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, 39 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/openrisc/opencores/or1ksim.txt b/Documentation/devicetree/bindings/openrisc/opencores/or1ksim.txt
new file mode 100644
index 000000000..4950c794e
--- /dev/null
+++ b/Documentation/devicetree/bindings/openrisc/opencores/or1ksim.txt
@@ -0,0 +1,39 @@
+OpenRISC Generic SoC
+====================
+
+Boards and FPGA SoC's which support the OpenRISC standard platform.  The
+platform essentially follows the conventions of the OpenRISC architecture
+specification, however some aspects, such as the boot protocol have been defined
+by the Linux port.
+
+Required properties
+-------------------
+ - compatible: Must include "opencores,or1ksim"
+
+CPU nodes:
+----------
+A "cpus" node is required.  Required properties:
+ - #address-cells: Must be 1.
+ - #size-cells: Must be 0.
+A CPU sub-node is also required for at least CPU 0.  Since the topology may
+be probed via CPS, it is not necessary to specify secondary CPUs.  Required
+properties:
+ - compatible: Must be "opencores,or1200-rtlsvn481".
+ - reg: CPU number.
+ - clock-frequency: The CPU clock frequency in Hz.
+Example:
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		cpu@0 {
+			compatible = "opencores,or1200-rtlsvn481";
+			reg = <0>;
+			clock-frequency = <20000000>;
+		};
+	};
+
+
+Boot protocol
+-------------
+The bootloader may pass the following arguments to the kernel:
+ - r3:  address of a flattened device-tree blob or 0x0.