From: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
We are heading towards a multiple-"port" system, so as part of weaning off
globals we encapsulate the information into 'struct port'.
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Signed-off-by: Amit Shah <amit.shah@xxxxxxxxxx>
---
drivers/char/virtio_console.c | 107 ++++++++++++++++++++++-------------------
1 files changed, 58 insertions(+), 49 deletions(-)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index bfc0abf..9ea9223 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -21,15 +21,19 @@
#include <linux/virtio_console.h>
#include "hvc_console.h"
-static struct virtqueue *in_vq, *out_vq;
-static struct virtio_device *vdev;
-
-/* This is our input buffer, and how much data is left in it. */
-static unsigned int in_len;
-static char *in, *inbuf;
+struct port {
+ struct virtqueue *in_vq, *out_vq;
+ struct virtio_device *vdev;
+ /* This is our input buffer, and how much data is left in it. */
+ char *inbuf;
+ unsigned int used_len, offset;
+
+ /* The hvc device */
+ struct hvc_struct *hvc;
+};
-/* The hvc device */
-static struct hvc_struct *hvc;
+/* We have one port ready to go immediately, for a console. */
+static struct port console;
/* This is the very early arch-specified put chars function. */
static int (*early_put_chars)(u32, const char *, int);
@@ -46,22 +50,21 @@ static int put_chars(u32 vtermno, const char *buf, int count)
{
struct scatterlist sg[1];
unsigned int len;
+ struct port *port;
if (unlikely(early_put_chars))
return early_put_chars(vtermno, buf, count);
+ port = &console;
+
/* This is a convenient routine to initialize a single-elem sg list */
sg_init_one(sg, buf, count);
- /*
- * add_buf wants a token to identify this buffer: we hand it
- * any non-NULL pointer, since there's only ever one buffer.
- */
- if (out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, (void *)1) >= 0) {
+ /* This shouldn't fail: if it does, we lose chars. */
+ if (port->out_vq->vq_ops->add_buf(port->out_vq, sg, 1, 0, port) >= 0) {
/* Tell Host to go! */
- out_vq->vq_ops->kick(out_vq);
- /* Chill out until it's done with the buffer. */
- while (!out_vq->vq_ops->get_buf(out_vq, &len))
+ port->out_vq->vq_ops->kick(port->out_vq);
+ while (!port->out_vq->vq_ops->get_buf(port->out_vq, &len))
cpu_relax();
}
@@ -73,15 +76,15 @@ static int put_chars(u32 vtermno, const char *buf, int count)
* Create a scatter-gather list representing our input buffer and put
* it in the queue.
*/
-static void add_inbuf(void)
+static void add_inbuf(struct port *port)
{
struct scatterlist sg[1];
- sg_init_one(sg, inbuf, PAGE_SIZE);
+ sg_init_one(sg, port->inbuf, PAGE_SIZE);
- /* We should always be able to add one buffer to an empty queue. */
- if (in_vq->vq_ops->add_buf(in_vq, sg, 0, 1, inbuf) < 0)
+ /* Should always be able to add one buffer to an empty queue. */
+ if (port->in_vq->vq_ops->add_buf(port->in_vq, sg, 0, 1, port) < 0)
BUG();
- in_vq->vq_ops->kick(in_vq);
+ port->in_vq->vq_ops->kick(port->in_vq);
}
/*
@@ -94,28 +97,31 @@ static void add_inbuf(void)
*/
static int get_chars(u32 vtermno, char *buf, int count)
{
+ struct port *port;
+
+ port = &console;
+
/* If we don't have an input queue yet, we can't get input. */
- BUG_ON(!in_vq);
+ BUG_ON(!port->in_vq);
- /* No buffer? Try to get one. */
- if (!in_len) {
- in = in_vq->vq_ops->get_buf(in_vq, &in_len);
- if (!in)
