[PATCH v21 00/13] Implement PSCI reboot mode driver for PSCI resets

Shivendra Pratap
2026-04-27T17:35:16Z

Userspace should be able to initiate device reboots using the various
PSCI SYSTEM_RESET and SYSTEM_RESET2 types defined by PSCI spec. This
patch series introduces psci-reboot-mode driver that will induce
command-based resets to psci driver for executing the device reset.

The PSCI system reset calls takes two arguments: reset_type and cookie.
It defines predefined reset types, such as warm and cold reset, and
vendor-specific reset types which are SoC vendor specific. To support
these requirements, the reboot-mode framework is enhanced in two key
ways:
1. 64-bit magic support: Extend reboot-mode to handle two 32-bit
arguments (reset_type and cookie) by encoding them into a single 64-bit
magic value.
2. Predefined modes: Add support for predefined reboot modes in the
framework.

With these enhancements, the patch series enables:
- Arch Warm reset and system reset cold as predefined reboot modes.
- Vendor-specific resets, configurable via the SoC-specific device tree.

Together, these changes allow userspace to trigger all above PSCI resets
from userspace.

Note on introducing PSCI-MFD:
In v19/20, psci-reboot-mode was implemented as a faux-device. Review
discussion suggested this may not be the best model for firmware-backed
consumers, and that representing PSCI users as regular platform devices
would be better. One suggestion was to add a PSCI-MFD driver, allowing
multiple consumers tied to a single PSCI node "arm,psci-1.0" be probed
as MFD cells.

Following this, the series adds a PSCI-MFD driver and introduces
cpuidle-psci-domain and psci-reboot-mode as child cells. To meet the
psci-reboot-mode requirement, the MFD core is extended to support
fwnode.
Reference discussions on this:
https://lore.kernel.org/all/20260306-faux-dev-with-fwnode-v1-1-792a86a62530@oss.qualcomm.com/

---
- Carrying Reviewed-by form Sebastian and Bart on Patch1.
- Carrying Reviewed-by form Sebastian on Patch2.
- Dropping Reviewed-by form Sebastian on Patch3 due to additional changes.

The patch is tested on rb3Gen2, lemans-ride, lemans-evk, monaco-ride,
qcs615-ride.

Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>

Changes in v21:
By Krzysztof
power: reset: reboot-mode: Remove devres based allocations
- remove fixes tag.
By Lorenzo
firmware: psci: Introduce command-based resets
- psci_set_reset_cmd() only takes reset_type/cookie as input params.
- updated this as a encoded u64 reset_command - from Pavan Kondeti.
- Update commit text for reason for explicit panic_handling.
- Clean split of reset flow in psci_sys_reset via handle_reboot_mode and handle_cmd_reset.
- Add psci_has_system_reset2_support() helper and PSCI reset-type defines.
By Lorenzo/Bart
power: reset: Add psci-reboot-mode driver
By Bart
- Drop faux-device based probe.
- Convert driver to platform-driver model (probed via PSCI MFD).
By Lorenzo:
- Use PSCI-specific predefined reset mode naming/magic.
- Register arch-warm predefined mode only when SYSTEM_RESET2 is supported.
- psci_reboot_mode_write to directly pass reset_type and cokie.
- Add MAINTAINERS entry for drivers/power/reset/psci-reboot-mode.c.
By Bart
mfd: psci-mfd: Introduce psci mfd driver for cpuidle-psci-domain cell
- Introduce psci-mfd driver.
mfd: Add psci-reboot-mode cell via fwnode
- Register psci-reboot-mode from psci-mfd with reboot-mode child node
fwnode.
- Update reset Kconfig dependency to tie PSCI reboot-mode to MFD PSCI path.
For alignment:
- mfd: core: Add firmware-node support to MFD cells
- Add firmware-node support to MFD cells.
By Pavan
power: reset: reboot-mode: Add support for predefined reboot modes
- Move redundant logic of adding modes to list to a common function.
By Arnd
- Remove refrences for Linux reboot-modes from code and commit text.
By Konrad
- Updated all dt changes to add reboot-mode for supported board files.
- Link to v20: https://lore.kernel.org/r/20260304-arm-psci-system_reset2-vendor-reboots-v20-0-cf7d346b8372@oss.qualcomm.com

Changes in v20:
By Bart:
power: reset: Add psci-reboot-mode driver
- Check for psci compatible in init arm,psci-1.0
- Node pointer should not be assigned in device probe.
To Align on above:
- Remove probe call for faux device.
- Set node using device_set_node after faux_device_create.
- Register the reboot mode using explicit call to psci_reboot_mode_register_device.
- Updated in-code documentation.
For Alignment to use of device_property_xx:
power: reset: reboot-mode: Add support for 64 bit magic
- Use device_property_count_u32 instead of device_property_read_u32.
- Check count of properties before reading.
- u64 magic changed to u32 magic[2].
- nvmem-reboot rebased on recent changes.
- Update documentation and commit text.
power: reset: reboot-mode: Remove devres based allocations
By Dmitry/Bart:
- pr_err to pr_debug in case of invalid reboot-mode prop.
By Bart:
- Use device_property_read_u32 instead of of_property_read_u32.
- Avoid repeated code for free list. Now calling unregister from
error path of regiister_reboot_mode.
- Fix magic assignment.
- Link to v19: https://lore.kernel.org/r/20251228-arm-psci-system_reset2-vendor-reboots-v19-0-ebb956053098@oss.qualcomm.com

