linux/drivers/dma/virt-dma.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Virtual DMA channel support for DMAengine
 *
 * Copyright (C) 2012 Russell King
 */
#include <linux/device.h>
#include <linux/dmaengine.h>
#include <linux/module.h>
#include <linux/spinlock.h>

#include "virt-dma.h"

static struct virt_dma_desc *to_virt_desc(struct dma_async_tx_descriptor *tx)
{ … }

dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *tx)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * vchan_tx_desc_free - free a reusable descriptor
 * @tx: the transfer
 *
 * This function frees a previously allocated reusable descriptor. The only
 * other way is to clear the DMA_CTRL_REUSE flag and submit one last time the
 * transfer.
 *
 * Returns 0 upon success
 */
int vchan_tx_desc_free(struct dma_async_tx_descriptor *tx)
{ … }
EXPORT_SYMBOL_GPL(…);

struct virt_dma_desc *vchan_find_desc(struct virt_dma_chan *vc,
	dma_cookie_t cookie)
{ … }
EXPORT_SYMBOL_GPL(…);

/*
 * This tasklet handles the completion of a DMA descriptor by
 * calling its callback and freeing it.
 */
static void vchan_complete(struct tasklet_struct *t)
{ … }

void vchan_dma_desc_free_list(struct virt_dma_chan *vc, struct list_head *head)
{ … }
EXPORT_SYMBOL_GPL(…);

void vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev)
{ … }
EXPORT_SYMBOL_GPL(…);

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