blob: a6c6051ec85811041277c64d675810f14d9da851 [file] [log] [blame]
Chris Leechc13c8262006-05-23 17:18:44 -07001/*
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
22/*
23 * This code implements the DMA subsystem. It provides a HW-neutral interface
24 * for other kernel code to use asynchronous memory copy capabilities,
25 * if present, and allows different HW DMA drivers to register as providing
26 * this capability.
27 *
28 * Due to the fact we are accelerating what is already a relatively fast
29 * operation, the code goes to great lengths to avoid additional overhead,
30 * such as locking.
31 *
32 * LOCKING:
33 *
Dan Williamsaa1e6f12009-01-06 11:38:17 -070034 * The subsystem keeps a global list of dma_device structs it is protected by a
35 * mutex, dma_list_mutex.
Chris Leechc13c8262006-05-23 17:18:44 -070036 *
Dan Williamsf27c5802009-01-06 11:38:18 -070037 * A subsystem can get access to a channel by calling dmaengine_get() followed
38 * by dma_find_channel(), or if it has need for an exclusive channel it can call
39 * dma_request_channel(). Once a channel is allocated a reference is taken
40 * against its corresponding driver to disable removal.
41 *
Chris Leechc13c8262006-05-23 17:18:44 -070042 * Each device has a channels list, which runs unlocked but is never modified
43 * once the device is registered, it's just setup by the driver.
44 *
Dan Williamsf27c5802009-01-06 11:38:18 -070045 * See Documentation/dmaengine.txt for more details
Chris Leechc13c8262006-05-23 17:18:44 -070046 */
47
Alexey Dobriyanb7f080c2011-06-16 11:01:34 +000048#include <linux/dma-mapping.h>
Chris Leechc13c8262006-05-23 17:18:44 -070049#include <linux/init.h>
50#include <linux/module.h>
Dan Williams7405f742007-01-02 11:10:43 -070051#include <linux/mm.h>
Chris Leechc13c8262006-05-23 17:18:44 -070052#include <linux/device.h>
53#include <linux/dmaengine.h>
54#include <linux/hardirq.h>
55#include <linux/spinlock.h>
56#include <linux/percpu.h>
57#include <linux/rcupdate.h>
58#include <linux/mutex.h>
Dan Williams7405f742007-01-02 11:10:43 -070059#include <linux/jiffies.h>
Dan Williams2ba05622009-01-06 11:38:14 -070060#include <linux/rculist.h>
Dan Williams864498a2009-01-06 11:38:21 -070061#include <linux/idr.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090062#include <linux/slab.h>
Chris Leechc13c8262006-05-23 17:18:44 -070063
64static DEFINE_MUTEX(dma_list_mutex);
Axel Lin21ef4b82011-07-20 11:32:28 +080065static DEFINE_IDR(dma_idr);
Chris Leechc13c8262006-05-23 17:18:44 -070066static LIST_HEAD(dma_device_list);
Dan Williams6f49a572009-01-06 11:38:14 -070067static long dmaengine_ref_count;
Chris Leechc13c8262006-05-23 17:18:44 -070068
69/* --- sysfs implementation --- */
70
Dan Williams41d5e592009-01-06 11:38:21 -070071/**
72 * dev_to_dma_chan - convert a device pointer to the its sysfs container object
73 * @dev - device node
74 *
75 * Must be called under dma_list_mutex
76 */
77static struct dma_chan *dev_to_dma_chan(struct device *dev)
78{
79 struct dma_chan_dev *chan_dev;
80
81 chan_dev = container_of(dev, typeof(*chan_dev), device);
82 return chan_dev->chan;
83}
84
Tony Jones891f78e2007-09-25 02:03:03 +020085static ssize_t show_memcpy_count(struct device *dev, struct device_attribute *attr, char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -070086{
Dan Williams41d5e592009-01-06 11:38:21 -070087 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -070088 unsigned long count = 0;
89 int i;
Dan Williams41d5e592009-01-06 11:38:21 -070090 int err;
Chris Leechc13c8262006-05-23 17:18:44 -070091
Dan Williams41d5e592009-01-06 11:38:21 -070092 mutex_lock(&dma_list_mutex);
93 chan = dev_to_dma_chan(dev);
94 if (chan) {
95 for_each_possible_cpu(i)
96 count += per_cpu_ptr(chan->local, i)->memcpy_count;
97 err = sprintf(buf, "%lu\n", count);
98 } else
99 err = -ENODEV;
100 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700101
Dan Williams41d5e592009-01-06 11:38:21 -0700102 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700103}
104
Tony Jones891f78e2007-09-25 02:03:03 +0200105static ssize_t show_bytes_transferred(struct device *dev, struct device_attribute *attr,
106 char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -0700107{
Dan Williams41d5e592009-01-06 11:38:21 -0700108 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -0700109 unsigned long count = 0;
110 int i;
Dan Williams41d5e592009-01-06 11:38:21 -0700111 int err;
Chris Leechc13c8262006-05-23 17:18:44 -0700112
Dan Williams41d5e592009-01-06 11:38:21 -0700113 mutex_lock(&dma_list_mutex);
114 chan = dev_to_dma_chan(dev);
115 if (chan) {
116 for_each_possible_cpu(i)
117 count += per_cpu_ptr(chan->local, i)->bytes_transferred;
118 err = sprintf(buf, "%lu\n", count);
119 } else
120 err = -ENODEV;
121 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700122
Dan Williams41d5e592009-01-06 11:38:21 -0700123 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700124}
125
Tony Jones891f78e2007-09-25 02:03:03 +0200126static ssize_t show_in_use(struct device *dev, struct device_attribute *attr, char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -0700127{
Dan Williams41d5e592009-01-06 11:38:21 -0700128 struct dma_chan *chan;
129 int err;
Chris Leechc13c8262006-05-23 17:18:44 -0700130
Dan Williams41d5e592009-01-06 11:38:21 -0700131 mutex_lock(&dma_list_mutex);
132 chan = dev_to_dma_chan(dev);
133 if (chan)
134 err = sprintf(buf, "%d\n", chan->client_count);
135 else
136 err = -ENODEV;
137 mutex_unlock(&dma_list_mutex);
138