+ /* No more in buffer? See if they've (re)used it. */
+ if (port->offset == port->used_len) {
+ if (!port->in_vq->vq_ops->get_buf(port->in_vq, &port->used_len))
return 0;
+ port->offset = 0;
}
/* You want more than we have to give? Well, try wanting less! */
- if (in_len < count)
- count = in_len;
+ if (port->offset + count > port->used_len)
+ count = port->used_len - port->offset;
/* Copy across to their buffer and increment offset. */
- memcpy(buf, in, count);
- in += count;
- in_len -= count;
+ memcpy(buf, port->inbuf + port->offset, count);
+ port->offset += count;
/* Finished? Re-register buffer so Host will use it again. */
- if (in_len == 0)
- add_inbuf();
+ if (port->offset == port->used_len)
+ add_inbuf(port);
return count;
}
@@ -135,7 +141,7 @@ static void virtcons_apply_config(struct virtio_device *dev)
dev->config->get(dev,
offsetof(struct virtio_console_config, rows),
&ws.ws_row, sizeof(u16));
- hvc_resize(hvc, ws);
+ hvc_resize(console.hvc, ws);
}
}
@@ -146,7 +152,7 @@ static void virtcons_apply_config(struct virtio_device *dev)
static int notifier_add_vio(struct hvc_struct *hp, int data)
{
hp->irq_requested = 1;
- virtcons_apply_config(vdev);
+ virtcons_apply_config(console.vdev);
return 0;
}
@@ -158,7 +164,7 @@ static void notifier_del_vio(struct hvc_struct *hp, int data)
static void hvc_handle_input(struct virtqueue *vq)
{
- if (hvc_poll(hvc))
+ if (hvc_poll(console.hvc))
hvc_kick();
}
@@ -197,23 +203,26 @@ int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
* Finally we put our input buffer in the input queue, ready to
* receive.
*/
-static int __devinit virtcons_probe(struct virtio_device *dev)
+static int __devinit virtcons_probe(struct virtio_device *vdev)
{
vq_callback_t *callbacks[] = { hvc_handle_input, NULL};
const char *names[] = { "input", "output" };
struct virtqueue *vqs[2];
+ struct port *port;
int err;
- if (vdev) {
- dev_warn(&vdev->dev,
+ port = &console;
+ if (port->vdev) {
+ dev_warn(&port->vdev->dev,
"Multiple virtio-console devices not supported yet\n");
return -EEXIST;
}
- vdev = dev;
+ port->vdev = vdev;
/* This is the scratch page we use to receive console input */
- inbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
- if (!inbuf) {
+ port->used_len = 0;
+ port->inbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!port->inbuf) {
err = -ENOMEM;
goto fail;
}
@@ -223,8 +232,8 @@ static int __devinit virtcons_probe(struct virtio_device *dev)
if (err)
goto free;
- in_vq = vqs[0];
- out_vq = vqs[1];
+ port->in_vq = vqs[0];
+ port->out_vq = vqs[1];
/*
* The first argument of hvc_alloc() is the virtual console
@@ -238,14 +247,14 @@ static int __devinit virtcons_probe(struct virtio_device *dev)
* pointers. The final argument is the output buffer size: we
* can do any size, so we put PAGE_SIZE here.
*/
- hvc = hvc_alloc(0, 0, &hv_ops, PAGE_SIZE);
- if (IS_ERR(hvc)) {
- err = PTR_ERR(hvc);
+ port->hvc = hvc_alloc(0, 0, &hv_ops, PAGE_SIZE);
+ if (IS_ERR(port->hvc)) {
+ err = PTR_ERR(port->hvc);
goto free_vqs;
}
/* Register the input buffer the first time. */
- add_inbuf();
+ add_inbuf(port);
/* Start using the new console output. */
early_put_chars = NULL;
@@ -254,7 +263,7 @@ static int __devinit virtcons_probe(struct virtio_device *dev)
free_vqs:
vdev->config->del_vqs(vdev);
free:
- kfree(inbuf);
+ kfree(port->inbuf);
fail:
return err;
}
--
1.6.2.5
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