Eric Lee / smarc-ti-linux-kernel

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Commit 582b910edafd283dfab78f41f437a92a65ee5103

Authored by Preeti U Murthy
Committed by Benjamin Herrenschmidt
1 parent fd17dc7b9a
Exists in master and in 13 other branches dlt-processor-sdk-linux-03.00.00.04, processor-sdk-linux-02.00.01, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.15.y, ti-lsk-linux-4.1.y

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

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>

Showing 1 changed file with 11 additions and 1 deletions Side-by-side Diff

arch/powerpc/kvm/book3s_hv_rmhandlers.S
Diff comments   View file @ 582b910
... ... @@ -315,6 +315,11 @@
315 315 li r0, KVM_HWTHREAD_IN_NAP
316 316 stb r0, HSTATE_HWTHREAD_STATE(r13)
317 317 kvm_do_nap:
  318 + /* Clear the runlatch bit before napping */
  319 + mfspr r2, SPRN_CTRLF
  320 + clrrdi r2, r2, 1
  321 + mtspr SPRN_CTRLT, r2
  322 +
318 323 li r3, LPCR_PECE0
319 324 mfspr r4, SPRN_LPCR
320 325 rlwimi r4, r3, 0, LPCR_PECE0 | LPCR_PECE1
321 326  
... ... @@ -2005,8 +2010,13 @@
2005 2010  
2006 2011 /*
2007 2012 * Take a nap until a decrementer or external or doobell interrupt
2008   - * occurs, with PECE1, PECE0 and PECEDP set in LPCR
  2013 + * occurs, with PECE1, PECE0 and PECEDP set in LPCR. Also clear the
  2014 + * runlatch bit before napping.
2009 2015 */
  2016 + mfspr r2, SPRN_CTRLF
  2017 + clrrdi r2, r2, 1
  2018 + mtspr SPRN_CTRLT, r2
  2019 +
2010 2020 li r0,1
2011 2021 stb r0,HSTATE_HWTHREAD_REQ(r13)
2012 2022 mfspr r5,SPRN_LPCR