include/drm/ttm/ttm_bo_driver.h

   1 /**************************************************************************
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   3  * Copyright (c) 2006-2009 Vmware, Inc., Palo Alto, CA., USA
   4  * All Rights Reserved.
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  11  * permit persons to whom the Software is furnished to do so, subject to
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  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
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  27 /*
  28  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
  29  */
  30 #ifndef _TTM_BO_DRIVER_H_
  31 #define _TTM_BO_DRIVER_H_
  32
  33 #include "ttm/ttm_bo_api.h"
  34 #include "ttm/ttm_memory.h"
  35 #include "ttm/ttm_module.h"
  36 #include "drm_mm.h"
  37 #include "linux/workqueue.h"
  38 #include "linux/fs.h"
  39 #include "linux/spinlock.h"
  40
  41 struct ttm_backend;
  42
  43 struct ttm_backend_func {
  44         /**
  45          * struct ttm_backend_func member populate
  46          *
  47          * @backend: Pointer to a struct ttm_backend.
  48          * @num_pages: Number of pages to populate.
  49          * @pages: Array of pointers to ttm pages.
  50          * @dummy_read_page: Page to be used instead of NULL pages in the
  51          * array @pages.
  52          *
  53          * Populate the backend with ttm pages. Depending on the backend,
  54          * it may or may not copy the @pages array.
  55          */
  56         int (*populate) (struct ttm_backend *backend,
  57                          unsigned long num_pages, struct page **pages,
  58                          struct page *dummy_read_page);
  59         /**
  60          * struct ttm_backend_func member clear
  61          *
  62          * @backend: Pointer to a struct ttm_backend.
  63          *
  64          * This is an "unpopulate" function. Release all resources
  65          * allocated with populate.
  66          */
  67         void (*clear) (struct ttm_backend *backend);
  68
  69         /**
  70          * struct ttm_backend_func member bind
  71          *
  72          * @backend: Pointer to a struct ttm_backend.
  73          * @bo_mem: Pointer to a struct ttm_mem_reg describing the
  74          * memory type and location for binding.
  75          *
  76          * Bind the backend pages into the aperture in the location
  77          * indicated by @bo_mem. This function should be able to handle
  78          * differences between aperture- and system page sizes.
  79          */
  80         int (*bind) (struct ttm_backend *backend, struct ttm_mem_reg *bo_mem);
  81
  82         /**
  83          * struct ttm_backend_func member unbind
  84          *
  85          * @backend: Pointer to a struct ttm_backend.
  86          *
  87          * Unbind previously bound backend pages. This function should be
  88          * able to handle differences between aperture- and system page sizes.
  89          */
  90         int (*unbind) (struct ttm_backend *backend);
  91
  92         /**
  93          * struct ttm_backend_func member destroy
  94          *
  95          * @backend: Pointer to a struct ttm_backend.
  96          *
  97          * Destroy the backend.
  98          */
  99         void (*destroy) (struct ttm_backend *backend);
 100 };
 101
 102 /**
 103  * struct ttm_backend
 104  *
 105  * @bdev: Pointer to a struct ttm_bo_device.
 106  * @flags: For driver use.
 107  * @func: Pointer to a struct ttm_backend_func that describes
 108  * the backend methods.
 109  *
 110  */
 111
 112 struct ttm_backend {
 113         struct ttm_bo_device *bdev;
 114         uint32_t flags;
 115         struct ttm_backend_func *func;
 116 };
 117
 118 #define TTM_PAGE_FLAG_VMALLOC         (1 << 0)
 119 #define TTM_PAGE_FLAG_USER            (1 << 1)
 120 #define TTM_PAGE_FLAG_USER_DIRTY      (1 << 2)
 121 #define TTM_PAGE_FLAG_WRITE           (1 << 3)
 122 #define TTM_PAGE_FLAG_SWAPPED         (1 << 4)
 123 #define TTM_PAGE_FLAG_PERSISTANT_SWAP (1 << 5)
 124 #define TTM_PAGE_FLAG_ZERO_ALLOC      (1 << 6)
 125 #define TTM_PAGE_FLAG_DMA32           (1 << 7)
 126
 127 enum ttm_caching_state {
 128         tt_uncached,
 129         tt_wc,
 130         tt_cached
 131 };
 132
 133 /**
 134  * struct ttm_tt
 135  *
 136  * @dummy_read_page: Page to map where the ttm_tt page array contains a NULL
 137  * pointer.
 138  * @pages: Array of pages backing the data.
 139  * @first_himem_page: Himem pages are put last in the page array, which
 140  * enables us to run caching attribute changes on only the first part
 141  * of the page array containing lomem pages. This is the index of the
 142  * first himem page.
