sh: Use MMU.TTB register as pointer to current pgd.

[linux-2.6-omap-h63xx.git] / arch / sh / mm / init.c

diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 8b275166f40008c00228ffd2a317c370601049b9..8c8d39118387ec451c1000e851af8cf5d9a1ad7b 100644 (file)
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -155,9 +155,6 @@ extern char __init_begin, __init_end;
 
 /*
  * paging_init() sets up the page tables
- *
- * This routines also unmaps the page at virtual kernel address 0, so
- * that we can trap those pesky NULL-reference errors in the kernel.
  */
 void __init paging_init(void)
 {
@@ -180,14 +177,11 @@ void __init paging_init(void)
         */
        {
                unsigned long max_dma, low, start_pfn;
-               pgd_t *pg_dir;
-               int i;
-
-               /* We don't need kernel mapping as hardware support that. */
-               pg_dir = swapper_pg_dir;
 
-               for (i = 0; i < PTRS_PER_PGD; i++)
-                       pgd_val(pg_dir[i]) = 0;
+               /* We don't need to map the kernel through the TLB, as
+                * it is permanatly mapped using P1. So clear the
+                * entire pgd. */
+               memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
 
                /* Turn on the MMU */
                enable_mmu();
@@ -206,6 +200,10 @@ void __init paging_init(void)
                }
        }
 
+       /* Set an initial value for the MMU.TTB so we don't have to
+        * check for a null value. */
+       set_TTB(swapper_pg_dir);
+
 #elif defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4)
        /*
         * If we don't have CONFIG_MMU set and the processor in question