[linux-2.6-block.git] / include / linux / dmaengine.h

/*
 * Copyright(c) 2004 - 2006 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * The full GNU General Public License is included in this distribution in the
 * file called COPYING.
 */
#ifndef DMAENGINE_H
#define DMAENGINE_H

#include <linux/device.h>
#include <linux/uio.h>
#include <linux/kref.h>
#include <linux/completion.h>
#include <linux/rcupdate.h>
#include <linux/dma-mapping.h>

/**
 * enum dma_state - resource PNP/power management state
 * @DMA_RESOURCE_SUSPEND: DMA device going into low power state
 * @DMA_RESOURCE_RESUME: DMA device returning to full power
 * @DMA_RESOURCE_AVAILABLE: DMA device available to the system
 * @DMA_RESOURCE_REMOVED: DMA device removed from the system
 */
enum dma_state {
	DMA_RESOURCE_SUSPEND,
	DMA_RESOURCE_RESUME,
	DMA_RESOURCE_AVAILABLE,
	DMA_RESOURCE_REMOVED,
};

/**
 * enum dma_state_client - state of the channel in the client
 * @DMA_ACK: client would like to use, or was using this channel
 * @DMA_DUP: client has already seen this channel, or is not using this channel
 * @DMA_NAK: client does not want to see any more channels
 */
enum dma_state_client {
	DMA_ACK,
	DMA_DUP,
	DMA_NAK,
};

/**
 * typedef dma_cookie_t - an opaque DMA cookie
 *
 * if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code
 */
typedef s32 dma_cookie_t;

#define dma_submit_error(cookie) ((cookie) < 0 ? 1 : 0)

/**
 * enum dma_status - DMA transaction status
 * @DMA_SUCCESS: transaction completed successfully
 * @DMA_IN_PROGRESS: transaction not yet processed
 * @DMA_ERROR: transaction failed
 */
enum dma_status {
	DMA_SUCCESS,
	DMA_IN_PROGRESS,
	DMA_ERROR,
};

/**
 * enum dma_transaction_type - DMA transaction types/indexes
 */
enum dma_transaction_type {
	DMA_MEMCPY,
	DMA_XOR,
	DMA_PQ_XOR,
	DMA_DUAL_XOR,
	DMA_PQ_UPDATE,
	DMA_ZERO_SUM,
	DMA_PQ_ZERO_SUM,
	DMA_MEMSET,
	DMA_MEMCPY_CRC32C,
	DMA_INTERRUPT,
};

/* last transaction type for creation of the capabilities mask */
#define DMA_TX_TYPE_END (DMA_INTERRUPT + 1)

/**
 * enum dma_prep_flags - DMA flags to augment operation preparation
 * @DMA_PREP_INTERRUPT - trigger an interrupt (callback) upon completion of
 * 	this transaction
 */
enum dma_prep_flags {
	DMA_PREP_INTERRUPT = (1 << 0),
};

/**
 * dma_cap_mask_t - capabilities bitmap modeled after cpumask_t.
 * See linux/cpumask.h
 */
typedef struct { DECLARE_BITMAP(bits, DMA_TX_TYPE_END); } dma_cap_mask_t;

/**
 * struct dma_chan_percpu - the per-CPU part of struct dma_chan
 * @refcount: local_t used for open-coded "bigref" counting
 * @memcpy_count: transaction counter
 * @bytes_transferred: byte counter
 */

struct dma_chan_percpu {
	local_t refcount;
	/* stats */
	unsigned long memcpy_count;
	unsigned long bytes_transferred;
};

/**
 * struct dma_chan - devices supply DMA channels, clients use them
 * @device: ptr to the dma device who supplies this channel, always !%NULL
 * @cookie: last cookie value returned to client
 * @chan_id: channel ID for sysfs
 * @class_dev: class device for sysfs
 * @refcount: kref, used in "bigref" slow-mode
 * @slow_ref: indicates that the DMA channel is free
 * @rcu: the DMA channel's RCU head
 * @device_node: used to add this to the device chan list
 * @local: per-cpu pointer to a struct dma_chan_percpu
 */
struct dma_chan {
	struct dma_device *device;
	dma_cookie_t cookie;

	/* sysfs */
	int chan_id;
	struct device dev;

	struct kref refcount;
	int slow_ref;
	struct rcu_head rcu;

	struct list_head device_node;
	struct dma_chan_percpu *local;
};

