1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * Copyright(c) 2004 - 2006 Intel Corporation. All rights reserved. 4 */ 5 6/* 7 * This code implements the DMA subsystem. It provides a HW-neutral interface 8 * for other kernel code to use asynchronous memory copy capabilities, 9 * if present, and allows different HW DMA drivers to register as providing 10 * this capability. 11 * 12 * Due to the fact we are accelerating what is already a relatively fast 13 * operation, the code goes to great lengths to avoid additional overhead, 14 * such as locking. 15 * 16 * LOCKING: 17 * 18 * The subsystem keeps a global list of dma_device structs it is protected by a 19 * mutex, dma_list_mutex. 20 * 21 * A subsystem can get access to a channel by calling dmaengine_get() followed 22 * by dma_find_channel(), or if it has need for an exclusive channel it can call 23 * dma_request_channel(). Once a channel is allocated a reference is taken 24 * against its corresponding driver to disable removal. 25 * 26 * Each device has a channels list, which runs unlocked but is never modified 27 * once the device is registered, it's just setup by the driver. 28 * 29 * See Documentation/driver-api/dmaengine for more details 30 */ 31 32#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 33 34#include <linux/platform_device.h> 35#include <linux/dma-mapping.h> 36#include <linux/init.h> 37#include <linux/module.h> 38#include <linux/mm.h> 39#include <linux/device.h> 40#include <linux/dmaengine.h> 41#include <linux/hardirq.h> 42#include <linux/spinlock.h> 43#include <linux/percpu.h> 44#include <linux/rcupdate.h> 45#include <linux/mutex.h> 46#include <linux/jiffies.h> 47#include <linux/rculist.h> 48#include <linux/idr.h> 49#include <linux/slab.h> 50#include <linux/acpi.h> 51#include <linux/acpi_dma.h> 52#include <linux/of_dma.h> 53#include <linux/mempool.h> 54#include <linux/numa.h> 55 56#include "dmaengine.h" 57 58static DEFINE_MUTEX(dma_list_mutex); 59static DEFINE_IDA(dma_ida); 60static LIST_HEAD(dma_device_list); 61static long dmaengine_ref_count; 62 63/* --- debugfs implementation --- */ 64#ifdef CONFIG_DEBUG_FS 65#include <linux/debugfs.h> 66 67static struct dentry *rootdir; 68 69static void dmaengine_debug_register(struct dma_device *dma_dev) 70{ 71 dma_dev->dbg_dev_root = debugfs_create_dir(dev_name(dma_dev->dev), 72 rootdir); 73 if (IS_ERR(dma_dev->dbg_dev_root)) 74 dma_dev->dbg_dev_root = NULL; 75} 76 77static void dmaengine_debug_unregister(struct dma_device *dma_dev) 78{ 79 debugfs_remove_recursive(dma_dev->dbg_dev_root); 80 dma_dev->dbg_dev_root = NULL; 81} 82 83static void dmaengine_dbg_summary_show(struct seq_file *s, 84 struct dma_device *dma_dev) 85{ 86 struct dma_chan *chan; 87 88 list_for_each_entry(chan, &dma_dev->channels, device_node) { 89 if (chan->client_count) { 90 seq_printf(s, " %-13s| %s", dma_chan_name(chan), 91 chan->dbg_client_name ?: "in-use"); 92 93 if (chan->router) 94 seq_printf(s, " (via router: %s)\n", 95 dev_name(chan->router->dev)); 96 else 97 seq_puts(s, "\n"); 98 } 99 } 100} 101 102static int dmaengine_summary_show(struct seq_file *s, void *data) 103{ 104 struct dma_device *dma_dev = NULL; 105 106 mutex_lock(&dma_list_mutex); 107 list_for_each_entry(dma_dev, &dma_device_list, global_node) { 108 seq_printf(s, "dma%d (%s): number of channels: %u\n", 109 dma_dev->dev_id, dev_name(dma_dev->dev), 110 dma_dev->chancnt); 111 112 if (dma_dev->dbg_summary_show) 113 dma_dev->dbg_summary_show(s, dma_dev); 114 else 115 dmaengine_dbg_summary_show(s, dma_dev); 116 117 if (!list_is_last(&dma_dev->global_node, &dma_device_list)) 118 seq_puts(s, "\n"); 119 } 120 mutex_unlock(&dma_list_mutex); 121 122 return 0; 123} 124DEFINE_SHOW_ATTRIBUTE(dmaengine_summary); 125 126static void __init dmaengine_debugfs_init(void) 127{ 128 rootdir = debugfs_create_dir("dmaengine", NULL); 129 130 /* /sys/kernel/debug/dmaengine/summary */ 131 debugfs_create_file("summary", 0444, rootdir, NULL, 132 &dmaengine_summary_fops); 133} 134#else 135static inline void dmaengine_debugfs_init(void) { } 136static inline int dmaengine_debug_register(struct dma_device *dma_dev) 137{ 138 return 0; 139} 140 141static inline void dmaengine_debug_unregister(struct dma_device *dma_dev) { } 142#endif /* DEBUG_FS */ 143 144/* --- sysfs implementation --- */ 145 146#define DMA_SLAVE_NAME "slave" 147 148/** 149 * dev_to_dma_chan - convert a device pointer to its sysfs container object 150 * @dev: device node 151 * 152 * Must be called under dma_list_mutex. 153 */ 154static struct dma_chan *dev_to_dma_chan(struct device *dev) 155{ 156 struct dma_chan_dev *chan_dev; 157 158 chan_dev = container_of(dev, typeof(*chan_dev), device); 159 return chan_dev->chan; 160} 161 162static ssize_t memcpy_count_show(struct device *dev, 163 struct device_attribute *attr, char *buf) 164{ 165 struct dma_chan *chan; 166 unsigned long count = 0; 167 int i; 168 int err; 169 170 mutex_lock(&dma_list_mutex); 171 chan = dev_to_dma_chan(dev); 172 if (chan) { 173 for_each_possible_cpu(i) 174 count += per_cpu_ptr(chan->local, i)->memcpy_count; 175 err = sprintf(buf, "%lu\n", count); 176 } else 177 err = -ENODEV; 178 mutex_unlock(&dma_list_mutex); 179 180 return err; 181} 182static DEVICE_ATTR_RO(memcpy_count); 183 184static ssize_t bytes_transferred_show(struct device *dev, 185 struct device_attribute *attr, char *buf) 186{ 187 struct dma_chan *chan; 188 unsigned long count = 0; 189 int i; 190 int err; 191 192 mutex_lock(&dma_list_mutex); 193 chan = dev_to_dma_chan(dev); 194 if (chan) { 195 for_each_possible_cpu(i) 196 count += per_cpu_ptr(chan->local, i)->bytes_transferred; 197 err = sprintf(buf, "%lu\n", count); 198 } else 199 err = -ENODEV; 200 mutex_unlock(&dma_list_mutex); 201 202 return err; 203} 204static DEVICE_ATTR_RO(bytes_transferred); 205 206static ssize_t in_use_show(struct device *dev, struct