2 * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
3 * Copyright (C) 2009, 2010, 2011 Red Hat, Inc.
4 * Copyright (C) 2009, 2010, 2011 Amit Shah <amit.shah@redhat.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 #include <linux/cdev.h>
21 #include <linux/debugfs.h>
22 #include <linux/completion.h>
23 #include <linux/device.h>
24 #include <linux/err.h>
25 #include <linux/freezer.h>
27 #include <linux/splice.h>
28 #include <linux/pagemap.h>
29 #include <linux/init.h>
30 #include <linux/list.h>
31 #include <linux/poll.h>
32 #include <linux/sched.h>
33 #include <linux/slab.h>
34 #include <linux/spinlock.h>
35 #include <linux/virtio.h>
36 #include <linux/virtio_console.h>
37 #include <linux/wait.h>
38 #include <linux/workqueue.h>
39 #include <linux/module.h>
40 #include <linux/dma-mapping.h>
41 #include <linux/kconfig.h>
42 #include "../tty/hvc/hvc_console.h"
44 #define is_rproc_enabled IS_ENABLED(CONFIG_REMOTEPROC)
47 * This is a global struct for storing common data for all the devices
48 * this driver handles.
50 * Mainly, it has a linked list for all the consoles in one place so
51 * that callbacks from hvc for get_chars(), put_chars() work properly
52 * across multiple devices and multiple ports per device.
54 struct ports_driver_data {
55 /* Used for registering chardevs */
58 /* Used for exporting per-port information to debugfs */
59 struct dentry *debugfs_dir;
61 /* List of all the devices we're handling */
62 struct list_head portdevs;
65 * This is used to keep track of the number of hvc consoles
66 * spawned by this driver. This number is given as the first
67 * argument to hvc_alloc(). To correctly map an initial
68 * console spawned via hvc_instantiate to the console being
69 * hooked up via hvc_alloc, we need to pass the same vtermno.
71 * We also just assume the first console being initialised was
72 * the first one that got used as the initial console.
74 unsigned int next_vtermno;
76 /* All the console devices handled by this driver */
77 struct list_head consoles;
79 static struct ports_driver_data pdrvdata;
81 static DEFINE_SPINLOCK(pdrvdata_lock);
82 static DECLARE_COMPLETION(early_console_added);
84 /* This struct holds information that's relevant only for console ports */
86 /* We'll place all consoles in a list in the pdrvdata struct */
87 struct list_head list;
89 /* The hvc device associated with this console port */
90 struct hvc_struct *hvc;
92 /* The size of the console */
96 * This number identifies the number that we used to register
97 * with hvc in hvc_instantiate() and hvc_alloc(); this is the
98 * number passed on by the hvc callbacks to us to
99 * differentiate between the other console ports handled by
108 /* size of the buffer in *buf above */
111 /* used length of the buffer */
113 /* offset in the buf from which to consume data */
116 /* DMA address of buffer */
119 /* Device we got DMA memory from */
122 /* List of pending dma buffers to free */
123 struct list_head list;
125 /* If sgpages == 0 then buf is used */
126 unsigned int sgpages;
128 /* sg is used if spages > 0. sg must be the last in is struct */
129 struct scatterlist sg[0];
133 * This is a per-device struct that stores data common to all the
134 * ports for that device (vdev->priv).
136 struct ports_device {
137 /* Next portdev in the list, head is in the pdrvdata struct */
138 struct list_head list;
141 * Workqueue handlers where we process deferred work after
144 struct work_struct control_work;
146 struct list_head ports;
148 /* To protect the list of ports */
149 spinlock_t ports_lock;
151 /* To protect the vq operations for the control channel */
152 spinlock_t c_ivq_lock;
153 spinlock_t c_ovq_lock;
155 /* The current config space is stored here */
156 struct virtio_console_config config;
158 /* The virtio device we're associated with */
159 struct virtio_device *vdev;
162 * A couple of virtqueues for the control channel: one for
163 * guest->host transfers, one for host->guest transfers
165 struct virtqueue *c_ivq, *c_ovq;
167 /* Array of per-port IO virtqueues */
168 struct virtqueue **in_vqs, **out_vqs;
170 /* Major number for this device. Ports will be created as minors. */
175 unsigned long bytes_sent, bytes_received, bytes_discarded;
178 /* This struct holds the per-port data */
180 /* Next port in the list, head is in the ports_device */
181 struct list_head list;
183 /* Pointer to the parent virtio_console device */
184 struct ports_device *portdev;
186 /* The current buffer from which data has to be fed to readers */
187 struct port_buffer *inbuf;
190 * To protect the operations on the in_vq associated with this
191 * port. Has to be a spinlock because it can be called from
192 * interrupt context (get_char()).
194 spinlock_t inbuf_lock;
196 /* Protect the operations on the out_vq. */
197 spinlock_t outvq_lock;
199 /* The IO vqs for this port */
200 struct virtqueue *in_vq, *out_vq;
202 /* File in the debugfs directory that exposes this port's information */
203 struct dentry *debugfs_file;
206 * Keep count of the bytes sent, received and discarded for
207 * this port for accounting and debugging purposes. These
208 * counts are not reset across port open / close events.