#define to_dma_chan(p) container_of(p, struct dma_chan, dev)

void dma_chan_cleanup(struct kref *kref);

static inline void dma_chan_get(struct dma_chan *chan)
{
	if (unlikely(chan->slow_ref))
		kref_get(&chan->refcount);
	else {
		local_inc(&(per_cpu_ptr(chan->local, get_cpu())->refcount));
		put_cpu();
	}
}

static inline void dma_chan_put(struct dma_chan *chan)
{
	if (unlikely(chan->slow_ref))
		kref_put(&chan->refcount, dma_chan_cleanup);
	else {
		local_dec(&(per_cpu_ptr(chan->local, get_cpu())->refcount));
		put_cpu();
	}
}

/*
 * typedef dma_event_callback - function pointer to a DMA event callback
 * For each channel added to the system this routine is called for each client.
 * If the client would like to use the channel it returns '1' to signal (ack)
 * the dmaengine core to take out a reference on the channel and its
 * corresponding device.  A client must not 'ack' an available channel more
 * than once.  When a channel is removed all clients are notified.  If a client
 * is using the channel it must 'ack' the removal.  A client must not 'ack' a
 * removed channel more than once.
 * @client - 'this' pointer for the client context
 * @chan - channel to be acted upon
 * @state - available or removed
 */
struct dma_client;
typedef enum dma_state_client (*dma_event_callback) (struct dma_client *client,
		struct dma_chan *chan, enum dma_state state);

/**
 * struct dma_client - info on the entity making use of DMA services
 * @event_callback: func ptr to call when something happens
 * @cap_mask: only return channels that satisfy the requested capabilities
 *  a value of zero corresponds to any capability
 * @global_node: list_head for global dma_client_list
 */
struct dma_client {
	dma_event_callback	event_callback;
	dma_cap_mask_t		cap_mask;
	struct list_head	global_node;
};

typedef void (*dma_async_tx_callback)(void *dma_async_param);
/**
 * struct dma_async_tx_descriptor - async transaction descriptor
 * ---dma generic offload fields---
 * @cookie: tracking cookie for this transaction, set to -EBUSY if
 *	this tx is sitting on a dependency list
 * @ack: the descriptor can not be reused until the client acknowledges
 *	receipt, i.e. has has a chance to establish any dependency chains
 * @phys: physical address of the descriptor
 * @tx_list: driver common field for operations that require multiple
 *	descriptors
 * @chan: target channel for this operation
 * @tx_submit: set the prepared descriptor(s) to be executed by the engine
 * @callback: routine to call after this operation is complete
 * @callback_param: general parameter to pass to the callback routine
 * ---async_tx api specific fields---
 * @next: at completion submit this descriptor
 * @parent: pointer to the next level up in the dependency chain
 * @lock: protect the parent and next pointers
 */
struct dma_async_tx_descriptor {
	dma_cookie_t cookie;
	int ack;
	dma_addr_t phys;
	struct list_head tx_list;
	struct dma_chan *chan;
	dma_cookie_t (*tx_submit)(struct dma_async_tx_descriptor *tx);
	dma_async_tx_callback callback;
	void *callback_param;
	struct dma_async_tx_descriptor *next;
	struct dma_async_tx_descriptor *parent;
	spinlock_t lock;
};

/**
 * struct dma_device - info on the entity supplying DMA services
 * @chancnt: how many DMA channels are supported
 * @channels: the list of struct dma_chan
 * @global_node: list_head for global dma_device_list
 * @cap_mask: one or more dma_capability flags
 * @max_xor: maximum number of xor sources, 0 if no capability
 * @refcount: reference count
 * @done: IO completion struct
 * @dev_id: unique device ID
 * @dev: struct device reference for dma mapping api
 * @device_alloc_chan_resources: allocate resources and return the
 *	number of allocated descriptors
 * @device_free_chan_resources: release DMA channel's resources
 * @device_prep_dma_memcpy: prepares a memcpy operation
 * @device_prep_dma_xor: prepares a xor operation
 * @device_prep_dma_zero_sum: prepares a zero_sum operation
 * @device_prep_dma_memset: prepares a memset operation
 * @device_prep_dma_interrupt: prepares an end of chain interrupt operation
 * @device_issue_pending: push pending transactions to hardware
 */
struct dma_device {

	unsigned int chancnt;
	struct list_head channels;
	struct list_head global_node;
	dma_cap_mask_t  cap_mask;
	int max_xor;

	struct kref refcount;
	struct completion done;

