24  * A GSI transaction abstracts the behavior of a GSI channel by representing
28  * by the GSI transaction core, allowing users to simply describe commands
29  * to be performed.  When a transaction has completed a callback function
31  * cleanup of resources associated with the transaction.
33  * To perform a command (or set of them), a user of the GSI transaction
34  * interface allocates a transaction, indicating the number of TREs required
36  * for use in the transaction and the allocation succeeds.  This way
38  * as early as possible.  All resources required to complete a transaction
39  * are allocated at transaction allocation time.
41  * Commands performed as part of a transaction are represented in an array
43  * transaction, and its entries are initialized using standard scatterlist
46  * Once a transaction's scatterlist structures have been initialized, the
47  * transaction is committed.  The caller is responsible for mapping buffers
49  * the transaction.  Between a successful allocation and commit of a
50  * transaction no errors should occur.
52  * Committing transfers ownership of the entire transaction to the GSI
53  * transaction core.  The GSI transaction code formats the content of
57  * The last TRE in each transaction is marked to interrupt the AP when the
60  * TRE in the transaction is sufficient to indicate the full transaction
63  * When a transaction is complete, ipa_gsi_trans_complete() is called by the
65  * required before the transaction is freed.
237 /* Map a given ring entry index to the transaction associated with it */
245 /* Return the transaction mapped to a given ring entry */
253 /* Return the oldest completed transaction for a channel (or null) */
260 /* Move a transaction from the allocated list to the pending list */
273 /* Move a transaction and all of its predecessors from the pending list
284 	/* Move this transaction and all predecessors to completed list */  in gsi_trans_move_complete()
291 /* Move a transaction from the completed list to the polled list */
327 /* Allocate a GSI transaction on a channel */
346 	/* Allocate and initialize non-zero fields in the the transaction */  in gsi_channel_trans_alloc()
370 /* Free a previously-allocated transaction */
398 	 * (if present) info[] arrays, plus the transaction itself.  in gsi_trans_free()
403 /* Add an immediate command to a transaction */
419 	 * When a transaction completes, the SGL is normally unmapped.  in gsi_trans_cmd_add()
420 	 * A command transaction has direction DMA_NONE, which tells  in gsi_trans_cmd_add()
438 /* Add a page transfer to a transaction.  It will fill the only TRE. */
453 	trans->used++;	/* Transaction now owns the (DMA mapped) page */  in gsi_trans_page_add()
458 /* Add an SKB transfer to a transaction.  No other TREs will be used. */
478 	trans->used += used;	/* Transaction now owns the (DMA mapped) skb */  in gsi_trans_skb_add()
531  * __gsi_trans_commit() - Common GSI transaction commit code
532  * @trans:	Transaction to commit
536  * Maps a transaction pointer to the last ring entry used for the transaction,
537  * so it can be recovered when it completes.  Moves the transaction to the
589 	/* Associate the last TRE with the transaction */  in __gsi_trans_commit()
603 /* Commit a GSI transaction */
612 /* Commit a GSI transaction and wait for it to complete */
628 /* Commit a GSI transaction and wait for it to complete, with timeout */
633 	unsigned long remaining = 1;	/* In case of empty transaction */  in gsi_trans_commit_wait_timeout()
650 /* Process the completion of a transaction; called while polling */
721 /* Initialize a channel's GSI transaction info */
732 	/* The map array is used to determine what transaction is associated  in gsi_channel_trans_init()
744 	 * Worst case is one TRE per transaction (but we actually limit  in gsi_channel_trans_init()
746 	 * for transactions (including transaction structures) based on  in gsi_channel_trans_init()
757 	/* A transaction uses a scatterlist array to represent the data  in gsi_channel_trans_init()
758 	 * transfers implemented by the transaction.  Each scatterlist  in gsi_channel_trans_init()
759 	 * element is used to fill a single TRE when the transaction is  in gsi_channel_trans_init()
763 	 * All TREs in a transaction must fit within the channel's TLV FIFO.  in gsi_channel_trans_init()
764 	 * A transaction on a channel can allocate as many TREs as that but  in gsi_channel_trans_init()
774 	 * of outstanding transactions and their resources.  A transaction  in gsi_channel_trans_init()
776 	 * what the transaction might need.  Transaction resource pools are  in gsi_channel_trans_init()