device_attribute *attr, 207 char *buf) 208{ 209 struct dma_chan *chan; 210 int err; 211 212 mutex_lock(&dma_list_mutex); 213 chan = dev_to_dma_chan(dev); 214 if (chan) 215 err = sprintf(buf, "%d\n", chan->client_count); 216 else 217 err = -ENODEV; 218 mutex_unlock(&dma_list_mutex); 219 220 return err; 221} 222static DEVICE_ATTR_RO(in_use); 223 224static struct attribute *dma_dev_attrs[] = { 225 &dev_attr_memcpy_count.attr, 226 &dev_attr_bytes_transferred.attr, 227 &dev_attr_in_use.attr, 228 NULL, 229}; 230ATTRIBUTE_GROUPS(dma_dev); 231 232static void chan_dev_release(struct device *dev) 233{ 234 struct dma_chan_dev *chan_dev; 235 236 chan_dev = container_of(dev, typeof(*chan_dev), device); 237 kfree(chan_dev); 238} 239 240static struct class dma_devclass = { 241 .name = "dma", 242 .dev_groups = dma_dev_groups, 243 .dev_release = chan_dev_release, 244}; 245 246/* --- client and device registration --- */ 247 248/* enable iteration over all operation types */ 249static dma_cap_mask_t dma_cap_mask_all; 250 251/** 252 * struct dma_chan_tbl_ent - tracks channel allocations per core/operation 253 * @chan: associated channel for this entry 254 */ 255struct dma_chan_tbl_ent { 256 struct dma_chan *chan; 257}; 258 259/* percpu lookup table for memory-to-memory offload providers */ 260static struct dma_chan_tbl_ent __percpu *channel_table[DMA_TX_TYPE_END]; 261 262static int __init dma_channel_table_init(void) 263{ 264 enum dma_transaction_type cap; 265 int err = 0; 266 267 bitmap_fill(dma_cap_mask_all.bits, DMA_TX_TYPE_END); 268 269 /* 'interrupt', 'private', and 'slave' are channel capabilities, 270 * but are not associated with an operation so they do not need 271 * an entry in the channel_table 272 */ 273 clear_bit(DMA_INTERRUPT, dma_cap_mask_all.bits); 274 clear_bit(DMA_PRIVATE, dma_cap_mask_all.bits); 275 clear_bit(DMA_SLAVE, dma_cap_mask_all.bits); 276 277 for_each_dma_cap_mask(cap, dma_cap_mask_all) { 278 channel_table[cap] = alloc_percpu(struct dma_chan_tbl_ent); 279 if (!channel_table[cap]) { 280 err = -ENOMEM; 281 break; 282 } 283 } 284 285 if (err) { 286 pr_err("dmaengine dma_channel_table_init failure: %d\n", err); 287 for_each_dma_cap_mask(cap, dma_cap_mask_all) 288 free_percpu(channel_table[cap]); 289 } 290 291 return err; 292} 293arch_initcall(dma_channel_table_init); 294 295/** 296 * dma_chan_is_local - checks if the channel is in the same NUMA-node as the CPU 297 * @chan: DMA channel to test 298 * @cpu: CPU index which the channel should be close to 299 * 300 * Returns true if the channel is in the same NUMA-node as the CPU. 301 */ 302static bool dma_chan_is_local(struct dma_chan *chan, int cpu) 303{ 304 int node = dev_to_node(chan->device->dev); 305 return node == NUMA_NO_NODE || 306 cpumask_test_cpu(cpu, cpumask_of_node(node)); 307} 308 309/** 310 * min_chan - finds the channel with min count and in the same NUMA-node as the CPU 311 * @cap: capability to match 312 * @cpu: CPU index which the channel should be close to 313 * 314 * If some channels are close to the given CPU, the one with the lowest 315 * reference count is returned. Otherwise, CPU is ignored and only the 316 * reference count is taken into account. 317 * 318 * Must be called under dma_list_mutex. 319 */ 320static struct dma_chan *min_chan(enum dma_transaction_type cap, int cpu) 321{ 322 struct dma_device *device; 323 struct dma_chan *chan; 324 struct dma_chan *min = NULL; 325 struct dma_chan *localmin = NULL; 326 327 list_for_each_entry(device, &dma_device_list, global_node) { 328 if (!dma_has_cap(cap, device->cap_mask) || 329 dma_has_cap(DMA_PRIVATE, device->cap_mask)) 330 continue; 331 list_for_each_entry(chan, &device->channels, device_node) { 332 if (!chan->client_count) 333 continue; 334 if (!min || chan->table_count < min->table_count) 335 min = chan; 336 337 if (dma_chan_is_local(chan, cpu)) 338 if (!localmin || 339 chan->table_count < localmin->table_count) 340 localmin = chan; 341 } 342 } 343 344 chan = localmin ? localmin : min; 345 346 if (chan) 347 chan->table_count++; 348 349 return chan; 350} 351 352/** 353 * dma_channel_rebalance - redistribute the available channels 354 * 355 * Optimize for CPU isolation (each CPU gets a dedicated channel for an 356 * operation type) in the SMP case, and operation isolation (avoid 357 * multi-tasking channels) in the non-SMP case. 358 * 359 * Must be called under dma_list_mutex. 360 */ 361static void dma_channel_rebalance(void) 362{ 363 struct dma_chan *chan; 364 struct dma_device *device; 365 int cpu; 366 int cap; 367 368 /* undo the last distribution */ 369 for_each_dma_cap_mask(cap, dma_cap_mask_all) 370 for_each_possible_cpu(cpu) 371 per_cpu_ptr(channel_table[cap], cpu)->chan = NULL; 372 373 list_for_each_entry(device, &dma_device_list, global_node) { 374 if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) 375 continue; 376 list_for_each_entry(chan, &device->channels, device_node) 377 chan->table_count = 0; 378 } 379 380 /* don't populate the channel_table if no clients are available */ 381 if (!dmaengine_ref_count) 382 return; 383 384 /* redistribute available channels */ 385 for_each_dma_cap_mask(cap, dma_cap_mask_all) 386 for_each_online_cpu(cpu) { 387 chan = min_chan(cap, cpu); 388 per_cpu_ptr(channel_table[cap], cpu)->chan = chan; 389 } 390} 391 392static int dma_device_satisfies_mask(struct dma_device *device, 393 const dma_cap_mask_t *want) 394{ 395 dma_cap_mask_t has; 396 397 bitmap_and(has.bits, want->bits, device->cap_mask.bits, 398 DMA_TX_TYPE_END); 399 return bitmap_equal(want->bits, has.bits, DMA_TX_TYPE_END); 400} 401 402static struct module *dma_chan_to_owner(struct dma_chan *chan) 403{ 404 return chan->device->owner; 405} 406 407/** 408 * balance_ref_count - catch up the channel reference count 409 * @chan: channel to balance ->client_count versus dmaengine_ref_count 410 * 411 * Must be called under dma_list_mutex. 