Re: [PATCH v10 00/10] Implement vendor resets for PSCI SYSTEM_RESET2

[Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>]

On 7/11/2025 1:50 AM, Florian Fainelli wrote:
> On 7/10/25 02:15, Shivendra Pratap wrote:
>> The PSCI SYSTEM_RESET2 call allows vendor firmware to define
>> additional reset types which could be mapped to the reboot
>> argument.
>>   User-space should be able to reboot a device into different
>> operational boot-states supported by underlying bootloader and
>> firmware. Generally, some HW registers need to be written, based
>> on which the bootloader and firmware decide the next boot state
>> of device, after the reset. For example, a requirement on
>> Qualcomm platforms may state that reboot with "bootloader"
>> command, should reboot the device into bootloader flashing mode
>> and reboot with “edl” command, should reboot the device into an
>> Emergency flashing mode.  Setting up such reboots on Qualcomm
>> devices can be inconsistent across SoC platforms and may require
>> setting different HW registers, where some of these registers may
>> not be accessible to HLOS. These knobs evolve over product
>> generations and require more drivers.  PSCI defines a
>> vendor-specific reset in SYSTEM_RESET2 spec, which enables the
>> firmware to take care of underlying setting for any such
>> supported vendor-specific reboot. Qualcomm firmwares are
>> beginning to support and expose PSCI SYSTEM_RESET2
>> vendor-specific reset types to simplify driver requirements from
>> Linux. With such support added in the firmware, we now need a
>> Linux interface which can make use of the firmware calls for PSCI
>> vendor-specific resets. This will align such reboot requirement
>> across platforms and vendors.
>>   The current psci driver supports two types of resets –
>> SYSTEM_RESET2 Arch warm-reset and SYSTEM_RESET cold-reset. The
>> patchset introduces the PSCI SYSTEM_RESET2 vendor-specific reset
>> into the reset path of the psci driver and aligns it to work with
>> reboot system call - LINUX_REBOOT_CMD_RESTART2, when used along
>> with a supported string-based command in “*arg”.
>>
>> The patchset uses reboot-mode based commands, to define the
>> supported vendor reset-types commands in psci device tree node
>> and registers these commands with the reboot-mode framework.
>>
>> The PSCI vendor-specific reset takes two arguments, being,
>> reset_type and cookie as defined by the spec. As the
>> vendor-specific reset needs two arguments reset_type and cookie
>> to be passes to the firmware, enhance the reboot-mode framework
>> to support two arguments (magic and cookie), for each reboot-mode
>> command, where cookie will be optional.
>>
>> Along this line, the patchset also extends the reboot-mode
>> framework to add a non-device-based registration function which
>> will allow drivers to register using DT node, while keeping
>> backward compatibility for existing users of reboot-mode. This
>> will enable psci driver to register for reboot-mode and implement
>> a write_with_cookie function which will save the
>> magic(reset_type) and cookie and then use it in psci reset path
>> to make a vendor-specific reset call into the firmware. In
>> addition, the patchset will expose a sysfs entry interface within
>> reboot-mode which can be used by userspace to view the supported
>> reboot-mode commands.
>>
>> The list of vendor-specific reset commands remains open due to
>> divergent requirements across vendors, but this can be
>> streamlined and standardized through dedicated device tree
>> bindings.
