Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright(c) 2004 - 2006 Intel Corporation. All rights reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License as published by the Free |
| 6 | * Software Foundation; either version 2 of the License, or (at your option) |
| 7 | * any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 12 | * more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License along with |
| 15 | * this program; if not, write to the Free Software Foundation, Inc., 59 |
| 16 | * Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 17 | * |
| 18 | * The full GNU General Public License is included in this distribution in the |
| 19 | * file called COPYING. |
| 20 | */ |
| 21 | |
| 22 | /* |
| 23 | * This code implements the DMA subsystem. It provides a HW-neutral interface |
| 24 | * for other kernel code to use asynchronous memory copy capabilities, |
| 25 | * if present, and allows different HW DMA drivers to register as providing |
| 26 | * this capability. |
| 27 | * |
| 28 | * Due to the fact we are accelerating what is already a relatively fast |
| 29 | * operation, the code goes to great lengths to avoid additional overhead, |
| 30 | * such as locking. |
| 31 | * |
| 32 | * LOCKING: |
| 33 | * |
| 34 | * The subsystem keeps two global lists, dma_device_list and dma_client_list. |
| 35 | * Both of these are protected by a mutex, dma_list_mutex. |
| 36 | * |
| 37 | * Each device has a channels list, which runs unlocked but is never modified |
| 38 | * once the device is registered, it's just setup by the driver. |
| 39 | * |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 40 | * Each client is responsible for keeping track of the channels it uses. See |
| 41 | * the definition of dma_event_callback in dmaengine.h. |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 42 | * |
| 43 | * Each device has a kref, which is initialized to 1 when the device is |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 44 | * registered. A kref_get is done for each device registered. When the |
Sebastian Siewior | 8a5703f | 2008-04-21 22:38:45 +0000 | [diff] [blame] | 45 | * device is released, the corresponding kref_put is done in the release |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 46 | * method. Every time one of the device's channels is allocated to a client, |
Sebastian Siewior | 8a5703f | 2008-04-21 22:38:45 +0000 | [diff] [blame] | 47 | * a kref_get occurs. When the channel is freed, the corresponding kref_put |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 48 | * happens. The device's release function does a completion, so |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 49 | * unregister_device does a remove event, device_unregister, a kref_put |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 50 | * for the first reference, then waits on the completion for all other |
| 51 | * references to finish. |
| 52 | * |
| 53 | * Each channel has an open-coded implementation of Rusty Russell's "bigref," |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 54 | * with a kref and a per_cpu local_t. A dma_chan_get is called when a client |
| 55 | * signals that it wants to use a channel, and dma_chan_put is called when |
Sebastian Siewior | 8a5703f | 2008-04-21 22:38:45 +0000 | [diff] [blame] | 56 | * a channel is removed or a client using it is unregistered. A client can |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 57 | * take extra references per outstanding transaction, as is the case with |
| 58 | * the NET DMA client. The release function does a kref_put on the device. |
| 59 | * -ChrisL, DanW |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 60 | */ |
| 61 | |
| 62 | #include <linux/init.h> |
| 63 | #include <linux/module.h> |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 64 | #include <linux/mm.h> |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 65 | #include <linux/device.h> |
| 66 | #include <linux/dmaengine.h> |
| 67 | #include <linux/hardirq.h> |
| 68 | #include <linux/spinlock.h> |
| 69 | #include <linux/percpu.h> |
| 70 | #include <linux/rcupdate.h> |
| 71 | #include <linux/mutex.h> |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 72 | #include <linux/jiffies.h> |
Dan Williams | 2ba0562 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 73 | #include <linux/rculist.h> |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 74 | |
| 75 | static DEFINE_MUTEX(dma_list_mutex); |
| 76 | static LIST_HEAD(dma_device_list); |
| 77 | static LIST_HEAD(dma_client_list); |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 78 | static long dmaengine_ref_count; |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 79 | |
| 80 | /* --- sysfs implementation --- */ |
| 81 | |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 82 | static ssize_t show_memcpy_count(struct device *dev, struct device_attribute *attr, char *buf) |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 83 | { |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 84 | struct dma_chan *chan = to_dma_chan(dev); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 85 | unsigned long count = 0; |
| 86 | int i; |
| 87 | |
Andrew Morton | 17f3ae0 | 2006-05-25 13:26:53 -0700 | [diff] [blame] | 88 | for_each_possible_cpu(i) |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 89 | count += per_cpu_ptr(chan->local, i)->memcpy_count; |
| 90 | |
| 91 | return sprintf(buf, "%lu\n", count); |
| 92 | } |
| 93 | |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 94 | static ssize_t show_bytes_transferred(struct device *dev, struct device_attribute *attr, |
| 95 | char *buf) |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 96 | { |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 97 | struct dma_chan *chan = to_dma_chan(dev); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 98 | unsigned long count = 0; |
| 99 | int i; |
| 100 | |
Andrew Morton | 17f3ae0 | 2006-05-25 13:26:53 -0700 | [diff] [blame] | 101 | for_each_possible_cpu(i) |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 102 | count += per_cpu_ptr(chan->local, i)->bytes_transferred; |
| 103 | |
| 104 | return sprintf(buf, "%lu\n", count); |
| 105 | } |
| 106 | |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 107 | static ssize_t show_in_use(struct device *dev, struct device_attribute *attr, char *buf) |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 108 | { |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 109 | struct dma_chan *chan = to_dma_chan(dev); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 110 | |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 111 | return sprintf(buf, "%d\n", chan->client_count); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 112 | } |