	int dev_id;
	struct device *dev;

	int (*device_alloc_chan_resources)(struct dma_chan *chan);
	void (*device_free_chan_resources)(struct dma_chan *chan);

	struct dma_async_tx_descriptor *(*device_prep_dma_memcpy)(
		struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
		size_t len, unsigned long flags);
	struct dma_async_tx_descriptor *(*device_prep_dma_xor)(
		struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
		unsigned int src_cnt, size_t len, unsigned long flags);
	struct dma_async_tx_descriptor *(*device_prep_dma_zero_sum)(
		struct dma_chan *chan, dma_addr_t *src,	unsigned int src_cnt,
		size_t len, u32 *result, unsigned long flags);
	struct dma_async_tx_descriptor *(*device_prep_dma_memset)(
		struct dma_chan *chan, dma_addr_t dest, int value, size_t len,
		unsigned long flags);
	struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)(
		struct dma_chan *chan);

	enum dma_status (*device_is_tx_complete)(struct dma_chan *chan,
			dma_cookie_t cookie, dma_cookie_t *last,
			dma_cookie_t *used);
	void (*device_issue_pending)(struct dma_chan *chan);
};

/* --- public DMA engine API --- */

void dma_async_client_register(struct dma_client *client);
void dma_async_client_unregister(struct dma_client *client);
void dma_async_client_chan_request(struct dma_client *client);
dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan,
	void *dest, void *src, size_t len);
dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan,
	struct page *page, unsigned int offset, void *kdata, size_t len);
dma_cookie_t dma_async_memcpy_pg_to_pg(struct dma_chan *chan,
	struct page *dest_pg, unsigned int dest_off, struct page *src_pg,
	unsigned int src_off, size_t len);
void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
	struct dma_chan *chan);

static inline void
async_tx_ack(struct dma_async_tx_descriptor *tx)
{
	tx->ack = 1;
}

#define first_dma_cap(mask) __first_dma_cap(&(mask))
static inline int __first_dma_cap(const dma_cap_mask_t *srcp)
{
	return min_t(int, DMA_TX_TYPE_END,
		find_first_bit(srcp->bits, DMA_TX_TYPE_END));
}

#define next_dma_cap(n, mask) __next_dma_cap((n), &(mask))
static inline int __next_dma_cap(int n, const dma_cap_mask_t *srcp)
{
	return min_t(int, DMA_TX_TYPE_END,
		find_next_bit(srcp->bits, DMA_TX_TYPE_END, n+1));
}

#define dma_cap_set(tx, mask) __dma_cap_set((tx), &(mask))
static inline void
__dma_cap_set(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp)
{
	set_bit(tx_type, dstp->bits);
}

#define dma_has_cap(tx, mask) __dma_has_cap((tx), &(mask))
static inline int
__dma_has_cap(enum dma_transaction_type tx_type, dma_cap_mask_t *srcp)
{
	return test_bit(tx_type, srcp->bits);
}

#define for_each_dma_cap_mask(cap, mask) \
	for ((cap) = first_dma_cap(mask);	\
		(cap) < DMA_TX_TYPE_END;	\
		(cap) = next_dma_cap((cap), (mask)))

/**
 * dma_async_issue_pending - flush pending transactions to HW
 * @chan: target DMA channel
 *
 * This allows drivers to push copies to HW in batches,
 * reducing MMIO writes where possible.
 */
static inline void dma_async_issue_pending(struct dma_chan *chan)
{
	chan->device->device_issue_pending(chan);
}

#define dma_async_memcpy_issue_pending(chan) dma_async_issue_pending(chan)

/**
 * dma_async_is_tx_complete - poll for transaction completion
 * @chan: DMA channel
 * @cookie: transaction identifier to check status of
 * @last: returns last completed cookie, can be NULL
 * @used: returns last issued cookie, can be NULL
 *
 * If @last and @used are passed in, upon return they reflect the driver
 * internal state and can be used with dma_async_is_complete() to check
 * the status of multiple cookies without re-checking hardware state.
 */
static inline enum dma_status dma_async_is_tx_complete(struct dma_chan *chan,
	dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used)
{
	return chan->device->device_is_tx_complete(chan, cookie, last, used);
}

#define dma_async_memcpy_complete(chan, cookie, last, used)\
	dma_async_is_tx_complete(chan, cookie, last, used)

