ARC: [optim] Cache "current" in Register r25
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 9eada5b..716f4f7 100644
--- a/arch/arc/include/asm/entry.h
+++ b/arch/arc/include/asm/entry.h
@@ -13,6 +13,8 @@
* was being "CLEARED" rather then "SET". Actually "SET" clears ZOL context
*
* Vineetg: May 5th 2008
+ * -Modified CALLEE_REG save/restore macros to handle the fact that
+ * r25 contains the kernel current task ptr
* - Defined Stack Switching Macro to be reused in all intr/excp hdlrs
* - Shaved off 11 instructions from RESTORE_ALL_INT1 by using the
* address Write back load ld.ab instead of seperate ld/add instn
@@ -28,6 +30,7 @@
#include <asm/asm-offsets.h>
#include <asm/arcregs.h>
#include <asm/ptrace.h>
+#include <asm/processor.h> /* For VMALLOC_START */
#include <asm/thread_info.h> /* For THREAD_SIZE */
/* Note on the LD/ST addr modes with addr reg wback
@@ -106,7 +109,14 @@
st.a r22, [sp, -4]
st.a r23, [sp, -4]
st.a r24, [sp, -4]
+
+#ifdef CONFIG_ARC_CURR_IN_REG
+ ; Retrieve orig r25 and save it on stack
+ ld r12, [r25, TASK_THREAD + THREAD_USER_R25]
+ st.a r12, [sp, -4]
+#else
st.a r25, [sp, -4]
+#endif
/* move up by 1 word to "create" callee_regs->"stack_place_holder" */
sub sp, sp, 4
@@ -131,8 +141,12 @@
st.a r22, [sp, -4]
st.a r23, [sp, -4]
st.a r24, [sp, -4]
+#ifdef CONFIG_ARC_CURR_IN_REG
+ sub sp, sp, 8
+#else
st.a r25, [sp, -4]
sub sp, sp, 4
+#endif
.endm
/*--------------------------------------------------------------
@@ -148,8 +162,14 @@
*-------------------------------------------------------------*/
.macro RESTORE_CALLEE_SAVED_KERNEL
+
+#ifdef CONFIG_ARC_CURR_IN_REG
+ add sp, sp, 8 /* skip callee_reg gutter and user r25 placeholder */
+#else
add sp, sp, 4 /* skip "callee_regs->stack_place_holder" */
ld.ab r25, [sp, 4]
+#endif
+
ld.ab r24, [sp, 4]
ld.ab r23, [sp, 4]
ld.ab r22, [sp, 4]
@@ -235,6 +255,7 @@
*
* Entry : r9 contains pre-IRQ/exception/trap status32
* Exit : SP is set to kernel mode stack pointer
+ * If CURR_IN_REG, r25 set to "current" task pointer
* Clobbers: r9
*-------------------------------------------------------------*/
@@ -259,6 +280,16 @@
GET_CURR_TASK_ON_CPU r9
+#ifdef CONFIG_ARC_CURR_IN_REG
+
+ /* If current task pointer cached in r25, time to
+ * -safekeep USER r25 in task->thread_struct->user_r25
+ * -load r25 with current task ptr
+ */
+ st.as r25, [r9, (TASK_THREAD + THREAD_USER_R25)/4]
+ mov r25, r9
+#endif
+
/* With current tsk in r9, get it's kernel mode stack base */
GET_TSK_STACK_BASE r9, r9
@@ -519,17 +550,31 @@
.macro SET_CURR_TASK_ON_CPU tsk, tmp
st \tsk, [@_current_task]
+#ifdef CONFIG_ARC_CURR_IN_REG
+ mov r25, \tsk
+#endif
.endm
/* ------------------------------------------------------------------
* Get the ptr to some field of Current Task at @off in task struct
+ * -Uses r25 for Current task ptr if that is enabled
*/
+#ifdef CONFIG_ARC_CURR_IN_REG
+
+.macro GET_CURR_TASK_FIELD_PTR off, reg
+ add \reg, r25, \off
+.endm
+
+#else
+
.macro GET_CURR_TASK_FIELD_PTR off, reg
GET_CURR_TASK_ON_CPU \reg
add \reg, \reg, \off
.endm
+#endif /* CONFIG_ARC_CURR_IN_REG */
+
#endif /* __ASSEMBLY__ */
#endif /* __ASM_ARC_ENTRY_H */