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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)) {
Joe Perches63433252012-07-18 09:51:28 -0700292 pr_err("%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 */
485 if (!test_bit(DMA_SLAVE, device->cap_mask.bits))
486 return -ENXIO;
487
488 /*
489 * Check whether it reports it uses the generic slave
490 * capabilities, if not, that means it doesn't support any
491 * kind of slave capabilities reporting.
492 */
493 if (!device->directions)
494 return -ENXIO;
495
496 caps->src_addr_widths = device->src_addr_widths;
497 caps->dst_addr_widths = device->dst_addr_widths;
498 caps->directions = device->directions;
Shawn Lin6d5bbed2016-01-22 19:06:50 +0800499 caps->max_burst = device->max_burst;
Laurent Pinchart0d5484b2014-10-29 00:30:58 +0200500 caps->residue_granularity = device->residue_granularity;
Robert Jarzmik9eeacd32015-10-13 21:54:29 +0200501 caps->descriptor_reuse = device->descriptor_reuse;
Laurent Pinchart0d5484b2014-10-29 00:30:58 +0200502
Krzysztof Kozlowski88d04642015-06-10 17:17:07 +0900503 /*
504 * Some devices implement only pause (e.g. to get residuum) but no
505 * resume. However cmd_pause is advertised as pause AND resume.
506 */
507 caps->cmd_pause = !!(device->device_pause && device->device_resume);
Laurent Pinchart0d5484b2014-10-29 00:30:58 +0200508 caps->cmd_terminate = !!device->device_terminate_all;
509
510 return 0;
511}
512EXPORT_SYMBOL_GPL(dma_get_slave_caps);
513
Lars-Peter Clausena53e28d2013-03-25 13:23:52 +0100514static struct dma_chan *private_candidate(const dma_cap_mask_t *mask,
515 struct dma_device *dev,
Dan Williamse2346672009-01-06 11:38:21 -0700516 dma_filter_fn fn, void *fn_param)
Dan Williams59b5ec22009-01-06 11:38:15 -0700517{
518 struct dma_chan *chan;
Dan Williams59b5ec22009-01-06 11:38:15 -0700519
Peter Ujfalusi26b64252015-12-14 22:47:38 +0200520 if (mask && !__dma_device_satisfies_mask(dev, mask)) {
Dan Williams59b5ec22009-01-06 11:38:15 -0700521 pr_debug("%s: wrong capabilities\n", __func__);
522 return NULL;
523 }
524 /* devices with multiple channels need special handling as we need to
525 * ensure that all channels are either private or public.
526 */
527 if (dev->chancnt > 1 && !dma_has_cap(DMA_PRIVATE, dev->cap_mask))
528 list_for_each_entry(chan, &dev->channels, device_node) {
529 /* some channels are already publicly allocated */
530 if (chan->client_count)
531 return NULL;
532 }
533
534 list_for_each_entry(chan, &dev->channels, device_node) {
535 if (chan->client_count) {
536 pr_debug("%s: %s busy\n",
Dan Williams41d5e592009-01-06 11:38:21 -0700537 __func__, dma_chan_name(chan));
Dan Williams59b5ec22009-01-06 11:38:15 -0700538 continue;
539 }
Dan Williamse2346672009-01-06 11:38:21 -0700540 if (fn && !fn(chan, fn_param)) {
541 pr_debug("%s: %s filter said false\n",
542 __func__, dma_chan_name(chan));
543 continue;
544 }
545 return chan;
Dan Williams59b5ec22009-01-06 11:38:15 -0700546 }
547
Dan Williamse2346672009-01-06 11:38:21 -0700548 return NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700549}
550
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200551static struct dma_chan *find_candidate(struct dma_device *device,
552 const dma_cap_mask_t *mask,
553 dma_filter_fn fn, void *fn_param)
554{
555 struct dma_chan *chan = private_candidate(mask, device, fn, fn_param);
556 int err;
557
558 if (chan) {
559 /* Found a suitable channel, try to grab, prep, and return it.
