[PATCH 3/5] drm/msm/iommu: introduce msm_iommu_disp_new() for msm_kms

[Rob Clark]

On Fri, Jun 28, 2024 at 2:49 PM Abhinav Kumar <quic_abhinavk at quicinc.com> wrote:
>
> Introduce a new API msm_iommu_disp_new() for display use-cases.
>
> Signed-off-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
> ---
>  drivers/gpu/drm/msm/msm_iommu.c | 26 ++++++++++++++++++++++++++
>  drivers/gpu/drm/msm/msm_mmu.h   |  1 +
>  2 files changed, 27 insertions(+)
>
> diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
> index a79cd18bc4c9..0420bdc4a224 100644
> --- a/drivers/gpu/drm/msm/msm_iommu.c
> +++ b/drivers/gpu/drm/msm/msm_iommu.c
> @@ -343,6 +343,17 @@ static int msm_gpu_fault_handler(struct iommu_domain *domain, struct device *dev
>         return 0;
>  }
>
> +static int msm_disp_fault_handler(struct iommu_domain *domain, struct device *dev,
> +                                 unsigned long iova, int flags, void *arg)
> +{
> +       struct msm_iommu *iommu = arg;
> +
> +       if (iommu->base.handler)
> +               return iommu->base.handler(iommu->base.arg, iova, flags, NULL);
> +
> +       return -ENOSYS;
> +}
> +
>  static void msm_iommu_resume_translation(struct msm_mmu *mmu)
>  {
>         struct adreno_smmu_priv *adreno_smmu = dev_get_drvdata(mmu->dev);
> @@ -434,6 +445,21 @@ struct msm_mmu *msm_iommu_new(struct device *dev, unsigned long quirks)
>         return &iommu->base;
>  }
>
> +struct msm_mmu *msm_iommu_disp_new(struct device *dev, unsigned long quirks)
> +{
> +       struct msm_iommu *iommu;
> +       struct msm_mmu *mmu;
> +
> +       mmu = msm_iommu_new(dev, quirks);
> +       if (IS_ERR_OR_NULL(mmu))
> +               return mmu;
> +
> +       iommu = to_msm_iommu(mmu);
> +       iommu_set_fault_handler(iommu->domain, msm_disp_fault_handler, iommu);
> +
> +       return mmu;
> +}

Hmm, are we using dev drvdata for the display pdev?  If
dev_get_drvdata() returns NULL for display pdev, we could get away
without having a different fault handler.

BR,
-R

> +
>  struct msm_mmu *msm_iommu_gpu_new(struct device *dev, struct msm_gpu *gpu, unsigned long quirks)
>  {
>         struct adreno_smmu_priv *adreno_smmu = dev_get_drvdata(dev);
> diff --git a/drivers/gpu/drm/msm/msm_mmu.h b/drivers/gpu/drm/msm/msm_mmu.h
> index 88af4f490881..730458d08d6b 100644
> --- a/drivers/gpu/drm/msm/msm_mmu.h
> +++ b/drivers/gpu/drm/msm/msm_mmu.h
> @@ -42,6 +42,7 @@ static inline void msm_mmu_init(struct msm_mmu *mmu, struct device *dev,
>
>  struct msm_mmu *msm_iommu_new(struct device *dev, unsigned long quirks);
>  struct msm_mmu *msm_iommu_gpu_new(struct device *dev, struct msm_gpu *gpu, unsigned long quirks);
> +struct msm_mmu *msm_iommu_disp_new(struct device *dev, unsigned long quirks);
>
>  static inline void msm_mmu_set_fault_handler(struct msm_mmu *mmu, void *arg,
>                 int (*handler)(void *arg, unsigned long iova, int flags, void *data))
> --
> 2.44.0
>