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authorNicolin Chen <nicoleotsuka@gmail.com>2020-09-02 01:16:46 +0300
committerChristoph Hellwig <hch@lst.de>2020-09-03 19:14:57 +0300
commit135ba11a7a07b4ce9197d9fa4b196329a57f1e06 (patch)
tree8ffbf80dc41135d70477e4e8dfe5a5ed92b6dde2 /include/linux/dma-mapping.h
parent1e9d90dbed120ec98517428ffff4dacd9797e39d (diff)
downloadlinux-135ba11a7a07b4ce9197d9fa4b196329a57f1e06.tar.xz
dma-mapping: set default segment_boundary_mask to ULONG_MAX
The default segment_boundary_mask was set to DMA_BIT_MAKS(32) a decade ago by referencing SCSI/block subsystem, as a 32-bit mask was good enough for most of the devices. Now more and more drivers set dma_masks above DMA_BIT_MAKS(32) while only a handful of them call dma_set_seg_boundary(). This means that most drivers have a 4GB segmention boundary because DMA API returns a 32-bit default value, though they might not really have such a limit. The default segment_boundary_mask should mean "no limit" since the device doesn't explicitly set the mask. But a 32-bit mask certainly limits those devices capable of 32+ bits addressing. So this patch sets default segment_boundary_mask to ULONG_MAX. Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com> Acked-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'include/linux/dma-mapping.h')
-rw-r--r--include/linux/dma-mapping.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index faab0a8210b9..df0bff2ea750 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -629,7 +629,7 @@ static inline unsigned long dma_get_seg_boundary(struct device *dev)
{
if (dev->dma_parms && dev->dma_parms->segment_boundary_mask)
return dev->dma_parms->segment_boundary_mask;
- return DMA_BIT_MASK(32);
+ return ULONG_MAX;
}
/**