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 /* Reference-counting to handle port hot-unplugs and file operations */
193 /* A waitqueue for poll() or blocking read operations */
194 wait_queue_head_t waitqueue
;
196 /* The 'name' of the port that we expose via sysfs properties */
199 /* We can notify apps of host connect / disconnect events via SIGIO */
200 struct fasync_struct
*async_queue
;
202 /* The 'id' to identify the port with the Host */
207 /* Is the host device open */
210 /* We should allow only one process to open a port */
211 bool guest_connected
;
214 /* This is the very early arch-specified put chars function. */
215 static int (*early_put_chars
)(u32
, const char *, int);
217 static struct port
*find_port_by_vtermno(u32 vtermno
)
220 struct console
*cons
;
223 spin_lock_irqsave(&pdrvdata_lock
, flags
);
224 list_for_each_entry(cons
, &pdrvdata
.consoles
, list
) {
225 if (cons
->vtermno
== vtermno
) {
226 port
= container_of(cons
, struct port
, cons
);
232 spin_unlock_irqrestore(&pdrvdata_lock
, flags
);
236 static struct port
*find_port_by_devt_in_portdev(struct ports_device
*portdev
,
242 spin_lock_irqsave(&portdev
->ports_lock
, flags
);
243 list_for_each_entry(port
, &portdev
->ports
, list
)
244 if (port
->cdev
->dev
== dev
)
248 spin_unlock_irqrestore(&portdev
->ports_lock
, flags
);
253 static struct port
*find_port_by_devt(dev_t dev
)
255 struct ports_device
*portdev
;
259 spin_lock_irqsave(&pdrvdata_lock
, flags
);
260 list_for_each_entry(portdev
, &pdrvdata
.portdevs
, list
) {
261 port
= find_port_by_devt_in_portdev(portdev
, dev
);
267 spin_unlock_irqrestore(&pdrvdata_lock
, flags
);
271 static struct port
*find_port_by_id(struct ports_device
*portdev
, u32 id
)
276 spin_lock_irqsave(&portdev
->ports_lock
, flags
);
277 list_for_each_entry(port
, &portdev
->ports
, list
)
282 spin_unlock_irqrestore(&portdev
->ports_lock
, flags
);
287 static struct port
*find_port_by_vq(struct ports_device
*portdev
,
288 struct virtqueue
*vq
)
293 spin_lock_irqsave(&portdev
->ports_lock
, flags
);
294 list_for_each_entry(port
, &portdev
->ports
, list
)
295 if (port
->in_vq
== vq
|| port
->out_vq
== vq
)
299 spin_unlock_irqrestore(&portdev
->ports_lock
, flags
);
303 static bool is_console_port(struct port
*port
)
310 static inline bool use_multiport(struct ports_device
*portdev
)
313 * This condition can be true when put_chars is called from
318 return portdev
->vdev
->features
[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT
);
321 static void free_buf(struct port_buffer
*buf
)
327 static struct port_buffer
*alloc_buf(size_t buf_size
)
329 struct port_buffer
*buf
;
331 buf
= kmalloc(sizeof(*buf
), GFP_KERNEL
);
334 buf
->buf
= kzalloc(buf_size
, GFP_KERNEL
);
339 buf
->size
= buf_size
;
348 /* Callers should take appropriate locks */
349 static void *get_inbuf(struct port
*port
)
351 struct port_buffer
*buf
;
352 struct virtqueue
*vq
;
356 buf
= virtqueue_get_buf(vq
, &len
);
365 * Create a scatter-gather list representing our input buffer and put
368 * Callers should take appropriate locks.
370 static int add_inbuf(struct virtqueue
*vq
, struct port_buffer
*buf
)
372 struct scatterlist sg
[1];
375 sg_init_one(sg
, buf
->buf
, buf
->size
);
377 ret
= virtqueue_add_buf(vq
, sg
, 0, 1, buf
);
382 /* Discard any unread data this port has. Callers lockers. */
383 static void discard_port_data(struct port
*port
)
385 struct port_buffer
*buf
;
386 struct virtqueue
*vq
;
394 buf
= virtqueue_get_buf(vq
, &len
);
398 if (add_inbuf(vq
, buf
) < 0) {
402 buf
= virtqueue_get_buf(vq
, &len
);
406 dev_warn(port
->dev
, "Errors adding %d buffers back to vq\n",
410 static bool port_has_data(struct port
*port
)
415 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
420 port
->inbuf
= get_inbuf(port
);
427 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
431 static ssize_t
__send_control_msg(struct ports_device
*portdev
, u32 port_id
,
432 unsigned int event
, unsigned int value
)
434 struct scatterlist sg
[1];
435 struct virtio_console_control cpkt
;
436 struct virtqueue
*vq
;
439 if (!use_multiport(portdev
))
448 sg_init_one(sg
, &cpkt
, sizeof(cpkt
));
449 if (virtqueue_add_buf(vq
, sg
, 1, 0, &cpkt
) >= 0) {
451 while (!virtqueue_get_buf(vq
, &len
))
457 static ssize_t
send_control_msg(struct port
*port
, unsigned int event
,
460 /* Did the port get unplugged before userspace closed it? */
462 return __send_control_msg(port
->portdev
, port
->id
, event
, value
);
466 /* Callers must take the port->outvq_lock */
467 static void reclaim_consumed_buffers(struct port
*port
)
472 while ((buf
= virtqueue_get_buf(port
->out_vq
, &len
))) {
474 port
->outvq_full
= false;
478 static ssize_t
send_buf(struct port
*port
, void *in_buf
, size_t in_count
,
481 struct scatterlist sg
[1];
482 struct virtqueue
*out_vq
;
487 out_vq
= port
->out_vq
;
489 spin_lock_irqsave(&port
->outvq_lock
, flags
);
491 reclaim_consumed_buffers(port
);
493 sg_init_one(sg
, in_buf
, in_count
);
494 ret
= virtqueue_add_buf(out_vq
, sg
, 1, 0, in_buf
);
496 /* Tell Host to go! */
497 virtqueue_kick(out_vq
);
505 port
->outvq_full
= true;
511 * Wait till the host acknowledges it pushed out the data we
512 * sent. This is done for data from the hvc_console; the tty
513 * operations are performed with spinlocks held so we can't
514 * sleep here. An alternative would be to copy the data to a
515 * buffer and relax the spinning requirement. The downside is
516 * we need to kmalloc a GFP_ATOMIC buffer each time the
517 * console driver writes something out.
