To allow a smooth transition from pinning buffer objects to dynamic invalidation we first start to cache the sg_table for an attachment.
Signed-off-by: Christian König christian.koenig@amd.com --- drivers/dma-buf/dma-buf.c | 24 ++++++++++++++++++++++++ include/linux/dma-buf.h | 14 ++++++++++++++ 2 files changed, 38 insertions(+)
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 7c858020d14b..775e13f54083 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -573,6 +573,20 @@ struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, list_add(&attach->node, &dmabuf->attachments);
mutex_unlock(&dmabuf->lock); + + if (!dma_buf_is_dynamic(dmabuf)) { + struct sg_table *sgt; + + sgt = dmabuf->ops->map_dma_buf(attach, DMA_BIDIRECTIONAL); + if (!sgt) + sgt = ERR_PTR(-ENOMEM); + if (IS_ERR(sgt)) { + dma_buf_detach(dmabuf, attach); + return ERR_CAST(sgt); + } + attach->sgt = sgt; + } + return attach;
err_attach: @@ -595,6 +609,10 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) if (WARN_ON(!dmabuf || !attach)) return;
+ if (attach->sgt) + dmabuf->ops->unmap_dma_buf(attach, attach->sgt, + DMA_BIDIRECTIONAL); + mutex_lock(&dmabuf->lock); list_del(&attach->node); if (dmabuf->ops->detach) @@ -630,6 +648,9 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, if (WARN_ON(!attach || !attach->dmabuf)) return ERR_PTR(-EINVAL);
+ if (attach->sgt) + return attach->sgt; + sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); if (!sg_table) sg_table = ERR_PTR(-ENOMEM); @@ -657,6 +678,9 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) return;
+ if (attach->sgt == sg_table) + return; + attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction); } diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 58725f890b5b..52031fdc75bb 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -322,6 +322,7 @@ struct dma_buf_attachment { struct dma_buf *dmabuf; struct device *dev; struct list_head node; + struct sg_table *sgt; void *priv; };
@@ -373,6 +374,19 @@ static inline void get_dma_buf(struct dma_buf *dmabuf) get_file(dmabuf->file); }
+/** + * dma_buf_is_dynamic - check if a DMA-buf uses dynamic mappings. + * @dmabuf: the DMA-buf to check + * + * Returns true if a DMA-buf exporter wants to create dynamic sg table mappings + * for each attachment. False if only a single static sg table should be used. + */ +static inline bool dma_buf_is_dynamic(struct dma_buf *dmabuf) +{ + /* Always use a static mapping for now */ + return false; +} + struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, struct device *dev); void dma_buf_detach(struct dma_buf *dmabuf,