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

[Ding Tianhong <dingtianhong@huawei.com>]

On 2017/6/22 2:28, Alexander Duyck wrote:
> On Sun, Jun 18, 2017 at 11:53 PM, Ding Tianhong <dingtianhong@huawei.com> wrote:
>> From: Casey Leedom <leedom@chelsio.com>
>>
>> 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@chelsio.com>
>> Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
>> ---
>>  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.
> 

Yes, I made a mistake here, thanks for correcting.

Ding

>>         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
>>
>>
> 
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