Merge branch 'sg_nents' into rdma.git for-next

From Maor Gottlieb
====================

Fix the use of nents and orig_nents in the sg table append helpers. The
nents should be used by the DMA layer to store the number of DMA mapped
sges, the orig_nents is the number of CPU sges.

Since the sg append logic doesn't always create a SGL with exactly
orig_nents entries store a total_nents as well to allow the table to be
properly free'd and reorganize the freeing logic to share across all the
use cases.

====================

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

* 'sg_nents':
  RDMA: Use the sg_table directly and remove the opencoded version from umem
  lib/scatterlist: Fix wrong update of orig_nents
  lib/scatterlist: Provide a dedicated function to support table append

2 files changed, 33 insertions, 6 deletions

diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h
index 676c57f5ca80..5ae9dff74dac 100644
--- a/include/rdma/ib_umem.h
+++ b/include/rdma/ib_umem.h
@@ -26,9 +26,7 @@ struct ib_umem {
 	u32 is_odp : 1;
 	u32 is_dmabuf : 1;
 	struct work_struct	work;
-	struct sg_table sg_head;
-	int             nmap;
-	unsigned int    sg_nents;
+	struct sg_append_table sgt_append;
 };
 
 struct ib_umem_dmabuf {
@@ -56,7 +54,7 @@ static inline int ib_umem_offset(struct ib_umem *umem)
 static inline unsigned long ib_umem_dma_offset(struct ib_umem *umem,
 					       unsigned long pgsz)
 {
-	return (sg_dma_address(umem->sg_head.sgl) + ib_umem_offset(umem)) &
+	return (sg_dma_address(umem->sgt_append.sgt.sgl) + ib_umem_offset(umem)) &
 	       (pgsz - 1);
 }
 
@@ -77,7 +75,8 @@ static inline void __rdma_umem_block_iter_start(struct ib_block_iter *biter,
 						struct ib_umem *umem,
 						unsigned long pgsz)
 {
-	__rdma_block_iter_start(biter, umem->sg_head.sgl, umem->nmap, pgsz);
+	__rdma_block_iter_start(biter, umem->sgt_append.sgt.sgl,
+				umem->sgt_append.sgt.nents, pgsz);
 }
 
 /**
@@ -128,7 +127,7 @@ static inline unsigned long ib_umem_find_best_pgoff(struct ib_umem *umem,
 						    unsigned long pgsz_bitmap,
 						    u64 pgoff_bitmask)
 {
-	struct scatterlist *sg = umem->sg_head.sgl;
+	struct scatterlist *sg = umem->sgt_append.sgt.sgl;
 	dma_addr_t dma_addr;
 
 	dma_addr = sg_dma_address(sg) + (umem->address & ~PAGE_MASK);
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index aa7806335cba..4b50d9a3018a 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -4086,6 +4086,34 @@ static inline void ib_dma_unmap_sg_attrs(struct ib_device *dev,
 }
 
 /**
+ * ib_dma_map_sgtable_attrs - Map a scatter/gather table to DMA addresses
+ * @dev: The device for which the DMA addresses are to be created
+ * @sg: The sg_table object describing the buffer
+ * @direction: The direction of the DMA
+ * @attrs: Optional DMA attributes for the map operation
+ */
+static inline int ib_dma_map_sgtable_attrs(struct ib_device *dev,
+					   struct sg_table *sgt,
+					   enum dma_data_direction direction,
+					   unsigned long dma_attrs)
+{
+	if (ib_uses_virt_dma(dev)) {
+		ib_dma_virt_map_sg(dev, sgt->sgl, sgt->orig_nents);
+		return 0;
+	}
+	return dma_map_sgtable(dev->dma_device, sgt, direction, dma_attrs);
+}
+
+static inline void ib_dma_unmap_sgtable_attrs(struct ib_device *dev,
+					      struct sg_table *sgt,
+					      enum dma_data_direction direction,
+					      unsigned long dma_attrs)
+{
+	if (!ib_uses_virt_dma(dev))
+		dma_unmap_sgtable(dev->dma_device, sgt, direction, dma_attrs);
+}
+
+/**
  * ib_dma_map_sg - Map a scatter/gather list to DMA addresses
  * @dev: The device for which the DMA addresses are to be created
  * @sg: The array of scatter/gather entries