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  * 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
  37  */
  38 enum dma_state {
  39         DMA_RESOURCE_SUSPEND,
  40         DMA_RESOURCE_RESUME,
  41         DMA_RESOURCE_AVAILABLE,
  42         DMA_RESOURCE_REMOVED,
  43 };
  44
  45 /**
  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
  50  */
  51 enum dma_state_client {
  52         DMA_ACK,
  53         DMA_DUP,
  54         DMA_NAK,
  55 };
  56
  57 /**
  58  * typedef dma_cookie_t - an opaque DMA cookie
  59  *
  60  * if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code
  61  */
  62 typedef s32 dma_cookie_t;
  63
  64 #define dma_submit_error(cookie) ((cookie) < 0 ? 1 : 0)
  65
  66 /**
  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
  71  */
  72 enum dma_status {
  73         DMA_SUCCESS,
  74         DMA_IN_PROGRESS,
  75         DMA_ERROR,
  76 };
  77
  78 /**
  79  * enum dma_transaction_type - DMA transaction types/indexes
  80  */
  81 enum dma_transaction_type {
  82         DMA_MEMCPY,
  83         DMA_XOR,
  84         DMA_PQ_XOR,
  85         DMA_DUAL_XOR,
  86         DMA_PQ_UPDATE,
  87         DMA_ZERO_SUM,
  88         DMA_PQ_ZERO_SUM,
  89         DMA_MEMSET,
  90         DMA_MEMCPY_CRC32C,
  91         DMA_INTERRUPT,
  92 };
  93
  94 /* last transaction type for creation of the capabilities mask */
  95 #define DMA_TX_TYPE_END (DMA_INTERRUPT + 1)
  96
  97 /**
  98  * dma_cap_mask_t - capabilities bitmap modeled after cpumask_t.
  99  * See linux/cpumask.h
 100  */
 101 typedef struct { DECLARE_BITMAP(bits, DMA_TX_TYPE_END); } dma_cap_mask_t;
 102
 103 /**
 104  * struct dma_chan_percpu - the per-CPU part of struct dma_chan
 105  * @refcount: local_t used for open-coded "bigref" counting
 106  * @memcpy_count: transaction counter
 107  * @bytes_transferred: byte counter
 108  */
 109
 110 struct dma_chan_percpu {
 111         local_t refcount;
 112         /* stats */
 113         unsigned long memcpy_count;
 114         unsigned long bytes_transferred;
 115 };
 116
 117 /**
 118  * struct dma_chan - devices supply DMA channels, clients use them
 119  * @device: ptr to the dma device who supplies this channel, always !%NULL
 120  * @cookie: last cookie value returned to client
 121  * @chan_id: channel ID for sysfs
 122  * @class_dev: class device for sysfs
 123  * @refcount: kref, used in "bigref" slow-mode
 124  * @slow_ref: indicates that the DMA channel is free
 125  * @rcu: the DMA channel's RCU head
 126  * @device_node: used to add this to the device chan list
 127  * @local: per-cpu pointer to a struct dma_chan_percpu
 128  */
 129 struct dma_chan {
 130         struct dma_device *device;
 131         dma_cookie_t cookie;
 132
 133         /* sysfs */
 134         int chan_id;
 135         struct device dev;
 136
 137         struct kref refcount;
 138         int slow_ref;
 139         struct rcu_head rcu;
 140
 141         struct list_head device_node;
 142         struct dma_chan_percpu *local;
 143 };
 144
 145 #define to_dma_chan(p) container_of(p, struct dma_chan, dev)
 146
 147 void dma_chan_cleanup(struct kref *kref);
 148
 149 static inline void dma_chan_get(struct dma_chan *chan)
 150 {
 151         if (unlikely(chan->slow_ref))
 152                 kref_get(&chan->refcount);
 153         else {
 154                 local_inc(&(per_cpu_ptr(chan->local, get_cpu())->refcount));
 155                 put_cpu();
 156         }
 157 }
 158
 159 static inline void dma_chan_put(struct dma_chan *chan)
 160 {
 161         if (unlikely(chan->slow_ref))
 162                 kref_put(&chan->refcount, dma_chan_cleanup);
 163         else {
 164                 local_dec(&(per_cpu_ptr(chan->local, get_cpu())->refcount));
 165                 put_cpu();
 166         }
 167 }
 168
 169 /*
 170  * typedef dma_event_callback - function pointer to a DMA event callback
 171  * For each channel added to the system this routine is called for each client.
