Messages in this thread | | | Date | Tue, 30 Apr 2024 14:29:11 +1000 | Subject | Re: [PATCH v8 12/16] arm64: psci: Ignore DENIED CPUs | From | Gavin Shan <> |
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On 4/26/24 23:51, Jonathan Cameron wrote: > From: Jean-Philippe Brucker <jean-philippe@linaro.org> > > When a CPU is marked as disabled, but online capable in the MADT, PSCI > applies some firmware policy to control when it can be brought online. > PSCI returns DENIED to a CPU_ON request if this is not currently > permitted. The OS can learn the current policy from the _STA enabled bit. > > Handle the PSCI DENIED return code gracefully instead of printing an > error. > > Note the alternatives to the PSCI cpu_boot() callback do not > return -EPERM so the change in smp.c has no affect. > > See https://developer.arm.com/documentation/den0022/f/?lang=en page 58. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> > [ morse: Rewrote commit message ] > Signed-off-by: James Morse <james.morse@arm.com> > Tested-by: Miguel Luis <miguel.luis@oracle.com> > Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com> > Tested-by: Jianyong Wu <jianyong.wu@arm.com> > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- > v8: Note in commit message that the -EPERM guard on the error print > only affects PSCI as other options never use this error code. > Should they do so in future, that may well indicate that they > now support similar refusal to boot. > --- > arch/arm64/kernel/psci.c | 2 +- > arch/arm64/kernel/smp.c | 3 ++- > 2 files changed, 3 insertions(+), 2 deletions(-) >
Thanks for the check and clarification that -EPERM is only sensible to PSCI. With the clarification:
Reviewed-by: Gavin Shan <gshan@redhat.com>
Thanks, Gavin
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