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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 /arch/powerpc/kernel/idle_power7.S
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>
Diffstat (limited to 'arch/powerpc/kernel/idle_power7.S')
-rw-r--r--arch/powerpc/kernel/idle_power7.S27
1 files changed, 27 insertions, 0 deletions
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)