diff options
| -rw-r--r-- | Documentation/DMA-attributes.txt | 18 | ||||
| -rw-r--r-- | drivers/infiniband/core/umem.c | 9 | ||||
| -rw-r--r-- | include/linux/dma-mapping.h | 5 |
3 files changed, 3 insertions, 29 deletions
diff --git a/Documentation/DMA-attributes.txt b/Documentation/DMA-attributes.txt index 8f8d97f65d73..29dcbe8826e8 100644 --- a/Documentation/DMA-attributes.txt +++ b/Documentation/DMA-attributes.txt @@ -5,24 +5,6 @@ DMA attributes This document describes the semantics of the DMA attributes that are defined in linux/dma-mapping.h. -DMA_ATTR_WRITE_BARRIER ----------------------- - -DMA_ATTR_WRITE_BARRIER is a (write) barrier attribute for DMA. DMA -to a memory region with the DMA_ATTR_WRITE_BARRIER attribute forces -all pending DMA writes to complete, and thus provides a mechanism to -strictly order DMA from a device across all intervening busses and -bridges. This barrier is not specific to a particular type of -interconnect, it applies to the system as a whole, and so its -implementation must account for the idiosyncrasies of the system all -the way from the DMA device to memory. - -As an example of a situation where DMA_ATTR_WRITE_BARRIER would be -useful, suppose that a device does a DMA write to indicate that data is -ready and available in memory. The DMA of the "completion indication" -could race with data DMA. Mapping the memory used for completion -indications with DMA_ATTR_WRITE_BARRIER would prevent the race. - DMA_ATTR_WEAK_ORDERING ---------------------- diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 24244a2f68cc..66148739b00f 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -199,7 +199,6 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr, struct mm_struct *mm; unsigned long npages; int ret; - unsigned long dma_attrs = 0; struct scatterlist *sg; unsigned int gup_flags = FOLL_WRITE; @@ -211,9 +210,6 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr, if (!context) return ERR_PTR(-EIO); - if (dmasync) - dma_attrs |= DMA_ATTR_WRITE_BARRIER; - /* * If the combination of the addr and size requested for this memory * region causes an integer overflow, return error. @@ -294,11 +290,10 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr, sg_mark_end(sg); - umem->nmap = ib_dma_map_sg_attrs(context->device, + umem->nmap = ib_dma_map_sg(context->device, umem->sg_head.sgl, umem->sg_nents, - DMA_BIDIRECTIONAL, - dma_attrs); + DMA_BIDIRECTIONAL); if (!umem->nmap) { ret = -ENOMEM; diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 4a1c4fca475a..8023071d6903 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -15,11 +15,8 @@ /** * List of possible attributes associated with a DMA mapping. The semantics * of each attribute should be defined in Documentation/DMA-attributes.txt. - * - * DMA_ATTR_WRITE_BARRIER: DMA to a memory region with this attribute - * forces all pending DMA writes to complete. */ -#define DMA_ATTR_WRITE_BARRIER (1UL << 0) + /* * DMA_ATTR_WEAK_ORDERING: Specifies that reads and writes to the mapping * may be weakly ordered, that is that reads and writes may pass each other. |