 172  * If the client would like to use the channel it returns '1' to signal (ack)
 173  * the dmaengine core to take out a reference on the channel and its
 174  * corresponding device.  A client must not 'ack' an available channel more
 175  * than once.  When a channel is removed all clients are notified.  If a client
 176  * is using the channel it must 'ack' the removal.  A client must not 'ack' a
 177  * removed channel more than once.
 178  * @client - 'this' pointer for the client context
 179  * @chan - channel to be acted upon
 180  * @state - available or removed
 181  */
 182 struct dma_client;
 183 typedef enum dma_state_client (*dma_event_callback) (struct dma_client *client,
 184                 struct dma_chan *chan, enum dma_state state);
 185
 186 /**
 187  * struct dma_client - info on the entity making use of DMA services
 188  * @event_callback: func ptr to call when something happens
 189  * @cap_mask: only return channels that satisfy the requested capabilities
 190  *  a value of zero corresponds to any capability
 191  * @global_node: list_head for global dma_client_list
 192  */
 193 struct dma_client {
 194         dma_event_callback      event_callback;
 195         dma_cap_mask_t          cap_mask;
 196         struct list_head        global_node;
 197 };
 198
 199 typedef void (*dma_async_tx_callback)(void *dma_async_param);
 200 /**
 201  * struct dma_async_tx_descriptor - async transaction descriptor
 202  * ---dma generic offload fields---
 203  * @cookie: tracking cookie for this transaction, set to -EBUSY if
 204  *      this tx is sitting on a dependency list
 205  * @ack: the descriptor can not be reused until the client acknowledges
 206  *      receipt, i.e. has has a chance to establish any dependency chains
 207  * @phys: physical address of the descriptor
 208  * @tx_list: driver common field for operations that require multiple
 209  *      descriptors
 210  * @chan: target channel for this operation
 211  * @tx_submit: set the prepared descriptor(s) to be executed by the engine
 212  * @tx_set_dest: set a destination address in a hardware descriptor
 213  * @tx_set_src: set a source address in a hardware descriptor
 214  * @callback: routine to call after this operation is complete
 215  * @callback_param: general parameter to pass to the callback routine
 216  * ---async_tx api specific fields---
 217  * @depend_list: at completion this list of transactions are submitted
 218  * @depend_node: allow this transaction to be executed after another
 219  *      transaction has completed, possibly on another channel
 220  * @parent: pointer to the next level up in the dependency chain
 221  * @lock: protect the dependency list
 222  */
 223 struct dma_async_tx_descriptor {
 224         dma_cookie_t cookie;
 225         int ack;
 226         dma_addr_t phys;
 227         struct list_head tx_list;
 228         struct dma_chan *chan;
 229         dma_cookie_t (*tx_submit)(struct dma_async_tx_descriptor *tx);
 230         void (*tx_set_dest)(dma_addr_t addr,
 231                 struct dma_async_tx_descriptor *tx, int index);
 232         void (*tx_set_src)(dma_addr_t addr,
 233                 struct dma_async_tx_descriptor *tx, int index);
 234         dma_async_tx_callback callback;
 235         void *callback_param;
 236         struct list_head depend_list;
 237         struct list_head depend_node;
 238         struct dma_async_tx_descriptor *parent;
 239         spinlock_t lock;
 240 };
 241
 242 /**
 243  * struct dma_device - info on the entity supplying DMA services
 244  * @chancnt: how many DMA channels are supported
 245  * @channels: the list of struct dma_chan
 246  * @global_node: list_head for global dma_device_list
 247  * @cap_mask: one or more dma_capability flags
 248  * @max_xor: maximum number of xor sources, 0 if no capability
 249  * @refcount: reference count
 250  * @done: IO completion struct
 251  * @dev_id: unique device ID
 252  * @dev: struct device reference for dma mapping api
 253  * @device_alloc_chan_resources: allocate resources and return the
 254  *      number of allocated descriptors
 255  * @device_free_chan_resources: release DMA channel's resources
 256  * @device_prep_dma_memcpy: prepares a memcpy operation
 257  * @device_prep_dma_xor: prepares a xor operation
