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, 73 insertions, 0 deletions

diff --git a/drivers/nfc/Kconfig b/drivers/nfc/Kconfig
new file mode 100644
index 000000000..288c6f1c6
--- /dev/null
+++ b/drivers/nfc/Kconfig
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Near Field Communication (NFC) devices
+#
+
+menu "Near Field Communication (NFC) devices"
+	depends on NFC
+
+config NFC_TRF7970A
+	tristate "Texas Instruments TRF7970a NFC driver"
+	depends on SPI && NFC_DIGITAL && GPIOLIB
+	help
+	  This option enables the NFC driver for Texas Instruments' TRF7970a
+	  device. Such device supports 5 different protocols: ISO14443A,
+	  ISO14443B, FeLiCa, ISO15693 and ISO18000-3.
+
+	  Say Y here to compile support for TRF7970a into the kernel or
+	  say M  to compile it as a module. The module will be called
+	  trf7970a.ko.
+
+config NFC_MEI_PHY
+	tristate "MEI bus NFC device support"
+	depends on INTEL_MEI && NFC_HCI
+	help
+	  This adds support to use an mei bus nfc device. Select this if you
+	  will use an HCI NFC driver for an NFC chip connected behind an
+	  Intel's Management Engine chip.
+
+	  If unsure, say N.
+
+config NFC_SIM
+	tristate "NFC hardware simulator driver"
+	depends on NFC_DIGITAL
+	help
+	  This driver declares two virtual NFC devices supporting NFC-DEP
+	  protocol. An LLCP connection can be established between them and
+	  all packets sent from one device is sent back to the other, acting as
+	  loopback devices.
+
+	  If unsure, say N.
+
+config NFC_PORT100
+	tristate "Sony NFC Port-100 Series USB device support"
+	depends on USB
+	depends on NFC_DIGITAL
+	help
+	  This adds support for Sony Port-100 chip based USB devices such as the
+	  RC-S380 dongle.
+
+	  If unsure, say N.
+
+config NFC_VIRTUAL_NCI
+	tristate "NCI device simulator driver"
+	depends on NFC_NCI
+	help
+	  NCI virtual device simulates a NCI device to the user.
+	  It can be used to validate the NCI module and applications.
+	  This driver supports communication between the virtual NCI device and
+	  module.
+
+	  If unsure, say N.
+
+source "drivers/nfc/fdp/Kconfig"
+source "drivers/nfc/pn544/Kconfig"
+source "drivers/nfc/pn533/Kconfig"
+source "drivers/nfc/microread/Kconfig"
+source "drivers/nfc/nfcmrvl/Kconfig"
+source "drivers/nfc/st21nfca/Kconfig"
+source "drivers/nfc/st-nci/Kconfig"
+source "drivers/nfc/nxp-nci/Kconfig"
+source "drivers/nfc/s3fwrn5/Kconfig"
+source "drivers/nfc/st95hf/Kconfig"
+endmenu