ARC: [plat-eznps] handle extra aux regs #2: kernel/entry exit
Preserve eflags and gpa1 aux during entry/exit into kernel as these
could be modified by kernel mode
These registers used by compare exchange instructions.
- GPA1 is used for compare value,
- EFLAGS got bit reflects atomic operation response.
EFLAGS is zeroed for each new user task so it won't get its
parent value.
Signed-off-by: Liav Rehana <liavr@mellanox.com>
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/include/asm/entry-compact.h b/arch/arc/include/asm/entry-compact.h
index 14c310f..ec36d5b 100644
--- a/arch/arc/include/asm/entry-compact.h
+++ b/arch/arc/include/asm/entry-compact.h
@@ -192,6 +192,12 @@
PUSHAX lp_start
PUSHAX erbta
+#ifdef CONFIG_ARC_PLAT_EZNPS
+ .word CTOP_INST_SCHD_RW
+ PUSHAX CTOP_AUX_GPA1
+ PUSHAX CTOP_AUX_EFLAGS
+#endif
+
lr r9, [ecr]
st r9, [sp, PT_event] /* EV_Trap expects r9 to have ECR */
.endm
@@ -208,6 +214,12 @@
* by hardware and that is not good.
*-------------------------------------------------------------*/
.macro EXCEPTION_EPILOGUE
+#ifdef CONFIG_ARC_PLAT_EZNPS
+ .word CTOP_INST_SCHD_RW
+ POPAX CTOP_AUX_EFLAGS
+ POPAX CTOP_AUX_GPA1
+#endif
+
POPAX erbta
POPAX lp_start
POPAX lp_end
@@ -265,6 +277,12 @@
PUSHAX lp_end
PUSHAX lp_start
PUSHAX bta_l\LVL\()
+
+#ifdef CONFIG_ARC_PLAT_EZNPS
+ .word CTOP_INST_SCHD_RW
+ PUSHAX CTOP_AUX_GPA1
+ PUSHAX CTOP_AUX_EFLAGS
+#endif
.endm
/*--------------------------------------------------------------
@@ -277,6 +295,12 @@
* by hardware and that is not good.
*-------------------------------------------------------------*/
.macro INTERRUPT_EPILOGUE LVL
+#ifdef CONFIG_ARC_PLAT_EZNPS
+ .word CTOP_INST_SCHD_RW
+ POPAX CTOP_AUX_EFLAGS
+ POPAX CTOP_AUX_GPA1
+#endif
+
POPAX bta_l\LVL\()
POPAX lp_start
POPAX lp_end
diff --git a/arch/arc/include/asm/ptrace.h b/arch/arc/include/asm/ptrace.h
index 5297faa..5a8cb22 100644
--- a/arch/arc/include/asm/ptrace.h
+++ b/arch/arc/include/asm/ptrace.h
@@ -19,6 +19,11 @@
#ifdef CONFIG_ISA_ARCOMPACT
struct pt_regs {
+#ifdef CONFIG_ARC_PLAT_EZNPS
+ unsigned long eflags; /* Extended FLAGS */
+ unsigned long gpa1; /* General Purpose Aux */
+#endif
+
/* Real registers */
unsigned long bta; /* bta_l1, bta_l2, erbta */
diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c
index 5c631a1..5ac3b54 100644
--- a/arch/arc/kernel/process.c
+++ b/arch/arc/kernel/process.c
@@ -234,6 +234,10 @@ void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long usp)
*/
regs->status32 = STATUS_U_MASK | STATUS_L_MASK | ISA_INIT_STATUS_BITS;
+#ifdef CONFIG_EZNPS_MTM_EXT
+ regs->eflags = 0;
+#endif
+
/* bogus seed values for debugging */
regs->lp_start = 0x10;
regs->lp_end = 0x80;