210 struct port_stats stats;
213 * The entries in this struct will be valid if this port is
214 * hooked up to an hvc console
218 /* Each port associates with a separate char device */
222 /* Reference-counting to handle port hot-unplugs and file operations */
225 /* A waitqueue for poll() or blocking read operations */
226 wait_queue_head_t waitqueue;
228 /* The 'name' of the port that we expose via sysfs properties */
231 /* We can notify apps of host connect / disconnect events via SIGIO */
232 struct fasync_struct *async_queue;
234 /* The 'id' to identify the port with the Host */
239 /* Is the host device open */
242 /* We should allow only one process to open a port */
243 bool guest_connected;
246 /* This is the very early arch-specified put chars function. */
247 static int (*early_put_chars)(u32, const char *, int);
249 static struct port *find_port_by_vtermno(u32 vtermno)
252 struct console *cons;
255 spin_lock_irqsave(&pdrvdata_lock, flags);
256 list_for_each_entry(cons, &pdrvdata.consoles, list) {
257 if (cons->vtermno == vtermno) {
258 port = container_of(cons, struct port, cons);
264 spin_unlock_irqrestore(&pdrvdata_lock, flags);
268 static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
274 spin_lock_irqsave(&portdev->ports_lock, flags);
275 list_for_each_entry(port, &portdev->ports, list) {
276 if (port->cdev->dev == dev) {
277 kref_get(&port->kref);
283 spin_unlock_irqrestore(&portdev->ports_lock, flags);
288 static struct port *find_port_by_devt(dev_t dev)
290 struct ports_device *portdev;
294 spin_lock_irqsave(&pdrvdata_lock, flags);
295 list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
296 port = find_port_by_devt_in_portdev(portdev, dev);
302 spin_unlock_irqrestore(&pdrvdata_lock, flags);
306 static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
311 spin_lock_irqsave(&portdev->ports_lock, flags);
312 list_for_each_entry(port, &portdev->ports, list)
317 spin_unlock_irqrestore(&portdev->ports_lock, flags);
322 static struct port *find_port_by_vq(struct ports_device *portdev,
323 struct virtqueue *vq)
328 spin_lock_irqsave(&portdev->ports_lock, flags);
329 list_for_each_entry(port, &portdev->ports, list)
330 if (port->in_vq == vq || port->out_vq == vq)
334 spin_unlock_irqrestore(&portdev->ports_lock, flags);
338 static bool is_console_port(struct port *port)
345 static bool is_rproc_serial(const struct virtio_device *vdev)
347 return is_rproc_enabled && vdev->id.device == VIRTIO_ID_RPROC_SERIAL;
350 static inline bool use_multiport(struct ports_device *portdev)
353 * This condition can be true when put_chars is called from
358 return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
361 static DEFINE_SPINLOCK(dma_bufs_lock);
362 static LIST_HEAD(pending_free_dma_bufs);
364 static void free_buf(struct port_buffer *buf, bool can_sleep)
368 for (i = 0; i < buf->sgpages; i++) {
369 struct page *page = sg_page(&buf->sg[i]);
377 } else if (is_rproc_enabled) {
380 /* dma_free_coherent requires interrupts to be enabled. */
382 /* queue up dma-buffers to be freed later */
383 spin_lock_irqsave(&dma_bufs_lock, flags);
384 list_add_tail(&buf->list, &pending_free_dma_bufs);
385 spin_unlock_irqrestore(&dma_bufs_lock, flags);
388 dma_free_coherent(buf->dev, buf->size, buf->buf, buf->dma);
390 /* Release device refcnt and allow it to be freed */
391 put_device(buf->dev);
397 static void reclaim_dma_bufs(void)
400 struct port_buffer *buf, *tmp;
403 if (list_empty(&pending_free_dma_bufs))
406 /* Create a copy of the pending_free_dma_bufs while holding the lock */
407 spin_lock_irqsave(&dma_bufs_lock, flags);
408 list_cut_position(&tmp_list, &pending_free_dma_bufs,
409 pending_free_dma_bufs.prev);
410 spin_unlock_irqrestore(&dma_bufs_lock, flags);
412 /* Release the dma buffers, without irqs enabled */
413 list_for_each_entry_safe(buf, tmp, &tmp_list, list) {
414 list_del(&buf->list);
419 static struct port_buffer *alloc_buf(struct virtqueue *vq, size_t buf_size,
422 struct port_buffer *buf;
427 * Allocate buffer and the sg list. The sg list array is allocated
428 * directly after the port_buffer struct.
430 buf = kmalloc(sizeof(*buf) + sizeof(struct scatterlist) * pages,
435 buf->sgpages = pages;
442 if (is_rproc_serial(vq->vdev)) {
444 * Allocate DMA memory from ancestor. When a virtio
445 * device is created by remoteproc, the DMA memory is
446 * associated with the grandparent device:
447 * vdev => rproc => platform-dev.
448 * The code here would have been less quirky if
449 * DMA_MEMORY_INCLUDES_CHILDREN had been supported
452 if (!vq->vdev->dev.parent || !vq->vdev->dev.parent->parent)
454 buf->dev = vq->vdev->dev.parent->parent;
456 /* Increase device refcnt to avoid freeing it */
457 get_device(buf->dev);
458 buf->buf = dma_alloc_coherent(buf->dev, buf_size, &buf->dma,
462 buf->buf = kmalloc(buf_size, GFP_KERNEL);
469 buf->size = buf_size;
478 /* Callers should take appropriate locks */
479 static struct port_buffer *get_inbuf(struct port *port)
481 struct port_buffer *buf;
487 buf = virtqueue_get_buf(port->in_vq, &len);
491 port->stats.bytes_received += len;
497 * Create a scatter-gather list representing our input buffer and put
500 * Callers should take appropriate locks.
502 static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
504 struct scatterlist sg[1];
507 sg_init_one(sg, buf->buf, buf->size);
509 ret = virtqueue_add_inbuf(vq, sg, 1, buf, GFP_ATOMIC);
516 /* Discard any unread data this port has. Callers lockers. */
517 static void discard_port_data(struct port *port)
519 struct port_buffer *buf;
522 if (!port->portdev) {
523 /* Device has been unplugged. vqs are already gone. */
526 buf = get_inbuf(port);
530 port->stats.bytes_discarded += buf->len - buf->offset;
531 if (add_inbuf(port->in_vq, buf) < 0) {
533 free_buf(buf, false);
536 buf = get_inbuf(port);
539 dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
543 static bool port_has_data(struct port *port)
549 spin_lock_irqsave(&port->inbuf_lock, flags);
550 port->inbuf = get_inbuf(port);
554 spin_unlock_irqrestore(&port->inbuf_lock, flags);
558 static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
559 unsigned int event, unsigned int value)
561 struct scatterlist sg[1];
562 struct virtio_console_control cpkt;
563 struct virtqueue *vq;
566 if (!use_multiport(portdev))
575 sg_init_one(sg, &cpkt, sizeof(cpkt));
577 spin_lock(&portdev->c_ovq_lock);
578 if (virtqueue_add_outbuf(vq, sg, 1, &cpkt, GFP_ATOMIC) == 0) {
580 while (!virtqueue_get_buf(vq, &len))
583 spin_unlock(&portdev->c_ovq_lock);
587 static ssize_t send_control_msg(struct port *port, unsigned int event,
590 /* Did the port get unplugged before userspace closed it? */
592 return __send_control_msg(port->portdev, port->id, event, value);
597 /* Callers must take the port->outvq_lock */
598 static void reclaim_consumed_buffers(struct port *port)
600 struct port_buffer *buf;
603 if (!port->portdev) {
604 /* Device has been unplugged. vqs are already gone. */
607 while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
608 free_buf(buf, false);
609 port->outvq_full = false;
613 static ssize_t __send_to_port(struct port *port, struct scatterlist *sg,
614 int nents, size_t in_count,
615 void *data, bool nonblock)
617 struct virtqueue *out_vq;
622 out_vq = port->out_vq;
624 spin_lock_irqsave(&port->outvq_lock, flags);
626 reclaim_consumed_buffers(port);
628 err = virtqueue_add_outbuf(out_vq, sg, nents, data, GFP_ATOMIC);
630 /* Tell Host to go! */
631 virtqueue_kick(out_vq);
638 if (out_vq->num_free == 0)
639 port->outvq_full = true;
645 * Wait till the host acknowledges it pushed out the data we
646 * sent. This is done for data from the hvc_console; the tty
647 * operations are performed with spinlocks held so we can't
648 * sleep here. An alternative would be to copy the data to a
649 * buffer and relax the spinning requirement. The downside is
650 * we need to kmalloc a GFP_ATOMIC buffer each time the
651 * console driver writes something out.
