blob: f1a441ab395d7529ebbc4f8d59e891e20c61419d [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 *
Chris Leechc13c8262006-05-23 17:18:44 -070014 * The full GNU General Public License is included in this distribution in the
15 * file called COPYING.
16 */
17
18/*
19 * This code implements the DMA subsystem. It provides a HW-neutral interface
20 * for other kernel code to use asynchronous memory copy capabilities,
21 * if present, and allows different HW DMA drivers to register as providing
22 * this capability.
23 *
24 * Due to the fact we are accelerating what is already a relatively fast
25 * operation, the code goes to great lengths to avoid additional overhead,
26 * such as locking.
27 *
28 * LOCKING:
29 *
Dan Williamsaa1e6f12009-01-06 11:38:17 -070030 * The subsystem keeps a global list of dma_device structs it is protected by a
31 * mutex, dma_list_mutex.
Chris Leechc13c8262006-05-23 17:18:44 -070032 *
Dan Williamsf27c5802009-01-06 11:38:18 -070033 * A subsystem can get access to a channel by calling dmaengine_get() followed
34 * by dma_find_channel(), or if it has need for an exclusive channel it can call
35 * dma_request_channel(). Once a channel is allocated a reference is taken
36 * against its corresponding driver to disable removal.
37 *
Chris Leechc13c8262006-05-23 17:18:44 -070038 * Each device has a channels list, which runs unlocked but is never modified
39 * once the device is registered, it's just setup by the driver.
40 *
Mauro Carvalho Chehab44348e8a2018-06-14 12:34:32 -030041 * See Documentation/driver-api/dmaengine for more details
Chris Leechc13c8262006-05-23 17:18:44 -070042 */
43
Joe Perches63433252012-07-18 09:51:28 -070044#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
45
Peter Ujfalusia8135d02015-12-14 22:47:40 +020046#include <linux/platform_device.h>
Alexey Dobriyanb7f080c2011-06-16 11:01:34 +000047#include <linux/dma-mapping.h>
Chris Leechc13c8262006-05-23 17:18:44 -070048#include <linux/init.h>
49#include <linux/module.h>
Dan Williams7405f742007-01-02 11:10:43 -070050#include <linux/mm.h>
Chris Leechc13c8262006-05-23 17:18:44 -070051#include <linux/device.h>
52#include <linux/dmaengine.h>
53#include <linux/hardirq.h>
54#include <linux/spinlock.h>
55#include <linux/percpu.h>
56#include <linux/rcupdate.h>
57#include <linux/mutex.h>
Dan Williams7405f742007-01-02 11:10:43 -070058#include <linux/jiffies.h>
Dan Williams2ba05622009-01-06 11:38:14 -070059#include <linux/rculist.h>
Dan Williams864498a2009-01-06 11:38:21 -070060#include <linux/idr.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090061#include <linux/slab.h>
Andy Shevchenko4e82f5d2013-04-09 14:05:44 +030062#include <linux/acpi.h>
63#include <linux/acpi_dma.h>
Jon Hunter9a6cecc2012-09-14 17:41:57 -050064#include <linux/of_dma.h>
Dan Williams45c463a2013-10-18 19:35:24 +020065#include <linux/mempool.h>
Chris Leechc13c8262006-05-23 17:18:44 -070066
67static DEFINE_MUTEX(dma_list_mutex);
Matthew Wilcoxadc064c2016-12-15 08:57:51 -080068static DEFINE_IDA(dma_ida);
Chris Leechc13c8262006-05-23 17:18:44 -070069static LIST_HEAD(dma_device_list);
Dan Williams6f49a572009-01-06 11:38:14 -070070static long dmaengine_ref_count;
Chris Leechc13c8262006-05-23 17:18:44 -070071
72/* --- sysfs implementation --- */
73
Dan Williams41d5e592009-01-06 11:38:21 -070074/**
75 * dev_to_dma_chan - convert a device pointer to the its sysfs container object
76 * @dev - device node
77 *
78 * Must be called under dma_list_mutex
79 */
80static struct dma_chan *dev_to_dma_chan(struct device *dev)
81{
82 struct dma_chan_dev *chan_dev;
83
84 chan_dev = container_of(dev, typeof(*chan_dev), device);
85 return chan_dev->chan;
86}
87
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -070088static ssize_t memcpy_count_show(struct device *dev,
89 struct device_attribute *attr, char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -070090{
Dan Williams41d5e592009-01-06 11:38:21 -070091 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -070092 unsigned long count = 0;
93 int i;
Dan Williams41d5e592009-01-06 11:38:21 -070094 int err;
Chris Leechc13c8262006-05-23 17:18:44 -070095
Dan Williams41d5e592009-01-06 11:38:21 -070096 mutex_lock(&dma_list_mutex);
97 chan = dev_to_dma_chan(dev);
98 if (chan) {
99 for_each_possible_cpu(i)
100 count += per_cpu_ptr(chan->local, i)->memcpy_count;
101 err = sprintf(buf, "%lu\n", count);
102 } else
103 err = -ENODEV;
104 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700105
Dan Williams41d5e592009-01-06 11:38:21 -0700106 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700107}
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700108static DEVICE_ATTR_RO(memcpy_count);
Chris Leechc13c8262006-05-23 17:18:44 -0700109
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700110static ssize_t bytes_transferred_show(struct device *dev,
111 struct device_attribute *attr, char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -0700112{
Dan Williams41d5e592009-01-06 11:38:21 -0700113 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -0700114 unsigned long count = 0;
115 int i;
Dan Williams41d5e592009-01-06 11:38:21 -0700116 int err;
Chris Leechc13c8262006-05-23 17:18:44 -0700117
Dan Williams41d5e592009-01-06 11:38:21 -0700118 mutex_lock(&dma_list_mutex);
119 chan = dev_to_dma_chan(dev);
120 if (chan) {
121 for_each_possible_cpu(i)
122 count += per_cpu_ptr(chan->local, i)->bytes_transferred;
123 err = sprintf(buf, "%lu\n", count);
124 } else
125 err = -ENODEV;
126 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700127
Dan Williams41d5e592009-01-06 11:38:21 -0700128 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700129}
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700130static DEVICE_ATTR_RO(bytes_transferred);
Chris Leechc13c8262006-05-23 17:18:44 -0700131
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700132static ssize_t in_use_show(struct device *dev, struct device_attribute *attr,
133 char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -0700134{
Dan Williams41d5e592009-01-06 11:38:21 -0700135 struct dma_chan *chan;
136 int err;
Chris Leechc13c8262006-05-23 17:18:44 -0700137
Dan Williams41d5e592009-01-06 11:38:21 -0700138 mutex_lock(&dma_list_mutex);
139 chan = dev_to_dma_chan(dev);
140 if (chan)
141 err = sprintf(buf, "%d\n", chan->client_count);
142 else
143 err = -ENODEV;
144 mutex_unlock(&dma_list_mutex);
145
146 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700147}
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700148static DEVICE_ATTR_RO(in_use);
Chris Leechc13c8262006-05-23 17:18:44 -0700149
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700150static struct attribute *dma_dev_attrs[] = {
151 &dev_attr_memcpy_count.attr,
152 &dev_attr_bytes_transferred.attr,
153 &dev_attr_in_use.attr,
154 NULL,
Chris Leechc13c8262006-05-23 17:18:44 -0700155};
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700156ATTRIBUTE_GROUPS(dma_dev);
Chris Leechc13c8262006-05-23 17:18:44 -0700157
Dan Williams41d5e592009-01-06 11:38:21 -0700158static void chan_dev_release(struct device *dev)
159{
160 struct dma_chan_dev *chan_dev;
161
162 chan_dev = container_of(dev, typeof(*chan_dev), device);
Dan Williams864498a2009-01-06 11:38:21 -0700163 if (atomic_dec_and_test(chan_dev->idr_ref)) {
Matthew Wilcox485258b2018-06-18 15:41:48 -0400164 ida_free(&dma_ida, chan_dev->dev_id);
Dan Williams864498a2009-01-06 11:38:21 -0700165 kfree(chan_dev->idr_ref);
166 }
Dan Williams41d5e592009-01-06 11:38:21 -0700167 kfree(chan_dev);
168}
169
Chris Leechc13c8262006-05-23 17:18:44 -0700170static struct class dma_devclass = {
Tony Jones891f78e2007-09-25 02:03:03 +0200171 .name = "dma",
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700172 .dev_groups = dma_dev_groups,
Dan Williams41d5e592009-01-06 11:38:21 -0700173 .dev_release = chan_dev_release,
Chris Leechc13c8262006-05-23 17:18:44 -0700174};
175
176/* --- client and device registration --- */
177
Dan Williams59b5ec22009-01-06 11:38:15 -0700178#define dma_device_satisfies_mask(device, mask) \
179 __dma_device_satisfies_mask((device), &(mask))
Dan Williamsd379b012007-07-09 11:56:42 -0700180static int
Lars-Peter Clausena53e28d2013-03-25 13:23:52 +0100181__dma_device_satisfies_mask(struct dma_device *device,
182 const dma_cap_mask_t *want)
Dan Williamsd379b012007-07-09 11:56:42 -0700183{
