Re: [PATCHv2 2/6] iommu/arm-smmu: Allow client devices to select direct mapping

Sai Prakash Ranjan
2020-04-20T16:28:33Z

On 2020-04-20 21:27, Robin Murphy wrote:
> On 2020-04-20 3:37 pm, Sai Prakash Ranjan wrote:
>> From: Jordan Crouse <jcrouse@codeaurora.org>
>>
>> Some client devices want to directly map the IOMMU themselves instead
>> of using the DMA domain. Allow those devices to opt in to direct
>> mapping by way of a list of compatible strings.
>>
>> Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
>> Co-developed-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
>> Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
>> ---
>> drivers/iommu/arm-smmu-qcom.c | 19 +++++++++++++++++++
>> drivers/iommu/arm-smmu.h | 1 +
>> 2 files changed, 20 insertions(+)
>>
>> diff --git a/drivers/iommu/arm-smmu-qcom.c
>> b/drivers/iommu/arm-smmu-qcom.c
>> index 64a4ab270ab7..0b3f159065aa 100644
>> --- a/drivers/iommu/arm-smmu-qcom.c
>> +++ b/drivers/iommu/arm-smmu-qcom.c
>> @@ -3,6 +3,7 @@
>> * Copyright (c) 2019, The Linux Foundation. All rights reserved.
>> */
>> +#include <linux/of_device.h>
>> #include <linux/qcom_scm.h>
>> #include "arm-smmu.h"
>> @@ -11,6 +12,23 @@ struct qcom_smmu {
>> struct arm_smmu_device smmu;
>> };
>> +static const struct of_device_id qcom_smmu_client_of_match[] = {
>> + { .compatible = "qcom,adreno" },
>> + { .compatible = "qcom,mdp4" },
>> + { .compatible = "qcom,mdss" },
>> + { .compatible = "qcom,sc7180-mdss" },
>> + { .compatible = "qcom,sdm845-mdss" },
>> + { }
>> +};
>> +
>> +static int qcom_smmu_request_domain(struct device *dev)
>> +{
>> + const struct of_device_id *match =
>> + of_match_device(qcom_smmu_client_of_match, dev);
>> +
>> + return match ? IOMMU_DOMAIN_IDENTITY : 0;
>> +}
>> +
>> static int qcom_sdm845_smmu500_reset(struct arm_smmu_device *smmu)
>> {
>> int ret;
>> @@ -41,6 +59,7 @@ static int qcom_smmu500_reset(struct arm_smmu_device
>> *smmu)
>> }
>> static const struct arm_smmu_impl qcom_smmu_impl = {
>> + .req_domain = qcom_smmu_request_domain,
>> .reset = qcom_smmu500_reset,
>> };
>> diff --git a/drivers/iommu/arm-smmu.h b/drivers/iommu/arm-smmu.h
>> index 8d1cd54d82a6..662fdb4dccd2 100644
>> --- a/drivers/iommu/arm-smmu.h
>> +++ b/drivers/iommu/arm-smmu.h
>> @@ -386,6 +386,7 @@ struct arm_smmu_impl {
>> int (*init_context)(struct arm_smmu_domain *smmu_domain);
>> void (*tlb_sync)(struct arm_smmu_device *smmu, int page, int sync,
>> int status);
>> + int (*req_domain)(struct device *dev);
>
> Nit: since the point is to implement the full
> iommu_ops::def_domain_type interface, can we call it def_domain_type
> please?
>

Sure, will send the next version shortly.

Thanks,
Sai

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