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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
Alexey Dobriyanb7f080c2011-06-16 11:01:34 +000046#include <linux/dma-mapping.h>
Chris Leechc13c8262006-05-23 17:18:44 -070047#include <linux/init.h>
48#include <linux/module.h>
Dan Williams7405f742007-01-02 11:10:43 -070049#include <linux/mm.h>
Chris Leechc13c8262006-05-23 17:18:44 -070050#include <linux/device.h>
51#include <linux/dmaengine.h>
52#include <linux/hardirq.h>
53#include <linux/spinlock.h>
54#include <linux/percpu.h>
55#include <linux/rcupdate.h>
56#include <linux/mutex.h>
Dan Williams7405f742007-01-02 11:10:43 -070057#include <linux/jiffies.h>
Dan Williams2ba05622009-01-06 11:38:14 -070058#include <linux/rculist.h>
Dan Williams864498a2009-01-06 11:38:21 -070059#include <linux/idr.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090060#include <linux/slab.h>
Andy Shevchenko4e82f5d2013-04-09 14:05:44 +030061#include <linux/acpi.h>
62#include <linux/acpi_dma.h>
Jon Hunter9a6cecc2012-09-14 17:41:57 -050063#include <linux/of_dma.h>
Dan Williams45c463a2013-10-18 19:35:24 +020064#include <linux/mempool.h>
Chris Leechc13c8262006-05-23 17:18:44 -070065
66static DEFINE_MUTEX(dma_list_mutex);
Axel Lin21ef4b82011-07-20 11:32:28 +080067static DEFINE_IDR(dma_idr);
Chris Leechc13c8262006-05-23 17:18:44 -070068static LIST_HEAD(dma_device_list);
Dan Williams6f49a572009-01-06 11:38:14 -070069static long dmaengine_ref_count;
Chris Leechc13c8262006-05-23 17:18:44 -070070
71/* --- sysfs implementation --- */
72
Dan Williams41d5e592009-01-06 11:38:21 -070073/**
74 * dev_to_dma_chan - convert a device pointer to the its sysfs container object
75 * @dev - device node
76 *
77 * Must be called under dma_list_mutex
78 */
79static struct dma_chan *dev_to_dma_chan(struct device *dev)
80{
81 struct dma_chan_dev *chan_dev;
82
83 chan_dev = container_of(dev, typeof(*chan_dev), device);
84 return chan_dev->chan;
85}
86
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -070087static ssize_t memcpy_count_show(struct device *dev,
88 struct device_attribute *attr, char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -070089{
Dan Williams41d5e592009-01-06 11:38:21 -070090 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -070091 unsigned long count = 0;
92 int i;
Dan Williams41d5e592009-01-06 11:38:21 -070093 int err;
Chris Leechc13c8262006-05-23 17:18:44 -070094
Dan Williams41d5e592009-01-06 11:38:21 -070095 mutex_lock(&dma_list_mutex);
96 chan = dev_to_dma_chan(dev);
97 if (chan) {
98 for_each_possible_cpu(i)
99 count += per_cpu_ptr(chan->local, i)->memcpy_count;
100 err = sprintf(buf, "%lu\n", count);
101 } else
102 err = -ENODEV;
103 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700104
Dan Williams41d5e592009-01-06 11:38:21 -0700105 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700106}
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700107static DEVICE_ATTR_RO(memcpy_count);
Chris Leechc13c8262006-05-23 17:18:44 -0700108
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700109static ssize_t bytes_transferred_show(struct device *dev,
110 struct device_attribute *attr, char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -0700111{
Dan Williams41d5e592009-01-06 11:38:21 -0700112 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -0700113 unsigned long count = 0;
114 int i;
Dan Williams41d5e592009-01-06 11:38:21 -0700115 int err;
Chris Leechc13c8262006-05-23 17:18:44 -0700116
Dan Williams41d5e592009-01-06 11:38:21 -0700117 mutex_lock(&dma_list_mutex);
118 chan = dev_to_dma_chan(dev);
119 if (chan) {
120 for_each_possible_cpu(i)
121 count += per_cpu_ptr(chan->local, i)->bytes_transferred;
122 err = sprintf(buf, "%lu\n", count);
123 } else
124 err = -ENODEV;
125 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700126
Dan Williams41d5e592009-01-06 11:38:21 -0700127 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700128}
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700129static DEVICE_ATTR_RO(bytes_transferred);
Chris Leechc13c8262006-05-23 17:18:44 -0700130
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700131static ssize_t in_use_show(struct device *dev, struct device_attribute *attr,
132 char *buf)
Chris Leechc13c8262006-05-23 17:18:44 -0700133{
Dan Williams41d5e592009-01-06 11:38:21 -0700134 struct dma_chan *chan;
135 int err;
Chris Leechc13c8262006-05-23 17:18:44 -0700136
Dan Williams41d5e592009-01-06 11:38:21 -0700137 mutex_lock(&dma_list_mutex);
138 chan = dev_to_dma_chan(dev);
139 if (chan)
140 err = sprintf(buf, "%d\n", chan->client_count);
141 else
142 err = -ENODEV;
143 mutex_unlock(&dma_list_mutex);
144
145 return err;
Chris Leechc13c8262006-05-23 17:18:44 -0700146}
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700147static DEVICE_ATTR_RO(in_use);
Chris Leechc13c8262006-05-23 17:18:44 -0700148
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700149static struct attribute *dma_dev_attrs[] = {
150 &dev_attr_memcpy_count.attr,
151 &dev_attr_bytes_transferred.attr,
152 &dev_attr_in_use.attr,
153 NULL,
Chris Leechc13c8262006-05-23 17:18:44 -0700154};
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700155ATTRIBUTE_GROUPS(dma_dev);
Chris Leechc13c8262006-05-23 17:18:44 -0700156
Dan Williams41d5e592009-01-06 11:38:21 -0700157static void chan_dev_release(struct device *dev)
158{
159 struct dma_chan_dev *chan_dev;
160
161 chan_dev = container_of(dev, typeof(*chan_dev), device);
Dan Williams864498a2009-01-06 11:38:21 -0700162 if (atomic_dec_and_test(chan_dev->idr_ref)) {
163 mutex_lock(&dma_list_mutex);
164 idr_remove(&dma_idr, chan_dev->dev_id);
165 mutex_unlock(&dma_list_mutex);
166 kfree(chan_dev->idr_ref);
167 }
Dan Williams41d5e592009-01-06 11:38:21 -0700168 kfree(chan_dev);
169}
170
Chris Leechc13c8262006-05-23 17:18:44 -0700171static struct class dma_devclass = {
Tony Jones891f78e2007-09-25 02:03:03 +0200172 .name = "dma",
Greg Kroah-Hartman58b267d2013-07-24 15:05:08 -0700173 .dev_groups = dma_dev_groups,
Dan Williams41d5e592009-01-06 11:38:21 -0700174 .dev_release = chan_dev_release,
Chris Leechc13c8262006-05-23 17:18:44 -0700175};
176
177/* --- client and device registration --- */
178
Dan Williams59b5ec22009-01-06 11:38:15 -0700179#define dma_device_satisfies_mask(device, mask) \
180 __dma_device_satisfies_mask((device), &(mask))
Dan Williamsd379b012007-07-09 11:56:42 -0700181static int
Lars-Peter Clausena53e28d2013-03-25 13:23:52 +0100182__dma_device_satisfies_mask(struct dma_device *device,
183 const dma_cap_mask_t *want)
Dan Williamsd379b012007-07-09 11:56:42 -0700184{
185 dma_cap_mask_t has;
186
Dan Williams59b5ec22009-01-06 11:38:15 -0700187 bitmap_and(has.bits, want->bits, device->cap_mask.bits,
Dan Williamsd379b012007-07-09 11:56:42 -0700188 DMA_TX_TYPE_END);
189 return bitmap_equal(want->bits, has.bits, DMA_TX_TYPE_END);
190}
191
Dan Williams6f49a572009-01-06 11:38:14 -0700192static struct module *dma_chan_to_owner(struct dma_chan *chan)
193{
194 return chan->device->dev->driver->owner;
195}
196
197/**
198 * balance_ref_count - catch up the channel reference count
199 * @chan - channel to balance ->client_count versus dmaengine_ref_count
200 *
201 * balance_ref_count must be called under dma_list_mutex
202 */
203static void balance_ref_count(struct dma_chan *chan)
204{
205 struct module *owner = dma_chan_to_owner(chan);
206
207 while (chan->client_count < dmaengine_ref_count) {
208 __module_get(owner);
