As discussed: http://lore.kernel.org/all/CACGkMEug-=C+VQhkMYSgUKMC==04m7-uem_yC21bgGkKZh845w@xxxxxxxxxxxxxx When the vq is premapped mode, the driver manages the dma info is a good way. So this commit make the virtio core not to store the dma info and release the memory which is used to store the dma info. If the use_dma_api is false, the memory is also not allocated. Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> --- drivers/virtio/virtio_ring.c | 120 ++++++++++++++++++++++++++++------- 1 file changed, 97 insertions(+), 23 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 980f81f5ab76..f67f4ac2d58f 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -69,23 +69,26 @@ struct vring_desc_state_split { void *data; /* Data for callback. */ - struct vring_desc_extra *indir_desc; /* Indirect descriptor, if any. */ + struct vring_desc_dma *indir_desc; /* Indirect descriptor, if any. */ }; struct vring_desc_state_packed { void *data; /* Data for callback. */ - struct vring_desc_extra *indir_desc; /* Indirect descriptor, if any. */ + struct vring_desc_dma *indir_desc; /* Indirect descriptor, if any. */ u16 num; /* Descriptor list length. */ u16 last; /* The last desc state in a list. */ }; struct vring_desc_extra { - dma_addr_t addr; /* Descriptor DMA addr. */ - u32 len; /* Descriptor length. */ u16 flags; /* Descriptor flags. */ u16 next; /* The next desc state in a list. */ }; +struct vring_desc_dma { + dma_addr_t addr; /* Descriptor DMA addr. */ + u32 len; /* Descriptor length. */ +}; + struct vring_virtqueue_split { /* Actual memory layout for this queue. */ struct vring vring; @@ -102,6 +105,7 @@ struct vring_virtqueue_split { /* Per-descriptor state. */ struct vring_desc_state_split *desc_state; struct vring_desc_extra *desc_extra; + struct vring_desc_dma *desc_dma; /* DMA address and size information */ dma_addr_t queue_dma_addr; @@ -142,6 +146,7 @@ struct vring_virtqueue_packed { /* Per-descriptor state. */ struct vring_desc_state_packed *desc_state; struct vring_desc_extra *desc_extra; + struct vring_desc_dma *desc_dma; /* DMA address and size information */ dma_addr_t ring_dma_addr; @@ -456,24 +461,25 @@ static unsigned int vring_unmap_one_split(const struct vring_virtqueue *vq, unsigned int i) { struct vring_desc_extra *extra = vq->split.desc_extra; + struct vring_desc_dma *dma = vq->split.desc_dma; u16 flags; flags = extra[i].flags; dma_unmap_page(vring_dma_dev(vq), - extra[i].addr, - extra[i].len, + dma[i].addr, + dma[i].len, (flags & VRING_DESC_F_WRITE) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); return extra[i].next; } -static struct vring_desc_extra *alloc_indirect_split(struct virtqueue *_vq, +static struct vring_desc_dma *alloc_indirect_split(struct virtqueue *_vq, unsigned int total_sg, gfp_t gfp) { - struct vring_desc_extra *in_extra; + struct vring_desc_dma *in_extra; struct vring_desc *desc; unsigned int i; u32 size; @@ -519,8 +525,11 @@ static inline unsigned int virtqueue_add_desc_split(struct virtqueue *vq, next = extra[i].next; desc[i].next = cpu_to_virtio16(vq->vdev, next); - extra[i].addr = addr; - extra[i].len = len; + if (vring->split.desc_dma) { + vring->split.desc_dma[i].addr = addr; + vring->split.desc_dma[i].len = len; + } + extra[i].flags = flags; } else next = virtio16_to_cpu(vq->vdev, desc[i].next); @@ -538,7 +547,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, gfp_t