Re: [PATCH v2 5/8] drm/msm: Attach the IOMMU device during initialization

[Rob Clark <robdclark@gmail.com>]

On Fri, Nov 22, 2019 at 3:32 PM Jordan Crouse <jcrouse@codeaurora.org> wrote:
>
> Everywhere an IOMMU object is created by msm_gpu_create_address_space
> the IOMMU device is attached immediately after. Instead of carrying around
> the infrastructure to do the attach from the device specific code do it
> directly in the msm_iommu_init() function. This gets it out of the way for
> more aggressive cleanups that follow.
>
> Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>

Hmm, yeah, now that we dropped the extra mmu->attach() args (which was
some ancient downstream compat thing), we don't need the separate
attach step.  I suppose we probably should do a similar cleanup for
mmu->detach(), but I guess that can be it's own patch

Reviewed-by: Rob Clark <robdclark@gmail.com>


> ---
>
>  drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c  |  8 --------
>  drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c |  4 ----
>  drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c |  7 -------
>  drivers/gpu/drm/msm/msm_gem_vma.c        | 23 +++++++++++++++++++----
>  drivers/gpu/drm/msm/msm_gpu.c            | 11 +----------
>  drivers/gpu/drm/msm/msm_gpummu.c         |  6 ------
>  drivers/gpu/drm/msm/msm_iommu.c          | 15 +++++++--------
>  drivers/gpu/drm/msm/msm_mmu.h            |  1 -
>  8 files changed, 27 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> index 6c92f0f..b082b23 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> @@ -704,7 +704,6 @@ static int _dpu_kms_mmu_init(struct dpu_kms *dpu_kms)
>  {
>         struct iommu_domain *domain;
>         struct msm_gem_address_space *aspace;
> -       int ret;
>
>         domain = iommu_domain_alloc(&platform_bus_type);
>         if (!domain)
> @@ -720,13 +719,6 @@ static int _dpu_kms_mmu_init(struct dpu_kms *dpu_kms)
>                 return PTR_ERR(aspace);
>         }
>
> -       ret = aspace->mmu->funcs->attach(aspace->mmu);
> -       if (ret) {
> -               DPU_ERROR("failed to attach iommu %d\n", ret);
> -               msm_gem_address_space_put(aspace);
> -               return ret;
> -       }
> -
>         dpu_kms->base.aspace = aspace;
>         return 0;
>  }
> diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
> index dda0543..9dba37c 100644
> --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
> +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
> @@ -518,10 +518,6 @@ struct msm_kms *mdp4_kms_init(struct drm_device *dev)
>                 }
>
>                 kms->aspace = aspace;
> -
> -               ret = aspace->mmu->funcs->attach(aspace->mmu);
> -               if (ret)
> -                       goto fail;
>         } else {
>                 DRM_DEV_INFO(dev->dev, "no iommu, fallback to phys "
>                                 "contig buffers for scanout\n");
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> index e43ecd4..653dab2 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> @@ -736,13 +736,6 @@ struct msm_kms *mdp5_kms_init(struct drm_device *dev)
>                 }
>
>                 kms->aspace = aspace;
> -
> -               ret = aspace->mmu->funcs->attach(aspace->mmu);
> -               if (ret) {
> -                       DRM_DEV_ERROR(&pdev->dev, "failed to attach iommu: %d\n",
> -                               ret);
> -                       goto fail;
> -               }
>         } else {
>                 DRM_DEV_INFO(&pdev->dev,
>                          "no iommu, fallback to phys contig buffers for scanout\n");
> diff --git a/drivers/gpu/drm/msm/msm_gem_vma.c b/drivers/gpu/drm/msm/msm_gem_vma.c
> index 1af5354..91d993a 100644
> --- a/drivers/gpu/drm/msm/msm_gem_vma.c
> +++ b/drivers/gpu/drm/msm/msm_gem_vma.c
> @@ -131,8 +131,8 @@ msm_gem_address_space_create(struct device *dev, struct iommu_domain *domain,
>                 const char *name)
>  {
>         struct msm_gem_address_space *aspace;
> -       u64 size = domain->geometry.aperture_end -
> -               domain->geometry.aperture_start;
> +       u64 start = domain->geometry.aperture_start;
> +       u64 size = domain->geometry.aperture_end - start;
>
>         aspace = kzalloc(sizeof(*aspace), GFP_KERNEL);
>         if (!aspace)
> @@ -141,9 +141,18 @@ msm_gem_address_space_create(struct device *dev, struct iommu_domain *domain,
>         spin_lock_init(&aspace->lock);
>         aspace->name = name;
>         aspace->mmu = msm_iommu_new(dev, domain);
> +       if (IS_ERR(aspace->mmu)) {
> +               int ret = PTR_ERR(aspace->mmu);
>
> -       drm_mm_init(&aspace->mm, (domain->geometry.aperture_start >> PAGE_SHIFT),
> -               size >> PAGE_SHIFT);
> +               kfree(aspace);
