notification mechanism (like irq number). We currently
765 * leave this as zero, virtqueues have implicit notifications.
767 * The third argument is a "struct hv_ops" containing the
768 * put_chars() get_chars(), notifier_add() and notifier_del()
769 * pointers. The final argument is the output buffer size: we
770 * can do any size, so we put PAGE_SIZE here.
772 port
->cons
.vtermno
= pdrvdata
.next_vtermno
;
774 port
->cons
.hvc
= hvc_alloc(port
->cons
.vtermno
, 0, &hv_ops
, PAGE_SIZE
);
775 if (IS_ERR(port
->cons
.hvc
)) {
776 ret
= PTR_ERR(port
->cons
.hvc
);
778 "error %d allocating hvc for port\n", ret
);
779 port
->cons
.hvc
= NULL
;
782 spin_lock_irq(&pdrvdata_lock
);
783 pdrvdata
.next_vtermno
++;
784 list_add_tail(&port
->cons
.list
, &pdrvdata
.consoles
);
785 spin_unlock_irq(&pdrvdata_lock
);
786 port
->guest_connected
= true;
788 /* Notify host of port being opened */
789 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
794 static ssize_t
show_port_name(struct device
*dev
,
795 struct device_attribute
*attr
, char *buffer
)
799 port
= dev_get_drvdata(dev
);
801 return sprintf(buffer
, "%s\n", port
->name
);
804 static DEVICE_ATTR(name
, S_IRUGO
, show_port_name
, NULL
);
806 static struct attribute
*port_sysfs_entries
[] = {
811 static struct attribute_group port_attribute_group
= {
812 .name
= NULL
, /* put in device directory */
813 .attrs
= port_sysfs_entries
,
816 static int debugfs_open(struct inode
*inode
, struct file
*filp
)
818 filp
->private_data
= inode
->i_private
;
822 static ssize_t
debugfs_read(struct file
*filp
, char __user
*ubuf
,
823 size_t count
, loff_t
*offp
)
827 ssize_t ret
, out_offset
, out_count
;
830 buf
= kmalloc(out_count
, GFP_KERNEL
);
834 port
= filp
->private_data
;
836 out_offset
+= snprintf(buf
+ out_offset
, out_count
,
837 "name: %s\n", port
->name
? port
->name
: "");
838 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
839 "guest_connected: %d\n", port
->guest_connected
);
840 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
841 "host_connected: %d\n", port
->host_connected
);
842 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
844 is_console_port(port
) ? "yes" : "no");
845 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
846 "console_vtermno: %u\n", port
->cons
.vtermno
);
848 ret
= simple_read_from_buffer(ubuf
, count
, offp
, buf
, out_offset
);
853 static const struct file_operations port_debugfs_ops
= {
854 .owner
= THIS_MODULE
,
855 .open
= debugfs_open
,
856 .read
= debugfs_read
,
859 /* Remove all port-specific data. */
860 static int remove_port(struct port
*port
)
862 struct port_buffer
*buf
;
864 spin_lock_irq(&port
->portdev
->ports_lock
);
865 list_del(&port
->list
);
866 spin_unlock_irq(&port
->portdev
->ports_lock
);
868 if (is_console_port(port
)) {
869 spin_lock_irq(&pdrvdata_lock
);
870 list_del(&port
->cons
.list
);
871 spin_unlock_irq(&pdrvdata_lock
);
872 hvc_remove(port
->cons
.hvc
);
874 if (port
->guest_connected
)
875 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
877 sysfs_remove_group(&port
->dev
->kobj
, &port_attribute_group
);
878 device_destroy(pdrvdata
.class, port
->dev
->devt
);
879 cdev_del(&port
->cdev
);
881 /* Remove unused data this port might have received. */
882 discard_port_data(port
);
884 /* Remove buffers we queued up for the Host to send us data in. */
885 while ((buf
= virtqueue_detach_unused_buf(port
->in_vq
)))
890 debugfs_remove(port
->debugfs_file
);
896 /* Any private messages that the Host and Guest want to share */
897 static void handle_control_message(struct ports_device
*portdev
,
898 struct port_buffer
*buf
)
900 struct virtio_console_control
*cpkt
;
905 cpkt
= (struct virtio_console_control
*)(buf
->buf
+ buf
->offset
);
907 port
= find_port_by_id(portdev
, cpkt
->id
);
909 /* No valid header at start of buffer. Drop it. */
910 dev_dbg(&portdev
->vdev
->dev
,
911 "Invalid index %u in control packet\n", cpkt
->id
);
915 switch (cpkt
->event
) {
916 case VIRTIO_CONSOLE_CONSOLE_PORT
:
919 if (is_console_port(port
))
922 init_port_console(port
);
924 * Could remove the port here in case init fails - but
925 * have to notify the host first.
