Re: [PATCH v6 3/6] PCI: endpoint: Add API to delegate EPC DMA channels to the host
[email protected] Tue, 04 Aug 2026 03:44:49 +0000
| Newsgroups | org.kernel.vger.linux-pci |
|---|---|
| Message-ID | <[email protected]> |
> Some endpoint functions expose an EPC-integrated DMA controller to the > host. The endpoint function should not need to know the backend-specific > mechanism used to reserve a channel locally and hand its programming > interface to the host. >=20 > Add pci_epc_delegate_dma_chan() and pci_epc_reclaim_dma_chan(). > Add matching EPC operations. The public API returns an opaque handle, > while the EPC backend keeps any private channel state. This lets generic > endpoint functions delegate channels without depending on a specific > DMAengine provider. >=20 > Let reclaim callers tell the backend whether hardware exposed to host > programming needs to be quiesced before local ownership is restored. > The quiesce may cover a provider-defined sharing group, so callers must > hold every delegated member and stop peer programming before reclaim. > Bind failure paths that only unwind local reservations can skip quiesce. >=20 > Reclaim is best-effort because it runs from teardown paths that cannot be > aborted. The backend always consumes the delegation and reports any > quiesce failure itself. The opaque handle is always freed. >=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= [email protected]?part=3D3