[mirror_ubuntu-hirsute-kernel.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_allocated;
	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 *);
	unsigned long flags;

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

	spin_lock_irqsave(&vc->lock, flags);
	list_add_tail(&vd->node, &vc->desc_allocated);
	spin_unlock_irqrestore(&vc->lock, flags);

	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 allocated, 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_allocated, 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)
{
	struct virt_dma_desc *vd;
	unsigned long flags;
	LIST_HEAD(head);

	spin_lock_irqsave(&vc->lock, flags);
	vchan_get_all_descriptors(vc, &head);
	list_for_each_entry(vd, &head, node)
		async_tx_clear_ack(&vd->tx);
	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 */
b9855f03	32	struct list_head desc_allocated;
50437bff RK	33	struct list_head desc_submitted;
	34	struct list_head desc_issued;
	35	struct list_head desc_completed;
571fa740 RK	36
571fa740 RK	37	struct virt_dma_desc *cyclic;
50437bff RK	38	};
	39
	40	static inline struct virt_dma_chan to_virt_chan(struct dma_chan chan)
	41	{
	42	return container_of(chan, struct virt_dma_chan, chan);
	43	}
	44
	45	void vchan_dma_desc_free_list(struct virt_dma_chan vc, struct list_head head);
50437bff	46	void vchan_init(struct virt_dma_chan vc, struct dma_device dmadev);
fe045874	47	struct virt_dma_desc vchan_find_desc(struct virt_dma_chan , dma_cookie_t);
50437bff RK	48
	49	/**
	50	* vchan_tx_prep - prepare a descriptor
	51	* vc: virtual channel allocating this descriptor
	52	* vd: virtual descriptor to prepare
	53	* tx_flags: flags argument passed in to prepare function
	54	*/
	55	static inline struct dma_async_tx_descriptor vchan_tx_prep(struct virt_dma_chan vc,
	56	struct virt_dma_desc *vd, unsigned long tx_flags)
	57	{
	58	extern dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *);
b9855f03	59	unsigned long flags;
50437bff RK	60
	61	dma_async_tx_descriptor_init(&vd->tx, &vc->chan);
	62	vd->tx.flags = tx_flags;
	63	vd->tx.tx_submit = vchan_tx_submit;
	64
b9855f03 RJ	65	spin_lock_irqsave(&vc->lock, flags);
	66	list_add_tail(&vd->node, &vc->desc_allocated);
	67	spin_unlock_irqrestore(&vc->lock, flags);
	68
50437bff RK	69	return &vd->tx;
	70	}
	71
	72	/**
	73	* vchan_issue_pending - move submitted descriptors to issued list
	74	* vc: virtual channel to update
	75	*
	76	* vc.lock must be held by caller
	77	*/
	78	static inline bool vchan_issue_pending(struct virt_dma_chan *vc)
	79	{
	80	list_splice_tail_init(&vc->desc_submitted, &vc->desc_issued);
	81	return !list_empty(&vc->desc_issued);
	82	}
	83
	84	/**
	85	* vchan_cookie_complete - report completion of a descriptor
	86	* vd: virtual descriptor to update
	87	*
	88	* vc.lock must be held by caller
	89	*/
	90	static inline void vchan_cookie_complete(struct virt_dma_desc *vd)
	91	{
	92	struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);
af58652a	93	dma_cookie_t cookie;
50437bff	94
af58652a	95	cookie = vd->tx.cookie;
50437bff RK	96	dma_cookie_complete(&vd->tx);
50437bff RK	97	dev_vdbg(vc->chan.device->dev, "txd %p[%x]: marked complete\n",
af58652a	98	vd, cookie);
50437bff RK	99	list_add_tail(&vd->node, &vc->desc_completed);
	100
	101	tasklet_schedule(&vc->task);
	102	}
	103
571fa740 RK	104	/**
	105	* vchan_cyclic_callback - report the completion of a period
	106	* vd: virtual descriptor
	107	*/
	108	static inline void vchan_cyclic_callback(struct virt_dma_desc *vd)
	109	{
	110	struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);
	111
	112	vc->cyclic = vd;
	113	tasklet_schedule(&vc->task);
	114	}
	115
50437bff RK	116	/**
	117	* vchan_next_desc - peek at the next descriptor to be processed
	118	* vc: virtual channel to obtain descriptor from
	119	*
	120	* vc.lock must be held by caller
	121	*/
	122	static inline struct virt_dma_desc vchan_next_desc(struct virt_dma_chan vc)
	123	{
	124	if (list_empty(&vc->desc_issued))
	125	return NULL;
	126
	127	return list_first_entry(&vc->desc_issued, struct virt_dma_desc, node);
	128	}
	129
	130	/**
b9855f03 RJ	131	* vchan_get_all_descriptors - obtain all allocated, submitted and issued
b9855f03 RJ	132	* descriptors
50437bff RK	133	* vc: virtual channel to get descriptors from
	134	* head: list of descriptors found
	135	*
	136	* vc.lock must be held by caller
	137	*
	138	* Removes all submitted and issued descriptors from internal lists, and
	139	* provides a list of all descriptors found
	140	*/
	141	static inline void vchan_get_all_descriptors(struct virt_dma_chan *vc,
	142	struct list_head *head)
	143	{
b9855f03	144	list_splice_tail_init(&vc->desc_allocated, head);
50437bff RK	145	list_splice_tail_init(&vc->desc_submitted, head);
	146	list_splice_tail_init(&vc->desc_issued, head);
	147	list_splice_tail_init(&vc->desc_completed, head);
	148	}
	149
	150	static inline void vchan_free_chan_resources(struct virt_dma_chan *vc)
	151	{
b9855f03	152	struct virt_dma_desc *vd;
50437bff RK	153	unsigned long flags;
	154	LIST_HEAD(head);
	155
	156	spin_lock_irqsave(&vc->lock, flags);
	157	vchan_get_all_descriptors(vc, &head);
b9855f03 RJ	158	list_for_each_entry(vd, &head, node)
b9855f03 RJ	159	async_tx_clear_ack(&vd->tx);
50437bff RK	160	spin_unlock_irqrestore(&vc->lock, flags);
	161
	162	vchan_dma_desc_free_list(vc, &head);
	163	}
	164
	165	#endif