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RDMA/irdma: Remove redundant dma_wmb() before writel()

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A dma_wmb() is not necessary before a writel() because writel()
already has an even stronger store barrier. A dma_wmb() is only
required to order writes to consistent/DMA memory whereas the
barrier in writel() is specified to order writes to DMA memory as
well as MMIO.

Signed-off-by: Jacob Moroni <jmoroni@google.com>
Link: https://patch.msgid.link/20260103172517.2088895-1-jmoroni@google.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
This commit is contained in:
Jacob Moroni
2026-01-03 17:25:17 +00:00
committed by Leon Romanovsky
parent 88f2bf22d9
commit 52f3d34c29
2 changed files with 0 additions and 5 deletions
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2
drivers/infiniband/hw/irdma/ctrl.c
View File

@@ -3887,8 +3887,6 @@ void irdma_sc_ccq_arm(struct irdma_sc_cq *ccq)
set_64bit_val(ccq->cq_uk.shadow_area, 32, temp_val);
spin_unlock_irqrestore(&ccq->dev->cqp_lock, flags);
dma_wmb(); /* make sure shadow area is updated before arming */
writel(ccq->cq_uk.cq_id, ccq->dev->cq_arm_db);
}

3
drivers/infiniband/hw/irdma/uk.c
View File

@@ -114,7 +114,6 @@ void irdma_clr_wqes(struct irdma_qp_uk *qp, u32 qp_wqe_idx)
*/
void irdma_uk_qp_post_wr(struct irdma_qp_uk *qp)
{
dma_wmb();
writel(qp->qp_id, qp->wqe_alloc_db);
}
@@ -1107,8 +1106,6 @@ void irdma_uk_cq_request_notification(struct irdma_cq_uk *cq,
set_64bit_val(cq->shadow_area, 32, temp_val);
dma_wmb(); /* make sure WQE is populated before valid bit is set */
writel(cq->cq_id, cq->cqe_alloc_db);
}