dmaengine: add a release for dma class devices and dependent infrastructure
[linux-block.git] / include / linux / dmaengine.h
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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
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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 30
c13c8260 31/**
fe4ada2d 32 * typedef dma_cookie_t - an opaque DMA cookie
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33 *
34 * if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code
35 */
36typedef s32 dma_cookie_t;
37
38#define dma_submit_error(cookie) ((cookie) < 0 ? 1 : 0)
39
40/**
41 * enum dma_status - DMA transaction status
42 * @DMA_SUCCESS: transaction completed successfully
43 * @DMA_IN_PROGRESS: transaction not yet processed
44 * @DMA_ERROR: transaction failed
45 */
46enum dma_status {
47 DMA_SUCCESS,
48 DMA_IN_PROGRESS,
49 DMA_ERROR,
50};
51
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52/**
53 * enum dma_transaction_type - DMA transaction types/indexes
54 */
55enum dma_transaction_type {
56 DMA_MEMCPY,
57 DMA_XOR,
58 DMA_PQ_XOR,
59 DMA_DUAL_XOR,
60 DMA_PQ_UPDATE,
61 DMA_ZERO_SUM,
62 DMA_PQ_ZERO_SUM,
63 DMA_MEMSET,
64 DMA_MEMCPY_CRC32C,
65 DMA_INTERRUPT,
59b5ec21 66 DMA_PRIVATE,
dc0ee643 67 DMA_SLAVE,
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68};
69
70/* last transaction type for creation of the capabilities mask */
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71#define DMA_TX_TYPE_END (DMA_SLAVE + 1)
72
7405f74b 73
d4c56f97 74/**
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75 * enum dma_ctrl_flags - DMA flags to augment operation preparation,
76 * control completion, and communicate status.
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77 * @DMA_PREP_INTERRUPT - trigger an interrupt (callback) upon completion of
78 * this transaction
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79 * @DMA_CTRL_ACK - the descriptor cannot be reused until the client
80 * acknowledges receipt, i.e. has has a chance to establish any
81 * dependency chains
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82 * @DMA_COMPL_SKIP_SRC_UNMAP - set to disable dma-unmapping the source buffer(s)
83 * @DMA_COMPL_SKIP_DEST_UNMAP - set to disable dma-unmapping the destination(s)
d4c56f97 84 */
636bdeaa 85enum dma_ctrl_flags {
d4c56f97 86 DMA_PREP_INTERRUPT = (1 << 0),
636bdeaa 87 DMA_CTRL_ACK = (1 << 1),
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88 DMA_COMPL_SKIP_SRC_UNMAP = (1 << 2),
89 DMA_COMPL_SKIP_DEST_UNMAP = (1 << 3),
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90};
91
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92/**
93 * dma_cap_mask_t - capabilities bitmap modeled after cpumask_t.
94 * See linux/cpumask.h
95 */
96typedef struct { DECLARE_BITMAP(bits, DMA_TX_TYPE_END); } dma_cap_mask_t;
97
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98/**
99 * struct dma_chan_percpu - the per-CPU part of struct dma_chan
100 * @refcount: local_t used for open-coded "bigref" counting
101 * @memcpy_count: transaction counter
102 * @bytes_transferred: byte counter
103 */
104
105struct dma_chan_percpu {
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106 /* stats */
107 unsigned long memcpy_count;
108 unsigned long bytes_transferred;
109};
110
111/**
112 * struct dma_chan - devices supply DMA channels, clients use them
fe4ada2d 113 * @device: ptr to the dma device who supplies this channel, always !%NULL
c13c8260 114 * @cookie: last cookie value returned to client
fe4ada2d 115 * @chan_id: channel ID for sysfs
41d5e59c 116 * @dev: class device for sysfs
c13c8260 117 * @refcount: kref, used in "bigref" slow-mode
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118 * @slow_ref: indicates that the DMA channel is free
119 * @rcu: the DMA channel's RCU head
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120 * @device_node: used to add this to the device chan list
121 * @local: per-cpu pointer to a struct dma_chan_percpu
7cc5bf9a 122 * @client-count: how many clients are using this channel
bec08513 123 * @table_count: number of appearances in the mem-to-mem allocation table
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124 */
125struct dma_chan {
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126 struct dma_device *device;
127 dma_cookie_t cookie;
128
129 /* sysfs */
130 int chan_id;
41d5e59c 131 struct dma_chan_dev *dev;
c13c8260 132
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133 struct list_head device_node;
134 struct dma_chan_percpu *local;
7cc5bf9a 135 int client_count;
bec08513 136 int table_count;
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137};
138
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139/**
140 * struct dma_chan_dev - relate sysfs device node to backing channel device
141 * @chan - driver channel device
142 * @device - sysfs device
143 */
144struct dma_chan_dev {
145 struct dma_chan *chan;
146 struct device device;
147};
148
149static inline const char *dma_chan_name(struct dma_chan *chan)
150{
151 return dev_name(&chan->dev->device);
152}
d379b01e 153
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154void dma_chan_cleanup(struct kref *kref);
155
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156/**
157 * typedef dma_filter_fn - callback filter for dma_request_channel
158 * @chan: channel to be reviewed
159 * @filter_param: opaque parameter passed through dma_request_channel
160 *
161 * When this optional parameter is specified in a call to dma_request_channel a
162 * suitable channel is passed to this routine for further dispositioning before
163 * being returned. Where 'suitable' indicates a non-busy channel that
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164 * satisfies the given capability mask. It returns 'true' to indicate that the
165 * channel is suitable.
