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, 46 insertions, 0 deletions

diff --git a/include/trace/events/qla.h b/include/trace/events/qla.h
new file mode 100644
index 000000000..8800c3552
--- /dev/null
+++ b/include/trace/events/qla.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#if !defined(_TRACE_QLA_H_) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_QLA_H_
+
+#include <linux/tracepoint.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM qla
+
+#define QLA_MSG_MAX 256
+
+#pragma GCC diagnostic push
+#ifndef __clang__
+#pragma GCC diagnostic ignored "-Wsuggest-attribute=format"
+#endif
+
+DECLARE_EVENT_CLASS(qla_log_event,
+	TP_PROTO(const char *buf,
+		struct va_format *vaf),
+
+	TP_ARGS(buf, vaf),
+
+	TP_STRUCT__entry(
+		__string(buf, buf)
+		__vstring(msg, vaf->fmt, vaf->va)
+	),
+	TP_fast_assign(
+		__assign_str(buf);
+		__assign_vstr(msg, vaf->fmt, vaf->va);
+	),
+
+	TP_printk("%s %s", __get_str(buf), __get_str(msg))
+);
+
+#pragma GCC diagnostic pop
+
+DEFINE_EVENT(qla_log_event, ql_dbg_log,
+	TP_PROTO(const char *buf, struct va_format *vaf),
+	TP_ARGS(buf, vaf)
+);
+
+#endif /* _TRACE_QLA_H */
+
+#define TRACE_INCLUDE_FILE qla
+
+#include <trace/define_trace.h>