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.
24 #include <linux/device.h>
25 #include <linux/uio.h>
26 #include <linux/kref.h>
27 #include <linux/completion.h>
28 #include <linux/rcupdate.h>
29 #include <linux/dma-mapping.h>
32 * enum dma_state - resource PNP/power management state
33 * @DMA_RESOURCE_SUSPEND: DMA device going into low power state
34 * @DMA_RESOURCE_RESUME: DMA device returning to full power
35 * @DMA_RESOURCE_AVAILABLE: DMA device available to the system
36 * @DMA_RESOURCE_REMOVED: DMA device removed from the system
41 DMA_RESOURCE_AVAILABLE
,
46 * enum dma_state_client - state of the channel in the client
47 * @DMA_ACK: client would like to use, or was using this channel
48 * @DMA_DUP: client has already seen this channel, or is not using this channel
49 * @DMA_NAK: client does not want to see any more channels
51 enum dma_state_client
{
58 * typedef dma_cookie_t - an opaque DMA cookie
60 * if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code
62 typedef s32 dma_cookie_t
;
64 #define dma_submit_error(cookie) ((cookie) < 0 ? 1 : 0)
67 * enum dma_status - DMA transaction status
68 * @DMA_SUCCESS: transaction completed successfully
69 * @DMA_IN_PROGRESS: transaction not yet processed
70 * @DMA_ERROR: transaction failed
79 * enum dma_transaction_type - DMA transaction types/indexes
81 enum dma_transaction_type
{
94 /* last transaction type for creation of the capabilities mask */
95 #define DMA_TX_TYPE_END (DMA_INTERRUPT + 1)
98 * enum dma_ctrl_flags - DMA flags to augment operation preparation,
99 * control completion, and communicate status.
100 * @DMA_PREP_INTERRUPT - trigger an interrupt (callback) upon completion of
102 * @DMA_CTRL_ACK - the descriptor cannot be reused until the client
103 * acknowledges receipt, i.e. has has a chance to establish any
106 enum dma_ctrl_flags
{
107 DMA_PREP_INTERRUPT
= (1 << 0),
108 DMA_CTRL_ACK
= (1 << 1),
112 * dma_cap_mask_t - capabilities bitmap modeled after cpumask_t.
113 * See linux/cpumask.h
115 typedef struct { DECLARE_BITMAP(bits
, DMA_TX_TYPE_END
); } dma_cap_mask_t
;
118 * struct dma_chan_percpu - the per-CPU part of struct dma_chan
119 * @refcount: local_t used for open-coded "bigref" counting
120 * @memcpy_count: transaction counter
121 * @bytes_transferred: byte counter
124 struct dma_chan_percpu
{
127 unsigned long memcpy_count
;
128 unsigned long bytes_transferred
;
132 * struct dma_chan - devices supply DMA channels, clients use them
133 * @device: ptr to the dma device who supplies this channel, always !%NULL
134 * @cookie: last cookie value returned to client
135 * @chan_id: channel ID for sysfs
136 * @class_dev: class device for sysfs
137 * @refcount: kref, used in "bigref" slow-mode
138 * @slow_ref: indicates that the DMA channel is free
139 * @rcu: the DMA channel's RCU head
140 * @device_node: used to add this to the device chan list
141 * @local: per-cpu pointer to a struct dma_chan_percpu
142 * @client-count: how many clients are using this channel
145 struct dma_device
*device
;
152 struct kref refcount
;
156 struct list_head device_node
;
157 struct dma_chan_percpu
*local
;
161 #define to_dma_chan(p) container_of(p, struct dma_chan, dev)
163 void dma_chan_cleanup(struct kref
*kref
);
165 static inline void dma_chan_get(struct dma_chan
*chan
)
167 if (unlikely(chan
->slow_ref
))
168 kref_get(&chan
->refcount
);
170 local_inc(&(per_cpu_ptr(chan
->local
, get_cpu())->refcount
));
175 static inline void dma_chan_put(struct dma_chan
*chan
)
177 if (unlikely(chan
->slow_ref
))
178 kref_put(&chan
->refcount
, dma_chan_cleanup
);
180 local_dec(&(per_cpu_ptr(chan
->local
, get_cpu())->refcount
));
186 * typedef dma_event_callback - function pointer to a DMA event callback
187 * For each channel added to the system this routine is called for each client.
188 * If the client would like to use the channel it returns '1' to signal (ack)
189 * the dmaengine core to take out a reference on the channel and its
190 * corresponding device. A client must not 'ack' an available channel more
191 * than once. When a channel is removed all clients are notified. If a client
192 * is using the channel it must 'ack' the removal. A client must not 'ack' a
193 * removed channel more than once.
