1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright(c) 2004 - 2006 Intel Corporation. All rights reserved.
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
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,
18 * The subsystem keeps a global list of dma_device structs it is protected by a
19 * mutex, dma_list_mutex.
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.
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.
29 * See Documentation/driver-api/dmaengine for more details
32 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
34 #include <linux/platform_device.h>
35 #include <linux/dma-mapping.h>
36 #include <linux/init.h>
37 #include <linux/module.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>
56 static DEFINE_MUTEX(dma_list_mutex);
57 static DEFINE_IDA(dma_ida);
58 static LIST_HEAD(dma_device_list);
59 static long dmaengine_ref_count;
61 /* --- sysfs implementation --- */
63 #define DMA_SLAVE_NAME "slave"
66 * dev_to_dma_chan - convert a device pointer to its sysfs container object
69 * Must be called under dma_list_mutex
71 static struct dma_chan *dev_to_dma_chan(struct device *dev)
73 struct dma_chan_dev *chan_dev;
75 chan_dev = container_of(dev, typeof(*chan_dev), device);
76 return chan_dev->chan;
79 static ssize_t memcpy_count_show(struct device *dev,
80 struct device_attribute *attr, char *buf)
82 struct dma_chan *chan;
83 unsigned long count = 0;
87 mutex_lock(&dma_list_mutex);
88 chan = dev_to_dma_chan(dev);
90 for_each_possible_cpu(i)
91 count += per_cpu_ptr(chan->local, i)->memcpy_count;
92 err = sprintf(buf, "%lu\n", count);
95 mutex_unlock(&dma_list_mutex);
99 static DEVICE_ATTR_RO(memcpy_count);
101 static ssize_t bytes_transferred_show(struct device *dev,
102 struct device_attribute *attr, char *buf)
104 struct dma_chan *chan;
105 unsigned long count = 0;
109 mutex_lock(&dma_list_mutex);
110 chan = dev_to_dma_chan(dev);
112 for_each_possible_cpu(i)
113 count += per_cpu_ptr(chan->local, i)->bytes_transferred;
114 err = sprintf(buf, "%lu\n", count);
117 mutex_unlock(&dma_list_mutex);
121 static DEVICE_ATTR_RO(bytes_transferred);
123 static ssize_t in_use_show(struct device *dev, struct device_attribute *attr,
126 struct dma_chan *chan;
129 mutex_lock(&dma_list_mutex);
130 chan = dev_to_dma_chan(dev);
132 err = sprintf(buf, "%d\n", chan->client_count);
135 mutex_unlock(&dma_list_mutex);
139 static DEVICE_ATTR_RO(in_use);
141 static struct attribute *dma_dev_attrs[] = {
142 &dev_attr_memcpy_count.attr,
143 &dev_attr_bytes_transferred.attr,
144 &dev_attr_in_use.attr,
147 ATTRIBUTE_GROUPS(dma_dev);
149 static void chan_dev_release(struct device *dev)
151 struct dma_chan_dev *chan_dev;
153 chan_dev = container_of(dev, typeof(*chan_dev), device);
154 if (atomic_dec_and_test(chan_dev->idr_ref)) {
155 ida_free(&dma_ida, chan_dev->dev_id);
156 kfree(chan_dev->idr_ref);
161 static struct class dma_devclass = {
163 .dev_groups = dma_dev_groups,
164 .dev_release = chan_dev_release,
167 /* --- client and device registration --- */
170 * dma_cap_mask_all - enable iteration over all operation types
172 static dma_cap_mask_t dma_cap_mask_all;
175 * dma_chan_tbl_ent - tracks channel allocations per core/operation
176 * @chan - associated channel for this entry
178 struct dma_chan_tbl_ent {
179 struct dma_chan *chan;
183 * channel_table - percpu lookup table for memory-to-memory offload providers
185 static struct dma_chan_tbl_ent __percpu *channel_table[DMA_TX_TYPE_END];
187 static int __init dma_channel_table_init(void)
189 enum dma_transaction_type cap;
192 bitmap_fill(dma_cap_mask_all.bits, DMA_TX_TYPE_END);
194 /* 'interrupt', 'private', and 'slave' are channel capabilities,
195 * but are not associated with an operation so they do not need
196 * an entry in the channel_table
198 clear_bit(DMA_INTERRUPT, dma_cap_mask_all.bits);
199 clear_bit(DMA_PRIVATE, dma_cap_mask_all.bits);
200 clear_bit(DMA_SLAVE, dma_cap_mask_all.bits);
202 for_each_dma_cap_mask(cap, dma_cap_mask_all) {
203 channel_table[cap] = alloc_percpu(struct dma_chan_tbl_ent);
204 if (!channel_table[cap]) {
211 pr_err("dmaengine dma_channel_table_init failure: %d\n", err);
212 for_each_dma_cap_mask(cap, dma_cap_mask_all)
213 free_percpu(channel_table[cap]);
218 arch_initcall(dma_channel_table_init);
221 * dma_chan_is_local - returns true if the channel is in the same numa-node as
224 static bool dma_chan_is_local(struct dma_chan *chan, int cpu)
226 int node = dev_to_node(chan->device->dev);
227 return node == NUMA_NO_NODE ||
228 cpumask_test_cpu(cpu, cpumask_of_node(node));
232 * min_chan - returns the channel with min count and in the same numa-node as
234 * @cap: capability to match
235 * @cpu: cpu index which the channel should be close to
237 * If some channels are close to the given cpu, the one with the lowest
238 * reference count is returned. Otherwise, cpu is ignored and only the
239 * reference count is taken into account.