gfp) { struct vring_virtqueue *vq = to_vvq(_vq); - struct vring_desc_extra *in_extra; + struct vring_desc_dma *in_extra; struct scatterlist *sg; struct vring_desc *desc; unsigned int i, n, avail, descs_used, prev, err_idx; @@ -792,7 +801,7 @@ static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, if (ctx) *ctx = vq->split.desc_state[head].indir_desc; } else { - struct vring_desc_extra *in_extra; + struct vring_desc_dma *in_extra; struct vring_desc *desc; u32 num; @@ -1059,6 +1068,23 @@ static void virtqueue_vring_attach_split(struct vring_virtqueue *vq, vq->free_head = 0; } +static int vring_alloc_dma_split(struct vring_virtqueue_split *vring_split, + bool need_unmap) +{ + u32 num = vring_split->vring.num; + struct vring_desc_dma *dma; + + if (!need_unmap) + return 0; + + dma = kmalloc_array(num, sizeof(struct vring_desc_dma), GFP_KERNEL); + if (!dma) + return -ENOMEM; + + vring_split->desc_dma = dma; + return 0; +} + static int vring_alloc_state_extra_split(struct vring_virtqueue_split *vring_split) { struct vring_desc_state_split *state; @@ -1095,6 +1121,7 @@ static void vring_free_split(struct vring_virtqueue_split *vring_split, kfree(vring_split->desc_state); kfree(vring_split->desc_extra); + kfree(vring_split->desc_dma); } static int vring_alloc_queue_split(struct vring_virtqueue_split *vring_split, @@ -1196,6 +1223,10 @@ static int virtqueue_resize_split(struct virtqueue *_vq, u32 num) if (err) goto err_state_extra; + err = vring_alloc_dma_split(&vring_split, vring_need_unmap_buffer(vq)); + if (err) + goto err_state_extra; + vring_free(&vq->vq); virtqueue_vring_init_split(&vring_split, vq); @@ -1228,14 +1259,16 @@ static u16 packed_last_used(u16 last_used_idx) /* caller must check vring_need_unmap_buffer() */ static void vring_unmap_extra_packed(const struct vring_virtqueue *vq, - const struct vring_desc_extra *extra) + unsigned int i) { + const struct vring_desc_extra *extra = &vq->packed.desc_extra[i]; + const struct vring_desc_dma *dma = &vq->packed.desc_dma[i]; u16 flags; flags = extra->flags; dma_unmap_page(vring_dma_dev(vq), - extra->addr, extra->len, + dma->addr, dma->len, (flags & VRING_DESC_F_WRITE) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } @@ -1255,10 +1288,10 @@ static void vring_unmap_desc_packed(const struct vring_virtqueue *vq, DMA_FROM_DEVICE : DMA_TO_DEVICE); } -static struct vring_desc_extra *alloc_indirect_packed(unsigned int total_sg, +static struct vring_desc_dma *alloc_indirect_packed(unsigned int total_sg, gfp_t gfp) { - struct vring_desc_extra *in_extra; + struct vring_desc_dma *in_extra; u32 size; size = sizeof(*in_extra) + sizeof(struct vring_packed_desc) * total_sg; @@ -1284,7 +1317,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, void *data, gfp_t gfp) { - struct vring_desc_extra *in_extra; + struct vring_desc_dma *in_extra; struct vring_packed_desc *desc; struct scatterlist *sg; unsigned int i, n, err_idx; @@ -1483,8 +1516,8 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, desc[i].id = cpu_to_le16(id); if (vring_need_unmap_buffer(vq)) { - vq->packed.desc_extra[curr].addr = addr; - vq->packed.desc_extra[curr].len = sg->length; + vq->packed.desc_dma[curr].addr = addr; + vq->packed.desc_dma[curr].len = sg->length; } vq->packed.desc_extra[curr].flags = le16_to_cpu(flags); @@ -1543,7 +1576,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, for (n = 0; n < total_sg; n++) { if (i == err_idx) break; - vring_unmap_extra_packed(vq, &vq->packed.desc_extra[curr]); + vring_unmap_extra_packed(vq, curr); curr = vq->packed.desc_extra[curr].next; i++; if (i >= vq->packed.vring.num) @@ -1624,8 +1657,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq, if (vring_need_unmap_buffer(vq)) { curr = id; for (i = 0; i < state->num; i++) { - vring_unmap_extra_packed(vq, - &vq->packed.desc_extra[curr]); + vring_unmap_extra_packed(vq, curr); curr = vq->packed.desc_extra[curr].next; } } @@ -1633,7 +1665,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq, if (ctx) *ctx = state->indir_desc; } else { - struct vring_desc_extra *in_extra; + struct vring_desc_dma *in_extra; struct vring_packed_desc *desc; u32 num; @@ -1943,6 +1975,7 @@ static void vring_free_packed(struct vring_virtqueue_packed *vring_packed, kfree(vring_packed->desc_state); kfree(vring_packed->desc_extra); + kfree(vring_packed->desc_dma); } static int vring_alloc_queue_packed(struct vring_virtqueue_packed *vring_packed, @@ -1999,6 +2032,23 @@ static int vring_alloc_queue_packed(struct vring_virtqueue_packed *vring_packed, return -ENOMEM; } +static int vring_alloc_dma_packed(struct vring_virtqueue_packed *vring_packed, + bool need_unmap) +{ + u32 num = vring_packed->vring.num; + struct vring_desc_dma *dma; + + if (!need_unmap) + return 0; + + dma = kmalloc_array(num, sizeof(struct vring_desc_dma), GFP_KERNEL); + if (!dma) + return -ENOMEM; + + vring_packed->desc_dma = dma; + return 0; +} + static int vring_alloc_state_extra_packed(struct vring_virtqueue_packed *vring_packed) { struct vring_desc_state_packed *state; @@ -2111,6 +2161,10 @@ static struct virtqueue *vring_create_virtqueue_packed(struct virtio_device *vde if (err) goto err_state_extra; + err = vring_alloc_dma_packed(&vring_packed, vring_need_unmap_buffer(vq)); + if (err) + goto err_state_extra; + virtqueue_vring_init_packed(&vring_packed, !!cfg_vq_val(cfg, callbacks)); virtqueue_init(vq, tp_cfg->num); @@ -2143,6 +2197,10 @@ static int virtqueue_resize_packed(struct virtqueue *_vq, u32 num) if (err) goto err_state_extra; + err = vring_alloc_dma_packed(&vring_packed, vring_need_unmap_buffer(vq)); + if (err) + goto err_state_extra; + vring_free(&vq->vq); virtqueue_vring_init_packed(&vring_packed, !!vq->vq.callback); @@ -2653,6 +2711,12 @@ static struct virtqueue *__vring_new_virtqueue(struct virtio_device *vdev, return NULL; } + err = vring_alloc_dma_split(vring_split, vring_need_unmap_buffer(vq)); + if (err) { + kfree(vq); + return NULL; + } + virtqueue_vring_init_split(vring_split, vq); virtqueue_init(vq, vring_split->vring.num); @@ -2770,6 +2834,14 @@ int virtqueue_set_dma_premapped(struct virtqueue *_vq) vq->premapped = true; + if (vq->packed_ring) { + kfree(vq->packed.desc_dma); + vq->packed.desc_dma = NULL; + } else { + kfree(vq->split.desc_dma); + vq->split.desc_dma = NULL; + } + END_USE(vq); return 0; @@ -2854,6 +2926,7 @@ static void vring_free(struct virtqueue *_vq) kfree(vq->packed.desc_state); kfree(vq->packed.desc_extra); + kfree(vq->packed.desc_dma); } else { vring_free_queue(vq->vq.vdev, vq->split.queue_size_in_bytes, @@ -2865,6 +2938,7 @@ static void vring_free(struct virtqueue *_vq) if (!vq->packed_ring) { kfree(vq->split.desc_state); kfree(vq->split.desc_extra); + kfree(vq->split.desc_dma); } } -- 2.32.0.3.g01195cf9f
