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, 32 insertions, 0 deletions

diff --git a/drivers/firmware/broadcom/Kconfig b/drivers/firmware/broadcom/Kconfig
new file mode 100644
index 000000000..8e3d355a6
--- /dev/null
+++ b/drivers/firmware/broadcom/Kconfig
@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config BCM47XX_NVRAM
+	bool "Broadcom NVRAM driver"
+	depends on BCM47XX || ARCH_BCM_5301X || COMPILE_TEST
+	help
+	  Broadcom home routers contain flash partition called "nvram" with all
+	  important hardware configuration as well as some minor user setup.
+	  NVRAM partition contains a text-like data representing name=value
+	  pairs.
+	  This driver provides an easy way to get value of requested parameter.
+	  It simply reads content of NVRAM and parses it. It doesn't control any
+	  hardware part itself.
+
+config BCM47XX_SPROM
+	bool "Broadcom SPROM driver"
+	depends on BCM47XX_NVRAM
+	select GENERIC_NET_UTILS
+	help
+	  Broadcom devices store configuration data in SPROM. Accessing it is
+	  specific to the bus host type, e.g. PCI(e) devices have it mapped in
+	  a PCI BAR.
+	  In case of SoC devices SPROM content is stored on a flash used by
+	  bootloader firmware CFE. This driver provides method to ssb and bcma
+	  drivers to read SPROM on SoC.
+
+config TEE_BNXT_FW
+	tristate "Broadcom BNXT firmware manager"
+	depends on (ARCH_BCM_IPROC && OPTEE) || (COMPILE_TEST && TEE)
+	default ARCH_BCM_IPROC
+	help
+	  This module help to manage firmware on Broadcom BNXT device. The module
+	  registers on tee bus and invoke calls to manage firmware on BNXT device.