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 <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Steve Wise <swise@opengridcomputing.com>
Cc: Parav Pandit <pandit.parav@gmail.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: <stable@vger.kernel.org> #v4.7+
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>
-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 */
static inline u32 rdma_rw_fr_page_list_len(struct ib_device *dev)
{
/* arbitrary limit to avoid allocating gigantic resources */
u64 remote_addr, u32 rkey, enum dma_data_direction dir)
{
struct ib_device *dev = qp->pd->device;
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;
struct ib_sge *sge;
u32 total_len = 0, i, j;
+ /*
+ * 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);
return qp;
}
EXPORT_SYMBOL(ib_create_qp);
+/*
+ * @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;
struct ib_qp {
struct ib_device *device;
struct ib_pd *pd;
void (*event_handler)(struct ib_event *, void *);
void *qp_context;
u32 qp_num;
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;
};
enum ib_qp_type qp_type;
};