drivers/char/drm/drm_context.c

   1 /**
   2  * \file drm_context.h
   3  * IOCTLs for generic contexts
   4  *
   5  * \author Rickard E. (Rik) Faith <faith@valinux.com>
   6  * \author Gareth Hughes <gareth@valinux.com>
   7  */
   8
   9 /*
  10  * Created: Fri Nov 24 18:31:37 2000 by gareth@valinux.com
  11  *
  12  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
  13  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  14  * All Rights Reserved.
  15  *
  16  * Permission is hereby granted, free of charge, to any person obtaining a
  17  * copy of this software and associated documentation files (the "Software"),
  18  * to deal in the Software without restriction, including without limitation
  19  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  20  * and/or sell copies of the Software, and to permit persons to whom the
  21  * Software is furnished to do so, subject to the following conditions:
  22  *
  23  * The above copyright notice and this permission notice (including the next
  24  * paragraph) shall be included in all copies or substantial portions of the
  25  * Software.
  26  *
  27  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  28  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  29  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  30  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  31  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  32  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  33  * OTHER DEALINGS IN THE SOFTWARE.
  34  */
  35
  36 /*
  37  * ChangeLog:
  38  *  2001-11-16  Torsten Duwe <duwe@caldera.de>
  39  *              added context constructor/destructor hooks,
  40  *              needed by SiS driver's memory management.
  41  */
  42
  43 #include "drmP.h"
  44
  45 /******************************************************************/
  46 /** \name Context bitmap support */
  47 /*@{*/
  48
  49 /**
  50  * Free a handle from the context bitmap.
  51  *
  52  * \param dev DRM device.
  53  * \param ctx_handle context handle.
  54  *
  55  * Clears the bit specified by \p ctx_handle in drm_device::ctx_bitmap and the entry
  56  * in drm_device::context_sareas, while holding the drm_device::struct_sem
  57  * lock.
  58  */
  59 void drm_ctxbitmap_free( drm_device_t *dev, int ctx_handle )
  60 {
  61         if ( ctx_handle < 0 ) goto failed;
  62         if ( !dev->ctx_bitmap ) goto failed;
  63
  64         if ( ctx_handle < DRM_MAX_CTXBITMAP ) {
  65                 down(&dev->struct_sem);
  66                 clear_bit( ctx_handle, dev->ctx_bitmap );
  67                 dev->context_sareas[ctx_handle] = NULL;
  68                 up(&dev->struct_sem);
  69                 return;
  70         }
  71 failed:
  72         DRM_ERROR( "Attempt to free invalid context handle: %d\n",
  73                    ctx_handle );
  74         return;
  75 }
  76
  77 /**
  78  * Context bitmap allocation.
  79  *
  80  * \param dev DRM device.
  81  * \return (non-negative) context handle on success or a negative number on failure.
  82  *
  83  * Find the first zero bit in drm_device::ctx_bitmap and (re)allocates
  84  * drm_device::context_sareas to accommodate the new entry while holding the
  85  * drm_device::struct_sem lock.
  86  */
  87 int drm_ctxbitmap_next( drm_device_t *dev )
  88 {
  89         int bit;
  90
  91         if(!dev->ctx_bitmap) return -1;
  92
  93         down(&dev->struct_sem);
  94         bit = find_first_zero_bit( dev->ctx_bitmap, DRM_MAX_CTXBITMAP );
  95         if ( bit < DRM_MAX_CTXBITMAP ) {
  96                 set_bit( bit, dev->ctx_bitmap );
  97                 DRM_DEBUG( "drm_ctxbitmap_next bit : %d\n", bit );
  98                 if((bit+1) > dev->max_context) {
  99                         dev->max_context = (bit+1);
 100                         if(dev->context_sareas) {
 101                                 drm_map_t **ctx_sareas;
 102
 103                                 ctx_sareas = drm_realloc(dev->context_sareas,
 104                                                 (dev->max_context - 1) *
 105                                                 sizeof(*dev->context_sareas),
 106                                                 dev->max_context *
 107                                                 sizeof(*dev->context_sareas),
 108                                                 DRM_MEM_MAPS);
 109                                 if(!ctx_sareas) {
 110                                         clear_bit(bit, dev->ctx_bitmap);
 111                                         up(&dev->struct_sem);
 112                                         return -1;
 113                                 }
 114                                 dev->context_sareas = ctx_sareas;
 115                                 dev->context_sareas[bit] = NULL;
 116                         } else {
 117                                 /* max_context == 1 at this point */
 118                                 dev->context_sareas = drm_alloc(
 119                                                 dev->max_context *
 120                                                 sizeof(*dev->context_sareas),
 121                                                 DRM_MEM_MAPS);
 122                                 if(!dev->context_sareas) {
 123                                         clear_bit(bit, dev->ctx_bitmap);
 124                                         up(&dev->struct_sem);
 125                                         return -1;
 126                                 }
 127                                 dev->context_sareas[bit] = NULL;
 128                         }
 129                 }
 130                 up(&dev->struct_sem);
 131                 return bit;
 132         }
 133         up(&dev->struct_sem);
 134         return -1;
 135 }
 136
 137 /**
 138  * Context bitmap initialization.
