blob: 8c9f45fd55fc16b3527e256591383583a2490d80 [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 *
Dan Williamsf27c5802009-01-06 11:38:18 -070041 * See Documentation/dmaengine.txt 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);
Axel Lin21ef4b82011-07-20 11:32:28 +080068static DEFINE_IDR(dma_idr);
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)) {
164 mutex_lock(&dma_list_mutex);
165 idr_remove(&dma_idr, chan_dev->dev_id);
166 mutex_unlock(&dma_list_mutex);
167 kfree(chan_dev->idr_ref);
168 }
Dan Williams41d5e592009-01-06 11:38:21 -0700169 kfree(chan_dev);
170}
171
Chris Leechc13c8262006-05-23 17:18:44 -0700172static struct class dma_devclass = {
Tony Jones891f78e2007-09-25 02:03:03 +0200173 .name = "dma",
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700174 .dev_groups = dma_dev_groups,
Dan Williams41d5e592009-01-06 11:38:21 -0700175 .dev_release = chan_dev_release,
Chris Leechc13c8262006-05-23 17:18:44 -0700176};
177
178/* --- client and device registration --- */
179
Dan Williams59b5ec22009-01-06 11:38:15 -0700180#define dma_device_satisfies_mask(device, mask) \
181 __dma_device_satisfies_mask((device), &(mask))
Dan Williamsd379b012007-07-09 11:56:42 -0700182static int
Lars-Peter Clausena53e28d2013-03-25 13:23:52 +0100183__dma_device_satisfies_mask(struct dma_device *device,
184 const dma_cap_mask_t *want)
Dan Williamsd379b012007-07-09 11:56:42 -0700185{
186 dma_cap_mask_t has;
187
Dan Williams59b5ec22009-01-06 11:38:15 -0700188 bitmap_and(has.bits, want->bits, device->cap_mask.bits,
Dan Williamsd379b012007-07-09 11:56:42 -0700189 DMA_TX_TYPE_END);
190 return bitmap_equal(want->bits, has.bits, DMA_TX_TYPE_END);
191}
192
Dan Williams6f49a572009-01-06 11:38:14 -0700193static struct module *dma_chan_to_owner(struct dma_chan *chan)
194{
195 return chan->device->dev->driver->owner;
196}
197
198/**
199 * balance_ref_count - catch up the channel reference count
200 * @chan - channel to balance ->client_count versus dmaengine_ref_count
201 *
202 * balance_ref_count must be called under dma_list_mutex
203 */
204static void balance_ref_count(struct dma_chan *chan)
205{
206 struct module *owner = dma_chan_to_owner(chan);
207
208 while (chan->client_count < dmaengine_ref_count) {
209 __module_get(owner);
210 chan->client_count++;
211 }
212}
213
214/**
215 * dma_chan_get - try to grab a dma channel's parent driver module
216 * @chan - channel to grab
217 *
218 * Must be called under dma_list_mutex
219 */
220static int dma_chan_get(struct dma_chan *chan)
221{
Dan Williams6f49a572009-01-06 11:38:14 -0700222 struct module *owner = dma_chan_to_owner(chan);
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100223 int ret;
Dan Williams6f49a572009-01-06 11:38:14 -0700224
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100225 /* The channel is already in use, update client count */
Dan Williams6f49a572009-01-06 11:38:14 -0700226 if (chan->client_count) {
227 __module_get(owner);
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100228 goto out;
Dan Williams6f49a572009-01-06 11:38:14 -0700229 }
230
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100231 if (!try_module_get(owner))
232 return -ENODEV;
233
234 /* allocate upon first client reference */
Maxime Ripardc4b54a62014-11-17 14:41:59 +0100235 if (chan->device->device_alloc_chan_resources) {
236 ret = chan->device->device_alloc_chan_resources(chan);
237 if (ret < 0)
238 goto err_out;
239 }
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100240
241 if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
242 balance_ref_count(chan);
243
244out:
245 chan->client_count++;
246 return 0;
247
248err_out:
249 module_put(owner);
250 return ret;
Dan Williams6f49a572009-01-06 11:38:14 -0700251}
252
253/**
254 * dma_chan_put - drop a reference to a dma channel's parent driver module
255 * @chan - channel to release
256 *
257 * Must be called under dma_list_mutex
258 */
259static void dma_chan_put(struct dma_chan *chan)
260{
Maxime Ripardc4b54a62014-11-17 14:41:59 +0100261 /* This channel is not in use, bail out */
Dan Williams6f49a572009-01-06 11:38:14 -0700262 if (!chan->client_count)
Maxime Ripardc4b54a62014-11-17 14:41:59 +0100263 return;
264
Dan Williams6f49a572009-01-06 11:38:14 -0700265 chan->client_count--;
266 module_put(dma_chan_to_owner(chan));
Maxime Ripardc4b54a62014-11-17 14:41:59 +0100267
268 /* This channel is not in use anymore, free it */
Lars-Peter Clausenb36f09c2015-10-20 11:46:28 +0200269 if (!chan->client_count && chan->device->device_free_chan_resources) {
270 /* Make sure all operations have completed */
271 dmaengine_synchronize(chan);
Dan Williams6f49a572009-01-06 11:38:14 -0700272 chan->device->device_free_chan_resources(chan);
Lars-Peter Clausenb36f09c2015-10-20 11:46:28 +0200273 }
Peter Ujfalusi56f13c02015-04-09 12:35:47 +0300274
275 /* If the channel is used via a DMA request router, free the mapping */
276 if (chan->router && chan->router->route_free) {
277 chan->router->route_free(chan->router->dev, chan->route_data);
278 chan->router = NULL;
279 chan->route_data = NULL;
280 }
Dan Williams6f49a572009-01-06 11:38:14 -0700281}
282
Dan Williams7405f742007-01-02 11:10:43 -0700283enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
284{
285 enum dma_status status;
286 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
287
288 dma_async_issue_pending(chan);
289 do {
290 status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
291 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
Jarkko Nikulaef859312016-03-14 16:51:09 +0200292 dev_err(chan->device->dev, "%s: timeout!\n", __func__);
Dan Williams7405f742007-01-02 11:10:43 -0700293 return DMA_ERROR;
294 }
Bartlomiej Zolnierkiewicz2cbe7fe2012-11-08 10:02:07 +0000295 if (status != DMA_IN_PROGRESS)
296 break;
297 cpu_relax();
298 } while (1);
Dan Williams7405f742007-01-02 11:10:43 -0700299
300 return status;
301}
302EXPORT_SYMBOL(dma_sync_wait);
303
