From f0edfea8ef93ed6cc5f747c46c85c8e53e0798a0 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 24 Aug 2018 10:31:08 +0200 Subject: [PATCH] dma-mapping: move the remap helpers to a separate file The dma remap code only makes sense for not cache coherent architectures (or possibly the corner case of highmem CMA allocations) and currently is only used by arm, arm64, csky and xtensa. Split it out into a separate file with a separate Kconfig symbol, which gets the right copyright notice given that this code was written by Laura Abbott working for Code Aurora at that point. Signed-off-by: Christoph Hellwig Acked-by: Laura Abbott Reviewed-by: Robin Murphy --- arch/arm/Kconfig | 1 + arch/arm64/Kconfig | 1 + arch/csky/Kconfig | 1 + arch/xtensa/Kconfig | 1 + kernel/dma/Kconfig | 4 ++ kernel/dma/Makefile | 2 +- kernel/dma/mapping.c | 84 ------------------------------------------ kernel/dma/remap.c | 88 ++++++++++++++++++++++++++++++++++++++++++++ 8 files changed, 97 insertions(+), 85 deletions(-) create mode 100644 kernel/dma/remap.c diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 91be74d8df65..3b2852df6eb3 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -30,6 +30,7 @@ config ARM select CPU_PM if (SUSPEND || CPU_IDLE) select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS select DMA_DIRECT_OPS if !MMU + select DMA_REMAP if MMU select EDAC_SUPPORT select EDAC_ATOMIC_SCRUB select GENERIC_ALLOCATOR diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 787d7850e064..5d065acb6d10 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -82,6 +82,7 @@ config ARM64 select CRC32 select DCACHE_WORD_ACCESS select DMA_DIRECT_OPS + select DMA_REMAP select EDAC_SUPPORT select FRAME_POINTER select GENERIC_ALLOCATOR diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig index cb64f8dacd08..8a30e006a845 100644 --- a/arch/csky/Kconfig +++ b/arch/csky/Kconfig @@ -9,6 +9,7 @@ config CSKY select CLKSRC_OF select DMA_DIRECT_OPS select DMA_NONCOHERENT_OPS + select DMA_REMAP select IRQ_DOMAIN select HANDLE_DOMAIN_IRQ select DW_APB_TIMER_OF diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig index d29b7365da8d..239bfb16c58b 100644 --- a/arch/xtensa/Kconfig +++ b/arch/xtensa/Kconfig @@ -11,6 +11,7 @@ config XTENSA select CLONE_BACKWARDS select COMMON_CLK select DMA_DIRECT_OPS + select DMA_REMAP if MMU select GENERIC_ATOMIC64 select GENERIC_CLOCKEVENTS select GENERIC_IRQ_SHOW diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index 645c7a2ecde8..c92e08173ed8 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -51,3 +51,7 @@ config SWIOTLB bool select DMA_DIRECT_OPS select NEED_DMA_MAP_STATE + +config DMA_REMAP + depends on MMU + bool diff --git a/kernel/dma/Makefile b/kernel/dma/Makefile index 7d581e4eea4a..f4feeceb8020 100644 --- a/kernel/dma/Makefile +++ b/kernel/dma/Makefile @@ -7,4 +7,4 @@ obj-$(CONFIG_DMA_DIRECT_OPS) += direct.o obj-$(CONFIG_DMA_VIRT_OPS) += virt.o obj-$(CONFIG_DMA_API_DEBUG) += debug.o obj-$(CONFIG_SWIOTLB) += swiotlb.o - +obj-$(CONFIG_DMA_REMAP) += remap.o diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 58dec7a92b7b..dfbc3deb95cd 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -262,87 +262,3 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, #endif /* !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */ } EXPORT_SYMBOL(dma_common_mmap); - -#ifdef CONFIG_MMU -static struct vm_struct *__dma_common_pages_remap(struct page **pages, - size_t size, unsigned long vm_flags, pgprot_t prot, - const void *caller) -{ - struct vm_struct *area; - - area = get_vm_area_caller(size, vm_flags, caller); - if (!area) - return NULL; - - if (map_vm_area(area, prot, pages)) { - vunmap(area->addr); - return NULL; - } - - return area; -} - -/* - * remaps an array of PAGE_SIZE pages into another vm_area - * Cannot be used in non-sleeping contexts - */ -void *dma_common_pages_remap(struct page **pages, size_t size, - unsigned long vm_flags, pgprot_t prot, - const void *caller) -{ - struct vm_struct *area; - - area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller); - if (!area) - return NULL; - - area->pages = pages; - - return area->addr; -} - -/* - * remaps an allocated contiguous region into another vm_area. - * Cannot be used in non-sleeping contexts - */ - -void *dma_common_contiguous_remap(struct page *page, size_t size, - unsigned long vm_flags, - pgprot_t prot, const void *caller) -{ - int i; - struct page **pages; - struct vm_struct *area; - - pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL); - if (!pages) - return NULL; - - for (i = 0; i < (size >> PAGE_SHIFT); i++) - pages[i] = nth_page(page, i); - - area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller); - - kfree(pages); - - if (!area) - return NULL; - return area->addr; -} - -/* - * unmaps a range previously mapped by dma_common_*_remap - */ -void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags) -{ - struct vm_struct *area = find_vm_area(cpu_addr); - - if (!area || (area->flags & vm_flags) != vm_flags) { - WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr); - return; - } - - unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size)); - vunmap(cpu_addr); -} -#endif diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c new file mode 100644 index 000000000000..a15c393ea4e5 --- /dev/null +++ b/kernel/dma/remap.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2014 The Linux Foundation + */ +#include +#include +#include + +static struct vm_struct *__dma_common_pages_remap(struct page **pages, + size_t size, unsigned long vm_flags, pgprot_t prot, + const void *caller) +{ + struct vm_struct *area; + + area = get_vm_area_caller(size, vm_flags, caller); + if (!area) + return NULL; + + if (map_vm_area(area, prot, pages)) { + vunmap(area->addr); + return NULL; + } + + return area; +} + +/* + * Remaps an array of PAGE_SIZE pages into another vm_area. + * Cannot be used in non-sleeping contexts + */ +void *dma_common_pages_remap(struct page **pages, size_t size, + unsigned long vm_flags, pgprot_t prot, + const void *caller) +{ + struct vm_struct *area; + + area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller); + if (!area) + return NULL; + + area->pages = pages; + + return area->addr; +} + +/* + * Remaps an allocated contiguous region into another vm_area. + * Cannot be used in non-sleeping contexts + */ +void *dma_common_contiguous_remap(struct page *page, size_t size, + unsigned long vm_flags, + pgprot_t prot, const void *caller) +{ + int i; + struct page **pages; + struct vm_struct *area; + + pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL); + if (!pages) + return NULL; + + for (i = 0; i < (size >> PAGE_SHIFT); i++) + pages[i] = nth_page(page, i); + + area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller); + + kfree(pages); + + if (!area) + return NULL; + return area->addr; +} + +/* + * Unmaps a range previously mapped by dma_common_*_remap + */ +void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags) +{ + struct vm_struct *area = find_vm_area(cpu_addr); + + if (!area || (area->flags & vm_flags) != vm_flags) { + WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr); + return; + } + + unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size)); + vunmap(cpu_addr); +}