519 while (!virtqueue_get_buf(out_vq
, &len
))
522 spin_unlock_irqrestore(&port
->outvq_lock
, flags
);
524 * We're expected to return the amount of data we wrote -- all
531 * Give out the data that's requested from the buffer that we have
534 static ssize_t
fill_readbuf(struct port
*port
, char *out_buf
, size_t out_count
,
537 struct port_buffer
*buf
;
540 if (!out_count
|| !port_has_data(port
))
544 out_count
= min(out_count
, buf
->len
- buf
->offset
);
549 ret
= copy_to_user(out_buf
, buf
->buf
+ buf
->offset
, out_count
);
553 memcpy(out_buf
, buf
->buf
+ buf
->offset
, out_count
);
556 buf
->offset
+= out_count
;
558 if (buf
->offset
== buf
->len
) {
560 * We're done using all the data in this buffer.
561 * Re-queue so that the Host can send us more data.
563 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
566 if (add_inbuf(port
->in_vq
, buf
) < 0)
567 dev_warn(port
->dev
, "failed add_buf\n");
569 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
571 /* Return the number of bytes actually copied */
575 /* The condition that must be true for polling to end */
576 static bool will_read_block(struct port
*port
)
578 if (!port
->guest_connected
) {
579 /* Port got hot-unplugged. Let's exit. */
582 return !port_has_data(port
) && port
->host_connected
;
585 static bool will_write_block(struct port
*port
)
589 if (!port
->guest_connected
) {
590 /* Port got hot-unplugged. Let's exit. */
593 if (!port
->host_connected
)
596 spin_lock_irq(&port
->outvq_lock
);
598 * Check if the Host has consumed any buffers since we last
599 * sent data (this is only applicable for nonblocking ports).
601 reclaim_consumed_buffers(port
);
602 ret
= port
->outvq_full
;
603 spin_unlock_irq(&port
->outvq_lock
);
608 static ssize_t
port_fops_read(struct file
*filp
, char __user
*ubuf
,
609 size_t count
, loff_t
*offp
)
614 port
= filp
->private_data
;
616 if (!port_has_data(port
)) {
618 * If nothing's connected on the host just return 0 in
619 * case of list_empty; this tells the userspace app
620 * that there's no connection
622 if (!port
->host_connected
)
624 if (filp
->f_flags
& O_NONBLOCK
)
627 ret
= wait_event_interruptible(port
->waitqueue
,
628 !will_read_block(port
));
632 /* Port got hot-unplugged. */
633 if (!port
->guest_connected
)
636 * We could've received a disconnection message while we were
637 * waiting for more data.
639 * This check is not clubbed in the if() statement above as we
640 * might receive some data as well as the host could get
641 * disconnected after we got woken up from our wait. So we
642 * really want to give off whatever data we have and only then
643 * check for host_connected.
645 if (!port_has_data(port
) && !port
->host_connected
)
648 return fill_readbuf(port
, ubuf
, count
, true);
651 static ssize_t
port_fops_write(struct file
*filp
, const char __user
*ubuf
,
652 size_t count
, loff_t
*offp
)
659 /* Userspace could be out to fool us */
663 port
= filp
->private_data
;
665 nonblock
= filp
->f_flags
& O_NONBLOCK
;
667 if (will_write_block(port
)) {
671 ret
= wait_event_interruptible(port
->waitqueue
,
672 !will_write_block(port
));
676 /* Port got hot-unplugged. */
677 if (!port
->guest_connected
)
680 count
= min((size_t)(32 * 1024), count
);
682 buf
= kmalloc(count
, GFP_KERNEL
);
686 ret
= copy_from_user(buf
, ubuf
, count
);
693 * We now ask send_buf() to not spin for generic ports -- we
694 * can re-use the same code path that non-blocking file
695 * descriptors take for blocking file descriptors since the
696 * wait is already done and we're certain the write will go
697 * through to the host.
