2 * Copyright(c) 2004 - 2006 Intel Corporation. All rights reserved.
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)
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
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.
18 * The full GNU General Public License is included in this distribution in the
19 * file called COPYING.
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
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,
34 * The subsystem keeps a global list of dma_device structs it is protected by a
35 * mutex, dma_list_mutex.
37 * A subsystem can get access to a channel by calling dmaengine_get() followed
38 * by dma_find_channel(), or if it has need for an exclusive channel it can call
39 * dma_request_channel(). Once a channel is allocated a reference is taken
40 * against its corresponding driver to disable removal.
42 * Each device has a channels list, which runs unlocked but is never modified
43 * once the device is registered, it's just setup by the driver.
45 * See Documentation/dmaengine.txt for more details
48 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
50 #include <linux/dma-mapping.h>
51 #include <linux/init.h>
52 #include <linux/module.h>
54 #include <linux/device.h>
55 #include <linux/dmaengine.h>
56 #include <linux/hardirq.h>
57 #include <linux/spinlock.h>
58 #include <linux/percpu.h>
59 #include <linux/rcupdate.h>
60 #include <linux/mutex.h>
61 #include <linux/jiffies.h>
62 #include <linux/rculist.h>
63 #include <linux/idr.h>
64 #include <linux/slab.h>
65 #include <linux/acpi.h>
66 #include <linux/acpi_dma.h>
67 #include <linux/of_dma.h>
68 #include <linux/mempool.h>
70 static DEFINE_MUTEX(dma_list_mutex
);
71 static DEFINE_IDR(dma_idr
);
72 static LIST_HEAD(dma_device_list
);
73 static long dmaengine_ref_count
;
75 /* --- sysfs implementation --- */
78 * dev_to_dma_chan - convert a device pointer to the its sysfs container object
81 * Must be called under dma_list_mutex
83 static struct dma_chan
*dev_to_dma_chan(struct device
*dev
)
85 struct dma_chan_dev
*chan_dev
;
87 chan_dev
= container_of(dev
, typeof(*chan_dev
), device
);
88 return chan_dev
->chan
;
91 static ssize_t
memcpy_count_show(struct device
*dev
,
92 struct device_attribute
*attr
, char *buf
)
94 struct dma_chan
*chan
;
95 unsigned long count
= 0;
99 mutex_lock(&dma_list_mutex
);
100 chan
= dev_to_dma_chan(dev
);
102 for_each_possible_cpu(i
)
103 count
+= per_cpu_ptr(chan
->local
, i
)->memcpy_count
;
104 err
= sprintf(buf
, "%lu\n", count
);
107 mutex_unlock(&dma_list_mutex
);
111 static DEVICE_ATTR_RO(memcpy_count
);
113 static ssize_t
bytes_transferred_show(struct device
*dev
,
114 struct device_attribute
*attr
, char *buf
)
116 struct dma_chan
*chan
;
117 unsigned long count
= 0;
121 mutex_lock(&dma_list_mutex
);
122 chan
= dev_to_dma_chan(dev
);
124 for_each_possible_cpu(i
)
125 count
+= per_cpu_ptr(chan
->local
, i
)->bytes_transferred
;
126 err
= sprintf(buf
, "%lu\n", count
);
129 mutex_unlock(&dma_list_mutex
);
133 static DEVICE_ATTR_RO(bytes_transferred
);
135 static ssize_t
in_use_show(struct device
*dev
, struct device_attribute
*attr
,
138 struct dma_chan
*chan
;
141 mutex_lock(&dma_list_mutex
);
142 chan
= dev_to_dma_chan(dev
);
144 err
= sprintf(buf
, "%d\n", chan
->client_count
);
147 mutex_unlock(&dma_list_mutex
);
151 static DEVICE_ATTR_RO(in_use
);
153 static struct attribute
*dma_dev_attrs
[] = {
154 &dev_attr_memcpy_count
.attr
,
155 &dev_attr_bytes_transferred
.attr
,
156 &dev_attr_in_use
.attr
,
159 ATTRIBUTE_GROUPS(dma_dev
);
161 static void chan_dev_release(struct device
*dev
)
163 struct dma_chan_dev
*chan_dev
;
165 chan_dev
= container_of(dev
, typeof(*chan_dev
), device
);
166 if (atomic_dec_and_test(chan_dev
->idr_ref
)) {
167 mutex_lock(&dma_list_mutex
);
168 idr_remove(&dma_idr
, chan_dev
->dev_id
);
169 mutex_unlock(&dma_list_mutex
);
170 kfree(chan_dev
->idr_ref
);
175 static struct class dma_devclass
= {
177 .dev_groups
= dma_dev_groups
,
178 .dev_release
= chan_dev_release
,
181 /* --- client and device registration --- */
183 #define dma_device_satisfies_mask(device, mask) \
184 __dma_device_satisfies_mask((device), &(mask))
186 __dma_device_satisfies_mask(struct dma_device
*device
,
187 const dma_cap_mask_t
*want
)
191 bitmap_and(has
.bits
, want
->bits
, device
->cap_mask
.bits
,
193 return bitmap_equal(want
->bits
, has
.bits
, DMA_TX_TYPE_END
);
196 static struct module
*dma_chan_to_owner(struct dma_chan
*chan
)
198 return chan
->device
->dev
->driver
->owner
;
202 * balance_ref_count - catch up the channel reference count
203 * @chan - channel to balance ->client_count versus dmaengine_ref_count
205 * balance_ref_count must be called under dma_list_mutex
207 static void balance_ref_count(struct dma_chan
