Re: [PATCH 05/13] PCI: Add ACS egress control vector accessor

Logan Gunthorpe <[email protected]> Tue, 4 Aug 2026 15:55:43 -0600
Newsgroups gmane.linux.kernel,gmane.linux.kernel.pci,gmane.linux.documentation
Message-ID <[email protected]>

On 2026-08-02 09:09, Leon Romanovsky wrote:
> From: Leon Romanovsky <[email protected]>
> 
> Whether ACS P2P Egress Control routes, redirects, or blocks a peer-to-peer
> request depends on the Egress Control Vector bit for the target port, not
> on the enable bit alone (PCIe r7.0, sec 6.12.3).
> 
> Provide a helper to read that bit for a peer Root or Switch Downstream
> Port. Report an unreadable or uncovered vector as an error rather than as
> a clear bit, so callers do not mistake it for permission to route
> directly.
> 
> Signed-off-by: Leon Romanovsky <[email protected]>

Reviewed-by: Logan Gunthorpe <[email protected]>