Re: [PATCH v5 04/11] drm/amdgpu: Add user save area params validation

[Alex Deucher]

On Fri, Jan 30, 2026 at 4:22 AM Lijo Lazar <lijo.la...@amd.com> wrote:
>
> Add an interface to validate user provided save area parameters. Address
> validation is not done and expected to be done outside.
>
> Signed-off-by: Lijo Lazar <lijo.la...@amd.com>

Reviewed-by: Alex Deucher <alexander.deuc...@amd.com>

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_cwsr.c | 39 ++++++++++++++++++++++++
>  drivers/gpu/drm/amd/amdgpu/amdgpu_cwsr.h | 10 ++++++
>  2 files changed, 49 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cwsr.c 
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_cwsr.c
> index 80020fd33ce6..f4907172ebeb 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cwsr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cwsr.c
> @@ -64,6 +64,15 @@ static inline bool amdgpu_cwsr_is_supported(struct 
> amdgpu_device *adev)
>         return true;
>  }
>
> +uint32_t amdgpu_cwsr_size_needed(struct amdgpu_device *adev, int num_xcc)
> +{
> +       if (!amdgpu_cwsr_is_enabled(adev))
> +               return 0;
> +
> +       return num_xcc *
> +              (adev->cwsr_info->xcc_cwsr_sz + 
> adev->cwsr_info->xcc_dbg_mem_sz);
> +}
> +
>  static void amdgpu_cwsr_init_isa_details(struct amdgpu_device *adev,
>                                          struct amdgpu_cwsr_info *cwsr_info)
>  {
> @@ -425,6 +434,36 @@ int amdgpu_cwsr_alloc(struct amdgpu_device *adev, struct 
> amdgpu_vm *vm,
>         return r;
>  }
>
> +int amdgpu_cwsr_validate_params(struct amdgpu_device *adev,
> +                               struct amdgpu_cwsr_params *cwsr_params,
> +                               int num_xcc)
> +{
> +       uint32_t min_size, max_size;
> +
> +       if (!amdgpu_cwsr_is_enabled(adev))
> +               return -EOPNOTSUPP;
> +
> +       if (!cwsr_params)
> +               return -EINVAL;
> +
> +       min_size = amdgpu_cwsr_size_needed(adev, num_xcc);
> +       max_size = 2 * min_size;
> +       /*
> +        * Only save area size details checked. Address validation needs to be
> +        * carried out separately. User is expected to pass a cwsr buffer area
> +        * with size >= ctl stack size + wg data size + debug memory size
> +        */
> +       if (cwsr_params->cwsr_sz < min_size ||
> +           cwsr_params->cwsr_sz > max_size) {
> +               dev_dbg(adev->dev,
> +                       "queue cwsr size 0x%x should be within min %u : max 
> %u\n",
> +                       cwsr_params->cwsr_sz, min_size, max_size);
> +               return -EINVAL;
> +       }
> +
> +       return 0;
> +}
> +
>  void amdgpu_cwsr_free(struct amdgpu_device *adev, struct amdgpu_vm *vm,
>                       struct amdgpu_cwsr_trap_obj **trap_obj)
>  {
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cwsr.h 
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_cwsr.h
> index 3c80d057bbed..7f922559e297 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cwsr.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cwsr.h
> @@ -56,6 +56,12 @@ struct amdgpu_cwsr_info {
>         uint32_t xcc_cwsr_sz;
>  };
>
> +struct amdgpu_cwsr_params {
> +       uint64_t ctx_save_area_address;
> +       /* cwsr size info */
> +       uint32_t cwsr_sz;
> +};
> +
>  int amdgpu_cwsr_init(struct amdgpu_device *adev);
>  void amdgpu_cwsr_fini(struct amdgpu_device *adev);
>
> @@ -68,4 +74,8 @@ static inline bool amdgpu_cwsr_is_enabled(struct 
> amdgpu_device *adev)
>         return adev->cwsr_info != NULL;
>  }
>
> +uint32_t amdgpu_cwsr_size_needed(struct amdgpu_device *adev, int num_xcc);
> +int amdgpu_cwsr_validate_params(struct amdgpu_device *adev,
> +                               struct amdgpu_cwsr_params *cwsr_params,
> +                               int num_xcc);
>  #endif
> --
> 2.49.0
>