 143  * @last_lomem_page: Index of the last lomem page in the page array.
 144  * @num_pages: Number of pages in the page array.
 145  * @bdev: Pointer to the current struct ttm_bo_device.
 146  * @be: Pointer to the ttm backend.
 147  * @tsk: The task for user ttm.
 148  * @start: virtual address for user ttm.
 149  * @swap_storage: Pointer to shmem struct file for swap storage.
 150  * @caching_state: The current caching state of the pages.
 151  * @state: The current binding state of the pages.
 152  *
 153  * This is a structure holding the pages, caching- and aperture binding
 154  * status for a buffer object that isn't backed by fixed (VRAM / AGP)
 155  * memory.
 156  */
 157
 158 struct ttm_tt {
 159         struct page *dummy_read_page;
 160         struct page **pages;
 161         long first_himem_page;
 162         long last_lomem_page;
 163         uint32_t page_flags;
 164         unsigned long num_pages;
 165         struct ttm_bo_global *glob;
 166         struct ttm_backend *be;
 167         struct task_struct *tsk;
 168         unsigned long start;
 169         struct file *swap_storage;
 170         enum ttm_caching_state caching_state;
 171         enum {
 172                 tt_bound,
 173                 tt_unbound,
 174                 tt_unpopulated,
 175         } state;
 176 };
 177
 178 #define TTM_MEMTYPE_FLAG_FIXED         (1 << 0) /* Fixed (on-card) PCI memory */
 179 #define TTM_MEMTYPE_FLAG_MAPPABLE      (1 << 1) /* Memory mappable */
 180 #define TTM_MEMTYPE_FLAG_NEEDS_IOREMAP (1 << 2) /* Fixed memory needs ioremap
 181                                                    before kernel access. */
 182 #define TTM_MEMTYPE_FLAG_CMA           (1 << 3) /* Can't map aperture */
 183
 184 /**
 185  * struct ttm_mem_type_manager
 186  *
 187  * @has_type: The memory type has been initialized.
 188  * @use_type: The memory type is enabled.
 189  * @flags: TTM_MEMTYPE_XX flags identifying the traits of the memory
 190  * managed by this memory type.
 191  * @gpu_offset: If used, the GPU offset of the first managed page of
 192  * fixed memory or the first managed location in an aperture.
 193  * @io_offset: The io_offset of the first managed page of IO memory or
 194  * the first managed location in an aperture. For TTM_MEMTYPE_FLAG_CMA
 195  * memory, this should be set to NULL.
 196  * @io_size: The size of a managed IO region (fixed memory or aperture).
 197  * @io_addr: Virtual kernel address if the io region is pre-mapped. For
 198  * TTM_MEMTYPE_FLAG_NEEDS_IOREMAP there is no pre-mapped io map and
 199  * @io_addr should be set to NULL.
 200  * @size: Size of the managed region.
 201  * @available_caching: A mask of available caching types, TTM_PL_FLAG_XX,
 202  * as defined in ttm_placement_common.h
 203  * @default_caching: The default caching policy used for a buffer object
 204  * placed in this memory type if the user doesn't provide one.
 205  * @manager: The range manager used for this memory type. FIXME: If the aperture
 206  * has a page size different from the underlying system, the granularity
 207  * of this manager should take care of this. But the range allocating code
 208  * in ttm_bo.c needs to be modified for this.
 209  * @lru: The lru list for this memory type.
 210  *
 211  * This structure is used to identify and manage memory types for a device.
 212  * It's set up by the ttm_bo_driver::init_mem_type method.
 213  */
 214
 215 struct ttm_mem_type_manager {
 216
 217         /*
 218          * No protection. Constant from start.
 219          */
 220
 221         bool has_type;
 222         bool use_type;
 223         uint32_t flags;
 224         unsigned long gpu_offset;
 225         unsigned long io_offset;
 226         unsigned long io_size;
 227         void *io_addr;
 228         uint64_t size;
 229         uint32_t available_caching;
 230         uint32_t default_caching;
 231
 232         /*
 233          * Protected by the bdev->lru_lock.
 234          * TODO: Consider one lru_lock per ttm_mem_type_manager.
 235          * Plays ill with list removal, though.
 236          */
 237
 238         struct drm_mm manager;
 239         struct list_head lru;
 240 };
 241
 242 /**
 243  * struct ttm_bo_driver
 244  *
 245  * @create_ttm_backend_entry: Callback to create a struct ttm_backend.
 246  * @invalidate_caches: Callback to invalidate read caches when a buffer object
 247  * has been evicted.
