Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9c120d5b authored by Laura Abbott's avatar Laura Abbott Committed by Matt Wagantall
Browse files

ARM: dma-mapping: Allow highmem pages to not have a mapping 



The DMA_ATTR_NO_KERNEL_MAPPING is used to make sure that CMA
pages have no kernel mapping. Add support to make sure that
highmem pages have no mapping.

Change-Id: Ife76df126ecfedf0dba81a35e0de8a1787355b3d
Signed-off-by: default avatarLaura Abbott <lauraa@codeaurora.org>
Signed-off-by: default avatarRohit Vaswani <rvaswani@codeaurora.org>
parent 7b3555b5

arch/arm/mm/dma-mapping.c

+22 −11
Original line number Diff line number Diff line
@@ -326,10 +326,10 @@ __dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot, 
			prot, caller);

}



static void __dma_free_remap(void *cpu_addr, size_t size)

static void __dma_free_remap(void *cpu_addr, size_t size, bool no_warn)

{

	dma_common_free_remap(cpu_addr, size,

			VM_ARM_DMA_CONSISTENT | VM_USERMAP);

			VM_ARM_DMA_CONSISTENT | VM_USERMAP, no_warn);

}



#define DEFAULT_DMA_COHERENT_POOL_SIZE	SZ_256K
@@ -374,8 +374,8 @@ static int __init atomic_pool_init(void) 
		goto out;



	if (IS_ENABLED(CONFIG_DMA_CMA))

		ptr = __alloc_from_contiguous(NULL, pool->size, prot, &page,

					      atomic_pool_init, false);

		ptr = __alloc_from_contiguous(NULL, atomic_pool_size, prot,

				&page, atomic_pool_init, false);

	else

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

					   &page, atomic_pool_init);
@@ -555,6 +555,7 @@ static int __free_from_pool(void *start, size_t size) 
	return 1;

}



#define NO_KERNEL_MAPPING_DUMMY	0x2222

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

				     pgprot_t prot, struct page **ret_page,

				     const void *caller,
@@ -572,11 +573,21 @@ static void *__alloc_from_contiguous(struct device *dev, size_t size, 
	__dma_clear_buffer(page, size);



	if (PageHighMem(page)) {

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

		if (no_kernel_mapping) {

			/*

			 * Something non-NULL needs to be returned here. Give

			 * back a dummy address that is unmapped to catch

			 * clients trying to use the address incorrectly

			 */

			ptr = (void *)NO_KERNEL_MAPPING_DUMMY;

		} else {

			ptr = __dma_alloc_remap(page, size, GFP_KERNEL, prot,

						caller);

			if (!ptr) {

				dma_release_from_contiguous(dev, page, count);

				return NULL;

			}

		}

	} else {

		__dma_remap(page, size, prot, no_kernel_mapping);

		ptr = page_address(page);
@@ -589,7 +600,7 @@ static void __free_from_contiguous(struct device *dev, struct page *page, 
				   void *cpu_addr, size_t size)

{

	if (PageHighMem(page))

		__dma_free_remap(cpu_addr, size);

		__dma_free_remap(cpu_addr, size, true);

	else

		__dma_remap(page, size, pgprot_kernel, false);

	dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
@@ -620,7 +631,7 @@ static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot) 
#define __alloc_from_contiguous(dev, size, prot, ret, c, w)	NULL

#define __free_from_pool(cpu_addr, size)			0

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

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

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



#endif	/* CONFIG_MMU */
@@ -802,7 +813,7 @@ 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)) {

		__dma_free_remap(cpu_addr, size);

		__dma_free_remap(cpu_addr, size, false);

		__dma_free_buffer(page, size);

	} else {

		/*