560 * We first set DMA_PRIVATE to disable balance_ref_count as this
561 * channel will not be published in the general-purpose
562 * allocator
563 */
564 dma_cap_set(DMA_PRIVATE, device->cap_mask);
565 device->privatecnt++;
566 err = dma_chan_get(chan);
567
568 if (err) {
569 if (err == -ENODEV) {
570 pr_debug("%s: %s module removed\n", __func__,
571 dma_chan_name(chan));
572 list_del_rcu(&device->global_node);
573 } else
574 pr_debug("%s: failed to get %s: (%d)\n",
575 __func__, dma_chan_name(chan), err);
576
577 if (--device->privatecnt == 0)
578 dma_cap_clear(DMA_PRIVATE, device->cap_mask);
579
580 chan = ERR_PTR(err);
581 }
582 }
583
584 return chan ? chan : ERR_PTR(-EPROBE_DEFER);
585}
586
Dan Williams59b5ec22009-01-06 11:38:15 -0700587/**
Stefan Agner19d643d2015-06-01 23:53:43 +0200588 * dma_get_slave_channel - try to get specific channel exclusively
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800589 * @chan: target channel
590 */
591struct dma_chan *dma_get_slave_channel(struct dma_chan *chan)
592{
593 int err = -EBUSY;
594
595 /* lock against __dma_request_channel */
596 mutex_lock(&dma_list_mutex);
597
Vinod Kould9a6c8f2013-08-19 10:47:26 +0530598 if (chan->client_count == 0) {
Peter Ujfalusi214fc4e2015-09-24 12:03:35 +0300599 struct dma_device *device = chan->device;
600
601 dma_cap_set(DMA_PRIVATE, device->cap_mask);
602 device->privatecnt++;
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800603 err = dma_chan_get(chan);
Peter Ujfalusi214fc4e2015-09-24 12:03:35 +0300604 if (err) {
Vinod Kould9a6c8f2013-08-19 10:47:26 +0530605 pr_debug("%s: failed to get %s: (%d)\n",
606 __func__, dma_chan_name(chan), err);
Peter Ujfalusi214fc4e2015-09-24 12:03:35 +0300607 chan = NULL;
608 if (--device->privatecnt == 0)
609 dma_cap_clear(DMA_PRIVATE, device->cap_mask);
610 }
Vinod Kould9a6c8f2013-08-19 10:47:26 +0530611 } else
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800612 chan = NULL;
613
614 mutex_unlock(&dma_list_mutex);
615
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800616
617 return chan;
618}
619EXPORT_SYMBOL_GPL(dma_get_slave_channel);
620
Stephen Warren8010dad2013-11-26 12:40:51 -0700621struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
622{
623 dma_cap_mask_t mask;
624 struct dma_chan *chan;
Stephen Warren8010dad2013-11-26 12:40:51 -0700625
626 dma_cap_zero(mask);
627 dma_cap_set(DMA_SLAVE, mask);
628
629 /* lock against __dma_request_channel */
630 mutex_lock(&dma_list_mutex);
631
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200632 chan = find_candidate(device, &mask, NULL, NULL);
Stephen Warren8010dad2013-11-26 12:40:51 -0700633
634 mutex_unlock(&dma_list_mutex);
635
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200636 return IS_ERR(chan) ? NULL : chan;
Stephen Warren8010dad2013-11-26 12:40:51 -0700637}
638EXPORT_SYMBOL_GPL(dma_get_any_slave_channel);
639
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800640/**
Daniel Mack6b9019a2013-08-14 18:35:03 +0200641 * __dma_request_channel - try to allocate an exclusive channel
Dan Williams59b5ec22009-01-06 11:38:15 -0700642 * @mask: capabilities that the channel must satisfy
643 * @fn: optional callback to disposition available channels
644 * @fn_param: opaque parameter to pass to dma_filter_fn
Stephen Warren0ad7c002013-11-26 10:04:22 -0700645 *
646 * Returns pointer to appropriate DMA channel on success or NULL.
Dan Williams59b5ec22009-01-06 11:38:15 -0700647 */
Lars-Peter Clausena53e28d2013-03-25 13:23:52 +0100648struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
649 dma_filter_fn fn, void *fn_param)
Dan Williams59b5ec22009-01-06 11:38:15 -0700650{
651 struct dma_device *device, *_d;
652 struct dma_chan *chan = NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700653
654 /* Find a channel */
655 mutex_lock(&dma_list_mutex);
656 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200657 chan = find_candidate(device, mask, fn, fn_param);
658 if (!IS_ERR(chan))
659 break;
Dan Williams59b5ec22009-01-06 11:38:15 -0700660
Peter Ujfalusi7bd903c2015-12-14 22:47:39 +0200661 chan = NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700662 }
663 mutex_unlock(&dma_list_mutex);
664
Joe Perches63433252012-07-18 09:51:28 -0700665 pr_debug("%s: %s (%s)\n",
666 __func__,
667 chan ? "success" : "fail",
Dan Williams41d5e592009-01-06 11:38:21 -0700668 chan ? dma_chan_name(chan) : NULL);
Dan Williams59b5ec22009-01-06 11:38:15 -0700669
670 return chan;
671}
672EXPORT_SYMBOL_GPL(__dma_request_channel);
673
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200674static const struct dma_slave_map *dma_filter_match(struct dma_device *device,
675 const char *name,
676 struct device *dev)
677{
678 int i;
679
680 if (!device->filter.mapcnt)
681 return NULL;
682
683 for (i = 0; i < device->filter.mapcnt; i++) {
684 const struct dma_slave_map *map = &device->filter.map[i];
685
686 if (!strcmp(map->devname, dev_name(dev)) &&
687 !strcmp(map->slave, name))
688 return map;
689 }
690
691 return NULL;
692}
693
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500694/**
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200695 * dma_request_chan - try to allocate an exclusive slave channel
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500696 * @dev: pointer to client device structure
697 * @name: slave channel name
Stephen Warren0ad7c002013-11-26 10:04:22 -0700698 *
699 * Returns pointer to appropriate DMA channel on success or an error pointer.