184 dma_cap_mask_t has;
185
Dan Williams59b5ec22009-01-06 11:38:15 -0700186 bitmap_and(has.bits, want->bits, device->cap_mask.bits,
Dan Williamsd379b012007-07-09 11:56:42 -0700187 DMA_TX_TYPE_END);
188 return bitmap_equal(want->bits, has.bits, DMA_TX_TYPE_END);
189}
190
Dan Williams6f49a572009-01-06 11:38:14 -0700191static struct module *dma_chan_to_owner(struct dma_chan *chan)
192{
193 return chan->device->dev->driver->owner;
194}
195
196/**
197 * balance_ref_count - catch up the channel reference count
198 * @chan - channel to balance ->client_count versus dmaengine_ref_count
199 *
200 * balance_ref_count must be called under dma_list_mutex
201 */
202static void balance_ref_count(struct dma_chan *chan)
203{
204 struct module *owner = dma_chan_to_owner(chan);
205
206 while (chan->client_count < dmaengine_ref_count) {
207 __module_get(owner);
208 chan->client_count++;
209 }
210}
211
212/**
213 * dma_chan_get - try to grab a dma channel's parent driver module
214 * @chan - channel to grab
215 *
216 * Must be called under dma_list_mutex
217 */
218static int dma_chan_get(struct dma_chan *chan)
219{
Dan Williams6f49a572009-01-06 11:38:14 -0700220 struct module *owner = dma_chan_to_owner(chan);
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100221 int ret;
Dan Williams6f49a572009-01-06 11:38:14 -0700222
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100223 /* The channel is already in use, update client count */
Dan Williams6f49a572009-01-06 11:38:14 -0700224 if (chan->client_count) {
225 __module_get(owner);
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100226 goto out;
Dan Williams6f49a572009-01-06 11:38:14 -0700227 }
228
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100229 if (!try_module_get(owner))
230 return -ENODEV;
231
232 /* allocate upon first client reference */
Maxime Ripardc4b54a62014-11-17 14:41:59 +0100233 if (chan->device->device_alloc_chan_resources) {
234 ret = chan->device->device_alloc_chan_resources(chan);
235 if (ret < 0)
236 goto err_out;
237 }
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100238
239 if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
240 balance_ref_count(chan);
241
242out:
243 chan->client_count++;
244 return 0;
245
246err_out:
247 module_put(owner);
248 return ret;
Dan Williams6f49a572009-01-06 11:38:14 -0700249}
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{
Maxime Ripardc4b54a62014-11-17 14:41:59 +0100259 /* This channel is not in use, bail out */
Dan Williams6f49a572009-01-06 11:38:14 -0700260 if (!chan->client_count)
Maxime Ripardc4b54a62014-11-17 14:41:59 +0100261 return;
262
Dan Williams6f49a572009-01-06 11:38:14 -0700263 chan->client_count--;
264 module_put(dma_chan_to_owner(chan));
Maxime Ripardc4b54a62014-11-17 14:41:59 +0100265
266 /* This channel is not in use anymore, free it */
Lars-Peter Clausenb36f09c2015-10-20 11:46:28 +0200267 if (!chan->client_count && chan->device->device_free_chan_resources) {
268 /* Make sure all operations have completed */
269 dmaengine_synchronize(chan);
Dan Williams6f49a572009-01-06 11:38:14 -0700270 chan->device->device_free_chan_resources(chan);
Lars-Peter Clausenb36f09c2015-10-20 11:46:28 +0200271 }
Peter Ujfalusi56f13c02015-04-09 12:35:47 +0300272
273 /* If the channel is used via a DMA request router, free the mapping */
274 if (chan->router && chan->router->route_free) {
275 chan->router->route_free(chan->router->dev, chan->route_data);
276 chan->router = NULL;
277 chan->route_data = NULL;
278 }
Dan Williams6f49a572009-01-06 11:38:14 -0700279}
280
Dan Williams7405f742007-01-02 11:10:43 -0700281enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
282{
283 enum dma_status status;
284 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
285
286 dma_async_issue_pending(chan);
287 do {
288 status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
289 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
Jarkko Nikulaef859312016-03-14 16:51:09 +0200290 dev_err(chan->device->dev, "%s: timeout!\n", __func__);
Dan Williams7405f742007-01-02 11:10:43 -0700291 return DMA_ERROR;
292 }
Bartlomiej Zolnierkiewicz2cbe7fe2012-11-08 10:02:07 +0000293 if (status != DMA_IN_PROGRESS)
294 break;
295 cpu_relax();
296 } while (1);
Dan Williams7405f742007-01-02 11:10:43 -0700297
298 return status;
299}
300EXPORT_SYMBOL(dma_sync_wait);
301
Chris Leechc13c8262006-05-23 17:18:44 -0700302/**
Dan Williamsbec08512009-01-06 11:38:14 -0700303 * dma_cap_mask_all - enable iteration over all operation types
304 */
305static dma_cap_mask_t dma_cap_mask_all;
306
307/**
308 * dma_chan_tbl_ent - tracks channel allocations per core/operation
309 * @chan - associated channel for this entry
310 */
311struct dma_chan_tbl_ent {
312 struct dma_chan *chan;
313};
314
315/**
316 * channel_table - percpu lookup table for memory-to-memory offload providers
317 */
Tejun Heoa29d8b82010-02-02 14:39:15 +0900318static struct dma_chan_tbl_ent __percpu *channel_table[DMA_TX_TYPE_END];
Dan Williamsbec08512009-01-06 11:38:14 -0700319
320static int __init dma_channel_table_init(void)
321{
322 enum dma_transaction_type cap;
323 int err = 0;
324
325 bitmap_fill(dma_cap_mask_all.bits, DMA_TX_TYPE_END);
326
Dan Williams59b5ec22009-01-06 11:38:15 -0700327 /* 'interrupt', 'private', and 'slave' are channel capabilities,
328 * but are not associated with an operation so they do not need
329 * an entry in the channel_table
Dan Williamsbec08512009-01-06 11:38:14 -0700330 */
331 clear_bit(DMA_INTERRUPT, dma_cap_mask_all.bits);
Dan Williams59b5ec22009-01-06 11:38:15 -0700332 clear_bit(DMA_PRIVATE, dma_cap_mask_all.bits);
Dan Williamsbec08512009-01-06 11:38:14 -0700333 clear_bit(DMA_SLAVE, dma_cap_mask_all.bits);
334
335 for_each_dma_cap_mask(cap, dma_cap_mask_all) {
336 channel_table[cap] = alloc_percpu(struct dma_chan_tbl_ent);
337 if (!channel_table[cap]) {
338 err = -ENOMEM;
339 break;
340 }
341 }
342
343 if (err) {
Joe Perches63433252012-07-18 09:51:28 -0700344 pr_err("initialization failure\n");
Dan Williamsbec08512009-01-06 11:38:14 -0700345 for_each_dma_cap_mask(cap, dma_cap_mask_all)
Markus Elfringa9507ca2014-12-01 06:06:57 +0100346 free_percpu(channel_table[cap]);
Dan Williamsbec08512009-01-06 11:38:14 -0700347 }
348
349 return err;
350}
Dan Williams652afc22009-01-06 11:38:22 -0700351arch_initcall(dma_channel_table_init);
Dan Williamsbec08512009-01-06 11:38:14 -0700352
353/**
354 * dma_find_channel - find a channel to carry out the operation
355 * @tx_type: transaction type
356 */
357struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type)
358{
Christoph Lametere7dcaa42009-10-03 19:48:23 +0900359 return this_cpu_read(channel_table[tx_type]->chan);
Dan Williamsbec08512009-01-06 11:38:14 -0700360}
361EXPORT_SYMBOL(dma_find_channel);
362
363/**
Dan Williams2ba05622009-01-06 11:38:14 -0700364 * dma_issue_pending_all - flush all pending operations across all channels
365 */
366void dma_issue_pending_all(void)
367{
368 struct dma_device *device;
369 struct dma_chan *chan;
370
Dan Williams2ba05622009-01-06 11:38:14 -0700371 rcu_read_lock();
Dan Williams59b5ec22009-01-06 11:38:15 -0700372 list_for_each_entry_rcu(device, &dma_device_list, global_node) {
373 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
374 continue;
Dan Williams2ba05622009-01-06 11:38:14 -0700375 list_for_each_entry(chan, &device->channels, device_node)
376 if (chan->client_count)
377 device->device_issue_pending(chan);
Dan Williams59b5ec22009-01-06 11:38:15 -0700378 }
Dan Williams2ba05622009-01-06 11:38:14 -0700379 rcu_read_unlock();
380}
381EXPORT_SYMBOL(dma_issue_pending_all);
382
383/**
Brice Goglinc4d27c42013-08-19 11:43:35 +0200384 * 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 -0700385 */
Brice Goglinc4d27c42013-08-19 11:43:35 +0200386static bool dma_chan_is_local(struct dma_chan *chan, int cpu)
387{
388 int node = dev_to_node(chan->device->dev);
389 return node == -1 || cpumask_test_cpu(cpu, cpumask_of_node(node));
390}
391
392/**
393 * min_chan - returns the channel with min count and in the same numa-node as the cpu
394 * @cap: capability to match
395 * @cpu: cpu index which the channel should be close to
396 *
397 * If some channels are close to the given cpu, the one with the lowest
398 * reference count is returned. Otherwise, cpu is ignored and only the
399 * reference count is taken into account.