 248  * @init_mem_type: Callback to initialize a struct ttm_mem_type_manager
 249  * structure.
 250  * @evict_flags: Callback to obtain placement flags when a buffer is evicted.
 251  * @move: Callback for a driver to hook in accelerated functions to
 252  * move a buffer.
 253  * If set to NULL, a potentially slow memcpy() move is used.
 254  * @sync_obj_signaled: See ttm_fence_api.h
 255  * @sync_obj_wait: See ttm_fence_api.h
 256  * @sync_obj_flush: See ttm_fence_api.h
 257  * @sync_obj_unref: See ttm_fence_api.h
 258  * @sync_obj_ref: See ttm_fence_api.h
 259  */
 260
 261 struct ttm_bo_driver {
 262         /**
 263          * struct ttm_bo_driver member create_ttm_backend_entry
 264          *
 265          * @bdev: The buffer object device.
 266          *
 267          * Create a driver specific struct ttm_backend.
 268          */
 269
 270         struct ttm_backend *(*create_ttm_backend_entry)
 271          (struct ttm_bo_device *bdev);
 272
 273         /**
 274          * struct ttm_bo_driver member invalidate_caches
 275          *
 276          * @bdev: the buffer object device.
 277          * @flags: new placement of the rebound buffer object.
 278          *
 279          * A previosly evicted buffer has been rebound in a
 280          * potentially new location. Tell the driver that it might
 281          * consider invalidating read (texture) caches on the next command
 282          * submission as a consequence.
 283          */
 284
 285         int (*invalidate_caches) (struct ttm_bo_device *bdev, uint32_t flags);
 286         int (*init_mem_type) (struct ttm_bo_device *bdev, uint32_t type,
 287                               struct ttm_mem_type_manager *man);
 288         /**
 289          * struct ttm_bo_driver member evict_flags:
 290          *
 291          * @bo: the buffer object to be evicted
 292          *
 293          * Return the bo flags for a buffer which is not mapped to the hardware.
 294          * These will be placed in proposed_flags so that when the move is
 295          * finished, they'll end up in bo->mem.flags
 296          */
 297
 298          void(*evict_flags) (struct ttm_buffer_object *bo,
 299                                 struct ttm_placement *placement);
 300         /**
 301          * struct ttm_bo_driver member move:
 302          *
 303          * @bo: the buffer to move
 304          * @evict: whether this motion is evicting the buffer from
 305          * the graphics address space
 306          * @interruptible: Use interruptible sleeps if possible when sleeping.
 307          * @no_wait: whether this should give up and return -EBUSY
 308          * if this move would require sleeping
 309          * @new_mem: the new memory region receiving the buffer
 310          *
 311          * Move a buffer between two memory regions.
 312          */
 313         int (*move) (struct ttm_buffer_object *bo,
 314                      bool evict, bool interruptible,
 315                      bool no_wait, struct ttm_mem_reg *new_mem);
 316
 317         /**
 318          * struct ttm_bo_driver_member verify_access
 319          *
 320          * @bo: Pointer to a buffer object.
 321          * @filp: Pointer to a struct file trying to access the object.
 322          *
 323          * Called from the map / write / read methods to verify that the
 324          * caller is permitted to access the buffer object.
 325          * This member may be set to NULL, which will refuse this kind of
 326          * access for all buffer objects.
 327          * This function should return 0 if access is granted, -EPERM otherwise.
 328          */
 329         int (*verify_access) (struct ttm_buffer_object *bo,
 330                               struct file *filp);
 331
 332         /**
 333          * In case a driver writer dislikes the TTM fence objects,
 334          * the driver writer can replace those with sync objects of
 335          * his / her own. If it turns out that no driver writer is
 336          * using these. I suggest we remove these hooks and plug in
 337          * fences directly. The bo driver needs the following functionality:
 338          * See the corresponding functions in the fence object API
 339          * documentation.
 340          */
 341
 342         bool (*sync_obj_signaled) (void *sync_obj, void *sync_arg);
 343         int (*sync_obj_wait) (void *sync_obj, void *sync_arg,
 344                               bool lazy, bool interruptible);
 345         int (*sync_obj_flush) (void *sync_obj, void *sync_arg);
 346         void (*sync_obj_unref) (void **sync_obj);
 347         void *(*sync_obj_ref) (void *sync_obj);
 348
 349         /* hook to notify driver about a driver move so it
 350          * can do tiling things */
 351         void (*move_notify)(struct ttm_buffer_object *bo,
 352                             struct ttm_mem_reg *new_mem);
 353         /* notify the driver we are taking a fault on this BO
 354          * and have reserved it */
 355         void (*fault_reserve_notify)(struct ttm_buffer_object *bo);
 356 };
 357
 358 /**
 359  * struct ttm_bo_global_ref - Argument to initialize a struct ttm_bo_global.
