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, 313 insertions, 0 deletions

diff --git a/include/trace/events/clk.h b/include/trace/events/clk.h
new file mode 100644
index 000000000..759f7371a
--- /dev/null
+++ b/include/trace/events/clk.h
@@ -0,0 +1,313 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM clk
+
+#if !defined(_TRACE_CLK_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_CLK_H
+
+#include <linux/tracepoint.h>
+
+struct clk_core;
+
+DECLARE_EVENT_CLASS(clk,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core),
+
+	TP_STRUCT__entry(
+		__string(        name,           core->name       )
+	),
+
+	TP_fast_assign(
+		__assign_str(name);
+	),
+
+	TP_printk("%s", __get_str(name))
+);
+
+DEFINE_EVENT(clk, clk_enable,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DEFINE_EVENT(clk, clk_enable_complete,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DEFINE_EVENT(clk, clk_disable,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DEFINE_EVENT(clk, clk_disable_complete,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DEFINE_EVENT(clk, clk_prepare,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DEFINE_EVENT(clk, clk_prepare_complete,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DEFINE_EVENT(clk, clk_unprepare,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DEFINE_EVENT(clk, clk_unprepare_complete,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DECLARE_EVENT_CLASS(clk_rate,
+
+	TP_PROTO(struct clk_core *core, unsigned long rate),
+
+	TP_ARGS(core, rate),
+
+	TP_STRUCT__entry(
+		__string(        name,           core->name                )
+		__field(unsigned long,           rate                      )
+	),
+
+	TP_fast_assign(
+		__assign_str(name);
+		__entry->rate = rate;
+	),
+
+	TP_printk("%s %lu", __get_str(name), (unsigned long)__entry->rate)
+);
+
+DEFINE_EVENT(clk_rate, clk_set_rate,
+
+	TP_PROTO(struct clk_core *core, unsigned long rate),
+
+	TP_ARGS(core, rate)
+);
+
+DEFINE_EVENT(clk_rate, clk_set_rate_complete,
+
+	TP_PROTO(struct clk_core *core, unsigned long rate),
+
+	TP_ARGS(core, rate)
+);
+
+DEFINE_EVENT(clk_rate, clk_set_min_rate,
+
+	TP_PROTO(struct clk_core *core, unsigned long rate),
+
+	TP_ARGS(core, rate)
+);
+
+DEFINE_EVENT(clk_rate, clk_set_max_rate,
+
+	TP_PROTO(struct clk_core *core, unsigned long rate),
+
+	TP_ARGS(core, rate)
+);
+
+DECLARE_EVENT_CLASS(clk_rate_range,
+
+	TP_PROTO(struct clk_core *core, unsigned long min, unsigned long max),
+
+	TP_ARGS(core, min, max),
+
+	TP_STRUCT__entry(
+		__string(        name,           core->name                )
+		__field(unsigned long,           min                       )
+		__field(unsigned long,           max                       )
+	),
+
+	TP_fast_assign(
+		__assign_str(name);
+		__entry->min = min;
+		__entry->max = max;
+	),
+
+	TP_printk("%s min %lu max %lu", __get_str(name),
+		  (unsigned long)__entry->min,
+		  (unsigned long)__entry->max)
+);
+
+DEFINE_EVENT(clk_rate_range, clk_set_rate_range,
+
+	TP_PROTO(struct clk_core *core, unsigned long min, unsigned long max),
+
+	TP_ARGS(core, min, max)
+);
+
+DECLARE_EVENT_CLASS(clk_parent,
+
+	TP_PROTO(struct clk_core *core, struct clk_core *parent),
+
+	TP_ARGS(core, parent),
+