 139  *
 140  * \param dev DRM device.
 141  *
 142  * Allocates and initialize drm_device::ctx_bitmap and drm_device::context_sareas, while holding
 143  * the drm_device::struct_sem lock.
 144  */
 145 int drm_ctxbitmap_init( drm_device_t *dev )
 146 {
 147         int i;
 148         int temp;
 149
 150         down(&dev->struct_sem);
 151         dev->ctx_bitmap = (unsigned long *) drm_alloc( PAGE_SIZE,
 152                                                         DRM_MEM_CTXBITMAP );
 153         if ( dev->ctx_bitmap == NULL ) {
 154                 up(&dev->struct_sem);
 155                 return -ENOMEM;
 156         }
 157         memset( (void *)dev->ctx_bitmap, 0, PAGE_SIZE );
 158         dev->context_sareas = NULL;
 159         dev->max_context = -1;
 160         up(&dev->struct_sem);
 161
 162         for ( i = 0 ; i < DRM_RESERVED_CONTEXTS ; i++ ) {
 163                 temp = drm_ctxbitmap_next( dev );
 164                 DRM_DEBUG( "drm_ctxbitmap_init : %d\n", temp );
 165         }
 166
 167         return 0;
 168 }
 169
 170 /**
 171  * Context bitmap cleanup.
 172  *
 173  * \param dev DRM device.
 174  *
 175  * Frees drm_device::ctx_bitmap and drm_device::context_sareas, while holding
 176  * the drm_device::struct_sem lock.
 177  */
 178 void drm_ctxbitmap_cleanup( drm_device_t *dev )
 179 {
 180         down(&dev->struct_sem);
 181         if( dev->context_sareas ) drm_free( dev->context_sareas,
 182                                              sizeof(*dev->context_sareas) *
 183                                              dev->max_context,
 184                                              DRM_MEM_MAPS );
 185         drm_free( (void *)dev->ctx_bitmap, PAGE_SIZE, DRM_MEM_CTXBITMAP );
 186         up(&dev->struct_sem);
 187 }
 188
 189 /*@}*/
 190
 191 /******************************************************************/
 192 /** \name Per Context SAREA Support */
 193 /*@{*/
 194
 195 /**
 196  * Get per-context SAREA.
 197  *
 198  * \param inode device inode.
 199  * \param filp file pointer.
 200  * \param cmd command.
 201  * \param arg user argument pointing to a drm_ctx_priv_map structure.
 202  * \return zero on success or a negative number on failure.
 203  *
 204  * Gets the map from drm_device::context_sareas with the handle specified and
 205  * returns its handle.
 206  */
 207 int drm_getsareactx(struct inode *inode, struct file *filp,
 208                      unsigned int cmd, unsigned long arg)
 209 {
 210         drm_file_t      *priv   = filp->private_data;
 211         drm_device_t    *dev    = priv->head->dev;
 212         drm_ctx_priv_map_t __user *argp = (void __user *)arg;
 213         drm_ctx_priv_map_t request;
 214         drm_map_t *map;
 215
 216         if (copy_from_user(&request, argp, sizeof(request)))
 217                 return -EFAULT;
 218
 219         down(&dev->struct_sem);
 220         if (dev->max_context < 0 || request.ctx_id >= (unsigned) dev->max_context) {
 221                 up(&dev->struct_sem);
 222                 return -EINVAL;
 223         }
 224
 225         map = dev->context_sareas[request.ctx_id];
 226         up(&dev->struct_sem);
 227
 228         request.handle = map->handle;
 229         if (copy_to_user(argp, &request, sizeof(request)))
 230                 return -EFAULT;
 231         return 0;
 232 }
 233
 234 /**
 235  * Set per-context SAREA.