653 while (!virtqueue_get_buf(out_vq, &len))
656 spin_unlock_irqrestore(&port->outvq_lock, flags);
658 port->stats.bytes_sent += in_count;
660 * We're expected to return the amount of data we wrote -- all
667 * Give out the data that's requested from the buffer that we have
670 static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count,
673 struct port_buffer *buf;
676 if (!out_count || !port_has_data(port))
680 out_count = min(out_count, buf->len - buf->offset);
685 ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
689 memcpy(out_buf, buf->buf + buf->offset, out_count);
692 buf->offset += out_count;
694 if (buf->offset == buf->len) {
696 * We're done using all the data in this buffer.
697 * Re-queue so that the Host can send us more data.
699 spin_lock_irqsave(&port->inbuf_lock, flags);
702 if (add_inbuf(port->in_vq, buf) < 0)
703 dev_warn(port->dev, "failed add_buf\n");
705 spin_unlock_irqrestore(&port->inbuf_lock, flags);
707 /* Return the number of bytes actually copied */
711 /* The condition that must be true for polling to end */
712 static bool will_read_block(struct port *port)
714 if (!port->guest_connected) {
715 /* Port got hot-unplugged. Let's exit. */
718 return !port_has_data(port) && port->host_connected;
721 static bool will_write_block(struct port *port)
725 if (!port->guest_connected) {
726 /* Port got hot-unplugged. Let's exit. */
729 if (!port->host_connected)
732 spin_lock_irq(&port->outvq_lock);
734 * Check if the Host has consumed any buffers since we last
735 * sent data (this is only applicable for nonblocking ports).
737 reclaim_consumed_buffers(port);
738 ret = port->outvq_full;
739 spin_unlock_irq(&port->outvq_lock);
744 static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
745 size_t count, loff_t *offp)
750 port = filp->private_data;
752 /* Port is hot-unplugged. */
753 if (!port->guest_connected)
756 if (!port_has_data(port)) {
758 * If nothing's connected on the host just return 0 in
759 * case of list_empty; this tells the userspace app
760 * that there's no connection
762 if (!port->host_connected)
764 if (filp->f_flags & O_NONBLOCK)
767 ret = wait_event_freezable(port->waitqueue,
768 !will_read_block(port));
772 /* Port got hot-unplugged while we were waiting above. */
773 if (!port->guest_connected)
776 * We could've received a disconnection message while we were
777 * waiting for more data.
779 * This check is not clubbed in the if() statement above as we
780 * might receive some data as well as the host could get
781 * disconnected after we got woken up from our wait. So we
782 * really want to give off whatever data we have and only then
783 * check for host_connected.
785 if (!port_has_data(port) && !port->host_connected)
788 return fill_readbuf(port, ubuf, count, true);
791 static int wait_port_writable(struct port *port, bool nonblock)
795 if (will_write_block(port)) {
799 ret = wait_event_freezable(port->waitqueue,
800 !will_write_block(port));
804 /* Port got hot-unplugged. */
805 if (!port->guest_connected)
811 static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
812 size_t count, loff_t *offp)
815 struct port_buffer *buf;
818 struct scatterlist sg[1];
820 /* Userspace could be out to fool us */
824 port = filp->private_data;
826 nonblock = filp->f_flags & O_NONBLOCK;
828 ret = wait_port_writable(port, nonblock);
832 count = min((size_t)(32 * 1024), count);
834 buf = alloc_buf(port->out_vq, count, 0);
838 ret = copy_from_user(buf->buf, ubuf, count);
845 * We now ask send_buf() to not spin for generic ports -- we
846 * can re-use the same code path that non-blocking file
847 * descriptors take for blocking file descriptors since the
848 * wait is already done and we're certain the write will go
849 * through to the host.
852 sg_init_one(sg, buf->buf, count);
853 ret = __send_to_port(port, sg, 1, count, buf, nonblock);
855 if (nonblock && ret > 0)
868 struct scatterlist *sg;
871 static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
872 struct splice_desc *sd)
874 struct sg_list *sgl = sd->u.data;
875 unsigned int offset, len;
877 if (sgl->n == sgl->size)
880 /* Try lock this page */
881 if (buf->ops->steal(pipe, buf) == 0) {
882 /* Get reference and unlock page for moving */
884 unlock_page(buf->page);
886 len = min(buf->len, sd->len);
887 sg_set_page(&(sgl->sg[sgl->n]), buf->page, len, buf->offset);
889 /* Failback to copying a page */
890 struct page *page = alloc_page(GFP_KERNEL);
891 char *src = buf->ops->map(pipe, buf, 1);
898 offset = sd->pos & ~PAGE_MASK;
901 if (len + offset > PAGE_SIZE)
902 len = PAGE_SIZE - offset;
904 memcpy(dst + offset, src + buf->offset, len);
907 buf->ops->unmap(pipe, buf, src);
909 sg_set_page(&(sgl->sg[sgl->n]), page, len, offset);
917 /* Faster zero-copy write by splicing */
918 static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
919 struct file *filp, loff_t *ppos,
920 size_t len, unsigned int flags)
922 struct port *port = filp->private_data;
925 struct port_buffer *buf;
926 struct splice_desc sd = {
934 * Rproc_serial does not yet support splice. To support splice
935 * pipe_to_sg() must allocate dma-buffers and copy content from
936 * regular pages to dma pages. And alloc_buf and free_buf must
937 * support allocating and freeing such a list of dma-buffers.
939 if (is_rproc_serial(port->out_vq->vdev))
943 * pipe->nrbufs == 0 means there are no data to transfer,
944 * so this returns just 0 for no data.
