Re: [PATCH 03/14] PCI/P2PDMA: Apply host bridge white list for ACS

Koenig, Christian
2019-07-23T16:23:31Z

Am 23.07.19 um 01:08 schrieb Logan Gunthorpe:
> When a P2PDMA transfer is rejected due to ACS being set, we
> can also check the white list and allow the transactions.
>
> Do this by pushing the whitelist check into the
> upstream_bridge_distance() function.
>
> Signed-off-by: Logan Gunthorpe <logang@deltatee.com>

This one and patch #2 are Reviewed-by: Christian König
<christian.koenig@amd.com>.

But I actually think the two patches could be merged.

Christian.

> ---
> drivers/pci/p2pdma.c | 25 ++++++++++++++-----------
> 1 file changed, 14 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
> index 289d03a31e7d..d5034e28d1e1 100644
> --- a/drivers/pci/p2pdma.c
> +++ b/drivers/pci/p2pdma.c
> @@ -324,15 +324,7 @@ static int __upstream_bridge_distance(struct pci_dev *provider,
> dist_a++;
> }
>
> - /*
> - * Allow the connection if both devices are on a whitelisted root
> - * complex, but add an arbitrary large value to the distance.
> - */
> - if (root_complex_whitelist(provider) &&
> - root_complex_whitelist(client))
> - return (dist_a + dist_b) | P2PDMA_THRU_HOST_BRIDGE;
> -
> - return (dist_a + dist_b) | P2PDMA_NOT_SUPPORTED;
> + return (dist_a + dist_b) | P2PDMA_THRU_HOST_BRIDGE;
>
> check_b_path_acs:
> bb = b;
> @@ -350,7 +342,8 @@ static int __upstream_bridge_distance(struct pci_dev *provider,
> }
>
> if (acs_cnt)
> - return P2PDMA_NOT_SUPPORTED | P2PDMA_ACS_FORCES_UPSTREAM;
> + return (dist_a + dist_b) | P2PDMA_ACS_FORCES_UPSTREAM |
> + P2PDMA_THRU_HOST_BRIDGE;
>
> return dist_a + dist_b;
> }
> @@ -397,7 +390,17 @@ static int upstream_bridge_distance(struct pci_dev *provider,
> struct pci_dev *client,
> struct seq_buf *acs_list)
> {
> - return __upstream_bridge_distance(provider, client, acs_list);
> + int dist;
> +
> + dist = __upstream_bridge_distance(provider, client, acs_list);
> +
> + if (!(dist & P2PDMA_THRU_HOST_BRIDGE))
> + return dist;
> +
> + if (root_complex_whitelist(provider) && root_complex_whitelist(client))
> + return dist;
> +
> + return dist | P2PDMA_NOT_SUPPORTED;
> }
>
> static int upstream_bridge_distance_warn(struct pci_dev *provider,