[linux-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_ctrl_flags - DMA flags to augment operation preparation,
 * 	control completion, and communicate status.
 * @DMA_PREP_INTERRUPT - trigger an interrupt (callback) upon completion of
 * 	this transaction
 * @DMA_CTRL_ACK - the descriptor cannot be reused until the client
 * 	acknowledges receipt, i.e. has has a chance to establish any
 * 	dependency chains
 * @DMA_COMPL_SKIP_SRC_UNMAP - set to disable dma-unmapping the source buffer(s)
 * @DMA_COMPL_SKIP_DEST_UNMAP - set to disable dma-unmapping the destination(s)
 */
enum dma_ctrl_flags {
	DMA_PREP_INTERRUPT = (1 << 0),
	DMA_CTRL_ACK = (1 << 1),
	DMA_COMPL_SKIP_SRC_UNMAP = (1 << 2),
	DMA_COMPL_SKIP_DEST_UNMAP = (1 << 3),
};

/**
 * 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
 * @client-count: how many clients are using this channel
 */
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;
	int client_count;
};

#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
 * @flags: flags to augment operation preparation, control completion, and
 * 	communicate status
 * @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;
	enum dma_ctrl_flags flags; /* not a 'long' to pack with cookie */
	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,
			struct dma_client *client);
	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, unsigned long flags);

	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->flags |= DMA_CTRL_ACK;
}

static inline int
async_tx_test_ack(struct dma_async_tx_descriptor *tx)
{
	return tx->flags & DMA_CTRL_ACK;
}

#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 separated 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	97	/**
636bdeaa DW	98	* enum dma_ctrl_flags - DMA flags to augment operation preparation,
636bdeaa DW	99	* control completion, and communicate status.
d4c56f97 DW	100	* @DMA_PREP_INTERRUPT - trigger an interrupt (callback) upon completion of
d4c56f97 DW	101	* this transaction
636bdeaa DW	102	* @DMA_CTRL_ACK - the descriptor cannot be reused until the client
	103	* acknowledges receipt, i.e. has has a chance to establish any
	104	* dependency chains
e1d181ef DW	105	* @DMA_COMPL_SKIP_SRC_UNMAP - set to disable dma-unmapping the source buffer(s)
e1d181ef DW	106	* @DMA_COMPL_SKIP_DEST_UNMAP - set to disable dma-unmapping the destination(s)
d4c56f97	107	*/
636bdeaa	108	enum dma_ctrl_flags {
d4c56f97	109	DMA_PREP_INTERRUPT = (1 << 0),
636bdeaa	110	DMA_CTRL_ACK = (1 << 1),
e1d181ef DW	111	DMA_COMPL_SKIP_SRC_UNMAP = (1 << 2),
e1d181ef DW	112	DMA_COMPL_SKIP_DEST_UNMAP = (1 << 3),
d4c56f97 DW	113	};
d4c56f97 DW	114
7405f74b DW	115	/**
	116	* dma_cap_mask_t - capabilities bitmap modeled after cpumask_t.
