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, 124 insertions, 0 deletions

diff --git a/drivers/message/fusion/Kconfig b/drivers/message/fusion/Kconfig
new file mode 100644
index 000000000..88a6e506a
--- /dev/null
+++ b/drivers/message/fusion/Kconfig
@@ -0,0 +1,124 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menuconfig FUSION
+	bool "Fusion MPT device support"
+	depends on PCI && HAS_IOPORT
+	help
+	Say Y here to get to see options for Fusion Message
+	Passing Technology (MPT) drivers.
+	This option alone does not add any kernel code.
+
+	If you say N, all options in this submenu will be skipped and disabled.
+
+if FUSION
+
+config FUSION_SPI
+	tristate "Fusion MPT ScsiHost drivers for SPI"
+	depends on PCI && SCSI
+	select SCSI_SPI_ATTRS
+	help
+	  SCSI HOST support for a parallel SCSI host adapters.
+
+	  List of supported controllers:
+
+	  LSI53C1020
+	  LSI53C1020A
+	  LSI53C1030
+	  LSI53C1035
+	  ATTO UL4D
+
+config FUSION_FC
+	tristate "Fusion MPT ScsiHost drivers for FC"
+	depends on PCI && SCSI
+	depends on SCSI_FC_ATTRS
+	help
+	  SCSI HOST support for a Fiber Channel host adapters.
+
+	  List of supported controllers:
+
+	  LSIFC909
+	  LSIFC919
+	  LSIFC919X
+	  LSIFC929
+	  LSIFC929X
+	  LSIFC929XL
+	  LSIFC949X
+	  LSIFC949E
+	  Brocade FC 410/420
+
+config FUSION_SAS
+	tristate "Fusion MPT ScsiHost drivers for SAS"
+	depends on PCI && SCSI
+	select SCSI_SAS_ATTRS
+	help
+	  SCSI HOST support for a SAS host adapters.
+
+	  List of supported controllers:
+
+	  LSISAS1064
+	  LSISAS1068
+	  LSISAS1064E
+	  LSISAS1068E
+	  LSISAS1078
+
+config FUSION_MAX_SGE
+	int "Maximum number of scatter gather entries (16 - 128)"
+	default "128"
+	range 16 128
+	help
+	  This option allows you to specify the maximum number of scatter-
+	  gather entries per I/O. The driver default is 128, which matches
+	  SCSI_MAX_PHYS_SEGMENTS. However, it may decreased down to 16.
+	  Decreasing this parameter will reduce memory requirements
+	  on a per controller instance.
+
+config FUSION_CTL
+	tristate "Fusion MPT misc device (ioctl) driver"
+	depends on FUSION_SPI || FUSION_FC || FUSION_SAS
+	help
+	  The Fusion MPT misc device driver provides specialized control
+	  of MPT adapters via system ioctl calls.  Use of ioctl calls to
+	  the MPT driver requires that you create and use a misc device
+	  node ala:
+	  mknod /dev/mptctl c 10 240
+
+	  One use of this ioctl interface is to perform an upgrade (reflash)
+	  of the MPT adapter firmware.  Refer to readme file(s) distributed
+	  with the Fusion MPT linux driver for additional details.
+
+	  If enabled by saying M to this, a driver named: mptctl
+	  will be compiled.
+
+	  If unsure whether you really want or need this, say N.
+
+config FUSION_LAN
+	tristate "Fusion MPT LAN driver"
+	depends on FUSION_FC && NET_FC
+	help
+	  This module supports LAN IP traffic over Fibre Channel port(s)
+	  on Fusion MPT compatible hardware (LSIFC9xx chips).
+	  The physical interface used is defined in RFC 2625.
+	  Please refer to that document for details.
+
+	  Installing this driver requires the knowledge to configure and
+	  activate a new network interface, "fc0", using standard Linux tools.
+
+	  If enabled by saying M to this, a driver named: mptlan
+	  will be compiled.
+
+	  If unsure whether you really want or need this, say N.
+
+config FUSION_LOGGING
+	bool "Fusion MPT logging facility"
+	help
+	  This turns on a logging facility that can be used to debug a number
+	  of Fusion MPT related problems.
+
+	  The debug level can be programmed on the fly via SysFS (hex values)
+
+	  echo [level] > /sys/class/scsi_host/host#/debug_level
+
+	  There are various debug levels that can be found in the source:
+	  file:drivers/message/fusion/mptdebug.h
+
+endif # FUSION