209 chan->client_count++;
210 }
211}
212
213/**
214 * dma_chan_get - try to grab a dma channel's parent driver module
215 * @chan - channel to grab
216 *
217 * Must be called under dma_list_mutex
218 */
219static int dma_chan_get(struct dma_chan *chan)
220{
Dan Williams6f49a572009-01-06 11:38:14 -0700221 struct module *owner = dma_chan_to_owner(chan);
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100222 int ret;
Dan Williams6f49a572009-01-06 11:38:14 -0700223
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100224 /* The channel is already in use, update client count */
Dan Williams6f49a572009-01-06 11:38:14 -0700225 if (chan->client_count) {
226 __module_get(owner);
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100227 goto out;
Dan Williams6f49a572009-01-06 11:38:14 -0700228 }
229
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100230 if (!try_module_get(owner))
231 return -ENODEV;
232
233 /* allocate upon first client reference */
Maxime Ripardc4b54a62014-11-17 14:41:59 +0100234 if (chan->device->device_alloc_chan_resources) {
235 ret = chan->device->device_alloc_chan_resources(chan);
236 if (ret < 0)
237 goto err_out;
238 }
Maxime Ripardd2f4f992014-11-17 14:41:58 +0100239
240 if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
241 balance_ref_count(chan);
242
243out:
244 chan->client_count++;
245 return 0;
246
247err_out:
248 module_put(owner);
249 return ret;
Dan Williams6f49a572009-01-06 11:38:14 -0700250}
251
252/**
253 * dma_chan_put - drop a reference to a dma channel's parent driver module
254 * @chan - channel to release
255 *
256 * Must be called under dma_list_mutex
257 */
258static void dma_chan_put(struct dma_chan *chan)
259{
Maxime Ripardc4b54a62014-11-17 14:41:59 +0100260 /* This channel is not in use, bail out */
Dan Williams6f49a572009-01-06 11:38:14 -0700261 if (!chan->client_count)
Maxime Ripardc4b54a62014-11-17 14:41:59 +0100262 return;
263
Dan Williams6f49a572009-01-06 11:38:14 -0700264 chan->client_count--;
265 module_put(dma_chan_to_owner(chan));
Maxime Ripardc4b54a62014-11-17 14:41:59 +0100266
267 /* This channel is not in use anymore, free it */
268 if (!chan->client_count && chan->device->device_free_chan_resources)
Dan Williams6f49a572009-01-06 11:38:14 -0700269 chan->device->device_free_chan_resources(chan);
Peter Ujfalusi56f13c02015-04-09 12:35:47 +0300270
271 /* If the channel is used via a DMA request router, free the mapping */
272 if (chan->router && chan->router->route_free) {
273 chan->router->route_free(chan->router->dev, chan->route_data);
274 chan->router = NULL;
275 chan->route_data = NULL;
276 }
Dan Williams6f49a572009-01-06 11:38:14 -0700277}
278
Dan Williams7405f742007-01-02 11:10:43 -0700279enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
280{
281 enum dma_status status;
282 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
283
284 dma_async_issue_pending(chan);
285 do {
286 status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
287 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
Joe Perches63433252012-07-18 09:51:28 -0700288 pr_err("%s: timeout!\n", __func__);
Dan Williams7405f742007-01-02 11:10:43 -0700289 return DMA_ERROR;
290 }
Bartlomiej Zolnierkiewicz2cbe7fe2012-11-08 10:02:07 +0000291 if (status != DMA_IN_PROGRESS)
292 break;
293 cpu_relax();
294 } while (1);
Dan Williams7405f742007-01-02 11:10:43 -0700295
296 return status;
297}
298EXPORT_SYMBOL(dma_sync_wait);
299
Chris Leechc13c8262006-05-23 17:18:44 -0700300/**
Dan Williamsbec08512009-01-06 11:38:14 -0700301 * dma_cap_mask_all - enable iteration over all operation types
302 */
303static dma_cap_mask_t dma_cap_mask_all;
304
305/**
306 * dma_chan_tbl_ent - tracks channel allocations per core/operation
307 * @chan - associated channel for this entry
308 */
309struct dma_chan_tbl_ent {
310 struct dma_chan *chan;
311};
312
313/**
314 * channel_table - percpu lookup table for memory-to-memory offload providers
315 */
Tejun Heoa29d8b82010-02-02 14:39:15 +0900316static struct dma_chan_tbl_ent __percpu *channel_table[DMA_TX_TYPE_END];
Dan Williamsbec08512009-01-06 11:38:14 -0700317
318static int __init dma_channel_table_init(void)
319{
320 enum dma_transaction_type cap;
321 int err = 0;
322
323 bitmap_fill(dma_cap_mask_all.bits, DMA_TX_TYPE_END);
324
Dan Williams59b5ec22009-01-06 11:38:15 -0700325 /* 'interrupt', 'private', and 'slave' are channel capabilities,
326 * but are not associated with an operation so they do not need
327 * an entry in the channel_table
Dan Williamsbec08512009-01-06 11:38:14 -0700328 */
329 clear_bit(DMA_INTERRUPT, dma_cap_mask_all.bits);
Dan Williams59b5ec22009-01-06 11:38:15 -0700330 clear_bit(DMA_PRIVATE, dma_cap_mask_all.bits);
Dan Williamsbec08512009-01-06 11:38:14 -0700331 clear_bit(DMA_SLAVE, dma_cap_mask_all.bits);
332
333 for_each_dma_cap_mask(cap, dma_cap_mask_all) {
334 channel_table[cap] = alloc_percpu(struct dma_chan_tbl_ent);
335 if (!channel_table[cap]) {
336 err = -ENOMEM;
337 break;
338 }
339 }
340
341 if (err) {
Joe Perches63433252012-07-18 09:51:28 -0700342 pr_err("initialization failure\n");
Dan Williamsbec08512009-01-06 11:38:14 -0700343 for_each_dma_cap_mask(cap, dma_cap_mask_all)
Markus Elfringa9507ca2014-12-01 06:06:57 +0100344 free_percpu(channel_table[cap]);
Dan Williamsbec08512009-01-06 11:38:14 -0700345 }
346
347 return err;
348}
Dan Williams652afc22009-01-06 11:38:22 -0700349arch_initcall(dma_channel_table_init);
Dan Williamsbec08512009-01-06 11:38:14 -0700350
351/**
352 * dma_find_channel - find a channel to carry out the operation
353 * @tx_type: transaction type
354 */
355struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type)
356{
Christoph Lametere7dcaa42009-10-03 19:48:23 +0900357 return this_cpu_read(channel_table[tx_type]->chan);
Dan Williamsbec08512009-01-06 11:38:14 -0700358}
359EXPORT_SYMBOL(dma_find_channel);
360
361/**
Dan Williams2ba05622009-01-06 11:38:14 -0700362 * dma_issue_pending_all - flush all pending operations across all channels
363 */
364void dma_issue_pending_all(void)
365{
366 struct dma_device *device;
367 struct dma_chan *chan;
368
Dan Williams2ba05622009-01-06 11:38:14 -0700369 rcu_read_lock();
Dan Williams59b5ec22009-01-06 11:38:15 -0700370 list_for_each_entry_rcu(device, &dma_device_list, global_node) {
371 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
372 continue;
Dan Williams2ba05622009-01-06 11:38:14 -0700373 list_for_each_entry(chan, &device->channels, device_node)
374 if (chan->client_count)
375 device->device_issue_pending(chan);
Dan Williams59b5ec22009-01-06 11:38:15 -0700376 }
Dan Williams2ba05622009-01-06 11:38:14 -0700377 rcu_read_unlock();
378}
379EXPORT_SYMBOL(dma_issue_pending_all);
380
381/**
Brice Goglinc4d27c42013-08-19 11:43:35 +0200382 * 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 -0700383 */
Brice Goglinc4d27c42013-08-19 11:43:35 +0200384static bool dma_chan_is_local(struct dma_chan *chan, int cpu)
385{
386 int node = dev_to_node(chan->device->dev);
387 return node == -1 || cpumask_test_cpu(cpu, cpumask_of_node(node));
388}
389
390/**
391 * min_chan - returns the channel with min count and in the same numa-node as the cpu
392 * @cap: capability to match
393 * @cpu: cpu index which the channel should be close to
394 *
395 * If some channels are close to the given cpu, the one with the lowest
396 * reference count is returned. Otherwise, cpu is ignored and only the
397 * reference count is taken into account.