240 * Must be called under dma_list_mutex.
242 static struct dma_chan *min_chan(enum dma_transaction_type cap, int cpu)
244 struct dma_device *device;
245 struct dma_chan *chan;
246 struct dma_chan *min = NULL;
247 struct dma_chan *localmin = NULL;
249 list_for_each_entry(device, &dma_device_list, global_node) {
250 if (!dma_has_cap(cap, device->cap_mask) ||
251 dma_has_cap(DMA_PRIVATE, device->cap_mask))
253 list_for_each_entry(chan, &device->channels, device_node) {
254 if (!chan->client_count)
256 if (!min || chan->table_count < min->table_count)
259 if (dma_chan_is_local(chan, cpu))
261 chan->table_count < localmin->table_count)
266 chan = localmin ? localmin : min;
275 * dma_channel_rebalance - redistribute the available channels
277 * Optimize for cpu isolation (each cpu gets a dedicated channel for an
278 * operation type) in the SMP case, and operation isolation (avoid
279 * multi-tasking channels) in the non-SMP case. Must be called under
282 static void dma_channel_rebalance(void)
284 struct dma_chan *chan;
285 struct dma_device *device;
289 /* undo the last distribution */
290 for_each_dma_cap_mask(cap, dma_cap_mask_all)
291 for_each_possible_cpu(cpu)
292 per_cpu_ptr(channel_table[cap], cpu)->chan = NULL;
294 list_for_each_entry(device, &dma_device_list, global_node) {
295 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
297 list_for_each_entry(chan, &device->channels, device_node)
298 chan->table_count = 0;
301 /* don't populate the channel_table if no clients are available */
302 if (!dmaengine_ref_count)
305 /* redistribute available channels */
306 for_each_dma_cap_mask(cap, dma_cap_mask_all)
307 for_each_online_cpu(cpu) {
308 chan = min_chan(cap, cpu);
309 per_cpu_ptr(channel_table[cap], cpu)->chan = chan;
313 static int dma_device_satisfies_mask(struct dma_device *device,
314 const dma_cap_mask_t *want)
318 bitmap_and(has.bits, want->bits, device->cap_mask.bits,
320 return bitmap_equal(want->bits, has.bits, DMA_TX_TYPE_END);
323 static struct module *dma_chan_to_owner(struct dma_chan *chan)
325 return chan->device->owner;
329 * balance_ref_count - catch up the channel reference count
330 * @chan - channel to balance ->client_count versus dmaengine_ref_count
332 * balance_ref_count must be called under dma_list_mutex
334 static void balance_ref_count(struct dma_chan *chan)
336 struct module *owner = dma_chan_to_owner(chan);
338 while (chan->client_count < dmaengine_ref_count) {
340 chan->client_count++;
344 static void dma_device_release(struct kref *ref)
346 struct dma_device *device = container_of(ref, struct dma_device, ref);
348 list_del_rcu(&device->global_node);
349 dma_channel_rebalance();
351 if (device->device_release)
352 device->device_release(device);
355 static void dma_device_put(struct dma_device *device)
357 lockdep_assert_held(&dma_list_mutex);
358 kref_put(&device->ref, dma_device_release);
362 * dma_chan_get - try to grab a dma channel's parent driver module
363 * @chan - channel to grab
365 * Must be called under dma_list_mutex
367 static int dma_chan_get(struct dma_chan *chan)
369 struct module *owner = dma_chan_to_owner(chan);
372 /* The channel is already in use, update client count */
373 if (chan->client_count) {
378 if (!try_module_get(owner))
381 ret = kref_get_unless_zero(&chan->device->ref);
387 /* allocate upon first client reference */
388 if (chan->device->device_alloc_chan_resources) {
389 ret = chan->device->device_alloc_chan_resources(chan);
394 if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
395 balance_ref_count(chan);
398 chan->client_count++;
402 dma_device_put(chan->device);
409 * dma_chan_put - drop a reference to a dma channel's parent driver module
410 * @chan - channel to release
412 * Must be called under dma_list_mutex
414 static void dma_chan_put(struct dma_chan *chan)
416 /* This channel is not in use, bail out */
417 if (!chan->client_count)
420 chan->client_count--;