/**
 * dma_async_is_complete - test a cookie against chan state
 * @cookie: transaction identifier to test status of
 * @last_complete: last know completed transaction
 * @last_used: last cookie value handed out
 *
 * dma_async_is_complete() is used in dma_async_memcpy_complete()
 * the test logic is seperated for lightweight testing of multiple cookies
 */
static inline enum dma_status dma_async_is_complete(dma_cookie_t cookie,
			dma_cookie_t last_complete, dma_cookie_t last_used)
{
	if (last_complete <= last_used) {
		if ((cookie <= last_complete) || (cookie > last_used))
			return DMA_SUCCESS;
	} else {
		if ((cookie <= last_complete) && (cookie > last_used))
			return DMA_SUCCESS;
	}
	return DMA_IN_PROGRESS;
}

enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);

/* --- DMA device --- */

int dma_async_device_register(struct dma_device *device);
void dma_async_device_unregister(struct dma_device *device);

/* --- Helper iov-locking functions --- */

struct dma_page_list {
	char __user *base_address;
	int nr_pages;
	struct page **pages;
};

struct dma_pinned_list {
	int nr_iovecs;
	struct dma_page_list page_list[0];
};

struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len);
void dma_unpin_iovec_pages(struct dma_pinned_list* pinned_list);

dma_cookie_t dma_memcpy_to_iovec(struct dma_chan *chan, struct iovec *iov,
	struct dma_pinned_list *pinned_list, unsigned char *kdata, size_t len);
dma_cookie_t dma_memcpy_pg_to_iovec(struct dma_chan *chan, struct iovec *iov,
	struct dma_pinned_list *pinned_list, struct page *page,
	unsigned int offset, size_t len);

