ARM: entry: prefetch abort: tail-call the main prefetch abort handler

Tail-call the main C prefetch abort handler code from the per-CPU
helper code.  Also note that the helper function becomes ABI
compliant in terms of the registers preserved.

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

4 files changed, 19 insertions, 18 deletions

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index b17e57949d3b..af2fba7a4cae 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -45,7 +45,7 @@
         .endm
 
         .macro  pabt_helper
-        @ PABORT handler takes fault address in r4
+        @ PABORT handler takes pt_regs in r2, fault address in r4 and psr in r5
 #ifdef MULTI_PABORT
         ldr     ip, .LCprocfns
         mov     lr, pc
@@ -306,9 +306,8 @@ ENDPROC(__und_svc)
         .align  5
 __pabt_svc:
         svc_entry
-        pabt_helper
         mov     r2, sp                          @ regs
-        bl      do_PrefetchAbort                @ call abort handler
+        pabt_helper
 
         @
         @ IRQs off again before pulling preserved data off the stack
@@ -653,9 +652,8 @@ ENDPROC(__und_usr_unknown)
         .align  5
 __pabt_usr:
         usr_entry
-        pabt_helper
         mov     r2, sp                          @ regs
-        bl      do_PrefetchAbort                @ call abort handler
+        pabt_helper
  UNWIND(.fnend          )
         /* fall through */
 /*
diff --git a/arch/arm/mm/pabort-legacy.S b/arch/arm/mm/pabort-legacy.S
index 8a5d8aaf2d5e..8bbff025269a 100644
--- a/arch/arm/mm/pabort-legacy.S
+++ b/arch/arm/mm/pabort-legacy.S
@@ -4,10 +4,11 @@
 /*
  * Function: legacy_pabort
  *
- * Params  : r4 = address of aborted instruction
+ * Params  : r2 = pt_regs
+ *         : r4 = address of aborted instruction
+ *         : r5 = psr for parent context
  *
- * Returns : r0 = address of abort
- *         : r1 = Simulated IFSR with section translation fault status
+ * Returns : r4 - r11, r13 preserved
  *
  * Purpose : obtain information about current prefetch abort.
  */
@@ -16,5 +17,5 @@
 ENTRY(legacy_pabort)
         mov     r0, r4
         mov     r1, #5
-        mov     pc, lr
+        b       do_PrefetchAbort
 ENDPROC(legacy_pabort)
diff --git a/arch/arm/mm/pabort-v6.S b/arch/arm/mm/pabort-v6.S
index eaac1cb7c4cc..9627646ce783 100644
--- a/arch/arm/mm/pabort-v6.S
+++ b/arch/arm/mm/pabort-v6.S
@@ -4,10 +4,11 @@
 /*
  * Function: v6_pabort
  *
- * Params  : r4 = address of aborted instruction
+ * Params  : r2 = pt_regs
+ *         : r4 = address of aborted instruction
+ *         : r5 = psr for parent context
  *
- * Returns : r0 = address of abort
- *         : r1 = IFSR
+ * Returns : r4 - r11, r13 preserved
  *
  * Purpose : obtain information about current prefetch abort.
  */
@@ -16,5 +17,5 @@
 ENTRY(v6_pabort)
         mov     r0, r4
         mrc     p15, 0, r1, c5, c0, 1           @ get IFSR
-        mov     pc, lr
+        b       do_PrefetchAbort
 ENDPROC(v6_pabort)
diff --git a/arch/arm/mm/pabort-v7.S b/arch/arm/mm/pabort-v7.S
index b515e0b059b3..875761f44f3b 100644
--- a/arch/arm/mm/pabort-v7.S
+++ b/arch/arm/mm/pabort-v7.S
@@ -2,12 +2,13 @@
 #include <asm/assembler.h>
 
 /*
- * Function: v6_pabort
+ * Function: v7_pabort
  *
- * Params  : r4 = address of aborted instruction
+ * Params  : r2 = pt_regs
+ *         : r4 = address of aborted instruction
+ *         : r5 = psr for parent context
  *
- * Returns : r0 = address of abort
- *         : r1 = IFSR
+ * Returns : r4 - r11, r13 preserved
  *
  * Purpose : obtain information about current prefetch abort.
  */
@@ -16,5 +17,5 @@
 ENTRY(v7_pabort)
         mrc     p15, 0, r0, c6, c0, 2           @ get IFAR
         mrc     p15, 0, r1, c5, c0, 1           @ get IFSR
-        mov     pc, lr
+        b       do_PrefetchAbort
 ENDPROC(v7_pabort)