blob: 9162ac80c18f303ac9a509eb97298eba33d4753b [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>
Andy Shevchenko4e82f5d2013-04-09 14:05:44 +030065#include <linux/acpi.h>
66#include <linux/acpi_dma.h>
Jon Hunter9a6cecc2012-09-14 17:41:57 -050067#include <linux/of_dma.h>
Chris Leechc13c8262006-05-23 17:18:44 -070068
69static DEFINE_MUTEX(dma_list_mutex);
Axel Lin21ef4b82011-07-20 11:32:28 +080070static DEFINE_IDR(dma_idr);
Chris Leechc13c8262006-05-23 17:18:44 -070071static LIST_HEAD(dma_device_list);
Dan Williams6f49a572009-01-06 11:38:14 -070072static long dmaengine_ref_count;
Chris Leechc13c8262006-05-23 17:18:44 -070073
74/* --- sysfs implementation --- */
75
Dan Williams41d5e592009-01-06 11:38:21 -070076/**
77 * dev_to_dma_chan - convert a device pointer to the its sysfs container object
78 * @dev - device node
79 *
80 * Must be called under dma_list_mutex
81 */
82static struct dma_chan *dev_to_dma_chan(struct device *dev)
83{
84 struct dma_chan_dev *chan_dev;
85
86 chan_dev = container_of(dev, typeof(*chan_dev), device);
87 return chan_dev->chan;
88}
89
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -070090static ssize_t memcpy_count_show(struct device *dev,
91 struct device_attribute *attr, char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -070092{
Dan Williams41d5e592009-01-06 11:38:21 -070093 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -070094 unsigned long count = 0;
95 int i;
Dan Williams41d5e592009-01-06 11:38:21 -070096 int err;
Chris Leechc13c8262006-05-23 17:18:44 -070097
Dan Williams41d5e592009-01-06 11:38:21 -070098 mutex_lock(&dma_list_mutex);
99 chan = dev_to_dma_chan(dev);
100 if (chan) {
101 for_each_possible_cpu(i)
102 count += per_cpu_ptr(chan->local, i)->memcpy_count;
103 err = sprintf(buf, "%lu\n", count);
104 } else
105 err = -ENODEV;
106 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700107
Dan Williams41d5e592009-01-06 11:38:21 -0700108 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700109}
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700110static DEVICE_ATTR_RO(memcpy_count);
Chris Leechc13c8262006-05-23 17:18:44 -0700111
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700112static ssize_t bytes_transferred_show(struct device *dev,
113 struct device_attribute *attr, char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -0700114{
Dan Williams41d5e592009-01-06 11:38:21 -0700115 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -0700116 unsigned long count = 0;
117 int i;
Dan Williams41d5e592009-01-06 11:38:21 -0700118 int err;
Chris Leechc13c8262006-05-23 17:18:44 -0700119
Dan Williams41d5e592009-01-06 11:38:21 -0700120 mutex_lock(&dma_list_mutex);
121 chan = dev_to_dma_chan(dev);
122 if (chan) {
123 for_each_possible_cpu(i)
124 count += per_cpu_ptr(chan->local, i)->bytes_transferred;
125 err = sprintf(buf, "%lu\n", count);
126 } else
127 err = -ENODEV;
128 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700129
Dan Williams41d5e592009-01-06 11:38:21 -0700130 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700131}
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700132static DEVICE_ATTR_RO(bytes_transferred);
Chris Leechc13c8262006-05-23 17:18:44 -0700133
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700134static ssize_t in_use_show(struct device *dev, struct device_attribute *attr,
135 char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -0700136{
Dan Williams41d5e592009-01-06 11:38:21 -0700137 struct dma_chan *chan;
138 int err;
Chris Leechc13c8262006-05-23 17:18:44 -0700139
Dan Williams41d5e592009-01-06 11:38:21 -0700140 mutex_lock(&dma_list_mutex);
141 chan = dev_to_dma_chan(dev);
142 if (chan)
143 err = sprintf(buf, "%d\n", chan->client_count);
144 else
145 err = -ENODEV;
146 mutex_unlock(&dma_list_mutex);
147
148 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700149}
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700150static DEVICE_ATTR_RO(in_use);
Chris Leechc13c8262006-05-23 17:18:44 -0700151
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700152static struct attribute *dma_dev_attrs[] = {
153 &dev_attr_memcpy_count.attr,
154 &dev_attr_bytes_transferred.attr,
155 &dev_attr_in_use.attr,
156 NULL,
Chris Leechc13c8262006-05-23 17:18:44 -0700157};
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700158ATTRIBUTE_GROUPS(dma_dev);
Chris Leechc13c8262006-05-23 17:18:44 -0700159
Dan Williams41d5e592009-01-06 11:38:21 -0700160static void chan_dev_release(struct device *dev)
161{
162 struct dma_chan_dev *chan_dev;
163
164 chan_dev = container_of(dev, typeof(*chan_dev), device);
Dan Williams864498a2009-01-06 11:38:21 -0700165 if (atomic_dec_and_test(chan_dev->idr_ref)) {
166 mutex_lock(&dma_list_mutex);
167 idr_remove(&dma_idr, chan_dev->dev_id);
168 mutex_unlock(&dma_list_mutex);
169 kfree(chan_dev->idr_ref);
170 }
Dan Williams41d5e592009-01-06 11:38:21 -0700171 kfree(chan_dev);
172}
173
Chris Leechc13c8262006-05-23 17:18:44 -0700174static struct class dma_devclass = {
Tony Jones891f78e2007-09-25 02:03:03 +0200175 .name = "dma",
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700176 .dev_groups = dma_dev_groups,
Dan Williams41d5e592009-01-06 11:38:21 -0700177 .dev_release = chan_dev_release,
Chris Leechc13c8262006-05-23 17:18:44 -0700178};
179
180/* --- client and device registration --- */
181
Dan Williams59b5ec22009-01-06 11:38:15 -0700182#define dma_device_satisfies_mask(device, mask) \
183 __dma_device_satisfies_mask((device), &(mask))
Dan Williamsd379b012007-07-09 11:56:42 -0700184static int
Lars-Peter Clausena53e28d2013-03-25 13:23:52 +0100185__dma_device_satisfies_mask(struct dma_device *device,
186 const dma_cap_mask_t *want)
Dan Williamsd379b012007-07-09 11:56:42 -0700187{
188 dma_cap_mask_t has;
189
Dan Williams59b5ec22009-01-06 11:38:15 -0700190 bitmap_and(has.bits, want->bits, device->cap_mask.bits,
Dan Williamsd379b012007-07-09 11:56:42 -0700191 DMA_TX_TYPE_END);
192 return bitmap_equal(want->bits, has.bits, DMA_TX_TYPE_END);
193}
194
Dan Williams6f49a572009-01-06 11:38:14 -0700195static struct module *dma_chan_to_owner(struct dma_chan *chan)
196{
197 return chan->device->dev->driver->owner;
198}
199
200/**
201 * balance_ref_count - catch up the channel reference count
202 * @chan - channel to balance ->client_count versus dmaengine_ref_count
203 *
204 * balance_ref_count must be called under dma_list_mutex
205 */
206static void balance_ref_count(struct dma_chan *chan)
207{
208 struct module *owner = dma_chan_to_owner(chan);
209
210 while (chan->client_count < dmaengine_ref_count) {
211 __module_get(owner);
212 chan->client_count++;
213 }
214}
215
216/**
217 * dma_chan_get - try to grab a dma channel's parent driver module
