// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation
* Copyright (C) 2009, 2010, 2011 Red Hat, Inc.
* Copyright (C) 2009, 2010, 2011 Amit Shah <[email protected]>
*/
#include <linux/cdev.h>
#include <linux/debugfs.h>
#include <linux/completion.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/freezer.h>
#include <linux/fs.h>
#include <linux/splice.h>
#include <linux/pagemap.h>
#include <linux/idr.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/virtio.h>
#include <linux/virtio_console.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <linux/module.h>
#include <linux/dma-mapping.h>
#include "../tty/hvc/hvc_console.h"
#define is_rproc_enabled IS_ENABLED(CONFIG_REMOTEPROC)
#define VIRTCONS_MAX_PORTS 0x8000
/*
* This is a global struct for storing common data for all the devices
* this driver handles.
*
* Mainly, it has a linked list for all the consoles in one place so
* that callbacks from hvc for get_chars(), put_chars() work properly
* across multiple devices and multiple ports per device.
*/
struct ports_driver_data {
/* Used for exporting per-port information to debugfs */
struct dentry *debugfs_dir;
/* List of all the devices we're handling */
struct list_head portdevs;
/* All the console devices handled by this driver */
struct list_head consoles;
};
static struct ports_driver_data pdrvdata;
static const struct class port_class = {
.name = "virtio-ports",
};
static DEFINE_SPINLOCK(pdrvdata_lock);
static DECLARE_COMPLETION(early_console_added);
/* This struct holds information that's relevant only for console ports */
struct console {
/* We'll place all consoles in a list in the pdrvdata struct */
struct list_head list;
/* The hvc device associated with this console port */
struct hvc_struct *hvc;
/* The size of the console */
struct winsize ws;
/*
* This number identifies the number that we used to register
* with hvc in hvc_instantiate() and hvc_alloc(); this is the
* number passed on by the hvc callbacks to us to
* differentiate between the other console ports handled by
* this driver
*/
u32 vtermno;
};
static DEFINE_IDA(vtermno_ida);
struct port_buffer {
char *buf;
/* size of the buffer in *buf above */
size_t size;
/* used length of the buffer */
size_t len;
/* offset in the buf from which to consume data */
size_t offset;
/* DMA address of buffer */
dma_addr_t dma;
/* Device we got DMA memory from */
struct device *dev;
/* List of pending dma buffers to free */
struct list_head list;
/* If sgpages == 0 then buf is used */
unsigned int sgpages;
/* sg is used if spages > 0. sg must be the last in is struct */
struct scatterlist sg[] __counted_by(sgpages);
};
/*
* This is a per-device struct that stores data common to all the
* ports for that device (vdev->priv).
*/
struct ports_device {
/* Next portdev in the list, head is in the pdrvdata struct */
struct list_head list;
/*
* Workqueue handlers where we process deferred work after
* notification
*/
struct work_struct control_work;
struct work_struct config_work;
struct list_head ports;
/* To protect the list of ports */
spinlock_t ports_lock;
/* To protect the vq operations for the control channel */
spinlock_t c_ivq_lock;
spinlock_t c_ovq_lock;
/* max. number of ports this device can hold */
u32 max_nr_ports;
/* The virtio device we're associated with */
struct virtio_device *vdev;
/*
* A couple of virtqueues for the control channel: one for
* guest->host transfers, one for host->guest transfers
*/
struct virtqueue *c_ivq, *c_ovq;
/*
* A control packet buffer for guest->host requests, protected
* by c_ovq_lock.
*/
struct virtio_console_control cpkt;
/* Array of per-port IO virtqueues */
struct virtqueue **in_vqs, **out_vqs;
/* Major number for this device. Ports will be created as minors. */
int chr_major;
};
struct port_stats {
unsigned long bytes_sent, bytes_received, bytes_discarded;
};
/* This struct holds the per-port data */
struct port {
/* Next port in the list, head is in the ports_device */
struct list_head list;
/* Pointer to the parent virtio_console device */
struct ports_device *portdev;
/* The current buffer from which data has to be fed to readers */
struct port_buffer *inbuf;
/*
* To protect the operations on the in_vq associated with this
* port. Has to be a spinlock because it can be called from
* interrupt context (get_char()).
*/
spinlock_t inbuf_lock;
/* Protect the operations on the out_vq. */
spinlock_t outvq_lock;
/* The IO vqs for this port */
struct virtqueue *in_vq, *out_vq;
/* File in the debugfs directory that exposes this port's information */
struct dentry *debugfs_file;
/*
* Keep count of the bytes sent, received and discarded for
* this port for accounting and debugging purposes. These
* counts are not reset across port open / close events.
*/
struct port_stats stats;
/*
* The entries in this struct will be valid if this port is
* hooked up to an hvc console
*/
struct console cons;
/* Each port associates with a separate char device */
struct cdev *cdev;
struct device *dev;
/* Reference-counting to handle port hot-unplugs and file operations */
struct kref kref;
/* A waitqueue for poll() or blocking read operations */
wait_queue_head_t waitqueue;
/* The 'name' of the port that we expose via sysfs properties */
char *name;
/* We can notify apps of host connect / disconnect events via SIGIO */
struct fasync_struct *async_queue;
/* The 'id' to identify the port with the Host */
u32 id;
bool outvq_full;
/* Is the host device open */
bool host_connected;
/* We should allow only one process to open a port */
bool guest_connected;
};
static struct port *find_port_by_vtermno(u32 vtermno)
{
struct port *port;
struct console *cons;
unsigned long flags;
spin_lock_irqsave(&pdrvdata_lock, flags);
list_for_each_entry(cons, &pdrvdata.consoles, list) {
if (cons->vtermno == vtermno) {
port = container_of(cons, struct port, cons);
goto out;
}
}
port = NULL;
out:
spin_unlock_irqrestore(&pdrvdata_lock, flags);
return port;
}
static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev,
dev_t dev)
{
struct port *port;
unsigned long flags;
spin_lock_irqsave(&portdev->ports_lock, flags);
list_for_each_entry(port, &portdev->ports, list) {
if (port->cdev->dev == dev) {
kref_get(&port->kref);
goto out;
}
}
port = NULL;
out:
spin_unlock_irqrestore(&portdev->ports_lock, flags);
return port;
}
static struct port *find_port_by_devt(dev_t dev)
{
struct ports_device *portdev;
struct port *port;
unsigned long flags;
spin_lock_irqsave(&pdrvdata_lock, flags);
list_for_each_entry(portdev, &pdrvdata.portdevs, list) {
port = find_port_by_devt_in_portdev(portdev, dev);
if (port)
goto out;
}
port = NULL;
out:
spin_unlock_irqrestore(&pdrvdata_lock, flags);
return port;
}
static struct port *find_port_by_id(struct ports_device *portdev, u32 id)
{
struct port *port;
unsigned long flags;
spin_lock_irqsave(&portdev->ports_lock, flags);
list_for_each_entry(port, &portdev->ports, list)
if (port->id == id)
goto out;
port = NULL;
out:
spin_unlock_irqrestore(&portdev->ports_lock, flags);
return port;
}
