Merge tag 'rds-odp-for-5.5' of https://git.kernel.org/pub/scm/linux/kernel/git/leon/linux-rdma

Leon Romanovsky says:

====================
Use ODP MRs for kernel ULPs

The following series extends MR creation routines to allow creation of
user MRs through kernel ULPs as a proxy. The immediate use case is to
allow RDS to work over FS-DAX, which requires ODP (on-demand-paging)
MRs to be created and such MRs were not possible to create prior this
series.

The first part of this patchset extends RDMA to have special verb
ib_reg_user_mr(). The common use case that uses this function is a
userspace application that allocates memory for HCA access but the
responsibility to register the memory at the HCA is on an kernel ULP.
This ULP acts as an agent for the userspace application.

The second part provides advise MR functionality for ULPs. This is
integral part of ODP flows and used to trigger pagefaults in advance
to prepare memory before running working set.

The third part is actual user of those in-kernel APIs.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 10 deletions

diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index ea8bfc3e2d8d..44a0ee6bd9f1 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -737,10 +737,9 @@ static int mr_cache_max_order(struct mlx5_ib_dev *dev)
 	return MLX5_MAX_UMR_SHIFT;
 }
 
-static int mr_umem_get(struct mlx5_ib_dev *dev, struct ib_udata *udata,
-		       u64 start, u64 length, int access_flags,
-		       struct ib_umem **umem, int *npages, int *page_shift,
-		       int *ncont, int *order)
+static int mr_umem_get(struct mlx5_ib_dev *dev, u64 start, u64 length,
+		       int access_flags, struct ib_umem **umem, int *npages,
+		       int *page_shift, int *ncont, int *order)
 {
 	struct ib_umem *u;
 
@@ -749,7 +748,7 @@ static int mr_umem_get(struct mlx5_ib_dev *dev, struct ib_udata *udata,
 	if (access_flags & IB_ACCESS_ON_DEMAND) {
 		struct ib_umem_odp *odp;
 
-		odp = ib_umem_odp_get(udata, start, length, access_flags,
+		odp = ib_umem_odp_get(&dev->ib_dev, start, length, access_flags,
 				      &mlx5_mn_ops);
 		if (IS_ERR(odp)) {
 			mlx5_ib_dbg(dev, "umem get failed (%ld)\n",
@@ -765,7 +764,7 @@ static int mr_umem_get(struct mlx5_ib_dev *dev, struct ib_udata *udata,
 		if (order)
 			*order = ilog2(roundup_pow_of_two(*ncont));
 	} else {
-		u = ib_umem_get(udata, start, length, access_flags);
+		u = ib_umem_get(&dev->ib_dev, start, length, access_flags);
 		if (IS_ERR(u)) {
 			mlx5_ib_dbg(dev, "umem get failed (%ld)\n", PTR_ERR(u));
 			return PTR_ERR(u);
@@ -1247,6 +1246,8 @@ struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
 
 	if (IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING) && !start &&
 	    length == U64_MAX) {
+		if (virt_addr != start)
+			return ERR_PTR(-EINVAL);
 		if (!(access_flags & IB_ACCESS_ON_DEMAND) ||
 		    !(dev->odp_caps.general_caps & IB_ODP_SUPPORT_IMPLICIT))
 			return ERR_PTR(-EINVAL);
@@ -1257,7 +1258,7 @@ struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
 		return &mr->ibmr;
 	}
 
-	err = mr_umem_get(dev, udata, start, length, access_flags, &umem,
+	err = mr_umem_get(dev, start, length, access_flags, &umem,
 			  &npages, &page_shift, &ncont, &order);
 
 	if (err < 0)
@@ -1424,9 +1425,8 @@ int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start,
 		flags |= IB_MR_REREG_TRANS;
 		ib_umem_release(mr->umem);
 		mr->umem = NULL;
-		err = mr_umem_get(dev, udata, addr, len, access_flags,
-				  &mr->umem, &npages, &page_shift, &ncont,
-				  &order);
+		err = mr_umem_get(dev, addr, len, access_flags, &mr->umem,
+				  &npages, &page_shift, &ncont, &order);
 		if (err)
 			goto err;
 	}