[PATCH 1/2][jammy linux-azure] RDMA/mlx5: Reorder calls to pcie_relaxed_ordering_enabled()

Tim Gardner tim.gardner at canonical.com
Thu Oct 12 17:14:49 UTC 2023


From: Aharon Landau <aharonl at nvidia.com>

BugLink: https://bugs.launchpad.net/bugs/2039208

The mkc is the key for the mkey cache, hence, created in each attempt to
get a cache mkey, while pcie_relaxed_ordering_enabled() is called during
the setting of the mkc, but used only for cases where
IB_ACCESS_RELAXED_ORDERING is set.

pcie_relaxed_ordering_enabled() is an expensive call (26 us). Reorder the
code so the driver will call it only when it is needed.

Link: https://lore.kernel.org/r/684be1366cb1d4f05aa3e78986205e4bc410443a.1644947594.git.leonro@nvidia.com
Signed-off-by: Aharon Landau <aharonl at nvidia.com>
Signed-off-by: Leon Romanovsky <leonro at nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
(cherry picked from commit 77528e2aed9246cf8017b8a6f1b658a264d6f2b2)
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
---
 drivers/infiniband/hw/mlx5/mr.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index b938093ffa3f..a2b93f19d9fe 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -69,7 +69,6 @@ static void set_mkc_access_pd_addr_fields(void *mkc, int acc, u64 start_addr,
 					  struct ib_pd *pd)
 {
 	struct mlx5_ib_dev *dev = to_mdev(pd->device);
-	bool ro_pci_enabled = pcie_relaxed_ordering_enabled(dev->mdev->pdev);
 
 	MLX5_SET(mkc, mkc, a, !!(acc & IB_ACCESS_REMOTE_ATOMIC));
 	MLX5_SET(mkc, mkc, rw, !!(acc & IB_ACCESS_REMOTE_WRITE));
@@ -77,12 +76,13 @@ static void set_mkc_access_pd_addr_fields(void *mkc, int acc, u64 start_addr,
 	MLX5_SET(mkc, mkc, lw, !!(acc & IB_ACCESS_LOCAL_WRITE));
 	MLX5_SET(mkc, mkc, lr, 1);
 
-	if (MLX5_CAP_GEN(dev->mdev, relaxed_ordering_write))
-		MLX5_SET(mkc, mkc, relaxed_ordering_write,
-			 (acc & IB_ACCESS_RELAXED_ORDERING) && ro_pci_enabled);
-	if (MLX5_CAP_GEN(dev->mdev, relaxed_ordering_read))
-		MLX5_SET(mkc, mkc, relaxed_ordering_read,
-			 (acc & IB_ACCESS_RELAXED_ORDERING) && ro_pci_enabled);
+	if ((acc & IB_ACCESS_RELAXED_ORDERING) &&
+	    pcie_relaxed_ordering_enabled(dev->mdev->pdev)) {
+		if (MLX5_CAP_GEN(dev->mdev, relaxed_ordering_write))
+			MLX5_SET(mkc, mkc, relaxed_ordering_write, 1);
+		if (MLX5_CAP_GEN(dev->mdev, relaxed_ordering_read))
+			MLX5_SET(mkc, mkc, relaxed_ordering_read, 1);
+	}
 
 	MLX5_SET(mkc, mkc, pd, to_mpd(pd)->pdn);
 	MLX5_SET(mkc, mkc, qpn, 0xffffff);
-- 
2.34.1




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