x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.

Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.

Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.

Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL.

Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching")
Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com
Reported-by: Sashiko <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 86 insertions, 0 deletions

diff --git a/include/uapi/regulator/regulator.h b/include/uapi/regulator/regulator.h
new file mode 100644
index 000000000..c4f2d1c19
--- /dev/null
+++ b/include/uapi/regulator/regulator.h
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Regulator uapi header
+ *
+ * Author: Naresh Solanki <Naresh.Solanki@9elements.com>
+ */
+
+#ifndef _UAPI_REGULATOR_H
+#define _UAPI_REGULATOR_H
+
+#include <linux/types.h>
+
+/*
+ * Regulator notifier events.
+ *
+ * UNDER_VOLTAGE  Regulator output is under voltage.
+ * OVER_CURRENT   Regulator output current is too high.
+ * REGULATION_OUT Regulator output is out of regulation.
+ * FAIL           Regulator output has failed.
+ * OVER_TEMP      Regulator over temp.
+ * FORCE_DISABLE  Regulator forcibly shut down by software.
+ * VOLTAGE_CHANGE Regulator voltage changed.
+ *                Data passed is old voltage cast to (void *).
+ * DISABLE        Regulator was disabled.
+ * PRE_VOLTAGE_CHANGE   Regulator is about to have voltage changed.
+ *                      Data passed is "struct pre_voltage_change_data"
+ * ABORT_VOLTAGE_CHANGE Regulator voltage change failed for some reason.
+ *                      Data passed is old voltage cast to (void *).
+ * PRE_DISABLE    Regulator is about to be disabled
+ * ABORT_DISABLE  Regulator disable failed for some reason
+ *
+ * NOTE: These events can be OR'ed together when passed into handler.
+ */
+
+#define REGULATOR_EVENT_UNDER_VOLTAGE		0x01
+#define REGULATOR_EVENT_OVER_CURRENT		0x02
+#define REGULATOR_EVENT_REGULATION_OUT		0x04
+#define REGULATOR_EVENT_FAIL			0x08
+#define REGULATOR_EVENT_OVER_TEMP		0x10
+#define REGULATOR_EVENT_FORCE_DISABLE		0x20
+#define REGULATOR_EVENT_VOLTAGE_CHANGE		0x40
+#define REGULATOR_EVENT_DISABLE			0x80
+#define REGULATOR_EVENT_PRE_VOLTAGE_CHANGE	0x100
+#define REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE	0x200
+#define REGULATOR_EVENT_PRE_DISABLE		0x400
+#define REGULATOR_EVENT_ABORT_DISABLE		0x800
+#define REGULATOR_EVENT_ENABLE			0x1000
+/*
+ * Following notifications should be emitted only if detected condition
+ * is such that the HW is likely to still be working but consumers should
+ * take a recovery action to prevent problems escalating into errors.
+ */
+#define REGULATOR_EVENT_UNDER_VOLTAGE_WARN	0x2000
+#define REGULATOR_EVENT_OVER_CURRENT_WARN	0x4000
+#define REGULATOR_EVENT_OVER_VOLTAGE_WARN	0x8000
+#define REGULATOR_EVENT_OVER_TEMP_WARN		0x10000
+#define REGULATOR_EVENT_WARN_MASK		0x1E000
+
+struct reg_genl_event {
+	char reg_name[32];
+	__u64 event;
+};
+
+/* attributes of reg_genl_family */
+enum {
+	REG_GENL_ATTR_UNSPEC,
+	REG_GENL_ATTR_EVENT,	/* reg event info needed by user space */
+	__REG_GENL_ATTR_MAX,
+};
+
+#define REG_GENL_ATTR_MAX (__REG_GENL_ATTR_MAX - 1)
+
+/* commands supported by the reg_genl_family */
+enum {
+	REG_GENL_CMD_UNSPEC,
+	REG_GENL_CMD_EVENT,	/* kernel->user notifications for reg events */
+	__REG_GENL_CMD_MAX,
+};
+
+#define REG_GENL_CMD_MAX (__REG_GENL_CMD_MAX - 1)
+
+#define REG_GENL_FAMILY_NAME		"reg_event"
+#define REG_GENL_VERSION		0x01
+#define REG_GENL_MCAST_GROUP_NAME	"reg_mc_group"
+
+#endif /* _UAPI_REGULATOR_H */