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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
23
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>
29#include <linux/dma-mapping.h>
30
31/**
32 * typedef dma_cookie_t - an opaque DMA cookie
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
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,
66 DMA_PRIVATE,
67 DMA_SLAVE,
68};
69
70/* last transaction type for creation of the capabilities mask */
71#define DMA_TX_TYPE_END (DMA_SLAVE + 1)
72
73
74/**
75 * enum dma_ctrl_flags - DMA flags to augment operation preparation,
76 * control completion, and communicate status.
77 * @DMA_PREP_INTERRUPT - trigger an interrupt (callback) upon completion of
78 * this transaction
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
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)
84 */
85enum dma_ctrl_flags {
86 DMA_PREP_INTERRUPT = (1 << 0),
87 DMA_CTRL_ACK = (1 << 1),
88 DMA_COMPL_SKIP_SRC_UNMAP = (1 << 2),
89 DMA_COMPL_SKIP_DEST_UNMAP = (1 << 3),
90};
91
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
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 {
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
113 * @device: ptr to the dma device who supplies this channel, always !%NULL
114 * @cookie: last cookie value returned to client
115 * @chan_id: channel ID for sysfs
116 * @dev: class device for sysfs
117 * @refcount: kref, used in "bigref" slow-mode
118 * @slow_ref: indicates that the DMA channel is free
119 * @rcu: the DMA channel's RCU head
120 * @device_node: used to add this to the device chan list
121 * @local: per-cpu pointer to a struct dma_chan_percpu
122 * @client-count: how many clients are using this channel
123 * @table_count: number of appearances in the mem-to-mem allocation table
124 */
125struct dma_chan {
126 struct dma_device *device;
127 dma_cookie_t cookie;
128
129 /* sysfs */
130 int chan_id;
131 struct dma_chan_dev *dev;
132
133 struct list_head device_node;
134 struct dma_chan_percpu *local;
135 int client_count;
136 int table_count;
137};
138
139/**
140 * struct dma_chan_dev - relate sysfs device node to backing channel device
141 * @chan - driver channel device
142 * @device - sysfs device
143 * @dev_id - parent dma_device dev_id
144 * @idr_ref - reference count to gate release of dma_device dev_id
145 */
146struct dma_chan_dev {
147 struct dma_chan *chan;
148 struct device device;
149 int dev_id;
150 atomic_t *idr_ref;
151};
152
153static inline const char *dma_chan_name(struct dma_chan *chan)
154{
155 return dev_name(&chan->dev->device);
156}
157
158void dma_chan_cleanup(struct kref *kref);
159
160/**
161 * typedef dma_filter_fn - callback filter for dma_request_channel
162 * @chan: channel to be reviewed
163 * @filter_param: opaque parameter passed through dma_request_channel
164 *
165 * When this optional parameter is specified in a call to dma_request_channel a
166 * suitable channel is passed to this routine for further dispositioning before
167 * being returned. Where 'suitable' indicates a non-busy channel that
168 * satisfies the given capability mask. It returns 'true' to indicate that the
169 * channel is suitable.
170 */
171typedef bool (*dma_filter_fn)(struct dma_chan *chan, void *filter_param);
172
173typedef void (*dma_async_tx_callback)(void *dma_async_param);
174/**
175 * struct dma_async_tx_descriptor - async transaction descriptor
176 * ---dma generic offload fields---
177 * @cookie: tracking cookie for this transaction, set to -EBUSY if
178 * this tx is sitting on a dependency list
179 * @flags: flags to augment operation preparation, control completion, and
180 * communicate status
181 * @phys: physical address of the descriptor
182 * @tx_list: driver common field for operations that require multiple
183 * descriptors
184 * @chan: target channel for this operation
185 * @tx_submit: set the prepared descriptor(s) to be executed by the engine
186 * @callback: routine to call after this operation is complete
187 * @callback_param: general parameter to pass to the callback routine
188 * ---async_tx api specific fields---
189 * @next: at completion submit this descriptor
190 * @parent: pointer to the next level up in the dependency chain
191 * @lock: protect the parent and next pointers
192 */
193struct dma_async_tx_descriptor {
194 dma_cookie_t cookie;
195 enum dma_ctrl_flags flags; /* not a 'long' to pack with cookie */
196 dma_addr_t phys;
197 struct list_head tx_list;
198 struct dma_chan *chan;
199 dma_cookie_t (*tx_submit)(struct dma_async_tx_descriptor *tx);
200 dma_async_tx_callback callback;
201 void *callback_param;
202 struct dma_async_tx_descriptor *next;
203 struct dma_async_tx_descriptor *parent;
204 spinlock_t lock;
205};
206
207/**
208 * struct dma_device - info on the entity supplying DMA services
209 * @chancnt: how many DMA channels are supported
210 * @channels: the list of struct dma_chan
211 * @global_node: list_head for global dma_device_list
