[PATCH 2/8] drm/amdgpu: update one PDE at a time

[Chunming Zhou]

On 2017年12月09日 00:41, Christian König wrote:
> Horrible inefficient, but avoids problems when the root PD size becomes
> to big.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 81 +++++++++++++++-------------------
>   1 file changed, 36 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index d15b6edf7cce..796375484f6f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -1069,17 +1069,20 @@ static int amdgpu_vm_wait_pd(struct amdgpu_device *adev, struct amdgpu_vm *vm,
>    * Makes sure all entries in @parent are up to date.
>    * Returns 0 for success, error for failure.
>    */
> -static int amdgpu_vm_update_level(struct amdgpu_device *adev,
> -				  struct amdgpu_vm *vm,
> -				  struct amdgpu_vm_pt *parent)
> +static int amdgpu_vm_update_pde(struct amdgpu_device *adev,
> +				struct amdgpu_vm *vm,
> +				struct amdgpu_vm_pt *parent,
> +				struct amdgpu_vm_pt *entry)
>   {
> +	struct amdgpu_pte_update_params params;
> +	struct amdgpu_bo *bo = entry->base.bo;
>   	struct amdgpu_bo *shadow;
>   	struct amdgpu_ring *ring = NULL;
>   	uint64_t pd_addr, shadow_addr = 0;
> -	unsigned pt_idx, ndw = 0;
>   	struct amdgpu_job *job;
> -	struct amdgpu_pte_update_params params;
>   	struct dma_fence *fence = NULL;
> +	unsigned ndw = 0;
> +	uint64_t pde, pt;
>   	uint32_t incr;
>   
>   	int r;
> @@ -1102,20 +1105,14 @@ static int amdgpu_vm_update_level(struct amdgpu_device *adev,
>   		ring = container_of(vm->entity.sched, struct amdgpu_ring,
>   				    sched);
>   
> -		/* padding, etc. */
> +		/* should be sufficient for two commands plus padding, etc. */
>   		ndw = 64;
>   
> -		/* assume the worst case */
> -		ndw += parent->last_entry_used * 6;
> -
>   		pd_addr = amdgpu_bo_gpu_offset(parent->base.bo);
> -
> -		if (shadow) {
> +		if (shadow)
>   			shadow_addr = amdgpu_bo_gpu_offset(shadow);
> -			ndw *= 2;
> -		} else {
> +		else
>   			shadow_addr = 0;
> -		}
>   
>   		r = amdgpu_job_alloc_with_ib(adev, ndw * 4, &job);
>   		if (r)
> @@ -1125,40 +1122,32 @@ static int amdgpu_vm_update_level(struct amdgpu_device *adev,
>   		params.func = amdgpu_vm_do_set_ptes;
>   	}
>   
> +	spin_lock(&vm->status_lock);
> +	list_del_init(&entry->base.vm_status);
> +	spin_unlock(&vm->status_lock);
>   
> -	/* walk over the address space and update the directory */
> -	for (pt_idx = 0; pt_idx <= parent->last_entry_used; ++pt_idx) {
> -		struct amdgpu_vm_pt *entry = &parent->entries[pt_idx];
> -		struct amdgpu_bo *bo = entry->base.bo;
> -		uint64_t pde, pt;
> -
> -		if (bo == NULL)
> -			continue;
> -
> -		spin_lock(&vm->status_lock);
> -		list_del_init(&entry->base.vm_status);
> -		spin_unlock(&vm->status_lock);
> -
> -		pt = amdgpu_bo_gpu_offset(bo);
> -		pt = amdgpu_gart_get_vm_pde(adev, pt);
> -		/* Don't update huge pages here */
> -		if ((parent->entries[pt_idx].addr & AMDGPU_PDE_PTE) ||
> -		    parent->entries[pt_idx].addr == (pt | AMDGPU_PTE_VALID))
> -			continue;
> -
> -		parent->entries[pt_idx].addr = pt | AMDGPU_PTE_VALID;
> +	pt = amdgpu_bo_gpu_offset(bo);
> +	pt = amdgpu_gart_get_vm_pde(adev, pt);
> +	/* Don't update huge pages here */
> +	if (entry->addr & AMDGPU_PDE_PTE ||
> +	    entry->addr == (pt | AMDGPU_PTE_VALID)) {
> +		if (!vm->use_cpu_for_update)
> +			amdgpu_job_free(job);
> +		return 0;
> +	}
>   
> -		incr = amdgpu_bo_size(bo);
> -		if (shadow) {
> -			pde = shadow_addr + pt_idx * 8;
> -			params.func(&params, pde, pt, 1, incr,
> -				    AMDGPU_PTE_VALID);
> -		}
> +	entry->addr = pt | AMDGPU_PTE_VALID;
>   
> -		pde = pd_addr + pt_idx * 8;
> -		params.func(&params, pde, pt, 1, incr, AMDGPU_PTE_VALID);
> +	incr = amdgpu_bo_size(bo);
nit pick: When cound == 1, incr is meanness, we can just pass 0.
otherwise the patch is Reviewed-by: Chunming Zhou <davdi1.zhou at amd.com>


> +	if (shadow) {
> +		pde = shadow_addr + (entry - parent->entries) * 8;
> +		params.func(&params, pde, pt, 1, incr,
> +			    AMDGPU_PTE_VALID);

>   	}
>   
> +	pde = pd_addr + (entry - parent->entries) * 8;
> +	params.func(&params, pde, pt, 1, incr, AMDGPU_PTE_VALID);
> +
>   	if (!vm->use_cpu_for_update) {
>   		if (params.ib->length_dw == 0) {
>   			amdgpu_job_free(job);
> @@ -1249,14 +1238,16 @@ int amdgpu_vm_update_directories(struct amdgpu_device *adev,
>   		bo = bo_base->bo->parent;
>   		if (bo) {
>   			struct amdgpu_vm_bo_base *parent;
> -			struct amdgpu_vm_pt *pt;
> +			struct amdgpu_vm_pt *pt, *entry;
>   
>   			parent = list_first_entry(&bo->va,
>   						  struct amdgpu_vm_bo_base,
>   						  bo_list);
>   			pt = container_of(parent, struct amdgpu_vm_pt, base);
> +			entry = container_of(bo_base, struct amdgpu_vm_pt,
> +					     base);
>   
> -			r = amdgpu_vm_update_level(adev, vm, pt);
> +			r = amdgpu_vm_update_pde(adev, vm, pt, entry);
>   			if (r) {
>   				amdgpu_vm_invalidate_level(vm, &vm->root);
>   				return r;