Chris Leechc13c8262006-05-23 17:18:44 -0700304/**
Dan Williamsbec08512009-01-06 11:38:14 -0700305 * dma_cap_mask_all - enable iteration over all operation types
306 */
307static dma_cap_mask_t dma_cap_mask_all;
308
309/**
310 * dma_chan_tbl_ent - tracks channel allocations per core/operation
311 * @chan - associated channel for this entry
312 */
313struct dma_chan_tbl_ent {
314 struct dma_chan *chan;
315};
316
317/**
318 * channel_table - percpu lookup table for memory-to-memory offload providers
319 */
Tejun Heoa29d8b82010-02-02 14:39:15 +0900320static struct dma_chan_tbl_ent __percpu *channel_table[DMA_TX_TYPE_END];
Dan Williamsbec08512009-01-06 11:38:14 -0700321
322static int __init dma_channel_table_init(void)
323{
324 enum dma_transaction_type cap;
325 int err = 0;
326
327 bitmap_fill(dma_cap_mask_all.bits, DMA_TX_TYPE_END);
328
Dan Williams59b5ec22009-01-06 11:38:15 -0700329 /* 'interrupt', 'private', and 'slave' are channel capabilities,
330 * but are not associated with an operation so they do not need
331 * an entry in the channel_table
Dan Williamsbec08512009-01-06 11:38:14 -0700332 */
333 clear_bit(DMA_INTERRUPT, dma_cap_mask_all.bits);
Dan Williams59b5ec22009-01-06 11:38:15 -0700334 clear_bit(DMA_PRIVATE, dma_cap_mask_all.bits);
Dan Williamsbec08512009-01-06 11:38:14 -0700335 clear_bit(DMA_SLAVE, dma_cap_mask_all.bits);
336
337 for_each_dma_cap_mask(cap, dma_cap_mask_all) {
338 channel_table[cap] = alloc_percpu(struct dma_chan_tbl_ent);
339 if (!channel_table[cap]) {
340 err = -ENOMEM;
341 break;
342 }
343 }
344
345 if (err) {
Joe Perches63433252012-07-18 09:51:28 -0700346 pr_err("initialization failure\n");
Dan Williamsbec08512009-01-06 11:38:14 -0700347 for_each_dma_cap_mask(cap, dma_cap_mask_all)
Markus Elfringa9507ca2014-12-01 06:06:57 +0100348 free_percpu(channel_table[cap]);
Dan Williamsbec08512009-01-06 11:38:14 -0700349 }
350
351 return err;
352}
Dan Williams652afc22009-01-06 11:38:22 -0700353arch_initcall(dma_channel_table_init);
Dan Williamsbec08512009-01-06 11:38:14 -0700354
355/**
356 * dma_find_channel - find a channel to carry out the operation
357 * @tx_type: transaction type
358 */
359struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type)
360{
Christoph Lametere7dcaa42009-10-03 19:48:23 +0900361 return this_cpu_read(channel_table[tx_type]->chan);
Dan Williamsbec08512009-01-06 11:38:14 -0700362}
363EXPORT_SYMBOL(dma_find_channel);
364
365/**
Dan Williams2ba05622009-01-06 11:38:14 -0700366 * dma_issue_pending_all - flush all pending operations across all channels
367 */
368void dma_issue_pending_all(void)
369{
370 struct dma_device *device;
371 struct dma_chan *chan;
372
Dan Williams2ba05622009-01-06 11:38:14 -0700373 rcu_read_lock();
Dan Williams59b5ec22009-01-06 11:38:15 -0700374 list_for_each_entry_rcu(device, &dma_device_list, global_node) {
375 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
376 continue;
Dan Williams2ba05622009-01-06 11:38:14 -0700377 list_for_each_entry(chan, &device->channels, device_node)
378 if (chan->client_count)
379 device->device_issue_pending(chan);
Dan Williams59b5ec22009-01-06 11:38:15 -0700380 }
Dan Williams2ba05622009-01-06 11:38:14 -0700381 rcu_read_unlock();
382}
383EXPORT_SYMBOL(dma_issue_pending_all);
384
385/**
Brice Goglinc4d27c42013-08-19 11:43:35 +0200386 * 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 -0700387 */
Brice Goglinc4d27c42013-08-19 11:43:35 +0200388static bool dma_chan_is_local(struct dma_chan *chan, int cpu)
389{
390 int node = dev_to_node(chan->device->dev);
391 return node == -1 || cpumask_test_cpu(cpu, cpumask_of_node(node));
392}
393
394/**
395 * min_chan - returns the channel with min count and in the same numa-node as the cpu
396 * @cap: capability to match
397 * @cpu: cpu index which the channel should be close to
398 *
399 * If some channels are close to the given cpu, the one with the lowest
400 * reference count is returned. Otherwise, cpu is ignored and only the
401 * reference count is taken into account.
402 * Must be called under dma_list_mutex.
403 */
404static struct dma_chan *min_chan(enum dma_transaction_type cap, int cpu)
Dan Williamsbec08512009-01-06 11:38:14 -0700405{
406 struct dma_device *device;
407 struct dma_chan *chan;
Dan Williamsbec08512009-01-06 11:38:14 -0700408 struct dma_chan *min = NULL;
Brice Goglinc4d27c42013-08-19 11:43:35 +0200409 struct dma_chan *localmin = NULL;
Dan Williamsbec08512009-01-06 11:38:14 -0700410
411 list_for_each_entry(device, &dma_device_list, global_node) {
Dan Williams59b5ec22009-01-06 11:38:15 -0700412 if (!dma_has_cap(cap, device->cap_mask) ||
413 dma_has_cap(DMA_PRIVATE, device->cap_mask))
Dan Williamsbec08512009-01-06 11:38:14 -0700414 continue;
415 list_for_each_entry(chan, &device->channels, device_node) {
416 if (!chan->client_count)
417 continue;
Brice Goglinc4d27c42013-08-19 11:43:35 +0200418 if (!min || chan->table_count < min->table_count)
Dan Williamsbec08512009-01-06 11:38:14 -0700419 min = chan;
420
Brice Goglinc4d27c42013-08-19 11:43:35 +0200421 if (dma_chan_is_local(chan, cpu))
422 if (!localmin ||
423 chan->table_count < localmin->table_count)
424 localmin = chan;
Dan Williamsbec08512009-01-06 11:38:14 -0700425 }
Dan Williamsbec08512009-01-06 11:38:14 -0700426 }
427
Brice Goglinc4d27c42013-08-19 11:43:35 +0200428 chan = localmin ? localmin : min;
Dan Williamsbec08512009-01-06 11:38:14 -0700429
Brice Goglinc4d27c42013-08-19 11:43:35 +0200430 if (chan)
431 chan->table_count++;
Dan Williamsbec08512009-01-06 11:38:14 -0700432
Brice Goglinc4d27c42013-08-19 11:43:35 +0200433 return chan;
Dan Williamsbec08512009-01-06 11:38:14 -0700434}
435
436/**
437 * dma_channel_rebalance - redistribute the available channels
438 *
439 * Optimize for cpu isolation (each cpu gets a dedicated channel for an
440 * operation type) in the SMP case, and operation isolation (avoid
441 * multi-tasking channels) in the non-SMP case. Must be called under
442 * dma_list_mutex.
443 */
444static void dma_channel_rebalance(void)
445{
446 struct dma_chan *chan;
447 struct dma_device *device;
448 int cpu;
449 int cap;
Dan Williamsbec08512009-01-06 11:38:14 -0700450
451 /* undo the last distribution */
452 for_each_dma_cap_mask(cap, dma_cap_mask_all)
453 for_each_possible_cpu(cpu)
454 per_cpu_ptr(channel_table[cap], cpu)->chan = NULL;
455
Dan Williams59b5ec22009-01-06 11:38:15 -0700456 list_for_each_entry(device, &dma_device_list, global_node) {
457 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
458 continue;
Dan Williamsbec08512009-01-06 11:38:14 -0700459 list_for_each_entry(chan, &device->channels, device_node)
460 chan->table_count = 0;
Dan Williams59b5ec22009-01-06 11:38:15 -0700461 }
Dan Williamsbec08512009-01-06 11:38:14 -0700462
463 /* don't populate the channel_table if no clients are available */
464 if (!dmaengine_ref_count)
465 return;
466
467 /* redistribute available channels */
Dan Williamsbec08512009-01-06 11:38:14 -0700468 for_each_dma_cap_mask(cap, dma_cap_mask_all)
469 for_each_online_cpu(cpu) {
Brice Goglinc4d27c42013-08-19 11:43:35 +0200470 chan = min_chan(cap, cpu);
Dan Williamsbec08512009-01-06 11:38:14 -0700471 per_cpu_ptr(channel_table[cap], cpu)->chan = chan;
472 }
473}
474
Laurent Pinchart0d5484b2014-10-29 00:30:58 +0200475int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
476{
477 struct dma_device *device;
478
479 if (!chan || !caps)
480 return -EINVAL;
481
482 device = chan->device;
483
484 /* check if the channel supports slave transactions */
Andy Shevchenkodd4e91d2016-05-10 20:43:34 +0300485 if (!(test_bit(DMA_SLAVE, device->cap_mask.bits) ||
486 test_bit(DMA_CYCLIC, device->cap_mask.bits)))
Laurent Pinchart0d5484b2014-10-29 00:30:58 +0200487 return -ENXIO;
488
489 /*
490 * Check whether it reports it uses the generic slave
491 * capabilities, if not, that means it doesn't support any
492 * kind of slave capabilities reporting.
493 */
494 if (!device->directions)
495 return -ENXIO;
496
497 caps->src_addr_widths = device->src_addr_widths;
498 caps->dst_addr_widths = device->dst_addr_widths;
499 caps->directions = device->directions;
Shawn Lin6d5bbed2016-01-22 19:06:50 +0800500 caps->max_burst = device->max_burst;
Laurent Pinchart0d5484b2014-10-29 00:30:58 +0200501 caps->residue_granularity = device->residue_granularity;
Robert Jarzmik9eeacd32015-10-13 21:54:29 +0200502 caps->descriptor_reuse = device->descriptor_reuse;
Laurent Pinchart0d5484b2014-10-29 00:30:58 +0200503
Krzysztof Kozlowski88d04642015-06-10 17:17:07 +0900504 /*
505 * Some devices implement only pause (e.g. to get residuum) but no
506 * resume. However cmd_pause is advertised as pause AND resume.
507 */
508 caps->cmd_pause = !!(device->device_pause && device->device_resume);
Laurent Pinchart0d5484b2014-10-29 00:30:58 +0200509 caps->cmd_terminate = !!device->device_terminate_all;
510
511 return 0;
512}
513EXPORT_SYMBOL_GPL(dma_get_slave_caps);
514
Lars-Peter Clausena53e28d2013-03-25 13:23:52 +0100515static struct dma_chan *private_candidate(const dma_cap_mask_t *mask,
516 struct dma_device *dev,
Dan Williamse2346672009-01-06 11:38:21 -0700517 dma_filter_fn fn, void *fn_param)
Dan Williams59b5ec22009-01-06 11:38:15 -0700518{
519 struct dma_chan *chan;
Dan Williams59b5ec22009-01-06 11:38:15 -0700520
Peter Ujfalusi26b64252015-12-14 22:47:38 +0200521 if (mask && !__dma_device_satisfies_mask(dev, mask)) {
Jarkko Nikulaef859312016-03-14 16:51:09 +0200522 dev_dbg(dev->dev, "%s: wrong capabilities\n", __func__);
Dan Williams59b5ec22009-01-06 11:38:15 -0700523 return NULL;
524 }
525 /* devices with multiple channels need special handling as we need to
526 * ensure that all channels are either private or public.
527 */
528 if (dev->chancnt > 1 && !dma_has_cap(DMA_PRIVATE, dev->cap_mask))
529 list_for_each_entry(chan, &dev->channels, device_node) {
530 /* some channels are already publicly allocated */
531 if (chan->client_count)
532 return NULL;
533 }
534
535 list_for_each_entry(chan, &dev->channels, device_node) {
536 if (chan->client_count) {
Jarkko Nikulaef859312016-03-14 16:51:09 +0200537 dev_dbg(dev->dev, "%s: %s busy\n",
Dan Williams41d5e592009-01-06 11:38:21 -0700538 __func__, dma_chan_name(chan));
Dan Williams59b5ec22009-01-06 11:38:15 -0700539 continue;
540 }
Dan Williamse2346672009-01-06 11:38:21 -0700541 if (fn && !fn(chan, fn_param)) {
Jarkko Nikulaef859312016-03-14 16:51:09 +0200542 dev_dbg(dev->dev, "%s: %s filter said false\n",
Dan Williamse2346672009-01-06 11:38:21 -0700543 __func__, dma_chan_name(chan));
544 continue;
545 }
546 return chan;
Dan Williams59b5ec22009-01-06 11:38:15 -0700547 }
548
Dan Williamse2346672009-01-06 11:38:21 -0700549 return NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700550}
551
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200552static struct dma_chan *find_candidate(struct dma_device *device,
553 const dma_cap_mask_t *mask,
554 dma_filter_fn fn, void *fn_param)
555{
556 struct dma_chan *chan = private_candidate(mask, device, fn, fn_param);
557 int err;
558
559 if (chan) {
560 /* Found a suitable channel, try to grab, prep, and return it.