400 * Must be called under dma_list_mutex.
401 */
402static struct dma_chan *min_chan(enum dma_transaction_type cap, int cpu)
Dan Williamsbec08512009-01-06 11:38:14 -0700403{
404 struct dma_device *device;
405 struct dma_chan *chan;
Dan Williamsbec08512009-01-06 11:38:14 -0700406 struct dma_chan *min = NULL;
Brice Goglinc4d27c42013-08-19 11:43:35 +0200407 struct dma_chan *localmin = NULL;
Dan Williamsbec08512009-01-06 11:38:14 -0700408
409 list_for_each_entry(device, &dma_device_list, global_node) {
Dan Williams59b5ec22009-01-06 11:38:15 -0700410 if (!dma_has_cap(cap, device->cap_mask) ||
411 dma_has_cap(DMA_PRIVATE, device->cap_mask))
Dan Williamsbec08512009-01-06 11:38:14 -0700412 continue;
413 list_for_each_entry(chan, &device->channels, device_node) {
414 if (!chan->client_count)
415 continue;
Brice Goglinc4d27c42013-08-19 11:43:35 +0200416 if (!min || chan->table_count < min->table_count)
Dan Williamsbec08512009-01-06 11:38:14 -0700417 min = chan;
418
Brice Goglinc4d27c42013-08-19 11:43:35 +0200419 if (dma_chan_is_local(chan, cpu))
420 if (!localmin ||
421 chan->table_count < localmin->table_count)
422 localmin = chan;
Dan Williamsbec08512009-01-06 11:38:14 -0700423 }
Dan Williamsbec08512009-01-06 11:38:14 -0700424 }
425
Brice Goglinc4d27c42013-08-19 11:43:35 +0200426 chan = localmin ? localmin : min;
Dan Williamsbec08512009-01-06 11:38:14 -0700427
Brice Goglinc4d27c42013-08-19 11:43:35 +0200428 if (chan)
429 chan->table_count++;
Dan Williamsbec08512009-01-06 11:38:14 -0700430
Brice Goglinc4d27c42013-08-19 11:43:35 +0200431 return chan;
Dan Williamsbec08512009-01-06 11:38:14 -0700432}
433
434/**
435 * dma_channel_rebalance - redistribute the available channels
436 *
437 * Optimize for cpu isolation (each cpu gets a dedicated channel for an
438 * operation type) in the SMP case, and operation isolation (avoid
439 * multi-tasking channels) in the non-SMP case. Must be called under
440 * dma_list_mutex.
441 */
442static void dma_channel_rebalance(void)
443{
444 struct dma_chan *chan;
445 struct dma_device *device;
446 int cpu;
447 int cap;
Dan Williamsbec08512009-01-06 11:38:14 -0700448
449 /* undo the last distribution */
450 for_each_dma_cap_mask(cap, dma_cap_mask_all)
451 for_each_possible_cpu(cpu)
452 per_cpu_ptr(channel_table[cap], cpu)->chan = NULL;
453
Dan Williams59b5ec22009-01-06 11:38:15 -0700454 list_for_each_entry(device, &dma_device_list, global_node) {
455 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
456 continue;
Dan Williamsbec08512009-01-06 11:38:14 -0700457 list_for_each_entry(chan, &device->channels, device_node)
458 chan->table_count = 0;
Dan Williams59b5ec22009-01-06 11:38:15 -0700459 }
Dan Williamsbec08512009-01-06 11:38:14 -0700460
461 /* don't populate the channel_table if no clients are available */
462 if (!dmaengine_ref_count)
463 return;
464
465 /* redistribute available channels */
Dan Williamsbec08512009-01-06 11:38:14 -0700466 for_each_dma_cap_mask(cap, dma_cap_mask_all)
467 for_each_online_cpu(cpu) {
Brice Goglinc4d27c42013-08-19 11:43:35 +0200468 chan = min_chan(cap, cpu);
Dan Williamsbec08512009-01-06 11:38:14 -0700469 per_cpu_ptr(channel_table[cap], cpu)->chan = chan;
470 }
471}
472
Laurent Pinchart0d5484b2014-10-29 00:30:58 +0200473int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
474{
475 struct dma_device *device;
476
477 if (!chan || !caps)
478 return -EINVAL;
479
480 device = chan->device;
481
482 /* check if the channel supports slave transactions */
Andy Shevchenkodd4e91d2016-05-10 20:43:34 +0300483 if (!(test_bit(DMA_SLAVE, device->cap_mask.bits) ||
484 test_bit(DMA_CYCLIC, device->cap_mask.bits)))
Laurent Pinchart0d5484b2014-10-29 00:30:58 +0200485 return -ENXIO;
486
487 /*
488 * Check whether it reports it uses the generic slave
489 * capabilities, if not, that means it doesn't support any
490 * kind of slave capabilities reporting.
491 */
492 if (!device->directions)
493 return -ENXIO;
494
495 caps->src_addr_widths = device->src_addr_widths;
496 caps->dst_addr_widths = device->dst_addr_widths;
497 caps->directions = device->directions;
Shawn Lin6d5bbed2016-01-22 19:06:50 +0800498 caps->max_burst = device->max_burst;
Laurent Pinchart0d5484b2014-10-29 00:30:58 +0200499 caps->residue_granularity = device->residue_granularity;
Robert Jarzmik9eeacd32015-10-13 21:54:29 +0200500 caps->descriptor_reuse = device->descriptor_reuse;
Marek Szyprowskid8095f92018-07-02 15:08:10 +0200501 caps->cmd_pause = !!device->device_pause;
502 caps->cmd_resume = !!device->device_resume;
Laurent Pinchart0d5484b2014-10-29 00:30:58 +0200503 caps->cmd_terminate = !!device->device_terminate_all;
504
505 return 0;
506}
507EXPORT_SYMBOL_GPL(dma_get_slave_caps);
508
Lars-Peter Clausena53e28d2013-03-25 13:23:52 +0100509static struct dma_chan *private_candidate(const dma_cap_mask_t *mask,
510 struct dma_device *dev,
Dan Williamse2346672009-01-06 11:38:21 -0700511 dma_filter_fn fn, void *fn_param)
Dan Williams59b5ec22009-01-06 11:38:15 -0700512{
513 struct dma_chan *chan;
Dan Williams59b5ec22009-01-06 11:38:15 -0700514
Peter Ujfalusi26b64252015-12-14 22:47:38 +0200515 if (mask && !__dma_device_satisfies_mask(dev, mask)) {
Jarkko Nikulaef859312016-03-14 16:51:09 +0200516 dev_dbg(dev->dev, "%s: wrong capabilities\n", __func__);
Dan Williams59b5ec22009-01-06 11:38:15 -0700517 return NULL;
518 }
519 /* devices with multiple channels need special handling as we need to
520 * ensure that all channels are either private or public.