194 * @client - 'this' pointer for the client context
195 * @chan - channel to be acted upon
196 * @state - available or removed
199 typedef enum dma_state_client (*dma_event_callback
) (struct dma_client
*client
,
200 struct dma_chan
*chan
, enum dma_state state
);
203 * struct dma_client - info on the entity making use of DMA services
204 * @event_callback: func ptr to call when something happens
205 * @cap_mask: only return channels that satisfy the requested capabilities
206 * a value of zero corresponds to any capability
207 * @global_node: list_head for global dma_client_list
210 dma_event_callback event_callback
;
211 dma_cap_mask_t cap_mask
;
212 struct list_head global_node
;
215 typedef void (*dma_async_tx_callback
)(void *dma_async_param
);
217 * struct dma_async_tx_descriptor - async transaction descriptor
218 * ---dma generic offload fields---
219 * @cookie: tracking cookie for this transaction, set to -EBUSY if
220 * this tx is sitting on a dependency list
221 * @flags: flags to augment operation preparation, control completion, and
223 * @phys: physical address of the descriptor
224 * @tx_list: driver common field for operations that require multiple
226 * @chan: target channel for this operation
227 * @tx_submit: set the prepared descriptor(s) to be executed by the engine
228 * @callback: routine to call after this operation is complete
229 * @callback_param: general parameter to pass to the callback routine
230 * ---async_tx api specific fields---
231 * @next: at completion submit this descriptor
232 * @parent: pointer to the next level up in the dependency chain
233 * @lock: protect the parent and next pointers
235 struct dma_async_tx_descriptor
{
237 enum dma_ctrl_flags flags
; /* not a 'long' to pack with cookie */
239 struct list_head tx_list
;
240 struct dma_chan
*chan
;
241 dma_cookie_t (*tx_submit
)(struct dma_async_tx_descriptor
*tx
);
242 dma_async_tx_callback callback
;
243 void *callback_param
;
244 struct dma_async_tx_descriptor
*next
;
245 struct dma_async_tx_descriptor
*parent
;
250 * struct dma_device - info on the entity supplying DMA services
251 * @chancnt: how many DMA channels are supported
252 * @channels: the list of struct dma_chan
253 * @global_node: list_head for global dma_device_list
254 * @cap_mask: one or more dma_capability flags
255 * @max_xor: maximum number of xor sources, 0 if no capability
256 * @refcount: reference count
257 * @done: IO completion struct
258 * @dev_id: unique device ID
259 * @dev: struct device reference for dma mapping api
260 * @device_alloc_chan_resources: allocate resources and return the
261 * number of allocated descriptors
262 * @device_free_chan_resources: release DMA channel's resources
263 * @device_prep_dma_memcpy: prepares a memcpy operation
264 * @device_prep_dma_xor: prepares a xor operation
265 * @device_prep_dma_zero_sum: prepares a zero_sum operation
266 * @device_prep_dma_memset: prepares a memset operation
267 * @device_prep_dma_interrupt: prepares an end of chain interrupt operation
268 * @device_issue_pending: push pending transactions to hardware
272 unsigned int chancnt
;
273 struct list_head channels
;
274 struct list_head global_node
;
275 dma_cap_mask_t cap_mask
;
278 struct kref refcount
;
279 struct completion done
;
284 int (*device_alloc_chan_resources
)(struct dma_chan
*chan
,
285 struct dma_client
*client
);
286 void (*device_free_chan_resources
)(struct dma_chan
*chan
);
288 struct dma_async_tx_descriptor
*(*device_prep_dma_memcpy
)(
289 struct dma_chan
*chan
, dma_addr_t dest
, dma_addr_t src
,
290 size_t len
, unsigned long flags
);
291 struct dma_async_tx_descriptor
*(*device_prep_dma_xor
)(
292 struct dma_chan
*chan
, dma_addr_t dest
, dma_addr_t
*src
,
293 unsigned int src_cnt
, size_t len
, unsigned long flags
);
294 struct dma_async_tx_descriptor
*(*device_prep_dma_zero_sum
)(
295 struct dma_chan
*chan
, dma_addr_t
*src
, unsigned int src_cnt
,
296 size_t len
, u32
*result
, unsigned long flags
);
297 struct dma_async_tx_descriptor
*(*device_prep_dma_memset
)(
298 struct dma_chan
*chan
, dma_addr_t dest
, int value
, size_t len
,
299 unsigned long flags
);
300 struct dma_async_tx_descriptor
*(*device_prep_dma_interrupt
)(
301 struct dma_chan
*chan
, unsigned long flags
);
303 enum dma_status (*device_is_tx_complete
)(struct dma_chan
*chan
,
304 dma_cookie_t cookie
, dma_cookie_t
*last
,
306 void (*device_issue_pending
)(struct dma_chan
*chan
);
309 /* --- public DMA engine API --- */
311 void dma_async_client_register(struct dma_client
*client
);
312 void dma_async_client_unregister(struct dma_client
*client
