virtio_console: Add support for remoteproc serial
Add a simple serial connection driver called VIRTIO_ID_RPROC_SERIAL (11) for communicating with a remote processor in an asymmetric multi-processing configuration. This implementation reuses the existing virtio_console implementation, and adds support for DMA allocation of data buffers and disables use of tty console and the virtio control queue. Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com> Acked-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Sjur Brændeland
Rusty Russell
parent
276a3e954c
commit
1b6370463e
2 changed files with 170 additions and 23 deletions
|
|
@ -37,8 +37,12 @@
|
|||
#include <linux/wait.h>
|
||||
#include <linux/workqueue.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/dma-mapping.h>
|
||||
#include <linux/kconfig.h>
|
||||
#include "../tty/hvc/hvc_console.h"
|
||||
|
||||
#define is_rproc_enabled IS_ENABLED(CONFIG_REMOTEPROC)
|
||||
|
||||
/*
|
||||
* This is a global struct for storing common data for all the devices
|
||||
* this driver handles.
|
||||
|
|
@ -112,6 +116,15 @@ struct port_buffer {
|
|||
/* 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;
|
||||
|
||||
|
|
@ -331,6 +344,11 @@ static bool is_console_port(struct port *port)
|
|||
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)
|
||||
{
|
||||
/*
|
||||
|
|
@ -342,11 +360,13 @@ static inline bool use_multiport(struct ports_device *portdev)
|
|||
return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
|
||||
}
|
||||
|
||||
static void free_buf(struct port_buffer *buf)
|
||||
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;
|
||||
|
||||
kfree(buf->buf);
|
||||
for (i = 0; i < buf->sgpages; i++) {
|
||||
struct page *page = sg_page(&buf->sg[i]);
|
||||
if (!page)
|
||||
|
|
@ -354,14 +374,57 @@ static void free_buf(struct port_buffer *buf)
|
|||
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 virtqueue *vq, 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.
|
||||
|
|
@ -373,11 +436,34 @@ static struct port_buffer *alloc_buf(struct virtqueue *vq, size_t buf_size,
|
|||
|
||||
buf->sgpages = pages;
|
||||
if (pages > 0) {
|
||||
buf->dev = NULL;
|
||||
buf->buf = NULL;
|
||||
return buf;
|
||||
}
|
||||
|
||||
buf->buf = kmalloc(buf_size, GFP_KERNEL);
|
||||
if (is_rproc_serial(vq->vdev)) {
|
||||
/*
|
||||
* Allocate DMA memory from ancestor. When a virtio
|
||||
* device is created by remoteproc, the DMA memory is
|
||||
* associated with the grandparent device:
|
||||
* vdev => rproc => platform-dev.
|
||||
* The code here would have been less quirky if
|
||||
* DMA_MEMORY_INCLUDES_CHILDREN had been supported
|
||||
* in dma-coherent.c
|
||||
*/
|
||||
if (!vq->vdev->dev.parent || !vq->vdev->dev.parent->parent)
|
||||
goto free_buf;
|
||||
buf->dev = vq->vdev->dev.parent->parent;
|
||||
|
||||
/* 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;
|
||||
|
|
@ -446,7 +532,7 @@ static void discard_port_data(struct port *port)
|
|||
port->stats.bytes_discarded += buf->len - buf->offset;
|
||||
if (add_inbuf(port->in_vq, buf) < 0) {
|
||||
err++;
|
||||
free_buf(buf);
|
||||
free_buf(buf, false);
|
||||
}
|
||||
port->inbuf = NULL;
|
||||
buf = get_inbuf(port);
|
||||
|
|