422 /* This channel is not in use anymore, free it */
423 if (!chan->client_count && chan->device->device_free_chan_resources) {
424 /* Make sure all operations have completed */
425 dmaengine_synchronize(chan);
426 chan->device->device_free_chan_resources(chan);
429 /* If the channel is used via a DMA request router, free the mapping */
430 if (chan->router && chan->router->route_free) {
431 chan->router->route_free(chan->router->dev, chan->route_data);
433 chan->route_data = NULL;
436 dma_device_put(chan->device);
437 module_put(dma_chan_to_owner(chan));
440 enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
442 enum dma_status status;
443 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
445 dma_async_issue_pending(chan);
447 status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
448 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
449 dev_err(chan->device->dev, "%s: timeout!\n", __func__);
452 if (status != DMA_IN_PROGRESS)
459 EXPORT_SYMBOL(dma_sync_wait);
462 * dma_find_channel - find a channel to carry out the operation
463 * @tx_type: transaction type
465 struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type)
467 return this_cpu_read(channel_table[tx_type]->chan);
469 EXPORT_SYMBOL(dma_find_channel);
472 * dma_issue_pending_all - flush all pending operations across all channels
474 void dma_issue_pending_all(void)
476 struct dma_device *device;
477 struct dma_chan *chan;
480 list_for_each_entry_rcu(device, &dma_device_list, global_node) {
481 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
483 list_for_each_entry(chan, &device->channels, device_node)
484 if (chan->client_count)
485 device->device_issue_pending(chan);
489 EXPORT_SYMBOL(dma_issue_pending_all);
491 int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
493 struct dma_device *device;
498 device = chan->device;
500 /* check if the channel supports slave transactions */
501 if (!(test_bit(DMA_SLAVE, device->cap_mask.bits) ||
502 test_bit(DMA_CYCLIC, device->cap_mask.bits)))
506 * Check whether it reports it uses the generic slave
507 * capabilities, if not, that means it doesn't support any
508 * kind of slave capabilities reporting.
510 if (!device->directions)
513 caps->src_addr_widths = device->src_addr_widths;
514 caps->dst_addr_widths = device->dst_addr_widths;
515 caps->directions = device->directions;
516 caps->max_burst = device->max_burst;
517 caps->residue_granularity = device->residue_granularity;
518 caps->descriptor_reuse = device->descriptor_reuse;
519 caps->cmd_pause = !!device->device_pause;
520 caps->cmd_resume = !!device->device_resume;
521 caps->cmd_terminate = !!device->device_terminate_all;
525 EXPORT_SYMBOL_GPL(dma_get_slave_caps);
527 static struct dma_chan *private_candidate(const dma_cap_mask_t *mask,
528 struct dma_device *dev,
529 dma_filter_fn fn, void *fn_param)
531 struct dma_chan *chan;
533 if (mask && !dma_device_satisfies_mask(dev, mask)) {
534 dev_dbg(dev->dev, "%s: wrong capabilities\n", __func__);
537 /* devices with multiple channels need special handling as we need to
538 * ensure that all channels are either private or public.
540 if (dev->chancnt > 1 && !dma_has_cap(DMA_PRIVATE, dev->cap_mask))
541 list_for_each_entry(chan, &dev->channels, device_node) {
542 /* some channels are already publicly allocated */
543 if (chan->client_count)
547 list_for_each_entry(chan, &dev->channels, device_node) {
548 if (chan->client_count) {
549 dev_dbg(dev->dev, "%s: %s busy\n",
550 __func__, dma_chan_name(chan));
553 if (fn && !fn(chan, fn_param)) {
554 dev_dbg(dev->dev, "%s: %s filter said false\n",
555 __func__, dma_chan_name(chan));
564 static struct dma_chan *find_candidate(struct dma_device *device,
565 const dma_cap_mask_t *mask,
566 dma_filter_fn fn, void *fn_param)
568 struct dma_chan *chan = private_candidate(mask, device, fn, fn_param);
572 /* Found a suitable channel, try to grab, prep, and return it.
