IB/mlx4: Support the new memory registration API

Support the new memory registration API by allocating a
private page list array in mlx4_ib_mr and populate it when
mlx4_ib_map_mr_sg is invoked. Also, support IB_WR_REG_MR
by setting the exact WQE as IB_WR_FAST_REG_MR, just take the
needed information from different places:
- page_size, iova, length, access flags (ib_mr)
- page array (mlx4_ib_mr)
- key (ib_reg_wr)

The IB_WR_FAST_REG_MR handlers will be removed later when
all the ULPs will be converted.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx4/mr.c

@@ -59,7 +59,7 @@ struct ib_mr *mlx4_ib_get_dma_mr(struct ib_pd *pd, int acc)
 	struct mlx4_ib_mr *mr;
 	int err;
 
-	mr = kmalloc(sizeof *mr, GFP_KERNEL);
+	mr = kzalloc(sizeof(*mr), GFP_KERNEL);
 	if (!mr)
 		return ERR_PTR(-ENOMEM);
 
@@ -140,7 +140,7 @@ struct ib_mr *mlx4_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
 	int err;
 	int n;
 
-	mr = kmalloc(sizeof *mr, GFP_KERNEL);
+	mr = kzalloc(sizeof(*mr), GFP_KERNEL);
 	if (!mr)
 		return ERR_PTR(-ENOMEM);
 
@@ -271,11 +271,59 @@ release_mpt_entry:
 	return err;
 }
 
+static int
+mlx4_alloc_priv_pages(struct ib_device *device,
+		      struct mlx4_ib_mr *mr,
+		      int max_pages)
+{
+	int size = max_pages * sizeof(u64);
+	int add_size;
+	int ret;
+
+	add_size = max_t(int, MLX4_MR_PAGES_ALIGN - ARCH_KMALLOC_MINALIGN, 0);
+
+	mr->pages_alloc = kzalloc(size + add_size, GFP_KERNEL);
+	if (!mr->pages_alloc)
+		return -ENOMEM;
+
+	mr->pages = PTR_ALIGN(mr->pages_alloc, MLX4_MR_PAGES_ALIGN);
+
+	mr->page_map = dma_map_single(device->dma_device, mr->pages,
+				      size, DMA_TO_DEVICE);
+
+	if (dma_mapping_error(device->dma_device, mr->page_map)) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	return 0;
+err:
+	kfree(mr->pages_alloc);
+
+	return ret;
+}
+
+static void
+mlx4_free_priv_pages(struct mlx4_ib_mr *mr)
+{
+	if (mr->pages) {
+		struct ib_device *device = mr->ibmr.device;
+		int size = mr->max_pages * sizeof(u64);
+
+		dma_unmap_single(device->dma_device, mr->page_map,
+				 size, DMA_TO_DEVICE);
+		kfree(mr->pages_alloc);
+		mr->pages = NULL;
+	}
+}
+
 int mlx4_ib_dereg_mr(struct ib_mr *ibmr)
 {
 	struct mlx4_ib_mr *mr = to_mmr(ibmr);
 	int ret;
 
+	mlx4_free_priv_pages(mr);
+
 	ret = mlx4_mr_free(to_mdev(ibmr->device)->dev, &mr->mmr);
 	if (ret)
 		return ret;
@@ -362,7 +410,7 @@ struct ib_mr *mlx4_ib_alloc_mr(struct ib_pd *pd,
 	    max_num_sg > MLX4_MAX_FAST_REG_PAGES)
 		return ERR_PTR(-EINVAL);
 
-	mr = kmalloc(sizeof *mr, GFP_KERNEL);
+	mr = kzalloc(sizeof(*mr), GFP_KERNEL);
 	if (!mr)
 		return ERR_PTR(-ENOMEM);
 
@@ -371,18 +419,25 @@ struct ib_mr *mlx4_ib_alloc_mr(struct ib_pd *pd,
 	if (err)
 		goto err_free;
 
+	err = mlx4_alloc_priv_pages(pd->device, mr, max_num_sg);
+	if (err)
+		goto err_free_mr;
+
+	mr->max_pages = max_num_sg;
+
 	err = mlx4_mr_enable(dev->dev, &mr->mmr);
 	if (err)
-		goto err_mr;
+		goto err_free_pl;
 
 	mr->ibmr.rkey = mr->ibmr.lkey = mr->mmr.key;
 	mr->umem = NULL;
 
 	return &mr->ibmr;
 
-err_mr:
+err_free_pl:
+	mlx4_free_priv_pages(mr);
+err_free_mr:
 	(void) mlx4_mr_free(dev->dev, &mr->mmr);
-
 err_free:
 	kfree(mr);
 	return ERR_PTR(err);
@@ -528,3 +583,37 @@ int mlx4_ib_fmr_dealloc(struct ib_fmr *ibfmr)
 
 	return err;
 }
+
+static int mlx4_set_page(struct ib_mr *ibmr, u64 addr)
+{
+	struct mlx4_ib_mr *mr = to_mmr(ibmr);
+
+	if (unlikely(mr->npages == mr->max_pages))
+		return -ENOMEM;
+
+	mr->pages[mr->npages++] = cpu_to_be64(addr | MLX4_MTT_FLAG_PRESENT);
+
+	return 0;
+}
+
+int mlx4_ib_map_mr_sg(struct ib_mr *ibmr,
+		      struct scatterlist *sg,
+		      int sg_nents)
+{
+	struct mlx4_ib_mr *mr = to_mmr(ibmr);
+	int rc;
+
+	mr->npages = 0;
+
+	ib_dma_sync_single_for_cpu(ibmr->device, mr->page_map,
+				   sizeof(u64) * mr->max_pages,
+				   DMA_TO_DEVICE);
+
+	rc = ib_sg_to_pages(ibmr, sg, sg_nents, mlx4_set_page);
+
+	ib_dma_sync_single_for_device(ibmr->device, mr->page_map,
+				      sizeof(u64) * mr->max_pages,
+				      DMA_TO_DEVICE);
+
+	return rc;
+}