700 ret
= send_buf(port
, buf
, count
, nonblock
);
702 if (nonblock
&& ret
> 0)
711 static unsigned int port_fops_poll(struct file
*filp
, poll_table
*wait
)
716 port
= filp
->private_data
;
717 poll_wait(filp
, &port
->waitqueue
, wait
);
719 if (!port
->guest_connected
) {
720 /* Port got unplugged */
724 if (!will_read_block(port
))
725 ret
|= POLLIN
| POLLRDNORM
;
726 if (!will_write_block(port
))
728 if (!port
->host_connected
)
734 static void remove_port(struct kref
*kref
);
736 static int port_fops_release(struct inode
*inode
, struct file
*filp
)
740 port
= filp
->private_data
;
742 /* Notify host of port being closed */
743 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 0);
745 spin_lock_irq(&port
->inbuf_lock
);
746 port
->guest_connected
= false;
748 discard_port_data(port
);
750 spin_unlock_irq(&port
->inbuf_lock
);
752 spin_lock_irq(&port
->outvq_lock
);
753 reclaim_consumed_buffers(port
);
754 spin_unlock_irq(&port
->outvq_lock
);
757 * Locks aren't necessary here as a port can't be opened after
758 * unplug, and if a port isn't unplugged, a kref would already
759 * exist for the port. Plus, taking ports_lock here would
760 * create a dependency on other locks taken by functions
761 * inside remove_port if we're the last holder of the port,
762 * creating many problems.
764 kref_put(&port
->kref
, remove_port
);
769 static int port_fops_open(struct inode
*inode
, struct file
*filp
)
771 struct cdev
*cdev
= inode
->i_cdev
;
775 port
= find_port_by_devt(cdev
->dev
);
776 filp
->private_data
= port
;
778 /* Prevent against a port getting hot-unplugged at the same time */
779 spin_lock_irq(&port
->portdev
->ports_lock
);
780 kref_get(&port
->kref
);
781 spin_unlock_irq(&port
->portdev
->ports_lock
);
784 * Don't allow opening of console port devices -- that's done
787 if (is_console_port(port
)) {
792 /* Allow only one process to open a particular port at a time */
793 spin_lock_irq(&port
->inbuf_lock
);
794 if (port
->guest_connected
) {
795 spin_unlock_irq(&port
->inbuf_lock
);
800 port
->guest_connected
= true;
801 spin_unlock_irq(&port
->inbuf_lock
);
803 spin_lock_irq(&port
->outvq_lock
);
805 * There might be a chance that we missed reclaiming a few
806 * buffers in the window of the port getting previously closed
809 reclaim_consumed_buffers(port
);
810 spin_unlock_irq(&port
->outvq_lock
);
812 nonseekable_open(inode
, filp
);
814 /* Notify host of port being opened */
815 send_control_msg(filp
->private_data
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
819 kref_put(&port
->kref
, remove_port
);
823 static int port_fops_fasync(int fd
, struct file
*filp
, int mode
)
827 port
= filp
->private_data
;
828 return fasync_helper(fd
, filp
, mode
, &port
->async_queue
);
832 * The file operations that we support: programs in the guest can open
833 * a console device, read from it, write to it, poll for data and
834 * close it. The devices are at
835 * /dev/vport<device number>p<port number>
837 static const struct file_operations port_fops
= {
838 .owner
= THIS_MODULE
,
839 .open
= port_fops_open
,
840 .read
= port_fops_read
,
841 .write
= port_fops_write
,
842 .poll
= port_fops_poll
,
843 .release
= port_fops_release
,
844 .fasync
= port_fops_fasync
,
849 * The put_chars() callback is pretty straightforward.
851 * We turn the characters into a scatter-gather list, add it to the
852 * output queue and then kick the Host. Then we sit here waiting for
853 * it to finish: inefficient in theory, but in practice
854 * implementations will do it immediately (lguest's Launcher does).
856 static int put_chars(u32 vtermno
, const char *buf
, int count
)
860 if (unlikely(early_put_chars
))
861 return early_put_chars(vtermno
, buf
, count
);
863 port
= find_port_by_vtermno(vtermno
);
867 return send_buf(port
, (void *)buf
, count
, false);
871 * get_chars() is the callback from the hvc_console infrastructure
872 * when an interrupt is received.
874 * We call out to fill_readbuf that gets us the required data from the
875 * buffers that are queued up.
877 static int get_chars(u32 vtermno
, char *buf
, int count
)
881 /* If we've not set up the port yet, we have no input to give. */
882 if (unlikely(early_put_chars
))
885 port
= find_port_by_vtermno(vtermno
);
889 /* If we don't have an input queue yet, we can't get input. */
890 BUG_ON(!port
->in_vq
);
892 return fill_readbuf(port
, buf
, count
, false);
895 static void resize_console(struct port
*port
)
897 struct virtio_device
*vdev
;
899 /* The port could have been hot-unplugged */
900 if (!port
|| !is_console_port(port
))
903 vdev
= port
->portdev
->vdev
;
904 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_SIZE
))
905 hvc_resize(port
->cons
.hvc
, port
->cons
.ws
);
908 /* We set the configuration at this point, since we now have a tty */
909 static int notifier_add_vio(struct hvc_struct
*hp
, int data
)
913 port
= find_port_by_vtermno(hp
->vtermno
);
917 hp
->irq_requested
= 1;
918 resize_console(port
);
923 static void notifier_del_vio(struct hvc_struct
*hp
, int data
)
925 hp
->irq_requested
= 0;
928 /* The operations for console ports. */
929 static const struct hv_ops hv_ops
= {
930 .get_chars
= get_chars
,
931 .put_chars
= put_chars
,
932 .notifier_add
= notifier_add_vio
,
933 .notifier_del
= notifier_del_vio
,
934 .notifier_hangup
= notifier_del_vio
,
938 * Console drivers are initialized very early so boot messages can go
939 * out, so we do things slightly differently from the generic virtio
940 * initialization of the net and block drivers.