static struct port *find_port_by_vq(struct ports_device *portdev,
struct virtqueue *vq)
{
struct port *port;
unsigned long flags;
spin_lock_irqsave(&portdev->ports_lock, flags);
list_for_each_entry(port, &portdev->ports, list)
if (port->in_vq == vq || port->out_vq == vq)
goto out;
port = NULL;
out:
spin_unlock_irqrestore(&portdev->ports_lock, flags);
return port;
}
static bool is_console_port(struct port *port)
{
if (port->cons.hvc)
return true;
return false;
}
static bool is_rproc_serial(const struct virtio_device *vdev)
{
return is_rproc_enabled && vdev->id.device == VIRTIO_ID_RPROC_SERIAL;
}
static inline bool use_multiport(struct ports_device *portdev)
{
/*
* This condition can be true when put_chars is called from
* early_init
*/
if (!portdev->vdev)
return false;
return __virtio_test_bit(portdev->vdev, VIRTIO_CONSOLE_F_MULTIPORT);
}
static DEFINE_SPINLOCK(dma_bufs_lock);
static LIST_HEAD(pending_free_dma_bufs);
static void free_buf(struct port_buffer *buf, bool can_sleep)
{
unsigned int i;
for (i = 0; i < buf->sgpages; i++) {
struct page *page = sg_page(&buf->sg[i]);
if (!page)
break;
put_page(page);
}
if (!buf->dev) {
kfree(buf->buf);
} else if (is_rproc_enabled) {
unsigned long flags;
/* dma_free_coherent requires interrupts to be enabled. */
if (!can_sleep) {
/* queue up dma-buffers to be freed later */
spin_lock_irqsave(&dma_bufs_lock, flags);
list_add_tail(&buf->list, &pending_free_dma_bufs);
spin_unlock_irqrestore(&dma_bufs_lock, flags);
return;
}
dma_free_coherent(buf->dev, buf->size, buf->buf, buf->dma);
/* Release device refcnt and allow it to be freed */
put_device(buf->dev);
}
kfree(buf);
}
static void reclaim_dma_bufs(void)
{
unsigned long flags;
struct port_buffer *buf, *tmp;
LIST_HEAD(tmp_list);
if (list_empty(&pending_free_dma_bufs))
return;
/* Create a copy of the pending_free_dma_bufs while holding the lock */
spin_lock_irqsave(&dma_bufs_lock, flags);
list_cut_position(&tmp_list, &pending_free_dma_bufs,
pending_free_dma_bufs.prev);
spin_unlock_irqrestore(&dma_bufs_lock, flags);
/* Release the dma buffers, without irqs enabled */
list_for_each_entry_safe(buf, tmp, &tmp_list, list) {
list_del(&buf->list);
free_buf(buf, true);
}
}
static struct port_buffer *alloc_buf(struct virtio_device *vdev, size_t buf_size,
int pages)
{
struct port_buffer *buf;
reclaim_dma_bufs();
/*
* Allocate buffer and the sg list. The sg list array is allocated
* directly after the port_buffer struct.
*/
buf = kmalloc(struct_size(buf, sg, pages), GFP_KERNEL);
if (!buf)
goto fail;
buf->sgpages = pages;
if (pages > 0) {
buf->dev = NULL;
buf->buf = NULL;
return buf;
}
if (is_rproc_serial(vdev)) {
/*
* Allocate DMA memory from ancestor. When a virtio
* device is created by remoteproc, the DMA memory is
* associated with the parent device:
* virtioY => remoteprocX#vdevYbuffer.
*/
buf->dev = vdev->dev.parent;
if (!buf->dev)
goto free_buf;
/* Increase device refcnt to avoid freeing it */
get_device(buf->dev);
buf->buf = dma_alloc_coherent(buf->dev, buf_size, &buf->dma,
GFP_KERNEL);
} else {
buf->dev = NULL;
buf->buf = kmalloc(buf_size, GFP_KERNEL);
}
if (!buf->buf)
goto free_buf;
buf->len = 0;
buf->offset = 0;
buf->size = buf_size;
return buf;
free_buf:
kfree(buf);
fail:
return NULL;
}
/* Callers should take appropriate locks */
static struct port_buffer *get_inbuf(struct port *port)
{
struct port_buffer *buf;
unsigned int len;
if (port->inbuf)
return port->inbuf;
buf = virtqueue_get_buf(port->in_vq, &len);
if (buf) {
buf->len = min_t(size_t, len, buf->size);
buf->offset = 0;
port->stats.bytes_received += len;
}
return buf;
}
/*
* Create a scatter-gather list representing our input buffer and put
* it in the queue.
*
* Callers should take appropriate locks.
*/
static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf)
{
struct scatterlist sg[1];
int ret;
sg_init_one(sg, buf->buf, buf->size);
ret = virtqueue_add_inbuf(vq, sg, 1, buf, GFP_ATOMIC);
virtqueue_kick(vq);
if (!ret)
ret = vq->num_free;
return ret;
}
/* Discard any unread data this port has. Callers lockers. */
static void discard_port_data(struct port *port)
{
struct port_buffer *buf;
unsigned int err;
if (!port->portdev) {
/* Device has been unplugged. vqs are already gone. */
return;
}
buf = get_inbuf(port);
err = 0;
while (buf) {
port->stats.bytes_discarded += buf->len - buf->offset;
if (add_inbuf(port->in_vq, buf) < 0) {
err++;
free_buf(buf, false);
}
port->inbuf = NULL;
buf = get_inbuf(port);
}
if (err)
dev_warn(port->dev, "Errors adding %d buffers back to vq\n",
err);
}
static bool port_has_data(struct port *port)
{
unsigned long flags;
bool ret;
ret = false;
spin_lock_irqsave(&port->inbuf_lock, flags);
port->inbuf = get_inbuf(port);
if (port->inbuf)
ret = true;
spin_unlock_irqrestore(&port->inbuf_lock, flags);
return ret;
}
static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id,
unsigned int event, unsigned int value)
{
struct scatterlist sg[1];
struct virtqueue *vq;
unsigned int len;
if (!use_multiport(portdev))
return 0;
vq = portdev->c_ovq;
spin_lock(&portdev->c_ovq_lock);
portdev->cpkt.id = cpu_to_virtio32(portdev->vdev, port_id);
portdev->cpkt.event = cpu_to_virtio16(portdev->vdev, event);
portdev->cpkt.value = cpu_to_virtio16(portdev->vdev, value);
sg_init_one(sg, &portdev->cpkt, sizeof(struct virtio_console_control));
if (virtqueue_add_outbuf(vq, sg, 1, &portdev->cpkt, GFP_ATOMIC) == 0) {
virtqueue_kick(vq);
while (!virtqueue_get_buf(vq, &len)
&& !virtqueue_is_broken(vq))
cpu_relax();
}
spin_unlock(&portdev->c_ovq_lock);
return 0;
}
static ssize_t send_control_msg(struct port *port, unsigned int event,
unsigned int value)
{
/* Did the port get unplugged before userspace closed it? */
if (port->portdev)
return __send_control_msg(port->portdev, port->id, event, value);
return 0;
}
/* Callers must take the port->outvq_lock */
static void reclaim_consumed_buffers(struct port *port)
{
struct port_buffer *buf;
unsigned int len;
if (!port->portdev) {
/* Device has been unplugged. vqs are already gone. */
return;
}
while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
free_buf(buf, false);
port->outvq_full = false;
}
}
static ssize_t __send_to_port(struct port *port, struct scatterlist *sg,
int nents, size_t in_count,
void *data, bool nonblock)
{
struct virtqueue *out_vq;
int err;
unsigned long flags;
unsigned int len;
out_vq = port->out_vq;
spin_lock_irqsave(&port->outvq_lock, flags);
reclaim_consumed_buffers(port);
err = virtqueue_add_outbuf(out_vq, sg, nents, data, GFP_ATOMIC);
/* Tell Host to go! */
virtqueue_kick(out_vq);
if (err) {
in_count = 0;
goto done;
}
if (out_vq->num_free == 0)
port->outvq_full = true;
if (nonblock)
goto done;
/*
* Wait till the host acknowledges it pushed out the data we
* sent. This is done for data from the hvc_console; the tty
* operations are performed with spinlocks held so we can't
* sleep here. An alternative would be to copy the data to a
* buffer and relax the spinning requirement. The downside is
* we need to kmalloc a GFP_ATOMIC buffer each time the
* console driver writes something out.
