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powerpc: Turn off CPU_FTR_P9_TM_HV_ASSIST in non-hypervisor mode

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When doing nested virtualization, it is only necessary to do the
transactional memory hypervisor assist at level 0, that is, when
we are in hypervisor mode.  Nested hypervisors can just use the TM
facilities as architected.  Therefore we should clear the
CPU_FTR_P9_TM_HV_ASSIST bit when we are not in hypervisor mode,
along with the CPU_FTR_HVMODE bit.

Doing this will not change anything at this stage because the only
code that tests CPU_FTR_P9_TM_HV_ASSIST is in HV KVM, which currently
can only be used when when CPU_FTR_HVMODE is set.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Paul Mackerras 2018-10-08 16:30:47 +11:00 committed by Michael Ellerman
parent a3ac077b75
commit e7b17d5047
1 changed files with 2 additions and 2 deletions
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4
arch/powerpc/kernel/cpu_setup_power.S
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@ -147,8 +147,8 @@ __init_hvmode_206:
rldicl. r0,r3,4,63
bnelr
ld r5,CPU_SPEC_FEATURES(r4)
LOAD_REG_IMMEDIATE(r6,CPU_FTR_HVMODE)
xor r5,r5,r6
LOAD_REG_IMMEDIATE(r6,CPU_FTR_HVMODE | CPU_FTR_P9_TM_HV_ASSIST)
andc r5,r5,r6
std r5,CPU_SPEC_FEATURES(r4)
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