218 * @chan - channel to grab
219 *
220 * Must be called under dma_list_mutex
221 */
222static int dma_chan_get(struct dma_chan *chan)
223{
224 int err = -ENODEV;
225 struct module *owner = dma_chan_to_owner(chan);
226
227 if (chan->client_count) {
228 __module_get(owner);
229 err = 0;
230 } else if (try_module_get(owner))
231 err = 0;
232
233 if (err == 0)
234 chan->client_count++;
235
236 /* allocate upon first client reference */
237 if (chan->client_count == 1 && err == 0) {
Dan Williamsaa1e6f12009-01-06 11:38:17 -0700238 int desc_cnt = chan->device->device_alloc_chan_resources(chan);
Dan Williams6f49a572009-01-06 11:38:14 -0700239
240 if (desc_cnt < 0) {
241 err = desc_cnt;
242 chan->client_count = 0;
243 module_put(owner);
Dan Williams59b5ec22009-01-06 11:38:15 -0700244 } else if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
Dan Williams6f49a572009-01-06 11:38:14 -0700245 balance_ref_count(chan);
246 }
247
248 return err;
249}
250
251/**
252 * dma_chan_put - drop a reference to a dma channel's parent driver module
253 * @chan - channel to release
254 *
255 * Must be called under dma_list_mutex
256 */
257static void dma_chan_put(struct dma_chan *chan)
258{
259 if (!chan->client_count)
260 return; /* this channel failed alloc_chan_resources */
261 chan->client_count--;
262 module_put(dma_chan_to_owner(chan));
263 if (chan->client_count == 0)
264 chan->device->device_free_chan_resources(chan);
265}
266
Dan Williams7405f742007-01-02 11:10:43 -0700267enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
268{
269 enum dma_status status;
270 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
271
272 dma_async_issue_pending(chan);
273 do {
274 status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
275 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
Joe Perches63433252012-07-18 09:51:28 -0700276 pr_err("%s: timeout!\n", __func__);
Dan Williams7405f742007-01-02 11:10:43 -0700277 return DMA_ERROR;
278 }
Bartlomiej Zolnierkiewicz2cbe7fe2012-11-08 10:02:07 +0000279 if (status != DMA_IN_PROGRESS)
280 break;
281 cpu_relax();
282 } while (1);
Dan Williams7405f742007-01-02 11:10:43 -0700283
284 return status;
285}
286EXPORT_SYMBOL(dma_sync_wait);
287
Chris Leechc13c8262006-05-23 17:18:44 -0700288/**
Dan Williamsbec08512009-01-06 11:38:14 -0700289 * dma_cap_mask_all - enable iteration over all operation types
290 */
291static dma_cap_mask_t dma_cap_mask_all;
292
293/**
294 * dma_chan_tbl_ent - tracks channel allocations per core/operation
295 * @chan - associated channel for this entry
296 */
297struct dma_chan_tbl_ent {
298 struct dma_chan *chan;
299};
300
301/**
302 * channel_table - percpu lookup table for memory-to-memory offload providers
303 */
Tejun Heoa29d8b82010-02-02 14:39:15 +0900304static struct dma_chan_tbl_ent __percpu *channel_table[DMA_TX_TYPE_END];
Dan Williamsbec08512009-01-06 11:38:14 -0700305
306static int __init dma_channel_table_init(void)
307{
308 enum dma_transaction_type cap;
309 int err = 0;
310
311 bitmap_fill(dma_cap_mask_all.bits, DMA_TX_TYPE_END);
312
Dan Williams59b5ec22009-01-06 11:38:15 -0700313 /* 'interrupt', 'private', and 'slave' are channel capabilities,
314 * but are not associated with an operation so they do not need
315 * an entry in the channel_table
Dan Williamsbec08512009-01-06 11:38:14 -0700316 */
317 clear_bit(DMA_INTERRUPT, dma_cap_mask_all.bits);
Dan Williams59b5ec22009-01-06 11:38:15 -0700318 clear_bit(DMA_PRIVATE, dma_cap_mask_all.bits);
Dan Williamsbec08512009-01-06 11:38:14 -0700319 clear_bit(DMA_SLAVE, dma_cap_mask_all.bits);
320
321 for_each_dma_cap_mask(cap, dma_cap_mask_all) {
322 channel_table[cap] = alloc_percpu(struct dma_chan_tbl_ent);
323 if (!channel_table[cap]) {
324 err = -ENOMEM;
325 break;
326 }
327 }
328
329 if (err) {
Joe Perches63433252012-07-18 09:51:28 -0700330 pr_err("initialization failure\n");
Dan Williamsbec08512009-01-06 11:38:14 -0700331 for_each_dma_cap_mask(cap, dma_cap_mask_all)
332 if (channel_table[cap])
333 free_percpu(channel_table[cap]);
334 }
335
336 return err;
337}
Dan Williams652afc22009-01-06 11:38:22 -0700338arch_initcall(dma_channel_table_init);
Dan Williamsbec08512009-01-06 11:38:14 -0700339
340/**
341 * dma_find_channel - find a channel to carry out the operation
342 * @tx_type: transaction type
343 */
344struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type)
345{
Christoph Lametere7dcaa42009-10-03 19:48:23 +0900346 return this_cpu_read(channel_table[tx_type]->chan);
Dan Williamsbec08512009-01-06 11:38:14 -0700347}
348EXPORT_SYMBOL(dma_find_channel);
349
Dave Jianga2bd1142012-04-04 16:10:46 -0700350/*
351 * net_dma_find_channel - find a channel for net_dma
352 * net_dma has alignment requirements
353 */
354struct dma_chan *net_dma_find_channel(void)
355{
356 struct dma_chan *chan = dma_find_channel(DMA_MEMCPY);
357 if (chan && !is_dma_copy_aligned(chan->device, 1, 1, 1))
358 return NULL;
359
360 return chan;
361}
362EXPORT_SYMBOL(net_dma_find_channel);
363
Dan Williamsbec08512009-01-06 11:38:14 -0700364/**
Dan Williams2ba05622009-01-06 11:38:14 -0700365 * dma_issue_pending_all - flush all pending operations across all channels
366 */
367void dma_issue_pending_all(void)
368{
369 struct dma_device *device;
370 struct dma_chan *chan;
371
Dan Williams2ba05622009-01-06 11:38:14 -0700372 rcu_read_lock();
Dan Williams59b5ec22009-01-06 11:38:15 -0700373 list_for_each_entry_rcu(device, &dma_device_list, global_node) {
374 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
375 continue;
Dan Williams2ba05622009-01-06 11:38:14 -0700376 list_for_each_entry(chan, &device->channels, device_node)
377 if (chan->client_count)
378 device->device_issue_pending(chan);
Dan Williams59b5ec22009-01-06 11:38:15 -0700379 }
Dan Williams2ba05622009-01-06 11:38:14 -0700380 rcu_read_unlock();
381}
382EXPORT_SYMBOL(dma_issue_pending_all);
383
384/**
Brice Goglinc4d27c42013-08-19 11:43:35 +0200385 * dma_chan_is_local - returns true if the channel is in the same numa-node as the cpu
Dan Williamsbec08512009-01-06 11:38:14 -0700386 */
Brice Goglinc4d27c42013-08-19 11:43:35 +0200387static bool dma_chan_is_local(struct dma_chan *chan, int cpu)
388{
389 int node = dev_to_node(chan->device->dev);
390 return node == -1 || cpumask_test_cpu(cpu, cpumask_of_node(node));
391}
392
393/**
394 * min_chan - returns the channel with min count and in the same numa-node as the cpu
395 * @cap: capability to match
396 * @cpu: cpu index which the channel should be close to
397 *
398 * If some channels are close to the given cpu, the one with the lowest
399 * reference count is returned. Otherwise, cpu is ignored and only the
400 * reference count is taken into account.