561 * We first set DMA_PRIVATE to disable balance_ref_count as this
562 * channel will not be published in the general-purpose
563 * allocator
564 */
565 dma_cap_set(DMA_PRIVATE, device->cap_mask);
566 device->privatecnt++;
567 err = dma_chan_get(chan);
568
569 if (err) {
570 if (err == -ENODEV) {
Jarkko Nikulaef859312016-03-14 16:51:09 +0200571 dev_dbg(device->dev, "%s: %s module removed\n",
572 __func__, dma_chan_name(chan));
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200573 list_del_rcu(&device->global_node);
574 } else
Jarkko Nikulaef859312016-03-14 16:51:09 +0200575 dev_dbg(device->dev,
576 "%s: failed to get %s: (%d)\n",
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200577 __func__, dma_chan_name(chan), err);
578
579 if (--device->privatecnt == 0)
580 dma_cap_clear(DMA_PRIVATE, device->cap_mask);
581
582 chan = ERR_PTR(err);
583 }
584 }
585
586 return chan ? chan : ERR_PTR(-EPROBE_DEFER);
587}
588
Dan Williams59b5ec22009-01-06 11:38:15 -0700589/**
Stefan Agner19d643d2015-06-01 23:53:43 +0200590 * dma_get_slave_channel - try to get specific channel exclusively
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800591 * @chan: target channel
592 */
593struct dma_chan *dma_get_slave_channel(struct dma_chan *chan)
594{
595 int err = -EBUSY;
596
597 /* lock against __dma_request_channel */
598 mutex_lock(&dma_list_mutex);
599
Vinod Kould9a6c8f2013-08-19 10:47:26 +0530600 if (chan->client_count == 0) {
Peter Ujfalusi214fc4e2015-09-24 12:03:35 +0300601 struct dma_device *device = chan->device;
602
603 dma_cap_set(DMA_PRIVATE, device->cap_mask);
604 device->privatecnt++;
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800605 err = dma_chan_get(chan);
Peter Ujfalusi214fc4e2015-09-24 12:03:35 +0300606 if (err) {
Jarkko Nikulaef859312016-03-14 16:51:09 +0200607 dev_dbg(chan->device->dev,
608 "%s: failed to get %s: (%d)\n",
Vinod Kould9a6c8f2013-08-19 10:47:26 +0530609 __func__, dma_chan_name(chan), err);
Peter Ujfalusi214fc4e2015-09-24 12:03:35 +0300610 chan = NULL;
611 if (--device->privatecnt == 0)
612 dma_cap_clear(DMA_PRIVATE, device->cap_mask);
613 }
Vinod Kould9a6c8f2013-08-19 10:47:26 +0530614 } else
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800615 chan = NULL;
616
617 mutex_unlock(&dma_list_mutex);
618
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800619
620 return chan;
621}
622EXPORT_SYMBOL_GPL(dma_get_slave_channel);
623
Stephen Warren8010dad2013-11-26 12:40:51 -0700624struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
625{
626 dma_cap_mask_t mask;
627 struct dma_chan *chan;
Stephen Warren8010dad2013-11-26 12:40:51 -0700628
629 dma_cap_zero(mask);
630 dma_cap_set(DMA_SLAVE, mask);
631
632 /* lock against __dma_request_channel */
633 mutex_lock(&dma_list_mutex);
634
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200635 chan = find_candidate(device, &mask, NULL, NULL);
Stephen Warren8010dad2013-11-26 12:40:51 -0700636
637 mutex_unlock(&dma_list_mutex);
638
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200639 return IS_ERR(chan) ? NULL : chan;
Stephen Warren8010dad2013-11-26 12:40:51 -0700640}
641EXPORT_SYMBOL_GPL(dma_get_any_slave_channel);
642
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800643/**
Daniel Mack6b9019a2013-08-14 18:35:03 +0200644 * __dma_request_channel - try to allocate an exclusive channel
Dan Williams59b5ec22009-01-06 11:38:15 -0700645 * @mask: capabilities that the channel must satisfy
646 * @fn: optional callback to disposition available channels
647 * @fn_param: opaque parameter to pass to dma_filter_fn
Stephen Warren0ad7c002013-11-26 10:04:22 -0700648 *
649 * Returns pointer to appropriate DMA channel on success or NULL.
Dan Williams59b5ec22009-01-06 11:38:15 -0700650 */
Lars-Peter Clausena53e28d2013-03-25 13:23:52 +0100651struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
652 dma_filter_fn fn, void *fn_param)
Dan Williams59b5ec22009-01-06 11:38:15 -0700653{
654 struct dma_device *device, *_d;
655 struct dma_chan *chan = NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700656
657 /* Find a channel */
658 mutex_lock(&dma_list_mutex);
659 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200660 chan = find_candidate(device, mask, fn, fn_param);
661 if (!IS_ERR(chan))
662 break;
Dan Williams59b5ec22009-01-06 11:38:15 -0700663
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200664 chan = NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700665 }
666 mutex_unlock(&dma_list_mutex);
667
Jarkko Nikula4c4d7f872016-04-07 16:49:43 +0300668 pr_debug("%s: %s (%s)\n",
Joe Perches63433252012-07-18 09:51:28 -0700669 __func__,
670 chan ? "success" : "fail",
Dan Williams41d5e592009-01-06 11:38:21 -0700671 chan ? dma_chan_name(chan) : NULL);
Dan Williams59b5ec22009-01-06 11:38:15 -0700672
673 return chan;
674}
675EXPORT_SYMBOL_GPL(__dma_request_channel);
676
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200677static const struct dma_slave_map *dma_filter_match(struct dma_device *device,
678 const char *name,
679 struct device *dev)
680{
681 int i;
682
683 if (!device->filter.mapcnt)
684 return NULL;
685
686 for (i = 0; i < device->filter.mapcnt; i++) {
687 const struct dma_slave_map *map = &device->filter.map[i];
688
689 if (!strcmp(map->devname, dev_name(dev)) &&
690 !strcmp(map->slave, name))
691 return map;
692 }
693
694 return NULL;
695}
696
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500697/**
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200698 * dma_request_chan - try to allocate an exclusive slave channel
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500699 * @dev: pointer to client device structure
700 * @name: slave channel name
Stephen Warren0ad7c002013-11-26 10:04:22 -0700701 *
702 * Returns pointer to appropriate DMA channel on success or an error pointer.
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500703 */
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200704struct dma_chan *dma_request_chan(struct device *dev, const char *name)
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500705{
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200706 struct dma_device *d, *_d;
707 struct dma_chan *chan = NULL;
708
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500709 /* If device-tree is present get slave info from here */
710 if (dev->of_node)
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200711 chan = of_dma_request_slave_channel(dev->of_node, name);
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500712
Andy Shevchenko4e82f5d2013-04-09 14:05:44 +0300713 /* If device was enumerated by ACPI get slave info from here */
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200714 if (has_acpi_companion(dev) && !chan)
715 chan = acpi_dma_request_slave_chan_by_name(dev, name);
Andy Shevchenko4e82f5d2013-04-09 14:05:44 +0300716
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200717 if (chan) {
718 /* Valid channel found or requester need to be deferred */
719 if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
720 return chan;
721 }
722
723 /* Try to find the channel via the DMA filter map(s) */
724 mutex_lock(&dma_list_mutex);
725 list_for_each_entry_safe(d, _d, &dma_device_list, global_node) {
726 dma_cap_mask_t mask;
727 const struct dma_slave_map *map = dma_filter_match(d, name, dev);
728
729 if (!map)
730 continue;
731
732 dma_cap_zero(mask);
733 dma_cap_set(DMA_SLAVE, mask);
734
735 chan = find_candidate(d, &mask, d->filter.fn, map->param);
736 if (!IS_ERR(chan))
737 break;
738 }
739 mutex_unlock(&dma_list_mutex);
740
741 return chan ? chan : ERR_PTR(-EPROBE_DEFER);
Stephen Warren0ad7c002013-11-26 10:04:22 -0700742}
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200743EXPORT_SYMBOL_GPL(dma_request_chan);
Stephen Warren0ad7c002013-11-26 10:04:22 -0700744
745/**
746 * dma_request_slave_channel - try to allocate an exclusive slave channel
747 * @dev: pointer to client device structure
748 * @name: slave channel name
749 *
750 * Returns pointer to appropriate DMA channel on success or NULL.
751 */
752struct dma_chan *dma_request_slave_channel(struct device *dev,
753 const char *name)
754{
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200755 struct dma_chan *ch = dma_request_chan(dev, name);
Stephen Warren0ad7c002013-11-26 10:04:22 -0700756 if (IS_ERR(ch))
757 return NULL;
Robert Baldyga05aa1a72015-08-07 12:26:47 +0200758
Stephen Warren0ad7c002013-11-26 10:04:22 -0700759 return ch;
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500760}
761EXPORT_SYMBOL_GPL(dma_request_slave_channel);
762
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200763/**
764 * dma_request_chan_by_mask - allocate a channel satisfying certain capabilities
765 * @mask: capabilities that the channel must satisfy
766 *
767 * Returns pointer to appropriate DMA channel on success or an error pointer.
768 */
769struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask)
770{
771 struct dma_chan *chan;
772
773 if (!mask)
774 return ERR_PTR(-ENODEV);
775
776 chan = __dma_request_channel(mask, NULL, NULL);
777 if (!chan)
778 chan = ERR_PTR(-ENODEV);
779
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{
899 int rc;
900
Dan Williams257b17c2009-03-25 09:13:23 -0700901 mutex_lock(&dma_list_mutex);
Dan Williams257b17c2009-03-25 09:13:23 -0700902
Tejun Heo69ee2662013-02-27 17:04:03 -0800903 rc = idr_alloc(&dma_idr, NULL, 0, 0, GFP_KERNEL);
904 if (rc >= 0)
905 device->dev_id = rc;
906
907 mutex_unlock(&dma_list_mutex);
908 return rc < 0 ? rc : 0;
Dan Williams257b17c2009-03-25 09:13:23 -0700909}
910
Chris Leechc13c8262006-05-23 17:18:44 -0700911/**
Randy Dunlap65088712006-07-03 19:45:31 -0700912 * dma_async_device_register - registers DMA devices found
Chris Leechc13c8262006-05-23 17:18:44 -0700913 * @device: &dma_device
914 */
915int dma_async_device_register(struct dma_device *device)
916{
Jeff Garzikff487fb2007-03-08 09:57:34 -0800917 int chancnt = 0, rc;
Chris Leechc13c8262006-05-23 17:18:44 -0700918 struct dma_chan* chan;
Dan Williams864498a2009-01-06 11:38:21 -0700919 atomic_t *idr_ref;
Chris Leechc13c8262006-05-23 17:18:44 -0700920
921 if (!device)
922 return -ENODEV;
923
Dan Williams7405f742007-01-02 11:10:43 -0700924 /* validate device routines */
925 BUG_ON(dma_has_cap(DMA_MEMCPY, device->cap_mask) &&
926 !device->device_prep_dma_memcpy);
927 BUG_ON(dma_has_cap(DMA_XOR, device->cap_mask) &&
928 !device->device_prep_dma_xor);
Dan Williams099f53c2009-04-08 14:28:37 -0700929 BUG_ON(dma_has_cap(DMA_XOR_VAL, device->cap_mask) &&
930 !device->device_prep_dma_xor_val);
Dan Williamsb2f46fd2009-07-14 12:20:36 -0700931 BUG_ON(dma_has_cap(DMA_PQ, device->cap_mask) &&
932 !device->device_prep_dma_pq);
933 BUG_ON(dma_has_cap(DMA_PQ_VAL, device->cap_mask) &&
934 !device->device_prep_dma_pq_val);
Maxime Ripard4983a502015-05-18 13:46:15 +0200935 BUG_ON(dma_has_cap(DMA_MEMSET, device->cap_mask) &&
936 !device->device_prep_dma_memset);
Zhang Wei9b941c62008-03-13 17:45:28 -0700937 BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) &&
Dan Williams7405f742007-01-02 11:10:43 -0700938 !device->device_prep_dma_interrupt);
Ira Snydera86ee032010-09-30 11:46:44 +0000939 BUG_ON(dma_has_cap(DMA_SG, device->cap_mask) &&
940 !device->device_prep_dma_sg);
Sascha Hauer782bc952010-09-30 13:56:32 +0000941 BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
942 !device->device_prep_dma_cyclic);
Jassi Brarb14dab72011-10-13 12:33:30 +0530943 BUG_ON(dma_has_cap(DMA_INTERLEAVE, device->cap_mask) &&