#endif /* DMAENGINE_H */
Commit	Line	Data
c13c8260 CL	1	/*
	2	* Copyright(c) 2004 - 2006 Intel Corporation. All rights reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms of the GNU General Public License as published by the Free
	6	* Software Foundation; either version 2 of the License, or (at your option)
	7	* any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful, but WITHOUT
	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	12	* more details.
	13	*
	14	* You should have received a copy of the GNU General Public License along with
	15	* this program; if not, write to the Free Software Foundation, Inc., 59
	16	* Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	17	*
	18	* The full GNU General Public License is included in this distribution in the
	19	* file called COPYING.
	20	*/
	21	#ifndef DMAENGINE_H
	22	#define DMAENGINE_H
1c0f16e5	23
c13c8260 CL	24	#include <linux/device.h>
	25	#include <linux/uio.h>
	26	#include <linux/kref.h>
	27	#include <linux/completion.h>
	28	#include <linux/rcupdate.h>
7405f74b	29	#include <linux/dma-mapping.h>
c13c8260 CL	30
c13c8260 CL	31	/**
fd3f8984	32	* enum dma_state - resource PNP/power management state
c13c8260 CL	33	* @DMA_RESOURCE_SUSPEND: DMA device going into low power state
c13c8260 CL	34	* @DMA_RESOURCE_RESUME: DMA device returning to full power
d379b01e	35	* @DMA_RESOURCE_AVAILABLE: DMA device available to the system
c13c8260 CL	36	* @DMA_RESOURCE_REMOVED: DMA device removed from the system
c13c8260 CL	37	*/
d379b01e	38	enum dma_state {
c13c8260 CL	39	DMA_RESOURCE_SUSPEND,
c13c8260 CL	40	DMA_RESOURCE_RESUME,
d379b01e	41	DMA_RESOURCE_AVAILABLE,
c13c8260 CL	42	DMA_RESOURCE_REMOVED,
	43	};
	44
d379b01e DW	45	/**
	46	* enum dma_state_client - state of the channel in the client
	47	* @DMA_ACK: client would like to use, or was using this channel
	48	* @DMA_DUP: client has already seen this channel, or is not using this channel
	49	* @DMA_NAK: client does not want to see any more channels
	50	*/
	51	enum dma_state_client {
	52	DMA_ACK,
	53	DMA_DUP,
	54	DMA_NAK,
	55	};
	56
c13c8260	57	/**
fe4ada2d	58	* typedef dma_cookie_t - an opaque DMA cookie
c13c8260 CL	59	*
	60	* if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code
	61	*/
	62	typedef s32 dma_cookie_t;
	63
	64	#define dma_submit_error(cookie) ((cookie) < 0 ? 1 : 0)
	65
	66	/**
	67	* enum dma_status - DMA transaction status
	68	* @DMA_SUCCESS: transaction completed successfully
	69	* @DMA_IN_PROGRESS: transaction not yet processed
	70	* @DMA_ERROR: transaction failed
	71	*/
	72	enum dma_status {
	73	DMA_SUCCESS,
	74	DMA_IN_PROGRESS,
	75	DMA_ERROR,
	76	};
	77
7405f74b DW	78	/**
	79	* enum dma_transaction_type - DMA transaction types/indexes
	80	*/
	81	enum dma_transaction_type {
	82	DMA_MEMCPY,
	83	DMA_XOR,
	84	DMA_PQ_XOR,
	85	DMA_DUAL_XOR,
	86	DMA_PQ_UPDATE,
	87	DMA_ZERO_SUM,
	88	DMA_PQ_ZERO_SUM,
	89	DMA_MEMSET,
	90	DMA_MEMCPY_CRC32C,
	91	DMA_INTERRUPT,
	92	};
	93
	94	/* last transaction type for creation of the capabilities mask */
	95	#define DMA_TX_TYPE_END (DMA_INTERRUPT + 1)
	96
d4c56f97 DW	97	/**
	98	* enum dma_prep_flags - DMA flags to augment operation preparation
	99	* @DMA_PREP_INTERRUPT - trigger an interrupt (callback) upon completion of
	100	* this transaction
	101	*/
	102	enum dma_prep_flags {
	103	DMA_PREP_INTERRUPT = (1 << 0),
	104	};
	105
7405f74b DW	106	/**
	107	* dma_cap_mask_t - capabilities bitmap modeled after cpumask_t.
	108	* See linux/cpumask.h
	109	*/
	110	typedef struct { DECLARE_BITMAP(bits, DMA_TX_TYPE_END); } dma_cap_mask_t;
	111
c13c8260 CL	112	/**
	113	* struct dma_chan_percpu - the per-CPU part of struct dma_chan
	114	* @refcount: local_t used for open-coded "bigref" counting
	115	* @memcpy_count: transaction counter
	116	* @bytes_transferred: byte counter
	117	*/
	118
	119	struct dma_chan_percpu {
	120	local_t refcount;
	121	/* stats */
	122	unsigned long memcpy_count;
	123	unsigned long bytes_transferred;
	124	};
	125
	126	/**
	127	* struct dma_chan - devices supply DMA channels, clients use them
fe4ada2d	128	* @device: ptr to the dma device who supplies this channel, always !%NULL
c13c8260	129	* @cookie: last cookie value returned to client
fe4ada2d RD	130	* @chan_id: channel ID for sysfs
fe4ada2d RD	131	* @class_dev: class device for sysfs
