RE: [PATCH 34/39] arm64: psci: Ignore DENIED CPUs

Jianyong Wu
2023-11-20T09:36:15Z

> -----Original Message-----
> From: Russell King <linux@armlinux.org.uk>
> Sent: 2023年11月20日 17:25
> To: Jianyong Wu <Jianyong.Wu@arm.com>
> Cc: linux-pm@vger.kernel.org; loongarch@lists.linux.dev;
> linux-acpi@vger.kernel.org; linux-arch@vger.kernel.org;
> linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> linux-riscv@lists.infradead.org; kvmarm@lists.linux.dev; x86@kernel.org;
> linux-csky@vger.kernel.org; linux-doc@vger.kernel.org;
> linux-ia64@vger.kernel.org; linux-parisc@vger.kernel.org; Salil Mehta
> <salil.mehta@huawei.com>; Jean-Philippe Brucker <jean-philippe@linaro.org>;
> Justin He <Justin.He@arm.com>; James Morse <James.Morse@arm.com>;
> Catalin Marinas <Catalin.Marinas@arm.com>; Will Deacon <will@kernel.org>;
> Mark Rutland <Mark.Rutland@arm.com>; Lorenzo Pieralisi
> <lpieralisi@kernel.org>
> Subject: Re: [PATCH 34/39] arm64: psci: Ignore DENIED CPUs
>
> On Thu, Nov 16, 2023 at 07:45:51AM +0000, Jianyong Wu wrote:
> > Hi Russell,
> >
> > One inline comment.
> ...
> > > Changes since RFC v2
> > > * Add specification reference
> > > * Use EPERM rather than EPROBE_DEFER
> ...
> > > @@ -40,7 +40,7 @@ static int cpu_psci_cpu_boot(unsigned int cpu) {
> > > phys_addr_t pa_secondary_entry = __pa_symbol(secondary_entry);
> > > int err = psci_ops.cpu_on(cpu_logical_map(cpu), pa_secondary_entry);
> > > - if (err)
> > > + if (err && err != -EPROBE_DEFER)
> >
> > Should this be EPERM? As the following psci cpu_on op will return it.
> > I think you miss to change this when apply Jean-Philippe's patch.
>
> It looks like James didn't properly update all places. Also,
>
> > > diff --git a/drivers/firmware/psci/psci.c
> > > b/drivers/firmware/psci/psci.c index d9629ff87861..ee82e7880d8c
> > > 100644
> > > --- a/drivers/firmware/psci/psci.c
> > > +++ b/drivers/firmware/psci/psci.c
> > > @@ -218,6 +218,8 @@ static int __psci_cpu_on(u32 fn, unsigned long
> > > cpuid, unsigned long entry_point)
> > > int err;
> > >
> > > err = invoke_psci_fn(fn, cpuid, entry_point, 0);
> > > + if (err == PSCI_RET_DENIED)
> > > + return -EPERM;
> > > return psci_to_linux_errno(err);
>
> This change is unnecessary - probably comes from when -EPROBE_DEFER was
> being used. psci_to_linux_errno() already does:

But may print lots of noise like:

[ 0.008955] smp: Bringing up secondary CPUs ...
[ 0.009661] psci: failed to boot CPU1 (-1)
[ 0.010360] psci: failed to boot CPU2 (-1)
[ 0.011164] psci: failed to boot CPU3 (-1)
[ 0.011946] psci: failed to boot CPU4 (-1)
[ 0.012764] psci: failed to boot CPU5 (-1)
[ 0.013534] psci: failed to boot CPU6 (-1)
[ 0.014349] psci: failed to boot CPU7 (-1)
[ 0.014820] smp: Brought up 1 node, 1 CPU

Is this expected?

Thanks
Jianyong
>
> case PSCI_RET_DENIED:
> return -EPERM;
>
> Thanks.
>
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