blob: a815d44c70a41b802c771dea337bf2e5348592a8 [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
Joe Perches63433252012-07-18 09:51:28 -070048#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
49
Alexey Dobriyanb7f080c2011-06-16 11:01:34 +000050#include <linux/dma-mapping.h>
Chris Leechc13c8262006-05-23 17:18:44 -070051#include <linux/init.h>
52#include <linux/module.h>
Dan Williams7405f742007-01-02 11:10:43 -070053#include <linux/mm.h>
Chris Leechc13c8262006-05-23 17:18:44 -070054#include <linux/device.h>
55#include <linux/dmaengine.h>
56#include <linux/hardirq.h>
57#include <linux/spinlock.h>
58#include <linux/percpu.h>
59#include <linux/rcupdate.h>
60#include <linux/mutex.h>
Dan Williams7405f742007-01-02 11:10:43 -070061#include <linux/jiffies.h>
Dan Williams2ba05622009-01-06 11:38:14 -070062#include <linux/rculist.h>
Dan Williams864498a2009-01-06 11:38:21 -070063#include <linux/idr.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090064#include <linux/slab.h>
Chris Leechc13c8262006-05-23 17:18:44 -070065
66static DEFINE_MUTEX(dma_list_mutex);
Axel Lin21ef4b82011-07-20 11:32:28 +080067static DEFINE_IDR(dma_idr);
Chris Leechc13c8262006-05-23 17:18:44 -070068static LIST_HEAD(dma_device_list);
Dan Williams6f49a572009-01-06 11:38:14 -070069static long dmaengine_ref_count;
Chris Leechc13c8262006-05-23 17:18:44 -070070
71/* --- sysfs implementation --- */
72
Dan Williams41d5e592009-01-06 11:38:21 -070073/**
74 * dev_to_dma_chan - convert a device pointer to the its sysfs container object
75 * @dev - device node
76 *
77 * Must be called under dma_list_mutex
78 */
79static struct dma_chan *dev_to_dma_chan(struct device *dev)
80{
81 struct dma_chan_dev *chan_dev;
82
83 chan_dev = container_of(dev, typeof(*chan_dev), device);
84 return chan_dev->chan;
85}
86
Tony Jones891f78e2007-09-25 02:03:03 +020087static ssize_t show_memcpy_count(struct device *dev, struct device_attribute *attr, char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -070088{
Dan Williams41d5e592009-01-06 11:38:21 -070089 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -070090 unsigned long count = 0;
91 int i;
Dan Williams41d5e592009-01-06 11:38:21 -070092 int err;
Chris Leechc13c8262006-05-23 17:18:44 -070093
Dan Williams41d5e592009-01-06 11:38:21 -070094 mutex_lock(&dma_list_mutex);
95 chan = dev_to_dma_chan(dev);
96 if (chan) {
97 for_each_possible_cpu(i)
98 count += per_cpu_ptr(chan->local, i)->memcpy_count;
99 err = sprintf(buf, "%lu\n", count);
100 } else
101 err = -ENODEV;
102 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700103
Dan Williams41d5e592009-01-06 11:38:21 -0700104 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700105}
106
Tony Jones891f78e2007-09-25 02:03:03 +0200107static ssize_t show_bytes_transferred(struct device *dev, struct device_attribute *attr,
108 char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -0700109{
Dan Williams41d5e592009-01-06 11:38:21 -0700110 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -0700111 unsigned long count = 0;
112 int i;
Dan Williams41d5e592009-01-06 11:38:21 -0700113 int err;
Chris Leechc13c8262006-05-23 17:18:44 -0700114
Dan Williams41d5e592009-01-06 11:38:21 -0700115 mutex_lock(&dma_list_mutex);
116 chan = dev_to_dma_chan(dev);
117 if (chan) {
118 for_each_possible_cpu(i)
119 count += per_cpu_ptr(chan->local, i)->bytes_transferred;
120 err = sprintf(buf, "%lu\n", count);
121 } else
122 err = -ENODEV;
123 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700124
Dan Williams41d5e592009-01-06 11:38:21 -0700125 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700126}
127
Tony Jones891f78e2007-09-25 02:03:03 +0200128static ssize_t show_in_use(struct device *dev, struct device_attribute *attr, char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -0700129{
Dan Williams41d5e592009-01-06 11:38:21 -0700130 struct dma_chan *chan;
131 int err;
Chris Leechc13c8262006-05-23 17:18:44 -0700132
Dan Williams41d5e592009-01-06 11:38:21 -0700133 mutex_lock(&dma_list_mutex);
134 chan = dev_to_dma_chan(dev);
135 if (chan)
136 err = sprintf(buf, "%d\n", chan->client_count);
137 else
138 err = -ENODEV;
139 mutex_unlock(&dma_list_mutex);
140
141 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700142}
143
Tony Jones891f78e2007-09-25 02:03:03 +0200144static struct device_attribute dma_attrs[] = {
Chris Leechc13c8262006-05-23 17:18:44 -0700145 __ATTR(memcpy_count, S_IRUGO, show_memcpy_count, NULL),
146 __ATTR(bytes_transferred, S_IRUGO, show_bytes_transferred, NULL),
147 __ATTR(in_use, S_IRUGO, show_in_use, NULL),
148 __ATTR_NULL
149};
150
Dan Williams41d5e592009-01-06 11:38:21 -0700151static void chan_dev_release(struct device *dev)
152{
153 struct dma_chan_dev *chan_dev;
154
155 chan_dev = container_of(dev, typeof(*chan_dev), device);
Dan Williams864498a2009-01-06 11:38:21 -0700156 if (atomic_dec_and_test(chan_dev->idr_ref)) {
157 mutex_lock(&dma_list_mutex);
158 idr_remove(&dma_idr, chan_dev->dev_id);
159 mutex_unlock(&dma_list_mutex);
160 kfree(chan_dev->idr_ref);
161 }
Dan Williams41d5e592009-01-06 11:38:21 -0700162 kfree(chan_dev);
163}
164
Chris Leechc13c8262006-05-23 17:18:44 -0700165static struct class dma_devclass = {
Tony Jones891f78e2007-09-25 02:03:03 +0200166 .name = "dma",
167 .dev_attrs = dma_attrs,
Dan Williams41d5e592009-01-06 11:38:21 -0700168 .dev_release = chan_dev_release,
Chris Leechc13c8262006-05-23 17:18:44 -0700169};
170
171/* --- client and device registration --- */
172
Dan Williams59b5ec22009-01-06 11:38:15 -0700173#define dma_device_satisfies_mask(device, mask) \
174 __dma_device_satisfies_mask((device), &(mask))
Dan Williamsd379b012007-07-09 11:56:42 -0700175static int
Dan Williams59b5ec22009-01-06 11:38:15 -0700176__dma_device_satisfies_mask(struct dma_device *device, dma_cap_mask_t *want)
Dan Williamsd379b012007-07-09 11:56:42 -0700177{
178 dma_cap_mask_t has;
179
Dan Williams59b5ec22009-01-06 11:38:15 -0700180 bitmap_and(has.bits, want->bits, device->cap_mask.bits,
Dan Williamsd379b012007-07-09 11:56:42 -0700181 DMA_TX_TYPE_END);
182 return bitmap_equal(want->bits, has.bits, DMA_TX_TYPE_END);
183}
184
Dan Williams6f49a572009-01-06 11:38:14 -0700185static struct module *dma_chan_to_owner(struct dma_chan *chan)
186{
187 return chan->device->dev->driver->owner;
188}
189
190/**
191 * balance_ref_count - catch up the channel reference count
192 * @chan - channel to balance ->client_count versus dmaengine_ref_count
193 *
