[PATCH] drm/amdgpu: add safeguards for accessing mmhub CG registers

[Christian König]

Am 26.01.22 um 08:53 schrieb Lang Yu:
> We observed a gpu hang when querying mmhub CG status(i.e.,
> cat amdgpu_pm_info) on cyan skillfish. Acctually, cyan
> skillfish doesn't support any CG features.
>
> Only allow asics which support CG features accessing related
> registers. Will add similar safeguards for other IPs in the
> furture.

I think you should probably add a macro or function for this check, 
apart from that looks good to me.

Christian.

>
> Signed-off-by: Lang Yu <Lang.Yu at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c | 3 +++
>   drivers/gpu/drm/amd/amdgpu/mmhub_v1_7.c | 3 +++
>   drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c | 3 +++
>   drivers/gpu/drm/amd/amdgpu/mmhub_v2_3.c | 3 +++
>   drivers/gpu/drm/amd/amdgpu/mmhub_v9_4.c | 3 +++
>   5 files changed, 15 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c b/drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c
> index 4c9f0c0f3116..1869e2019461 100644
> --- a/drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c
> @@ -550,6 +550,9 @@ static void mmhub_v1_0_get_clockgating(struct amdgpu_device *adev, u32 *flags)
>   {
>   	int data, data1;
>   
> +	if (!(adev->cg_flags & (AMD_CG_SUPPORT_MC_MGCG | AMD_CG_SUPPORT_MC_LS)))
> +		return;
> +
>   	if (amdgpu_sriov_vf(adev))
>   		*flags = 0;
>   
> diff --git a/drivers/gpu/drm/amd/amdgpu/mmhub_v1_7.c b/drivers/gpu/drm/amd/amdgpu/mmhub_v1_7.c
> index 3b901f941627..f7b9843b36e6 100644
> --- a/drivers/gpu/drm/amd/amdgpu/mmhub_v1_7.c
> +++ b/drivers/gpu/drm/amd/amdgpu/mmhub_v1_7.c
> @@ -546,6 +546,9 @@ static void mmhub_v1_7_get_clockgating(struct amdgpu_device *adev, u32 *flags)
>   {
>   	int data, data1;
>   
> +	if (!(adev->cg_flags & (AMD_CG_SUPPORT_MC_MGCG | AMD_CG_SUPPORT_MC_LS)))
> +		return;
> +
>   	if (amdgpu_sriov_vf(adev))
>   		*flags = 0;
>   
> diff --git a/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c b/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c
> index 3718ff610ab2..3f5f326379b7 100644
> --- a/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c
> @@ -686,6 +686,9 @@ static void mmhub_v2_0_get_clockgating(struct amdgpu_device *adev, u32 *flags)
>   {
>   	int data, data1;
>   
> +	if (!(adev->cg_flags & (AMD_CG_SUPPORT_MC_MGCG | AMD_CG_SUPPORT_MC_LS)))
> +		return;
> +
>   	if (amdgpu_sriov_vf(adev))
>   		*flags = 0;
>   
> diff --git a/drivers/gpu/drm/amd/amdgpu/mmhub_v2_3.c b/drivers/gpu/drm/amd/amdgpu/mmhub_v2_3.c
> index 9e16da28505a..b23dd9ddfb5c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/mmhub_v2_3.c
> +++ b/drivers/gpu/drm/amd/amdgpu/mmhub_v2_3.c
> @@ -580,6 +580,9 @@ static void mmhub_v2_3_get_clockgating(struct amdgpu_device *adev, u32 *flags)
>   {
>   	int data, data1, data2, data3;
>   
> +	if (!(adev->cg_flags & (AMD_CG_SUPPORT_MC_MGCG | AMD_CG_SUPPORT_MC_LS)))
> +		return;
> +
>   	if (amdgpu_sriov_vf(adev))
>   		*flags = 0;
>   
> diff --git a/drivers/gpu/drm/amd/amdgpu/mmhub_v9_4.c b/drivers/gpu/drm/amd/amdgpu/mmhub_v9_4.c
> index 619106f7d23d..a2d5c8424e2b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/mmhub_v9_4.c
> +++ b/drivers/gpu/drm/amd/amdgpu/mmhub_v9_4.c
> @@ -651,6 +651,9 @@ static void mmhub_v9_4_get_clockgating(struct amdgpu_device *adev, u32 *flags)
>   {
>   	int data, data1;
>   
> +	if (!(adev->cg_flags & (AMD_CG_SUPPORT_MC_MGCG | AMD_CG_SUPPORT_MC_LS)))
> +		return;
> +
>   	if (amdgpu_sriov_vf(adev))
>   		*flags = 0;
>