*chan
)
209 struct module
*owner
= dma_chan_to_owner(chan
);
211 while (chan
->client_count
< dmaengine_ref_count
) {
213 chan
->client_count
++;
218 * dma_chan_get - try to grab a dma channel's parent driver module
219 * @chan - channel to grab
221 * Must be called under dma_list_mutex
223 static int dma_chan_get(struct dma_chan
*chan
)
226 struct module
*owner
= dma_chan_to_owner(chan
);
228 if (chan
->client_count
) {
231 } else if (try_module_get(owner
))
235 chan
->client_count
++;
237 /* allocate upon first client reference */
238 if (chan
->client_count
== 1 && err
== 0) {
239 int desc_cnt
= chan
->device
->device_alloc_chan_resources(chan
);
243 chan
->client_count
= 0;
245 } else if (!dma_has_cap(DMA_PRIVATE
, chan
->device
->cap_mask
))
246 balance_ref_count(chan
);
253 * dma_chan_put - drop a reference to a dma channel's parent driver module
254 * @chan - channel to release
256 * Must be called under dma_list_mutex
258 static void dma_chan_put(struct dma_chan
*chan
)
260 if (!chan
->client_count
)
261 return; /* this channel failed alloc_chan_resources */
262 chan
->client_count
--;
263 module_put(dma_chan_to_owner(chan
));
264 if (chan
->client_count
== 0)
265 chan
->device
->device_free_chan_resources(chan
);
268 enum dma_status
dma_sync_wait(struct dma_chan
*chan
, dma_cookie_t cookie
)
270 enum dma_status status
;
271 unsigned long dma_sync_wait_timeout
= jiffies
+ msecs_to_jiffies(5000);
273 dma_async_issue_pending(chan
);
275 status
= dma_async_is_tx_complete(chan
, cookie
, NULL
, NULL
);
276 if (time_after_eq(jiffies
, dma_sync_wait_timeout
)) {
277 pr_err("%s: timeout!\n", __func__
);
280 if (status
!= DMA_IN_PROGRESS
)
287 EXPORT_SYMBOL(dma_sync_wait
);
290 * dma_cap_mask_all - enable iteration over all operation types
292 static dma_cap_mask_t dma_cap_mask_all
;
295 * dma_chan_tbl_ent - tracks channel allocations per core/operation
296 * @chan - associated channel for this entry
298 struct dma_chan_tbl_ent
{
299 struct dma_chan
*chan
;
303 * channel_table - percpu lookup table for memory-to-memory offload providers
305 static struct dma_chan_tbl_ent __percpu
*channel_table
[DMA_TX_TYPE_END
];
307 static int __init
dma_channel_table_init(void)
309 enum dma_transaction_type cap
;
312 bitmap_fill(dma_cap_mask_all
.bits
, DMA_TX_TYPE_END
);
314 /* 'interrupt', 'private', and 'slave' are channel capabilities,
315 * but are not associated with an operation so they do not need
316 * an entry in the channel_table
318 clear_bit(DMA_INTERRUPT
, dma_cap_mask_all
.bits
);
319 clear_bit(DMA_PRIVATE
, dma_cap_mask_all
.bits
);
320 clear_bit(DMA_SLAVE
, dma_cap_mask_all
.bits
);
322 for_each_dma_cap_mask(cap
, dma_cap_mask_all
) {
323 channel_table
[cap
] = alloc_percpu(struct dma_chan_tbl_ent
);
324 if (!channel_table
[cap
]) {
331 pr_err("initialization failure\n");
332 for_each_dma_cap_mask(cap
, dma_cap_mask_all
)
333 if (channel_table
[cap
])
334 free_percpu(channel_table
[cap
]);
339 arch_initcall(dma_channel_table_init
);
342 * dma_find_channel - find a channel to carry out the operation
343 * @tx_type: transaction type
345 struct dma_chan
*dma_find_channel(enum dma_transaction_type tx_type
)
347 return this_cpu_read(channel_table
[tx_type
]->chan
);
349 EXPORT_SYMBOL(dma_find_channel
);
352 * net_dma_find_channel - find a channel for net_dma
353 * net_dma has alignment requirements
355 struct dma_chan
*net_dma_find_channel(void)
357 struct dma_chan
*chan
= dma_find_channel(DMA_MEMCPY
);
358 if (chan
&& !is_dma_copy_aligned(chan
->device
, 1, 1, 1))
363 EXPORT_SYMBOL(net_dma_find_channel
);
366 * dma_issue_pending_all - flush all pending operations across all channels
368 void dma_issue_pending_all(void)
370 struct dma_device
*device
;
371 struct dma_chan
*chan
;
374 list_for_each_entry_rcu(device
, &dma_device_list
, global_node
) {
375 if (dma_has_cap(DMA_PRIVATE
, device
->cap_mask
))
377 list_for_each_entry(chan
, &device
->channels
, device_node
)
378 if (chan
->client_count
)
379 device
->device_issue_pending(chan
);
383 EXPORT_SYMBOL(dma_issue_pending_all
);
386 * dma_chan_is_local - returns true if the channel is in the same numa-node as the cpu
388 static bool dma_chan_is_local(struct dma_chan
*chan
, int cpu
)
390 int node
= dev_to_node(chan
->device
->dev
);
391 return node
== -1 || cpumask_test_cpu(cpu
, cpumask_of_node(node
));
395 * min_chan - returns the channel with min count and in the same numa-node as the cpu
396 * @cap: capability to match
397 * @cpu: cpu index which the channel should be close to
399 * If some channels are close to the given cpu, the one with the lowest
400 * reference count is returned. Otherwise, cpu is ignored and only the
401 * reference count is taken into account.
