/*
   * Copyright © 2006, Intel Corporation.
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms and conditions of the GNU General Public License,
   * version 2, as published by the Free Software Foundation.
   *
   * This program is distributed in the hope 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.
   *
   * You should have received a copy of the GNU General Public License along with
   * this program; if not, write to the Free Software Foundation, Inc.,
   * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
   *
   */
  #ifndef _ASYNC_TX_H_
  #define _ASYNC_TX_H_
  #include <linux/dmaengine.h>
  #include <linux/spinlock.h>
  #include <linux/interrupt.h>
  
  /* on architectures without dma-mapping capabilities we need to ensure
   * that the asynchronous path compiles away
   */
  #ifdef CONFIG_HAS_DMA
  #define __async_inline
  #else
  #define __async_inline __always_inline
  #endif
  
  /**
   * dma_chan_ref - object used to manage dma channels received from the
   *   dmaengine core.
   * @chan - the channel being tracked
   * @node - node for the channel to be placed on async_tx_master_list
   * @rcu - for list_del_rcu
   * @count - number of times this channel is listed in the pool
   *	(for channels with multiple capabiities)
   */
  struct dma_chan_ref {
  	struct dma_chan *chan;
  	struct list_head node;
  	struct rcu_head rcu;
  	atomic_t count;
  };
  
  /**
   * async_tx_flags - modifiers for the async_* calls
   * @ASYNC_TX_XOR_ZERO_DST: this flag must be used for xor operations where the
   * the destination address is not a source.  The asynchronous case handles this
   * implicitly, the synchronous case needs to zero the destination block.
   * @ASYNC_TX_XOR_DROP_DST: this flag must be used if the destination address is
   * also one of the source addresses.  In the synchronous case the destination
   * address is an implied source, whereas the asynchronous case it must be listed
   * as a source.  The destination address must be the first address in the source
   * array.
   * @ASYNC_TX_ACK: immediately ack the descriptor, precludes setting up a
   * dependency chain
   * @ASYNC_TX_FENCE: specify that the next operation in the dependency
   * chain uses this operation's result as an input
   */
  enum async_tx_flags {
  	ASYNC_TX_XOR_ZERO_DST	 = (1 << 0),
  	ASYNC_TX_XOR_DROP_DST	 = (1 << 1),
  	ASYNC_TX_ACK		 = (1 << 2),
  	ASYNC_TX_FENCE		 = (1 << 3),
  };
  
  /**
   * struct async_submit_ctl - async_tx submission/completion modifiers
   * @flags: submission modifiers
   * @depend_tx: parent dependency of the current operation being submitted
   * @cb_fn: callback routine to run at operation completion
   * @cb_param: parameter for the callback routine
   * @scribble: caller provided space for dma/page address conversions
   */
  struct async_submit_ctl {
  	enum async_tx_flags flags;
  	struct dma_async_tx_descriptor *depend_tx;
  	dma_async_tx_callback cb_fn;
  	void *cb_param;
  	void *scribble;
  };
  
  #ifdef CONFIG_DMA_ENGINE
  #define async_tx_issue_pending_all dma_issue_pending_all
  
  /**
   * async_tx_issue_pending - send pending descriptor to the hardware channel
   * @tx: descriptor handle to retrieve hardware context
   *
   * Note: any dependent operations will have already been issued by
   * async_tx_channel_switch, or (in the case of no channel switch) will
   * be already pending on this channel.
   */
  static inline void async_tx_issue_pending(struct dma_async_tx_descriptor *tx)
  {
  	if (likely(tx)) {
  		struct dma_chan *chan = tx->chan;
  		struct dma_device *dma = chan->device;
  
  		dma->device_issue_pending(chan);
  	}
  }
  #ifdef CONFIG_ARCH_HAS_ASYNC_TX_FIND_CHANNEL
  #include <asm/async_tx.h>
  #else
  #define async_tx_find_channel(dep, type, dst, dst_count, src, src_count, len) \
  	 __async_tx_find_channel(dep, type)
  struct dma_chan *
  __async_tx_find_channel(struct async_submit_ctl *submit,
  			enum dma_transaction_type tx_type);
  #endif /* CONFIG_ARCH_HAS_ASYNC_TX_FIND_CHANNEL */
  #else
  static inline void async_tx_issue_pending_all(void)
  {
  	do { } while (0);
  }
  
  static inline void async_tx_issue_pending(struct dma_async_tx_descriptor *tx)
  {
  	do { } while (0);
  }
  
  static inline struct dma_chan *
  async_tx_find_channel(struct async_submit_ctl *submit,
  		      enum dma_transaction_type tx_type, struct page **dst,
  		      int dst_count, struct page **src, int src_count,
  		      size_t len)
  {
  	return NULL;
  }
  #endif
  
  /**
   * async_tx_sync_epilog - actions to take if an operation is run synchronously
   * @cb_fn: function to call when the transaction completes
   * @cb_fn_param: parameter to pass to the callback routine
   */
  static inline void
  async_tx_sync_epilog(struct async_submit_ctl *submit)
  {
  	if (submit->cb_fn)
  		submit->cb_fn(submit->cb_param);
  }
  
  typedef union {
  	unsigned long addr;
  	struct page *page;
  	dma_addr_t dma;
  } addr_conv_t;
  
  static inline void
  init_async_submit(struct async_submit_ctl *args, enum async_tx_flags flags,
  		  struct dma_async_tx_descriptor *tx,
  		  dma_async_tx_callback cb_fn, void *cb_param,
  		  addr_conv_t *scribble)
  {
  	args->flags = flags;
  	args->depend_tx = tx;
  	args->cb_fn = cb_fn;
  	args->cb_param = cb_param;
  	args->scribble = scribble;
  }
  
  void async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx,
  		     struct async_submit_ctl *submit);
  
  struct dma_async_tx_descriptor *
  async_xor(struct page *dest, struct page **src_list, unsigned int offset,
  	  int src_cnt, size_t len, struct async_submit_ctl *submit);
  
  struct dma_async_tx_descriptor *
  async_xor_val(struct page *dest, struct page **src_list, unsigned int offset,
  	      int src_cnt, size_t len, enum sum_check_flags *result,
  	      struct async_submit_ctl *submit);
  
  struct dma_async_tx_descriptor *
  async_memcpy(struct page *dest, struct page *src, unsigned int dest_offset,
  	     unsigned int src_offset, size_t len,
  	     struct async_submit_ctl *submit);
  
  struct dma_async_tx_descriptor *async_trigger_callback(struct async_submit_ctl *submit);
  
  struct dma_async_tx_descriptor *
  async_gen_syndrome(struct page **blocks, unsigned int offset, int src_cnt,
  		   size_t len, struct async_submit_ctl *submit);
  
  struct dma_async_tx_descriptor *
  async_syndrome_val(struct page **blocks, unsigned int offset, int src_cnt,
  		   size_t len, enum sum_check_flags *pqres, struct page *spare,
  		   struct async_submit_ctl *submit);
  
  struct dma_async_tx_descriptor *
  async_raid6_2data_recov(int src_num, size_t bytes, int faila, int failb,
  			struct page **ptrs, struct async_submit_ctl *submit);
  
  struct dma_async_tx_descriptor *
  async_raid6_datap_recov(int src_num, size_t bytes, int faila,
  			struct page **ptrs, struct async_submit_ctl *submit);
  
  void async_tx_quiesce(struct dma_async_tx_descriptor **tx);
  #endif /* _ASYNC_TX_H_ */