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Message-ID: <b605d666-8b79-67c2-f16e-1e45c01287c2@quicinc.com>
Date:   Tue, 6 Jun 2023 10:51:36 -0700
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Subject: Re: [Freedreno] [PATCH] drm/msm/dpu: re-introduce dpu core revision
 to the catalog
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To:     Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
CC:     Sean Paul <sean@poorly.run>, <linux-arm-msm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <dri-devel@lists.freedesktop.org>,
        <quic_khsieh@quicinc.com>,
        Marijn Suijten <marijn.suijten@somainline.org>,
        <quic_jesszhan@quicinc.com>, <freedreno@lists.freedesktop.org>
References: <20230531005358.18090-1-quic_abhinavk@quicinc.com>
 <CAA8EJpryw0h8TgpJ+SFJ7s0=LCjkQ6oqAjCKsm60dk_Q5e+wWA@mail.gmail.com>
 <0af4df3d-8048-98cd-6c91-7cd553f4f65f@quicinc.com>
 <98e4bda7-19e9-09b6-f008-383adada97cb@linaro.org>
 <a0b7a9fc-eb3c-3b26-b11d-fe1fb47b2c51@quicinc.com>
 <451b114c-05e1-541c-1d3e-26bb81a307c4@linaro.org>
 <47fda908-d76f-65d5-e001-8773c5b160b9@quicinc.com>
 <48cc3d26-10fe-5b10-30b6-0772d62a2a53@linaro.org>
 <804363cf-f6cf-71a6-be8f-5fc00eea3154@quicinc.com>
 <CAA8EJprDSd79AXQvqW+=0xvTrTMCTL+CJ2E6Rhjro3g3E9UWog@mail.gmail.com>
From:   Abhinav Kumar <quic_abhinavk@quicinc.com>
In-Reply-To: <CAA8EJprDSd79AXQvqW+=0xvTrTMCTL+CJ2E6Rhjro3g3E9UWog@mail.gmail.com>
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On 6/6/2023 4:14 AM, Dmitry Baryshkov wrote:
> On Tue, 6 Jun 2023 at 05:35, Abhinav Kumar <quic_abhinavk@quicinc.com> wrote:
>>
>>
>>
>> On 6/5/2023 6:03 PM, Dmitry Baryshkov wrote:
>>> On 06/06/2023 03:55, Abhinav Kumar wrote:
>>>>
>>>>
>>>> On 6/3/2023 7:21 PM, Dmitry Baryshkov wrote:
>>>>> On 31/05/2023 21:25, Abhinav Kumar wrote:
>>>>>>
>>>>>>
>>>>>> On 5/31/2023 3:07 AM, Dmitry Baryshkov wrote:
>>>>>>> On 31/05/2023 06:05, Abhinav Kumar wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>> On 5/30/2023 7:53 PM, Dmitry Baryshkov wrote:
>>>>>>>>> On Wed, 31 May 2023 at 03:54, Abhinav Kumar
>>>>>>>>> <quic_abhinavk@quicinc.com> wrote:
>>>>>>>>>>
>>>>>>>>>> With [1] dpu core revision was dropped in favor of using the
>>>>>>>>>> compatible string from the device tree to select the dpu catalog
>>>>>>>>>> being used in the device.
>>>>>>>>>>
>>>>>>>>>> This approach works well however also necessitates adding catalog
>>>>>>>>>> entries for small register level details as dpu capabilities and/or
>>>>>>>>>> features bloating the catalog unnecessarily. Examples include but
>>>>>>>>>> are not limited to data_compress, interrupt register set,
>>>>>>>>>> widebus etc.
>>>>>>>>>>
>>>>>>>>>> Introduce the dpu core revision back as an entry to the catalog
>>>>>>>>>> so that
>>>>>>>>>> we can just use dpu revision checks and enable those bits which
>>>>>>>>>> should be enabled unconditionally and not controlled by a catalog
>>>>>>>>>> and also simplify the changes to do something like:
>>>>>>>>>>
>>>>>>>>>> if (dpu_core_revision > xxxxx && dpu_core_revision < xxxxx)
>>>>>>>>>>           enable the bit;
>>>>>>>>>>
>>>>>>>>>> Also, add some of the useful macros back to be able to use dpu core
>>>>>>>>>> revision effectively.
>>>>>>>>>>
>>>>>>>>>> [1]:
>>>>>>>>>> https://patchwork.freedesktop.org/patch/530891/?series=113910&rev=4
>>>>>>>>>>
>>>>>>>>>> Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
>>>>>>>>>> ---
>>>>>>>>>>    .../msm/disp/dpu1/catalog/dpu_3_0_msm8998.h   |  1 +
>>>>>>>>>>    .../msm/disp/dpu1/catalog/dpu_4_0_sdm845.h    |  1 +
>>>>>>>>>>    .../msm/disp/dpu1/catalog/dpu_5_0_sm8150.h    |  1 +
>>>>>>>>>>    .../msm/disp/dpu1/catalog/dpu_5_1_sc8180x.h   |  1 +
>>>>>>>>>>    .../msm/disp/dpu1/catalog/dpu_6_0_sm8250.h    |  1 +
