[PATCH RFC 02/25] PCI/LUO: Add struct dev_liveupdate

[Chris Li <chrisl@kernel.org>]

Introduce struct dev_liveupdate and add it to struct device.

Use the new struct to track a device's liveupdate states.
- requested: The device is requested for a live update.
- depended:  One of the child devices is requested for live update.

When the device is requested, the dev->lu.requested will
set to 1.

Signed-off-by: Chris Li <chrisl@kernel.org>
---
 drivers/pci/liveupdate.c       |  3 +++
 include/linux/dev_liveupdate.h | 35 +++++++++++++++++++++++++++++++++++
 include/linux/device.h         |  6 ++++++
 3 files changed, 44 insertions(+)

diff --git a/drivers/pci/liveupdate.c b/drivers/pci/liveupdate.c
index 86b4f3a2fb44781c6e323ba029db510450556fa9..1c69adf412255c8ee5bc6db588ff04b1642e8e19 100644
--- a/drivers/pci/liveupdate.c
+++ b/drivers/pci/liveupdate.c
@@ -6,8 +6,11 @@
  */
 
 #define pr_fmt(fmt) "PCI liveupdate: " fmt
+#define dev_fmt(fmt) "PCI liveupdate: " fmt
 
+#include <linux/types.h>
 #include <linux/liveupdate.h>
+#include "pci.h"
 
 #define PCI_SUBSYSTEM_NAME "pci"
 
diff --git a/include/linux/dev_liveupdate.h b/include/linux/dev_liveupdate.h
new file mode 100644
index 0000000000000000000000000000000000000000..057407c030b0872bfa8cd666e6ffc305f7aa4083
--- /dev/null
+++ b/include/linux/dev_liveupdate.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Copyright (c) 2025, Google LLC.
+ * Pasha Tatashin <pasha.tatashin@soleen.com>
+ * Chris Li <chrisl@kernel.org>
+ */
+#ifndef _LINUX_DEV_LIVEUPDATE_H
+#define _LINUX_DEV_LIVEUPDATE_H
+
+#include <linux/liveupdate.h>
+
+#ifdef CONFIG_LIVEUPDATE
+
+/**
+ * struct dev_liveupdate - Device state for live update operations
+ * @lu_next:	List head for linking the device into live update
+ *		related lists (e.g., a list of devices participating
+ *		in a live update sequence).
+ * @requested:	Set if a live update has been requested for this
+ *		device (i.e. device will participate in live update).
+ * @depended:	Set if the device participtate the live update due to
+ *		one of its child device is requested in live update.
+ *
+ * This structure holds the state information required for performing
+ * live update operations on a device. It is embedded within a struct device.
+ */
+struct dev_liveupdate {
+	struct list_head lu_next;
+	bool requested:1;
+	bool depended:1;
+};
+
+#endif /* CONFIG_LIVEUPDATE */
+#endif /* _LINUX_DEV_LIVEUPDATE_H */
diff --git a/include/linux/device.h b/include/linux/device.h
index 4940db137fffff4ceacf819b32433a0f4898b125..4aee7912218865168a73fe4c6d3a82646b8dd86f 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -21,6 +21,7 @@
 #include <linux/lockdep.h>
 #include <linux/compiler.h>
 #include <linux/types.h>
+#include <linux/dev_liveupdate.h>
 #include <linux/mutex.h>
 #include <linux/pm.h>
 #include <linux/atomic.h>
@@ -508,6 +509,7 @@ struct device_physical_location {
  * @pm_domain:	Provide callbacks that are executed during system suspend,
  * 		hibernation, system resume and during runtime PM transitions
  * 		along with subsystem-level and driver-level callbacks.
+ * @lu:		Live update state.
  * @em_pd:	device's energy model performance domain
  * @pins:	For device pin management.
  *		See Documentation/driver-api/pin-control.rst for details.
@@ -603,6 +605,10 @@ struct device {
 	struct dev_pm_info	power;
 	struct dev_pm_domain	*pm_domain;
 
+#ifdef CONFIG_LIVEUPDATE
+	struct dev_liveupdate	lu;
+#endif
+
 #ifdef CONFIG_ENERGY_MODEL
 	struct em_perf_domain	*em_pd;
 #endif

-- 
2.50.1.487.gc89ff58d15-goog