On Fri, Nov 22, 2019 at 3:32 PM Jordan Crouse <jcro...@codeaurora.org> wrote: > > Attempt to enable split pagetables if the arm-smmu driver supports it. > This will move the default address space from the default region to > the address range assigned to TTBR1. The behavior should be transparent > to the driver for now but it gets the default buffers out of the way > when we want to start swapping TTBR0 for context-specific pagetables. > > Signed-off-by: Jordan Crouse <jcro...@codeaurora.org> > --- > > drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 46 > ++++++++++++++++++++++++++++++++++- > 1 file changed, 45 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c > b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c > index 5dc0b2c..96b3b28 100644 > --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c > +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c > @@ -811,6 +811,50 @@ static unsigned long a6xx_gpu_busy(struct msm_gpu *gpu) > return (unsigned long)busy_time; > } > > +static struct msm_gem_address_space * > +a6xx_create_address_space(struct msm_gpu *gpu, struct platform_device *pdev) > +{ > + struct iommu_domain *iommu = iommu_domain_alloc(&platform_bus_type); > + struct msm_gem_address_space *aspace; > + struct msm_mmu *mmu; > + u64 start, size; > + u32 val = 1; > + int ret; > + > + if (!iommu) > + return ERR_PTR(-ENOMEM); > + > + /* Try to request split pagetables */ > + iommu_domain_set_attr(iommu, DOMAIN_ATTR_SPLIT_TABLES, &val); > + > + mmu = msm_iommu_new(&pdev->dev, iommu); > + if (IS_ERR(mmu)) { > + iommu_domain_free(iommu); > + return ERR_CAST(mmu); > + } > + > + /* Check to see if split pagetables were successful */ > + ret = iommu_domain_get_attr(iommu, DOMAIN_ATTR_SPLIT_TABLES, &val);
I assume the split between this and iommu_domain_set_attr() is because attach needs to happen in between? At any rate, if it needs to be like this, maybe a comment is in order. As it is it looks like something future-self would "cleanup".. BR, -R > + if (!ret && val) { > + /* > + * The aperture start will be at the beginning of the TTBR1 > + * space so use that as a base > + */ > + start = iommu->geometry.aperture_start; > + size = 0xffffffff; > + } else { > + /* Otherwise use the legacy 32 bit region */ > + start = SZ_16M; > + size = 0xffffffff - SZ_16M; > + } > + > + aspace = msm_gem_address_space_create(mmu, "gpu", start, size); > + if (IS_ERR(aspace)) > + iommu_domain_free(iommu); > + > + return aspace; > +} > + > static const struct adreno_gpu_funcs funcs = { > .base = { > .get_param = adreno_get_param, > @@ -832,7 +876,7 @@ static const struct adreno_gpu_funcs funcs = { > #if defined(CONFIG_DRM_MSM_GPU_STATE) > .gpu_state_get = a6xx_gpu_state_get, > .gpu_state_put = a6xx_gpu_state_put, > - .create_address_space = adreno_iommu_create_address_space, > + .create_address_space = a6xx_create_address_space, > #endif > }, > .get_timestamp = a6xx_get_timestamp, > -- > 2.7.4 > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu