Add a new file that contains helpera for misc DMA ops, which is only built when CONFIG_DMA_OPS is set.
Signed-off-by: Christoph Hellwig hch@lst.de --- kernel/dma/Makefile | 1 + kernel/dma/mapping.c | 47 +----------------------------------- kernel/dma/ops_helpers.c | 51 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 53 insertions(+), 46 deletions(-) create mode 100644 kernel/dma/ops_helpers.c
diff --git a/kernel/dma/Makefile b/kernel/dma/Makefile index 32c7c1942bbd6c..dc755ab68aabf9 100644 --- a/kernel/dma/Makefile +++ b/kernel/dma/Makefile @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_HAS_DMA) += mapping.o direct.o +obj-$(CONFIG_DMA_OPS) += ops_helpers.o obj-$(CONFIG_DMA_OPS) += dummy.o obj-$(CONFIG_DMA_CMA) += contiguous.o obj-$(CONFIG_DMA_DECLARE_COHERENT) += coherent.o diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 0d129421e75fc8..848c95c27d79ff 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -8,7 +8,7 @@ #include <linux/memblock.h> /* for max_pfn */ #include <linux/acpi.h> #include <linux/dma-direct.h> -#include <linux/dma-noncoherent.h> +#include <linux/dma-mapping.h> #include <linux/export.h> #include <linux/gfp.h> #include <linux/of_device.h> @@ -295,22 +295,6 @@ void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, } EXPORT_SYMBOL(dma_sync_sg_for_device);
-/* - * Create scatter-list for the already allocated DMA buffer. - */ -int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, - void *cpu_addr, dma_addr_t dma_addr, size_t size, - unsigned long attrs) -{ - struct page *page = virt_to_page(cpu_addr); - int ret; - - ret = sg_alloc_table(sgt, 1, GFP_KERNEL); - if (!ret) - sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); - return ret; -} - /* * The whole dma_get_sgtable() idea is fundamentally unsafe - it seems * that the intention is to allow exporting memory allocated via the @@ -358,35 +342,6 @@ pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs) } #endif /* CONFIG_MMU */
-/* - * Create userspace mapping for the DMA-coherent memory. - */ -int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, - void *cpu_addr, dma_addr_t dma_addr, size_t size, - unsigned long attrs) -{ -#ifdef CONFIG_MMU - unsigned long user_count = vma_pages(vma); - unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; - unsigned long off = vma->vm_pgoff; - int ret = -ENXIO; - - vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs); - - if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret)) - return ret; - - if (off >= count || user_count > count - off) - return -ENXIO; - - return remap_pfn_range(vma, vma->vm_start, - page_to_pfn(virt_to_page(cpu_addr)) + vma->vm_pgoff, - user_count << PAGE_SHIFT, vma->vm_page_prot); -#else - return -ENXIO; -#endif /* CONFIG_MMU */ -} - /** * dma_can_mmap - check if a given device supports dma_mmap_* * @dev: device to check diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c new file mode 100644 index 00000000000000..e443c69be4299f --- /dev/null +++ b/kernel/dma/ops_helpers.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Helpers for DMA ops implementations. These generally rely on the fact that + * the allocated memory contains normal pages in the direct kernel mapping. + */ +#include <linux/dma-noncoherent.h> + +/* + * Create scatter-list for the already allocated DMA buffer. + */ +int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt, + void *cpu_addr, dma_addr_t dma_addr, size_t size, + unsigned long attrs) +{ + struct page *page = virt_to_page(cpu_addr); + int ret; + + ret = sg_alloc_table(sgt, 1, GFP_KERNEL); + if (!ret) + sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); + return ret; +} + +/* + * Create userspace mapping for the DMA-coherent memory. + */ +int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t dma_addr, size_t size, + unsigned long attrs) +{ +#ifdef CONFIG_MMU + unsigned long user_count = vma_pages(vma); + unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; + unsigned long off = vma->vm_pgoff; + int ret = -ENXIO; + + vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs); + + if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret)) + return ret; + + if (off >= count || user_count > count - off) + return -ENXIO; + + return remap_pfn_range(vma, vma->vm_start, + page_to_pfn(virt_to_page(cpu_addr)) + vma->vm_pgoff, + user_count << PAGE_SHIFT, vma->vm_page_prot); +#else + return -ENXIO; +#endif /* CONFIG_MMU */ +}