This series adds support for the Non-Transparent Bridge (NTB) endpoints integrated in AMD EPYC Embedded "Turin", "Genoa" and "Siena" processors to the raw/ntb driver.
The NTB rawdev framework was originally written around the Intel back-to-back topology and the built-in scratchpad handshake protocol. Patch 1 generalizes it with a few vendor-neutral hooks so other vendors can reuse the common code; the Intel driver is unaffected since the new hooks fall back to the built-in paths when NULL. Patch 2 adds the AMD hardware driver, and patch 3 documents the new support. A few AMD-specific hardware details worth noting for reviewers: - Primary/secondary topology. One endpoint enumerates as the primary (device ID 0x14c0) and the other as the secondary (0x14c3), rather than the Intel back-to-back model. - Packed scratchpad handshake. The hardware exposes a single shared 16-register scratchpad bank split into two disjoint 8-register sets (one per side), so the driver uses a packed handshake layout that fits in 8 registers, plugged in through the dev_handshake and read_peer_config hooks. - Outbound translation window. AMD NTB uses an outbound translation window: a write to a BARxx memory-window offset is forwarded to (xlat_base | offset) in the peer's memory rather than (xlat_base + offset). The translation base must therefore be aligned to a power of two >= the window length so that no offset bit collides with a set bit in the base. This is reported to applications through a new mw_addr_align field in struct ntb_dev_info and honoured by the ntb example when reserving the memory window memzone. - Secondary-side link status. On the secondary side the device's own PCIe link status does not reflect the true inter-host link, so the speed and width are read from the upstream switch port via sysfs. Tested on a two-node setup (primary + secondary EPYC Embedded hosts) with the dpdk-ntb example: the link comes up at the expected speed and width on both sides, and file transfers are byte-correct end to end for both small and large files. Raghavendra Ningoji (3): raw/ntb: generalize framework for multiple vendors raw/ntb: add AMD NTB support doc: add AMD NTB support MAINTAINERS | 1 + doc/guides/rawdevs/ntb.rst | 18 +- doc/guides/rel_notes/release_26_11.rst | 8 + drivers/raw/ntb/meson.build | 3 +- drivers/raw/ntb/ntb.c | 115 ++-- drivers/raw/ntb/ntb.h | 18 + drivers/raw/ntb/ntb_hw_amd.c | 709 +++++++++++++++++++++++++ drivers/raw/ntb/ntb_hw_amd.h | 114 ++++ drivers/raw/ntb/rte_pmd_ntb.h | 10 + examples/ntb/ntb_fwd.c | 22 +- usertools/dpdk-devbind.py | 4 +- 11 files changed, 985 insertions(+), 37 deletions(-) create mode 100644 drivers/raw/ntb/ntb_hw_amd.c create mode 100644 drivers/raw/ntb/ntb_hw_amd.h -- 2.34.1