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500700 */
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200701struct dma_chan *dma_request_chan(struct device *dev, const char *name)
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500702{
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200703 struct dma_device *d, *_d;
704 struct dma_chan *chan = NULL;
705
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500706 /* If device-tree is present get slave info from here */
707 if (dev->of_node)
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200708 chan = of_dma_request_slave_channel(dev->of_node, name);
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500709
Andy Shevchenko4e82f5d2013-04-09 14:05:44 +0300710 /* If device was enumerated by ACPI get slave info from here */
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200711 if (has_acpi_companion(dev) && !chan)
712 chan = acpi_dma_request_slave_chan_by_name(dev, name);
Andy Shevchenko4e82f5d2013-04-09 14:05:44 +0300713
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200714 if (chan) {
715 /* Valid channel found or requester need to be deferred */
716 if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
717 return chan;
718 }
719
720 /* Try to find the channel via the DMA filter map(s) */
721 mutex_lock(&dma_list_mutex);
722 list_for_each_entry_safe(d, _d, &dma_device_list, global_node) {
723 dma_cap_mask_t mask;
724 const struct dma_slave_map *map = dma_filter_match(d, name, dev);
725
726 if (!map)
727 continue;
728
729 dma_cap_zero(mask);
730 dma_cap_set(DMA_SLAVE, mask);
731
732 chan = find_candidate(d, &mask, d->filter.fn, map->param);
733 if (!IS_ERR(chan))
734 break;
735 }
736 mutex_unlock(&dma_list_mutex);
737
738 return chan ? chan : ERR_PTR(-EPROBE_DEFER);
Stephen Warren0ad7c002013-11-26 10:04:22 -0700739}
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200740EXPORT_SYMBOL_GPL(dma_request_chan);
Stephen Warren0ad7c002013-11-26 10:04:22 -0700741
742/**
743 * dma_request_slave_channel - try to allocate an exclusive slave channel
744 * @dev: pointer to client device structure
745 * @name: slave channel name
746 *
747 * Returns pointer to appropriate DMA channel on success or NULL.
748 */
749struct dma_chan *dma_request_slave_channel(struct device *dev,
750 const char *name)
751{
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200752 struct dma_chan *ch = dma_request_chan(dev, name);
Stephen Warren0ad7c002013-11-26 10:04:22 -0700753 if (IS_ERR(ch))
754 return NULL;
Robert Baldyga05aa1a72015-08-07 12:26:47 +0200755
Stephen Warren0ad7c002013-11-26 10:04:22 -0700756 return ch;
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500757}
758EXPORT_SYMBOL_GPL(dma_request_slave_channel);
759
Peter Ujfalusia8135d02015-12-14 22:47:40 +0200760/**
761 * dma_request_chan_by_mask - allocate a channel satisfying certain capabilities
762 * @mask: capabilities that the channel must satisfy
763 *
764 * Returns pointer to appropriate DMA channel on success or an error pointer.
765 */
766struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask)
767{
768 struct dma_chan *chan;
769
770 if (!mask)
771 return ERR_PTR(-ENODEV);
772
773 chan = __dma_request_channel(mask, NULL, NULL);
774 if (!chan)
775 chan = ERR_PTR(-ENODEV);
776
777 return chan;
778}
779EXPORT_SYMBOL_GPL(dma_request_chan_by_mask);
780
Dan Williams59b5ec22009-01-06 11:38:15 -0700781void dma_release_channel(struct dma_chan *chan)
782{
783 mutex_lock(&dma_list_mutex);
784 WARN_ONCE(chan->client_count != 1,
785 "chan reference count %d != 1\n", chan->client_count);
786 dma_chan_put(chan);
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900787 /* drop PRIVATE cap enabled by __dma_request_channel() */
788 if (--chan->device->privatecnt == 0)
789 dma_cap_clear(DMA_PRIVATE, chan->device->cap_mask);
Dan Williams59b5ec22009-01-06 11:38:15 -0700790 mutex_unlock(&dma_list_mutex);
791}
792EXPORT_SYMBOL_GPL(dma_release_channel);
793
Dan Williamsbec08512009-01-06 11:38:14 -0700794/**
Dan Williams209b84a2009-01-06 11:38:17 -0700795 * dmaengine_get - register interest in dma_channels
Chris Leechc13c8262006-05-23 17:18:44 -0700796 */
Dan Williams209b84a2009-01-06 11:38:17 -0700797void dmaengine_get(void)
Chris Leechc13c8262006-05-23 17:18:44 -0700798{
Dan Williams6f49a572009-01-06 11:38:14 -0700799 struct dma_device *device, *_d;