573 * We first set DMA_PRIVATE to disable balance_ref_count as this
574 * channel will not be published in the general-purpose
577 dma_cap_set(DMA_PRIVATE, device->cap_mask);
578 device->privatecnt++;
579 err = dma_chan_get(chan);
582 if (err == -ENODEV) {
583 dev_dbg(device->dev, "%s: %s module removed\n",
584 __func__, dma_chan_name(chan));
585 list_del_rcu(&device->global_node);
588 "%s: failed to get %s: (%d)\n",
589 __func__, dma_chan_name(chan), err);
591 if (--device->privatecnt == 0)
592 dma_cap_clear(DMA_PRIVATE, device->cap_mask);
598 return chan ? chan : ERR_PTR(-EPROBE_DEFER);
602 * dma_get_slave_channel - try to get specific channel exclusively
603 * @chan: target channel
605 struct dma_chan *dma_get_slave_channel(struct dma_chan *chan)
609 /* lock against __dma_request_channel */
610 mutex_lock(&dma_list_mutex);
612 if (chan->client_count == 0) {
613 struct dma_device *device = chan->device;
615 dma_cap_set(DMA_PRIVATE, device->cap_mask);
616 device->privatecnt++;
617 err = dma_chan_get(chan);
619 dev_dbg(chan->device->dev,
620 "%s: failed to get %s: (%d)\n",
621 __func__, dma_chan_name(chan), err);
623 if (--device->privatecnt == 0)
624 dma_cap_clear(DMA_PRIVATE, device->cap_mask);
629 mutex_unlock(&dma_list_mutex);
634 EXPORT_SYMBOL_GPL(dma_get_slave_channel);
636 struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
639 struct dma_chan *chan;
642 dma_cap_set(DMA_SLAVE, mask);
644 /* lock against __dma_request_channel */
645 mutex_lock(&dma_list_mutex);
647 chan = find_candidate(device, &mask, NULL, NULL);
649 mutex_unlock(&dma_list_mutex);
651 return IS_ERR(chan) ? NULL : chan;
653 EXPORT_SYMBOL_GPL(dma_get_any_slave_channel);
656 * __dma_request_channel - try to allocate an exclusive channel
657 * @mask: capabilities that the channel must satisfy
658 * @fn: optional callback to disposition available channels
659 * @fn_param: opaque parameter to pass to dma_filter_fn
660 * @np: device node to look for DMA channels
662 * Returns pointer to appropriate DMA channel on success or NULL.
664 struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
665 dma_filter_fn fn, void *fn_param,
666 struct device_node *np)
668 struct dma_device *device, *_d;
669 struct dma_chan *chan = NULL;
672 mutex_lock(&dma_list_mutex);
673 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
674 /* Finds a DMA controller with matching device node */
675 if (np && device->dev->of_node && np != device->dev->of_node)
678 chan = find_candidate(device, mask, fn, fn_param);
684 mutex_unlock(&dma_list_mutex);
686 pr_debug("%s: %s (%s)\n",
688 chan ? "success" : "fail",
689 chan ? dma_chan_name(chan) : NULL);
693 EXPORT_SYMBOL_GPL(__dma_request_channel);
695 static const struct dma_slave_map *dma_filter_match(struct dma_device *device,
701 if (!device->filter.mapcnt)
704 for (i = 0; i < device->filter.mapcnt; i++) {
705 const struct dma_slave_map *map = &device->filter.map[i];
707 if (!strcmp(map->devname, dev_name(dev)) &&
708 !strcmp(map->slave, name))
716 * dma_request_chan - try to allocate an exclusive slave channel
717 * @dev: pointer to client device structure
718 * @name: slave channel name
720 * Returns pointer to appropriate DMA channel on success or an error pointer.
722 struct dma_chan *dma_request_chan(struct device *dev, const char *name)
724 struct dma_device *d, *_d;
725 struct dma_chan *chan = NULL;
727 /* If device-tree is present get slave info from here */
729 chan = of_dma_request_slave_channel(dev->of_node, name);
731 /* If device was enumerated by ACPI get slave info from here */
732 if (has_acpi_companion(dev) && !chan)
733 chan = acpi_dma_request_slave_chan_by_name(dev, name);
735 if (PTR_ERR(chan) == -EPROBE_DEFER)
738 if (!IS_ERR_OR_NULL(chan))
741 /* Try to find the channel via the DMA filter map(s) */
742 mutex_lock(&dma_list_mutex);
743 list_for_each_entry_safe(d, _d, &dma_device_list, global_node) {
745 const struct dma_slave_map *map = dma_filter_match(d, name, dev);
751 dma_cap_set(DMA_SLAVE, mask);
753 chan = find_candidate(d, &mask, d->filter.fn, map->param);
757 mutex_unlock(&dma_list_mutex);
759 if (IS_ERR_OR_NULL(chan))
760 return chan ? chan : ERR_PTR(-EPROBE_DEFER);
763 chan->name = kasprintf(GFP_KERNEL, "dma:%s", name);
768 if (sysfs_create_link(&chan->dev->device.kobj, &dev->kobj,
770 dev_warn(dev, "Cannot create DMA %s symlink\n", DMA_SLAVE_NAME);
771 if (sysfs_create_link(&dev->kobj, &chan->dev->device.kobj, chan->name))
772 dev_warn(dev, "Cannot create DMA %s symlink\n", chan->name);
776 EXPORT_SYMBOL_GPL(dma_request_chan);
779 * dma_request_slave_channel - try to allocate an exclusive slave channel
780 * @dev: pointer to client device structure
781 * @name: slave channel name
783 * Returns pointer to appropriate DMA channel on success or NULL.
785 struct dma_chan *dma_request_slave_channel(struct device *dev,
788 struct dma_chan *ch = dma_request_chan(dev, name);
794 EXPORT_SYMBOL_GPL(dma_request_slave_channel);
797 * dma_request_chan_by_mask - allocate a channel satisfying certain capabilities
798 * @mask: capabilities that the channel must satisfy
800 * Returns pointer to appropriate DMA channel on success or an error pointer.