944 !device->device_prep_interleaved_dma);
Dan Williams7405f742007-01-02 11:10:43 -0700945
Linus Walleij07934482010-03-26 16:50:49 -0700946 BUG_ON(!device->device_tx_status);
Dan Williams7405f742007-01-02 11:10:43 -0700947 BUG_ON(!device->device_issue_pending);
948 BUG_ON(!device->dev);
949
Dan Williams138f4c32009-09-08 17:42:51 -0700950 /* note: this only matters in the
Dan Williams5fc6d892010-10-07 16:44:50 -0700951 * CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH=n case
Dan Williams138f4c32009-09-08 17:42:51 -0700952 */
953 if (device_has_all_tx_types(device))
954 dma_cap_set(DMA_ASYNC_TX, device->cap_mask);
955
Dan Williams864498a2009-01-06 11:38:21 -0700956 idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL);
957 if (!idr_ref)
958 return -ENOMEM;
Dan Williams257b17c2009-03-25 09:13:23 -0700959 rc = get_dma_id(device);
960 if (rc != 0) {
961 kfree(idr_ref);
Dan Williams864498a2009-01-06 11:38:21 -0700962 return rc;
Dan Williams257b17c2009-03-25 09:13:23 -0700963 }
964
965 atomic_set(idr_ref, 0);
Chris Leechc13c8262006-05-23 17:18:44 -0700966
967 /* represent channels in sysfs. Probably want devs too */
968 list_for_each_entry(chan, &device->channels, device_node) {
Dan Williams257b17c2009-03-25 09:13:23 -0700969 rc = -ENOMEM;
Chris Leechc13c8262006-05-23 17:18:44 -0700970 chan->local = alloc_percpu(typeof(*chan->local));
971 if (chan->local == NULL)
Dan Williams257b17c2009-03-25 09:13:23 -0700972 goto err_out;
Dan Williams41d5e592009-01-06 11:38:21 -0700973 chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL);
974 if (chan->dev == NULL) {
975 free_percpu(chan->local);
Dan Williams257b17c2009-03-25 09:13:23 -0700976 chan->local = NULL;
977 goto err_out;
Dan Williams41d5e592009-01-06 11:38:21 -0700978 }
Chris Leechc13c8262006-05-23 17:18:44 -0700979
980 chan->chan_id = chancnt++;
Dan Williams41d5e592009-01-06 11:38:21 -0700981 chan->dev->device.class = &dma_devclass;
982 chan->dev->device.parent = device->dev;
983 chan->dev->chan = chan;
Dan Williams864498a2009-01-06 11:38:21 -0700984 chan->dev->idr_ref = idr_ref;
985 chan->dev->dev_id = device->dev_id;
986 atomic_inc(idr_ref);
Dan Williams41d5e592009-01-06 11:38:21 -0700987 dev_set_name(&chan->dev->device, "dma%dchan%d",
Kay Sievers06190d82008-11-11 13:12:33 -0700988 device->dev_id, chan->chan_id);
Chris Leechc13c8262006-05-23 17:18:44 -0700989
Dan Williams41d5e592009-01-06 11:38:21 -0700990 rc = device_register(&chan->dev->device);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800991 if (rc) {
Jeff Garzikff487fb2007-03-08 09:57:34 -0800992 free_percpu(chan->local);
993 chan->local = NULL;
Dan Williams257b17c2009-03-25 09:13:23 -0700994 kfree(chan->dev);
995 atomic_dec(idr_ref);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800996 goto err_out;
997 }
Dan Williams7cc5bf92008-07-08 11:58:21 -0700998 chan->client_count = 0;
Chris Leechc13c8262006-05-23 17:18:44 -0700999 }
Dan Williams59b5ec22009-01-06 11:38:15 -07001000 device->chancnt = chancnt;
Chris Leechc13c8262006-05-23 17:18:44 -07001001
1002 mutex_lock(&dma_list_mutex);
Dan Williams59b5ec22009-01-06 11:38:15 -07001003 /* take references on public channels */
1004 if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask))
Dan Williams6f49a572009-01-06 11:38:14 -07001005 list_for_each_entry(chan, &device->channels, device_node) {
1006 /* if clients are already waiting for channels we need
1007 * to take references on their behalf
1008 */
1009 if (dma_chan_get(chan) == -ENODEV) {
1010 /* note we can only get here for the first
1011 * channel as the remaining channels are
1012 * guaranteed to get a reference
1013 */
1014 rc = -ENODEV;
1015 mutex_unlock(&dma_list_mutex);
1016 goto err_out;
1017 }
1018 }
Dan Williams2ba05622009-01-06 11:38:14 -07001019 list_add_tail_rcu(&device->global_node, &dma_device_list);
Atsushi Nemoto0f571512009-03-06 20:07:14 +09001020 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
1021 device->privatecnt++; /* Always private */
Dan Williamsbec08512009-01-06 11:38:14 -07001022 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -07001023 mutex_unlock(&dma_list_mutex);
1024
Chris Leechc13c8262006-05-23 17:18:44 -07001025 return 0;
Jeff Garzikff487fb2007-03-08 09:57:34 -08001026
1027err_out:
Dan Williams257b17c2009-03-25 09:13:23 -07001028 /* if we never registered a channel just release the idr */
1029 if (atomic_read(idr_ref) == 0) {
1030 mutex_lock(&dma_list_mutex);
1031 idr_remove(&dma_idr, device->dev_id);
1032 mutex_unlock(&dma_list_mutex);
1033 kfree(idr_ref);
1034 return rc;
1035 }
1036
Jeff Garzikff487fb2007-03-08 09:57:34 -08001037 list_for_each_entry(chan, &device->channels, device_node) {
1038 if (chan->local == NULL)
1039 continue;
Dan Williams41d5e592009-01-06 11:38:21 -07001040 mutex_lock(&dma_list_mutex);
1041 chan->dev->chan = NULL;
1042 mutex_unlock(&dma_list_mutex);
1043 device_unregister(&chan->dev->device);
Jeff Garzikff487fb2007-03-08 09:57:34 -08001044 free_percpu(chan->local);
1045 }
1046 return rc;
Chris Leechc13c8262006-05-23 17:18:44 -07001047}
David Brownell765e3d82007-03-16 13:38:05 -08001048EXPORT_SYMBOL(dma_async_device_register);
Chris Leechc13c8262006-05-23 17:18:44 -07001049
1050/**
Dan Williams6f49a572009-01-06 11:38:14 -07001051 * dma_async_device_unregister - unregister a DMA device
Randy Dunlap65088712006-07-03 19:45:31 -07001052 * @device: &dma_device
Dan Williamsf27c5802009-01-06 11:38:18 -07001053 *
1054 * This routine is called by dma driver exit routines, dmaengine holds module
1055 * references to prevent it being called while channels are in use.