402 * Must be called under dma_list_mutex.
404 static struct dma_chan
*min_chan(enum dma_transaction_type cap
, int cpu
)
406 struct dma_device
*device
;
407 struct dma_chan
*chan
;
408 struct dma_chan
*min
= NULL
;
409 struct dma_chan
*localmin
= NULL
;
411 list_for_each_entry(device
, &dma_device_list
, global_node
) {
412 if (!dma_has_cap(cap
, device
->cap_mask
) ||
413 dma_has_cap(DMA_PRIVATE
, device
->cap_mask
))
415 list_for_each_entry(chan
, &device
->channels
, device_node
) {
416 if (!chan
->client_count
)
418 if (!min
|| chan
->table_count
< min
->table_count
)
421 if (dma_chan_is_local(chan
, cpu
))
423 chan
->table_count
< localmin
->table_count
)
428 chan
= localmin
? localmin
: min
;
437 * dma_channel_rebalance - redistribute the available channels
439 * Optimize for cpu isolation (each cpu gets a dedicated channel for an
440 * operation type) in the SMP case, and operation isolation (avoid
441 * multi-tasking channels) in the non-SMP case. Must be called under
444 static void dma_channel_rebalance(void)
446 struct dma_chan
*chan
;
447 struct dma_device
*device
;
451 /* undo the last distribution */
452 for_each_dma_cap_mask(cap
, dma_cap_mask_all
)
453 for_each_possible_cpu(cpu
)
454 per_cpu_ptr(channel_table
[cap
], cpu
)->chan
= NULL
;
456 list_for_each_entry(device
, &dma_device_list
, global_node
) {
457 if (dma_has_cap(DMA_PRIVATE
, device
->cap_mask
))
459 list_for_each_entry(chan
, &device
->channels
, device_node
)
460 chan
->table_count
= 0;
463 /* don't populate the channel_table if no clients are available */
464 if (!dmaengine_ref_count
)
467 /* redistribute available channels */
468 for_each_dma_cap_mask(cap
, dma_cap_mask_all
)
469 for_each_online_cpu(cpu
) {
470 chan
= min_chan(cap
, cpu
);
471 per_cpu_ptr(channel_table
[cap
], cpu
)->chan
= chan
;
475 static struct dma_chan
*private_candidate(const dma_cap_mask_t
*mask
,
476 struct dma_device
*dev
,
477 dma_filter_fn fn
, void *fn_param
)
479 struct dma_chan
*chan
;
481 if (!__dma_device_satisfies_mask(dev
, mask
)) {
482 pr_debug("%s: wrong capabilities\n", __func__
);
485 /* devices with multiple channels need special handling as we need to
486 * ensure that all channels are either private or public.