952 ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK);
956 buf = alloc_buf(port->out_vq, 0, pipe->nrbufs);
964 sgl.size = pipe->nrbufs;
966 sg_init_table(sgl.sg, sgl.size);
967 ret = __splice_from_pipe(pipe, &sd, pipe_to_sg);
970 ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true);
972 if (unlikely(ret <= 0))
981 static unsigned int port_fops_poll(struct file *filp, poll_table *wait)
986 port = filp->private_data;
987 poll_wait(filp, &port->waitqueue, wait);
989 if (!port->guest_connected) {
990 /* Port got unplugged */
994 if (!will_read_block(port))
995 ret |= POLLIN | POLLRDNORM;
996 if (!will_write_block(port))
998 if (!port->host_connected)
1004 static void remove_port(struct kref *kref);
1006 static int port_fops_release(struct inode *inode, struct file *filp)
1010 port = filp->private_data;
1012 /* Notify host of port being closed */
1013 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
1015 spin_lock_irq(&port->inbuf_lock);
1016 port->guest_connected = false;
1018 discard_port_data(port);
1020 spin_unlock_irq(&port->inbuf_lock);
1022 spin_lock_irq(&port->outvq_lock);
1023 reclaim_consumed_buffers(port);
1024 spin_unlock_irq(&port->outvq_lock);
1028 * Locks aren't necessary here as a port can't be opened after
1029 * unplug, and if a port isn't unplugged, a kref would already
1030 * exist for the port. Plus, taking ports_lock here would
1031 * create a dependency on other locks taken by functions
1032 * inside remove_port if we're the last holder of the port,
1033 * creating many problems.
1035 kref_put(&port->kref, remove_port);
1040 static int port_fops_open(struct inode *inode, struct file *filp)
1042 struct cdev *cdev = inode->i_cdev;
1046 /* We get the port with a kref here */
1047 port = find_port_by_devt(cdev->dev);
1049 /* Port was unplugged before we could proceed */
1052 filp->private_data = port;
1055 * Don't allow opening of console port devices -- that's done
1058 if (is_console_port(port)) {
1063 /* Allow only one process to open a particular port at a time */
1064 spin_lock_irq(&port->inbuf_lock);
1065 if (port->guest_connected) {
1066 spin_unlock_irq(&port->inbuf_lock);
1071 port->guest_connected = true;
1072 spin_unlock_irq(&port->inbuf_lock);
1074 spin_lock_irq(&port->outvq_lock);
1076 * There might be a chance that we missed reclaiming a few
1077 * buffers in the window of the port getting previously closed
1080 reclaim_consumed_buffers(port);
1081 spin_unlock_irq(&port->outvq_lock);
1083 nonseekable_open(inode, filp);
1085 /* Notify host of port being opened */
1086 send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
1090 kref_put(&port->kref, remove_port);
1094 static int port_fops_fasync(int fd, struct file *filp, int mode)
1098 port = filp->private_data;
1099 return fasync_helper(fd, filp, mode, &port->async_queue);
1103 * The file operations that we support: programs in the guest can open
1104 * a console device, read from it, write to it, poll for data and
1105 * close it. The devices are at
1106 * /dev/vport<device number>p<port number>
1108 static const struct file_operations port_fops = {
1109 .owner = THIS_MODULE,
1110 .open = port_fops_open,
1111 .read = port_fops_read,
1112 .write = port_fops_write,
1113 .splice_write = port_fops_splice_write,
1114 .poll = port_fops_poll,
1115 .release = port_fops_release,
1116 .fasync = port_fops_fasync,
1117 .llseek = no_llseek,
1121 * The put_chars() callback is pretty straightforward.
1123 * We turn the characters into a scatter-gather list, add it to the
1124 * output queue and then kick the Host. Then we sit here waiting for
1125 * it to finish: inefficient in theory, but in practice
1126 * implementations will do it immediately (lguest's Launcher does).
1128 static int put_chars(u32 vtermno, const char *buf, int count)
1131 struct scatterlist sg[1];
1133 if (unlikely(early_put_chars))
1134 return early_put_chars(vtermno, buf, count);
1136 port = find_port_by_vtermno(vtermno);
1140 sg_init_one(sg, buf, count);
1141 return __send_to_port(port, sg, 1, count, (void *)buf, false);
1145 * get_chars() is the callback from the hvc_console infrastructure
1146 * when an interrupt is received.
1148 * We call out to fill_readbuf that gets us the required data from the
1149 * buffers that are queued up.
1151 static int get_chars(u32 vtermno, char *buf, int count)
1155 /* If we've not set up the port yet, we have no input to give. */
1156 if (unlikely(early_put_chars))
1159 port = find_port_by_vtermno(vtermno);
1163 /* If we don't have an input queue yet, we can't get input. */
1164 BUG_ON(!port->in_vq);
1166 return fill_readbuf(port, buf, count, false);
1169 static void resize_console(struct port *port)
1171 struct virtio_device *vdev;
1173 /* The port could have been hot-unplugged */
1174 if (!port || !is_console_port(port))
1177 vdev = port->portdev->vdev;
1179 /* Don't test F_SIZE at all if we're rproc: not a valid feature! */
1180 if (!is_rproc_serial(vdev) &&
1181 virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
1182 hvc_resize(port->cons.hvc, port->cons.ws);
1185 /* We set the configuration at this point, since we now have a tty */
1186 static int notifier_add_vio(struct hvc_struct *hp, int data)
1190 port = find_port_by_vtermno(hp->vtermno);
1194 hp->irq_requested = 1;
1195 resize_console(port);
1200 static void notifier_del_vio(struct hvc_struct *hp, int data)
1202 hp->irq_requested = 0;
1205 /* The operations for console ports. */
1206 static const struct hv_ops hv_ops = {
1207 .get_chars = get_chars,
1208 .put_chars = put_chars,
1209 .notifier_add = notifier_add_vio,
1210 .notifier_del = notifier_del_vio,
1211 .notifier_hangup = notifier_del_vio,
1215 * Console drivers are initialized very early so boot messages can go
1216 * out, so we do things slightly differently from the generic virtio
1217 * initialization of the net and block drivers.
1219 * At this stage, the console is output-only. It's too early to set
1220 * up a virtqueue, so we let the drivers do some boutique early-output
1223 int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
1225 early_put_chars = put_chars;
1226 return hvc_instantiate(0, 0, &hv_ops);
1229 static int init_port_console(struct port *port)
1234 * The Host's telling us this port is a console port. Hook it
1235 * up with an hvc console.
1237 * To set up and manage our virtual console, we call
1240 * The first argument of hvc_alloc() is the virtual console
1241 * number. The second argument is the parameter for the
1242 * notification mechanism (like irq number). We currently
1243 * leave this as zero, virtqueues have implicit notifications.
