Commit af2880ec authored by Robin Murphy's avatar Robin Murphy Committed by Andrew Morton
Browse files

scatterlist: add dedicated config for DMA flags 

The DMA flags field will be useful for users beyond PCI P2P, so upgrade to
its own dedicated config option.

[catalin.marinas@arm.com: use #ifdef CONFIG_NEED_SG_DMA_FLAGS in scatterlist.h]
[catalin.marinas@arm.com: update PCI_P2PDMA dma_flags comment in scatterlist.h]
Link: https://lkml.kernel.org/r/20230612153201.554742-13-catalin.marinas@arm.com


Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Tested-by: default avatarIsaac J. Manjarres <isaacmanjarres@google.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jerry Snitselaar <jsnitsel@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 9382bc44

drivers/pci/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -168,6 +168,7 @@ config PCI_P2PDMA 
	#

	depends on 64BIT

	select GENERIC_ALLOCATOR

	select NEED_SG_DMA_FLAGS

	help

	  Enableѕ drivers to do PCI peer-to-peer transactions to and from

	  BARs that are exposed in other devices that are the part of

include/linux/scatterlist.h

+6 −7
Original line number Diff line number Diff line
@@ -16,7 +16,7 @@ struct scatterlist { 
#ifdef CONFIG_NEED_SG_DMA_LENGTH

	unsigned int	dma_length;

#endif

#ifdef CONFIG_PCI_P2PDMA

#ifdef CONFIG_NEED_SG_DMA_FLAGS

	unsigned int    dma_flags;

#endif

};
@@ -249,12 +249,11 @@ static inline void sg_unmark_end(struct scatterlist *sg) 
}



/*

 * CONFGI_PCI_P2PDMA depends on CONFIG_64BIT which means there is 4 bytes

 * in struct scatterlist (assuming also CONFIG_NEED_SG_DMA_LENGTH is set).

 * Use this padding for DMA flags bits to indicate when a specific

 * dma address is a bus address.

 * One 64-bit architectures there is a 4-byte padding in struct scatterlist

 * (assuming also CONFIG_NEED_SG_DMA_LENGTH is set). Use this padding for DMA

 * flags bits to indicate when a specific dma address is a bus address.

 */

#ifdef CONFIG_PCI_P2PDMA

#ifdef CONFIG_NEED_SG_DMA_FLAGS



#define SG_DMA_BUS_ADDRESS (1 << 0)
@@ -312,7 +311,7 @@ static inline void sg_dma_unmark_bus_address(struct scatterlist *sg) 
{

}



#endif

#endif	/* CONFIG_NEED_SG_DMA_FLAGS */



/**

 * sg_phys - Return physical address of an sg entry

kernel/dma/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -24,6 +24,9 @@ config DMA_OPS_BYPASS 
config ARCH_HAS_DMA_MAP_DIRECT

	bool



config NEED_SG_DMA_FLAGS

	bool



config NEED_SG_DMA_LENGTH

	bool