From: Srivatsa S. Bhat <srivatsa.b...@linux.vnet.ibm.com>
Now that the support for fast sleep is present, threads could have woken up
from fast sleep on getting a machine check interrupt. Hence add code to allow
threads to go back to the idle state they woke up from after handling the
interrupt. Today they go back to nap by default.
Signed-off-by: Srivatsa S. Bhat <srivatsa.b...@linux.vnet.ibm.com>
[ Changelog added by <pre...@linux.vnet.ibm.com> ]
Signed-off-by: Preeti U Murthy <pre...@linux.vnet.ibm.com>
---
arch/powerpc/kernel/exceptions-64s.S | 21 +++++++++++++++------
arch/powerpc/kernel/idle_power7.S | 2 +-
2 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S
b/arch/powerpc/kernel/exceptions-64s.S
index b4bf464..94cee3c 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1396,15 +1396,16 @@ machine_check_handle_early:
* of the following is true:
* a. thread wasn't in power saving mode
* b. thread was in power saving mode with no state loss or
- * supervisor state loss
+ * supervisor state loss or hypervisor state loss (fastsleep)
*
- * Go back to nap again if (b) is true.
+ * Go back to nap or fastsleep again if (b) is true.
*/
rlwinm. r11,r12,47-31,30,31 /* Was it in power saving mode? */
beq 4f /* No, it wasn;t */
- /* Thread was in power saving mode. Go back to nap again. */
- cmpwi r11,2
- bne 3f
+ /* Thread was in power saving mode. Go back to the same state again. */
+ cmpwi cr1,r11,2
+ blt cr1,3f
+7:
/* Supervisor state loss */
li r0,1
stb r0,PACA_NAPSTATELOST(r13)
@@ -1412,7 +1413,15 @@ machine_check_handle_early:
MACHINE_CHECK_HANDLER_WINDUP
GET_PACA(r13)
ld r1,PACAR1(r13)
- b .power7_enter_nap_mode
+ /* We need to pass the idle state in r3: 0 -> nap, 1 -> sleep */
+ bgt cr1,8f
+ li r3,0
+ b .power7_enter_idle
+ /* No return */
+
+8: li r3,1 /* Pass 1 in r3 to request sleep in power7_enter_idle */
+ b .power7_enter_idle
+ /* No return */
4:
#endif
/*
diff --git a/arch/powerpc/kernel/idle_power7.S
b/arch/powerpc/kernel/idle_power7.S
index c3ab869..e13e21b 100644
--- a/arch/powerpc/kernel/idle_power7.S
+++ b/arch/powerpc/kernel/idle_power7.S
@@ -95,7 +95,7 @@ _GLOBAL(power7_powersave_common)
std r9,_MSR(r1)
std r1,PACAR1(r13)
-_GLOBAL(power7_enter_nap_mode)
+_GLOBAL(power7_enter_idle)
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
/* Tell KVM we're napping */
li r4,KVM_HWTHREAD_IN_NAP
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