59b5ec21 166 */
7dd60251 167typedef bool (*dma_filter_fn)(struct dma_chan *chan, void *filter_param);
59b5ec21 168
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169typedef void (*dma_async_tx_callback)(void *dma_async_param);
170/**
171 * struct dma_async_tx_descriptor - async transaction descriptor
172 * ---dma generic offload fields---
173 * @cookie: tracking cookie for this transaction, set to -EBUSY if
174 * this tx is sitting on a dependency list
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175 * @flags: flags to augment operation preparation, control completion, and
176 * communicate status
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177 * @phys: physical address of the descriptor
178 * @tx_list: driver common field for operations that require multiple
179 * descriptors
180 * @chan: target channel for this operation
181 * @tx_submit: set the prepared descriptor(s) to be executed by the engine
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182 * @callback: routine to call after this operation is complete
183 * @callback_param: general parameter to pass to the callback routine
184 * ---async_tx api specific fields---
19242d72 185 * @next: at completion submit this descriptor
7405f74b 186 * @parent: pointer to the next level up in the dependency chain
19242d72 187 * @lock: protect the parent and next pointers
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188 */
189struct dma_async_tx_descriptor {
190 dma_cookie_t cookie;
636bdeaa 191 enum dma_ctrl_flags flags; /* not a 'long' to pack with cookie */
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192 dma_addr_t phys;
193 struct list_head tx_list;
194 struct dma_chan *chan;
195 dma_cookie_t (*tx_submit)(struct dma_async_tx_descriptor *tx);
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196 dma_async_tx_callback callback;
197 void *callback_param;
19242d72 198 struct dma_async_tx_descriptor *next;
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199 struct dma_async_tx_descriptor *parent;
200 spinlock_t lock;
201};
202
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203/**
204 * struct dma_device - info on the entity supplying DMA services
205 * @chancnt: how many DMA channels are supported
206 * @channels: the list of struct dma_chan
207 * @global_node: list_head for global dma_device_list
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208 * @cap_mask: one or more dma_capability flags
209 * @max_xor: maximum number of xor sources, 0 if no capability
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210 * @refcount: reference count
211 * @done: IO completion struct
212 * @dev_id: unique device ID
7405f74b 213 * @dev: struct device reference for dma mapping api
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214 * @device_alloc_chan_resources: allocate resources and return the
215 * number of allocated descriptors
216 * @device_free_chan_resources: release DMA channel's resources
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217 * @device_prep_dma_memcpy: prepares a memcpy operation
218 * @device_prep_dma_xor: prepares a xor operation
219 * @device_prep_dma_zero_sum: prepares a zero_sum operation
220 * @device_prep_dma_memset: prepares a memset operation
221 * @device_prep_dma_interrupt: prepares an end of chain interrupt operation
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222 * @device_prep_slave_sg: prepares a slave dma operation
223 * @device_terminate_all: terminate all pending operations
7405f74b 224 * @device_issue_pending: push pending transactions to hardware
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225 */
226struct dma_device {
227
228 unsigned int chancnt;
229 struct list_head channels;
230 struct list_head global_node;
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231 dma_cap_mask_t cap_mask;
232 int max_xor;
c13c8260 233
c13c8260 234 int dev_id;
7405f74b 235 struct device *dev;
c13c8260 236
aa1e6f1a 237 int (*device_alloc_chan_resources)(struct dma_chan *chan);
c13c8260 238 void (*device_free_chan_resources)(struct dma_chan *chan);
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239
240 struct dma_async_tx_descriptor *(*device_prep_dma_memcpy)(
0036731c 241 struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
d4c56f97 242 size_t len, unsigned long flags);
7405f74b 243 struct dma_async_tx_descriptor *(*device_prep_dma_xor)(
0036731c 244 struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