| 113 | |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 114 | static struct device_attribute dma_attrs[] = { |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 115 | __ATTR(memcpy_count, S_IRUGO, show_memcpy_count, NULL), |
| 116 | __ATTR(bytes_transferred, S_IRUGO, show_bytes_transferred, NULL), |
| 117 | __ATTR(in_use, S_IRUGO, show_in_use, NULL), |
| 118 | __ATTR_NULL |
| 119 | }; |
| 120 | |
| 121 | static void dma_async_device_cleanup(struct kref *kref); |
| 122 | |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 123 | static void dma_dev_release(struct device *dev) |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 124 | { |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 125 | struct dma_chan *chan = to_dma_chan(dev); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 126 | kref_put(&chan->device->refcount, dma_async_device_cleanup); |
| 127 | } |
| 128 | |
| 129 | static struct class dma_devclass = { |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 130 | .name = "dma", |
| 131 | .dev_attrs = dma_attrs, |
| 132 | .dev_release = dma_dev_release, |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 133 | }; |
| 134 | |
| 135 | /* --- client and device registration --- */ |
| 136 | |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 137 | #define dma_device_satisfies_mask(device, mask) \ |
| 138 | __dma_device_satisfies_mask((device), &(mask)) |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 139 | static int |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 140 | __dma_device_satisfies_mask(struct dma_device *device, dma_cap_mask_t *want) |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 141 | { |
| 142 | dma_cap_mask_t has; |
| 143 | |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 144 | bitmap_and(has.bits, want->bits, device->cap_mask.bits, |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 145 | DMA_TX_TYPE_END); |
| 146 | return bitmap_equal(want->bits, has.bits, DMA_TX_TYPE_END); |
| 147 | } |
| 148 | |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 149 | static struct module *dma_chan_to_owner(struct dma_chan *chan) |
| 150 | { |
| 151 | return chan->device->dev->driver->owner; |
| 152 | } |
| 153 | |
| 154 | /** |
| 155 | * balance_ref_count - catch up the channel reference count |
| 156 | * @chan - channel to balance ->client_count versus dmaengine_ref_count |
| 157 | * |
| 158 | * balance_ref_count must be called under dma_list_mutex |
| 159 | */ |
| 160 | static void balance_ref_count(struct dma_chan *chan) |
| 161 | { |
| 162 | struct module *owner = dma_chan_to_owner(chan); |
| 163 | |
| 164 | while (chan->client_count < dmaengine_ref_count) { |
| 165 | __module_get(owner); |
| 166 | chan->client_count++; |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | /** |
| 171 | * dma_chan_get - try to grab a dma channel's parent driver module |
| 172 | * @chan - channel to grab |
| 173 | * |
| 174 | * Must be called under dma_list_mutex |
| 175 | */ |
| 176 | static int dma_chan_get(struct dma_chan *chan) |
| 177 | { |
| 178 | int err = -ENODEV; |
| 179 | struct module *owner = dma_chan_to_owner(chan); |
| 180 | |
| 181 | if (chan->client_count) { |
| 182 | __module_get(owner); |
| 183 | err = 0; |
| 184 | } else if (try_module_get(owner)) |
| 185 | err = 0; |
| 186 | |
| 187 | if (err == 0) |
| 188 | chan->client_count++; |
| 189 | |
| 190 | /* allocate upon first client reference */ |
| 191 | if (chan->client_count == 1 && err == 0) { |
| 192 | int desc_cnt = chan->device->device_alloc_chan_resources(chan, NULL); |
| 193 | |
| 194 | if (desc_cnt < 0) { |
| 195 | err = desc_cnt; |
| 196 | chan->client_count = 0; |
| 197 | module_put(owner); |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 198 | } else if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask)) |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 199 | balance_ref_count(chan); |
| 200 | } |
| 201 | |
| 202 | return err; |
| 203 | } |
| 204 | |
| 205 | /** |
| 206 | * dma_chan_put - drop a reference to a dma channel's parent driver module |
| 207 | * @chan - channel to release |
| 208 | * |
| 209 | * Must be called under dma_list_mutex |
| 210 | */ |
| 211 | static void dma_chan_put(struct dma_chan *chan) |
| 212 | { |
| 213 | if (!chan->client_count) |
| 214 | return; /* this channel failed alloc_chan_resources */ |
| 215 | chan->client_count--; |
| 216 | module_put(dma_chan_to_owner(chan)); |
| 217 | if (chan->client_count == 0) |
| 218 | chan->device->device_free_chan_resources(chan); |
| 219 | } |
| 220 | |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 221 | /** |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 222 | * dma_client_chan_alloc - try to allocate channels to a client |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 223 | * @client: &dma_client |
| 224 | * |
| 225 | * Called with dma_list_mutex held. |
| 226 | */ |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 227 | static void dma_client_chan_alloc(struct dma_client *client) |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 228 | { |
| 229 | struct dma_device *device; |
| 230 | struct dma_chan *chan; |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 231 | enum dma_state_client ack; |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 232 | |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 233 | /* Find a channel */ |
Haavard Skinnemoen | dc0ee643 | 2008-07-08 11:59:35 -0700 | [diff] [blame] | 234 | list_for_each_entry(device, &dma_device_list, global_node) { |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 235 | if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) |
| 236 | continue; |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 237 | if (!dma_device_satisfies_mask(device, client->cap_mask)) |
| 238 | continue; |
Haavard Skinnemoen | dc0ee643 | 2008-07-08 11:59:35 -0700 | [diff] [blame] | 239 | |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 240 | list_for_each_entry(chan, &device->channels, device_node) { |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 241 | if (!chan->client_count) |
| 242 | continue; |
| 243 | ack = client->event_callback(client, chan, |
