[PATCH v14 00/10] Implement vendor resets for PSCI SYSTEM_RESET2

[PATCH v14 00/10] Implement vendor resets for PSCI SYSTEM_RESET2

[Shivendra Pratap]

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. To accommodate this
requirement, enhance the reboot-mode framework to support two
32-bit arguments by switching to 64-bit magic values.

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 device tree 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 function, which will save the magic 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

On gs101 we also pass kernel-generated modes from kernel_restart()
or panic(), specifically DM verity's 'dm-verity device corrupted':
	mode-dm-verity-device-corrupted = <0x50>;

- thanks Andre' for providing this.

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>

Changes in v14:
- mode-dm-verity-device-corrupted documented in cover letter -by André
 ABI Documentation:
- Updated KernelVersion in ABI documentation to reflect base commit
  version. – by André
- Revised ABI documentation to clarify space-separated format for
  supported reboot-mode commands. – by André
 power: reset: reboot-mode: Expose sysfs patch
- Modified `show_modes` to output a space-separated list of supported
  reboot modes – by André
- Added error handling in `create_reboot_mode_device()` to ensure
  proper cleanup on failure.
 firmware: psci:
- Locate psci/reboot-mode node using psci compatible. - by Krzysztof,
  Dmitry, Sudeep.
- Added error handling for additional code for compatible.
- Converted hex values to lowercase for consistency. – by André
- Introduced panic notifier to disable valid vendor-reset flag in
  panic path. – by André
- Added check for `psci_system_reset2` before registering vendor reset
  commands.
- Updated Commit text.
 dts: sa8775p:
- DT file name changed from sa8775p to lemans and commit text updated
  accordingly. – for dt renaming in base commit (sa8775p to lemans).
- Link to v13: https://lore.kernel.org/r/20250727-arm-psci-system_reset2-vendor-reboots-v13-0-6b8d23315898@oss.qualcomm.com

Changes in v13:
- Split patch1 into two (Synchronize list traversal and DT node-based
  registration) - by Dmitry.
- Move mutex lock inside get_reboot_mode_magic - by Dmitry.
- Reorder the patches – pull patch8 for exposing reboot-mode sysfs before
  psci patch - to align the change in reboot-mode sysfs patch.
- Update patch- reboot-mode: Expose sysfs for registered reboot_modes
     - Introduce a driver_name in reboot_mode_register. This will be used
       in sysfs creation  -  by Arnd.
     - Update documentation and commit text for above.
     - Fix release function to properly call delete attr file.
     - Fix sparse warning for devres_find.
     - Add error handling for devres_find.
- Split ABI documentation as a separate patch and update ABI documentation
  for usage of driver-name in sysfs - by Arnd
- Update patch - psci: Implement vendor-specific resets as reboot-mode
     - Fix Kconfig for CONFIG related warning.
     - Add driver_name as "psci" in register call to reboot-mode - by Arnd
- Link to v12: https://lore.kernel.org/r/20250721-arm-psci-system_reset2-vendor-reboots-v12-0-87bac3ec422e@oss.qualcomm.com

Changes in v12:
- Added lock for list traversals in reboot-mode - by Dmitry.
- Added proper handling for BE and LE cases in reboot-mode - by Dmitry.
- Removed type casting for u64 to u32 conversions. Added limit checks
  and used bitwise operations for same - by Andrew.
- Link to v11: https://lore.kernel.org/r/20250717-arm-psci-system_reset2-vendor-reboots-v11-0-df3e2b2183c3@oss.qualcomm.com

Changes in v11:
- Remove reference of cookie in reboot-mode – Arnd/Rob
- Introduce 64-bit magic in reboot-mode to accommodate two 32-bit
  arguments – Arnd
- Change reset-type to reboot-mode in psci device tree binding – Arnd
	- binding no more mandates two arguments as in v10.
	- dt changes done to support this binding.
- Remove obvious comments in psci reset path – Konrad
- Merge sysfs and ABI doc into single patch.
- Fix compilation issue on X86 configs.
- Fix warnings for pr_fmt.
- Link to v10: https://lore.kernel.org/all/569f154d-c714-1714-b898-83a42a38771c@oss.qualcomm.com/

Changes in V10:
- Change in reset-type binding to make cookie as a mandatory
  argument.
- Change reboot-mode binding to support additional argument
  "cookie".
 From Lorenzo:
- Use reboot-mode framework for implementing vendor-resets.
- Modify reboot-mode framework to support two arguments
  (magic and cookie).
- Expose sysfs for supported reboot-modes commands.
- List out all existing reboot-mode commands and their users.
   - Added this to cover letter.
 From Dmitry:
- Modify reboot-mode to support non-device based registration.
- Modify reboot-mode to create a class and device to expose
  sysfs interface.
- Link to v9: https://lore.kernel.org/all/20250303-arm-psci-system_reset2-vendor-reboots-v9-0-b2cf4a20feda@oss.qualcomm.com/

Changes in v9:
- Don't fallback to architecturally defined resets from Lorenzo.
- Link to v8: https://lore.kernel.org/r/20241107-arm-psci-system_reset2-vendor-reboots-v8-0-e8715fa65cb5@quicinc.com

Changes in v8:
- Code style nits from Stephen
- Add rb3gen2
- Link to v7: https://lore.kernel.org/r/20241028-arm-psci-system_reset2-vendor-reboots-v7-0-a4c40b0ebc54@quicinc.com

Changes in v7:
- Code style nits from Stephen
- Dropped unnecessary hunk from the sa8775p-ride patch
- Link to v6: https://lore.kernel.org/r/20241018-arm-psci-system_reset2-vendor-reboots-v6-0-50cbe88b0a24@quicinc.com

Changes in v6:
- Rebase to v6.11 and fix trivial conflicts in qcm6490-idp
- Add sa8775p-ride support (same as qcm6490-idp)
- Link to v5: https://lore.kernel.org/r/20240617-arm-psci-system_reset2-vendor-reboots-v5-0-086950f650c8@quicinc.com

Changes in v5:
- Drop the nested "items" in prep for future dtschema tools
- Link to v4: https://lore.kernel.org/r/20240611-arm-psci-system_reset2-vendor-reboots-v4-0-98f55aa74ae8@quicinc.com

Changes in v4:
- Change mode- properties from uint32-matrix to uint32-array
- Restructure the reset-types node so only the restriction is in the
  if/then schemas and not the entire definition
- Link to v3: https://lore.kernel.org/r/20240515-arm-psci-system_reset2-vendor-reboots-v3-0-16dd4f9c0ab4@quicinc.com

Changes in v3:
- Limit outer number of items to 1 for mode-* properties
- Move the reboot-mode for psci under a subnode "reset-types"
- Fix the DT node in qcm6490-idp so it doesn't overwrite the one from
  sc7820.dtsi
- Link to v2: https://lore.kernel.org/r/20240414-arm-psci-system_reset2-vendor-reboots-v2-0-da9a055a648f@quicinc.com

Changes in v2:
- Fixes to schema as suggested by Rob and Krzysztof
- Add qcm6490 idp as first Qualcomm device to support
- Link to v1: https://lore.kernel.org/r/20231117-arm-psci-system_reset2-vendor-reboots-v1-0-03c4612153e2@quicinc.com

Changes in v1:
- Reference reboot-mode bindings as suggeted by Rob.
- Link to RFC: https://lore.kernel.org/r/20231030-arm-psci-system_reset2-vendor-reboots-v1-0-dcdd63352ad1@quicinc.com

---
Elliot Berman (4):
      dt-bindings: arm: Document reboot mode magic
      arm64: dts: qcom: qcm6490-idp: Add PSCI SYSTEM_RESET2 types
      arm64: dts: qcom: qcs6490-rb3gen2: Add PSCI SYSTEM_RESET2 types
      arm64: dts: qcom: lemans-ride: Add PSCI SYSTEM_RESET2 types

Shivendra Pratap (6):
      power: reset: reboot-mode: Synchronize list traversal
      power: reset: reboot-mode: Add device tree node-based registration
      power: reset: reboot-mode: Add support for 64 bit magic
      Documentation: ABI: Add sysfs-class-reboot-mode-reboot_modes
      power: reset: reboot-mode: Expose sysfs for registered reboot_modes
      firmware: psci: Implement vendor-specific resets as reboot-mode

 .../testing/sysfs-class-reboot-mode-reboot_modes   |  39 +++++
 Documentation/devicetree/bindings/arm/psci.yaml    |  43 +++++
 arch/arm64/boot/dts/qcom/lemans-ride-common.dtsi   |   7 +
 arch/arm64/boot/dts/qcom/lemans.dtsi               |   2 +-
 arch/arm64/boot/dts/qcom/qcm6490-idp.dts           |   7 +
 arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts       |   7 +
 arch/arm64/boot/dts/qcom/sc7280.dtsi               |   2 +-
 drivers/firmware/psci/Kconfig                      |   2 +
 drivers/firmware/psci/psci.c                       |  88 +++++++++-
 drivers/power/reset/nvmem-reboot-mode.c            |  13 +-
 drivers/power/reset/qcom-pon.c                     |  11 +-
 drivers/power/reset/reboot-mode.c                  | 179 +++++++++++++++++----
 drivers/power/reset/syscon-reboot-mode.c           |  11 +-
 include/linux/reboot-mode.h                        |  11 +-
 14 files changed, 378 insertions(+), 44 deletions(-)
---
base-commit: 931e46dcbc7e6035a90e9c4a27a84b660e083f0a
change-id: 20250709-arm-psci-system_reset2-vendor-reboots-46c80044afcf

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

[PATCH v14 01/10] power: reset: reboot-mode: Synchronize list traversal

[Shivendra Pratap]

List traversals must be synchronized to prevent race conditions
and data corruption. The reboot-mode list is not protected by a
lock currently, which can lead to concurrent access and race.

