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, 45 insertions, 0 deletions

diff --git a/drivers/pps/Kconfig b/drivers/pps/Kconfig
new file mode 100644
index 000000000..e1651d51c
--- /dev/null
+++ b/drivers/pps/Kconfig
@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# PPS support configuration
+#
+
+menuconfig PPS
+	tristate "PPS support"
+	help
+	  PPS (Pulse Per Second) is a special pulse provided by some GPS
+	  antennae. Userland can use it to get a high-precision time
+	  reference.
+
+	  Some antennae's PPS signals are connected with the CD (Carrier
+	  Detect) pin of the serial line they use to communicate with the
+	  host. In this case use the SERIAL_LINE client support.
+
+	  Some antennae's PPS signals are connected with some special host
+	  inputs so you have to enable the corresponding client support.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pps_core.ko.
+
+if PPS
+
+config PPS_DEBUG
+	bool "PPS debugging messages"
+	help
+	  Say Y here if you want the PPS support to produce a bunch of debug
+	  messages to the system log.  Select this if you are having a
+	  problem with PPS support and want to see more of what is going on.
+
+config NTP_PPS
+	bool "PPS kernel consumer support"
+	depends on !NO_HZ_COMMON
+	help
+	  This option adds support for direct in-kernel time
+	  synchronization using an external PPS signal.
+
+	  It doesn't work on tickless systems at the moment.
+
+source "drivers/pps/clients/Kconfig"
+
+source "drivers/pps/generators/Kconfig"
+
+endif # PPS