>>>>>>>>>>    .../msm/disp/dpu1/catalog/dpu_6_2_sc7180.h    |  1 +
>>>>>>>>>>    .../msm/disp/dpu1/catalog/dpu_6_3_sm6115.h    |  1 +
>>>>>>>>>>    .../msm/disp/dpu1/catalog/dpu_6_5_qcm2290.h   |  1 +
>>>>>>>>>>    .../msm/disp/dpu1/catalog/dpu_7_0_sm8350.h    |  1 +
>>>>>>>>>>    .../msm/disp/dpu1/catalog/dpu_7_2_sc7280.h    |  1 +
>>>>>>>>>>    .../msm/disp/dpu1/catalog/dpu_8_0_sc8280xp.h  |  1 +
>>>>>>>>>>    .../msm/disp/dpu1/catalog/dpu_8_1_sm8450.h    |  1 +
>>>>>>>>>>    .../msm/disp/dpu1/catalog/dpu_9_0_sm8550.h    |  1 +
>>>>>>>>>>    .../gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h    | 31
>>>>>>>>>> ++++++++++++++++++-
>>>>>>>>>>    14 files changed, 43 insertions(+), 1 deletion(-)
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> [skipped catalog changes]
>>>>>>>>>
>>>>>>>>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
>>>>>>>>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
>>>>>>>>>> index 677048cc3b7d..cc4aa75a1219 100644
>>>>>>>>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
>>>>>>>>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
>>>>>>>>>> @@ -19,6 +19,33 @@
>>>>>>>>>>     */
>>>>>>>>>>    #define MAX_BLOCKS    12
>>>>>>>>>>
>>>>>>>>>> +#define DPU_HW_VER(MAJOR, MINOR, STEP)\
>>>>>>>>>> +                 ((((unsigned int)MAJOR & 0xF) << 28) |\
>>>>>>>>>> +                 ((MINOR & 0xFFF) << 16) |\
>>>>>>>>>> +                 (STEP & 0xFFFF))
>>>>>>>>>> +
>>>>>>>>>> +#define DPU_HW_MAJOR(rev)((rev) >> 28)
>>>>>>>>>> +#define DPU_HW_MINOR(rev)(((rev) >> 16) & 0xFFF)
>>>>>>>>>> +#define DPU_HW_STEP(rev)((rev) & 0xFFFF)
>>>>>>>>>> +#define DPU_HW_MAJOR_MINOR(rev)((rev) >> 16)
>>>>>>>>>> +
>>>>>>>>>> +#define IS_DPU_MAJOR_MINOR_SAME(rev1, rev2)   \
>>>>>>>>>> +(DPU_HW_MAJOR_MINOR((rev1)) == DPU_HW_MAJOR_MINOR((rev2)))
>>>>>>>>>> +
>>>>>>>>>> +#define DPU_HW_VER_300 DPU_HW_VER(3, 0, 0) /* 8998 v1.0 */
>>>>>>>>>> +#define DPU_HW_VER_400 DPU_HW_VER(4, 0, 0) /* sdm845 v1.0 */
>>>>>>>>>> +#define DPU_HW_VER_500 DPU_HW_VER(5, 0, 0) /* sm8150 v1.0 */
>>>>>>>>>> +#define DPU_HW_VER_510 DPU_HW_VER(5, 1, 1) /* sc8180 */
>>>>>>>>>> +#define DPU_HW_VER_600 DPU_HW_VER(6, 0, 0) /* sm8250 */
>>>>>>>>>> +#define DPU_HW_VER_620 DPU_HW_VER(6, 2, 0) /* sc7180 v1.0 */
>>>>>>>>>> +#define DPU_HW_VER_630 DPU_HW_VER(6, 3, 0) /* sm6115|sm4250 */
>>>>>>>>>> +#define DPU_HW_VER_650 DPU_HW_VER(6, 5, 0) /* qcm2290|sm4125 */
>>>>>>>>>> +#define DPU_HW_VER_700 DPU_HW_VER(7, 0, 0) /* sm8350 */
>>>>>>>>>> +#define DPU_HW_VER_720 DPU_HW_VER(7, 2, 0) /* sc7280 */
>>>>>>>>>> +#define DPU_HW_VER_800 DPU_HW_VER(8, 0, 0) /* sc8280xp */
>>>>>>>>>> +#define DPU_HW_VER_810 DPU_HW_VER(8, 1, 0) /* sm8450 */
>>>>>>>>>> +#define DPU_HW_VER_900 DPU_HW_VER(9, 0, 0) /* sm8550 */
>>>>>>>>>
>>>>>>>>> Instead of having defines for all SoCs (which can quickly become
>>>>>>>>> unmanageable) and can cause merge conflicts, I'd suggest inlining
>>>>>>>>> all
>>>>>>>>> the defines into respective catalog files.
>>>>>>>>>
>>>>>>>>
>>>>>>>> Sure, that can be done.
>>>>>>>>
>>>>>>>>> Also, I'm not sure that the "step" should be a part of the
>>>>>>>>> catalog. I
>>>>>>>>> know that this follows the hardware revision. However, please
>>>>>>>>> correct
>>>>>>>>> me if I'm wrong, different step levels are used for revisions of the
>>>>>>>>> same SoC. The original code that was reading the hw revision from
>>>>>>>>> the
>>>>>>>>> hardware register, listed both 5.0.0 and 5.0.1 for sm8150.
>>>>>>>>>
>>>>>>>>
>>>>>>>> This is one of the things i noticed while making this change.
>>>>>>>>
>>>>>>>> Before the catalog rework, we used to handle even steps as we used
>>>>>>>> to read that from the register and match it with the mdss_cfg
>>>>>>>> handler. But after the rework, we dont handle steps anymore. Yes,
