ARM: make_coherent: split adjust_pte() in two

adjust_pte() walks the page tables, and do_adjust_pte() does the
page table manipulation.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 32 insertions, 20 deletions

diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c
index 56ee15321b00..074e6bb54eb3 100644
--- a/arch/arm/mm/fault-armv.c
+++ b/arch/arm/mm/fault-armv.c
@@ -36,28 +36,12 @@ static unsigned long shared_pte_mask = L_PTE_MT_BUFFERABLE;
  * Therefore those configurations which might call adjust_pte (those
  * without CONFIG_CPU_CACHE_VIPT) cannot support split page_table_lock.
  */
-static int adjust_pte(struct vm_area_struct *vma, unsigned long address)
+static int do_adjust_pte(struct vm_area_struct *vma, unsigned long address,
+        pte_t *ptep)
 {
-        pgd_t *pgd;
-        pmd_t *pmd;
-        pte_t *pte, entry;
+        pte_t entry = *ptep;
         int ret;
 
-        pgd = pgd_offset(vma->vm_mm, address);
-        if (pgd_none(*pgd))
-                goto no_pgd;
-        if (pgd_bad(*pgd))
-                goto bad_pgd;
-
-        pmd = pmd_offset(pgd, address);
-        if (pmd_none(*pmd))
-                goto no_pmd;
-        if (pmd_bad(*pmd))
-                goto bad_pmd;
-
-        pte = pte_offset_map(pmd, address);
-        entry = *pte;
-
         /*
          * If this page is present, it's actually being shared.
          */
@@ -74,10 +58,38 @@ static int adjust_pte(struct vm_area_struct *vma, unsigned long address)
                                   (pfn << PAGE_SHIFT) + PAGE_SIZE);
                 pte_val(entry) &= ~L_PTE_MT_MASK;
                 pte_val(entry) |= shared_pte_mask;
-                set_pte_at(vma->vm_mm, address, pte, entry);
+                set_pte_at(vma->vm_mm, address, ptep, entry);
                 flush_tlb_page(vma, address);
         }
+
+        return ret;
+}
+
+static int adjust_pte(struct vm_area_struct *vma, unsigned long address)
+{
+        pgd_t *pgd;
+        pmd_t *pmd;
+        pte_t *pte;
+        int ret;
+
+        pgd = pgd_offset(vma->vm_mm, address);
+        if (pgd_none(*pgd))
+                goto no_pgd;
+        if (pgd_bad(*pgd))
+                goto bad_pgd;
+
+        pmd = pmd_offset(pgd, address);
+        if (pmd_none(*pmd))
+                goto no_pmd;
+        if (pmd_bad(*pmd))
+                goto bad_pmd;
+
+        pte = pte_offset_map(pmd, address);
+
+        ret = do_adjust_pte(vma, address, pte);
+
         pte_unmap(pte);
+
         return ret;
 
 bad_pgd: