[deliverable/linux.git] / drivers / dma / virt-dma.h

/*
 * Virtual DMA channel support for DMAengine
 *
 * Copyright (C) 2012 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#ifndef VIRT_DMA_H
#define VIRT_DMA_H

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

#include "dmaengine.h"

struct virt_dma_desc {
	struct dma_async_tx_descriptor tx;
	/* protected by vc.lock */
	struct list_head node;
};

struct virt_dma_chan {
	struct dma_chan	chan;
	struct tasklet_struct task;
	void (*desc_free)(struct virt_dma_desc *);

	spinlock_t lock;

	/* protected by vc.lock */
	struct list_head desc_submitted;
	struct list_head desc_issued;
	struct list_head desc_completed;
};

static inline struct virt_dma_chan *to_virt_chan(struct dma_chan *chan)
{
	return container_of(chan, struct virt_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);

/**
 * 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)
{
	extern dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *);

	dma_async_tx_descriptor_init(&vd->tx, &vc->chan);
	vd->tx.flags = tx_flags;
	vd->tx.tx_submit = vchan_tx_submit;

	return &vd->tx;
}

/**
 * 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)
{
	list_splice_tail_init(&vc->desc_submitted, &vc->desc_issued);
	return !list_empty(&vc->desc_issued);
}

/**
 * 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)
{
	struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);

	dma_cookie_complete(&vd->tx);
	dev_vdbg(vc->chan.device->dev, "txd %p[%x]: marked complete\n",
		vd, vd->tx.cookie);
	list_add_tail(&vd->node, &vc->desc_completed);

	tasklet_schedule(&vc->task);
}

/**
 * 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)
{
	if (list_empty(&vc->desc_issued))
		return NULL;

	return list_first_entry(&vc->desc_issued, struct virt_dma_desc, node);
}

/**
 * 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)
{
	list_splice_tail_init(&vc->desc_submitted, head);
	list_splice_tail_init(&vc->desc_issued, head);
	list_splice_tail_init(&vc->desc_completed, head);
}

static inline void vchan_free_chan_resources(struct virt_dma_chan *vc)
{
	unsigned long flags;
	LIST_HEAD(head);

	spin_lock_irqsave(&vc->lock, flags);
	vchan_get_all_descriptors(vc, &head);
	spin_unlock_irqrestore(&vc->lock, flags);

	vchan_dma_desc_free_list(vc, &head);
}

#endif
Commit	Line	Data
50437bff RK	1	/*
	2	* Virtual DMA channel support for DMAengine
	3	*
	4	* Copyright (C) 2012 Russell King
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10	#ifndef VIRT_DMA_H
	11	#define VIRT_DMA_H
	12
	13	#include <linux/dmaengine.h>
	14	#include <linux/interrupt.h>
	15
	16	#include "dmaengine.h"
	17
	18	struct virt_dma_desc {
	19	struct dma_async_tx_descriptor tx;
	20	/* protected by vc.lock */
	21	struct list_head node;
	22	};
	23
	24	struct virt_dma_chan {
	25	struct dma_chan chan;
	26	struct tasklet_struct task;
	27	void (desc_free)(struct virt_dma_desc );
	28
	29	spinlock_t lock;
	30
	31	/* protected by vc.lock */
	32	struct list_head desc_submitted;
	33	struct list_head desc_issued;
	34	struct list_head desc_completed;
	35	};
	36
	37	static inline struct virt_dma_chan to_virt_chan(struct dma_chan chan)
	38	{
	39	return container_of(chan, struct virt_dma_chan, chan);
	40	}
	41
	42	void vchan_dma_desc_free_list(struct virt_dma_chan vc, struct list_head head);
50437bff	43	void vchan_init(struct virt_dma_chan vc, struct dma_device dmadev);
fe045874	44	struct virt_dma_desc vchan_find_desc(struct virt_dma_chan , dma_cookie_t);
50437bff RK	45
	46	/**
	47	* vchan_tx_prep - prepare a descriptor
	48	* vc: virtual channel allocating this descriptor
	49	* vd: virtual descriptor to prepare
	50	* tx_flags: flags argument passed in to prepare function
	51	*/
	52	static inline struct dma_async_tx_descriptor vchan_tx_prep(struct virt_dma_chan vc,
	53	struct virt_dma_desc *vd, unsigned long tx_flags)
	54	{
	55	extern dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *);
	56
	57	dma_async_tx_descriptor_init(&vd->tx, &vc->chan);
	58	vd->tx.flags = tx_flags;
	59	vd->tx.tx_submit = vchan_tx_submit;
	60
	61	return &vd->tx;
	62	}
	63
	64	/**
	65	* vchan_issue_pending - move submitted descriptors to issued list
	66	* vc: virtual channel to update
	67	*
	68	* vc.lock must be held by caller
	69	*/
	70	static inline bool vchan_issue_pending(struct virt_dma_chan *vc)
	71	{
	72	list_splice_tail_init(&vc->desc_submitted, &vc->desc_issued);
	73	return !list_empty(&vc->desc_issued);
	74	}
	75
	76	/**
	77	* vchan_cookie_complete - report completion of a descriptor
	78	* vd: virtual descriptor to update
	79	*
	80	* vc.lock must be held by caller
	81	*/
	82	static inline void vchan_cookie_complete(struct virt_dma_desc *vd)
	83	{
	84	struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);
	85
	86	dma_cookie_complete(&vd->tx);
	87	dev_vdbg(vc->chan.device->dev, "txd %p[%x]: marked complete\n",
	88	vd, vd->tx.cookie);
	89	list_add_tail(&vd->node, &vc->desc_completed);
	90
	91	tasklet_schedule(&vc->task);
	92	}
	93
	94	/**
	95	* vchan_next_desc - peek at the next descriptor to be processed
	96	* vc: virtual channel to obtain descriptor from
	97	*
	98	* vc.lock must be held by caller
	99	*/
	100	static inline struct virt_dma_desc vchan_next_desc(struct virt_dma_chan vc)
	101	{
	102	if (list_empty(&vc->desc_issued))
	103	return NULL;
	104
	105	return list_first_entry(&vc->desc_issued, struct virt_dma_desc, node);
	106	}
	107
	108	/**
109	* vchan_get_all_descriptors - obtain all submitted and issued descriptors
110	* vc: virtual channel to get descriptors from
111	* head: list of descriptors found
112	*
113	* vc.lock must be held by caller
114	*
115	* Removes all submitted and issued descriptors from internal lists, and
116	* provides a list of all descriptors found
117	*/
118	static inline void vchan_get_all_descriptors(struct virt_dma_chan *vc,
119	struct list_head *head)
120	{
121	list_splice_tail_init(&vc->desc_submitted, head);
122	list_splice_tail_init(&vc->desc_issued, head);
123	list_splice_tail_init(&vc->desc_completed, head);
124	}
125
126	static inline void vchan_free_chan_resources(struct virt_dma_chan *vc)
127	{
128	unsigned long flags;
129	LIST_HEAD(head);
130
131	spin_lock_irqsave(&vc->lock, flags);
132	vchan_get_all_descriptors(vc, &head);
133	spin_unlock_irqrestore(&vc->lock, flags);
134
135	vchan_dma_desc_free_list(vc, &head);
136	}
137
138	#endif