412 */ 413static void balance_ref_count(struct dma_chan *chan) 414{ 415 struct module *owner = dma_chan_to_owner(chan); 416 417 while (chan->client_count < dmaengine_ref_count) { 418 __module_get(owner); 419 chan->client_count++; 420 } 421} 422 423static void dma_device_release(struct kref *ref) 424{ 425 struct dma_device *device = container_of(ref, struct dma_device, ref); 426 427 list_del_rcu(&device->global_node); 428 dma_channel_rebalance(); 429 430 if (device->device_release) 431 device->device_release(device); 432} 433 434static void dma_device_put(struct dma_device *device) 435{ 436 lockdep_assert_held(&dma_list_mutex); 437 kref_put(&device->ref, dma_device_release); 438} 439 440/** 441 * dma_chan_get - try to grab a DMA channel's parent driver module 442 * @chan: channel to grab 443 * 444 * Must be called under dma_list_mutex. 445 */ 446static int dma_chan_get(struct dma_chan *chan) 447{ 448 struct module *owner = dma_chan_to_owner(chan); 449 int ret; 450 451 /* The channel is already in use, update client count */ 452 if (chan->client_count) { 453 __module_get(owner); 454 chan->client_count++; 455 return 0; 456 } 457 458 if (!try_module_get(owner)) 459 return -ENODEV; 460 461 ret = kref_get_unless_zero(&chan->device->ref); 462 if (!ret) { 463 ret = -ENODEV; 464 goto module_put_out; 465 } 466 467 /* allocate upon first client reference */ 468 if (chan->device->device_alloc_chan_resources) { 469 ret = chan->device->device_alloc_chan_resources(chan); 470 if (ret < 0) 471 goto err_out; 472 } 473 474 chan->client_count++; 475 476 if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask)) 477 balance_ref_count(chan); 478 479 return 0; 480 481err_out: 482 dma_device_put(chan->device); 483module_put_out: 484 module_put(owner); 485 return ret; 486} 487 488/** 489 * dma_chan_put - drop a reference to a DMA channel's parent driver module 490 * @chan: channel to release 491 * 492 * Must be called under dma_list_mutex. 493 */ 494static void dma_chan_put(struct dma_chan *chan) 495{ 496 /* This channel is not in use, bail out */ 497 if (!chan->client_count) 498 return; 499 500 chan->client_count--; 501 502 /* This channel is not in use anymore, free it */ 503 if (!chan->client_count && chan->device->device_free_chan_resources) { 504 /* Make sure all operations have completed */ 505 dmaengine_synchronize(chan); 506 chan->device->device_free_chan_resources(chan); 507 } 508 509 /* If the channel is used via a DMA request router, free the mapping */ 510 if (chan->router && chan->router->route_free) { 511 chan->router->route_free(chan->router->dev, chan->route_data); 512 chan->router = NULL; 513 chan->route_data = NULL; 514 } 515 516 dma_device_put(chan->device); 517 module_put(dma_chan_to_owner(chan)); 518} 519 520enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie) 521{ 522 enum dma_status status; 523 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000); 524 525 dma_async_issue_pending(chan); 526 do { 527 status = dma_async_is_tx_complete(chan, cookie, NULL, NULL); 528 if (time_after_eq(jiffies, dma_sync_wait_timeout)) { 529 dev_err(chan->device->dev, "%s: timeout!\n", __func__); 530 return DMA_ERROR; 531 } 532 if (status != DMA_IN_PROGRESS) 533 break; 534 cpu_relax(); 535 } while (1); 536 537 return status; 538} 539EXPORT_SYMBOL(dma_sync_wait); 540 541/** 542 * dma_find_channel - find a channel to carry out the operation 543 * @tx_type: transaction type 544 */ 545struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type) 546{ 547 return this_cpu_read(channel_table[tx_type]->chan); 548} 549EXPORT_SYMBOL(dma_find_channel); 550 551/** 552 * dma_issue_pending_all - flush all pending operations across all channels 553 */ 554void dma_issue_pending_all(void) 555{ 556 struct dma_device *device; 557 struct dma_chan *chan; 558 559 rcu_read_lock(); 560 list_for_each_entry_rcu(device, &dma_device_list, global_node) { 561 if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) 562 continue; 563 list_for_each_entry(chan, &device->channels, device_node) 564 if (chan->client_count) 565 device->device_issue_pending(chan); 566 } 567 rcu_read_unlock(); 568} 569EXPORT_SYMBOL(dma_issue_pending_all); 570 571int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps) 572{ 573 struct dma_device *device; 574 575 if (!chan || !caps) 576 return -EINVAL; 577 578 device = chan->device; 579 580 /* check if the channel supports slave transactions */ 581 if (!(test_bit(DMA_SLAVE, device->cap_mask.bits) || 582 test_bit(DMA_CYCLIC, device->cap_mask.bits))) 583 return -ENXIO; 584 585 /* 586 * Check whether it reports it uses the generic slave 587 * capabilities, if not, that means it doesn't support any 588 * kind of slave capabilities reporting. 589 */ 590 if (!device->directions) 591 return -ENXIO; 592 593 caps->src_addr_widths = device->src_addr_widths; 594 caps->dst_addr_widths = device->dst_addr_widths; 595 caps->directions = device->directions; 596 caps->min_burst = device->min_burst; 597 caps->max_burst = device->max_burst; 598 caps->max_sg_burst = device->max_sg_burst; 599 caps->residue_granularity = device->residue_granularity; 600 caps->descriptor_reuse = device->descriptor_reuse; 601 caps->cmd_pause = !!device->device_pause; 602 caps->cmd_resume = !!device->device_resume; 603 caps->cmd_terminate = !!device->device_terminate_all; 604 605 /* 606 * DMA engine device might be configured with non-uniformly 607 * distributed slave capabilities per device channels. In this 608 * case the corresponding driver may provide the device_caps 609 * callback to override the generic capabilities with 610 * channel-specific ones. 611 */ 612 if (device->device_caps) 613 device->device_caps(chan, caps); 614 615 return 0; 616} 617EXPORT_SYMBOL_GPL(dma_get_slave_caps); 618 619static struct dma_chan *private_candidate(const dma_cap_mask_t *mask, 620 struct dma_device *dev, 621 dma_filter_fn fn, void *fn_param) 622{ 623 struct dma_chan *chan; 624 625 if (mask && !dma_device_satisfies_mask(dev, mask)) { 626 dev_dbg(dev->dev, "%s: wrong capabilities\n", __func__); 627 return NULL; 628 } 629 /* devices with multiple channels need special handling as we need to 630 * ensure that all channels are either private or public. 