Re: [PATCH v3] firmware: stratix10-svc: add PSCI secondary CPU offline on warm reboot for agilex and stratix10

[NG, ADRIAN HO YIN]

On 9/5/2026 12:55 AM, Dinh Nguyen wrote:
> On 9/4/26 00:52, Adrian Ng Ho Yin wrote:
> > On Agilex7 and Stratix10 SoCs, secondary CPUs must be offlined before
> > a warm reboot to ensure a clean PSCI state. Agilex5 warm reset is a
> > SDM-owned HPS reset that holds secondaries in the new reset-release 
> > until
> > ATF releases them, so the secondary cores dont have to be put offline
> > first. Register a reboot notifier that calls remove_cpu() on each
> > secondary CPU when SYS_RESTART is triggered in REBOOT_WARM mode.
> >
> > A snapshot of cpu_online_mask is taken before the loop since 
> > remove_cpu()
> > modifies the mask as CPUs go down. CPU 0 is excluded as it is typically
> > not hotpluggable. Failures are logged and the loop continues so the
> > reboot is not blocked by a single CPU that refuses to offline.
> > The of_device_id table carries a per-compatible pdata flag to enable the
> > notifier only on platforms that need it; Agilex5 leaves the flag unset.
> >
> > The notifier is unregistered at the start of remove(), before async
> > channel teardown, to prevent a reboot notification from racing with
> > driver shutdown.
> >
> > Signed-off-by: Adrian Ng Ho Yin <adrian.ho.yin.ng@xxxxxxxxxx>
> > ---
> > changelog:
> > v2 -> v3:
> > - Use ctrl in psci_offline_secondary_cpus() via dev_err(ctrl->dev, ...)
> >    instead of pr_err(). The controller pointer was unused; this both
> >    consumes it and attributes the failure to the svc device.
> > - Keep of_device_id.data / stratix10_svc_pdata rather than dropping it
> >    because both intel,stratix10-svc and intel,agilex-svc happen to share
> >    the same notifier path. A separate patch adds intel,agilex5-svc 
> > without
> >    .data so Agilex5 does not run this sequence. Agilex5 warm reset is an
> >    SDM-owned HPS reset (REBOOT_HPS) that holds secondaries in the
> >    reset-release / P-channel block until ATF CPURSTRELEASE; Linux must
> >    not PSCI-offline them first.
> >
> > v1 -> v2:
> > - Drop workqueue fan-out: remove_cpu() serialises on device_hotplug_lock
> >    internally so concurrent workers provided no parallelism. Replace 
> > with
> >    a single sequential loop over a cpumask snapshot.
> > - Fix CPU identity bug: get_cpu()/put_cpu() did not prevent task 
> > migration
> >    and the notifier can run on any CPU before migrate_to_reboot_cpu().
> >    Exclude CPU 0 (typically not hotpluggable) and offline everything 
> > else.
> > - Fix pre-count race: the two-loop atomic pre-count had a window where a
> >    concurrent hotplug event could cause dec_and_test() to fire 
> > prematurely.
> >    Eliminated entirely along with the completion and timeout.
> > - Replace of_device_is_compatible() checks with a stratix10_svc_pdata
> >    struct carried in of_device_id.data, retrieved via 
> > of_device_get_match_data().
> > - Move psci_cpu_off_teardown() to the top of stratix10_svc_drv_remove(),
> >    before async channel teardown, to close the race where a warm-reboot
> >    notification could fire while the driver is being dismantled.
> >
> > ---
> >   drivers/firmware/stratix10-svc.c | 88 ++++++++++++++++++++++++++++++--
> >   1 file changed, 85 insertions(+), 3 deletions(-)
> I had some erros apply this patch, but was able to finally do it. 
> Please double-check the applied patch on my branch: 
> socfpga_firmware_for_v7.4

Hi Dinh,

The patch looks good on socfpga_firmware_for_v7.4.

Thank You
Adrian