From a315b723e87ba4e4573e1e5c759d512f38bdc0b3 Mon Sep 17 00:00:00 2001 From: Cosmin Ratiu Date: Tue, 16 Sep 2025 17:11:40 +0300 Subject: net/mlx5e: Prepare for using different CQ doorbells Completion queues (CQs) in mlx5 use the same global doorbell, which may become contended when accessed concurrently from many cores. This patch prepares the CQ management code for supporting different doorbells per CQ. This will be used in downstream patches to allow separate doorbells to be used by channels CQs. The main change is moving the 'uar' pointer from struct mlx5_core_cq to struct mlx5e_cq, as the uar page to be used is better off stored directly there. Other users of mlx5_core_cq also store the UAR to be used separately and therefore the pointer being removed is dead weight for them. As evidence, in this patch there are two users which set the mcq.uar pointer but didn't use it, Software Steering and old Innova CQ creation code. Instead, they rang the doorbell directly from another pointer. The 'uar' pointer added to struct mlx5e_cq remains in a hot cacheline (as before), because it may get accessed for each packet. Signed-off-by: Cosmin Ratiu Reviewed-by: Dragos Tatulea Signed-off-by: Tariq Toukan Reviewed-by: Simon Horman Signed-off-by: Jakub Kicinski --- include/linux/mlx5/cq.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/mlx5/cq.h b/include/linux/mlx5/cq.h index 991526039ccb..7ef2c7c7d803 100644 --- a/include/linux/mlx5/cq.h +++ b/include/linux/mlx5/cq.h @@ -41,7 +41,6 @@ struct mlx5_core_cq { int cqe_sz; __be32 *set_ci_db; __be32 *arm_db; - struct mlx5_uars_page *uar; refcount_t refcount; struct completion free; unsigned vector; -- cgit v1.2.3