139 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700140}
141
Tony Jones891f78e2007-09-25 02:03:03 +0200142static struct device_attribute dma_attrs[] = {
Chris Leechc13c8262006-05-23 17:18:44 -0700143 __ATTR(memcpy_count, S_IRUGO, show_memcpy_count, NULL),
144 __ATTR(bytes_transferred, S_IRUGO, show_bytes_transferred, NULL),
145 __ATTR(in_use, S_IRUGO, show_in_use, NULL),
146 __ATTR_NULL
147};
148
Dan Williams41d5e592009-01-06 11:38:21 -0700149static void chan_dev_release(struct device *dev)
150{
151 struct dma_chan_dev *chan_dev;
152
153 chan_dev = container_of(dev, typeof(*chan_dev), device);
Dan Williams864498a2009-01-06 11:38:21 -0700154 if (atomic_dec_and_test(chan_dev->idr_ref)) {
155 mutex_lock(&dma_list_mutex);
156 idr_remove(&dma_idr, chan_dev->dev_id);
157 mutex_unlock(&dma_list_mutex);
158 kfree(chan_dev->idr_ref);
159 }
Dan Williams41d5e592009-01-06 11:38:21 -0700160 kfree(chan_dev);
161}
162
Chris Leechc13c8262006-05-23 17:18:44 -0700163static struct class dma_devclass = {
Tony Jones891f78e2007-09-25 02:03:03 +0200164 .name = "dma",
165 .dev_attrs = dma_attrs,
Dan Williams41d5e592009-01-06 11:38:21 -0700166 .dev_release = chan_dev_release,
Chris Leechc13c8262006-05-23 17:18:44 -0700167};
168
169/* --- client and device registration --- */
170
Dan Williams59b5ec22009-01-06 11:38:15 -0700171#define dma_device_satisfies_mask(device, mask) \
172 __dma_device_satisfies_mask((device), &(mask))
Dan Williamsd379b012007-07-09 11:56:42 -0700173static int
Dan Williams59b5ec22009-01-06 11:38:15 -0700174__dma_device_satisfies_mask(struct dma_device *device, dma_cap_mask_t *want)
Dan Williamsd379b012007-07-09 11:56:42 -0700175{
176 dma_cap_mask_t has;
177
Dan Williams59b5ec22009-01-06 11:38:15 -0700178 bitmap_and(has.bits, want->bits, device->cap_mask.bits,
Dan Williamsd379b012007-07-09 11:56:42 -0700179 DMA_TX_TYPE_END);
180 return bitmap_equal(want->bits, has.bits, DMA_TX_TYPE_END);
181}
182
Dan Williams6f49a572009-01-06 11:38:14 -0700183static struct module *dma_chan_to_owner(struct dma_chan *chan)
184{
185 return chan->device->dev->driver->owner;
186}
187
188/**
189 * balance_ref_count - catch up the channel reference count
190 * @chan - channel to balance ->client_count versus dmaengine_ref_count
191 *
192 * balance_ref_count must be called under dma_list_mutex
193 */
194static void balance_ref_count(struct dma_chan *chan)
195{
196 struct module *owner = dma_chan_to_owner(chan);
197
198 while (chan->client_count < dmaengine_ref_count) {
199 __module_get(owner);
200 chan->client_count++;
201 }
202}
203
204/**
205 * dma_chan_get - try to grab a dma channel's parent driver module
206 * @chan - channel to grab
207 *
208 * Must be called under dma_list_mutex
209 */
210static int dma_chan_get(struct dma_chan *chan)
211{
212 int err = -ENODEV;
213 struct module *owner = dma_chan_to_owner(chan);
214
215 if (chan->client_count) {
216 __module_get(owner);
217 err = 0;
218 } else if (try_module_get(owner))
219 err = 0;
220
221 if (err == 0)
222 chan->client_count++;
223
224 /* allocate upon first client reference */
225 if (chan->client_count == 1 && err == 0) {
Dan Williamsaa1e6f12009-01-06 11:38:17 -0700226 int desc_cnt = chan->device->device_alloc_chan_resources(chan);
Dan Williams6f49a572009-01-06 11:38:14 -0700227
228 if (desc_cnt < 0) {
229 err = desc_cnt;
230 chan->client_count = 0;
231 module_put(owner);
Dan Williams59b5ec22009-01-06 11:38:15 -0700232 } else if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
Dan Williams6f49a572009-01-06 11:38:14 -0700233 balance_ref_count(chan);
234 }
235
236 return err;
237}
238
239/**
240 * dma_chan_put - drop a reference to a dma channel's parent driver module
241 * @chan - channel to release
242 *
243 * Must be called under dma_list_mutex
244 */
245static void dma_chan_put(struct dma_chan *chan)
246{
247 if (!chan->client_count)
248 return; /* this channel failed alloc_chan_resources */
249 chan->client_count--;
250 module_put(dma_chan_to_owner(chan));
251 if (chan->client_count == 0)
252 chan->device->device_free_chan_resources(chan);
253}
254
Dan Williams7405f742007-01-02 11:10:43 -0700255enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
256{
257 enum dma_status status;
258 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
259
260 dma_async_issue_pending(chan);
261 do {
262 status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
263 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
264 printk(KERN_ERR "dma_sync_wait_timeout!\n");
265 return DMA_ERROR;
266 }
267 } while (status == DMA_IN_PROGRESS);
268
269 return status;
270}
271EXPORT_SYMBOL(dma_sync_wait);
272
Chris Leechc13c8262006-05-23 17:18:44 -0700273/**
Dan Williamsbec08512009-01-06 11:38:14 -0700274 * dma_cap_mask_all - enable iteration over all operation types
275 */
276static dma_cap_mask_t dma_cap_mask_all;
277
278/**
279 * dma_chan_tbl_ent - tracks channel allocations per core/operation
280 * @chan - associated channel for this entry
281 */
282struct dma_chan_tbl_ent {
283 struct dma_chan *chan;
284};
285
286/**
287 * channel_table - percpu lookup table for memory-to-memory offload providers
288 */
Tejun Heoa29d8b82010-02-02 14:39:15 +0900289static struct dma_chan_tbl_ent __percpu *channel_table[DMA_TX_TYPE_END];
Dan Williamsbec08512009-01-06 11:38:14 -0700290
291static int __init dma_channel_table_init(void)
292{
293 enum dma_transaction_type cap;
294 int err = 0;
295
296 bitmap_fill(dma_cap_mask_all.bits, DMA_TX_TYPE_END);
297
Dan Williams59b5ec22009-01-06 11:38:15 -0700298 /* 'interrupt', 'private', and 'slave' are channel capabilities,
