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, 27 insertions, 0 deletions

diff --git a/drivers/of/Makefile b/drivers/of/Makefile
new file mode 100644
index 000000000..379a0afcb
--- /dev/null
+++ b/drivers/of/Makefile
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-y = base.o cpu.o device.o module.o platform.o property.o
+obj-$(CONFIG_OF_KOBJ) += kobj.o
+obj-$(CONFIG_OF_DYNAMIC) += dynamic.o
+obj-$(CONFIG_OF_FLATTREE) += fdt.o empty_root.dtb.o
+obj-$(CONFIG_OF_EARLY_FLATTREE) += fdt_address.o
+obj-$(CONFIG_OF_PROMTREE) += pdt.o
+obj-$(CONFIG_OF_ADDRESS)  += address.o
+obj-$(CONFIG_OF_IRQ)    += irq.o
+obj-$(CONFIG_OF_UNITTEST) += unittest.o
+obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
+obj-$(CONFIG_OF_RESOLVE)  += resolver.o
+obj-$(CONFIG_OF_OVERLAY) += overlay.o
+obj-$(CONFIG_OF_NUMA) += of_numa.o
+
+ifdef CONFIG_KEXEC_FILE
+ifdef CONFIG_OF_FLATTREE
+obj-y	+= kexec.o
+endif
+endif
+
+obj-$(CONFIG_KUNIT) += of_kunit_helpers.o
+obj-$(CONFIG_OF_KUNIT_TEST) += of_test.o
+obj-$(CONFIG_OF_OVERLAY_KUNIT_TEST) += overlay-test.o
+overlay-test-y := overlay_test.o kunit_overlay_test.dtbo.o
+
+obj-$(CONFIG_OF_UNITTEST) += unittest-data/