 360  */
 361
 362 struct ttm_bo_global_ref {
 363         struct ttm_global_reference ref;
 364         struct ttm_mem_global *mem_glob;
 365 };
 366
 367 /**
 368  * struct ttm_bo_global - Buffer object driver global data.
 369  *
 370  * @mem_glob: Pointer to a struct ttm_mem_global object for accounting.
 371  * @dummy_read_page: Pointer to a dummy page used for mapping requests
 372  * of unpopulated pages.
 373  * @shrink: A shrink callback object used for buffer object swap.
 374  * @ttm_bo_extra_size: Extra size (sizeof(struct ttm_buffer_object) excluded)
 375  * used by a buffer object. This is excluding page arrays and backing pages.
 376  * @ttm_bo_size: This is @ttm_bo_extra_size + sizeof(struct ttm_buffer_object).
 377  * @device_list_mutex: Mutex protecting the device list.
 378  * This mutex is held while traversing the device list for pm options.
 379  * @lru_lock: Spinlock protecting the bo subsystem lru lists.
 380  * @device_list: List of buffer object devices.
 381  * @swap_lru: Lru list of buffer objects used for swapping.
 382  */
 383
 384 struct ttm_bo_global {
 385
 386         /**
 387          * Constant after init.
 388          */
 389
 390         struct kobject kobj;
 391         struct ttm_mem_global *mem_glob;
 392         struct page *dummy_read_page;
 393         struct ttm_mem_shrink shrink;
 394         size_t ttm_bo_extra_size;
 395         size_t ttm_bo_size;
 396         struct mutex device_list_mutex;
 397         spinlock_t lru_lock;
 398
 399         /**
 400          * Protected by device_list_mutex.
 401          */
 402         struct list_head device_list;
 403
 404         /**
 405          * Protected by the lru_lock.
 406          */
 407         struct list_head swap_lru;
 408
 409         /**
 410          * Internal protection.
 411          */
 412         atomic_t bo_count;
 413 };
 414
 415
 416 #define TTM_NUM_MEM_TYPES 8
 417
 418 #define TTM_BO_PRIV_FLAG_MOVING  0      /* Buffer object is moving and needs
 419                                            idling before CPU mapping */
 420 #define TTM_BO_PRIV_FLAG_MAX 1
 421 /**
 422  * struct ttm_bo_device - Buffer object driver device-specific data.
 423  *
 424  * @driver: Pointer to a struct ttm_bo_driver struct setup by the driver.
 425  * @man: An array of mem_type_managers.
 426  * @addr_space_mm: Range manager for the device address space.
 427  * lru_lock: Spinlock that protects the buffer+device lru lists and
 428  * ddestroy lists.
 429  * @nice_mode: Try nicely to wait for buffer idle when cleaning a manager.
 430  * If a GPU lockup has been detected, this is forced to 0.
 431  * @dev_mapping: A pointer to the struct address_space representing the
 432  * device address space.
 433  * @wq: Work queue structure for the delayed delete workqueue.
 434  *
 435  */
 436
 437 struct ttm_bo_device {
 438
 439         /*
 440          * Constant after bo device init / atomic.
 441          */
 442         struct list_head device_list;
 443         struct ttm_bo_global *glob;
 444         struct ttm_bo_driver *driver;
 445         rwlock_t vm_lock;
 446         struct ttm_mem_type_manager man[TTM_NUM_MEM_TYPES];
 447         /*
 448          * Protected by the vm lock.
 449          */
 450         struct rb_root addr_space_rb;
 451         struct drm_mm addr_space_mm;
 452
 453         /*
 454          * Protected by the global:lru lock.
 455          */
 456         struct list_head ddestroy;
 457
 458         /*
 459          * Protected by load / firstopen / lastclose /unload sync.
 460          */
 461
 462         bool nice_mode;
 463         struct address_space *dev_mapping;
 464
 465         /*
 466          * Internal protection.
 467          */
 468
 469         struct delayed_work wq;
 470
 471         bool need_dma32;
 472 };
 473
 474 /**
 475  * ttm_flag_masked
 476  *
 477  * @old: Pointer to the result and original value.
 478  * @new: New value of bits.
 479  * @mask: Mask of bits to change.
 480  *
 481  * Convenience function to change a number of bits identified by a mask.
