[PATCH 7/8] drm/etnaviv: reference MMU context when setting up hardware state

[Christian Gmeiner]

Am Fr., 20. Aug. 2021 um 22:18 Uhr schrieb Lucas Stach <l.stach at pengutronix.de>:
>
> Move the refcount manipulation of the MMU context to the point where the
> hardware state is programmed. At that point it is also known if a previous
> MMU state is still there, or the state needs to be reprogrammed with a
> potentially different context.
>
> Cc: stable at vger.kernel.org # 5.4
> Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
> Tested-by: Michael Walle <michael at walle.cc>
> ---
>  drivers/gpu/drm/etnaviv/etnaviv_gpu.c      | 24 +++++++++++-----------
>  drivers/gpu/drm/etnaviv/etnaviv_iommu.c    |  4 ++++
>  drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c |  8 ++++++++
>  3 files changed, 24 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> index f420c4f14657..1fa98ce870f7 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> @@ -641,17 +641,19 @@ void etnaviv_gpu_start_fe(struct etnaviv_gpu *gpu, u32 address, u16 prefetch)
>         gpu->fe_running = true;
>  }
>
> -static void etnaviv_gpu_start_fe_idleloop(struct etnaviv_gpu *gpu)
> +static void etnaviv_gpu_start_fe_idleloop(struct etnaviv_gpu *gpu,
> +                                         struct etnaviv_iommu_context *context)
>  {
> -       u32 address = etnaviv_cmdbuf_get_va(&gpu->buffer,
> -                               &gpu->mmu_context->cmdbuf_mapping);
>         u16 prefetch;
> +       u32 address;
>
>         /* setup the MMU */
> -       etnaviv_iommu_restore(gpu, gpu->mmu_context);
> +       etnaviv_iommu_restore(gpu, context);
>
>         /* Start command processor */
>         prefetch = etnaviv_buffer_init(gpu);
> +       address = etnaviv_cmdbuf_get_va(&gpu->buffer,
> +                                       &gpu->mmu_context->cmdbuf_mapping);
>
>         etnaviv_gpu_start_fe(gpu, address, prefetch);
>  }
> @@ -1369,14 +1371,12 @@ struct dma_fence *etnaviv_gpu_submit(struct etnaviv_gem_submit *submit)
>                 goto out_unlock;
>         }
>
> -       if (!gpu->fe_running) {
> -               gpu->mmu_context = etnaviv_iommu_context_get(submit->mmu_context);
> -               etnaviv_gpu_start_fe_idleloop(gpu);
> -       } else {
> -               if (submit->prev_mmu_context)
> -                       etnaviv_iommu_context_put(submit->prev_mmu_context);
> -               submit->prev_mmu_context = etnaviv_iommu_context_get(gpu->mmu_context);
> -       }
> +       if (!gpu->fe_running)
> +               etnaviv_gpu_start_fe_idleloop(gpu, submit->mmu_context);
> +
> +       if (submit->prev_mmu_context)
> +               etnaviv_iommu_context_put(submit->prev_mmu_context);
> +       submit->prev_mmu_context = etnaviv_iommu_context_get(gpu->mmu_context);
>
>         if (submit->nr_pmrs) {
>                 gpu->event[event[1]].sync_point = &sync_point_perfmon_sample_pre;
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_iommu.c b/drivers/gpu/drm/etnaviv/etnaviv_iommu.c
> index 1a7c89a67bea..afe5dd6a9925 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_iommu.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_iommu.c
> @@ -92,6 +92,10 @@ static void etnaviv_iommuv1_restore(struct etnaviv_gpu *gpu,
>         struct etnaviv_iommuv1_context *v1_context = to_v1_context(context);
>         u32 pgtable;
>
> +       if (gpu->mmu_context)
> +               etnaviv_iommu_context_put(gpu->mmu_context);
> +       gpu->mmu_context = etnaviv_iommu_context_get(context);
> +
>         /* set base addresses */
>         gpu_write(gpu, VIVS_MC_MEMORY_BASE_ADDR_RA, context->global->memory_base);
>         gpu_write(gpu, VIVS_MC_MEMORY_BASE_ADDR_FE, context->global->memory_base);
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c b/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c
> index f8bf488e9d71..d664ae29ae20 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_iommu_v2.c
> @@ -172,6 +172,10 @@ static void etnaviv_iommuv2_restore_nonsec(struct etnaviv_gpu *gpu,
>         if (gpu_read(gpu, VIVS_MMUv2_CONTROL) & VIVS_MMUv2_CONTROL_ENABLE)
>                 return;
>
> +       if (gpu->mmu_context)
> +               etnaviv_iommu_context_put(gpu->mmu_context);
> +       gpu->mmu_context = etnaviv_iommu_context_get(context);
> +
>         prefetch = etnaviv_buffer_config_mmuv2(gpu,
>                                 (u32)v2_context->mtlb_dma,
>                                 (u32)context->global->bad_page_dma);
> @@ -192,6 +196,10 @@ static void etnaviv_iommuv2_restore_sec(struct etnaviv_gpu *gpu,
>         if (gpu_read(gpu, VIVS_MMUv2_SEC_CONTROL) & VIVS_MMUv2_SEC_CONTROL_ENABLE)
>                 return;
>
> +       if (gpu->mmu_context)
> +               etnaviv_iommu_context_put(gpu->mmu_context);
> +       gpu->mmu_context = etnaviv_iommu_context_get(context);
> +

I have seen this pattern now more than two times - maybe put the
assignment of a new mmu context into its own function?

>         gpu_write(gpu, VIVS_MMUv2_PTA_ADDRESS_LOW,
>                   lower_32_bits(context->global->v2.pta_dma));
>         gpu_write(gpu, VIVS_MMUv2_PTA_ADDRESS_HIGH,
> --
> 2.30.2
>


-- 
greets
--
Christian Gmeiner, MSc

https://christian-gmeiner.info/privacypolicy