 236  *
 237  * \param inode device inode.
 238  * \param filp file pointer.
 239  * \param cmd command.
 240  * \param arg user argument pointing to a drm_ctx_priv_map structure.
 241  * \return zero on success or a negative number on failure.
 242  *
 243  * Searches the mapping specified in \p arg and update the entry in
 244  * drm_device::context_sareas with it.
 245  */
 246 int drm_setsareactx(struct inode *inode, struct file *filp,
 247                      unsigned int cmd, unsigned long arg)
 248 {
 249         drm_file_t      *priv   = filp->private_data;
 250         drm_device_t    *dev    = priv->head->dev;
 251         drm_ctx_priv_map_t request;
 252         drm_map_t *map = NULL;
 253         drm_map_list_t *r_list = NULL;
 254         struct list_head *list;
 255
 256         if (copy_from_user(&request,
 257                            (drm_ctx_priv_map_t __user *)arg,
 258                            sizeof(request)))
 259                 return -EFAULT;
 260
 261         down(&dev->struct_sem);
 262         list_for_each(list, &dev->maplist->head) {
 263                 r_list = list_entry(list, drm_map_list_t, head);
 264                 if(r_list->map &&
 265                    r_list->map->handle == request.handle)
 266                         goto found;
 267         }
 268 bad:
 269         up(&dev->struct_sem);
 270         return -EINVAL;
 271
 272 found:
 273         map = r_list->map;
 274         if (!map) goto bad;
 275         if (dev->max_context < 0)
 276                 goto bad;
 277         if (request.ctx_id >= (unsigned) dev->max_context)
 278                 goto bad;
 279         dev->context_sareas[request.ctx_id] = map;
 280         up(&dev->struct_sem);
 281         return 0;
 282 }
 283
 284 /*@}*/
 285
 286 /******************************************************************/
 287 /** \name The actual DRM context handling routines */
 288 /*@{*/
 289
 290 /**
 291  * Switch context.
 292  *
 293  * \param dev DRM device.
 294  * \param old old context handle.
 295  * \param new new context handle.
 296  * \return zero on success or a negative number on failure.
 297  *
 298  * Attempt to set drm_device::context_flag.
 299  */
 300 int drm_context_switch( drm_device_t *dev, int old, int new )
 301 {
 302         if ( test_and_set_bit( 0, &dev->context_flag ) ) {
 303                 DRM_ERROR( "Reentering -- FIXME\n" );
 304                 return -EBUSY;
 305         }
 306
 307
 308         DRM_DEBUG( "Context switch from %d to %d\n", old, new );
 309
 310         if ( new == dev->last_context ) {
 311                 clear_bit( 0, &dev->context_flag );
 312                 return 0;
 313         }
 314
 315         return 0;
 316 }
 317
 318 /**
 319  * Complete context switch.
 320  *
 321  * \param dev DRM device.
 322  * \param new new context handle.
 323  * \return zero on success or a negative number on failure.
 324  *
 325  * Updates drm_device::last_context and drm_device::last_switch. Verifies the
 326  * hardware lock is held, clears the drm_device::context_flag and wakes up
 327  * drm_device::context_wait.
 328  */
 329 int drm_context_switch_complete( drm_device_t *dev, int new )
 330 {
 331         dev->last_context = new;  /* PRE/POST: This is the _only_ writer. */
 332         dev->last_switch  = jiffies;
 333
 334         if ( !_DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) ) {
 335                 DRM_ERROR( "Lock isn't held after context switch\n" );
 336         }
 337
 338                                 /* If a context switch is ever initiated
 339                                    when the kernel holds the lock, release
 340                                    that lock here. */
 341         clear_bit( 0, &dev->context_flag );
 342         wake_up( &dev->context_wait );
 343
 344         return 0;
 345 }
 346
 347 /**
 348  * Reserve contexts.
 349  *
 350  * \param inode device inode.
 351  * \param filp file pointer.
 352  * \param cmd command.
 353  * \param arg user argument pointing to a drm_ctx_res structure.
 354  * \return zero on success or a negative number on failure.
