[PATCH v9 1/4] PM: Introduce new PMSG_POWEROFF event

["Mario Limonciello (AMD)" <superm1@kernel.org>]

PMSG_POWEROFF will be used for the PM core to allow differentiating between
a hibernation or shutdown sequence when re-using callbacks for common code.

Hibernation is started by writing a hibernation method (such as 'platform'
'shutdown', or 'reboot') to use into /sys/power/disk and writing 'disk' to
/sys/power/state.

Shutdown is initiated with the reboot() syscall with arguments on whether
to halt the system or power it off.

Tested-by: Eric Naim <dnaim@cachyos.org>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
---
v9:
 * Add more detail to commit message (Bjorn)
v8:
 * Break series into 3 parts
 * Drop PMSG_NO_WAKEUP change
v7:
 * Reword commit
v5:
 * Re-order and split
 * Add tags
v4:
 * https://lore.kernel.org/linux-pci/20250616175019.3471583-1-superm1@kernel.org/
---
 drivers/base/power/main.c    | 7 +++++++
 include/linux/pm.h           | 3 +++
 include/trace/events/power.h | 3 ++-
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 451d54486645b..ecdd88b578a04 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -95,6 +95,8 @@ static const char *pm_verb(int event)
 		return "restore";
 	case PM_EVENT_RECOVER:
 		return "recover";
+	case PM_EVENT_POWEROFF:
+		return "poweroff";
 	default:
 		return "(unknown PM event)";
 	}
@@ -367,6 +369,7 @@ static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
 	case PM_EVENT_FREEZE:
 	case PM_EVENT_QUIESCE:
 		return ops->freeze;
+	case PM_EVENT_POWEROFF:
 	case PM_EVENT_HIBERNATE:
 		return ops->poweroff;
 	case PM_EVENT_THAW:
@@ -401,6 +404,7 @@ static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
 	case PM_EVENT_FREEZE:
 	case PM_EVENT_QUIESCE:
 		return ops->freeze_late;
+	case PM_EVENT_POWEROFF:
 	case PM_EVENT_HIBERNATE:
 		return ops->poweroff_late;
 	case PM_EVENT_THAW:
@@ -435,6 +439,7 @@ static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t stat
 	case PM_EVENT_FREEZE:
 	case PM_EVENT_QUIESCE:
 		return ops->freeze_noirq;
+	case PM_EVENT_POWEROFF:
 	case PM_EVENT_HIBERNATE:
 		return ops->poweroff_noirq;
 	case PM_EVENT_THAW:
@@ -1385,6 +1390,8 @@ static pm_message_t resume_event(pm_message_t sleep_state)
 		return PMSG_RECOVER;
 	case PM_EVENT_HIBERNATE:
 		return PMSG_RESTORE;
+	case PM_EVENT_POWEROFF:
+		return PMSG_ON;
 	}
 	return PMSG_ON;
 }
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 52ee38d72aa23..564133e53f0d3 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -507,6 +507,7 @@ const struct dev_pm_ops name = { \
  * RECOVER	Creation of a hibernation image or restoration of the main
  *		memory contents from a hibernation image has failed, call
  *		->thaw() and ->complete() for all devices.
+ * POWEROFF	System will poweroff, call ->poweroff() for all devices.
  *
  * The following PM_EVENT_ messages are defined for internal use by
  * kernel subsystems.  They are never issued by the PM core.
@@ -537,6 +538,7 @@ const struct dev_pm_ops name = { \
 #define PM_EVENT_USER		0x0100
 #define PM_EVENT_REMOTE		0x0200
 #define PM_EVENT_AUTO		0x0400
+#define PM_EVENT_POWEROFF	0x0800
 
 #define PM_EVENT_SLEEP		(PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
 #define PM_EVENT_USER_SUSPEND	(PM_EVENT_USER | PM_EVENT_SUSPEND)
@@ -551,6 +553,7 @@ const struct dev_pm_ops name = { \
 #define PMSG_QUIESCE	((struct pm_message){ .event = PM_EVENT_QUIESCE, })
 #define PMSG_SUSPEND	((struct pm_message){ .event = PM_EVENT_SUSPEND, })
 #define PMSG_HIBERNATE	((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
+#define PMSG_POWEROFF	((struct pm_message){ .event = PM_EVENT_POWEROFF, })
 #define PMSG_RESUME	((struct pm_message){ .event = PM_EVENT_RESUME, })
 #define PMSG_THAW	((struct pm_message){ .event = PM_EVENT_THAW, })
 #define PMSG_RESTORE	((struct pm_message){ .event = PM_EVENT_RESTORE, })
diff --git a/include/trace/events/power.h b/include/trace/events/power.h
index 82904291c2b81..370f8df2fdb4b 100644
--- a/include/trace/events/power.h
+++ b/include/trace/events/power.h
@@ -179,7 +179,8 @@ TRACE_EVENT(pstate_sample,
 		{ PM_EVENT_HIBERNATE, "hibernate" }, \
 		{ PM_EVENT_THAW, "thaw" }, \
 		{ PM_EVENT_RESTORE, "restore" }, \
-		{ PM_EVENT_RECOVER, "recover" })
+		{ PM_EVENT_RECOVER, "recover" }, \
+		{ PM_EVENT_POWEROFF, "poweroff" })
 
 DEFINE_EVENT(cpu, cpu_frequency,
 
-- 
2.43.0