> +               return ERR_PTR(ret);
> +       }
> +
> +       /*
> +        * Attaching the IOMMU device changes the aperture values so use the
> +        * cached values instead
> +        */
> +       drm_mm_init(&aspace->mm, start >> PAGE_SHIFT, size >> PAGE_SHIFT);
>
>         kref_init(&aspace->kref);
>
> @@ -164,6 +173,12 @@ msm_gem_address_space_create_a2xx(struct device *dev, struct msm_gpu *gpu,
>         spin_lock_init(&aspace->lock);
>         aspace->name = name;
>         aspace->mmu = msm_gpummu_new(dev, gpu);
> +       if (IS_ERR(aspace->mmu)) {
> +               int ret = PTR_ERR(aspace->mmu);
> +
> +               kfree(aspace);
> +               return ERR_PTR(ret);
> +       }
>
>         drm_mm_init(&aspace->mm, (va_start >> PAGE_SHIFT),
>                 size >> PAGE_SHIFT);
> diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> index 18f3a5c..f7bf80e 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.c
> +++ b/drivers/gpu/drm/msm/msm_gpu.c
> @@ -808,7 +808,6 @@ msm_gpu_create_address_space(struct msm_gpu *gpu, struct platform_device *pdev,
>                 uint64_t va_start, uint64_t va_end)
>  {
>         struct msm_gem_address_space *aspace;
> -       int ret;
>
>         /*
>          * Setup IOMMU.. eventually we will (I think) do this once per context
> @@ -833,17 +832,9 @@ msm_gpu_create_address_space(struct msm_gpu *gpu, struct platform_device *pdev,
>                         va_start, va_end);
>         }
>
> -       if (IS_ERR(aspace)) {
> +       if (IS_ERR(aspace))
>                 DRM_DEV_ERROR(gpu->dev->dev, "failed to init mmu: %ld\n",
>                         PTR_ERR(aspace));
> -               return ERR_CAST(aspace);
> -       }
> -
> -       ret = aspace->mmu->funcs->attach(aspace->mmu);
> -       if (ret) {
> -               msm_gem_address_space_put(aspace);
> -               return ERR_PTR(ret);
> -       }
>
>         return aspace;
>  }
> diff --git a/drivers/gpu/drm/msm/msm_gpummu.c b/drivers/gpu/drm/msm/msm_gpummu.c
> index 34980d8..0ad0f84 100644
> --- a/drivers/gpu/drm/msm/msm_gpummu.c
> +++ b/drivers/gpu/drm/msm/msm_gpummu.c
> @@ -21,11 +21,6 @@ struct msm_gpummu {
>  #define GPUMMU_PAGE_SIZE SZ_4K
>  #define TABLE_SIZE (sizeof(uint32_t) * GPUMMU_VA_RANGE / GPUMMU_PAGE_SIZE)
>
> -static int msm_gpummu_attach(struct msm_mmu *mmu)
> -{
> -       return 0;
> -}
> -
>  static void msm_gpummu_detach(struct msm_mmu *mmu)
>  {
>  }
> @@ -85,7 +80,6 @@ static void msm_gpummu_destroy(struct msm_mmu *mmu)
>  }
>
>  static const struct msm_mmu_funcs funcs = {
> -               .attach = msm_gpummu_attach,
>                 .detach = msm_gpummu_detach,
>                 .map = msm_gpummu_map,
>                 .unmap = msm_gpummu_unmap,
> diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
> index ad58cfe..544c519 100644
> --- a/drivers/gpu/drm/msm/msm_iommu.c
> +++ b/drivers/gpu/drm/msm/msm_iommu.c
> @@ -23,13 +23,6 @@ static int msm_fault_handler(struct iommu_domain *domain, struct device *dev,
>         return 0;
>  }
>
> -static int msm_iommu_attach(struct msm_mmu *mmu)
> -{
> -       struct msm_iommu *iommu = to_msm_iommu(mmu);
> -
> -       return iommu_attach_device(iommu->domain, mmu->dev);
> -}
> -
>  static void msm_iommu_detach(struct msm_mmu *mmu)
>  {
>         struct msm_iommu *iommu = to_msm_iommu(mmu);
> @@ -66,7 +59,6 @@ static void msm_iommu_destroy(struct msm_mmu *mmu)
>  }
>
>  static const struct msm_mmu_funcs funcs = {
> -               .attach = msm_iommu_attach,
>                 .detach = msm_iommu_detach,
>                 .map = msm_iommu_map,
>                 .unmap = msm_iommu_unmap,
> @@ -76,6 +68,7 @@ static const struct msm_mmu_funcs funcs = {
>  struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain)
>  {
>         struct msm_iommu *iommu;
> +       int ret;
>
>         iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
>         if (!iommu)
> @@ -85,5 +78,11 @@ struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain)
>         msm_mmu_init(&iommu->base, dev, &funcs);
>         iommu_set_fault_handler(domain, msm_fault_handler, iommu);
>
> +       ret = iommu_attach_device(iommu->domain, dev);
> +       if (ret) {
> +               kfree(iommu);
> +               return ERR_PTR(ret);
> +       }
> +
>         return &iommu->base;
>  }
> diff --git a/drivers/gpu/drm/msm/msm_mmu.h b/drivers/gpu/drm/msm/msm_mmu.h
> index 67a623f..bae9e8e 100644
> --- a/drivers/gpu/drm/msm/msm_mmu.h
> +++ b/drivers/gpu/drm/msm/msm_mmu.h
> @@ -10,7 +10,6 @@
>  #include <linux/iommu.h>
>
>  struct msm_mmu_funcs {
> -       int (*attach)(struct msm_mmu *mmu);
>         void (*detach)(struct msm_mmu *mmu);
>         int (*map)(struct msm_mmu *mmu, uint64_t iova, struct sg_table *sgt,
>                         unsigned len, int prot);
> --
> 2.7.4
>