Messages in this thread | | | Date | Tue, 22 Jun 2021 13:16:11 +0100 | From | Will Deacon <> | Subject | Re: [PATCH net-next 2/3] net: hns3: add support for TX push mode |
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On Tue, Jun 22, 2021 at 07:11:10PM +0800, Guangbin Huang wrote: > From: Huazhong Tan <tanhuazhong@huawei.com> > > For the device that supports the TX push capability, the BD can > be directly copied to the device memory. However, due to hardware > restrictions, the push mode can be used only when there are no > more than two BDs, otherwise, the doorbell mode based on device > memory is used. > > Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com> > Signed-off-by: Yufeng Mo <moyufeng@huawei.com> > --- > drivers/net/ethernet/hisilicon/hns3/hnae3.h | 1 + > drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 83 ++++++++++++++++++++-- > drivers/net/ethernet/hisilicon/hns3/hns3_enet.h | 6 ++ > drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c | 2 + > .../net/ethernet/hisilicon/hns3/hns3pf/hclge_cmd.c | 2 + > .../ethernet/hisilicon/hns3/hns3pf/hclge_main.c | 11 ++- > .../ethernet/hisilicon/hns3/hns3pf/hclge_main.h | 8 +++ > .../ethernet/hisilicon/hns3/hns3vf/hclgevf_cmd.c | 2 + > .../ethernet/hisilicon/hns3/hns3vf/hclgevf_main.c | 11 ++- > .../ethernet/hisilicon/hns3/hns3vf/hclgevf_main.h | 8 +++ > 10 files changed, 126 insertions(+), 8 deletions(-) > > diff --git a/drivers/net/ethernet/hisilicon/hns3/hnae3.h b/drivers/net/ethernet/hisilicon/hns3/hnae3.h > index 0b202f4def83..3979d5d2e842 100644 > --- a/drivers/net/ethernet/hisilicon/hns3/hnae3.h > +++ b/drivers/net/ethernet/hisilicon/hns3/hnae3.h > @@ -163,6 +163,7 @@ struct hnae3_handle; > > struct hnae3_queue { > void __iomem *io_base; > + void __iomem *mem_base; > struct hnae3_ae_algo *ae_algo; > struct hnae3_handle *handle; > int tqp_index; /* index in a handle */ > diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c > index cdb5f14fb6bc..8649bd8e1b57 100644 > --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c > +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c > @@ -2002,9 +2002,77 @@ static int hns3_fill_skb_to_desc(struct hns3_enet_ring *ring, > return bd_num; > } > > +static void hns3_tx_push_bd(struct hns3_enet_ring *ring, int num) > +{ > +#define HNS3_BYTES_PER_64BIT 8 > + > + struct hns3_desc desc[HNS3_MAX_PUSH_BD_NUM] = {}; > + int offset = 0; > + > + /* make sure everything is visible to device before > + * excuting tx push or updating doorbell > + */ > + dma_wmb(); > + > + do { > + int idx = (ring->next_to_use - num + ring->desc_num) % > + ring->desc_num; > + > + u64_stats_update_begin(&ring->syncp); > + ring->stats.tx_push++; > + u64_stats_update_end(&ring->syncp); > + memcpy(&desc[offset], &ring->desc[idx], > + sizeof(struct hns3_desc)); > + offset++; > + } while (--num); > + > + __iowrite64_copy(ring->tqp->mem_base, desc, > + (sizeof(struct hns3_desc) * HNS3_MAX_PUSH_BD_NUM) / > + HNS3_BYTES_PER_64BIT); > + > +#if defined(CONFIG_ARM64) > + dgh(); > +#endif
It looks a bit weird putting this at the end of the function, given that it's supposed to do something to a pair of accesses. Please can you explain what it's doing, and also provide some numbers to show that it's worthwhile (given that it's a performance hint not a correctness thing afaict).
> +} > + > +static void hns3_tx_mem_doorbell(struct hns3_enet_ring *ring) > +{ > +#define HNS3_MEM_DOORBELL_OFFSET 64 > + > + __le64 bd_num = cpu_to_le64((u64)ring->pending_buf); > + > + /* make sure everything is visible to device before > + * excuting tx push or updating doorbell > + */ > + dma_wmb(); > + > + __iowrite64_copy(ring->tqp->mem_base + HNS3_MEM_DOORBELL_OFFSET, > + &bd_num, 1); > + u64_stats_update_begin(&ring->syncp); > + ring->stats.tx_mem_doorbell += ring->pending_buf; > + u64_stats_update_end(&ring->syncp); > + > +#if defined(CONFIG_ARM64) > + dgh(); > +#endif
Same here.
Thanks,
Will
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