Re: [PATCH v5 07/27] drm/amdgpu: Remap all page faults to per process dummy page.

["Christian König" <ckoenig.leichtzumerken@gmail.com>]

Am 28.04.21 um 17:11 schrieb Andrey Grodzovsky:
> On device removal reroute all CPU mappings to dummy page
> per drm_file instance or imported GEM object.
>
> v4:
> Update for modified ttm_bo_vm_dummy_page
>
> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 21 ++++++++++++++++-----
>   1 file changed, 16 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index a785acc09f20..93163b220e46 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -49,6 +49,7 @@
>   
>   #include <drm/drm_debugfs.h>
>   #include <drm/amdgpu_drm.h>
> +#include <drm/drm_drv.h>
>   
>   #include "amdgpu.h"
>   #include "amdgpu_object.h"
> @@ -1982,18 +1983,28 @@ void amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
>   static vm_fault_t amdgpu_ttm_fault(struct vm_fault *vmf)
>   {
>   	struct ttm_buffer_object *bo = vmf->vma->vm_private_data;
> +	struct drm_device *ddev = bo->base.dev;
>   	vm_fault_t ret;
> +	int idx;
>   
>   	ret = ttm_bo_vm_reserve(bo, vmf);
>   	if (ret)
>   		return ret;
>   
> -	ret = amdgpu_bo_fault_reserve_notify(bo);
> -	if (ret)
> -		goto unlock;
> +	if (drm_dev_enter(ddev, &idx)) {
> +		ret = amdgpu_bo_fault_reserve_notify(bo);
> +		if (ret) {
> +			drm_dev_exit(idx);
> +			goto unlock;
> +		}
>   
> -	ret = ttm_bo_vm_fault_reserved(vmf, vmf->vma->vm_page_prot,
> -				       TTM_BO_VM_NUM_PREFAULT, 1);
> +		 ret = ttm_bo_vm_fault_reserved(vmf, vmf->vma->vm_page_prot,
> +						TTM_BO_VM_NUM_PREFAULT, 1);
> +
> +		 drm_dev_exit(idx);
> +	} else {
> +		ret = ttm_bo_vm_dummy_page(vmf, vmf->vma->vm_page_prot);
> +	}
>   	if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
>   		return ret;
>