212 * @cap_mask: one or more dma_capability flags
213 * @max_xor: maximum number of xor sources, 0 if no capability
214 * @refcount: reference count
215 * @done: IO completion struct
216 * @dev_id: unique device ID
217 * @dev: struct device reference for dma mapping api
218 * @device_alloc_chan_resources: allocate resources and return the
219 * number of allocated descriptors
220 * @device_free_chan_resources: release DMA channel's resources
221 * @device_prep_dma_memcpy: prepares a memcpy operation
222 * @device_prep_dma_xor: prepares a xor operation
223 * @device_prep_dma_zero_sum: prepares a zero_sum operation
224 * @device_prep_dma_memset: prepares a memset operation
225 * @device_prep_dma_interrupt: prepares an end of chain interrupt operation
226 * @device_prep_slave_sg: prepares a slave dma operation
227 * @device_terminate_all: terminate all pending operations
228 * @device_issue_pending: push pending transactions to hardware
229 */
230struct dma_device {
231
232 unsigned int chancnt;
233 struct list_head channels;
234 struct list_head global_node;
235 dma_cap_mask_t cap_mask;
236 int max_xor;
237
238 int dev_id;
239 struct device *dev;
240
241 int (*device_alloc_chan_resources)(struct dma_chan *chan);
242 void (*device_free_chan_resources)(struct dma_chan *chan);
243
244 struct dma_async_tx_descriptor *(*device_prep_dma_memcpy)(
245 struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
246 size_t len, unsigned long flags);
247 struct dma_async_tx_descriptor *(*device_prep_dma_xor)(
248 struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
249 unsigned int src_cnt, size_t len, unsigned long flags);
250 struct dma_async_tx_descriptor *(*device_prep_dma_zero_sum)(
251 struct dma_chan *chan, dma_addr_t *src, unsigned int src_cnt,
252 size_t len, u32 *result, unsigned long flags);
253 struct dma_async_tx_descriptor *(*device_prep_dma_memset)(
254 struct dma_chan *chan, dma_addr_t dest, int value, size_t len,
255 unsigned long flags);
256 struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)(
257 struct dma_chan *chan, unsigned long flags);
258
259 struct dma_async_tx_descriptor *(*device_prep_slave_sg)(
260 struct dma_chan *chan, struct scatterlist *sgl,
261 unsigned int sg_len, enum dma_data_direction direction,
262 unsigned long flags);
263 void (*device_terminate_all)(struct dma_chan *chan);
264
265 enum dma_status (*device_is_tx_complete)(struct dma_chan *chan,
266 dma_cookie_t cookie, dma_cookie_t *last,
267 dma_cookie_t *used);
268 void (*device_issue_pending)(struct dma_chan *chan);
269};
270
271/* --- public DMA engine API --- */
272
273#ifdef CONFIG_DMA_ENGINE
274void dmaengine_get(void);
275void dmaengine_put(void);
276#else
277static inline void dmaengine_get(void)
278{
279}
280static inline void dmaengine_put(void)
281{
282}
283#endif
284
285dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan,
286 void *dest, void *src, size_t len);
287dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan,
288 struct page *page, unsigned int offset, void *kdata, size_t len);
289dma_cookie_t dma_async_memcpy_pg_to_pg(struct dma_chan *chan,
290 struct page *dest_pg, unsigned int dest_off, struct page *src_pg,
291 unsigned int src_off, size_t len);
292void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
293 struct dma_chan *chan);
294
295static inline void async_tx_ack(struct dma_async_tx_descriptor *tx)
296{
297 tx->flags |= DMA_CTRL_ACK;
298}
299
300static inline bool async_tx_test_ack(struct dma_async_tx_descriptor *tx)
301{
302 return (tx->flags & DMA_CTRL_ACK) == DMA_CTRL_ACK;
303}
304
305#define first_dma_cap(mask) __first_dma_cap(&(mask))
306static inline int __first_dma_cap(const dma_cap_mask_t *srcp)
307{
308 return min_t(int, DMA_TX_TYPE_END,
309 find_first_bit(srcp->bits, DMA_TX_TYPE_END));
310}
311
312#define next_dma_cap(n, mask) __next_dma_cap((n), &(mask))
313static inline int __next_dma_cap(int n, const dma_cap_mask_t *srcp)
314{
315 return min_t(int, DMA_TX_TYPE_END,
316 find_next_bit(srcp->bits, DMA_TX_TYPE_END, n+1));
317}
318
319#define dma_cap_set(tx, mask) __dma_cap_set((tx), &(mask))
320static inline void
321__dma_cap_set(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp)
322{
323 set_bit(tx_type, dstp->bits);
324}
325
326#define dma_cap_zero(mask) __dma_cap_zero(&(mask))
327static inline void __dma_cap_zero(dma_cap_mask_t *dstp)
328{
329 bitmap_zero(dstp->bits, DMA_TX_TYPE_END);
330}
331
332#define dma_has_cap(tx, mask) __dma_has_cap((tx), &(mask))
333static inline int
334__dma_has_cap(enum dma_transaction_type tx_type, dma_cap_mask_t *srcp)
335{
336 return test_bit(tx_type, srcp->bits);
337}
338
339#define for_each_dma_cap_mask(cap, mask) \
340 for ((cap) = first_dma_cap(mask); \
341 (cap) < DMA_TX_TYPE_END; \
342 (cap) = next_dma_cap((cap), (mask)))
343
344/**
345 * dma_async_issue_pending - flush pending transactions to HW
346 * @chan: target DMA channel
347 *
348 * This allows drivers to push copies to HW in batches,
349 * reducing MMIO writes where possible.
