summaryrefslogtreecommitdiff
path: root/drivers/char/hw_random/virtio-rng.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/char/hw_random/virtio-rng.c')
-rw-r--r--drivers/char/hw_random/virtio-rng.c105
1 files changed, 67 insertions, 38 deletions
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index 2ce0e225e58c..f3e71501de54 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -25,88 +25,115 @@
#include <linux/virtio_rng.h>
#include <linux/module.h>
-static struct virtqueue *vq;
-static unsigned int data_avail;
-static DECLARE_COMPLETION(have_data);
-static bool busy;
+static DEFINE_IDA(rng_index_ida);
+
+struct virtrng_info {
+ struct virtio_device *vdev;
+ struct hwrng hwrng;
+ struct virtqueue *vq;
+ unsigned int data_avail;
+ struct completion have_data;
+ bool busy;
+ char name[25];
+ int index;
+};
static void random_recv_done(struct virtqueue *vq)
{
+ struct virtrng_info *vi = vq->vdev->priv;
+
/* We can get spurious callbacks, e.g. shared IRQs + virtio_pci. */
- if (!virtqueue_get_buf(vq, &data_avail))
+ if (!virtqueue_get_buf(vi->vq, &vi->data_avail))
return;
- complete(&have_data);
+ complete(&vi->have_data);
}
/* The host will fill any buffer we give it with sweet, sweet randomness. */
-static void register_buffer(u8 *buf, size_t size)
+static void register_buffer(struct virtrng_info *vi, u8 *buf, size_t size)
{
struct scatterlist sg;
sg_init_one(&sg, buf, size);
/* There should always be room for one buffer. */
- virtqueue_add_inbuf(vq, &sg, 1, buf, GFP_KERNEL);
+ virtqueue_add_inbuf(vi->vq, &sg, 1, buf, GFP_KERNEL);
- virtqueue_kick(vq);
+ virtqueue_kick(vi->vq);
}
static int virtio_read(struct hwrng *rng, void *buf, size_t size, bool wait)
{
int ret;
+ struct virtrng_info *vi = (struct virtrng_info *)rng->priv;
- if (!busy) {
- busy = true;
- init_completion(&have_data);
- register_buffer(buf, size);
+ if (!vi->busy) {
+ vi->busy = true;
+ init_completion(&vi->have_data);
+ register_buffer(vi, buf, size);
}
if (!wait)
return 0;
- ret = wait_for_completion_killable(&have_data);
+ ret = wait_for_completion_killable(&vi->have_data);
if (ret < 0)
return ret;
- busy = false;
+ vi->busy = false;
- return data_avail;
+ return vi->data_avail;
}
static void virtio_cleanup(struct hwrng *rng)
{
- if (busy)
- wait_for_completion(&have_data);
-}
+ struct virtrng_info *vi = (struct virtrng_info *)rng->priv;
-
-static struct hwrng virtio_hwrng = {
- .name = "virtio",
- .cleanup = virtio_cleanup,
- .read = virtio_read,
-};
+ if (vi->busy)
+ wait_for_completion(&vi->have_data);
+}
static int probe_common(struct virtio_device *vdev)
{
- int err;
+ int err, index;
+ struct virtrng_info *vi = NULL;
+
+ vi = kzalloc(sizeof(struct virtrng_info), GFP_KERNEL);
+ if (!vi)
+ return -ENOMEM;
- if (vq) {
- /* We only support one device for now */
- return -EBUSY;
+ vi->index = index = ida_simple_get(&rng_index_ida, 0, 0, GFP_KERNEL);
+ if (index < 0) {
+ kfree(vi);
+ return index;
}
+ sprintf(vi->name, "virtio_rng.%d", index);
+ init_completion(&vi->have_data);
+
+ vi->hwrng = (struct hwrng) {
+ .read = virtio_read,
+ .cleanup = virtio_cleanup,
+ .priv = (unsigned long)vi,
+ .name = vi->name,
+ };
+ vdev->priv = vi;
+
/* We expect a single virtqueue. */
- vq = virtio_find_single_vq(vdev, random_recv_done, "input");
- if (IS_ERR(vq)) {
- err = PTR_ERR(vq);
- vq = NULL;
+ vi->vq = virtio_find_single_vq(vdev, random_recv_done, "input");
+ if (IS_ERR(vi->vq)) {
+ err = PTR_ERR(vi->vq);
+ vi->vq = NULL;
+ kfree(vi);
+ ida_simple_remove(&rng_index_ida, index);
return err;
}
- err = hwrng_register(&virtio_hwrng);
+ err = hwrng_register(&vi->hwrng);
if (err) {
vdev->config->del_vqs(vdev);
- vq = NULL;
+ vi->vq = NULL;
+ kfree(vi);
+ ida_simple_remove(&rng_index_ida, index);
return err;
}
@@ -115,11 +142,13 @@ static int probe_common(struct virtio_device *vdev)
static void remove_common(struct virtio_device *vdev)
{
+ struct virtrng_info *vi = vdev->priv;
vdev->config->reset(vdev);
- busy = false;
- hwrng_unregister(&virtio_hwrng);
+ vi->busy = false;
+ hwrng_unregister(&vi->hwrng);
vdev->config->del_vqs(vdev);
- vq = NULL;
+ ida_simple_remove(&rng_index_ida, vi->index);
+ kfree(vi);
}
static int virtrng_probe(struct virtio_device *vdev)