From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() 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 Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- Documentation/networking/bareudp.rst | 59 ++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 Documentation/networking/bareudp.rst (limited to 'Documentation/networking/bareudp.rst') diff --git a/Documentation/networking/bareudp.rst b/Documentation/networking/bareudp.rst new file mode 100644 index 000000000..621cb9575 --- /dev/null +++ b/Documentation/networking/bareudp.rst @@ -0,0 +1,59 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======================================== +Bare UDP Tunnelling Module Documentation +======================================== + +There are various L3 encapsulation standards using UDP being discussed to +leverage the UDP based load balancing capability of different networks. +MPLSoUDP (https://tools.ietf.org/html/rfc7510) is one among them. + +The Bareudp tunnel module provides a generic L3 encapsulation support for +tunnelling different L3 protocols like MPLS, IP, NSH etc. inside a UDP tunnel. + +Special Handling +---------------- + +The bareudp device supports special handling for MPLS & IP as they can have +multiple ethertypes. +The MPLS protocol can have ethertypes ETH_P_MPLS_UC (unicast) & ETH_P_MPLS_MC (multicast). +IP protocol can have ethertypes ETH_P_IP (v4) & ETH_P_IPV6 (v6). +This special handling can be enabled only for ethertypes ETH_P_IP & ETH_P_MPLS_UC +with a flag called multiproto mode. + +Usage +------ + +1) Device creation & deletion + + a) ip link add dev bareudp0 type bareudp dstport 6635 ethertype mpls_uc + + This creates a bareudp tunnel device which tunnels L3 traffic with ethertype + 0x8847 (MPLS traffic). The destination port of the UDP header will be set to + 6635.The device will listen on UDP port 6635 to receive traffic. + + b) ip link delete bareudp0 + +2) Device creation with multiproto mode enabled + +The multiproto mode allows bareudp tunnels to handle several protocols of the +same family. It is currently only available for IP and MPLS. This mode has to +be enabled explicitly with the "multiproto" flag. + + a) ip link add dev bareudp0 type bareudp dstport 6635 ethertype ipv4 multiproto + + For an IPv4 tunnel the multiproto mode allows the tunnel to also handle + IPv6. + + b) ip link add dev bareudp0 type bareudp dstport 6635 ethertype mpls_uc multiproto + + For MPLS, the multiproto mode allows the tunnel to handle both unicast + and multicast MPLS packets. + +3) Device Usage + +The bareudp device could be used along with OVS or flower filter in TC. +The OVS or TC flower layer must set the tunnel information in the SKB dst field before +sending the packet buffer to the bareudp device for transmission. On reception, the +bareUDP device extracts and stores the tunnel information in the SKB dst field before +passing the packet buffer to the network stack. -- cgit v1.3.1