Re: [PATCH 1/2] scsi: ufs: Add Multi-Circular Queue support

Can Guo
2022-07-26T02:56:25Z

Hi Avri,

On 7/23/2022 10:59 PM, Avri Altman wrote:
>> +#define MCQ_ROP_OFFSET_n(p, i) \
>> + hba->mcq_rop[(p)].offset + hba->mcq_rop[(p)].stride * (i)
> Can you please explain the 0x100 stride thing?
> Theoretically, each rop set is 48Bytes long, or did I get it wrong?

In the draft, there are 4 sets of MCQ Operation & Runtime Registers,
i.e. SQD_n, SQIS_n, CQD_n and CQIS_n.

They may be interleaved or segregated, depends on realistic HW designs.

For example, either #1 or #2 can be the case, and QCOM uses case #1, in
which 'stride' means the size (in bytes)

that one register has to hop over to reach the same register on next
round (for example, addr of SQHP_n == (addr of SQHP_0) + (stride * n)).

To allow flexibility, SoC vendors, depends on realistic HW designs, (by
using vops_config_mcq_rop) can manipulate

the 'offset' and 'stride' of each MCQ Operation & Runtime Register such
that SQDAO_n, SQISAO_n, CQDAO_n and

CQISAO_n are programmed with wanted offsets/values.

#1 -

SQHP_0
SQTP_0
SQRTC_0
SQCTI_0
SQRTS_0
SQIS_0
SQIE_0
CQHP_0
CQTP_0
CQIS_0
CQIE_0
CQIACR_0
SQHP_1
SQTP_1
SQRTC_1
SQCTI_1
SQRTS_1
SQIS_1
SQIE_1
CQHP_1
CQTP_1
CQIS_1
CQIE_1
CQIACR_1
...
SQHP_n
SQTP_n
SQRTC_n
SQCTI_n
SQRTS_n
SQIS_n
SQIE_n
CQHP_n
CQTP_n
CQIS_n
CQIE_n
CQIACR_n

#2 -

SQHP_0
SQTP_0
SQRTC_0
SQCTI_0
SQRTS_0
SQHP_1
SQTP_1
SQRTC_1
SQCTI_1
SQRTS_1
...
SQHP_n
SQTP_n
SQRTC_n
SQCTI_n
SQRTS_n

SQIS_0
SQIE_0
SQIS_1
SQIE_1
...
SQIS_n
SQIE_n

CQHP_0
CQTP_0
CQHP_1
CQTP_1
...
CQHP_n
CQTP_n

CQIS_0
CQIE_0
CQIACR_0
CQIS_1
CQIE_1
CQIACR_1
...
CQIS_n
CQIE_n
CQIACR_n

Thanks,

Can Guo.

> Thanks,
> Avri