linux/crypto/async_tx/async_tx.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * core routines for the asynchronous memory transfer/transform api
 *
 * Copyright © 2006, Intel Corporation.
 *
 *	Dan Williams <[email protected]>
 *
 *	with architecture considerations by:
 *	Neil Brown <[email protected]>
 *	Jeff Garzik <[email protected]>
 */
#include <linux/rculist.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/async_tx.h>

#ifdef CONFIG_DMA_ENGINE
static int __init async_tx_init(void)
{ … }

static void __exit async_tx_exit(void)
{ … }

module_init(…) …;
module_exit(async_tx_exit);

/**
 * __async_tx_find_channel - find a channel to carry out the operation or let
 *	the transaction execute synchronously
 * @submit: transaction dependency and submission modifiers
 * @tx_type: transaction type
 */
struct dma_chan *
__async_tx_find_channel(struct async_submit_ctl *submit,
			enum dma_transaction_type tx_type)
{ … }
EXPORT_SYMBOL_GPL(…);
#endif


/**
 * async_tx_channel_switch - queue an interrupt descriptor with a dependency
 * 	pre-attached.
 * @depend_tx: the operation that must finish before the new operation runs
 * @tx: the new operation
 */
static void
async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx,
			struct dma_async_tx_descriptor *tx)
{ … }


/**
 * enum submit_disposition - flags for routing an incoming operation
 * @ASYNC_TX_SUBMITTED: we were able to append the new operation under the lock
 * @ASYNC_TX_CHANNEL_SWITCH: when the lock is dropped schedule a channel switch
 * @ASYNC_TX_DIRECT_SUBMIT: when the lock is dropped submit directly
 *
 * while holding depend_tx->lock we must avoid submitting new operations
 * to prevent a circular locking dependency with drivers that already
 * hold a channel lock when calling async_tx_run_dependencies.
 */
enum submit_disposition { … };

void
async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx,
		struct async_submit_ctl *submit)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * async_trigger_callback - schedules the callback function to be run
 * @submit: submission and completion parameters
 *
 * honored flags: ASYNC_TX_ACK
 *
 * The callback is run after any dependent operations have completed.
 */
struct dma_async_tx_descriptor *
async_trigger_callback(struct async_submit_ctl *submit)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * async_tx_quiesce - ensure tx is complete and freeable upon return
 * @tx: transaction to quiesce
 */
void async_tx_quiesce(struct dma_async_tx_descriptor **tx)
{ … }
EXPORT_SYMBOL_GPL(…);

MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;