488 if (dev
->chancnt
> 1 && !dma_has_cap(DMA_PRIVATE
, dev
->cap_mask
))
489 list_for_each_entry(chan
, &dev
->channels
, device_node
) {
490 /* some channels are already publicly allocated */
491 if (chan
->client_count
)
495 list_for_each_entry(chan
, &dev
->channels
, device_node
) {
496 if (chan
->client_count
) {
497 pr_debug("%s: %s busy\n",
498 __func__
, dma_chan_name(chan
));
501 if (fn
&& !fn(chan
, fn_param
)) {
502 pr_debug("%s: %s filter said false\n",
503 __func__
, dma_chan_name(chan
));
513 * dma_request_slave_channel - try to get specific channel exclusively
514 * @chan: target channel
516 struct dma_chan
*dma_get_slave_channel(struct dma_chan
*chan
)
520 /* lock against __dma_request_channel */
521 mutex_lock(&dma_list_mutex
);
523 if (chan
->client_count
== 0) {
524 err
= dma_chan_get(chan
);
526 pr_debug("%s: failed to get %s: (%d)\n",
527 __func__
, dma_chan_name(chan
), err
);
531 mutex_unlock(&dma_list_mutex
);
536 EXPORT_SYMBOL_GPL(dma_get_slave_channel
);
538 struct dma_chan
*dma_get_any_slave_channel(struct dma_device
*device
)
541 struct dma_chan
*chan
;
545 dma_cap_set(DMA_SLAVE
, mask
);
547 /* lock against __dma_request_channel */
548 mutex_lock(&dma_list_mutex
);
550 chan
= private_candidate(&mask
, device
, NULL
, NULL
);
552 err
= dma_chan_get(chan
);
554 pr_debug("%s: failed to get %s: (%d)\n",
555 __func__
, dma_chan_name(chan
), err
);
560 mutex_unlock(&dma_list_mutex
);
564 EXPORT_SYMBOL_GPL(dma_get_any_slave_channel
);
567 * __dma_request_channel - try to allocate an exclusive channel
568 * @mask: capabilities that the channel must satisfy
569 * @fn: optional callback to disposition available channels
570 * @fn_param: opaque parameter to pass to dma_filter_fn
572 * Returns pointer to appropriate DMA channel on success or NULL.
574 struct dma_chan
*__dma_request_channel(const dma_cap_mask_t
*mask
,
575 dma_filter_fn fn
, void *fn_param
)
577 struct dma_device
*device
, *_d
;
578 struct dma_chan
*chan
= NULL
;
582 mutex_lock(&dma_list_mutex
);
583 list_for_each_entry_safe(device
, _d
, &dma_device_list
, global_node
) {
584 chan
= private_candidate(mask
, device
, fn
, fn_param
);
586 /* Found a suitable channel, try to grab, prep, and
587 * return it. We first set DMA_PRIVATE to disable
588 * balance_ref_count as this channel will not be
589 * published in the general-purpose allocator
591 dma_cap_set(DMA_PRIVATE
, device
->cap_mask
);
592 device
->privatecnt
++;
593 err
= dma_chan_get(chan
);
595 if (err
== -ENODEV
) {
596 pr_debug("%s: %s module removed\n",
597 __func__
, dma_chan_name(chan
));
598 list_del_rcu(&device
->global_node
);
600 pr_debug("%s: failed to get %s: (%d)\n",
601 __func__
, dma_chan_name(chan
), err
);
604 if (--device
->privatecnt
== 0)
605 dma_cap_clear(DMA_PRIVATE
, device
->cap_mask
);
609 mutex_unlock(&dma_list_mutex
);
611 pr_debug("%s: %s (%s)\n",
613 chan
? "success" : "fail",
614 chan
? dma_chan_name(chan
) : NULL
);
618 EXPORT_SYMBOL_GPL(__dma_request_channel
);
621 * dma_request_slave_channel - try to allocate an exclusive slave channel
622 * @dev: pointer to client device structure
623 * @name: slave channel name
625 * Returns pointer to appropriate DMA channel on success or an error pointer.
627 struct dma_chan
*dma_request_slave_channel_reason(struct device
*dev
,
630 /* If device-tree is present get slave info from here */
632 return of_dma_request_slave_channel(dev
->of_node
, name
);
634 /* If device was enumerated by ACPI get slave info from here */
635 if (ACPI_HANDLE(dev
))
636 return acpi_dma_request_slave_chan_by_name(dev
, name
);
638 return ERR_PTR(-ENODEV
);
640 EXPORT_SYMBOL_GPL(dma_request_slave_channel_reason
);
643 * dma_request_slave_channel - try to allocate an exclusive slave channel
644 * @dev: pointer to client device structure
645 * @name: slave channel name
647 * Returns pointer to appropriate DMA channel on success or NULL.