398 * Must be called under dma_list_mutex.
399 */
400static struct dma_chan *min_chan(enum dma_transaction_type cap, int cpu)
Dan Williamsbec08512009-01-06 11:38:14 -0700401{
402 struct dma_device *device;
403 struct dma_chan *chan;
Dan Williamsbec08512009-01-06 11:38:14 -0700404 struct dma_chan *min = NULL;
Brice Goglinc4d27c42013-08-19 11:43:35 +0200405 struct dma_chan *localmin = NULL;
Dan Williamsbec08512009-01-06 11:38:14 -0700406
407 list_for_each_entry(device, &dma_device_list, global_node) {
Dan Williams59b5ec22009-01-06 11:38:15 -0700408 if (!dma_has_cap(cap, device->cap_mask) ||
409 dma_has_cap(DMA_PRIVATE, device->cap_mask))
Dan Williamsbec08512009-01-06 11:38:14 -0700410 continue;
411 list_for_each_entry(chan, &device->channels, device_node) {
412 if (!chan->client_count)
413 continue;
Brice Goglinc4d27c42013-08-19 11:43:35 +0200414 if (!min || chan->table_count < min->table_count)
Dan Williamsbec08512009-01-06 11:38:14 -0700415 min = chan;
416
Brice Goglinc4d27c42013-08-19 11:43:35 +0200417 if (dma_chan_is_local(chan, cpu))
418 if (!localmin ||
419 chan->table_count < localmin->table_count)
420 localmin = chan;
Dan Williamsbec08512009-01-06 11:38:14 -0700421 }
Dan Williamsbec08512009-01-06 11:38:14 -0700422 }
423
Brice Goglinc4d27c42013-08-19 11:43:35 +0200424 chan = localmin ? localmin : min;
Dan Williamsbec08512009-01-06 11:38:14 -0700425
Brice Goglinc4d27c42013-08-19 11:43:35 +0200426 if (chan)
427 chan->table_count++;
Dan Williamsbec08512009-01-06 11:38:14 -0700428
Brice Goglinc4d27c42013-08-19 11:43:35 +0200429 return chan;
Dan Williamsbec08512009-01-06 11:38:14 -0700430}
431
432/**
433 * dma_channel_rebalance - redistribute the available channels
434 *
435 * Optimize for cpu isolation (each cpu gets a dedicated channel for an
436 * operation type) in the SMP case, and operation isolation (avoid
437 * multi-tasking channels) in the non-SMP case. Must be called under
438 * dma_list_mutex.
439 */
440static void dma_channel_rebalance(void)
441{
442 struct dma_chan *chan;
443 struct dma_device *device;
444 int cpu;
445 int cap;
Dan Williamsbec08512009-01-06 11:38:14 -0700446
447 /* undo the last distribution */
448 for_each_dma_cap_mask(cap, dma_cap_mask_all)
449 for_each_possible_cpu(cpu)
450 per_cpu_ptr(channel_table[cap], cpu)->chan = NULL;
451
Dan Williams59b5ec22009-01-06 11:38:15 -0700452 list_for_each_entry(device, &dma_device_list, global_node) {
453 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
454 continue;
Dan Williamsbec08512009-01-06 11:38:14 -0700455 list_for_each_entry(chan, &device->channels, device_node)
456 chan->table_count = 0;
Dan Williams59b5ec22009-01-06 11:38:15 -0700457 }
Dan Williamsbec08512009-01-06 11:38:14 -0700458
459 /* don't populate the channel_table if no clients are available */
460 if (!dmaengine_ref_count)
461 return;
462
463 /* redistribute available channels */
Dan Williamsbec08512009-01-06 11:38:14 -0700464 for_each_dma_cap_mask(cap, dma_cap_mask_all)
465 for_each_online_cpu(cpu) {
Brice Goglinc4d27c42013-08-19 11:43:35 +0200466 chan = min_chan(cap, cpu);
Dan Williamsbec08512009-01-06 11:38:14 -0700467 per_cpu_ptr(channel_table[cap], cpu)->chan = chan;
468 }
469}
470
Laurent Pinchart0d5484b2014-10-29 00:30:58 +0200471int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
472{
473 struct dma_device *device;
474
475 if (!chan || !caps)
476 return -EINVAL;
477
478 device = chan->device;
479
480 /* check if the channel supports slave transactions */
481 if (!test_bit(DMA_SLAVE, device->cap_mask.bits))
482 return -ENXIO;
483
484 /*
485 * Check whether it reports it uses the generic slave
486 * capabilities, if not, that means it doesn't support any
487 * kind of slave capabilities reporting.
488 */
489 if (!device->directions)
490 return -ENXIO;
491
492 caps->src_addr_widths = device->src_addr_widths;
493 caps->dst_addr_widths = device->dst_addr_widths;
494 caps->directions = device->directions;
495 caps->residue_granularity = device->residue_granularity;
496
Krzysztof Kozlowski88d04642015-06-10 17:17:07 +0900497 /*
498 * Some devices implement only pause (e.g. to get residuum) but no
499 * resume. However cmd_pause is advertised as pause AND resume.
500 */
501 caps->cmd_pause = !!(device->device_pause && device->device_resume);
Laurent Pinchart0d5484b2014-10-29 00:30:58 +0200502 caps->cmd_terminate = !!device->device_terminate_all;
503
504 return 0;
505}
506EXPORT_SYMBOL_GPL(dma_get_slave_caps);
507
Lars-Peter Clausena53e28d2013-03-25 13:23:52 +0100508static struct dma_chan *private_candidate(const dma_cap_mask_t *mask,
509 struct dma_device *dev,
Dan Williamse2346672009-01-06 11:38:21 -0700510 dma_filter_fn fn, void *fn_param)
Dan Williams59b5ec22009-01-06 11:38:15 -0700511{
512 struct dma_chan *chan;
Dan Williams59b5ec22009-01-06 11:38:15 -0700513
514 if (!__dma_device_satisfies_mask(dev, mask)) {
515 pr_debug("%s: wrong capabilities\n", __func__);
516 return NULL;
517 }
518 /* devices with multiple channels need special handling as we need to
519 * ensure that all channels are either private or public.
