From c1395a2a8c01e8a919e47d64eb3d23d00e824b8b Mon Sep 17 00:00:00 2001 From: Haggai Eran Date: Thu, 11 Dec 2014 17:04:14 +0200 Subject: [PATCH] IB/mlx5: Add function to read WQE from user-space Add a helper function mlx5_ib_read_user_wqe to read information from user-space owned work queues. The function will be used in a later patch by the page-fault handling code in mlx5_ib. Signed-off-by: Haggai Eran [ Add stub for ib_umem_copy_from() for CONFIG_INFINIBAND_USER_MEM=n - Roland ] Signed-off-by: Roland Dreier --- drivers/infiniband/hw/mlx5/mlx5_ib.h | 2 + drivers/infiniband/hw/mlx5/qp.c | 71 ++++++++++++++++++++++++++++ include/linux/mlx5/qp.h | 3 ++ include/rdma/ib_umem.h | 5 +- 4 files changed, 80 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h index 53d19e6e69a4..14a0311eaa1c 100644 --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h @@ -503,6 +503,8 @@ int mlx5_ib_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr, int mlx5_ib_post_recv(struct ib_qp *ibqp, struct ib_recv_wr *wr, struct ib_recv_wr **bad_wr); void *mlx5_get_send_wqe(struct mlx5_ib_qp *qp, int n); +int mlx5_ib_read_user_wqe(struct mlx5_ib_qp *qp, int send, int wqe_index, + void *buffer, u32 length); struct ib_cq *mlx5_ib_create_cq(struct ib_device *ibdev, int entries, int vector, struct ib_ucontext *context, struct ib_udata *udata); diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c index 36e2cfe1c2fe..9783c3342dbf 100644 --- a/drivers/infiniband/hw/mlx5/qp.c +++ b/drivers/infiniband/hw/mlx5/qp.c @@ -101,6 +101,77 @@ void *mlx5_get_send_wqe(struct mlx5_ib_qp *qp, int n) return get_wqe(qp, qp->sq.offset + (n << MLX5_IB_SQ_STRIDE)); } +/** + * mlx5_ib_read_user_wqe() - Copy a user-space WQE to kernel space. + * + * @qp: QP to copy from. + * @send: copy from the send queue when non-zero, use the receive queue + * otherwise. + * @wqe_index: index to start copying from. For send work queues, the + * wqe_index is in units of MLX5_SEND_WQE_BB. + * For receive work queue, it is the number of work queue + * element in the queue. + * @buffer: destination buffer. + * @length: maximum number of bytes to copy. + * + * Copies at least a single WQE, but may copy more data. + * + * Return: the number of bytes copied, or an error code. + */ +int mlx5_ib_read_user_wqe(struct mlx5_ib_qp *qp, int send, int wqe_index, + void *buffer, u32 length) +{ + struct ib_device *ibdev = qp->ibqp.device; + struct mlx5_ib_dev *dev = to_mdev(ibdev); + struct mlx5_ib_wq *wq = send ? &qp->sq : &qp->rq; + size_t offset; + size_t wq_end; + struct ib_umem *umem = qp->umem; + u32 first_copy_length; + int wqe_length; + int ret; + + if (wq->wqe_cnt == 0) { + mlx5_ib_dbg(dev, "mlx5_ib_read_user_wqe for a QP with wqe_cnt == 0. qp_type: 0x%x\n", + qp->ibqp.qp_type); + return -EINVAL; + } + + offset = wq->offset + ((wqe_index % wq->wqe_cnt) << wq->wqe_shift); + wq_end = wq->offset + (wq->wqe_cnt << wq->wqe_shift); + + if (send && length < sizeof(struct mlx5_wqe_ctrl_seg)) + return -EINVAL; + + if (offset > umem->length || + (send && offset + sizeof(struct mlx5_wqe_ctrl_seg) > umem->length)) + return -EINVAL; + + first_copy_length = min_t(u32, offset + length, wq_end) - offset; + ret = ib_umem_copy_from(buffer, umem, offset, first_copy_length); + if (ret) + return ret; + + if (send) { + struct mlx5_wqe_ctrl_seg *ctrl = buffer; + int ds = be32_to_cpu(ctrl->qpn_ds) & MLX5_WQE_CTRL_DS_MASK; + + wqe_length = ds * MLX5_WQE_DS_UNITS; + } else { + wqe_length = 1 << wq->wqe_shift; + } + + if (wqe_length <= first_copy_length) + return first_copy_length; + + ret = ib_umem_copy_from(buffer + first_copy_length, umem, wq->offset, + wqe_length - first_copy_length); + if (ret) + return ret; + + return wqe_length; +} + static void mlx5_ib_qp_event(struct mlx5_core_qp *qp, int type) { struct ib_qp *ibqp = &to_mibqp(qp)->ibqp; diff --git a/include/linux/mlx5/qp.h b/include/linux/mlx5/qp.h index 3fa075daeb1d..67f4b9660b06 100644 --- a/include/linux/mlx5/qp.h +++ b/include/linux/mlx5/qp.h @@ -189,6 +189,9 @@ struct mlx5_wqe_ctrl_seg { __be32 imm; }; +#define MLX5_WQE_CTRL_DS_MASK 0x3f +#define MLX5_WQE_DS_UNITS 16 + struct mlx5_wqe_xrc_seg { __be32 xrc_srqn; u8 rsvd[12]; diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h index 45bb04bc88cd..a51f4091489a 100644 --- a/include/rdma/ib_umem.h +++ b/include/rdma/ib_umem.h @@ -98,7 +98,10 @@ static inline struct ib_umem *ib_umem_get(struct ib_ucontext *context, } static inline void ib_umem_release(struct ib_umem *umem) { } static inline int ib_umem_page_count(struct ib_umem *umem) { return 0; } - +static inline int ib_umem_copy_from(void *dst, struct ib_umem *umem, size_t offset, + size_t length) { + return -EINVAL; +} #endif /* CONFIG_INFINIBAND_USER_MEM */ #endif /* IB_UMEM_H */ -- 2.20.1