 355  */
 356 int drm_resctx( struct inode *inode, struct file *filp,
 357                  unsigned int cmd, unsigned long arg )
 358 {
 359         drm_ctx_res_t res;
 360         drm_ctx_t __user *argp = (void __user *)arg;
 361         drm_ctx_t ctx;
 362         int i;
 363
 364         if ( copy_from_user( &res, argp, sizeof(res) ) )
 365                 return -EFAULT;
 366
 367         if ( res.count >= DRM_RESERVED_CONTEXTS ) {
 368                 memset( &ctx, 0, sizeof(ctx) );
 369                 for ( i = 0 ; i < DRM_RESERVED_CONTEXTS ; i++ ) {
 370                         ctx.handle = i;
 371                         if ( copy_to_user( &res.contexts[i],
 372                                            &i, sizeof(i) ) )
 373                                 return -EFAULT;
 374                 }
 375         }
 376         res.count = DRM_RESERVED_CONTEXTS;
 377
 378         if ( copy_to_user( argp, &res, sizeof(res) ) )
 379                 return -EFAULT;
 380         return 0;
 381 }
 382
 383 /**
 384  * Add context.
 385  *
 386  * \param inode device inode.
 387  * \param filp file pointer.
 388  * \param cmd command.
 389  * \param arg user argument pointing to a drm_ctx structure.
 390  * \return zero on success or a negative number on failure.
 391  *
 392  * Get a new handle for the context and copy to userspace.
 393  */
 394 int drm_addctx( struct inode *inode, struct file *filp,
 395                  unsigned int cmd, unsigned long arg )
 396 {
 397         drm_file_t *priv = filp->private_data;
 398         drm_device_t *dev = priv->head->dev;
 399         drm_ctx_list_t * ctx_entry;
 400         drm_ctx_t __user *argp = (void __user *)arg;
 401         drm_ctx_t ctx;
 402
 403         if ( copy_from_user( &ctx, argp, sizeof(ctx) ) )
 404                 return -EFAULT;
 405
 406         ctx.handle = drm_ctxbitmap_next( dev );
 407         if ( ctx.handle == DRM_KERNEL_CONTEXT ) {
 408                                 /* Skip kernel's context and get a new one. */
 409                 ctx.handle = drm_ctxbitmap_next( dev );
 410         }
 411         DRM_DEBUG( "%d\n", ctx.handle );
 412         if ( ctx.handle == -1 ) {
 413                 DRM_DEBUG( "Not enough free contexts.\n" );
 414                                 /* Should this return -EBUSY instead? */
 415                 return -ENOMEM;
 416         }
 417
 418         if ( ctx.handle != DRM_KERNEL_CONTEXT )
 419         {
 420                 if (dev->driver->context_ctor)
 421                         dev->driver->context_ctor(dev, ctx.handle);
 422         }
 423
 424         ctx_entry = drm_alloc( sizeof(*ctx_entry), DRM_MEM_CTXLIST );
 425         if ( !ctx_entry ) {
 426                 DRM_DEBUG("out of memory\n");
 427                 return -ENOMEM;
 428         }
 429
 430         INIT_LIST_HEAD( &ctx_entry->head );
 431         ctx_entry->handle = ctx.handle;
 432         ctx_entry->tag = priv;
 433
 434         down( &dev->ctxlist_sem );
 435         list_add( &ctx_entry->head, &dev->ctxlist->head );
 436         ++dev->ctx_count;
 437         up( &dev->ctxlist_sem );
 438
 439         if ( copy_to_user( argp, &ctx, sizeof(ctx) ) )
 440                 return -EFAULT;
 441         return 0;
 442 }
 443
 444 int drm_modctx( struct inode *inode, struct file *filp,
 445                  unsigned int cmd, unsigned long arg )
 446 {
 447         /* This does nothing */
 448         return 0;
 449 }
 450
 451 /**
 452  * Get context.
 453  *
 454  * \param inode device inode.
 455  * \param filp file pointer.
 456  * \param cmd command.
 457  * \param arg user argument pointing to a drm_ctx structure.
 458  * \return zero on success or a negative number on failure.