c13c8260	132	* @refcount: kref, used in "bigref" slow-mode
fe4ada2d RD	133	* @slow_ref: indicates that the DMA channel is free
fe4ada2d RD	134	* @rcu: the DMA channel's RCU head
c13c8260 CL	135	* @device_node: used to add this to the device chan list
	136	* @local: per-cpu pointer to a struct dma_chan_percpu
	137	*/
	138	struct dma_chan {
c13c8260 CL	139	struct dma_device *device;
	140	dma_cookie_t cookie;
	141
	142	/* sysfs */
	143	int chan_id;
891f78ea	144	struct device dev;
c13c8260 CL	145
	146	struct kref refcount;
	147	int slow_ref;
	148	struct rcu_head rcu;
	149
c13c8260 CL	150	struct list_head device_node;
	151	struct dma_chan_percpu *local;
	152	};
	153
891f78ea	154	#define to_dma_chan(p) container_of(p, struct dma_chan, dev)
d379b01e	155
c13c8260 CL	156	void dma_chan_cleanup(struct kref *kref);
	157
	158	static inline void dma_chan_get(struct dma_chan *chan)
	159	{
	160	if (unlikely(chan->slow_ref))
	161	kref_get(&chan->refcount);
	162	else {
	163	local_inc(&(per_cpu_ptr(chan->local, get_cpu())->refcount));
	164	put_cpu();
	165	}
	166	}
	167
	168	static inline void dma_chan_put(struct dma_chan *chan)
	169	{
	170	if (unlikely(chan->slow_ref))
	171	kref_put(&chan->refcount, dma_chan_cleanup);
	172	else {
	173	local_dec(&(per_cpu_ptr(chan->local, get_cpu())->refcount));
	174	put_cpu();
	175	}
	176	}
	177
	178	/*
	179	* typedef dma_event_callback - function pointer to a DMA event callback
d379b01e DW	180	* For each channel added to the system this routine is called for each client.
	181	* If the client would like to use the channel it returns '1' to signal (ack)
	182	* the dmaengine core to take out a reference on the channel and its
	183	* corresponding device. A client must not 'ack' an available channel more
	184	* than once. When a channel is removed all clients are notified. If a client
	185	* is using the channel it must 'ack' the removal. A client must not 'ack' a
	186	* removed channel more than once.
	187	* @client - 'this' pointer for the client context
	188	* @chan - channel to be acted upon
	189	* @state - available or removed
c13c8260	190	*/
d379b01e DW	191	struct dma_client;
	192	typedef enum dma_state_client (dma_event_callback) (struct dma_client client,
	193	struct dma_chan *chan, enum dma_state state);
c13c8260 CL	194
	195	/**
	196	* struct dma_client - info on the entity making use of DMA services
	197	* @event_callback: func ptr to call when something happens
d379b01e DW	198	* @cap_mask: only return channels that satisfy the requested capabilities
d379b01e DW	199	* a value of zero corresponds to any capability
c13c8260 CL	200	* @global_node: list_head for global dma_client_list
	201	*/
	202	struct dma_client {
	203	dma_event_callback event_callback;
d379b01e	204	dma_cap_mask_t cap_mask;
c13c8260 CL	205	struct list_head global_node;
	206	};
	207
7405f74b DW	208	typedef void (dma_async_tx_callback)(void dma_async_param);
	209	/**
	210	* struct dma_async_tx_descriptor - async transaction descriptor
	211	* ---dma generic offload fields---
	212	* @cookie: tracking cookie for this transaction, set to -EBUSY if
	213	* this tx is sitting on a dependency list
	214	* @ack: the descriptor can not be reused until the client acknowledges
	215	* receipt, i.e. has has a chance to establish any dependency chains
	216	* @phys: physical address of the descriptor
	217	* @tx_list: driver common field for operations that require multiple
	218	* descriptors
	219	* @chan: target channel for this operation
	220	* @tx_submit: set the prepared descriptor(s) to be executed by the engine
7405f74b DW	221	* @callback: routine to call after this operation is complete
	222	* @callback_param: general parameter to pass to the callback routine
	223	* ---async_tx api specific fields---
19242d72	224	* @next: at completion submit this descriptor
7405f74b	225	* @parent: pointer to the next level up in the dependency chain
19242d72	226	* @lock: protect the parent and next pointers
7405f74b DW	227	*/
	228	struct dma_async_tx_descriptor {
	229	dma_cookie_t cookie;
	230	int ack;
	231	dma_addr_t phys;
	232	struct list_head tx_list;
	233	struct dma_chan *chan;
	234	dma_cookie_t (tx_submit)(struct dma_async_tx_descriptor tx);
7405f74b DW	235	dma_async_tx_callback callback;
7405f74b DW	236	void *callback_param;
19242d72	237	struct dma_async_tx_descriptor *next;