942 * At this stage, the console is output-only. It's too early to set
943 * up a virtqueue, so we let the drivers do some boutique early-output
946 int __init
virtio_cons_early_init(int (*put_chars
)(u32
, const char *, int))
948 early_put_chars
= put_chars
;
949 return hvc_instantiate(0, 0, &hv_ops
);
952 int init_port_console(struct port
*port
)
957 * The Host's telling us this port is a console port. Hook it
958 * up with an hvc console.
960 * To set up and manage our virtual console, we call
963 * The first argument of hvc_alloc() is the virtual console
964 * number. The second argument is the parameter for the
965 * notification mechanism (like irq number). We currently
966 * leave this as zero, virtqueues have implicit notifications.
968 * The third argument is a "struct hv_ops" containing the
969 * put_chars() get_chars(), notifier_add() and notifier_del()
970 * pointers. The final argument is the output buffer size: we
971 * can do any size, so we put PAGE_SIZE here.
973 port
->cons
.vtermno
= pdrvdata
.next_vtermno
;
975 port
->cons
.hvc
= hvc_alloc(port
->cons
.vtermno
, 0, &hv_ops
, PAGE_SIZE
);
976 if (IS_ERR(port
->cons
.hvc
)) {
977 ret
= PTR_ERR(port
->cons
.hvc
);
979 "error %d allocating hvc for port\n", ret
);
980 port
->cons
.hvc
= NULL
;
983 spin_lock_irq(&pdrvdata_lock
);
984 pdrvdata
.next_vtermno
++;
985 list_add_tail(&port
->cons
.list
, &pdrvdata
.consoles
);
986 spin_unlock_irq(&pdrvdata_lock
);
987 port
->guest_connected
= true;
990 * Start using the new console output if this is the first
991 * console to come up.
994 early_put_chars
= NULL
;
996 /* Notify host of port being opened */
997 send_control_msg(port
, VIRTIO_CONSOLE_PORT_OPEN
, 1);
1002 static ssize_t
show_port_name(struct device
*dev
,
1003 struct device_attribute
*attr
, char *buffer
)
1007 port
= dev_get_drvdata(dev
);
1009 return sprintf(buffer
, "%s\n", port
->name
);
1012 static DEVICE_ATTR(name
, S_IRUGO
, show_port_name
, NULL
);
1014 static struct attribute
*port_sysfs_entries
[] = {
1015 &dev_attr_name
.attr
,
1019 static struct attribute_group port_attribute_group
= {
1020 .name
= NULL
, /* put in device directory */
1021 .attrs
= port_sysfs_entries
,
1024 static int debugfs_open(struct inode
*inode
, struct file
*filp
)
1026 filp
->private_data
= inode
->i_private
;
1030 static ssize_t
debugfs_read(struct file
*filp
, char __user
*ubuf
,
1031 size_t count
, loff_t
*offp
)
1035 ssize_t ret
, out_offset
, out_count
;
1038 buf
= kmalloc(out_count
, GFP_KERNEL
);
1042 port
= filp
->private_data
;
1044 out_offset
+= snprintf(buf
+ out_offset
, out_count
,
1045 "name: %s\n", port
->name
? port
->name
: "");
1046 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
1047 "guest_connected: %d\n", port
->guest_connected
);
1048 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
1049 "host_connected: %d\n", port
->host_connected
);
1050 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
1051 "outvq_full: %d\n", port
->outvq_full
);
1052 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
1054 is_console_port(port
) ? "yes" : "no");
1055 out_offset
+= snprintf(buf
+ out_offset
, out_count
- out_offset
,
1056 "console_vtermno: %u\n", port
->cons
.vtermno
);
1058 ret
= simple_read_from_buffer(ubuf
, count
, offp
, buf
, out_offset
);
1063 static const struct file_operations port_debugfs_ops
= {
1064 .owner
= THIS_MODULE
,
1065 .open
= debugfs_open
,
1066 .read
= debugfs_read
,
1069 static void set_console_size(struct port
*port
, u16 rows
, u16 cols
)
1071 if (!port
|| !is_console_port(port
))
1074 port
->cons
.ws
.ws_row
= rows
;
1075 port
->cons
.ws
.ws_col
= cols
;
1078 static unsigned int fill_queue(struct virtqueue
*vq
, spinlock_t
*lock
)
1080 struct port_buffer
*buf
;
1081 unsigned int nr_added_bufs
;
1086 buf
= alloc_buf(PAGE_SIZE
);
1090 spin_lock_irq(lock
);
1091 ret
= add_inbuf(vq
, buf
);
1093 spin_unlock_irq(lock
);
1098 spin_unlock_irq(lock
);
1101 return nr_added_bufs
;
1104 static void send_sigio_to_port(struct port
*port
)
1106 if (port
->async_queue
&& port
->guest_connected
)
1107 kill_fasync(&port
->async_queue
, SIGIO
, POLL_OUT
);
1110 static int add_port(struct ports_device