800 struct dma_chan *chan;
801 int err;
802
Chris Leechc13c8262006-05-23 17:18:44 -0700803 mutex_lock(&dma_list_mutex);
Dan Williams6f49a572009-01-06 11:38:14 -0700804 dmaengine_ref_count++;
805
806 /* try to grab channels */
Dan Williams59b5ec22009-01-06 11:38:15 -0700807 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
808 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
809 continue;
Dan Williams6f49a572009-01-06 11:38:14 -0700810 list_for_each_entry(chan, &device->channels, device_node) {
811 err = dma_chan_get(chan);
812 if (err == -ENODEV) {
813 /* module removed before we could use it */
Dan Williams2ba05622009-01-06 11:38:14 -0700814 list_del_rcu(&device->global_node);
Dan Williams6f49a572009-01-06 11:38:14 -0700815 break;
816 } else if (err)
Fabio Estevam0eb5a352012-10-04 17:11:16 -0700817 pr_debug("%s: failed to get %s: (%d)\n",
Joe Perches63433252012-07-18 09:51:28 -0700818 __func__, dma_chan_name(chan), err);
Dan Williams6f49a572009-01-06 11:38:14 -0700819 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700820 }
Dan Williams6f49a572009-01-06 11:38:14 -0700821
Dan Williamsbec08512009-01-06 11:38:14 -0700822 /* if this is the first reference and there were channels
823 * waiting we need to rebalance to get those channels
824 * incorporated into the channel table
825 */
826 if (dmaengine_ref_count == 1)
827 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -0700828 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700829}
Dan Williams209b84a2009-01-06 11:38:17 -0700830EXPORT_SYMBOL(dmaengine_get);
Chris Leechc13c8262006-05-23 17:18:44 -0700831
832/**
Dan Williams209b84a2009-01-06 11:38:17 -0700833 * dmaengine_put - let dma drivers be removed when ref_count == 0
Chris Leechc13c8262006-05-23 17:18:44 -0700834 */
Dan Williams209b84a2009-01-06 11:38:17 -0700835void dmaengine_put(void)
Chris Leechc13c8262006-05-23 17:18:44 -0700836{
Dan Williamsd379b012007-07-09 11:56:42 -0700837 struct dma_device *device;
Chris Leechc13c8262006-05-23 17:18:44 -0700838 struct dma_chan *chan;
839
Chris Leechc13c8262006-05-23 17:18:44 -0700840 mutex_lock(&dma_list_mutex);
Dan Williams6f49a572009-01-06 11:38:14 -0700841 dmaengine_ref_count--;
842 BUG_ON(dmaengine_ref_count < 0);
843 /* drop channel references */
Dan Williams59b5ec22009-01-06 11:38:15 -0700844 list_for_each_entry(device, &dma_device_list, global_node) {
845 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
846 continue;
Dan Williams6f49a572009-01-06 11:38:14 -0700847 list_for_each_entry(chan, &device->channels, device_node)
848 dma_chan_put(chan);
Dan Williams59b5ec22009-01-06 11:38:15 -0700849 }
Chris Leechc13c8262006-05-23 17:18:44 -0700850 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700851}
Dan Williams209b84a2009-01-06 11:38:17 -0700852EXPORT_SYMBOL(dmaengine_put);
Chris Leechc13c8262006-05-23 17:18:44 -0700853
Dan Williams138f4c32009-09-08 17:42:51 -0700854static bool device_has_all_tx_types(struct dma_device *device)
855{
856 /* A device that satisfies this test has channels that will never cause
857 * an async_tx channel switch event as all possible operation types can
858 * be handled.
859 */
860 #ifdef CONFIG_ASYNC_TX_DMA
861 if (!dma_has_cap(DMA_INTERRUPT, device->cap_mask))
862 return false;
863 #endif
864
865 #if defined(CONFIG_ASYNC_MEMCPY) || defined(CONFIG_ASYNC_MEMCPY_MODULE)
866 if (!dma_has_cap(DMA_MEMCPY, device->cap_mask))
867 return false;
868 #endif
869
Dan Williams138f4c32009-09-08 17:42:51 -0700870 #if defined(CONFIG_ASYNC_XOR) || defined(CONFIG_ASYNC_XOR_MODULE)
871 if (!dma_has_cap(DMA_XOR, device->cap_mask))
872 return false;
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700873
874 #ifndef CONFIG_ASYNC_TX_DISABLE_XOR_VAL_DMA
Dan Williams4499a242009-11-19 17:10:25 -0700875 if (!dma_has_cap(DMA_XOR_VAL, device->cap_mask))
876 return false;
Dan Williams138f4c32009-09-08 17:42:51 -0700877 #endif
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700878 #endif
Dan Williams138f4c32009-09-08 17:42:51 -0700879
880 #if defined(CONFIG_ASYNC_PQ) || defined(CONFIG_ASYNC_PQ_MODULE)
881 if (!dma_has_cap(DMA_PQ, device->cap_mask))
882 return false;
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700883
884 #ifndef CONFIG_ASYNC_TX_DISABLE_PQ_VAL_DMA
Dan Williams4499a242009-11-19 17:10:25 -0700885 if (!dma_has_cap(DMA_PQ_VAL, device->cap_mask))
