[linux-2.6-block.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;

	struct virt_dma_desc *cyclic;
};

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_t cookie;

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

	tasklet_schedule(&vc->task);
}

/**
 * vchan_cyclic_callback - report the completion of a period
 * vd: virtual descriptor
 */
static inline void vchan_cyclic_callback(struct virt_dma_desc *vd)
{
	struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);

	vc->cyclic = vd;
	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;
571fa740 RK	35
571fa740 RK	36	struct virt_dma_desc *cyclic;
50437bff RK	37	};
	38
	39	static inline struct virt_dma_chan to_virt_chan(struct dma_chan chan)
	40	{
	41	return container_of(chan, struct virt_dma_chan, chan);
	42	}
	43
	44	void vchan_dma_desc_free_list(struct virt_dma_chan vc, struct list_head head);
50437bff	45	void vchan_init(struct virt_dma_chan vc, struct dma_device dmadev);
fe045874	46	struct virt_dma_desc vchan_find_desc(struct virt_dma_chan , dma_cookie_t);
50437bff RK	47
	48	/**
	49	* vchan_tx_prep - prepare a descriptor
	50	* vc: virtual channel allocating this descriptor
	51	* vd: virtual descriptor to prepare
	52	* tx_flags: flags argument passed in to prepare function
	53	*/
	54	static inline struct dma_async_tx_descriptor vchan_tx_prep(struct virt_dma_chan vc,
	55	struct virt_dma_desc *vd, unsigned long tx_flags)
	56	{
	57	extern dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *);
	58
	59	dma_async_tx_descriptor_init(&vd->tx, &vc->chan);
	60	vd->tx.flags = tx_flags;
	61	vd->tx.tx_submit = vchan_tx_submit;
	62
	63	return &vd->tx;
	64	}
	65
	66	/**
	67	* vchan_issue_pending - move submitted descriptors to issued list
	68	* vc: virtual channel to update
	69	*
	70	* vc.lock must be held by caller
	71	*/
	72	static inline bool vchan_issue_pending(struct virt_dma_chan *vc)
	73	{
	74	list_splice_tail_init(&vc->desc_submitted, &vc->desc_issued);
	75	return !list_empty(&vc->desc_issued);
	76	}
	77
	78	/**
	79	* vchan_cookie_complete - report completion of a descriptor
	80	* vd: virtual descriptor to update
	81	*
	82	* vc.lock must be held by caller
	83	*/
	84	static inline void vchan_cookie_complete(struct virt_dma_desc *vd)
	85	{
	86	struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);
af58652a	87	dma_cookie_t cookie;
50437bff	88
af58652a	89	cookie = vd->tx.cookie;
50437bff RK	90	dma_cookie_complete(&vd->tx);
50437bff RK	91	dev_vdbg(vc->chan.device->dev, "txd %p[%x]: marked complete\n",
af58652a	92	vd, cookie);
50437bff RK	93	list_add_tail(&vd->node, &vc->desc_completed);
	94
	95	tasklet_schedule(&vc->task);
	96	}
	97
571fa740 RK	98	/**
	99	* vchan_cyclic_callback - report the completion of a period
	100	* vd: virtual descriptor
	101	*/
	102	static inline void vchan_cyclic_callback(struct virt_dma_desc *vd)
	103	{
	104	struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);
	105
	106	vc->cyclic = vd;
	107	tasklet_schedule(&vc->task);
	108	}
	109
50437bff RK	110	/**
	111	* vchan_next_desc - peek at the next descriptor to be processed
	112	* vc: virtual channel to obtain descriptor from
	113	*
	114	* vc.lock must be held by caller
	115	*/
	116	static inline struct virt_dma_desc vchan_next_desc(struct virt_dma_chan vc)
	117	{
	118	if (list_empty(&vc->desc_issued))
	119	return NULL;
	120
	121	return list_first_entry(&vc->desc_issued, struct virt_dma_desc, node);
	122	}
	123
	124	/**
8c8fe97b	125	* vchan_get_all_descriptors - obtain all submitted and issued descriptors
50437bff RK	126	* vc: virtual channel to get descriptors from
	127	* head: list of descriptors found
	128	*
	129	* vc.lock must be held by caller
	130	*
	131	* Removes all submitted and issued descriptors from internal lists, and
	132	* provides a list of all descriptors found
	133	*/
	134	static inline void vchan_get_all_descriptors(struct virt_dma_chan *vc,
	135	struct list_head *head)
	136	{
	137	list_splice_tail_init(&vc->desc_submitted, head);
	138	list_splice_tail_init(&vc->desc_issued, head);
	139	list_splice_tail_init(&vc->desc_completed, head);
	140	}
	141
	142	static inline void vchan_free_chan_resources(struct virt_dma_chan *vc)
	143	{
	144	unsigned long flags;
	145	LIST_HEAD(head);
	146
	147	spin_lock_irqsave(&vc->lock, flags);
	148	vchan_get_all_descriptors(vc, &head);
	149	spin_unlock_irqrestore(&vc->lock, flags);
	150
	151	vchan_dma_desc_free_list(vc, &head);
	152	}
	153
	154	#endif