Commit 36950f2d authored by Jianxiong Gao's avatar Jianxiong Gao Committed by Konrad Rzeszutek Wilk
Browse files

driver core: add a min_align_mask field to struct device_dma_parameters 



Some devices rely on the address offset in a page to function
correctly (NVMe driver as an example). These devices may use
a different page size than the Linux kernel. The address offset
has to be preserved upon mapping, and in order to do so, we
need to record the page_offset_mask first.

Signed-off-by: default avatarJianxiong Gao <jxgao@google.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 66e8d3b8

include/linux/device.h

+1 −0
Original line number Diff line number Diff line
@@ -291,6 +291,7 @@ struct device_dma_parameters { 
	 * sg limitations.

	 */

	unsigned int max_segment_size;

	unsigned int min_align_mask;

	unsigned long segment_boundary_mask;

};

include/linux/dma-mapping.h

+16 −0
Original line number Diff line number Diff line
@@ -500,6 +500,22 @@ static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask) 
	return -EIO;

}



static inline unsigned int dma_get_min_align_mask(struct device *dev)

{

	if (dev->dma_parms)

		return dev->dma_parms->min_align_mask;

	return 0;

}



static inline int dma_set_min_align_mask(struct device *dev,

		unsigned int min_align_mask)

{

	if (WARN_ON_ONCE(!dev->dma_parms))

		return -EIO;

	dev->dma_parms->min_align_mask = min_align_mask;

	return 0;

}



static inline int dma_get_cache_alignment(void)

{

#ifdef ARCH_DMA_MINALIGN