>>
>> Currently three drivers register with reboot-mode framework -
>> syscon-reboot-mode, nvmem-reboot-mode and qcom-pon. Consolidated
>> list of commands currently added across various vendor DTs:
>>   mode-loader
>>   mode-normal
>>   mode-bootloader
>>   mode-charge
>>   mode-fastboot
>>   mode-reboot-ab-update
>>   mode-recovery
>>   mode-rescue
>>   mode-shutdown-thermal
>>   mode-shutdown-thermal-battery
>>
>> Detailed list of commands being used by syscon-reboot-mode:
>>      arm64/boot/dts/exynos/exynosautov9.dtsi:
>>     mode-bootloader = <EXYNOSAUTOV9_BOOT_BOOTLOADER>;
>>     mode-fastboot = <EXYNOSAUTOV9_BOOT_FASTBOOT>;
>>     mode-recovery = <EXYNOSAUTOV9_BOOT_RECOVERY>;
>>
>>      arm64/boot/dts/exynos/google/gs101.dtsi:
>>          mode-bootloader = <0xfc>;
>>          mode-charge = <0x0a>;
>>          mode-fastboot = <0xfa>;
>>          mode-reboot-ab-update = <0x52>;
>>          mode-recovery = <0xff>;
>>          mode-rescue = <0xf9>;
>>          mode-shutdown-thermal = <0x51>;
>>          mode-shutdown-thermal-battery = <0x51>;
>>
>>      arm64/boot/dts/hisilicon/hi3660-hikey960.dts:
>>          mode-normal = <0x77665501>;
>>          mode-bootloader = <0x77665500>;
>>          mode-recovery = <0x77665502>;
>>
>>      arm64/boot/dts/hisilicon/hi6220-hikey.dts:
>>          mode-normal = <0x77665501>;
>>          mode-bootloader = <0x77665500>;
>>          mode-recovery = <0x77665502>;
>>
>>      arm64/boot/dts/rockchip/px30.dtsi:
>>          mode-bootloader = <BOOT_BL_DOWNLOAD>;
>>          mode-fastboot = <BOOT_FASTBOOT>;
>>          mode-loader = <BOOT_BL_DOWNLOAD>;
>>          mode-normal = <BOOT_NORMAL>;
>>          mode-recovery = <BOOT_RECOVERY>;
>>
>>      arm64/boot/dts/rockchip/rk3308.dtsi:           
>>          mode-bootloader = <BOOT_BL_DOWNLOAD>;
>>          mode-loader = <BOOT_BL_DOWNLOAD>;
>>          mode-normal = <BOOT_NORMAL>;
>>          mode-recovery = <BOOT_RECOVERY>;
>>          mode-fastboot = <BOOT_FASTBOOT>;
>>
>>      arm64/boot/dts/rockchip/rk3566-lckfb-tspi.dts:
>>          mode-normal = <BOOT_NORMAL>;
>>          mode-loader = <BOOT_BL_DOWNLOAD>;
>>             mode-recovery = <BOOT_RECOVERY>;
>>             mode-bootloader = <BOOT_FASTBOOT>;
>>
>> Detailed list of commands being used by nvmem-reboot-mode:
>>      arm64/boot/dts/qcom/pmXXXX.dtsi:(multiple qcom DTs)
>>             mode-recovery = <0x01>;
>>             mode-bootloader = <0x02>;
>>
>> Previous discussions around SYSTEM_RESET2:
>> - https://lore.kernel.org/lkml/20230724223057.1208122-2-quic_eberman@quicinc.com/T/
>> - https://lore.kernel.org/all/4a679542-b48d-7e11-f33a-63535a5c68cb@quicinc.com/
>>
>> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
>> Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
> 
> Humm, something changed compared to the last version that I tested from Elliot which worked ok. With this patch applied and the following Device Tree snippet:
> 
>         psci {
>                 method = "smc";
>                 compatible = "arm,psci-0.2", "arm,psci";
>                 cpu_on = <0xc4000003>;
>                 cpu_suspend = <0xc4000001>;
>                 cpu_off = <0x84000002>;
> 
>                 reset-types {
>                         mode-powercycle = <0x01>;
Yes, Now passing the cookie value is mandatory, when defining your "reset-types".
So your device tree entry should be:
			mode-powercycle = <0x01 0>;

Please try by passing changing the dt entry as above.

The dt-binding document is updated and does talks about the mandatory cookie
to be passed in reset-type.
