Commit 58b04406 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-mapping: consolidate the dma mmap implementations 



The only functional differences (modulo a few missing fixes in the arch
code) is that architectures without coherent caches need a hook to
convert a virtual or dma address into a pfn, given that we don't have
the kernel linear mapping available for the otherwise easy virt_to_page
call.  As a side effect we can support mmap of the per-device coherent
area even on architectures not providing the callback, and we make
previous dangerous default methods dma_common_mmap actually save for
non-coherent architectures by rejecting it without the right helper.

In addition to that we need a hook so that some architectures can
override the protection bits when mmaping a dma coherent allocations.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: Paul Burton <paul.burton@mips.com> # MIPS parts
parent bc3ec75d

arch/arc/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
config ARC

	def_bool y

	select ARC_TIMERS

	select ARCH_HAS_DMA_COHERENT_TO_PFN

	select ARCH_HAS_PTE_SPECIAL

	select ARCH_HAS_SYNC_DMA_FOR_CPU

	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
@@ -18,7 +19,6 @@ config ARC 
	select CLONE_BACKWARDS

	select COMMON_CLK

	select DMA_DIRECT_OPS

	select DMA_NONCOHERENT_MMAP

	select GENERIC_ATOMIC64 if !ISA_ARCV2 || !(ARC_HAS_LL64 && ARC_HAS_LLSC)

	select GENERIC_CLOCKEVENTS

	select GENERIC_FIND_FIRST_BIT

arch/arc/mm/dma.c

+3 −22
Original line number Diff line number Diff line
@@ -84,29 +84,10 @@ void arch_dma_free(struct device *dev, size_t size, void *vaddr, 
	__free_pages(page, get_order(size));

}



int arch_dma_mmap(struct device *dev, struct vm_area_struct *vma,

		void *cpu_addr, dma_addr_t dma_addr, size_t size,

		unsigned long attrs)

long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr,

		dma_addr_t dma_addr)

{

	unsigned long user_count = vma_pages(vma);

	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;

	unsigned long pfn = __phys_to_pfn(dma_addr);

	unsigned long off = vma->vm_pgoff;

	int ret = -ENXIO;



	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);



	if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))

		return ret;



	if (off < count && user_count <= (count - off)) {

		ret = remap_pfn_range(vma, vma->vm_start,

				      pfn + off,

				      user_count << PAGE_SHIFT,

				      vma->vm_page_prot);

	}



	return ret;

	return __phys_to_pfn(dma_addr);

}



/*

arch/arm/mm/dma-mapping-nommu.c

+1 −1
Original line number Diff line number Diff line
@@ -91,7 +91,7 @@ static int arm_nommu_dma_mmap(struct device *dev, struct vm_area_struct *vma, 
	if (dma_mmap_from_global_coherent(vma, cpu_addr, size, &ret))

		return ret;



	return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);

	return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size, attrs);

}

arch/microblaze/Kconfig

+1 −1
Original line number Diff line number Diff line 
config MICROBLAZE

	def_bool y

	select ARCH_NO_SWAP

	select ARCH_HAS_DMA_COHERENT_TO_PFN if MMU

	select ARCH_HAS_GCOV_PROFILE_ALL

	select ARCH_HAS_SYNC_DMA_FOR_CPU

	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
@@ -12,7 +13,6 @@ config MICROBLAZE 
	select CLONE_BACKWARDS3

	select COMMON_CLK

	select DMA_DIRECT_OPS

	select DMA_NONCOHERENT_MMAP

	select GENERIC_ATOMIC64

	select GENERIC_CLOCKEVENTS

	select GENERIC_CPU_DEVICES

arch/microblaze/include/asm/pgtable.h

+0 −2
Original line number Diff line number Diff line
@@ -553,8 +553,6 @@ void __init *early_get_page(void); 


extern unsigned long ioremap_bot, ioremap_base;



unsigned long consistent_virt_to_pfn(void *vaddr);



void setup_memory(void);

#endif /* __ASSEMBLY__ */

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