*/
while (!virtqueue_get_buf(out_vq, &len)
&& !virtqueue_is_broken(out_vq))
cpu_relax();
done:
spin_unlock_irqrestore(&port->outvq_lock, flags);
port->stats.bytes_sent += in_count;
/*
* We're expected to return the amount of data we wrote -- all
* of it
*/
return in_count;
}
/*
* Give out the data that's requested from the buffer that we have
* queued up.
*/
static ssize_t fill_readbuf(struct port *port, u8 __user *out_buf,
size_t out_count, bool to_user)
{
struct port_buffer *buf;
unsigned long flags;
if (!out_count || !port_has_data(port))
return 0;
buf = port->inbuf;
out_count = min(out_count, buf->len - buf->offset);
if (to_user) {
ssize_t ret;
ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count);
if (ret)
return -EFAULT;
} else {
memcpy((__force u8 *)out_buf, buf->buf + buf->offset,
out_count);
}
buf->offset += out_count;
if (buf->offset == buf->len) {
/*
* We're done using all the data in this buffer.
* Re-queue so that the Host can send us more data.
*/
spin_lock_irqsave(&port->inbuf_lock, flags);
port->inbuf = NULL;
if (add_inbuf(port->in_vq, buf) < 0)
dev_warn(port->dev, "failed add_buf\n");
spin_unlock_irqrestore(&port->inbuf_lock, flags);
}
/* Return the number of bytes actually copied */
return out_count;
}
/* The condition that must be true for polling to end */
static bool will_read_block(struct port *port)
{
if (!port->guest_connected) {
/* Port got hot-unplugged. Let's exit. */
return false;
}
return !port_has_data(port) && port->host_connected;
}
static bool will_write_block(struct port *port)
{
bool ret;
if (!port->guest_connected) {
/* Port got hot-unplugged. Let's exit. */
return false;
}
if (!port->host_connected)
return true;
spin_lock_irq(&port->outvq_lock);
/*
* Check if the Host has consumed any buffers since we last
* sent data (this is only applicable for nonblocking ports).
*/
reclaim_consumed_buffers(port);
ret = port->outvq_full;
spin_unlock_irq(&port->outvq_lock);
return ret;
}
static ssize_t port_fops_read(struct file *filp, char __user *ubuf,
size_t count, loff_t *offp)
{
struct port *port;
ssize_t ret;
port = filp->private_data;
/* Port is hot-unplugged. */
if (!port->guest_connected)
return -ENODEV;
if (!port_has_data(port)) {
/*
* If nothing's connected on the host just return 0 in
* case of list_empty; this tells the userspace app
* that there's no connection
*/
if (!port->host_connected)
return 0;
if (filp->f_flags & O_NONBLOCK)
return -EAGAIN;
ret = wait_event_freezable(port->waitqueue,
!will_read_block(port));
if (ret < 0)
return ret;
}
/* Port got hot-unplugged while we were waiting above. */
if (!port->guest_connected)
return -ENODEV;
/*
* We could've received a disconnection message while we were
* waiting for more data.
*
* This check is not clubbed in the if() statement above as we
* might receive some data as well as the host could get
* disconnected after we got woken up from our wait. So we
* really want to give off whatever data we have and only then
* check for host_connected.
*/
if (!port_has_data(port) && !port->host_connected)
return 0;
return fill_readbuf(port, ubuf, count, true);
}
static int wait_port_writable(struct port *port, bool nonblock)
{
int ret;
if (will_write_block(port)) {
if (nonblock)
return -EAGAIN;
ret = wait_event_freezable(port->waitqueue,
!will_write_block(port));
if (ret < 0)
return ret;
}
/* Port got hot-unplugged. */
if (!port->guest_connected)
return -ENODEV;
return 0;
}
static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
size_t count, loff_t *offp)
{
struct port *port;
struct port_buffer *buf;
ssize_t ret;
bool nonblock;
struct scatterlist sg[1];
/* Userspace could be out to fool us */
if (!count)
return 0;
port = filp->private_data;
nonblock = filp->f_flags & O_NONBLOCK;
ret = wait_port_writable(port, nonblock);
if (ret < 0)
return ret;
count = min((size_t)(32 * 1024), count);
buf = alloc_buf(port->portdev->vdev, count, 0);
if (!buf)
return -ENOMEM;
ret = copy_from_user(buf->buf, ubuf, count);
if (ret) {
ret = -EFAULT;
goto free_buf;
}
/*
* We now ask send_buf() to not spin for generic ports -- we
* can re-use the same code path that non-blocking file
* descriptors take for blocking file descriptors since the
* wait is already done and we're certain the write will go
* through to the host.
*/
nonblock = true;
sg_init_one(sg, buf->buf, count);
ret = __send_to_port(port, sg, 1, count, buf, nonblock);
if (nonblock && ret > 0)
goto out;
free_buf:
free_buf(buf, true);
out:
return ret;
}
struct sg_list {
unsigned int n;
unsigned int size;
size_t len;
struct scatterlist *sg;
};
static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
struct splice_desc *sd)
{
struct sg_list *sgl = sd->u.data;
unsigned int offset, len;
if (sgl->n == sgl->size)
return 0;
/* Try lock this page */
if (pipe_buf_try_steal(pipe, buf)) {
/* Get reference and unlock page for moving */
get_page(buf->page);
unlock_page(buf->page);
len = min(buf->len, sd->len);
sg_set_page(&(sgl->sg[sgl->n]), buf->page, len, buf->offset);
} else {
/* Failback to copying a page */
struct page *page = alloc_page(GFP_KERNEL);
char *src;
if (!page)
return -ENOMEM;
offset = sd->pos & ~PAGE_MASK;
len = sd->len;
if (len + offset > PAGE_SIZE)
len = PAGE_SIZE - offset;
src = kmap_atomic(buf->page);
memcpy(page_address(page) + offset, src + buf->offset, len);
kunmap_atomic(src);
sg_set_page(&(sgl->sg[sgl->n]), page, len, offset);
}
sgl->n++;
sgl->len += len;
return len;
}
/* Faster zero-copy write by splicing */
static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
struct file *filp, loff_t *ppos,
size_t len, unsigned int flags)
{
struct port *port = filp->private_data;
struct sg_list sgl;
ssize_t ret;
struct port_buffer *buf;
struct splice_desc sd = {
.total_len = len,
.flags = flags,
.pos = *ppos,
.u.data = &sgl,
};
unsigned int occupancy;
/*
* Rproc_serial does not yet support splice. To support splice
* pipe_to_sg() must allocate dma-buffers and copy content from
* regular pages to dma pages. And alloc_buf and free_buf must
* support allocating and freeing such a list of dma-buffers.
*/
if (is_rproc_serial(port->out_vq->vdev))
return -EINVAL;
pipe_lock(pipe);
ret = 0;
if (pipe_empty(pipe->head, pipe->tail))
goto error_out;
ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK);
if (ret < 0)
goto error_out;
occupancy = pipe_occupancy(pipe->head, pipe->tail);
buf = alloc_buf(port->portdev->vdev, 0, occupancy);
if (!buf) {
ret = -ENOMEM;
goto error_out;
}
sgl.n = 0;
sgl.len = 0;
sgl.size = occupancy;
sgl.sg = buf->sg;
sg_init_table(sgl.sg, sgl.size);
ret = __splice_from_pipe(pipe, &sd, pipe_to_sg);
pipe_unlock(pipe);
if (likely(ret > 0))
ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true);
if (unlikely(ret <= 0))
free_buf(buf, true);
return ret;
error_out:
pipe_unlock(pipe);
return ret;
}
static __poll_t port_fops_poll(struct file *filp, poll_table *wait)
{
struct port *port;
__poll_t ret;
port = filp->private_data;
poll_wait(filp, &port->waitqueue, wait);
if (!port->guest_connected) {
/* Port got unplugged */
return EPOLLHUP;
}
ret = 0;
if (!will_read_block(port))
ret |= EPOLLIN | EPOLLRDNORM;
if (!will_write_block(port))
ret |= EPOLLOUT;
if (!port->host_connected)
ret |= EPOLLHUP;
return ret;
}
static void remove_port(struct kref *kref);
static int port_fops_release(struct inode *inode, struct file *filp)
{
struct port *port;
port = filp->private_data;
/* Notify host of port being closed */
send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
spin_lock_irq(&port->inbuf_lock);
port->guest_connected = false;
discard_port_data(port);
spin_unlock_irq(&port->inbuf_lock);
spin_lock_irq(&port->outvq_lock);
reclaim_consumed_buffers(port);
spin_unlock_irq(&port->outvq_lock);
reclaim_dma_bufs();
/*
* Locks aren't necessary here as a port can't be opened after
* unplug, and if a port isn't unplugged, a kref would already
* exist for the port. Plus, taking ports_lock here would
* create a dependency on other locks taken by functions
* inside remove_port if we're the last holder of the port,
* creating many problems.
*/
kref_put(&port->kref, remove_port);
return 0;
}
static int port_fops_open(struct inode *inode, struct file *filp)
{
struct cdev *cdev = inode->i_cdev;
struct port *port;
int ret;
/* We get the port with a kref here */
port = find_port_by_devt(cdev->dev);
if (!port) {
/* Port was unplugged before we could proceed */
return -ENXIO;
}
filp->private_data = port;
/*
* Don't allow opening of console port devices -- that's done
* via /dev/hvc
*/
if (is_console_port(port)) {
ret = -ENXIO;
goto out;
}
/* Allow only one process to open a particular port at a time */
spin_lock_irq(&port->inbuf_lock);
if (port->guest_connected) {
spin_unlock_irq(&port->inbuf_lock);
ret = -EBUSY;
goto out;
}
port->guest_connected = true;
spin_unlock_irq(&port->inbuf_lock);
spin_lock_irq(&port->outvq_lock);
/*
* There might be a chance that we missed reclaiming a few
* buffers in the window of the port getting previously closed
* and opening now.
*/
reclaim_consumed_buffers(port);
spin_unlock_irq(&port->outvq_lock);
nonseekable_open(inode, filp);
/* Notify host of port being opened */
send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1);
return 0;
out:
kref_put(&port->kref, remove_port);
return ret;
}
static int port_fops_fasync(int fd, struct file *filp, int mode)
{
struct port *port;
port = filp->private_data;
return fasync_helper(fd, filp, mode, &port->async_queue);
}
/*
* The file operations that we support: programs in the guest can open
* a console device, read from it, write to it, poll for data and
* close it. The devices are at
* /dev/vport<device number>p<port number>
*/
static const struct file_operations port_fops = {
.owner = THIS_MODULE,
.open = port_fops_open,
.read = port_fops_read,
.write = port_fops_write,
.splice_write = port_fops_splice_write,
.poll = port_fops_poll,
.release = port_fops_release,
.fasync = port_fops_fasync,
};
/*
* The put_chars() callback is pretty straightforward.
*
* We turn the characters into a scatter-gather list, add it to the
* output queue and then kick the Host. Then we sit here waiting for
* it to finish: inefficient in theory, but in practice
* implementations will do it immediately.
*/
static ssize_t put_chars(u32 vtermno, const u8 *buf, size_t count)
{
struct port *port;
struct scatterlist sg[1];
void *data;
int ret;
port = find_port_by_vtermno(vtermno);
if (!port)
return -EPIPE;
data = kmemdup(buf, count, GFP_ATOMIC);
if (!data)
return -ENOMEM;
sg_init_one(sg, data, count);
ret = __send_to_port(port, sg, 1, count, data, false);
kfree(data);
return ret;
}
/*
* get_chars() is the callback from the hvc_console infrastructure
* when an interrupt is received.
*
* We call out to fill_readbuf that gets us the required data from the
* buffers that are queued up.
*/
static ssize_t get_chars(u32 vtermno, u8 *buf, size_t count)
{
struct port *port;
port = find_port_by_vtermno(vtermno);
if (!port)
return -EPIPE;
/* If we don't have an input queue yet, we can't get input. */
BUG_ON(!port->in_vq);
return fill_readbuf(port, (__force u8 __user *)buf, count, false);
}
static void resize_console(struct port *port)
{
struct virtio_device *vdev;
/* The port could have been hot-unplugged */
if (!port || !is_console_port(port))
return;
vdev = port->portdev->vdev;
/* Don't test F_SIZE at all if we're rproc: not a valid feature! */
if (!is_rproc_serial(vdev) &&
virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
hvc_resize(port->cons.hvc, port->cons.ws);
}
/* We set the configuration at this point, since we now have a tty */
static int notifier_add_vio(struct hvc_struct *hp, int data)
{
struct port *port;
port = find_port_by_vtermno(hp->vtermno);
if (!port)
return -EINVAL;
hp->irq_requested = 1;
resize_console(port);
return 0;
}
static void notifier_del_vio(struct hvc_struct *hp, int data)
{
hp->irq_requested = 0;
}
/* The operations for console ports. */
static const struct hv_ops hv_ops = {
.get_chars = get_chars,
.put_chars = put_chars,
.notifier_add = notifier_add_vio,
.notifier_del = notifier_del_vio,
.notifier_hangup = notifier_del_vio,
};
static int init_port_console(struct port *port)
{
int ret;
/*
* The Host's telling us this port is a console port. Hook it
* up with an hvc console.
