Merge "ARM: dma-mapping: Allow highmem pages to not have a mapping" (9bc9333e) · Commits · e / devices / android_kernel_fairphone_FP3

arch/arm/mm/dma-mapping.c

+45 −23

Original line number	Diff line number	Diff line
		@@ -375,10 +375,10 @@ __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, false);
		VM_ARM_DMA_CONSISTENT \| VM_USERMAP, no_warn);
		}

		#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
		@@ -527,21 +527,39 @@ static int __dma_update_pte(pte_t *pte, pgtable_t token, unsigned long addr,
		return 0;
		}

		static void __dma_remap(struct page *page, size_t size, pgprot_t prot)
		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 want_vaddr)
		{
		unsigned long start = (unsigned long) page_address(page);
		unsigned end = start + size;
		int (func)(pte_t pte, pgtable_t token, unsigned long addr,
		void *data);

		apply_to_page_range(&init_mm, start, size, __dma_update_pte, &prot);
		if (!want_vaddr)
		func = __dma_clear_pte;
		else
		func = __dma_update_pte;

		apply_to_page_range(&init_mm, start, size, func, &prot);
		mb(); /Ensure pte's are updated /
		flush_tlb_kernel_range(start, end);
		}


		#define NO_KERNEL_MAPPING_DUMMY 0x2222
		static void __alloc_remap_buffer(struct device dev, size_t size, gfp_t gfp,
		pgprot_t prot, struct page **ret_page,
		const void *caller, bool want_vaddr)
		{
		struct page *page;
		void *ptr = NULL;
		void ptr = (void )NO_KERNEL_MAPPING_DUMMY;
		/*
		* __alloc_remap_buffer is only called when the device is
		* non-coherent
		@@ -620,21 +638,27 @@ static void __alloc_from_contiguous(struct device dev, size_t size,
		if (!(skip_cpu_sync && skip_zeroing))
		__dma_clear_buffer(page, size, skip_zeroing, coherent_flag);

		if (!want_vaddr)
		goto out;

		if (PageHighMem(page)) {
		ptr = __dma_alloc_remap(page, size, GFP_KERNEL, prot, caller);
		if (!want_vaddr) {
		/*
		* 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);
		__dma_remap(page, size, prot, want_vaddr);
		ptr = page_address(page);
		}

		out:
		*ret_page = page;
		return ptr;
		}
		@@ -642,12 +666,10 @@ static void __alloc_from_contiguous(struct device dev, size_t size,
		static void __free_from_contiguous(struct device dev, struct page page,
		void *cpu_addr, size_t size, bool want_vaddr)
		{
		if (want_vaddr) {
		if (PageHighMem(page))
		__dma_free_remap(cpu_addr, size);
		__dma_free_remap(cpu_addr, size, true);
		else
		__dma_remap(page, size, PAGE_KERNEL);
		}
		__dma_remap(page, size, PAGE_KERNEL, true);
		dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
		}

		@@ -672,7 +694,7 @@ static inline pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot)
		wv, scs, sz, coherent_flag) NULL
		#define __free_from_pool(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)
		#define __dma_free_remap(cpu_addr, size, w) do { } while (0)

		#endif /* CONFIG_MMU */

		@@ -753,7 +775,7 @@ static void remap_allocator_alloc(struct arm_dma_alloc_args args,
		static void remap_allocator_free(struct arm_dma_free_args *args)
		{
		if (args->want_vaddr)
		__dma_free_remap(args->cpu_addr, args->size);
		__dma_free_remap(args->cpu_addr, args->size, false);

		__dma_free_buffer(args->page, args->size);
		}
		@@ -842,7 +864,7 @@ static void __dma_alloc(struct device dev, size_t size, dma_addr_t *handle,
		kfree(buf);
		}

		return args.want_vaddr ? addr : page;
		return addr;
		}

		/*