Changes in v19:
- Add missing To/Cc entries (include devicetree list) – Thanks to
Krzysztof for pointing this out.
- Fix compilation error in reboot-mode.c for ARCH=powerpc by explicitly
including <linux/slab.h>.
- Link to v18: https://lore.kernel.org/r/20251223-arm-psci-system_reset2-vendor-reboots-v18-0-32fa9e76efc3@oss.qualcomm.com

Changes in v18:
power: reset: reboot-mode: Remove devres based allocations
- Update commit text for alignment. – Bart
- Read magic before assigning kzalloc(info) in reboot_mode_register. - Mukesh
- Update error handling path. - Mukesh
By Bjorn
- Expose sysfs for reboot-mode bisected to different series-
Link: https://lore.kernel.org/all/20251222-next-15nov_expose_sysfs-v21-0-244614135fd8@oss.qualcomm.com/
By Bjorn/Lorenzo/Mukesh
power: reset: reboot-mode: Add support for 64 bit magic
- Use FIELD_GET/FIELD_PREP for u64 magic wherever required.
- Update commit text and add documentation for structure of 64 bit magic.
By Lorenzo
- Remove direct reboot-mode registration by psci driver.
- Add support for predefined reboot modes in reboot-mode framework.
- Add psci-reboot-mode driver and implement a psci-resets to accommodate
all psci-resets including warm, cold and customizable vendor-resets.
By Bjorn
- Update DT patches for qcm6490, lemans, monaco and tolos.
- Update commit text to include more details – By Bjorn
For Alignment
- dt-bindings: arm: Document reboot mode magic
- Update reboot mode documentation to clarify that argument1 should provide
full value of reset_type along with the 31st bit wherever required.
- DT patches for qcm6490, lemans, monaco and tolos.
- Provide full value of reset_type including 31st bit.(eg:0x80000001).
- Link to v17: https://lore.kernel.org/r/20251109-arm-psci-system_reset2-vendor-reboots-v17-0-46e085bca4cc@oss.qualcomm.com

Previous versions:
- Link to v16: https://lore.kernel.org/r/20251015-arm-psci-system_reset2-vendor-reboots-v16-0-b98aedaa23ee@oss.qualcomm.com
- Link to v15: https://lore.kernel.org/r/20250922-arm-psci-system_reset2-vendor-reboots-v15-0-7ce3a08878f1@oss.qualcomm.com
- Link to v14: https://lore.kernel.org/r/20250815-arm-psci-system_reset2-vendor-reboots-v14-0-37d29f59ac9a@oss.qualcomm.com
- Link to v13: https://lore.kernel.org/r/20250727-arm-psci-system_reset2-vendor-reboots-v13-0-6b8d23315898@oss.qualcomm.com
- Link to v12: https://lore.kernel.org/r/20250721-arm-psci-system_reset2-vendor-reboots-v12-0-87bac3ec422e@oss.qualcomm.com
- Link to v11: https://lore.kernel.org/r/20250717-arm-psci-system_reset2-vendor-reboots-v11-0-df3e2b2183c3@oss.qualcomm.com
- Link to v10: https://lore.kernel.org/all/569f154d-c714-1714-b898-83a42a38771c@oss.qualcomm.com/
- Link to v9: https://lore.kernel.org/all/20250303-arm-psci-system_reset2-vendor-reboots-v9-0-b2cf4a20feda@oss.qualcomm.com/
- Link to v8: https://lore.kernel.org/r/20241107-arm-psci-system_reset2-vendor-reboots-v8-0-e8715fa65cb5@quicinc.com
- Link to v7: https://lore.kernel.org/r/20241028-arm-psci-system_reset2-vendor-reboots-v7-0-a4c40b0ebc54@quicinc.com
- Link to v6: https://lore.kernel.org/r/20241018-arm-psci-system_reset2-vendor-reboots-v6-0-50cbe88b0a24@quicinc.com
- Link to v5: https://lore.kernel.org/r/20240617-arm-psci-system_reset2-vendor-reboots-v5-0-086950f650c8@quicinc.com
- Link to v4: https://lore.kernel.org/r/20240611-arm-psci-system_reset2-vendor-reboots-v4-0-98f55aa74ae8@quicinc.com
- Link to v3: https://lore.kernel.org/r/20240515-arm-psci-system_reset2-vendor-reboots-v3-0-16dd4f9c0ab4@quicinc.com
- Link to v2: https://lore.kernel.org/r/20240414-arm-psci-system_reset2-vendor-reboots-v2-0-da9a055a648f@quicinc.com
- Link to v1: https://lore.kernel.org/r/20231117-arm-psci-system_reset2-vendor-reboots-v1-0-03c4612153e2@quicinc.com
- Link to RFC: https://lore.kernel.org/r/20231030-arm-psci-system_reset2-vendor-reboots-v1-0-dcdd63352ad1@quicinc.com

