Commit 62356fcc authored by Jacob Moroni's avatar Jacob Moroni Committed by Leon Romanovsky
Browse files

RDMA/irdma: Remove doorbell elision logic 



In some cases, this logic can result in doorbell writes being
skipped when they should not have been (at least on GEN3 HW),
so remove it. This also means that the mb() can be safely
downgraded to dma_wmb().

Fixes: 551c46ed ("RDMA/irdma: Add user/kernel shared libraries")
Signed-off-by: default avatarJacob Moroni <jmoroni@google.com>
Signed-off-by: default avatarTatyana Nikolova <tatyana.e.nikolova@intel.com>
Link: https://patch.msgid.link/20251125025350.180-9-tatyana.e.nikolova@intel.com


Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
parent eef3ad03

drivers/infiniband/hw/irdma/puda.c

+0 −1
Original line number Diff line number Diff line
@@ -685,7 +685,6 @@ static int irdma_puda_qp_create(struct irdma_puda_rsrc *rsrc) 
	ukqp->rq_size = rsrc->rq_size;



	IRDMA_RING_INIT(ukqp->sq_ring, ukqp->sq_size);

	IRDMA_RING_INIT(ukqp->initial_ring, ukqp->sq_size);

	IRDMA_RING_INIT(ukqp->rq_ring, ukqp->rq_size);

	ukqp->wqe_alloc_db = qp->pd->dev->wqe_alloc_db;

drivers/infiniband/hw/irdma/uk.c

+2 −29
Original line number Diff line number Diff line
@@ -114,34 +114,9 @@ void irdma_clr_wqes(struct irdma_qp_uk *qp, u32 qp_wqe_idx) 
 */

void irdma_uk_qp_post_wr(struct irdma_qp_uk *qp)

{

	u64 temp;

	u32 hw_sq_tail;

	u32 sw_sq_head;



	/* valid bit is written and loads completed before reading shadow */

	mb();



	/* read the doorbell shadow area */

	get_64bit_val(qp->shadow_area, 0, &temp);



	hw_sq_tail = (u32)FIELD_GET(IRDMA_QP_DBSA_HW_SQ_TAIL, temp);

	sw_sq_head = IRDMA_RING_CURRENT_HEAD(qp->sq_ring);

	if (sw_sq_head != qp->initial_ring.head) {

		if (sw_sq_head != hw_sq_tail) {

			if (sw_sq_head > qp->initial_ring.head) {

				if (hw_sq_tail >= qp->initial_ring.head &&

				    hw_sq_tail < sw_sq_head)

					writel(qp->qp_id, qp->wqe_alloc_db);

			} else {

				if (hw_sq_tail >= qp->initial_ring.head ||

				    hw_sq_tail < sw_sq_head)

	dma_wmb();

	writel(qp->qp_id, qp->wqe_alloc_db);

}

		}

	}



	qp->initial_ring.head = qp->sq_ring.head;

}



/**

 * irdma_qp_get_next_send_wqe - pad with NOP if needed, return where next WR should go
@@ -1606,7 +1581,6 @@ static void irdma_setup_connection_wqes(struct irdma_qp_uk *qp, 
	qp->conn_wqes = move_cnt;

	IRDMA_RING_MOVE_HEAD_BY_COUNT_NOCHECK(qp->sq_ring, move_cnt);

	IRDMA_RING_MOVE_TAIL_BY_COUNT(qp->sq_ring, move_cnt);

	IRDMA_RING_MOVE_HEAD_BY_COUNT_NOCHECK(qp->initial_ring, move_cnt);

}



/**
@@ -1751,7 +1725,6 @@ int irdma_uk_qp_init(struct irdma_qp_uk *qp, struct irdma_qp_uk_init_info *info) 
	qp->max_sq_frag_cnt = info->max_sq_frag_cnt;

	sq_ring_size = qp->sq_size << info->sq_shift;

	IRDMA_RING_INIT(qp->sq_ring, sq_ring_size);

	IRDMA_RING_INIT(qp->initial_ring, sq_ring_size);

	if (info->first_sq_wq) {

		irdma_setup_connection_wqes(qp, info);

		qp->swqe_polarity = 1;

drivers/infiniband/hw/irdma/user.h

+0 −1
Original line number Diff line number Diff line
@@ -457,7 +457,6 @@ struct irdma_srq_uk { 
	struct irdma_uk_attrs *uk_attrs;

	__le64 *shadow_area;

	struct irdma_ring srq_ring;

	struct irdma_ring initial_ring;

	u32 srq_id;

	u32 srq_size;

	u32 max_srq_frag_cnt;