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/kref.h>
  27 #include <linux/completion.h>
  28 #include <linux/rcupdate.h>
  29 #include <linux/dma-mapping.h>
  30
  31 /**
  32  * typedef dma_cookie_t - an opaque DMA cookie
  33  *
  34  * if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code
  35  */
  36 typedef s32 dma_cookie_t;
  37
  38 #define dma_submit_error(cookie) ((cookie) < 0 ? 1 : 0)
  39
  40 /**
  41  * enum dma_status - DMA transaction status
  42  * @DMA_SUCCESS: transaction completed successfully
  43  * @DMA_IN_PROGRESS: transaction not yet processed
  44  * @DMA_ERROR: transaction failed
  45  */
  46 enum dma_status {
  47         DMA_SUCCESS,
  48         DMA_IN_PROGRESS,
  49         DMA_ERROR,
  50 };
  51
  52 /**
  53  * enum dma_transaction_type - DMA transaction types/indexes
  54  */
  55 enum dma_transaction_type {
  56         DMA_MEMCPY,
  57         DMA_XOR,
  58         DMA_PQ_XOR,
  59         DMA_DUAL_XOR,
  60         DMA_PQ_UPDATE,
  61         DMA_ZERO_SUM,
  62         DMA_PQ_ZERO_SUM,
  63         DMA_MEMSET,
  64         DMA_MEMCPY_CRC32C,
  65         DMA_INTERRUPT,
  66         DMA_PRIVATE,
  67         DMA_SLAVE,
  68 };
  69
  70 /* last transaction type for creation of the capabilities mask */
  71 #define DMA_TX_TYPE_END (DMA_SLAVE + 1)
  72
  73
  74 /**
  75  * enum dma_ctrl_flags - DMA flags to augment operation preparation,
  76  *      control completion, and communicate status.
  77  * @DMA_PREP_INTERRUPT - trigger an interrupt (callback) upon completion of
  78  *      this transaction
  79  * @DMA_CTRL_ACK - the descriptor cannot be reused until the client
  80  *      acknowledges receipt, i.e. has has a chance to establish any
  81  *      dependency chains
  82  * @DMA_COMPL_SKIP_SRC_UNMAP - set to disable dma-unmapping the source buffer(s)
  83  * @DMA_COMPL_SKIP_DEST_UNMAP - set to disable dma-unmapping the destination(s)
  84  */
  85 enum dma_ctrl_flags {
  86         DMA_PREP_INTERRUPT = (1 << 0),
  87         DMA_CTRL_ACK = (1 << 1),
  88         DMA_COMPL_SKIP_SRC_UNMAP = (1 << 2),
  89         DMA_COMPL_SKIP_DEST_UNMAP = (1 << 3),
  90 };
  91
  92 /**
  93  * dma_cap_mask_t - capabilities bitmap modeled after cpumask_t.
  94  * See linux/cpumask.h
  95  */
  96 typedef struct { DECLARE_BITMAP(bits, DMA_TX_TYPE_END); } dma_cap_mask_t;
  97
  98 /**
  99  * struct dma_chan_percpu - the per-CPU part of struct dma_chan
 100  * @refcount: local_t used for open-coded "bigref" counting
 101  * @memcpy_count: transaction counter
 102  * @bytes_transferred: byte counter
 103  */
 104
 105 struct dma_chan_percpu {
 106         /* stats */
 107         unsigned long memcpy_count;
 108         unsigned long bytes_transferred;
 109 };
 110
 111 /**
 112  * struct dma_chan - devices supply DMA channels, clients use them
 113  * @device: ptr to the dma device who supplies this channel, always !%NULL
 114  * @cookie: last cookie value returned to client
 115  * @chan_id: channel ID for sysfs
 116  * @dev: class device for sysfs
 117  * @refcount: kref, used in "bigref" slow-mode
 118  * @slow_ref: indicates that the DMA channel is free
 119  * @rcu: the DMA channel's RCU head
 120  * @device_node: used to add this to the device chan list
 121  * @local: per-cpu pointer to a struct dma_chan_percpu
 122  * @client-count: how many clients are using this channel
 123  * @table_count: number of appearances in the mem-to-mem allocation table
 124  */
 125 struct dma_chan {
 126         struct dma_device *device;
 127         dma_cookie_t cookie;
 128
 129         /* sysfs */
 130         int chan_id;
 131         struct dma_chan_dev *dev;
 132
 133         struct list_head device_node;
 134         struct dma_chan_percpu *local;
 135         int client_count;
 136         int table_count;
 137 };
 138
 139 /**
 140  * struct dma_chan_dev - relate sysfs device node to backing channel device
 141  * @chan - driver channel device
 142  * @device - sysfs device
 143  * @dev_id - parent dma_device dev_id
 144  * @idr_ref - reference count to gate release of dma_device dev_id
 145  */
 146 struct dma_chan_dev {
 147         struct dma_chan *chan;
 148         struct device device;
