Commit 6e8266e3 authored by Carlo Caione's avatar Carlo Caione Committed by Russell King
Browse files

ARM: 8304/1: Respect NO_KERNEL_MAPPING when we don't have an IOMMU 



Even without an iommu, NO_KERNEL_MAPPING is still convenient to save on
kernel address space in places where we don't need a kernel mapping.
Implement support for it in the two places where we're creating an
expensive mapping.

__alloc_from_pool uses an internal pool from which we already have
virtual addresses, so it's not relevant, and __alloc_simple_buffer uses
alloc_pages, which will always return a lowmem page, which is already
mapped into kernel space, so we can't prevent a mapping for it in that
case.

Signed-off-by: default avatarJasper St. Pierre <jstpierre@mecheye.net>
Signed-off-by: default avatarCarlo Caione <carlo@caione.org>
Reviewed-by: default avatarRob Clark <robdclark@gmail.com>
Reviewed-by: default avatarDaniel Drake <dsd@endlessm.com>
Acked-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 415ae101

arch/arm/mm/dma-mapping.c

+41 −26
Original line number Diff line number Diff line
@@ -289,11 +289,11 @@ static void __dma_free_buffer(struct page *page, size_t size) 


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

				     pgprot_t prot, struct page **ret_page,

				     const void *caller);

				     const void *caller, bool want_vaddr);



static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,

				 pgprot_t prot, struct page **ret_page,

				 const void *caller);

				 const void *caller, bool want_vaddr);



static void *

__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
@@ -357,10 +357,10 @@ static int __init atomic_pool_init(void) 


	if (dev_get_cma_area(NULL))

		ptr = __alloc_from_contiguous(NULL, atomic_pool_size, prot,

					      &page, atomic_pool_init);

					      &page, atomic_pool_init, true);

	else

		ptr = __alloc_remap_buffer(NULL, atomic_pool_size, gfp, prot,

					   &page, atomic_pool_init);

					   &page, atomic_pool_init, true);

	if (ptr) {

		int ret;
@@ -467,13 +467,15 @@ static void __dma_remap(struct page *page, size_t size, pgprot_t prot) 


static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,

				 pgprot_t prot, struct page **ret_page,

				 const void *caller)

				 const void *caller, bool want_vaddr)

{

	struct page *page;

	void *ptr;

	void *ptr = NULL;

	page = __dma_alloc_buffer(dev, size, gfp);

	if (!page)

		return NULL;

	if (!want_vaddr)

		goto out;



	ptr = __dma_alloc_remap(page, size, gfp, prot, caller);

	if (!ptr) {
@@ -481,6 +483,7 @@ static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp, 
		return NULL;

	}



 out:

	*ret_page = page;

	return ptr;

}
@@ -523,12 +526,12 @@ static int __free_from_pool(void *start, size_t size) 


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

				     pgprot_t prot, struct page **ret_page,

				     const void *caller)

				     const void *caller, bool want_vaddr)

{

	unsigned long order = get_order(size);

	size_t count = size >> PAGE_SHIFT;

	struct page *page;

	void *ptr;

	void *ptr = NULL;



	page = dma_alloc_from_contiguous(dev, count, order);

	if (!page)
@@ -536,6 +539,9 @@ static void *__alloc_from_contiguous(struct device *dev, size_t size, 


	__dma_clear_buffer(page, size);



	if (!want_vaddr)

		goto out;



	if (PageHighMem(page)) {

		ptr = __dma_alloc_remap(page, size, GFP_KERNEL, prot, caller);

		if (!ptr) {
@@ -546,17 +552,21 @@ static void *__alloc_from_contiguous(struct device *dev, size_t size, 
		__dma_remap(page, size, prot);

		ptr = page_address(page);

	}



 out:

	*ret_page = page;

	return ptr;

}



static void __free_from_contiguous(struct device *dev, struct page *page,

				   void *cpu_addr, size_t size)

				   void *cpu_addr, size_t size, bool want_vaddr)

{

	if (want_vaddr) {

		if (PageHighMem(page))

			__dma_free_remap(cpu_addr, size);

		else

			__dma_remap(page, size, PAGE_KERNEL);

	}

	dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);

}
@@ -575,11 +585,11 @@ static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot) 
#define nommu() 1



#define __get_dma_pgprot(attrs, prot)				__pgprot(0)

#define __alloc_remap_buffer(dev, size, gfp, prot, ret, c)	NULL

#define __alloc_remap_buffer(dev, size, gfp, prot, ret, c, wv)	NULL

#define __alloc_from_pool(size, ret_page)			NULL

#define __alloc_from_contiguous(dev, size, prot, ret, c)	NULL

#define __alloc_from_contiguous(dev, size, prot, ret, c, wv)	NULL

#define __free_from_pool(cpu_addr, size)			0

#define __free_from_contiguous(dev, page, cpu_addr, size)	do { } while (0)

#define __free_from_contiguous(dev, page, cpu_addr, size, wv)	do { } while (0)

#define __dma_free_remap(cpu_addr, size)			do { } while (0)



#endif	/* CONFIG_MMU */
@@ -599,11 +609,13 @@ 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, bool is_coherent, const void *caller)

			 gfp_t gfp, pgprot_t prot, bool is_coherent,

			 struct dma_attrs *attrs, const void *caller)

{

	u64 mask = get_coherent_dma_mask(dev);

	struct page *page = NULL;

	void *addr;

	bool want_vaddr;



#ifdef CONFIG_DMA_API_DEBUG

	u64 limit = (mask + 1) & ~mask;
@@ -631,20 +643,21 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, 


	*handle = DMA_ERROR_CODE;

	size = PAGE_ALIGN(size);

	want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs);



	if (is_coherent || nommu())

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

	else if (!(gfp & __GFP_WAIT))

		addr = __alloc_from_pool(size, &page);

	else if (!dev_get_cma_area(dev))

		addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller);

		addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller, want_vaddr);

	else

		addr = __alloc_from_contiguous(dev, size, prot, &page, caller);

		addr = __alloc_from_contiguous(dev, size, prot, &page, caller, want_vaddr);



	if (addr)

	if (page)

		*handle = pfn_to_dma(dev, page_to_pfn(page));



	return addr;

	return want_vaddr ? addr : page;

}



/*
@@ -661,7 +674,7 @@ void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, 
		return memory;



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

			   __builtin_return_address(0));

			   attrs, __builtin_return_address(0));

}



static void *arm_coherent_dma_alloc(struct device *dev, size_t size,
@@ -674,7 +687,7 @@ static void *arm_coherent_dma_alloc(struct device *dev, size_t size, 
		return memory;



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

			   __builtin_return_address(0));

			   attrs, __builtin_return_address(0));

}



/*
@@ -715,6 +728,7 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr, 
			   bool is_coherent)

{

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

	bool want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs);



	if (dma_release_from_coherent(dev, get_order(size), cpu_addr))

		return;
@@ -726,6 +740,7 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr, 
	} else if (__free_from_pool(cpu_addr, size)) {

		return;

	} else if (!dev_get_cma_area(dev)) {

		if (want_vaddr)

			__dma_free_remap(cpu_addr, size);

		__dma_free_buffer(page, size);

	} else {
@@ -733,7 +748,7 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr, 
		 * Non-atomic allocations cannot be freed with IRQs disabled

		 */

		WARN_ON(irqs_disabled());

		__free_from_contiguous(dev, page, cpu_addr, size);

		__free_from_contiguous(dev, page, cpu_addr, size, want_vaddr);

	}

}

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