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, 186 insertions, 0 deletions

diff --git a/include/trace/events/scmi.h b/include/trace/events/scmi.h
new file mode 100644
index 000000000..703b7bb68
--- /dev/null
+++ b/include/trace/events/scmi.h
@@ -0,0 +1,186 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM scmi
+
+#if !defined(_TRACE_SCMI_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SCMI_H
+
+#include <linux/tracepoint.h>
+
+#define TRACE_SCMI_MAX_TAG_LEN	6
+
+TRACE_EVENT(scmi_fc_call,
+	TP_PROTO(u8 protocol_id, u8 msg_id, u32 res_id, u32 val1, u32 val2),
+	TP_ARGS(protocol_id, msg_id, res_id, val1, val2),
+
+	TP_STRUCT__entry(
+		__field(u8, protocol_id)
+		__field(u8, msg_id)
+		__field(u32, res_id)
+		__field(u32, val1)
+		__field(u32, val2)
+	),
+
+	TP_fast_assign(
+		__entry->protocol_id = protocol_id;
+		__entry->msg_id = msg_id;
+		__entry->res_id = res_id;
+		__entry->val1 = val1;
+		__entry->val2 = val2;
+	),
+
+	TP_printk("pt=%02X msg_id=%02X res_id:%u vals=%u:%u",
+		__entry->protocol_id, __entry->msg_id,
+		__entry->res_id, __entry->val1, __entry->val2)
+);
+
+TRACE_EVENT(scmi_xfer_begin,
+	TP_PROTO(int transfer_id, u8 msg_id, u8 protocol_id, u16 seq,
+		 bool poll, int inflight),
+	TP_ARGS(transfer_id, msg_id, protocol_id, seq, poll, inflight),
+
+	TP_STRUCT__entry(
+		__field(int, transfer_id)
+		__field(u8, msg_id)
+		__field(u8, protocol_id)
+		__field(u16, seq)
+		__field(bool, poll)
+		__field(int, inflight)
+	),
+
+	TP_fast_assign(
+		__entry->transfer_id = transfer_id;
+		__entry->msg_id = msg_id;
+		__entry->protocol_id = protocol_id;
+		__entry->seq = seq;
+		__entry->poll = poll;
+		__entry->inflight = inflight;
+	),
+
+	TP_printk("pt=%02X msg_id=%02X seq=%04X transfer_id=%X poll=%u inflight=%d",
+		  __entry->protocol_id, __entry->msg_id, __entry->seq,
+		  __entry->transfer_id, __entry->poll, __entry->inflight)
+);
+
+TRACE_EVENT(scmi_xfer_response_wait,
+	TP_PROTO(int transfer_id, u8 msg_id, u8 protocol_id, u16 seq,
+		 u32 timeout, bool poll),
+	TP_ARGS(transfer_id, msg_id, protocol_id, seq, timeout, poll),
+
+	TP_STRUCT__entry(
+		__field(int, transfer_id)
+		__field(u8, msg_id)
+		__field(u8, protocol_id)
+		__field(u16, seq)
+		__field(u32, timeout)
+		__field(bool, poll)
+	),
+
+	TP_fast_assign(
+		__entry->transfer_id = transfer_id;
+		__entry->msg_id = msg_id;
+		__entry->protocol_id = protocol_id;
+		__entry->seq = seq;
+		__entry->timeout = timeout;
+		__entry->poll = poll;
+	),
+
+	TP_printk("pt=%02X msg_id=%02X seq=%04X transfer_id=%X tmo_ms=%u poll=%u",
+		__entry->protocol_id, __entry->msg_id, __entry->seq,
+		__entry->transfer_id, __entry->timeout, __entry->poll)
+);
+
+TRACE_EVENT(scmi_xfer_end,
+	TP_PROTO(int transfer_id, u8 msg_id, u8 protocol_id, u16 seq,
+		 int status, int inflight),
+	TP_ARGS(transfer_id, msg_id, protocol_id, seq, status, inflight),
+
+	TP_STRUCT__entry(
+		__field(int, transfer_id)
+		__field(u8, msg_id)
+		__field(u8, protocol_id)
+		__field(u16, seq)
+		__field(int, status)
+		__field(int, inflight)
+	),
+
+	TP_fast_assign(
+		__entry->transfer_id = transfer_id;
+		__entry->msg_id = msg_id;
+		__entry->protocol_id = protocol_id;
+		__entry->seq = seq;
+		__entry->status = status;
+		__entry->inflight = inflight;
+	),
+
+	TP_printk("pt=%02X msg_id=%02X seq=%04X transfer_id=%X s=%d inflight=%d",
+		  __entry->protocol_id, __entry->msg_id, __entry->seq,
+		  __entry->transfer_id, __entry->status, __entry->inflight)
+);
+
+TRACE_EVENT(scmi_rx_done,
+	TP_PROTO(int transfer_id, u8 msg_id, u8 protocol_id, u16 seq,
+		 u8 msg_type),
+	TP_ARGS(transfer_id, msg_id, protocol_id, seq, msg_type),
+
+	TP_STRUCT__entry(
+		__field(int, transfer_id)
+		__field(u8, msg_id)
+		__field(u8, protocol_id)
+		__field(u16, seq)
+		__field(u8, msg_type)
+	),
+
+	TP_fast_assign(
+		__entry->transfer_id = transfer_id;
+		__entry->msg_id = msg_id;
+		__entry->protocol_id = protocol_id;
+		__entry->seq = seq;
+		__entry->msg_type = msg_type;
+	),
+
+	TP_printk("pt=%02X msg_id=%02X seq=%04X transfer_id=%X msg_type=%u",
+		__entry->protocol_id, __entry->msg_id, __entry->seq,
+		__entry->transfer_id, __entry->msg_type)
+);
+
+TRACE_EVENT(scmi_msg_dump,
+	TP_PROTO(int id, u8 channel_id, u8 protocol_id, u8 msg_id,
+		 unsigned char *tag, u16 seq, int status,
+		 void *buf, size_t len),
+	TP_ARGS(id, channel_id, protocol_id, msg_id, tag, seq, status,
+		buf, len),
+
+	TP_STRUCT__entry(
+		__field(int, id)
+		__field(u8, channel_id)
+		__field(u8, protocol_id)
+		__field(u8, msg_id)
+		__array(char, tag, TRACE_SCMI_MAX_TAG_LEN)
+		__field(u16, seq)
+		__field(int, status)
+		__field(size_t, len)
+		__dynamic_array(unsigned char, cmd, len)
+	),
+
+	TP_fast_assign(
+		__entry->id = id;
+		__entry->channel_id = channel_id;
+		__entry->protocol_id = protocol_id;
+		__entry->msg_id = msg_id;
+		strscpy(__entry->tag, tag, TRACE_SCMI_MAX_TAG_LEN);
+		__entry->seq = seq;
+		__entry->status = status;
+		__entry->len = len;
+		memcpy(__get_dynamic_array(cmd), buf, __entry->len);
+	),
+
+	TP_printk("id=%d ch=%02X pt=%02X t=%s msg_id=%02X seq=%04X s=%d pyld=%s",
+		  __entry->id, __entry->channel_id, __entry->protocol_id,
+		  __entry->tag, __entry->msg_id, __entry->seq, __entry->status,
+		__print_hex_str(__get_dynamic_array(cmd), __entry->len))
+);
+#endif /* _TRACE_SCMI_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>