Messages in this thread Patch in this message | | | Subject | Re: [PATCH] dma-mapping: move the remap helpers to a separate file | From | Laura Abbott <> | Date | Sun, 21 Oct 2018 00:41:42 -0700 |
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On 10/14/2018 11:16 AM, Christoph Hellwig wrote: > The dma remap code only really makes sense for not cache coherent > architectures, and currently is only used by arm, arm64 and xtensa. > Split it out into a separate file with a separate Kconfig symbol. > > [Laura: you wrote this code back then, do you have a sensible > copyright statement to add, given that the mapping.c statement > obviously does not match your code that was written much later] >
Hmmmmm, that was written and committed via my codeaurora.org e-mail address. Probably best to use "Copyright (c) 2014, The Linux Foundation" since that was the standard. If you want,
Acked-by: Laura Abbott <labbott@redhat.com>
Thanks, Laura
> Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > arch/arm/Kconfig | 1 + > arch/arm64/Kconfig | 1 + > arch/xtensa/Kconfig | 1 + > kernel/dma/Kconfig | 4 +++ > kernel/dma/Makefile | 2 +- > kernel/dma/mapping.c | 84 ------------------------------------------- > kernel/dma/remap.c | 85 ++++++++++++++++++++++++++++++++++++++++++++ > 7 files changed, 93 insertions(+), 85 deletions(-) > create mode 100644 kernel/dma/remap.c > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index e8cd55a5b04c..cf54e572dafd 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 1b1a0e95c751..179994b67d11 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -77,6 +77,7 @@ config ARM64 > select CPU_PM if (SUSPEND || CPU_IDLE) > select DCACHE_WORD_ACCESS > select DMA_DIRECT_OPS > + select DMA_REMAP > select EDAC_SUPPORT > select FRAME_POINTER > select GENERIC_ALLOCATOR > diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig > index 9a7c654a7654..d57abe4cad0f 100644 > --- a/arch/xtensa/Kconfig > +++ b/arch/xtensa/Kconfig > @@ -10,6 +10,7 @@ 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..33dff4096d46 > --- /dev/null > +++ b/kernel/dma/remap.c > @@ -0,0 +1,85 @@ > +// SPDX-License-Identifier: GPL-2.0 > +#include <linux/dma-mapping.h> > +#include <linux/slab.h> > +#include <linux/vmalloc.h> > + > +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); > +}
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