401 * Must be called under dma_list_mutex.
402 */
403static struct dma_chan *min_chan(enum dma_transaction_type cap, int cpu)
Dan Williamsbec08512009-01-06 11:38:14 -0700404{
405 struct dma_device *device;
406 struct dma_chan *chan;
Dan Williamsbec08512009-01-06 11:38:14 -0700407 struct dma_chan *min = NULL;
Brice Goglinc4d27c42013-08-19 11:43:35 +0200408 struct dma_chan *localmin = NULL;
Dan Williamsbec08512009-01-06 11:38:14 -0700409
410 list_for_each_entry(device, &dma_device_list, global_node) {
Dan Williams59b5ec22009-01-06 11:38:15 -0700411 if (!dma_has_cap(cap, device->cap_mask) ||
412 dma_has_cap(DMA_PRIVATE, device->cap_mask))
Dan Williamsbec08512009-01-06 11:38:14 -0700413 continue;
414 list_for_each_entry(chan, &device->channels, device_node) {
415 if (!chan->client_count)
416 continue;
Brice Goglinc4d27c42013-08-19 11:43:35 +0200417 if (!min || chan->table_count < min->table_count)
Dan Williamsbec08512009-01-06 11:38:14 -0700418 min = chan;
419
Brice Goglinc4d27c42013-08-19 11:43:35 +0200420 if (dma_chan_is_local(chan, cpu))
421 if (!localmin ||
422 chan->table_count < localmin->table_count)
423 localmin = chan;
Dan Williamsbec08512009-01-06 11:38:14 -0700424 }
Dan Williamsbec08512009-01-06 11:38:14 -0700425 }
426
Brice Goglinc4d27c42013-08-19 11:43:35 +0200427 chan = localmin ? localmin : min;
Dan Williamsbec08512009-01-06 11:38:14 -0700428
Brice Goglinc4d27c42013-08-19 11:43:35 +0200429 if (chan)
430 chan->table_count++;
Dan Williamsbec08512009-01-06 11:38:14 -0700431
Brice Goglinc4d27c42013-08-19 11:43:35 +0200432 return chan;
Dan Williamsbec08512009-01-06 11:38:14 -0700433}
434
435/**
436 * dma_channel_rebalance - redistribute the available channels
437 *
438 * Optimize for cpu isolation (each cpu gets a dedicated channel for an
439 * operation type) in the SMP case, and operation isolation (avoid
440 * multi-tasking channels) in the non-SMP case. Must be called under
441 * dma_list_mutex.
442 */
443static void dma_channel_rebalance(void)
444{
445 struct dma_chan *chan;
446 struct dma_device *device;
447 int cpu;
448 int cap;
Dan Williamsbec08512009-01-06 11:38:14 -0700449
450 /* undo the last distribution */
451 for_each_dma_cap_mask(cap, dma_cap_mask_all)
452 for_each_possible_cpu(cpu)
453 per_cpu_ptr(channel_table[cap], cpu)->chan = NULL;
454
Dan Williams59b5ec22009-01-06 11:38:15 -0700455 list_for_each_entry(device, &dma_device_list, global_node) {
456 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
457 continue;
Dan Williamsbec08512009-01-06 11:38:14 -0700458 list_for_each_entry(chan, &device->channels, device_node)
459 chan->table_count = 0;
Dan Williams59b5ec22009-01-06 11:38:15 -0700460 }
Dan Williamsbec08512009-01-06 11:38:14 -0700461
462 /* don't populate the channel_table if no clients are available */
463 if (!dmaengine_ref_count)
464 return;
465
466 /* redistribute available channels */
Dan Williamsbec08512009-01-06 11:38:14 -0700467 for_each_dma_cap_mask(cap, dma_cap_mask_all)
468 for_each_online_cpu(cpu) {
Brice Goglinc4d27c42013-08-19 11:43:35 +0200469 chan = min_chan(cap, cpu);
Dan Williamsbec08512009-01-06 11:38:14 -0700470 per_cpu_ptr(channel_table[cap], cpu)->chan = chan;
471 }
472}
473
Lars-Peter Clausena53e28d2013-03-25 13:23:52 +0100474static struct dma_chan *private_candidate(const dma_cap_mask_t *mask,
475 struct dma_device *dev,
Dan Williamse2346672009-01-06 11:38:21 -0700476 dma_filter_fn fn, void *fn_param)
Dan Williams59b5ec22009-01-06 11:38:15 -0700477{
478 struct dma_chan *chan;
Dan Williams59b5ec22009-01-06 11:38:15 -0700479
480 if (!__dma_device_satisfies_mask(dev, mask)) {
481 pr_debug("%s: wrong capabilities\n", __func__);
482 return NULL;
483 }
484 /* devices with multiple channels need special handling as we need to
485 * ensure that all channels are either private or public.
