On 2020/11/17 16:50, Leon Romanovsky wrote:
> On Tue, Nov 17, 2020 at 08:35:55AM +0000, liweihang wrote:
>> On 2020/11/17 15:21, Leon Romanovsky wrote:
>>> On Tue, Nov 17, 2020 at 06:37:58AM +0000, liweihang wrote:
>>>> On 2020/11/16 21:47, Leon Romanovsky wrote:
>>>>> On Mon, Nov 16, 2020 at 07:58:38PM +0800, Weihang Li wrote:
>>>>>> From: Lang Cheng <chenglang@xxxxxxxxxx>
>>>>>>
>>>>>> Stash is a mechanism that uses the core information carried by the ARM AXI
>>>>>> bus to access the L3 cache. It can be used to improve the performance by
>>>>>> increasing the hit ratio of L3 cache. CQs need to enable stash by default.
>>>>>>
>>>>>> Signed-off-by: Lang Cheng <chenglang@xxxxxxxxxx>
>>>>>> Signed-off-by: Weihang Li <liweihang@xxxxxxxxxx>
>>>>>> ---
>>>>>> drivers/infiniband/hw/hns/hns_roce_common.h | 12 +++++++++
>>>>>> drivers/infiniband/hw/hns/hns_roce_device.h | 1 +
>>>>>> drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 3 +++
>>>>>> drivers/infiniband/hw/hns/hns_roce_hw_v2.h | 39 +++++++++++++++++------------
>>>>>> 4 files changed, 39 insertions(+), 16 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/infiniband/hw/hns/hns_roce_common.h b/drivers/infiniband/hw/hns/hns_roce_common.h
>>>>>> index f5669ff..8d96c4e 100644
>>>>>> --- a/drivers/infiniband/hw/hns/hns_roce_common.h
>>>>>> +++ b/drivers/infiniband/hw/hns/hns_roce_common.h
>>>>>> @@ -53,6 +53,18 @@
>>>>>> #define roce_set_bit(origin, shift, val) \
>>>>>> roce_set_field((origin), (1ul << (shift)), (shift), (val))
>>>>>>
>>>>>> +#define FIELD_LOC(field_h, field_l) field_h, field_l
>>>>>> +
>>>>>> +#define _hr_reg_set(arr, field_h, field_l) \
>>>>>> + do { \
>>>>>> + BUILD_BUG_ON(((field_h) / 32) != ((field_l) / 32)); \
>>>>>> + BUILD_BUG_ON((field_h) / 32 >= ARRAY_SIZE(arr)); \
>>>>>> + (arr)[(field_h) / 32] |= \
>>>>>> + cpu_to_le32(GENMASK((field_h) % 32, (field_l) % 32)); \
>>>>>> + } while (0)
>>>>>> +
>>>>>> +#define hr_reg_set(arr, field) _hr_reg_set(arr, field)
>>>>>
>>>>> I afraid that it is too much.
>>>>
>>>> Hi Leon,
>>>>
>>>> Thanks for the comments.
>>>>
>>>>> 1. FIELD_LOC() macro to hide two fields.
>>>>
>>>> Jason has suggested us to simplify the function of setting/getting bit/field in
>>>> hns driver like IBA_SET and IBA_GET.
>>>>
>>>> https://patchwork.kernel.org/project/linux-rdma/patch/1589982799-28728-3-git-send-email-liweihang@xxxxxxxxxx/
>>>>
>>>> So we try to make it easier and clearer to define a bitfield for developers.
>>>
>>> Jason asked to use genmask and FIELD_PREP, but you invented something else.
>>>
>>> Thanks
>>>
>>
>> We use them in another interface 'hr_reg_write(arr, field, val)' which hasn't been
>> used in this series.
>>
>> Does it make any unacceptable mistake? We would appreciate any suggestions :)
>
> The invention of FIELD_LOC() and hr_reg_set equal to __hr_reg_set are unacceptable.
> Pass directly your field_h and field_l to hr_reg_set().
>
> Thanks
>
Hi Leon,
We let hr_reg_set equal() to __hr_reg_set() because if not, there will be a compile error:
../hns_roce_hw_v2.c:4566:41: error: macro "_hr_reg_set" requires 3 arguments, but only 2 given
_hr_reg_set(cq_context->raw, CQC_STASH);
There are similar codes in iba.h, I think they are of the same reason:
#define _IBA_SET(field_struct, field_offset, field_mask, num_bits, ptr, value) \
({ \
field_struct *_ptr = ptr; \
_iba_set##num_bits((void *)_ptr + (field_offset), field_mask, \
FIELD_PREP(field_mask, value)); \
})
#define IBA_SET(field, ptr, value) _IBA_SET(field, ptr, value)
#define IBA_FIELD64_LOC(field_struct, byte_offset) \
field_struct, byte_offset, GENMASK_ULL(63, 0), 64
#define CM_FIELD64_LOC(field_struct, byte_offset) \
IBA_FIELD64_LOC(field_struct, (byte_offset + sizeof(struct ib_mad_hdr)))
#define CM_REQ_LOCAL_CA_GUID CM_FIELD64_LOC(struct cm_req_msg, 16)
IBA_SET(CM_REQ_LOCAL_CA_GUID, req_msg,
be64_to_cpu(cm_id_priv->id.device->node_guid));
As I said, we want to use a single symbol to represent a field to make it
easier and clearer to define and set a bitfield for developers.
Let's compare the following implementations:
#define _hr_reg_set(arr, field_h, field_l) \
(arr)[(field_h) / 32] |= \
cpu_to_le32(GENMASK((field_h) % 32, (field_l) % 32)) + \
BUILD_BUG_ON_ZERO(((field_h) / 32) != ((field_l) / 32)) + \
BUILD_BUG_ON_ZERO((field_h) / 32 >= ARRAY_SIZE(arr))
1)
#define hr_reg_set(arr, field) _hr_reg_set(arr, field)
#define QPCEX_PASID_EN FIELD_LOC(111, 95)
hr_reg_set(context->ext, QPCEX_PASID_EN);
In this way, we just need to define a single symbol and use it easily.
2)
#define QPCEX_PASID_EN_H 111
#define QPCEX_PASID_EN_L 95
_hr_reg_set(context->ext, QPCEX_PASID_EN_H, QPCEX_PASID_EN_L);
We have to define and pass 2 symbols.
3)
#define QPCEX_PASID_EN_H 111
#define QPCEX_PASID_EN 95
#define hr_reg_set(arr, field) _hr_reg_set(arr, field, field##_H)
hr_reg_set(context->ext, QPCEX_PASID_EN);
We have to define 2 symbols and use 1 symbols when setting field.
4)
#define _hr_reg_set(arr, field_h, field_l) \
...
#define QPCEX_PASID_EN_M GENMASK(111, 95) //mask
#define QPCEX_PASID_EN 95 // shift
#define hr_reg_set(arr, field) _hr_reg_set(arr, field, field##_M)
hr_reg_set(context->ext, QPCEX_PASID_EN);
We use mask and shift, similar with the way #3.
I think the first way is the best, and it doesn't seem to have any side effects.
Thanks
Weihang
