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 --- include/linux/mm.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/mm.h b/include/linux/mm.h index f0cdfd18db5..6a75a7a78bf 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -145,7 +145,7 @@ extern unsigned int kobjsize(const void *objp); #define VM_GROWSDOWN 0x00000100 /* general info on the segment */ #define VM_GROWSUP 0x00000200 #define VM_SHM 0x00000000 /* Means nothing: delete it later */ -#define VM_UNPAGED 0x00000400 /* Pages managed without map count */ +#define VM_PFNMAP 0x00000400 /* Page-ranges managed without "struct page", just pure PFN */ #define VM_DENYWRITE 0x00000800 /* ETXTBSY on write attempts.. */ #define VM_EXECUTABLE 0x00001000 @@ -664,6 +664,7 @@ struct zap_details { unsigned long truncate_count; /* Compare vm_truncate_count */ }; +struct page *vm_normal_page(struct vm_area_struct *, unsigned long, pte_t); unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address, unsigned long size, struct zap_details *); unsigned long unmap_vmas(struct mmu_gather **tlb, @@ -953,7 +954,7 @@ unsigned long vmalloc_to_pfn(void *addr); int remap_pfn_range(struct vm_area_struct *, unsigned long addr, unsigned long pfn, unsigned long size, pgprot_t); -struct page *follow_page(struct mm_struct *, unsigned long address, +struct page *follow_page(struct vm_area_struct *, unsigned long address, unsigned int foll_flags); #define FOLL_WRITE 0x01 /* check pte is writable */ #define FOLL_TOUCH 0x02 /* mark page accessed */ -- cgit v1.2.3