 258  * @device_prep_dma_zero_sum: prepares a zero_sum operation
 259  * @device_prep_dma_memset: prepares a memset operation
 260  * @device_prep_dma_interrupt: prepares an end of chain interrupt operation
 261  * @device_dependency_added: async_tx notifies the channel about new deps
 262  * @device_issue_pending: push pending transactions to hardware
 263  */
 264 struct dma_device {
 265
 266         unsigned int chancnt;
 267         struct list_head channels;
 268         struct list_head global_node;
 269         dma_cap_mask_t  cap_mask;
 270         int max_xor;
 271
 272         struct kref refcount;
 273         struct completion done;
 274
 275         int dev_id;
 276         struct device *dev;
 277
 278         int (*device_alloc_chan_resources)(struct dma_chan *chan);
 279         void (*device_free_chan_resources)(struct dma_chan *chan);
 280
 281         struct dma_async_tx_descriptor *(*device_prep_dma_memcpy)(
 282                 struct dma_chan *chan, size_t len, int int_en);
 283         struct dma_async_tx_descriptor *(*device_prep_dma_xor)(
 284                 struct dma_chan *chan, unsigned int src_cnt, size_t len,
 285                 int int_en);
 286         struct dma_async_tx_descriptor *(*device_prep_dma_zero_sum)(
 287                 struct dma_chan *chan, unsigned int src_cnt, size_t len,
 288                 u32 *result, int int_en);
 289         struct dma_async_tx_descriptor *(*device_prep_dma_memset)(
 290                 struct dma_chan *chan, int value, size_t len, int int_en);
 291         struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)(
 292                 struct dma_chan *chan);
 293
 294         void (*device_dependency_added)(struct dma_chan *chan);
 295         enum dma_status (*device_is_tx_complete)(struct dma_chan *chan,
 296                         dma_cookie_t cookie, dma_cookie_t *last,
 297                         dma_cookie_t *used);
 298         void (*device_issue_pending)(struct dma_chan *chan);
 299 };
 300
 301 /* --- public DMA engine API --- */
 302
 303 void dma_async_client_register(struct dma_client *client);
 304 void dma_async_client_unregister(struct dma_client *client);
 305 void dma_async_client_chan_request(struct dma_client *client);
 306 dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan,
 307         void *dest, void *src, size_t len);
 308 dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan,
 309         struct page *page, unsigned int offset, void *kdata, size_t len);
 310 dma_cookie_t dma_async_memcpy_pg_to_pg(struct dma_chan *chan,
 311         struct page *dest_pg, unsigned int dest_off, struct page *src_pg,
 312         unsigned int src_off, size_t len);
 313 void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
 314         struct dma_chan *chan);
 315
 316 static inline void
 317 async_tx_ack(struct dma_async_tx_descriptor *tx)
 318 {
 319         tx->ack = 1;
 320 }
 321
 322 #define first_dma_cap(mask) __first_dma_cap(&(mask))
 323 static inline int __first_dma_cap(const dma_cap_mask_t *srcp)
 324 {
 325         return min_t(int, DMA_TX_TYPE_END,
 326                 find_first_bit(srcp->bits, DMA_TX_TYPE_END));
 327 }
 328
 329 #define next_dma_cap(n, mask) __next_dma_cap((n), &(mask))
 330 static inline int __next_dma_cap(int n, const dma_cap_mask_t *srcp)
 331 {
 332         return min_t(int, DMA_TX_TYPE_END,
 333                 find_next_bit(srcp->bits, DMA_TX_TYPE_END, n+1));
 334 }
 335
 336 #define dma_cap_set(tx, mask) __dma_cap_set((tx), &(mask))
 337 static inline void
 338 __dma_cap_set(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp)
 339 {
 340         set_bit(tx_type, dstp->bits);
 341 }
 342
 343 #define dma_has_cap(tx, mask) __dma_has_cap((tx), &(mask))
 344 static inline int
 345 __dma_has_cap(enum dma_transaction_type tx_type, dma_cap_mask_t *srcp)
 346 {
 347         return test_bit(tx_type, srcp->bits);
 348 }
 349
 350 #define for_each_dma_cap_mask(cap, mask) \
 351         for ((cap) = first_dma_cap(mask);       \
 352                 (cap) < DMA_TX_TYPE_END;        \
 353                 (cap) = next_dma_cap((cap), (mask)))
 354
 355 /**
 356  * dma_async_issue_pending - flush pending transactions to HW
 357  * @chan: target DMA channel
 358  *
 359  * This allows drivers to push copies to HW in batches,
 360  * reducing MMIO writes where possible.
