Re: [PATCH] drm/msm: Only enable A6xx LLCC code on A6xx

[Rob Clark]

On Wed, Jan 6, 2021 at 8:50 PM Sai Prakash Ranjan
<saiprakash.ranjan@xxxxxxxxxxxxxx> wrote:
>
> On 2021-01-05 01:00, Konrad Dybcio wrote:
> > Using this code on A5xx (and probably older too) causes a
> > smmu bug.
> >
> > Fixes: 474dadb8b0d5 ("drm/msm/a6xx: Add support for using system
> > cache(LLC)")
> > Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxx>
> > Tested-by: AngeloGioacchino Del Regno
> > <angelogioacchino.delregno@xxxxxxxxxxxxxx>
> > ---
>
> Reviewed-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>
>
> >  drivers/gpu/drm/msm/adreno/adreno_gpu.c | 21 ++++++++++++---------
> >  drivers/gpu/drm/msm/adreno/adreno_gpu.h |  5 +++++
> >  2 files changed, 17 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> > b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> > index 6cf9975e951e..f09175698827 100644
> > --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> > +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> > @@ -191,8 +191,6 @@ adreno_iommu_create_address_space(struct msm_gpu
> > *gpu,
> >               struct platform_device *pdev)
> >  {
> >       struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
> > -     struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
> > -     struct io_pgtable_domain_attr pgtbl_cfg;
> >       struct iommu_domain *iommu;
> >       struct msm_mmu *mmu;
> >       struct msm_gem_address_space *aspace;
> > @@ -202,13 +200,18 @@ adreno_iommu_create_address_space(struct msm_gpu
> > *gpu,
> >       if (!iommu)
> >               return NULL;
> >
> > -     /*
> > -      * This allows GPU to set the bus attributes required to use system
> > -      * cache on behalf of the iommu page table walker.
> > -      */
> > -     if (!IS_ERR(a6xx_gpu->htw_llc_slice)) {
> > -             pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_ARM_OUTER_WBWA;
> > -             iommu_domain_set_attr(iommu, DOMAIN_ATTR_IO_PGTABLE_CFG,
> > &pgtbl_cfg);
> > +
> > +     if (adreno_is_a6xx(adreno_gpu)) {
> > +             struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
> > +             struct io_pgtable_domain_attr pgtbl_cfg;
> > +             /*
> > +             * This allows GPU to set the bus attributes required to use system
> > +             * cache on behalf of the iommu page table walker.
> > +             */
> > +             if (!IS_ERR(a6xx_gpu->htw_llc_slice)) {
> > +                     pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_ARM_OUTER_WBWA;
> > +                     iommu_domain_set_attr(iommu, DOMAIN_ATTR_IO_PGTABLE_CFG,
> > &pgtbl_cfg);
> > +             }

I'm applying for -fixes as this is an obvious problem..  But kinda
thinking that we should try to move it into an a6xx specific
create_address_space() (or wrapper for the generic fxn)

Sai/Jordan, could I talk one of you into trying to clean this up
better for next cycle?

BR,
-R

> >       }
> >
> >       mmu = msm_iommu_new(&pdev->dev, iommu);
> > diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> > b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> > index 4574d85c5680..08421fa54a50 100644
> > --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> > +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> > @@ -226,6 +226,11 @@ static inline int adreno_is_a540(struct adreno_gpu
> > *gpu)
> >       return gpu->revn == 540;
> >  }
> >
> > +static inline bool adreno_is_a6xx(struct adreno_gpu *gpu)
> > +{
> > +     return ((gpu->revn < 700 && gpu->revn > 599));
> > +}
> > +
> >  static inline int adreno_is_a618(struct adreno_gpu *gpu)
> >  {
> >         return gpu->revn == 618;
>
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
> member
> of Code Aurora Forum, hosted by The Linux Foundation