631 */ 632 if (dev->chancnt > 1 && !dma_has_cap(DMA_PRIVATE, dev->cap_mask)) 633 list_for_each_entry(chan, &dev->channels, device_node) { 634 /* some channels are already publicly allocated */ 635 if (chan->client_count) 636 return NULL; 637 } 638 639 list_for_each_entry(chan, &dev->channels, device_node) { 640 if (chan->client_count) { 641 dev_dbg(dev->dev, "%s: %s busy\n", 642 __func__, dma_chan_name(chan)); 643 continue; 644 } 645 if (fn && !fn(chan, fn_param)) { 646 dev_dbg(dev->dev, "%s: %s filter said false\n", 647 __func__, dma_chan_name(chan)); 648 continue; 649 } 650 return chan; 651 } 652 653 return NULL; 654} 655 656static struct dma_chan *find_candidate(struct dma_device *device, 657 const dma_cap_mask_t *mask, 658 dma_filter_fn fn, void *fn_param) 659{ 660 struct dma_chan *chan = private_candidate(mask, device, fn, fn_param); 661 int err; 662 663 if (chan) { 664 /* Found a suitable channel, try to grab, prep, and return it. 665 * We first set DMA_PRIVATE to disable balance_ref_count as this 666 * channel will not be published in the general-purpose 667 * allocator 668 */ 669 dma_cap_set(DMA_PRIVATE, device->cap_mask); 670 device->privatecnt++; 671 err = dma_chan_get(chan); 672 673 if (err) { 674 if (err == -ENODEV) { 675 dev_dbg(device->dev, "%s: %s module removed\n", 676 __func__, dma_chan_name(chan)); 677 list_del_rcu(&device->global_node); 678 } else 679 dev_dbg(device->dev, 680 "%s: failed to get %s: (%d)\n", 681 __func__, dma_chan_name(chan), err); 682 683 if (--device->privatecnt == 0) 684 dma_cap_clear(DMA_PRIVATE, device->cap_mask); 685 686 chan = ERR_PTR(err); 687 } 688 } 689 690 return chan ? chan : ERR_PTR(-EPROBE_DEFER); 691} 692 693/** 694 * dma_get_slave_channel - try to get specific channel exclusively 695 * @chan: target channel 696 */ 697struct dma_chan *dma_get_slave_channel(struct dma_chan *chan) 698{ 699 int err = -EBUSY; 700 701 /* lock against __dma_request_channel */ 702 mutex_lock(&dma_list_mutex); 703 704 if (chan->client_count == 0) { 705 struct dma_device *device = chan->device; 706 707 dma_cap_set(DMA_PRIVATE, device->cap_mask); 708 device->privatecnt++; 709 err = dma_chan_get(chan); 710 if (err) { 711 dev_dbg(chan->device->dev, 712 "%s: failed to get %s: (%d)\n", 713 __func__, dma_chan_name(chan), err); 714 chan = NULL; 715 if (--device->privatecnt == 0) 716 dma_cap_clear(DMA_PRIVATE, device->cap_mask); 717 } 718 } else 719 chan = NULL; 720 721 mutex_unlock(&dma_list_mutex); 722 723 724 return chan; 725} 726EXPORT_SYMBOL_GPL(dma_get_slave_channel); 727 728struct dma_chan *dma_get_any_slave_channel(struct dma_device *device) 729{ 730 dma_cap_mask_t mask; 731 struct dma_chan *chan; 732 733 dma_cap_zero(mask); 734 dma_cap_set(DMA_SLAVE, mask); 735 736 /* lock against __dma_request_channel */ 737 mutex_lock(&dma_list_mutex); 738 739 chan = find_candidate(device, &mask, NULL, NULL); 740 741 mutex_unlock(&dma_list_mutex); 742 743 return IS_ERR(chan) ? NULL : chan; 744} 745EXPORT_SYMBOL_GPL(dma_get_any_slave_channel); 746 747/** 748 * __dma_request_channel - try to allocate an exclusive channel 749 * @mask: capabilities that the channel must satisfy 750 * @fn: optional callback to disposition available channels 751 * @fn_param: opaque parameter to pass to dma_filter_fn() 752 * @np: device node to look for DMA channels 753 * 754 * Returns pointer to appropriate DMA channel on success or NULL. 755 */ 756struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, 757 dma_filter_fn fn, void *fn_param, 758 struct device_node *np) 759{ 760 struct dma_device *device, *_d; 761 struct dma_chan *chan = NULL; 762 763 /* Find a channel */ 764 mutex_lock(&dma_list_mutex); 765 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { 766 /* Finds a DMA controller with matching device node */ 767 if (np && device->dev->of_node && np != device->dev->of_node) 768 continue; 769 770 chan = find_candidate(device, mask, fn, fn_param); 771 if (!IS_ERR(chan)) 772 break; 773 774 chan = NULL; 775 } 776 mutex_unlock(&dma_list_mutex); 777 778 pr_debug("%s: %s (%s)\n", 779 __func__, 780 chan ? "success" : "fail", 781 chan ? dma_chan_name(chan) : NULL); 782 783 return chan; 784} 785EXPORT_SYMBOL_GPL(__dma_request_channel); 786 787static const struct dma_slave_map *dma_filter_match(struct dma_device *device, 788 const char *name, 789 struct device *dev) 790{ 791 int i; 792 793 if (!device->filter.mapcnt) 794 return NULL; 795 796 for (i = 0; i < device->filter.mapcnt; i++) { 797 const struct dma_slave_map *map = &device->filter.map[i]; 798 799 if (!strcmp(map->devname, dev_name(dev)) && 800 !strcmp(map->slave, name)) 801 return map; 802 } 803 804 return NULL; 805} 806 807/** 808 * dma_request_chan - try to allocate an exclusive slave channel 809 * @dev: pointer to client device structure 810 * @name: slave channel name 811 * 812 * Returns pointer to appropriate DMA channel on success or an error pointer. 