[PATCH 5.11 350/775] dmaengine: idxd: set DMA channel to be private

From: Greg Kroah-Hartman
Date: Mon Mar 01 2021 - 18:58:39 EST


From: Dave Jiang <dave.jiang@xxxxxxxxx>

[ Upstream commit c06e424be5f5184468c5f761c0d2cf1ed0a4e0fc ]

Add DMA_PRIVATE attribute flag to idxd DMA channels. The dedicated WQs are
expected to be used by a single client and not shared. While doing NTB
testing this mistake was discovered, which prevented ntb_transport from
requesting DSA wqs as DMA channels via dma_request_channel().

Reported-by: Srinijia Kambham <srinija.kambham@xxxxxxxxx>
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Tested-by: Srinijia Kambham <srinija.kambham@xxxxxxxxx>
Fixes: 8f47d1a5e545 ("dmaengine: idxd: connect idxd to dmaengine subsystem")
Link: https://lore.kernel.org/r/161074758743.2184057.3388557138816350980.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/dma/idxd/dma.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/dma/idxd/dma.c b/drivers/dma/idxd/dma.c
index 71fd6e4c42cd7..a15e50126434e 100644
--- a/drivers/dma/idxd/dma.c
+++ b/drivers/dma/idxd/dma.c
@@ -165,6 +165,7 @@ int idxd_register_dma_device(struct idxd_device *idxd)
INIT_LIST_HEAD(&dma->channels);
dma->dev = &idxd->pdev->dev;

+ dma_cap_set(DMA_PRIVATE, dma->cap_mask);
dma_cap_set(DMA_COMPLETION_NO_ORDER, dma->cap_mask);
dma->device_release = idxd_dma_release;

--
2.27.0