1245 * The third argument is a "struct hv_ops" containing the
1246 * put_chars() get_chars(), notifier_add() and notifier_del()
1247 * pointers. The final argument is the output buffer size: we
1248 * can do any size, so we put PAGE_SIZE here.
1250 port->cons.vtermno = pdrvdata.next_vtermno;
1252 port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
1253 if (IS_ERR(port->cons.hvc)) {
1254 ret = PTR_ERR(port->cons.hvc);
1256 "error %d allocating hvc for port\n", ret);
1257 port->cons.hvc = NULL;
1260 spin_lock_irq(&pdrvdata_lock);
1261 pdrvdata.next_vtermno++;
1262 list_add_tail(&port->cons.list, &pdrvdata.consoles);
1263 spin_unlock_irq(&pdrvdata_lock);
1264 port->guest_connected = true;
1267 * Start using the new console output if this is the first
1268 * console to come up.
1270 if (early_put_chars)
1271 early_put_chars = NULL;
1273 /* Notify host of port being opened */
1274 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
1279 static ssize_t show_port_name(struct device *dev,
1280 struct device_attribute *attr, char *buffer)
1284 port = dev_get_drvdata(dev);
1286 return sprintf(buffer, "%s\n", port->name);
1289 static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
1291 static struct attribute *port_sysfs_entries[] = {
1292 &dev_attr_name.attr,
1296 static struct attribute_group port_attribute_group = {
1297 .name = NULL, /* put in device directory */
1298 .attrs = port_sysfs_entries,
1301 static ssize_t debugfs_read(struct file *filp, char __user *ubuf,
1302 size_t count, loff_t *offp)
1306 ssize_t ret, out_offset, out_count;
1309 buf = kmalloc(out_count, GFP_KERNEL);
1313 port = filp->private_data;
1315 out_offset += snprintf(buf + out_offset, out_count,
1316 "name: %s\n", port->name ? port->name : "");
1317 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1318 "guest_connected: %d\n", port->guest_connected);
1319 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1320 "host_connected: %d\n", port->host_connected);
1321 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1322 "outvq_full: %d\n", port->outvq_full);
1323 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1324 "bytes_sent: %lu\n", port->stats.bytes_sent);
1325 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1326 "bytes_received: %lu\n",
1327 port->stats.bytes_received);
1328 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1329 "bytes_discarded: %lu\n",
1330 port->stats.bytes_discarded);
1331 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1333 is_console_port(port) ? "yes" : "no");
1334 out_offset += snprintf(buf + out_offset, out_count - out_offset,
1335 "console_vtermno: %u\n", port->cons.vtermno);
1337 ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
1342 static const struct file_operations port_debugfs_ops = {
1343 .owner = THIS_MODULE,
1344 .open = simple_open,
1345 .read = debugfs_read,
1348 static void set_console_size(struct port *port, u16 rows, u16 cols)
1350 if (!port || !is_console_port(port))
1353 port->cons.ws.ws_row = rows;
1354 port->cons.ws.ws_col = cols;
1357 static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
1359 struct port_buffer *buf;
1360 unsigned int nr_added_bufs;
1365 buf = alloc_buf(vq, PAGE_SIZE, 0);
1369 spin_lock_irq(lock);
1370 ret = add_inbuf(vq, buf);
1372 spin_unlock_irq(lock);
1373 free_buf(buf, true);
1377 spin_unlock_irq(lock);
1380 return nr_added_bufs;
1383 static void send_sigio_to_port(struct port *port)
1385 if (port->async_queue && port->guest_connected)
1386 kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
1389 static int add_port(struct ports_device *portdev, u32 id)
1391 char debugfs_name[16];
1393 struct port_buffer *buf;
1395 unsigned int nr_added_bufs;
1398 port = kmalloc(sizeof(*port), GFP_KERNEL);
1403 kref_init(&port->kref);
1405 port->portdev = portdev;
1410 port->cons.hvc = NULL;
1411 port->async_queue = NULL;
1413 port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
1415 port->host_connected = port->guest_connected = false;
1416 port->stats = (struct port_stats) { 0 };
1418 port->outvq_full = false;
1420 port->in_vq = portdev->in_vqs[port->id];
1421 port->out_vq = portdev->out_vqs[port->id];
1423 port->cdev = cdev_alloc();
1425 dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
1429 port->cdev->ops = &port_fops;
1431 devt = MKDEV(portdev->chr_major, id);
1432 err = cdev_add(port->cdev, devt, 1);
1434 dev_err(&port->portdev->vdev->dev,
1435 "Error %d adding cdev for port %u\n", err, id);
1438 port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev,
1439 devt, port, "vport%up%u",
1440 port->portdev->vdev->index, id);
1441 if (IS_ERR(port->dev)) {
1442 err = PTR_ERR(port->dev);
1443 dev_err(&port->portdev->vdev->dev,
1444 "Error %d creating device for port %u\n",
1449 spin_lock_init(&port->inbuf_lock);
1450 spin_lock_init(&port->outvq_lock);
1451 init_waitqueue_head(&port->waitqueue);
1453 /* Fill the in_vq with buffers so the host can send us data. */
1454 nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock);
1455 if (!nr_added_bufs) {
1456 dev_err(port->dev, "Error allocating inbufs\n");
1461 if (is_rproc_serial(port->portdev->vdev))
1463 * For rproc_serial assume remote processor is connected.
1464 * rproc_serial does not want the console port, only
1465 * the generic port implementation.
1467 port->host_connected = true;
1468 else if (!use_multiport(port->portdev)) {
1470 * If we're not using multiport support,
1471 * this has to be a console port.
1473 err = init_port_console(port);
1478 spin_lock_irq(&portdev->ports_lock);
1479 list_add_tail(&port->list, &port->portdev->ports);
1480 spin_unlock_irq(&portdev->ports_lock);
1483 * Tell the Host we're set so that it can send us various
1484 * configuration parameters for this port (eg, port name,
1485 * caching, whether this is a console port, etc.)