);
313 void dma_async_client_chan_request(struct dma_client
*client
);
314 dma_cookie_t
dma_async_memcpy_buf_to_buf(struct dma_chan
*chan
,
315 void *dest
, void *src
, size_t len
);
316 dma_cookie_t
dma_async_memcpy_buf_to_pg(struct dma_chan
*chan
,
317 struct page
*page
, unsigned int offset
, void *kdata
, size_t len
);
318 dma_cookie_t
dma_async_memcpy_pg_to_pg(struct dma_chan
*chan
,
319 struct page
*dest_pg
, unsigned int dest_off
, struct page
*src_pg
,
320 unsigned int src_off
, size_t len
);
321 void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor
*tx
,
322 struct dma_chan
*chan
);
325 async_tx_ack(struct dma_async_tx_descriptor
*tx
)
327 tx
->flags
|= DMA_CTRL_ACK
;
331 async_tx_test_ack(struct dma_async_tx_descriptor
*tx
)
333 return tx
->flags
& DMA_CTRL_ACK
;
336 #define first_dma_cap(mask) __first_dma_cap(&(mask))
337 static inline int __first_dma_cap(const dma_cap_mask_t
*srcp
)
339 return min_t(int, DMA_TX_TYPE_END
,
340 find_first_bit(srcp
->bits
, DMA_TX_TYPE_END
));
343 #define next_dma_cap(n, mask) __next_dma_cap((n), &(mask))
344 static inline int __next_dma_cap(int n
, const dma_cap_mask_t
*srcp
)
346 return min_t(int, DMA_TX_TYPE_END
,
347 find_next_bit(srcp
->bits
, DMA_TX_TYPE_END
, n
+1));
350 #define dma_cap_set(tx, mask) __dma_cap_set((tx), &(mask))
352 __dma_cap_set(enum dma_transaction_type tx_type
, dma_cap_mask_t
*dstp
)
354 set_bit(tx_type
, dstp
->bits
);
357 #define dma_has_cap(tx, mask) __dma_has_cap((tx), &(mask))
359 __dma_has_cap(enum dma_transaction_type tx_type
, dma_cap_mask_t
*srcp
)
361 return test_bit(tx_type
, srcp
->bits
);
364 #define for_each_dma_cap_mask(cap, mask) \
365 for ((cap) = first_dma_cap(mask); \
366 (cap) < DMA_TX_TYPE_END; \
367 (cap) = next_dma_cap((cap), (mask)))
370 * dma_async_issue_pending - flush pending transactions to HW
371 * @chan: target DMA channel
373 * This allows drivers to push copies to HW in batches,
374 * reducing MMIO writes where possible.
376 static inline void dma_async_issue_pending(struct dma_chan
*chan
)
378 chan
->device
->device_issue_pending(chan
);
381 #define dma_async_memcpy_issue_pending(chan) dma_async_issue_pending(chan)
384 * dma_async_is_tx_complete - poll for transaction completion
386 * @cookie: transaction identifier to check status of
387 * @last: returns last completed cookie, can be NULL
388 * @used: returns last issued cookie, can be NULL
390 * If @last and @used are passed in, upon return they reflect the driver
391 * internal state and can be used with dma_async_is_complete() to check
392 * the status of multiple cookies without re-checking hardware state.
394 static inline enum dma_status
dma_async_is_tx_complete(struct dma_chan
*chan
,
395 dma_cookie_t cookie
, dma_cookie_t
*last
, dma_cookie_t
*used
)
397 return chan
->device
->device_is_tx_complete(chan
, cookie
, last
, used
);
400 #define dma_async_memcpy_complete(chan, cookie, last, used)\
401 dma_async_is_tx_complete(chan, cookie, last, used)
404 * dma_async_is_complete - test a cookie against chan state
405 * @cookie: transaction identifier to test status of
406 * @last_complete: last know completed transaction
407 * @last_used: last cookie value handed out
409 * dma_async_is_complete() is used in dma_async_memcpy_complete()
410 * the test logic is separated for lightweight testing of multiple cookies
412 static inline enum dma_status
dma_async_is_complete(dma_cookie_t cookie
,
413 dma_cookie_t last_complete
, dma_cookie_t last_used
)
415 if (last_complete
<= last_used
) {
416 if ((cookie
<= last_complete
) || (cookie
> last_used
))
419 if ((cookie
<= last_complete
) && (cookie
> last_used
))
422 return DMA_IN_PROGRESS
;
425 enum dma_status
dma_sync_wait(struct dma_chan
*chan
, dma_cookie_t cookie
);
427 /* --- DMA device --- */
429 int dma_async_device_register(struct dma_device
*device
);
430 void dma_async_device_unregister(struct dma_device
*device
);
432 /* --- Helper iov-locking functions --- */
434 struct dma_page_list
{
435 char __user
*base_address
;
440 struct dma_pinned_list
{
442 struct dma_page_list page_list
[0];
445 struct dma_pinned_list
*dma_pin_iovec_pages(struct iovec
*iov
, size_t len
);
446 void dma_unpin_iovec_pages(struct dma_pinned_list
* pinned_list
);
448 dma_cookie_t
dma_memcpy_to_iovec(struct dma_chan
*chan
, struct iovec
*iov
,
449 struct dma_pinned_list
*pinned_list
, unsigned char *kdata
, size_t len
);
450 dma_cookie_t
dma_memcpy_pg_to_iovec(struct dma_chan
*chan
, struct iovec
*iov
,
451 struct dma_pinned_list
*pinned_list
, struct page
*page
,
452 unsigned int offset
, size_t len
);
454 #endif /* DMAENGINE_H */