649 struct dma_chan
*dma_request_slave_channel(struct device
*dev
,
652 struct dma_chan
*ch
= dma_request_slave_channel_reason(dev
, name
);
657 EXPORT_SYMBOL_GPL(dma_request_slave_channel
);
659 void dma_release_channel(struct dma_chan
*chan
)
661 mutex_lock(&dma_list_mutex
);
662 WARN_ONCE(chan
->client_count
!= 1,
663 "chan reference count %d != 1\n", chan
->client_count
);
665 /* drop PRIVATE cap enabled by __dma_request_channel() */
666 if (--chan
->device
->privatecnt
== 0)
667 dma_cap_clear(DMA_PRIVATE
, chan
->device
->cap_mask
);
668 mutex_unlock(&dma_list_mutex
);
670 EXPORT_SYMBOL_GPL(dma_release_channel
);
673 * dmaengine_get - register interest in dma_channels
675 void dmaengine_get(void)
677 struct dma_device
*device
, *_d
;
678 struct dma_chan
*chan
;
681 mutex_lock(&dma_list_mutex
);
682 dmaengine_ref_count
++;
684 /* try to grab channels */
685 list_for_each_entry_safe(device
, _d
, &dma_device_list
, global_node
) {
686 if (dma_has_cap(DMA_PRIVATE
, device
->cap_mask
))
688 list_for_each_entry(chan
, &device
->channels
, device_node
) {
689 err
= dma_chan_get(chan
);
690 if (err
== -ENODEV
) {
691 /* module removed before we could use it */
692 list_del_rcu(&device
->global_node
);
695 pr_debug("%s: failed to get %s: (%d)\n",
696 __func__
, dma_chan_name(chan
), err
);
700 /* if this is the first reference and there were channels
701 * waiting we need to rebalance to get those channels
702 * incorporated into the channel table
704 if (dmaengine_ref_count
== 1)
705 dma_channel_rebalance();
706 mutex_unlock(&dma_list_mutex
);
708 EXPORT_SYMBOL(dmaengine_get
);
711 * dmaengine_put - let dma drivers be removed when ref_count == 0
713 void dmaengine_put(void)
715 struct dma_device
*device
;
716 struct dma_chan
*chan
;
718 mutex_lock(&dma_list_mutex
);
719 dmaengine_ref_count
--;
720 BUG_ON(dmaengine_ref_count
< 0);
721 /* drop channel references */
722 list_for_each_entry(device
, &dma_device_list
, global_node
) {
723 if (dma_has_cap(DMA_PRIVATE
, device
->cap_mask
))
725 list_for_each_entry(chan
, &device
->channels
, device_node
)
728 mutex_unlock(&dma_list_mutex
);
730 EXPORT_SYMBOL(dmaengine_put
);
732 static bool device_has_all_tx_types(struct dma_device
*device
)
734 /* A device that satisfies this test has channels that will never cause
735 * an async_tx channel switch event as all possible operation types can
738 #ifdef CONFIG_ASYNC_TX_DMA
739 if (!dma_has_cap(DMA_INTERRUPT
, device
->cap_mask
))
743 #if defined(CONFIG_ASYNC_MEMCPY) || defined(CONFIG_ASYNC_MEMCPY_MODULE)
744 if (!dma_has_cap(DMA_MEMCPY
, device
->cap_mask
))
748 #if defined(CONFIG_ASYNC_XOR) || defined(CONFIG_ASYNC_XOR_MODULE)
749 if (!dma_has_cap(DMA_XOR
, device
->cap_mask
))
752 #ifndef CONFIG_ASYNC_TX_DISABLE_XOR_VAL_DMA
753 if (!dma_has_cap(DMA_XOR_VAL
, device
->cap_mask
))
758 #if defined(CONFIG_ASYNC_PQ) || defined(CONFIG_ASYNC_PQ_MODULE)
759 if (!dma_has_cap(DMA_PQ
, device
->cap_mask
))
762 #ifndef CONFIG_ASYNC_TX_DISABLE_PQ_VAL_DMA
763 if (!dma_has_cap(DMA_PQ_VAL
, device
->cap_mask
))
771 static int get_dma_id(struct dma_device
*device
)
775 mutex_lock(&dma_list_mutex
);
777 rc
= idr_alloc(&dma_idr
, NULL
, 0, 0, GFP_KERNEL
);
781 mutex_unlock(&dma_list_mutex
);
782 return rc
< 0 ? rc
: 0;
786 * dma_async_device_register - registers DMA devices found
787 * @device: &dma_device
789 int dma_async_device_register(struct dma_device
*device
)
792 struct dma_chan
* chan
;
798 /* validate device routines */
799 BUG_ON(dma_has_cap(DMA_MEMCPY
, device
->cap_mask
) &&
800 !device
->device_prep_dma_memcpy
);
801 BUG_ON(dma_has_cap(DMA_XOR
, device
->cap_mask
) &&
802 !device
->device_prep_dma_xor
);