802 struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask)
804 struct dma_chan *chan;
807 return ERR_PTR(-ENODEV);
809 chan = __dma_request_channel(mask, NULL, NULL, NULL);
811 mutex_lock(&dma_list_mutex);
812 if (list_empty(&dma_device_list))
813 chan = ERR_PTR(-EPROBE_DEFER);
815 chan = ERR_PTR(-ENODEV);
816 mutex_unlock(&dma_list_mutex);
821 EXPORT_SYMBOL_GPL(dma_request_chan_by_mask);
823 void dma_release_channel(struct dma_chan *chan)
825 mutex_lock(&dma_list_mutex);
826 WARN_ONCE(chan->client_count != 1,
827 "chan reference count %d != 1\n", chan->client_count);
829 /* drop PRIVATE cap enabled by __dma_request_channel() */
830 if (--chan->device->privatecnt == 0)
831 dma_cap_clear(DMA_PRIVATE, chan->device->cap_mask);
834 sysfs_remove_link(&chan->dev->device.kobj, DMA_SLAVE_NAME);
835 sysfs_remove_link(&chan->slave->kobj, chan->name);
840 mutex_unlock(&dma_list_mutex);
842 EXPORT_SYMBOL_GPL(dma_release_channel);
845 * dmaengine_get - register interest in dma_channels
847 void dmaengine_get(void)
849 struct dma_device *device, *_d;
850 struct dma_chan *chan;
853 mutex_lock(&dma_list_mutex);
854 dmaengine_ref_count++;
856 /* try to grab channels */
857 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
858 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
860 list_for_each_entry(chan, &device->channels, device_node) {
861 err = dma_chan_get(chan);
862 if (err == -ENODEV) {
863 /* module removed before we could use it */
864 list_del_rcu(&device->global_node);
867 dev_dbg(chan->device->dev,
868 "%s: failed to get %s: (%d)\n",
869 __func__, dma_chan_name(chan), err);
873 /* if this is the first reference and there were channels
874 * waiting we need to rebalance to get those channels
875 * incorporated into the channel table
877 if (dmaengine_ref_count == 1)
878 dma_channel_rebalance();
879 mutex_unlock(&dma_list_mutex);
881 EXPORT_SYMBOL(dmaengine_get);
884 * dmaengine_put - let dma drivers be removed when ref_count == 0
886 void dmaengine_put(void)
888 struct dma_device *device, *_d;
889 struct dma_chan *chan;
891 mutex_lock(&dma_list_mutex);
892 dmaengine_ref_count--;
893 BUG_ON(dmaengine_ref_count < 0);
894 /* drop channel references */
895 list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
896 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
898 list_for_each_entry(chan, &device->channels, device_node)
901 mutex_unlock(&dma_list_mutex);
903 EXPORT_SYMBOL(dmaengine_put);
905 static bool device_has_all_tx_types(struct dma_device *device)
907 /* A device that satisfies this test has channels that will never cause
908 * an async_tx channel switch event as all possible operation types can
911 #ifdef CONFIG_ASYNC_TX_DMA
912 if (!dma_has_cap(DMA_INTERRUPT, device->cap_mask))
916 #if IS_ENABLED(CONFIG_ASYNC_MEMCPY)
917 if (!dma_has_cap(DMA_MEMCPY, device->cap_mask))
921 #if IS_ENABLED(CONFIG_ASYNC_XOR)
922 if (!dma_has_cap(DMA_XOR, device->cap_mask))
925 #ifndef CONFIG_ASYNC_TX_DISABLE_XOR_VAL_DMA
926 if (!dma_has_cap(DMA_XOR_VAL, device->cap_mask))
931 #if IS_ENABLED(CONFIG_ASYNC_PQ)
932 if (!dma_has_cap(DMA_PQ, device->cap_mask))
935 #ifndef CONFIG_ASYNC_TX_DISABLE_PQ_VAL_DMA
936 if (!dma_has_cap(DMA_PQ_VAL, device->cap_mask))
944 static int get_dma_id(struct dma_device *device)
946 int rc = ida_alloc(&dma_ida, GFP_KERNEL);
954 static int __dma_async_device_channel_register(struct dma_device *device,
955 struct dma_chan *chan,
959 int chancnt = device->chancnt;
961 struct dma_chan *tchan;
963 tchan = list_first_entry_or_null(&device->channels,
964 struct dma_chan, device_node);
969 idr_ref = tchan->dev->idr_ref;
971 idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL);
974 atomic_set(idr_ref, 0);
977 chan->local = alloc_percpu(typeof(*chan->local));
980 chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL);
982 free_percpu(chan->local);
988 * When the chan_id is a negative value, we are dynamically adding
989 * the channel. Otherwise we are static enumerating.