886 return false;
Dan Williams138f4c32009-09-08 17:42:51 -0700887 #endif
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700888 #endif
Dan Williams138f4c32009-09-08 17:42:51 -0700889
890 return true;
891}
892
Dan Williams257b17c2009-03-25 09:13:23 -0700893static int get_dma_id(struct dma_device *device)
894{
895 int rc;
896
Dan Williams257b17c2009-03-25 09:13:23 -0700897 mutex_lock(&dma_list_mutex);
Dan Williams257b17c2009-03-25 09:13:23 -0700898
Tejun Heo69ee2662013-02-27 17:04:03 -0800899 rc = idr_alloc(&dma_idr, NULL, 0, 0, GFP_KERNEL);
900 if (rc >= 0)
901 device->dev_id = rc;
902
903 mutex_unlock(&dma_list_mutex);
904 return rc < 0 ? rc : 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 */
921 BUG_ON(dma_has_cap(DMA_MEMCPY, device->cap_mask) &&
922 !device->device_prep_dma_memcpy);
923 BUG_ON(dma_has_cap(DMA_XOR, device->cap_mask) &&
924 !device->device_prep_dma_xor);
Dan Williams099f53c2009-04-08 14:28:37 -0700925 BUG_ON(dma_has_cap(DMA_XOR_VAL, device->cap_mask) &&
926 !device->device_prep_dma_xor_val);
Dan Williamsb2f46fd2009-07-14 12:20:36 -0700927 BUG_ON(dma_has_cap(DMA_PQ, device->cap_mask) &&
928 !device->device_prep_dma_pq);
929 BUG_ON(dma_has_cap(DMA_PQ_VAL, device->cap_mask) &&
930 !device->device_prep_dma_pq_val);
Maxime Ripard4983a502015-05-18 13:46:15 +0200931 BUG_ON(dma_has_cap(DMA_MEMSET, device->cap_mask) &&
932 !device->device_prep_dma_memset);
Zhang Wei9b941c62008-03-13 17:45:28 -0700933 BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) &&
Dan Williams7405f742007-01-02 11:10:43 -0700934 !device->device_prep_dma_interrupt);
Ira Snydera86ee032010-09-30 11:46:44 +0000935 BUG_ON(dma_has_cap(DMA_SG, device->cap_mask) &&
936 !device->device_prep_dma_sg);
Sascha Hauer782bc952010-09-30 13:56:32 +0000937 BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
938 !device->device_prep_dma_cyclic);
Jassi Brarb14dab72011-10-13 12:33:30 +0530939 BUG_ON(dma_has_cap(DMA_INTERLEAVE, device->cap_mask) &&
940 !device->device_prep_interleaved_dma);
Dan Williams7405f742007-01-02 11:10:43 -0700941
Linus Walleij07934482010-03-26 16:50:49 -0700942 BUG_ON(!device->device_tx_status);
Dan Williams7405f742007-01-02 11:10:43 -0700943 BUG_ON(!device->device_issue_pending);
944 BUG_ON(!device->dev);
945
Dan Williams138f4c32009-09-08 17:42:51 -0700946 /* note: this only matters in the
Dan Williams5fc6d892010-10-07 16:44:50 -0700947 * CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH=n case
Dan Williams138f4c32009-09-08 17:42:51 -0700948 */
949 if (device_has_all_tx_types(device))
950 dma_cap_set(DMA_ASYNC_TX, device->cap_mask);
951
Dan Williams864498a2009-01-06 11:38:21 -0700952 idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL);
953 if (!idr_ref)
954 return -ENOMEM;
Dan Williams257b17c2009-03-25 09:13:23 -0700955 rc = get_dma_id(device);
956 if (rc != 0) {
957 kfree(idr_ref);
Dan Williams864498a2009-01-06 11:38:21 -0700958 return rc;
Dan Williams257b17c2009-03-25 09:13:23 -0700959 }
960
961 atomic_set(idr_ref, 0);
Chris Leechc13c8262006-05-23 17:18:44 -0700962
963 /* represent channels in sysfs. Probably want devs too */
964 list_for_each_entry(chan, &device->channels, device_node) {
Dan Williams257b17c2009-03-25 09:13:23 -0700965 rc = -ENOMEM;
Chris Leechc13c8262006-05-23 17:18:44 -0700966 chan->local = alloc_percpu(typeof(*chan->local));
967 if (chan->local == NULL)
Dan Williams257b17c2009-03-25 09:13:23 -0700968 goto err_out;
Dan Williams41d5e592009-01-06 11:38:21 -0700969 chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL);
970 if (chan->dev == NULL) {
971 free_percpu(chan->local);
Dan Williams257b17c2009-03-25 09:13:23 -0700972 chan->local = NULL;
973 goto err_out;
Dan Williams41d5e592009-01-06 11:38:21 -0700974 }
Chris Leechc13c8262006-05-23 17:18:44 -0700975
976 chan->chan_id = chancnt++;
Dan Williams41d5e592009-01-06 11:38:21 -0700977 chan->dev->device.class = &dma_devclass;
978 chan->dev->device.parent = device->dev;
979 chan->dev->chan = chan;
Dan Williams864498a2009-01-06 11:38:21 -0700980 chan->dev->idr_ref = idr_ref;
981 chan->dev->dev_id = device->dev_id;
982 atomic_inc(idr_ref);
Dan Williams41d5e592009-01-06 11:38:21 -0700983 dev_set_name(&chan->dev->device, "dma%dchan%d",
Kay Sievers06190d82008-11-11 13:12:33 -0700984 device->dev_id, chan->chan_id);
Chris Leechc13c8262006-05-23 17:18:44 -0700985
