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, 230 insertions, 0 deletions

diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
new file mode 100644
index 000000000..23b4b7400
--- /dev/null
+++ b/net/dsa/Kconfig
@@ -0,0 +1,230 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menuconfig NET_DSA
+	tristate "Distributed Switch Architecture"
+	depends on BRIDGE || BRIDGE=n
+	depends on HSR || HSR=n
+	depends on INET && NETDEVICES
+	select GRO_CELLS
+	select NET_SWITCHDEV
+	select PHYLINK
+	select NET_DEVLINK
+	imply NET_SELFTESTS
+	help
+	  Say Y if you want to enable support for the hardware switches supported
+	  by the Distributed Switch Architecture.
+
+if NET_DSA
+
+# Drivers must select the appropriate tagging format(s)
+
+config NET_DSA_TAG_NONE
+	tristate "No-op tag driver"
+	help
+	  Say Y or M if you want to enable support for switches which don't tag
+	  frames over the CPU port.
+
+config NET_DSA_TAG_AR9331
+	tristate "Tag driver for Atheros AR9331 SoC with built-in switch"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  the Atheros AR9331 SoC with built-in switch.
+
+config NET_DSA_TAG_BRCM_COMMON
+	tristate
+	default n
+
+config NET_DSA_TAG_BRCM
+	tristate "Tag driver for Broadcom switches using in-frame headers"
+	select NET_DSA_TAG_BRCM_COMMON
+	help
+	  Say Y if you want to enable support for tagging frames for the
+	  Broadcom switches which place the tag after the MAC source address.
+
+config NET_DSA_TAG_BRCM_LEGACY
+	tristate "Tag driver for BCM63xx legacy switches using in-frame headers"
+	select NET_DSA_TAG_BRCM_COMMON
+	help
+	  Say Y if you want to enable support for tagging frames for the
+	  BCM63xx legacy switches which place the tag after the MAC source
+	  address.
+	  This tag is used in BCM63xx legacy switches which work without the
+	  original FCS and length before the tag insertion.
+
+config NET_DSA_TAG_BRCM_LEGACY_FCS
+	tristate "Tag driver for BCM53xx legacy switches using in-frame headers"
+	select NET_DSA_TAG_BRCM_COMMON
+	help
+	  Say Y if you want to enable support for tagging frames for the
+	  BCM53xx legacy switches which place the tag after the MAC source
+	  address.
+	  This tag is used in BCM53xx legacy switches which expect original
+	  FCS and length before the tag insertion to be present.
+
+config NET_DSA_TAG_BRCM_PREPEND
+	tristate "Tag driver for Broadcom switches using prepended headers"
+	select NET_DSA_TAG_BRCM_COMMON
+	help
+	  Say Y if you want to enable support for tagging frames for the
+	  Broadcom switches which places the tag before the Ethernet header
+	  (prepended).
+
+config NET_DSA_TAG_HELLCREEK
+	tristate "Tag driver for Hirschmann Hellcreek TSN switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames
+	  for the Hirschmann Hellcreek TSN switches.
+
+config NET_DSA_TAG_GSWIP
+	tristate "Tag driver for Lantiq / Intel GSWIP switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for the
+	  Lantiq / Intel GSWIP switches.
+
+config NET_DSA_TAG_DSA_COMMON
+	tristate
+
+config NET_DSA_TAG_DSA
+	tristate "Tag driver for Marvell switches using DSA headers"
+	select NET_DSA_TAG_DSA_COMMON
+	help
+	  Say Y or M if you want to enable support for tagging frames for the
+	  Marvell switches which use DSA headers.
+
+config NET_DSA_TAG_EDSA
+	tristate "Tag driver for Marvell switches using EtherType DSA headers"
+	select NET_DSA_TAG_DSA_COMMON
+	help
+	  Say Y or M if you want to enable support for tagging frames for the
+	  Marvell switches which use EtherType DSA headers.
+
+config NET_DSA_TAG_MT7628
+	tristate "Tag driver for the MT7628 embedded switch"
+	help
+	  Say Y or M if you want to enable support for tagging frames for the
+	  switch embedded in the MT7628 SoC.
+
+config NET_DSA_TAG_MTK
+	tristate "Tag driver for Mediatek switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  Mediatek switches.
+
+config NET_DSA_TAG_MXL_862XX
+	tristate "Tag driver for MaxLinear MxL862xx switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for the
+	  MaxLinear MxL86252 and MxL86282 switches using their native 8-byte
+	  tagging protocol.
+
+config NET_DSA_TAG_MXL_GSW1XX
+	tristate "Tag driver for MaxLinear GSW1xx switches"
+	help
+	  The GSW1xx family of switches supports an 8-byte special tag which
+	  can be used on the CPU port of the switch.