299 * but are not associated with an operation so they do not need
300 * an entry in the channel_table
Dan Williamsbec08512009-01-06 11:38:14 -0700301 */
302 clear_bit(DMA_INTERRUPT, dma_cap_mask_all.bits);
Dan Williams59b5ec22009-01-06 11:38:15 -0700303 clear_bit(DMA_PRIVATE, dma_cap_mask_all.bits);
Dan Williamsbec08512009-01-06 11:38:14 -0700304 clear_bit(DMA_SLAVE, dma_cap_mask_all.bits);
305
306 for_each_dma_cap_mask(cap, dma_cap_mask_all) {
307 channel_table[cap] = alloc_percpu(struct dma_chan_tbl_ent);
308 if (!channel_table[cap]) {
309 err = -ENOMEM;
310 break;
311 }
312 }
313
314 if (err) {
315 pr_err("dmaengine: initialization failure\n");
316 for_each_dma_cap_mask(cap, dma_cap_mask_all)
317 if (channel_table[cap])
318 free_percpu(channel_table[cap]);
319 }
320
321 return err;
322}
Dan Williams652afc22009-01-06 11:38:22 -0700323arch_initcall(dma_channel_table_init);
Dan Williamsbec08512009-01-06 11:38:14 -0700324
325/**
326 * dma_find_channel - find a channel to carry out the operation
327 * @tx_type: transaction type
328 */
329struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type)
330{
Christoph Lametere7dcaa42009-10-03 19:48:23 +0900331 return this_cpu_read(channel_table[tx_type]->chan);
Dan Williamsbec08512009-01-06 11:38:14 -0700332}
333EXPORT_SYMBOL(dma_find_channel);
334
335/**
Dan Williams2ba05622009-01-06 11:38:14 -0700336 * dma_issue_pending_all - flush all pending operations across all channels
337 */
338void dma_issue_pending_all(void)
339{
340 struct dma_device *device;
341 struct dma_chan *chan;
342
Dan Williams2ba05622009-01-06 11:38:14 -0700343 rcu_read_lock();
Dan Williams59b5ec22009-01-06 11:38:15 -0700344 list_for_each_entry_rcu(device, &dma_device_list, global_node) {
345 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
346 continue;
Dan Williams2ba05622009-01-06 11:38:14 -0700347 list_for_each_entry(chan, &device->channels, device_node)
348 if (chan->client_count)
349 device->device_issue_pending(chan);
Dan Williams59b5ec22009-01-06 11:38:15 -0700350 }
Dan Williams2ba05622009-01-06 11:38:14 -0700351 rcu_read_unlock();
352}
353EXPORT_SYMBOL(dma_issue_pending_all);
354
355/**
Dan Williamsbec08512009-01-06 11:38:14 -0700356 * nth_chan - returns the nth channel of the given capability
357 * @cap: capability to match
358 * @n: nth channel desired
359 *
360 * Defaults to returning the channel with the desired capability and the
361 * lowest reference count when 'n' cannot be satisfied. Must be called
362 * under dma_list_mutex.
363 */
364static struct dma_chan *nth_chan(enum dma_transaction_type cap, int n)
365{
366 struct dma_device *device;
367 struct dma_chan *chan;
368 struct dma_chan *ret = NULL;
369 struct dma_chan *min = NULL;
370
371 list_for_each_entry(device, &dma_device_list, global_node) {
Dan Williams59b5ec22009-01-06 11:38:15 -0700372 if (!dma_has_cap(cap, device->cap_mask) ||
373 dma_has_cap(DMA_PRIVATE, device->cap_mask))
Dan Williamsbec08512009-01-06 11:38:14 -0700374 continue;
375 list_for_each_entry(chan, &device->channels, device_node) {
376 if (!chan->client_count)
377 continue;
378 if (!min)
379 min = chan;
380 else if (chan->table_count < min->table_count)
381 min = chan;
382
383 if (n-- == 0) {
384 ret = chan;
385 break; /* done */
386 }
387 }
388 if (ret)
389 break; /* done */
390 }
391
392 if (!ret)
393 ret = min;
394
395 if (ret)
396 ret->table_count++;
397
398 return ret;
399}
400
401/**
402 * dma_channel_rebalance - redistribute the available channels
403 *
404 * Optimize for cpu isolation (each cpu gets a dedicated channel for an
405 * operation type) in the SMP case, and operation isolation (avoid
406 * multi-tasking channels) in the non-SMP case. Must be called under
407 * dma_list_mutex.
408 */
409static void dma_channel_rebalance(void)
410{
411 struct dma_chan *chan;
412 struct dma_device *device;
413 int cpu;
414 int cap;
415 int n;
416
417 /* undo the last distribution */
418 for_each_dma_cap_mask(cap, dma_cap_mask_all)
419 for_each_possible_cpu(cpu)
420 per_cpu_ptr(channel_table[cap], cpu)->chan = NULL;
421
Dan Williams59b5ec22009-01-06 11:38:15 -0700422 list_for_each_entry(device, &dma_device_list, global_node) {
423 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
424 continue;
Dan Williamsbec08512009-01-06 11:38:14 -0700425 list_for_each_entry(chan, &device->channels, device_node)
426 chan->table_count = 0;
Dan Williams59b5ec22009-01-06 11:38:15 -0700427 }
Dan Williamsbec08512009-01-06 11:38:14 -0700428
429 /* don't populate the channel_table if no clients are available */
430 if (!dmaengine_ref_count)
431 return;
432
433 /* redistribute available channels */
434 n = 0;
435 for_each_dma_cap_mask(cap, dma_cap_mask_all)
436 for_each_online_cpu(cpu) {
437 if (num_possible_cpus() > 1)
438 chan = nth_chan(cap, n++);
439 else
440 chan = nth_chan(cap, -1);
441
442 per_cpu_ptr(channel_table[cap], cpu)->chan = chan;
443 }
444}
445
Dan Williamse2346672009-01-06 11:38:21 -0700446static struct dma_chan *private_candidate(dma_cap_mask_t *mask, struct dma_device *dev,
447 dma_filter_fn fn, void *fn_param)
Dan Williams59b5ec22009-01-06 11:38:15 -0700448{
449 struct dma_chan *chan;
Dan Williams59b5ec22009-01-06 11:38:15 -0700450
451 if (!__dma_device_satisfies_mask(dev, mask)) {
452 pr_debug("%s: wrong capabilities\n", __func__);
453 return NULL;
454 }
455 /* devices with multiple channels need special handling as we need to
456 * ensure that all channels are either private or public.
