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, 36 insertions, 0 deletions

diff --git a/drivers/i3c/Kconfig b/drivers/i3c/Kconfig
new file mode 100644
index 000000000..626c54b38
--- /dev/null
+++ b/drivers/i3c/Kconfig
@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: GPL-2.0
+
+menuconfig I3C
+	tristate "I3C support"
+	select I2C
+	help
+	  I3C is a serial protocol standardized by the MIPI alliance.
+
+	  It's supposed to be backward compatible with I2C while providing
+	  support for high speed transfers and native interrupt support
+	  without the need for extra pins.
+
+	  The I3C protocol also standardizes the slave device types and is
+	  mainly designed to communicate with sensors.
+
+	  If you want I3C support, you should say Y here and also to the
+	  specific driver for your bus adapter(s) below.
+
+	  This I3C support can also be built as a module.  If so, the module
+	  will be called i3c.
+
+if I3C
+source "drivers/i3c/master/Kconfig"
+endif # I3C
+
+config I3C_OR_I2C
+	tristate
+	default m if I3C=m
+	default I2C
+	help
+	  Device drivers using module_i3c_i2c_driver() can use either
+	  i2c or i3c hosts, but cannot be built-in for the kernel when
+	  CONFIG_I3C=m.
+
+	  Add 'depends on I2C_OR_I3C' in Kconfig for those drivers to
+	  get the correct dependencies.