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

[Lang Yu]

On 01/26/ , Christian König wrote:
> 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.

Thanks for you advice. Is it fine to use such a macro? 

#define amdgpu_device_cg_flag_isset(flag) ((adev->cg_flags) & (flag))

Regards,
Lang

> 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;
>