*
* To set up and manage our virtual console, we call
* hvc_alloc().
*
* The first argument of hvc_alloc() is the virtual console
* number. The second argument is the parameter for the
* notification mechanism (like irq number). We currently
* leave this as zero, virtqueues have implicit notifications.
*
* The third argument is a "struct hv_ops" containing the
* put_chars() get_chars(), notifier_add() and notifier_del()
* pointers. The final argument is the output buffer size: we
* can do any size, so we put PAGE_SIZE here.
*/
ret = ida_alloc_min(&vtermno_ida, 1, GFP_KERNEL);
if (ret < 0)
return ret;
port->cons.vtermno = ret;
port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE);
if (IS_ERR(port->cons.hvc)) {
ret = PTR_ERR(port->cons.hvc);
dev_err(port->dev,
"error %d allocating hvc for port\n", ret);
port->cons.hvc = NULL;
ida_free(&vtermno_ida, port->cons.vtermno);
return ret;
}
spin_lock_irq(&pdrvdata_lock);
list_add_tail(&port->cons.list, &pdrvdata.consoles);
spin_unlock_irq(&pdrvdata_lock);
port->guest_connected = true;
/* Notify host of port being opened */
send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
return 0;
}
static ssize_t show_port_name(struct device *dev,
struct device_attribute *attr, char *buffer)
{
struct port *port;
port = dev_get_drvdata(dev);
return sprintf(buffer, "%s\n", port->name);
}
static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL);
static struct attribute *port_sysfs_entries[] = {
&dev_attr_name.attr,
NULL
};
static const struct attribute_group port_attribute_group = {
.name = NULL, /* put in device directory */
.attrs = port_sysfs_entries,
};
static int port_debugfs_show(struct seq_file *s, void *data)
{
struct port *port = s->private;
seq_printf(s, "name: %s\n", port->name ? port->name : "");
seq_printf(s, "guest_connected: %d\n", port->guest_connected);
seq_printf(s, "host_connected: %d\n", port->host_connected);
seq_printf(s, "outvq_full: %d\n", port->outvq_full);
seq_printf(s, "bytes_sent: %lu\n", port->stats.bytes_sent);
seq_printf(s, "bytes_received: %lu\n", port->stats.bytes_received);
seq_printf(s, "bytes_discarded: %lu\n", port->stats.bytes_discarded);
seq_printf(s, "is_console: %s\n",
is_console_port(port) ? "yes" : "no");
seq_printf(s, "console_vtermno: %u\n", port->cons.vtermno);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(port_debugfs);
static void set_console_size(struct port *port, u16 rows, u16 cols)
{
if (!port || !is_console_port(port))
return;
port->cons.ws.ws_row = rows;
port->cons.ws.ws_col = cols;
}
static int fill_queue(struct virtqueue *vq, spinlock_t *lock)
{
struct port_buffer *buf;
int nr_added_bufs;
int ret;
nr_added_bufs = 0;
do {
buf = alloc_buf(vq->vdev, PAGE_SIZE, 0);
if (!buf)
return -ENOMEM;
spin_lock_irq(lock);
ret = add_inbuf(vq, buf);
if (ret < 0) {
spin_unlock_irq(lock);
free_buf(buf, true);
return ret;
}
nr_added_bufs++;
spin_unlock_irq(lock);
} while (ret > 0);
return nr_added_bufs;
}
static void send_sigio_to_port(struct port *port)
{
if (port->async_queue && port->guest_connected)
kill_fasync(&port->async_queue, SIGIO, POLL_OUT);
}
static int add_port(struct ports_device *portdev, u32 id)
{
char debugfs_name[16];
struct port *port;
dev_t devt;
int err;
port = kmalloc(sizeof(*port), GFP_KERNEL);
if (!port) {
err = -ENOMEM;
goto fail;
}
kref_init(&port->kref);
port->portdev = portdev;
port->id = id;
port->name = NULL;
port->inbuf = NULL;
port->cons.hvc = NULL;
port->async_queue = NULL;
port->cons.ws.ws_row = port->cons.ws.ws_col = 0;
port->cons.vtermno = 0;
port->host_connected = port->guest_connected = false;
port->stats = (struct port_stats) { 0 };
port->outvq_full = false;
port->in_vq = portdev->in_vqs[port->id];
port->out_vq = portdev->out_vqs[port->id];
port->cdev = cdev_alloc();
if (!port->cdev) {
dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n");
err = -ENOMEM;
goto free_port;
}
port->cdev->ops = &port_fops;
devt = MKDEV(portdev->chr_major, id);
err = cdev_add(port->cdev, devt, 1);
if (err < 0) {
dev_err(&port->portdev->vdev->dev,
"Error %d adding cdev for port %u\n", err, id);
goto free_cdev;
}
port->dev = device_create(&port_class, &port->portdev->vdev->dev,
devt, port, "vport%up%u",
port->portdev->vdev->index, id);
if (IS_ERR(port->dev)) {
err = PTR_ERR(port->dev);
dev_err(&port->portdev->vdev->dev,
"Error %d creating device for port %u\n",
err, id);
goto free_cdev;
}
spin_lock_init(&port->inbuf_lock);
spin_lock_init(&port->outvq_lock);
init_waitqueue_head(&port->waitqueue);
/* We can safely ignore ENOSPC because it means
* the queue already has buffers. Buffers are removed
* only by virtcons_remove(), not by unplug_port()
*/
err = fill_queue(port->in_vq, &port->inbuf_lock);
if (err < 0 && err != -ENOSPC) {
dev_err(port->dev, "Error allocating inbufs\n");
goto free_device;
}
if (is_rproc_serial(port->portdev->vdev))
/*
* For rproc_serial assume remote processor is connected.
* rproc_serial does not want the console port, only
* the generic port implementation.
*/
port->host_connected = true;
else if (!use_multiport(port->portdev)) {
/*
* If we're not using multiport support,
* this has to be a console port.
*/
err = init_port_console(port);
if (err)
goto free_inbufs;
}
spin_lock_irq(&portdev->ports_lock);
list_add_tail(&port->list, &port->portdev->ports);
spin_unlock_irq(&portdev->ports_lock);
/*
* Tell the Host we're set so that it can send us various
* configuration parameters for this port (eg, port name,
* caching, whether this is a console port, etc.)
