From 6aab341e0a28aff100a09831c5300a2994b8b986 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 28 Nov 2005 14:34:23 -0800 Subject: mm: re-architect the VM_UNPAGED logic This replaces the (in my opinion horrible) VM_UNMAPPED logic with very explicit support for a "remapped page range" aka VM_PFNMAP. It allows a VM area to contain an arbitrary range of page table entries that the VM never touches, and never considers to be normal pages. Any user of "remap_pfn_range()" automatically gets this new functionality, and doesn't even have to mark the pages reserved or indeed mark them any other way. It just works. As a side effect, doing mmap() on /dev/mem works for arbitrary ranges. Sparc update from David in the next commit. Signed-off-by: Linus Torvalds --- mm/rmap.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) (limited to 'mm/rmap.c') diff --git a/mm/rmap.c b/mm/rmap.c index 2e034a0b89a..6389cda02a2 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -226,8 +226,6 @@ vma_address(struct page *page, struct vm_area_struct *vma) /* * At what user virtual address is page expected in vma? checking that the * page matches the vma: currently only used on anon pages, by unuse_vma; - * and by extraordinary checks on anon pages in VM_UNPAGED vmas, taking - * care that an mmap of /dev/mem might window free and foreign pages. */ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma) { @@ -614,7 +612,6 @@ static void try_to_unmap_cluster(unsigned long cursor, struct page *page; unsigned long address; unsigned long end; - unsigned long pfn; address = (vma->vm_start + cursor) & CLUSTER_MASK; end = address + CLUSTER_SIZE; @@ -643,15 +640,8 @@ static void try_to_unmap_cluster(unsigned long cursor, for (; address < end; pte++, address += PAGE_SIZE) { if (!pte_present(*pte)) continue; - - pfn = pte_pfn(*pte); - if (unlikely(!pfn_valid(pfn))) { - print_bad_pte(vma, *pte, address); - continue; - } - - page = pfn_to_page(pfn); - BUG_ON(PageAnon(page)); + page = vm_normal_page(vma, address, *pte); + BUG_ON(!page || PageAnon(page)); if (ptep_clear_flush_young(vma, address, pte)) continue; -- cgit v1.2.3-70-g09d2