/*
   * fence-array: aggregates fence to be waited together
   *
   * Copyright (C) 2016 Collabora Ltd
   * Copyright (C) 2016 Advanced Micro Devices, Inc.
   * Authors:
   *	Gustavo Padovan <gustavo@padovan.org>
   *	Christian König <christian.koenig@amd.com>
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published by
   * the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
   * more details.
   */
  
  #ifndef __LINUX_DMA_FENCE_ARRAY_H
  #define __LINUX_DMA_FENCE_ARRAY_H
  
  #include <linux/dma-fence.h>

  #include <linux/irq_work.h>

  
  /**
   * struct dma_fence_array_cb - callback helper for fence array
   * @cb: fence callback structure for signaling
   * @array: reference to the parent fence array object
   */
  struct dma_fence_array_cb {
  	struct dma_fence_cb cb;
  	struct dma_fence_array *array;
  };
  
  /**
   * struct dma_fence_array - fence to represent an array of fences
   * @base: fence base class
   * @lock: spinlock for fence handling
   * @num_fences: number of fences in the array
   * @num_pending: fences in the array still pending
   * @fences: array of the fences
   */
  struct dma_fence_array {
  	struct dma_fence base;
  
  	spinlock_t lock;
  	unsigned num_fences;
  	atomic_t num_pending;
  	struct dma_fence **fences;

  
  	struct irq_work work;

  };
  
  extern const struct dma_fence_ops dma_fence_array_ops;
  
  /**
   * dma_fence_is_array - check if a fence is from the array subsclass
   * @fence: fence to test
   *
   * Return true if it is a dma_fence_array and false otherwise.
   */
  static inline bool dma_fence_is_array(struct dma_fence *fence)
  {
  	return fence->ops == &dma_fence_array_ops;
  }
  
  /**
   * to_dma_fence_array - cast a fence to a dma_fence_array
   * @fence: fence to cast to a dma_fence_array
   *
   * Returns NULL if the fence is not a dma_fence_array,
   * or the dma_fence_array otherwise.
   */
  static inline struct dma_fence_array *
  to_dma_fence_array(struct dma_fence *fence)
  {
  	if (fence->ops != &dma_fence_array_ops)
  		return NULL;
  
  	return container_of(fence, struct dma_fence_array, base);
  }
  
  struct dma_fence_array *dma_fence_array_create(int num_fences,
  					       struct dma_fence **fences,
  					       u64 context, unsigned seqno,
  					       bool signal_on_any);

  bool dma_fence_match_context(struct dma_fence *fence, u64 context);

  #endif /* __LINUX_DMA_FENCE_ARRAY_H */