RDMA: Use the sg_table directly and remove the opencoded version from umem

This allows using the normal sg_table APIs and makes all the code
cleaner. Remove sgt, nents and nmapd from ib_umem.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Maor Gottlieb <[e-mail]>
Signed-off-by: Leon Romanovsky <[e-mail]>
Signed-off-by: Jason Gunthorpe <[e-mail]>

drivers/infiniband/core/umem.c

···
 	struct scatterlist *sg;
 	unsigned int i;
 
-	if (umem->nmap > 0)
-		ib_dma_unmap_sg(dev, umem->sg_head.sgl, umem->sg_nents,
-				DMA_BIDIRECTIONAL);
+	if (dirty)
+		ib_dma_unmap_sgtable_attrs(dev, &umem->sgt_append.sgt,
+					   DMA_BIDIRECTIONAL, 0);
 
-	for_each_sg(umem->sg_head.sgl, sg, umem->sg_nents, i)
+	for_each_sgtable_sg(&umem->sgt_append.sgt, sg, i)
 		unpin_user_page_range_dirty_lock(sg_page(sg),
 			DIV_ROUND_UP(sg->length, PAGE_SIZE), make_dirty);
 
···
 	/* offset into first SGL */
 	pgoff = umem->address & ~PAGE_MASK;
 
-	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) {
+	for_each_sgtable_dma_sg(&umem->sgt_append.sgt, sg, i) {
 		/* Walk SGL and reduce max page size if VA/PA bits differ
 		 * for any address.
 		 */
···
 		 * the maximum possible page size as the low bits of the iova
 		 * must be zero when starting the next chunk.
 		 */
-		if (i != (umem->nmap - 1))
+		if (i != (umem->sgt_append.sgt.nents - 1))
 			mask |= va;
 		pgoff = 0;
 	}
···
 			&umem->sgt_append, page_list, pinned, 0,
 			pinned << PAGE_SHIFT, ib_dma_max_seg_size(device),
 			npages, GFP_KERNEL);
-		umem->sg_nents = umem->sgt_append.sgt.nents;
 		if (ret) {
-			memcpy(&umem->sg_head.sgl, &umem->sgt_append.sgt,
-			       sizeof(umem->sgt_append.sgt));
 			unpin_user_pages_dirty_lock(page_list, pinned, 0);
 			goto umem_release;
 		}
 	}
 
-	memcpy(&umem->sg_head.sgl, &umem->sgt_append.sgt,
-	       sizeof(umem->sgt_append.sgt));
 	if (access & IB_ACCESS_RELAXED_ORDERING)
 		dma_attr |= DMA_ATTR_WEAK_ORDERING;
 
-	umem->nmap =
-		ib_dma_map_sg_attrs(device, umem->sg_head.sgl, umem->sg_nents,
-				    DMA_BIDIRECTIONAL, dma_attr);
-
-	if (!umem->nmap) {
-		ret = -ENOMEM;
+	ret = ib_dma_map_sgtable_attrs(device, &umem->sgt_append.sgt,
+				       DMA_BIDIRECTIONAL, dma_attr);
+	if (ret)
 		goto umem_release;
-	}
-
-	ret = 0;
 	goto out;
 
 umem_release:
···
 		return -EINVAL;
 	}
 
-	ret = sg_pcopy_to_buffer(umem->sg_head.sgl, umem->sg_nents, dst, length,
+	ret = sg_pcopy_to_buffer(umem->sgt_append.sgt.sgl,
+				 umem->sgt_append.sgt.orig_nents, dst, length,
 				 offset + ib_umem_offset(umem));
 
 	if (ret < 0)

drivers/infiniband/core/umem_dmabuf.c

···
 		cur += sg_dma_len(sg);
 	}
 
-	umem_dmabuf->umem.sg_head.sgl = umem_dmabuf->first_sg;
-	umem_dmabuf->umem.sg_head.nents = nmap;
-	umem_dmabuf->umem.nmap = nmap;
+	umem_dmabuf->umem.sgt_append.sgt.sgl = umem_dmabuf->first_sg;
+	umem_dmabuf->umem.sgt_append.sgt.nents = nmap;
 	umem_dmabuf->sgt = sgt;
 
 wait_fence:

drivers/infiniband/hw/hns/hns_roce_db.c

···
 
 found:
 	offset = virt - page_addr;
-	db->dma = sg_dma_address(page->umem->sg_head.sgl) + offset;
-	db->virt_addr = sg_virt(page->umem->sg_head.sgl) + offset;
+	db->dma = sg_dma_address(page->umem->sgt_append.sgt.sgl) + offset;
+	db->virt_addr = sg_virt(page->umem->sgt_append.sgt.sgl) + offset;
 	db->u.user_page = page;
 	refcount_inc(&page->refcount);
 

