[PATCH v23 02/13] power: reset: reboot-mode: Support up to 3 magic values per mode
From: Shivendra Pratap
Date: Tue Jul 14 2026 - 13:18:58 EST
ARM PSCI vendor-specific resets, require a 32-bit reset_type and a 64-bit
cookie as arguments. This cannot be implemented via the reboot-mode
framework, which supports a single 32-bit argument as magic value.
Extend the reboot-mode framework to support up to three 32-bit arguments
as magic, per reboot-mode.
Signed-off-by: Shivendra Pratap <shivendra.pratap@xxxxxxxxxxxxxxxx>
---
drivers/power/reset/nvmem-reboot-mode.c | 10 ++++----
drivers/power/reset/qcom-pon.c | 8 ++++---
drivers/power/reset/reboot-mode.c | 41 +++++++++++++++++++++-----------
drivers/power/reset/syscon-reboot-mode.c | 8 ++++---
include/linux/reboot-mode.h | 4 +++-
5 files changed, 46 insertions(+), 25 deletions(-)
diff --git a/drivers/power/reset/nvmem-reboot-mode.c b/drivers/power/reset/nvmem-reboot-mode.c
index d260715fccf6..ac69b5f39fb4 100644
--- a/drivers/power/reset/nvmem-reboot-mode.c
+++ b/drivers/power/reset/nvmem-reboot-mode.c
@@ -17,14 +17,16 @@ 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, u32 *magic, int count)
{
struct nvmem_reboot_mode *nvmem_rbm;
size_t buf_len;
void *buf;
int ret;
+ if (count != 1)
+ return -EINVAL;
+
nvmem_rbm = container_of(reboot, struct nvmem_reboot_mode, reboot);
buf = nvmem_cell_read(nvmem_rbm->cell, &buf_len);
@@ -32,10 +34,10 @@ static int nvmem_reboot_mode_write(struct reboot_mode_driver *reboot,
return PTR_ERR(buf);
kfree(buf);
- if (buf_len > sizeof(magic))
+ if (buf_len > sizeof(magic[0]))
return -EINVAL;
- ret = nvmem_cell_write(nvmem_rbm->cell, &magic, buf_len);
+ ret = nvmem_cell_write(nvmem_rbm->cell, &magic[0], buf_len);
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 7e108982a582..a508ab26d03f 100644
--- a/drivers/power/reset/qcom-pon.c
+++ b/drivers/power/reset/qcom-pon.c
@@ -27,17 +27,19 @@ 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, u32 *magic, int count)
{
struct qcom_pon *pon = container_of
(reboot, struct qcom_pon, reboot_mode);
int ret;
+ if (count != 1)
+ return -EINVAL;
+
ret = regmap_update_bits(pon->regmap,
pon->baseaddr + PON_SOFT_RB_SPARE,
GENMASK(7, pon->reason_shift),
- magic << pon->reason_shift);
+ magic[0] << pon->reason_shift);
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 7a74f72a8313..db2129c72341 100644
--- a/drivers/power/reset/reboot-mode.c
+++ b/drivers/power/reset/reboot-mode.c
@@ -22,7 +22,8 @@
struct mode_info {
const char *mode;
- u32 magic;
+ u32 magic[3];
+ int count;
struct list_head list;
};
@@ -74,8 +75,7 @@ static const struct class reboot_mode_class = {
.dev_groups = reboot_mode_groups,
};
-static unsigned int get_reboot_mode_magic(struct reboot_mode_driver *reboot,
- const char *cmd)
+static struct mode_info *get_reboot_mode_info(struct reboot_mode_driver *reboot, const char *cmd)
{
const char *normal = "normal";
struct mode_info *info;
@@ -86,11 +86,11 @@ static unsigned int get_reboot_mode_magic(struct reboot_mode_driver *reboot,
list_for_each_entry(info, &reboot->head, list)
if (!strcmp(info->mode, cmd))
- return info->magic;
+ return info;
/* try to match again, replacing characters impossible in DT */
if (strscpy(cmd_, cmd, sizeof(cmd_)) == -E2BIG)
- return 0;
+ return NULL;
strreplace(cmd_, ' ', '-');
strreplace(cmd_, ',', '-');
@@ -98,21 +98,21 @@ static unsigned int get_reboot_mode_magic(struct reboot_mode_driver *reboot,
list_for_each_entry(info, &reboot->head, list)
if (!strcmp(info->mode, cmd_))
- return info->magic;
+ return info;
- return 0;
+ return NULL;
}
static int reboot_mode_notify(struct notifier_block *this,
unsigned long mode, void *cmd)
{
struct reboot_mode_driver *reboot;
- unsigned int magic;
+ struct mode_info *info;
reboot = container_of(this, struct reboot_mode_driver, reboot_notifier);
- magic = get_reboot_mode_magic(reboot, cmd);
- if (magic)
- reboot->write(reboot, magic);
+ info = get_reboot_mode_info(reboot, cmd);
+ if (info && info->count > 0)
+ reboot->write(reboot, info->magic, info->count);
return NOTIFY_DONE;
}
@@ -175,16 +175,22 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
struct property *prop;
struct device_node *np = reboot->dev->of_node;
size_t len = strlen(PREFIX);
- u32 magic;
+ u32 magic[3];
+ int count;
int ret;
INIT_LIST_HEAD(&reboot->head);
for_each_property_of_node(np, prop) {
+ memset(magic, 0, sizeof(magic));
+
if (strncmp(prop->name, PREFIX, len))
continue;
- if (device_property_read_u32(reboot->dev, prop->name, &magic)) {
+ count = device_property_count_u32(reboot->dev, prop->name);
+
+ if (count <= 0 || count > ARRAY_SIZE(magic) ||
+ device_property_read_u32_array(reboot->dev, prop->name, magic, count)) {
pr_debug("reboot mode %s without magic number\n", prop->name);
continue;
}
@@ -195,7 +201,14 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
goto error;
}
- info->magic = magic;
+ if (!memchr_inv(magic, 0, count * sizeof(u32))) {
+ pr_debug("reboot mode %s with zero magic values\n", prop->name);
+ info->count = -1;
+ } else {
+ memcpy(info->magic, magic, count * sizeof(u32));
+ info->count = count;
+ }
+
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 e0772c9f70f7..983b1fbf614a 100644
--- a/drivers/power/reset/syscon-reboot-mode.c
+++ b/drivers/power/reset/syscon-reboot-mode.c
@@ -20,16 +20,18 @@ 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, u32 *magic, int count)
{
struct syscon_reboot_mode *syscon_rbm;
int ret;
+ if (count != 1)
+ return -EINVAL;
+
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[0]);
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 4a2abb38d1d6..34a81e4b4f95 100644
--- a/include/linux/reboot-mode.h
+++ b/include/linux/reboot-mode.h
@@ -2,10 +2,12 @@
#ifndef __REBOOT_MODE_H__
#define __REBOOT_MODE_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, u32 *magic, int count);
struct notifier_block reboot_notifier;
};
--
2.34.1