@ -518,7 +604,7 @@ static void reclaim_consumed_buffers(struct port *port)
|
|||
return;
|
||||
}
|
||||
while ((buf = virtqueue_get_buf(port->out_vq, &len))) {
|
||||
free_buf(buf);
|
||||
free_buf(buf, false);
|
||||
port->outvq_full = false;
|
||||
}
|
||||
}
|
||||
|
|
@ -765,7 +851,7 @@ static ssize_t port_fops_write(struct file *filp, const char __user *ubuf,
|
|||
goto out;
|
||||
|
||||
free_buf:
|
||||
free_buf(buf);
|
||||
free_buf(buf, true);
|
||||
out:
|
||||
return ret;
|
||||
}
|
||||
|
|
@ -839,6 +925,15 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
|
|||
.u.data = &sgl,
|
||||
};
|
||||
|
||||
/*
|
||||
* 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;
|
||||
|
||||
ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
|
@ -857,7 +952,7 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe,
|
|||
ret = __send_to_port(port, buf->sg, sgl.n, sgl.len, buf, true);
|
||||
|
||||
if (unlikely(ret <= 0))
|
||||
kfree(sgl.sg);
|
||||
free_buf(buf, true);
|
||||
return ret;
|
||||
}
|
||||
|
||||
|
|
@ -906,6 +1001,7 @@ static int port_fops_release(struct inode *inode, struct file *filp)
|
|||
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
|
||||
|
|
@ -1057,7 +1153,10 @@ static void resize_console(struct port *port)
|
|||
return;
|
||||
|
||||
vdev = port->portdev->vdev;
|
||||
if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE))
|
||||
|
||||
/* 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);
|
||||
}
|
||||
|
||||
|
|
@ -1249,7 +1348,7 @@ static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock)
|
|||
ret = add_inbuf(vq, buf);
|
||||
if (ret < 0) {
|
||||
spin_unlock_irq(lock);
|
||||
free_buf(buf);
|
||||
free_buf(buf, true);
|
||||
break;
|
||||
}
|
||||
nr_added_bufs++;
|
||||
|
|
@ -1337,10 +1436,18 @@ static int add_port(struct ports_device *portdev, u32 id)
|
|||
goto free_device;
|
||||
}
|
||||
|
||||
/*
|
||||
* If we're not using multiport support, this has to be a console port
|
||||
*/
|
||||
if (!use_multiport(port->portdev)) {
|
||||
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;
|
||||
|
|
@ -1373,7 +1480,7 @@ static int add_port(struct ports_device *portdev, u32 id)
|
|||
|
||||
free_inbufs:
|
||||
while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
|
||||
free_buf(buf);
|
||||
free_buf(buf, true);
|
||||
free_device:
|
||||
device_destroy(pdrvdata.class, port->dev->devt);
|
||||
free_cdev:
|
||||
|
|
@ -1415,11 +1522,11 @@ static void remove_port_data(struct port *port)
|
|||
|
||||
/* Remove buffers we queued up for the Host to send us data in. */
|
||||
while ((buf = virtqueue_detach_unused_buf(port->in_vq)))
|
||||
free_buf(buf);
|
||||
free_buf(buf, true);
|
||||
|
||||
/* Free pending buffers from the out-queue. */
|
||||
while ((buf = virtqueue_detach_unused_buf(port->out_vq)))
|
||||
free_buf(buf);
|
||||
free_buf(buf, true);
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
@ -1621,7 +1728,7 @@ static void control_work_handler(struct work_struct *work)
|
|||
if (add_inbuf(portdev->c_ivq, buf) < 0) {
|
||||
dev_warn(&portdev->vdev->dev,
|
||||
"Error adding buffer to queue\n");
|
||||
free_buf(buf);
|
||||
free_buf(buf, false);
|
||||
}
|
||||
}
|
||||
spin_unlock(&portdev->cvq_lock);
|
||||
|
|
