diff options
| -rw-r--r-- | drivers/virtio/virtio_ring.c | 70 | ||||
| -rw-r--r-- | include/linux/virtio.h | 9 |
2 files changed, 66 insertions, 13 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index b23b5fae468b..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); @@ -951,7 +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. */ diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 7edfbdb55a99..ed04753278d4 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -44,6 +44,12 @@ int virtqueue_add_inbuf(struct virtqueue *vq, void *data, gfp_t gfp); +int virtqueue_add_inbuf_ctx(struct virtqueue *vq, + struct scatterlist sg[], unsigned int num, + void *data, + void *ctx, + gfp_t gfp); + int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[], unsigned int out_sgs, @@ -59,6 +65,9 @@ bool virtqueue_notify(struct virtqueue *vq); void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len); +void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len, + void **ctx); + void virtqueue_disable_cb(struct virtqueue *vq); bool virtqueue_enable_cb(struct virtqueue *vq); |