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*参照元 [#ce356618] #backlinks *説明 [#i6dcab09] -パス: --MMU 無効（CONFIG_MMU = n）の場合: [[linux-2.6.33/mm/nommu.c]] --MMU 有効（CONFIG_MMU = y）の場合: [[linux-2.6.33/mm/memory.c]] -FIXME: これは何？ --説明 **引数 [#m2126d24] -struct vm_area_struct *vma -- --[[linux-2.6.33/vm_area_struct]] -unsigned long from -- -unsigned long to -- -unsigned long size -- -pgprot_t prot -- --[[linux-2.6.33/pgprot_t]] **返り値 [#n9fba260] -int --成功ならば 0、失敗ならば負のエラー番号を返す。 **参考 [#sbbafe16] *実装 [#x413f449] **MMU 無効の場合 [#q7890196] int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long to, unsigned long size, pgprot_t prot) { vma->vm_start = vma->vm_pgoff << PAGE_SHIFT; - --[[linux-2.6.33/PAGE_SHIFT]] return 0; } EXPORT_SYMBOL(remap_pfn_range); -ライセンスに関わらずシンボルを公開する。 --[[linux-2.6.33/EXPORT_SYMBOL()]] **MMU 有効の場合 [#e04c8f21] /** * remap_pfn_range - remap kernel memory to userspace * @vma: user vma to map to * @addr: target user address to start at * @pfn: physical address of kernel memory * @size: size of map area * @prot: page protection flags for this mapping * * Note: this is only safe if the mm semaphore is held when called. */ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn, unsigned long size, pgprot_t prot) { pgd_t *pgd; unsigned long next; unsigned long end = addr + PAGE_ALIGN(size); struct mm_struct *mm = vma->vm_mm; int err; - --[[linux-2.6.33/pgd_t]] --[[linux-2.6.33/mm_struct]] --[[linux-2.6.33/PAGE_ALIGN()]] /* * Physically remapped pages are special. Tell the * rest of the world about it: * VM_IO tells people not to look at these pages * (accesses can have side effects). * VM_RESERVED is specified all over the place, because * in 2.4 it kept swapout's vma scan off this vma; but * in 2.6 the LRU scan won't even find its pages, so this * flag means no more than count its pages in reserved_vm, * and omit it from core dump, even when VM_IO turned off. * VM_PFNMAP tells the core MM that the base pages are just * raw PFN mappings, and do not have a "struct page" associated * with them. * * There's a horrible special case to handle copy-on-write * behaviour that some programs depend on. We mark the "original" * un-COW'ed pages by matching them up with "vma->vm_pgoff". */ if (addr == vma->vm_start && end == vma->vm_end) { vma->vm_pgoff = pfn; vma->vm_flags |= VM_PFN_AT_MMAP; - --[[linux-2.6.33/VM_PFN_AT_MMAP]] } else if (is_cow_mapping(vma->vm_flags)) return -EINVAL; - --[[linux-2.6.33/is_cow_mapping()]] - --[[linux-2.6.33/EINVAL]] vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP; - --[[linux-2.6.33/VM_IO]] --[[linux-2.6.33/VM_RESERVED]] --[[linux-2.6.33/VM_PFNMAP]] err = track_pfn_vma_new(vma, &prot, pfn, PAGE_ALIGN(size)); - --[[linux-2.6.33/track_pfn_vma_new()]] if (err) { /* * To indicate that track_pfn related cleanup is not * needed from higher level routine calling unmap_vmas */ vma->vm_flags &= ~(VM_IO | VM_RESERVED | VM_PFNMAP); vma->vm_flags &= ~VM_PFN_AT_MMAP; return -EINVAL; } BUG_ON(addr >= end); - --[[linux-2.6.33/BUG_ON()]] pfn -= addr >> PAGE_SHIFT; pgd = pgd_offset(mm, addr); - --[[linux-2.6.33/pgd_offset()]] --[[linux-2.6.33/PAGE_SHIFT]] flush_cache_range(vma, addr, end); - --[[linux-2.6.33/flush_cache_range()]] do { next = pgd_addr_end(addr, end); - --[[linux-2.6.33/pgd_addr_end()]] err = remap_pud_range(mm, pgd, addr, next, pfn + (addr >> PAGE_SHIFT), prot); if (err) break; - --[[linux-2.6.33/remap_pud_range()]] } while (pgd++, addr = next, addr != end); if (err) untrack_pfn_vma(vma, pfn, PAGE_ALIGN(size)); - --[[linux-2.6.33/untrack_pfn_vma()]] return err; } EXPORT_SYMBOL(remap_pfn_range); -ライセンスに関わらずシンボルを公開する。 --[[linux-2.6.33/EXPORT_SYMBOL()]] *コメント [#ie9c5b26]