	117	* See linux/cpumask.h
	118	*/
	119	typedef struct { DECLARE_BITMAP(bits, DMA_TX_TYPE_END); } dma_cap_mask_t;
	120
c13c8260 CL	121	/**
	122	* struct dma_chan_percpu - the per-CPU part of struct dma_chan
	123	* @refcount: local_t used for open-coded "bigref" counting
	124	* @memcpy_count: transaction counter
	125	* @bytes_transferred: byte counter
	126	*/
	127
	128	struct dma_chan_percpu {
	129	local_t refcount;
	130	/* stats */
	131	unsigned long memcpy_count;
	132	unsigned long bytes_transferred;
	133	};
	134
	135	/**
	136	* struct dma_chan - devices supply DMA channels, clients use them
fe4ada2d	137	* @device: ptr to the dma device who supplies this channel, always !%NULL
c13c8260	138	* @cookie: last cookie value returned to client
fe4ada2d RD	139	* @chan_id: channel ID for sysfs
fe4ada2d RD	140	* @class_dev: class device for sysfs
c13c8260	141	* @refcount: kref, used in "bigref" slow-mode
fe4ada2d RD	142	* @slow_ref: indicates that the DMA channel is free
fe4ada2d RD	143	* @rcu: the DMA channel's RCU head
c13c8260 CL	144	* @device_node: used to add this to the device chan list
c13c8260 CL	145	* @local: per-cpu pointer to a struct dma_chan_percpu
7cc5bf9a	146	* @client-count: how many clients are using this channel
c13c8260 CL	147	*/
c13c8260 CL	148	struct dma_chan {
c13c8260 CL	149	struct dma_device *device;
	150	dma_cookie_t cookie;
	151
	152	/* sysfs */
	153	int chan_id;
891f78ea	154	struct device dev;
c13c8260 CL	155
	156	struct kref refcount;
	157	int slow_ref;
	158	struct rcu_head rcu;
	159
c13c8260 CL	160	struct list_head device_node;
c13c8260 CL	161	struct dma_chan_percpu *local;
7cc5bf9a	162	int client_count;
c13c8260 CL	163	};
c13c8260 CL	164
891f78ea	165	#define to_dma_chan(p) container_of(p, struct dma_chan, dev)
d379b01e	166
c13c8260 CL	167	void dma_chan_cleanup(struct kref *kref);
	168
	169	static inline void dma_chan_get(struct dma_chan *chan)
	170	{
	171	if (unlikely(chan->slow_ref))
	172	kref_get(&chan->refcount);
	173	else {
	174	local_inc(&(per_cpu_ptr(chan->local, get_cpu())->refcount));
	175	put_cpu();
	176	}
	177	}
	178
	179	static inline void dma_chan_put(struct dma_chan *chan)
	180	{
	181	if (unlikely(chan->slow_ref))
	182	kref_put(&chan->refcount, dma_chan_cleanup);
	183	else {
	184	local_dec(&(per_cpu_ptr(chan->local, get_cpu())->refcount));
	185	put_cpu();
	186	}
	187	}
	188
	189	/*
	190	* typedef dma_event_callback - function pointer to a DMA event callback
d379b01e DW	191	* For each channel added to the system this routine is called for each client.
	192	* If the client would like to use the channel it returns '1' to signal (ack)
	193	* the dmaengine core to take out a reference on the channel and its
	194	* corresponding device. A client must not 'ack' an available channel more
	195	* than once. When a channel is removed all clients are notified. If a client
	196	* is using the channel it must 'ack' the removal. A client must not 'ack' a
	197	* removed channel more than once.
	198	* @client - 'this' pointer for the client context
	199	* @chan - channel to be acted upon
	200	* @state - available or removed
c13c8260	201	*/
d379b01e DW	202	struct dma_client;
	203	typedef enum dma_state_client (dma_event_callback) (struct dma_client client,
	204	struct dma_chan *chan, enum dma_state state);
c13c8260 CL	205
	206	/**
	207	* struct dma_client - info on the entity making use of DMA services
	208	* @event_callback: func ptr to call when something happens
d379b01e DW	209	* @cap_mask: only return channels that satisfy the requested capabilities
d379b01e DW	210	* a value of zero corresponds to any capability
c13c8260 CL	211	* @global_node: list_head for global dma_client_list
	212	*/
