[PATCH] ARM: Use top_pmd for V6 copy/clear user_page

Remove needless page table walking for v6 page operations.

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

1 files changed, 6 insertions, 22 deletions

diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c
index 694ac8208858..a8c00236bd3d 100644
--- a/arch/arm/mm/copypage-v6.c
+++ b/arch/arm/mm/copypage-v6.c
@@ -26,8 +26,8 @@
 #define to_address      (0xffffc000)
 #define to_pgprot       PAGE_KERNEL
 
-static pte_t *from_pte;
-static pte_t *to_pte;
+#define TOP_PTE(x)      pte_offset_kernel(top_pmd, x)
+
 static DEFINE_SPINLOCK(v6_lock);
 
 #define DCACHE_COLOUR(vaddr) ((vaddr & (SHMLBA - 1)) >> PAGE_SHIFT)
@@ -74,8 +74,8 @@ void v6_copy_user_page_aliasing(void *kto, const void *kfrom, unsigned long vadd
          */
         spin_lock(&v6_lock);
 
-        set_pte(from_pte + offset, pfn_pte(__pa(kfrom) >> PAGE_SHIFT, from_pgprot));
-        set_pte(to_pte + offset, pfn_pte(__pa(kto) >> PAGE_SHIFT, to_pgprot));
+        set_pte(TOP_PTE(from_address) + offset, pfn_pte(__pa(kfrom) >> PAGE_SHIFT, from_pgprot));
+        set_pte(TOP_PTE(to_address) + offset, pfn_pte(__pa(kto) >> PAGE_SHIFT, to_pgprot));
 
         from = from_address + (offset << PAGE_SHIFT);
         to   = to_address + (offset << PAGE_SHIFT);
@@ -114,7 +114,7 @@ void v6_clear_user_page_aliasing(void *kaddr, unsigned long vaddr)
          */
         spin_lock(&v6_lock);
 
-        set_pte(to_pte + offset, pfn_pte(__pa(kaddr) >> PAGE_SHIFT, to_pgprot));
+        set_pte(TOP_PTE(to_address) + offset, pfn_pte(__pa(kaddr) >> PAGE_SHIFT, to_pgprot));
         flush_tlb_kernel_page(to);
         clear_page((void *)to);
 
@@ -129,21 +129,6 @@ struct cpu_user_fns v6_user_fns __initdata = {
 static int __init v6_userpage_init(void)
 {
         if (cache_is_vipt_aliasing()) {
-                pgd_t *pgd;
-                pmd_t *pmd;
-
-                pgd = pgd_offset_k(from_address);
-                pmd = pmd_alloc(&init_mm, pgd, from_address);
-                if (!pmd)
-                        BUG();
-                from_pte = pte_alloc_kernel(&init_mm, pmd, from_address);
-                if (!from_pte)
-                        BUG();
-
-                to_pte = pte_alloc_kernel(&init_mm, pmd, to_address);
-                if (!to_pte)
-                        BUG();
-
                 cpu_user.cpu_clear_user_page = v6_clear_user_page_aliasing;
                 cpu_user.cpu_copy_user_page = v6_copy_user_page_aliasing;
         }
@@ -151,5 +136,4 @@ static int __init v6_userpage_init(void)
         return 0;
 }
 
-__initcall(v6_userpage_init);
-
+core_initcall(v6_userpage_init);