d4c56f97 245 unsigned int src_cnt, size_t len, unsigned long flags);
7405f74b 246 struct dma_async_tx_descriptor *(*device_prep_dma_zero_sum)(
0036731c 247 struct dma_chan *chan, dma_addr_t *src, unsigned int src_cnt,
d4c56f97 248 size_t len, u32 *result, unsigned long flags);
7405f74b 249 struct dma_async_tx_descriptor *(*device_prep_dma_memset)(
0036731c 250 struct dma_chan *chan, dma_addr_t dest, int value, size_t len,
d4c56f97 251 unsigned long flags);
7405f74b 252 struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)(
636bdeaa 253 struct dma_chan *chan, unsigned long flags);
7405f74b 254
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255 struct dma_async_tx_descriptor *(*device_prep_slave_sg)(
256 struct dma_chan *chan, struct scatterlist *sgl,
257 unsigned int sg_len, enum dma_data_direction direction,
258 unsigned long flags);
259 void (*device_terminate_all)(struct dma_chan *chan);
260
7405f74b 261 enum dma_status (*device_is_tx_complete)(struct dma_chan *chan,
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262 dma_cookie_t cookie, dma_cookie_t *last,
263 dma_cookie_t *used);
7405f74b 264 void (*device_issue_pending)(struct dma_chan *chan);
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265};
266
267/* --- public DMA engine API --- */
268
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269void dmaengine_get(void);
270void dmaengine_put(void);
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271dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan,
272 void *dest, void *src, size_t len);
273dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan,
274 struct page *page, unsigned int offset, void *kdata, size_t len);
275dma_cookie_t dma_async_memcpy_pg_to_pg(struct dma_chan *chan,
276 struct page *dest_pg, unsigned int dest_off, struct page *src_pg,
277 unsigned int src_off, size_t len);
278void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
279 struct dma_chan *chan);
c13c8260 280
0839875e 281static inline void async_tx_ack(struct dma_async_tx_descriptor *tx)
7405f74b 282{
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283 tx->flags |= DMA_CTRL_ACK;
284}
285
0839875e 286static inline bool async_tx_test_ack(struct dma_async_tx_descriptor *tx)
636bdeaa 287{
0839875e 288 return (tx->flags & DMA_CTRL_ACK) == DMA_CTRL_ACK;
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289}
290
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291#define first_dma_cap(mask) __first_dma_cap(&(mask))
292static inline int __first_dma_cap(const dma_cap_mask_t *srcp)
c13c8260 293{
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294 return min_t(int, DMA_TX_TYPE_END,
295 find_first_bit(srcp->bits, DMA_TX_TYPE_END));
296}
c13c8260 297
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298#define next_dma_cap(n, mask) __next_dma_cap((n), &(mask))
299static inline int __next_dma_cap(int n, const dma_cap_mask_t *srcp)
300{
301 return min_t(int, DMA_TX_TYPE_END,
302 find_next_bit(srcp->bits, DMA_TX_TYPE_END, n+1));
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303}
304
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305#define dma_cap_set(tx, mask) __dma_cap_set((tx), &(mask))
306static inline void
307__dma_cap_set(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp)
c13c8260 308{
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309 set_bit(tx_type, dstp->bits);
310}
c13c8260 311
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312#define dma_cap_zero(mask) __dma_cap_zero(&(mask))
313static inline void __dma_cap_zero(dma_cap_mask_t *dstp)
314{
315 bitmap_zero(dstp->bits, DMA_TX_TYPE_END);
316}
317
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318#define dma_has_cap(tx, mask) __dma_has_cap((tx), &(mask))
319static inline int
320__dma_has_cap(enum dma_transaction_type tx_type, dma_cap_mask_t *srcp)
321{
322 return test_bit(tx_type, srcp->bits);
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323}
324
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325#define for_each_dma_cap_mask(cap, mask) \
326 for ((cap) = first_dma_cap(mask); \
327 (cap) < DMA_TX_TYPE_END; \
328 (cap) = next_dma_cap((cap), (mask)))
329
c13c8260 330/**
7405f74b 331 * dma_async_issue_pending - flush pending transactions to HW
fe4ada2d 332 * @chan: target DMA channel
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333 *
334 * This allows drivers to push copies to HW in batches,
335 * reducing MMIO writes where possible.