+	TP_STRUCT__entry(
+		__string(        name,           core->name                )
+		__string(        pname, parent ? parent->name : "none"     )
+	),
+
+	TP_fast_assign(
+		__assign_str(name);
+		__assign_str(pname);
+	),
+
+	TP_printk("%s %s", __get_str(name), __get_str(pname))
+);
+
+DEFINE_EVENT(clk_parent, clk_set_parent,
+
+	TP_PROTO(struct clk_core *core, struct clk_core *parent),
+
+	TP_ARGS(core, parent)
+);
+
+DEFINE_EVENT(clk_parent, clk_set_parent_complete,
+
+	TP_PROTO(struct clk_core *core, struct clk_core *parent),
+
+	TP_ARGS(core, parent)
+);
+
+DECLARE_EVENT_CLASS(clk_phase,
+
+	TP_PROTO(struct clk_core *core, int phase),
+
+	TP_ARGS(core, phase),
+
+	TP_STRUCT__entry(
+		__string(        name,           core->name                )
+		__field(	  int,           phase                     )
+	),
+
+	TP_fast_assign(
+		__assign_str(name);
+		__entry->phase = phase;
+	),
+
+	TP_printk("%s %d", __get_str(name), (int)__entry->phase)
+);
+
+DEFINE_EVENT(clk_phase, clk_set_phase,
+
+	TP_PROTO(struct clk_core *core, int phase),
+
+	TP_ARGS(core, phase)
+);
+
+DEFINE_EVENT(clk_phase, clk_set_phase_complete,
+
+	TP_PROTO(struct clk_core *core, int phase),
+
+	TP_ARGS(core, phase)
+);
+
+DECLARE_EVENT_CLASS(clk_duty_cycle,
+
+	TP_PROTO(struct clk_core *core, struct clk_duty *duty),
+
+	TP_ARGS(core, duty),
+
+	TP_STRUCT__entry(
+		__string(        name,           core->name              )
+		__field( unsigned int,           num                     )
+		__field( unsigned int,           den                     )
+	),
+
+	TP_fast_assign(
+		__assign_str(name);
+		__entry->num = duty->num;
+		__entry->den = duty->den;
+	),
+
+	TP_printk("%s %u/%u", __get_str(name), (unsigned int)__entry->num,
+		  (unsigned int)__entry->den)
+);
+
+DEFINE_EVENT(clk_duty_cycle, clk_set_duty_cycle,
+
+	TP_PROTO(struct clk_core *core, struct clk_duty *duty),
+
+	TP_ARGS(core, duty)
+);
+
+DEFINE_EVENT(clk_duty_cycle, clk_set_duty_cycle_complete,
+
+	TP_PROTO(struct clk_core *core, struct clk_duty *duty),
+
+	TP_ARGS(core, duty)
+);
+
+DECLARE_EVENT_CLASS(clk_rate_request,
+
+	TP_PROTO(struct clk_rate_request *req),
+
+	TP_ARGS(req),
+
+	TP_STRUCT__entry(
+		__string(        name, req->core ? req->core->name : "none")
+		__string(       pname, req->best_parent_hw ? clk_hw_get_name(req->best_parent_hw) : "none" )
+		__field(unsigned long,           min                       )
+		__field(unsigned long,           max                       )
+		__field(unsigned long,           prate                     )
+	),
+
+	TP_fast_assign(
+		__assign_str(name);
+		__assign_str(pname);
+		__entry->min = req->min_rate;
+		__entry->max = req->max_rate;
+		__entry->prate = req->best_parent_rate;
+	),
+
+	TP_printk("%s min %lu max %lu, parent %s (%lu)", __get_str(name),
+		  (unsigned long)__entry->min,
+		  (unsigned long)__entry->max,
+		  __get_str(pname),
+		  (unsigned long)__entry->prate)
+);
+
+DEFINE_EVENT(clk_rate_request, clk_rate_request_start,
+
+	TP_PROTO(struct clk_rate_request *req),
+
+	TP_ARGS(req)
+);
+
+DEFINE_EVENT(clk_rate_request, clk_rate_request_done,
+
+	TP_PROTO(struct clk_rate_request *req),
+
+	TP_ARGS(req)
+);
+
+#endif /* _TRACE_CLK_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>