*portdev
, u32 id
)
1112 char debugfs_name
[16];
1114 struct port_buffer
*buf
;
1116 unsigned int nr_added_bufs
;
1119 port
= kmalloc(sizeof(*port
), GFP_KERNEL
);
1124 kref_init(&port
->kref
);
1126 port
->portdev
= portdev
;
1131 port
->cons
.hvc
= NULL
;
1132 port
->async_queue
= NULL
;
1134 port
->cons
.ws
.ws_row
= port
->cons
.ws
.ws_col
= 0;
1136 port
->host_connected
= port
->guest_connected
= false;
1138 port
->outvq_full
= false;
1140 port
->in_vq
= portdev
->in_vqs
[port
->id
];
1141 port
->out_vq
= portdev
->out_vqs
[port
->id
];
1143 port
->cdev
= cdev_alloc();
1145 dev_err(&port
->portdev
->vdev
->dev
, "Error allocating cdev\n");
1149 port
->cdev
->ops
= &port_fops
;
1151 devt
= MKDEV(portdev
->chr_major
, id
);
1152 err
= cdev_add(port
->cdev
, devt
, 1);
1154 dev_err(&port
->portdev
->vdev
->dev
,
1155 "Error %d adding cdev for port %u\n", err
, id
);
1158 port
->dev
= device_create(pdrvdata
.class, &port
->portdev
->vdev
->dev
,
1159 devt
, port
, "vport%up%u",
1160 port
->portdev
->drv_index
, id
);
1161 if (IS_ERR(port
->dev
)) {
1162 err
= PTR_ERR(port
->dev
);
1163 dev_err(&port
->portdev
->vdev
->dev
,
1164 "Error %d creating device for port %u\n",
1169 spin_lock_init(&port
->inbuf_lock
);
1170 spin_lock_init(&port
->outvq_lock
);
1171 init_waitqueue_head(&port
->waitqueue
);
1173 /* Fill the in_vq with buffers so the host can send us data. */
1174 nr_added_bufs
= fill_queue(port
->in_vq
, &port
->inbuf_lock
);
1175 if (!nr_added_bufs
) {
1176 dev_err(port
->dev
, "Error allocating inbufs\n");
1182 * If we're not using multiport support, this has to be a console port
1184 if (!use_multiport(port
->portdev
)) {
1185 err
= init_port_console(port
);
1190 spin_lock_irq(&portdev
->ports_lock
);
1191 list_add_tail(&port
->list
, &port
->portdev
->ports
);
1192 spin_unlock_irq(&portdev
->ports_lock
);
1195 * Tell the Host we're set so that it can send us various
1196 * configuration parameters for this port (eg, port name,
1197 * caching, whether this is a console port, etc.)
1199 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1201 if (pdrvdata
.debugfs_dir
) {
1203 * Finally, create the debugfs file that we can use to
1204 * inspect a port's state at any time
1206 sprintf(debugfs_name
, "vport%up%u",
1207 port
->portdev
->drv_index
, id
);
1208 port
->debugfs_file
= debugfs_create_file(debugfs_name
, 0444,
1209 pdrvdata
.debugfs_dir
,
1216 while ((buf
= virtqueue_detach_unused_buf(port
->in_vq
)))
1219 device_destroy(pdrvdata
.class, port
->dev
->devt
);
1221 cdev_del(port
->cdev
);
1225 /* The host might want to notify management sw about port add failure */
1226 __send_control_msg(portdev
, id
, VIRTIO_CONSOLE_PORT_READY
, 0);
1230 /* No users remain, remove all port-specific data. */
1231 static void remove_port(struct kref
*kref
)
1235 port
= container_of(kref
, struct port
, kref
);
1237 sysfs_remove_group(&port
->dev
->kobj
, &port_attribute_group
);
1238 device_destroy(pdrvdata
.class, port
->dev
->devt
);
1239 cdev_del(port
->cdev
);
1243 debugfs_remove(port
->debugfs_file
);
1249 * Port got unplugged. Remove port from portdev's list and drop the
1250 * kref reference. If no userspace has this port opened, it will
1251 * result in immediate removal the port.
1253 static void unplug_port(struct port
*port
)
1255 struct port_buffer
*buf
;
1257 spin_lock_irq(&port
->portdev
->ports_lock
);
1258 list_del(&port
->list
);
1259 spin_unlock_irq(&port
->portdev
->ports_lock
);
1261 if (port
->guest_connected
) {
1262 port
->guest_connected
= false;
1263 port
->host_connected
= false;
1264 wake_up_interruptible(&port
->waitqueue
);
1266 /* Let the app know the port is going down. */
1267 send_sigio_to_port(port
);
1270 if (is_console_port(port
)) {
1271 spin_lock_irq(&pdrvdata_lock
);
1272 list_del(&port
->cons
.list
);
1273 spin_unlock_irq(&pdrvdata_lock
);
1276 * hvc_remove() not called as removing one hvc port
1277 * results in other hvc ports getting frozen.
1279 * Once this is resolved in hvc, this functionality
1280 * will be enabled. Till that is done, the -EPIPE
1281 * return from get_chars() above will help
1282 * hvc_console.c to clean up on ports we remove here.