521 */
522 if (dev->chancnt > 1 && !dma_has_cap(DMA_PRIVATE, dev->cap_mask))
523 list_for_each_entry(chan, &dev->channels, device_node) {
524 /* some channels are already publicly allocated */
525 if (chan->client_count)
526 return NULL;
527 }
528
529 list_for_each_entry(chan, &dev->channels, device_node) {
530 if (chan->client_count) {
Jarkko Nikulaef859312016-03-14 16:51:09 +0200531 dev_dbg(dev->dev, "%s: %s busy\n",
Dan Williams41d5e592009-01-06 11:38:21 -0700532 __func__, dma_chan_name(chan));
Dan Williams59b5ec22009-01-06 11:38:15 -0700533 continue;
534 }
Dan Williamse2346672009-01-06 11:38:21 -0700535 if (fn && !fn(chan, fn_param)) {
Jarkko Nikulaef859312016-03-14 16:51:09 +0200536 dev_dbg(dev->dev, "%s: %s filter said false\n",
Dan Williamse2346672009-01-06 11:38:21 -0700537 __func__, dma_chan_name(chan));
538 continue;
539 }
540 return chan;
Dan Williams59b5ec22009-01-06 11:38:15 -0700541 }
542
Dan Williamse2346672009-01-06 11:38:21 -0700543 return NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700544}
545
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200546static struct dma_chan *find_candidate(struct dma_device *device,
547 const dma_cap_mask_t *mask,
548 dma_filter_fn fn, void *fn_param)
549{
550 struct dma_chan *chan = private_candidate(mask, device, fn, fn_param);
551 int err;
552
553 if (chan) {
554 /* Found a suitable channel, try to grab, prep, and return it.
555 * We first set DMA_PRIVATE to disable balance_ref_count as this
556 * channel will not be published in the general-purpose
557 * allocator
558 */
559 dma_cap_set(DMA_PRIVATE, device->cap_mask);
560 device->privatecnt++;
561 err = dma_chan_get(chan);
562
563 if (err) {
564 if (err == -ENODEV) {
Jarkko Nikulaef859312016-03-14 16:51:09 +0200565 dev_dbg(device->dev, "%s: %s module removed\n",
566 __func__, dma_chan_name(chan));
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200567 list_del_rcu(&device->global_node);
568 } else
Jarkko Nikulaef859312016-03-14 16:51:09 +0200569 dev_dbg(device->dev,
570 "%s: failed to get %s: (%d)\n",
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200571 __func__, dma_chan_name(chan), err);
572
573 if (--device->privatecnt == 0)
574 dma_cap_clear(DMA_PRIVATE, device->cap_mask);
575
576 chan = ERR_PTR(err);
577 }
578 }
579
580 return chan ? chan : ERR_PTR(-EPROBE_DEFER);
581}
582
Dan Williams59b5ec22009-01-06 11:38:15 -0700583/**
Stefan Agner19d643d2015-06-01 23:53:43 +0200584 * dma_get_slave_channel - try to get specific channel exclusively
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800585 * @chan: target channel
586 */
587struct dma_chan *dma_get_slave_channel(struct dma_chan *chan)
588{
589 int err = -EBUSY;
590
591 /* lock against __dma_request_channel */
592 mutex_lock(&dma_list_mutex);
593
Vinod Kould9a6c8f2013-08-19 10:47:26 +0530594 if (chan->client_count == 0) {
Peter Ujfalusi214fc4e2015-09-24 12:03:35 +0300595 struct dma_device *device = chan->device;
596
597 dma_cap_set(DMA_PRIVATE, device->cap_mask);
598 device->privatecnt++;
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800599 err = dma_chan_get(chan);
Peter Ujfalusi214fc4e2015-09-24 12:03:35 +0300600 if (err) {
Jarkko Nikulaef859312016-03-14 16:51:09 +0200601 dev_dbg(chan->device->dev,
602 "%s: failed to get %s: (%d)\n",
Vinod Kould9a6c8f2013-08-19 10:47:26 +0530603 __func__, dma_chan_name(chan), err);
Peter Ujfalusi214fc4e2015-09-24 12:03:35 +0300604 chan = NULL;
605 if (--device->privatecnt == 0)
606 dma_cap_clear(DMA_PRIVATE, device->cap_mask);
607 }
Vinod Kould9a6c8f2013-08-19 10:47:26 +0530608 } else
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800609 chan = NULL;
610
611 mutex_unlock(&dma_list_mutex);
612
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800613
614 return chan;
615}
616EXPORT_SYMBOL_GPL(dma_get_slave_channel);
617
Stephen Warren8010dad2013-11-26 12:40:51 -0700618struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
619{
620 dma_cap_mask_t mask;
621 struct dma_chan *chan;
Stephen Warren8010dad2013-11-26 12:40:51 -0700622
623 dma_cap_zero(mask);
624 dma_cap_set(DMA_SLAVE, mask);
625
626 /* lock against __dma_request_channel */
627 mutex_lock(&dma_list_mutex);
628
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200629 chan = find_candidate(device, &mask, NULL, NULL);
Stephen Warren8010dad2013-11-26 12:40:51 -0700630
631 mutex_unlock(&dma_list_mutex);
632
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200633 return IS_ERR(chan) ? NULL : chan;
Stephen Warren8010dad2013-11-26 12:40:51 -0700634}
635EXPORT_SYMBOL_GPL(dma_get_any_slave_channel);
636
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800637/**
Daniel Mack6b9019a2013-08-14 18:35:03 +0200638 * __dma_request_channel - try to allocate an exclusive channel
Dan Williams59b5ec22009-01-06 11:38:15 -0700639 * @mask: capabilities that the channel must satisfy
640 * @fn: optional callback to disposition available channels
641 * @fn_param: opaque parameter to pass to dma_filter_fn
Stephen Warren0ad7c002013-11-26 10:04:22 -0700642 *
643 * Returns pointer to appropriate DMA channel on success or NULL.
Dan Williams59b5ec22009-01-06 11:38:15 -0700644 */
Lars-Peter Clausena53e28d2013-03-25 13:23:52 +0100645struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
646 dma_filter_fn fn, void *fn_param)
Dan Williams59b5ec22009-01-06 11:38:15 -0700647{
648 struct dma_device *device, *_d;
649 struct dma_chan *chan = NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700650
651 /* Find a channel */
652 mutex_lock(&dma_list_mutex);
653 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200654 chan = find_candidate(device, mask, fn, fn_param);
655 if (!IS_ERR(chan))
656 break;
Dan Williams59b5ec22009-01-06 11:38:15 -0700657
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200658 chan = NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700659 }
660 mutex_unlock(&dma_list_mutex);
661
Jarkko Nikula4c4d7f872016-04-07 16:49:43 +0300662 pr_debug("%s: %s (%s)\n",
Joe Perches63433252012-07-18 09:51:28 -0700663 __func__,
664 chan ? "success" : "fail",
Dan Williams41d5e592009-01-06 11:38:21 -0700665 chan ? dma_chan_name(chan) : NULL);
Dan Williams59b5ec22009-01-06 11:38:15 -0700666
667 return chan;
668}
669EXPORT_SYMBOL_GPL(__dma_request_channel);
670
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200671static const struct dma_slave_map *dma_filter_match(struct dma_device *device,
672 const char *name,
673 struct device *dev)
674{
675 int i;
676
677 if (!device->filter.mapcnt)
678 return NULL;
679
680 for (i = 0; i < device->filter.mapcnt; i++) {
681 const struct dma_slave_map *map = &device->filter.map[i];
682
683 if (!strcmp(map->devname, dev_name(dev)) &&
684 !strcmp(map->slave, name))
685 return map;
686 }
687
688 return NULL;
689}
690
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500691/**
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200692 * dma_request_chan - try to allocate an exclusive slave channel
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500693 * @dev: pointer to client device structure
694 * @name: slave channel name
Stephen Warren0ad7c002013-11-26 10:04:22 -0700695 *
696 * Returns pointer to appropriate DMA channel on success or an error pointer.
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500697 */
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200698struct dma_chan *dma_request_chan(struct device *dev, const char *name)
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500699{
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200700 struct dma_device *d, *_d;
701 struct dma_chan *chan = NULL;
702
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500703 /* If device-tree is present get slave info from here */
704 if (dev->of_node)
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200705 chan = of_dma_request_slave_channel(dev->of_node, name);
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500706
Andy Shevchenko4e82f5d2013-04-09 14:05:44 +0300707 /* If device was enumerated by ACPI get slave info from here */
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200708 if (has_acpi_companion(dev) && !chan)
709 chan = acpi_dma_request_slave_chan_by_name(dev, name);
Andy Shevchenko4e82f5d2013-04-09 14:05:44 +0300710
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200711 if (chan) {
712 /* Valid channel found or requester need to be deferred */
713 if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
714 return chan;
715 }
716
717 /* Try to find the channel via the DMA filter map(s) */
718 mutex_lock(&dma_list_mutex);
719 list_for_each_entry_safe(d, _d, &dma_device_list, global_node) {
720 dma_cap_mask_t mask;
721 const struct dma_slave_map *map = dma_filter_match(d, name, dev);
722
723 if (!map)
724 continue;
725
726 dma_cap_zero(mask);
727 dma_cap_set(DMA_SLAVE, mask);
728
729 chan = find_candidate(d, &mask, d->filter.fn, map->param);
730 if (!IS_ERR(chan))
731 break;
732 }
733 mutex_unlock(&dma_list_mutex);
734
735 return chan ? chan : ERR_PTR(-EPROBE_DEFER);
Stephen Warren0ad7c002013-11-26 10:04:22 -0700736}
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200737EXPORT_SYMBOL_GPL(dma_request_chan);
Stephen Warren0ad7c002013-11-26 10:04:22 -0700738
739/**
740 * dma_request_slave_channel - try to allocate an exclusive slave channel
741 * @dev: pointer to client device structure
742 * @name: slave channel name
743 *
744 * Returns pointer to appropriate DMA channel on success or NULL.