928 case VIRTIO_CONSOLE_RESIZE
:
929 if (!is_console_port(port
))
931 port
->cons
.hvc
->irq_requested
= 1;
932 resize_console(port
);
934 case VIRTIO_CONSOLE_PORT_OPEN
:
935 port
->host_connected
= cpkt
->value
;
936 wake_up_interruptible(&port
->waitqueue
);
938 case VIRTIO_CONSOLE_PORT_NAME
:
940 * Skip the size of the header and the cpkt to get the size
941 * of the name that was sent
943 name_size
= buf
->len
- buf
->offset
- sizeof(*cpkt
) + 1;
945 port
->name
= kmalloc(name_size
, GFP_KERNEL
);
948 "Not enough space to store port name\n");
951 strncpy(port
->name
, buf
->buf
+ buf
->offset
+ sizeof(*cpkt
),
953 port
->name
[name_size
- 1] = 0;
956 * Since we only have one sysfs attribute, 'name',
957 * create it only if we have a name for the port.
959 err
= sysfs_create_group(&port
->dev
->kobj
,
960 &port_attribute_group
);
963 "Error %d creating sysfs device attributes\n",
967 * Generate a udev event so that appropriate
968 * symlinks can be created based on udev
971 kobject_uevent(&port
->dev
->kobj
, KOBJ_CHANGE
);
974 case VIRTIO_CONSOLE_PORT_REMOVE
:
976 * Hot unplug the port. We don't decrement nr_ports
977 * since we don't want to deal with extra complexities
978 * of using the lowest-available port id: We can just
979 * pick up the nr_ports number as the id and not have
980 * userspace send it to us. This helps us in two
983 * - We don't need to have a 'port_id' field in the
984 * config space when a port is hot-added. This is a
985 * good thing as we might queue up multiple hotplug
986 * requests issued in our workqueue.
988 * - Another way to deal with this would have been to
989 * use a bitmap of the active ports and select the
990 * lowest non-active port from that map. That
991 * bloats the already tight config space and we
992 * would end up artificially limiting the
993 * max. number of ports to sizeof(bitmap). Right
994 * now we can support 2^32 ports (as the port id is
995 * stored in a u32 type).
1003 static void control_work_handler(struct work_struct
*work
)
1005 struct ports_device
*portdev
;
1006 struct virtqueue
*vq
;
1007 struct port_buffer
*buf
;
1010 portdev
= container_of(work
, struct ports_device
, control_work
);
1011 vq
= portdev
->c_ivq
;
1013 spin_lock(&portdev
->cvq_lock
);
1014 while ((buf
= virtqueue_get_buf(vq
, &len
))) {
1015 spin_unlock(&portdev
->cvq_lock
);
1020 handle_control_message(portdev
, buf
);
1022 spin_lock(&portdev
->cvq_lock
);
1023 if (add_inbuf(portdev
->c_ivq
, buf
) < 0) {
1024 dev_warn(&portdev
->vdev
->dev
,
1025 "Error adding buffer to queue\n");
1029 spin_unlock(&portdev
->cvq_lock
);
1032 static void in_intr(struct virtqueue
*vq
)
1035 unsigned long flags
;
1037 port
= find_port_by_vq(vq
->vdev
->priv
, vq
);
1041 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
1043 port
->inbuf
= get_inbuf(port
);
1046 * Don't queue up data when port is closed. This condition
1047 * can be reached when a console port is not yet connected (no
1048 * tty is spawned) and the host sends out data to console
1049 * ports. For generic serial ports, the host won't
1050 * (shouldn't) send data till the guest is connected.