457 */
458 if (dev->chancnt > 1 && !dma_has_cap(DMA_PRIVATE, dev->cap_mask))
459 list_for_each_entry(chan, &dev->channels, device_node) {
460 /* some channels are already publicly allocated */
461 if (chan->client_count)
462 return NULL;
463 }
464
465 list_for_each_entry(chan, &dev->channels, device_node) {
466 if (chan->client_count) {
467 pr_debug("%s: %s busy\n",
Dan Williams41d5e592009-01-06 11:38:21 -0700468 __func__, dma_chan_name(chan));
Dan Williams59b5ec22009-01-06 11:38:15 -0700469 continue;
470 }
Dan Williamse2346672009-01-06 11:38:21 -0700471 if (fn && !fn(chan, fn_param)) {
472 pr_debug("%s: %s filter said false\n",
473 __func__, dma_chan_name(chan));
474 continue;
475 }
476 return chan;
Dan Williams59b5ec22009-01-06 11:38:15 -0700477 }
478
Dan Williamse2346672009-01-06 11:38:21 -0700479 return NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700480}
481
482/**
483 * dma_request_channel - try to allocate an exclusive channel
484 * @mask: capabilities that the channel must satisfy
485 * @fn: optional callback to disposition available channels
486 * @fn_param: opaque parameter to pass to dma_filter_fn
487 */
488struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param)
489{
490 struct dma_device *device, *_d;
491 struct dma_chan *chan = NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700492 int err;
493
494 /* Find a channel */
495 mutex_lock(&dma_list_mutex);
496 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
Dan Williamse2346672009-01-06 11:38:21 -0700497 chan = private_candidate(mask, device, fn, fn_param);
498 if (chan) {
Dan Williams59b5ec22009-01-06 11:38:15 -0700499 /* Found a suitable channel, try to grab, prep, and
500 * return it. We first set DMA_PRIVATE to disable
501 * balance_ref_count as this channel will not be
502 * published in the general-purpose allocator
503 */
504 dma_cap_set(DMA_PRIVATE, device->cap_mask);
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900505 device->privatecnt++;
Dan Williams59b5ec22009-01-06 11:38:15 -0700506 err = dma_chan_get(chan);
507
508 if (err == -ENODEV) {
509 pr_debug("%s: %s module removed\n", __func__,
Dan Williams41d5e592009-01-06 11:38:21 -0700510 dma_chan_name(chan));
Dan Williams59b5ec22009-01-06 11:38:15 -0700511 list_del_rcu(&device->global_node);
512 } else if (err)
Guennadi Liakhovetskia03a2022011-06-20 17:02:47 +0200513 pr_debug("dmaengine: failed to get %s: (%d)\n",
514 dma_chan_name(chan), err);
Dan Williams59b5ec22009-01-06 11:38:15 -0700515 else
516 break;
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900517 if (--device->privatecnt == 0)
518 dma_cap_clear(DMA_PRIVATE, device->cap_mask);
Dan Williamse2346672009-01-06 11:38:21 -0700519 chan = NULL;
520 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700521 }
522 mutex_unlock(&dma_list_mutex);
523
524 pr_debug("%s: %s (%s)\n", __func__, chan ? "success" : "fail",
Dan Williams41d5e592009-01-06 11:38:21 -0700525 chan ? dma_chan_name(chan) : NULL);
Dan Williams59b5ec22009-01-06 11:38:15 -0700526
527 return chan;
528}
529EXPORT_SYMBOL_GPL(__dma_request_channel);
530
531void dma_release_channel(struct dma_chan *chan)
532{
533 mutex_lock(&dma_list_mutex);
534 WARN_ONCE(chan->client_count != 1,
535 "chan reference count %d != 1\n", chan->client_count);
536 dma_chan_put(chan);
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900537 /* drop PRIVATE cap enabled by __dma_request_channel() */
538 if (--chan->device->privatecnt == 0)
539 dma_cap_clear(DMA_PRIVATE, chan->device->cap_mask);
Dan Williams59b5ec22009-01-06 11:38:15 -0700540 mutex_unlock(&dma_list_mutex);
541}
542EXPORT_SYMBOL_GPL(dma_release_channel);
543
Dan Williamsbec08512009-01-06 11:38:14 -0700544/**
Dan Williams209b84a2009-01-06 11:38:17 -0700545 * dmaengine_get - register interest in dma_channels
Chris Leechc13c8262006-05-23 17:18:44 -0700546 */
Dan Williams209b84a2009-01-06 11:38:17 -0700547void dmaengine_get(void)
Chris Leechc13c8262006-05-23 17:18:44 -0700548{
Dan Williams6f49a572009-01-06 11:38:14 -0700549 struct dma_device *device, *_d;
550 struct dma_chan *chan;
551 int err;
552
Chris Leechc13c8262006-05-23 17:18:44 -0700553 mutex_lock(&dma_list_mutex);
Dan Williams6f49a572009-01-06 11:38:14 -0700554 dmaengine_ref_count++;
555
556 /* try to grab channels */
Dan Williams59b5ec22009-01-06 11:38:15 -0700557 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
558 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
559 continue;
Dan Williams6f49a572009-01-06 11:38:14 -0700560 list_for_each_entry(chan, &device->channels, device_node) {
561 err = dma_chan_get(chan);
562 if (err == -ENODEV) {
563 /* module removed before we could use it */
Dan Williams2ba05622009-01-06 11:38:14 -0700564 list_del_rcu(&device->global_node);
Dan Williams6f49a572009-01-06 11:38:14 -0700565 break;
566 } else if (err)
567 pr_err("dmaengine: failed to get %s: (%d)\n",
Dan Williams41d5e592009-01-06 11:38:21 -0700568 dma_chan_name(chan), err);
Dan Williams6f49a572009-01-06 11:38:14 -0700569 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700570 }
Dan Williams6f49a572009-01-06 11:38:14 -0700571
Dan Williamsbec08512009-01-06 11:38:14 -0700572 /* if this is the first reference and there were channels
573 * waiting we need to rebalance to get those channels
574 * incorporated into the channel table
575 */
576 if (dmaengine_ref_count == 1)
577 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -0700578 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700579}
Dan Williams209b84a2009-01-06 11:38:17 -0700580EXPORT_SYMBOL(dmaengine_get);
Chris Leechc13c8262006-05-23 17:18:44 -0700581
582/**
Dan Williams209b84a2009-01-06 11:38:17 -0700583 * dmaengine_put - let dma drivers be removed when ref_count == 0
Chris Leechc13c8262006-05-23 17:18:44 -0700584 */
Dan Williams209b84a2009-01-06 11:38:17 -0700585void dmaengine_put(void)
Chris Leechc13c8262006-05-23 17:18:44 -0700586{
Dan Williamsd379b012007-07-09 11:56:42 -0700587 struct dma_device *device;
Chris Leechc13c8262006-05-23 17:18:44 -0700588 struct dma_chan *chan;
589
Chris Leechc13c8262006-05-23 17:18:44 -0700590 mutex_lock(&dma_list_mutex);
Dan Williams6f49a572009-01-06 11:38:14 -0700591 dmaengine_ref_count--;
592 BUG_ON(dmaengine_ref_count < 0);
593 /* drop channel references */
Dan Williams59b5ec22009-01-06 11:38:15 -0700594 list_for_each_entry(device, &dma_device_list, global_node) {
595 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
596 continue;
Dan Williams6f49a572009-01-06 11:38:14 -0700597 list_for_each_entry(chan, &device->channels, device_node)
598 dma_chan_put(chan);
Dan Williams59b5ec22009-01-06 11:38:15 -0700599 }
Chris Leechc13c8262006-05-23 17:18:44 -0700600 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700601}
Dan Williams209b84a2009-01-06 11:38:17 -0700602EXPORT_SYMBOL(dmaengine_put);
Chris Leechc13c8262006-05-23 17:18:44 -0700603
Dan Williams138f4c32009-09-08 17:42:51 -0700604static bool device_has_all_tx_types(struct dma_device *device)
605{
606 /* A device that satisfies this test has channels that will never cause
607 * an async_tx channel switch event as all possible operation types can
608 * be handled.
