linux-drivers/
drivers/dma/amd/ptdma

AMD PassThru DMA (PTDMA) engine on EPYC Embedded 7002 platforms

A built-in DMA copy engine found on AMD EPYC Embedded 7002 series server processors, exposed as a PCI device (vendor/device 1022:1498). It is mainly used to move data across AMD's Non-Transparent Bridge in embedded server and storage appliances, where two systems share memory over PCIe.

keep conf=0.84 deploy=low replacement=none subsystem=dma category=bus-other
84%

recommendation

It should stay in the kernel because the underlying silicon is still part of an AMD EPYC Embedded product line that was being sold new through 2025, and the code is still receiving upstream bug-fix patches as recently as April 2025. Real-world deployments are narrow — primarily Non-Transparent Bridge setups in embedded servers — but no other driver covers this hardware block, so removing it would strand existing users.

repository signals

6 files
1,692 source lines
10 commits, 5y
+1,777 / −75 lines added / removed, 5y
2 authors, 5y
monthly commits · 2021-04-21 → 2026-04-21 · 10 total · active in 3/61 months
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sources

  1. spinics.net

    PTDMA still received upstream patch traffic in April 2025, indicating active maintenance rather than removal.

  2. spinics.net

    PTDMA had dmaengine bug-fix traffic in February 2024, showing recent functional maintenance.

  3. cateee.net

    LKDDb maps CONFIG_AMD_PTDMA to PCI device 1022:1498 and describes it as AMD PassThru DMA for AMD Non-Transparent Bridge use, a niche deployment profile.

  4. amd.com

    AMD still listed EPYC Embedded 7002 products with NTB support and extended availability on a page crawled in 2026, supporting continued new-sales presence through 2025.

codex reasoning notes (technical)

Local source inspection (shell `rg`/`sed`) shows a real PCI driver with `MODULE_DESCRIPTION("AMD PassThru DMA driver")` and PCI ID 1022:1498 in `ptdma-pci.c`. `lei`/lore MCP were unavailable here, so lore evidence was approximated via web search fallback: spinics patch mirrors found 2024-02 and 2025-04 PTDMA fixes, with no removal discussion hits. LKDDb was found by web search and used for device/use-case mapping. AMD's EPYC Embedded 7002 product page was found by web search and used to justify `hardware_still_sold_new_in_2025=true`; deployments remain low because PTDMA is tied to NTB/niche server-embedded use rather than broad commodity peripherals. No natural upstream replacement driver covers the same hardware block.