 361  */
 362 static inline void dma_async_issue_pending(struct dma_chan *chan)
 363 {
 364         return chan->device->device_issue_pending(chan);
 365 }
 366
 367 #define dma_async_memcpy_issue_pending(chan) dma_async_issue_pending(chan)
 368
 369 /**
 370  * dma_async_is_tx_complete - poll for transaction completion
 371  * @chan: DMA channel
 372  * @cookie: transaction identifier to check status of
 373  * @last: returns last completed cookie, can be NULL
 374  * @used: returns last issued cookie, can be NULL
 375  *
 376  * If @last and @used are passed in, upon return they reflect the driver
 377  * internal state and can be used with dma_async_is_complete() to check
 378  * the status of multiple cookies without re-checking hardware state.
 379  */
 380 static inline enum dma_status dma_async_is_tx_complete(struct dma_chan *chan,
 381         dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used)
 382 {
 383         return chan->device->device_is_tx_complete(chan, cookie, last, used);
 384 }
 385
 386 #define dma_async_memcpy_complete(chan, cookie, last, used)\
 387         dma_async_is_tx_complete(chan, cookie, last, used)
 388
 389 /**
 390  * dma_async_is_complete - test a cookie against chan state
 391  * @cookie: transaction identifier to test status of
 392  * @last_complete: last know completed transaction
 393  * @last_used: last cookie value handed out
 394  *
 395  * dma_async_is_complete() is used in dma_async_memcpy_complete()
 396  * the test logic is seperated for lightweight testing of multiple cookies
 397  */
 398 static inline enum dma_status dma_async_is_complete(dma_cookie_t cookie,
 399                         dma_cookie_t last_complete, dma_cookie_t last_used)
 400 {
 401         if (last_complete <= last_used) {
 402                 if ((cookie <= last_complete) || (cookie > last_used))
 403                         return DMA_SUCCESS;
 404         } else {
 405                 if ((cookie <= last_complete) && (cookie > last_used))
 406                         return DMA_SUCCESS;
 407         }
 408         return DMA_IN_PROGRESS;
 409 }
 410
 411 enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);
 412
 413 /* --- DMA device --- */
 414
 415 int dma_async_device_register(struct dma_device *device);
 416 void dma_async_device_unregister(struct dma_device *device);
 417
 418 /* --- Helper iov-locking functions --- */
 419
 420 struct dma_page_list {
 421         char *base_address;
 422         int nr_pages;
 423         struct page **pages;
 424 };
 425
 426 struct dma_pinned_list {
 427         int nr_iovecs;
 428         struct dma_page_list page_list[0];
 429 };
 430
 431 struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len);
 432 void dma_unpin_iovec_pages(struct dma_pinned_list* pinned_list);
 433
 434 dma_cookie_t dma_memcpy_to_iovec(struct dma_chan *chan, struct iovec *iov,
 435         struct dma_pinned_list *pinned_list, unsigned char *kdata, size_t len);
 436 dma_cookie_t dma_memcpy_pg_to_iovec(struct dma_chan *chan, struct iovec *iov,
 437         struct dma_pinned_list *pinned_list, struct page *page,
 438         unsigned int offset, size_t len);
 439
 440 #endif /* DMAENGINE_H */