forked from Minki/linux
virtio_ring: put split ring functions together
Put the xxx_split() functions together to make the code more readable and avoid misuse after introducing the packed ring. There is no functional change. Signed-off-by: Tiwei Bie <tiwei.bie@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tiwei Bie
David S. Miller
parent
138fd25148
commit
e6f633e5be
@ -113,6 +113,11 @@ struct vring_virtqueue {
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struct vring_desc_state desc_state[];
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};
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/*
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* Helpers.
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*/
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#define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq)
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/*
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@ -200,6 +205,20 @@ static dma_addr_t vring_map_single(const struct vring_virtqueue *vq,
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cpu_addr, size, direction);
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}
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static int vring_mapping_error(const struct vring_virtqueue *vq,
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dma_addr_t addr)
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{
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if (!vring_use_dma_api(vq->vq.vdev))
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return 0;
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return dma_mapping_error(vring_dma_dev(vq), addr);
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}
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/*
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* Split ring specific functions - *_split().
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*/
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static void vring_unmap_one_split(const struct vring_virtqueue *vq,
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struct vring_desc *desc)
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{
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@ -225,15 +244,6 @@ static void vring_unmap_one_split(const struct vring_virtqueue *vq,
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}
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}
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static int vring_mapping_error(const struct vring_virtqueue *vq,
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dma_addr_t addr)
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{
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if (!vring_use_dma_api(vq->vq.vdev))
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return 0;
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return dma_mapping_error(vring_dma_dev(vq), addr);
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}
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static struct vring_desc *alloc_indirect_split(struct virtqueue *_vq,
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unsigned int total_sg,
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gfp_t gfp)
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@ -435,121 +445,6 @@ unmap_release:
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return -EIO;
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}
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static inline int virtqueue_add(struct virtqueue *_vq,
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struct scatterlist *sgs[],
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unsigned int total_sg,
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unsigned int out_sgs,
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unsigned int in_sgs,
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void *data,
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void *ctx,
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gfp_t gfp)
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{
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return virtqueue_add_split(_vq, sgs, total_sg,
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out_sgs, in_sgs, data, ctx, gfp);
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}
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/**
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* virtqueue_add_sgs - expose buffers to other end
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* @vq: the struct virtqueue we're talking about.
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* @sgs: array of terminated scatterlists.
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* @out_num: the number of scatterlists readable by other side
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* @in_num: the number of scatterlists which are writable (after readable ones)
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* @data: the token identifying the buffer.
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* @gfp: how to do memory allocations (if necessary).
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*
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* Caller must ensure we don't call this with other virtqueue operations
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* at the same time (except where noted).
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*
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* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
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*/
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int virtqueue_add_sgs(struct virtqueue *_vq,
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struct scatterlist *sgs[],
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unsigned int out_sgs,
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unsigned int in_sgs,
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void *data,
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gfp_t gfp)
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{
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unsigned int i, total_sg = 0;
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/* Count them first. */
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for (i = 0; i < out_sgs + in_sgs; i++) {
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struct scatterlist *sg;
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for (sg = sgs[i]; sg; sg = sg_next(sg))
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total_sg++;
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}
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return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs,
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data, NULL, gfp);
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}
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EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
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/**
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* virtqueue_add_outbuf - expose output buffers to other end
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* @vq: the struct virtqueue we're talking about.
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* @sg: scatterlist (must be well-formed and terminated!)
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* @num: the number of entries in @sg readable by other side
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* @data: the token identifying the buffer.
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* @gfp: how to do memory allocations (if necessary).
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*
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* Caller must ensure we don't call this with other virtqueue operations
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* at the same time (except where noted).
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*
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* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
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*/
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int virtqueue_add_outbuf(struct virtqueue *vq,
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struct scatterlist *sg, unsigned int num,
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void *data,
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gfp_t gfp)
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{
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return virtqueue_add(vq, &sg, num, 1, 0, data, NULL, gfp);
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}
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EXPORT_SYMBOL_GPL(virtqueue_add_outbuf);
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/**
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* virtqueue_add_inbuf - expose input buffers to other end
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* @vq: the struct virtqueue we're talking about.
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* @sg: scatterlist (must be well-formed and terminated!)
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* @num: the number of entries in @sg writable by other side
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* @data: the token identifying the buffer.
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* @gfp: how to do memory allocations (if necessary).
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*
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* Caller must ensure we don't call this with other virtqueue operations
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* at the same time (except where noted).
