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path: root/drivers/virtio/virtio_ring.c
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Diffstat (limited to 'drivers/virtio/virtio_ring.c')
-rw-r--r--drivers/virtio/virtio_ring.c77
1 files changed, 62 insertions, 15 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 409aeaa49246..5e1b548828e6 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -263,6 +263,7 @@ static inline int virtqueue_add(struct virtqueue *_vq,
unsigned int out_sgs,
unsigned int in_sgs,
void *data,
+ void *ctx,
gfp_t gfp)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@@ -275,6 +276,7 @@ static inline int virtqueue_add(struct virtqueue *_vq,
START_USE(vq);
BUG_ON(data == NULL);
+ BUG_ON(ctx && vq->indirect);
if (unlikely(vq->broken)) {
END_USE(vq);
@@ -389,6 +391,8 @@ static inline int virtqueue_add(struct virtqueue *_vq,
vq->desc_state[head].data = data;
if (indirect)
vq->desc_state[head].indir_desc = desc;
+ if (ctx)
+ vq->desc_state[head].indir_desc = ctx;
/* Put entry in available array (but don't update avail->idx until they
* do sync). */
@@ -461,7 +465,8 @@ int virtqueue_add_sgs(struct virtqueue *_vq,
for (sg = sgs[i]; sg; sg = sg_next(sg))
total_sg++;
}
- return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs, data, gfp);
+ return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs,
+ data, NULL, gfp);
}
EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
@@ -483,7 +488,7 @@ int virtqueue_add_outbuf(struct virtqueue *vq,
void *data,
gfp_t gfp)
{
- return virtqueue_add(vq, &sg, num, 1, 0, data, gfp);
+ return virtqueue_add(vq, &sg, num, 1, 0, data, NULL, gfp);
}
EXPORT_SYMBOL_GPL(virtqueue_add_outbuf);
@@ -505,11 +510,35 @@ int virtqueue_add_inbuf(struct virtqueue *vq,
void *data,
gfp_t gfp)
{
- return virtqueue_add(vq, &sg, num, 0, 1, data, gfp);
+ return virtqueue_add(vq, &sg, num, 0, 1, data, NULL, gfp);
}
EXPORT_SYMBOL_GPL(virtqueue_add_inbuf);
/**
+ * virtqueue_add_inbuf_ctx - expose input buffers to other end
+ * @vq: the struct virtqueue we're talking about.
+ * @sg: scatterlist (must be well-formed and terminated!)
+ * @num: the number of entries in @sg writable by other side
+ * @data: the token identifying the buffer.
+ * @ctx: extra context for the token
+ * @gfp: how to do memory allocations (if necessary).
+ *
+ * Caller must ensure we don't call this with other virtqueue operations
+ * at the same time (except where noted).
+ *
+ * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
+ */
+int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
+ struct scatterlist *sg, unsigned int num,
+ void *data,
+ void *ctx,
+ gfp_t gfp)
+{
+ return virtqueue_add(vq, &sg, num, 0, 1, data, ctx, gfp);
+}
+EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
+
+/**
* virtqueue_kick_prepare - first half of split virtqueue_kick call.
* @vq: the struct virtqueue
*
@@ -598,7 +627,8 @@ bool virtqueue_kick(struct virtqueue *vq)
}
EXPORT_SYMBOL_GPL(virtqueue_kick);
-static void detach_buf(struct vring_virtqueue *vq, unsigned int head)
+static void detach_buf(struct vring_virtqueue *vq, unsigned int head,
+ void **ctx)
{
unsigned int i, j;
__virtio16 nextflag = cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT);
@@ -622,10 +652,15 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head)
/* Plus final descriptor */
vq->vq.num_free++;
- /* Free the indirect table, if any, now that it's unmapped. */
- if (vq->desc_state[head].indir_desc) {
+ if (vq->indirect) {
struct vring_desc *indir_desc = vq->desc_state[head].indir_desc;
- u32 len = virtio32_to_cpu(vq->vq.vdev, vq->vring.desc[head].len);
+ u32 len;
+
+ /* Free the indirect table, if any, now that it's unmapped. */
+ if (!indir_desc)
+ return;
+
+ len = virtio32_to_cpu(vq->vq.vdev, vq->vring.desc[head].len);
BUG_ON(!(vq->vring.desc[head].flags &
cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_INDIRECT)));
@@ -634,8 +669,10 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head)
for (j = 0; j < len / sizeof(struct vring_desc); j++)
vring_unmap_one(vq, &indir_desc[j]);
- kfree(vq->desc_state[head].indir_desc);
+ kfree(indir_desc);
vq->desc_state[head].indir_desc = NULL;
+ } else if (ctx) {
+ *ctx = vq->desc_state[head].indir_desc;
}
}
@@ -660,7 +697,8 @@ static inline bool more_used(const struct vring_virtqueue *vq)
* Returns NULL if there are no used buffers, or the "data" token
* handed to virtqueue_add_*().
