mm: thp: make transhuge_vma_suitable available for anonymous THP

transhuge_vma_suitable() was only available for shmem THP, but anonymous
THP has the same check except pgoff check.  And, it will be used for THP
eligible check in the later patch, so make it available for all kind of
THPs.  This also helps reduce code duplication slightly.

Since anonymous THP doesn't have to check pgoff, so make pgoff check
shmem vma only.

And regroup some functions in include/linux/mm.h to solve compile issue
since transhuge_vma_suitable() needs call vma_is_anonymous() which was
defined after huge_mm.h is included.

[akpm@linux-foundation.org: fix typo]
[yang.shi@linux.alibaba.com: v4]
  Link: http://lkml.kernel.org/r/1563400758-124759-2-git-send-email-yang.shi@linux.alibaba.com
Link: http://lkml.kernel.org/r/1560401041-32207-2-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/huge_mm.h

@@ -121,6 +121,23 @@ static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma)
 
 bool transparent_hugepage_enabled(struct vm_area_struct *vma);
 
+#define HPAGE_CACHE_INDEX_MASK (HPAGE_PMD_NR - 1)
+
+static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
+		unsigned long haddr)
+{
+	/* Don't have to check pgoff for anonymous vma */
+	if (!vma_is_anonymous(vma)) {
+		if (((vma->vm_start >> PAGE_SHIFT) & HPAGE_CACHE_INDEX_MASK) !=
+			(vma->vm_pgoff & HPAGE_CACHE_INDEX_MASK))
+			return false;
+	}
+
+	if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end)
+		return false;
+	return true;
+}
+
 #define transparent_hugepage_use_zero_page()				\
 	(transparent_hugepage_flags &					\
 	 (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))
@@ -271,6 +288,12 @@ static inline bool transparent_hugepage_enabled(struct vm_area_struct *vma)
 	return false;
 }
 
+static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
+		unsigned long haddr)
+{
+	return false;
+}
+
 static inline void prep_transhuge_page(struct page *page) {}
 
 #define transparent_hugepage_flags 0UL

include/linux/mm.h

@@ -541,6 +541,23 @@ static inline void vma_set_anonymous(struct vm_area_struct *vma)
 	vma->vm_ops = NULL;
 }
 
+static inline bool vma_is_anonymous(struct vm_area_struct *vma)
+{
+	return !vma->vm_ops;
+}
+
+#ifdef CONFIG_SHMEM
+/*
+ * The vma_is_shmem is not inline because it is used only by slow
+ * paths in userfault.
+ */
+bool vma_is_shmem(struct vm_area_struct *vma);
+#else
+static inline bool vma_is_shmem(struct vm_area_struct *vma) { return false; }
+#endif
+
+int vma_is_stack_for_current(struct vm_area_struct *vma);
+
 /* flush_tlb_range() takes a vma, not a mm, and can care about flags */
 #define TLB_FLUSH_VMA(mm,flags) { .vm_mm = (mm), .vm_flags = (flags) }
 
@@ -1620,23 +1637,6 @@ int clear_page_dirty_for_io(struct page *page);
 
 int get_cmdline(struct task_struct *task, char *buffer, int buflen);
 
-static inline bool vma_is_anonymous(struct vm_area_struct *vma)
-{
-	return !vma->vm_ops;
-}
-
-#ifdef CONFIG_SHMEM
-/*
- * The vma_is_shmem is not inline because it is used only by slow
- * paths in userfault.
- */
-bool vma_is_shmem(struct vm_area_struct *vma);
-#else
-static inline bool vma_is_shmem(struct vm_area_struct *vma) { return false; }
-#endif
-
-int vma_is_stack_for_current(struct vm_area_struct *vma);
-
 extern unsigned long move_page_tables(struct vm_area_struct *vma,
 		unsigned long old_addr, struct vm_area_struct *new_vma,
 		unsigned long new_addr, unsigned long len,

mm/huge_memory.c

@@ -689,7 +689,7 @@ vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf)
 	struct page *page;
 	unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
 
-	if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end)
+	if (!transhuge_vma_suitable(vma, haddr))
 		return VM_FAULT_FALLBACK;
 	if (unlikely(anon_vma_prepare(vma)))
 		return VM_FAULT_OOM;

mm/memory.c

@@ -3162,19 +3162,6 @@ static vm_fault_t pte_alloc_one_map(struct vm_fault *vmf)
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
-
-#define HPAGE_CACHE_INDEX_MASK (HPAGE_PMD_NR - 1)
-static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
-		unsigned long haddr)
-{
-	if (((vma->vm_start >> PAGE_SHIFT) & HPAGE_CACHE_INDEX_MASK) !=
-			(vma->vm_pgoff & HPAGE_CACHE_INDEX_MASK))
-		return false;
-	if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end)
-		return false;
-	return true;
-}
-
 static void deposit_prealloc_pte(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;