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Message-ID: <40282b6e-9524-4a88-97ca-3ce890317279@quicinc.com>
Date:   Wed, 15 Nov 2023 19:24:16 +0530
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Subject: Re: [PATCH v2 1/3] iommu/arm-smmu: introduction of ACTLR for custom
 prefetcher settings
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To:     Robin Murphy <robin.murphy@arm.com>, <will@kernel.org>,
        <joro@8bytes.org>, <dmitry.baryshkov@linaro.org>,
        <a39.skl@gmail.com>, <konrad.dybcio@linaro.org>,
        <quic_pkondeti@quicinc.com>, <quic_molvera@quicinc.com>
CC:     <linux-arm-msm@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>, <iommu@lists.linux.dev>,
        <linux-kernel@vger.kernel.org>, <qipl.kernel.upstream@quicinc.com>
References: <20231114135654.30475-1-quic_bibekkum@quicinc.com>
 <20231114135654.30475-2-quic_bibekkum@quicinc.com>
 <372885ab-b24d-44ae-afb8-76755bcd6e21@arm.com>
From:   Bibek Kumar Patro <quic_bibekkum@quicinc.com>
In-Reply-To: <372885ab-b24d-44ae-afb8-76755bcd6e21@arm.com>
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>> @@ -467,6 +505,9 @@ static struct arm_smmu_device 
>> *qcom_smmu_create(struct arm_smmu_device *smmu,
>>       qsmmu->smmu.impl = impl;
>>       qsmmu->cfg = data->cfg;
>>
>> +    if (data->actlrcfg && (data->actlrcfg->size))
>> +        qsmmu->actlrcfg = data->actlrcfg;
> 
> Do we really need to replicate multiple parts of the data, or would it 
> be sensible to just replace qsmmu->cfg with qsmmu->data and handle the 
> further dereferences in the places that want them?
> 

Mm, could not understand this properly. :( Could you help explain more 
please?
As per my understanding aren't data and qsmmu different structures.
qcom_smmu is a superset of arm_smmu housing additonal properties
and qcom_smmu_match_data is kind of a superset of arm_smmu_impl with
additional specific implmentations, so both needs to be in place?
Apologies if I understood your statement incorrectly.

>> +
>>       return &qsmmu->smmu;
>>   }
>>
>> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.h 
>> b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.h
>> index 593910567b88..4b6862715070 100644
>> --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.h
>> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.h
>> @@ -9,6 +9,7 @@
>>   struct qcom_smmu {
>>       struct arm_smmu_device smmu;
>>       const struct qcom_smmu_config *cfg;
>> +    const struct actlr_config *actlrcfg;
>>       bool bypass_quirk;
>>       u8 bypass_cbndx;
>>       u32 stall_enabled;
>> @@ -25,6 +26,7 @@ struct qcom_smmu_config {
>>   };
>>