| 244 | DMA_RESOURCE_AVAILABLE); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 245 | |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 246 | /* we are done once this client rejects |
| 247 | * an available resource |
| 248 | */ |
| 249 | if (ack == DMA_NAK) |
| 250 | return; |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 251 | } |
Haavard Skinnemoen | dc0ee643 | 2008-07-08 11:59:35 -0700 | [diff] [blame] | 252 | } |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 253 | } |
| 254 | |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 255 | enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie) |
| 256 | { |
| 257 | enum dma_status status; |
| 258 | unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000); |
| 259 | |
| 260 | dma_async_issue_pending(chan); |
| 261 | do { |
| 262 | status = dma_async_is_tx_complete(chan, cookie, NULL, NULL); |
| 263 | if (time_after_eq(jiffies, dma_sync_wait_timeout)) { |
| 264 | printk(KERN_ERR "dma_sync_wait_timeout!\n"); |
| 265 | return DMA_ERROR; |
| 266 | } |
| 267 | } while (status == DMA_IN_PROGRESS); |
| 268 | |
| 269 | return status; |
| 270 | } |
| 271 | EXPORT_SYMBOL(dma_sync_wait); |
| 272 | |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 273 | /** |
Randy Dunlap | 6508871 | 2006-07-03 19:45:31 -0700 | [diff] [blame] | 274 | * dma_chan_cleanup - release a DMA channel's resources |
| 275 | * @kref: kernel reference structure that contains the DMA channel device |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 276 | */ |
| 277 | void dma_chan_cleanup(struct kref *kref) |
| 278 | { |
| 279 | struct dma_chan *chan = container_of(kref, struct dma_chan, refcount); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 280 | kref_put(&chan->device->refcount, dma_async_device_cleanup); |
| 281 | } |
David Brownell | 765e3d8 | 2007-03-16 13:38:05 -0800 | [diff] [blame] | 282 | EXPORT_SYMBOL(dma_chan_cleanup); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 283 | |
| 284 | static void dma_chan_free_rcu(struct rcu_head *rcu) |
| 285 | { |
| 286 | struct dma_chan *chan = container_of(rcu, struct dma_chan, rcu); |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 287 | |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 288 | kref_put(&chan->refcount, dma_chan_cleanup); |
| 289 | } |
| 290 | |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 291 | static void dma_chan_release(struct dma_chan *chan) |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 292 | { |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 293 | call_rcu(&chan->rcu, dma_chan_free_rcu); |
| 294 | } |
| 295 | |
| 296 | /** |
Dan Williams | bec0851 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 297 | * dma_cap_mask_all - enable iteration over all operation types |
| 298 | */ |
| 299 | static dma_cap_mask_t dma_cap_mask_all; |
| 300 | |
| 301 | /** |
| 302 | * dma_chan_tbl_ent - tracks channel allocations per core/operation |
| 303 | * @chan - associated channel for this entry |
| 304 | */ |
| 305 | struct dma_chan_tbl_ent { |
| 306 | struct dma_chan *chan; |
| 307 | }; |
| 308 | |
| 309 | /** |
| 310 | * channel_table - percpu lookup table for memory-to-memory offload providers |
| 311 | */ |
| 312 | static struct dma_chan_tbl_ent *channel_table[DMA_TX_TYPE_END]; |
| 313 | |
| 314 | static int __init dma_channel_table_init(void) |
| 315 | { |
| 316 | enum dma_transaction_type cap; |
| 317 | int err = 0; |
| 318 | |
| 319 | bitmap_fill(dma_cap_mask_all.bits, DMA_TX_TYPE_END); |
| 320 | |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 321 | /* 'interrupt', 'private', and 'slave' are channel capabilities, |
| 322 | * but are not associated with an operation so they do not need |
| 323 | * an entry in the channel_table |
Dan Williams | bec0851 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 324 | */ |
| 325 | clear_bit(DMA_INTERRUPT, dma_cap_mask_all.bits); |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 326 | clear_bit(DMA_PRIVATE, dma_cap_mask_all.bits); |
Dan Williams | bec0851 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 327 | clear_bit(DMA_SLAVE, dma_cap_mask_all.bits); |
| 328 | |
| 329 | for_each_dma_cap_mask(cap, dma_cap_mask_all) { |
| 330 | channel_table[cap] = alloc_percpu(struct dma_chan_tbl_ent); |
| 331 | if (!channel_table[cap]) { |
| 332 | err = -ENOMEM; |
| 333 | break; |
| 334 | } |
| 335 | } |
| 336 | |
| 337 | if (err) { |
| 338 | pr_err("dmaengine: initialization failure\n"); |
| 339 | for_each_dma_cap_mask(cap, dma_cap_mask_all) |
| 340 | if (channel_table[cap]) |
| 341 | free_percpu(channel_table[cap]); |
| 342 | } |
| 343 | |
| 344 | return err; |
| 345 | } |
| 346 | subsys_initcall(dma_channel_table_init); |
| 347 | |
| 348 | /** |
| 349 | * dma_find_channel - find a channel to carry out the operation |
| 350 | * @tx_type: transaction type |
| 351 | */ |
| 352 | struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type) |
| 353 | { |
| 354 | struct dma_chan *chan; |
| 355 | int cpu; |
| 356 | |
| 357 | WARN_ONCE(dmaengine_ref_count == 0, |
| 358 | "client called %s without a reference", __func__); |
| 359 | |
| 360 | cpu = get_cpu(); |
| 361 | chan = per_cpu_ptr(channel_table[tx_type], cpu)->chan; |
| 362 | put_cpu(); |
| 363 | |
| 364 | return chan; |
| 365 | } |
| 366 | EXPORT_SYMBOL(dma_find_channel); |
| 367 | |
| 368 | /** |
Dan Williams | 2ba0562 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 369 | * dma_issue_pending_all - flush all pending operations across all channels |
| 370 | */ |
| 371 | void dma_issue_pending_all(void) |
| 372 | { |
| 373 | struct dma_device *device; |
| 374 | struct dma_chan *chan; |
| 375 | |
| 376 | WARN_ONCE(dmaengine_ref_count == 0, |
| 377 | "client called %s without a reference", __func__); |
| 378 | |
| 379 | rcu_read_lock(); |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 380 | list_for_each_entry_rcu(device, &dma_device_list, global_node) { |
| 381 | if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) |
| 382 | continue; |
Dan Williams | 2ba0562 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 383 | list_for_each_entry(chan, &device->channels, device_node) |
| 384 | if (chan->client_count) |
| 385 | device->device_issue_pending(chan); |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 386 | } |
Dan Williams | 2ba0562 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 387 | rcu_read_unlock(); |
| 388 | } |
| 389 | EXPORT_SYMBOL(dma_issue_pending_all); |
| 390 | |
| 391 | /** |
Dan Williams | bec0851 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 392 | * nth_chan - returns the nth channel of the given capability |
