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path: root/drivers/char/hw_random/virtio-rng.c
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Diffstat (limited to 'drivers/char/hw_random/virtio-rng.c')
-rw-r--r--drivers/char/hw_random/virtio-rng.c30
1 files changed, 19 insertions, 11 deletions
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index 86e83f883139..32216b623248 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -35,13 +35,13 @@ static DECLARE_COMPLETION(have_data);
static void random_recv_done(struct virtqueue *vq)
{
- int len;
+ unsigned int len;
/* We can get spurious callbacks, e.g. shared IRQs + virtio_pci. */
if (!vq->vq_ops->get_buf(vq, &len))
return;
- data_left = len / sizeof(random_data[0]);
+ data_left += len;
complete(&have_data);
}
@@ -49,7 +49,7 @@ static void register_buffer(void)
{
struct scatterlist sg;
- sg_init_one(&sg, random_data, RANDOM_DATA_SIZE);
+ sg_init_one(&sg, random_data+data_left, RANDOM_DATA_SIZE-data_left);
/* There should always be room for one buffer. */
if (vq->vq_ops->add_buf(vq, &sg, 0, 1, random_data) != 0)
BUG();
@@ -59,24 +59,32 @@ static void register_buffer(void)
/* At least we don't udelay() in a loop like some other drivers. */
static int virtio_data_present(struct hwrng *rng, int wait)
{
- if (data_left)
+ if (data_left >= sizeof(u32))
return 1;
+again:
if (!wait)
return 0;
wait_for_completion(&have_data);
+
+ /* Not enough? Re-register. */
+ if (unlikely(data_left < sizeof(u32))) {
+ register_buffer();
+ goto again;
+ }
+
return 1;
}
/* virtio_data_present() must have succeeded before this is called. */
static int virtio_data_read(struct hwrng *rng, u32 *data)
{
- BUG_ON(!data_left);
-
- *data = random_data[--data_left];
+ BUG_ON(data_left < sizeof(u32));
+ data_left -= sizeof(u32);
+ *data = random_data[data_left / 4];
- if (!data_left) {
+ if (data_left < sizeof(u32)) {
init_completion(&have_data);
register_buffer();
}
@@ -94,13 +102,13 @@ static int virtrng_probe(struct virtio_device *vdev)
int err;
/* We expect a single virtqueue. */
- vq = vdev->config->find_vq(vdev, 0, random_recv_done);
+ vq = virtio_find_single_vq(vdev, random_recv_done, "input");
if (IS_ERR(vq))
return PTR_ERR(vq);
err = hwrng_register(&virtio_hwrng);
if (err) {
- vdev->config->del_vq(vq);
+ vdev->config->del_vqs(vdev);
return err;
}
@@ -112,7 +120,7 @@ static void virtrng_remove(struct virtio_device *vdev)
{
vdev->config->reset(vdev);
hwrng_unregister(&virtio_hwrng);
- vdev->config->del_vq(vq);
+ vdev->config->del_vqs(vdev);
}
static struct virtio_device_id id_table[] = {