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, 57 insertions, 0 deletions

diff --git a/include/acpi/apei.h b/include/acpi/apei.h
new file mode 100644
index 000000000..dc60f7db5
--- /dev/null
+++ b/include/acpi/apei.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * apei.h - ACPI Platform Error Interface
+ */
+
+#ifndef ACPI_APEI_H
+#define ACPI_APEI_H
+
+#include <linux/acpi.h>
+#include <linux/cper.h>
+#include <asm/ioctls.h>
+
+#define APEI_ERST_INVALID_RECORD_ID	0xffffffffffffffffULL
+
+#define APEI_ERST_CLEAR_RECORD		_IOW('E', 1, u64)
+#define APEI_ERST_GET_RECORD_COUNT	_IOR('E', 2, u32)
+
+#ifdef __KERNEL__
+
+enum hest_status {
+	HEST_ENABLED,
+	HEST_DISABLED,
+	HEST_NOT_FOUND,
+};
+
+extern int hest_disable;
+extern int erst_disable;
+#ifdef CONFIG_ACPI_APEI_GHES
+extern bool ghes_disable;
+void __init acpi_ghes_init(void);
+#else
+#define ghes_disable 1
+static inline void acpi_ghes_init(void) { }
+#endif
+
+#ifdef CONFIG_ACPI_APEI
+void __init acpi_hest_init(void);
+#else
+static inline void acpi_hest_init(void) { }
+#endif
+
+int erst_write(const struct cper_record_header *record);
+ssize_t erst_get_record_count(void);
+int erst_get_record_id_begin(int *pos);
+int erst_get_record_id_next(int *pos, u64 *record_id);
+void erst_get_record_id_end(void);
+ssize_t erst_read(u64 record_id, struct cper_record_header *record,
+		  size_t buflen);
+ssize_t erst_read_record(u64 record_id, struct cper_record_header *record,
+		size_t buflen, size_t recordlen, const guid_t *creatorid);
+int erst_clear(u64 record_id);
+
+int arch_apei_enable_cmcff(struct acpi_hest_header *hest_hdr, void *data);
+void arch_apei_report_mem_error(int sev, struct cper_sec_mem_err *mem_err);
+
+#endif
+#endif