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, 64 insertions, 0 deletions

diff --git a/include/acpi/acnames.h b/include/acpi/acnames.h
new file mode 100644
index 000000000..714d8f265
--- /dev/null
+++ b/include/acpi/acnames.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 */
+/******************************************************************************
+ *
+ * Name: acnames.h - Global names and strings
+ *
+ * Copyright (C) 2000 - 2026, Intel Corp.
+ *
+ *****************************************************************************/
+
+#ifndef __ACNAMES_H__
+#define __ACNAMES_H__
+
+/* Method names - these methods can appear anywhere in the namespace */
+
+#define METHOD_NAME__ADR        "_ADR"
+#define METHOD_NAME__AEI        "_AEI"
+#define METHOD_NAME__BBN        "_BBN"
+#define METHOD_NAME__CBA        "_CBA"
+#define METHOD_NAME__CID        "_CID"
+#define METHOD_NAME__CLS        "_CLS"
+#define METHOD_NAME__CRS        "_CRS"
+#define METHOD_NAME__DDN        "_DDN"
+#define METHOD_NAME__DIS        "_DIS"
+#define METHOD_NAME__DMA        "_DMA"
+#define METHOD_NAME__EVT        "_EVT"
+#define METHOD_NAME__HID        "_HID"
+#define METHOD_NAME__INI        "_INI"
+#define METHOD_NAME__PLD        "_PLD"
+#define METHOD_NAME__DSD        "_DSD"
+#define METHOD_NAME__PRS        "_PRS"
+#define METHOD_NAME__PRT        "_PRT"
+#define METHOD_NAME__PRW        "_PRW"
+#define METHOD_NAME__PS0        "_PS0"
+#define METHOD_NAME__PS1        "_PS1"
+#define METHOD_NAME__PS2        "_PS2"
+#define METHOD_NAME__PS3        "_PS3"
+#define METHOD_NAME__REG        "_REG"
+#define METHOD_NAME__SB_        "_SB_"
+#define METHOD_NAME__SEG        "_SEG"
+#define METHOD_NAME__SRS        "_SRS"
+#define METHOD_NAME__STA        "_STA"
+#define METHOD_NAME__SUB        "_SUB"
+#define METHOD_NAME__UID        "_UID"
+
+/* Method names - these methods must appear at the namespace root */
+
+#define METHOD_PATHNAME__PTS    "\\_PTS"
+#define METHOD_PATHNAME__SST    "\\_SI._SST"
+#define METHOD_PATHNAME__WAK    "\\_WAK"
+
+/* Definitions of the predefined namespace names  */
+
+#define ACPI_UNKNOWN_NAME       (u32) 0x3F3F3F3F	/* Unknown name is "????" */
+#define ACPI_PREFIX_MIXED       (u32) 0x69706341	/* "Acpi" */
+#define ACPI_PREFIX_LOWER       (u32) 0x69706361	/* "acpi" */
+
+/* Root name stuff */
+
+#define ACPI_ROOT_NAME          (u32) 0x5F5F5F5C	/* Root name is    "\___" */
+#define ACPI_ROOT_PATHNAME      "\\___"
+#define ACPI_NAMESPACE_ROOT     "Namespace Root"
+#define ACPI_NS_ROOT_PATH       "\\"
+
+#endif				/* __ACNAMES_H__  */