ARC: K/U SP saved from one location in stack switching macro
This paves way for further simplifications.
There's an overhead of 1 insn for the non-common case of interrupt taken
from kernel mode.
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 5191945..2cf6aa0 100644
--- a/arch/arc/include/asm/entry.h
+++ b/arch/arc/include/asm/entry.h
@@ -290,9 +290,8 @@
* safe-keeping not really needed, but it keeps the epilogue code
* (SP restore) simpler/uniform.
*/
- b.d 77f
-
- st.a sp, [sp, -12] ; Make room for orig_r0 and orig_r8
+ b.d 66f
+ mov r9, sp
88: /*------Intr/Ecxp happened in user mode, "switch" stack ------ */
@@ -311,6 +310,7 @@
/* With current tsk in r9, get it's kernel mode stack base */
GET_TSK_STACK_BASE r9, r9
+66:
/* Save Pre Intr/Exception User SP on kernel stack */
st.a sp, [r9, -12] ; Make room for orig_r0 and orig_r8
@@ -323,7 +323,7 @@
/* set SP to point to kernel mode stack */
mov sp, r9
-77: /* ----- Stack Switched to kernel Mode, Now save REG FILE ----- */
+ /* ----- Stack Switched to kernel Mode, Now save REG FILE ----- */
.endm