 149         int dev_id;
 150         atomic_t *idr_ref;
 151 };
 152
 153 static inline const char *dma_chan_name(struct dma_chan *chan)
 154 {
 155         return dev_name(&chan->dev->device);
 156 }
 157
 158 void dma_chan_cleanup(struct kref *kref);
 159
 160 /**
 161  * typedef dma_filter_fn - callback filter for dma_request_channel
 162  * @chan: channel to be reviewed
 163  * @filter_param: opaque parameter passed through dma_request_channel
 164  *
 165  * When this optional parameter is specified in a call to dma_request_channel a
 166  * suitable channel is passed to this routine for further dispositioning before
 167  * being returned.  Where 'suitable' indicates a non-busy channel that
 168  * satisfies the given capability mask.  It returns 'true' to indicate that the
 169  * channel is suitable.
 170  */
 171 typedef bool (*dma_filter_fn)(struct dma_chan *chan, void *filter_param);
 172
 173 typedef void (*dma_async_tx_callback)(void *dma_async_param);
 174 /**
 175  * struct dma_async_tx_descriptor - async transaction descriptor
 176  * ---dma generic offload fields---
 177  * @cookie: tracking cookie for this transaction, set to -EBUSY if
 178  *      this tx is sitting on a dependency list
 179  * @flags: flags to augment operation preparation, control completion, and
 180  *      communicate status
 181  * @phys: physical address of the descriptor
 182  * @tx_list: driver common field for operations that require multiple
 183  *      descriptors
 184  * @chan: target channel for this operation
 185  * @tx_submit: set the prepared descriptor(s) to be executed by the engine
 186  * @callback: routine to call after this operation is complete
 187  * @callback_param: general parameter to pass to the callback routine
 188  * ---async_tx api specific fields---
 189  * @next: at completion submit this descriptor
 190  * @parent: pointer to the next level up in the dependency chain
 191  * @lock: protect the parent and next pointers
 192  */
 193 struct dma_async_tx_descriptor {
 194         dma_cookie_t cookie;
 195         enum dma_ctrl_flags flags; /* not a 'long' to pack with cookie */
 196         dma_addr_t phys;
 197         struct list_head tx_list;
 198         struct dma_chan *chan;
 199         dma_cookie_t (*tx_submit)(struct dma_async_tx_descriptor *tx);
 200         dma_async_tx_callback callback;
 201         void *callback_param;
 202         struct dma_async_tx_descriptor *next;
 203         struct dma_async_tx_descriptor *parent;
 204         spinlock_t lock;
 205 };
 206
 207 /**
 208  * struct dma_device - info on the entity supplying DMA services
 209  * @chancnt: how many DMA channels are supported
 210  * @channels: the list of struct dma_chan
 211  * @global_node: list_head for global dma_device_list
 212  * @cap_mask: one or more dma_capability flags
 213  * @max_xor: maximum number of xor sources, 0 if no capability
 214  * @refcount: reference count
 215  * @done: IO completion struct
 216  * @dev_id: unique device ID
 217  * @dev: struct device reference for dma mapping api
 218  * @device_alloc_chan_resources: allocate resources and return the
 219  *      number of allocated descriptors
 220  * @device_free_chan_resources: release DMA channel's resources
 221  * @device_prep_dma_memcpy: prepares a memcpy operation
 222  * @device_prep_dma_xor: prepares a xor operation
 223  * @device_prep_dma_zero_sum: prepares a zero_sum operation
 224  * @device_prep_dma_memset: prepares a memset operation
 225  * @device_prep_dma_interrupt: prepares an end of chain interrupt operation
 226  * @device_prep_slave_sg: prepares a slave dma operation
 227  * @device_terminate_all: terminate all pending operations
 228  * @device_issue_pending: push pending transactions to hardware
 229  */
 230 struct dma_device {
 231
 232         unsigned int chancnt;
 233         struct list_head channels;
 234         struct list_head global_node;
 235         dma_cap_mask_t  cap_mask;
 236         int max_xor;
 237
 238         int dev_id;
 239         struct device *dev;
 240
 241         int (*device_alloc_chan_resources)(struct dma_chan *chan);
 242         void (*device_free_chan_resources)(struct dma_chan *chan);