745 */
746struct dma_chan *dma_request_slave_channel(struct device *dev,
747 const char *name)
748{
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200749 struct dma_chan *ch = dma_request_chan(dev, name);
Stephen Warren0ad7c002013-11-26 10:04:22 -0700750 if (IS_ERR(ch))
751 return NULL;
Robert Baldyga05aa1a72015-08-07 12:26:47 +0200752
Stephen Warren0ad7c002013-11-26 10:04:22 -0700753 return ch;
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500754}
755EXPORT_SYMBOL_GPL(dma_request_slave_channel);
756
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200757/**
758 * dma_request_chan_by_mask - allocate a channel satisfying certain capabilities
759 * @mask: capabilities that the channel must satisfy
760 *
761 * Returns pointer to appropriate DMA channel on success or an error pointer.
762 */
763struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask)
764{
765 struct dma_chan *chan;
766
767 if (!mask)
768 return ERR_PTR(-ENODEV);
769
770 chan = __dma_request_channel(mask, NULL, NULL);
Peter Ujfalusiec8ca8e2018-07-18 12:29:57 +0300771 if (!chan) {
772 mutex_lock(&dma_list_mutex);
773 if (list_empty(&dma_device_list))
774 chan = ERR_PTR(-EPROBE_DEFER);
775 else
776 chan = ERR_PTR(-ENODEV);
777 mutex_unlock(&dma_list_mutex);
778 }
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200779
780 return chan;
781}
782EXPORT_SYMBOL_GPL(dma_request_chan_by_mask);
783
Dan Williams59b5ec22009-01-06 11:38:15 -0700784void dma_release_channel(struct dma_chan *chan)
785{
786 mutex_lock(&dma_list_mutex);
787 WARN_ONCE(chan->client_count != 1,
788 "chan reference count %d != 1\n", chan->client_count);
789 dma_chan_put(chan);
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900790 /* drop PRIVATE cap enabled by __dma_request_channel() */
791 if (--chan->device->privatecnt == 0)
792 dma_cap_clear(DMA_PRIVATE, chan->device->cap_mask);
Dan Williams59b5ec22009-01-06 11:38:15 -0700793 mutex_unlock(&dma_list_mutex);
794}
795EXPORT_SYMBOL_GPL(dma_release_channel);
796
Dan Williamsbec08512009-01-06 11:38:14 -0700797/**
Dan Williams209b84a2009-01-06 11:38:17 -0700798 * dmaengine_get - register interest in dma_channels
Chris Leechc13c8262006-05-23 17:18:44 -0700799 */
Dan Williams209b84a2009-01-06 11:38:17 -0700800void dmaengine_get(void)
Chris Leechc13c8262006-05-23 17:18:44 -0700801{
Dan Williams6f49a572009-01-06 11:38:14 -0700802 struct dma_device *device, *_d;
803 struct dma_chan *chan;
804 int err;
805
Chris Leechc13c8262006-05-23 17:18:44 -0700806 mutex_lock(&dma_list_mutex);
Dan Williams6f49a572009-01-06 11:38:14 -0700807 dmaengine_ref_count++;
808
809 /* try to grab channels */
Dan Williams59b5ec22009-01-06 11:38:15 -0700810 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
811 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
812 continue;
Dan Williams6f49a572009-01-06 11:38:14 -0700813 list_for_each_entry(chan, &device->channels, device_node) {
814 err = dma_chan_get(chan);
815 if (err == -ENODEV) {
816 /* module removed before we could use it */
Dan Williams2ba05622009-01-06 11:38:14 -0700817 list_del_rcu(&device->global_node);
Dan Williams6f49a572009-01-06 11:38:14 -0700818 break;
819 } else if (err)
Jarkko Nikulaef859312016-03-14 16:51:09 +0200820 dev_dbg(chan->device->dev,
821 "%s: failed to get %s: (%d)\n",
822 __func__, dma_chan_name(chan), err);
Dan Williams6f49a572009-01-06 11:38:14 -0700823 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700824 }
Dan Williams6f49a572009-01-06 11:38:14 -0700825
Dan Williamsbec08512009-01-06 11:38:14 -0700826 /* if this is the first reference and there were channels
827 * waiting we need to rebalance to get those channels
828 * incorporated into the channel table
829 */
830 if (dmaengine_ref_count == 1)
831 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -0700832 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700833}
Dan Williams209b84a2009-01-06 11:38:17 -0700834EXPORT_SYMBOL(dmaengine_get);
Chris Leechc13c8262006-05-23 17:18:44 -0700835
836/**
Dan Williams209b84a2009-01-06 11:38:17 -0700837 * dmaengine_put - let dma drivers be removed when ref_count == 0
Chris Leechc13c8262006-05-23 17:18:44 -0700838 */
Dan Williams209b84a2009-01-06 11:38:17 -0700839void dmaengine_put(void)
Chris Leechc13c8262006-05-23 17:18:44 -0700840{
Dan Williamsd379b012007-07-09 11:56:42 -0700841 struct dma_device *device;
Chris Leechc13c8262006-05-23 17:18:44 -0700842 struct dma_chan *chan;
843
Chris Leechc13c8262006-05-23 17:18:44 -0700844 mutex_lock(&dma_list_mutex);
Dan Williams6f49a572009-01-06 11:38:14 -0700845 dmaengine_ref_count--;
846 BUG_ON(dmaengine_ref_count < 0);
847 /* drop channel references */
Dan Williams59b5ec22009-01-06 11:38:15 -0700848 list_for_each_entry(device, &dma_device_list, global_node) {
849 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
850 continue;
Dan Williams6f49a572009-01-06 11:38:14 -0700851 list_for_each_entry(chan, &device->channels, device_node)
852 dma_chan_put(chan);
Dan Williams59b5ec22009-01-06 11:38:15 -0700853 }
Chris Leechc13c8262006-05-23 17:18:44 -0700854 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700855}
Dan Williams209b84a2009-01-06 11:38:17 -0700856EXPORT_SYMBOL(dmaengine_put);
Chris Leechc13c8262006-05-23 17:18:44 -0700857
Dan Williams138f4c32009-09-08 17:42:51 -0700858static bool device_has_all_tx_types(struct dma_device *device)
859{
860 /* A device that satisfies this test has channels that will never cause
861 * an async_tx channel switch event as all possible operation types can
862 * be handled.