520 */
521 if (dev->chancnt > 1 && !dma_has_cap(DMA_PRIVATE, dev->cap_mask))
522 list_for_each_entry(chan, &dev->channels, device_node) {
523 /* some channels are already publicly allocated */
524 if (chan->client_count)
525 return NULL;
526 }
527
528 list_for_each_entry(chan, &dev->channels, device_node) {
529 if (chan->client_count) {
530 pr_debug("%s: %s busy\n",
Dan Williams41d5e592009-01-06 11:38:21 -0700531 __func__, dma_chan_name(chan));
Dan Williams59b5ec22009-01-06 11:38:15 -0700532 continue;
533 }
Dan Williamse2346672009-01-06 11:38:21 -0700534 if (fn && !fn(chan, fn_param)) {
535 pr_debug("%s: %s filter said false\n",
536 __func__, dma_chan_name(chan));
537 continue;
538 }
539 return chan;
Dan Williams59b5ec22009-01-06 11:38:15 -0700540 }
541
Dan Williamse2346672009-01-06 11:38:21 -0700542 return NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700543}
544
545/**
Stefan Agner19d643d2015-06-01 23:53:43 +0200546 * dma_get_slave_channel - try to get specific channel exclusively
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800547 * @chan: target channel
548 */
549struct dma_chan *dma_get_slave_channel(struct dma_chan *chan)
550{
551 int err = -EBUSY;
552
553 /* lock against __dma_request_channel */
554 mutex_lock(&dma_list_mutex);
555
Vinod Kould9a6c8f2013-08-19 10:47:26 +0530556 if (chan->client_count == 0) {
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800557 err = dma_chan_get(chan);
Vinod Kould9a6c8f2013-08-19 10:47:26 +0530558 if (err)
559 pr_debug("%s: failed to get %s: (%d)\n",
560 __func__, dma_chan_name(chan), err);
561 } else
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800562 chan = NULL;
563
564 mutex_unlock(&dma_list_mutex);
565
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800566
567 return chan;
568}
569EXPORT_SYMBOL_GPL(dma_get_slave_channel);
570
Stephen Warren8010dad2013-11-26 12:40:51 -0700571struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
572{
573 dma_cap_mask_t mask;
574 struct dma_chan *chan;
575 int err;
576
577 dma_cap_zero(mask);
578 dma_cap_set(DMA_SLAVE, mask);
579
580 /* lock against __dma_request_channel */
581 mutex_lock(&dma_list_mutex);
582
583 chan = private_candidate(&mask, device, NULL, NULL);
584 if (chan) {
Christopher Freeman63f89ca2015-03-04 01:16:58 -0800585 dma_cap_set(DMA_PRIVATE, device->cap_mask);
586 device->privatecnt++;
Stephen Warren8010dad2013-11-26 12:40:51 -0700587 err = dma_chan_get(chan);
588 if (err) {
589 pr_debug("%s: failed to get %s: (%d)\n",
590 __func__, dma_chan_name(chan), err);
591 chan = NULL;
Christopher Freeman63f89ca2015-03-04 01:16:58 -0800592 if (--device->privatecnt == 0)
593 dma_cap_clear(DMA_PRIVATE, device->cap_mask);
Stephen Warren8010dad2013-11-26 12:40:51 -0700594 }
595 }
596
597 mutex_unlock(&dma_list_mutex);
598
599 return chan;
600}
601EXPORT_SYMBOL_GPL(dma_get_any_slave_channel);
602
Zhangfei Gao7bb587f2013-06-28 20:39:12 +0800603/**
Daniel Mack6b9019a2013-08-14 18:35:03 +0200604 * __dma_request_channel - try to allocate an exclusive channel
Dan Williams59b5ec22009-01-06 11:38:15 -0700605 * @mask: capabilities that the channel must satisfy
606 * @fn: optional callback to disposition available channels
607 * @fn_param: opaque parameter to pass to dma_filter_fn
Stephen Warren0ad7c002013-11-26 10:04:22 -0700608 *
609 * Returns pointer to appropriate DMA channel on success or NULL.
Dan Williams59b5ec22009-01-06 11:38:15 -0700610 */
Lars-Peter Clausena53e28d2013-03-25 13:23:52 +0100611struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
612 dma_filter_fn fn, void *fn_param)
Dan Williams59b5ec22009-01-06 11:38:15 -0700613{
614 struct dma_device *device, *_d;
615 struct dma_chan *chan = NULL;
Dan Williams59b5ec22009-01-06 11:38:15 -0700616 int err;
617
618 /* Find a channel */
619 mutex_lock(&dma_list_mutex);
620 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
Dan Williamse2346672009-01-06 11:38:21 -0700621 chan = private_candidate(mask, device, fn, fn_param);
622 if (chan) {
Dan Williams59b5ec22009-01-06 11:38:15 -0700623 /* Found a suitable channel, try to grab, prep, and
624 * return it. We first set DMA_PRIVATE to disable
625 * balance_ref_count as this channel will not be
626 * published in the general-purpose allocator
627 */
628 dma_cap_set(DMA_PRIVATE, device->cap_mask);
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900629 device->privatecnt++;
Dan Williams59b5ec22009-01-06 11:38:15 -0700630 err = dma_chan_get(chan);
631
632 if (err == -ENODEV) {
Joe Perches63433252012-07-18 09:51:28 -0700633 pr_debug("%s: %s module removed\n",
634 __func__, dma_chan_name(chan));
Dan Williams59b5ec22009-01-06 11:38:15 -0700635 list_del_rcu(&device->global_node);
636 } else if (err)
Fabio Estevamd8b53482012-02-21 12:51:59 -0200637 pr_debug("%s: failed to get %s: (%d)\n",
Joe Perches63433252012-07-18 09:51:28 -0700638 __func__, dma_chan_name(chan), err);
Dan Williams59b5ec22009-01-06 11:38:15 -0700639 else
640 break;
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900641 if (--device->privatecnt == 0)
642 dma_cap_clear(DMA_PRIVATE, device->cap_mask);
Dan Williamse2346672009-01-06 11:38:21 -0700643 chan = NULL;
644 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700645 }
646 mutex_unlock(&dma_list_mutex);
647
Joe Perches63433252012-07-18 09:51:28 -0700648 pr_debug("%s: %s (%s)\n",
649 __func__,
650 chan ? "success" : "fail",
Dan Williams41d5e592009-01-06 11:38:21 -0700651 chan ? dma_chan_name(chan) : NULL);
Dan Williams59b5ec22009-01-06 11:38:15 -0700652
653 return chan;
654}
655EXPORT_SYMBOL_GPL(__dma_request_channel);
656
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500657/**
Stefan Agner19d643d2015-06-01 23:53:43 +0200658 * dma_request_slave_channel_reason - try to allocate an exclusive slave channel
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500659 * @dev: pointer to client device structure
660 * @name: slave channel name
Stephen Warren0ad7c002013-11-26 10:04:22 -0700661 *
662 * Returns pointer to appropriate DMA channel on success or an error pointer.
