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, 93 insertions, 0 deletions

diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig
new file mode 100644
index 000000000..3c76a5bf6
--- /dev/null
+++ b/drivers/base/regmap/Kconfig
@@ -0,0 +1,93 @@
+# SPDX-License-Identifier: GPL-2.0
+# Generic register map support.  There are no user servicable options here,
+# this is an API intended to be used by other kernel subsystems.  These
+# subsystems should select the appropriate symbols.
+
+config REGMAP
+	bool
+	default y if (REGMAP_I2C || REGMAP_SLIMBUS || REGMAP_SPI || REGMAP_SPMI || REGMAP_W1 || REGMAP_AC97 || REGMAP_MMIO || REGMAP_IRQ || REGMAP_SOUNDWIRE || REGMAP_SOUNDWIRE_MBQ || REGMAP_SCCB || REGMAP_I3C || REGMAP_SPI_AVMM || REGMAP_MDIO || REGMAP_FSI)
+	help
+	  Enable support for the Register Map (regmap) access API.
+
+	  Usually, this option is automatically selected when needed.
+	  However, you may want to enable it manually for running the regmap
+	  KUnit tests.
+
+	  If unsure, say N.
+
+config REGMAP_KUNIT
+	tristate "KUnit tests for regmap"
+	depends on KUNIT && REGMAP
+	default KUNIT_ALL_TESTS
+	select REGMAP_RAM
+
+config REGMAP_BUILD
+	bool "Enable regmap build"
+	depends on KUNIT
+	select REGMAP
+	help
+	  This option exists purely to allow the regmap KUnit tests to
+	  be enabled without having to enable some driver that uses
+	  regmap due to unfortunate issues with how KUnit tests are
+	  normally enabled.
+
+config REGMAP_AC97
+	tristate
+
+config REGMAP_I2C
+	tristate
+	depends on I2C
+
+config REGMAP_SLIMBUS
+	tristate
+	depends on SLIMBUS
+
+config REGMAP_SPI
+	tristate
+	depends on SPI
+
+config REGMAP_SPMI
+	tristate
+	depends on SPMI
+
+config REGMAP_W1
+	tristate
+	depends on W1
+
+config REGMAP_MDIO
+	tristate
+	depends on PHYLIB
+
+config REGMAP_MMIO
+	tristate
+
+config REGMAP_IRQ
+	bool
+	select IRQ_DOMAIN
+
+config REGMAP_RAM
+	tristate
+
+config REGMAP_SOUNDWIRE
+	tristate
+	depends on SOUNDWIRE
+
+config REGMAP_SOUNDWIRE_MBQ
+	tristate
+	depends on SOUNDWIRE
+
+config REGMAP_SCCB
+	tristate
+	depends on I2C
+
+config REGMAP_I3C
+	tristate
+	depends on I3C
+
+config REGMAP_SPI_AVMM
+	tristate
+	depends on SPI
+
+config REGMAP_FSI
+	tristate
+	depends on FSI