From: William Tu witu@nvidia.com
[ Upstream commit e1d68ea58c7e9ebacd9ad7a99b25a3578fa62182 ]
For the ECPF and representors, reduce the max MPWRQ size from 256KB (18) to 128KB (17). This prepares the later patch for saving representor memory.
With Striding RQ, there is a minimum of 4 MPWQEs. So with 128KB of max MPWRQ size, the minimal memory is 4 * 128KB = 512KB. When creating page pool, consider 1500 mtu, the minimal page pool size will be 512KB/4KB = 128 pages = 256 rx ring entries (2 entries per page).
Before this patch, setting RX ringsize (ethtool -G rx) to 256 causes driver to allocate page pool size more than it needs due to max MPWRQ is 256KB (18). Ex: 4 * 256KB = 1MB, 1MB/4KB = 256 pages, but actually 128 pages is good enough. Reducing the max MPWRQ to 128KB fixes the limitation.
Signed-off-by: William Tu witu@nvidia.com Signed-off-by: Tariq Toukan tariqt@nvidia.com Reviewed-by: Michal Swiatkowski michal.swiatkowski@linux.intel.com Link: https://patch.msgid.link/20250209101716.112774-7-tariqt@nvidia.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/mellanox/mlx5/core/en.h | 2 -- .../net/ethernet/mellanox/mlx5/core/en/params.c | 15 +++++++++++---- 2 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h index d6266f6a96d6e..e048a667e0758 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h @@ -94,8 +94,6 @@ struct page_pool; #define MLX5_MPWRQ_DEF_LOG_STRIDE_SZ(mdev) \ MLX5_MPWRQ_LOG_STRIDE_SZ(mdev, order_base_2(MLX5E_RX_MAX_HEAD))
-#define MLX5_MPWRQ_MAX_LOG_WQE_SZ 18 - /* Keep in sync with mlx5e_mpwrq_log_wqe_sz. * These are theoretical maximums, which can be further restricted by * capabilities. These values are used for static resource allocations and diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/params.c b/drivers/net/ethernet/mellanox/mlx5/core/en/params.c index 8c4d710e85675..58ec5e44aa7ad 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/params.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/params.c @@ -10,6 +10,9 @@ #include <net/page_pool/types.h> #include <net/xdp_sock_drv.h>
+#define MLX5_MPWRQ_MAX_LOG_WQE_SZ 18 +#define MLX5_REP_MPWRQ_MAX_LOG_WQE_SZ 17 + static u8 mlx5e_mpwrq_min_page_shift(struct mlx5_core_dev *mdev) { u8 min_page_shift = MLX5_CAP_GEN_2(mdev, log_min_mkey_entity_size); @@ -103,18 +106,22 @@ u8 mlx5e_mpwrq_log_wqe_sz(struct mlx5_core_dev *mdev, u8 page_shift, enum mlx5e_mpwrq_umr_mode umr_mode) { u8 umr_entry_size = mlx5e_mpwrq_umr_entry_size(umr_mode); - u8 max_pages_per_wqe, max_log_mpwqe_size; + u8 max_pages_per_wqe, max_log_wqe_size_calc; + u8 max_log_wqe_size_cap; u16 max_wqe_size;
/* Keep in sync with MLX5_MPWRQ_MAX_PAGES_PER_WQE. */ max_wqe_size = mlx5e_get_max_sq_aligned_wqebbs(mdev) * MLX5_SEND_WQE_BB; max_pages_per_wqe = ALIGN_DOWN(max_wqe_size - sizeof(struct mlx5e_umr_wqe), MLX5_UMR_FLEX_ALIGNMENT) / umr_entry_size; - max_log_mpwqe_size = ilog2(max_pages_per_wqe) + page_shift; + max_log_wqe_size_calc = ilog2(max_pages_per_wqe) + page_shift; + + WARN_ON_ONCE(max_log_wqe_size_calc < MLX5E_ORDER2_MAX_PACKET_MTU);
- WARN_ON_ONCE(max_log_mpwqe_size < MLX5E_ORDER2_MAX_PACKET_MTU); + max_log_wqe_size_cap = mlx5_core_is_ecpf(mdev) ? + MLX5_REP_MPWRQ_MAX_LOG_WQE_SZ : MLX5_MPWRQ_MAX_LOG_WQE_SZ;
- return min_t(u8, max_log_mpwqe_size, MLX5_MPWRQ_MAX_LOG_WQE_SZ); + return min_t(u8, max_log_wqe_size_calc, max_log_wqe_size_cap); }
u8 mlx5e_mpwrq_pages_per_wqe(struct mlx5_core_dev *mdev, u8 page_shift,