Introduce a mutex lock to guard all operations on the reboot-mode
list and ensure thread-safe access. The change prevents unsafe
concurrent access on reboot-mode list.

Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
---
 drivers/power/reset/reboot-mode.c | 24 ++++++++++++++++++++----
 include/linux/reboot-mode.h       |  4 ++++
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c
index fba53f638da04655e756b5f8b7d2d666d1379535..42bb99128ed3846d4bff62416dc31135ddeaeb90 100644
--- a/drivers/power/reset/reboot-mode.c
+++ b/drivers/power/reset/reboot-mode.c
@@ -29,9 +29,14 @@ static unsigned int get_reboot_mode_magic(struct reboot_mode_driver *reboot,
 	if (!cmd)
 		cmd = normal;
 
-	list_for_each_entry(info, &reboot->head, list)
-		if (!strcmp(info->mode, cmd))
+	mutex_lock(&reboot->rb_lock);
+	list_for_each_entry(info, &reboot->head, list) {
+		if (!strcmp(info->mode, cmd)) {
+			mutex_unlock(&reboot->rb_lock);
 			return info->magic;
+		}
+	}
+	mutex_unlock(&reboot->rb_lock);
 
 	/* try to match again, replacing characters impossible in DT */
 	if (strscpy(cmd_, cmd, sizeof(cmd_)) == -E2BIG)
@@ -41,9 +46,14 @@ static unsigned int get_reboot_mode_magic(struct reboot_mode_driver *reboot,
 	strreplace(cmd_, ',', '-');
 	strreplace(cmd_, '/', '-');
 
-	list_for_each_entry(info, &reboot->head, list)
-		if (!strcmp(info->mode, cmd_))
+	mutex_lock(&reboot->rb_lock);
+	list_for_each_entry(info, &reboot->head, list) {
+		if (!strcmp(info->mode, cmd_)) {
+			mutex_unlock(&reboot->rb_lock);
 			return info->magic;
+		}
+	}
+	mutex_unlock(&reboot->rb_lock);
 
 	return 0;
 }
@@ -77,7 +87,9 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
 	int ret;
 
 	INIT_LIST_HEAD(&reboot->head);
+	mutex_init(&reboot->rb_lock);
 
+	mutex_lock(&reboot->rb_lock);
 	for_each_property_of_node(np, prop) {
 		if (strncmp(prop->name, PREFIX, len))
 			continue;
@@ -113,12 +125,14 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
 	reboot->reboot_notifier.notifier_call = reboot_mode_notify;
 	register_reboot_notifier(&reboot->reboot_notifier);
 
+	mutex_unlock(&reboot->rb_lock);
 	return 0;
 
 error:
 	list_for_each_entry(info, &reboot->head, list)
 		kfree_const(info->mode);
 
+	mutex_unlock(&reboot->rb_lock);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(reboot_mode_register);
@@ -133,8 +147,10 @@ int reboot_mode_unregister(struct reboot_mode_driver *reboot)
 
 	unregister_reboot_notifier(&reboot->reboot_notifier);
 
+	mutex_lock(&reboot->rb_lock);
 	list_for_each_entry(info, &reboot->head, list)
 		kfree_const(info->mode);
+	mutex_unlock(&reboot->rb_lock);
 
 	return 0;
 }
diff --git a/include/linux/reboot-mode.h b/include/linux/reboot-mode.h
index 4a2abb38d1d612ec0fdf05eb18c98b210f631b7f..b73f80708197677db8dc2e43affc519782b7146e 100644
--- a/include/linux/reboot-mode.h
+++ b/include/linux/reboot-mode.h
@@ -2,11 +2,15 @@
 #ifndef __REBOOT_MODE_H__
 #define __REBOOT_MODE_H__
 
+#include <linux/mutex.h>
+
 struct reboot_mode_driver {
 	struct device *dev;
 	struct list_head head;
 	int (*write)(struct reboot_mode_driver *reboot, unsigned int magic);
 	struct notifier_block reboot_notifier;
+	/*Protects access to reboot mode list*/
+	struct mutex rb_lock;
 };
 
 int reboot_mode_register(struct reboot_mode_driver *reboot);

-- 
2.34.1

[PATCH v14 02/10] power: reset: reboot-mode: Add device tree node-based registration

[Shivendra Pratap]

The reboot-mode driver does not have a strict requirement for
device-based registration. It primarily uses the device's of_node
to read mode-<cmd> properties and the device pointer for logging.

Remove the dependency on struct device and introduce support for
Device Tree (DT) node-based registration. This enables drivers
that are not associated with a struct device to leverage the
reboot-mode framework.

Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
---
 drivers/power/reset/reboot-mode.c | 37 ++++++++++++++++++++++++++-----------
 include/linux/reboot-mode.h       |  2 +-
 2 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c
index 42bb99128ed3846d4bff62416dc31135ddeaeb90..9bb97bcd33cd3d58c75c791e9b568024e810e5b0 100644
--- a/drivers/power/reset/reboot-mode.c
+++ b/drivers/power/reset/reboot-mode.c
@@ -3,13 +3,17 @@
  * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
  */
 
+#define pr_fmt(fmt)	"reboot-mode: " fmt
+
 #include <linux/device.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/list.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/reboot.h>
 #include <linux/reboot-mode.h>
+#include <linux/slab.h>
 
 #define PREFIX "mode-"
 
@@ -75,17 +79,21 @@ static int reboot_mode_notify(struct notifier_block *this,
 /**
  * reboot_mode_register - register a reboot mode driver
  * @reboot: reboot mode driver
+ * @np: Pointer to device tree node
  *
  * Returns: 0 on success or a negative error code on failure.
  */
-int reboot_mode_register(struct reboot_mode_driver *reboot)
+int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *np)
 {
 	struct mode_info *info;
+	struct mode_info *next;
 	struct property *prop;
-	struct device_node *np = reboot->dev->of_node;
 	size_t len = strlen(PREFIX);
 	int ret;
 
+	if (!np)
+		return -EINVAL;
+
 	INIT_LIST_HEAD(&reboot->head);
 	mutex_init(&reboot->rb_lock);
 
@@ -94,28 +102,28 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
 		if (strncmp(prop->name, PREFIX, len))
 			continue;
 
-		info = devm_kzalloc(reboot->dev, sizeof(*info), GFP_KERNEL);
+		info = kzalloc(sizeof(*info), GFP_KERNEL);
 		if (!info) {
 			ret = -ENOMEM;
 			goto error;
 		}
 
 		if (of_property_read_u32(np, prop->name, &info->magic)) {
-			dev_err(reboot->dev, "reboot mode %s without magic number\n",
-				info->mode);
-			devm_kfree(reboot->dev, info);
+			pr_err("reboot mode %s without magic number\n", info->mode);
+			kfree(info);
 			continue;
 		}
 
 		info->mode = kstrdup_const(prop->name + len, GFP_KERNEL);
 		if (!info->mode) {
 			ret =  -ENOMEM;
+			kfree(info);
 			goto error;
 		} else if (info->mode[0] == '\0') {
 			kfree_const(info->mode);
+			kfree(info);
 			ret = -EINVAL;
-			dev_err(reboot->dev, "invalid mode name(%s): too short!\n",
-				prop->name);
+			pr_err("invalid mode name(%s): too short!\n", prop->name);
 			goto error;
 		}
 
