dmaengine: idxd: set DMA channel to be private

stable inclusion
from stable-5.10.20
commit 4f24543828faf117e1d1f89dae7df50c6e40c859
bugzilla: 50608

--------------------------------

[ Upstream commit c06e424b ]

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: NSrinijia Kambham <srinija.kambham@intel.com>
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Tested-by: NSrinijia Kambham <srinija.kambham@intel.com>
Fixes: 8f47d1a5 ("dmaengine: idxd: connect idxd to dmaengine subsystem")
Link: https://lore.kernel.org/r/161074758743.2184057.3388557138816350980.stgit@djiang5-desk3.ch.intel.comSigned-off-by: NVinod Koul <vkoul@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/dma/idxd/dma.c

@@ -174,6 +174,7 @@ 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;