diff options
| -rw-r--r-- | arch/x86/mm/pat.c | 5 | ||||
| -rw-r--r-- | include/linux/mm.h | 15 | ||||
| -rw-r--r-- | mm/memory.c | 6 |
3 files changed, 20 insertions, 6 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index e0ab173b697..21bc1f787ae 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -641,10 +641,11 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, is_ram = pat_pagerange_is_ram(paddr, paddr + size); /* - * reserve_pfn_range() doesn't support RAM pages. + * reserve_pfn_range() doesn't support RAM pages. Maintain the current + * behavior with RAM pages by returning success. */ if (is_ram != 0) - return -EINVAL; + return 0; ret = reserve_memtype(paddr, paddr + size, want_flags, &flags); if (ret) diff --git a/include/linux/mm.h b/include/linux/mm.h index 065cdf8c09f..3daa05feed9 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -98,7 +98,7 @@ extern unsigned int kobjsize(const void *objp); #define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */ #define VM_NONLINEAR 0x00800000 /* Is non-linear (remap_file_pages) */ #define VM_MAPPED_COPY 0x01000000 /* T if mapped copy of data (nommu mmap) */ -#define VM_INSERTPAGE 0x02000000 /* The vma has had "vm_insert_page()" done on it */ +#define VM_INSERTPAGE 0x02000000 /* The vma has had "vm_insert_page()" done on it. Refer note in VM_PFNMAP_AT_MMAP below */ #define VM_ALWAYSDUMP 0x04000000 /* Always include in core dumps */ #define VM_CAN_NONLINEAR 0x08000000 /* Has ->fault & does nonlinear pages */ @@ -127,6 +127,17 @@ extern unsigned int kobjsize(const void *objp); #define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP) /* + * pfnmap vmas that are fully mapped at mmap time (not mapped on fault). + * Used by x86 PAT to identify such PFNMAP mappings and optimize their handling. + * Note VM_INSERTPAGE flag is overloaded here. i.e, + * VM_INSERTPAGE && !VM_PFNMAP implies + * The vma has had "vm_insert_page()" done on it + * VM_INSERTPAGE && VM_PFNMAP implies + * The vma is PFNMAP with full mapping at mmap time + */ +#define VM_PFNMAP_AT_MMAP (VM_INSERTPAGE | VM_PFNMAP) + +/* * mapping from the currently active vm_flags protection bits (the * low four bits) to a page protection mask.. */ @@ -145,7 +156,7 @@ extern pgprot_t protection_map[16]; */ static inline int is_linear_pfn_mapping(struct vm_area_struct *vma) { - return ((vma->vm_flags & VM_PFNMAP) && vma->vm_pgoff); + return ((vma->vm_flags & VM_PFNMAP_AT_MMAP) == VM_PFNMAP_AT_MMAP); } static inline int is_pfn_mapping(struct vm_area_struct *vma) diff --git a/mm/memory.c b/mm/memory.c index baa999e87cd..d7df5babcba 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1665,9 +1665,10 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, * 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) + if (addr == vma->vm_start && end == vma->vm_end) { vma->vm_pgoff = pfn; - else if (is_cow_mapping(vma->vm_flags)) + vma->vm_flags |= VM_PFNMAP_AT_MMAP; + } else if (is_cow_mapping(vma->vm_flags)) return -EINVAL; vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP; @@ -1679,6 +1680,7 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, * needed from higher level routine calling unmap_vmas */ vma->vm_flags &= ~(VM_IO | VM_RESERVED | VM_PFNMAP); + vma->vm_flags &= ~VM_PFNMAP_AT_MMAP; return -EINVAL; } |