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, 22 insertions, 0 deletions

diff --git a/drivers/firewire/Makefile b/drivers/firewire/Makefile
new file mode 100644
index 000000000..1ff550e93
--- /dev/null
+++ b/drivers/firewire/Makefile
@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Linux IEEE 1394 implementation
+#
+
+firewire-core-y += core-trace.o core-card.o core-cdev.o core-device.o \
+                   core-iso.o core-topology.o core-transaction.o
+firewire-ohci-y += ohci.o
+firewire-sbp2-y += sbp2.o
+firewire-net-y  += net.o
+
+obj-$(CONFIG_FIREWIRE)      += firewire-core.o
+obj-$(CONFIG_FIREWIRE_OHCI) += firewire-ohci.o
+obj-$(CONFIG_FIREWIRE_SBP2) += firewire-sbp2.o
+obj-$(CONFIG_FIREWIRE_NET)  += firewire-net.o
+obj-$(CONFIG_FIREWIRE_NOSY) += nosy.o
+obj-$(CONFIG_PROVIDE_OHCI1394_DMA_INIT) += init_ohci1394_dma.o
+
+obj-$(CONFIG_FIREWIRE_KUNIT_UAPI_TEST) += uapi-test.o
+obj-$(CONFIG_FIREWIRE_KUNIT_PACKET_SERDES_TEST) += packet-serdes-test.o
+obj-$(CONFIG_FIREWIRE_KUNIT_SELF_ID_SEQUENCE_HELPER_TEST) += self-id-sequence-helper-test.o
+obj-$(CONFIG_FIREWIRE_KUNIT_OHCI_SERDES_TEST) += ohci-serdes-test.o