Re: [PATCH v7 02/10] PCI: endpoint: Define endpoint DMA BAR metadata format
| Newsgroups | org.kernel.vger.dmaengine,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. > > 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. > > 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. > > Signed-off-by: Koichiro Den <[email protected]> Sashiko has reviewed this patch and found no issues. It looks great! -- Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=2