	213	struct dma_client {
	214	dma_event_callback event_callback;
d379b01e	215	dma_cap_mask_t cap_mask;
c13c8260 CL	216	struct list_head global_node;
	217	};
	218
7405f74b DW	219	typedef void (dma_async_tx_callback)(void dma_async_param);
	220	/**
	221	* struct dma_async_tx_descriptor - async transaction descriptor
	222	* ---dma generic offload fields---
	223	* @cookie: tracking cookie for this transaction, set to -EBUSY if
	224	* this tx is sitting on a dependency list
636bdeaa DW	225	* @flags: flags to augment operation preparation, control completion, and
636bdeaa DW	226	* communicate status
7405f74b DW	227	* @phys: physical address of the descriptor
	228	* @tx_list: driver common field for operations that require multiple
	229	* descriptors
	230	* @chan: target channel for this operation
	231	* @tx_submit: set the prepared descriptor(s) to be executed by the engine
7405f74b DW	232	* @callback: routine to call after this operation is complete
	233	* @callback_param: general parameter to pass to the callback routine
	234	* ---async_tx api specific fields---
19242d72	235	* @next: at completion submit this descriptor
7405f74b	236	* @parent: pointer to the next level up in the dependency chain
19242d72	237	* @lock: protect the parent and next pointers
7405f74b DW	238	*/
	239	struct dma_async_tx_descriptor {
	240	dma_cookie_t cookie;
636bdeaa	241	enum dma_ctrl_flags flags; /* not a 'long' to pack with cookie */
7405f74b DW	242	dma_addr_t phys;
	243	struct list_head tx_list;
	244	struct dma_chan *chan;
	245	dma_cookie_t (tx_submit)(struct dma_async_tx_descriptor tx);
7405f74b DW	246	dma_async_tx_callback callback;
7405f74b DW	247	void *callback_param;
19242d72	248	struct dma_async_tx_descriptor *next;
7405f74b DW	249	struct dma_async_tx_descriptor *parent;
	250	spinlock_t lock;
	251	};
	252
c13c8260 CL	253	/**
	254	* struct dma_device - info on the entity supplying DMA services
	255	* @chancnt: how many DMA channels are supported
	256	* @channels: the list of struct dma_chan
	257	* @global_node: list_head for global dma_device_list
7405f74b DW	258	* @cap_mask: one or more dma_capability flags
7405f74b DW	259	* @max_xor: maximum number of xor sources, 0 if no capability
fe4ada2d RD	260	* @refcount: reference count
	261	* @done: IO completion struct
	262	* @dev_id: unique device ID
7405f74b	263	* @dev: struct device reference for dma mapping api
fe4ada2d RD	264	* @device_alloc_chan_resources: allocate resources and return the
	265	* number of allocated descriptors
	266	* @device_free_chan_resources: release DMA channel's resources
7405f74b DW	267	* @device_prep_dma_memcpy: prepares a memcpy operation
	268	* @device_prep_dma_xor: prepares a xor operation
	269	* @device_prep_dma_zero_sum: prepares a zero_sum operation
	270	* @device_prep_dma_memset: prepares a memset operation
	271	* @device_prep_dma_interrupt: prepares an end of chain interrupt operation
7405f74b	272	* @device_issue_pending: push pending transactions to hardware
c13c8260 CL	273	*/
	274	struct dma_device {
	275
	276	unsigned int chancnt;
	277	struct list_head channels;
	278	struct list_head global_node;
7405f74b DW	279	dma_cap_mask_t cap_mask;
7405f74b DW	280	int max_xor;
c13c8260 CL	281
	282	struct kref refcount;
	283	struct completion done;
	284
	285	int dev_id;
7405f74b	286	struct device *dev;
c13c8260	287
848c536a HS	288	int (device_alloc_chan_resources)(struct dma_chan chan,
848c536a HS	289	struct dma_client *client);
c13c8260	290	void (device_free_chan_resources)(struct dma_chan chan);
7405f74b DW	291
7405f74b DW	292	struct dma_async_tx_descriptor (device_prep_dma_memcpy)(
0036731c	293	struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