@@ -129,8 +137,11 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
 	return 0;
 
 error:
-	list_for_each_entry(info, &reboot->head, list)
+	list_for_each_entry_safe(info, next, &reboot->head, list) {
+		list_del(&info->list);
 		kfree_const(info->mode);
+		kfree(info);
+	}
 
 	mutex_unlock(&reboot->rb_lock);
 	return ret;
@@ -144,12 +155,16 @@ EXPORT_SYMBOL_GPL(reboot_mode_register);
 int reboot_mode_unregister(struct reboot_mode_driver *reboot)
 {
 	struct mode_info *info;
+	struct mode_info *next;
 
 	unregister_reboot_notifier(&reboot->reboot_notifier);
 
 	mutex_lock(&reboot->rb_lock);
-	list_for_each_entry(info, &reboot->head, list)
+	list_for_each_entry_safe(info, next, &reboot->head, list) {
+		list_del(&info->list);
 		kfree_const(info->mode);
+		kfree(info);
+	}
 	mutex_unlock(&reboot->rb_lock);
 
 	return 0;
@@ -178,7 +193,7 @@ int devm_reboot_mode_register(struct device *dev,
 	if (!dr)
 		return -ENOMEM;
 
-	rc = reboot_mode_register(reboot);
+	rc = reboot_mode_register(reboot, reboot->dev->of_node);
 	if (rc) {
 		devres_free(dr);
 		return rc;
diff --git a/include/linux/reboot-mode.h b/include/linux/reboot-mode.h
index b73f80708197677db8dc2e43affc519782b7146e..98f68f95c9e8460be23282c51ef7fcbed73887bd 100644
--- a/include/linux/reboot-mode.h
+++ b/include/linux/reboot-mode.h
@@ -13,7 +13,7 @@ struct reboot_mode_driver {
 	struct mutex rb_lock;
 };
 
-int reboot_mode_register(struct reboot_mode_driver *reboot);
+int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *np);
 int reboot_mode_unregister(struct reboot_mode_driver *reboot);
 int devm_reboot_mode_register(struct device *dev,
 			      struct reboot_mode_driver *reboot);

-- 
2.34.1

[PATCH v14 03/10] power: reset: reboot-mode: Add support for 64 bit magic

[Shivendra Pratap]

Current reboot-mode supports a single 32-bit argument for any
supported mode. Some reboot-mode based drivers may require
passing two independent 32-bit arguments during a reboot
sequence, for uses-cases, where a mode requires an additional
argument. Such drivers may not be able to use the reboot-mode
driver. For example, ARM PSCI vendor-specific resets, need two
arguments for its operation – reset_type and cookie, to complete
the reset operation. If a driver wants to implement this
firmware-based reset, it cannot use reboot-mode framework.

Introduce 64-bit magic values in reboot-mode driver to
accommodate dual 32-bit arguments when specified via device tree.
In cases, where no second argument is passed from device tree,
keep the upper 32-bit of magic un-changed(0) to maintain backward
compatibility.

Update the current drivers using reboot-mode for a 64-bit magic
value.

Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
---
 drivers/power/reset/nvmem-reboot-mode.c  | 13 +++++++++----
 drivers/power/reset/qcom-pon.c           | 11 ++++++++---
 drivers/power/reset/reboot-mode.c        | 19 +++++++++++++------
 drivers/power/reset/syscon-reboot-mode.c | 11 ++++++++---
 include/linux/reboot-mode.h              |  3 ++-
 5 files changed, 40 insertions(+), 17 deletions(-)

diff --git a/drivers/power/reset/nvmem-reboot-mode.c b/drivers/power/reset/nvmem-reboot-mode.c
index 41530b70cfc48c2a83fbbd96f523d5816960a0d1..5d73dde585b1fd438b1847f884feb37cd9e4dd5c 100644
--- a/drivers/power/reset/nvmem-reboot-mode.c
+++ b/drivers/power/reset/nvmem-reboot-mode.c
@@ -16,15 +16,20 @@ struct nvmem_reboot_mode {
 	struct nvmem_cell *cell;
 };
 
-static int nvmem_reboot_mode_write(struct reboot_mode_driver *reboot,
-				    unsigned int magic)
+static int nvmem_reboot_mode_write(struct reboot_mode_driver *reboot, u64 magic)
 {
-	int ret;
 	struct nvmem_reboot_mode *nvmem_rbm;
+	u32 magic_32;
+	int ret;
+
+	if (magic > U32_MAX)
+		return -EINVAL;
+
+	magic_32 = magic;
 
 	nvmem_rbm = container_of(reboot, struct nvmem_reboot_mode, reboot);
 
-	ret = nvmem_cell_write(nvmem_rbm->cell, &magic, sizeof(magic));
+	ret = nvmem_cell_write(nvmem_rbm->cell, &magic_32, sizeof(magic_32));
 	if (ret < 0)
 		dev_err(reboot->dev, "update reboot mode bits failed\n");
 
diff --git a/drivers/power/reset/qcom-pon.c b/drivers/power/reset/qcom-pon.c
index 7e108982a582e8243c5c806bd4a793646b87189f..d0ed9431a02313a7bbaa93743c16fa1ae713ddfe 100644
--- a/drivers/power/reset/qcom-pon.c
+++ b/drivers/power/reset/qcom-pon.c
@@ -27,17 +27,22 @@ struct qcom_pon {
 	long reason_shift;
 };
 
-static int qcom_pon_reboot_mode_write(struct reboot_mode_driver *reboot,
-				    unsigned int magic)
+static int qcom_pon_reboot_mode_write(struct reboot_mode_driver *reboot, u64 magic)
 {
 	struct qcom_pon *pon = container_of
 			(reboot, struct qcom_pon, reboot_mode);
+	u32 magic_32;
 	int ret;
 
+	if (magic > U32_MAX || (magic << pon->reason_shift) > U32_MAX)
+		return -EINVAL;
+
+	magic_32 = magic << pon->reason_shift;
+
 	ret = regmap_update_bits(pon->regmap,
 				 pon->baseaddr + PON_SOFT_RB_SPARE,
 				 GENMASK(7, pon->reason_shift),
-				 magic << pon->reason_shift);
+				 magic_32);
 	if (ret < 0)
 		dev_err(pon->dev, "update reboot mode bits failed\n");
 
diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c
index 9bb97bcd33cd3d58c75c791e9b568024e810e5b0..ac81b8b0a9b7fc31f8ef21024333a050087ce90f 100644
--- a/drivers/power/reset/reboot-mode.c
+++ b/drivers/power/reset/reboot-mode.c
@@ -19,12 +19,11 @@
 
 struct mode_info {
 	const char *mode;
-	u32 magic;
+	u64 magic;
 	struct list_head list;
 };
 
-static unsigned int get_reboot_mode_magic(struct reboot_mode_driver *reboot,
-					  const char *cmd)
+static u64 get_reboot_mode_magic(struct reboot_mode_driver *reboot, const char *cmd)
 {
 	const char *normal = "normal";
 	struct mode_info *info;
@@ -66,7 +65,7 @@ static int reboot_mode_notify(struct notifier_block *this,
 			      unsigned long mode, void *cmd)
 {
 	struct reboot_mode_driver *reboot;
-	unsigned int magic;
+	u64 magic;
 
 	reboot = container_of(this, struct reboot_mode_driver, reboot_notifier);
 	magic = get_reboot_mode_magic(reboot, cmd);
@@ -89,6 +88,8 @@ int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *
 	struct mode_info *next;
 	struct property *prop;
 	size_t len = strlen(PREFIX);
+	u32 magic_arg1;
+	u32 magic_arg2;
 	int ret;
 
 	if (!np)
@@ -108,12 +109,18 @@ int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *
 			goto error;
 		}
 
-		if (of_property_read_u32(np, prop->name, &info->magic)) {
-			pr_err("reboot mode %s without magic number\n", info->mode);
+		if (of_property_read_u32(np, prop->name, &magic_arg1)) {
+			pr_err("reboot mode without magic number\n");
 			kfree(info);
 			continue;
 		}
 
+		if (of_property_read_u32_index(np, prop->name, 1, &magic_arg2))
+			magic_arg2 = 0;
+
+		info->magic = magic_arg2;
+		info->magic = (info->magic << 32) | magic_arg1;
+
 		info->mode = kstrdup_const(prop->name + len, GFP_KERNEL);
 		if (!info->mode) {
 			ret =  -ENOMEM;
diff --git a/drivers/power/reset/syscon-reboot-mode.c b/drivers/power/reset/syscon-reboot-mode.c
index e0772c9f70f7a19cd8ec8a0b7fdbbaa7ba44afd0..3cbd000c512239b12ec51987e900d260540a9dea 100644
--- a/drivers/power/reset/syscon-reboot-mode.c
+++ b/drivers/power/reset/syscon-reboot-mode.c
@@ -20,16 +20,21 @@ struct syscon_reboot_mode {
 	u32 mask;
 };
 
-static int syscon_reboot_mode_write(struct reboot_mode_driver *reboot,
-				    unsigned int magic)
+static int syscon_reboot_mode_write(struct reboot_mode_driver *reboot, u64 magic)
 {
 	struct syscon_reboot_mode *syscon_rbm;
+	u32 magic_32;
 	int ret;
 
