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Message-ID: <65a19b36-56e8-4cdc-8112-4e5f7cfb7666@quicinc.com>
Date: Tue, 16 Jan 2024 17:12:44 +0530
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Subject: Re: [PATCH v7 3/5] iommu/arm-smmu: introduction of ACTLR for custom
 prefetcher settings
To: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
CC: Konrad Dybcio <konrad.dybcio@linaro.org>,
        Pavan Kondeti
	<quic_pkondeti@quicinc.com>, <will@kernel.org>,
        <robin.murphy@arm.com>, <joro@8bytes.org>, <jsnitsel@redhat.com>,
        <quic_bjorande@quicinc.com>, <mani@kernel.org>,
        <quic_eberman@quicinc.com>, <robdclark@chromium.org>,
        <u.kleine-koenig@pengutronix.de>, <robh@kernel.org>,
        <vladimir.oltean@nxp.com>, <quic_molvera@quicinc.com>,
        <linux-arm-msm@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>, <iommu@lists.linux.dev>,
        <linux-kernel@vger.kernel.org>
References: <20240109114220.30243-1-quic_bibekkum@quicinc.com>
 <20240109114220.30243-4-quic_bibekkum@quicinc.com>
 <2ad70157-27d1-41df-8866-c226af690cf6@quicinc.com>
 <ec31fafa-b912-454a-8b64-e0593911aaf2@quicinc.com>
 <4a595815-7fcc-47e2-b22c-dac349af6d79@quicinc.com>
 <492aeca3-a4df-47a3-9c77-02ea4235d736@linaro.org>
 <1a1f9b11-5a6d-41f7-8bcd-533a61a27a65@quicinc.com>
 <babd9514-6202-486f-a7c5-51ad793aaca6@linaro.org>
 <d7110cff-334f-40cd-9f11-62fafd8d722d@quicinc.com>
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From: Bibek Kumar Patro <quic_bibekkum@quicinc.com>
In-Reply-To: <CAA8EJpqO2vEQP3B3gpGHvMSiaMQspz+63WVVXbkd0Hrx-AFeCQ@mail.gmail.com>
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On 1/12/2024 6:44 PM, Dmitry Baryshkov wrote:
> On Fri, 12 Jan 2024 at 15:07, Bibek Kumar Patro
> <quic_bibekkum@quicinc.com> wrote:
>>
>>
>>
>> On 1/12/2024 3:31 PM, Konrad Dybcio wrote:
>>>
>>>
>>> On 1/11/24 19:09, Bibek Kumar Patro wrote:
>>>>
>>>>
>>>> On 1/10/2024 11:26 PM, Konrad Dybcio wrote:
>>>>>
>>>>>
>>>>> On 1/10/24 13:55, Bibek Kumar Patro wrote:
>>>>>>
>>>>>>
>>>>>> On 1/10/2024 4:46 PM, Bibek Kumar Patro wrote:
>>>>>>>
>>>>>>>
>>>>>>> On 1/10/2024 9:36 AM, Pavan Kondeti wrote:
>>>>>>
>>>>>> [...]
>>>>>>
>>>>>>>>> @@ -274,6 +321,21 @@ static const struct of_device_id
>>>>>>>>> qcom_smmu_client_of_match[] __maybe_unused = {
>>>>>>>>>    static int qcom_smmu_init_context(struct arm_smmu_domain
>>>>>>>>> *smmu_domain,
>>>>>>>>>            struct io_pgtable_cfg *pgtbl_cfg, struct device *dev)
>>>>>>>>>    {
>>>>>>>>> +    struct arm_smmu_device *smmu = smmu_domain->smmu;
>>>>>>>>> +    struct qcom_smmu *qsmmu = to_qcom_smmu(smmu);
>>>>>>>>> +    const struct actlr_variant *actlrvar;
>>>>>>>>> +    int cbndx = smmu_domain->cfg.cbndx;
>>>>>>>>> +
>>>>>>>>> +    if (qsmmu->data->actlrvar) {
>>>>>>>>> +        actlrvar = qsmmu->data->actlrvar;
>>>>>>>>> +        for (; actlrvar->io_start; actlrvar++) {
>>>>>>>>> +            if (actlrvar->io_start == smmu->ioaddr) {
>>>>>>>>> +                qcom_smmu_set_actlr(dev, smmu, cbndx,
>>>>>>>>> actlrvar->actlrcfg);
>>>>>>>>> +                break;
>>>>>>>>> +            }
>>>>>>>>> +        }
>>>>>>>>> +    }
>>>>>>>>> +
>>>>>>>>
>>>>>>>> This block and the one in qcom_adreno_smmu_init_context() are exactly