| 393 | * @cap: capability to match |
| 394 | * @n: nth channel desired |
| 395 | * |
| 396 | * Defaults to returning the channel with the desired capability and the |
| 397 | * lowest reference count when 'n' cannot be satisfied. Must be called |
| 398 | * under dma_list_mutex. |
| 399 | */ |
| 400 | static struct dma_chan *nth_chan(enum dma_transaction_type cap, int n) |
| 401 | { |
| 402 | struct dma_device *device; |
| 403 | struct dma_chan *chan; |
| 404 | struct dma_chan *ret = NULL; |
| 405 | struct dma_chan *min = NULL; |
| 406 | |
| 407 | list_for_each_entry(device, &dma_device_list, global_node) { |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 408 | if (!dma_has_cap(cap, device->cap_mask) || |
| 409 | dma_has_cap(DMA_PRIVATE, device->cap_mask)) |
Dan Williams | bec0851 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 410 | continue; |
| 411 | list_for_each_entry(chan, &device->channels, device_node) { |
| 412 | if (!chan->client_count) |
| 413 | continue; |
| 414 | if (!min) |
| 415 | min = chan; |
| 416 | else if (chan->table_count < min->table_count) |
| 417 | min = chan; |
| 418 | |
| 419 | if (n-- == 0) { |
| 420 | ret = chan; |
| 421 | break; /* done */ |
| 422 | } |
| 423 | } |
| 424 | if (ret) |
| 425 | break; /* done */ |
| 426 | } |
| 427 | |
| 428 | if (!ret) |
| 429 | ret = min; |
| 430 | |
| 431 | if (ret) |
| 432 | ret->table_count++; |
| 433 | |
| 434 | return ret; |
| 435 | } |
| 436 | |
| 437 | /** |
| 438 | * dma_channel_rebalance - redistribute the available channels |
| 439 | * |
| 440 | * Optimize for cpu isolation (each cpu gets a dedicated channel for an |
| 441 | * operation type) in the SMP case, and operation isolation (avoid |
| 442 | * multi-tasking channels) in the non-SMP case. Must be called under |
| 443 | * dma_list_mutex. |
| 444 | */ |
| 445 | static void dma_channel_rebalance(void) |
| 446 | { |
| 447 | struct dma_chan *chan; |
| 448 | struct dma_device *device; |
| 449 | int cpu; |
| 450 | int cap; |
| 451 | int n; |
| 452 | |
| 453 | /* undo the last distribution */ |
| 454 | for_each_dma_cap_mask(cap, dma_cap_mask_all) |
| 455 | for_each_possible_cpu(cpu) |
| 456 | per_cpu_ptr(channel_table[cap], cpu)->chan = NULL; |
| 457 | |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 458 | list_for_each_entry(device, &dma_device_list, global_node) { |
| 459 | if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) |
| 460 | continue; |
Dan Williams | bec0851 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 461 | list_for_each_entry(chan, &device->channels, device_node) |
| 462 | chan->table_count = 0; |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 463 | } |
Dan Williams | bec0851 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 464 | |
| 465 | /* don't populate the channel_table if no clients are available */ |
| 466 | if (!dmaengine_ref_count) |
| 467 | return; |
| 468 | |
| 469 | /* redistribute available channels */ |
| 470 | n = 0; |
| 471 | for_each_dma_cap_mask(cap, dma_cap_mask_all) |
| 472 | for_each_online_cpu(cpu) { |
| 473 | if (num_possible_cpus() > 1) |
| 474 | chan = nth_chan(cap, n++); |
| 475 | else |
| 476 | chan = nth_chan(cap, -1); |
| 477 | |
| 478 | per_cpu_ptr(channel_table[cap], cpu)->chan = chan; |
| 479 | } |
| 480 | } |
| 481 | |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 482 | static struct dma_chan *private_candidate(dma_cap_mask_t *mask, struct dma_device *dev) |
| 483 | { |
| 484 | struct dma_chan *chan; |
| 485 | struct dma_chan *ret = NULL; |
| 486 | |
| 487 | if (!__dma_device_satisfies_mask(dev, mask)) { |
| 488 | pr_debug("%s: wrong capabilities\n", __func__); |
| 489 | return NULL; |
| 490 | } |
| 491 | /* devices with multiple channels need special handling as we need to |
| 492 | * ensure that all channels are either private or public. |
| 493 | */ |
| 494 | if (dev->chancnt > 1 && !dma_has_cap(DMA_PRIVATE, dev->cap_mask)) |
| 495 | list_for_each_entry(chan, &dev->channels, device_node) { |
| 496 | /* some channels are already publicly allocated */ |
| 497 | if (chan->client_count) |
| 498 | return NULL; |
| 499 | } |
| 500 | |
| 501 | list_for_each_entry(chan, &dev->channels, device_node) { |
| 502 | if (chan->client_count) { |
| 503 | pr_debug("%s: %s busy\n", |
| 504 | __func__, dev_name(&chan->dev)); |
| 505 | continue; |
| 506 | } |
| 507 | ret = chan; |
| 508 | break; |
| 509 | } |
| 510 | |
| 511 | return ret; |
| 512 | } |
| 513 | |
| 514 | /** |
| 515 | * dma_request_channel - try to allocate an exclusive channel |
| 516 | * @mask: capabilities that the channel must satisfy |
| 517 | * @fn: optional callback to disposition available channels |
| 518 | * @fn_param: opaque parameter to pass to dma_filter_fn |
| 519 | */ |
| 520 | struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param) |
| 521 | { |
| 522 | struct dma_device *device, *_d; |
| 523 | struct dma_chan *chan = NULL; |
| 524 | enum dma_state_client ack; |
| 525 | int err; |
| 526 | |
| 527 | /* Find a channel */ |
| 528 | mutex_lock(&dma_list_mutex); |
| 529 | list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { |
| 530 | chan = private_candidate(mask, device); |
| 531 | if (!chan) |
| 532 | continue; |
| 533 | |
| 534 | if (fn) |
| 535 | ack = fn(chan, fn_param); |
| 536 | else |
| 537 | ack = DMA_ACK; |
| 538 | |
| 539 | if (ack == DMA_ACK) { |
| 540 | /* Found a suitable channel, try to grab, prep, and |
| 541 | * return it. We first set DMA_PRIVATE to disable |
| 542 | * balance_ref_count as this channel will not be |
| 543 | * published in the general-purpose allocator |
| 544 | */ |
| 545 | dma_cap_set(DMA_PRIVATE, device->cap_mask); |
| 546 | err = dma_chan_get(chan); |
| 547 | |
| 548 | if (err == -ENODEV) { |
| 549 | pr_debug("%s: %s module removed\n", __func__, |
| 550 | dev_name(&chan->dev)); |
| 551 | list_del_rcu(&device->global_node); |
| 552 | } else if (err) |
| 553 | pr_err("dmaengine: failed to get %s: (%d)\n", |
| 554 | dev_name(&chan->dev), err); |
| 555 | else |
| 556 | break; |
| 557 | } else if (ack == DMA_DUP) { |
| 558 | pr_debug("%s: %s filter said DMA_DUP\n", |
| 559 | __func__, dev_name(&chan->dev)); |
| 560 | } else if (ack == DMA_NAK) { |
| 561 | pr_debug("%s: %s filter said DMA_NAK\n", |
| 562 | __func__, dev_name(&chan->dev)); |
| 563 | break; |
| 564 | } else |
| 565 | WARN_ONCE(1, "filter_fn: unknown response?\n"); |
| 566 | chan = NULL; |
| 567 | } |
| 568 | mutex_unlock(&dma_list_mutex); |
| 569 | |
