[PATCH v14 03/10] power: reset: reboot-mode: Add support for 64 bit magic
From: Shivendra Pratap <hidden>
Date: 2025-08-15 14:36:55
Also in:
linux-arm-msm, linux-devicetree, linux-pm, lkml
Subsystem:
arm/qualcomm mailing list, system reset/shutdown drivers, the rest · Maintainers:
Sebastian Reichel, Linus Torvalds
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 <redacted> --- 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