d4c56f97	294	size_t len, unsigned long flags);
7405f74b	295	struct dma_async_tx_descriptor (device_prep_dma_xor)(
0036731c	296	struct dma_chan chan, dma_addr_t dest, dma_addr_t src,
d4c56f97	297	unsigned int src_cnt, size_t len, unsigned long flags);
7405f74b	298	struct dma_async_tx_descriptor (device_prep_dma_zero_sum)(
0036731c	299	struct dma_chan chan, dma_addr_t src, unsigned int src_cnt,
d4c56f97	300	size_t len, u32 *result, unsigned long flags);
7405f74b	301	struct dma_async_tx_descriptor (device_prep_dma_memset)(
0036731c	302	struct dma_chan *chan, dma_addr_t dest, int value, size_t len,
d4c56f97	303	unsigned long flags);
7405f74b	304	struct dma_async_tx_descriptor (device_prep_dma_interrupt)(
636bdeaa	305	struct dma_chan *chan, unsigned long flags);
7405f74b	306
7405f74b	307	enum dma_status (device_is_tx_complete)(struct dma_chan chan,
c13c8260 CL	308	dma_cookie_t cookie, dma_cookie_t *last,
c13c8260 CL	309	dma_cookie_t *used);
7405f74b	310	void (device_issue_pending)(struct dma_chan chan);
c13c8260 CL	311	};
	312
	313	/* --- public DMA engine API --- */
	314
d379b01e	315	void dma_async_client_register(struct dma_client *client);
c13c8260	316	void dma_async_client_unregister(struct dma_client *client);
d379b01e	317	void dma_async_client_chan_request(struct dma_client *client);
7405f74b DW	318	dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan,
	319	void dest, void src, size_t len);
	320	dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan,
	321	struct page page, unsigned int offset, void kdata, size_t len);
	322	dma_cookie_t dma_async_memcpy_pg_to_pg(struct dma_chan *chan,
	323	struct page dest_pg, unsigned int dest_off, struct page src_pg,
	324	unsigned int src_off, size_t len);
	325	void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
	326	struct dma_chan *chan);
c13c8260	327
7405f74b DW	328	static inline void
	329	async_tx_ack(struct dma_async_tx_descriptor *tx)
	330	{
636bdeaa DW	331	tx->flags \|= DMA_CTRL_ACK;
	332	}
	333
	334	static inline int
	335	async_tx_test_ack(struct dma_async_tx_descriptor *tx)
	336	{
	337	return tx->flags & DMA_CTRL_ACK;
c13c8260 CL	338	}
c13c8260 CL	339
7405f74b DW	340	#define first_dma_cap(mask) __first_dma_cap(&(mask))
7405f74b DW	341	static inline int __first_dma_cap(const dma_cap_mask_t *srcp)
c13c8260	342	{
7405f74b DW	343	return min_t(int, DMA_TX_TYPE_END,
	344	find_first_bit(srcp->bits, DMA_TX_TYPE_END));
	345	}
c13c8260	346
7405f74b DW	347	#define next_dma_cap(n, mask) __next_dma_cap((n), &(mask))
	348	static inline int __next_dma_cap(int n, const dma_cap_mask_t *srcp)
	349	{
	350	return min_t(int, DMA_TX_TYPE_END,
	351	find_next_bit(srcp->bits, DMA_TX_TYPE_END, n+1));
c13c8260 CL	352	}
c13c8260 CL	353
7405f74b DW	354	#define dma_cap_set(tx, mask) __dma_cap_set((tx), &(mask))
	355	static inline void
	356	__dma_cap_set(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp)
c13c8260	357	{
7405f74b DW	358	set_bit(tx_type, dstp->bits);
7405f74b DW	359	}
c13c8260	360
7405f74b DW	361	#define dma_has_cap(tx, mask) __dma_has_cap((tx), &(mask))
	362	static inline int
	363	__dma_has_cap(enum dma_transaction_type tx_type, dma_cap_mask_t *srcp)
	364	{
	365	return test_bit(tx_type, srcp->bits);
c13c8260 CL	366	}
c13c8260 CL	367
7405f74b DW	368	#define for_each_dma_cap_mask(cap, mask) \
	369	for ((cap) = first_dma_cap(mask); \
	370	(cap) < DMA_TX_TYPE_END; \
	371	(cap) = next_dma_cap((cap), (mask)))
	372
c13c8260	373	/**
7405f74b	374	* dma_async_issue_pending - flush pending transactions to HW
fe4ada2d	375	* @chan: target DMA channel
c13c8260 CL	376	*
	377	* This allows drivers to push copies to HW in batches,
	378	* reducing MMIO writes where possible.
