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, 46 insertions, 0 deletions

diff --git a/drivers/acpi/dptf/Kconfig b/drivers/acpi/dptf/Kconfig
new file mode 100644
index 000000000..4b3fdc03e
--- /dev/null
+++ b/drivers/acpi/dptf/Kconfig
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: GPL-2.0
+
+menuconfig ACPI_DPTF
+	bool "Intel DPTF (Dynamic Platform and Thermal Framework) Support"
+	depends on X86
+	help
+	  Intel Dynamic Platform and Thermal Framework (DPTF) is a platform
+	  level hardware/software solution for power and thermal management.
+
+	  As a container for multiple power/thermal technologies, DPTF provides
+	  a coordinated approach for different policies to effect the hardware
+	  state of a system.
+
+if ACPI_DPTF
+
+config DPTF_POWER
+	tristate "Platform Power DPTF Participant"
+	default m
+	help
+	  This driver adds support for Dynamic Platform and Thermal Framework
+	  (DPTF) Platform Power Participant device (INT3407) support.
+	  This participant is responsible for exposing platform telemetry:
+		max_platform_power
+		platform_power_source
+		adapter_rating
+		battery_steady_power
+		charger_type
+
+	  To compile this driver as a module, choose M here:
+	  the module will be called dptf_power.
+
+config DPTF_PCH_FIVR
+	tristate "PCH FIVR DPTF Participant"
+	default m
+	help
+	  This driver adds support for Dynamic Platform and Thermal Framework
+	  (DPTF) PCH FIVR Participant device support. This driver allows to
+	  switch the PCH FIVR (Fully Integrated Voltage Regulator) frequency.
+	  This participant is responsible for exposing:
+		freq_mhz_low_clock
+		freq_mhz_high_clock
+
+	  To compile this driver as a module, choose M here:
+	  the module will be called dptf_pch_fivr.
+
+endif