Re: [Freedreno] [PATCH v11 10/12] drm/msm: Add support for private address space instances

[Rob Clark <robdclark@gmail.com>]

On Mon, Aug 3, 2020 at 12:36 PM Jordan Crouse <jcrouse@codeaurora.org> wrote:
>
> Add support for allocating private address space instances. Targets that
> support per-context pagetables should implement their own function to
> allocate private address spaces.
>
> The default will return a pointer to the global address space.
>
> Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
> ---
>
>  drivers/gpu/drm/msm/msm_drv.c     | 13 +++++++------
>  drivers/gpu/drm/msm/msm_drv.h     |  5 +++++
>  drivers/gpu/drm/msm/msm_gem_vma.c |  9 +++++++++
>  drivers/gpu/drm/msm/msm_gpu.c     | 17 +++++++++++++++++
>  drivers/gpu/drm/msm/msm_gpu.h     |  5 +++++
>  5 files changed, 43 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 108b663c3ef2..f072306f1260 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -597,7 +597,7 @@ static int context_init(struct drm_device *dev, struct drm_file *file)
>         kref_init(&ctx->ref);
>         msm_submitqueue_init(dev, ctx);
>
> -       ctx->aspace = priv->gpu ? priv->gpu->aspace : NULL;
> +       ctx->aspace = msm_gpu_create_private_address_space(priv->gpu);
>         file->driver_priv = ctx;
>
>         return 0;
> @@ -780,18 +780,19 @@ static int msm_ioctl_gem_cpu_fini(struct drm_device *dev, void *data,
>  }
>
>  static int msm_ioctl_gem_info_iova(struct drm_device *dev,
> -               struct drm_gem_object *obj, uint64_t *iova)
> +               struct drm_file *file, struct drm_gem_object *obj,
> +               uint64_t *iova)
>  {
> -       struct msm_drm_private *priv = dev->dev_private;
> +       struct msm_file_private *ctx = file->driver_priv;
>
> -       if (!priv->gpu)
> +       if (!ctx->aspace)
>                 return -EINVAL;
>
>         /*
>          * Don't pin the memory here - just get an address so that userspace can
>          * be productive
>          */
> -       return msm_gem_get_iova(obj, priv->gpu->aspace, iova);
> +       return msm_gem_get_iova(obj, ctx->aspace, iova);
>  }
>
>  static int msm_ioctl_gem_info(struct drm_device *dev, void *data,
> @@ -830,7 +831,7 @@ static int msm_ioctl_gem_info(struct drm_device *dev, void *data,
>                 args->value = msm_gem_mmap_offset(obj);
>                 break;
>         case MSM_INFO_GET_IOVA:
> -               ret = msm_ioctl_gem_info_iova(dev, obj, &args->value);
> +               ret = msm_ioctl_gem_info_iova(dev, file, obj, &args->value);
>                 break;
>         case MSM_INFO_SET_NAME:
>                 /* length check should leave room for terminating null: */
> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> index f69c6d62584d..51a5c9083e13 100644
> --- a/drivers/gpu/drm/msm/msm_drv.h
> +++ b/drivers/gpu/drm/msm/msm_drv.h
> @@ -249,6 +249,10 @@ int msm_gem_map_vma(struct msm_gem_address_space *aspace,
>  void msm_gem_close_vma(struct msm_gem_address_space *aspace,
>                 struct msm_gem_vma *vma);
>
> +
> +struct msm_gem_address_space *
> +msm_gem_address_space_get(struct msm_gem_address_space *aspace);
> +
>  void msm_gem_address_space_put(struct msm_gem_address_space *aspace);
>
>  struct msm_gem_address_space *
> @@ -434,6 +438,7 @@ static inline void msm_file_private_destroy(struct kref *kref)
>         struct msm_file_private *ctx = container_of(kref,
>                 struct msm_file_private, ref);
>
> +       msm_gem_address_space_put(ctx->aspace);
>         kfree(ctx);
>  }
>
> diff --git a/drivers/gpu/drm/msm/msm_gem_vma.c b/drivers/gpu/drm/msm/msm_gem_vma.c
> index 5f6a11211b64..29cc1305cf37 100644
> --- a/drivers/gpu/drm/msm/msm_gem_vma.c
> +++ b/drivers/gpu/drm/msm/msm_gem_vma.c
> @@ -27,6 +27,15 @@ void msm_gem_address_space_put(struct msm_gem_address_space *aspace)
>                 kref_put(&aspace->kref, msm_gem_address_space_destroy);
>  }
>
> +struct msm_gem_address_space *
> +msm_gem_address_space_get(struct msm_gem_address_space *aspace)
> +{
> +       if (!IS_ERR_OR_NULL(aspace))
> +               kref_get(&aspace->kref);
> +
> +       return aspace;
> +}
> +
>  /* Actually unmap memory for the vma */
>  void msm_gem_purge_vma(struct msm_gem_address_space *aspace,
>                 struct msm_gem_vma *vma)
> diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> index a1f3da6550e5..aabbd7908ee5 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.c
> +++ b/drivers/gpu/drm/msm/msm_gpu.c
> @@ -823,6 +823,23 @@ static int get_clocks(struct platform_device *pdev, struct msm_gpu *gpu)
>         return 0;
>  }
>
> +/* Return a new address space for a msm_drm_private instance */
> +struct msm_gem_address_space *
> +msm_gpu_create_private_address_space(struct msm_gpu *gpu)
> +{
> +       if (!gpu)
> +               return NULL;
> +
> +       /*
> +        * If the target doesn't support private address spaces then return
> +        * the global one
> +        */
> +       if (!gpu->funcs->create_private_address_space)
> +               return msm_gem_address_space_get(gpu->aspace);
> +
> +       return gpu->funcs->create_private_address_space(gpu);