7405f74b DW	238	struct dma_async_tx_descriptor *parent;
	239	spinlock_t lock;
	240	};
	241
c13c8260 CL	242	/**
	243	* struct dma_device - info on the entity supplying DMA services
	244	* @chancnt: how many DMA channels are supported
	245	* @channels: the list of struct dma_chan
	246	* @global_node: list_head for global dma_device_list
7405f74b DW	247	* @cap_mask: one or more dma_capability flags
7405f74b DW	248	* @max_xor: maximum number of xor sources, 0 if no capability
fe4ada2d RD	249	* @refcount: reference count
	250	* @done: IO completion struct
	251	* @dev_id: unique device ID
7405f74b	252	* @dev: struct device reference for dma mapping api
fe4ada2d RD	253	* @device_alloc_chan_resources: allocate resources and return the
	254	* number of allocated descriptors
	255	* @device_free_chan_resources: release DMA channel's resources
7405f74b DW	256	* @device_prep_dma_memcpy: prepares a memcpy operation
	257	* @device_prep_dma_xor: prepares a xor operation
	258	* @device_prep_dma_zero_sum: prepares a zero_sum operation
	259	* @device_prep_dma_memset: prepares a memset operation
	260	* @device_prep_dma_interrupt: prepares an end of chain interrupt operation
7405f74b	261	* @device_issue_pending: push pending transactions to hardware
c13c8260 CL	262	*/
	263	struct dma_device {
	264
	265	unsigned int chancnt;
	266	struct list_head channels;
	267	struct list_head global_node;
7405f74b DW	268	dma_cap_mask_t cap_mask;
7405f74b DW	269	int max_xor;
c13c8260 CL	270
	271	struct kref refcount;
	272	struct completion done;
	273
	274	int dev_id;
7405f74b	275	struct device *dev;
c13c8260 CL	276
	277	int (device_alloc_chan_resources)(struct dma_chan chan);
	278	void (device_free_chan_resources)(struct dma_chan chan);
7405f74b DW	279
7405f74b DW	280	struct dma_async_tx_descriptor (device_prep_dma_memcpy)(
0036731c	281	struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
d4c56f97	282	size_t len, unsigned long flags);
7405f74b	283	struct dma_async_tx_descriptor (device_prep_dma_xor)(
0036731c	284	struct dma_chan chan, dma_addr_t dest, dma_addr_t src,
d4c56f97	285	unsigned int src_cnt, size_t len, unsigned long flags);
7405f74b	286	struct dma_async_tx_descriptor (device_prep_dma_zero_sum)(
0036731c	287	struct dma_chan chan, dma_addr_t src, unsigned int src_cnt,
d4c56f97	288	size_t len, u32 *result, unsigned long flags);
7405f74b	289	struct dma_async_tx_descriptor (device_prep_dma_memset)(
0036731c	290	struct dma_chan *chan, dma_addr_t dest, int value, size_t len,
d4c56f97	291	unsigned long flags);
7405f74b DW	292	struct dma_async_tx_descriptor (device_prep_dma_interrupt)(
	293	struct dma_chan *chan);
	294
7405f74b	295	enum dma_status (device_is_tx_complete)(struct dma_chan chan,
c13c8260 CL	296	dma_cookie_t cookie, dma_cookie_t *last,
c13c8260 CL	297	dma_cookie_t *used);
7405f74b	298	void (device_issue_pending)(struct dma_chan chan);
c13c8260 CL	299	};
	300
	301	/* --- public DMA engine API --- */
	302
d379b01e	303	void dma_async_client_register(struct dma_client *client);
c13c8260	304	void dma_async_client_unregister(struct dma_client *client);
d379b01e	305	void dma_async_client_chan_request(struct dma_client *client);
7405f74b DW	306	dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan,
	307	void dest, void src, size_t len);
	308	dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan,
	309	struct page page, unsigned int offset, void kdata, size_t len);
	310	dma_cookie_t dma_async_memcpy_pg_to_pg(struct dma_chan *chan,
	311	struct page dest_pg, unsigned int dest_off, struct page src_pg,
	312	unsigned int src_off, size_t len);
	313	void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
	314	struct dma_chan *chan);
c13c8260	315
7405f74b DW	316	static inline void
	317	async_tx_ack(struct dma_async_tx_descriptor *tx)
	318	{
	319	tx->ack = 1;
c13c8260 CL	320	}
c13c8260 CL	321
7405f74b DW	322	#define first_dma_cap(mask) __first_dma_cap(&(mask))
7405f74b DW	323	static inline int __first_dma_cap(const dma_cap_mask_t *srcp)
c13c8260	324	{
7405f74b DW	325	return min_t(int, DMA_TX_TYPE_END,
	326	find_first_bit(srcp->bits, DMA_TX_TYPE_END));
	327	}
c13c8260	328
7405f74b DW	329	#define next_dma_cap(n, mask) __next_dma_cap((n), &(mask))
	330	static inline int __next_dma_cap(int n, const dma_cap_mask_t *srcp)