803 BUG_ON(dma_has_cap(DMA_XOR_VAL
, device
->cap_mask
) &&
804 !device
->device_prep_dma_xor_val
);
805 BUG_ON(dma_has_cap(DMA_PQ
, device
->cap_mask
) &&
806 !device
->device_prep_dma_pq
);
807 BUG_ON(dma_has_cap(DMA_PQ_VAL
, device
->cap_mask
) &&
808 !device
->device_prep_dma_pq_val
);
809 BUG_ON(dma_has_cap(DMA_INTERRUPT
, device
->cap_mask
) &&
810 !device
->device_prep_dma_interrupt
);
811 BUG_ON(dma_has_cap(DMA_SG
, device
->cap_mask
) &&
812 !device
->device_prep_dma_sg
);
813 BUG_ON(dma_has_cap(DMA_CYCLIC
, device
->cap_mask
) &&
814 !device
->device_prep_dma_cyclic
);
815 BUG_ON(dma_has_cap(DMA_SLAVE
, device
->cap_mask
) &&
816 !device
->device_control
);
817 BUG_ON(dma_has_cap(DMA_INTERLEAVE
, device
->cap_mask
) &&
818 !device
->device_prep_interleaved_dma
);
820 BUG_ON(!device
->device_alloc_chan_resources
);
821 BUG_ON(!device
->device_free_chan_resources
);
822 BUG_ON(!device
->device_tx_status
);
823 BUG_ON(!device
->device_issue_pending
);
824 BUG_ON(!device
->dev
);
826 /* note: this only matters in the
827 * CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH=n case
829 if (device_has_all_tx_types(device
))
830 dma_cap_set(DMA_ASYNC_TX
, device
->cap_mask
);
832 idr_ref
= kmalloc(sizeof(*idr_ref
), GFP_KERNEL
);
835 rc
= get_dma_id(device
);
841 atomic_set(idr_ref
, 0);
843 /* represent channels in sysfs. Probably want devs too */
844 list_for_each_entry(chan
, &device
->channels
, device_node
) {
846 chan
->local
= alloc_percpu(typeof(*chan
->local
));
847 if (chan
->local
== NULL
)
849 chan
->dev
= kzalloc(sizeof(*chan
->dev
), GFP_KERNEL
);
850 if (chan
->dev
== NULL
) {
851 free_percpu(chan
->local
);
856 chan
->chan_id
= chancnt
++;
857 chan
->dev
->device
.class = &dma_devclass
;
858 chan
->dev
->device
.parent
= device
->dev
;
859 chan
->dev
->chan
= chan
;
860 chan
->dev
->idr_ref
= idr_ref
;
861 chan
->dev
->dev_id
= device
->dev_id
;
863 dev_set_name(&chan
->dev
->device
, "dma%dchan%d",
864 device
->dev_id
, chan
->chan_id
);
866 rc
= device_register(&chan
->dev
->device
);
868 free_percpu(chan
->local
);
874 chan
->client_count
= 0;
876 device
->chancnt
= chancnt
;
878 mutex_lock(&dma_list_mutex
);
879 /* take references on public channels */
880 if (dmaengine_ref_count
&& !dma_has_cap(DMA_PRIVATE
, device
->cap_mask
))
881 list_for_each_entry(chan
, &device
->channels
, device_node
) {
882 /* if clients are already waiting for channels we need
883 * to take references on their behalf
885 if (dma_chan_get(chan
) == -ENODEV
) {
886 /* note we can only get here for the first
887 * channel as the remaining channels are
888 * guaranteed to get a reference
891 mutex_unlock(&dma_list_mutex
);
895 list_add_tail_rcu(&device
->global_node
, &dma_device_list
);
896 if (dma_has_cap(DMA_PRIVATE
, device
->cap_mask
))
897 device
->privatecnt
++; /* Always private */
898 dma_channel_rebalance();
899 mutex_unlock(&dma_list_mutex
);
904 /* if we never registered a channel just release the idr */
905 if (atomic_read(idr_ref
) == 0) {
906 mutex_lock(&dma_list_mutex
);
907 idr_remove(&dma_idr
, device
->dev_id
);
908 mutex_unlock(&dma_list_mutex
);
913 list_for_each_entry(chan
, &device
->channels
, device_node
) {
914 if (chan
->local
== NULL
)
916 mutex_lock(&dma_list_mutex
);
917 chan
->dev
->chan
= NULL
;
918 mutex_unlock(&dma_list_mutex
);
919 device_unregister(&chan
->dev
->device
);
920 free_percpu(chan
->local
);
924 EXPORT_SYMBOL(dma_async_device_register
);
927 * dma_async_device_unregister - unregister a DMA device
928 * @device: &dma_device
930 * This routine is called by dma driver exit routines, dmaengine holds module
931 * references to prevent it being called while channels are in use.