| 570 | pr_debug("%s: %s (%s)\n", __func__, chan ? "success" : "fail", |
| 571 | chan ? dev_name(&chan->dev) : NULL); |
| 572 | |
| 573 | return chan; |
| 574 | } |
| 575 | EXPORT_SYMBOL_GPL(__dma_request_channel); |
| 576 | |
| 577 | void dma_release_channel(struct dma_chan *chan) |
| 578 | { |
| 579 | mutex_lock(&dma_list_mutex); |
| 580 | WARN_ONCE(chan->client_count != 1, |
| 581 | "chan reference count %d != 1\n", chan->client_count); |
| 582 | dma_chan_put(chan); |
| 583 | mutex_unlock(&dma_list_mutex); |
| 584 | } |
| 585 | EXPORT_SYMBOL_GPL(dma_release_channel); |
| 586 | |
Dan Williams | bec0851 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 587 | /** |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 588 | * dma_chans_notify_available - broadcast available channels to the clients |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 589 | */ |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 590 | static void dma_clients_notify_available(void) |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 591 | { |
| 592 | struct dma_client *client; |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 593 | |
| 594 | mutex_lock(&dma_list_mutex); |
| 595 | |
| 596 | list_for_each_entry(client, &dma_client_list, global_node) |
| 597 | dma_client_chan_alloc(client); |
| 598 | |
| 599 | mutex_unlock(&dma_list_mutex); |
| 600 | } |
| 601 | |
| 602 | /** |
Dan Williams | 209b84a | 2009-01-06 11:38:17 -0700 | [diff] [blame^] | 603 | * dmaengine_get - register interest in dma_channels |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 604 | */ |
Dan Williams | 209b84a | 2009-01-06 11:38:17 -0700 | [diff] [blame^] | 605 | void dmaengine_get(void) |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 606 | { |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 607 | struct dma_device *device, *_d; |
| 608 | struct dma_chan *chan; |
| 609 | int err; |
| 610 | |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 611 | mutex_lock(&dma_list_mutex); |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 612 | dmaengine_ref_count++; |
| 613 | |
| 614 | /* try to grab channels */ |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 615 | list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { |
| 616 | if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) |
| 617 | continue; |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 618 | list_for_each_entry(chan, &device->channels, device_node) { |
| 619 | err = dma_chan_get(chan); |
| 620 | if (err == -ENODEV) { |
| 621 | /* module removed before we could use it */ |
Dan Williams | 2ba0562 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 622 | list_del_rcu(&device->global_node); |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 623 | break; |
| 624 | } else if (err) |
| 625 | pr_err("dmaengine: failed to get %s: (%d)\n", |
| 626 | dev_name(&chan->dev), err); |
| 627 | } |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 628 | } |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 629 | |
Dan Williams | bec0851 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 630 | /* if this is the first reference and there were channels |
| 631 | * waiting we need to rebalance to get those channels |
| 632 | * incorporated into the channel table |
| 633 | */ |
| 634 | if (dmaengine_ref_count == 1) |
| 635 | dma_channel_rebalance(); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 636 | mutex_unlock(&dma_list_mutex); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 637 | } |
Dan Williams | 209b84a | 2009-01-06 11:38:17 -0700 | [diff] [blame^] | 638 | EXPORT_SYMBOL(dmaengine_get); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 639 | |
| 640 | /** |
Dan Williams | 209b84a | 2009-01-06 11:38:17 -0700 | [diff] [blame^] | 641 | * dmaengine_put - let dma drivers be removed when ref_count == 0 |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 642 | */ |
Dan Williams | 209b84a | 2009-01-06 11:38:17 -0700 | [diff] [blame^] | 643 | void dmaengine_put(void) |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 644 | { |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 645 | struct dma_device *device; |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 646 | struct dma_chan *chan; |
| 647 | |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 648 | mutex_lock(&dma_list_mutex); |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 649 | dmaengine_ref_count--; |
| 650 | BUG_ON(dmaengine_ref_count < 0); |
| 651 | /* drop channel references */ |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 652 | list_for_each_entry(device, &dma_device_list, global_node) { |
| 653 | if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) |
| 654 | continue; |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 655 | list_for_each_entry(chan, &device->channels, device_node) |
| 656 | dma_chan_put(chan); |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 657 | } |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 658 | mutex_unlock(&dma_list_mutex); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 659 | } |
Dan Williams | 209b84a | 2009-01-06 11:38:17 -0700 | [diff] [blame^] | 660 | EXPORT_SYMBOL(dmaengine_put); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 661 | |
| 662 | /** |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 663 | * dma_async_client_chan_request - send all available channels to the |
| 664 | * client that satisfy the capability mask |
| 665 | * @client - requester |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 666 | */ |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 667 | void dma_async_client_chan_request(struct dma_client *client) |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 668 | { |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 669 | mutex_lock(&dma_list_mutex); |
| 670 | dma_client_chan_alloc(client); |
| 671 | mutex_unlock(&dma_list_mutex); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 672 | } |
David Brownell | 765e3d8 | 2007-03-16 13:38:05 -0800 | [diff] [blame] | 673 | EXPORT_SYMBOL(dma_async_client_chan_request); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 674 | |
| 675 | /** |
Randy Dunlap | 6508871 | 2006-07-03 19:45:31 -0700 | [diff] [blame] | 676 | * dma_async_device_register - registers DMA devices found |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 677 | * @device: &dma_device |
| 678 | */ |
| 679 | int dma_async_device_register(struct dma_device *device) |
| 680 | { |
| 681 | static int id; |