863 */
864 #ifdef CONFIG_ASYNC_TX_DMA
865 if (!dma_has_cap(DMA_INTERRUPT, device->cap_mask))
866 return false;
867 #endif
868
Javier Martinez Canillasd57d3a42016-05-11 13:39:27 -0400869 #if IS_ENABLED(CONFIG_ASYNC_MEMCPY)
Dan Williams138f4c32009-09-08 17:42:51 -0700870 if (!dma_has_cap(DMA_MEMCPY, device->cap_mask))
871 return false;
872 #endif
873
Javier Martinez Canillasd57d3a42016-05-11 13:39:27 -0400874 #if IS_ENABLED(CONFIG_ASYNC_XOR)
Dan Williams138f4c32009-09-08 17:42:51 -0700875 if (!dma_has_cap(DMA_XOR, device->cap_mask))
876 return false;
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700877
878 #ifndef CONFIG_ASYNC_TX_DISABLE_XOR_VAL_DMA
Dan Williams4499a242009-11-19 17:10:25 -0700879 if (!dma_has_cap(DMA_XOR_VAL, device->cap_mask))
880 return false;
Dan Williams138f4c32009-09-08 17:42:51 -0700881 #endif
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700882 #endif
Dan Williams138f4c32009-09-08 17:42:51 -0700883
Javier Martinez Canillasd57d3a42016-05-11 13:39:27 -0400884 #if IS_ENABLED(CONFIG_ASYNC_PQ)
Dan Williams138f4c32009-09-08 17:42:51 -0700885 if (!dma_has_cap(DMA_PQ, device->cap_mask))
886 return false;
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700887
888 #ifndef CONFIG_ASYNC_TX_DISABLE_PQ_VAL_DMA
Dan Williams4499a242009-11-19 17:10:25 -0700889 if (!dma_has_cap(DMA_PQ_VAL, device->cap_mask))
890 return false;
Dan Williams138f4c32009-09-08 17:42:51 -0700891 #endif
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700892 #endif
Dan Williams138f4c32009-09-08 17:42:51 -0700893
894 return true;
895}
896
Dan Williams257b17c2009-03-25 09:13:23 -0700897static int get_dma_id(struct dma_device *device)
898{
Matthew Wilcox485258b2018-06-18 15:41:48 -0400899 int rc = ida_alloc(&dma_ida, GFP_KERNEL);
Dan Williams257b17c2009-03-25 09:13:23 -0700900
Matthew Wilcox485258b2018-06-18 15:41:48 -0400901 if (rc < 0)
902 return rc;
903 device->dev_id = rc;
904 return 0;
Dan Williams257b17c2009-03-25 09:13:23 -0700905}
906
Chris Leechc13c8262006-05-23 17:18:44 -0700907/**
Randy Dunlap65088712006-07-03 19:45:31 -0700908 * dma_async_device_register - registers DMA devices found
Chris Leechc13c8262006-05-23 17:18:44 -0700909 * @device: &dma_device
910 */
911int dma_async_device_register(struct dma_device *device)
912{
Jeff Garzikff487fb2007-03-08 09:57:34 -0800913 int chancnt = 0, rc;
Chris Leechc13c8262006-05-23 17:18:44 -0700914 struct dma_chan* chan;
Dan Williams864498a2009-01-06 11:38:21 -0700915 atomic_t *idr_ref;
Chris Leechc13c8262006-05-23 17:18:44 -0700916
917 if (!device)
918 return -ENODEV;
919
Dan Williams7405f742007-01-02 11:10:43 -0700920 /* validate device routines */
Vinod Koul3eeb5152017-08-27 16:55:32 +0530921 if (!device->dev) {
922 pr_err("DMAdevice must have dev\n");
923 return -EIO;
924 }
Dan Williams7405f742007-01-02 11:10:43 -0700925
Vinod Koul3eeb5152017-08-27 16:55:32 +0530926 if (dma_has_cap(DMA_MEMCPY, device->cap_mask) && !device->device_prep_dma_memcpy) {
927 dev_err(device->dev,
928 "Device claims capability %s, but op is not defined\n",
929 "DMA_MEMCPY");
930 return -EIO;
931 }
932
933 if (dma_has_cap(DMA_XOR, device->cap_mask) && !device->device_prep_dma_xor) {
934 dev_err(device->dev,
935 "Device claims capability %s, but op is not defined\n",
936 "DMA_XOR");
937 return -EIO;
938 }
939
940 if (dma_has_cap(DMA_XOR_VAL, device->cap_mask) && !device->device_prep_dma_xor_val) {
941 dev_err(device->dev,
942 "Device claims capability %s, but op is not defined\n",
943 "DMA_XOR_VAL");
944 return -EIO;
945 }
946
947 if (dma_has_cap(DMA_PQ, device->cap_mask) && !device->device_prep_dma_pq) {
948 dev_err(device->dev,
949 "Device claims capability %s, but op is not defined\n",
950 "DMA_PQ");
951 return -EIO;
952 }
953
954 if (dma_has_cap(DMA_PQ_VAL, device->cap_mask) && !device->device_prep_dma_pq_val) {
955 dev_err(device->dev,
956 "Device claims capability %s, but op is not defined\n",
957 "DMA_PQ_VAL");
958 return -EIO;
959 }
960
961 if (dma_has_cap(DMA_MEMSET, device->cap_mask) && !device->device_prep_dma_memset) {
962 dev_err(device->dev,
963 "Device claims capability %s, but op is not defined\n",
964 "DMA_MEMSET");
965 return -EIO;
966 }
967
968 if (dma_has_cap(DMA_INTERRUPT, device->cap_mask) && !device->device_prep_dma_interrupt) {
969 dev_err(device->dev,
970 "Device claims capability %s, but op is not defined\n",
971 "DMA_INTERRUPT");
972 return -EIO;
973 }
974
975 if (dma_has_cap(DMA_CYCLIC, device->cap_mask) && !device->device_prep_dma_cyclic) {
976 dev_err(device->dev,
977 "Device claims capability %s, but op is not defined\n",
978 "DMA_CYCLIC");
979 return -EIO;
980 }
981
982 if (dma_has_cap(DMA_INTERLEAVE, device->cap_mask) && !device->device_prep_interleaved_dma) {
983 dev_err(device->dev,
984 "Device claims capability %s, but op is not defined\n",
985 "DMA_INTERLEAVE");
986 return -EIO;
987 }
988
989
990 if (!device->device_tx_status) {
991 dev_err(device->dev, "Device tx_status is not defined\n");
992 return -EIO;
993 }
994
995
996 if (!device->device_issue_pending) {
997 dev_err(device->dev, "Device issue_pending is not defined\n");
998 return -EIO;
999 }
Dan Williams7405f742007-01-02 11:10:43 -07001000
Dan Williams138f4c32009-09-08 17:42:51 -07001001 /* note: this only matters in the
Dan Williams5fc6d892010-10-07 16:44:50 -07001002 * CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH=n case
Dan Williams138f4c32009-09-08 17:42:51 -07001003 */
1004 if (device_has_all_tx_types(device))
1005 dma_cap_set(DMA_ASYNC_TX, device->cap_mask);
1006
Dan Williams864498a2009-01-06 11:38:21 -07001007 idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL);
1008 if (!idr_ref)
1009 return -ENOMEM;
Dan Williams257b17c2009-03-25 09:13:23 -07001010 rc = get_dma_id(device);
1011 if (rc != 0) {
1012 kfree(idr_ref);
Dan Williams864498a2009-01-06 11:38:21 -07001013 return rc;
Dan Williams257b17c2009-03-25 09:13:23 -07001014 }
1015
1016 atomic_set(idr_ref, 0);
Chris Leechc13c8262006-05-23 17:18:44 -07001017
1018 /* represent channels in sysfs. Probably want devs too */
1019 list_for_each_entry(chan, &device->channels, device_node) {
Dan Williams257b17c2009-03-25 09:13:23 -07001020 rc = -ENOMEM;
Chris Leechc13c8262006-05-23 17:18:44 -07001021 chan->local = alloc_percpu(typeof(*chan->local));
1022 if (chan->local == NULL)
Dan Williams257b17c2009-03-25 09:13:23 -07001023 goto err_out;
Dan Williams41d5e592009-01-06 11:38:21 -07001024 chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL);
1025 if (chan->dev == NULL) {
1026 free_percpu(chan->local);
Dan Williams257b17c2009-03-25 09:13:23 -07001027 chan->local = NULL;
1028 goto err_out;
Dan Williams41d5e592009-01-06 11:38:21 -07001029 }
Chris Leechc13c8262006-05-23 17:18:44 -07001030
1031 chan->chan_id = chancnt++;
Dan Williams41d5e592009-01-06 11:38:21 -07001032 chan->dev->device.class = &dma_devclass;
1033 chan->dev->device.parent = device->dev;
1034 chan->dev->chan = chan;
Dan Williams864498a2009-01-06 11:38:21 -07001035 chan->dev->idr_ref = idr_ref;
1036 chan->dev->dev_id = device->dev_id;
1037 atomic_inc(idr_ref);
Dan Williams41d5e592009-01-06 11:38:21 -07001038 dev_set_name(&chan->dev->device, "dma%dchan%d",
Kay Sievers06190d82008-11-11 13:12:33 -07001039 device->dev_id, chan->chan_id);
Chris Leechc13c8262006-05-23 17:18:44 -07001040