 482  */
 483
 484 static inline uint32_t
 485 ttm_flag_masked(uint32_t *old, uint32_t new, uint32_t mask)
 486 {
 487         *old ^= (*old ^ new) & mask;
 488         return *old;
 489 }
 490
 491 /**
 492  * ttm_tt_create
 493  *
 494  * @bdev: pointer to a struct ttm_bo_device:
 495  * @size: Size of the data needed backing.
 496  * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
 497  * @dummy_read_page: See struct ttm_bo_device.
 498  *
 499  * Create a struct ttm_tt to back data with system memory pages.
 500  * No pages are actually allocated.
 501  * Returns:
 502  * NULL: Out of memory.
 503  */
 504 extern struct ttm_tt *ttm_tt_create(struct ttm_bo_device *bdev,
 505                                     unsigned long size,
 506                                     uint32_t page_flags,
 507                                     struct page *dummy_read_page);
 508
 509 /**
 510  * ttm_tt_set_user:
 511  *
 512  * @ttm: The struct ttm_tt to populate.
 513  * @tsk: A struct task_struct for which @start is a valid user-space address.
 514  * @start: A valid user-space address.
 515  * @num_pages: Size in pages of the user memory area.
 516  *
 517  * Populate a struct ttm_tt with a user-space memory area after first pinning
 518  * the pages backing it.
 519  * Returns:
 520  * !0: Error.
 521  */
 522
 523 extern int ttm_tt_set_user(struct ttm_tt *ttm,
 524                            struct task_struct *tsk,
 525                            unsigned long start, unsigned long num_pages);
 526
 527 /**
 528  * ttm_ttm_bind:
 529  *
 530  * @ttm: The struct ttm_tt containing backing pages.
 531  * @bo_mem: The struct ttm_mem_reg identifying the binding location.
 532  *
 533  * Bind the pages of @ttm to an aperture location identified by @bo_mem
 534  */
 535 extern int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);
 536
 537 /**
 538  * ttm_tt_populate:
 539  *
 540  * @ttm: The struct ttm_tt to contain the backing pages.
 541  *
 542  * Add backing pages to all of @ttm
 543  */
 544 extern int ttm_tt_populate(struct ttm_tt *ttm);
 545
 546 /**
 547  * ttm_ttm_destroy:
 548  *
 549  * @ttm: The struct ttm_tt.
 550  *
 551  * Unbind, unpopulate and destroy a struct ttm_tt.
 552  */
 553 extern void ttm_tt_destroy(struct ttm_tt *ttm);
 554
 555 /**
 556  * ttm_ttm_unbind:
 557  *
 558  * @ttm: The struct ttm_tt.
 559  *
 560  * Unbind a struct ttm_tt.
 561  */
 562 extern void ttm_tt_unbind(struct ttm_tt *ttm);
 563
 564 /**
 565  * ttm_ttm_destroy:
 566  *
 567  * @ttm: The struct ttm_tt.
 568  * @index: Index of the desired page.
 569  *
 570  * Return a pointer to the struct page backing @ttm at page
 571  * index @index. If the page is unpopulated, one will be allocated to
 572  * populate that index.
 573  *
 574  * Returns:
 575  * NULL on OOM.
 576  */
 577 extern struct page *ttm_tt_get_page(struct ttm_tt *ttm, int index);
 578
 579 /**
 580  * ttm_tt_cache_flush:
 581  *
 582  * @pages: An array of pointers to struct page:s to flush.
 583  * @num_pages: Number of pages to flush.
 584  *
 585  * Flush the data of the indicated pages from the cpu caches.
 586  * This is used when changing caching attributes of the pages from
 587  * cache-coherent.
 588  */
 589 extern void ttm_tt_cache_flush(struct page *pages[], unsigned long num_pages);
 590
 591 /**
 592  * ttm_tt_set_placement_caching:
 593  *
 594  * @ttm A struct ttm_tt the backing pages of which will change caching policy.
 595  * @placement: Flag indicating the desired caching policy.
 596  *
 597  * This function will change caching policy of any default kernel mappings of
 598  * the pages backing @ttm. If changing from cached to uncached or
 599  * write-combined,
 600  * all CPU caches will first be flushed to make sure the data of the pages
 601  * hit RAM. This function may be very costly as it involves global TLB
 602  * and cache flushes and potential page splitting / combining.
 603  */
 604 extern int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement);
 605 extern int ttm_tt_swapout(struct ttm_tt *ttm,
 606                           struct file *persistant_swap_storage);
 607
 608 /*
 609  * ttm_bo.c
 610  */
 611
 612 /**
 613  * ttm_mem_reg_is_pci
 614  *
 615  * @bdev: Pointer to a struct ttm_bo_device.
 616  * @mem: A valid struct ttm_mem_reg.
