ARM: entry: prefetch abort helper: pass aborted pc in r4 rather than r0

This avoids unnecessary instructions for CPUs which implement the IFAR
(instruction fault address register).

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

4 files changed, 6 insertions, 4 deletions

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 582bb2310446..d644d0240ad3 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -45,7 +45,7 @@
         .endm
 
         .macro  pabt_helper
-        mov     r0, r4                  @ pass address of aborted instruction.
+        @ PABORT handler takes fault address in r4
 #ifdef MULTI_PABORT
         ldr     ip, .LCprocfns
         mov     lr, pc
diff --git a/arch/arm/mm/pabort-legacy.S b/arch/arm/mm/pabort-legacy.S
index 87970eba88ea..8a5d8aaf2d5e 100644
--- a/arch/arm/mm/pabort-legacy.S
+++ b/arch/arm/mm/pabort-legacy.S
@@ -4,7 +4,7 @@
 /*
  * Function: legacy_pabort
  *
- * Params  : r0 = address of aborted instruction
+ * Params  : r4 = address of aborted instruction
  *
  * Returns : r0 = address of abort
  *         : r1 = Simulated IFSR with section translation fault status
@@ -14,6 +14,7 @@
 
         .align  5
 ENTRY(legacy_pabort)
+        mov     r0, r4
         mov     r1, #5
         mov     pc, lr
 ENDPROC(legacy_pabort)
diff --git a/arch/arm/mm/pabort-v6.S b/arch/arm/mm/pabort-v6.S
index 06e3d1ef2115..eaac1cb7c4cc 100644
--- a/arch/arm/mm/pabort-v6.S
+++ b/arch/arm/mm/pabort-v6.S
@@ -4,7 +4,7 @@
 /*
  * Function: v6_pabort
  *
- * Params  : r0 = address of aborted instruction
+ * Params  : r4 = address of aborted instruction
  *
  * Returns : r0 = address of abort
  *         : r1 = IFSR
@@ -14,6 +14,7 @@
 
         .align  5
 ENTRY(v6_pabort)
+        mov     r0, r4
         mrc     p15, 0, r1, c5, c0, 1           @ get IFSR
         mov     pc, lr
 ENDPROC(v6_pabort)
diff --git a/arch/arm/mm/pabort-v7.S b/arch/arm/mm/pabort-v7.S
index a8b3b300a18d..b515e0b059b3 100644
--- a/arch/arm/mm/pabort-v7.S
+++ b/arch/arm/mm/pabort-v7.S
@@ -4,7 +4,7 @@
 /*
  * Function: v6_pabort
  *
- * Params  : r0 = address of aborted instruction
+ * Params  : r4 = address of aborted instruction
  *
  * Returns : r0 = address of abort
  *         : r1 = IFSR