1 files changed, 10 insertions, 7 deletions

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 48469463f89..fc213294275 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -1124,9 +1124,8 @@ mmu_off:
         RFI
 
 /*
- * Use the first pair of BAT registers to map the 1st 16MB
- * of RAM to PAGE_OFFSET.  From this point on we can't safely
- * call OF any more.
+ * On 601, we use 3 BATs to map up to 24M of RAM at _PAGE_OFFSET
+ * (we keep one for debugging) and on others, we use one 256M BAT.
  */
 initial_bats:
         lis     r11,PAGE_OFFSET@h
@@ -1136,12 +1135,16 @@ initial_bats:
         bne     4f
         ori     r11,r11,4               /* set up BAT registers for 601 */
         li      r8,0x7f                 /* valid, block length = 8MB */
-        oris    r9,r11,0x800000@h       /* set up BAT reg for 2nd 8M */
-        oris    r10,r8,0x800000@h       /* set up BAT reg for 2nd 8M */
         mtspr   SPRN_IBAT0U,r11         /* N.B. 601 has valid bit in */
         mtspr   SPRN_IBAT0L,r8          /* lower BAT register */
-        mtspr   SPRN_IBAT1U,r9
-        mtspr   SPRN_IBAT1L,r10
+        addis   r11,r11,0x800000@h
+        addis   r8,r8,0x800000@h
+        mtspr   SPRN_IBAT1U,r11
+        mtspr   SPRN_IBAT1L,r8
+        addis   r11,r11,0x800000@h
+        addis   r8,r8,0x800000@h
+        mtspr   SPRN_IBAT2U,r11
+        mtspr   SPRN_IBAT2L,r8
         isync
         blr