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, 198 insertions, 0 deletions

diff --git a/drivers/soc/tegra/Kconfig b/drivers/soc/tegra/Kconfig
new file mode 100644
index 000000000..8b6fdb9ad
--- /dev/null
+++ b/drivers/soc/tegra/Kconfig
@@ -0,0 +1,198 @@
+# SPDX-License-Identifier: GPL-2.0-only
+if ARCH_TEGRA
+
+# 32-bit ARM SoCs
+if ARM
+
+config ARCH_TEGRA_2x_SOC
+	bool "Enable support for Tegra20 family"
+	default ARCH_TEGRA
+	select ARCH_NEEDS_CPU_IDLE_COUPLED if SMP
+	select ARM_ERRATA_720789
+	select ARM_ERRATA_754327 if SMP
+	select ARM_ERRATA_764369 if SMP
+	select PINCTRL_TEGRA20
+	select PL310_ERRATA_727915 if CACHE_L2X0
+	select PL310_ERRATA_769419 if CACHE_L2X0
+	select SOC_TEGRA_FLOWCTRL
+	select SOC_TEGRA_PMC
+	select SOC_TEGRA20_VOLTAGE_COUPLER if REGULATOR
+	select TEGRA_TIMER
+	help
+	  Support for NVIDIA Tegra AP20 and T20 processors, based on the
+	  ARM CortexA9MP CPU and the ARM PL310 L2 cache controller
+
+config ARCH_TEGRA_3x_SOC
+	bool "Enable support for Tegra30 family"
+	default ARCH_TEGRA
+	select ARM_ERRATA_754322
+	select ARM_ERRATA_764369 if SMP
+	select PINCTRL_TEGRA30
+	select PL310_ERRATA_769419 if CACHE_L2X0
+	select SOC_TEGRA_FLOWCTRL
+	select SOC_TEGRA_PMC
+	select SOC_TEGRA30_VOLTAGE_COUPLER if REGULATOR
+	select TEGRA_TIMER
+	help
+	  Support for NVIDIA Tegra T30 processor family, based on the
+	  ARM CortexA9MP CPU and the ARM PL310 L2 cache controller
+
+config ARCH_TEGRA_114_SOC
+	bool "Enable support for Tegra114 family"
+	default ARCH_TEGRA
+	select ARM_ERRATA_798181 if SMP
+	select HAVE_ARM_ARCH_TIMER
+	select PINCTRL_TEGRA114
+	select SOC_TEGRA_FLOWCTRL
+	select SOC_TEGRA_PMC
+	select TEGRA_TIMER
+	help
+	  Support for NVIDIA Tegra T114 processor family, based on the
+	  ARM CortexA15MP CPU
+
+config ARCH_TEGRA_124_SOC
+	bool "Enable support for Tegra124 family"
+	default ARCH_TEGRA
+	select HAVE_ARM_ARCH_TIMER
+	select PINCTRL_TEGRA124
+	select SOC_TEGRA_FLOWCTRL
+	select SOC_TEGRA_PMC
+	select TEGRA_TIMER
+	help
+	  Support for NVIDIA Tegra T124 processor family, based on the
+	  ARM CortexA15MP CPU
+
+endif
+
+# 64-bit ARM SoCs
+if ARM64
+
+config ARCH_TEGRA_132_SOC
+	bool "NVIDIA Tegra132 SoC"
+	default ARCH_TEGRA
+	select PINCTRL_TEGRA124
+	select SOC_TEGRA_FLOWCTRL
+	select SOC_TEGRA_PMC
+	help
+	  Enable support for NVIDIA Tegra132 SoC, based on the Denver
+	  ARMv8 CPU.  The Tegra132 SoC is similar to the Tegra124 SoC,
+	  but contains an NVIDIA Denver CPU complex in place of
+	  Tegra124's "4+1" Cortex-A15 CPU complex.
+
+config ARCH_TEGRA_210_SOC
+	bool "NVIDIA Tegra210 SoC"
+	default ARCH_TEGRA
+	select PINCTRL_TEGRA210
+	select SOC_TEGRA_FLOWCTRL
+	select SOC_TEGRA_PMC
+	select TEGRA_TIMER
+	help
+	  Enable support for the NVIDIA Tegra210 SoC. Also known as Tegra X1,
+	  the Tegra210 has four Cortex-A57 cores paired with four Cortex-A53
+	  cores in a switched configuration. It features a GPU of the Maxwell
+	  architecture with support for DX11, SM4, OpenGL 4.5, OpenGL ES 3.1
+	  and providing 256 CUDA cores. It supports hardware-accelerated en-
+	  and decoding of various video standards including H.265, H.264 and
+	  VP8 at 4K resolution and up to 60 fps.
