[PATCH 02/32] dma-direct: we might need GFP_DMA for 32-bit dma masks

From: Christoph Hellwig
Date: Wed Feb 13 2019 - 02:04:43 EST


If there is no ZONE_DMA32 we might need GFP_DMA to be able to
allocate memory that satisfies a 32-bit DMA mask.

Reported-by: Christian Zigotzky <chzigotzky@xxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Tested-by: Christian Zigotzky <chzigotzky@xxxxxxxxxxx>
---
kernel/dma/direct.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 355d16acee6d..d5bb51cf27c6 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -132,8 +132,7 @@ struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
goto again;
}

- if (IS_ENABLED(CONFIG_ZONE_DMA) &&
- phys_mask < DMA_BIT_MASK(32) && !(gfp & GFP_DMA)) {
+ if (IS_ENABLED(CONFIG_ZONE_DMA) && !(gfp & GFP_DMA)) {
gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
goto again;
}
--
2.20.1