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ppc/kvm: Clear the runlatch bit of a vcpu before napping

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When the guest cedes the vcpu or the vcpu has no guest to
run it naps. Clear the runlatch bit of the vcpu before
napping to indicate an idle cpu.

Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Preeti U Murthy 2014-04-11 16:02:08 +05:30 committed by Benjamin Herrenschmidt
parent fd17dc7b9a
commit 582b910eda
1 changed files with 11 additions and 1 deletions
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12
arch/powerpc/kvm/book3s_hv_rmhandlers.S
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@ -315,6 +315,11 @@ kvm_no_guest:
li r0, KVM_HWTHREAD_IN_NAP
stb r0, HSTATE_HWTHREAD_STATE(r13)
kvm_do_nap:
/* Clear the runlatch bit before napping */
mfspr r2, SPRN_CTRLF
clrrdi r2, r2, 1
mtspr SPRN_CTRLT, r2
li r3, LPCR_PECE0
mfspr r4, SPRN_LPCR
rlwimi r4, r3, 0, LPCR_PECE0 | LPCR_PECE1
@ -2005,8 +2010,13 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206)
/*
* Take a nap until a decrementer or external or doobell interrupt
* occurs, with PECE1, PECE0 and PECEDP set in LPCR
* occurs, with PECE1, PECE0 and PECEDP set in LPCR. Also clear the
* runlatch bit before napping.
*/
mfspr r2, SPRN_CTRLF
clrrdi r2, r2, 1
mtspr SPRN_CTRLT, r2
li r0,1
stb r0,HSTATE_HWTHREAD_REQ(r13)
mfspr r5,SPRN_LPCR