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, 45 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-block-aoe b/Documentation/ABI/testing/sysfs-block-aoe
new file mode 100644
index 000000000..b5837765b
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-block-aoe
@@ -0,0 +1,45 @@
+What:		/sys/block/etherd*/mac
+Date:		Apr, 2005
+KernelVersion:	v2.6.12
+Contact:	Ed L. Cashin <ed.cashin@acm.org>
+Description:
+		(RO) The ethernet address of the remote Ata over Ethernet (AoE)
+		device.
+
+What:		/sys/block/etherd*/netif
+Date:		Apr, 2005
+KernelVersion:	v2.6.12
+Contact:	Ed L. Cashin <ed.cashin@acm.org>
+Description:
+		(RO) The names of the network interfaces on the localhost (comma
+		separated) through which we are communicating with the remote
+		AoE device.
+
+What:		/sys/block/etherd*/state
+Date:		Apr, 2005
+KernelVersion:	v2.6.12
+Contact:	Ed L. Cashin <ed.cashin@acm.org>
+Description:
+		(RO) Device status. The state attribute is "up" when the device
+		is ready for I/O and "down" if detected but unusable. The
+		"down,closewait" state shows that the device is still open and
+		cannot come up again until it has been closed.  The "up,kickme"
+		state means that the driver wants to send more commands to the
+		target but found out there were already the max number of
+		commands waiting for a response. It will retry again after being
+		kicked by the periodic timer handler routine.
+
+What:		/sys/block/etherd*/firmware-version
+Date:		Apr, 2005
+KernelVersion:	v2.6.12
+Contact:	Ed L. Cashin <ed.cashin@acm.org>
+Description:
+		(RO) Version of the firmware in the target.
+
+What:		/sys/block/etherd*/payload
+Date:		Dec, 2012
+KernelVersion:	v3.10
+Contact:	Ed L. Cashin <ed.cashin@acm.org>
+Description:
+		(RO) The amount of user data transferred (in bytes) inside each AoE
+		command on the network, network headers excluded.