[PATCH] dma-mapping: reliably inform about DMA support for IOMMU

[Leon Romanovsky]

From: Leon Romanovsky <leonro@xxxxxxxxxx>

If the DMA IOMMU path is going to be used, the appropriate check should
return that DMA is supported.

Fixes: b5c58b2fdc42 ("dma-mapping: direct calls for dma-iommu")
Closes: https://lore.kernel.org/all/181e06ff-35a3-434f-b505-672f430bd1cb@notapiano
Reported-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx> #KernelCI
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
---
 kernel/dma/mapping.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 1a7de37bd643..38d7b3239dbb 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -824,6 +824,9 @@ static int dma_supported(struct device *dev, u64 mask)
 
 	if (WARN_ON(ops && use_dma_iommu(dev)))
 		return false;
+
+	if (use_dma_iommu(dev))
+		return true;
 	/*
 	 * ->dma_supported sets the bypass flag, so we must always call
 	 * into the method here unless the device is truly direct mapped.
-- 
2.46.0