4.7-stable review patch. If anyone has any objections, please let me know.
------------------ From: Bart Van Assche <[email protected]> commit 632bc3f65081dd1e2e5394a9161580a0f78e8839 upstream. Compute the SGE limit for RDMA READ and WRITE requests in ib_create_qp(). Use that limit in the RDMA RW API implementation. Signed-off-by: Bart Van Assche <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Sagi Grimberg <[email protected]> Cc: Steve Wise <[email protected]> Cc: Parav Pandit <[email protected]> Cc: Nicholas Bellinger <[email protected]> Cc: Laurence Oberman <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Signed-off-by: Doug Ledford <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/infiniband/core/rw.c | 10 ++-------- drivers/infiniband/core/verbs.c | 9 +++++++++ include/rdma/ib_verbs.h | 6 ++++++ 3 files changed, 17 insertions(+), 8 deletions(-) --- a/drivers/infiniband/core/rw.c +++ b/drivers/infiniband/core/rw.c @@ -58,13 +58,6 @@ static inline bool rdma_rw_io_needs_mr(s return false; } -static inline u32 rdma_rw_max_sge(struct ib_device *dev, - enum dma_data_direction dir) -{ - return dir == DMA_TO_DEVICE ? - dev->attrs.max_sge : dev->attrs.max_sge_rd; -} - static inline u32 rdma_rw_fr_page_list_len(struct ib_device *dev) { /* arbitrary limit to avoid allocating gigantic resources */ @@ -186,7 +179,8 @@ static int rdma_rw_init_map_wrs(struct r u64 remote_addr, u32 rkey, enum dma_data_direction dir) { struct ib_device *dev = qp->pd->device; - u32 max_sge = rdma_rw_max_sge(dev, dir); + u32 max_sge = dir == DMA_TO_DEVICE ? qp->max_write_sge : + qp->max_read_sge; struct ib_sge *sge; u32 total_len = 0, i, j; --- a/drivers/infiniband/core/verbs.c +++ b/drivers/infiniband/core/verbs.c @@ -814,6 +814,15 @@ struct ib_qp *ib_create_qp(struct ib_pd } } + /* + * Note: all hw drivers guarantee that max_send_sge is lower than + * the device RDMA WRITE SGE limit but not all hw drivers ensure that + * max_send_sge <= max_sge_rd. + */ + qp->max_write_sge = qp_init_attr->cap.max_send_sge; + qp->max_read_sge = min_t(u32, qp_init_attr->cap.max_send_sge, + device->attrs.max_sge_rd); + return qp; } EXPORT_SYMBOL(ib_create_qp); --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -1428,6 +1428,10 @@ struct ib_srq { } ext; }; +/* + * @max_write_sge: Maximum SGE elements per RDMA WRITE request. + * @max_read_sge: Maximum SGE elements per RDMA READ request. + */ struct ib_qp { struct ib_device *device; struct ib_pd *pd; @@ -1449,6 +1453,8 @@ struct ib_qp { void (*event_handler)(struct ib_event *, void *); void *qp_context; u32 qp_num; + u32 max_write_sge; + u32 max_read_sge; enum ib_qp_type qp_type; };
