include/linux/dmaengine.h

   1 /*
   2  * Copyright(c) 2004 - 2006 Intel Corporation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License as published by the Free
   6  * Software Foundation; either version 2 of the License, or (at your option)
   7  * any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 59
  16  * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  *
  18  * The full GNU General Public License is included in this distribution in the
  19  * file called COPYING.
  20  */
  21 #ifndef DMAENGINE_H
  22 #define DMAENGINE_H
  23
  24 #include <linux/device.h>
  25 #include <linux/uio.h>
  26 #include <linux/dma-mapping.h>
  27
  28 /**
  29  * typedef dma_cookie_t - an opaque DMA cookie
  30  *
  31  * if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code
  32  */
  33 typedef s32 dma_cookie_t;
  34
  35 #define dma_submit_error(cookie) ((cookie) < 0 ? 1 : 0)
  36
  37 /**
  38  * enum dma_status - DMA transaction status
  39  * @DMA_SUCCESS: transaction completed successfully
  40  * @DMA_IN_PROGRESS: transaction not yet processed
  41  * @DMA_ERROR: transaction failed
  42  */
  43 enum dma_status {
  44         DMA_SUCCESS,
  45         DMA_IN_PROGRESS,
  46         DMA_ERROR,
  47 };
  48
  49 /**
  50  * enum dma_transaction_type - DMA transaction types/indexes
  51  */
  52 enum dma_transaction_type {
  53         DMA_MEMCPY,
  54         DMA_XOR,
  55         DMA_PQ_XOR,
  56         DMA_DUAL_XOR,
  57         DMA_PQ_UPDATE,
  58         DMA_ZERO_SUM,
  59         DMA_PQ_ZERO_SUM,
  60         DMA_MEMSET,
  61         DMA_MEMCPY_CRC32C,
  62         DMA_INTERRUPT,
  63         DMA_PRIVATE,
  64         DMA_SLAVE,
  65 };
  66
  67 /* last transaction type for creation of the capabilities mask */
  68 #define DMA_TX_TYPE_END (DMA_SLAVE + 1)
  69
  70
  71 /**
  72  * enum dma_ctrl_flags - DMA flags to augment operation preparation,
  73  *      control completion, and communicate status.
  74  * @DMA_PREP_INTERRUPT - trigger an interrupt (callback) upon completion of
  75  *      this transaction
  76  * @DMA_CTRL_ACK - the descriptor cannot be reused until the client
  77  *      acknowledges receipt, i.e. has has a chance to establish any
  78  *      dependency chains
  79  * @DMA_COMPL_SKIP_SRC_UNMAP - set to disable dma-unmapping the source buffer(s)
  80  * @DMA_COMPL_SKIP_DEST_UNMAP - set to disable dma-unmapping the destination(s)
  81  */
  82 enum dma_ctrl_flags {
  83         DMA_PREP_INTERRUPT = (1 << 0),
  84         DMA_CTRL_ACK = (1 << 1),
  85         DMA_COMPL_SKIP_SRC_UNMAP = (1 << 2),
  86         DMA_COMPL_SKIP_DEST_UNMAP = (1 << 3),
  87 };
  88
  89 /**
  90  * dma_cap_mask_t - capabilities bitmap modeled after cpumask_t.
  91  * See linux/cpumask.h
  92  */
  93 typedef struct { DECLARE_BITMAP(bits, DMA_TX_TYPE_END); } dma_cap_mask_t;
  94
  95 /**
  96  * struct dma_chan_percpu - the per-CPU part of struct dma_chan
  97  * @memcpy_count: transaction counter
  98  * @bytes_transferred: byte counter
  99  */
 100
 101 struct dma_chan_percpu {
 102         /* stats */
 103         unsigned long memcpy_count;
 104         unsigned long bytes_transferred;
 105 };
 106
 107 /**
 108  * struct dma_chan - devices supply DMA channels, clients use them
 109  * @device: ptr to the dma device who supplies this channel, always !%NULL
 110  * @cookie: last cookie value returned to client
 111  * @chan_id: channel ID for sysfs
 112  * @dev: class device for sysfs
 113  * @device_node: used to add this to the device chan list
 114  * @local: per-cpu pointer to a struct dma_chan_percpu
 115  * @client-count: how many clients are using this channel
 116  * @table_count: number of appearances in the mem-to-mem allocation table
 117  * @private: private data for certain client-channel associations
 118  */
 119 struct dma_chan {
 120         struct dma_device *device;
 121         dma_cookie_t cookie;
 122
 123         /* sysfs */
 124         int chan_id;
 125         struct dma_chan_dev *dev;
 126
 127         struct list_head device_node;
 128         struct dma_chan_percpu *local;
 129         int client_count;
 130         int table_count;
 131         void *private;
 132 };
 133
 134 /**
 135  * struct dma_chan_dev - relate sysfs device node to backing channel device
 136  * @chan - driver channel device
 137  * @device - sysfs device
 138  * @dev_id - parent dma_device dev_id
 139  * @idr_ref - reference count to gate release of dma_device dev_id
 140  */
 141 struct dma_chan_dev {
 142         struct dma_chan *chan;
 143         struct device device;
 144         int dev_id;
 145         atomic_t *idr_ref;
 146 };
 147
 148 static inline const char *dma_chan_name(struct dma_chan *chan)
 149 {
 150         return dev_name(&chan->dev->device);
 151 }
 152
 153 void dma_chan_cleanup(struct kref *kref);
 154
 155 /**
 156  * typedef dma_filter_fn - callback filter for dma_request_channel
 157  * @chan: channel to be reviewed
 158  * @filter_param: opaque parameter passed through dma_request_channel
 159  *
 160  * When this optional parameter is specified in a call to dma_request_channel a
 161  * suitable channel is passed to this routine for further dispositioning before
 162  * being returned.  Where 'suitable' indicates a non-busy channel that
 163  * satisfies the given capability mask.  It returns 'true' to indicate that the
 164  * channel is suitable.