Dan Williams41d5e592009-01-06 11:38:21 -0700986 rc = device_register(&chan->dev->device);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800987 if (rc) {
Jeff Garzikff487fb2007-03-08 09:57:34 -0800988 free_percpu(chan->local);
989 chan->local = NULL;
Dan Williams257b17c2009-03-25 09:13:23 -0700990 kfree(chan->dev);
991 atomic_dec(idr_ref);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800992 goto err_out;
993 }
Dan Williams7cc5bf92008-07-08 11:58:21 -0700994 chan->client_count = 0;
Chris Leechc13c8262006-05-23 17:18:44 -0700995 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700996 device->chancnt = chancnt;
Chris Leechc13c8262006-05-23 17:18:44 -0700997
998 mutex_lock(&dma_list_mutex);
Dan Williams59b5ec22009-01-06 11:38:15 -0700999 /* take references on public channels */
1000 if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask))
Dan Williams6f49a572009-01-06 11:38:14 -07001001 list_for_each_entry(chan, &device->channels, device_node) {
1002 /* if clients are already waiting for channels we need
1003 * to take references on their behalf
1004 */
1005 if (dma_chan_get(chan) == -ENODEV) {
1006 /* note we can only get here for the first
1007 * channel as the remaining channels are
1008 * guaranteed to get a reference
1009 */
1010 rc = -ENODEV;
1011 mutex_unlock(&dma_list_mutex);
1012 goto err_out;
1013 }
1014 }
Dan Williams2ba05622009-01-06 11:38:14 -07001015 list_add_tail_rcu(&device->global_node, &dma_device_list);
Atsushi Nemoto0f571512009-03-06 20:07:14 +09001016 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
1017 device->privatecnt++; /* Always private */
Dan Williamsbec08512009-01-06 11:38:14 -07001018 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -07001019 mutex_unlock(&dma_list_mutex);
1020
Chris Leechc13c8262006-05-23 17:18:44 -07001021 return 0;
Jeff Garzikff487fb2007-03-08 09:57:34 -08001022
1023err_out:
Dan Williams257b17c2009-03-25 09:13:23 -07001024 /* if we never registered a channel just release the idr */
1025 if (atomic_read(idr_ref) == 0) {
1026 mutex_lock(&dma_list_mutex);
1027 idr_remove(&dma_idr, device->dev_id);
1028 mutex_unlock(&dma_list_mutex);
1029 kfree(idr_ref);
1030 return rc;
1031 }
1032
Jeff Garzikff487fb2007-03-08 09:57:34 -08001033 list_for_each_entry(chan, &device->channels, device_node) {
1034 if (chan->local == NULL)
1035 continue;
Dan Williams41d5e592009-01-06 11:38:21 -07001036 mutex_lock(&dma_list_mutex);
1037 chan->dev->chan = NULL;
1038 mutex_unlock(&dma_list_mutex);
1039 device_unregister(&chan->dev->device);
Jeff Garzikff487fb2007-03-08 09:57:34 -08001040 free_percpu(chan->local);
1041 }
1042 return rc;
Chris Leechc13c8262006-05-23 17:18:44 -07001043}
David Brownell765e3d82007-03-16 13:38:05 -08001044EXPORT_SYMBOL(dma_async_device_register);
Chris Leechc13c8262006-05-23 17:18:44 -07001045
1046/**
Dan Williams6f49a572009-01-06 11:38:14 -07001047 * dma_async_device_unregister - unregister a DMA device
Randy Dunlap65088712006-07-03 19:45:31 -07001048 * @device: &dma_device
Dan Williamsf27c5802009-01-06 11:38:18 -07001049 *
1050 * This routine is called by dma driver exit routines, dmaengine holds module
1051 * references to prevent it being called while channels are in use.
Randy Dunlap65088712006-07-03 19:45:31 -07001052 */
1053void dma_async_device_unregister(struct dma_device *device)
Chris Leechc13c8262006-05-23 17:18:44 -07001054{
1055 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -07001056
1057 mutex_lock(&dma_list_mutex);
Dan Williams2ba05622009-01-06 11:38:14 -07001058 list_del_rcu(&device->global_node);
Dan Williamsbec08512009-01-06 11:38:14 -07001059 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -07001060 mutex_unlock(&dma_list_mutex);
1061
1062 list_for_each_entry(chan, &device->channels, device_node) {
Dan Williams6f49a572009-01-06 11:38:14 -07001063 WARN_ONCE(chan->client_count,
1064 "%s called while %d clients hold a reference\n",
1065 __func__, chan->client_count);
Dan Williams41d5e592009-01-06 11:38:21 -07001066 mutex_lock(&dma_list_mutex);
1067 chan->dev->chan = NULL;
1068 mutex_unlock(&dma_list_mutex);
1069 device_unregister(&chan->dev->device);
Anatolij Gustschinadef4772010-01-26 10:26:06 +01001070 free_percpu(chan->local);
Chris Leechc13c8262006-05-23 17:18:44 -07001071 }
Chris Leechc13c8262006-05-23 17:18:44 -07001072}
David Brownell765e3d82007-03-16 13:38:05 -08001073EXPORT_SYMBOL(dma_async_device_unregister);