	331	{
	332	return min_t(int, DMA_TX_TYPE_END,
	333	find_next_bit(srcp->bits, DMA_TX_TYPE_END, n+1));
c13c8260 CL	334	}
c13c8260 CL	335
7405f74b DW	336	#define dma_cap_set(tx, mask) __dma_cap_set((tx), &(mask))
	337	static inline void
	338	__dma_cap_set(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp)
c13c8260	339	{
7405f74b DW	340	set_bit(tx_type, dstp->bits);
7405f74b DW	341	}
c13c8260	342
7405f74b DW	343	#define dma_has_cap(tx, mask) __dma_has_cap((tx), &(mask))
	344	static inline int
	345	__dma_has_cap(enum dma_transaction_type tx_type, dma_cap_mask_t *srcp)
	346	{
	347	return test_bit(tx_type, srcp->bits);
c13c8260 CL	348	}
c13c8260 CL	349
7405f74b DW	350	#define for_each_dma_cap_mask(cap, mask) \
	351	for ((cap) = first_dma_cap(mask); \
	352	(cap) < DMA_TX_TYPE_END; \
	353	(cap) = next_dma_cap((cap), (mask)))
	354
c13c8260	355	/**
7405f74b	356	* dma_async_issue_pending - flush pending transactions to HW
fe4ada2d	357	* @chan: target DMA channel
c13c8260 CL	358	*
	359	* This allows drivers to push copies to HW in batches,
	360	* reducing MMIO writes where possible.
	361	*/
7405f74b	362	static inline void dma_async_issue_pending(struct dma_chan *chan)
c13c8260	363	{
ec8670f1	364	chan->device->device_issue_pending(chan);
c13c8260 CL	365	}
c13c8260 CL	366
7405f74b DW	367	#define dma_async_memcpy_issue_pending(chan) dma_async_issue_pending(chan)
7405f74b DW	368
c13c8260	369	/**
7405f74b	370	* dma_async_is_tx_complete - poll for transaction completion
c13c8260 CL	371	* @chan: DMA channel
	372	* @cookie: transaction identifier to check status of
	373	* @last: returns last completed cookie, can be NULL
	374	* @used: returns last issued cookie, can be NULL
	375	*
	376	* If @last and @used are passed in, upon return they reflect the driver
	377	* internal state and can be used with dma_async_is_complete() to check
	378	* the status of multiple cookies without re-checking hardware state.
	379	*/
7405f74b	380	static inline enum dma_status dma_async_is_tx_complete(struct dma_chan *chan,
c13c8260 CL	381	dma_cookie_t cookie, dma_cookie_t last, dma_cookie_t used)
c13c8260 CL	382	{
7405f74b	383	return chan->device->device_is_tx_complete(chan, cookie, last, used);
c13c8260 CL	384	}
c13c8260 CL	385
7405f74b DW	386	#define dma_async_memcpy_complete(chan, cookie, last, used)\
	387	dma_async_is_tx_complete(chan, cookie, last, used)
	388
c13c8260 CL	389	/**
	390	* dma_async_is_complete - test a cookie against chan state
	391	* @cookie: transaction identifier to test status of
	392	* @last_complete: last know completed transaction
	393	* @last_used: last cookie value handed out
	394	*
	395	* dma_async_is_complete() is used in dma_async_memcpy_complete()
	396	* the test logic is seperated for lightweight testing of multiple cookies
	397	*/
	398	static inline enum dma_status dma_async_is_complete(dma_cookie_t cookie,
	399	dma_cookie_t last_complete, dma_cookie_t last_used)
	400	{
	401	if (last_complete <= last_used) {
	402	if ((cookie <= last_complete) \|\| (cookie > last_used))
	403	return DMA_SUCCESS;
	404	} else {
	405	if ((cookie <= last_complete) && (cookie > last_used))
	406	return DMA_SUCCESS;
	407	}
	408	return DMA_IN_PROGRESS;
	409	}
	410
7405f74b	411	enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);
c13c8260 CL	412
	413	/* --- DMA device --- */
	414
	415	int dma_async_device_register(struct dma_device *device);
	416	void dma_async_device_unregister(struct dma_device *device);
	417
de5506e1 CL	418	/* --- Helper iov-locking functions --- */
	419
	420	struct dma_page_list {
b2ddb901	421	char __user *base_address;
de5506e1 CL	422	int nr_pages;
	423	struct page **pages;
	424	};
	425
	426	struct dma_pinned_list {
	427	int nr_iovecs;
	428	struct dma_page_list page_list[0];
	429	};
	430
	431	struct dma_pinned_list dma_pin_iovec_pages(struct iovec iov, size_t len);
	432	void dma_unpin_iovec_pages(struct dma_pinned_list* pinned_list);
	433
	434	dma_cookie_t dma_memcpy_to_iovec(struct dma_chan chan, struct iovec iov,
	435	struct dma_pinned_list pinned_list, unsigned char kdata, size_t len);
	436	dma_cookie_t dma_memcpy_pg_to_iovec(struct dma_chan chan, struct iovec iov,
	437	struct dma_pinned_list pinned_list, struct page page,
	438	unsigned int offset, size_t len);
	439
c13c8260	440	#endif /* DMAENGINE_H */