 243
 244         struct dma_async_tx_descriptor *(*device_prep_dma_memcpy)(
 245                 struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 246                 size_t len, unsigned long flags);
 247         struct dma_async_tx_descriptor *(*device_prep_dma_xor)(
 248                 struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
 249                 unsigned int src_cnt, size_t len, unsigned long flags);
 250         struct dma_async_tx_descriptor *(*device_prep_dma_zero_sum)(
 251                 struct dma_chan *chan, dma_addr_t *src, unsigned int src_cnt,
 252                 size_t len, u32 *result, unsigned long flags);
 253         struct dma_async_tx_descriptor *(*device_prep_dma_memset)(
 254                 struct dma_chan *chan, dma_addr_t dest, int value, size_t len,
 255                 unsigned long flags);
 256         struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)(
 257                 struct dma_chan *chan, unsigned long flags);
 258
 259         struct dma_async_tx_descriptor *(*device_prep_slave_sg)(
 260                 struct dma_chan *chan, struct scatterlist *sgl,
 261                 unsigned int sg_len, enum dma_data_direction direction,
 262                 unsigned long flags);
 263         void (*device_terminate_all)(struct dma_chan *chan);
 264
 265         enum dma_status (*device_is_tx_complete)(struct dma_chan *chan,
 266                         dma_cookie_t cookie, dma_cookie_t *last,
 267                         dma_cookie_t *used);
 268         void (*device_issue_pending)(struct dma_chan *chan);
 269 };
 270
 271 /* --- public DMA engine API --- */
 272
 273 void dmaengine_get(void);
 274 void dmaengine_put(void);
 275 dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan,
 276         void *dest, void *src, size_t len);
 277 dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan,
 278         struct page *page, unsigned int offset, void *kdata, size_t len);
 279 dma_cookie_t dma_async_memcpy_pg_to_pg(struct dma_chan *chan,
 280         struct page *dest_pg, unsigned int dest_off, struct page *src_pg,
 281         unsigned int src_off, size_t len);
 282 void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
 283         struct dma_chan *chan);
 284
 285 static inline void async_tx_ack(struct dma_async_tx_descriptor *tx)
 286 {
 287         tx->flags |= DMA_CTRL_ACK;
 288 }
 289
 290 static inline bool async_tx_test_ack(struct dma_async_tx_descriptor *tx)
 291 {
 292         return (tx->flags & DMA_CTRL_ACK) == DMA_CTRL_ACK;
 293 }
 294
 295 #define first_dma_cap(mask) __first_dma_cap(&(mask))
 296 static inline int __first_dma_cap(const dma_cap_mask_t *srcp)
 297 {
 298         return min_t(int, DMA_TX_TYPE_END,
 299                 find_first_bit(srcp->bits, DMA_TX_TYPE_END));
 300 }
 301
 302 #define next_dma_cap(n, mask) __next_dma_cap((n), &(mask))
 303 static inline int __next_dma_cap(int n, const dma_cap_mask_t *srcp)
 304 {
 305         return min_t(int, DMA_TX_TYPE_END,
 306                 find_next_bit(srcp->bits, DMA_TX_TYPE_END, n+1));
 307 }
 308
 309 #define dma_cap_set(tx, mask) __dma_cap_set((tx), &(mask))
 310 static inline void
 311 __dma_cap_set(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp)
 312 {
 313         set_bit(tx_type, dstp->bits);
 314 }
 315
 316 #define dma_cap_zero(mask) __dma_cap_zero(&(mask))
 317 static inline void __dma_cap_zero(dma_cap_mask_t *dstp)
 318 {
 319         bitmap_zero(dstp->bits, DMA_TX_TYPE_END);
 320 }
 321
 322 #define dma_has_cap(tx, mask) __dma_has_cap((tx), &(mask))
 323 static inline int
 324 __dma_has_cap(enum dma_transaction_type tx_type, dma_cap_mask_t *srcp)
 325 {
 326         return test_bit(tx_type, srcp->bits);
 327 }
 328
 329 #define for_each_dma_cap_mask(cap, mask) \
 330         for ((cap) = first_dma_cap(mask);       \
 331                 (cap) < DMA_TX_TYPE_END;        \
 332                 (cap) = next_dma_cap((cap), (mask)))
 333
 334 /**
 335  * dma_async_issue_pending - flush pending transactions to HW
 336  * @chan: target DMA channel
 337  *
 338  * This allows drivers to push copies to HW in batches,
 339  * reducing MMIO writes where possible.