*/
-void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
+void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
+ void **ctx)
{
struct vring_virtqueue *vq = to_vvq(_vq);
void *ret;
@@ -698,7 +736,7 @@ void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
/* detach_buf clears data, so grab it now. */
ret = vq->desc_state[i].data;
- detach_buf(vq, i);
+ detach_buf(vq, i, ctx);
vq->last_used_idx++;
/* If we expect an interrupt for the next entry, tell host
* by writing event index and flush out the write before
@@ -715,8 +753,13 @@ void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
END_USE(vq);
return ret;
}
-EXPORT_SYMBOL_GPL(virtqueue_get_buf);
+EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);
+void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
+{
+ return virtqueue_get_buf_ctx(_vq, len, NULL);
+}
+EXPORT_SYMBOL_GPL(virtqueue_get_buf);
/**
* virtqueue_disable_cb - disable callbacks
* @vq: the struct virtqueue we're talking about.
@@ -878,7 +921,7 @@ void *virtqueue_detach_unused_buf(struct virtqueue *_vq)
continue;
/* detach_buf clears data, so grab it now. */
buf = vq->desc_state[i].data;
- detach_buf(vq, i);
+ detach_buf(vq, i, NULL);
vq->avail_idx_shadow--;
vq->vring.avail->idx = cpu_to_virtio16(_vq->vdev, vq->avail_idx_shadow);
END_USE(vq);
@@ -916,6 +959,7 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
struct vring vring,
struct virtio_device *vdev,
bool weak_barriers,
+ bool context,
bool (*notify)(struct virtqueue *),
void (*callback)(struct virtqueue *),
const char *name)
@@ -950,7 +994,8 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
vq->last_add_time_valid = false;
#endif
- vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC);
+ vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
+ !context;
vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
/* No callback? Tell other side not to bother us. */
@@ -1019,6 +1064,7 @@ struct virtqueue *vring_create_virtqueue(
struct virtio_device *vdev,
bool weak_barriers,
bool may_reduce_num,
+ bool context,
bool (*notify)(struct virtqueue *),
void (*callback)(struct virtqueue *),
const char *name)
@@ -1058,7 +1104,7 @@ struct virtqueue *vring_create_virtqueue(
queue_size_in_bytes = vring_size(num, vring_align);
vring_init(&vring, num, queue, vring_align);
- vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers,
+ vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers, context,
notify, callback, name);
if (!vq) {
vring_free_queue(vdev, queue_size_in_bytes, queue,
@@ -1079,6 +1125,7 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,
unsigned int vring_align,
struct virtio_device *vdev,
bool weak_barriers,
+ bool context,
void *pages,
bool (*notify)(struct virtqueue *vq),
void (*callback)(struct virtqueue *vq),
@@ -1086,7 +1133,7 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,
{
struct vring vring;
vring_init(&vring, num, pages, vring_align);
- return __vring_new_virtqueue(index, vring, vdev, weak_barriers,
+ return __vring_new_virtqueue(index, vring, vdev, weak_barriers, context,
notify, callback, name);
}
EXPORT_SYMBOL_GPL(vring_new_virtqueue);
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-04 09:16:16 +0000