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, 103 insertions, 0 deletions

diff --git a/drivers/i3c/master/Kconfig b/drivers/i3c/master/Kconfig
new file mode 100644
index 000000000..da96d2aaa
--- /dev/null
+++ b/drivers/i3c/master/Kconfig
@@ -0,0 +1,103 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config ADI_I3C_MASTER
+	tristate "Analog Devices I3C master driver"
+	depends on HAS_IOMEM
+	help
+	  Support for Analog Devices I3C Controller IP, an AXI-interfaced IP
+	  core that supports I3C and I2C devices, multiple speed-grades and I3C
+	  IBIs.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called adi-i3c-master.
+
+config CDNS_I3C_MASTER
+	tristate "Cadence I3C master driver"
+	depends on HAS_IOMEM
+	depends on !(ALPHA || PARISC)
+	help
+	  Enable this driver if you want to support Cadence I3C master block.
+
+config DW_I3C_MASTER
+	tristate "Synospsys DesignWare I3C master driver"
+	depends on HAS_IOMEM
+	depends on !(ALPHA || PARISC)
+	# ALPHA and PARISC needs {read,write}sl()
+	help
+	  Support for Synopsys DesignWare MIPI I3C Controller.
+
+	  For details please see
+	  https://www.synopsys.com/dw/ipdir.php?ds=mipi_i3c
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called dw-i3c-master.
+
+config AST2600_I3C_MASTER
+	tristate "ASPEED AST2600 I3C master driver"
+	depends on DW_I3C_MASTER
+	depends on ARCH_ASPEED || COMPILE_TEST
+	select MFD_SYSCON
+	help
+	  Support for ASPEED AST2600 I3C Controller.
+
+	  This hardware is an instance of the DW I3C controller; this
+	  driver adds platform- specific support for AST2600 hardware.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called ast2600-i3c-master.
+
+config SVC_I3C_MASTER
+	tristate "Silvaco I3C Dual-Role Master driver"
+	depends on HAS_IOMEM
+	depends on !(ALPHA || PARISC)
+	help
+	  Support for Silvaco I3C Dual-Role Master Controller.
+
+config MIPI_I3C_HCI
+	tristate "MIPI I3C Host Controller Interface driver (EXPERIMENTAL)"
+	depends on HAS_IOMEM
+	help
+	  Support for hardware following the MIPI Aliance's I3C Host Controller
+	  Interface specification.
+
+	  For details please see:
+	  https://www.mipi.org/specifications/i3c-hci
+
+	  This driver can also be built as a module.  If so, the module will be
+	  called mipi-i3c-hci.
+
+config MIPI_I3C_HCI_PCI
+	tristate "MIPI I3C Host Controller Interface PCI support"
+	depends on MIPI_I3C_HCI
+	depends on PCI
+	select MFD_CORE
+	help
+	  Support for MIPI I3C Host Controller Interface compatible hardware
+	  on the PCI bus.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called mipi-i3c-hci-pci.
+
+config RENESAS_I3C
+	tristate "Renesas I3C controller driver"
+	depends on HAS_IOMEM
+	depends on ARCH_RENESAS || COMPILE_TEST
+	help
+	  Support the Renesas I3C controller as found in some RZ variants.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called renesas-i3c.
+
+config AMD_AXI_I3C_MASTER
+	tristate "AMD AXI I3C Master driver"
+	depends on HAS_IOMEM
+	help
+	  Support for the AMD AXI I3C master controller, a soft IP used on
+	  AMD (Xilinx) FPGAs and adaptive SoCs with ARM or MicroBlaze
+	  processors.
+
+	  The controller currently supports Standard Data Rate (SDR) mode.
+	  Features include Dynamic Address Assignment, private transfers,
+	  and CCC transfers in both broadcast and direct modes.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called amd-i3c-master.