Re: [PATCH v6 03/18] PCI/P2PDMA: Derive routing from directional ACS controls

[Leon Romanovsky]

On Fri, Sep 18, 2026 at 01:39:55PM -0600, Logan Gunthorpe wrote:
> 
> 
> On 2026-09-14 05:22, Leon Romanovsky wrote:
> > From: Leon Romanovsky <leonro@xxxxxxxxxx>
> > 
> > pci_bridge_has_acs_redir() treats Request and Completion Redirect as
> > interchangeable. On asymmetric fabrics, a control for only the reverse TLP
> > direction can unnecessarily force P2PDMA through the host bridge.
> > 
> > Evaluate Request Redirect for client Requests and Completion Redirect for
> > provider read Completions. Continue treating enabled Egress Control
> > conservatively as a Request redirect.
> > 
> > Fixes: 52916982af48 ("PCI/P2PDMA: Support peer-to-peer memory")
> > Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
> 
> Core patch seems fine, minus one minor point below:
> 
> Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
> 
> > @@ -1132,10 +1173,10 @@ EXPORT_SYMBOL_GPL(pci_p2pmem_publish);
> >  /**
> >   * pci_p2pdma_map_type - Determine the mapping type for P2PDMA transfers
> >   * @provider: P2PDMA provider structure
> > - * @dev: Target device for the transfer
> > + * @dev: Client device that initiates the transfer
> >   *
> >   * Determines how peer-to-peer DMA transfers should be mapped between
> > - * the provider and the target device. The mapping type indicates whether
> > + * the provider and the client device. The mapping type indicates whether
> >   * the transfer can be done directly through PCI switches or must go
> >   * through the host bridge.
> >   */
> > 
> 
> This hunk does not seem like it belongs in this patch.

This is the first patch that distinguishes between client and provider
and starts using that terminology instead of target/initiator. Therefore,
the change belongs here.

Thanks