 617  *
 618  * Returns true if the memory described by @mem is PCI memory,
 619  * false otherwise.
 620  */
 621 extern bool ttm_mem_reg_is_pci(struct ttm_bo_device *bdev,
 622                                    struct ttm_mem_reg *mem);
 623
 624 /**
 625  * ttm_bo_mem_space
 626  *
 627  * @bo: Pointer to a struct ttm_buffer_object. the data of which
 628  * we want to allocate space for.
 629  * @proposed_placement: Proposed new placement for the buffer object.
 630  * @mem: A struct ttm_mem_reg.
 631  * @interruptible: Sleep interruptible when sliping.
 632  * @no_wait: Don't sleep waiting for space to become available.
 633  *
 634  * Allocate memory space for the buffer object pointed to by @bo, using
 635  * the placement flags in @mem, potentially evicting other idle buffer objects.
 636  * This function may sleep while waiting for space to become available.
 637  * Returns:
 638  * -EBUSY: No space available (only if no_wait == 1).
 639  * -ENOMEM: Could not allocate memory for the buffer object, either due to
 640  * fragmentation or concurrent allocators.
 641  * -ERESTARTSYS: An interruptible sleep was interrupted by a signal.
 642  */
 643 extern int ttm_bo_mem_space(struct ttm_buffer_object *bo,
 644                                 struct ttm_placement *placement,
 645                                 struct ttm_mem_reg *mem,
 646                                 bool interruptible, bool no_wait);
 647 /**
 648  * ttm_bo_wait_for_cpu
 649  *
 650  * @bo: Pointer to a struct ttm_buffer_object.
 651  * @no_wait: Don't sleep while waiting.
 652  *
 653  * Wait until a buffer object is no longer sync'ed for CPU access.
 654  * Returns:
 655  * -EBUSY: Buffer object was sync'ed for CPU access. (only if no_wait == 1).
 656  * -ERESTARTSYS: An interruptible sleep was interrupted by a signal.
 657  */
 658
 659 extern int ttm_bo_wait_cpu(struct ttm_buffer_object *bo, bool no_wait);
 660
 661 /**
 662  * ttm_bo_pci_offset - Get the PCI offset for the buffer object memory.
 663  *
 664  * @bo Pointer to a struct ttm_buffer_object.
 665  * @bus_base On return the base of the PCI region
 666  * @bus_offset On return the byte offset into the PCI region
 667  * @bus_size On return the byte size of the buffer object or zero if
 668  * the buffer object memory is not accessible through a PCI region.
 669  *
 670  * Returns:
 671  * -EINVAL if the buffer object is currently not mappable.
 672  * 0 otherwise.
 673  */
 674
 675 extern int ttm_bo_pci_offset(struct ttm_bo_device *bdev,
 676                              struct ttm_mem_reg *mem,
 677                              unsigned long *bus_base,
 678                              unsigned long *bus_offset,
 679                              unsigned long *bus_size);
 680
 681 extern void ttm_bo_global_release(struct ttm_global_reference *ref);
 682 extern int ttm_bo_global_init(struct ttm_global_reference *ref);
 683
 684 extern int ttm_bo_device_release(struct ttm_bo_device *bdev);
 685
 686 /**
 687  * ttm_bo_device_init
 688  *
 689  * @bdev: A pointer to a struct ttm_bo_device to initialize.
 690  * @mem_global: A pointer to an initialized struct ttm_mem_global.
 691  * @driver: A pointer to a struct ttm_bo_driver set up by the caller.
 692  * @file_page_offset: Offset into the device address space that is available
 693  * for buffer data. This ensures compatibility with other users of the
 694  * address space.
 695  *
 696  * Initializes a struct ttm_bo_device:
 697  * Returns:
 698  * !0: Failure.
 699  */
 700 extern int ttm_bo_device_init(struct ttm_bo_device *bdev,
 701                               struct ttm_bo_global *glob,
 702                               struct ttm_bo_driver *driver,
 703                               uint64_t file_page_offset, bool need_dma32);
 704
 705 /**
 706  * ttm_bo_unmap_virtual
 707  *
 708  * @bo: tear down the virtual mappings for this BO
 709  */
 710 extern void ttm_bo_unmap_virtual(struct ttm_buffer_object *bo);
 711
 712 /**
 713  * ttm_bo_reserve:
 714  *
 715  * @bo: A pointer to a struct ttm_buffer_object.
 716  * @interruptible: Sleep interruptible if waiting.
 717  * @no_wait: Don't sleep while trying to reserve, rather return -EBUSY.
