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, 178 insertions, 0 deletions

diff --git a/include/trace/events/pwm.h b/include/trace/events/pwm.h
new file mode 100644
index 000000000..8ba898fd3
--- /dev/null
+++ b/include/trace/events/pwm.h
@@ -0,0 +1,178 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM pwm
+
+#if !defined(_TRACE_PWM_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_PWM_H
+
+#include <linux/pwm.h>
+#include <linux/tracepoint.h>
+
+#define TP_PROTO_pwm(args...)							\
+	TP_PROTO(struct pwm_device *pwm, args)
+
+#define TP_ARGS_pwm(args...)							\
+	TP_ARGS(pwm, args)
+
+#define TP_STRUCT__entry_pwm(args...)						\
+	TP_STRUCT__entry(							\
+		__field(unsigned int, chipid)					\
+		__field(unsigned int, hwpwm)					\
+		args)
+
+#define TP_fast_assign_pwm(args...)						\
+	TP_fast_assign(								\
+		__entry->chipid = pwm->chip->id;				\
+		__entry->hwpwm = pwm->hwpwm;					\
+		args)
+
+#define TP_printk_pwm(fmt, args...)						\
+	TP_printk("pwmchip%u.%u: " fmt, __entry->chipid, __entry->hwpwm, args)
+
+#define __field_pwmwf(wf)							\
+	__field(u64, wf ## _period_length_ns)					\
+	__field(u64, wf ## _duty_length_ns)					\
+	__field(u64, wf ## _duty_offset_ns)					\
+
+#define fast_assign_pwmwf(wf)							\
+	__entry->wf ## _period_length_ns = wf->period_length_ns;		\
+	__entry->wf ## _duty_length_ns = wf->duty_length_ns;			\
+	__entry->wf ## _duty_offset_ns = wf->duty_offset_ns
+
+#define printk_pwmwf_format(wf)							\
+	"%lld/%lld [+%lld]"
+
+#define printk_pwmwf_formatargs(wf)						\
+	__entry->wf ## _duty_length_ns, __entry->wf ## _period_length_ns, __entry->wf ## _duty_offset_ns
+
+TRACE_EVENT(pwm_round_waveform_tohw,
+
+	TP_PROTO_pwm(const struct pwm_waveform *wf, void *wfhw, int err),
+
+	TP_ARGS_pwm(wf, wfhw, err),
+
+	TP_STRUCT__entry_pwm(
+		__field_pwmwf(wf)
+		__field(void *, wfhw)
+		__field(int, err)
+	),
+
+	TP_fast_assign_pwm(
+		fast_assign_pwmwf(wf);
+		__entry->wfhw = wfhw;
+		__entry->err = err;
+	),
+
+	TP_printk_pwm(printk_pwmwf_format(wf) " > %p err=%d",
+		printk_pwmwf_formatargs(wf), __entry->wfhw, __entry->err)
+);
+
+TRACE_EVENT(pwm_round_waveform_fromhw,
+
+	TP_PROTO_pwm(const void *wfhw, struct pwm_waveform *wf, int err),
+
+	TP_ARGS_pwm(wfhw, wf, err),
+
+	TP_STRUCT__entry_pwm(
+		__field(const void *, wfhw)
+		__field_pwmwf(wf)
+		__field(int, err)
+	),
+
+	TP_fast_assign_pwm(
+		__entry->wfhw = wfhw;
+		fast_assign_pwmwf(wf);
+		__entry->err = err;
+	),
+
+	TP_printk_pwm("%p > " printk_pwmwf_format(wf) " err=%d",
+		__entry->wfhw, printk_pwmwf_formatargs(wf), __entry->err)
+);
+
+TRACE_EVENT(pwm_read_waveform,
+
+	TP_PROTO_pwm(void *wfhw, int err),
+
+	TP_ARGS_pwm(wfhw, err),
+
+	TP_STRUCT__entry_pwm(
+		__field(void *, wfhw)
+		__field(int, err)
+	),
+
+	TP_fast_assign_pwm(
+		__entry->wfhw = wfhw;
+		__entry->err = err;
+	),
+
+	TP_printk_pwm("%p err=%d",
+		__entry->wfhw, __entry->err)
+);
+
+TRACE_EVENT(pwm_write_waveform,
+
+	TP_PROTO_pwm(const void *wfhw, int err),
+
+	TP_ARGS_pwm(wfhw, err),
+
+	TP_STRUCT__entry_pwm(
+		__field(const void *, wfhw)
+		__field(int, err)
+	),
+
+	TP_fast_assign_pwm(
+		__entry->wfhw = wfhw;
+		__entry->err = err;
+	),
+
+	TP_printk_pwm("%p err=%d",
+		__entry->wfhw, __entry->err)
+);
+
+
+DECLARE_EVENT_CLASS(pwm,
+
+	TP_PROTO(struct pwm_device *pwm, const struct pwm_state *state, int err),
+
+	TP_ARGS(pwm, state, err),
+
+	TP_STRUCT__entry_pwm(
+		__field(u64, period)
+		__field(u64, duty_cycle)
+		__field(enum pwm_polarity, polarity)
+		__field(bool, enabled)
+		__field(int, err)
+	),
+
+	TP_fast_assign_pwm(
+		__entry->period = state->period;
+		__entry->duty_cycle = state->duty_cycle;
+		__entry->polarity = state->polarity;
+		__entry->enabled = state->enabled;
+		__entry->err = err;
+	),
+
+	TP_printk_pwm("period=%llu duty_cycle=%llu polarity=%d enabled=%d err=%d",
+		  __entry->period, __entry->duty_cycle,
+		  __entry->polarity, __entry->enabled, __entry->err)
+
+);
+
+DEFINE_EVENT(pwm, pwm_apply,
+
+	TP_PROTO(struct pwm_device *pwm, const struct pwm_state *state, int err),
+
+	TP_ARGS(pwm, state, err)
+);
+
+DEFINE_EVENT(pwm, pwm_get,
+
+	TP_PROTO(struct pwm_device *pwm, const struct pwm_state *state, int err),
+
+	TP_ARGS(pwm, state, err)
+);
+
+#endif /* _TRACE_PWM_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>