1284 hvc_remove(port
->cons
.hvc
);
1288 /* Remove unused data this port might have received. */
1289 discard_port_data(port
);
1291 reclaim_consumed_buffers(port
);
1293 /* Remove buffers we queued up for the Host to send us data in. */
1294 while ((buf
= virtqueue_detach_unused_buf(port
->in_vq
)))
1298 * We should just assume the device itself has gone off --
1299 * else a close on an open port later will try to send out a
1302 port
->portdev
= NULL
;
1305 * Locks around here are not necessary - a port can't be
1306 * opened after we removed the port struct from ports_list
1309 kref_put(&port
->kref
, remove_port
);
1312 /* Any private messages that the Host and Guest want to share */
1313 static void handle_control_message(struct ports_device
*portdev
,
1314 struct port_buffer
*buf
)
1316 struct virtio_console_control
*cpkt
;
1321 cpkt
= (struct virtio_console_control
*)(buf
->buf
+ buf
->offset
);
1323 port
= find_port_by_id(portdev
, cpkt
->id
);
1324 if (!port
&& cpkt
->event
!= VIRTIO_CONSOLE_PORT_ADD
) {
1325 /* No valid header at start of buffer. Drop it. */
1326 dev_dbg(&portdev
->vdev
->dev
,
1327 "Invalid index %u in control packet\n", cpkt
->id
);
1331 switch (cpkt
->event
) {
1332 case VIRTIO_CONSOLE_PORT_ADD
:
1334 dev_dbg(&portdev
->vdev
->dev
,
1335 "Port %u already added\n", port
->id
);
1336 send_control_msg(port
, VIRTIO_CONSOLE_PORT_READY
, 1);
1339 if (cpkt
->id
>= portdev
->config
.max_nr_ports
) {
1340 dev_warn(&portdev
->vdev
->dev
,
1341 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1342 cpkt
->id
, portdev
->config
.max_nr_ports
- 1);
1345 add_port(portdev
, cpkt
->id
);
1347 case VIRTIO_CONSOLE_PORT_REMOVE
:
1350 case VIRTIO_CONSOLE_CONSOLE_PORT
:
1353 if (is_console_port(port
))
1356 init_port_console(port
);
1358 * Could remove the port here in case init fails - but
1359 * have to notify the host first.
1362 case VIRTIO_CONSOLE_RESIZE
: {
1368 if (!is_console_port(port
))
1371 memcpy(&size
, buf
->buf
+ buf
->offset
+ sizeof(*cpkt
),
1373 set_console_size(port
, size
.rows
, size
.cols
);
1375 port
->cons
.hvc
->irq_requested
= 1;
1376 resize_console(port
);
1379 case VIRTIO_CONSOLE_PORT_OPEN
:
1380 port
->host_connected
= cpkt
->value
;
1381 wake_up_interruptible(&port
->waitqueue
);
1383 * If the host port got closed and the host had any
1384 * unconsumed buffers, we'll be able to reclaim them
1387 spin_lock_irq(&port
->outvq_lock
);
1388 reclaim_consumed_buffers(port
);
1389 spin_unlock_irq(&port
->outvq_lock
);
1392 * If the guest is connected, it'll be interested in
1393 * knowing the host connection state changed.
1395 send_sigio_to_port(port
);
1397 case VIRTIO_CONSOLE_PORT_NAME
:
1399 * Skip the size of the header and the cpkt to get the size
1400 * of the name that was sent
1402 name_size
= buf
->len
- buf
->offset
- sizeof(*cpkt
) + 1;
1404 port
->name
= kmalloc(name_size
, GFP_KERNEL
);
1407 "Not enough space to store port name\n");
1410 strncpy(port
->name
, buf
->buf
+ buf
->offset
+ sizeof(*cpkt
),
1412 port
->name
[name_size
- 1] = 0;
1415 * Since we only have one sysfs attribute, 'name',
1416 * create it only if we have a name for the port.
1418 err
= sysfs_create_group(&port
->dev
->kobj
,
1419 &port_attribute_group
);
1422 "Error %d creating sysfs device attributes\n",
1426 * Generate a udev event so that appropriate
1427 * symlinks can be created based on udev
1430 kobject_uevent(&port
->dev
->kobj
, KOBJ_CHANGE
);
1436 static void control_work_handler(struct work_struct
*work
)
1438 struct ports_device
*portdev
;
1439 struct virtqueue
*vq
;
1440 struct port_buffer
*buf
;
1443 portdev
= container_of(work
, struct ports_device
, control_work
);
1444 vq
= portdev
->c_ivq
;
1446 spin_lock(&portdev
->cvq_lock
);
1447 while ((buf
= virtqueue_get_buf(vq
, &len
))) {
1448 spin_unlock(&portdev
->cvq_lock
);
1453 handle_control_message(portdev
, buf
);
1455 spin_lock(&portdev
->cvq_lock
);
1456 if (add_inbuf(portdev
->c_ivq
, buf
) < 0) {
1457 dev_warn(&portdev
->vdev
->dev
,
1458 "Error adding buffer to queue\n");
1462 spin_unlock(&portdev
->cvq_lock
);
1465 static void in_intr(struct virtqueue
*vq
)
1468 unsigned long flags
;
1470 port
= find_port_by_vq(vq
->vdev
->priv
, vq
);
1474 spin_lock_irqsave(&port
->inbuf_lock
, flags
);
1476 port
->inbuf
= get_inbuf(port
);
1479 * Don't queue up data when port is closed. This condition
1480 * can be reached when a console port is not yet connected (no
1481 * tty is spawned) and the host sends out data to console
1482 * ports. For generic serial ports, the host won't
1483 * (shouldn't) send data till the guest is connected.