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500663 */
Stephen Warren0ad7c002013-11-26 10:04:22 -0700664struct dma_chan *dma_request_slave_channel_reason(struct device *dev,
665 const char *name)
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500666{
667 /* If device-tree is present get slave info from here */
668 if (dev->of_node)
669 return of_dma_request_slave_channel(dev->of_node, name);
670
Andy Shevchenko4e82f5d2013-04-09 14:05:44 +0300671 /* If device was enumerated by ACPI get slave info from here */
Andy Shevchenko0f6a9282014-02-06 13:25:40 +0200672 if (ACPI_HANDLE(dev))
673 return acpi_dma_request_slave_chan_by_name(dev, name);
Andy Shevchenko4e82f5d2013-04-09 14:05:44 +0300674
Stephen Warren0ad7c002013-11-26 10:04:22 -0700675 return ERR_PTR(-ENODEV);
676}
677EXPORT_SYMBOL_GPL(dma_request_slave_channel_reason);
678
679/**
680 * dma_request_slave_channel - try to allocate an exclusive slave channel
681 * @dev: pointer to client device structure
682 * @name: slave channel name
683 *
684 * Returns pointer to appropriate DMA channel on success or NULL.
685 */
686struct dma_chan *dma_request_slave_channel(struct device *dev,
687 const char *name)
688{
689 struct dma_chan *ch = dma_request_slave_channel_reason(dev, name);
690 if (IS_ERR(ch))
691 return NULL;
692 return ch;
Jon Hunter9a6cecc2012-09-14 17:41:57 -0500693}
694EXPORT_SYMBOL_GPL(dma_request_slave_channel);
695
Dan Williams59b5ec22009-01-06 11:38:15 -0700696void dma_release_channel(struct dma_chan *chan)
697{
698 mutex_lock(&dma_list_mutex);
699 WARN_ONCE(chan->client_count != 1,
700 "chan reference count %d != 1\n", chan->client_count);
701 dma_chan_put(chan);
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900702 /* drop PRIVATE cap enabled by __dma_request_channel() */
703 if (--chan->device->privatecnt == 0)
704 dma_cap_clear(DMA_PRIVATE, chan->device->cap_mask);
Dan Williams59b5ec22009-01-06 11:38:15 -0700705 mutex_unlock(&dma_list_mutex);
706}
707EXPORT_SYMBOL_GPL(dma_release_channel);
708
Dan Williamsbec08512009-01-06 11:38:14 -0700709/**
Dan Williams209b84a2009-01-06 11:38:17 -0700710 * dmaengine_get - register interest in dma_channels
Chris Leechc13c8262006-05-23 17:18:44 -0700711 */
Dan Williams209b84a2009-01-06 11:38:17 -0700712void dmaengine_get(void)
Chris Leechc13c8262006-05-23 17:18:44 -0700713{
Dan Williams6f49a572009-01-06 11:38:14 -0700714 struct dma_device *device, *_d;
715 struct dma_chan *chan;
716 int err;
717
Chris Leechc13c8262006-05-23 17:18:44 -0700718 mutex_lock(&dma_list_mutex);
Dan Williams6f49a572009-01-06 11:38:14 -0700719 dmaengine_ref_count++;
720
721 /* try to grab channels */
Dan Williams59b5ec22009-01-06 11:38:15 -0700722 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
723 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
724 continue;
Dan Williams6f49a572009-01-06 11:38:14 -0700725 list_for_each_entry(chan, &device->channels, device_node) {
726 err = dma_chan_get(chan);
727 if (err == -ENODEV) {
728 /* module removed before we could use it */
Dan Williams2ba05622009-01-06 11:38:14 -0700729 list_del_rcu(&device->global_node);
Dan Williams6f49a572009-01-06 11:38:14 -0700730 break;
731 } else if (err)
Fabio Estevam0eb5a352012-10-04 17:11:16 -0700732 pr_debug("%s: failed to get %s: (%d)\n",
Joe Perches63433252012-07-18 09:51:28 -0700733 __func__, dma_chan_name(chan), err);
Dan Williams6f49a572009-01-06 11:38:14 -0700734 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700735 }
Dan Williams6f49a572009-01-06 11:38:14 -0700736
Dan Williamsbec08512009-01-06 11:38:14 -0700737 /* if this is the first reference and there were channels
738 * waiting we need to rebalance to get those channels
739 * incorporated into the channel table
740 */
741 if (dmaengine_ref_count == 1)
742 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -0700743 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700744}
Dan Williams209b84a2009-01-06 11:38:17 -0700745EXPORT_SYMBOL(dmaengine_get);
Chris Leechc13c8262006-05-23 17:18:44 -0700746
747/**
Dan Williams209b84a2009-01-06 11:38:17 -0700748 * dmaengine_put - let dma drivers be removed when ref_count == 0
Chris Leechc13c8262006-05-23 17:18:44 -0700749 */
Dan Williams209b84a2009-01-06 11:38:17 -0700750void dmaengine_put(void)
Chris Leechc13c8262006-05-23 17:18:44 -0700751{
Dan Williamsd379b012007-07-09 11:56:42 -0700752 struct dma_device *device;
Chris Leechc13c8262006-05-23 17:18:44 -0700753 struct dma_chan *chan;
754
Chris Leechc13c8262006-05-23 17:18:44 -0700755 mutex_lock(&dma_list_mutex);
Dan Williams6f49a572009-01-06 11:38:14 -0700756 dmaengine_ref_count--;
757 BUG_ON(dmaengine_ref_count < 0);
758 /* drop channel references */
Dan Williams59b5ec22009-01-06 11:38:15 -0700759 list_for_each_entry(device, &dma_device_list, global_node) {
760 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
761 continue;
Dan Williams6f49a572009-01-06 11:38:14 -0700762 list_for_each_entry(chan, &device->channels, device_node)
763 dma_chan_put(chan);
Dan Williams59b5ec22009-01-06 11:38:15 -0700764 }
Chris Leechc13c8262006-05-23 17:18:44 -0700765 mutex_unlock(&dma_list_mutex);
Chris Leechc13c8262006-05-23 17:18:44 -0700766}
Dan Williams209b84a2009-01-06 11:38:17 -0700767EXPORT_SYMBOL(dmaengine_put);
Chris Leechc13c8262006-05-23 17:18:44 -0700768
Dan Williams138f4c32009-09-08 17:42:51 -0700769static bool device_has_all_tx_types(struct dma_device *device)
770{
771 /* A device that satisfies this test has channels that will never cause
772 * an async_tx channel switch event as all possible operation types can
773 * be handled.