Jeff Garzik | ff487fb | 2007-03-08 09:57:34 -0800 | [diff] [blame] | 682 | int chancnt = 0, rc; |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 683 | struct dma_chan* chan; |
| 684 | |
| 685 | if (!device) |
| 686 | return -ENODEV; |
| 687 | |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 688 | /* validate device routines */ |
| 689 | BUG_ON(dma_has_cap(DMA_MEMCPY, device->cap_mask) && |
| 690 | !device->device_prep_dma_memcpy); |
| 691 | BUG_ON(dma_has_cap(DMA_XOR, device->cap_mask) && |
| 692 | !device->device_prep_dma_xor); |
| 693 | BUG_ON(dma_has_cap(DMA_ZERO_SUM, device->cap_mask) && |
| 694 | !device->device_prep_dma_zero_sum); |
| 695 | BUG_ON(dma_has_cap(DMA_MEMSET, device->cap_mask) && |
| 696 | !device->device_prep_dma_memset); |
Zhang Wei | 9b941c6 | 2008-03-13 17:45:28 -0700 | [diff] [blame] | 697 | BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) && |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 698 | !device->device_prep_dma_interrupt); |
Haavard Skinnemoen | dc0ee643 | 2008-07-08 11:59:35 -0700 | [diff] [blame] | 699 | BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) && |
| 700 | !device->device_prep_slave_sg); |
| 701 | BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) && |
| 702 | !device->device_terminate_all); |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 703 | |
| 704 | BUG_ON(!device->device_alloc_chan_resources); |
| 705 | BUG_ON(!device->device_free_chan_resources); |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 706 | BUG_ON(!device->device_is_tx_complete); |
| 707 | BUG_ON(!device->device_issue_pending); |
| 708 | BUG_ON(!device->dev); |
| 709 | |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 710 | init_completion(&device->done); |
| 711 | kref_init(&device->refcount); |
Dan Williams | b0b42b1 | 2008-12-03 17:17:07 -0700 | [diff] [blame] | 712 | |
| 713 | mutex_lock(&dma_list_mutex); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 714 | device->dev_id = id++; |
Dan Williams | b0b42b1 | 2008-12-03 17:17:07 -0700 | [diff] [blame] | 715 | mutex_unlock(&dma_list_mutex); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 716 | |
| 717 | /* represent channels in sysfs. Probably want devs too */ |
| 718 | list_for_each_entry(chan, &device->channels, device_node) { |
| 719 | chan->local = alloc_percpu(typeof(*chan->local)); |
| 720 | if (chan->local == NULL) |
| 721 | continue; |
| 722 | |
| 723 | chan->chan_id = chancnt++; |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 724 | chan->dev.class = &dma_devclass; |
Haavard Skinnemoen | 1099dc7 | 2008-07-08 11:58:05 -0700 | [diff] [blame] | 725 | chan->dev.parent = device->dev; |
Kay Sievers | 06190d8 | 2008-11-11 13:12:33 -0700 | [diff] [blame] | 726 | dev_set_name(&chan->dev, "dma%dchan%d", |
| 727 | device->dev_id, chan->chan_id); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 728 | |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 729 | rc = device_register(&chan->dev); |
Jeff Garzik | ff487fb | 2007-03-08 09:57:34 -0800 | [diff] [blame] | 730 | if (rc) { |
| 731 | chancnt--; |
| 732 | free_percpu(chan->local); |
| 733 | chan->local = NULL; |
| 734 | goto err_out; |
| 735 | } |
| 736 | |
Haavard Skinnemoen | 348badf | 2007-11-14 16:59:27 -0800 | [diff] [blame] | 737 | /* One for the channel, one of the class device */ |
| 738 | kref_get(&device->refcount); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 739 | kref_get(&device->refcount); |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 740 | kref_init(&chan->refcount); |
Dan Williams | 7cc5bf9 | 2008-07-08 11:58:21 -0700 | [diff] [blame] | 741 | chan->client_count = 0; |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 742 | chan->slow_ref = 0; |
| 743 | INIT_RCU_HEAD(&chan->rcu); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 744 | } |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 745 | device->chancnt = chancnt; |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 746 | |
| 747 | mutex_lock(&dma_list_mutex); |
Dan Williams | 59b5ec2 | 2009-01-06 11:38:15 -0700 | [diff] [blame] | 748 | /* take references on public channels */ |
| 749 | if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask)) |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 750 | list_for_each_entry(chan, &device->channels, device_node) { |
| 751 | /* if clients are already waiting for channels we need |
| 752 | * to take references on their behalf |
| 753 | */ |
| 754 | if (dma_chan_get(chan) == -ENODEV) { |
| 755 | /* note we can only get here for the first |
| 756 | * channel as the remaining channels are |
| 757 | * guaranteed to get a reference |
| 758 | */ |
| 759 | rc = -ENODEV; |
| 760 | mutex_unlock(&dma_list_mutex); |
| 761 | goto err_out; |
| 762 | } |
| 763 | } |
Dan Williams | 2ba0562 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 764 | list_add_tail_rcu(&device->global_node, &dma_device_list); |
Dan Williams | bec0851 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 765 | dma_channel_rebalance(); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 766 | mutex_unlock(&dma_list_mutex); |
| 767 | |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 768 | dma_clients_notify_available(); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 769 | |
| 770 | return 0; |
Jeff Garzik | ff487fb | 2007-03-08 09:57:34 -0800 | [diff] [blame] | 771 | |
| 772 | err_out: |
| 773 | list_for_each_entry(chan, &device->channels, device_node) { |
| 774 | if (chan->local == NULL) |
| 775 | continue; |
| 776 | kref_put(&device->refcount, dma_async_device_cleanup); |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 777 | device_unregister(&chan->dev); |
Jeff Garzik | ff487fb | 2007-03-08 09:57:34 -0800 | [diff] [blame] | 778 | chancnt--; |
| 779 | free_percpu(chan->local); |
| 780 | } |
| 781 | return rc; |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 782 | } |
David Brownell | 765e3d8 | 2007-03-16 13:38:05 -0800 | [diff] [blame] | 783 | EXPORT_SYMBOL(dma_async_device_register); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 784 | |
| 785 | /** |
Randy Dunlap | 6508871 | 2006-07-03 19:45:31 -0700 | [diff] [blame] | 786 | * dma_async_device_cleanup - function called when all references are released |
| 787 | * @kref: kernel reference object |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 788 | */ |
| 789 | static void dma_async_device_cleanup(struct kref *kref) |
| 790 | { |
| 791 | struct dma_device *device; |
| 792 | |
| 793 | device = container_of(kref, struct dma_device, refcount); |