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*
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* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
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*/
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int virtqueue_add_inbuf(struct virtqueue *vq,
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struct scatterlist *sg, unsigned int num,
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void *data,
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gfp_t gfp)
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{
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return virtqueue_add(vq, &sg, num, 0, 1, data, NULL, gfp);
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}
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EXPORT_SYMBOL_GPL(virtqueue_add_inbuf);
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/**
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* virtqueue_add_inbuf_ctx - expose input buffers to other end
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* @vq: the struct virtqueue we're talking about.
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* @sg: scatterlist (must be well-formed and terminated!)
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* @num: the number of entries in @sg writable by other side
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* @data: the token identifying the buffer.
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* @ctx: extra context for the token
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* @gfp: how to do memory allocations (if necessary).
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*
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* Caller must ensure we don't call this with other virtqueue operations
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* at the same time (except where noted).
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*
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* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
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*/
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int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
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struct scatterlist *sg, unsigned int num,
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void *data,
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void *ctx,
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gfp_t gfp)
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{
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return virtqueue_add(vq, &sg, num, 0, 1, data, ctx, gfp);
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}
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EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
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static bool virtqueue_kick_prepare_split(struct virtqueue *_vq)
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{
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struct vring_virtqueue *vq = to_vvq(_vq);
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@ -583,67 +478,6 @@ static bool virtqueue_kick_prepare_split(struct virtqueue *_vq)
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return needs_kick;
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}
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/**
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* virtqueue_kick_prepare - first half of split virtqueue_kick call.
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* @vq: the struct virtqueue
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*
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* Instead of virtqueue_kick(), you can do:
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* if (virtqueue_kick_prepare(vq))
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* virtqueue_notify(vq);
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*
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* This is sometimes useful because the virtqueue_kick_prepare() needs
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* to be serialized, but the actual virtqueue_notify() call does not.
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*/
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bool virtqueue_kick_prepare(struct virtqueue *_vq)
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{
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return virtqueue_kick_prepare_split(_vq);
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}
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EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
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/**
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* virtqueue_notify - second half of split virtqueue_kick call.
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* @vq: the struct virtqueue
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*
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* This does not need to be serialized.
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*
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* Returns false if host notify failed or queue is broken, otherwise true.
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*/
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bool virtqueue_notify(struct virtqueue *_vq)
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{
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struct vring_virtqueue *vq = to_vvq(_vq);
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if (unlikely(vq->broken))
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return false;
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/* Prod other side to tell it about changes. */
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if (!vq->notify(_vq)) {
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vq->broken = true;
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return false;
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}
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return true;
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}
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EXPORT_SYMBOL_GPL(virtqueue_notify);
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/**
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* virtqueue_kick - update after add_buf
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* @vq: the struct virtqueue
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*
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* After one or more virtqueue_add_* calls, invoke this to kick
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* the other side.
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*
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* Caller must ensure we don't call this with other virtqueue
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* operations at the same time (except where noted).
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*
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* Returns false if kick failed, otherwise true.
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*/
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bool virtqueue_kick(struct virtqueue *vq)
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{
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if (virtqueue_kick_prepare(vq))
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return virtqueue_notify(vq);
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return true;
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}
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EXPORT_SYMBOL_GPL(virtqueue_kick);
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static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head,
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void **ctx)
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{
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@ -756,35 +590,6 @@ static void *virtqueue_get_buf_ctx_split(struct virtqueue *_vq,
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return ret;
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}
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/**
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* virtqueue_get_buf - get the next used buffer
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* @vq: the struct virtqueue we're talking about.
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* @len: the length written into the buffer
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*
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* If the device wrote data into the buffer, @len will be set to the
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* amount written. This means you don't need to clear the buffer
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* beforehand to ensure there's no data leakage in the case of short
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* writes.
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*
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* Caller must ensure we don't call this with other virtqueue
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* operations at the same time (except where noted).
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*
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* Returns NULL if there are no used buffers, or the "data" token
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* handed to virtqueue_add_*().
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*/
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void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
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void **ctx)
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{
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return virtqueue_get_buf_ctx_split(_vq, len, ctx);
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}
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EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);
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void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
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{
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return virtqueue_get_buf_ctx(_vq, len, NULL);
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}
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EXPORT_SYMBOL_GPL(virtqueue_get_buf);
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static void virtqueue_disable_cb_split(struct virtqueue *_vq)
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{
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struct vring_virtqueue *vq = to_vvq(_vq);
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@ -796,21 +601,6 @@ static void virtqueue_disable_cb_split(struct virtqueue *_vq)
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}
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}
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/**
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* virtqueue_disable_cb - disable callbacks
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* @vq: the struct virtqueue we're talking about.