194 * balance_ref_count must be called under dma_list_mutex
195 */
196static void balance_ref_count(struct dma_chan *chan)
197{
198 struct module *owner = dma_chan_to_owner(chan);
199
200 while (chan->client_count < dmaengine_ref_count) {
201 __module_get(owner);
202 chan->client_count++;
203 }
204}
205
206/**
207 * dma_chan_get - try to grab a dma channel's parent driver module
208 * @chan - channel to grab
209 *
210 * Must be called under dma_list_mutex
211 */
212static int dma_chan_get(struct dma_chan *chan)
213{
214 int err = -ENODEV;
215 struct module *owner = dma_chan_to_owner(chan);
216
217 if (chan->client_count) {
218 __module_get(owner);
219 err = 0;
220 } else if (try_module_get(owner))
221 err = 0;
222
223 if (err == 0)
224 chan->client_count++;
225
226 /* allocate upon first client reference */
227 if (chan->client_count == 1 && err == 0) {
Dan Williamsaa1e6f12009-01-06 11:38:17 -0700228 int desc_cnt = chan->device->device_alloc_chan_resources(chan);
Dan Williams6f49a572009-01-06 11:38:14 -0700229
230 if (desc_cnt < 0) {
231 err = desc_cnt;
232 chan->client_count = 0;
233 module_put(owner);
Dan Williams59b5ec22009-01-06 11:38:15 -0700234 } else if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
Dan Williams6f49a572009-01-06 11:38:14 -0700235 balance_ref_count(chan);
236 }
237
238 return err;
239}
240
241/**
242 * dma_chan_put - drop a reference to a dma channel's parent driver module
243 * @chan - channel to release
244 *
245 * Must be called under dma_list_mutex
246 */
247static void dma_chan_put(struct dma_chan *chan)
248{
249 if (!chan->client_count)
250 return; /* this channel failed alloc_chan_resources */
251 chan->client_count--;
252 module_put(dma_chan_to_owner(chan));
253 if (chan->client_count == 0)
254 chan->device->device_free_chan_resources(chan);
255}
256
Dan Williams7405f742007-01-02 11:10:43 -0700257enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
258{
259 enum dma_status status;
260 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
261
262 dma_async_issue_pending(chan);
263 do {
264 status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
265 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
Joe Perches63433252012-07-18 09:51:28 -0700266 pr_err("%s: timeout!\n", __func__);
Dan Williams7405f742007-01-02 11:10:43 -0700267 return DMA_ERROR;
268 }
269 } while (status == DMA_IN_PROGRESS);
270
271 return status;
272}
273EXPORT_SYMBOL(dma_sync_wait);
274
Chris Leechc13c8262006-05-23 17:18:44 -0700275/**
Dan Williamsbec08512009-01-06 11:38:14 -0700276 * dma_cap_mask_all - enable iteration over all operation types
277 */
278static dma_cap_mask_t dma_cap_mask_all;
279
280/**
281 * dma_chan_tbl_ent - tracks channel allocations per core/operation
282 * @chan - associated channel for this entry
283 */
284struct dma_chan_tbl_ent {
285 struct dma_chan *chan;
286};
287
288/**
289 * channel_table - percpu lookup table for memory-to-memory offload providers
290 */
Tejun Heoa29d8b82010-02-02 14:39:15 +0900291static struct dma_chan_tbl_ent __percpu *channel_table[DMA_TX_TYPE_END];
Dan Williamsbec08512009-01-06 11:38:14 -0700292
293static int __init dma_channel_table_init(void)
294{
295 enum dma_transaction_type cap;
296 int err = 0;
297
298 bitmap_fill(dma_cap_mask_all.bits, DMA_TX_TYPE_END);
299
Dan Williams59b5ec22009-01-06 11:38:15 -0700300 /* 'interrupt', 'private', and 'slave' are channel capabilities,
301 * but are not associated with an operation so they do not need
302 * an entry in the channel_table
Dan Williamsbec08512009-01-06 11:38:14 -0700303 */
304 clear_bit(DMA_INTERRUPT, dma_cap_mask_all.bits);
Dan Williams59b5ec22009-01-06 11:38:15 -0700305 clear_bit(DMA_PRIVATE, dma_cap_mask_all.bits);
Dan Williamsbec08512009-01-06 11:38:14 -0700306 clear_bit(DMA_SLAVE, dma_cap_mask_all.bits);
307
308 for_each_dma_cap_mask(cap, dma_cap_mask_all) {
309 channel_table[cap] = alloc_percpu(struct dma_chan_tbl_ent);
310 if (!channel_table[cap]) {
311 err = -ENOMEM;
312 break;
313 }
314 }
315
316 if (err) {
Joe Perches63433252012-07-18 09:51:28 -0700317 pr_err("initialization failure\n");
Dan Williamsbec08512009-01-06 11:38:14 -0700318 for_each_dma_cap_mask(cap, dma_cap_mask_all)
319 if (channel_table[cap])
320 free_percpu(channel_table[cap]);
321 }
322
323 return err;
324}
Dan Williams652afc22009-01-06 11:38:22 -0700325arch_initcall(dma_channel_table_init);
Dan Williamsbec08512009-01-06 11:38:14 -0700326
327/**
328 * dma_find_channel - find a channel to carry out the operation
329 * @tx_type: transaction type
330 */
331struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type)
332{
Christoph Lametere7dcaa42009-10-03 19:48:23 +0900333 return this_cpu_read(channel_table[tx_type]->chan);
Dan Williamsbec08512009-01-06 11:38:14 -0700334}
335EXPORT_SYMBOL(dma_find_channel);
336
Dave Jianga2bd1142012-04-04 16:10:46 -0700337/*
338 * net_dma_find_channel - find a channel for net_dma
339 * net_dma has alignment requirements
340 */
341struct dma_chan *net_dma_find_channel(void)
342{
343 struct dma_chan *chan = dma_find_channel(DMA_MEMCPY);
344 if (chan && !is_dma_copy_aligned(chan->device, 1, 1, 1))
345 return NULL;
346
347 return chan;
348}
349EXPORT_SYMBOL(net_dma_find_channel);
350
Dan Williamsbec08512009-01-06 11:38:14 -0700351/**
Dan Williams2ba05622009-01-06 11:38:14 -0700352 * dma_issue_pending_all - flush all pending operations across all channels
353 */
354void dma_issue_pending_all(void)
355{
356 struct dma_device *device;
357 struct dma_chan *chan;
358
Dan Williams2ba05622009-01-06 11:38:14 -0700359 rcu_read_lock();
Dan Williams59b5ec22009-01-06 11:38:15 -0700360 list_for_each_entry_rcu(device, &dma_device_list, global_node) {
361 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
362 continue;
Dan Williams2ba05622009-01-06 11:38:14 -0700363 list_for_each_entry(chan, &device->channels, device_node)
364 if (chan->client_count)
365 device->device_issue_pending(chan);
Dan Williams59b5ec22009-01-06 11:38:15 -0700366 }
Dan Williams2ba05622009-01-06 11:38:14 -0700367 rcu_read_unlock();
368}
369EXPORT_SYMBOL(dma_issue_pending_all);
370
371/**
Dan Williamsbec08512009-01-06 11:38:14 -0700372 * nth_chan - returns the nth channel of the given capability
373 * @cap: capability to match
374 * @n: nth channel desired
375 *
376 * Defaults to returning the channel with the desired capability and the
377 * lowest reference count when 'n' cannot be satisfied. Must be called
378 * under dma_list_mutex.
