Commit 419e2f18 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-mapping: remove arch_dma_mmap_pgprot 



arch_dma_mmap_pgprot is used for two things:

 1) to override the "normal" uncached page attributes for mapping
    memory coherent to devices that can't snoop the CPU caches
 2) to provide the special DMA_ATTR_WRITE_COMBINE semantics on older
    arm systems and some mips platforms

Replace one with the pgprot_dmacoherent macro that is already provided
by arm and much simpler to use, and lift the DMA_ATTR_WRITE_COMBINE
handling to common code with an explicit arch opt-in.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	# m68k
Acked-by: Paul Burton <paul.burton@mips.com>		# mips
parent b898e50f

arch/arm/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -8,7 +8,7 @@ config ARM 
	select ARCH_HAS_DEBUG_VIRTUAL if MMU

	select ARCH_HAS_DEVMEM_IS_ALLOWED

	select ARCH_HAS_DMA_COHERENT_TO_PFN if SWIOTLB

	select ARCH_HAS_DMA_MMAP_PGPROT if SWIOTLB

	select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE

	select ARCH_HAS_ELF_RANDOMIZE

	select ARCH_HAS_FORTIFY_SOURCE

	select ARCH_HAS_KEEPINITRD

arch/arm/mm/dma-mapping.c

+0 −6
Original line number Diff line number Diff line
@@ -2402,12 +2402,6 @@ long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr, 
	return dma_to_pfn(dev, dma_addr);

}



pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot,

		unsigned long attrs)

{

	return __get_dma_pgprot(attrs, prot);

}



void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,

		gfp_t gfp, unsigned long attrs)

{

arch/arm64/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -13,7 +13,6 @@ config ARM64 
	select ARCH_HAS_DEBUG_VIRTUAL

	select ARCH_HAS_DEVMEM_IS_ALLOWED

	select ARCH_HAS_DMA_COHERENT_TO_PFN

	select ARCH_HAS_DMA_MMAP_PGPROT

	select ARCH_HAS_DMA_PREP_COHERENT

	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI

	select ARCH_HAS_ELF_RANDOMIZE

arch/arm64/include/asm/pgtable.h

+4 −0
Original line number Diff line number Diff line
@@ -435,6 +435,10 @@ static inline pmd_t pmd_mkdevmap(pmd_t pmd) 
	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)

#define pgprot_device(prot) \

	__pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)

#define pgprot_dmacoherent(prot) \

	__pgprot_modify(prot, PTE_ATTRINDX_MASK, \

			PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)



#define __HAVE_PHYS_MEM_ACCESS_PROT

struct file;

extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,

arch/arm64/mm/dma-mapping.c

+0 −6
Original line number Diff line number Diff line
@@ -11,12 +11,6 @@ 


#include <asm/cacheflush.h>



pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot,

		unsigned long attrs)

{

	return pgprot_writecombine(prot);

}



void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,

		size_t size, enum dma_data_direction dir)

{

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