Re: [PATCH for-next 1/4] RDMA/hns: Fix the endian problem for hns

oulijun
2018-02-01T08:14:34Z

在 2018/1/31 23:44, Doug Ledford 写道:
> On Tue, 2018-01-30 at 20:20 +0800, Lijun Ou wrote:
>> The hip06 and hip08 run on a little endian ARM, it needs to
>> revise the annotations to indicate that the HW uses little
>> endian data in the various DMA buffers, and flow the necessary
>> swaps throughout.
>>
>> The imm_data use big endian mode. The cpu_to_le32/le32_to_cpu
>> swaps are no-op for this, which makes the only substantive
>> change the handling of imm_data which is now mandatory swapped.
>>
>> This also keep match with the userspace hns driver and resolve
>> the warning by sparse.
>>
>> Signed-off-by: Lijun Ou <oulijun-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
>> ---
>> drivers/infiniband/hw/hns/hns_roce_common.h | 6 +-
>> drivers/infiniband/hw/hns/hns_roce_device.h | 2 +-
>> drivers/infiniband/hw/hns/hns_roce_hw_v1.c | 57 ++++--
>> drivers/infiniband/hw/hns/hns_roce_hw_v1.h | 258 ++++++++++++-------------
>> drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 51 +++--
>> drivers/infiniband/hw/hns/hns_roce_hw_v2.h | 283 ++++++++++++++--------------
>> drivers/infiniband/hw/hns/hns_roce_main.c | 2 +-
>> drivers/infiniband/hw/hns/hns_roce_qp.c | 18 +-
>> 8 files changed, 357 insertions(+), 320 deletions(-)
>>
>> diff --git a/drivers/infiniband/hw/hns/hns_roce_common.h b/drivers/infiniband/hw/hns/hns_roce_common.h
>> index dd67faf..319cb74 100644
>> --- a/drivers/infiniband/hw/hns/hns_roce_common.h
>> +++ b/drivers/infiniband/hw/hns/hns_roce_common.h
>> @@ -43,15 +43,15 @@
>> __raw_writel((__force u32)cpu_to_le32(value), (addr))
>>
>> #define roce_get_field(origin, mask, shift) \
>> - (((origin) & (mask)) >> (shift))
>> + (((le32_to_cpu(origin)) & (mask)) >> (shift))
>>
>> #define roce_get_bit(origin, shift) \
>> roce_get_field((origin), (1ul << (shift)), (shift))
>>
>> #define roce_set_field(origin, mask, shift, val) \
>> do { \
>> - (origin) &= (~(mask)); \
>> - (origin) |= (((u32)(val) << (shift)) & (mask)); \
>> + (origin) &= ~cpu_to_le32(mask); \
>> + (origin) |= cpu_to_le32(((u32)(val) << (shift)) & (mask)); \
>> } while (0)
>>
>> #define roce_set_bit(origin, shift, val) \
>> diff --git a/drivers/infiniband/hw/hns/hns_roce_device.h b/drivers/infiniband/hw/hns/hns_roce_device.h
>> index 42c3b5a..2503d7f 100644
>> --- a/drivers/infiniband/hw/hns/hns_roce_device.h
>> +++ b/drivers/infiniband/hw/hns/hns_roce_device.h
>> @@ -466,7 +466,7 @@ struct hns_roce_qp {
>> struct ib_qp ibqp;
>> struct hns_roce_buf hr_buf;
>> struct hns_roce_wq rq;
>> - __le64 doorbell_qpn;
>> + u32 doorbell_qpn;
>
> Why the change in size here? Did you mean to go from 64bits down to
> 32bits?
>
Maybe the 64bit is wasted after anlaysis. because the qpn of qpc and wqe are 24bit. the max value of qpn
is 2 ^ 24 - 1 and the 32bit is enough.
>>
>> } else if (ibqp->qp_type == IB_QPT_RC) {
>> ctrl = wqe;
>> memset(ctrl, 0, sizeof(struct hns_roce_wqe_ctrl_seg));
>> for (i = 0; i < wr->num_sge; i++)
>> - ctrl->msg_length += wr->sg_list[i].length;
>> + ctrl->msg_length =
>> + cpu_to_le32(le32_to_cpu(ctrl->msg_length) +
>> + wr->sg_list[i].length);
>
> Minor nit:
>
> Doing le32_to_cpu and cpu_to_le32 over and over again in a loop is
> horribly inefficient. It would be much better IMO if you had a local
> variable to use for the length, used that in the loop, and then only at
> the end of the loop do a single cpu_to_le32 of the local variable to
> store in msg_length. Same comment applies to the other spot in this
> patch that does the same loop.