 340  */
 341 static inline void dma_async_issue_pending(struct dma_chan *chan)
 342 {
 343         chan->device->device_issue_pending(chan);
 344 }
 345
 346 #define dma_async_memcpy_issue_pending(chan) dma_async_issue_pending(chan)
 347
 348 /**
 349  * dma_async_is_tx_complete - poll for transaction completion
 350  * @chan: DMA channel
 351  * @cookie: transaction identifier to check status of
 352  * @last: returns last completed cookie, can be NULL
 353  * @used: returns last issued cookie, can be NULL
 354  *
 355  * If @last and @used are passed in, upon return they reflect the driver
 356  * internal state and can be used with dma_async_is_complete() to check
 357  * the status of multiple cookies without re-checking hardware state.
 358  */
 359 static inline enum dma_status dma_async_is_tx_complete(struct dma_chan *chan,
 360         dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used)
 361 {
 362         return chan->device->device_is_tx_complete(chan, cookie, last, used);
 363 }
 364
 365 #define dma_async_memcpy_complete(chan, cookie, last, used)\
 366         dma_async_is_tx_complete(chan, cookie, last, used)
 367
 368 /**
 369  * dma_async_is_complete - test a cookie against chan state
 370  * @cookie: transaction identifier to test status of
 371  * @last_complete: last know completed transaction
 372  * @last_used: last cookie value handed out
 373  *
 374  * dma_async_is_complete() is used in dma_async_memcpy_complete()
 375  * the test logic is separated for lightweight testing of multiple cookies
 376  */
 377 static inline enum dma_status dma_async_is_complete(dma_cookie_t cookie,
 378                         dma_cookie_t last_complete, dma_cookie_t last_used)
 379 {
 380         if (last_complete <= last_used) {
 381                 if ((cookie <= last_complete) || (cookie > last_used))
 382                         return DMA_SUCCESS;
 383         } else {
 384                 if ((cookie <= last_complete) && (cookie > last_used))
 385                         return DMA_SUCCESS;
 386         }
 387         return DMA_IN_PROGRESS;
 388 }
 389
 390 enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);
 391 #ifdef CONFIG_DMA_ENGINE
 392 enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx);
 393 #else
 394 static inline enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
 395 {
 396         return DMA_SUCCESS;
 397 }
 398 #endif
 399
 400 /* --- DMA device --- */
 401
 402 int dma_async_device_register(struct dma_device *device);
 403 void dma_async_device_unregister(struct dma_device *device);
 404 void dma_run_dependencies(struct dma_async_tx_descriptor *tx);
 405 struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type);
 406 void dma_issue_pending_all(void);
 407 #define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y)
 408 struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param);
 409 void dma_release_channel(struct dma_chan *chan);
 410
 411 /* --- Helper iov-locking functions --- */
 412
 413 struct dma_page_list {
 414         char __user *base_address;
 415         int nr_pages;
 416         struct page **pages;
 417 };
 418
 419 struct dma_pinned_list {
 420         int nr_iovecs;
 421         struct dma_page_list page_list[0];
 422 };
 423
 424 struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len);
 425 void dma_unpin_iovec_pages(struct dma_pinned_list* pinned_list);
 426
 427 dma_cookie_t dma_memcpy_to_iovec(struct dma_chan *chan, struct iovec *iov,
 428         struct dma_pinned_list *pinned_list, unsigned char *kdata, size_t len);
 429 dma_cookie_t dma_memcpy_pg_to_iovec(struct dma_chan *chan, struct iovec *iov,
 430         struct dma_pinned_list *pinned_list, struct page *page,
 431         unsigned int offset, size_t len);
 432
 433 #endif /* DMAENGINE_H */