Commit c1395a2a authored by Haggai Eran's avatar Haggai Eran Committed by Roland Dreier

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: default avatarHaggai Eran <haggaie@mellanox.com>

[ Add stub for ib_umem_copy_from() for CONFIG_INFINIBAND_USER_MEM=n
  - Roland ]
Signed-off-by: default avatarRoland Dreier <roland@purestorage.com>
parent c5d76f13
...@@ -503,6 +503,8 @@ int mlx5_ib_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr, ...@@ -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, int mlx5_ib_post_recv(struct ib_qp *ibqp, struct ib_recv_wr *wr,
struct ib_recv_wr **bad_wr); struct ib_recv_wr **bad_wr);
void *mlx5_get_send_wqe(struct mlx5_ib_qp *qp, int n); 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, struct ib_cq *mlx5_ib_create_cq(struct ib_device *ibdev, int entries,
int vector, struct ib_ucontext *context, int vector, struct ib_ucontext *context,
struct ib_udata *udata); struct ib_udata *udata);
......
...@@ -101,6 +101,77 @@ void *mlx5_get_send_wqe(struct mlx5_ib_qp *qp, int n) ...@@ -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)); 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) static void mlx5_ib_qp_event(struct mlx5_core_qp *qp, int type)
{ {
struct ib_qp *ibqp = &to_mibqp(qp)->ibqp; struct ib_qp *ibqp = &to_mibqp(qp)->ibqp;
......
...@@ -189,6 +189,9 @@ struct mlx5_wqe_ctrl_seg { ...@@ -189,6 +189,9 @@ struct mlx5_wqe_ctrl_seg {
__be32 imm; __be32 imm;
}; };
#define MLX5_WQE_CTRL_DS_MASK 0x3f
#define MLX5_WQE_DS_UNITS 16
struct mlx5_wqe_xrc_seg { struct mlx5_wqe_xrc_seg {
__be32 xrc_srqn; __be32 xrc_srqn;
u8 rsvd[12]; u8 rsvd[12];
......
...@@ -98,7 +98,10 @@ static inline struct ib_umem *ib_umem_get(struct ib_ucontext *context, ...@@ -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 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_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 /* CONFIG_INFINIBAND_USER_MEM */
#endif /* IB_UMEM_H */ #endif /* IB_UMEM_H */
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