VM, x86, PAT: add a new vm flag to track full pfnmap at mmap

Impact: cleanup

Add a new vm flag VM_PFN_AT_MMAP to identify a PFNMAP that is
fully mapped with remap_pfn_range. Patch removes the overloading
of VM_INSERTPAGE from the earlier patch.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Nick Piggin <npiggin@suse.de>
LKML-Reference: <20090313233543.GA19909@linux-os.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 3daa05f..b1ea37f 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -98,12 +98,13 @@ 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. Refer note in VM_PFNMAP_AT_MMAP below */
+#define VM_INSERTPAGE  0x02000000      /* The vma has had "vm_insert_page()" done on it */
 #define VM_ALWAYSDUMP  0x04000000      /* Always include in core dumps */
 
 #define VM_CAN_NONLINEAR 0x08000000    /* Has ->fault & does nonlinear pages */
 #define VM_MIXEDMAP    0x10000000      /* Can contain "struct page" and pure PFN pages */
 #define VM_SAO         0x20000000      /* Strong Access Ordering (powerpc) */
+#define VM_PFN_AT_MMAP 0x40000000      /* PFNMAP vma that is fully mapped at mmap time */
 
 #ifndef VM_STACK_DEFAULT_FLAGS         /* arch can override this */
 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
@@ -127,17 +128,6 @@ 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..
  */
@@ -156,7 +146,7 @@ extern pgprot_t protection_map[16];
  */
 static inline int is_linear_pfn_mapping(struct vm_area_struct *vma)
 {
-       return ((vma->vm_flags & VM_PFNMAP_AT_MMAP) == VM_PFNMAP_AT_MMAP);
+       return (vma->vm_flags & VM_PFN_AT_MMAP);
 }
 
 static inline int is_pfn_mapping(struct vm_area_struct *vma)

diff --git a/mm/memory.c b/mm/memory.c
index d7df5ba..2032ad2 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1667,7 +1667,7 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
         */
        if (addr == vma->vm_start && end == vma->vm_end) {
                vma->vm_pgoff = pfn;
-               vma->vm_flags |= VM_PFNMAP_AT_MMAP;
+               vma->vm_flags |= VM_PFN_AT_MMAP;
        } else if (is_cow_mapping(vma->vm_flags))
                return -EINVAL;
 
@@ -1680,7 +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;
+               vma->vm_flags &= ~VM_PFN_AT_MMAP;
                return -EINVAL;
        }