 718  * @use_sequence: If @bo is already reserved, Only sleep waiting for
 719  * it to become unreserved if @sequence < (@bo)->sequence.
 720  *
 721  * Locks a buffer object for validation. (Or prevents other processes from
 722  * locking it for validation) and removes it from lru lists, while taking
 723  * a number of measures to prevent deadlocks.
 724  *
 725  * Deadlocks may occur when two processes try to reserve multiple buffers in
 726  * different order, either by will or as a result of a buffer being evicted
 727  * to make room for a buffer already reserved. (Buffers are reserved before
 728  * they are evicted). The following algorithm prevents such deadlocks from
 729  * occuring:
 730  * 1) Buffers are reserved with the lru spinlock held. Upon successful
 731  * reservation they are removed from the lru list. This stops a reserved buffer
 732  * from being evicted. However the lru spinlock is released between the time
 733  * a buffer is selected for eviction and the time it is reserved.
 734  * Therefore a check is made when a buffer is reserved for eviction, that it
 735  * is still the first buffer in the lru list, before it is removed from the
 736  * list. @check_lru == 1 forces this check. If it fails, the function returns
 737  * -EINVAL, and the caller should then choose a new buffer to evict and repeat
 738  * the procedure.
 739  * 2) Processes attempting to reserve multiple buffers other than for eviction,
 740  * (typically execbuf), should first obtain a unique 32-bit
 741  * validation sequence number,
 742  * and call this function with @use_sequence == 1 and @sequence == the unique
 743  * sequence number. If upon call of this function, the buffer object is already
 744  * reserved, the validation sequence is checked against the validation
 745  * sequence of the process currently reserving the buffer,
 746  * and if the current validation sequence is greater than that of the process
 747  * holding the reservation, the function returns -EAGAIN. Otherwise it sleeps
 748  * waiting for the buffer to become unreserved, after which it retries
 749  * reserving.
 750  * The caller should, when receiving an -EAGAIN error
 751  * release all its buffer reservations, wait for @bo to become unreserved, and
 752  * then rerun the validation with the same validation sequence. This procedure
 753  * will always guarantee that the process with the lowest validation sequence
 754  * will eventually succeed, preventing both deadlocks and starvation.
 755  *
 756  * Returns:
 757  * -EAGAIN: The reservation may cause a deadlock.
 758  * Release all buffer reservations, wait for @bo to become unreserved and
 759  * try again. (only if use_sequence == 1).
 760  * -ERESTARTSYS: A wait for the buffer to become unreserved was interrupted by
 761  * a signal. Release all buffer reservations and return to user-space.
 762  */
 763 extern int ttm_bo_reserve(struct ttm_buffer_object *bo,
 764                           bool interruptible,
 765                           bool no_wait, bool use_sequence, uint32_t sequence);
 766
 767 /**
 768  * ttm_bo_unreserve
 769  *
 770  * @bo: A pointer to a struct ttm_buffer_object.
 771  *
 772  * Unreserve a previous reservation of @bo.
 773  */
 774 extern void ttm_bo_unreserve(struct ttm_buffer_object *bo);
 775
 776 /**
 777  * ttm_bo_wait_unreserved
 778  *
 779  * @bo: A pointer to a struct ttm_buffer_object.
 780  *
 781  * Wait for a struct ttm_buffer_object to become unreserved.
 782  * This is typically used in the execbuf code to relax cpu-usage when
 783  * a potential deadlock condition backoff.
 784  */
 785 extern int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo,
 786                                   bool interruptible);
 787
 788 /**
 789  * ttm_bo_block_reservation
 790  *
 791  * @bo: A pointer to a struct ttm_buffer_object.
 792  * @interruptible: Use interruptible sleep when waiting.
 793  * @no_wait: Don't sleep, but rather return -EBUSY.
 794  *
 795  * Block reservation for validation by simply reserving the buffer.
 796  * This is intended for single buffer use only without eviction,
 797  * and thus needs no deadlock protection.
 798  *
 799  * Returns:
 800  * -EBUSY: If no_wait == 1 and the buffer is already reserved.
 801  * -ERESTARTSYS: If interruptible == 1 and the process received a signal
 802  * while sleeping.
 803  */
 804 extern int ttm_bo_block_reservation(struct ttm_buffer_object *bo,
 805                                     bool interruptible, bool no_wait);
 806
 807 /**
 808  * ttm_bo_unblock_reservation
 809  *
 810  * @bo: A pointer to a struct ttm_buffer_object.
 811  *
 812  * Unblocks reservation leaving lru lists untouched.
