diff options
author | Amit Shah <amit.shah@redhat.com> | 2010-02-12 10:32:18 +0530 |
---|---|---|
committer | Rusty Russell <rusty@rustcorp.com.au> | 2010-02-24 14:23:06 +1030 |
commit | d6933561924d8022f5d986ce7c511a2646eeadce (patch) | |
tree | 8e0a0c86a079400df7919f80194289258b7f5144 /drivers/char | |
parent | 22a29eacd2a17f22c8260a8106a4e36bae7fb6ea (diff) | |
download | kernel_samsung_smdk4412-d6933561924d8022f5d986ce7c511a2646eeadce.zip kernel_samsung_smdk4412-d6933561924d8022f5d986ce7c511a2646eeadce.tar.gz kernel_samsung_smdk4412-d6933561924d8022f5d986ce7c511a2646eeadce.tar.bz2 |
virtio: console: Fill ports' entire in_vq with buffers
Instead of allocating just one buffer for a port's in_vq, fill
the entire in_vq with buffers so the host need not stall while
an application consumes the data and makes the buffer available
again for the host.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/char')
-rw-r--r-- | drivers/char/virtio_console.c | 53 |
1 files changed, 32 insertions, 21 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index c407037..213373b 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -330,6 +330,7 @@ static void discard_port_data(struct port *port) struct port_buffer *buf; struct virtqueue *vq; unsigned int len; + int ret; vq = port->in_vq; if (port->inbuf) @@ -337,16 +338,18 @@ static void discard_port_data(struct port *port) else buf = vq->vq_ops->get_buf(vq, &len); - if (!buf) - return; - - if (add_inbuf(vq, buf) < 0) { - buf->len = buf->offset = 0; - dev_warn(port->dev, "Error adding buffer back to vq\n"); - return; + ret = 0; + while (buf) { + if (add_inbuf(vq, buf) < 0) { + ret++; + free_buf(buf); + } + buf = vq->vq_ops->get_buf(vq, &len); } - port->inbuf = NULL; + if (ret) + dev_warn(port->dev, "Errors adding %d buffers back to vq\n", + ret); } static bool port_has_data(struct port *port) @@ -354,12 +357,19 @@ static bool port_has_data(struct port *port) unsigned long flags; bool ret; - ret = false; spin_lock_irqsave(&port->inbuf_lock, flags); - if (port->inbuf) + if (port->inbuf) { ret = true; + goto out; + } + port->inbuf = get_inbuf(port); + if (port->inbuf) { + ret = true; + goto out; + } + ret = false; +out: spin_unlock_irqrestore(&port->inbuf_lock, flags); - return ret; } @@ -1011,7 +1021,8 @@ static void in_intr(struct virtqueue *vq) return; spin_lock_irqsave(&port->inbuf_lock, flags); - port->inbuf = get_inbuf(port); + if (!port->inbuf) + port->inbuf = get_inbuf(port); /* * Don't queue up data when port is closed. This condition @@ -1087,7 +1098,7 @@ static int add_port(struct ports_device *portdev, u32 id) { char debugfs_name[16]; struct port *port; - struct port_buffer *inbuf; + struct port_buffer *buf; dev_t devt; int err; @@ -1132,22 +1143,21 @@ static int add_port(struct ports_device *portdev, u32 id) spin_lock_init(&port->inbuf_lock); init_waitqueue_head(&port->waitqueue); - inbuf = alloc_buf(PAGE_SIZE); - if (!inbuf) { + /* Fill the in_vq with buffers so the host can send us data. */ + err = fill_queue(port->in_vq, &port->inbuf_lock); + if (!err) { + dev_err(port->dev, "Error allocating inbufs\n"); err = -ENOMEM; goto free_device; } - /* Register the input buffer the first time. */ - add_inbuf(port->in_vq, inbuf); - /* * If we're not using multiport support, this has to be a console port */ if (!use_multiport(port->portdev)) { err = init_port_console(port); if (err) - goto free_inbuf; + goto free_inbufs; } spin_lock_irq(&portdev->ports_lock); @@ -1175,8 +1185,9 @@ static int add_port(struct ports_device *portdev, u32 id) } return 0; -free_inbuf: - free_buf(inbuf); +free_inbufs: + while ((buf = port->in_vq->vq_ops->detach_unused_buf(port->in_vq))) + free_buf(buf); free_device: device_destroy(pdrvdata.class, port->dev->devt); free_cdev: |