drivers/infiniband/hw/irdma/verbs.c

···
 	pinfo = (level == PBLE_LEVEL_1) ? NULL : palloc->level2.leaf;
 
 	if (iwmr->type == IRDMA_MEMREG_TYPE_QP)
-		iwpbl->qp_mr.sq_page = sg_page(region->sg_head.sgl);
+		iwpbl->qp_mr.sq_page = sg_page(region->sgt_append.sgt.sgl);
 
 	rdma_umem_for_each_dma_block(region, &biter, iwmr->page_size) {
 		*pbl = rdma_block_iter_dma_address(&biter);

drivers/infiniband/hw/mlx4/doorbell.c

···
 	list_add(&page->list, &context->db_page_list);
 
 found:
-	db->dma = sg_dma_address(page->umem->sg_head.sgl) + (virt & ~PAGE_MASK);
+	db->dma = sg_dma_address(page->umem->sgt_append.sgt.sgl) +
+		  (virt & ~PAGE_MASK);
 	db->u.user_page = page;
 	++page->refcnt;
 

drivers/infiniband/hw/mlx4/mr.c

···
 	mtt_shift = mtt->page_shift;
 	mtt_size = 1ULL << mtt_shift;
 
-	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) {
+	for_each_sgtable_dma_sg(&umem->sgt_append.sgt, sg, i) {
 		if (cur_start_addr + len == sg_dma_address(sg)) {
 			/* still the same block */
 			len += sg_dma_len(sg);
···
 
 	*num_of_mtts = ib_umem_num_dma_blocks(umem, PAGE_SIZE);
 
-	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) {
+	for_each_sgtable_dma_sg(&umem->sgt_append.sgt, sg, i) {
 		/*
 		 * Initialization - save the first chunk start as the
 		 * current_block_start - block means contiguous pages.

drivers/infiniband/hw/mlx5/doorbell.c

···
 	list_add(&page->list, &context->db_page_list);
 
 found:
-	db->dma = sg_dma_address(page->umem->sg_head.sgl) + (virt & ~PAGE_MASK);
+	db->dma = sg_dma_address(page->umem->sgt_append.sgt.sgl) +
+		  (virt & ~PAGE_MASK);
 	db->u.user_page = page;
 	++page->refcnt;
 

drivers/infiniband/hw/mlx5/mr.c

···
 	orig_sg_length = sg.length;
 
 	cur_mtt = mtt;
-	rdma_for_each_block (mr->umem->sg_head.sgl, &biter, mr->umem->nmap,
+	rdma_for_each_block (mr->umem->sgt_append.sgt.sgl, &biter,
+			     mr->umem->sgt_append.sgt.nents,
 			     BIT(mr->page_shift)) {
 		if (cur_mtt == (void *)mtt + sg.length) {
 			dma_sync_single_for_device(ddev, sg.addr, sg.length,

drivers/infiniband/hw/qedr/verbs.c

···
 		return PTR_ERR(srq->prod_umem);
 	}
 
-	sg = srq->prod_umem->sg_head.sgl;
+	sg = srq->prod_umem->sgt_append.sgt.sgl;
 	srq->hw_srq.phy_prod_pair_addr = sg_dma_address(sg);
 
 	return 0;

drivers/infiniband/sw/rdmavt/mr.c

···
 	mr->mr.page_shift = PAGE_SHIFT;
 	m = 0;
 	n = 0;
-	for_each_sg_page (umem->sg_head.sgl, &sg_iter, umem->nmap, 0) {
+	for_each_sgtable_page (&umem->sgt_append.sgt, &sg_iter, 0) {
 		void *vaddr;
 
 		vaddr = page_address(sg_page_iter_page(&sg_iter));

drivers/infiniband/sw/rxe/rxe_mr.c

···
 	if (length > 0) {
 		buf = map[0]->buf;
 
-		for_each_sg_page(umem->sg_head.sgl, &sg_iter, umem->nmap, 0) {
+		for_each_sgtable_page (&umem->sgt_append.sgt, &sg_iter, 0) {
 			if (num_buf >= RXE_BUF_PER_MAP) {
 				map++;
 				buf = map[0]->buf;

include/rdma/ib_umem.h

···
 	u32 is_odp : 1;
 	u32 is_dmabuf : 1;
 	struct work_struct	work;
-	struct sg_append_table  sgt_append;
-	struct sg_table sg_head;
-	int             nmap;
-	unsigned int    sg_nents;
+	struct sg_append_table sgt_append;
 };
 
 struct ib_umem_dmabuf {
···
 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);
 }
 
···
 						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);
 }
 
 /**
···
 						    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);

include/rdma/ib_verbs.h

···
 }
 
 /**
+ * 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