1485 if (!port
->guest_connected
)
1486 discard_port_data(port
);
1488 spin_unlock_irqrestore(&port
->inbuf_lock
, flags
);
1490 wake_up_interruptible(&port
->waitqueue
);
1492 /* Send a SIGIO indicating new data in case the process asked for it */
1493 send_sigio_to_port(port
);
1495 if (is_console_port(port
) && hvc_poll(port
->cons
.hvc
))
1499 static void control_intr(struct virtqueue
*vq
)
1501 struct ports_device
*portdev
;
1503 portdev
= vq
->vdev
->priv
;
1504 schedule_work(&portdev
->control_work
);
1507 static void config_intr(struct virtio_device
*vdev
)
1509 struct ports_device
*portdev
;
1511 portdev
= vdev
->priv
;
1513 if (!use_multiport(portdev
)) {
1517 vdev
->config
->get(vdev
,
1518 offsetof(struct virtio_console_config
, cols
),
1519 &cols
, sizeof(u16
));
1520 vdev
->config
->get(vdev
,
1521 offsetof(struct virtio_console_config
, rows
),
1522 &rows
, sizeof(u16
));
1524 port
= find_port_by_id(portdev
, 0);
1525 set_console_size(port
, rows
, cols
);
1528 * We'll use this way of resizing only for legacy
1529 * support. For newer userspace
1530 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1531 * to indicate console size changes so that it can be
1534 resize_console(port
);
1538 static int init_vqs(struct ports_device
*portdev
)
1540 vq_callback_t
**io_callbacks
;
1542 struct virtqueue
**vqs
;
1543 u32 i
, j
, nr_ports
, nr_queues
;
1546 nr_ports
= portdev
->config
.max_nr_ports
;
1547 nr_queues
= use_multiport(portdev
) ? (nr_ports
+ 1) * 2 : 2;
1549 vqs
= kmalloc(nr_queues
* sizeof(struct virtqueue
*), GFP_KERNEL
);
1554 io_callbacks
= kmalloc(nr_queues
* sizeof(vq_callback_t
*), GFP_KERNEL
);
1555 if (!io_callbacks
) {
1559 io_names
= kmalloc(nr_queues
* sizeof(char *), GFP_KERNEL
);
1562 goto free_callbacks
;
1564 portdev
->in_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1566 if (!portdev
->in_vqs
) {
1570 portdev
->out_vqs
= kmalloc(nr_ports
* sizeof(struct virtqueue
*),
1572 if (!portdev
->out_vqs
) {
1578 * For backward compat (newer host but older guest), the host
1579 * spawns a console port first and also inits the vqs for port
1583 io_callbacks
[j
] = in_intr
;
1584 io_callbacks
[j
+ 1] = NULL
;
1585 io_names
[j
] = "input";
1586 io_names
[j
+ 1] = "output";
1589 if (use_multiport(portdev
)) {
1590 io_callbacks
[j
] = control_intr
;
1591 io_callbacks
[j
+ 1] = NULL
;
1592 io_names
[j
] = "control-i";
1593 io_names
[j
+ 1] = "control-o";
1595 for (i
= 1; i
< nr_ports
; i
++) {
1597 io_callbacks
[j
] = in_intr
;
1598 io_callbacks
[j
+ 1] = NULL
;
1599 io_names
[j
] = "input";
1600 io_names
[j
+ 1] = "output";
1603 /* Find the queues. */
1604 err
= portdev
->vdev
->config
->find_vqs(portdev
->vdev
, nr_queues
, vqs
,
1606 (const char **)io_names
);
1611 portdev
->in_vqs
[0] = vqs
[0];
1612 portdev
->out_vqs
[0] = vqs
[1];
1614 if (use_multiport(portdev
)) {
1615 portdev
->c_ivq
= vqs
[j
];
1616 portdev
->c_ovq
= vqs
[j
+ 1];
1618 for (i
= 1; i
< nr_ports
; i
++) {
1620 portdev
->in_vqs
[i
] = vqs
[j
];
1621 portdev
->out_vqs
[i
] = vqs
[j
+ 1];
1624 kfree(io_callbacks
);
1633 kfree(io_callbacks
);
1635 kfree(portdev
->out_vqs
);
1637 kfree(portdev
->in_vqs
);
1644 static const struct file_operations portdev_fops
= {
1645 .owner
= THIS_MODULE
,
1649 * Once we're further in boot, we get probed like any other virtio
1652 * If the host also supports multiple console ports, we check the
1653 * config space to see how many ports the host has spawned. We
1654 * initialize each port found.
1656 static int __devinit
virtcons_probe(struct virtio_device
*vdev
)
1658 struct ports_device
*portdev
;
1662 portdev
= kmalloc(sizeof(*portdev
), GFP_KERNEL
);
1668 /* Attach this portdev to this virtio_device, and vice-versa. */
1669 portdev
->vdev
= vdev
;
1670 vdev
->priv
= portdev
;
1672 spin_lock_irq(&pdrvdata_lock
);
1673 portdev
->drv_index
= pdrvdata
.index
++;
1674 spin_unlock_irq(&pdrvdata_lock
);
1676 portdev
->chr_major
= register_chrdev(0, "virtio-portsdev",
1678 if (portdev
->chr_major
< 0) {
1680 "Error %d registering chrdev for device %u\n",
1681 portdev
->chr_major
, portdev
->drv_index
);
1682 err
= portdev
->chr_major
;
1687 portdev
->config
.max_nr_ports
= 1;
1688 if (virtio_has_feature(vdev
, VIRTIO_CONSOLE_F_MULTIPORT
)) {
1690 vdev
->features
[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT
;
1692 vdev
->config
->get(vdev
, offsetof(struct virtio_console_config
,
1694 &portdev
->config
.max_nr_ports
,
1695 sizeof(portdev
->config
.max_nr_ports
));
1698 /* Let the Host know we support multiple ports.*/
1699 vdev
->config
->finalize_features(vdev
);
1701 err
= init_vqs(portdev
);
1703 dev_err(&vdev
->dev
, "Error %d initializing vqs\n", err
);
1707 spin_lock_init(&portdev
->ports_lock
);
1708 INIT_LIST_HEAD(&portdev
->ports
);
1711 unsigned int nr_added_bufs
;
1713 spin_lock_init(&portdev
->cvq_lock
);
1714 INIT_WORK(&portdev
->control_work
, &control_work_handler
);
1716 nr_added_bufs
= fill_queue(portdev
->c_ivq
, &portdev
->cvq_lock
);
1717 if (!nr_added_bufs
) {
1719 "Error allocating buffers for control queue\n");
1725 * For backward compatibility: Create a console port
1726 * if we're running on older host.
