diff options
| -rw-r--r-- | drivers/virtio/virtio_ring.c | 112 |
1 files changed, 52 insertions, 60 deletions
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 97590c201aa2..405d5a348795 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -69,7 +69,11 @@ struct vring_desc_state_split { void *data; /* Data for callback. */ - struct vring_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_desc *indir_desc; }; struct vring_desc_state_packed { @@ -440,38 +444,20 @@ static void virtqueue_init(struct vring_virtqueue *vq, u32 num) * Split ring specific functions - *_split(). */ -static void vring_unmap_one_split_indirect(const struct vring_virtqueue *vq, - const struct vring_desc *desc) -{ - u16 flags; - - if (!vring_need_unmap_buffer(vq)) - return; - - flags = virtio16_to_cpu(vq->vq.vdev, desc->flags); - - dma_unmap_page(vring_dma_dev(vq), - virtio64_to_cpu(vq->vq.vdev, desc->addr), - virtio32_to_cpu(vq->vq.vdev, desc->len), - (flags & VRING_DESC_F_WRITE) ? - DMA_FROM_DEVICE : DMA_TO_DEVICE); -} - static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq, - unsigned int i) + struct vring_desc_extra *extra) { - struct vring_desc_extra *extra = vq->split.desc_extra; u16 flags; - flags = extra[i].flags; + flags = extra->flags; if (flags & VRING_DESC_F_INDIRECT) { if (!vq->use_dma_api) goto out; dma_unmap_single(vring_dma_dev(vq), - extra[i].addr, - extra[i].len, + extra->addr, + extra->len, (flags & VRING_DESC_F_WRITE) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } else { @@ -479,22 +465,23 @@ static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq, goto out; dma_unmap_page(vring_dma_dev(vq), - extra[i].addr, - extra[i].len, + extra->addr, + extra->len, (flags & VRING_DESC_F_WRITE) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } out: - return extra[i].next; + return extra->next; } static struct vring_desc *alloc_indirect_split(struct virtqueue *_vq, unsigned int total_sg, gfp_t gfp) { + struct vring_desc_extra *extra; struct vring_desc *desc; - unsigned int i; + unsigned int i, size; /* * We require lowmem mappings for the descriptors because @@ -503,40 +490,41 @@ static struct vring_desc *alloc_indirect_split(struct virtqueue *_vq, */ gfp &= ~__GFP_HIGHMEM; - desc = kmalloc_array(total_sg, sizeof(struct vring_desc), gfp); + size = sizeof(*desc) * total_sg + 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++) - desc[i].next = cpu_to_virtio16(_vq->vdev, i + 1); + extra[i].next = i + 1; + return desc; } static inline unsigned int virtqueue_add_desc_split(struct virtqueue *vq, struct vring_desc *desc, + struct vring_desc_extra *extra, unsigned int i, dma_addr_t addr, unsigned int len, - u16 flags, - bool indirect) + u16 flags) { - struct vring_virtqueue *vring = to_vvq(vq); - struct vring_desc_extra *extra = vring->split.desc_extra; u16 next; desc[i].flags = cpu_to_virtio16(vq->vdev, flags); desc[i].addr = cpu_to_virtio64(vq->vdev, addr); desc[i].len = cpu_to_virtio32(vq->vdev, len); - if (!indirect) { - next = extra[i].next; - desc[i].next = cpu_to_virtio16(vq->vdev, next); + extra[i].addr = addr; + extra[i].len = len; + extra[i].flags = flags; + + next = extra[i].next; - extra[i].addr = addr; - extra[i].len = len; - extra[i].flags = flags; - } else - next = virtio16_to_cpu(vq->vdev, desc[i].next); + desc[i].next = cpu_to_virtio16(vq->vdev, next); return next; } @@ -551,6 +539,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, gfp_t gfp) { struct vring_virtqueue *vq = to_vvq(_vq); + struct vring_desc_extra *extra; struct scatterlist *sg; struct vring_desc *desc; unsigned int i, n, avail, descs_used, prev, err_idx; @@ -586,9 +575,11 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, /* Set up rest to use this indirect table. */ i = 0; descs_used = 1; + extra = (struct vring_desc_extra *)&desc[total_sg]; } else { indirect = false; desc = vq->split.vring.desc; + extra = vq->split.desc_extra; i = head; descs_used = total_sg; } @@ -618,9 +609,8 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, /* Note that we trust indirect descriptor * table since it use stream DMA mapping. */ - i = virtqueue_add_desc_split(_vq, desc, i, addr, sg->length, - VRING_DESC_F_NEXT, - indirect); + i = virtqueue_add_desc_split(_vq, desc, extra, i, addr, sg->length, + VRING_DESC_F_NEXT); } } for (; n < (out_sgs + in_sgs); n++) { @@ -634,11 +624,10 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, /* Note that we trust indirect descriptor * table since it use stream DMA mapping. */ - i = virtqueue_add_desc_split(_vq, desc, i, addr, + i = virtqueue_add_desc_split(_vq, desc, extra, i, addr, sg->length, VRING_DESC_F_NEXT | - VRING_DESC_F_WRITE, - indirect); + VRING_DESC_F_WRITE); } } /* Last one doesn't continue. */ @@ -660,10 +649,10 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, } virtqueue_add_desc_split(_vq, vq->split.vring.desc, + vq->split.desc_extra, head, addr, total_sg * sizeof(struct vring_desc), - VRING_DESC_F_INDIRECT, - false); + VRING_DESC_F_INDIRECT); } /* We're using some buffers from the free list. */ @@ -716,11 +705,8 @@ unmap_release: for (n = 0; n < total_sg; n++) { if (i == err_idx) break; - if (indirect) { - vring_unmap_one_split_indirect(vq, &desc[i]); - i = virtio16_to_cpu(_vq->vdev, desc[i].next); - } else - i = vring_unmap_one_split(vq, i); + + i = vring_unmap_one_split(vq, &extra[i]); } free_indirect: @@ -765,22 +751,25 @@ static bool virtqueue_kick_prepare_split(struct virtqueue *_vq) static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, void **ctx) { + struct vring_desc_extra *extra; unsigned int i, j; __virtio16 nextflag = cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT); /* Clear data ptr. */ vq->split.desc_state[head].data = NULL; + extra = vq->split.desc_extra; + /* Put back on free list: unmap first-level descriptors and find end */ i = head; while (vq->split.vring.desc[i].flags & nextflag) { - vring_unmap_one_split(vq, i); + vring_unmap_one_split(vq, &extra[i]); i = vq->split.desc_extra[i].next; vq->vq.num_free++; } - vring_unmap_one_split(vq, i); + vring_unmap_one_split(vq, &extra[i]); vq->split.desc_extra[i].next = vq->free_head; vq->free_head = head; @@ -790,21 +779,24 @@ static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, if (vq->indirect) { struct vring_desc *indir_desc = vq->split.desc_state[head].indir_desc; - u32 len; + u32 len, num; /* Free the indirect table, if any, now that it's unmapped. */ if (!indir_desc) return; - len = vq->split.desc_extra[head].len; BUG_ON(!(vq->split.desc_extra[head].flags & VRING_DESC_F_INDIRECT)); BUG_ON(len == 0 || len % sizeof(struct vring_desc)); + num = len / sizeof(struct vring_desc); + + extra = (struct vring_desc_extra *)&indir_desc[num]; + if (vring_need_unmap_buffer(vq)) { - for (j = 0; j < len / sizeof(struct vring_desc); j++) - vring_unmap_one_split_indirect(vq, &indir_desc[j]); + for (j = 0; j < num; j++) + vring_unmap_one_split(vq, &extra[j]); } kfree(indir_desc); |