+	if (magic > U32_MAX)
+		return -EINVAL;
+
+	magic_32 = magic;
+
 	syscon_rbm = container_of(reboot, struct syscon_reboot_mode, reboot);
 
 	ret = regmap_update_bits(syscon_rbm->map, syscon_rbm->offset,
-				 syscon_rbm->mask, magic);
+				 syscon_rbm->mask, magic_32);
 	if (ret < 0)
 		dev_err(reboot->dev, "update reboot mode bits failed\n");
 
diff --git a/include/linux/reboot-mode.h b/include/linux/reboot-mode.h
index 98f68f95c9e8460be23282c51ef7fcbed73887bd..370228b5161963aac1d75af752ada0e8282b1078 100644
--- a/include/linux/reboot-mode.h
+++ b/include/linux/reboot-mode.h
@@ -3,11 +3,12 @@
 #define __REBOOT_MODE_H__
 
 #include <linux/mutex.h>
+#include <linux/types.h>
 
 struct reboot_mode_driver {
 	struct device *dev;
 	struct list_head head;
-	int (*write)(struct reboot_mode_driver *reboot, unsigned int magic);
+	int (*write)(struct reboot_mode_driver *reboot, u64 magic);
 	struct notifier_block reboot_notifier;
 	/*Protects access to reboot mode list*/
 	struct mutex rb_lock;

-- 
2.34.1

[PATCH v14 04/10] Documentation: ABI: Add sysfs-class-reboot-mode-reboot_modes

[Shivendra Pratap]

Add ABI documentation for /sys/class/reboot-mode/*/reboot_modes,
a read-only sysfs attribute exposing the list of supported
reboot-mode arguments. This file is created by reboot-mode
framework and provides a user-readable interface to query
available reboot-mode arguments.

Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
---
 .../testing/sysfs-class-reboot-mode-reboot_modes   | 39 ++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-class-reboot-mode-reboot_modes b/Documentation/ABI/testing/sysfs-class-reboot-mode-reboot_modes
new file mode 100644
index 0000000000000000000000000000000000000000..6a3fc379afae3a6caf56ad0b73b1c06c43a9fee7
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-reboot-mode-reboot_modes
@@ -0,0 +1,39 @@
+What:		/sys/class/reboot-mode/<driver>/reboot_modes
+Date:		August 2025
+KernelVersion:	6.17.0-rc1
+Contact:	linux-pm@vger.kernel.org
+		Description:
+		This interface exposes the reboot-mode arguments
+		registered with the reboot-mode framework. It is
+		a read-only interface and provides a space
+		separated list of reboot-mode arguments supported
+		on the current platform.
+		Example:
+		 recovery fastboot bootloader
+
+		The exact sysfs path may vary depending on the
+		name of the driver that registers the arguments.
+		Example:
+		 /sys/class/reboot-mode/nvmem-reboot-mode/reboot_modes
+		 /sys/class/reboot-mode/syscon-reboot-mode/reboot_modes
+		 /sys/class/reboot-mode/qcom-pon/reboot_modes
+
+		The supported arguments can be used by userspace
+		to invoke device reset using the reboot() system
+		call, with the "argument" as string to "*arg"
+		parameter along with LINUX_REBOOT_CMD_RESTART2.
+		Example:
+		 reboot(LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
+		        LINUX_REBOOT_CMD_RESTART2, "bootloader");
+
+		A driver can expose the supported arguments by
+		registering them with the reboot-mode framework
+		using the property names that follow the
+		mode-<argument> format.
+		Example:
+		 mode-bootloader, mode-recovery.
+
+		This attribute is useful for scripts or initramfs
+		logic that need to programmatically determine
+		which reboot-mode arguments are valid before
+		triggering a reboot.

-- 
2.34.1

[PATCH v14 05/10] power: reset: reboot-mode: Expose sysfs for registered reboot_modes

[Shivendra Pratap]

Currently, there is no standardized mechanism for userspace to
discover which reboot-modes are supported on a given platform.
This limitation forces tools and scripts to rely on hardcoded
assumptions about the supported reboot-modes.

Create a class 'reboot-mode' and a device under it to expose a
sysfs interface to show the available reboot mode arguments to
userspace.

Provision the register function with an additional parameter to
get an explicit driver_name. Create the device using this
driver_name. For platform drivers, use the driver_name configured
in dev node.

This results in the creation of:
  /sys/class/reboot-mode/<driver>/reboot_modes

This read-only sysfs file will exposes the list of supported
reboot modes arguments provided by the driver, enabling userspace
to query the list of arguments.

Align the clean up path to maintain backward compatibility for
existing reboot-mode based drivers.

Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
---
 drivers/power/reset/reboot-mode.c | 131 +++++++++++++++++++++++++++++++-------
 include/linux/reboot-mode.h       |   4 +-
 2 files changed, 110 insertions(+), 25 deletions(-)

diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c
index ac81b8b0a9b7fc31f8ef21024333a050087ce90f..7ecab050e496af3e1cc01c1a4614787707cb74b4 100644
--- a/drivers/power/reset/reboot-mode.c
+++ b/drivers/power/reset/reboot-mode.c
@@ -6,6 +6,7 @@
 #define pr_fmt(fmt)	"reboot-mode: " fmt
 
 #include <linux/device.h>
+#include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
@@ -23,6 +24,8 @@ struct mode_info {
 	struct list_head list;
 };
 
+static struct class *rb_class;
+
 static u64 get_reboot_mode_magic(struct reboot_mode_driver *reboot, const char *cmd)
 {
 	const char *normal = "normal";
@@ -75,26 +78,121 @@ static int reboot_mode_notify(struct notifier_block *this,
 	return NOTIFY_DONE;
 }
 
+static void release_reboot_mode_device(struct device *dev, void *res);
+
+static ssize_t reboot_modes_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct reboot_mode_driver **devres_reboot;
+	struct reboot_mode_driver *reboot;
+	struct mode_info *info;
+	ssize_t size = 0;
+
+	devres_reboot = devres_find(dev, release_reboot_mode_device, NULL, NULL);
+	if (!devres_reboot || !(*devres_reboot))
+		return -ENODATA;
+
+	reboot = *devres_reboot;
+	mutex_lock(&reboot->rb_lock);
+	list_for_each_entry(info, &reboot->head, list) {
+		size += sprintf(buf + size, "%s ", info->mode);
+	}
+	mutex_unlock(&reboot->rb_lock);
+
+	if (size) {
+		size += sprintf(buf + size - 1, "\n");
+		return size;
+	}
+
+	return -ENODATA;
+}
+static DEVICE_ATTR_RO(reboot_modes);
+
+static void release_reboot_mode_device(struct device *dev, void *res)
+{
+	struct reboot_mode_driver *reboot = *(struct reboot_mode_driver **)res;
+	struct mode_info *info;
+	struct mode_info *next;
+
+	unregister_reboot_notifier(&reboot->reboot_notifier);
+
+	mutex_lock(&reboot->rb_lock);
+	list_for_each_entry_safe(info, next, &reboot->head, list) {
+		list_del(&info->list);
+		kfree_const(info->mode);
+		kfree(info);
+	}
+	mutex_unlock(&reboot->rb_lock);
+
+	device_remove_file(reboot->reboot_dev, &dev_attr_reboot_modes);
+}
+
+static int create_reboot_mode_device(struct reboot_mode_driver *reboot,
+				     const char *dev_name)
+{
+	struct reboot_mode_driver **dr;
+	int ret = 0;
+
+	if (!rb_class) {
+		rb_class = class_create("reboot-mode");
+		if (IS_ERR(rb_class))
+			return PTR_ERR(rb_class);
+	}
+
+	reboot->reboot_dev = device_create(rb_class, NULL, 0, NULL, dev_name);
+	if (IS_ERR(reboot->reboot_dev))
+		return PTR_ERR(reboot->reboot_dev);
+
+	ret = device_create_file(reboot->reboot_dev, &dev_attr_reboot_modes);
+	if (ret)
+		goto create_file_err;
+
+	dr = devres_alloc(release_reboot_mode_device, sizeof(*dr), GFP_KERNEL);
+	if (!dr) {
+		ret = -ENOMEM;
+		goto devres_alloc_error;
+	}
+
+	*dr = reboot;
+	devres_add(reboot->reboot_dev, dr);
+	return ret;
+
+devres_alloc_error:
+	device_remove_file(reboot->reboot_dev, &dev_attr_reboot_modes);
+create_file_err:
+	device_unregister(reboot->reboot_dev);
+	return ret;
+}
+
 /**
  * reboot_mode_register - register a reboot mode driver
  * @reboot: reboot mode driver
  * @np: Pointer to device tree node
+ * @driver_name: Name to use when exposing the sysfs interface
+ *
+ * Registers a reboot mode driver and sets up its sysfs entries
+ * under /sys/class/reboot-mode/<driver_name>/ to allow userspace
+ * interaction with available reboot modes. The DT node is used
+ * for parsing reboot-mode arguments.
  *
  * Returns: 0 on success or a negative error code on failure.
  */
-int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *np)
+int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *np,
+			 const char *driver_name)
 {
 	struct mode_info *info;
-	struct mode_info *next;
 	struct property *prop;
 	size_t len = strlen(PREFIX);
 	u32 magic_arg1;
 	u32 magic_arg2;
 	int ret;
 
