Commit bf583470 authored by Bart Van Assche's avatar Bart Van Assche Committed by Jason Gunthorpe
Browse files

RDMA/srp: Honor the max_send_sge device attribute 

Instead of assuming that max_send_sge >= 3, restrict the number of scatter
gather elements to what is supported by the RDMA adapter.

Link: https://lore.kernel.org/r/20190930231707.48259-8-bvanassche@acm.org


Cc: Honggang LI <honli@redhat.com>
Cc: Laurence Oberman <loberman@redhat.com>
Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 14673778

drivers/infiniband/ulp/srp/ib_srp.c

+5 −2
Original line number Diff line number Diff line
@@ -552,6 +552,7 @@ static int srp_create_ch_ib(struct srp_rdma_ch *ch) 
{

	struct srp_target_port *target = ch->target;

	struct srp_device *dev = target->srp_host->srp_dev;

	const struct ib_device_attr *attr = &dev->dev->attrs;

	struct ib_qp_init_attr *init_attr;

	struct ib_cq *recv_cq, *send_cq;

	struct ib_qp *qp;
@@ -583,12 +584,14 @@ static int srp_create_ch_ib(struct srp_rdma_ch *ch) 
	init_attr->cap.max_send_wr     = m * target->queue_size;

	init_attr->cap.max_recv_wr     = target->queue_size + 1;

	init_attr->cap.max_recv_sge    = 1;

	init_attr->cap.max_send_sge    = SRP_MAX_SGE;

	init_attr->cap.max_send_sge    = min(SRP_MAX_SGE, attr->max_send_sge);

	init_attr->sq_sig_type         = IB_SIGNAL_REQ_WR;

	init_attr->qp_type             = IB_QPT_RC;

	init_attr->send_cq             = send_cq;

	init_attr->recv_cq             = recv_cq;



	ch->max_imm_sge = min(init_attr->cap.max_send_sge - 1U, 255U);



	if (target->using_rdma_cm) {

		ret = rdma_create_qp(ch->rdma_cm.cm_id, dev->pd, init_attr);

		qp = ch->rdma_cm.cm_id->qp;
@@ -1838,7 +1841,7 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch, 
		return -EIO;



	if (ch->use_imm_data &&

	    count <= SRP_MAX_IMM_SGE &&

	    count <= ch->max_imm_sge &&

	    SRP_IMM_DATA_OFFSET + data_len <= ch->max_it_iu_len &&

	    scmnd->sc_data_direction == DMA_TO_DEVICE) {

		struct srp_imm_buf *buf;

drivers/infiniband/ulp/srp/ib_srp.h

+1 −0
Original line number Diff line number Diff line
@@ -161,6 +161,7 @@ struct srp_rdma_ch { 
	};

	uint32_t		max_it_iu_len;

	uint32_t		max_ti_iu_len;

	u8			max_imm_sge;

	bool			use_imm_data;



	/* Everything above this point is used in the hot path of