609 */
610 #ifdef CONFIG_ASYNC_TX_DMA
611 if (!dma_has_cap(DMA_INTERRUPT, device->cap_mask))
612 return false;
613 #endif
614
615 #if defined(CONFIG_ASYNC_MEMCPY) || defined(CONFIG_ASYNC_MEMCPY_MODULE)
616 if (!dma_has_cap(DMA_MEMCPY, device->cap_mask))
617 return false;
618 #endif
619
620 #if defined(CONFIG_ASYNC_MEMSET) || defined(CONFIG_ASYNC_MEMSET_MODULE)
621 if (!dma_has_cap(DMA_MEMSET, device->cap_mask))
622 return false;
623 #endif
624
625 #if defined(CONFIG_ASYNC_XOR) || defined(CONFIG_ASYNC_XOR_MODULE)
626 if (!dma_has_cap(DMA_XOR, device->cap_mask))
627 return false;
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700628
629 #ifndef CONFIG_ASYNC_TX_DISABLE_XOR_VAL_DMA
Dan Williams4499a242009-11-19 17:10:25 -0700630 if (!dma_has_cap(DMA_XOR_VAL, device->cap_mask))
631 return false;
Dan Williams138f4c32009-09-08 17:42:51 -0700632 #endif
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700633 #endif
Dan Williams138f4c32009-09-08 17:42:51 -0700634
635 #if defined(CONFIG_ASYNC_PQ) || defined(CONFIG_ASYNC_PQ_MODULE)
636 if (!dma_has_cap(DMA_PQ, device->cap_mask))
637 return false;
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700638
639 #ifndef CONFIG_ASYNC_TX_DISABLE_PQ_VAL_DMA
Dan Williams4499a242009-11-19 17:10:25 -0700640 if (!dma_has_cap(DMA_PQ_VAL, device->cap_mask))
641 return false;
Dan Williams138f4c32009-09-08 17:42:51 -0700642 #endif
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700643 #endif
Dan Williams138f4c32009-09-08 17:42:51 -0700644
645 return true;
646}
647
Dan Williams257b17c2009-03-25 09:13:23 -0700648static int get_dma_id(struct dma_device *device)
649{
650 int rc;
651
652 idr_retry:
653 if (!idr_pre_get(&dma_idr, GFP_KERNEL))
654 return -ENOMEM;
655 mutex_lock(&dma_list_mutex);
656 rc = idr_get_new(&dma_idr, NULL, &device->dev_id);
657 mutex_unlock(&dma_list_mutex);
658 if (rc == -EAGAIN)
659 goto idr_retry;
660 else if (rc != 0)
661 return rc;
662
663 return 0;
664}
665
Chris Leechc13c8262006-05-23 17:18:44 -0700666/**
Randy Dunlap65088712006-07-03 19:45:31 -0700667 * dma_async_device_register - registers DMA devices found
Chris Leechc13c8262006-05-23 17:18:44 -0700668 * @device: &dma_device
669 */
670int dma_async_device_register(struct dma_device *device)
671{
Jeff Garzikff487fb2007-03-08 09:57:34 -0800672 int chancnt = 0, rc;
Chris Leechc13c8262006-05-23 17:18:44 -0700673 struct dma_chan* chan;
Dan Williams864498a2009-01-06 11:38:21 -0700674 atomic_t *idr_ref;
Chris Leechc13c8262006-05-23 17:18:44 -0700675
676 if (!device)
677 return -ENODEV;
678
Dan Williams7405f742007-01-02 11:10:43 -0700679 /* validate device routines */
680 BUG_ON(dma_has_cap(DMA_MEMCPY, device->cap_mask) &&
681 !device->device_prep_dma_memcpy);
682 BUG_ON(dma_has_cap(DMA_XOR, device->cap_mask) &&
683 !device->device_prep_dma_xor);
Dan Williams099f53c2009-04-08 14:28:37 -0700684 BUG_ON(dma_has_cap(DMA_XOR_VAL, device->cap_mask) &&
685 !device->device_prep_dma_xor_val);
Dan Williamsb2f46fd2009-07-14 12:20:36 -0700686 BUG_ON(dma_has_cap(DMA_PQ, device->cap_mask) &&
687 !device->device_prep_dma_pq);
688 BUG_ON(dma_has_cap(DMA_PQ_VAL, device->cap_mask) &&
689 !device->device_prep_dma_pq_val);
Dan Williams7405f742007-01-02 11:10:43 -0700690 BUG_ON(dma_has_cap(DMA_MEMSET, device->cap_mask) &&
691 !device->device_prep_dma_memset);
Zhang Wei9b941c62008-03-13 17:45:28 -0700692 BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) &&
Dan Williams7405f742007-01-02 11:10:43 -0700693 !device->device_prep_dma_interrupt);
Ira Snydera86ee032010-09-30 11:46:44 +0000694 BUG_ON(dma_has_cap(DMA_SG, device->cap_mask) &&
695 !device->device_prep_dma_sg);
Sascha Hauer782bc952010-09-30 13:56:32 +0000696 BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
697 !device->device_prep_dma_cyclic);
Haavard Skinnemoendc0ee6432008-07-08 11:59:35 -0700698 BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
Linus Walleijc3635c72010-03-26 16:44:01 -0700699 !device->device_control);
Jassi Brarb14dab72011-10-13 12:33:30 +0530700 BUG_ON(dma_has_cap(DMA_INTERLEAVE, device->cap_mask) &&
701 !device->device_prep_interleaved_dma);
Dan Williams7405f742007-01-02 11:10:43 -0700702
703 BUG_ON(!device->device_alloc_chan_resources);
704 BUG_ON(!device->device_free_chan_resources);
Linus Walleij07934482010-03-26 16:50:49 -0700705 BUG_ON(!device->device_tx_status);
Dan Williams7405f742007-01-02 11:10:43 -0700706 BUG_ON(!device->device_issue_pending);
707 BUG_ON(!device->dev);
708
Dan Williams138f4c32009-09-08 17:42:51 -0700709 /* note: this only matters in the
Dan Williams5fc6d892010-10-07 16:44:50 -0700710 * CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH=n case
Dan Williams138f4c32009-09-08 17:42:51 -0700711 */
712 if (device_has_all_tx_types(device))
713 dma_cap_set(DMA_ASYNC_TX, device->cap_mask);
714
Dan Williams864498a2009-01-06 11:38:21 -0700715 idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL);