336 */
7405f74b 337static inline void dma_async_issue_pending(struct dma_chan *chan)
c13c8260 338{
ec8670f1 339 chan->device->device_issue_pending(chan);
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340}
341
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342#define dma_async_memcpy_issue_pending(chan) dma_async_issue_pending(chan)
343
c13c8260 344/**
7405f74b 345 * dma_async_is_tx_complete - poll for transaction completion
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346 * @chan: DMA channel
347 * @cookie: transaction identifier to check status of
348 * @last: returns last completed cookie, can be NULL
349 * @used: returns last issued cookie, can be NULL
350 *
351 * If @last and @used are passed in, upon return they reflect the driver
352 * internal state and can be used with dma_async_is_complete() to check
353 * the status of multiple cookies without re-checking hardware state.
354 */
7405f74b 355static inline enum dma_status dma_async_is_tx_complete(struct dma_chan *chan,
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356 dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used)
357{
7405f74b 358 return chan->device->device_is_tx_complete(chan, cookie, last, used);
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359}
360
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361#define dma_async_memcpy_complete(chan, cookie, last, used)\
362 dma_async_is_tx_complete(chan, cookie, last, used)
363
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364/**
365 * dma_async_is_complete - test a cookie against chan state
366 * @cookie: transaction identifier to test status of
367 * @last_complete: last know completed transaction
368 * @last_used: last cookie value handed out
369 *
370 * dma_async_is_complete() is used in dma_async_memcpy_complete()
8a5703f8 371 * the test logic is separated for lightweight testing of multiple cookies
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372 */
373static inline enum dma_status dma_async_is_complete(dma_cookie_t cookie,
374 dma_cookie_t last_complete, dma_cookie_t last_used)
375{
376 if (last_complete <= last_used) {
377 if ((cookie <= last_complete) || (cookie > last_used))
378 return DMA_SUCCESS;
379 } else {
380 if ((cookie <= last_complete) && (cookie > last_used))
381 return DMA_SUCCESS;
382 }
383 return DMA_IN_PROGRESS;
384}
385
7405f74b 386enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);
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387#ifdef CONFIG_DMA_ENGINE
388enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx);
389#else
390static inline enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
391{
392 return DMA_SUCCESS;
393}
394#endif
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395
396/* --- DMA device --- */
397
398int dma_async_device_register(struct dma_device *device);
399void dma_async_device_unregister(struct dma_device *device);
07f2211e 400void dma_run_dependencies(struct dma_async_tx_descriptor *tx);
bec08513 401struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type);
2ba05622 402void dma_issue_pending_all(void);
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403#define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y)
404struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param);
405void dma_release_channel(struct dma_chan *chan);
c13c8260 406
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407/* --- Helper iov-locking functions --- */
408
409struct dma_page_list {
b2ddb901 410 char __user *base_address;
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411 int nr_pages;
412 struct page **pages;
413};
414
415struct dma_pinned_list {
416 int nr_iovecs;
417 struct dma_page_list page_list[0];
418};
419
420struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len);
421void dma_unpin_iovec_pages(struct dma_pinned_list* pinned_list);
422
423dma_cookie_t dma_memcpy_to_iovec(struct dma_chan *chan, struct iovec *iov,
424 struct dma_pinned_list *pinned_list, unsigned char *kdata, size_t len);
425dma_cookie_t dma_memcpy_pg_to_iovec(struct dma_chan *chan, struct iovec *iov,
426 struct dma_pinned_list *pinned_list, struct page *page,
427 unsigned int offset, size_t len);
428
c13c8260 429#endif /* DMAENGINE_H */