+	  Say Y or M if you want to enable support for tagging frames for
+	  MaxLinear GSW1xx switches.
+
+config NET_DSA_TAG_KSZ
+	tristate "Tag driver for Microchip 8795/937x/9477/9893 families of switches"
+	help
+	  Say Y if you want to enable support for tagging frames for the
+	  Microchip 8795/937x/9477/9893 families of switches.
+
+config NET_DSA_TAG_NETC
+	tristate "Tag driver for NXP NETC switches"
+	help
+	  Say Y or M if you want to enable support for the NXP Switch Tag (NST),
+	  as implemented by NXP NETC switches having version 4.3 or later. The
+	  switch tag is a proprietary header added to frames after the source
+	  MAC address, it has 3 types and each type has different subtypes, so
+	  its length depends on the type and subtype of the tag, the maximum
+	  length is 14 bytes.
+
+config NET_DSA_TAG_OCELOT
+	tristate "Tag driver for Ocelot family of switches, using NPI port"
+	select PACKING
+	help
+	  Say Y or M if you want to enable NPI tagging for the Ocelot switches
+	  (VSC7511, VSC7512, VSC7513, VSC7514, VSC9953, VSC9959). In this mode,
+	  the frames over the Ethernet CPU port are prepended with a
+	  hardware-defined injection/extraction frame header.  Flow control
+	  (PAUSE frames) over the CPU port is not supported when operating in
+	  this mode.
+
+config NET_DSA_TAG_OCELOT_8021Q
+	tristate "Tag driver for Ocelot family of switches, using VLAN"
+	help
+	  Say Y or M if you want to enable support for tagging frames with a
+	  custom VLAN-based header. Frames that require timestamping, such as
+	  PTP, are not delivered over Ethernet but over register-based MMIO.
+	  Flow control over the CPU port is functional in this mode. When using
+	  this mode, less TCAM resources (VCAP IS1, IS2, ES0) are available for
+	  use with tc-flower.
+
+config NET_DSA_TAG_QCA
+	tristate "Tag driver for Qualcomm Atheros QCA8K switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  the Qualcomm Atheros QCA8K switches.
+
+config NET_DSA_TAG_RTL4_A
+	tristate "Tag driver for Realtek 4 byte protocol A tags"
+	help
+	  Say Y or M if you want to enable support for tagging frames for the
+	  Realtek switches with 4 byte protocol A tags, such as found in
+	  the Realtek RTL8366RB.
+
+config NET_DSA_TAG_RTL8_4
+	tristate "Tag driver for Realtek 8 byte protocol 4 tags"
+	help
+	  Say Y or M if you want to enable support for tagging frames for Realtek
+	  switches with 8 byte protocol 4 tags, such as the Realtek RTL8365MB-VC.
+
+config NET_DSA_TAG_RZN1_A5PSW
+	tristate "Tag driver for Renesas RZ/N1 A5PSW switch"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  Renesas RZ/N1 embedded switch that uses an 8 byte tag located after
+	  destination MAC address.
+
+config NET_DSA_TAG_LAN9303
+	tristate "Tag driver for SMSC/Microchip LAN9303 family of switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for the
+	  SMSC/Microchip LAN9303 family of switches.
+
+config NET_DSA_TAG_SJA1105
+	tristate "Tag driver for NXP SJA1105 switches"
+	select PACKING
+	help
+	  Say Y or M if you want to enable support for tagging frames with the
+	  NXP SJA1105 switch family. Both the native tagging protocol (which
+	  is only for link-local traffic) as well as non-native tagging (based
+	  on a custom 802.1Q VLAN header) are available.
+
+config NET_DSA_TAG_TRAILER
+	tristate "Tag driver for switches using a trailer tag"
+	help
+	  Say Y or M if you want to enable support for tagging frames at
+	  with a trailed. e.g. Marvell 88E6060.
+
+config NET_DSA_TAG_VSC73XX_8021Q
+	tristate "Tag driver for Microchip/Vitesse VSC73xx family of switches, using VLAN"
+	help
+	  Say Y or M if you want to enable support for tagging frames with a
+	  custom VLAN-based header.
+
+config NET_DSA_TAG_XRS700X
+	tristate "Tag driver for XRS700x switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  Arrow SpeedChips XRS700x switches that use a single byte tag trailer.
+
+config NET_DSA_TAG_YT921X
+	tristate "Tag driver for Motorcomm YT921x switches"
+	help
+	  Say Y or M if you want to enable support for tagging frames for
+	  Motorcomm YT921x switches.
+
+endif