1052 if (!port
->guest_connected
)
1053 discard_port_data(port
);
1055 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
1057 wake_up_interruptible(&port
->waitqueue
);
1059 if (is_console_port(port
) && hvc_poll(port
->cons
.hvc
))
1063 static void control_intr(struct virtqueue
*vq
)
1065 struct ports_device
*portdev
;
1067 portdev
= vq
->vdev
->priv
;
1068 schedule_work(&portdev
->control_work
);
1071 static void config_intr(struct virtio_device
*vdev
)
1073 struct ports_device
*portdev
;
1075 portdev
= vdev
->priv
;
1076 if (use_multiport(portdev
)) {
1077 /* Handle port hot-add */
1078 schedule_work(&portdev
->config_work
);
1081 * We'll use this way of resizing only for legacy support.
1082 * For newer userspace (VIRTIO_CONSOLE_F_MULTPORT+), use
1083 * control messages to indicate console size changes so that
1084 * it can be done per-port
1086 resize_console(find_port_by_id(portdev
, 0));
1089 static unsigned int fill_queue(struct virtqueue
*vq
, spinlock_t
*lock
)
1091 struct port_buffer
*buf
;
1092 unsigned int nr_added_bufs
;
1097 buf
= alloc_buf(PAGE_SIZE
);
1101 spin_lock_irq(lock
);
1102 ret
= add_inbuf(vq
, buf
);
1104 spin_unlock_irq(lock
);
1109 spin_unlock_irq(lock
);
1112 return nr_added_bufs
;
1115 static int add_port(struct ports_device
*portdev
, u32 id
)
1117 char debugfs_name
[16];
1119 struct port_buffer
*buf
;
1121 unsigned int nr_added_bufs
;
1124 port
= kmalloc(sizeof(*port
), GFP_KERNEL
);
1130 port
->portdev
= portdev
;
1135 port
->cons
.hvc
= NULL
;
1137 port
->host_connected
= port
->guest_connected
= false;
1139 port
->in_vq
= portdev
->in_vqs
[port
->id
];
1140 port
->out_vq
= portdev
->out_vqs
[port
->id
];
1142 cdev_init(&port
->cdev
, &port_fops
);
1144 devt
= MKDEV(portdev
->chr_major
, id
);
1145 err
= cdev_add(&port
->cdev
, devt
, 1);
1147 dev_err(&port
->portdev
->vdev
->dev
,
1148 "Error %d adding cdev for port %u\n", err
, id
);
1151 port
->dev
= device_create(pdrvdata
.class, &port
->portdev
->vdev
->dev
,
1152 devt
, port
, "vport%up%u",
1153 port
->portdev
->drv_index
, id
);
1154 if (IS_ERR(port
->dev
)) {
1155 err
= PTR_ERR(port
->dev
);
1156 dev_err(&port
->portdev
->vdev
->dev
,
1157 "Error %d creating device for port %u\n",
1162 spin_lock_init(&port
->inbuf_lock
);
1163 init_waitqueue_head(&port
->waitqueue
);
1165 /* Fill the in_vq with buffers so the host can send us data. */
1166 nr_added_bufs
= fill_queue(port
->in_vq
, &port
->inbuf_lock
);
1167 if (!nr_added_bufs
) {
1168 dev_err(port
->dev
, "Error allocating inbufs\n");
1174 * If we're not using multiport support, this has to be a console port
1176 if (!use_multiport(port
->portdev
)) {
1177 err
= init_port_console(port
);
1182 spin_lock_irq(&portdev
->ports_lock
);
1183 list_add_tail(&port
->list
, &port
->portdev
->ports
);
1184 spin_unlock_irq(&portdev
->ports_lock
);
1187 * Tell the Host we're set so that it can send us various
1188 * configuration parameters for this port (eg, port name,
1189 * caching, whether this is a console port, etc.)