so if you flip the logic around here, you can get rid of the
msm_gem_address_space_get() in per-gen backend and consolidate the
error handling here, ie.

  struct msm_gem_address_space *aspace = NULL;

  if (gpu->funcs->create_private_address_space)
     aspace = gpu->funcs->create_private_address_space(...);

  if (IS_ERR_OR_NULL(aspace))
    aspace = msm_gem_address_space_get(...);

(and that also simplifies a bit the patch I have on top to show comm in debugfs)

BR,
-R

> +}
> +
>  int msm_gpu_init(struct drm_device *drm, struct platform_device *pdev,
>                 struct msm_gpu *gpu, const struct msm_gpu_funcs *funcs,
>                 const char *name, struct msm_gpu_config *config)
> diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
> index d496d488222c..d298657b4730 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.h
> +++ b/drivers/gpu/drm/msm/msm_gpu.h
> @@ -64,6 +64,8 @@ struct msm_gpu_funcs {
>         void (*gpu_set_freq)(struct msm_gpu *gpu, struct dev_pm_opp *opp);
>         struct msm_gem_address_space *(*create_address_space)
>                 (struct msm_gpu *gpu, struct platform_device *pdev);
> +       struct msm_gem_address_space *(*create_private_address_space)
> +               (struct msm_gpu *gpu);
>  };
>
>  struct msm_gpu {
> @@ -286,6 +288,9 @@ int msm_gpu_init(struct drm_device *drm, struct platform_device *pdev,
>                 struct msm_gpu *gpu, const struct msm_gpu_funcs *funcs,
>                 const char *name, struct msm_gpu_config *config);
>
> +struct msm_gem_address_space *
> +msm_gpu_create_private_address_space(struct msm_gpu *gpu);
> +
>  void msm_gpu_cleanup(struct msm_gpu *gpu);
>
>  struct msm_gpu *adreno_load_gpu(struct drm_device *dev);
> --
> 2.25.1
>
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