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authorVaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>2014-02-26 05:38:43 +0530
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2014-03-05 15:56:54 +1100
commit97eb001f03494758a938300908b88929163650ce (patch)
treea266f44413ae0418c95436e505b7441d041e328e
parentaca79d2b6ec2c0b955b22abb71c6dab90fa1d4d5 (diff)
downloadlinux-97eb001f03494758a938300908b88929163650ce.tar.bz2
powerpc/powernv: Add OPAL call to resync timebase on wakeup
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 <svaidy@linux.vnet.ibm.com> Signed-off-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-rw-r--r--arch/powerpc/include/asm/opal.h2
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S2
-rw-r--r--arch/powerpc/kernel/idle_power7.S27
-rw-r--r--arch/powerpc/platforms/powernv/opal-wrappers.S1
4 files changed, 31 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 40157e2ca691..c71c72e47d47 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -154,6 +154,7 @@ 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
#define OPAL_GET_MSG 85
#define OPAL_CHECK_ASYNC_COMPLETION 86
#define OPAL_SYNC_HOST_REBOOT 87
@@ -865,6 +866,7 @@ 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 b01a9cb441e4..9533d7a9223c 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 14f78bec62c4..c3ab86975614 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
@@ -125,6 +126,32 @@ _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 3e8829c40fbb..aab54b60334f 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -126,6 +126,7 @@ 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);
OPAL_CALL(opal_get_msg, OPAL_GET_MSG);
OPAL_CALL(opal_check_completion, OPAL_CHECK_ASYNC_COMPLETION);
OPAL_CALL(opal_sync_host_reboot, OPAL_SYNC_HOST_REBOOT);