Re: [PATCH v5 3/3] net/cxgb4: Use new PCI_DEV_FLAGS_NO_RELAXED_ORDERING flag

[Alexander Duyck]

On Sun, Jun 18, 2017 at 11:53 PM, Ding Tianhong <dingtianhong@xxxxxxxxxx> wrote:
> From: Casey Leedom <leedom@xxxxxxxxxxx>
>
> cxgb4 Ethernet driver now queries PCIe configuration space to determine
> if it can send TLPs to it with the Relaxed Ordering Attribute set.
>
> Signed-off-by: Casey Leedom <leedom@xxxxxxxxxxx>
> Signed-off-by: Ding Tianhong <dingtianhong@xxxxxxxxxx>
> ---
>  drivers/net/ethernet/chelsio/cxgb4/cxgb4.h      |  1 +
>  drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c | 17 +++++++++++++++++
>  drivers/net/ethernet/chelsio/cxgb4/sge.c        |  5 +++--
>  3 files changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h b/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
> index e88c180..478f25a 100644
> --- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
> +++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
> @@ -521,6 +521,7 @@ enum {                                 /* adapter flags */
>         USING_SOFT_PARAMS  = (1 << 6),
>         MASTER_PF          = (1 << 7),
>         FW_OFLD_CONN       = (1 << 9),
> +       ROOT_NO_RELAXED_ORDERING = (1 << 10),
>  };
>
>  enum {
> diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> index ea1bfcf..7cd4e1b 100644
> --- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> +++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
> @@ -4735,6 +4735,23 @@ static int init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
>         adapter->msg_enable = DFLT_MSG_ENABLE;
>         memset(adapter->chan_map, 0xff, sizeof(adapter->chan_map));
>
> +       /* If possible, we use PCIe Relaxed Ordering Attribute to deliver
> +        * Ingress Packet Data to Free List Buffers in order to allow for
> +        * chipset performance optimizations between the Root Complex and
> +        * Memory Controllers.  (Messages to the associated Ingress Queue
> +        * notifying new Packet Placement in the Free Lists Buffers will be
> +        * send without the Relaxed Ordering Attribute thus guaranteeing that
> +        * all preceding PCIe Transaction Layer Packets will be processed
> +        * first.)  But some Root Complexes have various issues with Upstream
> +        * Transaction Layer Packets with the Relaxed Ordering Attribute set.
> +        * The PCIe devices which under the Root Complexes will be cleared the
> +        * Relaxed Ordering bit in the configuration space, So we check our
> +        * PCIe configuration space to see if it's flagged with advice against
> +        * using Relaxed Ordering.
> +        */
> +       if (pcie_relaxed_ordering_supported(pdev))
> +               adapter->flags |= ROOT_NO_RELAXED_ORDERING;
> +

Looks like you have a typo here. It should be
"!pcie_relaxed_ordering_supported(pdev)" that you are testing for to
set this flag shouldn't it? Right now it appears the flag is getting
set if relaxed ordering is supported.

>         spin_lock_init(&adapter->stats_lock);
>         spin_lock_init(&adapter->tid_release_lock);
>         spin_lock_init(&adapter->win0_lock);
> diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c b/drivers/net/ethernet/chelsio/cxgb4/sge.c
> index f05f0d4..ac229a3 100644
> --- a/drivers/net/ethernet/chelsio/cxgb4/sge.c
> +++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c
> @@ -2571,6 +2571,7 @@ int t4_sge_alloc_rxq(struct adapter *adap, struct sge_rspq *iq, bool fwevtq,
>         struct fw_iq_cmd c;
>         struct sge *s = &adap->sge;
>         struct port_info *pi = netdev_priv(dev);
> +       int relaxed = !(adap->flags & ROOT_NO_RELAXED_ORDERING);
>
>         /* Size needs to be multiple of 16, including status entry. */
>         iq->size = roundup(iq->size, 16);
> @@ -2624,8 +2625,8 @@ int t4_sge_alloc_rxq(struct adapter *adap, struct sge_rspq *iq, bool fwevtq,
>
>                 flsz = fl->size / 8 + s->stat_len / sizeof(struct tx_desc);
>                 c.iqns_to_fl0congen |= htonl(FW_IQ_CMD_FL0PACKEN_F |
> -                                            FW_IQ_CMD_FL0FETCHRO_F |
> -                                            FW_IQ_CMD_FL0DATARO_F |
> +                                            FW_IQ_CMD_FL0FETCHRO_V(relaxed) |
> +                                            FW_IQ_CMD_FL0DATARO_V(relaxed) |
>                                              FW_IQ_CMD_FL0PADEN_F);
>                 if (cong >= 0)
>                         c.iqns_to_fl0congen |=
> --
> 1.9.0
>
>