1728 add_port(portdev
, 0);
1731 spin_lock_irq(&pdrvdata_lock
);
1732 list_add_tail(&portdev
->list
, &pdrvdata
.portdevs
);
1733 spin_unlock_irq(&pdrvdata_lock
);
1735 __send_control_msg(portdev
, VIRTIO_CONSOLE_BAD_ID
,
1736 VIRTIO_CONSOLE_DEVICE_READY
, 1);
1740 /* The host might want to notify mgmt sw about device add failure */
1741 __send_control_msg(portdev
, VIRTIO_CONSOLE_BAD_ID
,
1742 VIRTIO_CONSOLE_DEVICE_READY
, 0);
1743 vdev
->config
->del_vqs(vdev
);
1744 kfree(portdev
->in_vqs
);
1745 kfree(portdev
->out_vqs
);
1747 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1754 static void virtcons_remove(struct virtio_device
*vdev
)
1756 struct ports_device
*portdev
;
1757 struct port
*port
, *port2
;
1759 portdev
= vdev
->priv
;
1761 spin_lock_irq(&pdrvdata_lock
);
1762 list_del(&portdev
->list
);
1763 spin_unlock_irq(&pdrvdata_lock
);
1765 /* Disable interrupts for vqs */
1766 vdev
->config
->reset(vdev
);
1767 /* Finish up work that's lined up */
1768 cancel_work_sync(&portdev
->control_work
);
1770 list_for_each_entry_safe(port
, port2
, &portdev
->ports
, list
)
1773 unregister_chrdev(portdev
->chr_major
, "virtio-portsdev");
1776 * When yanking out a device, we immediately lose the
1777 * (device-side) queues. So there's no point in keeping the
1778 * guest side around till we drop our final reference. This
1779 * also means that any ports which are in an open state will
1780 * have to just stop using the port, as the vqs are going
1783 if (use_multiport(portdev
)) {
1784 struct port_buffer
*buf
;
1787 while ((buf
= virtqueue_get_buf(portdev
->c_ivq
, &len
)))
1790 while ((buf
= virtqueue_detach_unused_buf(portdev
->c_ivq
)))
1794 vdev
->config
->del_vqs(vdev
);
1795 kfree(portdev
->in_vqs
);
1796 kfree(portdev
->out_vqs
);
1801 static struct virtio_device_id id_table
[] = {
1802 { VIRTIO_ID_CONSOLE
, VIRTIO_DEV_ANY_ID
},
1806 static unsigned int features
[] = {
1807 VIRTIO_CONSOLE_F_SIZE
,
1808 VIRTIO_CONSOLE_F_MULTIPORT
,
1811 static struct virtio_driver virtio_console
= {
1812 .feature_table
= features
,
1813 .feature_table_size
= ARRAY_SIZE(features
),
1814 .driver
.name
= KBUILD_MODNAME
,
1815 .driver
.owner
= THIS_MODULE
,
1816 .id_table
= id_table
,
1817 .probe
= virtcons_probe
,
1818 .remove
= virtcons_remove
,
1819 .config_changed
= config_intr
,
1822 static int __init
init(void)
1826 pdrvdata
.class = class_create(THIS_MODULE
, "virtio-ports");
1827 if (IS_ERR(pdrvdata
.class)) {
1828 err
= PTR_ERR(pdrvdata
.class);
1829 pr_err("Error %d creating virtio-ports class\n", err
);
1833 pdrvdata
.debugfs_dir
= debugfs_create_dir("virtio-ports", NULL
);
1834 if (!pdrvdata
.debugfs_dir
) {
1835 pr_warning("Error %ld creating debugfs dir for virtio-ports\n",
1836 PTR_ERR(pdrvdata
.debugfs_dir
));
1838 INIT_LIST_HEAD(&pdrvdata
.consoles
);
1839 INIT_LIST_HEAD(&pdrvdata
.portdevs
);
1841 return register_virtio_driver(&virtio_console
);
1844 static void __exit
fini(void)
1846 unregister_virtio_driver(&virtio_console
);
1848 class_destroy(pdrvdata
.class);
1849 if (pdrvdata
.debugfs_dir
)
1850 debugfs_remove_recursive(pdrvdata
.debugfs_dir
);
1855 MODULE_DEVICE_TABLE(virtio
, id_table
);
1856 MODULE_DESCRIPTION("Virtio console driver");
1857 MODULE_LICENSE("GPL");