991 chan->chan_id = chan_id < 0 ? chancnt : chan_id;
992 chan->dev->device.class = &dma_devclass;
993 chan->dev->device.parent = device->dev;
994 chan->dev->chan = chan;
995 chan->dev->idr_ref = idr_ref;
996 chan->dev->dev_id = device->dev_id;
998 dev_set_name(&chan->dev->device, "dma%dchan%d",
999 device->dev_id, chan->chan_id);
1001 rc = device_register(&chan->dev->device);
1004 chan->client_count = 0;
1005 device->chancnt = chan->chan_id + 1;
1010 free_percpu(chan->local);
1012 if (atomic_dec_return(idr_ref) == 0)
1017 int dma_async_device_channel_register(struct dma_device *device,
1018 struct dma_chan *chan)
1022 rc = __dma_async_device_channel_register(device, chan, -1);
1026 dma_channel_rebalance();
1029 EXPORT_SYMBOL_GPL(dma_async_device_channel_register);
1031 static void __dma_async_device_channel_unregister(struct dma_device *device,
1032 struct dma_chan *chan)
1034 WARN_ONCE(!device->device_release && chan->client_count,
1035 "%s called while %d clients hold a reference\n",
1036 __func__, chan->client_count);
1037 mutex_lock(&dma_list_mutex);
1038 list_del(&chan->device_node);
1040 chan->dev->chan = NULL;
1041 mutex_unlock(&dma_list_mutex);
1042 device_unregister(&chan->dev->device);
1043 free_percpu(chan->local);
1046 void dma_async_device_channel_unregister(struct dma_device *device,
1047 struct dma_chan *chan)
1049 __dma_async_device_channel_unregister(device, chan);
1050 dma_channel_rebalance();
1052 EXPORT_SYMBOL_GPL(dma_async_device_channel_unregister);
1055 * dma_async_device_register - registers DMA devices found
1056 * @device: &dma_device
1058 * After calling this routine the structure should not be freed except in the
1059 * device_release() callback which will be called after
1060 * dma_async_device_unregister() is called and no further references are taken.
1062 int dma_async_device_register(struct dma_device *device)
1065 struct dma_chan* chan;
1070 /* validate device routines */
1072 pr_err("DMAdevice must have dev\n");
1076 device->owner = device->dev->driver->owner;
1078 if (dma_has_cap(DMA_MEMCPY, device->cap_mask) && !device->device_prep_dma_memcpy) {
1079 dev_err(device->dev,
1080 "Device claims capability %s, but op is not defined\n",
1085 if (dma_has_cap(DMA_XOR, device->cap_mask) && !device->device_prep_dma_xor) {
1086 dev_err(device->dev,
1087 "Device claims capability %s, but op is not defined\n",
1092 if (dma_has_cap(DMA_XOR_VAL, device->cap_mask) && !device->device_prep_dma_xor_val) {
1093 dev_err(device->dev,
1094 "Device claims capability %s, but op is not defined\n",
1099 if (dma_has_cap(DMA_PQ, device->cap_mask) && !device->device_prep_dma_pq) {
1100 dev_err(device->dev,
1101 "Device claims capability %s, but op is not defined\n",
1106 if (dma_has_cap(DMA_PQ_VAL, device->cap_mask) && !device->device_prep_dma_pq_val) {
1107 dev_err(device->dev,
1108 "Device claims capability %s, but op is not defined\n",
1113 if (dma_has_cap(DMA_MEMSET, device->cap_mask) && !device->device_prep_dma_memset) {
1114 dev_err(device->dev,
1115 "Device claims capability %s, but op is not defined\n",
1120 if (dma_has_cap(DMA_INTERRUPT, device->cap_mask) && !device->device_prep_dma_interrupt) {
1121 dev_err(device->dev,
1122 "Device claims capability %s, but op is not defined\n",
1127 if (dma_has_cap(DMA_CYCLIC, device->cap_mask) && !device->device_prep_dma_cyclic) {
1128 dev_err(device->dev,
1129 "Device claims capability %s, but op is not defined\n",
1134 if (dma_has_cap(DMA_INTERLEAVE, device->cap_mask) && !device->device_prep_interleaved_dma) {
1135 dev_err(device->dev,
1136 "Device claims capability %s, but op is not defined\n",
1142 if (!device->device_tx_status) {
1143 dev_err(device->dev, "Device tx_status is not defined\n");
1148 if (!device->device_issue_pending) {
1149 dev_err(device->dev, "Device issue_pending is not defined\n");
1153 if (!device->device_release)
1154 dev_warn(device->dev,
1155 "WARN: Device release is not defined so it is not safe to unbind this driver while in use\n");
1157 kref_init(&device->ref);
1159 /* note: this only matters in the
1160 * CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH=n case
1162 if (device_has_all_tx_types(device))
1163 dma_cap_set(DMA_ASYNC_TX, device->cap_mask);
1165 rc = get_dma_id(device);
1169 /* represent channels in sysfs. Probably want devs too */
1170 list_for_each_entry(chan, &device->channels, device_node) {
1171 rc = __dma_async_device_channel_register(device, chan, i++);
1176 mutex_lock(&dma_list_mutex);
1177 /* take references on public channels */
1178 if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask))
1179 list_for_each_entry(chan, &device->channels, device_node) {
1180 /* if clients are already waiting for channels we need
1181 * to take references on their behalf
1183 if (dma_chan_get(chan) == -ENODEV) {
1184 /* note we can only get here for the first
1185 * channel as the remaining channels are
1186 * guaranteed to get a reference
1189 mutex_unlock(&dma_list_mutex);
1193 list_add_tail_rcu(&device->global_node, &dma_device_list);
1194 if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
1195 device->privatecnt++; /* Always private */
1196 dma_channel_rebalance();
1197 mutex_unlock(&dma_list_mutex);
1202 /* if we never registered a channel just release the idr */
1203 if (!device->chancnt) {
1204 ida_free(&dma_ida, device->dev_id);
1208 list_for_each_entry(chan, &device->channels, device_node) {
1209 if (chan->local == NULL)
1211 mutex_lock(&dma_list_mutex);
1212 chan->dev->chan = NULL;
1213 mutex_unlock(&dma_list_mutex);
1214 device_unregister(&chan->dev->device);
1215 free_percpu(chan->local);
1219 EXPORT_SYMBOL(dma_async_device_register);
1222 * dma_async_device_unregister - unregister a DMA device
1223 * @device: &dma_device
1225 * This routine is called by dma driver exit routines, dmaengine holds module
1226 * references to prevent it being called while channels are in use.
