ARM: pgtable: switch order of Linux vs hardware page tables

This switches the ordering of the Linux vs hardware page tables in
each page, thereby eliminating some of the arithmetic in the page
table walks.  As we now place the Linux page table at the beginning
of the page, we can deal with the offset in the pgt by simply masking
it away, along with the other control bits.

This also makes the arithmetic all be positive, rather than a mixture.

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

1 files changed, 3 insertions, 5 deletions

diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 53cbe2225153..89c31a6dae5c 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -124,15 +124,13 @@ ENDPROC(cpu_v7_switch_mm)
  *      Set a level 2 translation table entry.
  *
  *      - ptep  - pointer to level 2 translation table entry
- *                (hardware version is stored at -1024 bytes)
+ *                (hardware version is stored at +2048 bytes)
  *      - pte   - PTE value to store
  *      - ext   - value for extended PTE bits
  */
 ENTRY(cpu_v7_set_pte_ext)
 #ifdef CONFIG_MMU
- ARM(   str     r1, [r0], #-2048        )       @ linux version
- THUMB( str     r1, [r0]                )       @ linux version
- THUMB( sub     r0, r0, #2048           )
+        str     r1, [r0]                        @ linux version
 
         bic     r3, r1, #0x000003f0
         bic     r3, r3, #PTE_TYPE_MASK
@@ -158,7 +156,7 @@ ENTRY(cpu_v7_set_pte_ext)
         tstne   r1, #L_PTE_PRESENT
         moveq   r3, #0
 
-        str     r3, [r0]
+        str     r3, [r0, #2048]!
         mcr     p15, 0, r0, c7, c10, 1          @ flush_pte
 #endif
         mov     pc, lr