| 794 | complete(&device->done); |
| 795 | } |
| 796 | |
Randy Dunlap | 6508871 | 2006-07-03 19:45:31 -0700 | [diff] [blame] | 797 | /** |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 798 | * dma_async_device_unregister - unregister a DMA device |
Randy Dunlap | 6508871 | 2006-07-03 19:45:31 -0700 | [diff] [blame] | 799 | * @device: &dma_device |
| 800 | */ |
| 801 | void dma_async_device_unregister(struct dma_device *device) |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 802 | { |
| 803 | struct dma_chan *chan; |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 804 | |
| 805 | mutex_lock(&dma_list_mutex); |
Dan Williams | 2ba0562 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 806 | list_del_rcu(&device->global_node); |
Dan Williams | bec0851 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 807 | dma_channel_rebalance(); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 808 | mutex_unlock(&dma_list_mutex); |
| 809 | |
| 810 | list_for_each_entry(chan, &device->channels, device_node) { |
Dan Williams | 6f49a57 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 811 | WARN_ONCE(chan->client_count, |
| 812 | "%s called while %d clients hold a reference\n", |
| 813 | __func__, chan->client_count); |
Tony Jones | 891f78e | 2007-09-25 02:03:03 +0200 | [diff] [blame] | 814 | device_unregister(&chan->dev); |
Dan Williams | d379b01 | 2007-07-09 11:56:42 -0700 | [diff] [blame] | 815 | dma_chan_release(chan); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 816 | } |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 817 | |
| 818 | kref_put(&device->refcount, dma_async_device_cleanup); |
| 819 | wait_for_completion(&device->done); |
| 820 | } |
David Brownell | 765e3d8 | 2007-03-16 13:38:05 -0800 | [diff] [blame] | 821 | EXPORT_SYMBOL(dma_async_device_unregister); |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 822 | |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 823 | /** |
| 824 | * dma_async_memcpy_buf_to_buf - offloaded copy between virtual addresses |
| 825 | * @chan: DMA channel to offload copy to |
| 826 | * @dest: destination address (virtual) |
| 827 | * @src: source address (virtual) |
| 828 | * @len: length |
| 829 | * |
| 830 | * Both @dest and @src must be mappable to a bus address according to the |
| 831 | * DMA mapping API rules for streaming mappings. |
| 832 | * Both @dest and @src must stay memory resident (kernel memory or locked |
| 833 | * user space pages). |
| 834 | */ |
| 835 | dma_cookie_t |
| 836 | dma_async_memcpy_buf_to_buf(struct dma_chan *chan, void *dest, |
| 837 | void *src, size_t len) |
| 838 | { |
| 839 | struct dma_device *dev = chan->device; |
| 840 | struct dma_async_tx_descriptor *tx; |
Dan Williams | 0036731 | 2008-02-02 19:49:57 -0700 | [diff] [blame] | 841 | dma_addr_t dma_dest, dma_src; |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 842 | dma_cookie_t cookie; |
| 843 | int cpu; |
| 844 | |
Dan Williams | 0036731 | 2008-02-02 19:49:57 -0700 | [diff] [blame] | 845 | dma_src = dma_map_single(dev->dev, src, len, DMA_TO_DEVICE); |
| 846 | dma_dest = dma_map_single(dev->dev, dest, len, DMA_FROM_DEVICE); |
Dan Williams | 636bdea | 2008-04-17 20:17:26 -0700 | [diff] [blame] | 847 | tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, |
| 848 | DMA_CTRL_ACK); |
Dan Williams | 0036731 | 2008-02-02 19:49:57 -0700 | [diff] [blame] | 849 | |
| 850 | if (!tx) { |
| 851 | dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE); |
| 852 | dma_unmap_single(dev->dev, dma_dest, len, DMA_FROM_DEVICE); |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 853 | return -ENOMEM; |
Dan Williams | 0036731 | 2008-02-02 19:49:57 -0700 | [diff] [blame] | 854 | } |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 855 | |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 856 | tx->callback = NULL; |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 857 | cookie = tx->tx_submit(tx); |
| 858 | |
| 859 | cpu = get_cpu(); |
| 860 | per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; |
| 861 | per_cpu_ptr(chan->local, cpu)->memcpy_count++; |
| 862 | put_cpu(); |
| 863 | |
| 864 | return cookie; |
| 865 | } |
| 866 | EXPORT_SYMBOL(dma_async_memcpy_buf_to_buf); |
| 867 | |
| 868 | /** |
| 869 | * dma_async_memcpy_buf_to_pg - offloaded copy from address to page |
| 870 | * @chan: DMA channel to offload copy to |
| 871 | * @page: destination page |
| 872 | * @offset: offset in page to copy to |
| 873 | * @kdata: source address (virtual) |
| 874 | * @len: length |
| 875 | * |
| 876 | * Both @page/@offset and @kdata must be mappable to a bus address according |
| 877 | * to the DMA mapping API rules for streaming mappings. |
| 878 | * Both @page/@offset and @kdata must stay memory resident (kernel memory or |
| 879 | * locked user space pages) |
| 880 | */ |
| 881 | dma_cookie_t |
| 882 | dma_async_memcpy_buf_to_pg(struct dma_chan *chan, struct page *page, |
| 883 | unsigned int offset, void *kdata, size_t len) |
| 884 | { |
| 885 | struct dma_device *dev = chan->device; |
| 886 | struct dma_async_tx_descriptor *tx; |
Dan Williams | 0036731 | 2008-02-02 19:49:57 -0700 | [diff] [blame] | 887 | dma_addr_t dma_dest, dma_src; |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 888 | dma_cookie_t cookie; |
| 889 | int cpu; |
| 890 | |
Dan Williams | 0036731 | 2008-02-02 19:49:57 -0700 | [diff] [blame] | 891 | dma_src = dma_map_single(dev->dev, kdata, len, DMA_TO_DEVICE); |
| 892 | dma_dest = dma_map_page(dev->dev, page, offset, len, DMA_FROM_DEVICE); |
Dan Williams | 636bdea | 2008-04-17 20:17:26 -0700 | [diff] [blame] | 893 | tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, |
| 894 | DMA_CTRL_ACK); |
Dan Williams | 0036731 | 2008-02-02 19:49:57 -0700 | [diff] [blame] | 895 | |
| 896 | if (!tx) { |
| 897 | dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE); |
| 898 | dma_unmap_page(dev->dev, dma_dest, len, DMA_FROM_DEVICE); |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 899 | return -ENOMEM; |
Dan Williams | 0036731 | 2008-02-02 19:49:57 -0700 | [diff] [blame] | 900 | } |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 901 | |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 902 | tx->callback = NULL; |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 903 | cookie = tx->tx_submit(tx); |
| 904 | |
| 905 | cpu = get_cpu(); |
| 906 | per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; |
| 907 | per_cpu_ptr(chan->local, cpu)->memcpy_count++; |
| 908 | put_cpu(); |
| 909 | |
| 910 | return cookie; |