1228 void dma_async_device_unregister(struct dma_device *device)
1230 struct dma_chan *chan, *n;
1232 list_for_each_entry_safe(chan, n, &device->channels, device_node)
1233 __dma_async_device_channel_unregister(device, chan);
1235 mutex_lock(&dma_list_mutex);
1237 * setting DMA_PRIVATE ensures the device being torn down will not
1238 * be used in the channel_table
1240 dma_cap_set(DMA_PRIVATE, device->cap_mask);
1241 dma_channel_rebalance();
1242 dma_device_put(device);
1243 mutex_unlock(&dma_list_mutex);
1245 EXPORT_SYMBOL(dma_async_device_unregister);
1247 static void dmam_device_release(struct device *dev, void *res)
1249 struct dma_device *device;
1251 device = *(struct dma_device **)res;
1252 dma_async_device_unregister(device);
1256 * dmaenginem_async_device_register - registers DMA devices found
1257 * @device: &dma_device
1259 * The operation is managed and will be undone on driver detach.
1261 int dmaenginem_async_device_register(struct dma_device *device)
1266 p = devres_alloc(dmam_device_release, sizeof(void *), GFP_KERNEL);
1270 ret = dma_async_device_register(device);
1272 *(struct dma_device **)p = device;
1273 devres_add(device->dev, p);
1280 EXPORT_SYMBOL(dmaenginem_async_device_register);
1282 struct dmaengine_unmap_pool {
1283 struct kmem_cache *cache;
1289 #define __UNMAP_POOL(x) { .size = x, .name = "dmaengine-unmap-" __stringify(x) }
1290 static struct dmaengine_unmap_pool unmap_pool[] = {
1292 #if IS_ENABLED(CONFIG_DMA_ENGINE_RAID)
1299 static struct dmaengine_unmap_pool *__get_unmap_pool(int nr)
1301 int order = get_count_order(nr);
1305 return &unmap_pool[0];
1306 #if IS_ENABLED(CONFIG_DMA_ENGINE_RAID)
1308 return &unmap_pool[1];
1310 return &unmap_pool[2];
1312 return &unmap_pool[3];
1320 static void dmaengine_unmap(struct kref *kref)
1322 struct dmaengine_unmap_data *unmap = container_of(kref, typeof(*unmap), kref);
1323 struct device *dev = unmap->dev;
1326 cnt = unmap->to_cnt;
1327 for (i = 0; i < cnt; i++)
1328 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1330 cnt += unmap->from_cnt;
1331 for (; i < cnt; i++)
1332 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1334 cnt += unmap->bidi_cnt;
1335 for (; i < cnt; i++) {
1336 if (unmap->addr[i] == 0)
1338 dma_unmap_page(dev, unmap->addr[i], unmap->len,
1341 cnt = unmap->map_cnt;
1342 mempool_free(unmap, __get_unmap_pool(cnt)->pool);
1345 void dmaengine_unmap_put(struct dmaengine_unmap_data *unmap)
1348 kref_put(&unmap->kref, dmaengine_unmap);
1350 EXPORT_SYMBOL_GPL(dmaengine_unmap_put);
1352 static void dmaengine_destroy_unmap_pool(void)
1356 for (i = 0; i < ARRAY_SIZE(unmap_pool); i++) {
1357 struct dmaengine_unmap_pool *p = &unmap_pool[i];
1359 mempool_destroy(p->pool);
1361 kmem_cache_destroy(p->cache);
1366 static int __init dmaengine_init_unmap_pool(void)
1370 for (i = 0; i < ARRAY_SIZE(unmap_pool); i++) {
1371 struct dmaengine_unmap_pool *p = &unmap_pool[i];
1374 size = sizeof(struct dmaengine_unmap_data) +
1375 sizeof(dma_addr_t) * p->size;
1377 p->cache = kmem_cache_create(p->name, size, 0,
1378 SLAB_HWCACHE_ALIGN, NULL);
1381 p->pool = mempool_create_slab_pool(1, p->cache);
1386 if (i == ARRAY_SIZE(unmap_pool))
1389 dmaengine_destroy_unmap_pool();
1393 struct dmaengine_unmap_data *
1394 dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags)
1396 struct dmaengine_unmap_data *unmap;
1398 unmap = mempool_alloc(__get_unmap_pool(nr)->pool, flags);
1402 memset(unmap, 0, sizeof(*unmap));
1403 kref_init(&unmap->kref);
1405 unmap->map_cnt = nr;