486 */
487 if (dev->chancnt > 1 && !dma_has_cap(DMA_PRIVATE, dev->cap_mask))
488 list_for_each_entry(chan, &dev->channels, device_node) {
489 /* some channels are already publicly allocated */
490 if (chan->client_count)
491 return NULL;
492 }
493
494 list_for_each_entry(chan, &dev->channels, device_node) {
495 if (chan->client_count) {
496 pr_debug("%s: %s busy\n",
Dan Williams41d5e592009-01-06 11:38:21 -0700497 __func__, dma_chan_name(chan));
Dan Williams59b5ec22009-01-06 11:38:15 -0700498 continue;
499 }
Dan Williamse2346672009-01-06 11:38:21 -0700500 if (fn && !fn(chan, fn_param)) {
501 pr_debug("%s: %s filter said false\n",
502 __func__, dma_chan_name(chan));
503 continue;
504 }
505 return chan;
Dan Williams59b5ec22009-01-06 11:38:15 -0700506 }
507
Dan Williamse2346672009-01-06 11:38:21 -0700508 return NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700509}
510
511/**
Daniel Mack6b9019a2013-08-14 18:35:03 +0200512 * dma_request_slave_channel - try to get specific channel exclusively
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800513 * @chan: target channel
514 */
515struct dma_chan *dma_get_slave_channel(struct dma_chan *chan)
516{
517 int err = -EBUSY;
518
519 /* lock against __dma_request_channel */
520 mutex_lock(&dma_list_mutex);
521
Vinod Kould9a6c8f2013-08-19 10:47:26 +0530522 if (chan->client_count == 0) {
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800523 err = dma_chan_get(chan);
Vinod Kould9a6c8f2013-08-19 10:47:26 +0530524 if (err)
525 pr_debug("%s: failed to get %s: (%d)\n",
526 __func__, dma_chan_name(chan), err);
527 } else
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800528 chan = NULL;
529
530 mutex_unlock(&dma_list_mutex);
531
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800532
533 return chan;
534}
535EXPORT_SYMBOL_GPL(dma_get_slave_channel);
536
537/**
Daniel Mack6b9019a2013-08-14 18:35:03 +0200538 * __dma_request_channel - try to allocate an exclusive channel
Dan Williams59b5ec22009-01-06 11:38:15 -0700539 * @mask: capabilities that the channel must satisfy
540 * @fn: optional callback to disposition available channels
541 * @fn_param: opaque parameter to pass to dma_filter_fn
542 */
Lars-Peter Clausena53e28d2013-03-25 13:23:52 +0100543struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
544 dma_filter_fn fn, void *fn_param)
Dan Williams59b5ec22009-01-06 11:38:15 -0700545{
546 struct dma_device *device, *_d;
547 struct dma_chan *chan = NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700548 int err;
549
550 /* Find a channel */
551 mutex_lock(&dma_list_mutex);
552 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
Dan Williamse2346672009-01-06 11:38:21 -0700553 chan = private_candidate(mask, device, fn, fn_param);
554 if (chan) {
Dan Williams59b5ec22009-01-06 11:38:15 -0700555 /* Found a suitable channel, try to grab, prep, and
556 * return it. We first set DMA_PRIVATE to disable
557 * balance_ref_count as this channel will not be
558 * published in the general-purpose allocator
559 */
560 dma_cap_set(DMA_PRIVATE, device->cap_mask);
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900561 device->privatecnt++;
Dan Williams59b5ec22009-01-06 11:38:15 -0700562 err = dma_chan_get(chan);
563
564 if (err == -ENODEV) {
Joe Perches63433252012-07-18 09:51:28 -0700565 pr_debug("%s: %s module removed\n",
566 __func__, dma_chan_name(chan));
Dan Williams59b5ec22009-01-06 11:38:15 -0700567 list_del_rcu(&device->global_node);
568 } else if (err)
Fabio Estevamd8b53482012-02-21 12:51:59 -0200569 pr_debug("%s: failed to get %s: (%d)\n",
Joe Perches63433252012-07-18 09:51:28 -0700570 __func__, dma_chan_name(chan), err);
Dan Williams59b5ec22009-01-06 11:38:15 -0700571 else
572 break;
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900573 if (--device->privatecnt == 0)
574 dma_cap_clear(DMA_PRIVATE, device->cap_mask);
Dan Williamse2346672009-01-06 11:38:21 -0700575 chan = NULL;
576 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700577 }
578 mutex_unlock(&dma_list_mutex);
579
Joe Perches63433252012-07-18 09:51:28 -0700580 pr_debug("%s: %s (%s)\n",
581 __func__,
582 chan ? "success" : "fail",
Dan Williams41d5e592009-01-06 11:38:21 -0700583 chan ? dma_chan_name(chan) : NULL);
Dan Williams59b5ec22009-01-06 11:38:15 -0700584
585 return chan;
586}
587EXPORT_SYMBOL_GPL(__dma_request_channel);
588
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500589/**
590 * dma_request_slave_channel - try to allocate an exclusive slave channel
591 * @dev: pointer to client device structure
592 * @name: slave channel name
593 */
Markus Pargmannbef29ec2013-02-24 16:36:09 +0100594struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name)
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500595{
596 /* If device-tree is present get slave info from here */
597 if (dev->of_node)
598 return of_dma_request_slave_channel(dev->of_node, name);
599
Andy Shevchenko4e82f5d2013-04-09 14:05:44 +0300600 /* If device was enumerated by ACPI get slave info from here */
601 if (ACPI_HANDLE(dev))
602 return acpi_dma_request_slave_chan_by_name(dev, name);
603
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500604 return NULL;
605}
606EXPORT_SYMBOL_GPL(dma_request_slave_channel);
607
Dan Williams59b5ec22009-01-06 11:38:15 -0700608void dma_release_channel(struct dma_chan *chan)
609{
610 mutex_lock(&dma_list_mutex);
611 WARN_ONCE(chan->client_count != 1,
612 "chan reference count %d != 1\n", chan->client_count);
613 dma_chan_put(chan);
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900614 /* drop PRIVATE cap enabled by __dma_request_channel() */
615 if (--chan->device->privatecnt == 0)
616 dma_cap_clear(DMA_PRIVATE, chan->device->cap_mask);
Dan Williams59b5ec22009-01-06 11:38:15 -0700617 mutex_unlock(&dma_list_mutex);
618}
619EXPORT_SYMBOL_GPL(dma_release_channel);
620
Dan Williamsbec08512009-01-06 11:38:14 -0700621/**
Dan Williams209b84a2009-01-06 11:38:17 -0700622 * dmaengine_get - register interest in dma_channels
Chris Leechc13c8262006-05-23 17:18:44 -0700623 */
Dan Williams209b84a2009-01-06 11:38:17 -0700624void dmaengine_get(void)
Chris Leechc13c8262006-05-23 17:18:44 -0700625{
Dan Williams6f49a572009-01-06 11:38:14 -0700626 struct dma_device *device, *_d;
627 struct dma_chan *chan;
628 int err;
629