*/
send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
/*
* Finally, create the debugfs file that we can use to
* inspect a port's state at any time
*/
snprintf(debugfs_name, sizeof(debugfs_name), "vport%up%u",
port->portdev->vdev->index, id);
port->debugfs_file = debugfs_create_file(debugfs_name, 0444,
pdrvdata.debugfs_dir,
port, &port_debugfs_fops);
return 0;
free_inbufs:
free_device:
device_destroy(&port_class, port->dev->devt);
free_cdev:
cdev_del(port->cdev);
free_port:
kfree(port);
fail:
/* The host might want to notify management sw about port add failure */
__send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0);
return err;
}
/* No users remain, remove all port-specific data. */
static void remove_port(struct kref *kref)
{
struct port *port;
port = container_of(kref, struct port, kref);
kfree(port);
}
static void remove_port_data(struct port *port)
{
spin_lock_irq(&port->inbuf_lock);
/* Remove unused data this port might have received. */
discard_port_data(port);
spin_unlock_irq(&port->inbuf_lock);
spin_lock_irq(&port->outvq_lock);
reclaim_consumed_buffers(port);
spin_unlock_irq(&port->outvq_lock);
}
/*
* Port got unplugged. Remove port from portdev's list and drop the
* kref reference. If no userspace has this port opened, it will
* result in immediate removal the port.
*/
static void unplug_port(struct port *port)
{
spin_lock_irq(&port->portdev->ports_lock);
list_del(&port->list);
spin_unlock_irq(&port->portdev->ports_lock);
spin_lock_irq(&port->inbuf_lock);
if (port->guest_connected) {
/* Let the app know the port is going down. */
send_sigio_to_port(port);
/* Do this after sigio is actually sent */
port->guest_connected = false;
port->host_connected = false;
wake_up_interruptible(&port->waitqueue);
}
spin_unlock_irq(&port->inbuf_lock);
if (is_console_port(port)) {
spin_lock_irq(&pdrvdata_lock);
list_del(&port->cons.list);
spin_unlock_irq(&pdrvdata_lock);
hvc_remove(port->cons.hvc);
ida_free(&vtermno_ida, port->cons.vtermno);
}
remove_port_data(port);
/*
* We should just assume the device itself has gone off --
* else a close on an open port later will try to send out a
* control message.
*/
port->portdev = NULL;
sysfs_remove_group(&port->dev->kobj, &port_attribute_group);
device_destroy(&port_class, port->dev->devt);
cdev_del(port->cdev);
debugfs_remove(port->debugfs_file);
kfree(port->name);
/*
* Locks around here are not necessary - a port can't be
* opened after we removed the port struct from ports_list
* above.
*/
kref_put(&port->kref, remove_port);
}
/* Any private messages that the Host and Guest want to share */
static void handle_control_message(struct virtio_device *vdev,
struct ports_device *portdev,
struct port_buffer *buf)
{
struct virtio_console_control *cpkt;
struct port *port;
size_t name_size;
int err;
cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
port = find_port_by_id(portdev, virtio32_to_cpu(vdev, cpkt->id));
if (!port &&
cpkt->event != cpu_to_virtio16(vdev, VIRTIO_CONSOLE_PORT_ADD)) {
/* No valid header at start of buffer. Drop it. */
dev_dbg(&portdev->vdev->dev,
"Invalid index %u in control packet\n", cpkt->id);
return;
}
switch (virtio16_to_cpu(vdev, cpkt->event)) {
case VIRTIO_CONSOLE_PORT_ADD:
if (port) {
dev_dbg(&portdev->vdev->dev,
"Port %u already added\n", port->id);
send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
break;
}
if (virtio32_to_cpu(vdev, cpkt->id) >=
portdev->max_nr_ports) {
dev_warn(&portdev->vdev->dev,
"Request for adding port with "
"out-of-bound id %u, max. supported id: %u\n",
cpkt->id, portdev->max_nr_ports - 1);
break;
}
add_port(portdev, virtio32_to_cpu(vdev, cpkt->id));
break;
case VIRTIO_CONSOLE_PORT_REMOVE:
unplug_port(port);
break;
case VIRTIO_CONSOLE_CONSOLE_PORT:
if (!cpkt->value)
break;
if (is_console_port(port))
break;
init_port_console(port);
complete(&early_console_added);
/*
* Could remove the port here in case init fails - but
* have to notify the host first.
*/
break;
case VIRTIO_CONSOLE_RESIZE: {
struct {
__u16 rows;
__u16 cols;
} size;
if (!is_console_port(port))
break;
memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt),
sizeof(size));
set_console_size(port, size.rows, size.cols);
port->cons.hvc->irq_requested = 1;
resize_console(port);
break;
}
case VIRTIO_CONSOLE_PORT_OPEN:
port->host_connected = virtio16_to_cpu(vdev, cpkt->value);
wake_up_interruptible(&port->waitqueue);
/*
* If the host port got closed and the host had any
* unconsumed buffers, we'll be able to reclaim them
* now.
*/
spin_lock_irq(&port->outvq_lock);
reclaim_consumed_buffers(port);
spin_unlock_irq(&port->outvq_lock);
/*
* If the guest is connected, it'll be interested in
* knowing the host connection state changed.
*/
spin_lock_irq(&port->inbuf_lock);
send_sigio_to_port(port);
spin_unlock_irq(&port->inbuf_lock);
break;
case VIRTIO_CONSOLE_PORT_NAME:
/*
* If we woke up after hibernation, we can get this
* again. Skip it in that case.
*/
if (port->name)
break;
/*
* Skip the size of the header and the cpkt to get the size
* of the name that was sent
*/
name_size = buf->len - buf->offset - sizeof(*cpkt) + 1;
port->name = kmalloc(name_size, GFP_KERNEL);
if (!port->name) {
dev_err(port->dev,
"Not enough space to store port name\n");
break;
}
strscpy(port->name, buf->buf + buf->offset + sizeof(*cpkt),
name_size);
/*
* Since we only have one sysfs attribute, 'name',
* create it only if we have a name for the port.
*/
err = sysfs_create_group(&port->dev->kobj,
&port_attribute_group);
if (err) {
dev_err(port->dev,
"Error %d creating sysfs device attributes\n",
err);
} else {
/*
* Generate a udev event so that appropriate
* symlinks can be created based on udev
* rules.
*/
kobject_uevent(&port->dev->kobj, KOBJ_CHANGE);
}
break;
}
}
static void control_work_handler(struct work_struct *work)
{
struct ports_device *portdev;
struct virtqueue *vq;
struct port_buffer *buf;
unsigned int len;
portdev = container_of(work, struct ports_device, control_work);
vq = portdev->c_ivq;
spin_lock(&portdev->c_ivq_lock);
while ((buf = virtqueue_get_buf(vq, &len))) {
spin_unlock(&portdev->c_ivq_lock);
buf->len = min_t(size_t, len, buf->size);
buf->offset = 0;
handle_control_message(vq->vdev, portdev, buf);
spin_lock(&portdev->c_ivq_lock);
if (add_inbuf(portdev->c_ivq, buf) < 0) {
dev_warn(&portdev->vdev->dev,
"Error adding buffer to queue\n");
free_buf(buf, false);
}
}
spin_unlock(&portdev->c_ivq_lock);
}
static void flush_bufs(struct virtqueue *vq, bool can_sleep)
{
struct port_buffer *buf;
unsigned int len;
while ((buf = virtqueue_get_buf(vq, &len)))
free_buf(buf, can_sleep);
}
static void out_intr(struct virtqueue *vq)
{
struct port *port;
port = find_port_by_vq(vq->vdev->priv, vq);
if (!port) {
flush_bufs(vq, false);
return;
}
wake_up_interruptible(&port->waitqueue);
}
static void in_intr(struct virtqueue *vq)
{
struct port *port;
unsigned long flags;
port = find_port_by_vq(vq->vdev->priv, vq);
if (!port) {
flush_bufs(vq, false);
return;
}
spin_lock_irqsave(&port->inbuf_lock, flags);
port->inbuf = get_inbuf(port);
/*
* Normally the port should not accept data when the port is
* closed. For generic serial ports, the host won't (shouldn't)
* send data till the guest is connected. But this condition
* can be reached when a console port is not yet connected (no
* tty is spawned) and the other side sends out data over the
* vring, or when a remote devices start sending data before
* the ports are opened.
