diff mbox series

[net-next,09/15] net/mlx5e: XDP, Consider large muti-buffer packets in Striding RQ params calculations

Message ID 20230417121903.46218-10-tariqt@nvidia.com (mailing list archive)
State Accepted
Delegated to: Netdev Maintainers
Headers show
Series net/mlx5e: Extend XDP multi-buffer capabilities | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 18 this patch: 18
netdev/cc_maintainers warning 8 maintainers not CCed: leon@kernel.org linux-rdma@vger.kernel.org daniel@iogearbox.net john.fastabend@gmail.com bpf@vger.kernel.org maxtram95@gmail.com hawk@kernel.org ast@kernel.org
netdev/build_clang success Errors and warnings before: 18 this patch: 18
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 18 this patch: 18
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 24 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Tariq Toukan April 17, 2023, 12:18 p.m. UTC 
Function mlx5e_rx_get_linear_stride_sz() returns PAGE_SIZE immediately
in case an XDP program is attached. The more accurate formula is
ALIGN(sz, PAGE_SIZE), to prevent two packets from residing on the same
page.

The assumption behind the current code is that sz <= PAGE_SIZE holds for
all cases with XDP program set.

This is true because it is being called from:
- 3 times from Striding RQ flows, in which XDP is not supported for such
  large packets.
- 1 time from Legacy RQ flow, under the condition
  mlx5e_rx_is_linear_skb().

No functional change here, just removing the implied assumption in
preparation for supporting XDP multi-buffer in Striding RQ.

Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en/params.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/params.c b/drivers/net/ethernet/mellanox/mlx5/core/en/params.c
index 31f3c6e51d9e..196862e67af3 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/params.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/params.c
@@ -253,17 +253,20 @@  static u32 mlx5e_rx_get_linear_stride_sz(struct mlx5_core_dev *mdev,
 					 struct mlx5e_xsk_param *xsk,
 					 bool mpwqe)
 {
+	u32 sz;
+
 	/* XSK frames are mapped as individual pages, because frames may come in
 	 * an arbitrary order from random locations in the UMEM.
 	 */
 	if (xsk)
 		return mpwqe ? 1 << mlx5e_mpwrq_page_shift(mdev, xsk) : PAGE_SIZE;
 
-	/* XDP in mlx5e doesn't support multiple packets per page. */
-	if (params->xdp_prog)
-		return PAGE_SIZE;
+	sz = roundup_pow_of_two(mlx5e_rx_get_linear_sz_skb(params, false));
 
-	return roundup_pow_of_two(mlx5e_rx_get_linear_sz_skb(params, false));
+	/* XDP in mlx5e doesn't support multiple packets per page.
+	 * Do not assume sz <= PAGE_SIZE if params->xdp_prog is set.
+	 */
+	return params->xdp_prog && sz < PAGE_SIZE ? PAGE_SIZE : sz;
 }
 
 static u8 mlx5e_mpwqe_log_pkts_per_wqe(struct mlx5_core_dev *mdev,