1487 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1489 if (pdrvdata.debugfs_dir) {
1491 * Finally, create the debugfs file that we can use to
1492 * inspect a port's state at any time
1494 sprintf(debugfs_name, "vport%up%u",
1495 port->portdev->vdev->index, id);
1496 port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
1497 pdrvdata.debugfs_dir,
1504 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1505 free_buf(buf, true);
1507 device_destroy(pdrvdata.class, port->dev->devt);
1509 cdev_del(port->cdev);
1513 /* The host might want to notify management sw about port add failure */
1514 __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
1518 /* No users remain, remove all port-specific data. */
1519 static void remove_port(struct kref *kref)
1523 port = container_of(kref, struct port, kref);
1528 static void remove_port_data(struct port *port)
1530 struct port_buffer *buf;
1532 spin_lock_irq(&port->inbuf_lock);
1533 /* Remove unused data this port might have received. */
1534 discard_port_data(port);
1536 /* Remove buffers we queued up for the Host to send us data in. */
1537 while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
1538 free_buf(buf, true);
1539 spin_unlock_irq(&port->inbuf_lock);
1541 spin_lock_irq(&port->outvq_lock);
1542 reclaim_consumed_buffers(port);
1544 /* Free pending buffers from the out-queue. */
1545 while ((buf = virtqueue_detach_unused_buf(port->out_vq)))
1546 free_buf(buf, true);
1547 spin_unlock_irq(&port->outvq_lock);
1551 * Port got unplugged. Remove port from portdev's list and drop the
1552 * kref reference. If no userspace has this port opened, it will
1553 * result in immediate removal the port.
1555 static void unplug_port(struct port *port)
1557 spin_lock_irq(&port->portdev->ports_lock);
1558 list_del(&port->list);
1559 spin_unlock_irq(&port->portdev->ports_lock);
1561 spin_lock_irq(&port->inbuf_lock);
1562 if (port->guest_connected) {
1563 /* Let the app know the port is going down. */
1564 send_sigio_to_port(port);
1566 /* Do this after sigio is actually sent */
1567 port->guest_connected = false;
1568 port->host_connected = false;
1570 wake_up_interruptible(&port->waitqueue);
1572 spin_unlock_irq(&port->inbuf_lock);
1574 if (is_console_port(port)) {
1575 spin_lock_irq(&pdrvdata_lock);
1576 list_del(&port->cons.list);
1577 spin_unlock_irq(&pdrvdata_lock);
1578 hvc_remove(port->cons.hvc);
1581 remove_port_data(port);
1584 * We should just assume the device itself has gone off --
1585 * else a close on an open port later will try to send out a
1588 port->portdev = NULL;
1590 sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
1591 device_destroy(pdrvdata.class, port->dev->devt);
1592 cdev_del(port->cdev);
1594 debugfs_remove(port->debugfs_file);
1598 * Locks around here are not necessary - a port can't be
1599 * opened after we removed the port struct from ports_list
1602 kref_put(&port->kref, remove_port);
1605 /* Any private messages that the Host and Guest want to share */
1606 static void handle_control_message(struct ports_device *portdev,
1607 struct port_buffer *buf)
1609 struct virtio_console_control *cpkt;
1614 cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
1616 port = find_port_by_id(portdev, cpkt->id);
1617 if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) {
1618 /* No valid header at start of buffer. Drop it. */
1619 dev_dbg(&portdev->vdev->dev,
1620 "Invalid index %u in control packet\n", cpkt->id);
1624 switch (cpkt->event) {
1625 case VIRTIO_CONSOLE_PORT_ADD:
1627 dev_dbg(&portdev->vdev->dev,
1628 "Port %u already added\n", port->id);
1629 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
1632 if (cpkt->id >= portdev->config.max_nr_ports) {
1633 dev_warn(&portdev->vdev->dev,
1634 "Request for adding port with out-of-bound id %u, max. supported id: %u\n",
1635 cpkt->id, portdev->config.max_nr_ports - 1);
1638 add_port(portdev, cpkt->id);
1640 case VIRTIO_CONSOLE_PORT_REMOVE:
1643 case VIRTIO_CONSOLE_CONSOLE_PORT:
1646 if (is_console_port(port))
1649 init_port_console(port);
1650 complete(&early_console_added);
1652 * Could remove the port here in case init fails - but
1653 * have to notify the host first.
1656 case VIRTIO_CONSOLE_RESIZE: {
1662 if (!is_console_port(port))
1665 memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
1667 set_console_size(port, size.rows, size.cols);
1669 port->cons.hvc->irq_requested = 1;
1670 resize_console(port);
1673 case VIRTIO_CONSOLE_PORT_OPEN:
1674 port->host_connected = cpkt->value;
1675 wake_up_interruptible(&port->waitqueue);
1677 * If the host port got closed and the host had any
1678 * unconsumed buffers, we'll be able to reclaim them
1681 spin_lock_irq(&port->outvq_lock);
1682 reclaim_consumed_buffers(port);
1683 spin_unlock_irq(&port->outvq_lock);
1686 * If the guest is connected, it'll be interested in
1687 * knowing the host connection state changed.
1689 spin_lock_irq(&port->inbuf_lock);
1690 send_sigio_to_port(port);
1691 spin_unlock_irq(&port->inbuf_lock);
1693 case VIRTIO_CONSOLE_PORT_NAME:
1695 * If we woke up after hibernation, we can get this
1696 * again. Skip it in that case.
1702 * Skip the size of the header and the cpkt to get the size
1703 * of the name that was sent
1705 name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
1707 port->name = kmalloc(name_size, GFP_KERNEL);
1710 "Not enough space to store port name\n");
1713 strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
1715 port->name[name_size - 1] = 0;
1718 * Since we only have one sysfs attribute, 'name',
1719 * create it only if we have a name for the port.
1721 err = sysfs_create_group(&port->dev->kobj,
1722 &port_attribute_group);
1725 "Error %d creating sysfs device attributes\n",
1729 * Generate a udev event so that appropriate
1730 * symlinks can be created based on udev
1733 kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
1739 static void control_work_handler(struct work_struct *work)
1741 struct ports_device *portdev;
1742 struct virtqueue *vq;
1743 struct port_buffer *buf;
1746 portdev = container_of(work, struct ports_device, control_work);
1747 vq = portdev->c_ivq;
1749 spin_lock(&portdev->c_ivq_lock);
1750 while ((buf = virtqueue_get_buf(vq, &len))) {
1751 spin_unlock(&portdev->c_ivq_lock);
1756 handle_control_message(portdev, buf);
1758 spin_lock(&portdev->c_ivq_lock);
1759 if (add_inbuf(portdev->c_ivq, buf) < 0) {
1760 dev_warn(&portdev->vdev->dev,
1761 "Error adding buffer to queue\n");
1762 free_buf(buf, false);
1765 spin_unlock(&portdev->c_ivq_lock);
1768 static void out_intr(struct virtqueue *vq)
1772 port = find_port_by_vq(vq->vdev->priv, vq);
1776 wake_up_interruptible(&port->waitqueue);
1779 static void in_intr(struct virtqueue *vq)
1782 unsigned long flags;
1784 port = find_port_by_vq(vq->vdev->priv, vq);
1788 spin_lock_irqsave(&port->inbuf_lock, flags);
1789 port->inbuf = get_inbuf(port);
1792 * Normally the port should not accept data when the port is
1793 * closed. For generic serial ports, the host won't (shouldn't)
1794 * send data till the guest is connected. But this condition
1795 * can be reached when a console port is not yet connected (no
1796 * tty is spawned) and the other side sends out data over the
1797 * vring, or when a remote devices start sending data before
1798 * the ports are opened.