 165  */
 166 typedef bool (*dma_filter_fn)(struct dma_chan *chan, void *filter_param);
 167
 168 typedef void (*dma_async_tx_callback)(void *dma_async_param);
 169 /**
 170  * struct dma_async_tx_descriptor - async transaction descriptor
 171  * ---dma generic offload fields---
 172  * @cookie: tracking cookie for this transaction, set to -EBUSY if
 173  *      this tx is sitting on a dependency list
 174  * @flags: flags to augment operation preparation, control completion, and
 175  *      communicate status
 176  * @phys: physical address of the descriptor
 177  * @tx_list: driver common field for operations that require multiple
 178  *      descriptors
 179  * @chan: target channel for this operation
 180  * @tx_submit: set the prepared descriptor(s) to be executed by the engine
 181  * @callback: routine to call after this operation is complete
 182  * @callback_param: general parameter to pass to the callback routine
 183  * ---async_tx api specific fields---
 184  * @next: at completion submit this descriptor
 185  * @parent: pointer to the next level up in the dependency chain
 186  * @lock: protect the parent and next pointers
 187  */
 188 struct dma_async_tx_descriptor {
 189         dma_cookie_t cookie;
 190         enum dma_ctrl_flags flags; /* not a 'long' to pack with cookie */
 191         dma_addr_t phys;
 192         struct list_head tx_list;
 193         struct dma_chan *chan;
 194         dma_cookie_t (*tx_submit)(struct dma_async_tx_descriptor *tx);
 195         dma_async_tx_callback callback;
 196         void *callback_param;
 197         struct dma_async_tx_descriptor *next;
 198         struct dma_async_tx_descriptor *parent;
 199         spinlock_t lock;
 200 };
 201
 202 /**
 203  * struct dma_device - info on the entity supplying DMA services
 204  * @chancnt: how many DMA channels are supported
 205  * @privatecnt: how many DMA channels are requested by dma_request_channel
 206  * @channels: the list of struct dma_chan
 207  * @global_node: list_head for global dma_device_list
 208  * @cap_mask: one or more dma_capability flags
 209  * @max_xor: maximum number of xor sources, 0 if no capability
 210  * @dev_id: unique device ID
 211  * @dev: struct device reference for dma mapping api
 212  * @device_alloc_chan_resources: allocate resources and return the
 213  *      number of allocated descriptors
 214  * @device_free_chan_resources: release DMA channel's resources
 215  * @device_prep_dma_memcpy: prepares a memcpy operation
 216  * @device_prep_dma_xor: prepares a xor operation
 217  * @device_prep_dma_zero_sum: prepares a zero_sum operation
 218  * @device_prep_dma_memset: prepares a memset operation
 219  * @device_prep_dma_interrupt: prepares an end of chain interrupt operation
 220  * @device_prep_slave_sg: prepares a slave dma operation
 221  * @device_terminate_all: terminate all pending operations
 222  * @device_is_tx_complete: poll for transaction completion
 223  * @device_issue_pending: push pending transactions to hardware
 224  */
 225 struct dma_device {
 226
 227         unsigned int chancnt;
 228         unsigned int privatecnt;
 229         struct list_head channels;
 230         struct list_head global_node;
 231         dma_cap_mask_t  cap_mask;
 232         int max_xor;
 233
 234         int dev_id;
 235         struct device *dev;
 236
 237         int (*device_alloc_chan_resources)(struct dma_chan *chan);
 238         void (*device_free_chan_resources)(struct dma_chan *chan);
 239
 240         struct dma_async_tx_descriptor *(*device_prep_dma_memcpy)(
 241                 struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 242                 size_t len, unsigned long flags);
 243         struct dma_async_tx_descriptor *(*device_prep_dma_xor)(
 244                 struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
 245                 unsigned int src_cnt, size_t len, unsigned long flags);
 246         struct dma_async_tx_descriptor *(*device_prep_dma_zero_sum)(
 247                 struct dma_chan *chan, dma_addr_t *src, unsigned int src_cnt,
 248                 size_t len, u32 *result, unsigned long flags);
 249         struct dma_async_tx_descriptor *(*device_prep_dma_memset)(
 250                 struct dma_chan *chan, dma_addr_t dest, int value, size_t len,
 251                 unsigned long flags);
 252         struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)(
 253                 struct dma_chan *chan, unsigned long flags);