Chris Leechc13c8262006-05-23 17:18:44 -0700630 mutex_lock(&dma_list_mutex);
Dan Williams6f49a572009-01-06 11:38:14 -0700631 dmaengine_ref_count++;
632
633 /* try to grab channels */
Dan Williams59b5ec22009-01-06 11:38:15 -0700634 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
635 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
636 continue;
Dan Williams6f49a572009-01-06 11:38:14 -0700637 list_for_each_entry(chan, &device->channels, device_node) {
638 err = dma_chan_get(chan);
639 if (err == -ENODEV) {
640 /* module removed before we could use it */
Dan Williams2ba05622009-01-06 11:38:14 -0700641 list_del_rcu(&device->global_node);
Dan Williams6f49a572009-01-06 11:38:14 -0700642 break;
643 } else if (err)
Fabio Estevam0eb5a352012-10-04 17:11:16 -0700644 pr_debug("%s: failed to get %s: (%d)\n",
Joe Perches63433252012-07-18 09:51:28 -0700645 __func__, dma_chan_name(chan), err);
Dan Williams6f49a572009-01-06 11:38:14 -0700646 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700647 }
Dan Williams6f49a572009-01-06 11:38:14 -0700648
Dan Williamsbec08512009-01-06 11:38:14 -0700649 /* if this is the first reference and there were channels
650 * waiting we need to rebalance to get those channels
651 * incorporated into the channel table
652 */
653 if (dmaengine_ref_count == 1)
654 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -0700655 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700656}
Dan Williams209b84a2009-01-06 11:38:17 -0700657EXPORT_SYMBOL(dmaengine_get);
Chris Leechc13c8262006-05-23 17:18:44 -0700658
659/**
Dan Williams209b84a2009-01-06 11:38:17 -0700660 * dmaengine_put - let dma drivers be removed when ref_count == 0
Chris Leechc13c8262006-05-23 17:18:44 -0700661 */
Dan Williams209b84a2009-01-06 11:38:17 -0700662void dmaengine_put(void)
Chris Leechc13c8262006-05-23 17:18:44 -0700663{
Dan Williamsd379b012007-07-09 11:56:42 -0700664 struct dma_device *device;
Chris Leechc13c8262006-05-23 17:18:44 -0700665 struct dma_chan *chan;
666
Chris Leechc13c8262006-05-23 17:18:44 -0700667 mutex_lock(&dma_list_mutex);
Dan Williams6f49a572009-01-06 11:38:14 -0700668 dmaengine_ref_count--;
669 BUG_ON(dmaengine_ref_count < 0);
670 /* drop channel references */
Dan Williams59b5ec22009-01-06 11:38:15 -0700671 list_for_each_entry(device, &dma_device_list, global_node) {
672 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
673 continue;
Dan Williams6f49a572009-01-06 11:38:14 -0700674 list_for_each_entry(chan, &device->channels, device_node)
675 dma_chan_put(chan);
Dan Williams59b5ec22009-01-06 11:38:15 -0700676 }
Chris Leechc13c8262006-05-23 17:18:44 -0700677 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700678}
Dan Williams209b84a2009-01-06 11:38:17 -0700679EXPORT_SYMBOL(dmaengine_put);
Chris Leechc13c8262006-05-23 17:18:44 -0700680
Dan Williams138f4c32009-09-08 17:42:51 -0700681static bool device_has_all_tx_types(struct dma_device *device)
682{
683 /* A device that satisfies this test has channels that will never cause
684 * an async_tx channel switch event as all possible operation types can
685 * be handled.
686 */
687 #ifdef CONFIG_ASYNC_TX_DMA
688 if (!dma_has_cap(DMA_INTERRUPT, device->cap_mask))
689 return false;
690 #endif
691
692 #if defined(CONFIG_ASYNC_MEMCPY) || defined(CONFIG_ASYNC_MEMCPY_MODULE)
693 if (!dma_has_cap(DMA_MEMCPY, device->cap_mask))
694 return false;
695 #endif
696
Dan Williams138f4c32009-09-08 17:42:51 -0700697 #if defined(CONFIG_ASYNC_XOR) || defined(CONFIG_ASYNC_XOR_MODULE)
698 if (!dma_has_cap(DMA_XOR, device->cap_mask))
699 return false;
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700700
701 #ifndef CONFIG_ASYNC_TX_DISABLE_XOR_VAL_DMA
Dan Williams4499a242009-11-19 17:10:25 -0700702 if (!dma_has_cap(DMA_XOR_VAL, device->cap_mask))
703 return false;
Dan Williams138f4c32009-09-08 17:42:51 -0700704 #endif
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700705 #endif
Dan Williams138f4c32009-09-08 17:42:51 -0700706
707 #if defined(CONFIG_ASYNC_PQ) || defined(CONFIG_ASYNC_PQ_MODULE)
708 if (!dma_has_cap(DMA_PQ, device->cap_mask))
709 return false;
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700710
711 #ifndef CONFIG_ASYNC_TX_DISABLE_PQ_VAL_DMA
Dan Williams4499a242009-11-19 17:10:25 -0700712 if (!dma_has_cap(DMA_PQ_VAL, device->cap_mask))
713 return false;
Dan Williams138f4c32009-09-08 17:42:51 -0700714 #endif
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700715 #endif
Dan Williams138f4c32009-09-08 17:42:51 -0700716
717 return true;
718}
719
Dan Williams257b17c2009-03-25 09:13:23 -0700720static int get_dma_id(struct dma_device *device)
721{
722 int rc;
723
Dan Williams257b17c2009-03-25 09:13:23 -0700724 mutex_lock(&dma_list_mutex);
Dan Williams257b17c2009-03-25 09:13:23 -0700725
Tejun Heo69ee2662013-02-27 17:04:03 -0800726 rc = idr_alloc(&dma_idr, NULL, 0, 0, GFP_KERNEL);
727 if (rc >= 0)
728 device->dev_id = rc;
729
730 mutex_unlock(&dma_list_mutex);
731 return rc < 0 ? rc : 0;
Dan Williams257b17c2009-03-25 09:13:23 -0700732}
733
Chris Leechc13c8262006-05-23 17:18:44 -0700734/**
Randy Dunlap65088712006-07-03 19:45:31 -0700735 * dma_async_device_register - registers DMA devices found
Chris Leechc13c8262006-05-23 17:18:44 -0700736 * @device: &dma_device
737 */
738int dma_async_device_register(struct dma_device *device)
739{
Jeff Garzikff487fb2007-03-08 09:57:34 -0800740 int chancnt = 0, rc;
Chris Leechc13c8262006-05-23 17:18:44 -0700741 struct dma_chan* chan;
Dan Williams864498a2009-01-06 11:38:21 -0700742 atomic_t *idr_ref;
Chris Leechc13c8262006-05-23 17:18:44 -0700743
744 if (!device)
745 return -ENODEV;
746
Dan Williams7405f742007-01-02 11:10:43 -0700747 /* validate device routines */
748 BUG_ON(dma_has_cap(DMA_MEMCPY, device->cap_mask) &&
749 !device->device_prep_dma_memcpy);
750 BUG_ON(dma_has_cap(DMA_XOR, device->cap_mask) &&
751 !device->device_prep_dma_xor);
Dan Williams099f53c2009-04-08 14:28:37 -0700752 BUG_ON(dma_has_cap(DMA_XOR_VAL, device->cap_mask) &&
753 !device->device_prep_dma_xor_val);
Dan Williamsb2f46fd2009-07-14 12:20:36 -0700754 BUG_ON(dma_has_cap(DMA_PQ, device->cap_mask) &&
755 !device->device_prep_dma_pq);
756 BUG_ON(dma_has_cap(DMA_PQ_VAL, device->cap_mask) &&
757 !device->device_prep_dma_pq_val);
Zhang Wei9b941c62008-03-13 17:45:28 -0700758 BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) &&
