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, 41 insertions, 0 deletions

diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
new file mode 100644
index 000000000..be46f1e1d
--- /dev/null
+++ b/drivers/firmware/Makefile
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux kernel.
+#
+obj-$(CONFIG_ARM_SCPI_PROTOCOL)	+= arm_scpi.o
+obj-$(CONFIG_ARM_SDE_INTERFACE)	+= arm_sdei.o
+obj-$(CONFIG_ARM_SDEI_NMI)	+= arm_sdei_nmi.o
+obj-$(CONFIG_DMI)		+= dmi_scan.o
+obj-$(CONFIG_DMI_SYSFS)		+= dmi-sysfs.o
+obj-$(CONFIG_EDD)		+= edd.o
+obj-$(CONFIG_DMIID)		+= dmi-id.o
+obj-$(CONFIG_INTEL_STRATIX10_SERVICE) += stratix10-svc.o
+obj-$(CONFIG_INTEL_STRATIX10_RSU)     += stratix10-rsu.o
+obj-$(CONFIG_ISCSI_IBFT_FIND)	+= iscsi_ibft_find.o
+obj-$(CONFIG_ISCSI_IBFT)	+= iscsi_ibft.o
+obj-$(CONFIG_FIRMWARE_MEMMAP)	+= memmap.o
+obj-$(CONFIG_MTK_ADSP_IPC)	+= mtk-adsp-ipc.o
+obj-$(CONFIG_RASPBERRYPI_FIRMWARE) += raspberrypi.o
+obj-$(CONFIG_FW_CFG_SYSFS)	+= qemu_fw_cfg.o
+obj-$(CONFIG_SYSFB)		+= sysfb.o
+obj-$(CONFIG_SYSFB_SIMPLEFB)	+= sysfb_simplefb.o
+obj-$(CONFIG_TH1520_AON_PROTOCOL) += thead,th1520-aon.o
+obj-$(CONFIG_TI_SCI_PROTOCOL)	+= ti_sci.o
+obj-$(CONFIG_TRUSTED_FOUNDATIONS) += trusted_foundations.o
+obj-$(CONFIG_TURRIS_MOX_RWTM)	+= turris-mox-rwtm.o
+
+obj-y				+= arm_ffa/
+obj-y				+= arm_scmi/
+obj-y				+= broadcom/
+obj-y				+= cirrus/
+obj-y				+= meson/
+obj-y				+= microchip/
+obj-$(CONFIG_GOOGLE_FIRMWARE)	+= google/
+obj-y				+= efi/
+obj-y				+= imx/
+obj-y				+= psci/
+obj-y				+= qcom/
+obj-y				+= samsung/
+obj-y				+= smccc/
+obj-y				+= tegra/
+obj-y				+= xilinx/