@ -1817,10 +1924,10 @@ static void remove_controlq_data(struct ports_device *portdev)
|
|||
return;
|
||||
|
||||
while ((buf = virtqueue_get_buf(portdev->c_ivq, &len)))
|
||||
free_buf(buf);
|
||||
free_buf(buf, true);
|
||||
|
||||
while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq)))
|
||||
free_buf(buf);
|
||||
free_buf(buf, true);
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
@ -1867,11 +1974,15 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
|
|||
|
||||
multiport = false;
|
||||
portdev->config.max_nr_ports = 1;
|
||||
if (virtio_config_val(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
|
||||
offsetof(struct virtio_console_config,
|
||||
max_nr_ports),
|
||||
&portdev->config.max_nr_ports) == 0)
|
||||
|
||||
/* Don't test MULTIPORT at all if we're rproc: not a valid feature! */
|
||||
if (!is_rproc_serial(vdev) &&
|
||||
virtio_config_val(vdev, VIRTIO_CONSOLE_F_MULTIPORT,
|
||||
offsetof(struct virtio_console_config,
|
||||
max_nr_ports),
|
||||
&portdev->config.max_nr_ports) == 0) {
|
||||
multiport = true;
|
||||
}
|
||||
|
||||
err = init_vqs(portdev);
|
||||
if (err < 0) {
|
||||
|
|
@ -1981,6 +2092,16 @@ static unsigned int features[] = {
|
|||
VIRTIO_CONSOLE_F_MULTIPORT,
|
||||
};
|
||||
|
||||
static struct virtio_device_id rproc_serial_id_table[] = {
|
||||
#if IS_ENABLED(CONFIG_REMOTEPROC)
|
||||
{ VIRTIO_ID_RPROC_SERIAL, VIRTIO_DEV_ANY_ID },
|
||||
#endif
|
||||
{ 0 },
|
||||
};
|
||||
|
||||
static unsigned int rproc_serial_features[] = {
|
||||
};
|
||||
|
||||
#ifdef CONFIG_PM
|
||||
static int virtcons_freeze(struct virtio_device *vdev)
|
||||
{
|
||||
|
|
@ -2065,6 +2186,20 @@ static struct virtio_driver virtio_console = {
|
|||
#endif
|
||||
};
|
||||
|
||||
/*
|
||||
* virtio_rproc_serial refers to __devinit function which causes
|
||||
* section mismatch warnings. So use __refdata to silence warnings.
|
||||
*/
|
||||
static struct virtio_driver __refdata virtio_rproc_serial = {
|
||||
.feature_table = rproc_serial_features,
|
||||
.feature_table_size = ARRAY_SIZE(rproc_serial_features),
|
||||
.driver.name = "virtio_rproc_serial",
|
||||
.driver.owner = THIS_MODULE,
|
||||
.id_table = rproc_serial_id_table,
|
||||
.probe = virtcons_probe,
|
||||
.remove = virtcons_remove,
|
||||
};
|
||||
|
||||
static int __init init(void)
|
||||
{
|
||||
int err;
|
||||
|
|
@ -2089,7 +2224,15 @@ static int __init init(void)
|
|||
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:
|
||||
if (pdrvdata.debugfs_dir)
|
||||
debugfs_remove_recursive(pdrvdata.debugfs_dir);
|
||||
|
|
@ -2099,7 +2242,10 @@ static int __init init(void)
|
|||
|
||||
static void __exit fini(void)
|
||||
{
|
||||
reclaim_dma_bufs();
|
||||
|
||||
unregister_virtio_driver(&virtio_console);
|
||||
unregister_virtio_driver(&virtio_rproc_serial);
|
||||
|
||||
class_destroy(pdrvdata.class);
|
||||
if (pdrvdata.debugfs_dir)
|
||||
|
|
|
|||
|
|
@ -37,5 +37,6 @@
|
|||
#define VIRTIO_ID_RPMSG 7 /* virtio remote processor messaging */
|
||||
#define VIRTIO_ID_SCSI 8 /* virtio scsi */
|
||||
#define VIRTIO_ID_9P 9 /* 9p virtio console */
|
||||
#define VIRTIO_ID_RPROC_SERIAL 11 /* virtio remoteproc serial link */
|
||||
|
||||
#endif /* _LINUX_VIRTIO_IDS_H */
|
||||
|
|
|
|||
Loading…
Reference in a new issue