Dan Williams7405f742007-01-02 11:10:43 -0700759 !device->device_prep_dma_interrupt);
Ira Snydera86ee032010-09-30 11:46:44 +0000760 BUG_ON(dma_has_cap(DMA_SG, device->cap_mask) &&
761 !device->device_prep_dma_sg);
Sascha Hauer782bc952010-09-30 13:56:32 +0000762 BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
763 !device->device_prep_dma_cyclic);
Haavard Skinnemoendc0ee6432008-07-08 11:59:35 -0700764 BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
Linus Walleijc3635c72010-03-26 16:44:01 -0700765 !device->device_control);
Jassi Brarb14dab72011-10-13 12:33:30 +0530766 BUG_ON(dma_has_cap(DMA_INTERLEAVE, device->cap_mask) &&
767 !device->device_prep_interleaved_dma);
Dan Williams7405f742007-01-02 11:10:43 -0700768
769 BUG_ON(!device->device_alloc_chan_resources);
770 BUG_ON(!device->device_free_chan_resources);
Linus Walleij07934482010-03-26 16:50:49 -0700771 BUG_ON(!device->device_tx_status);
Dan Williams7405f742007-01-02 11:10:43 -0700772 BUG_ON(!device->device_issue_pending);
773 BUG_ON(!device->dev);
774
Dan Williams138f4c32009-09-08 17:42:51 -0700775 /* note: this only matters in the
Dan Williams5fc6d892010-10-07 16:44:50 -0700776 * CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH=n case
Dan Williams138f4c32009-09-08 17:42:51 -0700777 */
778 if (device_has_all_tx_types(device))
779 dma_cap_set(DMA_ASYNC_TX, device->cap_mask);
780
Dan Williams864498a2009-01-06 11:38:21 -0700781 idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL);
782 if (!idr_ref)
783 return -ENOMEM;
Dan Williams257b17c2009-03-25 09:13:23 -0700784 rc = get_dma_id(device);
785 if (rc != 0) {
786 kfree(idr_ref);
Dan Williams864498a2009-01-06 11:38:21 -0700787 return rc;
Dan Williams257b17c2009-03-25 09:13:23 -0700788 }
789
790 atomic_set(idr_ref, 0);
Chris Leechc13c8262006-05-23 17:18:44 -0700791
792 /* represent channels in sysfs. Probably want devs too */
793 list_for_each_entry(chan, &device->channels, device_node) {
Dan Williams257b17c2009-03-25 09:13:23 -0700794 rc = -ENOMEM;
Chris Leechc13c8262006-05-23 17:18:44 -0700795 chan->local = alloc_percpu(typeof(*chan->local));
796 if (chan->local == NULL)
Dan Williams257b17c2009-03-25 09:13:23 -0700797 goto err_out;
Dan Williams41d5e592009-01-06 11:38:21 -0700798 chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL);
799 if (chan->dev == NULL) {
800 free_percpu(chan->local);
Dan Williams257b17c2009-03-25 09:13:23 -0700801 chan->local = NULL;
802 goto err_out;
Dan Williams41d5e592009-01-06 11:38:21 -0700803 }
Chris Leechc13c8262006-05-23 17:18:44 -0700804
805 chan->chan_id = chancnt++;
Dan Williams41d5e592009-01-06 11:38:21 -0700806 chan->dev->device.class = &dma_devclass;
807 chan->dev->device.parent = device->dev;
808 chan->dev->chan = chan;
Dan Williams864498a2009-01-06 11:38:21 -0700809 chan->dev->idr_ref = idr_ref;
810 chan->dev->dev_id = device->dev_id;
811 atomic_inc(idr_ref);
Dan Williams41d5e592009-01-06 11:38:21 -0700812 dev_set_name(&chan->dev->device, "dma%dchan%d",
Kay Sievers06190d82008-11-11 13:12:33 -0700813 device->dev_id, chan->chan_id);
Chris Leechc13c8262006-05-23 17:18:44 -0700814
Dan Williams41d5e592009-01-06 11:38:21 -0700815 rc = device_register(&chan->dev->device);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800816 if (rc) {
Jeff Garzikff487fb2007-03-08 09:57:34 -0800817 free_percpu(chan->local);
818 chan->local = NULL;
Dan Williams257b17c2009-03-25 09:13:23 -0700819 kfree(chan->dev);
820 atomic_dec(idr_ref);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800821 goto err_out;
822 }
Dan Williams7cc5bf92008-07-08 11:58:21 -0700823 chan->client_count = 0;
Chris Leechc13c8262006-05-23 17:18:44 -0700824 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700825 device->chancnt = chancnt;
Chris Leechc13c8262006-05-23 17:18:44 -0700826
827 mutex_lock(&dma_list_mutex);
Dan Williams59b5ec22009-01-06 11:38:15 -0700828 /* take references on public channels */
829 if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask))
Dan Williams6f49a572009-01-06 11:38:14 -0700830 list_for_each_entry(chan, &device->channels, device_node) {
831 /* if clients are already waiting for channels we need
832 * to take references on their behalf
833 */
834 if (dma_chan_get(chan) == -ENODEV) {
835 /* note we can only get here for the first
836 * channel as the remaining channels are
837 * guaranteed to get a reference
838 */
839 rc = -ENODEV;
840 mutex_unlock(&dma_list_mutex);
841 goto err_out;
842 }
843 }
Dan Williams2ba05622009-01-06 11:38:14 -0700844 list_add_tail_rcu(&device->global_node, &dma_device_list);
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900845 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
846 device->privatecnt++; /* Always private */
Dan Williamsbec08512009-01-06 11:38:14 -0700847 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -0700848 mutex_unlock(&dma_list_mutex);
849
Chris Leechc13c8262006-05-23 17:18:44 -0700850 return 0;
Jeff Garzikff487fb2007-03-08 09:57:34 -0800851
852err_out:
Dan Williams257b17c2009-03-25 09:13:23 -0700853 /* if we never registered a channel just release the idr */
854 if (atomic_read(idr_ref) == 0) {
855 mutex_lock(&dma_list_mutex);
856 idr_remove(&dma_idr, device->dev_id);
857 mutex_unlock(&dma_list_mutex);
858 kfree(idr_ref);
859 return rc;
860 }
861
Jeff Garzikff487fb2007-03-08 09:57:34 -0800862 list_for_each_entry(chan, &device->channels, device_node) {
863 if (chan->local == NULL)
864 continue;
Dan Williams41d5e592009-01-06 11:38:21 -0700865 mutex_lock(&dma_list_mutex);
866 chan->dev->chan = NULL;
867 mutex_unlock(&dma_list_mutex);
868 device_unregister(&chan->dev->device);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800869 free_percpu(chan->local);
870 }
871 return rc;
Chris Leechc13c8262006-05-23 17:18:44 -0700872}
David Brownell765e3d82007-03-16 13:38:05 -0800873EXPORT_SYMBOL(dma_async_device_register);
Chris Leechc13c8262006-05-23 17:18:44 -0700874
875/**
Dan Williams6f49a572009-01-06 11:38:14 -0700876 * dma_async_device_unregister - unregister a DMA device
Randy Dunlap65088712006-07-03 19:45:31 -0700877 * @device: &dma_device
Dan Williamsf27c5802009-01-06 11:38:18 -0700878 *
879 * This routine is called by dma driver exit routines, dmaengine holds module
880 * references to prevent it being called while channels are in use.