1800 * A generic serial port will discard data if not connected,
1801 * while console ports and rproc-serial ports accepts data at
1802 * any time. rproc-serial is initiated with guest_connected to
1803 * false because port_fops_open expects this. Console ports are
1804 * hooked up with an HVC console and is initialized with
1805 * guest_connected to true.
1808 if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev))
1809 discard_port_data(port);
1811 /* Send a SIGIO indicating new data in case the process asked for it */
1812 send_sigio_to_port(port);
1814 spin_unlock_irqrestore(&port->inbuf_lock, flags);
1816 wake_up_interruptible(&port->waitqueue);
1818 if (is_console_port(port) && hvc_poll(port->cons.hvc))
1822 static void control_intr(struct virtqueue *vq)
1824 struct ports_device *portdev;
1826 portdev = vq->vdev->priv;
1827 schedule_work(&portdev->control_work);
1830 static void config_intr(struct virtio_device *vdev)
1832 struct ports_device *portdev;
1834 portdev = vdev->priv;
1836 if (!use_multiport(portdev)) {
1840 vdev->config->get(vdev,
1841 offsetof(struct virtio_console_config, cols),
1842 &cols, sizeof(u16));
1843 vdev->config->get(vdev,
1844 offsetof(struct virtio_console_config, rows),
1845 &rows, sizeof(u16));
1847 port = find_port_by_id(portdev, 0);
1848 set_console_size(port, rows, cols);
1851 * We'll use this way of resizing only for legacy
1852 * support. For newer userspace
1853 * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
1854 * to indicate console size changes so that it can be
1857 resize_console(port);
1861 static int init_vqs(struct ports_device *portdev)
1863 vq_callback_t **io_callbacks;
1865 struct virtqueue **vqs;
1866 u32 i, j, nr_ports, nr_queues;
1869 nr_ports = portdev->config.max_nr_ports;
1870 nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
1872 vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL);
1873 io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL);
1874 io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL);
1875 portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1877 portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *),
1879 if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs ||
1880 !portdev->out_vqs) {
1886 * For backward compat (newer host but older guest), the host
1887 * spawns a console port first and also inits the vqs for port
1891 io_callbacks[j] = in_intr;
1892 io_callbacks[j + 1] = out_intr;
1893 io_names[j] = "input";
1894 io_names[j + 1] = "output";
1897 if (use_multiport(portdev)) {
1898 io_callbacks[j] = control_intr;
1899 io_callbacks[j + 1] = NULL;
1900 io_names[j] = "control-i";
1901 io_names[j + 1] = "control-o";
1903 for (i = 1; i < nr_ports; i++) {
1905 io_callbacks[j] = in_intr;
1906 io_callbacks[j + 1] = out_intr;
1907 io_names[j] = "input";
1908 io_names[j + 1] = "output";
1911 /* Find the queues. */
1912 err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs,
1914 (const char **)io_names);
1919 portdev->in_vqs[0] = vqs[0];
1920 portdev->out_vqs[0] = vqs[1];
1922 if (use_multiport(portdev)) {
1923 portdev->c_ivq = vqs[j];
1924 portdev->c_ovq = vqs[j + 1];
1926 for (i = 1; i < nr_ports; i++) {
1928 portdev->in_vqs[i] = vqs[j];
1929 portdev->out_vqs[i] = vqs[j + 1];
1933 kfree(io_callbacks);
1939 kfree(portdev->out_vqs);
1940 kfree(portdev->in_vqs);
1942 kfree(io_callbacks);
1948 static const struct file_operations portdev_fops = {
1949 .owner = THIS_MODULE,
1952 static void remove_vqs(struct ports_device *portdev)
1954 portdev->vdev->config->del_vqs(portdev->vdev);
1955 kfree(portdev->in_vqs);
1956 kfree(portdev->out_vqs);
1959 static void remove_controlq_data(struct ports_device *portdev)
1961 struct port_buffer *buf;
1964 if (!use_multiport(portdev))
1967 while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
1968 free_buf(buf, true);
1970 while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
1971 free_buf(buf, true);
1975 * Once we're further in boot, we get probed like any other virtio
1978 * If the host also supports multiple console ports, we check the
1979 * config space to see how many ports the host has spawned. We
1980 * initialize each port found.
1982 static int virtcons_probe(struct virtio_device *vdev)
1984 struct ports_device *portdev;
1987 bool early = early_put_chars != NULL;
1989 /* Ensure to read early_put_chars now */
1992 portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
1998 /* Attach this portdev to this virtio_device, and vice-versa. */
1999 portdev->vdev = vdev;
2000 vdev->priv = portdev;
2002 portdev->chr_major = register_chrdev(0, "virtio-portsdev",
2004 if (portdev->chr_major < 0) {
2006 "Error %d registering chrdev for device %u\n",
2007 portdev->chr_major, vdev->index);
2008 err = portdev->chr_major;
2013 portdev->config.max_nr_ports = 1;
2015 /* Don't test MULTIPORT at all if we're rproc: not a valid feature! */
2016 if (!is_rproc_serial(vdev) &&
2017 virtio_config_val(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
2018 offsetof(struct virtio_console_config,
2020 &portdev->config.max_nr_ports) == 0) {
2024 err = init_vqs(portdev);
2026 dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
2030 spin_lock_init(&portdev->ports_lock);
2031 INIT_LIST_HEAD(&portdev->ports);
2034 unsigned int nr_added_bufs;
2036 spin_lock_init(&portdev->c_ivq_lock);
2037 spin_lock_init(&portdev->c_ovq_lock);
2038 INIT_WORK(&portdev->control_work, &control_work_handler);
2040 nr_added_bufs = fill_queue(portdev->c_ivq,
2041 &portdev->c_ivq_lock);
2042 if (!nr_added_bufs) {
2044 "Error allocating buffers for control queue\n");
2050 * For backward compatibility: Create a console port
2051 * if we're running on older host.
