diff options
| -rw-r--r-- | drivers/virtio/virtio_ring.c | 60 |
1 files changed, 36 insertions, 24 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 405d5a348795..cfe70c40f630 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -78,7 +78,11 @@ struct vring_desc_state_split { struct vring_desc_state_packed { void *data; /* Data for callback. */ - struct vring_packed_desc *indir_desc; /* Indirect descriptor, if any. */ + + /* Indirect desc table and extra table, if any. These two will be + * allocated together. So we won't stress more to the memory allocator. + */ + struct vring_packed_desc *indir_desc; u16 num; /* Descriptor list length. */ u16 last; /* The last desc state in a list. */ }; @@ -1238,27 +1242,12 @@ static void vring_unmap_extra_packed(const struct vring_virtqueue *vq, } } -static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, - const struct vring_packed_desc *desc) -{ - u16 flags; - - if (!vring_need_unmap_buffer(vq)) - return; - - flags = le16_to_cpu(desc->flags); - - dma_unmap_page(vring_dma_dev(vq), - le64_to_cpu(desc->addr), - le32_to_cpu(desc->len), - (flags & VRING_DESC_F_WRITE) ? - DMA_FROM_DEVICE : DMA_TO_DEVICE); -} - static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, gfp_t gfp) { + struct vring_desc_extra *extra; struct vring_packed_desc *desc; + int i, size; /* * We require lowmem mappings for the descriptors because @@ -1267,7 +1256,16 @@ static struct vring_packed_desc *alloc_indirect_packed(unsigned int total_sg, */ gfp &= ~__GFP_HIGHMEM; - desc = kmalloc_array(total_sg, sizeof(struct vring_packed_desc), gfp); + size = (sizeof(*desc) + sizeof(*extra)) * total_sg; + + desc = kmalloc(size, gfp); + if (!desc) + return NULL; + + extra = (struct vring_desc_extra *)&desc[total_sg]; + + for (i = 0; i < total_sg; i++) + extra[i].next = i + 1; return desc; } @@ -1280,6 +1278,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, void *data, gfp_t gfp) { + struct vring_desc_extra *extra; struct vring_packed_desc *desc; struct scatterlist *sg; unsigned int i, n, err_idx; @@ -1291,6 +1290,8 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, if (!desc) return -ENOMEM; + extra = (struct vring_desc_extra *)&desc[total_sg]; + if (unlikely(vq->vq.num_free < 1)) { pr_debug("Can't add buf len 1 - avail = 0\n"); kfree(desc); @@ -1312,6 +1313,13 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, 0 : VRING_DESC_F_WRITE); desc[i].addr = cpu_to_le64(addr); desc[i].len = cpu_to_le32(sg->length); + + if (unlikely(vq->use_dma_api)) { + extra[i].addr = addr; + extra[i].len = sg->length; + extra[i].flags = n < out_sgs ? 0 : VRING_DESC_F_WRITE; + } + i++; } } @@ -1381,7 +1389,7 @@ unmap_release: err_idx = i; for (i = 0; i < err_idx; i++) - vring_unmap_desc_packed(vq, &desc[i]); + vring_unmap_extra_packed(vq, &extra[i]); free_desc: kfree(desc); @@ -1617,7 +1625,8 @@ static void detach_buf_packed(struct vring_virtqueue *vq, } if (vq->indirect) { - u32 len; + struct vring_desc_extra *extra; + u32 len, num; /* Free the indirect table, if any, now that it's unmapped. */ desc = state->indir_desc; @@ -1626,9 +1635,12 @@ static void detach_buf_packed(struct vring_virtqueue *vq, if (vring_need_unmap_buffer(vq)) { len = vq->packed.desc_extra[id].len; - for (i = 0; i < len / sizeof(struct vring_packed_desc); - i++) - vring_unmap_desc_packed(vq, &desc[i]); + num = len / sizeof(struct vring_packed_desc); + + extra = (struct vring_desc_extra *)&desc[num]; + + for (i = 0; i < num; i++) + vring_unmap_extra_packed(vq, &extra[i]); } kfree(desc); state->indir_desc = NULL; |