Randy Dunlap65088712006-07-03 19:45:31 -0700881 */
882void dma_async_device_unregister(struct dma_device *device)
Chris Leechc13c8262006-05-23 17:18:44 -0700883{
884 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -0700885
886 mutex_lock(&dma_list_mutex);
Dan Williams2ba05622009-01-06 11:38:14 -0700887 list_del_rcu(&device->global_node);
Dan Williamsbec08512009-01-06 11:38:14 -0700888 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -0700889 mutex_unlock(&dma_list_mutex);
890
891 list_for_each_entry(chan, &device->channels, device_node) {
Dan Williams6f49a572009-01-06 11:38:14 -0700892 WARN_ONCE(chan->client_count,
893 "%s called while %d clients hold a reference\n",
894 __func__, chan->client_count);
Dan Williams41d5e592009-01-06 11:38:21 -0700895 mutex_lock(&dma_list_mutex);
896 chan->dev->chan = NULL;
897 mutex_unlock(&dma_list_mutex);
898 device_unregister(&chan->dev->device);
Anatolij Gustschinadef4772010-01-26 10:26:06 +0100899 free_percpu(chan->local);
Chris Leechc13c8262006-05-23 17:18:44 -0700900 }
Chris Leechc13c8262006-05-23 17:18:44 -0700901}
David Brownell765e3d82007-03-16 13:38:05 -0800902EXPORT_SYMBOL(dma_async_device_unregister);
Chris Leechc13c8262006-05-23 17:18:44 -0700903
Dan Williams7405f742007-01-02 11:10:43 -0700904/**
905 * dma_async_memcpy_buf_to_buf - offloaded copy between virtual addresses
906 * @chan: DMA channel to offload copy to
907 * @dest: destination address (virtual)
908 * @src: source address (virtual)
909 * @len: length
910 *
911 * Both @dest and @src must be mappable to a bus address according to the
912 * DMA mapping API rules for streaming mappings.
913 * Both @dest and @src must stay memory resident (kernel memory or locked
914 * user space pages).
915 */
916dma_cookie_t
917dma_async_memcpy_buf_to_buf(struct dma_chan *chan, void *dest,
918 void *src, 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, src, len, DMA_TO_DEVICE);
927 dma_dest = dma_map_single(dev->dev, dest, len, DMA_FROM_DEVICE);
Maciej Sosnowski4f005db2009-04-23 12:31:51 +0200928 flags = DMA_CTRL_ACK |
929 DMA_COMPL_SRC_UNMAP_SINGLE |
930 DMA_COMPL_DEST_UNMAP_SINGLE;
931 tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags);
Dan Williams00367312008-02-02 19:49:57 -0700932
933 if (!tx) {
934 dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE);
935 dma_unmap_single(dev->dev, dma_dest, len, DMA_FROM_DEVICE);
Dan Williams7405f742007-01-02 11:10:43 -0700936 return -ENOMEM;
Dan Williams00367312008-02-02 19:49:57 -0700937 }
Dan Williams7405f742007-01-02 11:10:43 -0700938
Dan Williams7405f742007-01-02 11:10:43 -0700939 tx->callback = NULL;
Dan Williams7405f742007-01-02 11:10:43 -0700940 cookie = tx->tx_submit(tx);
941
Christoph Lametere7dcaa42009-10-03 19:48:23 +0900942 preempt_disable();
943 __this_cpu_add(chan->local->bytes_transferred, len);
944 __this_cpu_inc(chan->local->memcpy_count);
945 preempt_enable();
Dan Williams7405f742007-01-02 11:10:43 -0700946
947 return cookie;
948}
949EXPORT_SYMBOL(dma_async_memcpy_buf_to_buf);
950
951/**
952 * dma_async_memcpy_buf_to_pg - offloaded copy from address to page
953 * @chan: DMA channel to offload copy to
954 * @page: destination page
955 * @offset: offset in page to copy to
956 * @kdata: source address (virtual)
957 * @len: length
958 *
959 * Both @page/@offset and @kdata must be mappable to a bus address according
960 * to the DMA mapping API rules for streaming mappings.
961 * Both @page/@offset and @kdata must stay memory resident (kernel memory or
962 * locked user space pages)
963 */
964dma_cookie_t
965dma_async_memcpy_buf_to_pg(struct dma_chan *chan, struct page *page,
966 unsigned int offset, void *kdata, 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_single(dev->dev, kdata, len, DMA_TO_DEVICE);
975 dma_dest = dma_map_page(dev->dev, page, offset, len, DMA_FROM_DEVICE);
Maciej Sosnowski4f005db2009-04-23 12:31:51 +0200976 flags = DMA_CTRL_ACK | DMA_COMPL_SRC_UNMAP_SINGLE;
977 tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags);
Dan Williams00367312008-02-02 19:49:57 -0700978
979 if (!tx) {
980 dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE);
981 dma_unmap_page(dev->dev, dma_dest, len, DMA_FROM_DEVICE);
Dan Williams7405f742007-01-02 11:10:43 -0700982 return -ENOMEM;
Dan Williams00367312008-02-02 19:49:57 -0700983 }
Dan Williams7405f742007-01-02 11:10:43 -0700984
Dan Williams7405f742007-01-02 11:10:43 -0700985 tx->callback = NULL;
Dan Williams7405f742007-01-02 11:10:43 -0700986 cookie = tx->tx_submit(tx);
987
Christoph Lametere7dcaa42009-10-03 19:48:23 +0900988 preempt_disable();
989 __this_cpu_add(chan->local->bytes_transferred, len);
990 __this_cpu_inc(chan->local->memcpy_count);
991 preempt_enable();
Dan Williams7405f742007-01-02 11:10:43 -0700992
993 return cookie;
994}
995EXPORT_SYMBOL(dma_async_memcpy_buf_to_pg);
996
997/**
998 * dma_async_memcpy_pg_to_pg - offloaded copy from page to page
999 * @chan: DMA channel to offload copy to
1000 * @dest_pg: destination page
1001 * @dest_off: offset in page to copy to
1002 * @src_pg: source page
1003 * @src_off: offset in page to copy from
1004 * @len: length
1005 *
1006 * Both @dest_page/@dest_off and @src_page/@src_off must be mappable to a bus
1007 * address according to the DMA mapping API rules for streaming mappings.
