Re: [PATCH] drm/amdgpu: add workarounds for Raven VCN TMZ issue

["Christian König" <christian.koenig@amd.com>]

Am 04.03.22 um 10:15 schrieb Lang Yu:
> It is a hardware issue that VCN can't handle a GTT
> backing stored TMZ buffer on Raven.
>
> Move such a TMZ buffer to VRAM domain before command
> submission.

Please don't touch the CS code with that. What you can do is to 
implement a Raven specific patch_cs_in_place callback in the vcn_v*.c file.

See amdgpu_uvd_force_into_uvd_segment() how we handle the 256MiB window 
on really old UVD blocks. You just don't need to implement the full 
parsing of the command stream (yet).

Regards,
Christian.

>
> Signed-off-by: Lang Yu <Lang.Yu@amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 27 ++++++++++++++++++++++++++
>   1 file changed, 27 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> index af12256e1bd3..66345f2ce6ba 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> @@ -393,6 +393,24 @@ void amdgpu_cs_report_moved_bytes(struct amdgpu_device *adev, u64 num_bytes,
>   	spin_unlock(&adev->mm_stats.lock);
>   }
>   
> +static int raven_vcn_tmz_quirks(struct amdgpu_cs_parser *p, struct amdgpu_bo *bo, uint32_t *domain)
> +{
> +	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> +	struct amdgpu_ring *ring = to_amdgpu_ring(p->entity->rq->sched);
> +
> +	if ((adev->asic_type == CHIP_RAVEN) &&
> +	    (bo->flags & AMDGPU_GEM_CREATE_ENCRYPTED) &&
> +	    (ring->funcs->type == AMDGPU_HW_IP_VCN_DEC ||
> +	    ring->funcs->type == AMDGPU_HW_IP_VCN_ENC ||
> +	    ring->funcs->type == AMDGPU_HW_IP_VCN_JPEG)) {
> +		if (domain)
> +			*domain = AMDGPU_GEM_DOMAIN_VRAM;
> +		return 1;
> +	}
> +
> +	return 0;
> +}
> +
>   static int amdgpu_cs_bo_validate(void *param, struct amdgpu_bo *bo)
>   {
>   	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> @@ -403,6 +421,7 @@ static int amdgpu_cs_bo_validate(void *param, struct amdgpu_bo *bo)
>   		.resv = bo->tbo.base.resv
>   	};
>   	uint32_t domain;
> +	bool need_retry = 1;
>   	int r;
>   
>   	if (bo->tbo.pin_count)
> @@ -431,6 +450,8 @@ static int amdgpu_cs_bo_validate(void *param, struct amdgpu_bo *bo)
>   		domain = bo->allowed_domains;
>   	}
>   
> +	raven_vcn_tmz_quirks(p, bo, &domain);
> +
>   retry:
>   	amdgpu_bo_placement_from_domain(bo, domain);
>   	r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
> @@ -442,6 +463,12 @@ static int amdgpu_cs_bo_validate(void *param, struct amdgpu_bo *bo)
>   
>   	if (unlikely(r == -ENOMEM) && domain != bo->allowed_domains) {
>   		domain = bo->allowed_domains;
> +		if (raven_vcn_tmz_quirks(p, bo, &domain)) {
> +			if (need_retry)
> +				need_retry = 0;
> +			else
> +				return r;
> +		}
>   		goto retry;
>   	}
>