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*
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* Note that this is not necessarily synchronous, hence unreliable and only
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* useful as an optimization.
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*
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* Unlike other operations, this need not be serialized.
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*/
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void virtqueue_disable_cb(struct virtqueue *_vq)
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{
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virtqueue_disable_cb_split(_vq);
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}
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EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
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static unsigned virtqueue_enable_cb_prepare_split(struct virtqueue *_vq)
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{
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struct vring_virtqueue *vq = to_vvq(_vq);
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@ -833,24 +623,6 @@ static unsigned virtqueue_enable_cb_prepare_split(struct virtqueue *_vq)
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return last_used_idx;
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}
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/**
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* virtqueue_enable_cb_prepare - restart callbacks after disable_cb
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* @vq: the struct virtqueue we're talking about.
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*
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* This re-enables callbacks; it returns current queue state
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* in an opaque unsigned value. This value should be later tested by
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* virtqueue_poll, to detect a possible race between the driver checking for
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* more work, and enabling callbacks.
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*
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* Caller must ensure we don't call this with other virtqueue
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* operations at the same time (except where noted).
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*/
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unsigned virtqueue_enable_cb_prepare(struct virtqueue *_vq)
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{
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return virtqueue_enable_cb_prepare_split(_vq);
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}
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EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
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static bool virtqueue_poll_split(struct virtqueue *_vq, unsigned last_used_idx)
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{
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struct vring_virtqueue *vq = to_vvq(_vq);
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@ -859,42 +631,6 @@ static bool virtqueue_poll_split(struct virtqueue *_vq, unsigned last_used_idx)
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vq->vring.used->idx);
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}
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/**
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* virtqueue_poll - query pending used buffers
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* @vq: the struct virtqueue we're talking about.
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* @last_used_idx: virtqueue state (from call to virtqueue_enable_cb_prepare).
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*
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* Returns "true" if there are pending used buffers in the queue.
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*
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* This does not need to be serialized.
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*/
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bool virtqueue_poll(struct virtqueue *_vq, unsigned last_used_idx)
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{
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struct vring_virtqueue *vq = to_vvq(_vq);
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virtio_mb(vq->weak_barriers);
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return virtqueue_poll_split(_vq, last_used_idx);
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}
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EXPORT_SYMBOL_GPL(virtqueue_poll);
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/**
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* virtqueue_enable_cb - restart callbacks after disable_cb.
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* @vq: the struct virtqueue we're talking about.
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*
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* This re-enables callbacks; it returns "false" if there are pending
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* buffers in the queue, to detect a possible race between the driver
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* checking for more work, and enabling callbacks.
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*
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* Caller must ensure we don't call this with other virtqueue
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* operations at the same time (except where noted).
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*/
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bool virtqueue_enable_cb(struct virtqueue *_vq)
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{
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unsigned last_used_idx = virtqueue_enable_cb_prepare(_vq);
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return !virtqueue_poll(_vq, last_used_idx);
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}
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EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
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static bool virtqueue_enable_cb_delayed_split(struct virtqueue *_vq)
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{
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struct vring_virtqueue *vq = to_vvq(_vq);
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@ -928,25 +664,6 @@ static bool virtqueue_enable_cb_delayed_split(struct virtqueue *_vq)
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return true;
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}
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/**
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* virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
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* @vq: the struct virtqueue we're talking about.
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*
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* This re-enables callbacks but hints to the other side to delay
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* interrupts until most of the available buffers have been processed;
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* it returns "false" if there are many pending buffers in the queue,
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* to detect a possible race between the driver checking for more work,
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* and enabling callbacks.
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*
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* Caller must ensure we don't call this with other virtqueue
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* operations at the same time (except where noted).
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*/
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bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
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{
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return virtqueue_enable_cb_delayed_split(_vq);
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}
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EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
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static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq)
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{
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struct vring_virtqueue *vq = to_vvq(_vq);
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@ -973,6 +690,306 @@ static void *virtqueue_detach_unused_buf_split(struct virtqueue *_vq)
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return NULL;
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}
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/*
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* Generic functions and exported symbols.
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*/
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static inline int virtqueue_add(struct virtqueue *_vq,
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struct scatterlist *sgs[],
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unsigned int total_sg,
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unsigned int out_sgs,
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unsigned int in_sgs,
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void *data,
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void *ctx,
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gfp_t gfp)
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{
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return virtqueue_add_split(_vq, sgs, total_sg,
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out_sgs, in_sgs, data, ctx, gfp);
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}
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/**
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* virtqueue_add_sgs - expose buffers to other end
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* @vq: the struct virtqueue we're talking about.