Randy Dunlap65088712006-07-03 19:45:31 -07001056 */
1057void dma_async_device_unregister(struct dma_device *device)
Chris Leechc13c8262006-05-23 17:18:44 -07001058{
1059 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -07001060
1061 mutex_lock(&dma_list_mutex);
Dan Williams2ba05622009-01-06 11:38:14 -07001062 list_del_rcu(&device->global_node);
Dan Williamsbec08512009-01-06 11:38:14 -07001063 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -07001064 mutex_unlock(&dma_list_mutex);
1065
1066 list_for_each_entry(chan, &device->channels, device_node) {
Dan Williams6f49a572009-01-06 11:38:14 -07001067 WARN_ONCE(chan->client_count,
1068 "%s called while %d clients hold a reference\n",
1069 __func__, chan->client_count);
Dan Williams41d5e592009-01-06 11:38:21 -07001070 mutex_lock(&dma_list_mutex);
1071 chan->dev->chan = NULL;
1072 mutex_unlock(&dma_list_mutex);
1073 device_unregister(&chan->dev->device);
Anatolij Gustschinadef4772010-01-26 10:26:06 +01001074 free_percpu(chan->local);
Chris Leechc13c8262006-05-23 17:18:44 -07001075 }
Chris Leechc13c8262006-05-23 17:18:44 -07001076}
David Brownell765e3d82007-03-16 13:38:05 -08001077EXPORT_SYMBOL(dma_async_device_unregister);
Chris Leechc13c8262006-05-23 17:18:44 -07001078
Dan Williams45c463a2013-10-18 19:35:24 +02001079struct dmaengine_unmap_pool {
1080 struct kmem_cache *cache;
1081 const char *name;
1082 mempool_t *pool;
1083 size_t size;
1084};
1085
1086#define __UNMAP_POOL(x) { .size = x, .name = "dmaengine-unmap-" __stringify(x) }
1087static struct dmaengine_unmap_pool unmap_pool[] = {
1088 __UNMAP_POOL(2),
Dan Williams3cc377b2013-12-09 10:33:16 -08001089 #if IS_ENABLED(CONFIG_DMA_ENGINE_RAID)
Dan Williams45c463a2013-10-18 19:35:24 +02001090 __UNMAP_POOL(16),
1091 __UNMAP_POOL(128),
1092 __UNMAP_POOL(256),
1093 #endif
1094};
1095
1096static struct dmaengine_unmap_pool *__get_unmap_pool(int nr)
Dan Williams7405f742007-01-02 11:10:43 -07001097{
Dan Williams45c463a2013-10-18 19:35:24 +02001098 int order = get_count_order(nr);
Dan Williams7405f742007-01-02 11:10:43 -07001099
Dan Williams45c463a2013-10-18 19:35:24 +02001100 switch (order) {
1101 case 0 ... 1:
1102 return &unmap_pool[0];
1103 case 2 ... 4:
1104 return &unmap_pool[1];
1105 case 5 ... 7:
1106 return &unmap_pool[2];
1107 case 8:
1108 return &unmap_pool[3];
1109 default:
1110 BUG();
1111 return NULL;
1112 }
1113}
Dan Williams00367312008-02-02 19:49:57 -07001114
Dan Williams45c463a2013-10-18 19:35:24 +02001115static void dmaengine_unmap(struct kref *kref)
1116{
1117 struct dmaengine_unmap_data *unmap = container_of(kref, typeof(*unmap), kref);
1118 struct device *dev = unmap->dev;
1119 int cnt, i;
1120
1121 cnt = unmap->to_cnt;
1122 for (i = 0; i < cnt; i++)
1123 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1124 DMA_TO_DEVICE);
1125 cnt += unmap->from_cnt;
1126 for (; i < cnt; i++)
1127 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1128 DMA_FROM_DEVICE);
1129 cnt += unmap->bidi_cnt;
Dan Williams7476bd72013-10-18 19:35:29 +02001130 for (; i < cnt; i++) {
1131 if (unmap->addr[i] == 0)
1132 continue;
Dan Williams45c463a2013-10-18 19:35:24 +02001133 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1134 DMA_BIDIRECTIONAL);
Dan Williams7476bd72013-10-18 19:35:29 +02001135 }
Xuelin Shic1f43dd2014-05-21 14:02:37 -07001136 cnt = unmap->map_cnt;
Dan Williams45c463a2013-10-18 19:35:24 +02001137 mempool_free(unmap, __get_unmap_pool(cnt)->pool);
1138}
1139
1140void dmaengine_unmap_put(struct dmaengine_unmap_data *unmap)
1141{
1142 if (unmap)
1143 kref_put(&unmap->kref, dmaengine_unmap);
1144}
1145EXPORT_SYMBOL_GPL(dmaengine_unmap_put);
1146
1147static void dmaengine_destroy_unmap_pool(void)
1148{
1149 int i;
1150
1151 for (i = 0; i < ARRAY_SIZE(unmap_pool); i++) {
1152 struct dmaengine_unmap_pool *p = &unmap_pool[i];
1153
Julia Lawall240eb9162015-09-13 14:15:19 +02001154 mempool_destroy(p->pool);
Dan Williams45c463a2013-10-18 19:35:24 +02001155 p->pool = NULL;
Julia Lawall240eb9162015-09-13 14:15:19 +02001156 kmem_cache_destroy(p->cache);
Dan Williams45c463a2013-10-18 19:35:24 +02001157 p->cache = NULL;
1158 }
1159}
1160
1161static int __init dmaengine_init_unmap_pool(void)
1162{
1163 int i;
1164
1165 for (i = 0; i < ARRAY_SIZE(unmap_pool); i++) {
1166 struct dmaengine_unmap_pool *p = &unmap_pool[i];
1167 size_t size;
1168
1169 size = sizeof(struct dmaengine_unmap_data) +
1170 sizeof(dma_addr_t) * p->size;
1171
1172 p->cache = kmem_cache_create(p->name, size, 0,
1173 SLAB_HWCACHE_ALIGN, NULL);
1174 if (!p->cache)
1175 break;
1176 p->pool = mempool_create_slab_pool(1, p->cache);
1177 if (!p->pool)
1178 break;
Dan Williams00367312008-02-02 19:49:57 -07001179 }
Dan Williams7405f742007-01-02 11:10:43 -07001180
Dan Williams45c463a2013-10-18 19:35:24 +02001181 if (i == ARRAY_SIZE(unmap_pool))
1182 return 0;
Dan Williams7405f742007-01-02 11:10:43 -07001183
Dan Williams45c463a2013-10-18 19:35:24 +02001184 dmaengine_destroy_unmap_pool();
1185 return -ENOMEM;
