[PATCH 3/5] drm/amdgpu: add context flags for dedicated vmid reqest

[Christian König]

Am 21.04.2017 um 12:05 schrieb Chunming Zhou:
> ctx_alloc will check dedicated flag for its process by this flag.
>
> Change-Id: I5f80dc39dc9d44660a96a2b710b0dbb4d3b9039d
> Signed-off-by: Chunming Zhou <David1.Zhou at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c |  9 ++++--
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c  | 50 +++++++++++++++++++++++++++++++++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h  |  4 +++
>   include/uapi/drm/amdgpu_drm.h           |  3 ++
>   4 files changed, 64 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> index c2b2896..b620923 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> @@ -109,8 +109,13 @@ static int amdgpu_ctx_alloc(struct amdgpu_device *adev,
>   	struct amdgpu_ctx *ctx;
>   	int r;
>   
> -	if (flags)
> -		return -EINVAL;
> +	if ((flags & AMDGPU_CTX_FLAGS_DEDICATED_VMID) &&
> +	    !amdgpu_vm_dedicated_vmid_ready(&fpriv->vm)) {
> +		r = amdgpu_vm_alloc_dedicated_vmid(adev, &fpriv->vm);
> +		if (r)
> +			return r;
> +	}
> +
>   	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
>   	if (!ctx)
>   		return -ENOMEM;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index e7dd8d1..21cca99 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);
>   }
>   
> +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;
> +	}
> +	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;
>   }
>   
> +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;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> index a056e01..90453af 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> @@ -212,6 +212,10 @@ int amdgpu_vm_alloc_pts(struct amdgpu_device *adev,
>   int amdgpu_vm_grab_id(struct amdgpu_vm *vm, struct amdgpu_ring *ring,
>   		      struct amdgpu_sync *sync, struct fence *fence,
>   		      struct amdgpu_job *job);
> +int amdgpu_vm_alloc_dedicated_vmid(struct amdgpu_device *adev,
> +				   struct amdgpu_vm *vm);
> +bool amdgpu_vm_dedicated_vmid_ready(struct amdgpu_vm *vm);
> +
>   int amdgpu_vm_flush(struct amdgpu_ring *ring, struct amdgpu_job *job);
>   void amdgpu_vm_reset_id(struct amdgpu_device *adev, unsigned vmhub,
>   			unsigned vmid);
> diff --git a/include/uapi/drm/amdgpu_drm.h b/include/uapi/drm/amdgpu_drm.h
> index 56b7a2f3..754208e 100644
> --- a/include/uapi/drm/amdgpu_drm.h
> +++ b/include/uapi/drm/amdgpu_drm.h
> @@ -182,6 +182,9 @@ struct drm_amdgpu_bo_list_out {
>   /* unknown cause */
>   #define AMDGPU_CTX_UNKNOWN_RESET	3
>   
> +/* context flags */
> +#define AMDGPU_CTX_FLAGS_DEDICATED_VMID	(1ULL << 0)

At minimum we should call this AMDGPU_CTX_FLAGS_TRACED or something like 
that.

Allocating a static VMID is the effect it has currently, but not 
necessary in the future.

On the other hand putting it on the context looks more and more like a 
bad idea to me.

Christian.

> +
>   struct drm_amdgpu_ctx_in {
>   	/** AMDGPU_CTX_OP_* */
>   	__u32	op;