+
+	  Besides the multimedia features it also comes with a variety of I/O
+	  controllers, such as GPIO, I2C, SPI, SDHCI, PCIe, SATA and XHCI, to
+	  name only a few.
+
+config ARCH_TEGRA_186_SOC
+	bool "NVIDIA Tegra186 SoC"
+	default ARCH_TEGRA
+	depends on !CPU_BIG_ENDIAN
+	select PINCTRL_TEGRA186
+	select MAILBOX
+	select SOC_TEGRA_PMC
+	help
+	  Enable support for the NVIDIA Tegar186 SoC. The Tegra186 features a
+	  combination of Denver and Cortex-A57 CPU cores and a GPU based on
+	  the Pascal architecture. It contains an ADSP with a Cortex-A9 CPU
+	  used for audio processing, hardware video encoders/decoders with
+	  multi-format support, ISP for image capture processing and BPMP for
+	  power management.
+
+config ARCH_TEGRA_194_SOC
+	bool "NVIDIA Tegra194 SoC"
+	default ARCH_TEGRA
+	depends on !CPU_BIG_ENDIAN
+	select MAILBOX
+	select PINCTRL_TEGRA194
+	select SOC_TEGRA_PMC
+	help
+	  Enable support for the NVIDIA Tegra194 SoC.
+
+config ARCH_TEGRA_234_SOC
+	bool "NVIDIA Tegra234 SoC"
+	default ARCH_TEGRA
+	depends on !CPU_BIG_ENDIAN
+	select MAILBOX
+	select PINCTRL_TEGRA234
+	select SOC_TEGRA_PMC
+	help
+	  Enable support for the NVIDIA Tegra234 SoC.
+
+config ARCH_TEGRA_238_SOC
+	bool "NVIDIA Tegra238 SoC"
+	default ARCH_TEGRA
+	depends on !CPU_BIG_ENDIAN
+	select MAILBOX
+	select SOC_TEGRA_PMC
+	help
+	  Enable support for the NVIDIA Tegra238 SoC.
+
+config ARCH_TEGRA_241_SOC
+	bool "NVIDIA Tegra241 SoC"
+	default ARCH_TEGRA
+	help
+	  Enable support for the NVIDIA Tegra241 SoC.
+
+config ARCH_TEGRA_264_SOC
+	bool "NVIDIA Tegra264 SoC"
+	default ARCH_TEGRA
+	depends on !CPU_BIG_ENDIAN
+	select MAILBOX
+	select SOC_TEGRA_PMC
+	help
+	  Enable support for the NVIDIA Tegra264 SoC.
+
+endif
+endif
+
+config SOC_TEGRA_FUSE
+	def_bool y
+	depends on ARCH_TEGRA
+	select SOC_BUS
+
+config SOC_TEGRA_FLOWCTRL
+	bool
+
+config SOC_TEGRA_PMC
+	bool
+	depends on PM
+	select GENERIC_PINCONF
+	select IRQ_DOMAIN_HIERARCHY
+	select PM_OPP
+	select PM_GENERIC_DOMAINS
+	select REGMAP
+
+config SOC_TEGRA20_VOLTAGE_COUPLER
+	bool "Voltage scaling support for Tegra20 SoCs"
+	depends on ARCH_TEGRA_2x_SOC || COMPILE_TEST
+	depends on REGULATOR
+
+config SOC_TEGRA30_VOLTAGE_COUPLER
+	bool "Voltage scaling support for Tegra30 SoCs"
+	depends on ARCH_TEGRA_3x_SOC || COMPILE_TEST
+	depends on REGULATOR
+
+config SOC_TEGRA_CBB
+	tristate "Tegra driver to handle error from CBB"
+	depends on ARCH_TEGRA_194_SOC || ARCH_TEGRA_234_SOC
+	default y
+	help
+	  Support for handling error from Tegra Control Backbone(CBB).
+	  This driver handles the errors from CBB and prints debug
+	  information about the failed transactions.