Dan Williams7405f742007-01-02 11:10:43 -07001186}
Dan Williams7405f742007-01-02 11:10:43 -07001187
Dan Williams89716462013-10-18 19:35:25 +02001188struct dmaengine_unmap_data *
Dan Williams45c463a2013-10-18 19:35:24 +02001189dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags)
Dan Williams7405f742007-01-02 11:10:43 -07001190{
Dan Williams45c463a2013-10-18 19:35:24 +02001191 struct dmaengine_unmap_data *unmap;
Dan Williams7405f742007-01-02 11:10:43 -07001192
Dan Williams45c463a2013-10-18 19:35:24 +02001193 unmap = mempool_alloc(__get_unmap_pool(nr)->pool, flags);
1194 if (!unmap)
1195 return NULL;
Dan Williams00367312008-02-02 19:49:57 -07001196
Dan Williams45c463a2013-10-18 19:35:24 +02001197 memset(unmap, 0, sizeof(*unmap));
1198 kref_init(&unmap->kref);
1199 unmap->dev = dev;
Xuelin Shic1f43dd2014-05-21 14:02:37 -07001200 unmap->map_cnt = nr;
Dan Williams7405f742007-01-02 11:10:43 -07001201
Dan Williams45c463a2013-10-18 19:35:24 +02001202 return unmap;
Dan Williams7405f742007-01-02 11:10:43 -07001203}
Dan Williams89716462013-10-18 19:35:25 +02001204EXPORT_SYMBOL(dmaengine_get_unmap_data);
Dan Williams7405f742007-01-02 11:10:43 -07001205
Dan Williams7405f742007-01-02 11:10:43 -07001206void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
1207 struct dma_chan *chan)
1208{
1209 tx->chan = chan;
Dan Williams5fc6d892010-10-07 16:44:50 -07001210 #ifdef CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH
Dan Williams7405f742007-01-02 11:10:43 -07001211 spin_lock_init(&tx->lock);
Dan Williamscaa20d972010-05-17 16:24:16 -07001212 #endif
Dan Williams7405f742007-01-02 11:10:43 -07001213}
1214EXPORT_SYMBOL(dma_async_tx_descriptor_init);
1215
Dan Williams07f22112009-01-05 17:14:31 -07001216/* dma_wait_for_async_tx - spin wait for a transaction to complete
1217 * @tx: in-flight transaction to wait on
Dan Williams07f22112009-01-05 17:14:31 -07001218 */
1219enum dma_status
1220dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
1221{
Dan Williams95475e52009-07-14 12:19:02 -07001222 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
Dan Williams07f22112009-01-05 17:14:31 -07001223
1224 if (!tx)
Vinod Kouladfedd92013-10-16 13:29:02 +05301225 return DMA_COMPLETE;
Dan Williams07f22112009-01-05 17:14:31 -07001226
Dan Williams95475e52009-07-14 12:19:02 -07001227 while (tx->cookie == -EBUSY) {
1228 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
Jarkko Nikulaef859312016-03-14 16:51:09 +02001229 dev_err(tx->chan->device->dev,
1230 "%s timeout waiting for descriptor submission\n",
1231 __func__);
Dan Williams95475e52009-07-14 12:19:02 -07001232 return DMA_ERROR;
1233 }
1234 cpu_relax();
1235 }
1236 return dma_sync_wait(tx->chan, tx->cookie);
Dan Williams07f22112009-01-05 17:14:31 -07001237}
1238EXPORT_SYMBOL_GPL(dma_wait_for_async_tx);
1239
1240/* dma_run_dependencies - helper routine for dma drivers to process
1241 * (start) dependent operations on their target channel
1242 * @tx: transaction with dependencies
1243 */
1244void dma_run_dependencies(struct dma_async_tx_descriptor *tx)
1245{
Dan Williamscaa20d972010-05-17 16:24:16 -07001246 struct dma_async_tx_descriptor *dep = txd_next(tx);
Dan Williams07f22112009-01-05 17:14:31 -07001247 struct dma_async_tx_descriptor *dep_next;
1248 struct dma_chan *chan;
1249
1250 if (!dep)
1251 return;
1252
Yuri Tikhonovdd59b852009-01-12 15:17:20 -07001253 /* we'll submit tx->next now, so clear the link */
Dan Williamscaa20d972010-05-17 16:24:16 -07001254 txd_clear_next(tx);
Dan Williams07f22112009-01-05 17:14:31 -07001255 chan = dep->chan;
1256
1257 /* keep submitting up until a channel switch is detected
1258 * in that case we will be called again as a result of
1259 * processing the interrupt from async_tx_channel_switch
1260 */
1261 for (; dep; dep = dep_next) {
Dan Williamscaa20d972010-05-17 16:24:16 -07001262 txd_lock(dep);
1263 txd_clear_parent(dep);
1264 dep_next = txd_next(dep);
Dan Williams07f22112009-01-05 17:14:31 -07001265 if (dep_next && dep_next->chan == chan)
Dan Williamscaa20d972010-05-17 16:24:16 -07001266 txd_clear_next(dep); /* ->next will be submitted */
Dan Williams07f22112009-01-05 17:14:31 -07001267 else
1268 dep_next = NULL; /* submit current dep and terminate */
Dan Williamscaa20d972010-05-17 16:24:16 -07001269 txd_unlock(dep);
Dan Williams07f22112009-01-05 17:14:31 -07001270
1271 dep->tx_submit(dep);
1272 }
1273
1274 chan->device->device_issue_pending(chan);
1275}
1276EXPORT_SYMBOL_GPL(dma_run_dependencies);
1277
Chris Leechc13c8262006-05-23 17:18:44 -07001278static int __init dma_bus_init(void)
1279{
Dan Williams45c463a2013-10-18 19:35:24 +02001280 int err = dmaengine_init_unmap_pool();
1281
1282 if (err)
1283 return err;
Chris Leechc13c8262006-05-23 17:18:44 -07001284 return class_register(&dma_devclass);
1285}
Dan Williams652afc22009-01-06 11:38:22 -07001286arch_initcall(dma_bus_init);
Chris Leechc13c8262006-05-23 17:18:44 -07001287
Dan Williamsbec08512009-01-06 11:38:14 -07001288