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/fremap.c | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-) (limited to 'mm/fremap.c') diff --git a/mm/fremap.c b/mm/fremap.c index 007cbad9331..f851775e09c 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -27,24 +27,20 @@ static int zap_pte(struct mm_struct *mm, struct vm_area_struct *vma, struct page *page = NULL; if (pte_present(pte)) { - unsigned long pfn = pte_pfn(pte); - flush_cache_page(vma, addr, pfn); + flush_cache_page(vma, addr, pte_pfn(pte)); pte = ptep_clear_flush(vma, addr, ptep); - if (unlikely(!pfn_valid(pfn))) { - print_bad_pte(vma, pte, addr); - goto out; + page = vm_normal_page(vma, addr, pte); + if (page) { + if (pte_dirty(pte)) + set_page_dirty(page); + page_remove_rmap(page); + page_cache_release(page); } - page = pfn_to_page(pfn); - if (pte_dirty(pte)) - set_page_dirty(page); - page_remove_rmap(page); - page_cache_release(page); } else { if (!pte_file(pte)) free_swap_and_cache(pte_to_swp_entry(pte)); pte_clear(mm, addr, ptep); } -out: return !!page; } @@ -65,8 +61,6 @@ int install_page(struct mm_struct *mm, struct vm_area_struct *vma, pte_t pte_val; spinlock_t *ptl; - BUG_ON(vma->vm_flags & VM_UNPAGED); - pgd = pgd_offset(mm, addr); pud = pud_alloc(mm, pgd, addr); if (!pud) @@ -122,8 +116,6 @@ int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, pte_t pte_val; spinlock_t *ptl; - BUG_ON(vma->vm_flags & VM_UNPAGED); - pgd = pgd_offset(mm, addr); pud = pud_alloc(mm, pgd, addr); if (!pud) -- cgit v1.2.3-18-g5258