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, 86 insertions, 0 deletions

diff --git a/net/mac80211/led.h b/net/mac80211/led.h
new file mode 100644
index 000000000..d25f13346
--- /dev/null
+++ b/net/mac80211/led.h
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2006, Johannes Berg <johannes@sipsolutions.net>
+ */
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/leds.h>
+#include "ieee80211_i.h"
+
+#define MAC80211_BLINK_DELAY 50 /* ms */
+
+static inline void ieee80211_led_rx(struct ieee80211_local *local)
+{
+#ifdef CONFIG_MAC80211_LEDS
+	if (!atomic_read(&local->rx_led_active))
+		return;
+	led_trigger_blink_oneshot(&local->rx_led, MAC80211_BLINK_DELAY, MAC80211_BLINK_DELAY, 0);
+#endif
+}
+
+static inline void ieee80211_led_tx(struct ieee80211_local *local)
+{
+#ifdef CONFIG_MAC80211_LEDS
+	if (!atomic_read(&local->tx_led_active))
+		return;
+	led_trigger_blink_oneshot(&local->tx_led, MAC80211_BLINK_DELAY, MAC80211_BLINK_DELAY, 0);
+#endif
+}
+
+#ifdef CONFIG_MAC80211_LEDS
+void ieee80211_led_assoc(struct ieee80211_local *local,
+			 bool associated);
+void ieee80211_led_radio(struct ieee80211_local *local,
+			 bool enabled);
+void ieee80211_alloc_led_names(struct ieee80211_local *local);
+void ieee80211_free_led_names(struct ieee80211_local *local);
+void ieee80211_led_init(struct ieee80211_local *local);
+void ieee80211_led_exit(struct ieee80211_local *local);
+void ieee80211_mod_tpt_led_trig(struct ieee80211_local *local,
+				unsigned int types_on, unsigned int types_off);
+#else
+static inline void ieee80211_led_assoc(struct ieee80211_local *local,
+				       bool associated)
+{
+}
+static inline void ieee80211_led_radio(struct ieee80211_local *local,
+				       bool enabled)
+{
+}
+static inline void ieee80211_alloc_led_names(struct ieee80211_local *local)
+{
+}
+static inline void ieee80211_free_led_names(struct ieee80211_local *local)
+{
+}
+static inline void ieee80211_led_init(struct ieee80211_local *local)
+{
+}
+static inline void ieee80211_led_exit(struct ieee80211_local *local)
+{
+}
+static inline void ieee80211_mod_tpt_led_trig(struct ieee80211_local *local,
+					      unsigned int types_on,
+					      unsigned int types_off)
+{
+}
+#endif
+
+static inline void
+ieee80211_tpt_led_trig_tx(struct ieee80211_local *local, int bytes)
+{
+#ifdef CONFIG_MAC80211_LEDS
+	if (atomic_read(&local->tpt_led_active))
+		local->tpt_led_trigger->tx_bytes += bytes;
+#endif
+}
+
+static inline void
+ieee80211_tpt_led_trig_rx(struct ieee80211_local *local, int bytes)
+{
+#ifdef CONFIG_MAC80211_LEDS
+	if (atomic_read(&local->tpt_led_active))
+		local->tpt_led_trigger->rx_bytes += bytes;
+#endif
+}