>>>>>>>> the same. Possible to do some refactoring?
>>>>>>>>
>>>>>>>
>>>>>>> I will check if this repeated blocks can be accomodated this into
>>>>>>> qcom_smmu_set_actlr function if that would be fine.
>>>>>>>
>>>>>>
>>>>>> Also adding to this, this might increase the number of indentation
>>>>>> inside qcom_smmu_set_actlr as well, to around 5. So wouldn't this
>>>>>> be an issue?
>>>>>
>>>>> By the way, we can refactor this:
>>>>>
>>>>> if (qsmmu->data->actlrvar) {
>>>>>       actlrvar = qsmmu->data->actlrvar;
>>>>>       for (; actlrvar->io_start; actlrvar++) {
>>>>>           if (actlrvar->io_start == smmu->ioaddr) {
>>>>>               qcom_smmu_set_actlr(dev, smmu, cbndx, actlrvar->actlrcfg);
>>>>>               break;
>>>>>           }
>>>>>       }
>>>>> }
>>>>>
>>>>> into
>>>>>
>>>>> // add const u8 num_actlrcfgs to struct actrl_variant to
>>>>> // save on sentinel space:
>>>>> //   sizeof(u8) < sizeof(ptr) + sizeof(resource_size_t)
>>>>>
>>>>
>>>> Git it, Would it be better to add this in struct qcom_smmu_match_data ?
>>>
>>> Yes, right.
>>>
>>
>> Actually, I noticed now, we can do both the actlr_config (num_actlrcfg
>> is used) and actlr_var (num_smmu is used) in the similar by storing the
>> number of elements in each of them.
>> something like this:
>>
>> +static const struct actlr_config sc7280_apps_actlr_cfg[] = {
>> +       { 0x0800, 0x24e1, PREFETCH_DEFAULT | CMTLB },
>> +       { 0x2000, 0x0163, PREFETCH_DEFAULT | CMTLB },
>> +       { 0x2080, 0x0461, PREFETCH_DEFAULT | CMTLB },
>> +       { 0x2100, 0x0161, PREFETCH_DEFAULT | CMTLB },
>> +       { 0x0900, 0x0407, PREFETCH_SHALLOW | CPRE | CMTLB },
>> +       { 0x2180, 0x0027, PREFETCH_SHALLOW | CPRE | CMTLB },
>> +       { 0x1000, 0x07ff, PREFETCH_DEEP | CPRE | CMTLB },
>> +};
>> +
>> +static const struct actlr_config sc7280_gfx_actlr_cfg[] = {
>> +       { 0x0000, 0x07ff, PREFETCH_SWITCH_GFX | PREFETCH_DEEP | CPRE | CMTLB },
>> +};
>> +
>> +static const struct actlr_variant sc7280_actlr[] = {
>> +       { .io_start = 0x15000000, .actlrcfg = sc7280_apps_actlr_cfg,
>> .num_actlrcfg = 7 },
>> +       { .io_start = 0x03da0000, .actlrcfg = sc7280_gfx_actlr_cfg,
>> .num_actlrcfg = 1 },
>> +};
>> +
>>    static const struct actlr_config sm8550_apps_actlr_cfg[] = {
>>          { 0x18a0, 0x0000, PREFETCH_SHALLOW | CPRE | CMTLB },
>>          { 0x18e0, 0x0000, PREFETCH_SHALLOW | CPRE | CMTLB },
>> @@ -661,6 +680,13 @@ static const struct qcom_smmu_match_data
>> sdm845_smmu_500_data = {
>>          /* Also no debug configuration. */
>>    };
>>
>> +static const struct qcom_smmu_match_data sc7280_smmu_500_impl0_data = {
>> +       .impl = &qcom_smmu_500_impl,
>> +       .adreno_impl = &qcom_adreno_smmu_500_impl,
>> +       .cfg = &qcom_smmu_impl0_cfg,
>> +       .actlrvar = sc7280_actlr,
>> +       .num_smmu = 2,
>> +};
>>
>> Just for note , there's a small hiccup here as we have to manually
>> calculate and the number of elements in actlr_config size everytime we
>> add this info for a new target, won't be an issue though but just a
>> hindrance to automation (?)
> 
> Just use ARRAY_SIZE(sc7280_actlr).
> 

Noted, ARRAY_SIZE makes sense now for this new io_address based
matching.

Thanks & regards,
Bibek

>