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* @sgs: array of terminated scatterlists.
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* @out_num: the number of scatterlists readable by other side
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* @in_num: the number of scatterlists which are writable (after readable ones)
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* @data: the token identifying the buffer.
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* @gfp: how to do memory allocations (if necessary).
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*
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* Caller must ensure we don't call this with other virtqueue operations
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* at the same time (except where noted).
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*
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* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
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*/
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int virtqueue_add_sgs(struct virtqueue *_vq,
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struct scatterlist *sgs[],
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unsigned int out_sgs,
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unsigned int in_sgs,
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void *data,
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gfp_t gfp)
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{
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unsigned int i, total_sg = 0;
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/* Count them first. */
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for (i = 0; i < out_sgs + in_sgs; i++) {
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struct scatterlist *sg;
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for (sg = sgs[i]; sg; sg = sg_next(sg))
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total_sg++;
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}
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return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs,
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data, NULL, gfp);
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}
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EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
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/**
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* virtqueue_add_outbuf - expose output buffers to other end
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* @vq: the struct virtqueue we're talking about.
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* @sg: scatterlist (must be well-formed and terminated!)
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* @num: the number of entries in @sg readable by other side
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* @data: the token identifying the buffer.
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* @gfp: how to do memory allocations (if necessary).
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*
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* Caller must ensure we don't call this with other virtqueue operations
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* at the same time (except where noted).
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*
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* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
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*/
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int virtqueue_add_outbuf(struct virtqueue *vq,
|
||||
struct scatterlist *sg, unsigned int num,
|
||||
void *data,
|
||||
gfp_t gfp)
|
||||
{
|
||||
return virtqueue_add(vq, &sg, num, 1, 0, data, NULL, gfp);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(virtqueue_add_outbuf);
|
||||
|
||||
/**
|
||||
* virtqueue_add_inbuf - 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.
|
||||
* @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(struct virtqueue *vq,
|
||||
struct scatterlist *sg, unsigned int num,
|
||||
void *data,
|
||||
gfp_t 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
|
||||
*
|
||||
* Instead of virtqueue_kick(), you can do:
|
||||
* if (virtqueue_kick_prepare(vq))
|
||||
* virtqueue_notify(vq);
|
||||
*
|
||||
* This is sometimes useful because the virtqueue_kick_prepare() needs
|
||||
* to be serialized, but the actual virtqueue_notify() call does not.
|
||||
*/
|
||||
bool virtqueue_kick_prepare(struct virtqueue *_vq)
|
||||
{
|
||||
return virtqueue_kick_prepare_split(_vq);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
|
||||
|
||||
/**
|
||||
* virtqueue_notify - second half of split virtqueue_kick call.
|
||||
* @vq: the struct virtqueue
|
||||
*
|
||||
* This does not need to be serialized.
|
||||
*
|
||||
* Returns false if host notify failed or queue is broken, otherwise true.
|
||||
*/
|
||||
bool virtqueue_notify(struct virtqueue *_vq)
|
||||
{
|
||||
struct vring_virtqueue *vq = to_vvq(_vq);
|
||||
|
||||
if (unlikely(vq->broken))
|
||||
return false;
|
||||
|
||||
/* Prod other side to tell it about changes. */
|
||||
if (!vq->notify(_vq)) {
|
||||
vq->broken = true;
|
||||
return false;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(virtqueue_notify);
|
||||
|
||||
/**
|
||||
* virtqueue_kick - update after add_buf
|
||||
* @vq: the struct virtqueue
|
||||
*
|
||||
* After one or more virtqueue_add_* calls, invoke this to kick
|
||||
* the other side.
|
||||
*
|
||||
* Caller must ensure we don't call this with other virtqueue
|
||||
* operations at the same time (except where noted).
|
||||
*
|
||||
* Returns false if kick failed, otherwise true.
|
||||
*/
|
||||
bool virtqueue_kick(struct virtqueue *vq)
|
||||
{
|
||||
if (virtqueue_kick_prepare(vq))
|
||||
return virtqueue_notify(vq);
|
||||
return true;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(virtqueue_kick);
|
||||
|
||||
/**
|
||||
* virtqueue_get_buf - get the next used buffer
|
||||
* @vq: the struct virtqueue we're talking about.
