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Commit 4ac42c44 authored by Laura Abbott's avatar Laura Abbott Committed by Saravana Kannan
Browse files

ANDROID: GKI: arm64: add support for NO_KERNEL_MAPPING and STRONGLY_ORDERED 



arm64 needs support for both DMA_ATTR_NO_KERNEL_MAPPING and
DMA_ATTR_STRONGLY_ORDERD. Add support for both of them.

Change-Id: I35d670b8639fed465d2adbe8972ded40bd9f1d1c
Signed-off-by: default avatarLaura Abbott <lauraa@codeaurora.org>
Signed-off-by: default avatarPatrick Daly <pdaly@codeaurora.org>
Bug: 155522481
Signed-off-by: default avatarMark Salyzyn <salyzyn@google.com>
[saravanak snapshot from commit 79efc458af96 that approximately matches
commit 28a88c9d84abb3180bc651a29074f79ef0474b48]
Signed-off-by: default avatarSaravana Kannan <saravanak@google.com>
parent 9257548d

arch/arm64/mm/dma-mapping.c

+69 −11
Original line number Diff line number Diff line
@@ -44,13 +44,16 @@ static int swiotlb __ro_after_init; 
static pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot,

				 bool coherent)

{

	if (!coherent || (attrs & DMA_ATTR_WRITE_COMBINE))

	if (attrs & DMA_ATTR_STRONGLY_ORDERED)

		return pgprot_noncached(prot);

	else if (!coherent || (attrs & DMA_ATTR_WRITE_COMBINE))

		return pgprot_writecombine(prot);

	return prot;

}



static struct gen_pool *atomic_pool __ro_after_init;



#define NO_KERNEL_MAPPING_DUMMY 0x2222

#define DEFAULT_DMA_COHERENT_POOL_SIZE  SZ_256K

static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE;
@@ -98,6 +101,43 @@ static int __free_from_pool(void *start, size_t size) 
	return 1;

}



static int __dma_update_pte(pte_t *pte, pgtable_t token, unsigned long addr,

			    void *data)

{

	struct page *page = virt_to_page(addr);

	pgprot_t prot = *(pgprot_t *)data;



	set_pte(pte, mk_pte(page, prot));

	return 0;

}



static int __dma_clear_pte(pte_t *pte, pgtable_t token, unsigned long addr,

			    void *data)

{

	pte_clear(&init_mm, addr, pte);

	return 0;

}



static void __dma_remap(struct page *page, size_t size, pgprot_t prot,

			bool no_kernel_map)

{

	unsigned long start = (unsigned long) page_address(page);

	unsigned long end = start + size;

	int (*func)(pte_t *pte, pgtable_t token, unsigned long addr,

			    void *data);



	if (no_kernel_map)

		func = __dma_clear_pte;

	else

		func = __dma_update_pte;



	apply_to_page_range(&init_mm, start, size, func, &prot);

	/* ensure prot is applied before returning */

	mb();

	flush_tlb_kernel_range(start, end);

}





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

			 dma_addr_t *dma_handle, gfp_t flags,

			 unsigned long attrs)
@@ -127,19 +167,31 @@ static void *__dma_alloc(struct device *dev, size_t size, 
	if (coherent)

		return ptr;



	/* remove any dirty cache lines on the kernel alias */

	__dma_flush_area(ptr, size);



	if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) {

		coherent_ptr = (void *)NO_KERNEL_MAPPING_DUMMY;

		__dma_remap(virt_to_page(ptr), size, __pgprot(0), true);

	} else {

		if ((attrs & DMA_ATTR_STRONGLY_ORDERED))

			__dma_remap(virt_to_page(ptr), size, __pgprot(0), true);



		/* create a coherent mapping */

		page = virt_to_page(ptr);

	coherent_ptr = dma_common_contiguous_remap(page, size, VM_USERMAP,

						   prot, __builtin_return_address(0));

		coherent_ptr = dma_common_contiguous_remap(

					page, size, VM_USERMAP, prot,

					__builtin_return_address(0));

		if (!coherent_ptr)

			goto no_map;



	}

	return coherent_ptr;



no_map:

	if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) ||

	    (attrs & DMA_ATTR_STRONGLY_ORDERED))

		__dma_remap(phys_to_page(dma_to_phys(dev, *dma_handle)),

				size, PAGE_KERNEL, false);



	swiotlb_free(dev, size, ptr, *dma_handle, attrs);

no_mem:

	return NULL;
@@ -153,11 +205,17 @@ static void __dma_free(struct device *dev, size_t size, 


	size = PAGE_ALIGN(size);



	if (!is_device_dma_coherent(dev)) {

	if (!is_dma_coherent(dev, attrs)) {

		if (__free_from_pool(vaddr, size))

			return;

		if (!(attrs & DMA_ATTR_NO_KERNEL_MAPPING))

			vunmap(vaddr);

	}

	if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) ||

	    (attrs & DMA_ATTR_STRONGLY_ORDERED))

		__dma_remap(phys_to_page(dma_to_phys(dev, dma_handle)),

				size, PAGE_KERNEL, false);



	swiotlb_free(dev, size, swiotlb_addr, dma_handle, attrs);

}