>                 };
>         };
> 
> I get the following invoking "reboot powercycle":
> 
> # reboot powercycle
> [   21.403188] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 is not a phandle reference
> [   21.412032] Mem abort info:extended_property): /rdb/waketimer@841a840:interrupts-extended: cell 0 is not a phandle reference
> [   21.414840]   ESR = 0x0000000086000004operty): /rdb/waketimer@841a840:interrupts-extended: cell 2 is not a phandle reference
> [   21.418601]   EC = 0x21: IABT (current EL), IL = 32 bitsparent: cell 0 is not a phandle reference
> [   21.423927]   SET = 0, FnV = 0: /rdb/xhci_v2@8d00000:phys: cell 0 is not a phandle reference
> [   21.426988]   EA = 0, S1PTW = 0 /rdb/sata@8b0a000/sata-port@0:phys: cell 0 is not a phandle reference
> [   21.430138]   FSC = 0x04: level 0 translation fault:phys: cell 0 is not a phandle reference
> [   21.435054] user pgtable: 4k pages, 48-bit VAs, pgdp=000000010112c000 a phandle reference
> [   21.441508] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000handle reference
> [   21.448318] Internal error: Oops: 0000000086000004 [#1]  SMPcell 0 is not a phandle reference
> [   21.453990] Modules linked in: bdc udc_core/thermal-zones/cpu-thermal:thermal-sensors: cell 0 is not a phandle reference
> [   21.458188] CPU: 0 UID: 0 PID: 1566 Comm: reboot Not tainted 6.16.0-rc5-next-20250710-gdd78270edd5a #2 NONE 4)
> [   21.468032] Hardware name: BCX972160DV (DT)ases property name must include only lowercase and '-'
> [   21.472221] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)only lowercase and '-'
> [   21.479193] pc : 0x0s_paths): /aliases:pcie0: aliases property is not a valid node (/pcie@8b10000)
> [   21.481388] lr : reboot_mode_notify+0x64/0x80es property name must include only lowercase and '-'
> [   21.485760] sp : ffff80008344bbe0iases: aliases property name must include only lowercase and '-'
> [   21.489079] x29: ffff80008344bbe0 x28: ffff0000c3bb3d00 x27: ffff800080ab58e8ly lowercase and '-'
> [   21.496228] x26: 0000000000000000 x25: ffff0000c3bb3d00 x24: ffff800082cf9bc8ly lowercase and '-'
> [   21.503376] x23: ffff80008344bcb8 x22: 0000000000000001 x21: ffff0000c31b87b0
> [   21.510524] x20: 00000000fffffffc x19: ffff0000c31b8780 x18: 0000000000000000
> [   21.517673] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
> [   21.524821] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
> [   21.531969] x11: 0000000000000000 x10: 00007fffc02bb958 x9 : 0000000000000010
> [   21.539118] x8 : 0101010101010101 x7 : 0000000000000000 x6 : 000080c38080ffff
> [   21.546266] x5 : ffff0000c3000000 x4 : 0000808000800000 x3 : 0000000000000000
> [   21.553415] x2 : 0000000000000000 x1 : 0000000000000001 x0 : ffff0000c31b8780
> [   21.560565] Call trace:
> [   21.563014]  0x0 (P)
> [   21.565205]  notifier_call_chain+0x70/0x120
> [   21.569401]  blocking_notifier_call_chain+0x4c/0x78
> [   21.574288]  kernel_restart+0x30/0xc8
> [   21.577957]  __do_sys_reboot+0x1c8/0x268
> [   21.581886]  __arm64_sys_reboot+0x28/0x38
> [   21.585902]  invoke_syscall+0x4c/0x118
> [   21.589660]  el0_svc_common.constprop.0+0x44/0xe8
> [   21.594373]  do_el0_svc+0x20/0x30
> [   21.597694]  el0_svc+0x18/0x58
> [   21.600758]  el0t_64_sync_handler+0x98/0xe0
> [   21.604947]  el0t_64_sync+0x154/0x158
> [   21.608625] Code: ???????? ???????? ???????? ???????? (????????)
> [   21.614730] ---[ end trace 0000000000000000 ]---
> Segmentation fault
> #
> 
> -- 
> Florian