1191 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1193 if (pdrvdata
.debugfs_dir
) {
1195 * Finally, create the debugfs file that we can use to
1196 * inspect a port's state at any time
1198 sprintf(debugfs_name
, "vport%up%u",
1199 port
->portdev
->drv_index
, id
);
1200 port
->debugfs_file
= debugfs_create_file(debugfs_name
, 0444,
1201 pdrvdata
.debugfs_dir
,
1208 while ((buf
= virtqueue_detach_unused_buf(port
->in_vq
)))
1211 device_destroy(pdrvdata
.class, port
->dev
->devt
);
1213 cdev_del(&port
->cdev
);
1217 /* The host might want to notify management sw about port add failure */
1218 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 0);
1223 * The workhandler for config-space updates.
1225 * This is called when ports are hot-added.
1227 static void config_work_handler(struct work_struct
*work
)
1229 struct virtio_console_config virtconconf
;
1230 struct ports_device
*portdev
;
1231 struct virtio_device
*vdev
;
1234 portdev
= container_of(work
, struct ports_device
, config_work
);
1236 vdev
= portdev
->vdev
;
1237 vdev
->config
->get(vdev
,
1238 offsetof(struct virtio_console_config
, nr_ports
),
1239 &virtconconf
.nr_ports
,
1240 sizeof(virtconconf
.nr_ports
));
1242 if (portdev
->config
.nr_ports
== virtconconf
.nr_ports
) {
1244 * Port 0 got hot-added. Since we already did all the
1245 * other initialisation for it, just tell the Host
1246 * that the port is ready if we find the port. In
1247 * case the port was hot-removed earlier, we call
1248 * add_port to add the port.
1252 port
= find_port_by_id(portdev
, 0);
1254 add_port(portdev
, 0);
1256 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1259 if (virtconconf
.nr_ports
> portdev
->config
.max_nr_ports
) {
1260 dev_warn(&vdev
->dev
,
1261 "More ports specified (%u) than allowed (%u)",
1262 portdev
->config
.nr_ports
+ 1,
1263 portdev
->config
.max_nr_ports
);
1266 if (virtconconf
.nr_ports
< portdev
->config
.nr_ports
)
1270 while (virtconconf
.nr_ports
- portdev
->config
.nr_ports
) {
1271 err
= add_port(portdev
, portdev
->config
.nr_ports
);
1274 portdev
->config
.nr_ports
++;
1278 static int init_vqs(struct ports_device
*portdev
)
1280 vq_callback_t
**io_callbacks
;
1282 struct virtqueue
**vqs
;
1283 u32 i
, j
, nr_ports
, nr_queues
;
1286 nr_ports
= portdev
->config
.max_nr_ports
;
1287 nr_queues
= use_multiport(portdev
) ? (nr_ports
+ 1) * 2 : 2;
1289 vqs
= kmalloc(nr_queues
* sizeof(struct virtqueue
*), GFP_KERNEL
);
1294 io_callbacks
= kmalloc(nr_queues
* sizeof(vq_callback_t
*), GFP_KERNEL
);
1295 if (!io_callbacks
) {
1299 io_names
= kmalloc(nr_queues
* sizeof(char *), GFP_KERNEL
);
1302 goto free_callbacks
;
1304 portdev
->in_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1306 if (!portdev
->in_vqs
) {
1310 portdev
->out_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1312 if (!portdev
->out_vqs
) {
1318 * For backward compat (newer host but older guest), the host
1319 * spawns a console port first and also inits the vqs for port
1323 io_callbacks
[j
] = in_intr
;
1324 io_callbacks