774 */
775 #ifdef CONFIG_ASYNC_TX_DMA
776 if (!dma_has_cap(DMA_INTERRUPT, device->cap_mask))
777 return false;
778 #endif
779
780 #if defined(CONFIG_ASYNC_MEMCPY) || defined(CONFIG_ASYNC_MEMCPY_MODULE)
781 if (!dma_has_cap(DMA_MEMCPY, device->cap_mask))
782 return false;
783 #endif
784
Dan Williams138f4c32009-09-08 17:42:51 -0700785 #if defined(CONFIG_ASYNC_XOR) || defined(CONFIG_ASYNC_XOR_MODULE)
786 if (!dma_has_cap(DMA_XOR, device->cap_mask))
787 return false;
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700788
789 #ifndef CONFIG_ASYNC_TX_DISABLE_XOR_VAL_DMA
Dan Williams4499a242009-11-19 17:10:25 -0700790 if (!dma_has_cap(DMA_XOR_VAL, device->cap_mask))
791 return false;
Dan Williams138f4c32009-09-08 17:42:51 -0700792 #endif
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700793 #endif
Dan Williams138f4c32009-09-08 17:42:51 -0700794
795 #if defined(CONFIG_ASYNC_PQ) || defined(CONFIG_ASYNC_PQ_MODULE)
796 if (!dma_has_cap(DMA_PQ, device->cap_mask))
797 return false;
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700798
799 #ifndef CONFIG_ASYNC_TX_DISABLE_PQ_VAL_DMA
Dan Williams4499a242009-11-19 17:10:25 -0700800 if (!dma_has_cap(DMA_PQ_VAL, device->cap_mask))
801 return false;
Dan Williams138f4c32009-09-08 17:42:51 -0700802 #endif
Dan Williams7b3cc2b2009-11-19 17:10:37 -0700803 #endif
Dan Williams138f4c32009-09-08 17:42:51 -0700804
805 return true;
806}
807
Dan Williams257b17c2009-03-25 09:13:23 -0700808static int get_dma_id(struct dma_device *device)
809{
810 int rc;
811
Dan Williams257b17c2009-03-25 09:13:23 -0700812 mutex_lock(&dma_list_mutex);
Dan Williams257b17c2009-03-25 09:13:23 -0700813
Tejun Heo69ee2662013-02-27 17:04:03 -0800814 rc = idr_alloc(&dma_idr, NULL, 0, 0, GFP_KERNEL);
815 if (rc >= 0)
816 device->dev_id = rc;
817
818 mutex_unlock(&dma_list_mutex);
819 return rc < 0 ? rc : 0;
Dan Williams257b17c2009-03-25 09:13:23 -0700820}
821
Chris Leechc13c8262006-05-23 17:18:44 -0700822/**
Randy Dunlap65088712006-07-03 19:45:31 -0700823 * dma_async_device_register - registers DMA devices found
Chris Leechc13c8262006-05-23 17:18:44 -0700824 * @device: &dma_device
825 */
826int dma_async_device_register(struct dma_device *device)
827{
Jeff Garzikff487fb2007-03-08 09:57:34 -0800828 int chancnt = 0, rc;
Chris Leechc13c8262006-05-23 17:18:44 -0700829 struct dma_chan* chan;
Dan Williams864498a2009-01-06 11:38:21 -0700830 atomic_t *idr_ref;
Chris Leechc13c8262006-05-23 17:18:44 -0700831
832 if (!device)
833 return -ENODEV;
834
Dan Williams7405f742007-01-02 11:10:43 -0700835 /* validate device routines */
836 BUG_ON(dma_has_cap(DMA_MEMCPY, device->cap_mask) &&
837 !device->device_prep_dma_memcpy);
838 BUG_ON(dma_has_cap(DMA_XOR, device->cap_mask) &&
839 !device->device_prep_dma_xor);
Dan Williams099f53c2009-04-08 14:28:37 -0700840 BUG_ON(dma_has_cap(DMA_XOR_VAL, device->cap_mask) &&
841 !device->device_prep_dma_xor_val);
Dan Williamsb2f46fd2009-07-14 12:20:36 -0700842 BUG_ON(dma_has_cap(DMA_PQ, device->cap_mask) &&
843 !device->device_prep_dma_pq);
844 BUG_ON(dma_has_cap(DMA_PQ_VAL, device->cap_mask) &&
845 !device->device_prep_dma_pq_val);
Maxime Ripard4983a502015-05-18 13:46:15 +0200846 BUG_ON(dma_has_cap(DMA_MEMSET, device->cap_mask) &&
847 !device->device_prep_dma_memset);
Zhang Wei9b941c62008-03-13 17:45:28 -0700848 BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) &&
Dan Williams7405f742007-01-02 11:10:43 -0700849 !device->device_prep_dma_interrupt);
Ira Snydera86ee032010-09-30 11:46:44 +0000850 BUG_ON(dma_has_cap(DMA_SG, device->cap_mask) &&
851 !device->device_prep_dma_sg);
Sascha Hauer782bc952010-09-30 13:56:32 +0000852 BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
853 !device->device_prep_dma_cyclic);
Jassi Brarb14dab72011-10-13 12:33:30 +0530854 BUG_ON(dma_has_cap(DMA_INTERLEAVE, device->cap_mask) &&
855 !device->device_prep_interleaved_dma);
Dan Williams7405f742007-01-02 11:10:43 -0700856
Linus Walleij07934482010-03-26 16:50:49 -0700857 BUG_ON(!device->device_tx_status);
Dan Williams7405f742007-01-02 11:10:43 -0700858 BUG_ON(!device->device_issue_pending);
859 BUG_ON(!device->dev);
860
Dan Williams138f4c32009-09-08 17:42:51 -0700861 /* note: this only matters in the
Dan Williams5fc6d892010-10-07 16:44:50 -0700862 * CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH=n case
Dan Williams138f4c32009-09-08 17:42:51 -0700863 */
864 if (device_has_all_tx_types(device))
865 dma_cap_set(DMA_ASYNC_TX, device->cap_mask);
866
Dan Williams864498a2009-01-06 11:38:21 -0700867 idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL);
868 if (!idr_ref)
869 return -ENOMEM;
Dan Williams257b17c2009-03-25 09:13:23 -0700870 rc = get_dma_id(device);
871 if (rc != 0) {
872 kfree(idr_ref);
Dan Williams864498a2009-01-06 11:38:21 -0700873 return rc;
Dan Williams257b17c2009-03-25 09:13:23 -0700874 }
875
876 atomic_set(idr_ref, 0);
Chris Leechc13c8262006-05-23 17:18:44 -0700877
878 /* represent channels in sysfs. Probably want devs too */
879 list_for_each_entry(chan, &device->channels, device_node) {
Dan Williams257b17c2009-03-25 09:13:23 -0700880 rc = -ENOMEM;
Chris Leechc13c8262006-05-23 17:18:44 -0700881 chan->local = alloc_percpu(typeof(*chan->local));
882 if (chan->local == NULL)
Dan Williams257b17c2009-03-25 09:13:23 -0700883 goto err_out;
Dan Williams41d5e592009-01-06 11:38:21 -0700884 chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL);
885 if (chan->dev == NULL) {
886 free_percpu(chan->local);
Dan Williams257b17c2009-03-25 09:13:23 -0700887 chan->local = NULL;
888 goto err_out;
Dan Williams41d5e592009-01-06 11:38:21 -0700889 }
Chris Leechc13c8262006-05-23 17:18:44 -0700890
891 chan->chan_id = chancnt++;
Dan Williams41d5e592009-01-06 11:38:21 -0700892 chan->dev->device.class = &dma_devclass;
893 chan->dev->device.parent = device->dev;
894 chan->dev->chan = chan;
Dan Williams864498a2009-01-06 11:38:21 -0700895 chan->dev->idr_ref = idr_ref;
896 chan->dev->dev_id = device->dev_id;
897 atomic_inc(idr_ref);
Dan Williams41d5e592009-01-06 11:38:21 -0700898 dev_set_name(&chan->dev->device, "dma%dchan%d",
Kay Sievers06190d82008-11-11 13:12:33 -0700899 device->dev_id, chan->chan_id);
Chris Leechc13c8262006-05-23 17:18:44 -0700900
Dan Williams41d5e592009-01-06 11:38:21 -0700901 rc = device_register(&chan->dev->device);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800902 if (rc) {