>>>>>>>> you are right that different step levels are used for the
>>>>>>>> revisions of the same SOC and so with that, i dont expect or
>>>>>>>> atleast am not aware of DPU differences between steps but I am not
>>>>>>>> able to rule it out.
>>>>>>>>
>>>>>>>> So are you suggesting we drop step altogether and DPU_HW_VER()
>>>>>>>> macro shall only handle major and minor versions? With the current
>>>>>>>> chipsets I see, it should not make a difference . Its just that I
>>>>>>>> am not sure if that will never happen.
>>>>>>>
>>>>>>> Yes. The goal of this rework would be to drop generic features and
>>>>>>> to replace those checks with DPU-revision lookups. Correct?
>>>>>>
>>>>>> Yes thats right.
>>>>>>
>>>>>>> I think that from this perspective having to handle toe step
>>>>>>> revision is a sign of an overkill. Having to handle the step
>>>>>>> revision is a sign of paltform feature (or mis-feature) rather than
>>>>>>> a generic DPU bit.
>>>>>>>
>>>>>>
>>>>>> Not entirely. Lets not forget that at the moment even dpu_perf_cfg
>>>>>> is part of the catalog. Even if in terms of major HW blocks steps
>>>>>> shouldnt change, there is absolutely no guarantee that perf data
>>>>>> cannot.
>>>>>>
>>>>>> This is what is the sticking point for me which is holding me back
>>>>>> against dropping step. Thoughts?
>>>>>
>>>>> We usually do not support ES versions of the chips, only the final
>>>>> version. So supporting the perf data for earlier revisions is also
>>>>> not required.
>>>>>
>>>>
>>>> ack, we will drop step in that case. and good to know about the ES
>>>> versions.
>>>>
>>>>>>
>>>>>>> In fact I suppose that even handling a minor revision would be an
>>>>>>> overkill. Why don't we start with .dpu_major instead of .core_rev?
>>>>>>> We can add .dpu_minor if/when required.
>>>>>>>
>>>>>>
>>>>>> No, unfortunately we cannot drop minor version for sure. I am seeing
>>>>>> examples in downstream code where some of the features are available
>>>>>> after a minor verion as well.
>>>>>
>>>>> Can you please give an example?
>>>>>
>>>>
>>>> Yes, watchdog timer, intf reset counter are available only after DPU
>>>> HW version 8.1 (not major version 8).
>>>
>>> Hmm, IIRC, wd timer was available for ages. Was it moved together with
>>> the introduction of MDSS_PERIPH_0_REMOVED?
>>>
>>
>> I am not sure of the timeline but its certainly tied to 8.1.
>>
>>> But anyway, I see your point. Let's have major and minor. I'd probably
>>> still ask for the separate major and minor fields, if you don't mind.
>>>
>>
>> hmmm so something like this?
>>
>> +#define DPU_HW_VER_300 DPU_HW_VER(3, 0) /* 8998 v1.0 */
>>
>> const struct dpu_mdss_cfg dpu_msm8998_cfg = {
>> .......
>> .dpu_major_rev = DPU_HW_MAJOR(DPU_HW_VER_300),
>> .dpu_minor_rev = DPU_HW_MINOR(DPU_HW_VER_300)
> 
> Just:
> 
> const struct dpu_mdss_cfg dpu_msm8998_cfg = {
>      .dpu_major_rev = 3,
>      .dpu_minor_rev = 0,
>      /* .... */
> };
> 
> We do not need a single enumeration of all the versions. It can easily
> become a source of merge conflicts.
> 

The issue with this approch is then the DPU_HW_VER_xxx macros become 
redundant but we should keep them. Because in the code, its much more 
readable to have

if (core_rev > DPU_HW_MAJOR(DPU_HW_VER_xxx))
	then enable feature;

But now we will have to do

if (dpu_major_rev > xxx && dpu_minor_ver > yyy)
	then enable feature;

/// probably folks will question this xxx and yyy as to what it means.

Can you please explain the single enumeration a bit more?

I thought we are going to move each revision to its separate file to 
avoid the conflicts as you suggested earlier in the comments. Isnt that 
enough?

>> .......
>> }
>>
>> But may I ask why? Since the manor/minor version macros handle this
>> nicely for us.
> 
> 
>