Commit dd37e940 authored by Rob Herring's avatar Rob Herring Committed by Marek Szyprowski
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ARM: add coherent dma ops 



arch_is_coherent is problematic as it is a global symbol. This
doesn't work for multi-platform kernels or platforms which can support
per device coherent DMA.

This adds arm_coherent_dma_ops to be used for devices which connected
coherently (i.e. to the ACP port on Cortex-A9 or A15). The arm_dma_ops
are modified at boot when arch_is_coherent is true.

Signed-off-by: default avatarRob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
parent a0d271cb

arch/arm/include/asm/dma-mapping.h

+1 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 


#define DMA_ERROR_CODE	(~0)

extern struct dma_map_ops arm_dma_ops;

extern struct dma_map_ops arm_coherent_dma_ops;



static inline struct dma_map_ops *get_dma_ops(struct device *dev)

{

arch/arm/mm/dma-mapping.c

+59 −12
Original line number Diff line number Diff line
@@ -73,11 +73,18 @@ static dma_addr_t arm_dma_map_page(struct device *dev, struct page *page, 
	     unsigned long offset, size_t size, enum dma_data_direction dir,

	     struct dma_attrs *attrs)

{

	if (!arch_is_coherent() && !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))

	if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))

		__dma_page_cpu_to_dev(page, offset, size, dir);

	return pfn_to_dma(dev, page_to_pfn(page)) + offset;

}



static dma_addr_t arm_coherent_dma_map_page(struct device *dev, struct page *page,

	     unsigned long offset, size_t size, enum dma_data_direction dir,

	     struct dma_attrs *attrs)

{

	return pfn_to_dma(dev, page_to_pfn(page)) + offset;

}



/**

 * arm_dma_unmap_page - unmap a buffer previously mapped through dma_map_page()

 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
@@ -96,7 +103,7 @@ static void arm_dma_unmap_page(struct device *dev, dma_addr_t handle, 
		size_t size, enum dma_data_direction dir,

		struct dma_attrs *attrs)

{

	if (!arch_is_coherent() && !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))

	if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))

		__dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),

				      handle & ~PAGE_MASK, size, dir);

}
@@ -106,7 +113,6 @@ static void arm_dma_sync_single_for_cpu(struct device *dev, 
{

	unsigned int offset = handle & (PAGE_SIZE - 1);

	struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));

	if (!arch_is_coherent())

	__dma_page_dev_to_cpu(page, offset, size, dir);

}
@@ -115,7 +121,6 @@ static void arm_dma_sync_single_for_device(struct device *dev, 
{

	unsigned int offset = handle & (PAGE_SIZE - 1);

	struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));

	if (!arch_is_coherent())

	__dma_page_cpu_to_dev(page, offset, size, dir);

}
@@ -138,6 +143,22 @@ struct dma_map_ops arm_dma_ops = { 
};

EXPORT_SYMBOL(arm_dma_ops);



static void *arm_coherent_dma_alloc(struct device *dev, size_t size,

	dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs);

static void arm_coherent_dma_free(struct device *dev, size_t size, void *cpu_addr,

				  dma_addr_t handle, struct dma_attrs *attrs);



struct dma_map_ops arm_coherent_dma_ops = {

	.alloc			= arm_coherent_dma_alloc,

	.free			= arm_coherent_dma_free,

	.mmap			= arm_dma_mmap,

	.get_sgtable		= arm_dma_get_sgtable,

	.map_page		= arm_coherent_dma_map_page,

	.map_sg			= arm_dma_map_sg,

	.set_dma_mask		= arm_dma_set_mask,

};

EXPORT_SYMBOL(arm_coherent_dma_ops);



static u64 get_coherent_dma_mask(struct device *dev)

{

	u64 mask = (u64)arm_dma_limit;
@@ -586,7 +607,7 @@ static void *__alloc_simple_buffer(struct device *dev, size_t size, gfp_t gfp, 




static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,

			 gfp_t gfp, pgprot_t prot, const void *caller)

			 gfp_t gfp, pgprot_t prot, bool is_coherent, const void *caller)

{

	u64 mask = get_coherent_dma_mask(dev);

	struct page *page;
@@ -619,7 +640,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, 
	*handle = DMA_ERROR_CODE;

	size = PAGE_ALIGN(size);



	if (arch_is_coherent() || nommu())

	if (is_coherent || nommu())

		addr = __alloc_simple_buffer(dev, size, gfp, &page);

	else if (gfp & GFP_ATOMIC)

		addr = __alloc_from_pool(size, &page);
@@ -647,7 +668,20 @@ void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, 
	if (dma_alloc_from_coherent(dev, size, handle, &memory))

		return memory;



	return __dma_alloc(dev, size, handle, gfp, prot,

	return __dma_alloc(dev, size, handle, gfp, prot, false,

			   __builtin_return_address(0));

}



static void *arm_coherent_dma_alloc(struct device *dev, size_t size,

	dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)

{

	pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);

	void *memory;



	if (dma_alloc_from_coherent(dev, size, handle, &memory))

		return memory;



	return __dma_alloc(dev, size, handle, gfp, prot, true,

			   __builtin_return_address(0));

}
@@ -684,8 +718,9 @@ int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma, 
/*

 * Free a buffer as defined by the above mapping.

 */

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

		  dma_addr_t handle, struct dma_attrs *attrs)

static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,

			   dma_addr_t handle, struct dma_attrs *attrs,

			   bool is_coherent)

{

	struct page *page = pfn_to_page(dma_to_pfn(dev, handle));
@@ -694,7 +729,7 @@ void arm_dma_free(struct device *dev, size_t size, void *cpu_addr, 


	size = PAGE_ALIGN(size);



	if (arch_is_coherent() || nommu()) {

	if (is_coherent || nommu()) {

		__dma_free_buffer(page, size);

	} else if (__free_from_pool(cpu_addr, size)) {

		return;
@@ -710,6 +745,18 @@ void arm_dma_free(struct device *dev, size_t size, void *cpu_addr, 
	}

}



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

		  dma_addr_t handle, struct dma_attrs *attrs)

{

	__arm_dma_free(dev, size, cpu_addr, handle, attrs, false);

}



static void arm_coherent_dma_free(struct device *dev, size_t size, void *cpu_addr,

				  dma_addr_t handle, struct dma_attrs *attrs)

{

	__arm_dma_free(dev, size, cpu_addr, handle, attrs, true);

}



int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,

		 void *cpu_addr, dma_addr_t handle, size_t size,

		 struct dma_attrs *attrs)

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