-	if (!np)
+	if (!np || !driver_name)
 		return -EINVAL;
 
+	ret = create_reboot_mode_device(reboot, driver_name);
+	if (ret)
+		return ret;
+
 	INIT_LIST_HEAD(&reboot->head);
 	mutex_init(&reboot->rb_lock);
 
@@ -144,13 +242,8 @@ int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *
 	return 0;
 
 error:
-	list_for_each_entry_safe(info, next, &reboot->head, list) {
-		list_del(&info->list);
-		kfree_const(info->mode);
-		kfree(info);
-	}
-
 	mutex_unlock(&reboot->rb_lock);
+	device_unregister(reboot->reboot_dev);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(reboot_mode_register);
@@ -161,26 +254,16 @@ EXPORT_SYMBOL_GPL(reboot_mode_register);
  */
 int reboot_mode_unregister(struct reboot_mode_driver *reboot)
 {
-	struct mode_info *info;
-	struct mode_info *next;
-
-	unregister_reboot_notifier(&reboot->reboot_notifier);
-
-	mutex_lock(&reboot->rb_lock);
-	list_for_each_entry_safe(info, next, &reboot->head, list) {
-		list_del(&info->list);
-		kfree_const(info->mode);
-		kfree(info);
-	}
-	mutex_unlock(&reboot->rb_lock);
-
+	device_unregister(reboot->reboot_dev);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(reboot_mode_unregister);
 
 static void devm_reboot_mode_release(struct device *dev, void *res)
 {
-	reboot_mode_unregister(*(struct reboot_mode_driver **)res);
+	struct reboot_mode_driver *reboot = *(struct reboot_mode_driver **)res;
+
+	device_unregister(reboot->reboot_dev);
 }
 
 /**
@@ -200,7 +283,7 @@ int devm_reboot_mode_register(struct device *dev,
 	if (!dr)
 		return -ENOMEM;
 
-	rc = reboot_mode_register(reboot, reboot->dev->of_node);
+	rc = reboot_mode_register(reboot, reboot->dev->of_node, reboot->dev->driver->name);
 	if (rc) {
 		devres_free(dr);
 		return rc;
diff --git a/include/linux/reboot-mode.h b/include/linux/reboot-mode.h
index 370228b5161963aac1d75af752ada0e8282b1078..0b9844a71224b3e4bcc0d1e396d6c9cb11ad8c97 100644
--- a/include/linux/reboot-mode.h
+++ b/include/linux/reboot-mode.h
@@ -7,6 +7,7 @@
 
 struct reboot_mode_driver {
 	struct device *dev;
+	struct device *reboot_dev;
 	struct list_head head;
 	int (*write)(struct reboot_mode_driver *reboot, u64 magic);
 	struct notifier_block reboot_notifier;
@@ -14,7 +15,8 @@ struct reboot_mode_driver {
 	struct mutex rb_lock;
 };
 
-int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *np);
+int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *np,
+			 const char *driver_name);
 int reboot_mode_unregister(struct reboot_mode_driver *reboot);
 int devm_reboot_mode_register(struct device *dev,
 			      struct reboot_mode_driver *reboot);

-- 
2.34.1

[PATCH v14 06/10] dt-bindings: arm: Document reboot mode magic

[Shivendra Pratap]

From: Elliot Berman <elliot.berman@oss.qualcomm.com>

Add bindings to describe vendor-specific reboot modes. Values here
correspond to valid parameters to vendor-specific reset types in PSCI
SYSTEM_RESET2 call.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Elliot Berman <elliot.berman@oss.qualcomm.com>
Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
---
 Documentation/devicetree/bindings/arm/psci.yaml | 43 +++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/psci.yaml b/Documentation/devicetree/bindings/arm/psci.yaml
index 7360a2849b5bd1e4cbadac533c1a7228573288d4..eca38f8747d320e8371c1dc37cee2287d71821c4 100644
--- a/Documentation/devicetree/bindings/arm/psci.yaml
+++ b/Documentation/devicetree/bindings/arm/psci.yaml
@@ -98,6 +98,27 @@ properties:
       [1] Kernel documentation - ARM idle states bindings
         Documentation/devicetree/bindings/cpu/idle-states.yaml
 
+  reboot-mode:
+    type: object
+    $ref: /schemas/power/reset/reboot-mode.yaml#
+    unevaluatedProperties: false
+    properties:
+      # "mode-normal" is just SYSTEM_RESET
+      mode-normal: false
+    patternProperties:
+      "^mode-.*$":
+        minItems: 1
+        maxItems: 2
+        description: |
+          Describes a vendor-specific reset type. The string after "mode-"
+          maps a reboot mode to the parameters in the PSCI SYSTEM_RESET2 call.
+
+          Parameters are named mode-xxx = <type[, cookie]>, where xxx
+          is the name of the magic reboot mode, type is the lower 31 bits
+          of the reset_type, and, optionally, the cookie value. If the cookie
+          is not provided, it is defaulted to zero.
+          The 31st bit (vendor-resets) will be implicitly set by the driver.
+
 patternProperties:
   "^power-domain-":
     $ref: /schemas/power/power-domain.yaml#
@@ -137,6 +158,15 @@ allOf:
       required:
         - cpu_off
         - cpu_on
+  - if:
+      not:
+        properties:
+          compatible:
+            contains:
+              const: arm,psci-1.0
+    then:
+      properties:
+        reboot-mode: false
 
 additionalProperties: false
 
@@ -261,4 +291,17 @@ examples:
         domain-idle-states = <&cluster_ret>, <&cluster_pwrdn>;
       };
     };
+
+  - |+
+
+    // Case 5: SYSTEM_RESET2 vendor resets
+    psci {
+      compatible = "arm,psci-1.0";
+      method = "smc";
+
+      reboot-mode {
+        mode-edl = <0>;
+        mode-bootloader = <1 2>;
+      };
+    };
 ...

-- 
2.34.1

[PATCH v14 07/10] firmware: psci: Implement vendor-specific resets as reboot-mode

[Shivendra Pratap]

SoC vendors have different types of resets which are controlled
through various hardware registers. For instance, Qualcomm SoC
may have a requirement that reboot with “bootloader” command
should reboot the device to bootloader flashing mode and reboot
with “edl” should reboot the device into 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 spec defines, SYSTEM_RESET2, vendor-specific
reset which can help align this requirement. Add support for PSCI
SYSTEM_RESET2, vendor-specific resets and align the implementation
to allow user-space initiated reboots to trigger these resets.

Implement the PSCI vendor-specific resets by registering to the
reboot-mode framework. As psci init is done at early kernel init,
reboot-mode registration cannot be done at the time of psci init.
This is because reboot-mode creates a “reboot-mode” class for
exposing sysfs, which can fail at early kernel init. To overcome
this, introduce a late_initcall to register PSCI vendor-specific
resets as reboot modes. Implement a reboot-mode write function
that sets reset_type and cookie values during the reboot notifier
callback.  Introduce a firmware-based call for SYSTEM_RESET2
vendor-specific reset in the psci_sys_reset path, using
reset_type and cookie if supported by secure firmware. Register a
panic notifier and clear vendor_reset valid status during panic.
This is needed for any kernel panic that occurs post
reboot_notifiers.

By using the above implementation, userspace will be able to issue
such resets using the reboot() system call with the "*arg"
parameter as a string based command. The commands can be defined
in PSCI device tree node under “reboot-mode” and are based on the
reboot-mode based commands.

Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
---
 drivers/firmware/psci/Kconfig |  2 +
 drivers/firmware/psci/psci.c  | 88 ++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 89 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/psci/Kconfig b/drivers/firmware/psci/Kconfig
index 97944168b5e66aea1e38a7eb2d4ced8348fce64b..93ff7b071a0c364a376699733e6bc5654d56a17f 100644
--- a/drivers/firmware/psci/Kconfig
+++ b/drivers/firmware/psci/Kconfig
@@ -1,6 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config ARM_PSCI_FW
 	bool
+	select POWER_RESET
+	select REBOOT_MODE
 
 config ARM_PSCI_CHECKER
 	bool "ARM PSCI checker"
diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index 38ca190d4a22d6e7e0f06420e8478a2b0ec2fe6f..58fa5fae40f6643e46a1efa5f3b2f5d1d101a1b9 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -13,10 +13,12 @@
 #include <linux/errno.h>
 #include <linux/linkage.h>
 #include <linux/of.h>
+#include <linux/panic_notifier.h>
 #include <linux/pm.h>
 #include <linux/printk.h>
 #include <linux/psci.h>
 #include <linux/reboot.h>
+#include <linux/reboot-mode.h>
 #include <linux/slab.h>
 #include <linux/suspend.h>
 
@@ -51,6 +53,24 @@ static int resident_cpu = -1;
 struct psci_operations psci_ops;
 static enum arm_smccc_conduit psci_conduit = SMCCC_CONDUIT_NONE;
 
+struct psci_vendor_sysreset2 {
+	u32 reset_type;
+	u32 cookie;
+	bool valid;
+};
+
+static struct psci_vendor_sysreset2 vendor_reset;
+
+static int psci_panic_event(struct notifier_block *nb, unsigned long v, void *p)
+{
+	vendor_reset.valid = false;
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block psci_panic_block = {
+	.notifier_call = psci_panic_event
+};
+
 bool psci_tos_resident_on(int cpu)
 {
 	return cpu == resident_cpu;
@@ -309,7 +329,10 @@ static int get_set_conduit_method(const struct device_node *np)
 static int psci_sys_reset(struct notifier_block *nb, unsigned long action,
 			  void *data)
 {
-	if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) &&
+	if (vendor_reset.valid && psci_system_reset2_supported) {
+		invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), vendor_reset.reset_type,
+			       vendor_reset.cookie, 0);
+	} else if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) &&
 	    psci_system_reset2_supported) {
 		/*
 		 * reset_type[31] = 0 (architectural)
@@ -547,6 +570,69 @@ static const struct platform_suspend_ops psci_suspend_ops = {
 	.enter          = psci_system_suspend_enter,
 };
 
+static int psci_set_vendor_sys_reset2(struct reboot_mode_driver *reboot, u64 magic)
+{
+	u32 magic_32;
+
+	if (psci_system_reset2_supported) {
+		magic_32 = magic & 0xffffffff;
+		vendor_reset.reset_type = PSCI_1_1_RESET_TYPE_VENDOR_START | magic_32;
+		vendor_reset.cookie = (magic >> 32) & 0xffffffff;
+		vendor_reset.valid = true;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static int __init psci_init_vendor_reset(void)
+{
+	struct reboot_mode_driver *reboot;
+	struct device_node *psci_np;
+	struct device_node *np;
+	int ret;
+
+	if (!psci_system_reset2_supported)
+		return -EINVAL;
+
+	psci_np = of_find_compatible_node(NULL, NULL, "arm,psci-1.0");
+	if (!psci_np)
+		return -ENODEV;
+
+	np = of_find_node_by_name(psci_np, "reboot-mode");
+	if (!np) {
+		of_node_put(psci_np);
+		return -ENODEV;
+	}
+
+	ret = atomic_notifier_chain_register(&panic_notifier_list, &psci_panic_block);
+	if (ret)
+		goto err_notifier;
+
+	reboot = kzalloc(sizeof(*reboot), GFP_KERNEL);
+	if (!reboot) {
+		ret = -ENOMEM;
+		goto err_kzalloc;
+	}
+
+	reboot->write = psci_set_vendor_sys_reset2;
+
+	ret = reboot_mode_register(reboot, np, "psci");
+	if (ret)
+		goto err_register;
+
+	return 0;
+
+err_register:
+	kfree(reboot);
+err_kzalloc:
+	atomic_notifier_chain_unregister(&panic_notifier_list, &psci_panic_block);
+err_notifier:
+	of_node_put(psci_np);
+	of_node_put(np);
+	return ret;
+}
+late_initcall(psci_init_vendor_reset)
+
 static void __init psci_init_system_reset2(void)
 {
 	int ret;

-- 
2.34.1

[PATCH v14 08/10] arm64: dts: qcom: qcm6490-idp: Add PSCI SYSTEM_RESET2 types

[Shivendra Pratap]

From: Elliot Berman <elliot.berman@oss.qualcomm.com>

Add support for SYSTEM_RESET2 vendor-specific resets in
qcm6490-idp as reboot-modes.  Describe the resets: "bootloader"
will cause device to reboot and stop in the bootloader's fastboot
mode. "edl" will cause device to reboot into "emergency download
mode", which permits loading images via the Firehose protocol.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Elliot Berman <elliot.berman@oss.qualcomm.com>
Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/qcm6490-idp.dts | 7 +++++++
 arch/arm64/boot/dts/qcom/sc7280.dtsi     | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/qcm6490-idp.dts b/arch/arm64/boot/dts/qcom/qcm6490-idp.dts
index 8ed6e28b0c2977b831a1f156014eb9d6f70d0243..51d5991a5c392d2b7afcb5dd7726a01ededc199c 100644
--- a/arch/arm64/boot/dts/qcom/qcm6490-idp.dts
+++ b/arch/arm64/boot/dts/qcom/qcm6490-idp.dts
@@ -654,6 +654,13 @@ &pon_resin {
 	status = "okay";
 };
 
+&psci {
+	reboot-mode {
+		mode-bootloader = <0x10001 0x2>;
+		mode-edl = <0 0x1>;
+	};
+};
+
 &qupv3_id_0 {
 	status = "okay";
 };
diff --git a/arch/arm64/boot/dts/qcom/sc7280.dtsi b/arch/arm64/boot/dts/qcom/sc7280.dtsi
index 0dd6a5c91d109c78333f6b90104fa51fcf3bd64c..0db3fab9915b247d3c30d7484625fbd89a3514d1 100644
--- a/arch/arm64/boot/dts/qcom/sc7280.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7280.dtsi
@@ -857,7 +857,7 @@ pmu-a78 {
 		interrupts = <GIC_PPI 7 IRQ_TYPE_LEVEL_LOW>;
 	};
 
-	psci {
+	psci: psci {
 		compatible = "arm,psci-1.0";
 		method = "smc";
 

-- 
2.34.1

[PATCH v14 09/10] arm64: dts: qcom: qcs6490-rb3gen2: Add PSCI SYSTEM_RESET2 types

[Shivendra Pratap]

From: Elliot Berman <elliot.berman@oss.qualcomm.com>

Add support for SYSTEM_RESET2 vendor-specific resets in
qcs6490-rb3gen2 as reboot-modes.  Describe the resets:
"bootloader" will cause device to reboot and stop in the
bootloader's fastboot mode. "edl" will cause device to reboot
into "emergency download mode", which permits loading images via
the Firehose protocol.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Elliot Berman <elliot.berman@oss.qualcomm.com>
Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
index 7509c27bd3f8f3e43877ded3b898205bdb66a847..621628311a3e36cea70697872b63282d1ba83e1d 100644
--- a/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
+++ b/arch/arm64/boot/dts/qcom/qcs6490-rb3gen2.dts
@@ -966,6 +966,13 @@ &pon_resin {
 	status = "okay";
 };
 
+&psci {
+	reboot-mode {
+		mode-bootloader = <0x10001 0x2>;
+		mode-edl = <0 0x1>;
+	};
+};
+
 &qup_uart7_cts {
 	/*
 	 * Configure a bias-bus-hold on CTS to lower power

-- 
2.34.1

[PATCH v14 10/10] arm64: dts: qcom: lemans-ride: Add PSCI SYSTEM_RESET2 types

[Shivendra Pratap]

From: Elliot Berman <elliot.berman@oss.qualcomm.com>

Add support for SYSTEM_RESET2 vendor-specific resets in
lemans-ride as reboot-modes.  Describe the resets:
"bootloader" will cause device to reboot and stop in the
bootloader's fastboot mode.  "edl" will cause device to reboot
into "emergency download mode", which permits loading images via
the Firehose protocol.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Elliot Berman <elliot.berman@oss.qualcomm.com>
Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/lemans-ride-common.dtsi | 7 +++++++
 arch/arm64/boot/dts/qcom/lemans.dtsi             | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/lemans-ride-common.dtsi b/arch/arm64/boot/dts/qcom/lemans-ride-common.dtsi
index 25e756c141606fbe0876ed48a54809b372650903..016f0a93a432b5e3f5b095b428e0c3de026edd45 100644
--- a/arch/arm64/boot/dts/qcom/lemans-ride-common.dtsi
+++ b/arch/arm64/boot/dts/qcom/lemans-ride-common.dtsi
@@ -722,6 +722,13 @@ &pmm8654au_3_gpios {
 			  "GNSS_BOOT_MODE";
 };
 
+&psci {
+	reboot-mode {
+		mode-bootloader = <0x10001 0x2>;
+		mode-edl = <0 0x1>;
+	};
+};
+
 &qupv3_id_1 {
 	status = "okay";
 };
diff --git a/arch/arm64/boot/dts/qcom/lemans.dtsi b/arch/arm64/boot/dts/qcom/lemans.dtsi
index 64f5378c6a4770cee2c7d76cde1098d7df17a24a..dbcda335fe117e608950c20de9a87c7eeb6b5475 100644
--- a/arch/arm64/boot/dts/qcom/lemans.dtsi
+++ b/arch/arm64/boot/dts/qcom/lemans.dtsi
@@ -620,7 +620,7 @@ pmu {
 		interrupts = <GIC_PPI 7 IRQ_TYPE_LEVEL_HIGH>;
 	};
 