933 void dma_async_device_unregister(struct dma_device
*device
)
935 struct dma_chan
*chan
;
937 mutex_lock(&dma_list_mutex
);
938 list_del_rcu(&device
->global_node
);
939 dma_channel_rebalance();
940 mutex_unlock(&dma_list_mutex
);
942 list_for_each_entry(chan
, &device
->channels
, device_node
) {
943 WARN_ONCE(chan
->client_count
,
944 "%s called while %d clients hold a reference\n",
945 __func__
, chan
->client_count
);
946 mutex_lock(&dma_list_mutex
);
947 chan
->dev
->chan
= NULL
;
948 mutex_unlock(&dma_list_mutex
);
949 device_unregister(&chan
->dev
->device
);
950 free_percpu(chan
->local
);
953 EXPORT_SYMBOL(dma_async_device_unregister
);
955 struct dmaengine_unmap_pool
{
956 struct kmem_cache
*cache
;
962 #define __UNMAP_POOL(x) { .size = x, .name = "dmaengine-unmap-" __stringify(x) }
963 static struct dmaengine_unmap_pool unmap_pool
[] = {
965 #if IS_ENABLED(CONFIG_DMA_ENGINE_RAID)
972 static struct dmaengine_unmap_pool
*__get_unmap_pool(int nr
)
974 int order
= get_count_order(nr
);
978 return &unmap_pool
[0];
980 return &unmap_pool
[1];
982 return &unmap_pool
[2];
984 return &unmap_pool
[3];
991 static void dmaengine_unmap(struct kref
*kref
)
993 struct dmaengine_unmap_data
*unmap
= container_of(kref
, typeof(*unmap
), kref
);
994 struct device
*dev
= unmap
->dev
;
998 for (i
= 0; i
< cnt
; i
++)
999 dma_unmap_page(dev
, unmap
->addr
[i
], unmap
->len
,
1001 cnt
+= unmap
->from_cnt
;
1002 for (; i
< cnt
; i
++)
1003 dma_unmap_page(dev
, unmap
->addr
[i
], unmap
->len
,
1005 cnt
+= unmap
->bidi_cnt
;
1006 for (; i
< cnt
; i
++) {
1007 if (unmap
->addr
[i
] == 0)
1009 dma_unmap_page(dev
, unmap
->addr
[i
], unmap
->len
,
1012 cnt
= unmap
->map_cnt
;
1013 mempool_free(unmap
, __get_unmap_pool(cnt
)->pool
);
1016 void dmaengine_unmap_put(struct dmaengine_unmap_data
*unmap
)
1019 kref_put(&unmap
->kref
, dmaengine_unmap
);
1021 EXPORT_SYMBOL_GPL(dmaengine_unmap_put
);
1023 static void dmaengine_destroy_unmap_pool(void)
1027 for (i
= 0; i
< ARRAY_SIZE(unmap_pool
); i
++) {
1028 struct dmaengine_unmap_pool
*p
= &unmap_pool
[i
];
1031 mempool_destroy(p
->pool
);
1034 kmem_cache_destroy(p
->cache
);
1039 static int __init
dmaengine_init_unmap_pool(void)
1043 for (i
= 0; i
< ARRAY_SIZE(unmap_pool
); i
++) {
1044 struct dmaengine_unmap_pool
*p
= &unmap_pool
[i
];
1047 size
= sizeof(struct dmaengine_unmap_data
) +
1048 sizeof(dma_addr_t
) * p
->size
;
1050 p
->cache
= kmem_cache_create(p
->name
, size
, 0,
1051 SLAB_HWCACHE_ALIGN
, NULL
);
1054 p
->pool
= mempool_create_slab_pool(1, p
->cache
);
1059 if (i
== ARRAY_SIZE(unmap_pool
))
1062 dmaengine_destroy_unmap_pool();
1066 struct dmaengine_unmap_data
*
1067 dmaengine_get_unmap_data(struct device
*dev
, int nr
, gfp_t flags
)
1069 struct dmaengine_unmap_data
*unmap
;
1071 unmap
= mempool_alloc(__get_unmap_pool(nr
)->pool
, flags
);
1075 memset(unmap
, 0, sizeof(*unmap
));
1076 kref_init(&unmap
->kref
);
1078 unmap
->map_cnt
= nr
;
1082 EXPORT_SYMBOL(dmaengine_get_unmap_data
);
1085 * dma_async_memcpy_pg_to_pg - offloaded copy from page to page
1086 * @chan: DMA channel to offload copy to
1087 * @dest_pg: destination page
1088 * @dest_off: offset in page to copy to
1089 * @src_pg: source page
1090 * @src_off: offset in page to copy from
1093 * Both @dest_page/@dest_off and @src_page/@src_off must be mappable to a bus
1094 * address according to the DMA mapping API rules for streaming mappings.
1095 * Both @dest_page/@dest_off and @src_page/@src_off must stay memory resident
1096 * (kernel memory or locked user space pages).