 459  */
 460 int drm_getctx( struct inode *inode, struct file *filp,
 461                  unsigned int cmd, unsigned long arg )
 462 {
 463         drm_ctx_t __user *argp = (void __user *)arg;
 464         drm_ctx_t ctx;
 465
 466         if ( copy_from_user( &ctx, argp, sizeof(ctx) ) )
 467                 return -EFAULT;
 468
 469         /* This is 0, because we don't handle any context flags */
 470         ctx.flags = 0;
 471
 472         if ( copy_to_user( argp, &ctx, sizeof(ctx) ) )
 473                 return -EFAULT;
 474         return 0;
 475 }
 476
 477 /**
 478  * Switch context.
 479  *
 480  * \param inode device inode.
 481  * \param filp file pointer.
 482  * \param cmd command.
 483  * \param arg user argument pointing to a drm_ctx structure.
 484  * \return zero on success or a negative number on failure.
 485  *
 486  * Calls context_switch().
 487  */
 488 int drm_switchctx( struct inode *inode, struct file *filp,
 489                     unsigned int cmd, unsigned long arg )
 490 {
 491         drm_file_t *priv = filp->private_data;
 492         drm_device_t *dev = priv->head->dev;
 493         drm_ctx_t ctx;
 494
 495         if ( copy_from_user( &ctx, (drm_ctx_t __user *)arg, sizeof(ctx) ) )
 496                 return -EFAULT;
 497
 498         DRM_DEBUG( "%d\n", ctx.handle );
 499         return drm_context_switch( dev, dev->last_context, ctx.handle );
 500 }
 501
 502 /**
 503  * New context.
 504  *
 505  * \param inode device inode.
 506  * \param filp file pointer.
 507  * \param cmd command.
 508  * \param arg user argument pointing to a drm_ctx structure.
 509  * \return zero on success or a negative number on failure.
 510  *
 511  * Calls context_switch_complete().
 512  */
 513 int drm_newctx( struct inode *inode, struct file *filp,
 514                  unsigned int cmd, unsigned long arg )
 515 {
 516         drm_file_t *priv = filp->private_data;
 517         drm_device_t *dev = priv->head->dev;
 518         drm_ctx_t ctx;
 519
 520         if ( copy_from_user( &ctx, (drm_ctx_t __user *)arg, sizeof(ctx) ) )
 521                 return -EFAULT;
 522
 523         DRM_DEBUG( "%d\n", ctx.handle );
 524         drm_context_switch_complete( dev, ctx.handle );
 525
 526         return 0;
 527 }
 528
 529 /**
 530  * Remove context.
 531  *
 532  * \param inode device inode.
 533  * \param filp file pointer.
 534  * \param cmd command.
 535  * \param arg user argument pointing to a drm_ctx structure.
 536  * \return zero on success or a negative number on failure.
 537  *
 538  * If not the special kernel context, calls ctxbitmap_free() to free the specified context.
 539  */
 540 int drm_rmctx( struct inode *inode, struct file *filp,
 541                 unsigned int cmd, unsigned long arg )
 542 {
 543         drm_file_t *priv = filp->private_data;
 544         drm_device_t *dev = priv->head->dev;
 545         drm_ctx_t ctx;
 546
 547         if ( copy_from_user( &ctx, (drm_ctx_t __user *)arg, sizeof(ctx) ) )
 548                 return -EFAULT;
 549
 550         DRM_DEBUG( "%d\n", ctx.handle );
 551         if ( ctx.handle == DRM_KERNEL_CONTEXT + 1 ) {
 552                 priv->remove_auth_on_close = 1;
 553         }
 554         if ( ctx.handle != DRM_KERNEL_CONTEXT ) {
 555                 if (dev->driver->context_dtor)
 556                         dev->driver->context_dtor(dev, ctx.handle);
 557                 drm_ctxbitmap_free( dev, ctx.handle );
 558         }
 559
 560         down( &dev->ctxlist_sem );
 561         if ( !list_empty( &dev->ctxlist->head ) ) {
 562                 drm_ctx_list_t *pos, *n;
 563
 564                 list_for_each_entry_safe( pos, n, &dev->ctxlist->head, head ) {
 565                         if ( pos->handle == ctx.handle ) {
 566                                 list_del( &pos->head );
 567                                 drm_free( pos, sizeof(*pos), DRM_MEM_CTXLIST );
 568                                 --dev->ctx_count;
 569                         }
 570                 }
 571         }
 572         up( &dev->ctxlist_sem );
 573
 574         return 0;
 575 }
 576
 577 /*@}*/
 578