Dan Williams41d5e592009-01-06 11:38:21 -07001041 rc = device_register(&chan->dev->device);
Jeff Garzikff487fb2007-03-08 09:57:34 -08001042 if (rc) {
Jeff Garzikff487fb2007-03-08 09:57:34 -08001043 free_percpu(chan->local);
1044 chan->local = NULL;
Dan Williams257b17c2009-03-25 09:13:23 -07001045 kfree(chan->dev);
1046 atomic_dec(idr_ref);
Jeff Garzikff487fb2007-03-08 09:57:34 -08001047 goto err_out;
1048 }
Dan Williams7cc5bf92008-07-08 11:58:21 -07001049 chan->client_count = 0;
Chris Leechc13c8262006-05-23 17:18:44 -07001050 }
Viresh Kumar76d7b842016-07-27 14:32:58 -07001051
1052 if (!chancnt) {
1053 dev_err(device->dev, "%s: device has no channels!\n", __func__);
1054 rc = -ENODEV;
1055 goto err_out;
1056 }
1057
Dan Williams59b5ec22009-01-06 11:38:15 -07001058 device->chancnt = chancnt;
Chris Leechc13c8262006-05-23 17:18:44 -07001059
1060 mutex_lock(&dma_list_mutex);
Dan Williams59b5ec22009-01-06 11:38:15 -07001061 /* take references on public channels */
1062 if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask))
Dan Williams6f49a572009-01-06 11:38:14 -07001063 list_for_each_entry(chan, &device->channels, device_node) {
1064 /* if clients are already waiting for channels we need
1065 * to take references on their behalf
1066 */
1067 if (dma_chan_get(chan) == -ENODEV) {
1068 /* note we can only get here for the first
1069 * channel as the remaining channels are
1070 * guaranteed to get a reference
1071 */
1072 rc = -ENODEV;
1073 mutex_unlock(&dma_list_mutex);
1074 goto err_out;
1075 }
1076 }
Dan Williams2ba05622009-01-06 11:38:14 -07001077 list_add_tail_rcu(&device->global_node, &dma_device_list);
Atsushi Nemoto0f571512009-03-06 20:07:14 +09001078 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
1079 device->privatecnt++; /* Always private */
Dan Williamsbec08512009-01-06 11:38:14 -07001080 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -07001081 mutex_unlock(&dma_list_mutex);
1082
Chris Leechc13c8262006-05-23 17:18:44 -07001083 return 0;
Jeff Garzikff487fb2007-03-08 09:57:34 -08001084
1085err_out:
Dan Williams257b17c2009-03-25 09:13:23 -07001086 /* if we never registered a channel just release the idr */
1087 if (atomic_read(idr_ref) == 0) {
Matthew Wilcox485258b2018-06-18 15:41:48 -04001088 ida_free(&dma_ida, device->dev_id);
Dan Williams257b17c2009-03-25 09:13:23 -07001089 kfree(idr_ref);
1090 return rc;
1091 }
1092
Jeff Garzikff487fb2007-03-08 09:57:34 -08001093 list_for_each_entry(chan, &device->channels, device_node) {
1094 if (chan->local == NULL)
1095 continue;
Dan Williams41d5e592009-01-06 11:38:21 -07001096 mutex_lock(&dma_list_mutex);
1097 chan->dev->chan = NULL;
1098 mutex_unlock(&dma_list_mutex);
1099 device_unregister(&chan->dev->device);
Jeff Garzikff487fb2007-03-08 09:57:34 -08001100 free_percpu(chan->local);
1101 }
1102 return rc;
Chris Leechc13c8262006-05-23 17:18:44 -07001103}
David Brownell765e3d82007-03-16 13:38:05 -08001104EXPORT_SYMBOL(dma_async_device_register);
Chris Leechc13c8262006-05-23 17:18:44 -07001105
1106/**
Dan Williams6f49a572009-01-06 11:38:14 -07001107 * dma_async_device_unregister - unregister a DMA device
Randy Dunlap65088712006-07-03 19:45:31 -07001108 * @device: &dma_device
Dan Williamsf27c5802009-01-06 11:38:18 -07001109 *
1110 * This routine is called by dma driver exit routines, dmaengine holds module
1111 * references to prevent it being called while channels are in use.
Randy Dunlap65088712006-07-03 19:45:31 -07001112 */
1113void dma_async_device_unregister(struct dma_device *device)
Chris Leechc13c8262006-05-23 17:18:44 -07001114{
1115 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -07001116
1117 mutex_lock(&dma_list_mutex);
Dan Williams2ba05622009-01-06 11:38:14 -07001118 list_del_rcu(&device->global_node);
Dan Williamsbec08512009-01-06 11:38:14 -07001119 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -07001120 mutex_unlock(&dma_list_mutex);
1121
1122 list_for_each_entry(chan, &device->channels, device_node) {
Dan Williams6f49a572009-01-06 11:38:14 -07001123 WARN_ONCE(chan->client_count,
1124 "%s called while %d clients hold a reference\n",
1125 __func__, chan->client_count);
Dan Williams41d5e592009-01-06 11:38:21 -07001126 mutex_lock(&dma_list_mutex);
1127 chan->dev->chan = NULL;
1128 mutex_unlock(&dma_list_mutex);
1129 device_unregister(&chan->dev->device);
Anatolij Gustschinadef4772010-01-26 10:26:06 +01001130 free_percpu(chan->local);
Chris Leechc13c8262006-05-23 17:18:44 -07001131 }
Chris Leechc13c8262006-05-23 17:18:44 -07001132}
David Brownell765e3d82007-03-16 13:38:05 -08001133EXPORT_SYMBOL(dma_async_device_unregister);
Chris Leechc13c8262006-05-23 17:18:44 -07001134
Huang Shijief39b9482018-07-26 14:45:53 +08001135static void dmam_device_release(struct device *dev, void *res)
1136{
1137 struct dma_device *device;
1138
1139 device = *(struct dma_device **)res;
1140 dma_async_device_unregister(device);
1141}
1142
1143/**
1144 * dmaenginem_async_device_register - registers DMA devices found
1145 * @device: &dma_device
1146 *
1147 * The operation is managed and will be undone on driver detach.
1148 */
1149int dmaenginem_async_device_register(struct dma_device *device)
1150{
1151 void *p;
1152 int ret;
1153
1154 p = devres_alloc(dmam_device_release, sizeof(void *), GFP_KERNEL);
1155 if (!p)
1156 return -ENOMEM;
1157
1158 ret = dma_async_device_register(device);
1159 if (!ret) {
1160 *(struct dma_device **)p = device;
1161 devres_add(device->dev, p);
1162 } else {
1163 devres_free(p);
1164 }
1165
1166 return ret;
1167}
1168EXPORT_SYMBOL(dmaenginem_async_device_register);
1169
Dan Williams45c463a2013-10-18 19:35:24 +02001170struct dmaengine_unmap_pool {
1171 struct kmem_cache *cache;
1172 const char *name;
1173 mempool_t *pool;
1174 size_t size;
1175};
1176
1177#define __UNMAP_POOL(x) { .size = x, .name = "dmaengine-unmap-" __stringify(x) }
1178static struct dmaengine_unmap_pool unmap_pool[] = {
1179 __UNMAP_POOL(2),
Dan Williams3cc377b2013-12-09 10:33:16 -08001180 #if IS_ENABLED(CONFIG_DMA_ENGINE_RAID)
Dan Williams45c463a2013-10-18 19:35:24 +02001181 __UNMAP_POOL(16),
1182 __UNMAP_POOL(128),
1183 __UNMAP_POOL(256),
1184 #endif
1185};
1186
1187static struct dmaengine_unmap_pool *__get_unmap_pool(int nr)
Dan Williams7405f742007-01-02 11:10:43 -07001188{
Dan Williams45c463a2013-10-18 19:35:24 +02001189 int order = get_count_order(nr);
Dan Williams7405f742007-01-02 11:10:43 -07001190
Dan Williams45c463a2013-10-18 19:35:24 +02001191 switch (order) {
1192 case 0 ... 1:
1193 return &unmap_pool[0];
Matthias Kaehlcke23f963e92017-03-13 14:30:29 -07001194#if IS_ENABLED(CONFIG_DMA_ENGINE_RAID)
Dan Williams45c463a2013-10-18 19:35:24 +02001195 case 2 ... 4:
1196 return &unmap_pool[1];
1197 case 5 ... 7:
1198 return &unmap_pool[2];
1199 case 8:
1200 return &unmap_pool[3];
Matthias Kaehlcke23f963e92017-03-13 14:30:29 -07001201#endif
Dan Williams45c463a2013-10-18 19:35:24 +02001202 default:
1203 BUG();
1204 return NULL;
1205 }
1206}
Dan Williams00367312008-02-02 19:49:57 -07001207
Dan Williams45c463a2013-10-18 19:35:24 +02001208static void dmaengine_unmap(struct kref *kref)
1209{
1210 struct dmaengine_unmap_data *unmap = container_of(kref, typeof(*unmap), kref);
1211 struct device *dev = unmap->dev;
1212 int cnt, i;
1213