716 if (!idr_ref)
717 return -ENOMEM;
Dan Williams257b17c2009-03-25 09:13:23 -0700718 rc = get_dma_id(device);
719 if (rc != 0) {
720 kfree(idr_ref);
Dan Williams864498a2009-01-06 11:38:21 -0700721 return rc;
Dan Williams257b17c2009-03-25 09:13:23 -0700722 }
723
724 atomic_set(idr_ref, 0);
Chris Leechc13c8262006-05-23 17:18:44 -0700725
726 /* represent channels in sysfs. Probably want devs too */
727 list_for_each_entry(chan, &device->channels, device_node) {
Dan Williams257b17c2009-03-25 09:13:23 -0700728 rc = -ENOMEM;
Chris Leechc13c8262006-05-23 17:18:44 -0700729 chan->local = alloc_percpu(typeof(*chan->local));
730 if (chan->local == NULL)
Dan Williams257b17c2009-03-25 09:13:23 -0700731 goto err_out;
Dan Williams41d5e592009-01-06 11:38:21 -0700732 chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL);
733 if (chan->dev == NULL) {
734 free_percpu(chan->local);
Dan Williams257b17c2009-03-25 09:13:23 -0700735 chan->local = NULL;
736 goto err_out;
Dan Williams41d5e592009-01-06 11:38:21 -0700737 }
Chris Leechc13c8262006-05-23 17:18:44 -0700738
739 chan->chan_id = chancnt++;
Dan Williams41d5e592009-01-06 11:38:21 -0700740 chan->dev->device.class = &dma_devclass;
741 chan->dev->device.parent = device->dev;
742 chan->dev->chan = chan;
Dan Williams864498a2009-01-06 11:38:21 -0700743 chan->dev->idr_ref = idr_ref;
744 chan->dev->dev_id = device->dev_id;
745 atomic_inc(idr_ref);
Dan Williams41d5e592009-01-06 11:38:21 -0700746 dev_set_name(&chan->dev->device, "dma%dchan%d",
Kay Sievers06190d82008-11-11 13:12:33 -0700747 device->dev_id, chan->chan_id);
Chris Leechc13c8262006-05-23 17:18:44 -0700748
Dan Williams41d5e592009-01-06 11:38:21 -0700749 rc = device_register(&chan->dev->device);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800750 if (rc) {
Jeff Garzikff487fb2007-03-08 09:57:34 -0800751 free_percpu(chan->local);
752 chan->local = NULL;
Dan Williams257b17c2009-03-25 09:13:23 -0700753 kfree(chan->dev);
754 atomic_dec(idr_ref);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800755 goto err_out;
756 }
Dan Williams7cc5bf92008-07-08 11:58:21 -0700757 chan->client_count = 0;
Chris Leechc13c8262006-05-23 17:18:44 -0700758 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700759 device->chancnt = chancnt;
Chris Leechc13c8262006-05-23 17:18:44 -0700760
761 mutex_lock(&dma_list_mutex);
Dan Williams59b5ec22009-01-06 11:38:15 -0700762 /* take references on public channels */
763 if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask))
Dan Williams6f49a572009-01-06 11:38:14 -0700764 list_for_each_entry(chan, &device->channels, device_node) {
765 /* if clients are already waiting for channels we need
766 * to take references on their behalf
767 */
768 if (dma_chan_get(chan) == -ENODEV) {
769 /* note we can only get here for the first
770 * channel as the remaining channels are
771 * guaranteed to get a reference
772 */
773 rc = -ENODEV;
774 mutex_unlock(&dma_list_mutex);
775 goto err_out;
776 }
777 }
Dan Williams2ba05622009-01-06 11:38:14 -0700778 list_add_tail_rcu(&device->global_node, &dma_device_list);
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900779 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
780 device->privatecnt++; /* Always private */
Dan Williamsbec08512009-01-06 11:38:14 -0700781 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -0700782 mutex_unlock(&dma_list_mutex);
783
Chris Leechc13c8262006-05-23 17:18:44 -0700784 return 0;
Jeff Garzikff487fb2007-03-08 09:57:34 -0800785
786err_out:
Dan Williams257b17c2009-03-25 09:13:23 -0700787 /* if we never registered a channel just release the idr */
788 if (atomic_read(idr_ref) == 0) {
789 mutex_lock(&dma_list_mutex);
790 idr_remove(&dma_idr, device->dev_id);
791 mutex_unlock(&dma_list_mutex);
792 kfree(idr_ref);
793 return rc;
794 }
795
Jeff Garzikff487fb2007-03-08 09:57:34 -0800796 list_for_each_entry(chan, &device->channels, device_node) {
797 if (chan->local == NULL)
798 continue;
Dan Williams41d5e592009-01-06 11:38:21 -0700799 mutex_lock(&dma_list_mutex);
800 chan->dev->chan = NULL;
801 mutex_unlock(&dma_list_mutex);
802 device_unregister(&chan->dev->device);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800803 free_percpu(chan->local);
804 }
805 return rc;
Chris Leechc13c8262006-05-23 17:18:44 -0700806}
David Brownell765e3d82007-03-16 13:38:05 -0800807EXPORT_SYMBOL(dma_async_device_register);
Chris Leechc13c8262006-05-23 17:18:44 -0700808
809/**
Dan Williams6f49a572009-01-06 11:38:14 -0700810 * dma_async_device_unregister - unregister a DMA device
Randy Dunlap65088712006-07-03 19:45:31 -0700811 * @device: &dma_device
Dan Williamsf27c5802009-01-06 11:38:18 -0700812 *
813 * This routine is called by dma driver exit routines, dmaengine holds module
814 * references to prevent it being called while channels are in use.
