*参照元 [#j0e2c692] #backlinks *説明 [#oa955ac5] -パス: [[linux-4.4.1/arch/arm/mm/dma-mapping.c]] -FIXME: これは何? --説明 **引数 [#vc775079] -struct device *dev -- --[[linux-4.4.1/device]] -struct vm_area_struct *vma -- --[[linux-4.4.1/vm_area_struct]] -void *cpu_addr -- -dma_addr_t dma_addr -- --[[linux-4.4.1/dma_addr_t]] -size_t size -- -struct dma_attrs *attrs -- --[[linux-4.4.1/dma_attrs]] **返り値 [#h03bec6c] -int -- **参考 [#t3640eb0] *実装 [#g05af261] static int __arm_dma_mmap(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs) { int ret = -ENXIO; #ifdef CONFIG_MMU - --[[linux-4.4.1/CONFIG_MMU]] unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; unsigned long pfn = dma_to_pfn(dev, dma_addr); unsigned long off = vma->vm_pgoff; - --[[linux-4.4.1/PAGE_ALIGN()]] --[[linux-4.4.1/PAGE_SHIFT]] --[[linux-4.4.1/dma_to_pfn()]] if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret)) return ret; - --[[linux-4.4.1/dma_mmap_from_coherent()]] if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) { ret = remap_pfn_range(vma, vma->vm_start, pfn + off, vma->vm_end - vma->vm_start, vma->vm_page_prot); - --[[linux-4.4.1/remap_pfn_range()]] } #endif /* CONFIG_MMU */ return ret; } *コメント [#vf05078d]