813 */ 814struct dma_chan *dma_request_chan(struct device *dev, const char *name) 815{ 816 struct dma_device *d, *_d; 817 struct dma_chan *chan = NULL; 818 819 /* If device-tree is present get slave info from here */ 820 if (dev->of_node) 821 chan = of_dma_request_slave_channel(dev->of_node, name); 822 823 /* If device was enumerated by ACPI get slave info from here */ 824 if (has_acpi_companion(dev) && !chan) 825 chan = acpi_dma_request_slave_chan_by_name(dev, name); 826 827 if (PTR_ERR(chan) == -EPROBE_DEFER) 828 return chan; 829 830 if (!IS_ERR_OR_NULL(chan)) 831 goto found; 832 833 /* Try to find the channel via the DMA filter map(s) */ 834 mutex_lock(&dma_list_mutex); 835 list_for_each_entry_safe(d, _d, &dma_device_list, global_node) { 836 dma_cap_mask_t mask; 837 const struct dma_slave_map *map = dma_filter_match(d, name, dev); 838 839 if (!map) 840 continue; 841 842 dma_cap_zero(mask); 843 dma_cap_set(DMA_SLAVE, mask); 844 845 chan = find_candidate(d, &mask, d->filter.fn, map->param); 846 if (!IS_ERR(chan)) 847 break; 848 } 849 mutex_unlock(&dma_list_mutex); 850 851 if (IS_ERR(chan)) 852 return chan; 853 if (!chan) 854 return ERR_PTR(-EPROBE_DEFER); 855 856found: 857#ifdef CONFIG_DEBUG_FS 858 chan->dbg_client_name = kasprintf(GFP_KERNEL, "%s:%s", dev_name(dev), 859 name); 860#endif 861 862 chan->name = kasprintf(GFP_KERNEL, "dma:%s", name); 863 if (!chan->name) 864 return chan; 865 chan->slave = dev; 866 867 if (sysfs_create_link(&chan->dev->device.kobj, &dev->kobj, 868 DMA_SLAVE_NAME)) 869 dev_warn(dev, "Cannot create DMA %s symlink\n", DMA_SLAVE_NAME); 870 if (sysfs_create_link(&dev->kobj, &chan->dev->device.kobj, chan->name)) 871 dev_warn(dev, "Cannot create DMA %s symlink\n", chan->name); 872 873 return chan; 874} 875EXPORT_SYMBOL_GPL(dma_request_chan); 876 877/** 878 * dma_request_chan_by_mask - allocate a channel satisfying certain capabilities 879 * @mask: capabilities that the channel must satisfy 880 * 881 * Returns pointer to appropriate DMA channel on success or an error pointer. 882 */ 883struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask) 884{ 885 struct dma_chan *chan; 886 887 if (!mask) 888 return ERR_PTR(-ENODEV); 889 890 chan = __dma_request_channel(mask, NULL, NULL, NULL); 891 if (!chan) { 892 mutex_lock(&dma_list_mutex); 893 if (list_empty(&dma_device_list)) 894 chan = ERR_PTR(-EPROBE_DEFER); 895 else 896 chan = ERR_PTR(-ENODEV); 897 mutex_unlock(&dma_list_mutex); 898 } 899 900 return chan; 901} 902EXPORT_SYMBOL_GPL(dma_request_chan_by_mask); 903 904void dma_release_channel(struct dma_chan *chan) 905{ 906 mutex_lock(&dma_list_mutex); 907 WARN_ONCE(chan->client_count != 1, 908 "chan reference count %d != 1\n", chan->client_count); 909 dma_chan_put(chan); 910 /* drop PRIVATE cap enabled by __dma_request_channel() */ 911 if (--chan->device->privatecnt == 0) 912 dma_cap_clear(DMA_PRIVATE, chan->device->cap_mask); 913 914 if (chan->slave) { 915 sysfs_remove_link(&chan->dev->device.kobj, DMA_SLAVE_NAME); 916 sysfs_remove_link(&chan->slave->kobj, chan->name); 917 kfree(chan->name); 918 chan->name = NULL; 919 chan->slave = NULL; 920 } 921 922#ifdef CONFIG_DEBUG_FS 923 kfree(chan->dbg_client_name); 924 chan->dbg_client_name = NULL; 925#endif 926 mutex_unlock(&dma_list_mutex); 927} 928EXPORT_SYMBOL_GPL(dma_release_channel); 929 930/** 931 * dmaengine_get - register interest in dma_channels 932 */ 933void dmaengine_get(void) 934{ 935 struct dma_device *device, *_d; 936 struct dma_chan *chan; 937 int err; 938 939 mutex_lock(&dma_list_mutex); 940 dmaengine_ref_count++; 941 942 /* try to grab channels */ 943 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { 944 if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) 945 continue; 946 list_for_each_entry(chan, &device->channels, device_node) { 947 err = dma_chan_get(chan); 948 if (err == -ENODEV) { 949 /* module removed before we could use it */ 950 list_del_rcu(&device->global_node); 951 break; 952 } else if (err) 953 dev_dbg(chan->device->dev, 954 "%s: failed to get %s: (%d)\n", 955 __func__, dma_chan_name(chan), err); 956 } 957 } 958 959 /* if this is the first reference and there were channels 960 * waiting we need to rebalance to get those channels 961 * incorporated into the channel table 962 */ 963 if (dmaengine_ref_count == 1) 964 dma_channel_rebalance(); 965 mutex_unlock(&dma_list_mutex); 966} 967EXPORT_SYMBOL(dmaengine_get); 968 969/** 970 * dmaengine_put - let DMA drivers be removed when ref_count == 0 971 */ 972void dmaengine_put(void) 973{ 974 struct dma_device *device, *_d; 975 struct dma_chan *chan; 976 977 mutex_lock(&dma_list_mutex); 978 dmaengine_ref_count--; 979 BUG_ON(dmaengine_ref_count < 0); 980 /* drop channel references */ 981 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { 982 if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) 983 continue; 984 list_for_each_entry(chan, &device->channels, device_node) 985 dma_chan_put(chan); 986 } 987 mutex_unlock(&dma_list_mutex); 988} 989EXPORT_SYMBOL(dmaengine_put); 990 991static bool device_has_all_tx_types(struct dma_device *device) 992{ 993 /* A device that satisfies this test has channels that will never cause 994 * an async_tx channel switch event as all possible operation types can 995 * be handled. 996 */ 997 #ifdef CONFIG_ASYNC_TX_DMA 998 if (!dma_has_cap(DMA_INTERRUPT, device->cap_mask)) 999 return false; 1000 #endif 1001 1002 #if IS_ENABLED(CONFIG_ASYNC_MEMCPY) 1003 if (!dma_has_cap(DMA_MEMCPY, device->cap_mask)) 1004 return false; 1005 #endif 1006 1007 #if IS_ENABLED(CONFIG_ASYNC_XOR) 1008 if (!dma_has_cap(DMA_XOR, device->cap_mask)) 1009 return false; 1010 1011 #ifndef CONFIG_ASYNC_TX_DISABLE_XOR_VAL_DMA 1012 if (!dma_has_cap(DMA_XOR_VAL, device->cap_mask)) 1013 return false; 1014 #endif 1015 #endif 1016 1017 #if IS_ENABLED(CONFIG_ASYNC_PQ) 1018 if (!dma_has_cap(DMA_PQ, device->cap_mask)) 1019 return false; 1020 1021 #ifndef CONFIG_ASYNC_TX_DISABLE_PQ_VAL_DMA 1022 if (!dma_has_cap(DMA_PQ_VAL, device->cap_mask)) 1023 return false; 1024 #endif 1025 #endif 1026 1027 return true; 1028} 1029 1030static int get_dma_id(struct dma_device *device) 1031{ 1032 int rc = ida_alloc(&dma_ida, GFP_KERNEL); 1033 1034 if (rc < 0) 1035 return rc; 1036 device->dev_id = rc; 1037 return 0; 1038} 1039 1040static int __dma_async_device_channel_register(struct dma_device *device, 1041 struct dma_chan *chan) 1042{ 1043 int rc; 1044 1045 chan->local = alloc_percpu(typeof(*chan->local)); 1046 if (!chan->local) 1047 return -ENOMEM; 1048 chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL); 1049 if (!chan->dev) { 1050 rc = -ENOMEM; 1051 goto err_free_local; 1052 } 1053 1054 /* 1055 * When the chan_id is a negative value, we are dynamically adding 1056 * the channel. Otherwise we are static enumerating. 