[j
+ 1] = NULL
;
1325 io_names
[j
] = "input";
1326 io_names
[j
+ 1] = "output";
1329 if (use_multiport(portdev
)) {
1330 io_callbacks
[j
] = control_intr
;
1331 io_callbacks
[j
+ 1] = NULL
;
1332 io_names
[j
] = "control-i";
1333 io_names
[j
+ 1] = "control-o";
1335 for (i
= 1; i
< nr_ports
; i
++) {
1337 io_callbacks
[j
] = in_intr
;
1338 io_callbacks
[j
+ 1] = NULL
;
1339 io_names
[j
] = "input";
1340 io_names
[j
+ 1] = "output";
1343 /* Find the queues. */
1344 err
= portdev
->vdev
->config
->find_vqs(portdev
->vdev
, nr_queues
, vqs
,
1346 (const char **)io_names
);
1351 portdev
->in_vqs
[0] = vqs
[0];
1352 portdev
->out_vqs
[0] = vqs
[1];
1354 if (use_multiport(portdev
)) {
1355 portdev
->c_ivq
= vqs
[j
];
1356 portdev
->c_ovq
= vqs
[j
+ 1];
1358 for (i
= 1; i
< nr_ports
; i
++) {
1360 portdev
->in_vqs
[i
] = vqs
[j
];
1361 portdev
->out_vqs
[i
] = vqs
[j
+ 1];
1364 kfree(io_callbacks
);
1373 kfree(io_callbacks
);
1375 kfree(portdev
->out_vqs
);
1377 kfree(portdev
->in_vqs
);
1384 static const struct file_operations portdev_fops
= {
1385 .owner
= THIS_MODULE
,
1389 * Once we're further in boot, we get probed like any other virtio
1392 * If the host also supports multiple console ports, we check the
1393 * config space to see how many ports the host has spawned. We
1394 * initialize each port found.
1396 static int __devinit
virtcons_probe(struct virtio_device
*vdev
)
1398 struct ports_device
*portdev
;
1403 portdev
= kmalloc(sizeof(*portdev
), GFP_KERNEL
);
1409 /* Attach this portdev to this virtio_device, and vice-versa. */
1410 portdev
->vdev
= vdev
;
1411 vdev
->priv
= portdev
;
1413 spin_lock_irq(&pdrvdata_lock
);
1414 portdev
->drv_index
= pdrvdata
.index
++;
1415 spin_unlock_irq(&pdrvdata_lock
);
1417 portdev
->chr_major
= register_chrdev(0, "virtio-portsdev",
1419 if (portdev
->chr_major
< 0) {
1421 "Error %d registering chrdev for device %u\n",
1422 portdev
->chr_major
, portdev
->drv_index
);
1423 err
= portdev
->chr_major
;
1428 portdev
->config
.nr_ports
= 1;
1429 portdev
->config
.max_nr_ports
= 1;
1430 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_MULTIPORT
)) {
1432 vdev
->features
[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT
;
1434 vdev
->config
->get(vdev
, offsetof(struct virtio_console_config
,
1436 &portdev
->config
.nr_ports
,
1437 sizeof(portdev
->config
.nr_ports
));
1438 vdev
->config
->get(vdev
, offsetof(struct virtio_console_config
,
1440 &portdev
->config
.max_nr_ports
,
1441 sizeof(portdev
->config
.max_nr_ports
));
1442 if (portdev
->config
.nr_ports
> portdev
->config
.max_nr_ports
) {
1443 dev_warn(&vdev
->dev
,
1444 "More ports (%u) specified than allowed (%u). Will init %u ports.",
1445 portdev
->config
.nr_ports
,
1446 portdev
->config
.max_nr_ports
,
1447 portdev
->config
.max_nr_ports
);
1449 portdev
->config
.nr_ports
= portdev
->config
.max_nr_ports
;
1453 /* Let the Host know we support multiple ports.*/
1454 vdev
->config
->finalize_features(vdev
);
1456 err
= init_vqs(portdev
);
1458 dev_err(&vdev
->dev
