From: Vaidyanathan Srinivasan <sva...@linux.vnet.ibm.com>
During "Fast-sleep" and deeper power savings state, decrementer and
timebase could be stopped making it out of sync with rest
of the cores in the system.
Add a firmware call to request platform to resync timebase
using low level platform methods.
Signed-off-by: Vaidyanathan Srinivasan <sva...@linux.vnet.ibm.com>
Signed-off-by: Preeti U. Murthy <pre...@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/opal.h | 2 ++
arch/powerpc/kernel/exceptions-64s.S | 2 +-
arch/powerpc/kernel/idle_power7.S | 27 ++++++++++++++++++++++++
arch/powerpc/platforms/powernv/opal-wrappers.S | 1 +
4 files changed, 31 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 033c06b..a662d06 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -132,6 +132,7 @@ extern int opal_enter_rtas(struct rtas_args *args,
#define OPAL_FLASH_VALIDATE 76
#define OPAL_FLASH_MANAGE 77
#define OPAL_FLASH_UPDATE 78
+#define OPAL_RESYNC_TIMEBASE 79
#ifndef __ASSEMBLY__
@@ -763,6 +764,7 @@ extern void opal_flash_init(void);
extern int opal_machine_check(struct pt_regs *regs);
extern void opal_shutdown(void);
+extern int opal_resync_timebase(void);
extern void opal_lpc_init(void);
diff --git a/arch/powerpc/kernel/exceptions-64s.S
b/arch/powerpc/kernel/exceptions-64s.S
index b8139fb..91e6417 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -145,7 +145,7 @@ BEGIN_FTR_SECTION
/* Fast Sleep wakeup on PowerNV */
8: GET_PACA(r13)
- b .power7_wakeup_loss
+ b .power7_wakeup_tb_loss
9:
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
diff --git a/arch/powerpc/kernel/idle_power7.S
b/arch/powerpc/kernel/idle_power7.S
index e4bbca2..34c71e8 100644
--- a/arch/powerpc/kernel/idle_power7.S
+++ b/arch/powerpc/kernel/idle_power7.S
@@ -17,6 +17,7 @@
#include <asm/ppc-opcode.h>
#include <asm/hw_irq.h>
#include <asm/kvm_book3s_asm.h>
+#include <asm/opal.h>
#undef DEBUG
@@ -124,6 +125,32 @@ _GLOBAL(power7_sleep)
b power7_powersave_common
/* No return */
+_GLOBAL(power7_wakeup_tb_loss)
+ ld r2,PACATOC(r13);
+ ld r1,PACAR1(r13)
+
+ /* Time base re-sync */
+ li r0,OPAL_RESYNC_TIMEBASE
+ LOAD_REG_ADDR(r11,opal);
+ ld r12,8(r11);
+ ld r2,0(r11);
+ mtctr r12
+ bctrl
+
+ /* TODO: Check r3 for failure */
+
+ REST_NVGPRS(r1)
+ REST_GPR(2, r1)
+ ld r3,_CCR(r1)
+ ld r4,_MSR(r1)
+ ld r5,_NIP(r1)
+ addi r1,r1,INT_FRAME_SIZE
+ mtcr r3
+ mfspr r3,SPRN_SRR1 /* Return SRR1 */
+ mtspr SPRN_SRR1,r4
+ mtspr SPRN_SRR0,r5
+ rfid
+
_GLOBAL(power7_wakeup_loss)
ld r1,PACAR1(r13)
REST_NVGPRS(r1)
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S
b/arch/powerpc/platforms/powernv/opal-wrappers.S
index e780650..ddfe95a 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -126,3 +126,4 @@ OPAL_CALL(opal_return_cpu,
OPAL_RETURN_CPU);
OPAL_CALL(opal_validate_flash, OPAL_FLASH_VALIDATE);
OPAL_CALL(opal_manage_flash, OPAL_FLASH_MANAGE);
OPAL_CALL(opal_update_flash, OPAL_FLASH_UPDATE);
+OPAL_CALL(opal_resync_timebase, OPAL_RESYNC_TIMEBASE);
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