linux/drivers/dma/virt-dma.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Virtual DMA channel support for DMAengine
 *
 * Copyright (C) 2012 Russell King
 */
#ifndef VIRT_DMA_H
#define VIRT_DMA_H

#include <linux/dmaengine.h>
#include <linux/interrupt.h>

#include "dmaengine.h"

struct virt_dma_desc { … };

struct virt_dma_chan { … };

static inline struct virt_dma_chan *to_virt_chan(struct dma_chan *chan)
{ … }

void vchan_dma_desc_free_list(struct virt_dma_chan *vc, struct list_head *head);
void vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev);
struct virt_dma_desc *vchan_find_desc(struct virt_dma_chan *, dma_cookie_t);
extern dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *);
extern int vchan_tx_desc_free(struct dma_async_tx_descriptor *);

/**
 * vchan_tx_prep - prepare a descriptor
 * @vc: virtual channel allocating this descriptor
 * @vd: virtual descriptor to prepare
 * @tx_flags: flags argument passed in to prepare function
 */
static inline struct dma_async_tx_descriptor *vchan_tx_prep(struct virt_dma_chan *vc,
	struct virt_dma_desc *vd, unsigned long tx_flags)
{ … }

/**
 * vchan_issue_pending - move submitted descriptors to issued list
 * @vc: virtual channel to update
 *
 * vc.lock must be held by caller
 */
static inline bool vchan_issue_pending(struct virt_dma_chan *vc)
{ … }

/**
 * vchan_cookie_complete - report completion of a descriptor
 * @vd: virtual descriptor to update
 *
 * vc.lock must be held by caller
 */
static inline void vchan_cookie_complete(struct virt_dma_desc *vd)
{ … }

/**
 * vchan_vdesc_fini - Free or reuse a descriptor
 * @vd: virtual descriptor to free/reuse
 */
static inline void vchan_vdesc_fini(struct virt_dma_desc *vd)
{ … }

/**
 * vchan_cyclic_callback - report the completion of a period
 * @vd: virtual descriptor
 */
static inline void vchan_cyclic_callback(struct virt_dma_desc *vd)
{ … }

/**
 * vchan_terminate_vdesc - Disable pending cyclic callback
 * @vd: virtual descriptor to be terminated
 *
 * vc.lock must be held by caller
 */
static inline void vchan_terminate_vdesc(struct virt_dma_desc *vd)
{ … }

/**
 * vchan_next_desc - peek at the next descriptor to be processed
 * @vc: virtual channel to obtain descriptor from
 *
 * vc.lock must be held by caller
 */
static inline struct virt_dma_desc *vchan_next_desc(struct virt_dma_chan *vc)
{ … }

/**
 * vchan_get_all_descriptors - obtain all submitted and issued descriptors
 * @vc: virtual channel to get descriptors from
 * @head: list of descriptors found
 *
 * vc.lock must be held by caller
 *
 * Removes all submitted and issued descriptors from internal lists, and
 * provides a list of all descriptors found
 */
static inline void vchan_get_all_descriptors(struct virt_dma_chan *vc,
	struct list_head *head)
{ … }

static inline void vchan_free_chan_resources(struct virt_dma_chan *vc)
{ … }

/**
 * vchan_synchronize() - synchronize callback execution to the current context
 * @vc: virtual channel to synchronize
 *
 * Makes sure that all scheduled or active callbacks have finished running. For
 * proper operation the caller has to ensure that no new callbacks are scheduled
 * after the invocation of this function started.
 * Free up the terminated cyclic descriptor to prevent memory leakage.
 */
static inline void vchan_synchronize(struct virt_dma_chan *vc)
{ … }

#endif