, "Error %d initializing vqs\n", err
);
1462 spin_lock_init(&portdev
->ports_lock
);
1463 INIT_LIST_HEAD(&portdev
->ports
);
1466 unsigned int nr_added_bufs
;
1468 spin_lock_init(&portdev
->cvq_lock
);
1469 INIT_WORK(&portdev
->control_work
, &control_work_handler
);
1470 INIT_WORK(&portdev
->config_work
, &config_work_handler
);
1472 nr_added_bufs
= fill_queue(portdev
->c_ivq
, &portdev
->cvq_lock
);
1473 if (!nr_added_bufs
) {
1475 "Error allocating buffers for control queue\n");
1481 for (i
= 0; i
< portdev
->config
.nr_ports
; i
++)
1482 add_port(portdev
, i
);
1484 /* Start using the new console output. */
1485 early_put_chars
= NULL
;
1489 vdev
->config
->del_vqs(vdev
);
1490 kfree(portdev
->in_vqs
);
1491 kfree(portdev
->out_vqs
);
1493 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1497 /* The host might want to notify mgmt sw about device add failure */
1498 __send_control_msg(portdev
, VIRTIO_CONSOLE_BAD_ID
,
1499 VIRTIO_CONSOLE_DEVICE_READY
, 0);
1503 static void virtcons_remove(struct virtio_device
*vdev
)
1505 struct ports_device
*portdev
;
1506 struct port
*port
, *port2
;
1507 struct port_buffer
*buf
;
1510 portdev
= vdev
->priv
;
1512 cancel_work_sync(&portdev
->control_work
);
1513 cancel_work_sync(&portdev
->config_work
);
1515 list_for_each_entry_safe(port
, port2
, &portdev
->ports
, list
)
1518 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1520 while ((buf
= virtqueue_get_buf(portdev
->c_ivq
, &len
)))
1523 while ((buf
= virtqueue_detach_unused_buf(portdev
->c_ivq
)))
1526 vdev
->config
->del_vqs(vdev
);
1527 kfree(portdev
->in_vqs
);
1528 kfree(portdev
->out_vqs
);
1533 static struct virtio_device_id id_table
[] = {
1534 { VIRTIO_ID_CONSOLE
, VIRTIO_DEV_ANY_ID
},
1538 static unsigned int features
[] = {
1539 VIRTIO_CONSOLE_F_SIZE
,
1540 VIRTIO_CONSOLE_F_MULTIPORT
,
1543 static struct virtio_driver virtio_console
= {
1544 .feature_table
= features
,
1545 .feature_table_size
= ARRAY_SIZE(features
),
1546 .driver
.name
= KBUILD_MODNAME
,
1547 .driver
.owner
= THIS_MODULE
,
1548 .id_table
= id_table
,
1549 .probe
= virtcons_probe
,
1550 .remove
= virtcons_remove
,
1551 .config_changed
= config_intr
,
1554 static int __init
init(void)
1558 pdrvdata
.class = class_create(THIS_MODULE
, "virtio-ports");
1559 if (IS_ERR(pdrvdata
.class)) {
1560 err
= PTR_ERR(pdrvdata
.class);
1561 pr_err("Error %d creating virtio-ports class\n", err
);
1565 pdrvdata
.debugfs_dir
= debugfs_create_dir("virtio-ports", NULL
);
1566 if (!pdrvdata
.debugfs_dir
) {
1567 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1568 PTR_ERR(pdrvdata
.debugfs_dir
));
1570 INIT_LIST_HEAD(&pdrvdata
.consoles
);
1572 return register_virtio_driver(&virtio_console
);
1575 static void __exit
fini(void)
1577 unregister_virtio_driver(&virtio_console
);
1579 class_destroy(pdrvdata
.class);
1580 if (pdrvdata
.debugfs_dir
)
1581 debugfs_remove_recursive(pdrvdata
.debugfs_dir
);
1586 MODULE_DEVICE_TABLE(virtio
, id_table
);
1587 MODULE_DESCRIPTION("Virtio console driver");
1588 MODULE_LICENSE("GPL");