[PATCH 3/6] drm/amdgpu: reserve vmid by vm ioctl

[Zhang, Jerry (Junwei)]

On 04/24/2017 01:57 PM, Chunming Zhou wrote:
> Change-Id: I5f80dc39dc9d44660a96a2b710b0dbb4d3b9039d
> Signed-off-by: Chunming Zhou <David1.Zhou at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 56 ++++++++++++++++++++++++++++++++++
>   1 file changed, 56 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index acf9102..5f4dcc9 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -397,6 +397,17 @@ static bool amdgpu_vm_had_gpu_reset(struct amdgpu_device *adev,
>   		atomic_read(&adev->gpu_reset_counter);
>   }
>
> +static bool amdgpu_vm_dedicated_vmid_ready(struct amdgpu_vm *vm)
> +{
> +	unsigned vmhub;
> +
> +	for (vmhub = 0; vmhub < AMDGPU_MAX_VMHUBS; vmhub++) {
> +		if (!vm->dedicated_vmid[vmhub])
> +			return false;

Just note:
Seemingly for pre-gmcv9, it will always allocate one more dedicated/reserved 
vmid for the 2nd un-used vmhub.
anyway it will not be used either.

Jerry
> +	}
> +	return true;
> +}
> +
>   /**
>    * amdgpu_vm_grab_id - allocate the next free VMID
>    *
> @@ -546,6 +557,45 @@ int amdgpu_vm_grab_id(struct amdgpu_vm *vm, struct amdgpu_ring *ring,
>   	return r;
>   }
>
> +static int amdgpu_vm_alloc_dedicated_vmid(struct amdgpu_device *adev,
> +					  struct amdgpu_vm *vm)
> +{
> +	struct amdgpu_vm_id_manager *id_mgr;
> +	struct amdgpu_vm_id *idle;
> +	unsigned vmhub;
> +	int r;
> +
> +	for (vmhub = 0; vmhub < AMDGPU_MAX_VMHUBS; vmhub++) {
> +		id_mgr = &adev->vm_manager.id_mgr[vmhub];
> +
> +		mutex_lock(&id_mgr->lock);
> +		/* Select the first entry VMID */
> +		idle = list_first_entry(&id_mgr->ids_lru, struct amdgpu_vm_id,
> +					list);
> +		list_del_init(&idle->list);
> +		vm->dedicated_vmid[vmhub] = idle;
> +		mutex_unlock(&id_mgr->lock);
> +
> +		r = amdgpu_sync_wait(&idle->active);
> +		if (r)
> +			goto err;
> +	}
> +
> +	return 0;
> +err:
> +	for (vmhub = 0; vmhub < AMDGPU_MAX_VMHUBS; vmhub++) {
> +		id_mgr = &adev->vm_manager.id_mgr[vmhub];
> +
> +		mutex_lock(&id_mgr->lock);
> +		if (vm->dedicated_vmid[vmhub])
> +			list_add(&vm->dedicated_vmid[vmhub]->list,
> +				 &id_mgr->ids_lru);
> +		vm->dedicated_vmid[vmhub] = NULL;
> +		mutex_unlock(&id_mgr->lock);
> +	}
> +	return r;
> +}
> +
>   static bool amdgpu_vm_ring_has_compute_vm_bug(struct amdgpu_ring *ring)
>   {
>   	struct amdgpu_device *adev = ring->adev;
> @@ -2379,9 +2429,15 @@ int amdgpu_vm_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
>   	union drm_amdgpu_vm *args = data;
>   	struct amdgpu_device *adev = dev->dev_private;
>   	struct amdgpu_fpriv *fpriv = filp->driver_priv;
> +	int r;
>
>   	switch (args->in.op) {
>   	case AMDGPU_VM_OP_RESERVE_VMID:
> +		if (!amdgpu_vm_dedicated_vmid_ready(&fpriv->vm)) {
> +			r = amdgpu_vm_alloc_dedicated_vmid(adev, &fpriv->vm);

Could you change the return value in this ready checking func?
Usually we can easily get to know this kind of things.
if (sth_ready())
     do_sth();


> +			if (r)
> +				return r;
> +		}
>   		break;
>   	default:
>   		return -EINVAL;
>