[PATCH v2 2/3] powerpc/kvm/book3s_hv: Enable CPUs to run guest after waking up from fast-sleep

From: Shreyas B. Prabhu
Date: Wed Oct 01 2014 - 03:46:52 EST


When guests have to be launched, the secondary threads which are offline
are woken up to run the guests. Today these threads wake up from nap
and check if they have to run guests. Now that the offline secondary
threads can go to fastsleep or going ahead a deeper idle state such as winkle,
add this check in the wakeup from any of the deep idle states path as well.

Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Suggested-by: "Srivatsa S. Bhat" <srivatsa@xxxxxxx>
Signed-off-by: Shreyas B. Prabhu <shreyas@xxxxxxxxxxxxxxxxxx>
[ Changelog added by <preeti@xxxxxxxxxxxxxxxxxx> ]
Signed-off-by: Preeti U Murthy <preeti@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/exceptions-64s.S | 35 ++++++++++++++++-------------------
1 file changed, 16 insertions(+), 19 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 050f79a..c64f3cc0 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -100,25 +100,8 @@ system_reset_pSeries:
SET_SCRATCH0(r13)
#ifdef CONFIG_PPC_P7_NAP
BEGIN_FTR_SECTION
- /* Running native on arch 2.06 or later, check if we are
- * waking up from nap. We only handle no state loss and
- * supervisor state loss. We do -not- handle hypervisor
- * state loss at this time.
- */
- mfspr r13,SPRN_SRR1
- rlwinm. r13,r13,47-31,30,31
- beq 9f

- /* waking up from powersave (nap) state */
- cmpwi cr1,r13,2
- /* Total loss of HV state is fatal, we could try to use the
- * PIR to locate a PACA, then use an emergency stack etc...
- * OPAL v3 based powernv platforms have new idle states
- * which fall in this catagory.
- */
- bgt cr1,8f
GET_PACA(r13)
-
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
li r0,KVM_HWTHREAD_IN_KERNEL
stb r0,HSTATE_HWTHREAD_STATE(r13)
@@ -131,13 +114,27 @@ BEGIN_FTR_SECTION
1:
#endif

+ /* Running native on arch 2.06 or later, check if we are
+ * waking up from nap. We only handle no state loss and
+ * supervisor state loss. We do -not- handle hypervisor
+ * state loss at this time.
+ */
+ mfspr r13,SPRN_SRR1
+ rlwinm. r13,r13,47-31,30,31
+ beq 9f
+
+ /* waking up from powersave (nap) state */
+ cmpwi cr1,r13,2
+ GET_PACA(r13)
+
+ bgt cr1,8f
+
beq cr1,2f
b power7_wakeup_noloss
2: b power7_wakeup_loss

/* Fast Sleep wakeup on PowerNV */
-8: GET_PACA(r13)
- b power7_wakeup_tb_loss
+8: b power7_wakeup_tb_loss

9:
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
--
1.9.3

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