IB/mlx5: Add MR cache for large UMR regions

In this change we turn mlx5_ib_update_mtt() into generic
mlx5_ib_update_xlt() to perfrom HCA translation table modifiactions
supporting both atomic and process contexts and not limited by number
of modified entries.
Using this function we increase preallocated MRs up to 16GB.

Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/infiniband/hw/mlx5/main.c

@@ -1112,11 +1112,18 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev,
 	context->ibucontext.invalidate_range = &mlx5_ib_invalidate_range;
 #endif
 
+	context->upd_xlt_page = __get_free_page(GFP_KERNEL);
+	if (!context->upd_xlt_page) {
+		err = -ENOMEM;
+		goto out_uars;
+	}
+	mutex_init(&context->upd_xlt_page_mutex);
+
 	if (MLX5_CAP_GEN(dev->mdev, log_max_transport_domain)) {
 		err = mlx5_core_alloc_transport_domain(dev->mdev,
 						       &context->tdn);
 		if (err)
-			goto out_uars;
+			goto out_page;
 	}
 
 	INIT_LIST_HEAD(&context->vma_private_list);
@@ -1168,6 +1175,9 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev,
 	if (MLX5_CAP_GEN(dev->mdev, log_max_transport_domain))
 		mlx5_core_dealloc_transport_domain(dev->mdev, context->tdn);
 
+out_page:
+	free_page(context->upd_xlt_page);
+
 out_uars:
 	for (i--; i >= 0; i--)
 		mlx5_cmd_free_uar(dev->mdev, uars[i].index);
@@ -1195,6 +1205,8 @@ static int mlx5_ib_dealloc_ucontext(struct ib_ucontext *ibcontext)
 	if (MLX5_CAP_GEN(dev->mdev, log_max_transport_domain))
 		mlx5_core_dealloc_transport_domain(dev->mdev, context->tdn);
 
+	free_page(context->upd_xlt_page);
+
 	for (i = 0; i < uuari->num_uars; i++) {
 		if (mlx5_cmd_free_uar(dev->mdev, uuari->uars[i].index))
 			mlx5_ib_warn(dev, "failed to free UAR 0x%x\n", uuari->uars[i].index);

drivers/infiniband/hw/mlx5/mem.c

@@ -159,7 +159,7 @@ void __mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem,
 	unsigned long umem_page_shift = ilog2(umem->page_size);
 	int shift = page_shift - umem_page_shift;
 	int mask = (1 << shift) - 1;
-	int i, k;
+	int i, k, idx;
 	u64 cur = 0;
 	u64 base;
 	int len;
@@ -185,18 +185,36 @@ void __mlx5_ib_populate_pas(struct mlx5_ib_dev *dev, struct ib_umem *umem,
 	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
 		len = sg_dma_len(sg) >> umem_page_shift;
 		base = sg_dma_address(sg);
-		for (k = 0; k < len; k++) {
+
+		/* Skip elements below offset */
+		if (i + len < offset << shift) {
+			i += len;
+			continue;
+		}
+
+		/* Skip pages below offset */
+		if (i < offset << shift) {
+			k = (offset << shift) - i;
+			i = offset << shift;
+		} else {
+			k = 0;
+		}
+
+		for (; k < len; k++) {
 			if (!(i & mask)) {
 				cur = base + (k << umem_page_shift);
 				cur |= access_flags;
+				idx = (i >> shift) - offset;
 
-				pas[i >> shift] = cpu_to_be64(cur);
+				pas[idx] = cpu_to_be64(cur);
 				mlx5_ib_dbg(dev, "pas[%d] 0x%llx\n",
-					    i >> shift, be64_to_cpu(pas[i >> shift]));
-			}  else
-				mlx5_ib_dbg(dev, "=====> 0x%llx\n",
-					    base + (k << umem_page_shift));
+					    i >> shift, be64_to_cpu(pas[idx]));
+			}
 			i++;
+
+			/* Stop after num_pages reached */
+			if (i >> shift >= offset + num_pages)
+				return;
 		}
 	}
 }

drivers/infiniband/hw/mlx5/mlx5_ib.h

@@ -125,6 +125,10 @@ struct mlx5_ib_ucontext {
 	/* Transport Domain number */
 	u32			tdn;
 	struct list_head	vma_private_list;
+
+	unsigned long		upd_xlt_page;
+	/* protect ODP/KSM */
+	struct mutex		upd_xlt_page_mutex;
 };
 
 static inline struct mlx5_ib_ucontext *to_mucontext(struct ib_ucontext *ibucontext)
@@ -192,6 +196,13 @@ struct mlx5_ib_flow_db {
 #define MLX5_IB_UMR_OCTOWORD	       16
 #define MLX5_IB_UMR_XLT_ALIGNMENT      64
 
+#define MLX5_IB_UPD_XLT_ZAP	      BIT(0)
+#define MLX5_IB_UPD_XLT_ENABLE	      BIT(1)
+#define MLX5_IB_UPD_XLT_ATOMIC	      BIT(2)
+#define MLX5_IB_UPD_XLT_ADDR	      BIT(3)
+#define MLX5_IB_UPD_XLT_PD	      BIT(4)
+#define MLX5_IB_UPD_XLT_ACCESS	      BIT(5)
+
 /* Private QP creation flags to be passed in ib_qp_init_attr.create_flags.
  *
  * These flags are intended for internal use by the mlx5_ib driver, and they
@@ -788,8 +799,8 @@ struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
 struct ib_mw *mlx5_ib_alloc_mw(struct ib_pd *pd, enum ib_mw_type type,
 			       struct ib_udata *udata);
 int mlx5_ib_dealloc_mw(struct ib_mw *mw);
-int mlx5_ib_update_mtt(struct mlx5_ib_mr *mr, u64 start_page_index,
-		       int npages, int zap);
+int mlx5_ib_update_xlt(struct mlx5_ib_mr *mr, u64 idx, int npages,
+		       int page_shift, int flags);
 int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start,
 			  u64 length, u64 virt_addr, int access_flags,
 			  struct ib_pd *pd, struct ib_udata *udata);