Chris Leechc13c8262006-05-23 17:18:44 -07001074
Dan Williams45c463a2013-10-18 19:35:24 +02001075struct dmaengine_unmap_pool {
1076 struct kmem_cache *cache;
1077 const char *name;
1078 mempool_t *pool;
1079 size_t size;
1080};
1081
1082#define __UNMAP_POOL(x) { .size = x, .name = "dmaengine-unmap-" __stringify(x) }
1083static struct dmaengine_unmap_pool unmap_pool[] = {
1084 __UNMAP_POOL(2),
Dan Williams3cc377b2013-12-09 10:33:16 -08001085 #if IS_ENABLED(CONFIG_DMA_ENGINE_RAID)
Dan Williams45c463a2013-10-18 19:35:24 +02001086 __UNMAP_POOL(16),
1087 __UNMAP_POOL(128),
1088 __UNMAP_POOL(256),
1089 #endif
1090};
1091
1092static struct dmaengine_unmap_pool *__get_unmap_pool(int nr)
Dan Williams7405f742007-01-02 11:10:43 -07001093{
Dan Williams45c463a2013-10-18 19:35:24 +02001094 int order = get_count_order(nr);
Dan Williams7405f742007-01-02 11:10:43 -07001095
Dan Williams45c463a2013-10-18 19:35:24 +02001096 switch (order) {
1097 case 0 ... 1:
1098 return &unmap_pool[0];
1099 case 2 ... 4:
1100 return &unmap_pool[1];
1101 case 5 ... 7:
1102 return &unmap_pool[2];
1103 case 8:
1104 return &unmap_pool[3];
1105 default:
1106 BUG();
1107 return NULL;
1108 }
1109}
Dan Williams00367312008-02-02 19:49:57 -07001110
Dan Williams45c463a2013-10-18 19:35:24 +02001111static void dmaengine_unmap(struct kref *kref)
1112{
1113 struct dmaengine_unmap_data *unmap = container_of(kref, typeof(*unmap), kref);
1114 struct device *dev = unmap->dev;
1115 int cnt, i;
1116
1117 cnt = unmap->to_cnt;
1118 for (i = 0; i < cnt; i++)
1119 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1120 DMA_TO_DEVICE);
1121 cnt += unmap->from_cnt;
1122 for (; i < cnt; i++)
1123 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1124 DMA_FROM_DEVICE);
1125 cnt += unmap->bidi_cnt;
Dan Williams7476bd72013-10-18 19:35:29 +02001126 for (; i < cnt; i++) {
1127 if (unmap->addr[i] == 0)
1128 continue;
Dan Williams45c463a2013-10-18 19:35:24 +02001129 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1130 DMA_BIDIRECTIONAL);
Dan Williams7476bd72013-10-18 19:35:29 +02001131 }
Xuelin Shic1f43dd2014-05-21 14:02:37 -07001132 cnt = unmap->map_cnt;
Dan Williams45c463a2013-10-18 19:35:24 +02001133 mempool_free(unmap, __get_unmap_pool(cnt)->pool);
1134}
1135
1136void dmaengine_unmap_put(struct dmaengine_unmap_data *unmap)
1137{
1138 if (unmap)
1139 kref_put(&unmap->kref, dmaengine_unmap);
1140}
1141EXPORT_SYMBOL_GPL(dmaengine_unmap_put);
1142
1143static void dmaengine_destroy_unmap_pool(void)
1144{
1145 int i;
1146
1147 for (i = 0; i < ARRAY_SIZE(unmap_pool); i++) {
1148 struct dmaengine_unmap_pool *p = &unmap_pool[i];
1149
Julia Lawall240eb9162015-09-13 14:15:19 +02001150 mempool_destroy(p->pool);
Dan Williams45c463a2013-10-18 19:35:24 +02001151 p->pool = NULL;
Julia Lawall240eb9162015-09-13 14:15:19 +02001152 kmem_cache_destroy(p->cache);
Dan Williams45c463a2013-10-18 19:35:24 +02001153 p->cache = NULL;
1154 }
1155}
1156
1157static int __init dmaengine_init_unmap_pool(void)
1158{
1159 int i;
1160
1161 for (i = 0; i < ARRAY_SIZE(unmap_pool); i++) {
1162 struct dmaengine_unmap_pool *p = &unmap_pool[i];
1163 size_t size;
1164
1165 size = sizeof(struct dmaengine_unmap_data) +
1166 sizeof(dma_addr_t) * p->size;
1167
1168 p->cache = kmem_cache_create(p->name, size, 0,
1169 SLAB_HWCACHE_ALIGN, NULL);
1170 if (!p->cache)
1171 break;
1172 p->pool = mempool_create_slab_pool(1, p->cache);
1173 if (!p->pool)
1174 break;
Dan Williams00367312008-02-02 19:49:57 -07001175 }
Dan Williams7405f742007-01-02 11:10:43 -07001176
Dan Williams45c463a2013-10-18 19:35:24 +02001177 if (i == ARRAY_SIZE(unmap_pool))
1178 return 0;
Dan Williams7405f742007-01-02 11:10:43 -07001179
Dan Williams45c463a2013-10-18 19:35:24 +02001180 dmaengine_destroy_unmap_pool();
1181 return -ENOMEM;
Dan Williams7405f742007-01-02 11:10:43 -07001182}
Dan Williams7405f742007-01-02 11:10:43 -07001183
Dan Williams89716462013-10-18 19:35:25 +02001184struct dmaengine_unmap_data *
Dan Williams45c463a2013-10-18 19:35:24 +02001185dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags)
Dan Williams7405f742007-01-02 11:10:43 -07001186{
Dan Williams45c463a2013-10-18 19:35:24 +02001187 struct dmaengine_unmap_data *unmap;
Dan Williams7405f742007-01-02 11:10:43 -07001188
Dan Williams45c463a2013-10-18 19:35:24 +02001189 unmap = mempool_alloc(__get_unmap_pool(nr)->pool, flags);
