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, 118 insertions, 0 deletions

diff --git a/include/trace/events/qrtr.h b/include/trace/events/qrtr.h
new file mode 100644
index 000000000..14f822983
--- /dev/null
+++ b/include/trace/events/qrtr.h
@@ -0,0 +1,118 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM qrtr
+
+#if !defined(_TRACE_QRTR_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_QRTR_H
+
+#include <linux/qrtr.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(qrtr_ns_service_announce_new,
+
+	TP_PROTO(unsigned int service, unsigned int instance,
+		 unsigned int node, unsigned int port),
+
+	TP_ARGS(service, instance, node, port),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, service)
+		__field(unsigned int, instance)
+		__field(unsigned int, node)
+		__field(unsigned int, port)
+	),
+
+	TP_fast_assign(
+		__entry->service = service;
+		__entry->instance = instance;
+		__entry->node = node;
+		__entry->port = port;
+	),
+
+	TP_printk("advertising new server [%d:%x]@[%d:%d]",
+		  __entry->service, __entry->instance, __entry->node,
+		  __entry->port
+	)
+);
+
+TRACE_EVENT(qrtr_ns_service_announce_del,
+
+	TP_PROTO(unsigned int service, unsigned int instance,
+		 unsigned int node, unsigned int port),
+
+	TP_ARGS(service, instance, node, port),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, service)
+		__field(unsigned int, instance)
+		__field(unsigned int, node)
+		__field(unsigned int, port)
+	),
+
+	TP_fast_assign(
+		__entry->service = service;
+		__entry->instance = instance;
+		__entry->node = node;
+		__entry->port = port;
+	),
+
+	TP_printk("advertising removal of server [%d:%x]@[%d:%d]",
+		  __entry->service, __entry->instance, __entry->node,
+		  __entry->port
+	)
+);
+
+TRACE_EVENT(qrtr_ns_server_add,
+
+	TP_PROTO(unsigned int service, unsigned int instance,
+		 unsigned int node, unsigned int port),
+
+	TP_ARGS(service, instance, node, port),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, service)
+		__field(unsigned int, instance)
+		__field(unsigned int, node)
+		__field(unsigned int, port)
+	),
+
+	TP_fast_assign(
+		__entry->service = service;
+		__entry->instance = instance;
+		__entry->node = node;
+		__entry->port = port;
+	),
+
+	TP_printk("add server [%d:%x]@[%d:%d]",
+		  __entry->service, __entry->instance, __entry->node,
+		  __entry->port
+	)
+);
+
+TRACE_EVENT(qrtr_ns_message,
+
+	TP_PROTO(const char * const ctrl_pkt_str, __u32 sq_node, __u32 sq_port),
+
+	TP_ARGS(ctrl_pkt_str, sq_node, sq_port),
+
+	TP_STRUCT__entry(
+		__string(ctrl_pkt_str, ctrl_pkt_str)
+		__field(__u32, sq_node)
+		__field(__u32, sq_port)
+	),
+
+	TP_fast_assign(
+		__assign_str(ctrl_pkt_str);
+		__entry->sq_node = sq_node;
+		__entry->sq_port = sq_port;
+	),
+
+	TP_printk("%s from %d:%d",
+		  __get_str(ctrl_pkt_str), __entry->sq_node, __entry->sq_port
+	)
+);
+
+#endif /* _TRACE_QRTR_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>