-	psci {
+	psci: psci {
 		compatible = "arm,psci-1.0";
 		method = "smc";
 

-- 
2.34.1

Re: [PATCH v14 00/10] Implement vendor resets for PSCI SYSTEM_RESET2

[Florian Fainelli]

On 8/15/25 07:35, 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. To accommodate this
> requirement, enhance the reboot-mode framework to support two
> 32-bit arguments by switching to 64-bit magic values.
> 
> 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 device tree 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 function, which will save the magic 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
> 
> On gs101 we also pass kernel-generated modes from kernel_restart()
> or panic(), specifically DM verity's 'dm-verity device corrupted':
> 	mode-dm-verity-device-corrupted = <0x50>;
> 
> - thanks Andre' for providing this.
> 
> 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>

On ARCH_BRCMSTB:

Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>

Thanks!
-- 
Florian

Re: [PATCH v14 00/10] Implement vendor resets for PSCI SYSTEM_RESET2

[Kathiravan Thirumoorthy]

On 8/15/2025 8:05 PM, 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. To accommodate this
> requirement, enhance the reboot-mode framework to support two
> 32-bit arguments by switching to 64-bit magic values.
>
> 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 device tree 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 function, which will save the magic 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
>
> On gs101 we also pass kernel-generated modes from kernel_restart()
> or panic(), specifically DM verity's 'dm-verity device corrupted':
> 	mode-dm-verity-device-corrupted = <0x50>;
>
> - thanks Andre' for providing this.
>
> 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>


With this series, 'edl' mode is working fine in QCOM's IPQ5424 SoC. So

Tested-by: Kathiravan Thirumoorthy 
<kathiravan.thirumoorthy@oss.qualcomm.com> # IPQ5424-RDP466

Re: [PATCH v14 03/10] power: reset: reboot-mode: Add support for 64 bit magic

[Casey Connolly]

Hi Shivendra,

On 15/08/2025 16:35, Shivendra Pratap wrote:
> Current reboot-mode supports a single 32-bit argument for any
> supported mode. Some reboot-mode based drivers may require
> passing two independent 32-bit arguments during a reboot
> sequence, for uses-cases, where a mode requires an additional
> argument. Such drivers may not be able to use the reboot-mode
> driver. For example, ARM PSCI vendor-specific resets, need two
> arguments for its operation – reset_type and cookie, to complete
> the reset operation. If a driver wants to implement this
> firmware-based reset, it cannot use reboot-mode framework.
> 
> Introduce 64-bit magic values in reboot-mode driver to
> accommodate dual 32-bit arguments when specified via device tree.
> In cases, where no second argument is passed from device tree,
> keep the upper 32-bit of magic un-changed(0) to maintain backward
> compatibility.

How about adding a n_magic_args property to struct reboot_mode_driver?
Then in struct mode_info change magic to be a u32 array of a fixed
length (currently two in-keeping with the DT bindings).

Parsing the DT values then gets simpler (u32_array) and the magic value
can be passed into the ->write() cb as a pointer since all the
reboot_mode drivers already know how big the array is. Unpopulated DT
values would just be 0.

Kind regards,

> 
> Update the current drivers using reboot-mode for a 64-bit magic
> value.
> 
> Signed-off-by: Shivendra Pratap <shivendra.pratap@oss.qualcomm.com>
> ---
>  drivers/power/reset/nvmem-reboot-mode.c  | 13 +++++++++----
>  drivers/power/reset/qcom-pon.c           | 11 ++++++++---
>  drivers/power/reset/reboot-mode.c        | 19 +++++++++++++------
>  drivers/power/reset/syscon-reboot-mode.c | 11 ++++++++---
>  include/linux/reboot-mode.h              |  3 ++-
>  5 files changed, 40 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/power/reset/nvmem-reboot-mode.c b/drivers/power/reset/nvmem-reboot-mode.c
> index 41530b70cfc48c2a83fbbd96f523d5816960a0d1..5d73dde585b1fd438b1847f884feb37cd9e4dd5c 100644
> --- a/drivers/power/reset/nvmem-reboot-mode.c
> +++ b/drivers/power/reset/nvmem-reboot-mode.c
> @@ -16,15 +16,20 @@ struct nvmem_reboot_mode {
>  	struct nvmem_cell *cell;
>  };
>  
> -static int nvmem_reboot_mode_write(struct reboot_mode_driver *reboot,
> -				    unsigned int magic)
> +static int nvmem_reboot_mode_write(struct reboot_mode_driver *reboot, u64 magic)
>  {
> -	int ret;
>  	struct nvmem_reboot_mode *nvmem_rbm;
> +	u32 magic_32;
> +	int ret;
> +
> +	if (magic > U32_MAX)
> +		return -EINVAL;
> +
> +	magic_32 = magic;
>  
>  	nvmem_rbm = container_of(reboot, struct nvmem_reboot_mode, reboot);
>  
> -	ret = nvmem_cell_write(nvmem_rbm->cell, &magic, sizeof(magic));
> +	ret = nvmem_cell_write(nvmem_rbm->cell, &magic_32, sizeof(magic_32));
>  	if (ret < 0)
>  		dev_err(reboot->dev, "update reboot mode bits failed\n");
>  
> diff --git a/drivers/power/reset/qcom-pon.c b/drivers/power/reset/qcom-pon.c
> index 7e108982a582e8243c5c806bd4a793646b87189f..d0ed9431a02313a7bbaa93743c16fa1ae713ddfe 100644
> --- a/drivers/power/reset/qcom-pon.c
> +++ b/drivers/power/reset/qcom-pon.c
> @@ -27,17 +27,22 @@ struct qcom_pon {
>  	long reason_shift;
>  };
>  
> -static int qcom_pon_reboot_mode_write(struct reboot_mode_driver *reboot,
> -				    unsigned int magic)
> +static int qcom_pon_reboot_mode_write(struct reboot_mode_driver *reboot, u64 magic)
>  {
>  	struct qcom_pon *pon = container_of
>  			(reboot, struct qcom_pon, reboot_mode);
> +	u32 magic_32;
>  	int ret;
>  
> +	if (magic > U32_MAX || (magic << pon->reason_shift) > U32_MAX)
> +		return -EINVAL;
> +
> +	magic_32 = magic << pon->reason_shift;
> +
>  	ret = regmap_update_bits(pon->regmap,
>  				 pon->baseaddr + PON_SOFT_RB_SPARE,
>  				 GENMASK(7, pon->reason_shift),
> -				 magic << pon->reason_shift);
> +				 magic_32);
>  	if (ret < 0)
>  		dev_err(pon->dev, "update reboot mode bits failed\n");
>  
> diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c
> index 9bb97bcd33cd3d58c75c791e9b568024e810e5b0..ac81b8b0a9b7fc31f8ef21024333a050087ce90f 100644
> --- a/drivers/power/reset/reboot-mode.c
> +++ b/drivers/power/reset/reboot-mode.c
> @@ -19,12 +19,11 @@
>  
>  struct mode_info {
>  	const char *mode;
> -	u32 magic;
> +	u64 magic;
>  	struct list_head list;
>  };
>  
> -static unsigned int get_reboot_mode_magic(struct reboot_mode_driver *reboot,
> -					  const char *cmd)
> +static u64 get_reboot_mode_magic(struct reboot_mode_driver *reboot, const char *cmd)
>  {
>  	const char *normal = "normal";
>  	struct mode_info *info;
> @@ -66,7 +65,7 @@ static int reboot_mode_notify(struct notifier_block *this,
>  			      unsigned long mode, void *cmd)
>  {
>  	struct reboot_mode_driver *reboot;
> -	unsigned int magic;
> +	u64 magic;
>  
>  	reboot = container_of(this, struct reboot_mode_driver, reboot_notifier);
>  	magic = get_reboot_mode_magic(reboot, cmd);
> @@ -89,6 +88,8 @@ int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *
>  	struct mode_info *next;
>  	struct property *prop;
>  	size_t len = strlen(PREFIX);
> +	u32 magic_arg1;
> +	u32 magic_arg2;
>  	int ret;
>  
>  	if (!np)
> @@ -108,12 +109,18 @@ int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *
>  			goto error;
>  		}
>  
> -		if (of_property_read_u32(np, prop->name, &info->magic)) {
> -			pr_err("reboot mode %s without magic number\n", info->mode);
> +		if (of_property_read_u32(np, prop->name, &magic_arg1)) {
> +			pr_err("reboot mode without magic number\n");
>  			kfree(info);
>  			continue;
>  		}
>  
> +		if (of_property_read_u32_index(np, prop->name, 1, &magic_arg2))
> +			magic_arg2 = 0;
> +
> +		info->magic = magic_arg2;
> +		info->magic = (info->magic << 32) | magic_arg1;
> +
>  		info->mode = kstrdup_const(prop->name + len, GFP_KERNEL);
>  		if (!info->mode) {
>  			ret =  -ENOMEM;
> diff --git a/drivers/power/reset/syscon-reboot-mode.c b/drivers/power/reset/syscon-reboot-mode.c
> index e0772c9f70f7a19cd8ec8a0b7fdbbaa7ba44afd0..3cbd000c512239b12ec51987e900d260540a9dea 100644
> --- a/drivers/power/reset/syscon-reboot-mode.c
> +++ b/drivers/power/reset/syscon-reboot-mode.c
> @@ -20,16 +20,21 @@ struct syscon_reboot_mode {
>  	u32 mask;
>  };
>  
> -static int syscon_reboot_mode_write(struct reboot_mode_driver *reboot,
> -				    unsigned int magic)
> +static int syscon_reboot_mode_write(struct reboot_mode_driver *reboot, u64 magic)
>  {
>  	struct syscon_reboot_mode *syscon_rbm;
> +	u32 magic_32;
>  	int ret;
>  
> +	if (magic > U32_MAX)
> +		return -EINVAL;
> +
> +	magic_32 = magic;
> +
>  	syscon_rbm = container_of(reboot, struct syscon_reboot_mode, reboot);
>  
>  	ret = regmap_update_bits(syscon_rbm->map, syscon_rbm->offset,
> -				 syscon_rbm->mask, magic);
> +				 syscon_rbm->mask, magic_32);
>  	if (ret < 0)
>  		dev_err(reboot->dev, "update reboot mode bits failed\n");
>  
> diff --git a/include/linux/reboot-mode.h b/include/linux/reboot-mode.h
> index 98f68f95c9e8460be23282c51ef7fcbed73887bd..370228b5161963aac1d75af752ada0e8282b1078 100644
> --- a/include/linux/reboot-mode.h
> +++ b/include/linux/reboot-mode.h
> @@ -3,11 +3,12 @@
>  #define __REBOOT_MODE_H__
>  
>  #include <linux/mutex.h>
> +#include <linux/types.h>
>  
>  struct reboot_mode_driver {
>  	struct device *dev;
>  	struct list_head head;
> -	int (*write)(struct reboot_mode_driver *reboot, unsigned int magic);
> +	int (*write)(struct reboot_mode_driver *reboot, u64 magic);
>  	struct notifier_block reboot_notifier;
>  	/*Protects access to reboot mode list*/
>  	struct mutex rb_lock;
> 