| 911 | } |
| 912 | EXPORT_SYMBOL(dma_async_memcpy_buf_to_pg); |
| 913 | |
| 914 | /** |
| 915 | * dma_async_memcpy_pg_to_pg - offloaded copy from page to page |
| 916 | * @chan: DMA channel to offload copy to |
| 917 | * @dest_pg: destination page |
| 918 | * @dest_off: offset in page to copy to |
| 919 | * @src_pg: source page |
| 920 | * @src_off: offset in page to copy from |
| 921 | * @len: length |
| 922 | * |
| 923 | * Both @dest_page/@dest_off and @src_page/@src_off must be mappable to a bus |
| 924 | * address according to the DMA mapping API rules for streaming mappings. |
| 925 | * Both @dest_page/@dest_off and @src_page/@src_off must stay memory resident |
| 926 | * (kernel memory or locked user space pages). |
| 927 | */ |
| 928 | dma_cookie_t |
| 929 | dma_async_memcpy_pg_to_pg(struct dma_chan *chan, struct page *dest_pg, |
| 930 | unsigned int dest_off, struct page *src_pg, unsigned int src_off, |
| 931 | size_t len) |
| 932 | { |
| 933 | struct dma_device *dev = chan->device; |
| 934 | struct dma_async_tx_descriptor *tx; |
Dan Williams | 0036731 | 2008-02-02 19:49:57 -0700 | [diff] [blame] | 935 | dma_addr_t dma_dest, dma_src; |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 936 | dma_cookie_t cookie; |
| 937 | int cpu; |
| 938 | |
Dan Williams | 0036731 | 2008-02-02 19:49:57 -0700 | [diff] [blame] | 939 | dma_src = dma_map_page(dev->dev, src_pg, src_off, len, DMA_TO_DEVICE); |
| 940 | dma_dest = dma_map_page(dev->dev, dest_pg, dest_off, len, |
| 941 | DMA_FROM_DEVICE); |
Dan Williams | 636bdea | 2008-04-17 20:17:26 -0700 | [diff] [blame] | 942 | tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, |
| 943 | DMA_CTRL_ACK); |
Dan Williams | 0036731 | 2008-02-02 19:49:57 -0700 | [diff] [blame] | 944 | |
| 945 | if (!tx) { |
| 946 | dma_unmap_page(dev->dev, dma_src, len, DMA_TO_DEVICE); |
| 947 | dma_unmap_page(dev->dev, dma_dest, len, DMA_FROM_DEVICE); |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 948 | return -ENOMEM; |
Dan Williams | 0036731 | 2008-02-02 19:49:57 -0700 | [diff] [blame] | 949 | } |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 950 | |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 951 | tx->callback = NULL; |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 952 | cookie = tx->tx_submit(tx); |
| 953 | |
| 954 | cpu = get_cpu(); |
| 955 | per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; |
| 956 | per_cpu_ptr(chan->local, cpu)->memcpy_count++; |
| 957 | put_cpu(); |
| 958 | |
| 959 | return cookie; |
| 960 | } |
| 961 | EXPORT_SYMBOL(dma_async_memcpy_pg_to_pg); |
| 962 | |
| 963 | void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx, |
| 964 | struct dma_chan *chan) |
| 965 | { |
| 966 | tx->chan = chan; |
| 967 | spin_lock_init(&tx->lock); |
Dan Williams | 7405f74 | 2007-01-02 11:10:43 -0700 | [diff] [blame] | 968 | } |
| 969 | EXPORT_SYMBOL(dma_async_tx_descriptor_init); |
| 970 | |
Dan Williams | 07f2211 | 2009-01-05 17:14:31 -0700 | [diff] [blame] | 971 | /* dma_wait_for_async_tx - spin wait for a transaction to complete |
| 972 | * @tx: in-flight transaction to wait on |
| 973 | * |
| 974 | * This routine assumes that tx was obtained from a call to async_memcpy, |
| 975 | * async_xor, async_memset, etc which ensures that tx is "in-flight" (prepped |
| 976 | * and submitted). Walking the parent chain is only meant to cover for DMA |
| 977 | * drivers that do not implement the DMA_INTERRUPT capability and may race with |
| 978 | * the driver's descriptor cleanup routine. |
| 979 | */ |
| 980 | enum dma_status |
| 981 | dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx) |
| 982 | { |
| 983 | enum dma_status status; |
| 984 | struct dma_async_tx_descriptor *iter; |
| 985 | struct dma_async_tx_descriptor *parent; |
| 986 | |
| 987 | if (!tx) |
| 988 | return DMA_SUCCESS; |
| 989 | |
| 990 | WARN_ONCE(tx->parent, "%s: speculatively walking dependency chain for" |
| 991 | " %s\n", __func__, dev_name(&tx->chan->dev)); |
| 992 | |
| 993 | /* poll through the dependency chain, return when tx is complete */ |
| 994 | do { |
| 995 | iter = tx; |
| 996 | |
| 997 | /* find the root of the unsubmitted dependency chain */ |
| 998 | do { |
| 999 | parent = iter->parent; |
| 1000 | if (!parent) |
| 1001 | break; |
| 1002 | else |
| 1003 | iter = parent; |
| 1004 | } while (parent); |
| 1005 | |
| 1006 | /* there is a small window for ->parent == NULL and |
| 1007 | * ->cookie == -EBUSY |
| 1008 | */ |
| 1009 | while (iter->cookie == -EBUSY) |
| 1010 | cpu_relax(); |
| 1011 | |
| 1012 | status = dma_sync_wait(iter->chan, iter->cookie); |
| 1013 | } while (status == DMA_IN_PROGRESS || (iter != tx)); |
| 1014 | |
| 1015 | return status; |
| 1016 | } |
| 1017 | EXPORT_SYMBOL_GPL(dma_wait_for_async_tx); |
| 1018 | |
| 1019 | /* dma_run_dependencies - helper routine for dma drivers to process |
| 1020 | * (start) dependent operations on their target channel |
| 1021 | * @tx: transaction with dependencies |
| 1022 | */ |
| 1023 | void dma_run_dependencies(struct dma_async_tx_descriptor *tx) |
| 1024 | { |
| 1025 | struct dma_async_tx_descriptor *dep = tx->next; |
| 1026 | struct dma_async_tx_descriptor *dep_next; |
| 1027 | struct dma_chan *chan; |
| 1028 | |
| 1029 | if (!dep) |
| 1030 | return; |
| 1031 | |
| 1032 | chan = dep->chan; |
| 1033 | |
| 1034 | /* keep submitting up until a channel switch is detected |
| 1035 | * in that case we will be called again as a result of |
| 1036 | * processing the interrupt from async_tx_channel_switch |
| 1037 | */ |
| 1038 | for (; dep; dep = dep_next) { |
| 1039 | spin_lock_bh(&dep->lock); |
| 1040 | dep->parent = NULL; |
| 1041 | dep_next = dep->next; |
| 1042 | if (dep_next && dep_next->chan == chan) |
| 1043 | dep->next = NULL; /* ->next will be submitted */ |
| 1044 | else |
| 1045 | dep_next = NULL; /* submit current dep and terminate */ |
| 1046 | spin_unlock_bh(&dep->lock); |
| 1047 | |
| 1048 | dep->tx_submit(dep); |
| 1049 | } |
| 1050 | |
| 1051 | chan->device->device_issue_pending(chan); |
| 1052 | } |
| 1053 | EXPORT_SYMBOL_GPL(dma_run_dependencies); |
| 1054 | |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 1055 | static int __init dma_bus_init(void) |
| 1056 | { |
| 1057 | mutex_init(&dma_list_mutex); |
| 1058 | return class_register(&dma_devclass); |
| 1059 | } |
Chris Leech | c13c826 | 2006-05-23 17:18:44 -0700 | [diff] [blame] | 1060 | subsys_initcall(dma_bus_init); |
| 1061 | |
Dan Williams | bec0851 | 2009-01-06 11:38:14 -0700 | [diff] [blame] | 1062 | |