2053 add_port(portdev, 0);
2056 spin_lock_irq(&pdrvdata_lock);
2057 list_add_tail(&portdev->list, &pdrvdata.portdevs);
2058 spin_unlock_irq(&pdrvdata_lock);
2060 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2061 VIRTIO_CONSOLE_DEVICE_READY, 1);
2064 * If there was an early virtio console, assume that there are no
2065 * other consoles. We need to wait until the hvc_alloc matches the
2066 * hvc_instantiate, otherwise tty_open will complain, resulting in
2067 * a "Warning: unable to open an initial console" boot failure.
2068 * Without multiport this is done in add_port above. With multiport
2069 * this might take some host<->guest communication - thus we have to
2072 if (multiport && early)
2073 wait_for_completion(&early_console_added);
2078 /* The host might want to notify mgmt sw about device add failure */
2079 __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
2080 VIRTIO_CONSOLE_DEVICE_READY, 0);
2081 remove_vqs(portdev);
2083 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
2090 static void virtcons_remove(struct virtio_device *vdev)
2092 struct ports_device *portdev;
2093 struct port *port, *port2;
2095 portdev = vdev->priv;
2097 spin_lock_irq(&pdrvdata_lock);
2098 list_del(&portdev->list);
2099 spin_unlock_irq(&pdrvdata_lock);
2101 /* Disable interrupts for vqs */
2102 vdev->config->reset(vdev);
2103 /* Finish up work that's lined up */
2104 if (use_multiport(portdev))
2105 cancel_work_sync(&portdev->control_work);
2107 list_for_each_entry_safe(port, port2, &portdev->ports, list)
2110 unregister_chrdev(portdev->chr_major, "virtio-portsdev");
2113 * When yanking out a device, we immediately lose the
2114 * (device-side) queues. So there's no point in keeping the
2115 * guest side around till we drop our final reference. This
2116 * also means that any ports which are in an open state will
2117 * have to just stop using the port, as the vqs are going
2120 remove_controlq_data(portdev);
2121 remove_vqs(portdev);
2125 static struct virtio_device_id id_table[] = {
2126 { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
2130 static unsigned int features[] = {
2131 VIRTIO_CONSOLE_F_SIZE,
2132 VIRTIO_CONSOLE_F_MULTIPORT,
2135 static struct virtio_device_id rproc_serial_id_table[] = {
2136 #if IS_ENABLED(CONFIG_REMOTEPROC)
2137 { VIRTIO_ID_RPROC_SERIAL, VIRTIO_DEV_ANY_ID },
2142 static unsigned int rproc_serial_features[] = {
2146 static int virtcons_freeze(struct virtio_device *vdev)
2148 struct ports_device *portdev;
2151 portdev = vdev->priv;
2153 vdev->config->reset(vdev);
2155 virtqueue_disable_cb(portdev->c_ivq);
2156 cancel_work_sync(&portdev->control_work);
2158 * Once more: if control_work_handler() was running, it would
2159 * enable the cb as the last step.
2161 virtqueue_disable_cb(portdev->c_ivq);
2162 remove_controlq_data(portdev);
2164 list_for_each_entry(port, &portdev->ports, list) {
2165 virtqueue_disable_cb(port->in_vq);
2166 virtqueue_disable_cb(port->out_vq);
2168 * We'll ask the host later if the new invocation has
2169 * the port opened or closed.
2171 port->host_connected = false;
2172 remove_port_data(port);
2174 remove_vqs(portdev);
2179 static int virtcons_restore(struct virtio_device *vdev)
2181 struct ports_device *portdev;
2185 portdev = vdev->priv;
2187 ret = init_vqs(portdev);
2191 if (use_multiport(portdev))
2192 fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
2194 list_for_each_entry(port, &portdev->ports, list) {
2195 port->in_vq = portdev->in_vqs[port->id];
2196 port->out_vq = portdev->out_vqs[port->id];
2198 fill_queue(port->in_vq, &port->inbuf_lock);
2200 /* Get port open/close status on the host */
2201 send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
2204 * If a port was open at the time of suspending, we
2205 * have to let the host know that it's still open.
2207 if (port->guest_connected)
2208 send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
2214 static struct virtio_driver virtio_console = {
2215 .feature_table = features,
2216 .feature_table_size = ARRAY_SIZE(features),
2217 .driver.name = KBUILD_MODNAME,
2218 .driver.owner = THIS_MODULE,
2219 .id_table = id_table,
2220 .probe = virtcons_probe,
2221 .remove = virtcons_remove,
2222 .config_changed = config_intr,
2224 .freeze = virtcons_freeze,
2225 .restore = virtcons_restore,
2229 static struct virtio_driver virtio_rproc_serial = {
2230 .feature_table = rproc_serial_features,
2231 .feature_table_size = ARRAY_SIZE(rproc_serial_features),
2232 .driver.name = "virtio_rproc_serial",
2233 .driver.owner = THIS_MODULE,
2234 .id_table = rproc_serial_id_table,
2235 .probe = virtcons_probe,
2236 .remove = virtcons_remove,
2239 static int __init init(void)
2243 pdrvdata.class = class_create(THIS_MODULE, "virtio-ports");
2244 if (IS_ERR(pdrvdata.class)) {
2245 err = PTR_ERR(pdrvdata.class);
2246 pr_err("Error %d creating virtio-ports class\n", err);
2250 pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
2251 if (!pdrvdata.debugfs_dir)
2252 pr_warning("Error creating debugfs dir for virtio-ports\n");
2253 INIT_LIST_HEAD(&pdrvdata.consoles);
2254 INIT_LIST_HEAD(&pdrvdata.portdevs);
2256 err = register_virtio_driver(&virtio_console);
2258 pr_err("Error %d registering virtio driver\n", err);
2261 err = register_virtio_driver(&virtio_rproc_serial);
2263 pr_err("Error %d registering virtio rproc serial driver\n",
2269 unregister_virtio_driver(&virtio_console);
2271 if (pdrvdata.debugfs_dir)
2272 debugfs_remove_recursive(pdrvdata.debugfs_dir);
2273 class_destroy(pdrvdata.class);
2277 static void __exit fini(void)
2281 unregister_virtio_driver(&virtio_console);
2282 unregister_virtio_driver(&virtio_rproc_serial);
2284 class_destroy(pdrvdata.class);
2285 if (pdrvdata.debugfs_dir)
2286 debugfs_remove_recursive(pdrvdata.debugfs_dir);
2291 MODULE_DEVICE_TABLE(virtio, id_table);
2292 MODULE_DESCRIPTION("Virtio console driver");
2293 MODULE_LICENSE("GPL");