Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'powerpc-5.15-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
- Fix a bug exposed by a previous fix, where running guests with
certain SMT topologies could crash the host on Power8.
- Fix atomic sleep warnings when re-onlining CPUs, when PREEMPT is
enabled.
Thanks to Nathan Lynch, Srikar Dronamraju, and Valentin Schneider.
* tag 'powerpc-5.15-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/smp: do not decrement idle task preempt count in CPU offline
powerpc/idle: Don't corrupt back chain when going idle
+6
-6
+6
-4
arch/powerpc/kernel/idle_book3s.S
+6
-4
arch/powerpc/kernel/idle_book3s.S
···
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/*
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* This is the sequence required to execute idle instructions, as
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* specified in ISA v2.07 (and earlier). MSR[IR] and MSR[DR] must be 0.
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-
*
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-
* The 0(r1) slot is used to save r2 in isa206, so use that here.
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+
* We have to store a GPR somewhere, ptesync, then reload it, and create
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+
* a false dependency on the result of the load. It doesn't matter which
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+
* GPR we store, or where we store it. We have already stored r2 to the
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+
* stack at -8(r1) in isa206_idle_insn_mayloss, so use that.
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*/
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#define IDLE_STATE_ENTER_SEQ_NORET(IDLE_INST) \
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/* Magic NAP/SLEEP/WINKLE mode enter sequence */ \
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-
std r2,0(r1); \
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+
std r2,-8(r1); \
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ptesync; \
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-
ld r2,0(r1); \
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+
ld r2,-8(r1); \
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236: cmpd cr0,r2,r2; \
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bne 236b; \
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IDLE_INST; \