1099 dma_async_memcpy_pg_to_pg(struct dma_chan
*chan
, struct page
*dest_pg
,
1100 unsigned int dest_off
, struct page
*src_pg
, unsigned int src_off
,
1103 struct dma_device
*dev
= chan
->device
;
1104 struct dma_async_tx_descriptor
*tx
;
1105 struct dmaengine_unmap_data
*unmap
;
1106 dma_cookie_t cookie
;
1107 unsigned long flags
;
1109 unmap
= dmaengine_get_unmap_data(dev
->dev
, 2, GFP_NOWAIT
);
1114 unmap
->from_cnt
= 1;
1115 unmap
->addr
[0] = dma_map_page(dev
->dev
, src_pg
, src_off
, len
,
1117 unmap
->addr
[1] = dma_map_page(dev
->dev
, dest_pg
, dest_off
, len
,
1120 flags
= DMA_CTRL_ACK
;
1121 tx
= dev
->device_prep_dma_memcpy(chan
, unmap
->addr
[1], unmap
->addr
[0],
1125 dmaengine_unmap_put(unmap
);
1129 dma_set_unmap(tx
, unmap
);
1130 cookie
= tx
->tx_submit(tx
);
1131 dmaengine_unmap_put(unmap
);
1134 __this_cpu_add(chan
->local
->bytes_transferred
, len
);
1135 __this_cpu_inc(chan
->local
->memcpy_count
);
1140 EXPORT_SYMBOL(dma_async_memcpy_pg_to_pg
);
1143 * dma_async_memcpy_buf_to_buf - offloaded copy between virtual addresses
1144 * @chan: DMA channel to offload copy to
1145 * @dest: destination address (virtual)
1146 * @src: source address (virtual)
1149 * Both @dest and @src must be mappable to a bus address according to the
1150 * DMA mapping API rules for streaming mappings.
1151 * Both @dest and @src must stay memory resident (kernel memory or locked
1152 * user space pages).
1155 dma_async_memcpy_buf_to_buf(struct dma_chan
*chan
, void *dest
,
1156 void *src
, size_t len
)
1158 return dma_async_memcpy_pg_to_pg(chan
, virt_to_page(dest
),
1159 (unsigned long) dest
& ~PAGE_MASK
,
1161 (unsigned long) src
& ~PAGE_MASK
, len
);
1163 EXPORT_SYMBOL(dma_async_memcpy_buf_to_buf
);
1166 * dma_async_memcpy_buf_to_pg - offloaded copy from address to page
1167 * @chan: DMA channel to offload copy to
1168 * @page: destination page
1169 * @offset: offset in page to copy to
1170 * @kdata: source address (virtual)
1173 * Both @page/@offset and @kdata must be mappable to a bus address according
1174 * to the DMA mapping API rules for streaming mappings.
1175 * Both @page/@offset and @kdata must stay memory resident (kernel memory or
1176 * locked user space pages)
1179 dma_async_memcpy_buf_to_pg(struct dma_chan
*chan
, struct page
*page
,
1180 unsigned int offset
, void *kdata
, size_t len
)
1182 return dma_async_memcpy_pg_to_pg(chan
, page
, offset
,
1183 virt_to_page(kdata
),
1184 (unsigned long) kdata
& ~PAGE_MASK
, len
);
1186 EXPORT_SYMBOL(dma_async_memcpy_buf_to_pg
);
1188 void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor
*tx
,
1189 struct dma_chan
*chan
)
1192 #ifdef CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH
1193 spin_lock_init(&tx
->lock
);
1196 EXPORT_SYMBOL(dma_async_tx_descriptor_init
);
1198 /* dma_wait_for_async_tx - spin wait for a transaction to complete
1199 * @tx: in-flight transaction to wait on
1202 dma_wait_for_async_tx(struct dma_async_tx_descriptor
*tx
)
1204 unsigned long dma_sync_wait_timeout
= jiffies
+ msecs_to_jiffies(5000);
1207 return DMA_COMPLETE
;
1209 while (tx
->cookie
== -EBUSY
) {
1210 if (time_after_eq(jiffies
, dma_sync_wait_timeout
)) {
1211 pr_err("%s timeout waiting for descriptor submission\n",
1217 return dma_sync_wait(tx
->chan
, tx
->cookie
);
1219 EXPORT_SYMBOL_GPL(dma_wait_for_async_tx
);
1221 /* dma_run_dependencies - helper routine for dma drivers to process
1222 * (start) dependent operations on their target channel
1223 * @tx: transaction with dependencies
1225 void dma_run_dependencies(struct dma_async_tx_descriptor
*tx
)
1227 struct dma_async_tx_descriptor
*dep
= txd_next(tx
);
1228 struct dma_async_tx_descriptor
*dep_next
;
1229 struct dma_chan
*chan
;
1234 /* we'll submit tx->next now, so clear the link */
1238 /* keep submitting up until a channel switch is detected
1239 * in that case we will be called again as a result of
1240 * processing the interrupt from async_tx_channel_switch
1242 for (; dep
; dep
= dep_next
) {
1244 txd_clear_parent(dep
);
1245 dep_next
= txd_next(dep
);
1246 if (dep_next
&& dep_next
->chan
== chan
)
1247 txd_clear_next(dep
); /* ->next will be submitted */
1249 dep_next
= NULL
; /* submit current dep and terminate */
1252 dep
->tx_submit(dep
);
1255 chan
->device
->device_issue_pending(chan
);
1257 EXPORT_SYMBOL_GPL(dma_run_dependencies
);
1259 static int __init
dma_bus_init(void)
1261 int err
= dmaengine_init_unmap_pool();
1265 return class_register(&dma_devclass
);
1267 arch_initcall(dma_bus_init
);