Randy Dunlap65088712006-07-03 19:45:31 -0700815 */
816void dma_async_device_unregister(struct dma_device *device)
Chris Leechc13c8262006-05-23 17:18:44 -0700817{
818 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -0700819
820 mutex_lock(&dma_list_mutex);
Dan Williams2ba05622009-01-06 11:38:14 -0700821 list_del_rcu(&device->global_node);
Dan Williamsbec08512009-01-06 11:38:14 -0700822 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -0700823 mutex_unlock(&dma_list_mutex);
824
825 list_for_each_entry(chan, &device->channels, device_node) {
Dan Williams6f49a572009-01-06 11:38:14 -0700826 WARN_ONCE(chan->client_count,
827 "%s called while %d clients hold a reference\n",
828 __func__, chan->client_count);
Dan Williams41d5e592009-01-06 11:38:21 -0700829 mutex_lock(&dma_list_mutex);
830 chan->dev->chan = NULL;
831 mutex_unlock(&dma_list_mutex);
832 device_unregister(&chan->dev->device);
Anatolij Gustschinadef4772010-01-26 10:26:06 +0100833 free_percpu(chan->local);
Chris Leechc13c8262006-05-23 17:18:44 -0700834 }
Chris Leechc13c8262006-05-23 17:18:44 -0700835}
David Brownell765e3d82007-03-16 13:38:05 -0800836EXPORT_SYMBOL(dma_async_device_unregister);
Chris Leechc13c8262006-05-23 17:18:44 -0700837
Dan Williams7405f742007-01-02 11:10:43 -0700838/**
839 * dma_async_memcpy_buf_to_buf - offloaded copy between virtual addresses
840 * @chan: DMA channel to offload copy to
841 * @dest: destination address (virtual)
842 * @src: source address (virtual)
843 * @len: length
844 *
845 * Both @dest and @src must be mappable to a bus address according to the
846 * DMA mapping API rules for streaming mappings.
847 * Both @dest and @src must stay memory resident (kernel memory or locked
848 * user space pages).
849 */
850dma_cookie_t
851dma_async_memcpy_buf_to_buf(struct dma_chan *chan, void *dest,
852 void *src, size_t len)
853{
854 struct dma_device *dev = chan->device;
855 struct dma_async_tx_descriptor *tx;
Dan Williams00367312008-02-02 19:49:57 -0700856 dma_addr_t dma_dest, dma_src;
Dan Williams7405f742007-01-02 11:10:43 -0700857 dma_cookie_t cookie;
Maciej Sosnowski4f005db2009-04-23 12:31:51 +0200858 unsigned long flags;
Dan Williams7405f742007-01-02 11:10:43 -0700859
Dan Williams00367312008-02-02 19:49:57 -0700860 dma_src = dma_map_single(dev->dev, src, len, DMA_TO_DEVICE);
861 dma_dest = dma_map_single(dev->dev, dest, len, DMA_FROM_DEVICE);
Maciej Sosnowski4f005db2009-04-23 12:31:51 +0200862 flags = DMA_CTRL_ACK |
863 DMA_COMPL_SRC_UNMAP_SINGLE |
864 DMA_COMPL_DEST_UNMAP_SINGLE;
865 tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags);
Dan Williams00367312008-02-02 19:49:57 -0700866
867 if (!tx) {
868 dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE);
869 dma_unmap_single(dev->dev, dma_dest, len, DMA_FROM_DEVICE);
Dan Williams7405f742007-01-02 11:10:43 -0700870 return -ENOMEM;
Dan Williams00367312008-02-02 19:49:57 -0700871 }
Dan Williams7405f742007-01-02 11:10:43 -0700872
Dan Williams7405f742007-01-02 11:10:43 -0700873 tx->callback = NULL;
Dan Williams7405f742007-01-02 11:10:43 -0700874 cookie = tx->tx_submit(tx);
875
Christoph Lametere7dcaa42009-10-03 19:48:23 +0900876 preempt_disable();
877 __this_cpu_add(chan->local->bytes_transferred, len);
878 __this_cpu_inc(chan->local->memcpy_count);
879 preempt_enable();
Dan Williams7405f742007-01-02 11:10:43 -0700880
881 return cookie;
882}
883EXPORT_SYMBOL(dma_async_memcpy_buf_to_buf);
884
885/**
886 * dma_async_memcpy_buf_to_pg - offloaded copy from address to page
887 * @chan: DMA channel to offload copy to
888 * @page: destination page
889 * @offset: offset in page to copy to
890 * @kdata: source address (virtual)
891 * @len: length
892 *
893 * Both @page/@offset and @kdata must be mappable to a bus address according
894 * to the DMA mapping API rules for streaming mappings.
895 * Both @page/@offset and @kdata must stay memory resident (kernel memory or
896 * locked user space pages)
897 */
898dma_cookie_t
899dma_async_memcpy_buf_to_pg(struct dma_chan *chan, struct page *page,
900 unsigned int offset, void *kdata, size_t len)
901{
902 struct dma_device *dev = chan->device;
903 struct dma_async_tx_descriptor *tx;
Dan Williams00367312008-02-02 19:49:57 -0700904 dma_addr_t dma_dest, dma_src;
Dan Williams7405f742007-01-02 11:10:43 -0700905 dma_cookie_t cookie;
Maciej Sosnowski4f005db2009-04-23 12:31:51 +0200906 unsigned long flags;
Dan Williams7405f742007-01-02 11:10:43 -0700907
Dan Williams00367312008-02-02 19:49:57 -0700908 dma_src = dma_map_single(dev->dev, kdata, len, DMA_TO_DEVICE);
909 dma_dest = dma_map_page(dev->dev, page, offset, len, DMA_FROM_DEVICE);
Maciej Sosnowski4f005db2009-04-23 12:31:51 +0200910 flags = DMA_CTRL_ACK | DMA_COMPL_SRC_UNMAP_SINGLE;
911 tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags);
Dan Williams00367312008-02-02 19:49:57 -0700912
913 if (!tx) {
914 dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE);
915 dma_unmap_page(dev->dev, dma_dest, len, DMA_FROM_DEVICE);
Dan Williams7405f742007-01-02 11:10:43 -0700916 return -ENOMEM;
Dan Williams00367312008-02-02 19:49:57 -0700917 }
Dan Williams7405f742007-01-02 11:10:43 -0700918
Dan Williams7405f742007-01-02 11:10:43 -0700919 tx->callback = NULL;
Dan Williams7405f742007-01-02 11:10:43 -0700920 cookie = tx->tx_submit(tx);
921
Christoph Lametere7dcaa42009-10-03 19:48:23 +0900922 preempt_disable();
923 __this_cpu_add(chan->local->bytes_transferred, len);
924 __this_cpu_inc(chan->local->memcpy_count);
925 preempt_enable();
Dan Williams7405f742007-01-02 11:10:43 -0700926
927 return cookie;
928}
929EXPORT_SYMBOL(dma_async_memcpy_buf_to_pg);
930
931/**
932 * dma_async_memcpy_pg_to_pg - offloaded copy from page to page
933 * @chan: DMA channel to offload copy to
934 * @dest_pg: destination page
935 * @dest_off: offset in page to copy to
936 * @src_pg: source page
937 * @src_off: offset in page to copy from
938 * @len: length
939 *
940 * Both @dest_page/@dest_off and @src_page/@src_off must be mappable to a bus
941 * address according to the DMA mapping API rules for streaming mappings.