1057 */ 1058 mutex_lock(&device->chan_mutex); 1059 chan->chan_id = ida_alloc(&device->chan_ida, GFP_KERNEL); 1060 mutex_unlock(&device->chan_mutex); 1061 if (chan->chan_id < 0) { 1062 pr_err("%s: unable to alloc ida for chan: %d\n", 1063 __func__, chan->chan_id); 1064 rc = chan->chan_id; 1065 goto err_free_dev; 1066 } 1067 1068 chan->dev->device.class = &dma_devclass; 1069 chan->dev->device.parent = device->dev; 1070 chan->dev->chan = chan; 1071 chan->dev->dev_id = device->dev_id; 1072 dev_set_name(&chan->dev->device, "dma%dchan%d", 1073 device->dev_id, chan->chan_id); 1074 rc = device_register(&chan->dev->device); 1075 if (rc) 1076 goto err_out_ida; 1077 chan->client_count = 0; 1078 device->chancnt++; 1079 1080 return 0; 1081 1082 err_out_ida: 1083 mutex_lock(&device->chan_mutex); 1084 ida_free(&device->chan_ida, chan->chan_id); 1085 mutex_unlock(&device->chan_mutex); 1086 err_free_dev: 1087 kfree(chan->dev); 1088 err_free_local: 1089 free_percpu(chan->local); 1090 chan->local = NULL; 1091 return rc; 1092} 1093 1094int dma_async_device_channel_register(struct dma_device *device, 1095 struct dma_chan *chan) 1096{ 1097 int rc; 1098 1099 rc = __dma_async_device_channel_register(device, chan); 1100 if (rc < 0) 1101 return rc; 1102 1103 dma_channel_rebalance(); 1104 return 0; 1105} 1106EXPORT_SYMBOL_GPL(dma_async_device_channel_register); 1107 1108static void __dma_async_device_channel_unregister(struct dma_device *device, 1109 struct dma_chan *chan) 1110{ 1111 if (chan->local == NULL) 1112 return; 1113 1114 WARN_ONCE(!device->device_release && chan->client_count, 1115 "%s called while %d clients hold a reference\n", 1116 __func__, chan->client_count); 1117 mutex_lock(&dma_list_mutex); 1118 device->chancnt--; 1119 chan->dev->chan = NULL; 1120 mutex_unlock(&dma_list_mutex); 1121 mutex_lock(&device->chan_mutex); 1122 ida_free(&device->chan_ida, chan->chan_id); 1123 mutex_unlock(&device->chan_mutex); 1124 device_unregister(&chan->dev->device); 1125 free_percpu(chan->local); 1126} 1127 1128void dma_async_device_channel_unregister(struct dma_device *device, 1129 struct dma_chan *chan) 1130{ 1131 __dma_async_device_channel_unregister(device, chan); 1132 dma_channel_rebalance(); 1133} 1134EXPORT_SYMBOL_GPL(dma_async_device_channel_unregister); 1135 1136/** 1137 * dma_async_device_register - registers DMA devices found 1138 * @device: pointer to &struct dma_device 1139 * 1140 * After calling this routine the structure should not be freed except in the 1141 * device_release() callback which will be called after 1142 * dma_async_device_unregister() is called and no further references are taken. 1143 */ 1144int dma_async_device_register(struct dma_device *device) 1145{ 1146 int rc; 1147 struct dma_chan* chan; 1148 1149 if (!device) 1150 return -ENODEV; 1151 1152 /* validate device routines */ 1153 if (!device->dev) { 1154 pr_err("DMAdevice must have dev\n"); 1155 return -EIO; 1156 } 1157 1158 device->owner = device->dev->driver->owner; 1159 1160 if (dma_has_cap(DMA_MEMCPY, device->cap_mask) && !device->device_prep_dma_memcpy) { 1161 dev_err(device->dev, 1162 "Device claims capability %s, but op is not defined\n", 1163 "DMA_MEMCPY"); 1164 return -EIO; 1165 } 1166 1167 if (dma_has_cap(DMA_XOR, device->cap_mask) && !device->device_prep_dma_xor) { 1168 dev_err(device->dev, 1169 "Device claims capability %s, but op is not defined\n", 1170 "DMA_XOR"); 1171 return -EIO; 1172 } 1173 1174 if (dma_has_cap(DMA_XOR_VAL, device->cap_mask) && !device->device_prep_dma_xor_val) { 1175 dev_err(device->dev, 1176 "Device claims capability %s, but op is not defined\n", 1177 "DMA_XOR_VAL"); 1178 return -EIO; 1179 } 1180 1181 if (dma_has_cap(DMA_PQ, device->cap_mask) && !device->device_prep_dma_pq) { 1182 dev_err(device->dev, 1183 "Device claims capability %s, but op is not defined\n", 1184 "DMA_PQ"); 1185 return -EIO; 1186 } 1187 1188 if (dma_has_cap(DMA_PQ_VAL, device->cap_mask) && !device->device_prep_dma_pq_val) { 1189 dev_err(device->dev, 1190 "Device claims capability %s, but op is not defined\n", 1191 "DMA_PQ_VAL"); 1192 return -EIO; 1193 } 1194 1195 if (dma_has_cap(DMA_MEMSET, device->cap_mask) && !device->device_prep_dma_memset) { 1196 dev_err(device->dev, 1197 "Device claims capability %s, but op is not defined\n", 1198 "DMA_MEMSET"); 1199 return -EIO; 1200 } 1201 1202 if (dma_has_cap(DMA_INTERRUPT, device->cap_mask) && !device->device_prep_dma_interrupt) { 1203 dev_err(device->dev, 1204 "Device claims capability %s, but op is not defined\n", 1205 "DMA_INTERRUPT"); 1206 return -EIO; 1207 } 1208 1209 if (dma_has_cap(DMA_CYCLIC, device->cap_mask) && !device->device_prep_dma_cyclic) { 1210 dev_err(device->dev, 1211 "Device claims capability %s, but op is not defined\n", 1212 "DMA_CYCLIC"); 1213 return -EIO; 1214 } 1215 1216 if (dma_has_cap(DMA_INTERLEAVE, device->cap_mask) && !device->device_prep_interleaved_dma) { 1217 dev_err(device->dev, 1218 "Device claims capability %s, but op is not defined\n", 1219 "DMA_INTERLEAVE"); 1220 return -EIO; 1221 } 1222 1223 1224 if (!device->device_tx_status) { 1225 dev_err(device->dev, "Device tx_status is not defined\n"); 1226 return -EIO; 1227 } 1228 1229 1230 if (!device->device_issue_pending) { 1231 dev_err(device->dev, "Device issue_pending is not defined\n"); 1232 return -EIO; 1233 } 1234 1235 if (!device->device_release) 1236 dev_dbg(device->dev, 1237 "WARN: Device release is not defined so it is not safe to unbind this driver while in use\n"); 1238 1239 