1190 if (!unmap)
1191 return NULL;
Dan Williams00367312008-02-02 19:49:57 -07001192
Dan Williams45c463a2013-10-18 19:35:24 +02001193 memset(unmap, 0, sizeof(*unmap));
1194 kref_init(&unmap->kref);
1195 unmap->dev = dev;
Xuelin Shic1f43dd2014-05-21 14:02:37 -07001196 unmap->map_cnt = nr;
Dan Williams7405f742007-01-02 11:10:43 -07001197
Dan Williams45c463a2013-10-18 19:35:24 +02001198 return unmap;
Dan Williams7405f742007-01-02 11:10:43 -07001199}
Dan Williams89716462013-10-18 19:35:25 +02001200EXPORT_SYMBOL(dmaengine_get_unmap_data);
Dan Williams7405f742007-01-02 11:10:43 -07001201
Dan Williams7405f742007-01-02 11:10:43 -07001202void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
1203 struct dma_chan *chan)
1204{
1205 tx->chan = chan;
Dan Williams5fc6d892010-10-07 16:44:50 -07001206 #ifdef CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH
Dan Williams7405f742007-01-02 11:10:43 -07001207 spin_lock_init(&tx->lock);
Dan Williamscaa20d972010-05-17 16:24:16 -07001208 #endif
Dan Williams7405f742007-01-02 11:10:43 -07001209}
1210EXPORT_SYMBOL(dma_async_tx_descriptor_init);
1211
Dan Williams07f22112009-01-05 17:14:31 -07001212/* dma_wait_for_async_tx - spin wait for a transaction to complete
1213 * @tx: in-flight transaction to wait on
Dan Williams07f22112009-01-05 17:14:31 -07001214 */
1215enum dma_status
1216dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
1217{
Dan Williams95475e52009-07-14 12:19:02 -07001218 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
Dan Williams07f22112009-01-05 17:14:31 -07001219
1220 if (!tx)
Vinod Kouladfedd92013-10-16 13:29:02 +05301221 return DMA_COMPLETE;
Dan Williams07f22112009-01-05 17:14:31 -07001222
Dan Williams95475e52009-07-14 12:19:02 -07001223 while (tx->cookie == -EBUSY) {
1224 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
1225 pr_err("%s timeout waiting for descriptor submission\n",
Joe Perches63433252012-07-18 09:51:28 -07001226 __func__);
Dan Williams95475e52009-07-14 12:19:02 -07001227 return DMA_ERROR;
1228 }
1229 cpu_relax();
1230 }
1231 return dma_sync_wait(tx->chan, tx->cookie);
Dan Williams07f22112009-01-05 17:14:31 -07001232}
1233EXPORT_SYMBOL_GPL(dma_wait_for_async_tx);
1234
1235/* dma_run_dependencies - helper routine for dma drivers to process
1236 * (start) dependent operations on their target channel
1237 * @tx: transaction with dependencies
1238 */
1239void dma_run_dependencies(struct dma_async_tx_descriptor *tx)
1240{
Dan Williamscaa20d972010-05-17 16:24:16 -07001241 struct dma_async_tx_descriptor *dep = txd_next(tx);
Dan Williams07f22112009-01-05 17:14:31 -07001242 struct dma_async_tx_descriptor *dep_next;
1243 struct dma_chan *chan;
1244
1245 if (!dep)
1246 return;
1247
Yuri Tikhonovdd59b852009-01-12 15:17:20 -07001248 /* we'll submit tx->next now, so clear the link */
Dan Williamscaa20d972010-05-17 16:24:16 -07001249 txd_clear_next(tx);
Dan Williams07f22112009-01-05 17:14:31 -07001250 chan = dep->chan;
1251
1252 /* keep submitting up until a channel switch is detected
1253 * in that case we will be called again as a result of
1254 * processing the interrupt from async_tx_channel_switch
1255 */
1256 for (; dep; dep = dep_next) {
Dan Williamscaa20d972010-05-17 16:24:16 -07001257 txd_lock(dep);
1258 txd_clear_parent(dep);
1259 dep_next = txd_next(dep);
Dan Williams07f22112009-01-05 17:14:31 -07001260 if (dep_next && dep_next->chan == chan)
Dan Williamscaa20d972010-05-17 16:24:16 -07001261 txd_clear_next(dep); /* ->next will be submitted */
Dan Williams07f22112009-01-05 17:14:31 -07001262 else
1263 dep_next = NULL; /* submit current dep and terminate */
Dan Williamscaa20d972010-05-17 16:24:16 -07001264 txd_unlock(dep);
Dan Williams07f22112009-01-05 17:14:31 -07001265
1266 dep->tx_submit(dep);
1267 }
1268
1269 chan->device->device_issue_pending(chan);
1270}
1271EXPORT_SYMBOL_GPL(dma_run_dependencies);
1272
Chris Leechc13c8262006-05-23 17:18:44 -07001273static int __init dma_bus_init(void)
1274{
Dan Williams45c463a2013-10-18 19:35:24 +02001275 int err = dmaengine_init_unmap_pool();
1276
1277 if (err)
1278 return err;
Chris Leechc13c8262006-05-23 17:18:44 -07001279 return class_register(&dma_devclass);
1280}
Dan Williams652afc22009-01-06 11:38:22 -07001281arch_initcall(dma_bus_init);
Chris Leechc13c8262006-05-23 17:18:44 -07001282
Dan Williamsbec08512009-01-06 11:38:14 -07001283