1008 * Both @dest_page/@dest_off and @src_page/@src_off must stay memory resident
1009 * (kernel memory or locked user space pages).
1010 */
1011dma_cookie_t
1012dma_async_memcpy_pg_to_pg(struct dma_chan *chan, struct page *dest_pg,
1013 unsigned int dest_off, struct page *src_pg, unsigned int src_off,
1014 size_t len)
1015{
1016 struct dma_device *dev = chan->device;
1017 struct dma_async_tx_descriptor *tx;
Dan Williams00367312008-02-02 19:49:57 -07001018 dma_addr_t dma_dest, dma_src;
Dan Williams7405f742007-01-02 11:10:43 -07001019 dma_cookie_t cookie;
Maciej Sosnowski4f005db2009-04-23 12:31:51 +02001020 unsigned long flags;
Dan Williams7405f742007-01-02 11:10:43 -07001021
Dan Williams00367312008-02-02 19:49:57 -07001022 dma_src = dma_map_page(dev->dev, src_pg, src_off, len, DMA_TO_DEVICE);
1023 dma_dest = dma_map_page(dev->dev, dest_pg, dest_off, len,
1024 DMA_FROM_DEVICE);
Maciej Sosnowski4f005db2009-04-23 12:31:51 +02001025 flags = DMA_CTRL_ACK;
1026 tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags);
Dan Williams00367312008-02-02 19:49:57 -07001027
1028 if (!tx) {
1029 dma_unmap_page(dev->dev, dma_src, len, DMA_TO_DEVICE);
1030 dma_unmap_page(dev->dev, dma_dest, len, DMA_FROM_DEVICE);
Dan Williams7405f742007-01-02 11:10:43 -07001031 return -ENOMEM;
Dan Williams00367312008-02-02 19:49:57 -07001032 }
Dan Williams7405f742007-01-02 11:10:43 -07001033
Dan Williams7405f742007-01-02 11:10:43 -07001034 tx->callback = NULL;
Dan Williams7405f742007-01-02 11:10:43 -07001035 cookie = tx->tx_submit(tx);
1036
Christoph Lametere7dcaa42009-10-03 19:48:23 +09001037 preempt_disable();
1038 __this_cpu_add(chan->local->bytes_transferred, len);
1039 __this_cpu_inc(chan->local->memcpy_count);
1040 preempt_enable();
Dan Williams7405f742007-01-02 11:10:43 -07001041
1042 return cookie;
1043}
1044EXPORT_SYMBOL(dma_async_memcpy_pg_to_pg);
1045
1046void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
1047 struct dma_chan *chan)
1048{
1049 tx->chan = chan;
Dan Williams5fc6d892010-10-07 16:44:50 -07001050 #ifdef CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH
Dan Williams7405f742007-01-02 11:10:43 -07001051 spin_lock_init(&tx->lock);
Dan Williamscaa20d972010-05-17 16:24:16 -07001052 #endif
Dan Williams7405f742007-01-02 11:10:43 -07001053}
1054EXPORT_SYMBOL(dma_async_tx_descriptor_init);
1055
Dan Williams07f22112009-01-05 17:14:31 -07001056/* dma_wait_for_async_tx - spin wait for a transaction to complete
1057 * @tx: in-flight transaction to wait on
Dan Williams07f22112009-01-05 17:14:31 -07001058 */
1059enum dma_status
1060dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
1061{
Dan Williams95475e52009-07-14 12:19:02 -07001062 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
Dan Williams07f22112009-01-05 17:14:31 -07001063
1064 if (!tx)
1065 return DMA_SUCCESS;
1066
Dan Williams95475e52009-07-14 12:19:02 -07001067 while (tx->cookie == -EBUSY) {
1068 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
1069 pr_err("%s timeout waiting for descriptor submission\n",
Joe Perches63433252012-07-18 09:51:28 -07001070 __func__);
Dan Williams95475e52009-07-14 12:19:02 -07001071 return DMA_ERROR;
1072 }
1073 cpu_relax();
1074 }
1075 return dma_sync_wait(tx->chan, tx->cookie);
Dan Williams07f22112009-01-05 17:14:31 -07001076}
1077EXPORT_SYMBOL_GPL(dma_wait_for_async_tx);
1078
1079/* dma_run_dependencies - helper routine for dma drivers to process
1080 * (start) dependent operations on their target channel
1081 * @tx: transaction with dependencies
1082 */
1083void dma_run_dependencies(struct dma_async_tx_descriptor *tx)
1084{
Dan Williamscaa20d972010-05-17 16:24:16 -07001085 struct dma_async_tx_descriptor *dep = txd_next(tx);
Dan Williams07f22112009-01-05 17:14:31 -07001086 struct dma_async_tx_descriptor *dep_next;
1087 struct dma_chan *chan;
1088
1089 if (!dep)
1090 return;
1091
Yuri Tikhonovdd59b852009-01-12 15:17:20 -07001092 /* we'll submit tx->next now, so clear the link */
Dan Williamscaa20d972010-05-17 16:24:16 -07001093 txd_clear_next(tx);
Dan Williams07f22112009-01-05 17:14:31 -07001094 chan = dep->chan;
1095
1096 /* keep submitting up until a channel switch is detected
1097 * in that case we will be called again as a result of
1098 * processing the interrupt from async_tx_channel_switch
1099 */
1100 for (; dep; dep = dep_next) {
Dan Williamscaa20d972010-05-17 16:24:16 -07001101 txd_lock(dep);
1102 txd_clear_parent(dep);
1103 dep_next = txd_next(dep);
Dan Williams07f22112009-01-05 17:14:31 -07001104 if (dep_next && dep_next->chan == chan)
Dan Williamscaa20d972010-05-17 16:24:16 -07001105 txd_clear_next(dep); /* ->next will be submitted */
Dan Williams07f22112009-01-05 17:14:31 -07001106 else
1107 dep_next = NULL; /* submit current dep and terminate */
Dan Williamscaa20d972010-05-17 16:24:16 -07001108 txd_unlock(dep);
Dan Williams07f22112009-01-05 17:14:31 -07001109
1110 dep->tx_submit(dep);
1111 }
1112
1113 chan->device->device_issue_pending(chan);
1114}
1115EXPORT_SYMBOL_GPL(dma_run_dependencies);
1116
Chris Leechc13c8262006-05-23 17:18:44 -07001117static int __init dma_bus_init(void)
1118{
Chris Leechc13c8262006-05-23 17:18:44 -07001119 return class_register(&dma_devclass);
1120}
Dan Williams652afc22009-01-06 11:38:22 -07001121arch_initcall(dma_bus_init);
Chris Leechc13c8262006-05-23 17:18:44 -07001122
Dan Williamsbec08512009-01-06 11:38:14 -07001123