Jeff Garzikff487fb2007-03-08 09:57:34 -0800903 free_percpu(chan->local);
904 chan->local = NULL;
Dan Williams257b17c2009-03-25 09:13:23 -0700905 kfree(chan->dev);
906 atomic_dec(idr_ref);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800907 goto err_out;
908 }
Dan Williams7cc5bf92008-07-08 11:58:21 -0700909 chan->client_count = 0;
Chris Leechc13c8262006-05-23 17:18:44 -0700910 }
Dan Williams59b5ec22009-01-06 11:38:15 -0700911 device->chancnt = chancnt;
Chris Leechc13c8262006-05-23 17:18:44 -0700912
913 mutex_lock(&dma_list_mutex);
Dan Williams59b5ec22009-01-06 11:38:15 -0700914 /* take references on public channels */
915 if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask))
Dan Williams6f49a572009-01-06 11:38:14 -0700916 list_for_each_entry(chan, &device->channels, device_node) {
917 /* if clients are already waiting for channels we need
918 * to take references on their behalf
919 */
920 if (dma_chan_get(chan) == -ENODEV) {
921 /* note we can only get here for the first
922 * channel as the remaining channels are
923 * guaranteed to get a reference
924 */
925 rc = -ENODEV;
926 mutex_unlock(&dma_list_mutex);
927 goto err_out;
928 }
929 }
Dan Williams2ba05622009-01-06 11:38:14 -0700930 list_add_tail_rcu(&device->global_node, &dma_device_list);
Atsushi Nemoto0f571512009-03-06 20:07:14 +0900931 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
932 device->privatecnt++; /* Always private */
Dan Williamsbec08512009-01-06 11:38:14 -0700933 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -0700934 mutex_unlock(&dma_list_mutex);
935
Chris Leechc13c8262006-05-23 17:18:44 -0700936 return 0;
Jeff Garzikff487fb2007-03-08 09:57:34 -0800937
938err_out:
Dan Williams257b17c2009-03-25 09:13:23 -0700939 /* if we never registered a channel just release the idr */
940 if (atomic_read(idr_ref) == 0) {
941 mutex_lock(&dma_list_mutex);
942 idr_remove(&dma_idr, device->dev_id);
943 mutex_unlock(&dma_list_mutex);
944 kfree(idr_ref);
945 return rc;
946 }
947
Jeff Garzikff487fb2007-03-08 09:57:34 -0800948 list_for_each_entry(chan, &device->channels, device_node) {
949 if (chan->local == NULL)
950 continue;
Dan Williams41d5e592009-01-06 11:38:21 -0700951 mutex_lock(&dma_list_mutex);
952 chan->dev->chan = NULL;
953 mutex_unlock(&dma_list_mutex);
954 device_unregister(&chan->dev->device);
Jeff Garzikff487fb2007-03-08 09:57:34 -0800955 free_percpu(chan->local);
956 }
957 return rc;
Chris Leechc13c8262006-05-23 17:18:44 -0700958}
David Brownell765e3d82007-03-16 13:38:05 -0800959EXPORT_SYMBOL(dma_async_device_register);
Chris Leechc13c8262006-05-23 17:18:44 -0700960
961/**
Dan Williams6f49a572009-01-06 11:38:14 -0700962 * dma_async_device_unregister - unregister a DMA device
Randy Dunlap65088712006-07-03 19:45:31 -0700963 * @device: &dma_device
Dan Williamsf27c5802009-01-06 11:38:18 -0700964 *
965 * This routine is called by dma driver exit routines, dmaengine holds module
966 * references to prevent it being called while channels are in use.
Randy Dunlap65088712006-07-03 19:45:31 -0700967 */
968void dma_async_device_unregister(struct dma_device *device)
Chris Leechc13c8262006-05-23 17:18:44 -0700969{
970 struct dma_chan *chan;
Chris Leechc13c8262006-05-23 17:18:44 -0700971
972 mutex_lock(&dma_list_mutex);
Dan Williams2ba05622009-01-06 11:38:14 -0700973 list_del_rcu(&device->global_node);
Dan Williamsbec08512009-01-06 11:38:14 -0700974 dma_channel_rebalance();
Chris Leechc13c8262006-05-23 17:18:44 -0700975 mutex_unlock(&dma_list_mutex);
976
977 list_for_each_entry(chan, &device->channels, device_node) {
Dan Williams6f49a572009-01-06 11:38:14 -0700978 WARN_ONCE(chan->client_count,
979 "%s called while %d clients hold a reference\n",
980 __func__, chan->client_count);
Dan Williams41d5e592009-01-06 11:38:21 -0700981 mutex_lock(&dma_list_mutex);
982 chan->dev->chan = NULL;
983 mutex_unlock(&dma_list_mutex);
984 device_unregister(&chan->dev->device);
Anatolij Gustschinadef4772010-01-26 10:26:06 +0100985 free_percpu(chan->local);
Chris Leechc13c8262006-05-23 17:18:44 -0700986 }
Chris Leechc13c8262006-05-23 17:18:44 -0700987}
David Brownell765e3d82007-03-16 13:38:05 -0800988EXPORT_SYMBOL(dma_async_device_unregister);
Chris Leechc13c8262006-05-23 17:18:44 -0700989
Dan Williams45c463a2013-10-18 19:35:24 +0200990struct dmaengine_unmap_pool {
991 struct kmem_cache *cache;
992 const char *name;
993 mempool_t *pool;
994 size_t size;
995};
996
997#define __UNMAP_POOL(x) { .size = x, .name = "dmaengine-unmap-" __stringify(x) }
998static struct dmaengine_unmap_pool unmap_pool[] = {
999 __UNMAP_POOL(2),
Dan Williams3cc377b2013-12-09 10:33:16 -08001000 #if IS_ENABLED(CONFIG_DMA_ENGINE_RAID)
Dan Williams45c463a2013-10-18 19:35:24 +02001001 __UNMAP_POOL(16),
1002 __UNMAP_POOL(128),
1003 __UNMAP_POOL(256),
1004 #endif
1005};
1006
1007static struct dmaengine_unmap_pool *__get_unmap_pool(int nr)
Dan Williams7405f742007-01-02 11:10:43 -07001008{
Dan Williams45c463a2013-10-18 19:35:24 +02001009 int order = get_count_order(nr);
Dan Williams7405f742007-01-02 11:10:43 -07001010
Dan Williams45c463a2013-10-18 19:35:24 +02001011 switch (order) {
1012 case 0 ... 1:
1013 return &unmap_pool[0];
1014 case 2 ... 4:
1015 return &unmap_pool[1];
1016 case 5 ... 7:
1017 return &unmap_pool[2];
1018 case 8:
1019 return &unmap_pool[3];
1020 default:
1021 BUG();
1022 return NULL;
1023 }
1024}
Dan Williams00367312008-02-02 19:49:57 -07001025
Dan Williams45c463a2013-10-18 19:35:24 +02001026static void dmaengine_unmap(struct kref *kref)
1027{
1028 struct dmaengine_unmap_data *unmap = container_of(kref, typeof(*unmap), kref);
1029 struct device *dev = unmap->dev;
1030 int cnt, i;
1031
1032 cnt = unmap->to_cnt;
1033 for (i = 0; i < cnt; i++)
1034 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1035 DMA_TO_DEVICE);
1036 cnt += unmap->from_cnt;
1037 for (; i < cnt; i++)
1038 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1039 DMA_FROM_DEVICE);
1040 cnt += unmap->bidi_cnt;
Dan Williams7476bd72013-10-18 19:35:29 +02001041 for (; i < cnt; i++) {
1042 if (unmap->addr[i] == 0)
1043 continue;
Dan Williams45c463a2013-10-18 19:35:24 +02001044 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1045 DMA_BIDIRECTIONAL);
Dan Williams7476bd72013-10-18 19:35:29 +02001046 }
Xuelin Shic1f43dd2014-05-21 14:02:37 -07001047 cnt = unmap->map_cnt;
Dan Williams45c463a2013-10-18 19:35:24 +02001048 mempool_free(unmap, __get_unmap_pool(cnt)->pool);
