Merge branch 'davinci-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[pandora-kernel.git] / arch / arm / mm / fault-armv.c

diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c
index 56ee153..c9b97e9 100644 (file)
--- 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,
+       unsigned long pfn, 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.
         */
@@ -68,33 +52,55 @@ static int adjust_pte(struct vm_area_struct *vma, unsigned long address)
         * fault (ie, is old), we can safely ignore any issues.
         */
        if (ret && (pte_val(entry) & L_PTE_MT_MASK) != shared_pte_mask) {
-               unsigned long pfn = pte_pfn(entry);
                flush_cache_page(vma, address, pfn);
                outer_flush_range((pfn << PAGE_SHIFT),
                                  (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);
        }
-       pte_unmap(pte);
+
        return ret;
+}
+
+static int adjust_pte(struct vm_area_struct *vma, unsigned long address,
+       unsigned long pfn)
+{
+       spinlock_t *ptl;
+       pgd_t *pgd;
+       pmd_t *pmd;
+       pte_t *pte;
+       int ret;
+
+       pgd = pgd_offset(vma->vm_mm, address);
+       if (pgd_none_or_clear_bad(pgd))
+               return 0;
+
+       pmd = pmd_offset(pgd, address);
+       if (pmd_none_or_clear_bad(pmd))
+               return 0;
 
-bad_pgd:
-       pgd_ERROR(*pgd);
-       pgd_clear(pgd);
-no_pgd:
-       return 0;
-
-bad_pmd:
-       pmd_ERROR(*pmd);
-       pmd_clear(pmd);
-no_pmd:
-       return 0;
+       /*
+        * This is called while another page table is mapped, so we
+        * must use the nested version.  This also means we need to
+        * open-code the spin-locking.
+        */
+       ptl = pte_lockptr(vma->vm_mm, pmd);
+       pte = pte_offset_map_nested(pmd, address);
+       spin_lock(ptl);
+
+       ret = do_adjust_pte(vma, address, pfn, pte);
+
+       spin_unlock(ptl);
+       pte_unmap_nested(pte);
+
+       return ret;
 }
 
 static void
-make_coherent(struct address_space *mapping, struct vm_area_struct *vma, unsigned long addr, unsigned long pfn)
+make_coherent(struct address_space *mapping, struct vm_area_struct *vma,
+       unsigned long addr, pte_t *ptep, unsigned long pfn)
 {
        struct mm_struct *mm = vma->vm_mm;
        struct vm_area_struct *mpnt;
@@ -122,11 +128,11 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma, unsigne
                if (!(mpnt->vm_flags & VM_MAYSHARE))
                        continue;
                offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
-               aliases += adjust_pte(mpnt, mpnt->vm_start + offset);
+               aliases += adjust_pte(mpnt, mpnt->vm_start + offset, pfn);
        }
        flush_dcache_mmap_unlock(mapping);
        if (aliases)
-               adjust_pte(vma, addr);
+               do_adjust_pte(vma, addr, pfn, ptep);
        else
                flush_cache_page(vma, addr, pfn);
 }
@@ -144,9 +150,10 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma, unsigne
  *
  * Note that the pte lock will be held.
  */
-void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr,
+       pte_t *ptep)
 {
-       unsigned long pfn = pte_pfn(pte);
+       unsigned long pfn = pte_pfn(*ptep);
        struct address_space *mapping;
        struct page *page;
 
@@ -168,7 +175,7 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
 #endif
        if (mapping) {
                if (cache_is_vivt())
-                       make_coherent(mapping, vma, addr, pfn);
+                       make_coherent(mapping, vma, addr, ptep, pfn);
                else if (vma->vm_flags & VM_EXEC)
                        __flush_icache_all();
        }