379 */
380static struct dma_chan *nth_chan(enum dma_transaction_type cap, int n)
381{
382 struct dma_device *device;
383 struct dma_chan *chan;
384 struct dma_chan *ret = NULL;
385 struct dma_chan *min = NULL;
386
387 list_for_each_entry(device, &dma_device_list, global_node) {
Dan Williams59b5ec22009-01-06 11:38:15 -0700388 if (!dma_has_cap(cap, device->cap_mask) ||
389 dma_has_cap(DMA_PRIVATE, device->cap_mask))
Dan Williamsbec08512009-01-06 11:38:14 -0700390 continue;
391 list_for_each_entry(chan, &device->channels, device_node) {
392 if (!chan->client_count)
393 continue;
394 if (!min)
395 min = chan;
396 else if (chan->table_count < min->table_count)
397 min = chan;
398
399 if (n-- == 0) {
400 ret = chan;
401 break; /* done */
402 }
403 }
404 if (ret)
405 break; /* done */
406 }
407
408 if (!ret)
409 ret = min;
410
411 if (ret)
412 ret->table_count++;
413
414 return ret;
415}
416
417/**
418 * dma_channel_rebalance - redistribute the available channels
419 *
420 * Optimize for cpu isolation (each cpu gets a dedicated channel for an
421 * operation type) in the SMP case, and operation isolation (avoid
422 * multi-tasking channels) in the non-SMP case. Must be called under
423 * dma_list_mutex.
424 */
425static void dma_channel_rebalance(void)
426{
427 struct dma_chan *chan;
428 struct dma_device *device;
429 int cpu;
430 int cap;
431 int n;
432
433 /* undo the last distribution */
434 for_each_dma_cap_mask(cap, dma_cap_mask_all)
435 for_each_possible_cpu(cpu)
436 per_cpu_ptr(channel_table[cap], cpu)->chan = NULL;
437
Dan Williams59b5ec22009-01-06 11:38:15 -0700438 list_for_each_entry(device, &dma_device_list, global_node) {
439 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
440 continue;
Dan Williamsbec08512009-01-06 11:38:14 -0700441 list_for_each_entry(chan, &device->channels, device_node)
442 chan->table_count = 0;
Dan Williams59b5ec22009-01-06 11:38:15 -0700443 }
Dan Williamsbec08512009-01-06 11:38:14 -0700444
445 /* don't populate the channel_table if no clients are available */
446 if (!dmaengine_ref_count)
447 return;
448
449 /* redistribute available channels */
450 n = 0;
451 for_each_dma_cap_mask(cap, dma_cap_mask_all)
452 for_each_online_cpu(cpu) {
453 if (num_possible_cpus() > 1)
454 chan = nth_chan(cap, n++);
455 else
456 chan = nth_chan(cap, -1);
457
458 per_cpu_ptr(channel_table[cap], cpu)->chan = chan;
459 }
460}
461
Dan Williamse2346672009-01-06 11:38:21 -0700462static struct dma_chan *private_candidate(dma_cap_mask_t *mask, struct dma_device *dev,
463 dma_filter_fn fn, void *fn_param)
Dan Williams59b5ec22009-01-06 11:38:15 -0700464{
465 struct dma_chan *chan;
Dan Williams59b5ec22009-01-06 11:38:15 -0700466
467 if (!__dma_device_satisfies_mask(dev, mask)) {
468 pr_debug("%s: wrong capabilities\n", __func__);
469 return NULL;
470 }
471 /* devices with multiple channels need special handling as we need to
472 * ensure that all channels are either private or public.
473 */
474 if (dev->chancnt > 1 && !dma_has_cap(DMA_PRIVATE, dev->cap_mask))
475 list_for_each_entry(chan, &dev->channels, device_node) {
476 /* some channels are already publicly allocated */
477 if (chan->client_count)
478 return NULL;
479 }
480
481 list_for_each_entry(chan, &dev->channels, device_node) {
482 if (chan->client_count) {
483 pr_debug("%s: %s busy\n",
Dan Williams41d5e592009-01-06 11:38:21 -0700484 __func__, dma_chan_name(chan));
Dan Williams59b5ec22009-01-06 11:38:15 -0700485 continue;
486 }
Dan Williamse2346672009-01-06 11:38:21 -0700487 if (fn && !fn(chan, fn_param)) {
488 pr_debug("%s: %s filter said false\n",
489 __func__, dma_chan_name(chan));
490 continue;
491 }
492 return chan;
Dan Williams59b5ec22009-01-06 11:38:15 -0700493 }
494
Dan Williamse2346672009-01-06 11:38:21 -0700495 return NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700496}
497
498/**
499 * dma_request_channel - try to allocate an exclusive channel
500 * @mask: capabilities that the channel must satisfy
501 * @fn: optional callback to disposition available channels
502 * @fn_param: opaque parameter to pass to dma_filter_fn
503 */
504struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param)
505{
506 struct dma_device *device, *_d;
507 struct dma_chan *chan = NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700508 int err;
509
510 /* Find a channel */
511 mutex_lock(&dma_list_mutex);
512 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
Dan Williamse2346672009-01-06 11:38:21 -0700513 chan = private_candidate(mask, device, fn, fn_param);
514 if (chan) {
Dan Williams59b5ec22009-01-06 11:38:15 -0700515 /* Found a suitable channel, try to grab, prep, and
516 * return it. We first set DMA_PRIVATE to disable
517 * balance_ref_count as this channel will not be
518 * published in the general-purpose allocator
519 */
520 dma_cap_set(DMA_PRIVATE, device->cap_mask);
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900521 device->privatecnt++;
Dan Williams59b5ec22009-01-06 11:38:15 -0700522 err = dma_chan_get(chan);
523
524 if (err == -ENODEV) {
Joe Perches63433252012-07-18 09:51:28 -0700525 pr_debug("%s: %s module removed\n",
526 __func__, dma_chan_name(chan));
Dan Williams59b5ec22009-01-06 11:38:15 -0700527 list_del_rcu(&device->global_node);
528 } else if (err)
Fabio Estevamd8b53482012-02-21 12:51:59 -0200529 pr_debug("%s: failed to get %s: (%d)\n",
Joe Perches63433252012-07-18 09:51:28 -0700530 __func__, dma_chan_name(chan), err);
Dan Williams59b5ec22009-01-06 11:38:15 -0700531 else
532 break;
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900533 if (--device->privatecnt == 0)
534 dma_cap_clear(DMA_PRIVATE, device->cap_mask);
Dan Williamse2346672009-01-06 11:38:21 -0700535 chan = NULL;
536 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700537 }
538 mutex_unlock(&dma_list_mutex);
539
Joe Perches63433252012-07-18 09:51:28 -0700540 pr_debug("%s: %s (%s)\n",
541 __func__,
542 chan ? "success" : "fail",
Dan Williams41d5e592009-01-06 11:38:21 -0700543 chan ? dma_chan_name(chan) : NULL);
Dan Williams59b5ec22009-01-06 11:38:15 -0700544
545 return chan;
546}
547EXPORT_SYMBOL_GPL(__dma_request_channel);
548
549void dma_release_channel(struct dma_chan *chan)
550{
551 mutex_lock(&dma_list_mutex);
552 WARN_ONCE(chan->client_count != 1,
553 "chan reference count %d != 1\n", chan->client_count);
554 dma_chan_put(chan);
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900555 /* drop PRIVATE cap enabled by __dma_request_channel() */
556 if (--chan->device->privatecnt == 0)
557 dma_cap_clear(DMA_PRIVATE, chan->device->cap_mask);
Dan Williams59b5ec22009-01-06 11:38:15 -0700558 mutex_unlock(&dma_list_mutex);
559}
560EXPORT_SYMBOL_GPL(dma_release_channel);
561
Dan Williamsbec08512009-01-06 11:38:14 -0700562/**
Dan Williams209b84a2009-01-06 11:38:17 -0700563 * dmaengine_get - register interest in dma_channels
Chris Leechc13c8262006-05-23 17:18:44 -0700564 */
Dan Williams209b84a2009-01-06 11:38:17 -0700565void dmaengine_get(void)
Chris Leechc13c8262006-05-23 17:18:44 -0700566{
Dan Williams6f49a572009-01-06 11:38:14 -0700567 struct dma_device *device, *_d;
568 struct dma_chan *chan;
569 int err;
570
Chris Leechc13c8262006-05-23 17:18:44 -0700571 mutex_lock(&dma_list_mutex);
Dan Williams6f49a572009-01-06 11:38:14 -0700572 dmaengine_ref_count++;
573
574 /* try to grab channels */
Dan Williams59b5ec22009-01-06 11:38:15 -0700575 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
576 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
577 continue;
Dan Williams6f49a572009-01-06 11:38:14 -0700578 list_for_each_entry(chan, &device->channels, device_node) {
579 err = dma_chan_get(chan);
580 if (err == -ENODEV) {
581 /* module removed before we could use it */
Dan Williams2ba05622009-01-06 11:38:14 -0700582 list_del_rcu(&device->global_node);
Dan Williams6f49a572009-01-06 11:38:14 -0700583 break;
584 } else if (err)
Fabio Estevam0eb5a352012-10-04 17:11:16 -0700585 pr_debug("%s: failed to get %s: (%d)\n",
Joe Perches63433252012-07-18 09:51:28 -0700586 __func__, dma_chan_name(chan), err);
Dan Williams6f49a572009-01-06 11:38:14 -0700587 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700588 }
Dan Williams6f49a572009-01-06 11:38:14 -0700589
Dan Williamsbec08512009-01-06 11:38:14 -0700590 /* if this is the first reference and there were channels
591 * waiting we need to rebalance to get those channels
592 * incorporated into the channel table
593 */
594 if (dmaengine_ref_count == 1)
595 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -0700596 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700597}
Dan Williams209b84a2009-01-06 11:38:17 -0700598EXPORT_SYMBOL(dmaengine_get);
Chris Leechc13c8262006-05-23 17:18:44 -0700599
600/**
Dan Williams209b84a2009-01-06 11:38:17 -0700601 * dmaengine_put - let dma drivers be removed when ref_count == 0
Chris Leechc13c8262006-05-23 17:18:44 -0700602 */
Dan Williams209b84a2009-01-06 11:38:17 -0700603void dmaengine_put(void)
Chris Leechc13c8262006-05-23 17:18:44 -0700604{
Dan Williamsd379b012007-07-09 11:56:42 -0700605 struct dma_device *device;
Chris Leechc13c8262006-05-23 17:18:44 -0700606 struct dma_chan *chan;
607
Chris Leechc13c8262006-05-23 17:18:44 -0700608 mutex_lock(&dma_list_mutex);
Dan Williams6f49a572009-01-06 11:38:14 -0700609 dmaengine_ref_count--;
610 BUG_ON(dmaengine_ref_count < 0);
611 /* drop channel references */
Dan Williams59b5ec22009-01-06 11:38:15 -0700612 list_for_each_entry(device, &dma_device_list, global_node) {
613 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
614 continue;
Dan Williams6f49a572009-01-06 11:38:14 -0700615 list_for_each_entry(chan, &device->channels, device_node)
616 dma_chan_put(chan);
Dan Williams59b5ec22009-01-06 11:38:15 -0700617 }
Chris Leechc13c8262006-05-23 17:18:44 -0700618 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700619}
Dan Williams209b84a2009-01-06 11:38:17 -0700620EXPORT_SYMBOL(dmaengine_put);
Chris Leechc13c8262006-05-23 17:18:44 -0700621
Dan Williams138f4c32009-09-08 17:42:51 -0700622static bool device_has_all_tx_types(struct dma_device *device)
623{
624 /* A device that satisfies this test has channels that will never cause
625 * an async_tx channel switch event as all possible operation types can
626 * be handled.
627 */
628 #ifdef CONFIG_ASYNC_TX_DMA
629 if (!dma_has_cap(DMA_INTERRUPT, device->cap_mask))
630 return false;
631 #endif
632
633 #if defined(CONFIG_ASYNC_MEMCPY) || defined(CONFIG_ASYNC_MEMCPY_MODULE)
634 if (!dma_has_cap(DMA_MEMCPY, device->cap_mask))
635 return false;
636 #endif
637
638 #if defined(CONFIG_ASYNC_MEMSET) || defined(CONFIG_ASYNC_MEMSET_MODULE)
639 if (!dma_has_cap(DMA_MEMSET, device->cap_mask))
640 return false;
641 #endif
642
643 #if defined(CONFIG_ASYNC_XOR) || defined(CONFIG_ASYNC_XOR_MODULE)
644 if (!dma_has_cap(DMA_XOR, device->cap_mask))
645 return false;
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700646
647 #ifndef CONFIG_ASYNC_TX_DISABLE_XOR_VAL_DMA
Dan Williams4499a242009-11-19 17:10:25 -0700648 if (!dma_has_cap(DMA_XOR_VAL, device->cap_mask))
649 return false;
Dan Williams138f4c32009-09-08 17:42:51 -0700650 #endif
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700651 #endif
Dan Williams138f4c32009-09-08 17:42:51 -0700652
653 #if defined(CONFIG_ASYNC_PQ) || defined(CONFIG_ASYNC_PQ_MODULE)
654 if (!dma_has_cap(DMA_PQ, device->cap_mask))
655 return false;
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700656
657 #ifndef CONFIG_ASYNC_TX_DISABLE_PQ_VAL_DMA
Dan Williams4499a242009-11-19 17:10:25 -0700658 if (!dma_has_cap(DMA_PQ_VAL, device->cap_mask))
659 return false;
Dan Williams138f4c32009-09-08 17:42:51 -0700660 #endif
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700661 #endif
Dan Williams138f4c32009-09-08 17:42:51 -0700662
663 return true;
664}
665
Dan Williams257b17c2009-03-25 09:13:23 -0700666static int get_dma_id(struct dma_device *device)
667{
668 int rc;
669
670 idr_retry:
671 if (!idr_pre_get(&dma_idr, GFP_KERNEL))
672 return -ENOMEM;
673 mutex_lock(&dma_list_mutex);
674 rc = idr_get_new(&dma_idr, NULL, &device->dev_id);
675 mutex_unlock(&dma_list_mutex);
676 if (rc == -EAGAIN)
677 goto idr_retry;
678 else if (rc != 0)
679 return rc;
680
681 return 0;
682}
683
Chris Leechc13c8262006-05-23 17:18:44 -0700684/**
Randy Dunlap65088712006-07-03 19:45:31 -0700685 * dma_async_device_register - registers DMA devices found
Chris Leechc13c8262006-05-23 17:18:44 -0700686 * @device: &dma_device
687 */
688int dma_async_device_register(struct dma_device *device)
689{
Jeff Garzikff487fb2007-03-08 09:57:34 -0800690 int chancnt = 0, rc;
Chris Leechc13c8262006-05-23 17:18:44 -0700691 struct dma_chan* chan;
Dan Williams864498a2009-01-06 11:38:21 -0700692 atomic_t *idr_ref;
Chris Leechc13c8262006-05-23 17:18:44 -0700693
694 if (!device)
695 return -ENODEV;
696
Dan Williams7405f742007-01-02 11:10:43 -0700697 /* validate device routines */
698 BUG_ON(dma_has_cap(DMA_MEMCPY, device->cap_mask) &&
699 !device->device_prep_dma_memcpy);
700 BUG_ON(dma_has_cap(DMA_XOR, device->cap_mask) &&
701 !device->device_prep_dma_xor);
Dan Williams099f53c2009-04-08 14:28:37 -0700702 BUG_ON(dma_has_cap(DMA_XOR_VAL, device->cap_mask) &&
703 !device->device_prep_dma_xor_val);
Dan Williamsb2f46fd2009-07-14 12:20:36 -0700704 BUG_ON(dma_has_cap(DMA_PQ, device->cap_mask) &&
705 !device->device_prep_dma_pq);
706 BUG_ON(dma_has_cap(DMA_PQ_VAL, device->cap_mask) &&
707 !device->device_prep_dma_pq_val);
Dan Williams7405f742007-01-02 11:10:43 -0700708 BUG_ON(dma_has_cap(DMA_MEMSET, device->cap_mask) &&
709 !device->device_prep_dma_memset);
Zhang Wei9b941c62008-03-13 17:45:28 -0700710 BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) &&
Dan Williams7405f742007-01-02 11:10:43 -0700711 !device->device_prep_dma_interrupt);
Ira Snydera86ee032010-09-30 11:46:44 +0000712 BUG_ON(dma_has_cap(DMA_SG, device->cap_mask) &&
713 !device->device_prep_dma_sg);
Sascha Hauer782bc952010-09-30 13:56:32 +0000714 BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
715 !device->device_prep_dma_cyclic);
Haavard Skinnemoendc0ee6432008-07-08 11:59:35 -0700716 BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
Linus Walleijc3635c72010-03-26 16:44:01 -0700717 !device->device_control);
Jassi Brarb14dab72011-10-13 12:33:30 +0530718 BUG_ON(dma_has_cap(DMA_INTERLEAVE, device->cap_mask) &&
719 !device->device_prep_interleaved_dma);
Dan Williams7405f742007-01-02 11:10:43 -0700720
721 BUG_ON(!device->device_alloc_chan_resources);
722 BUG_ON(!device->device_free_chan_resources);
Linus Walleij07934482010-03-26 16:50:49 -0700723 BUG_ON(!device->device_tx_status);
Dan Williams7405f742007-01-02 11:10:43 -0700724 BUG_ON(!device->device_issue_pending);
725 BUG_ON(!device->dev);
726
Dan Williams138f4c32009-09-08 17:42:51 -0700727 /* note: this only matters in the
Dan Williams5fc6d892010-10-07 16:44:50 -0700728 * CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH=n case
Dan Williams138f4c32009-09-08 17:42:51 -0700729 */
730 if (device_has_all_tx_types(device))
731 dma_cap_set(DMA_ASYNC_TX, device->cap_mask);
732
Dan Williams864498a2009-01-06 11:38:21 -0700733 idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL);
734 if (!idr_ref)
735 return -ENOMEM;
Dan Williams257b17c2009-03-25 09:13:23 -0700736 rc = get_dma_id(device);
737 if (rc != 0) {
738 kfree(idr_ref);
Dan Williams864498a2009-01-06 11:38:21 -0700739 return rc;
Dan Williams257b17c2009-03-25 09:13:23 -0700740 }
741
742 atomic_set(idr_ref, 0);
Chris Leechc13c8262006-05-23 17:18:44 -0700743
744 /* represent channels in sysfs. Probably want devs too */
745 list_for_each_entry(chan, &device->channels, device_node) {
Dan Williams257b17c2009-03-25 09:13:23 -0700746 rc = -ENOMEM;
Chris Leechc13c8262006-05-23 17:18:44 -0700747 chan->local = alloc_percpu(typeof(*chan->local));
748 if (chan->local == NULL)
Dan Williams257b17c2009-03-25 09:13:23 -0700749 goto err_out;
Dan Williams41d5e592009-01-06 11:38:21 -0700750 chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL);
751 if (chan->dev == NULL) {
752 free_percpu(chan->local);
Dan Williams257b17c2009-03-25 09:13:23 -0700753 chan->local = NULL;
754 goto err_out;
Dan Williams41d5e592009-01-06 11:38:21 -0700755 }
Chris Leechc13c8262006-05-23 17:18:44 -0700756
757 chan->chan_id = chancnt++;
Dan Williams41d5e592009-01-06 11:38:21 -0700758 chan->dev->device.class = &dma_devclass;
759 chan->dev->device.parent = device->dev;
760 chan->dev->chan = chan;
Dan Williams864498a2009-01-06 11:38:21 -0700761 chan->dev->idr_ref = idr_ref;
762 chan->dev->dev_id = device->dev_id;
763 atomic_inc(idr_ref);
Dan Williams41d5e592009-01-06 11:38:21 -0700764 dev_set_name(&chan->dev->device, "dma%dchan%d",
Kay Sievers06190d82008-11-11 13:12:33 -0700765 device->dev_id, chan->chan_id);
Chris Leechc13c8262006-05-23 17:18:44 -0700766
Dan Williams41d5e592009-01-06 11:38:21 -0700767 rc = device_register(&chan->dev->device);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800768 if (rc) {
Jeff Garzikff487fb2007-03-08 09:57:34 -0800769 free_percpu(chan->local);
770 chan->local = NULL;
Dan Williams257b17c2009-03-25 09:13:23 -0700771 kfree(chan->dev);
772 atomic_dec(idr_ref);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800773 goto err_out;
774 }
Dan Williams7cc5bf92008-07-08 11:58:21 -0700775 chan->client_count = 0;
Chris Leechc13c8262006-05-23 17:18:44 -0700776 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700777 device->chancnt = chancnt;
Chris Leechc13c8262006-05-23 17:18:44 -0700778
779 mutex_lock(&dma_list_mutex);
Dan Williams59b5ec22009-01-06 11:38:15 -0700780 /* take references on public channels */
781 if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask))
Dan Williams6f49a572009-01-06 11:38:14 -0700782 list_for_each_entry(chan, &device->channels, device_node) {
783 /* if clients are already waiting for channels we need
784 * to take references on their behalf
785 */
786 if (dma_chan_get(chan) == -ENODEV) {
787 /* note we can only get here for the first
788 * channel as the remaining channels are
789 * guaranteed to get a reference
790 */
791 rc = -ENODEV;
792 mutex_unlock(&dma_list_mutex);
793 goto err_out;
794 }
795 }
Dan Williams2ba05622009-01-06 11:38:14 -0700796 list_add_tail_rcu(&device->global_node, &dma_device_list);
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900797 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
798 device->privatecnt++; /* Always private */
Dan Williamsbec08512009-01-06 11:38:14 -0700799 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -0700800 mutex_unlock(&dma_list_mutex);
801
Chris Leechc13c8262006-05-23 17:18:44 -0700802 return 0;
Jeff Garzikff487fb2007-03-08 09:57:34 -0800803
804err_out:
Dan Williams257b17c2009-03-25 09:13:23 -0700805 /* if we never registered a channel just release the idr */
806 if (atomic_read(idr_ref) == 0) {
807 mutex_lock(&dma_list_mutex);
808 idr_remove(&dma_idr, device->dev_id);
809 mutex_unlock(&dma_list_mutex);
810 kfree(idr_ref);
811 return rc;
812 }
813
Jeff Garzikff487fb2007-03-08 09:57:34 -0800814 list_for_each_entry(chan, &device->channels, device_node) {
815 if (chan->local == NULL)
816 continue;
Dan Williams41d5e592009-01-06 11:38:21 -0700817 mutex_lock(&dma_list_mutex);
818 chan->dev->chan = NULL;
819 mutex_unlock(&dma_list_mutex);
820 device_unregister(&chan->dev->device);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800821 free_percpu(chan->local);
822 }
823 return rc;
Chris Leechc13c8262006-05-23 17:18:44 -0700824}
David Brownell765e3d82007-03-16 13:38:05 -0800825EXPORT_SYMBOL(dma_async_device_register);
Chris Leechc13c8262006-05-23 17:18:44 -0700826
827/**
Dan Williams6f49a572009-01-06 11:38:14 -0700828 * dma_async_device_unregister - unregister a DMA device
Randy Dunlap65088712006-07-03 19:45:31 -0700829 * @device: &dma_device
Dan Williamsf27c5802009-01-06 11:38:18 -0700830 *
831 * This routine is called by dma driver exit routines, dmaengine holds module
832 * references to prevent it being called while channels are in use.
Randy Dunlap65088712006-07-03 19:45:31 -0700833 */
834void dma_async_device_unregister(struct dma_device *device)
Chris Leechc13c8262006-05-23 17:18:44 -0700835{
836 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -0700837
838 mutex_lock(&dma_list_mutex);
Dan Williams2ba05622009-01-06 11:38:14 -0700839 list_del_rcu(&device->global_node);
Dan Williamsbec08512009-01-06 11:38:14 -0700840 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -0700841 mutex_unlock(&dma_list_mutex);
842
843 list_for_each_entry(chan, &device->channels, device_node) {
Dan Williams6f49a572009-01-06 11:38:14 -0700844 WARN_ONCE(chan->client_count,
845 "%s called while %d clients hold a reference\n",
846 __func__, chan->client_count);
Dan Williams41d5e592009-01-06 11:38:21 -0700847 mutex_lock(&dma_list_mutex);
848 chan->dev->chan = NULL;
849 mutex_unlock(&dma_list_mutex);
850 device_unregister(&chan->dev->device);
Anatolij Gustschinadef4772010-01-26 10:26:06 +0100851 free_percpu(chan->local);
Chris Leechc13c8262006-05-23 17:18:44 -0700852 }
Chris Leechc13c8262006-05-23 17:18:44 -0700853}
David Brownell765e3d82007-03-16 13:38:05 -0800854EXPORT_SYMBOL(dma_async_device_unregister);
Chris Leechc13c8262006-05-23 17:18:44 -0700855
Dan Williams7405f742007-01-02 11:10:43 -0700856/**
857 * dma_async_memcpy_buf_to_buf - offloaded copy between virtual addresses
858 * @chan: DMA channel to offload copy to
859 * @dest: destination address (virtual)
860 * @src: source address (virtual)
861 * @len: length
862 *
863 * Both @dest and @src must be mappable to a bus address according to the
864 * DMA mapping API rules for streaming mappings.
865 * Both @dest and @src must stay memory resident (kernel memory or locked
866 * user space pages).
867 */
868dma_cookie_t
869dma_async_memcpy_buf_to_buf(struct dma_chan *chan, void *dest,
870 void *src, size_t len)
871{
872 struct dma_device *dev = chan->device;
873 struct dma_async_tx_descriptor *tx;
Dan Williams00367312008-02-02 19:49:57 -0700874 dma_addr_t dma_dest, dma_src;
Dan Williams7405f742007-01-02 11:10:43 -0700875 dma_cookie_t cookie;
Maciej Sosnowski4f005db2009-04-23 12:31:51 +0200876 unsigned long flags;
Dan Williams7405f742007-01-02 11:10:43 -0700877
Dan Williams00367312008-02-02 19:49:57 -0700878 dma_src = dma_map_single(dev->dev, src, len, DMA_TO_DEVICE);
879 dma_dest = dma_map_single(dev->dev, dest, len, DMA_FROM_DEVICE);
Maciej Sosnowski4f005db2009-04-23 12:31:51 +0200880 flags = DMA_CTRL_ACK |
881 DMA_COMPL_SRC_UNMAP_SINGLE |
882 DMA_COMPL_DEST_UNMAP_SINGLE;
883 tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags);
Dan Williams00367312008-02-02 19:49:57 -0700884
885 if (!tx) {
886 dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE);
887 dma_unmap_single(dev->dev, dma_dest, len, DMA_FROM_DEVICE);
Dan Williams7405f742007-01-02 11:10:43 -0700888 return -ENOMEM;
Dan Williams00367312008-02-02 19:49:57 -0700889 }
Dan Williams7405f742007-01-02 11:10:43 -0700890
Dan Williams7405f742007-01-02 11:10:43 -0700891 tx->callback = NULL;
Dan Williams7405f742007-01-02 11:10:43 -0700892 cookie = tx->tx_submit(tx);
893
Christoph Lametere7dcaa42009-10-03 19:48:23 +0900894 preempt_disable();
895 __this_cpu_add(chan->local->bytes_transferred, len);
896 __this_cpu_inc(chan->local->memcpy_count);
897 preempt_enable();
Dan Williams7405f742007-01-02 11:10:43 -0700898
899 return cookie;
900}
901EXPORT_SYMBOL(dma_async_memcpy_buf_to_buf);
902
903/**
904 * dma_async_memcpy_buf_to_pg - offloaded copy from address to page
905 * @chan: DMA channel to offload copy to
906 * @page: destination page
907 * @offset: offset in page to copy to
908 * @kdata: source address (virtual)
909 * @len: length
910 *
911 * Both @page/@offset and @kdata must be mappable to a bus address according
912 * to the DMA mapping API rules for streaming mappings.
913 * Both @page/@offset and @kdata must stay memory resident (kernel memory or
914 * locked user space pages)
915 */
916dma_cookie_t
917dma_async_memcpy_buf_to_pg(struct dma_chan *chan, struct page *page,
918 unsigned int offset, void *kdata, size_t len)
919{
920 struct dma_device *dev = chan->device;
921 struct dma_async_tx_descriptor *tx;
Dan Williams00367312008-02-02 19:49:57 -0700922 dma_addr_t dma_dest, dma_src;
Dan Williams7405f742007-01-02 11:10:43 -0700923 dma_cookie_t cookie;
Maciej Sosnowski4f005db2009-04-23 12:31:51 +0200924 unsigned long flags;
Dan Williams7405f742007-01-02 11:10:43 -0700925
Dan Williams00367312008-02-02 19:49:57 -0700926 dma_src = dma_map_single(dev->dev, kdata, len, DMA_TO_DEVICE);
927 dma_dest = dma_map_page(dev->dev, page, offset, len, DMA_FROM_DEVICE);
Maciej Sosnowski4f005db2009-04-23 12:31:51 +0200928 flags = DMA_CTRL_ACK | DMA_COMPL_SRC_UNMAP_SINGLE;
929 tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags);
Dan Williams00367312008-02-02 19:49:57 -0700930
931 if (!tx) {
932 dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE);
933 dma_unmap_page(dev->dev, dma_dest, len, DMA_FROM_DEVICE);
Dan Williams7405f742007-01-02 11:10:43 -0700934 return -ENOMEM;
Dan Williams00367312008-02-02 19:49:57 -0700935 }
Dan Williams7405f742007-01-02 11:10:43 -0700936
Dan Williams7405f742007-01-02 11:10:43 -0700937 tx->callback = NULL;
Dan Williams7405f742007-01-02 11:10:43 -0700938 cookie = tx->tx_submit(tx);
939
Christoph Lametere7dcaa42009-10-03 19:48:23 +0900940 preempt_disable();
941 __this_cpu_add(chan->local->bytes_transferred, len);
942 __this_cpu_inc(chan->local->memcpy_count);
943 preempt_enable();
Dan Williams7405f742007-01-02 11:10:43 -0700944
945 return cookie;
946}
947EXPORT_SYMBOL(dma_async_memcpy_buf_to_pg);
948
949/**
950 * dma_async_memcpy_pg_to_pg - offloaded copy from page to page
951 * @chan: DMA channel to offload copy to
952 * @dest_pg: destination page
953 * @dest_off: offset in page to copy to
954 * @src_pg: source page
955 * @src_off: offset in page to copy from
956 * @len: length
957 *
958 * Both @dest_page/@dest_off and @src_page/@src_off must be mappable to a bus
959 * address according to the DMA mapping API rules for streaming mappings.
960 * Both @dest_page/@dest_off and @src_page/@src_off must stay memory resident
961 * (kernel memory or locked user space pages).
962 */
963dma_cookie_t
964dma_async_memcpy_pg_to_pg(struct dma_chan *chan, struct page *dest_pg,
965 unsigned int dest_off, struct page *src_pg, unsigned int src_off,
966 size_t len)
967{
968 struct dma_device *dev = chan->device;
969 struct dma_async_tx_descriptor *tx;
Dan Williams00367312008-02-02 19:49:57 -0700970 dma_addr_t dma_dest, dma_src;
Dan Williams7405f742007-01-02 11:10:43 -0700971 dma_cookie_t cookie;
Maciej Sosnowski4f005db2009-04-23 12:31:51 +0200972 unsigned long flags;
Dan Williams7405f742007-01-02 11:10:43 -0700973
Dan Williams00367312008-02-02 19:49:57 -0700974 dma_src = dma_map_page(dev->dev, src_pg, src_off, len, DMA_TO_DEVICE);
975 dma_dest = dma_map_page(dev->dev, dest_pg, dest_off, len,
976 DMA_FROM_DEVICE);
Maciej Sosnowski4f005db2009-04-23 12:31:51 +0200977 flags = DMA_CTRL_ACK;
978 tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags);
Dan Williams00367312008-02-02 19:49:57 -0700979
980 if (!tx) {
981 dma_unmap_page(dev->dev, dma_src, len, DMA_TO_DEVICE);
982 dma_unmap_page(dev->dev, dma_dest, len, DMA_FROM_DEVICE);
Dan Williams7405f742007-01-02 11:10:43 -0700983 return -ENOMEM;
Dan Williams00367312008-02-02 19:49:57 -0700984 }
Dan Williams7405f742007-01-02 11:10:43 -0700985
Dan Williams7405f742007-01-02 11:10:43 -0700986 tx->callback = NULL;
Dan Williams7405f742007-01-02 11:10:43 -0700987 cookie = tx->tx_submit(tx);
988
Christoph Lametere7dcaa42009-10-03 19:48:23 +0900989 preempt_disable();
990 __this_cpu_add(chan->local->bytes_transferred, len);
991 __this_cpu_inc(chan->local->memcpy_count);
992 preempt_enable();
Dan Williams7405f742007-01-02 11:10:43 -0700993
994 return cookie;
995}
996EXPORT_SYMBOL(dma_async_memcpy_pg_to_pg);
997
998void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
999 struct dma_chan *chan)
1000{
1001 tx->chan = chan;
Dan Williams5fc6d892010-10-07 16:44:50 -07001002 #ifdef CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH
Dan Williams7405f742007-01-02 11:10:43 -07001003 spin_lock_init(&tx->lock);
Dan Williamscaa20d972010-05-17 16:24:16 -07001004 #endif
Dan Williams7405f742007-01-02 11:10:43 -07001005}
1006EXPORT_SYMBOL(dma_async_tx_descriptor_init);
1007
Dan Williams07f22112009-01-05 17:14:31 -07001008/* dma_wait_for_async_tx - spin wait for a transaction to complete
1009 * @tx: in-flight transaction to wait on
Dan Williams07f22112009-01-05 17:14:31 -07001010 */
1011enum dma_status
1012dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
1013{
Dan Williams95475e52009-07-14 12:19:02 -07001014 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
Dan Williams07f22112009-01-05 17:14:31 -07001015
1016 if (!tx)
1017 return DMA_SUCCESS;
1018
Dan Williams95475e52009-07-14 12:19:02 -07001019 while (tx->cookie == -EBUSY) {
1020 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
1021 pr_err("%s timeout waiting for descriptor submission\n",
Joe Perches63433252012-07-18 09:51:28 -07001022 __func__);
Dan Williams95475e52009-07-14 12:19:02 -07001023 return DMA_ERROR;
1024 }
1025 cpu_relax();
1026 }
1027 return dma_sync_wait(tx->chan, tx->cookie);
Dan Williams07f22112009-01-05 17:14:31 -07001028}
1029EXPORT_SYMBOL_GPL(dma_wait_for_async_tx);
1030
1031/* dma_run_dependencies - helper routine for dma drivers to process
1032 * (start) dependent operations on their target channel
1033 * @tx: transaction with dependencies
1034 */
1035void dma_run_dependencies(struct dma_async_tx_descriptor *tx)
1036{
Dan Williamscaa20d972010-05-17 16:24:16 -07001037 struct dma_async_tx_descriptor *dep = txd_next(tx);
Dan Williams07f22112009-01-05 17:14:31 -07001038 struct dma_async_tx_descriptor *dep_next;
1039 struct dma_chan *chan;
1040
1041 if (!dep)
1042 return;
1043
Yuri Tikhonovdd59b852009-01-12 15:17:20 -07001044 /* we'll submit tx->next now, so clear the link */
Dan Williamscaa20d972010-05-17 16:24:16 -07001045 txd_clear_next(tx);
Dan Williams07f22112009-01-05 17:14:31 -07001046 chan = dep->chan;
1047
1048 /* keep submitting up until a channel switch is detected
1049 * in that case we will be called again as a result of
1050 * processing the interrupt from async_tx_channel_switch
1051 */
1052 for (; dep; dep = dep_next) {
Dan Williamscaa20d972010-05-17 16:24:16 -07001053 txd_lock(dep);
1054 txd_clear_parent(dep);
1055 dep_next = txd_next(dep);
Dan Williams07f22112009-01-05 17:14:31 -07001056 if (dep_next && dep_next->chan == chan)
Dan Williamscaa20d972010-05-17 16:24:16 -07001057 txd_clear_next(dep); /* ->next will be submitted */
Dan Williams07f22112009-01-05 17:14:31 -07001058 else
1059 dep_next = NULL; /* submit current dep and terminate */
Dan Williamscaa20d972010-05-17 16:24:16 -07001060 txd_unlock(dep);
Dan Williams07f22112009-01-05 17:14:31 -07001061
1062 dep->tx_submit(dep);
1063 }
1064
1065 chan->device->device_issue_pending(chan);
1066}
1067EXPORT_SYMBOL_GPL(dma_run_dependencies);
1068
Chris Leechc13c8262006-05-23 17:18:44 -07001069static int __init dma_bus_init(void)
1070{
Chris Leechc13c8262006-05-23 17:18:44 -07001071 return class_register(&dma_devclass);
1072}
Dan Williams652afc22009-01-06 11:38:22 -07001073arch_initcall(dma_bus_init);
Chris Leechc13c8262006-05-23 17:18:44 -07001074
Dan Williamsbec08512009-01-06 11:38:14 -07001075