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

From: Rob Clark
Date: Thu Jan 07 2021 - 12:25:20 EST


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;
>
> --
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