mincore: break do_mincore() into logical pieces

[linux-drm-fsl-dcu.git] / mm / mincore.c

diff --git a/mm/mincore.c b/mm/mincore.c
index 1f6574c5167b5d4394233b80825ad992f186d9cc..a0c4c10bbab7bec64ea525d6e57f51da5aa879c1 100644 (file)
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -19,6 +19,42 @@
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
 
+static void mincore_hugetlb_page_range(struct vm_area_struct *vma,
+                               unsigned long addr, unsigned long nr,
+                               unsigned char *vec)
+{
+#ifdef CONFIG_HUGETLB_PAGE
+       struct hstate *h;
+       int i;
+
+       i = 0;
+       h = hstate_vma(vma);
+       while (1) {
+               unsigned char present;
+               pte_t *ptep;
+               /*
+                * Huge pages are always in RAM for now, but
+                * theoretically it needs to be checked.
+                */
+               ptep = huge_pte_offset(current->mm,
+                                      addr & huge_page_mask(h));
+               present = ptep && !huge_pte_none(huge_ptep_get(ptep));
+               while (1) {
+                       vec[i++] = present;
+                       addr += PAGE_SIZE;
+                       /* reach buffer limit */
+                       if (i == nr)
+                               return;
+                       /* check hugepage border */
+                       if (!(addr & ~huge_page_mask(h)))
+                               break;
+               }
+       }
+#else
+       BUG();
+#endif
+}
+
 /*
  * Later we can get more picky about what "in core" means precisely.
  * For now, simply check to see if the page is in the page cache,
@@ -49,6 +85,64 @@ static unsigned char mincore_page(struct address_space *mapping, pgoff_t pgoff)
        return present;
 }
 
+static void mincore_unmapped_range(struct vm_area_struct *vma,
+                               unsigned long addr, unsigned long nr,
+                               unsigned char *vec)
+{
+       int i;
+
+       if (vma->vm_file) {
+               pgoff_t pgoff;
+
+               pgoff = linear_page_index(vma, addr);
+               for (i = 0; i < nr; i++, pgoff++)
+                       vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff);
+       } else {
+               for (i = 0; i < nr; i++)
+                       vec[i] = 0;
+       }
+}
+
+static void mincore_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
+                       unsigned long addr, unsigned long nr,
+                       unsigned char *vec)
+{
+       spinlock_t *ptl;
+       pte_t *ptep;
+       int i;
+
+       ptep = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+       for (i = 0; i < nr; i++, ptep++, addr += PAGE_SIZE) {
+               pte_t pte = *ptep;
+               pgoff_t pgoff;
+
+               if (pte_none(pte))
+                       mincore_unmapped_range(vma, addr, 1, vec);
+               else if (pte_present(pte))
+                       vec[i] = 1;
+               else if (pte_file(pte)) {
+                       pgoff = pte_to_pgoff(pte);
+                       vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff);
+               } else { /* pte is a swap entry */
+                       swp_entry_t entry = pte_to_swp_entry(pte);
+
+                       if (is_migration_entry(entry)) {
+                               /* migration entries are always uptodate */
+                               vec[i] = 1;
+                       } else {
+#ifdef CONFIG_SWAP
+                               pgoff = entry.val;
+                               vec[i] = mincore_page(&swapper_space, pgoff);
+#else
+                               WARN_ON(1);
+                               vec[i] = 1;
+#endif
+                       }
+               }
+       }
+       pte_unmap_unlock(ptep - 1, ptl);
+}
+
 /*
  * Do a chunk of "sys_mincore()". We've already checked
  * all the arguments, we hold the mmap semaphore: we should
@@ -59,11 +153,7 @@ static long do_mincore(unsigned long addr, unsigned long pages, unsigned char *v
        pgd_t *pgd;
        pud_t *pud;
        pmd_t *pmd;
-       pte_t *ptep;
-       spinlock_t *ptl;
        unsigned long nr;
-       int i;
-       pgoff_t pgoff;
        struct vm_area_struct *vma;
 
        vma = find_vma(current->mm, addr);
@@ -72,35 +162,10 @@ static long do_mincore(unsigned long addr, unsigned long pages, unsigned char *v
 
        nr = min(pages, (vma->vm_end - addr) >> PAGE_SHIFT);
 
-#ifdef CONFIG_HUGETLB_PAGE
        if (is_vm_hugetlb_page(vma)) {
-               struct hstate *h;
-
-               i = 0;
-               h = hstate_vma(vma);
-               while (1) {
-                       unsigned char present;
-                       /*
-                        * Huge pages are always in RAM for now, but
-                        * theoretically it needs to be checked.
-                        */
-                       ptep = huge_pte_offset(current->mm,
-                                              addr & huge_page_mask(h));
-                       present = ptep && !huge_pte_none(huge_ptep_get(ptep));
-                       while (1) {
-                               vec[i++] = present;
-                               addr += PAGE_SIZE;
-                               /* reach buffer limit */
-                               if (i == nr)
-                                       return nr;
-                               /* check hugepage border */
-                               if (!(addr & ~huge_page_mask(h)))
-                                       break;
-                       }
-               }
+               mincore_hugetlb_page_range(vma, addr, nr, vec);
                return nr;
        }
-#endif
 
        /*
         * Calculate how many pages there are left in the last level of the
@@ -118,53 +183,11 @@ static long do_mincore(unsigned long addr, unsigned long pages, unsigned char *v
        if (pmd_none_or_clear_bad(pmd))
                goto none_mapped;
 
-       ptep = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
-       for (i = 0; i < nr; i++, ptep++, addr += PAGE_SIZE) {
-               pte_t pte = *ptep;
-
-               if (pte_none(pte)) {
-                       if (vma->vm_file) {
-                               pgoff = linear_page_index(vma, addr);
-                               vec[i] = mincore_page(vma->vm_file->f_mapping,
-                                               pgoff);
-                       } else
-                               vec[i] = 0;
-               } else if (pte_present(pte))
-                       vec[i] = 1;
-               else if (pte_file(pte)) {
-                       pgoff = pte_to_pgoff(pte);
-                       vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff);
-               } else { /* pte is a swap entry */
-                       swp_entry_t entry = pte_to_swp_entry(pte);
-
-                       if (is_migration_entry(entry)) {
-                               /* migration entries are always uptodate */
-                               vec[i] = 1;
-                       } else {
-#ifdef CONFIG_SWAP
-                               pgoff = entry.val;
-                               vec[i] = mincore_page(&swapper_space, pgoff);
-#else
-                               WARN_ON(1);
-                               vec[i] = 1;
-#endif
-                       }
-               }
-       }
-       pte_unmap_unlock(ptep - 1, ptl);
-
+       mincore_pte_range(vma, pmd, addr, nr, vec);
        return nr;
 
 none_mapped:
-       if (vma->vm_file) {
-               pgoff = linear_page_index(vma, addr);
-               for (i = 0; i < nr; i++, pgoff++)
-                       vec[i] = mincore_page(vma->vm_file->f_mapping, pgoff);
-       } else {
-               for (i = 0; i < nr; i++)
-                       vec[i] = 0;
-       }
-
+       mincore_unmapped_range(vma, addr, nr, vec);
        return nr;
 }