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, 192 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-led-trigger-netdev b/Documentation/ABI/testing/sysfs-class-led-trigger-netdev
new file mode 100644
index 000000000..ed46b37ab
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-led-trigger-netdev
@@ -0,0 +1,192 @@
+What:		/sys/class/leds/<led>/device_name
+Date:		Dec 2017
+KernelVersion:	4.16
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Specifies the network device name to monitor.
+
+What:		/sys/class/leds/<led>/interval
+Date:		Dec 2017
+KernelVersion:	4.16
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Specifies the duration of the LED blink in milliseconds.
+		Defaults to 50 ms.
+
+		When offloaded is true, the interval value MUST be set to the
+		default value and cannot be changed.
+		Trying to set any value in this specific mode will return
+		an EINVAL error.
+
+What:		/sys/class/leds/<led>/link
+Date:		Dec 2017
+KernelVersion:	4.16
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Signal the link state of the named network device.
+
+		If set to 0 (default), the LED's normal state is off.
+
+		If set to 1, the LED's normal state reflects the link state
+		of the named network device.
+		Setting this value also immediately changes the LED state.
+
+
+What:		/sys/class/leds/<led>/tx
+Date:		Dec 2017
+KernelVersion:	4.16
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Signal transmission of data on the named network device.
+
+		If set to 0 (default), the LED will not blink on transmission.
+
+		If set to 1, the LED will blink for the milliseconds specified
+		in interval to signal transmission.
+
+		When offloaded is true, the blink interval is controlled by
+		hardware and won't reflect the value set in interval.
+
+What:		/sys/class/leds/<led>/rx
+Date:		Dec 2017
+KernelVersion:	4.16
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Signal reception of data on the named network device.
+
+		If set to 0 (default), the LED will not blink on reception.
+
+		If set to 1, the LED will blink for the milliseconds specified
+		in interval to signal reception.
+
+		When offloaded is true, the blink interval is controlled by
+		hardware and won't reflect the value set in interval.
+
+What:		/sys/class/leds/<led>/offloaded
+Date:		Jun 2023
+KernelVersion:	6.5
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Communicate whether the LED trigger modes are offloaded to
+		hardware or whether software fallback is used.
+
+		If 0, the LED is using software fallback to blink.
+
+		If 1, the LED blinking in requested mode is offloaded to
+		hardware.
+
+What:		/sys/class/leds/<led>/link_10
+Date:		Jun 2023
+KernelVersion:	6.5
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Signal the link speed state of 10Mbps of the named network device.
+
+		If set to 0 (default), the LED's normal state is off.
+
+		If set to 1, the LED's normal state reflects the link state
+		speed of 10MBps of the named network device.
+		Setting this value also immediately changes the LED state.
+
+		Present only if the named network device supports 10Mbps link speed.
+
+What:		/sys/class/leds/<led>/link_100
+Date:		Jun 2023
+KernelVersion:	6.5
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Signal the link speed state of 100Mbps of the named network device.
+
+		If set to 0 (default), the LED's normal state is off.
+
+		If set to 1, the LED's normal state reflects the link state
+		speed of 100Mbps of the named network device.
+		Setting this value also immediately changes the LED state.
+
+		Present only if the named network device supports 100Mbps link speed.
+
+What:		/sys/class/leds/<led>/link_1000
+Date:		Jun 2023
+KernelVersion:	6.5
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Signal the link speed state of 1000Mbps of the named network device.
+
+		If set to 0 (default), the LED's normal state is off.
+
+		If set to 1, the LED's normal state reflects the link state
+		speed of 1000Mbps of the named network device.
+		Setting this value also immediately changes the LED state.
+
+		Present only if the named network device supports 1000Mbps link speed.
+
+What:		/sys/class/leds/<led>/link_2500
+Date:		Nov 2023
+KernelVersion:	6.8
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Signal the link speed state of 2500Mbps of the named network device.
+
+		If set to 0 (default), the LED's normal state is off.
+
+		If set to 1, the LED's normal state reflects the link state
+		speed of 2500Mbps of the named network device.
+		Setting this value also immediately changes the LED state.
+
+		Present only if the named network device supports 2500Mbps link speed.
+
+What:		/sys/class/leds/<led>/link_5000
+Date:		Nov 2023
+KernelVersion:	6.8
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Signal the link speed state of 5000Mbps of the named network device.
+
+		If set to 0 (default), the LED's normal state is off.
+
+		If set to 1, the LED's normal state reflects the link state
+		speed of 5000Mbps of the named network device.
+		Setting this value also immediately changes the LED state.
+
+		Present only if the named network device supports 5000Mbps link speed.
+
+What:		/sys/class/leds/<led>/link_10000
+Date:		Nov 2023
+KernelVersion:	6.8
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Signal the link speed state of 10000Mbps of the named network device.
+
+		If set to 0 (default), the LED's normal state is off.
+
+		If set to 1, the LED's normal state reflects the link state
+		speed of 10000Mbps of the named network device.
+		Setting this value also immediately changes the LED state.
+
+		Present only if the named network device supports 10000Mbps link speed.
+
+What:		/sys/class/leds/<led>/half_duplex
+Date:		Jun 2023
+KernelVersion:	6.5
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Signal the link half duplex state of the named network device.
+
+		If set to 0 (default), the LED's normal state is off.
+
+		If set to 1, the LED's normal state reflects the link half
+		duplex state of the named network device.
+		Setting this value also immediately changes the LED state.
+
+What:		/sys/class/leds/<led>/full_duplex
+Date:		Jun 2023
+KernelVersion:	6.5
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Signal the link full duplex state of the named network device.
+
+		If set to 0 (default), the LED's normal state is off.
+
+		If set to 1, the LED's normal state reflects the link full
+		duplex state of the named network device.
+		Setting this value also immediately changes the LED state.