942 * Both @dest_page/@dest_off and @src_page/@src_off must stay memory resident
943 * (kernel memory or locked user space pages).
944 */
945dma_cookie_t
946dma_async_memcpy_pg_to_pg(struct dma_chan *chan, struct page *dest_pg,
947 unsigned int dest_off, struct page *src_pg, unsigned int src_off,
948 size_t len)
949{
950 struct dma_device *dev = chan->device;
951 struct dma_async_tx_descriptor *tx;
Dan Williams00367312008-02-02 19:49:57 -0700952 dma_addr_t dma_dest, dma_src;
Dan Williams7405f742007-01-02 11:10:43 -0700953 dma_cookie_t cookie;
Maciej Sosnowski4f005db2009-04-23 12:31:51 +0200954 unsigned long flags;
Dan Williams7405f742007-01-02 11:10:43 -0700955
Dan Williams00367312008-02-02 19:49:57 -0700956 dma_src = dma_map_page(dev->dev, src_pg, src_off, len, DMA_TO_DEVICE);
957 dma_dest = dma_map_page(dev->dev, dest_pg, dest_off, len,
958 DMA_FROM_DEVICE);
Maciej Sosnowski4f005db2009-04-23 12:31:51 +0200959 flags = DMA_CTRL_ACK;
960 tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags);
Dan Williams00367312008-02-02 19:49:57 -0700961
962 if (!tx) {
963 dma_unmap_page(dev->dev, dma_src, len, DMA_TO_DEVICE);
964 dma_unmap_page(dev->dev, dma_dest, len, DMA_FROM_DEVICE);
Dan Williams7405f742007-01-02 11:10:43 -0700965 return -ENOMEM;
Dan Williams00367312008-02-02 19:49:57 -0700966 }
Dan Williams7405f742007-01-02 11:10:43 -0700967
Dan Williams7405f742007-01-02 11:10:43 -0700968 tx->callback = NULL;
Dan Williams7405f742007-01-02 11:10:43 -0700969 cookie = tx->tx_submit(tx);
970
Christoph Lametere7dcaa42009-10-03 19:48:23 +0900971 preempt_disable();
972 __this_cpu_add(chan->local->bytes_transferred, len);
973 __this_cpu_inc(chan->local->memcpy_count);
974 preempt_enable();
Dan Williams7405f742007-01-02 11:10:43 -0700975
976 return cookie;
977}
978EXPORT_SYMBOL(dma_async_memcpy_pg_to_pg);
979
980void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
981 struct dma_chan *chan)
982{
983 tx->chan = chan;
Dan Williams5fc6d892010-10-07 16:44:50 -0700984 #ifdef CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH
Dan Williams7405f742007-01-02 11:10:43 -0700985 spin_lock_init(&tx->lock);
Dan Williamscaa20d972010-05-17 16:24:16 -0700986 #endif
Dan Williams7405f742007-01-02 11:10:43 -0700987}
988EXPORT_SYMBOL(dma_async_tx_descriptor_init);
989
Dan Williams07f22112009-01-05 17:14:31 -0700990/* dma_wait_for_async_tx - spin wait for a transaction to complete
991 * @tx: in-flight transaction to wait on
Dan Williams07f22112009-01-05 17:14:31 -0700992 */
993enum dma_status
994dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
995{
Dan Williams95475e52009-07-14 12:19:02 -0700996 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
Dan Williams07f22112009-01-05 17:14:31 -0700997
998 if (!tx)
999 return DMA_SUCCESS;
1000
Dan Williams95475e52009-07-14 12:19:02 -07001001 while (tx->cookie == -EBUSY) {
1002 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
1003 pr_err("%s timeout waiting for descriptor submission\n",
1004 __func__);
1005 return DMA_ERROR;
1006 }
1007 cpu_relax();
1008 }
1009 return dma_sync_wait(tx->chan, tx->cookie);
Dan Williams07f22112009-01-05 17:14:31 -07001010}
1011EXPORT_SYMBOL_GPL(dma_wait_for_async_tx);
1012
1013/* dma_run_dependencies - helper routine for dma drivers to process
1014 * (start) dependent operations on their target channel
1015 * @tx: transaction with dependencies
1016 */
1017void dma_run_dependencies(struct dma_async_tx_descriptor *tx)
1018{
Dan Williamscaa20d972010-05-17 16:24:16 -07001019 struct dma_async_tx_descriptor *dep = txd_next(tx);
Dan Williams07f22112009-01-05 17:14:31 -07001020 struct dma_async_tx_descriptor *dep_next;
1021 struct dma_chan *chan;
1022
1023 if (!dep)
1024 return;
1025
Yuri Tikhonovdd59b852009-01-12 15:17:20 -07001026 /* we'll submit tx->next now, so clear the link */
Dan Williamscaa20d972010-05-17 16:24:16 -07001027 txd_clear_next(tx);
Dan Williams07f22112009-01-05 17:14:31 -07001028 chan = dep->chan;
1029
1030 /* keep submitting up until a channel switch is detected
1031 * in that case we will be called again as a result of
1032 * processing the interrupt from async_tx_channel_switch
1033 */
1034 for (; dep; dep = dep_next) {
Dan Williamscaa20d972010-05-17 16:24:16 -07001035 txd_lock(dep);
1036 txd_clear_parent(dep);
1037 dep_next = txd_next(dep);
Dan Williams07f22112009-01-05 17:14:31 -07001038 if (dep_next && dep_next->chan == chan)
Dan Williamscaa20d972010-05-17 16:24:16 -07001039 txd_clear_next(dep); /* ->next will be submitted */
Dan Williams07f22112009-01-05 17:14:31 -07001040 else
1041 dep_next = NULL; /* submit current dep and terminate */
Dan Williamscaa20d972010-05-17 16:24:16 -07001042 txd_unlock(dep);
Dan Williams07f22112009-01-05 17:14:31 -07001043
1044 dep->tx_submit(dep);
1045 }
1046
1047 chan->device->device_issue_pending(chan);
1048}
1049EXPORT_SYMBOL_GPL(dma_run_dependencies);
1050
Chris Leechc13c8262006-05-23 17:18:44 -07001051static int __init dma_bus_init(void)
1052{
Chris Leechc13c8262006-05-23 17:18:44 -07001053 return class_register(&dma_devclass);
1054}
Dan Williams652afc22009-01-06 11:38:22 -07001055arch_initcall(dma_bus_init);
Chris Leechc13c8262006-05-23 17:18:44 -07001056
Dan Williamsbec08512009-01-06 11:38:14 -07001057