From: Srivatsa S. Bhat <srivatsa.b...@linux.vnet.ibm.com>
Now that the support for fast sleep idle state is present, the KVM
standby threads can be put to fast sleep when they are either idle
or do not have a guest to run. Today they enter nap in these scenarios.
The purpose is to gain maximum power savings in a KVM scenario as well
when an entire cpu core is idle.
As a precursor, consolidate the code common across all idle states.
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/kvm/book3s_hv_rmhandlers.S | 30 ++++++++++++++++--------------
1 file changed, 16 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index b031f93..43aa806 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -40,6 +40,17 @@
#define NAPPING_CEDE 1
#define NAPPING_NOVCPU 2
+#define IDLE_STATE_ENTER_SEQ_HV(IDLE_INST) \
+ /* Magic NAP/SLEEP/WINKLE mode enter sequence */ \
+ std r0, HSTATE_SCRATCH0(r13); \
+ ptesync; \
+ ld r0, HSTATE_SCRATCH0(r13); \
+1: cmpd r0, r0; \
+ bne 1b; \
+ IDLE_INST; \
+ b .
+
+
/*
* Call kvmppc_hv_entry in real mode.
* Must be called with interrupts hard-disabled.
@@ -325,13 +336,9 @@ kvm_do_nap:
rlwimi r4, r3, 0, LPCR_PECE0 | LPCR_PECE1
mtspr SPRN_LPCR, r4
isync
- std r0, HSTATE_SCRATCH0(r13)
- ptesync
- ld r0, HSTATE_SCRATCH0(r13)
-1: cmpd r0, r0
- bne 1b
- nap
- b .
+ IDLE_STATE_ENTER_SEQ_HV(PPC_NAP)
+ /* No return */
+
/******************************************************************************
* *
@@ -2027,13 +2034,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
mtspr SPRN_LPCR,r5
isync
li r0, 0
- std r0, HSTATE_SCRATCH0(r13)
- ptesync
- ld r0, HSTATE_SCRATCH0(r13)
-1: cmpd r0, r0
- bne 1b
- nap
- b .
+ IDLE_STATE_ENTER_SEQ_HV(PPC_NAP)
+ /* No return */
33: mr r4, r3
li r3, 0
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