 813  */
 814 extern void ttm_bo_unblock_reservation(struct ttm_buffer_object *bo);
 815
 816 /*
 817  * ttm_bo_util.c
 818  */
 819
 820 /**
 821  * ttm_bo_move_ttm
 822  *
 823  * @bo: A pointer to a struct ttm_buffer_object.
 824  * @evict: 1: This is an eviction. Don't try to pipeline.
 825  * @no_wait: Never sleep, but rather return with -EBUSY.
 826  * @new_mem: struct ttm_mem_reg indicating where to move.
 827  *
 828  * Optimized move function for a buffer object with both old and
 829  * new placement backed by a TTM. The function will, if successful,
 830  * free any old aperture space, and set (@new_mem)->mm_node to NULL,
 831  * and update the (@bo)->mem placement flags. If unsuccessful, the old
 832  * data remains untouched, and it's up to the caller to free the
 833  * memory space indicated by @new_mem.
 834  * Returns:
 835  * !0: Failure.
 836  */
 837
 838 extern int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
 839                            bool evict, bool no_wait,
 840                            struct ttm_mem_reg *new_mem);
 841
 842 /**
 843  * ttm_bo_move_memcpy
 844  *
 845  * @bo: A pointer to a struct ttm_buffer_object.
 846  * @evict: 1: This is an eviction. Don't try to pipeline.
 847  * @no_wait: Never sleep, but rather return with -EBUSY.
 848  * @new_mem: struct ttm_mem_reg indicating where to move.
 849  *
 850  * Fallback move function for a mappable buffer object in mappable memory.
 851  * The function will, if successful,
 852  * free any old aperture space, and set (@new_mem)->mm_node to NULL,
 853  * and update the (@bo)->mem placement flags. If unsuccessful, the old
 854  * data remains untouched, and it's up to the caller to free the
 855  * memory space indicated by @new_mem.
 856  * Returns:
 857  * !0: Failure.
 858  */
 859
 860 extern int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
 861                               bool evict,
 862                               bool no_wait, struct ttm_mem_reg *new_mem);
 863
 864 /**
 865  * ttm_bo_free_old_node
 866  *
 867  * @bo: A pointer to a struct ttm_buffer_object.
 868  *
 869  * Utility function to free an old placement after a successful move.
 870  */
 871 extern void ttm_bo_free_old_node(struct ttm_buffer_object *bo);
 872
 873 /**
 874  * ttm_bo_move_accel_cleanup.
 875  *
 876  * @bo: A pointer to a struct ttm_buffer_object.
 877  * @sync_obj: A sync object that signals when moving is complete.
 878  * @sync_obj_arg: An argument to pass to the sync object idle / wait
 879  * functions.
 880  * @evict: This is an evict move. Don't return until the buffer is idle.
 881  * @no_wait: Never sleep, but rather return with -EBUSY.
 882  * @new_mem: struct ttm_mem_reg indicating where to move.
 883  *
 884  * Accelerated move function to be called when an accelerated move
 885  * has been scheduled. The function will create a new temporary buffer object
 886  * representing the old placement, and put the sync object on both buffer
 887  * objects. After that the newly created buffer object is unref'd to be
 888  * destroyed when the move is complete. This will help pipeline
 889  * buffer moves.
 890  */
 891
 892 extern int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
 893                                      void *sync_obj,
 894                                      void *sync_obj_arg,
 895                                      bool evict, bool no_wait,
 896                                      struct ttm_mem_reg *new_mem);
 897 /**
 898  * ttm_io_prot
 899  *
 900  * @c_state: Caching state.
 901  * @tmp: Page protection flag for a normal, cached mapping.
 902  *
 903  * Utility function that returns the pgprot_t that should be used for
 904  * setting up a PTE with the caching model indicated by @c_state.
 905  */
 906 extern pgprot_t ttm_io_prot(enum ttm_caching_state c_state, pgprot_t tmp);
 907
 908 #if (defined(CONFIG_AGP) || (defined(CONFIG_AGP_MODULE) && defined(MODULE)))
 909 #define TTM_HAS_AGP
 910 #include <linux/agp_backend.h>
 911
 912 /**
 913  * ttm_agp_backend_init
 914  *
 915  * @bdev: Pointer to a struct ttm_bo_device.
 916  * @bridge: The agp bridge this device is sitting on.
 917  *
 918  * Create a TTM backend that uses the indicated AGP bridge as an aperture
 919  * for TT memory. This function uses the linux agpgart interface to
 920  * bind and unbind memory backing a ttm_tt.
 921  */
 922 extern struct ttm_backend *ttm_agp_backend_init(struct ttm_bo_device *bdev,
 923                                                 struct agp_bridge_data *bridge);
 924 #endif
 925
 926 #endif