ARC: entry.S: common'ize scrtach reg freeup in intr + exceptions

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h
index 8840810..9e844ab 100644 (file)
--- a/arch/arc/include/asm/entry.h
+++ b/arch/arc/include/asm/entry.h
@@ -360,26 +360,26 @@
 .endm
 
 /*--------------------------------------------------------------
- * For early Exception Prologue, a core reg is temporarily needed to
+ * For early Exception/ISR Prologue, a core reg is temporarily needed to
  * code the rest of prolog (stack switching). This is done by stashing
  * 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 pt_regs.
  *-------------------------------------------------------------*/
-.macro EXCPN_PROLOG_FREEUP_REG reg
+.macro PROLOG_FREEUP_REG       reg, mem
 #ifdef CONFIG_SMP
        sr  \reg, [ARC_REG_SCRATCH_DATA0]
 #else
-       st  \reg, [@ex_saved_reg1]
+       st  \reg, [\mem]
 #endif
 .endm
 
-.macro EXCPN_PROLOG_RESTORE_REG        reg
+.macro PROLOG_RESTORE_REG      reg, mem
 #ifdef CONFIG_SMP
        lr  \reg, [ARC_REG_SCRATCH_DATA0]
 #else
-       ld  \reg, [@ex_saved_reg1]
+       ld  \reg, [\mem]
 #endif
 .endm
 
@@ -393,7 +393,7 @@
 .macro EXCEPTION_PROLOGUE
 
        /* Need at least 1 reg to code the early exception prologue */
-       EXCPN_PROLOG_FREEUP_REG r9
+       PROLOG_FREEUP_REG r9, @ex_saved_reg1
 
        /* U/K mode at time of exception (stack not switched if already K) */
        lr  r9, [erstatus]
@@ -421,7 +421,7 @@
        st      r0, [sp, 4]    /* orig_r0, needed only for sys calls */
 
        /* Restore r9 used to code the early prologue */
-       EXCPN_PROLOG_RESTORE_REG  r9
+       PROLOG_RESTORE_REG  r9, @ex_saved_reg1
 
        SAVE_R0_TO_R12
        PUSH    gp
@@ -471,12 +471,8 @@
  *-------------------------------------------------------------*/
 .macro SAVE_ALL_INT1
 
-       /* restore original r9 to be saved as part of reg-file */
-#ifdef CONFIG_SMP
-       lr  r9, [ARC_REG_SCRATCH_DATA0]
-#else
-       ld  r9, [@int1_saved_reg]
-#endif
+       /* restore original r9 */
+       PROLOG_RESTORE_REG  r9, @int1_saved_reg
 
        /* now we are ready to save the remaining context :) */
        st      event_IRQ1, [sp, 8]    /* Dummy ECR */
@@ -496,12 +492,13 @@
 
 .macro SAVE_ALL_INT2
 
-       /* TODO-vineetg: SMP we can't use global nor can we use
-       *   SCRATCH0 as we do for int1 because while int1 is using
-       *   it, int2 can come
-       */
-       /* retsore original r9 , saved in sys_saved_r9 */
-       ld  r9, [@int2_saved_reg]
+       /*
+        * In SMP we can't use mem nor can we use SCRARCH_DATA0
+        * as we do for int1 because int2 can clobber it
+        * Hence 2 levels of intr are NOT allowed in SMP (by Kconfig)
+        */
+       /* restore original r9 */
+       PROLOG_RESTORE_REG r9, @int2_saved_reg
 
        /* now we are ready to save the remaining context :) */
        st      event_IRQ2, [sp, 8]    /* Dummy ECR */

diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index d868289..13b14b8 100644 (file)
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -186,9 +186,8 @@ reserved:           ; processor restart
 ; ---------------------------------------------
 ENTRY(handle_interrupt_level2)
 
-       ; TODO-vineetg for SMP this wont work
        ; free up r9 as scratchpad
-       st  r9, [@int2_saved_reg]
+       PROLOG_FREEUP_REG r9, @int2_saved_reg
 
        ;Which mode (user/kernel) was the system in when intr occured
        lr  r9, [status32_l2]
@@ -234,12 +233,7 @@ END(handle_interrupt_level2)
 ; ---------------------------------------------
 ENTRY(handle_interrupt_level1)
 
-       /* free up r9 as scratchpad */
-#ifdef CONFIG_SMP
-       sr  r9, [ARC_REG_SCRATCH_DATA0]
-#else
-       st   r9, [@int1_saved_reg]
-#endif
+       PROLOG_FREEUP_REG r9, @int1_saved_reg
 
        ;Which mode (user/kernel) was the system in when intr occured
        lr  r9, [status32_l1]