-- 
// Casey (she/her)

Re: [PATCH v14 03/10] power: reset: reboot-mode: Add support for 64 bit magic

[Shivendra Pratap]

On 8/28/2025 6:52 PM, Casey Connolly wrote:
> Hi Shivendra,
> 
> On 15/08/2025 16:35, Shivendra Pratap wrote:
>> Current reboot-mode supports a single 32-bit argument for any
>> supported mode. Some reboot-mode based drivers may require
>> passing two independent 32-bit arguments during a reboot
>> sequence, for uses-cases, where a mode requires an additional
>> argument. Such drivers may not be able to use the reboot-mode
>> driver. For example, ARM PSCI vendor-specific resets, need two
>> arguments for its operation – reset_type and cookie, to complete
>> the reset operation. If a driver wants to implement this
>> firmware-based reset, it cannot use reboot-mode framework.
>>
>> Introduce 64-bit magic values in reboot-mode driver to
>> accommodate dual 32-bit arguments when specified via device tree.
>> In cases, where no second argument is passed from device tree,
>> keep the upper 32-bit of magic un-changed(0) to maintain backward
>> compatibility.
> 
> How about adding a n_magic_args property to struct reboot_mode_driver?
> Then in struct mode_info change magic to be a u32 array of a fixed
> length (currently two in-keeping with the DT bindings).
> 
> Parsing the DT values then gets simpler (u32_array) and the magic value
> can be passed into the ->write() cb as a pointer since all the
> reboot_mode drivers already know how big the array is. Unpopulated DT
> values would just be 0.


sure. Will convert it to u32 magic[2] and ->write can now pass
"u32*" and can be de-referenced by the using driver.

Could not understand that how we want to use n_magic_args and who shall
set it? Do we statically define it to two for now? or should we skip
n_magic_args for now?

thanks,
Shivendra

Re: [PATCH v14 00/10] Implement vendor resets for PSCI SYSTEM_RESET2

[Shivendra Pratap]

On 8/28/2025 1:35 PM, Kathiravan Thirumoorthy wrote:
> 
> On 8/15/2025 8:05 PM, 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. To accommodate this
>> requirement, enhance the reboot-mode framework to support two
>> 32-bit arguments by switching to 64-bit magic values.
>>
>> 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 device tree 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 function, which will save the magic 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
>>
>> On gs101 we also pass kernel-generated modes from kernel_restart()
>> or panic(), specifically DM verity's 'dm-verity device corrupted':
>>     mode-dm-verity-device-corrupted = <0x50>;
>>
>> - thanks Andre' for providing this.
>>
>> 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>
> 
> 
> With this series, 'edl' mode is working fine in QCOM's IPQ5424 SoC. So
> 
> Tested-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com> # IPQ5424-RDP466
> 

Thanks for giving time for testing this series for IPQ5424. So we have PSCI SYS reset2 support for
IPQ5424 firmware? and did we make any extra changes in DT for edl mode?

thanks,
Shivendra

Re: [PATCH v14 03/10] power: reset: reboot-mode: Add support for 64 bit magic

[Shivendra Pratap]

On 8/28/2025 6:52 PM, Casey Connolly wrote:
> Hi Shivendra,
> 
> On 15/08/2025 16:35, Shivendra Pratap wrote:
>> Current reboot-mode supports a single 32-bit argument for any
>> supported mode. Some reboot-mode based drivers may require
>> passing two independent 32-bit arguments during a reboot
>> sequence, for uses-cases, where a mode requires an additional
>> argument. Such drivers may not be able to use the reboot-mode
>> driver. For example, ARM PSCI vendor-specific resets, need two
>> arguments for its operation – reset_type and cookie, to complete
>> the reset operation. If a driver wants to implement this
>> firmware-based reset, it cannot use reboot-mode framework.
>>
>> Introduce 64-bit magic values in reboot-mode driver to
>> accommodate dual 32-bit arguments when specified via device tree.
>> In cases, where no second argument is passed from device tree,
>> keep the upper 32-bit of magic un-changed(0) to maintain backward
>> compatibility.
> 
> How about adding a n_magic_args property to struct reboot_mode_driver?
> Then in struct mode_info change magic to be a u32 array of a fixed
> length (currently two in-keeping with the DT bindings).

Arnd/Rob,

As per previous discussion on patch v10, magic and cookie were implemented
as a 64 bit number (64 bit magic).

Need you thoughts that if we should change the magic to 32bit array, as being
suggested in the above comments.

thanks,
Shivendra

Re: [PATCH v14 00/10] Implement vendor resets for PSCI SYSTEM_RESET2

[Kathiravan Thirumoorthy]

On 9/2/2025 6:40 PM, Shivendra Pratap wrote:
>
> On 8/28/2025 1:35 PM, Kathiravan Thirumoorthy wrote:
>> On 8/15/2025 8:05 PM, 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. To accommodate this
>>> requirement, enhance the reboot-mode framework to support two
>>> 32-bit arguments by switching to 64-bit magic values.
>>>
>>> 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 device tree 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 function, which will save the magic 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
>>>
>>> On gs101 we also pass kernel-generated modes from kernel_restart()
>>> or panic(), specifically DM verity's 'dm-verity device corrupted':
>>>      mode-dm-verity-device-corrupted = <0x50>;
>>>
>>> - thanks Andre' for providing this.
>>>
>>> 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>
>>
>> With this series, 'edl' mode is working fine in QCOM's IPQ5424 SoC. So
>>
>> Tested-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com> # IPQ5424-RDP466
>>
> Thanks for giving time for testing this series for IPQ5424. So we have PSCI SYS reset2 support for
> IPQ5424 firmware?


Yeah, the latest IPQ5424 firmware (To be specific - 
TZ.WIN_WC.1.0-00043-IPQ5424MAPAANAZT-1 onwards) supports PSCI SYS RESET2.


> and did we make any extra changes in DT for edl mode?


Yes, I submitted the DTS patch[1] for this similar to the other platforms.

[1] [PATCH] arm64: dts: qcom: ipq5424: Add support for emergency 
download mode - Kathiravan Thirumoorthy 
<https://lore.kernel.org/linux-arm-msm/20250828-ipq5424-edl-v1-1-d6a403800023@oss.qualcomm.com/>.


>
> thanks,
> Shivendra