 254
 255         struct dma_async_tx_descriptor *(*device_prep_slave_sg)(
 256                 struct dma_chan *chan, struct scatterlist *sgl,
 257                 unsigned int sg_len, enum dma_data_direction direction,
 258                 unsigned long flags);
 259         void (*device_terminate_all)(struct dma_chan *chan);
 260
 261         enum dma_status (*device_is_tx_complete)(struct dma_chan *chan,
 262                         dma_cookie_t cookie, dma_cookie_t *last,
 263                         dma_cookie_t *used);
 264         void (*device_issue_pending)(struct dma_chan *chan);
 265 };
 266
 267 /* --- public DMA engine API --- */
 268
 269 #ifdef CONFIG_DMA_ENGINE
 270 void dmaengine_get(void);
 271 void dmaengine_put(void);
 272 #else
 273 static inline void dmaengine_get(void)
 274 {
 275 }
 276 static inline void dmaengine_put(void)
 277 {
 278 }
 279 #endif
 280
 281 #ifdef CONFIG_NET_DMA
 282 #define net_dmaengine_get()     dmaengine_get()
 283 #define net_dmaengine_put()     dmaengine_put()
 284 #else
 285 static inline void net_dmaengine_get(void)
 286 {
 287 }
 288 static inline void net_dmaengine_put(void)
 289 {
 290 }
 291 #endif
 292
 293 #ifdef CONFIG_ASYNC_TX_DMA
 294 #define async_dmaengine_get()   dmaengine_get()
 295 #define async_dmaengine_put()   dmaengine_put()
 296 #define async_dma_find_channel(type) dma_find_channel(type)
 297 #else
 298 static inline void async_dmaengine_get(void)
 299 {
 300 }
 301 static inline void async_dmaengine_put(void)
 302 {
 303 }
 304 static inline struct dma_chan *
 305 async_dma_find_channel(enum dma_transaction_type type)
 306 {
 307         return NULL;
 308 }
 309 #endif
 310
 311 dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan,
 312         void *dest, void *src, size_t len);
 313 dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan,
 314         struct page *page, unsigned int offset, void *kdata, size_t len);
 315 dma_cookie_t dma_async_memcpy_pg_to_pg(struct dma_chan *chan,
 316         struct page *dest_pg, unsigned int dest_off, struct page *src_pg,
 317         unsigned int src_off, size_t len);
 318 void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
 319         struct dma_chan *chan);
 320
 321 static inline void async_tx_ack(struct dma_async_tx_descriptor *tx)
 322 {
 323         tx->flags |= DMA_CTRL_ACK;
 324 }
 325
 326 static inline void async_tx_clear_ack(struct dma_async_tx_descriptor *tx)
 327 {
 328         tx->flags &= ~DMA_CTRL_ACK;
 329 }
 330
 331 static inline bool async_tx_test_ack(struct dma_async_tx_descriptor *tx)
 332 {
 333         return (tx->flags & DMA_CTRL_ACK) == DMA_CTRL_ACK;
 334 }
 335
 336 #define first_dma_cap(mask) __first_dma_cap(&(mask))
 337 static inline int __first_dma_cap(const dma_cap_mask_t *srcp)
 338 {
 339         return min_t(int, DMA_TX_TYPE_END,
 340                 find_first_bit(srcp->bits, DMA_TX_TYPE_END));
 341 }
 342
 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)
 345 {
 346         return min_t(int, DMA_TX_TYPE_END,
 347                 find_next_bit(srcp->bits, DMA_TX_TYPE_END, n+1));
 348 }
 349
 350 #define dma_cap_set(tx, mask) __dma_cap_set((tx), &(mask))
 351 static inline void
 352 __dma_cap_set(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp)
 353 {
 354         set_bit(tx_type, dstp->bits);
 355 }
 356
 357 #define dma_cap_clear(tx, mask) __dma_cap_clear((tx), &(mask))
 358 static inline void
 359 __dma_cap_clear(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp)
 360 {
 361         clear_bit(tx_type, dstp->bits);
 362 }
 363
 364 #define dma_cap_zero(mask) __dma_cap_zero(&(mask))
 365 static inline void __dma_cap_zero(dma_cap_mask_t *dstp)
 366 {
 367         bitmap_zero(dstp->bits, DMA_TX_TYPE_END);
 368 }
 369
 370 #define dma_has_cap(tx, mask) __dma_has_cap((tx), &(mask))
 371 static inline int
 372 __dma_has_cap(enum dma_transaction_type tx_type, dma_cap_mask_t *srcp)
 373 {
 374         return test_bit(tx_type, srcp->bits);
 375 }
 376
 377 #define for_each_dma_cap_mask(cap, mask) \
 378         for ((cap) = first_dma_cap(mask);       \
 379                 (cap) < DMA_TX_TYPE_END;        \
 380                 (cap) = next_dma_cap((cap), (mask)))
 381
 382 /**
 383  * dma_async_issue_pending - flush pending transactions to HW
 384  * @chan: target DMA channel
 385  *
 386  * This allows drivers to push copies to HW in batches,
 387  * reducing MMIO writes where possible.
