Commit 782e6769 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-mapping: provide a generic dma-noncoherent implementation 



Add a new dma_map_ops implementation that uses dma-direct for the
address mapping of streaming mappings, and which requires arch-specific
implemenations of coherent allocate/free.

Architectures have to provide flushing helpers to ownership trasnfers
to the device and/or CPU, and can provide optional implementations of
the coherent mmap functionality, and the cache_flush routines for
non-coherent long term allocations.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Tested-by: default avatarAlexey Brodkin <abrodkin@synopsys.com>
Acked-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent 35ddb69c

MAINTAINERS

+2 −0
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@@ -4334,12 +4334,14 @@ W: http://git.infradead.org/users/hch/dma-mapping.git 
S:	Supported

F:	lib/dma-debug.c

F:	lib/dma-direct.c

F:	lib/dma-noncoherent.c

F:	lib/dma-virt.c

F:	drivers/base/dma-mapping.c

F:	drivers/base/dma-coherent.c

F:	include/asm-generic/dma-mapping.h

F:	include/linux/dma-direct.h

F:	include/linux/dma-mapping.h

F:	include/linux/dma-noncoherent.h



DME1737 HARDWARE MONITOR DRIVER

M:	Juerg Haefliger <juergh@gmail.com>

include/asm-generic/dma-mapping.h

+9 −0
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@@ -4,7 +4,16 @@ 


static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)

{

	/*

	 * Use the non-coherent ops if available.  If an architecture wants a

	 * more fine-grained selection of operations it will have to implement

	 * get_arch_dma_ops itself or use the per-device dma_ops.

	 */

#ifdef CONFIG_DMA_NONCOHERENT_OPS

	return &dma_noncoherent_ops;

#else

	return &dma_direct_ops;

#endif

}



#endif /* _ASM_GENERIC_DMA_MAPPING_H */

include/linux/dma-direct.h

+6 −1
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@@ -59,6 +59,11 @@ void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, 
		gfp_t gfp, unsigned long attrs);

void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,

		dma_addr_t dma_addr, unsigned long attrs);

dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,

		unsigned long offset, size_t size, enum dma_data_direction dir,

		unsigned long attrs);

int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,

		enum dma_data_direction dir, unsigned long attrs);

int dma_direct_supported(struct device *dev, u64 mask);



int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr);

#endif /* _LINUX_DMA_DIRECT_H */

include/linux/dma-mapping.h

+1 −0
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@@ -136,6 +136,7 @@ struct dma_map_ops { 
};



extern const struct dma_map_ops dma_direct_ops;

extern const struct dma_map_ops dma_noncoherent_ops;

extern const struct dma_map_ops dma_virt_ops;



#define DMA_BIT_MASK(n)	(((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))

include/linux/dma-noncoherent.h

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/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _LINUX_DMA_NONCOHERENT_H

#define _LINUX_DMA_NONCOHERENT_H 1



#include <linux/dma-mapping.h>



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

		gfp_t gfp, unsigned long attrs);

void arch_dma_free(struct device *dev, size_t size, void *cpu_addr,

		dma_addr_t dma_addr, unsigned long attrs);



#ifdef CONFIG_DMA_NONCOHERENT_MMAP

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);

#else

#define arch_dma_mmap NULL

#endif /* CONFIG_DMA_NONCOHERENT_MMAP */



#ifdef CONFIG_DMA_NONCOHERENT_CACHE_SYNC

void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size,

		enum dma_data_direction direction);

#else

#define arch_dma_cache_sync NULL

#endif /* CONFIG_DMA_NONCOHERENT_CACHE_SYNC */



#ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE

void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,

		size_t size, enum dma_data_direction dir);

#else

static inline void arch_sync_dma_for_device(struct device *dev,

		phys_addr_t paddr, size_t size, enum dma_data_direction dir)

{

}

#endif /* ARCH_HAS_SYNC_DMA_FOR_DEVICE */



#ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU

void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,

		size_t size, enum dma_data_direction dir);

#else

static inline void arch_sync_dma_for_cpu(struct device *dev,

		phys_addr_t paddr, size_t size, enum dma_data_direction dir)

{

}

#endif /* ARCH_HAS_SYNC_DMA_FOR_CPU */



#endif /* _LINUX_DMA_NONCOHERENT_H */

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