*
* A generic serial port will discard data if not connected,
* while console ports and rproc-serial ports accepts data at
* any time. rproc-serial is initiated with guest_connected to
* false because port_fops_open expects this. Console ports are
* hooked up with an HVC console and is initialized with
* guest_connected to true.
*/
if (!port->guest_connected && !is_rproc_serial(port->portdev->vdev))
discard_port_data(port);
/* Send a SIGIO indicating new data in case the process asked for it */
send_sigio_to_port(port);
spin_unlock_irqrestore(&port->inbuf_lock, flags);
wake_up_interruptible(&port->waitqueue);
if (is_console_port(port) && hvc_poll(port->cons.hvc))
hvc_kick();
}
static void control_intr(struct virtqueue *vq)
{
struct ports_device *portdev;
portdev = vq->vdev->priv;
schedule_work(&portdev->control_work);
}
static void config_intr(struct virtio_device *vdev)
{
struct ports_device *portdev;
portdev = vdev->priv;
if (!use_multiport(portdev))
schedule_work(&portdev->config_work);
}
static void config_work_handler(struct work_struct *work)
{
struct ports_device *portdev;
portdev = container_of(work, struct ports_device, config_work);
if (!use_multiport(portdev)) {
struct virtio_device *vdev;
struct port *port;
u16 rows, cols;
vdev = portdev->vdev;
virtio_cread(vdev, struct virtio_console_config, cols, &cols);
virtio_cread(vdev, struct virtio_console_config, rows, &rows);
port = find_port_by_id(portdev, 0);
set_console_size(port, rows, cols);
/*
* We'll use this way of resizing only for legacy
* support. For newer userspace
* (VIRTIO_CONSOLE_F_MULTPORT+), use control messages
* to indicate console size changes so that it can be
* done per-port.
*/
resize_console(port);
}
}
static int init_vqs(struct ports_device *portdev)
{
struct virtqueue_info *vqs_info;
struct virtqueue **vqs;
u32 i, j, nr_ports, nr_queues;
int err;
nr_ports = portdev->max_nr_ports;
nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2;
vqs = kmalloc_array(nr_queues, sizeof(struct virtqueue *), GFP_KERNEL);
vqs_info = kcalloc(nr_queues, sizeof(*vqs_info), GFP_KERNEL);
portdev->in_vqs = kmalloc_array(nr_ports, sizeof(struct virtqueue *),
GFP_KERNEL);
portdev->out_vqs = kmalloc_array(nr_ports, sizeof(struct virtqueue *),
GFP_KERNEL);
if (!vqs || !vqs_info || !portdev->in_vqs || !portdev->out_vqs) {
err = -ENOMEM;
goto free;
}
/*
* For backward compat (newer host but older guest), the host
* spawns a console port first and also inits the vqs for port
* 0 before others.
*/
j = 0;
vqs_info[j].callback = in_intr;
vqs_info[j + 1].callback = out_intr;
vqs_info[j].name = "input";
vqs_info[j + 1].name = "output";
j += 2;
if (use_multiport(portdev)) {
vqs_info[j].callback = control_intr;
vqs_info[j].name = "control-i";
vqs_info[j + 1].name = "control-o";
for (i = 1; i < nr_ports; i++) {
j += 2;
vqs_info[j].callback = in_intr;
vqs_info[j + 1].callback = out_intr;
vqs_info[j].name = "input";
vqs_info[j + 1].name = "output";
}
}
/* Find the queues. */
err = virtio_find_vqs(portdev->vdev, nr_queues, vqs, vqs_info, NULL);
if (err)
goto free;
j = 0;
portdev->in_vqs[0] = vqs[0];
portdev->out_vqs[0] = vqs[1];
j += 2;
if (use_multiport(portdev)) {
portdev->c_ivq = vqs[j];
portdev->c_ovq = vqs[j + 1];
for (i = 1; i < nr_ports; i++) {
j += 2;
portdev->in_vqs[i] = vqs[j];
portdev->out_vqs[i] = vqs[j + 1];
}
}
kfree(vqs_info);
kfree(vqs);
return 0;
free:
kfree(portdev->out_vqs);
kfree(portdev->in_vqs);
kfree(vqs_info);
kfree(vqs);
return err;
}
static const struct file_operations portdev_fops = {
.owner = THIS_MODULE,
};
static void remove_vqs(struct ports_device *portdev)
{
struct virtqueue *vq;
virtio_device_for_each_vq(portdev->vdev, vq) {
struct port_buffer *buf;
flush_bufs(vq, true);
while ((buf = virtqueue_detach_unused_buf(vq)))
free_buf(buf, true);
cond_resched();
}
portdev->vdev->config->del_vqs(portdev->vdev);
kfree(portdev->in_vqs);
kfree(portdev->out_vqs);
}
static void virtcons_remove(struct virtio_device *vdev)
{
struct ports_device *portdev;
struct port *port, *port2;
portdev = vdev->priv;
spin_lock_irq(&pdrvdata_lock);
list_del(&portdev->list);
spin_unlock_irq(&pdrvdata_lock);
/* Device is going away, exit any polling for buffers */
virtio_break_device(vdev);
if (use_multiport(portdev))
flush_work(&portdev->control_work);
else
flush_work(&portdev->config_work);
/* Disable interrupts for vqs */
virtio_reset_device(vdev);
/* Finish up work that's lined up */
if (use_multiport(portdev))
cancel_work_sync(&portdev->control_work);
else
cancel_work_sync(&portdev->config_work);
list_for_each_entry_safe(port, port2, &portdev->ports, list)
unplug_port(port);
unregister_chrdev(portdev->chr_major, "virtio-portsdev");
/*
* When yanking out a device, we immediately lose the
* (device-side) queues. So there's no point in keeping the
* guest side around till we drop our final reference. This
* also means that any ports which are in an open state will
* have to just stop using the port, as the vqs are going
* away.
*/
remove_vqs(portdev);
kfree(portdev);
}
/*
* Once we're further in boot, we get probed like any other virtio
* device.
*
* If the host also supports multiple console ports, we check the
* config space to see how many ports the host has spawned. We
* initialize each port found.
