RDMA/umem: Use consistent DMA attributes when unmapping entries

The DMA API expects that mapping and unmapping use the same DMA
attributes. The RDMA umem code did not meet this requirement, so fix
the mismatch.

Fixes: f03d9fa ("RDMA/core: Add weak ordering dma attr to dma mapping")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>

Author: rleon

drivers/infiniband/core/umem.c

@@ -55,8 +55,7 @@ static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int d
 
 	if (dirty)
 		ib_dma_unmap_sgtable_attrs(dev, &umem->sgt_append.sgt,
-					   DMA_BIDIRECTIONAL,
-					   DMA_ATTR_REQUIRE_COHERENT);
+					   DMA_BIDIRECTIONAL, umem->dma_attrs);
 
 	for_each_sgtable_sg(&umem->sgt_append.sgt, sg, i) {
 		unpin_user_page_range_dirty_lock(sg_page(sg),
@@ -170,7 +169,6 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
 	unsigned long lock_limit;
 	unsigned long new_pinned;
 	unsigned long cur_base;
-	unsigned long dma_attr = DMA_ATTR_REQUIRE_COHERENT;
 	struct mm_struct *mm;
 	unsigned long npages;
 	int pinned, ret;
@@ -203,6 +201,10 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
 	umem->iova = addr;
 	umem->writable   = ib_access_writable(access);
 	umem->owning_mm = mm = current->mm;
+	umem->dma_attrs = DMA_ATTR_REQUIRE_COHERENT;
+	if (access & IB_ACCESS_RELAXED_ORDERING)
+		umem->dma_attrs |= DMA_ATTR_WEAK_ORDERING;
+
 	mmgrab(mm);
 
 	page_list = (struct page **) __get_free_page(GFP_KERNEL);
@@ -255,11 +257,8 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
 		}
 	}
 
-	if (access & IB_ACCESS_RELAXED_ORDERING)
-		dma_attr |= DMA_ATTR_WEAK_ORDERING;
-
 	ret = ib_dma_map_sgtable_attrs(device, &umem->sgt_append.sgt,
-				       DMA_BIDIRECTIONAL, dma_attr);
+				       DMA_BIDIRECTIONAL, umem->dma_attrs);
 	if (ret)
 		goto umem_release;
 	goto out;

include/rdma/ib_umem.h

@@ -18,6 +18,7 @@ struct ib_umem {
 	u64 iova;
 	size_t			length;
 	unsigned long		address;
+	unsigned long		dma_attrs;
 	u32 writable : 1;
 	u32 is_odp : 1;
 	u32 is_dmabuf : 1;