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 so other vendors can reuse the common code, and patch 2 adds the AMD hardware driver together with its documentation. 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 the new rte_pmd_ntb_get_mem_align() API 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. Changes since v1: - Replaced the mw_addr_align field in struct ntb_dev_info with a mem_align op and the rte_pmd_ntb_get_mem_align() API, so the base-address alignment computation lives in the driver and the application just queries it. The ntb example no longer open-codes the power-of-two/alignment logic (Bruce Richardson's review of patch 2). - Squashed the documentation, release note and MAINTAINERS update into the AMD driver patch, and documented the alignment API in the guide (2 patches instead of 3). - Minor meson.build formatting cleanup (trailing comma). - Patch 1 keeps the ntb_dev_ops hooks (interrupt_handler, dev_handshake, read_peer_config) as optional, with the built-in scratchpad path used when a hook is NULL, as discussed on the v1 thread. v1: https://patches.dpdk.org/project/dpdk/patch/[email protected]/ Raghavendra Ningoji (2): raw/ntb: generalize framework for multiple vendors raw/ntb: add AMD NTB support MAINTAINERS | 1 + doc/guides/rawdevs/ntb.rst | 28 +- doc/guides/rel_notes/release_26_11.rst | 8 + drivers/raw/ntb/meson.build | 7 +- drivers/raw/ntb/ntb.c | 122 +++-- drivers/raw/ntb/ntb.h | 22 + drivers/raw/ntb/ntb_hw_amd.c | 722 +++++++++++++++++++++++++ drivers/raw/ntb/ntb_hw_amd.h | 114 ++++ drivers/raw/ntb/ntb_hw_intel.c | 11 + drivers/raw/ntb/rte_pmd_ntb.h | 26 + examples/ntb/ntb_fwd.c | 6 +- usertools/dpdk-devbind.py | 4 +- 12 files changed, 1033 insertions(+), 38 deletions(-) create mode 100644 drivers/raw/ntb/ntb_hw_amd.c create mode 100644 drivers/raw/ntb/ntb_hw_amd.h -- 2.34.1