1214 cnt = unmap->to_cnt;
1215 for (i = 0; i < cnt; i++)
1216 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1217 DMA_TO_DEVICE);
1218 cnt += unmap->from_cnt;
1219 for (; i < cnt; i++)
1220 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1221 DMA_FROM_DEVICE);
1222 cnt += unmap->bidi_cnt;
Dan Williams7476bd72013-10-18 19:35:29 +02001223 for (; i < cnt; i++) {
1224 if (unmap->addr[i] == 0)
1225 continue;
Dan Williams45c463a2013-10-18 19:35:24 +02001226 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1227 DMA_BIDIRECTIONAL);
Dan Williams7476bd72013-10-18 19:35:29 +02001228 }
Xuelin Shic1f43dd2014-05-21 14:02:37 -07001229 cnt = unmap->map_cnt;
Dan Williams45c463a2013-10-18 19:35:24 +02001230 mempool_free(unmap, __get_unmap_pool(cnt)->pool);
1231}
1232
1233void dmaengine_unmap_put(struct dmaengine_unmap_data *unmap)
1234{
1235 if (unmap)
1236 kref_put(&unmap->kref, dmaengine_unmap);
1237}
1238EXPORT_SYMBOL_GPL(dmaengine_unmap_put);
1239
1240static void dmaengine_destroy_unmap_pool(void)
1241{
1242 int i;
1243
1244 for (i = 0; i < ARRAY_SIZE(unmap_pool); i++) {
1245 struct dmaengine_unmap_pool *p = &unmap_pool[i];
1246
Julia Lawall240eb9162015-09-13 14:15:19 +02001247 mempool_destroy(p->pool);
Dan Williams45c463a2013-10-18 19:35:24 +02001248 p->pool = NULL;
Julia Lawall240eb9162015-09-13 14:15:19 +02001249 kmem_cache_destroy(p->cache);
Dan Williams45c463a2013-10-18 19:35:24 +02001250 p->cache = NULL;
1251 }
1252}
1253
1254static int __init dmaengine_init_unmap_pool(void)
1255{
1256 int i;
1257
1258 for (i = 0; i < ARRAY_SIZE(unmap_pool); i++) {
1259 struct dmaengine_unmap_pool *p = &unmap_pool[i];
1260 size_t size;
1261
1262 size = sizeof(struct dmaengine_unmap_data) +
1263 sizeof(dma_addr_t) * p->size;
1264
1265 p->cache = kmem_cache_create(p->name, size, 0,
1266 SLAB_HWCACHE_ALIGN, NULL);
1267 if (!p->cache)
1268 break;
1269 p->pool = mempool_create_slab_pool(1, p->cache);
1270 if (!p->pool)
1271 break;
Dan Williams00367312008-02-02 19:49:57 -07001272 }
Dan Williams7405f742007-01-02 11:10:43 -07001273
Dan Williams45c463a2013-10-18 19:35:24 +02001274 if (i == ARRAY_SIZE(unmap_pool))
1275 return 0;
Dan Williams7405f742007-01-02 11:10:43 -07001276
Dan Williams45c463a2013-10-18 19:35:24 +02001277 dmaengine_destroy_unmap_pool();
1278 return -ENOMEM;
Dan Williams7405f742007-01-02 11:10:43 -07001279}
Dan Williams7405f742007-01-02 11:10:43 -07001280
Dan Williams89716462013-10-18 19:35:25 +02001281struct dmaengine_unmap_data *
Dan Williams45c463a2013-10-18 19:35:24 +02001282dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags)
Dan Williams7405f742007-01-02 11:10:43 -07001283{
Dan Williams45c463a2013-10-18 19:35:24 +02001284 struct dmaengine_unmap_data *unmap;
Dan Williams7405f742007-01-02 11:10:43 -07001285
Dan Williams45c463a2013-10-18 19:35:24 +02001286 unmap = mempool_alloc(__get_unmap_pool(nr)->pool, flags);
1287 if (!unmap)
1288 return NULL;
Dan Williams00367312008-02-02 19:49:57 -07001289
Dan Williams45c463a2013-10-18 19:35:24 +02001290 memset(unmap, 0, sizeof(*unmap));
1291 kref_init(&unmap->kref);
1292 unmap->dev = dev;
Xuelin Shic1f43dd2014-05-21 14:02:37 -07001293 unmap->map_cnt = nr;
Dan Williams7405f742007-01-02 11:10:43 -07001294
Dan Williams45c463a2013-10-18 19:35:24 +02001295 return unmap;
Dan Williams7405f742007-01-02 11:10:43 -07001296}
Dan Williams89716462013-10-18 19:35:25 +02001297EXPORT_SYMBOL(dmaengine_get_unmap_data);
Dan Williams7405f742007-01-02 11:10:43 -07001298
Dan Williams7405f742007-01-02 11:10:43 -07001299void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
1300 struct dma_chan *chan)
1301{
1302 tx->chan = chan;
Dan Williams5fc6d892010-10-07 16:44:50 -07001303 #ifdef CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH
Dan Williams7405f742007-01-02 11:10:43 -07001304 spin_lock_init(&tx->lock);
Dan Williamscaa20d972010-05-17 16:24:16 -07001305 #endif
Dan Williams7405f742007-01-02 11:10:43 -07001306}
1307EXPORT_SYMBOL(dma_async_tx_descriptor_init);
1308
Dan Williams07f22112009-01-05 17:14:31 -07001309/* dma_wait_for_async_tx - spin wait for a transaction to complete
1310 * @tx: in-flight transaction to wait on
Dan Williams07f22112009-01-05 17:14:31 -07001311 */
1312enum dma_status
1313dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
1314{
Dan Williams95475e52009-07-14 12:19:02 -07001315 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
Dan Williams07f22112009-01-05 17:14:31 -07001316
1317 if (!tx)
Vinod Kouladfedd92013-10-16 13:29:02 +05301318 return DMA_COMPLETE;
Dan Williams07f22112009-01-05 17:14:31 -07001319
Dan Williams95475e52009-07-14 12:19:02 -07001320 while (tx->cookie == -EBUSY) {
1321 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
Jarkko Nikulaef859312016-03-14 16:51:09 +02001322 dev_err(tx->chan->device->dev,
1323 "%s timeout waiting for descriptor submission\n",
1324 __func__);
Dan Williams95475e52009-07-14 12:19:02 -07001325 return DMA_ERROR;
1326 }
1327 cpu_relax();
1328 }
1329 return dma_sync_wait(tx->chan, tx->cookie);
Dan Williams07f22112009-01-05 17:14:31 -07001330}
1331EXPORT_SYMBOL_GPL(dma_wait_for_async_tx);
1332
1333/* dma_run_dependencies - helper routine for dma drivers to process
1334 * (start) dependent operations on their target channel
1335 * @tx: transaction with dependencies
1336 */
1337void dma_run_dependencies(struct dma_async_tx_descriptor *tx)
1338{
Dan Williamscaa20d972010-05-17 16:24:16 -07001339 struct dma_async_tx_descriptor *dep = txd_next(tx);
Dan Williams07f22112009-01-05 17:14:31 -07001340 struct dma_async_tx_descriptor *dep_next;
1341 struct dma_chan *chan;
1342
1343 if (!dep)
1344 return;
1345
Yuri Tikhonovdd59b852009-01-12 15:17:20 -07001346 /* we'll submit tx->next now, so clear the link */
Dan Williamscaa20d972010-05-17 16:24:16 -07001347 txd_clear_next(tx);
Dan Williams07f22112009-01-05 17:14:31 -07001348 chan = dep->chan;
1349
1350 /* keep submitting up until a channel switch is detected
1351 * in that case we will be called again as a result of
1352 * processing the interrupt from async_tx_channel_switch
1353 */
1354 for (; dep; dep = dep_next) {
Dan Williamscaa20d972010-05-17 16:24:16 -07001355 txd_lock(dep);
1356 txd_clear_parent(dep);
1357 dep_next = txd_next(dep);
Dan Williams07f22112009-01-05 17:14:31 -07001358 if (dep_next && dep_next->chan == chan)
Dan Williamscaa20d972010-05-17 16:24:16 -07001359 txd_clear_next(dep); /* ->next will be submitted */
Dan Williams07f22112009-01-05 17:14:31 -07001360 else
1361 dep_next = NULL; /* submit current dep and terminate */
Dan Williamscaa20d972010-05-17 16:24:16 -07001362 txd_unlock(dep);
Dan Williams07f22112009-01-05 17:14:31 -07001363
1364 dep->tx_submit(dep);
1365 }
1366
1367 chan->device->device_issue_pending(chan);
1368}
1369EXPORT_SYMBOL_GPL(dma_run_dependencies);
1370
Chris Leechc13c8262006-05-23 17:18:44 -07001371static int __init dma_bus_init(void)
1372{
Dan Williams45c463a2013-10-18 19:35:24 +02001373 int err = dmaengine_init_unmap_pool();
1374
1375 if (err)
1376 return err;
Chris Leechc13c8262006-05-23 17:18:44 -07001377 return class_register(&dma_devclass);
1378}
Dan Williams652afc22009-01-06 11:38:22 -07001379arch_initcall(dma_bus_init);
Chris Leechc13c8262006-05-23 17:18:44 -07001380
Dan Williamsbec08512009-01-06 11:38:14 -07001381