To: Lorenzo Pieralisi <lpieralisi@kernel.org>
To: Arnd Bergmann <arnd@arndb.de>
To: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
To: Bjorn Andersson <andersson@kernel.org>
To: Sebastian Reichel <sre@kernel.org>
To: Rob Herring <robh@kernel.org>
To: Sudeep Holla <sudeep.holla@arm.com>
To: Souvik Chakravarty <Souvik.Chakravarty@arm.com>
To: Krzysztof Kozlowski <krzk+dt@kernel.org>
To: Andy Yan <andy.yan@rock-chips.com>
To: Matthias Brugger <matthias.bgg@gmail.com>
To: Mark Rutland <mark.rutland@arm.com>
To: Conor Dooley <conor+dt@kernel.org>
To: Konrad Dybcio <konradybcio@kernel.org>
To: John Stultz <john.stultz@linaro.org>
To: Moritz Fischer <moritz.fischer@ettus.com>
To: Rafael J. Wysocki <rafael@kernel.org>
To: Daniel Lezcano <daniel.lezcano@kernel.org>
To: Christian Loehle <christian.loehle@arm.com>
To: Ulf Hansson <ulf.hansson@linaro.org>
To: Lee Jones <lee@kernel.org>
To: Ulf Hansson <ulfh@kernel.org>
Cc: Florian Fainelli <florian.fainelli@broadcom.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Cc: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
Cc: Andre Draszik <andre.draszik@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arm-msm@vger.kernel.org
Cc: devicetree@vger.kernel.org

---
Shivendra Pratap (13):
power: reset: reboot-mode: Remove devres based allocations
power: reset: reboot-mode: Add support for 64 bit magic
power: reset: reboot-mode: Add support for predefined reboot modes
firmware: psci: Introduce command-based with magic
mfd: psci-mfd: Add PSCI MFD driver for cpuidle-psci-domain cell
dt-bindings: arm: Document reboot mode magic
power: reset: Add psci-reboot-mode driver
mfd: core: Add firmware-node support to MFD cells
mfd: psci-mfd: Add psci-reboot-mode child cell
arm64: dts: qcom: Add psci reboot-modes for kodiak boards
arm64: dts: qcom: Add psci reboot-modes for lemans boards
arm64: dts: qcom: Add psci reboot-modes for monaco boards
arm64: dts: qcom: Add psci reboot-modes for talos boards

Documentation/devicetree/bindings/arm/psci.yaml | 42 +++++++++
MAINTAINERS | 2 +
arch/arm64/boot/dts/qcom/kodiak.dtsi | 2 +-
arch/arm64/boot/dts/qcom/lemans-evk.dts | 7 ++
arch/arm64/boot/dts/qcom/lemans-ride-common.dtsi | 7 ++
arch/arm64/boot/dts/qcom/lemans.dtsi | 2 +-
arch/arm64/boot/dts/qcom/monaco-evk.dts | 7 ++
arch/arm64/boot/dts/qcom/monaco.dtsi | 2 +-
arch/arm64/boot/dts/qcom/qcm6490-idp.dts | 7 ++
arch/arm64/boot/dts/qcom/qcs615-ride.dts | 7 ++
arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts | 7 ++
arch/arm64/boot/dts/qcom/qcs8300-ride.dts | 7 ++
arch/arm64/boot/dts/qcom/talos.dtsi | 2 +-
drivers/cpuidle/Kconfig.arm | 1 +
drivers/cpuidle/cpuidle-psci-domain.c | 9 +-
drivers/firmware/psci/psci.c | 75 +++++++++++++++-
drivers/mfd/Kconfig | 10 +++
drivers/mfd/Makefile | 2 +
drivers/mfd/mfd-core.c | 10 +++
drivers/mfd/psci-mfd.c | 62 +++++++++++++
drivers/power/reset/Kconfig | 10 +++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/nvmem-reboot-mode.c | 9 +-
drivers/power/reset/psci-reboot-mode.c | 109 +++++++++++++++++++++++
drivers/power/reset/qcom-pon.c | 7 +-
drivers/power/reset/reboot-mode.c | 91 ++++++++++++-------
drivers/power/reset/syscon-reboot-mode.c | 7 +-
include/linux/mfd/core.h | 6 ++
include/linux/psci.h | 19 ++++
include/linux/reboot-mode.h | 23 ++++-
30 files changed, 496 insertions(+), 56 deletions(-)
---
base-commit: 39704f00f747aba3144289870b5fd8ac230a9aaf
change-id: 20250709-arm-psci-system_reset2-vendor-reboots-46c80044afcf

Best regards,
--
Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>