*/
static int virtcons_probe(struct virtio_device *vdev)
{
struct ports_device *portdev;
int err;
bool multiport;
/* We only need a config space if features are offered */
if (!vdev->config->get &&
(virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)
|| virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT))) {
dev_err(&vdev->dev, "%s failure: config access disabled\n",
__func__);
return -EINVAL;
}
portdev = kmalloc(sizeof(*portdev), GFP_KERNEL);
if (!portdev) {
err = -ENOMEM;
goto fail;
}
/* Attach this portdev to this virtio_device, and vice-versa. */
portdev->vdev = vdev;
vdev->priv = portdev;
portdev->chr_major = register_chrdev(0, "virtio-portsdev",
&portdev_fops);
if (portdev->chr_major < 0) {
dev_err(&vdev->dev,
"Error %d registering chrdev for device %u\n",
portdev->chr_major, vdev->index);
err = portdev->chr_major;
goto free;
}
multiport = false;
portdev->max_nr_ports = 1;
/* Don't test MULTIPORT at all if we're rproc: not a valid feature! */
if (!is_rproc_serial(vdev) &&
virtio_cread_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
struct virtio_console_config, max_nr_ports,
&portdev->max_nr_ports) == 0) {
if (portdev->max_nr_ports == 0 ||
portdev->max_nr_ports > VIRTCONS_MAX_PORTS) {
dev_err(&vdev->dev,
"Invalidate max_nr_ports %d",
portdev->max_nr_ports);
err = -EINVAL;
goto free;
}
multiport = true;
}
err = init_vqs(portdev);
if (err < 0) {
dev_err(&vdev->dev, "Error %d initializing vqs\n", err);
goto free_chrdev;
}
spin_lock_init(&portdev->ports_lock);
INIT_LIST_HEAD(&portdev->ports);
INIT_LIST_HEAD(&portdev->list);
virtio_device_ready(portdev->vdev);
INIT_WORK(&portdev->config_work, &config_work_handler);
INIT_WORK(&portdev->control_work, &control_work_handler);
if (multiport) {
spin_lock_init(&portdev->c_ivq_lock);
spin_lock_init(&portdev->c_ovq_lock);
err = fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
if (err < 0) {
dev_err(&vdev->dev,
"Error allocating buffers for control queue\n");
/*
* The host might want to notify mgmt sw about device
* add failure.
*/
__send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
VIRTIO_CONSOLE_DEVICE_READY, 0);
/* Device was functional: we need full cleanup. */
virtcons_remove(vdev);
return err;
}
} else {
/*
* For backward compatibility: Create a console port
* if we're running on older host.
*/
add_port(portdev, 0);
}
spin_lock_irq(&pdrvdata_lock);
list_add_tail(&portdev->list, &pdrvdata.portdevs);
spin_unlock_irq(&pdrvdata_lock);
__send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID,
VIRTIO_CONSOLE_DEVICE_READY, 1);
return 0;
free_chrdev:
unregister_chrdev(portdev->chr_major, "virtio-portsdev");
free:
kfree(portdev);
fail:
return err;
}
static const struct virtio_device_id id_table[] = {
{ VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
{ 0 },
};
MODULE_DEVICE_TABLE(virtio, id_table);
static const unsigned int features[] = {
VIRTIO_CONSOLE_F_SIZE,
VIRTIO_CONSOLE_F_MULTIPORT,
};
static const struct virtio_device_id rproc_serial_id_table[] = {
#if IS_ENABLED(CONFIG_REMOTEPROC)
{ VIRTIO_ID_RPROC_SERIAL, VIRTIO_DEV_ANY_ID },
#endif
{ 0 },
};
MODULE_DEVICE_TABLE(virtio, rproc_serial_id_table);
static const unsigned int rproc_serial_features[] = {
};
#ifdef CONFIG_PM_SLEEP
static int virtcons_freeze(struct virtio_device *vdev)
{
struct ports_device *portdev;
struct port *port;
portdev = vdev->priv;
virtio_reset_device(vdev);
if (use_multiport(portdev))
virtqueue_disable_cb(portdev->c_ivq);
cancel_work_sync(&portdev->control_work);
cancel_work_sync(&portdev->config_work);
/*
* Once more: if control_work_handler() was running, it would
* enable the cb as the last step.
*/
if (use_multiport(portdev))
virtqueue_disable_cb(portdev->c_ivq);
list_for_each_entry(port, &portdev->ports, list) {
virtqueue_disable_cb(port->in_vq);
virtqueue_disable_cb(port->out_vq);
/*
* We'll ask the host later if the new invocation has
* the port opened or closed.
*/
port->host_connected = false;
remove_port_data(port);
}
remove_vqs(portdev);
return 0;
}
static int virtcons_restore(struct virtio_device *vdev)
{
struct ports_device *portdev;
struct port *port;
int ret;
portdev = vdev->priv;
ret = init_vqs(portdev);
if (ret)
return ret;
virtio_device_ready(portdev->vdev);
if (use_multiport(portdev))
fill_queue(portdev->c_ivq, &portdev->c_ivq_lock);
list_for_each_entry(port, &portdev->ports, list) {
port->in_vq = portdev->in_vqs[port->id];
port->out_vq = portdev->out_vqs[port->id];
fill_queue(port->in_vq, &port->inbuf_lock);
/* Get port open/close status on the host */
send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1);
/*
* If a port was open at the time of suspending, we
* have to let the host know that it's still open.
*/
if (port->guest_connected)
send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
}
return 0;
}
#endif
static struct virtio_driver virtio_console = {
.feature_table = features,
.feature_table_size = ARRAY_SIZE(features),
.driver.name = KBUILD_MODNAME,
.id_table = id_table,
.probe = virtcons_probe,
.remove = virtcons_remove,
.config_changed = config_intr,
#ifdef CONFIG_PM_SLEEP
.freeze = virtcons_freeze,
.restore = virtcons_restore,
#endif
};
static struct virtio_driver virtio_rproc_serial = {
.feature_table = rproc_serial_features,
.feature_table_size = ARRAY_SIZE(rproc_serial_features),
.driver.name = "virtio_rproc_serial",
.id_table = rproc_serial_id_table,
.probe = virtcons_probe,
.remove = virtcons_remove,
};
static int __init virtio_console_init(void)
{
int err;
err = class_register(&port_class);
if (err)
return err;
pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
INIT_LIST_HEAD(&pdrvdata.consoles);
INIT_LIST_HEAD(&pdrvdata.portdevs);
err = register_virtio_driver(&virtio_console);
if (err < 0) {
pr_err("Error %d registering virtio driver\n", err);
goto free;
}
err = register_virtio_driver(&virtio_rproc_serial);
if (err < 0) {
pr_err("Error %d registering virtio rproc serial driver\n",
err);
goto unregister;
}
return 0;
unregister:
unregister_virtio_driver(&virtio_console);
free:
debugfs_remove_recursive(pdrvdata.debugfs_dir);
class_unregister(&port_class);
return err;
}
static void __exit virtio_console_fini(void)
{
reclaim_dma_bufs();
unregister_virtio_driver(&virtio_console);
unregister_virtio_driver(&virtio_rproc_serial);
class_unregister(&port_class);
debugfs_remove_recursive(pdrvdata.debugfs_dir);
}
module_init(virtio_console_init);
module_exit(virtio_console_fini);
MODULE_DESCRIPTION("Virtio console driver");
MODULE_LICENSE("GPL");
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