Re: [PATCH v6 1/6] PCI: endpoint: Define endpoint DMA BAR metadata format

[email protected] Tue, 04 Aug 2026 03:41:22 +0000
Newsgroups org.kernel.vger.linux-pci
Message-ID <[email protected]>
> Define the BAR-resident metadata format used by endpoint functions that
> expose an endpoint-integrated DMA controller to the host.
>=20
> A VSEC-based discovery scheme would be a natural fit, and existing
> dw-edma-pcie providers such as Synopsys EDDA and AMD (Xilinx) MDB/CPM6
> already use VSECs for DMA discovery. However, some endpoint controllers
> cannot provide enough writable configuration-space storage for a
> complete, controller-defined payload. Keep the extensible metadata in a
> BAR instead, where the endpoint function controls the layout and size.
>=20
> The format describes the DMA register window, exported channel counts,
> descriptor windows, optional auxiliary windows, endpoint-local descriptor
> and auxiliary DMA addresses, and a ready bit that tells the host when the
> described BAR windows are usable. Channel entries keep the auxiliary
> window optional so layouts that need a separate data or auxiliary aperture
> can describe it without a format bump.
>=20
> Signed-off-by: Koichiro Den <[email protected]>

Sashiko has reviewed this patch and found no issues. It looks great!

--=20
Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260804033855.2115=
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