	379	*/
7405f74b	380	static inline void dma_async_issue_pending(struct dma_chan *chan)
c13c8260	381	{
ec8670f1	382	chan->device->device_issue_pending(chan);
c13c8260 CL	383	}
c13c8260 CL	384
7405f74b DW	385	#define dma_async_memcpy_issue_pending(chan) dma_async_issue_pending(chan)
7405f74b DW	386
c13c8260	387	/**
7405f74b	388	* dma_async_is_tx_complete - poll for transaction completion
c13c8260 CL	389	* @chan: DMA channel
	390	* @cookie: transaction identifier to check status of
	391	* @last: returns last completed cookie, can be NULL
	392	* @used: returns last issued cookie, can be NULL
	393	*
	394	* If @last and @used are passed in, upon return they reflect the driver
	395	* internal state and can be used with dma_async_is_complete() to check
	396	* the status of multiple cookies without re-checking hardware state.
	397	*/
7405f74b	398	static inline enum dma_status dma_async_is_tx_complete(struct dma_chan *chan,
c13c8260 CL	399	dma_cookie_t cookie, dma_cookie_t last, dma_cookie_t used)
c13c8260 CL	400	{
7405f74b	401	return chan->device->device_is_tx_complete(chan, cookie, last, used);
c13c8260 CL	402	}
c13c8260 CL	403
7405f74b DW	404	#define dma_async_memcpy_complete(chan, cookie, last, used)\
	405	dma_async_is_tx_complete(chan, cookie, last, used)
	406
c13c8260 CL	407	/**
	408	* dma_async_is_complete - test a cookie against chan state
	409	* @cookie: transaction identifier to test status of
	410	* @last_complete: last know completed transaction
	411	* @last_used: last cookie value handed out
	412	*
	413	* dma_async_is_complete() is used in dma_async_memcpy_complete()
8a5703f8	414	* the test logic is separated for lightweight testing of multiple cookies
c13c8260 CL	415	*/
	416	static inline enum dma_status dma_async_is_complete(dma_cookie_t cookie,
	417	dma_cookie_t last_complete, dma_cookie_t last_used)
	418	{
	419	if (last_complete <= last_used) {
	420	if ((cookie <= last_complete) \|\| (cookie > last_used))
	421	return DMA_SUCCESS;
	422	} else {
	423	if ((cookie <= last_complete) && (cookie > last_used))
	424	return DMA_SUCCESS;
	425	}
	426	return DMA_IN_PROGRESS;
	427	}
	428
7405f74b	429	enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);
c13c8260 CL	430
	431	/* --- DMA device --- */
	432
	433	int dma_async_device_register(struct dma_device *device);
	434	void dma_async_device_unregister(struct dma_device *device);
	435
de5506e1 CL	436	/* --- Helper iov-locking functions --- */
	437
	438	struct dma_page_list {
b2ddb901	439	char __user *base_address;
de5506e1 CL	440	int nr_pages;
	441	struct page **pages;
	442	};
	443
	444	struct dma_pinned_list {
	445	int nr_iovecs;
	446	struct dma_page_list page_list[0];
	447	};
	448
	449	struct dma_pinned_list dma_pin_iovec_pages(struct iovec iov, size_t len);
	450	void dma_unpin_iovec_pages(struct dma_pinned_list* pinned_list);
	451
	452	dma_cookie_t dma_memcpy_to_iovec(struct dma_chan chan, struct iovec iov,
	453	struct dma_pinned_list pinned_list, unsigned char kdata, size_t len);
	454	dma_cookie_t dma_memcpy_pg_to_iovec(struct dma_chan chan, struct iovec iov,
	455	struct dma_pinned_list pinned_list, struct page page,
	456	unsigned int offset, size_t len);
	457
c13c8260	458	#endif /* DMAENGINE_H */