x86: PAT: move track untrack pfnmap stubs to asm-generic

Impact: Cleanup and branch hints only.

Move the track and untrack pfn stub routines from memory.c to asm-generic.
Also add unlikely to pfnmap related calls in fork and exit path.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

2 files changed, 46 insertions, 6 deletions

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index b84633801fb6..72ebe91005a8 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -293,6 +293,52 @@ static inline void ptep_modify_prot_commit(struct mm_struct *mm,
 #define arch_flush_lazy_cpu_mode()	do {} while (0)
 #endif
 
+#ifndef __HAVE_PFNMAP_TRACKING
+/*
+ * Interface that can be used by architecture code to keep track of
+ * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
+ *
+ * track_pfn_vma_new is called when a _new_ pfn mapping is being established
+ * for physical range indicated by pfn and size.
+ */
+static inline int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot,
+					unsigned long pfn, unsigned long size)
+{
+	return 0;
+}
+
+/*
+ * Interface that can be used by architecture code to keep track of
+ * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
+ *
+ * track_pfn_vma_copy is called when vma that is covering the pfnmap gets
+ * copied through copy_page_range().
+ */
+static inline int track_pfn_vma_copy(struct vm_area_struct *vma)
+{
+	return 0;
+}
+
+/*
+ * Interface that can be used by architecture code to keep track of
+ * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
+ *
+ * untrack_pfn_vma is called while unmapping a pfnmap for a region.
+ * untrack can be called for a specific region indicated by pfn and size or
+ * can be for the entire vma (in which case size can be zero).
+ */
+static inline void untrack_pfn_vma(struct vm_area_struct *vma,
+					unsigned long pfn, unsigned long size)
+{
+}
+#else
+extern int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot,
+				unsigned long pfn, unsigned long size);
+extern int track_pfn_vma_copy(struct vm_area_struct *vma);
+extern void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,
+				unsigned long size);
+#endif
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* _ASM_GENERIC_PGTABLE_H */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 36f9b3fa5e15..d3ddd735e375 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -163,12 +163,6 @@ static inline int is_pfn_mapping(struct vm_area_struct *vma)
 	return (vma->vm_flags & VM_PFNMAP);
 }
 
-extern int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot,
-				unsigned long pfn, unsigned long size);
-extern int track_pfn_vma_copy(struct vm_area_struct *vma);
-extern void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,
-				unsigned long size);
-
 /*
  * vm_fault is filled by the the pagefault handler and passed to the vma's
  * ->fault function. The vma's ->fault is responsible for returning a bitmask