1049}
1050
1051void dmaengine_unmap_put(struct dmaengine_unmap_data *unmap)
1052{
1053 if (unmap)
1054 kref_put(&unmap->kref, dmaengine_unmap);
1055}
1056EXPORT_SYMBOL_GPL(dmaengine_unmap_put);
1057
1058static void dmaengine_destroy_unmap_pool(void)
1059{
1060 int i;
1061
1062 for (i = 0; i < ARRAY_SIZE(unmap_pool); i++) {
1063 struct dmaengine_unmap_pool *p = &unmap_pool[i];
1064
1065 if (p->pool)
1066 mempool_destroy(p->pool);
1067 p->pool = NULL;
1068 if (p->cache)
1069 kmem_cache_destroy(p->cache);
1070 p->cache = NULL;
1071 }
1072}
1073
1074static int __init dmaengine_init_unmap_pool(void)
1075{
1076 int i;
1077
1078 for (i = 0; i < ARRAY_SIZE(unmap_pool); i++) {
1079 struct dmaengine_unmap_pool *p = &unmap_pool[i];
1080 size_t size;
1081
1082 size = sizeof(struct dmaengine_unmap_data) +
1083 sizeof(dma_addr_t) * p->size;
1084
1085 p->cache = kmem_cache_create(p->name, size, 0,
1086 SLAB_HWCACHE_ALIGN, NULL);
1087 if (!p->cache)
1088 break;
1089 p->pool = mempool_create_slab_pool(1, p->cache);
1090 if (!p->pool)
1091 break;
Dan Williams00367312008-02-02 19:49:57 -07001092 }
Dan Williams7405f742007-01-02 11:10:43 -07001093
Dan Williams45c463a2013-10-18 19:35:24 +02001094 if (i == ARRAY_SIZE(unmap_pool))
1095 return 0;
Dan Williams7405f742007-01-02 11:10:43 -07001096
Dan Williams45c463a2013-10-18 19:35:24 +02001097 dmaengine_destroy_unmap_pool();
1098 return -ENOMEM;
Dan Williams7405f742007-01-02 11:10:43 -07001099}
Dan Williams7405f742007-01-02 11:10:43 -07001100
Dan Williams89716462013-10-18 19:35:25 +02001101struct dmaengine_unmap_data *
Dan Williams45c463a2013-10-18 19:35:24 +02001102dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags)
Dan Williams7405f742007-01-02 11:10:43 -07001103{
Dan Williams45c463a2013-10-18 19:35:24 +02001104 struct dmaengine_unmap_data *unmap;
Dan Williams7405f742007-01-02 11:10:43 -07001105
Dan Williams45c463a2013-10-18 19:35:24 +02001106 unmap = mempool_alloc(__get_unmap_pool(nr)->pool, flags);
1107 if (!unmap)
1108 return NULL;
Dan Williams00367312008-02-02 19:49:57 -07001109
Dan Williams45c463a2013-10-18 19:35:24 +02001110 memset(unmap, 0, sizeof(*unmap));
1111 kref_init(&unmap->kref);
1112 unmap->dev = dev;
Xuelin Shic1f43dd2014-05-21 14:02:37 -07001113 unmap->map_cnt = nr;
Dan Williams7405f742007-01-02 11:10:43 -07001114
Dan Williams45c463a2013-10-18 19:35:24 +02001115 return unmap;
Dan Williams7405f742007-01-02 11:10:43 -07001116}
Dan Williams89716462013-10-18 19:35:25 +02001117EXPORT_SYMBOL(dmaengine_get_unmap_data);
Dan Williams7405f742007-01-02 11:10:43 -07001118
Dan Williams7405f742007-01-02 11:10:43 -07001119void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
1120 struct dma_chan *chan)
1121{
1122 tx->chan = chan;
Dan Williams5fc6d892010-10-07 16:44:50 -07001123 #ifdef CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH
Dan Williams7405f742007-01-02 11:10:43 -07001124 spin_lock_init(&tx->lock);
Dan Williamscaa20d972010-05-17 16:24:16 -07001125 #endif
Dan Williams7405f742007-01-02 11:10:43 -07001126}
1127EXPORT_SYMBOL(dma_async_tx_descriptor_init);
1128
Dan Williams07f22112009-01-05 17:14:31 -07001129/* dma_wait_for_async_tx - spin wait for a transaction to complete
1130 * @tx: in-flight transaction to wait on
Dan Williams07f22112009-01-05 17:14:31 -07001131 */
1132enum dma_status
1133dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
1134{
Dan Williams95475e52009-07-14 12:19:02 -07001135 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
Dan Williams07f22112009-01-05 17:14:31 -07001136
1137 if (!tx)
Vinod Kouladfedd92013-10-16 13:29:02 +05301138 return DMA_COMPLETE;
Dan Williams07f22112009-01-05 17:14:31 -07001139
Dan Williams95475e52009-07-14 12:19:02 -07001140 while (tx->cookie == -EBUSY) {
1141 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
1142 pr_err("%s timeout waiting for descriptor submission\n",
Joe Perches63433252012-07-18 09:51:28 -07001143 __func__);
Dan Williams95475e52009-07-14 12:19:02 -07001144 return DMA_ERROR;
1145 }
1146 cpu_relax();
1147 }
1148 return dma_sync_wait(tx->chan, tx->cookie);
Dan Williams07f22112009-01-05 17:14:31 -07001149}
1150EXPORT_SYMBOL_GPL(dma_wait_for_async_tx);
1151
1152/* dma_run_dependencies - helper routine for dma drivers to process
1153 * (start) dependent operations on their target channel
1154 * @tx: transaction with dependencies
1155 */
1156void dma_run_dependencies(struct dma_async_tx_descriptor *tx)
1157{
Dan Williamscaa20d972010-05-17 16:24:16 -07001158 struct dma_async_tx_descriptor *dep = txd_next(tx);
Dan Williams07f22112009-01-05 17:14:31 -07001159 struct dma_async_tx_descriptor *dep_next;
1160 struct dma_chan *chan;
1161
1162 if (!dep)
1163 return;
1164
Yuri Tikhonovdd59b852009-01-12 15:17:20 -07001165 /* we'll submit tx->next now, so clear the link */
Dan Williamscaa20d972010-05-17 16:24:16 -07001166 txd_clear_next(tx);
Dan Williams07f22112009-01-05 17:14:31 -07001167 chan = dep->chan;
1168
1169 /* keep submitting up until a channel switch is detected
1170 * in that case we will be called again as a result of
1171 * processing the interrupt from async_tx_channel_switch
1172 */
1173 for (; dep; dep = dep_next) {
Dan Williamscaa20d972010-05-17 16:24:16 -07001174 txd_lock(dep);
1175 txd_clear_parent(dep);
1176 dep_next = txd_next(dep);
Dan Williams07f22112009-01-05 17:14:31 -07001177 if (dep_next && dep_next->chan == chan)
Dan Williamscaa20d972010-05-17 16:24:16 -07001178 txd_clear_next(dep); /* ->next will be submitted */
Dan Williams07f22112009-01-05 17:14:31 -07001179 else
1180 dep_next = NULL; /* submit current dep and terminate */
Dan Williamscaa20d972010-05-17 16:24:16 -07001181 txd_unlock(dep);
Dan Williams07f22112009-01-05 17:14:31 -07001182
1183 dep->tx_submit(dep);
1184 }
1185
1186 chan->device->device_issue_pending(chan);
1187}
1188EXPORT_SYMBOL_GPL(dma_run_dependencies);
1189
Chris Leechc13c8262006-05-23 17:18:44 -07001190static int __init dma_bus_init(void)
1191{
Dan Williams45c463a2013-10-18 19:35:24 +02001192 int err = dmaengine_init_unmap_pool();
1193
1194 if (err)
1195 return err;
Chris Leechc13c8262006-05-23 17:18:44 -07001196 return class_register(&dma_devclass);
1197}
Dan Williams652afc22009-01-06 11:38:22 -07001198arch_initcall(dma_bus_init);
Chris Leechc13c8262006-05-23 17:18:44 -07001199
Dan Williamsbec08512009-01-06 11:38:14 -07001200