3 files changed, 37 insertions, 51 deletions

diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h
index df57611652e5..884081099f80 100644
--- a/arch/arc/include/asm/entry.h
+++ b/arch/arc/include/asm/entry.h
@@ -365,7 +365,7 @@
  * it to memory (non-SMP case) or SCRATCH0 Aux Reg (SMP).
  *
  * Before saving the full regfile - this reg is restored back, only
- * to be saved again on kernel mode stack, as part of ptregs.
+ * to be saved again on kernel mode stack, as part of pt_regs.
  *-------------------------------------------------------------*/
 .macro EXCPN_PROLOG_FREEUP_REG  reg
 #ifdef CONFIG_SMP
@@ -384,6 +384,28 @@
 .endm
 
 /*--------------------------------------------------------------
+ * Exception Entry prologue
+ * -Switches stack to K mode (if not already)
+ * -Saves the register file
+ *
+ * After this it is safe to call the "C" handlers
+ *-------------------------------------------------------------*/
+.macro EXCEPTION_PROLOGUE
+
+        /* Need at least 1 reg to code the early exception prologue */
+        EXCPN_PROLOG_FREEUP_REG r9
+
+        /* U/K mode at time of exception (stack not switched if already K) */
+        lr  r9, [erstatus]
+
+        /* ARC700 doesn't provide auto-stack switching */
+        SWITCH_TO_KERNEL_STK
+
+        /* save the regfile */
+        SAVE_ALL_SYS
+.endm
+
+/*--------------------------------------------------------------
  * Save all registers used by Exceptions (TLB Miss, Prot-V, Mem err etc)
  * Requires SP to be already switched to kernel mode Stack
  * sp points to the next free element on the stack at exit of this macro.
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index 1d7165156e17..059ca94e3df8 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -267,12 +267,7 @@ ARC_EXIT handle_interrupt_level1
 
 ARC_ENTRY instr_service
 
-        EXCPN_PROLOG_FREEUP_REG r9
-
-        lr  r9, [erstatus]
-
-        SWITCH_TO_KERNEL_STK
-        SAVE_ALL_SYS
+        EXCEPTION_PROLOGUE
 
         lr  r0, [efa]
         mov r1, sp
@@ -289,15 +284,13 @@ ARC_EXIT instr_service
 
 ARC_ENTRY mem_service
 
-        EXCPN_PROLOG_FREEUP_REG r9
-
-        lr  r9, [erstatus]
-
-        SWITCH_TO_KERNEL_STK
-        SAVE_ALL_SYS
+        EXCEPTION_PROLOGUE
 
         lr  r0, [efa]
         mov r1, sp
+
+        FAKE_RET_FROM_EXCPN r9
+
         bl  do_memory_error
         b   ret_from_exception
 ARC_EXIT mem_service
@@ -308,11 +301,7 @@ ARC_EXIT mem_service
 
 ARC_ENTRY EV_MachineCheck
 
-        EXCPN_PROLOG_FREEUP_REG r9
-        lr  r9, [erstatus]
-
-        SWITCH_TO_KERNEL_STK
-        SAVE_ALL_SYS
+        EXCEPTION_PROLOGUE
 
         lr  r2, [ecr]
         lr  r0, [efa]
@@ -342,13 +331,7 @@ ARC_EXIT EV_MachineCheck
 
 ARC_ENTRY EV_TLBProtV
 
-        EXCPN_PROLOG_FREEUP_REG r9
-
-        ;Which mode (user/kernel) was the system in when Exception occured
-        lr  r9, [erstatus]
-
-        SWITCH_TO_KERNEL_STK
-        SAVE_ALL_SYS
+        EXCEPTION_PROLOGUE
 
         ;---------(3) Save some more regs-----------------
         ;  vineetg: Mar 6th: Random Seg Fault issue #1
@@ -406,12 +389,7 @@ ARC_EXIT EV_TLBProtV
 ; ---------------------------------------------
 ARC_ENTRY EV_PrivilegeV
 
-        EXCPN_PROLOG_FREEUP_REG r9
-
-        lr  r9, [erstatus]
-
-        SWITCH_TO_KERNEL_STK
-        SAVE_ALL_SYS
+        EXCEPTION_PROLOGUE
 
         lr  r0, [efa]
         mov r1, sp
@@ -427,14 +405,13 @@ ARC_EXIT EV_PrivilegeV
 ; ---------------------------------------------
 ARC_ENTRY EV_Extension
 
-        EXCPN_PROLOG_FREEUP_REG r9
-        lr  r9, [erstatus]
-
-        SWITCH_TO_KERNEL_STK
-        SAVE_ALL_SYS
+        EXCEPTION_PROLOGUE
 
         lr  r0, [efa]
         mov r1, sp
+
+        FAKE_RET_FROM_EXCPN r9
+
         bl  do_extension_fault
         b   ret_from_exception
 ARC_EXIT EV_Extension
@@ -526,14 +503,7 @@ trap_with_param:
 
 ARC_ENTRY EV_Trap
 
-        ; Need at least 1 reg to code the early exception prolog
-        EXCPN_PROLOG_FREEUP_REG r9
-
-        ;Which mode (user/kernel) was the system in when intr occured
-        lr  r9, [erstatus]
-
-        SWITCH_TO_KERNEL_STK
-        SAVE_ALL_SYS
+        EXCEPTION_PROLOGUE
 
         ;------- (4) What caused the Trap --------------
         lr     r12, [ecr]
diff --git a/arch/arc/mm/tlbex.S b/arch/arc/mm/tlbex.S
index 5c5bb23001b0..fc34ebc103bc 100644
--- a/arch/arc/mm/tlbex.S
+++ b/arch/arc/mm/tlbex.S
@@ -371,13 +371,7 @@ do_slow_path_pf:
 
         ; Slow path TLB Miss handled as a regular ARC Exception
         ; (stack switching / save the complete reg-file).
-        ; That requires freeing up r9
-        EXCPN_PROLOG_FREEUP_REG r9
-
-        lr  r9, [erstatus]
-
-        SWITCH_TO_KERNEL_STK
-        SAVE_ALL_SYS
+        EXCEPTION_PROLOGUE
 
         ; ------- setup args for Linux Page fault Hanlder ---------
         mov_s r0, sp