1409 EXPORT_SYMBOL(dmaengine_get_unmap_data);
1411 void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
1412 struct dma_chan *chan)
1415 #ifdef CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH
1416 spin_lock_init(&tx->lock);
1419 EXPORT_SYMBOL(dma_async_tx_descriptor_init);
1421 static inline int desc_check_and_set_metadata_mode(
1422 struct dma_async_tx_descriptor *desc, enum dma_desc_metadata_mode mode)
1424 /* Make sure that the metadata mode is not mixed */
1425 if (!desc->desc_metadata_mode) {
1426 if (dmaengine_is_metadata_mode_supported(desc->chan, mode))
1427 desc->desc_metadata_mode = mode;
1430 } else if (desc->desc_metadata_mode != mode) {
1437 int dmaengine_desc_attach_metadata(struct dma_async_tx_descriptor *desc,
1438 void *data, size_t len)
1445 ret = desc_check_and_set_metadata_mode(desc, DESC_METADATA_CLIENT);
1449 if (!desc->metadata_ops || !desc->metadata_ops->attach)
1452 return desc->metadata_ops->attach(desc, data, len);
1454 EXPORT_SYMBOL_GPL(dmaengine_desc_attach_metadata);
1456 void *dmaengine_desc_get_metadata_ptr(struct dma_async_tx_descriptor *desc,
1457 size_t *payload_len, size_t *max_len)
1462 return ERR_PTR(-EINVAL);
1464 ret = desc_check_and_set_metadata_mode(desc, DESC_METADATA_ENGINE);
1466 return ERR_PTR(ret);
1468 if (!desc->metadata_ops || !desc->metadata_ops->get_ptr)
1469 return ERR_PTR(-ENOTSUPP);
1471 return desc->metadata_ops->get_ptr(desc, payload_len, max_len);
1473 EXPORT_SYMBOL_GPL(dmaengine_desc_get_metadata_ptr);
1475 int dmaengine_desc_set_metadata_len(struct dma_async_tx_descriptor *desc,
1483 ret = desc_check_and_set_metadata_mode(desc, DESC_METADATA_ENGINE);
1487 if (!desc->metadata_ops || !desc->metadata_ops->set_len)
1490 return desc->metadata_ops->set_len(desc, payload_len);
1492 EXPORT_SYMBOL_GPL(dmaengine_desc_set_metadata_len);
1494 /* dma_wait_for_async_tx - spin wait for a transaction to complete
1495 * @tx: in-flight transaction to wait on
1498 dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
1500 unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
1503 return DMA_COMPLETE;
1505 while (tx->cookie == -EBUSY) {
1506 if (time_after_eq(jiffies, dma_sync_wait_timeout)) {
1507 dev_err(tx->chan->device->dev,
1508 "%s timeout waiting for descriptor submission\n",
1514 return dma_sync_wait(tx->chan, tx->cookie);
1516 EXPORT_SYMBOL_GPL(dma_wait_for_async_tx);
1518 /* dma_run_dependencies - helper routine for dma drivers to process
1519 * (start) dependent operations on their target channel
1520 * @tx: transaction with dependencies
1522 void dma_run_dependencies(struct dma_async_tx_descriptor *tx)
1524 struct dma_async_tx_descriptor *dep = txd_next(tx);
1525 struct dma_async_tx_descriptor *dep_next;
1526 struct dma_chan *chan;
1531 /* we'll submit tx->next now, so clear the link */
1535 /* keep submitting up until a channel switch is detected
1536 * in that case we will be called again as a result of
1537 * processing the interrupt from async_tx_channel_switch
1539 for (; dep; dep = dep_next) {
1541 txd_clear_parent(dep);
1542 dep_next = txd_next(dep);
1543 if (dep_next && dep_next->chan == chan)
1544 txd_clear_next(dep); /* ->next will be submitted */
1546 dep_next = NULL; /* submit current dep and terminate */
1549 dep->tx_submit(dep);
1552 chan->device->device_issue_pending(chan);
1554 EXPORT_SYMBOL_GPL(dma_run_dependencies);
1556 static int __init dma_bus_init(void)
1558 int err = dmaengine_init_unmap_pool();
1562 return class_register(&dma_devclass);
1564 arch_initcall(dma_bus_init);