|
||||
* @len: the length written into the buffer
|
||||
*
|
||||
* If the device wrote data into the buffer, @len will be set to the
|
||||
* amount written. This means you don't need to clear the buffer
|
||||
* beforehand to ensure there's no data leakage in the case of short
|
||||
* writes.
|
||||
*
|
||||
* Caller must ensure we don't call this with other virtqueue
|
||||
* operations at the same time (except where noted).
|
||||
*
|
||||
* Returns NULL if there are no used buffers, or the "data" token
|
||||
* handed to virtqueue_add_*().
|
||||
*/
|
||||
void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
|
||||
void **ctx)
|
||||
{
|
||||
return virtqueue_get_buf_ctx_split(_vq, len, ctx);
|
||||
}
|
||||
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.
|
||||
*
|
||||
* Note that this is not necessarily synchronous, hence unreliable and only
|
||||
* useful as an optimization.
|
||||
*
|
||||
* Unlike other operations, this need not be serialized.
|
||||
*/
|
||||
void virtqueue_disable_cb(struct virtqueue *_vq)
|
||||
{
|
||||
virtqueue_disable_cb_split(_vq);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
|
||||
|
||||
/**
|
||||
* virtqueue_enable_cb_prepare - restart callbacks after disable_cb
|
||||
* @vq: the struct virtqueue we're talking about.
|
||||
*
|
||||
* This re-enables callbacks; it returns current queue state
|
||||
* in an opaque unsigned value. This value should be later tested by
|
||||
* virtqueue_poll, to detect a possible race between the driver checking for
|
||||
* more work, and enabling callbacks.
|
||||
*
|
||||
* Caller must ensure we don't call this with other virtqueue
|
||||
* operations at the same time (except where noted).
|
||||
*/
|
||||
unsigned virtqueue_enable_cb_prepare(struct virtqueue *_vq)
|
||||
{
|
||||
return virtqueue_enable_cb_prepare_split(_vq);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
|
||||
|
||||
/**
|
||||
* virtqueue_poll - query pending used buffers
|
||||
* @vq: the struct virtqueue we're talking about.
|
||||
* @last_used_idx: virtqueue state (from call to virtqueue_enable_cb_prepare).
|
||||
*
|
||||
* Returns "true" if there are pending used buffers in the queue.
|
||||
*
|
||||
* This does not need to be serialized.
|
||||
*/
|
||||
bool virtqueue_poll(struct virtqueue *_vq, unsigned last_used_idx)
|
||||
{
|
||||
struct vring_virtqueue *vq = to_vvq(_vq);
|
||||
|
||||
virtio_mb(vq->weak_barriers);
|
||||
return virtqueue_poll_split(_vq, last_used_idx);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(virtqueue_poll);
|
||||
|
||||
/**
|
||||
* virtqueue_enable_cb - restart callbacks after disable_cb.
|
||||
* @vq: the struct virtqueue we're talking about.
|
||||
*
|
||||
* This re-enables callbacks; it returns "false" if there are pending
|
||||
* buffers in the queue, to detect a possible race between the driver
|
||||
* checking for more work, and enabling callbacks.
|
||||
*
|
||||
* Caller must ensure we don't call this with other virtqueue
|
||||
* operations at the same time (except where noted).
|
||||
*/
|
||||
bool virtqueue_enable_cb(struct virtqueue *_vq)
|
||||
{
|
||||
unsigned last_used_idx = virtqueue_enable_cb_prepare(_vq);
|
||||
|
||||
return !virtqueue_poll(_vq, last_used_idx);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
|
||||
|
||||
/**
|
||||
* virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
|
||||
* @vq: the struct virtqueue we're talking about.
|
||||
*
|
||||
* This re-enables callbacks but hints to the other side to delay
|
||||
* interrupts until most of the available buffers have been processed;
|
||||
* it returns "false" if there are many pending buffers in the queue,
|
||||
* to detect a possible race between the driver checking for more work,
|
||||
* and enabling callbacks.
|
||||
*
|
||||
* Caller must ensure we don't call this with other virtqueue
|
||||
* operations at the same time (except where noted).
|
||||
*/
|
||||
bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
|
||||
{
|
||||
return virtqueue_enable_cb_delayed_split(_vq);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
|
||||
|
||||
/**
|
||||
* virtqueue_detach_unused_buf - detach first unused buffer
|
||||
* @vq: the struct virtqueue we're talking about.
|
||||
|
||||
Loading…
Reference in New Issue
Block a user