 388  */
 389 static inline void dma_async_issue_pending(struct dma_chan *chan)
 390 {
 391         chan->device->device_issue_pending(chan);
 392 }
 393
 394 #define dma_async_memcpy_issue_pending(chan) dma_async_issue_pending(chan)
 395
 396 /**
 397  * dma_async_is_tx_complete - poll for transaction completion
 398  * @chan: DMA channel
 399  * @cookie: transaction identifier to check status of
 400  * @last: returns last completed cookie, can be NULL
 401  * @used: returns last issued cookie, can be NULL
 402  *
 403  * If @last and @used are passed in, upon return they reflect the driver
 404  * internal state and can be used with dma_async_is_complete() to check
 405  * the status of multiple cookies without re-checking hardware state.
 406  */
 407 static inline enum dma_status dma_async_is_tx_complete(struct dma_chan *chan,
 408         dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used)
 409 {
 410         return chan->device->device_is_tx_complete(chan, cookie, last, used);
 411 }
 412
 413 #define dma_async_memcpy_complete(chan, cookie, last, used)\
 414         dma_async_is_tx_complete(chan, cookie, last, used)
 415
 416 /**
 417  * dma_async_is_complete - test a cookie against chan state
 418  * @cookie: transaction identifier to test status of
 419  * @last_complete: last know completed transaction
 420  * @last_used: last cookie value handed out
 421  *
 422  * dma_async_is_complete() is used in dma_async_memcpy_complete()
 423  * the test logic is separated for lightweight testing of multiple cookies
 424  */
 425 static inline enum dma_status dma_async_is_complete(dma_cookie_t cookie,
 426                         dma_cookie_t last_complete, dma_cookie_t last_used)
 427 {
 428         if (last_complete <= last_used) {
 429                 if ((cookie <= last_complete) || (cookie > last_used))
 430                         return DMA_SUCCESS;
 431         } else {
 432                 if ((cookie <= last_complete) && (cookie > last_used))
 433                         return DMA_SUCCESS;
 434         }
 435         return DMA_IN_PROGRESS;
 436 }
 437
 438 enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);
 439 #ifdef CONFIG_DMA_ENGINE
 440 enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx);
 441 void dma_issue_pending_all(void);
 442 #else
 443 static inline enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
 444 {
 445         return DMA_SUCCESS;
 446 }
 447 static inline void dma_issue_pending_all(void)
 448 {
 449         do { } while (0);
 450 }
 451 #endif
 452
 453 /* --- DMA device --- */
 454
 455 int dma_async_device_register(struct dma_device *device);
 456 void dma_async_device_unregister(struct dma_device *device);
 457 void dma_run_dependencies(struct dma_async_tx_descriptor *tx);
 458 struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type);
 459 #define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y)
 460 struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param);
 461 void dma_release_channel(struct dma_chan *chan);
 462
 463 /* --- Helper iov-locking functions --- */
 464
 465 struct dma_page_list {
 466         char __user *base_address;
 467         int nr_pages;
 468         struct page **pages;
 469 };
 470
 471 struct dma_pinned_list {
 472         int nr_iovecs;
 473         struct dma_page_list page_list[0];
 474 };
 475
 476 struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len);
 477 void dma_unpin_iovec_pages(struct dma_pinned_list* pinned_list);
 478
 479 dma_cookie_t dma_memcpy_to_iovec(struct dma_chan *chan, struct iovec *iov,
 480         struct dma_pinned_list *pinned_list, unsigned char *kdata, size_t len);
 481 dma_cookie_t dma_memcpy_pg_to_iovec(struct dma_chan *chan, struct iovec *iov,
 482         struct dma_pinned_list *pinned_list, struct page *page,
 483         unsigned int offset, size_t len);
 484
 485 #endif /* DMAENGINE_H */