kref_init(&device->ref); 1240 1241 /* note: this only matters in the 1242 * CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH=n case 1243 */ 1244 if (device_has_all_tx_types(device)) 1245 dma_cap_set(DMA_ASYNC_TX, device->cap_mask); 1246 1247 rc = get_dma_id(device); 1248 if (rc != 0) 1249 return rc; 1250 1251 mutex_init(&device->chan_mutex); 1252 ida_init(&device->chan_ida); 1253 1254 /* represent channels in sysfs. Probably want devs too */ 1255 list_for_each_entry(chan, &device->channels, device_node) { 1256 rc = __dma_async_device_channel_register(device, chan); 1257 if (rc < 0) 1258 goto err_out; 1259 } 1260 1261 mutex_lock(&dma_list_mutex); 1262 /* take references on public channels */ 1263 if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask)) 1264 list_for_each_entry(chan, &device->channels, device_node) { 1265 /* if clients are already waiting for channels we need 1266 * to take references on their behalf 1267 */ 1268 if (dma_chan_get(chan) == -ENODEV) { 1269 /* note we can only get here for the first 1270 * channel as the remaining channels are 1271 * guaranteed to get a reference 1272 */ 1273 rc = -ENODEV; 1274 mutex_unlock(&dma_list_mutex); 1275 goto err_out; 1276 } 1277 } 1278 list_add_tail_rcu(&device->global_node, &dma_device_list); 1279 if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) 1280 device->privatecnt++; /* Always private */ 1281 dma_channel_rebalance(); 1282 mutex_unlock(&dma_list_mutex); 1283 1284 dmaengine_debug_register(device); 1285 1286 return 0; 1287 1288err_out: 1289 /* if we never registered a channel just release the idr */ 1290 if (!device->chancnt) { 1291 ida_free(&dma_ida, device->dev_id); 1292 return rc; 1293 } 1294 1295 list_for_each_entry(chan, &device->channels, device_node) { 1296 if (chan->local == NULL) 1297 continue; 1298 mutex_lock(&dma_list_mutex); 1299 chan->dev->chan = NULL; 1300 mutex_unlock(&dma_list_mutex); 1301 device_unregister(&chan->dev->device); 1302 free_percpu(chan->local); 1303 } 1304 return rc; 1305} 1306EXPORT_SYMBOL(dma_async_device_register); 1307 1308/** 1309 * dma_async_device_unregister - unregister a DMA device 1310 * @device: pointer to &struct dma_device 1311 * 1312 * This routine is called by dma driver exit routines, dmaengine holds module 1313 * references to prevent it being called while channels are in use. 1314 */ 1315void dma_async_device_unregister(struct dma_device *device) 1316{ 1317 struct dma_chan *chan, *n; 1318 1319 dmaengine_debug_unregister(device); 1320 1321 list_for_each_entry_safe(chan, n, &device->channels, device_node) 1322 __dma_async_device_channel_unregister(device, chan); 1323 1324 mutex_lock(&dma_list_mutex); 1325 /* 1326 * setting DMA_PRIVATE ensures the device being torn down will not 1327 * be used in the channel_table 1328 */ 1329 dma_cap_set(DMA_PRIVATE, device->cap_mask); 1330 dma_channel_rebalance(); 1331 ida_free(&dma_ida, device->dev_id); 1332 dma_device_put(device); 1333 mutex_unlock(&dma_list_mutex); 1334} 1335EXPORT_SYMBOL(dma_async_device_unregister); 1336 1337static void dmam_device_release(struct device *dev, void *res) 1338{ 1339 struct dma_device *device; 1340 1341 device = *(struct dma_device **)res; 1342 dma_async_device_unregister(device); 1343} 1344 1345/** 1346 * dmaenginem_async_device_register - registers DMA devices found 1347 * @device: pointer to &struct dma_device 1348 * 1349 * The operation is managed and will be undone on driver detach. 1350 */ 1351int dmaenginem_async_device_register(struct dma_device *device) 1352{ 1353 void *p; 1354 int ret; 1355 1356 p = devres_alloc(dmam_device_release, sizeof(void *), GFP_KERNEL); 1357 if (!p) 1358 return -ENOMEM; 1359 1360 ret = dma_async_device_register(device); 1361 if (!ret) { 1362 *(struct dma_device **)p = device; 1363 devres_add(device->dev, p); 1364 } else { 1365 devres_free(p); 1366 } 1367 1368 return ret; 1369} 1370EXPORT_SYMBOL(dmaenginem_async_device_register); 1371 1372struct dmaengine_unmap_pool { 1373 struct kmem_cache *cache; 1374 const char *name; 1375 mempool_t *pool; 1376 size_t size; 1377}; 1378 1379#define __UNMAP_POOL(x) { .size = x, .name = "dmaengine-unmap-" __stringify(x) } 1380static struct dmaengine_unmap_pool unmap_pool[] = { 1381 __UNMAP_POOL(2), 1382 #if IS_ENABLED(CONFIG_DMA_ENGINE_RAID) 1383 __UNMAP_POOL(16), 1384 __UNMAP_POOL(128), 1385 __UNMAP_POOL(256), 1386 #endif 1387}; 1388 1389static struct dmaengine_unmap_pool *__get_unmap_pool(int nr) 1390{ 1391 int order = get_count_order(nr); 1392 1393 switch (order) { 1394 case 0 ... 1: 1395 return &unmap_pool[0]; 1396#if IS_ENABLED(CONFIG_DMA_ENGINE_RAID) 1397 case 2 ... 4: 1398 return &unmap_pool[1]; 1399 case 5 ... 7: 1400 return &unmap_pool[2]; 1401 case 8: 1402 return &unmap_pool[3]; 1403#endif 1404 default: 1405 BUG(); 1406 return NULL; 1407 } 1408} 1409 1410static void dmaengine_unmap(struct kref *kref) 1411{ 1412 struct dmaengine_unmap_data *unmap = container_of(kref, typeof(*unmap), kref); 1413 struct device *dev = unmap->dev; 1414 int cnt, i; 1415 1416 cnt = unmap->to_cnt; 1417 for (i = 0; i < cnt; i++) 1418 dma_unmap_page(dev, unmap->addr[i], unmap->len, 1419 DMA_TO_DEVICE); 1420 cnt += unmap->from_cnt; 1421 for (; i < cnt; i++) 1422 dma_unmap_page(dev, unmap->addr[i], unmap->len, 1423 DMA_FROM_DEVICE); 1424 cnt += unmap->bidi_cnt; 1425 for (; i < cnt; i++) { 1426 if (unmap->addr[i] == 0) 1427 continue; 1428 dma_unmap_page(dev, unmap->addr[i], unmap->len, 1429 DMA_BIDIRECTIONAL); 1430 } 1431 cnt = unmap->map_cnt; 1432 mempool_free(unmap, __get_unmap_pool(cnt)->pool); 1433} 1434 1435void dmaengine_unmap_put(struct dmaengine_unmap_data *unmap) 1436{ 1437 if (unmap) 1438 kref_put(&unmap->kref, dmaengine_unmap); 1439} 1440EXPORT_SYMBOL_GPL(dmaengine_unmap_put); 1441 1442static void dmaengine_destroy_unmap_pool(void) 1443{ 1444 int i; 1445 1446 for (i = 0; i < ARRAY_SIZE(unmap_pool); i++) { 1447 struct dmaengine_unmap_pool *p = &unmap_pool[i]; 1448 1449 mempool_destroy(p->pool); 1450 p->pool = NULL; 1451 kmem_cache_destroy(p->cache); 1452 p->cache = NULL; 1453 } 1454} 1455 1456static int __init dmaengine_init_unmap_pool(void) 1457{ 1458 int i; 1459 1460 for (i = 0; i < ARRAY_SIZE(unmap_pool); i++) { 1461 struct dmaengine_unmap_pool *p = &unmap_pool[i]; 1462 size_t size; 1463 1464 size = sizeof(struct dmaengine_unmap_data) + 1465 sizeof(dma_addr_t) * p->size; 1466 1467 p->cache = kmem_cache_create(p->name, size, 0, 1468 SLAB_HWCACHE_ALIGN, NULL); 1469 if (!p->cache) 1470 break; 1471 p->pool = mempool_create_slab_pool(1, p->cache); 1472 if (!p->pool) 1473 break; 1474 } 1475 1476 if (i == ARRAY_SIZE(unmap_pool)) 1477 return 0; 1478 1479 dmaengine_destroy_unmap_pool(); 1480 return -ENOMEM; 1481} 1482 1483struct dmaengine_unmap_data * 1484dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags) 1485{ 1486 struct dmaengine_unmap_data *unmap; 1487 1488 unmap = mempool_alloc(__get_unmap_pool(nr)->pool, flags); 1489 if (!unmap) 1490 return NULL; 1491 1492 memset(unmap, 0, sizeof(*unmap)); 1493 kref_init(&unmap->kref); 1494 unmap->dev = dev; 1495 unmap->map_cnt = nr; 1496 1497 return unmap; 1498} 1499EXPORT_SYMBOL(dmaengine_get_unmap_data); 1500 1501void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx, 1502 struct dma_chan *chan) 1503{ 1504 tx->chan = chan; 1505 #ifdef CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH 1506 spin_lock_init(&tx->lock); 1507 #endif 1508} 1509EXPORT_SYMBOL(dma_async_tx_descriptor_init); 1510 1511static inline int desc_check_and_set_metadata_mode( 1512 struct dma_async_tx_descriptor *desc, enum dma_desc_metadata_mode mode) 1513{ 1514 /* Make sure that the metadata mode is not mixed */ 1515 if (!desc->desc_metadata_mode) { 1516 if (dmaengine_is_metadata_mode_supported(desc->chan, mode)) 1517 desc->desc_metadata_mode = mode; 1518 else 1519 return -ENOTSUPP; 1520 } else if (desc->desc_metadata_mode != mode) { 1521 return -EINVAL; 1522 } 1523 1524 return 0; 1525} 1526 1527int dmaengine_desc_attach_metadata(struct dma_async_tx_descriptor *desc, 1528 void *data, size_t len) 1529{ 1530 int ret; 1531 1532 if (!desc) 1533 return -EINVAL; 1534 1535 ret = desc_check_and_set_metadata_mode(desc, DESC_METADATA_CLIENT); 1536 if (ret) 1537 return ret; 1538 1539 if (!desc->metadata_ops || !desc->metadata_ops->attach) 1540 return -ENOTSUPP; 1541 1542 return desc->metadata_ops->attach(desc, data, len); 1543} 1544EXPORT_SYMBOL_GPL(dmaengine_desc_attach_metadata); 1545 1546void *dmaengine_desc_get_metadata_ptr(struct dma_async_tx_descriptor *desc, 1547 size_t *payload_len, size_t *max_len) 1548{ 1549 int ret; 1550 1551 if (!desc) 1552 return ERR_PTR(-EINVAL); 1553 1554 ret = desc_check_and_set_metadata_mode(desc, DESC_METADATA_ENGINE); 1555 if (ret) 1556 return ERR_PTR(ret); 1557 1558 if (!desc->metadata_ops || !desc->metadata_ops->get_ptr) 1559 return ERR_PTR(-ENOTSUPP); 1560 1561 return desc->metadata_ops->get_ptr(desc, payload_len, max_len); 1562} 1563EXPORT_SYMBOL_GPL(dmaengine_desc_get_metadata_ptr); 1564 1565int dmaengine_desc_set_metadata_len(struct dma_async_tx_descriptor *desc, 1566 size_t payload_len) 1567{ 1568 int ret; 1569 1570 if (!desc) 1571 return -EINVAL; 1572 1573 ret = desc_check_and_set_metadata_mode(desc, DESC_METADATA_ENGINE); 1574 if (ret) 1575 return ret; 1576 1577 if (!desc->metadata_ops || !desc->metadata_ops->set_len) 1578 return -ENOTSUPP; 1579 1580 return desc->metadata_ops->set_len(desc, payload_len); 1581} 1582EXPORT_SYMBOL_GPL(dmaengine_desc_set_metadata_len); 1583 1584/** 1585 * dma_wait_for_async_tx - spin wait for a transaction to complete 1586 * @tx: in-flight transaction to wait on 1587 */ 1588enum dma_status 1589dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx) 1590{ 1591 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000); 1592 1593 if (!tx) 1594 return DMA_COMPLETE; 1595 1596 while (tx->cookie == -EBUSY) { 1597 if (time_after_eq(jiffies, dma_sync_wait_timeout)) { 1598 dev_err(tx->chan->device->dev, 1599 "%s timeout waiting for descriptor submission\n", 1600 __func__); 1601 return DMA_ERROR; 1602 } 1603 cpu_relax(); 1604 } 1605 return dma_sync_wait(tx->chan, tx->cookie); 1606} 1607EXPORT_SYMBOL_GPL(dma_wait_for_async_tx); 1608 1609/** 1610 * dma_run_dependencies - process dependent operations on the target channel 1611 * @tx: transaction with dependencies 1612 * 1613 * Helper routine for DMA drivers to process (start) dependent operations 1614 * on their target channel. 1615 */ 1616void dma_run_dependencies(struct dma_async_tx_descriptor *tx) 1617{ 1618 struct dma_async_tx_descriptor *dep = txd_next(tx); 1619 struct dma_async_tx_descriptor *dep_next; 1620 struct dma_chan *chan; 1621 1622 if (!dep) 1623 return; 1624 1625 /* we'll submit tx->next now, so clear the link */ 1626 txd_clear_next(tx); 1627 chan = dep->chan; 1628 1629 /* keep submitting up until a channel switch is detected 1630 * in that case we will be called again as a result of 1631 * processing the interrupt from async_tx_channel_switch 1632 */ 1633 for (; dep; dep = dep_next) { 1634 txd_lock(dep); 1635 txd_clear_parent(dep); 1636 dep_next = txd_next(dep); 1637 if (dep_next && dep_next->chan == chan) 1638 txd_clear_next(dep); /* ->next will be submitted */ 1639 else 1640 dep_next = NULL; /* submit current dep and terminate */ 1641 txd_unlock(dep); 1642 1643 dep->tx_submit(dep); 1644 } 1645 1646 chan->device->device_issue_pending(chan); 1647} 1648EXPORT_SYMBOL_GPL(dma_run_dependencies); 1649 1650static int __init dma_bus_init(void) 1651{ 1652 int err = dmaengine_init_unmap_pool(); 1653 1654 if (err) 1655 return err; 1656 1657 err = class_register(&dma_devclass); 1658 if (!err) 1659 dmaengine_debugfs_init(); 1660 1661 return err; 1662} 1663arch_initcall(dma_bus_init); 1664