From: Maxim Mikityanskiy Date: Fri, 29 Mar 2019 22:37:52 +0000 (-0700) Subject: net/mlx5: Remove spinlock support from mlx5_write64 X-Git-Tag: v5.2-rc1~114^2~82^2~14 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=bbf29f618e8c5bfd6efdad5fdc050a84bab795ab;p=linux.git net/mlx5: Remove spinlock support from mlx5_write64 As there is no user of mlx5_write64 that passes a spinlock to mlx5_write64, remove this functionality and simplify the function. Signed-off-by: Maxim Mikityanskiy Reviewed-by: Eran Ben Elisha Signed-off-by: Saeed Mahameed --- diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c index dd2ae640bc84..816c34ee91cf 100644 --- a/drivers/infiniband/hw/mlx5/qp.c +++ b/drivers/infiniband/hw/mlx5/qp.c @@ -5015,7 +5015,7 @@ static int _mlx5_ib_post_send(struct ib_qp *ibqp, const struct ib_send_wr *wr, wmb(); /* currently we support only regular doorbells */ - mlx5_write64((__be32 *)ctrl, bf->bfreg->map + bf->offset, NULL); + mlx5_write64((__be32 *)ctrl, bf->bfreg->map + bf->offset); /* Make sure doorbells don't leak out of SQ spinlock * and reach the HCA out of order. */ diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h index 8fa8fdd30b85..2623d3fb6b96 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h @@ -916,7 +916,7 @@ void mlx5e_notify_hw(struct mlx5_wq_cyc *wq, u16 pc, */ wmb(); - mlx5_write64((__be32 *)ctrl, uar_map, NULL); + mlx5_write64((__be32 *)ctrl, uar_map); } static inline void mlx5e_cq_arm(struct mlx5e_cq *cq) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fpga/conn.c b/drivers/net/ethernet/mellanox/mlx5/core/fpga/conn.c index 873541ef4c1b..ca2296a2f9ee 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/fpga/conn.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/fpga/conn.c @@ -135,7 +135,7 @@ static void mlx5_fpga_conn_notify_hw(struct mlx5_fpga_conn *conn, void *wqe) *conn->qp.wq.sq.db = cpu_to_be32(conn->qp.sq.pc); /* Make sure that doorbell record is visible before ringing */ wmb(); - mlx5_write64(wqe, conn->fdev->conn_res.uar->map + MLX5_BF_OFFSET, NULL); + mlx5_write64(wqe, conn->fdev->conn_res.uar->map + MLX5_BF_OFFSET); } static void mlx5_fpga_conn_post_send(struct mlx5_fpga_conn *conn, diff --git a/include/linux/mlx5/cq.h b/include/linux/mlx5/cq.h index 612c8c2f2466..769326ea1d9b 100644 --- a/include/linux/mlx5/cq.h +++ b/include/linux/mlx5/cq.h @@ -170,7 +170,7 @@ static inline void mlx5_cq_arm(struct mlx5_core_cq *cq, u32 cmd, doorbell[0] = cpu_to_be32(sn << 28 | cmd | ci); doorbell[1] = cpu_to_be32(cq->cqn); - mlx5_write64(doorbell, uar_page + MLX5_CQ_DOORBELL, NULL); + mlx5_write64(doorbell, uar_page + MLX5_CQ_DOORBELL); } static inline void mlx5_cq_hold(struct mlx5_core_cq *cq) diff --git a/include/linux/mlx5/doorbell.h b/include/linux/mlx5/doorbell.h index 9ef3f9d00154..5c267707e1df 100644 --- a/include/linux/mlx5/doorbell.h +++ b/include/linux/mlx5/doorbell.h @@ -36,38 +36,25 @@ #define MLX5_BF_OFFSET 0x800 #define MLX5_CQ_DOORBELL 0x20 -#if BITS_PER_LONG == 64 /* Assume that we can just write a 64-bit doorbell atomically. s390 * actually doesn't have writeq() but S/390 systems don't even have * PCI so we won't worry about it. + * + * Note that the write is not atomic on 32-bit systems! In contrast to 64-bit + * ones, it requires proper locking. mlx5_write64 doesn't do any locking, so use + * it at your own discretion, protected by some kind of lock on 32 bits. + * + * TODO: use write{q,l}_relaxed() */ -static inline void mlx5_write64(__be32 val[2], void __iomem *dest, - spinlock_t *doorbell_lock) +static inline void mlx5_write64(__be32 val[2], void __iomem *dest) { +#if BITS_PER_LONG == 64 __raw_writeq(*(u64 *)val, dest); -} - #else - -/* Just fall back to a spinlock to protect the doorbell if - * BITS_PER_LONG is 32 -- there's no portable way to do atomic 64-bit - * MMIO writes. - */ - -static inline void mlx5_write64(__be32 val[2], void __iomem *dest, - spinlock_t *doorbell_lock) -{ - unsigned long flags; - - if (doorbell_lock) - spin_lock_irqsave(doorbell_lock, flags); __raw_writel((__force u32) val[0], dest); __raw_writel((__force u32) val[1], dest + 4); - if (doorbell_lock) - spin_unlock_irqrestore(doorbell_lock, flags); -} - #endif +} #endif /* MLX5_DOORBELL_H */