350 */
351static inline void dma_async_issue_pending(struct dma_chan *chan)
352{
353 chan->device->device_issue_pending(chan);
354}
355
356#define dma_async_memcpy_issue_pending(chan) dma_async_issue_pending(chan)
357
358/**
359 * dma_async_is_tx_complete - poll for transaction completion
360 * @chan: DMA channel
361 * @cookie: transaction identifier to check status of
362 * @last: returns last completed cookie, can be NULL
363 * @used: returns last issued cookie, can be NULL
364 *
365 * If @last and @used are passed in, upon return they reflect the driver
366 * internal state and can be used with dma_async_is_complete() to check
367 * the status of multiple cookies without re-checking hardware state.
368 */
369static inline enum dma_status dma_async_is_tx_complete(struct dma_chan *chan,
370 dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used)
371{
372 return chan->device->device_is_tx_complete(chan, cookie, last, used);
373}
374
375#define dma_async_memcpy_complete(chan, cookie, last, used)\
376 dma_async_is_tx_complete(chan, cookie, last, used)
377
378/**
379 * dma_async_is_complete - test a cookie against chan state
380 * @cookie: transaction identifier to test status of
381 * @last_complete: last know completed transaction
382 * @last_used: last cookie value handed out
383 *
384 * dma_async_is_complete() is used in dma_async_memcpy_complete()
385 * the test logic is separated for lightweight testing of multiple cookies
386 */
387static inline enum dma_status dma_async_is_complete(dma_cookie_t cookie,
388 dma_cookie_t last_complete, dma_cookie_t last_used)
389{
390 if (last_complete <= last_used) {
391 if ((cookie <= last_complete) || (cookie > last_used))
392 return DMA_SUCCESS;
393 } else {
394 if ((cookie <= last_complete) && (cookie > last_used))
395 return DMA_SUCCESS;
396 }
397 return DMA_IN_PROGRESS;
398}
399
400enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);
401#ifdef CONFIG_DMA_ENGINE
402enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx);
403#else
404static inline enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
405{
406 return DMA_SUCCESS;
407}
408#endif
409
410/* --- DMA device --- */
411
412int dma_async_device_register(struct dma_device *device);
413void dma_async_device_unregister(struct dma_device *device);
414void dma_run_dependencies(struct dma_async_tx_descriptor *tx);
415struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type);
416void dma_issue_pending_all(void);
417#define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y)
418struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param);
419void dma_release_channel(struct dma_chan *chan);
420
421/* --- Helper iov-locking functions --- */
422
423struct dma_page_list {
424 char __user *base_address;
425 int nr_pages;
426 struct page **pages;
427};
428
429struct dma_pinned_list {
430 int nr_iovecs;
431 struct dma_page_list page_list[0];
432};
433
434struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len);
435void dma_unpin_iovec_pages(struct dma_pinned_list* pinned_list);
436
437dma_cookie_t dma_memcpy_to_iovec(struct dma_chan *chan, struct iovec *iov,
438 struct dma_pinned_list *pinned_list, unsigned char *kdata, size_t len);
439dma_cookie_t dma_memcpy_pg_to_iovec(struct dma_chan *chan, struct iovec *iov,
440 struct dma_pinned_list *pinned_list, struct page *page,
441 unsigned int offset, size_t len);
442
443#endif /* DMAENGINE_H */