sys/dev/drm/drm_context.c

   1 /*-
   2  * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
   3  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the next
  14  * paragraph) shall be included in all copies or substantial portions of the
  15  * Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  23  * OTHER DEALINGS IN THE SOFTWARE.
  24  *
  25  * Authors:
  26  *    Rickard E. (Rik) Faith <faith@valinux.com>
  27  *    Gareth Hughes <gareth@valinux.com>
  28  *
  29  * $DragonFly: src/sys/dev/drm/drm_context.c,v 1.1 2008/04/05 18:12:29 hasso Exp $
  30  */
  31
  32 /** @file drm_context.c
  33  * Implementation of the context management ioctls.
  34  */
  35
  36 #include "drmP.h"
  37
  38 /* ================================================================
  39  * Context bitmap support
  40  */
  41
  42 void drm_ctxbitmap_free(drm_device_t *dev, int ctx_handle)
  43 {
  44         if (ctx_handle < 0 || ctx_handle >= DRM_MAX_CTXBITMAP ||
  45             dev->ctx_bitmap == NULL) {
  46                 DRM_ERROR("Attempt to free invalid context handle: %d\n",
  47                    ctx_handle);
  48                 return;
  49         }
  50
  51         DRM_LOCK();
  52         clear_bit(ctx_handle, dev->ctx_bitmap);
  53         dev->context_sareas[ctx_handle] = NULL;
  54         DRM_UNLOCK();
  55         return;
  56 }
  57
  58 int drm_ctxbitmap_next(drm_device_t *dev)
  59 {
  60         int bit;
  61
  62         if (dev->ctx_bitmap == NULL)
  63                 return -1;
  64
  65         DRM_LOCK();
  66         bit = find_first_zero_bit( dev->ctx_bitmap, DRM_MAX_CTXBITMAP );
  67         if (bit >= DRM_MAX_CTXBITMAP) {
  68                 DRM_UNLOCK();
  69                 return -1;
  70         }
  71
  72         set_bit(bit, dev->ctx_bitmap);
  73         DRM_DEBUG("drm_ctxbitmap_next bit : %d\n", bit);
  74         if ((bit+1) > dev->max_context) {
  75                 dev->max_context = (bit+1);
  76                 if (dev->context_sareas != NULL) {
  77                         drm_local_map_t **ctx_sareas;
  78
  79                         ctx_sareas = realloc(dev->context_sareas,
  80                             dev->max_context * sizeof(*dev->context_sareas),
  81                             M_DRM, M_NOWAIT);
  82                         if (ctx_sareas == NULL) {
  83                                 clear_bit(bit, dev->ctx_bitmap);
  84                                 DRM_UNLOCK();
  85                                 return -1;
  86                         }
  87                         dev->context_sareas = ctx_sareas;
  88                         dev->context_sareas[bit] = NULL;
  89                 } else {
  90                         /* max_context == 1 at this point */
  91                         dev->context_sareas = malloc(dev->max_context *
  92                             sizeof(*dev->context_sareas), M_DRM, M_NOWAIT);
  93                         if (dev->context_sareas == NULL) {
  94                                 clear_bit(bit, dev->ctx_bitmap);
  95                                 DRM_UNLOCK();
  96                                 return -1;
  97                         }
  98                         dev->context_sareas[bit] = NULL;
  99                 }
 100         }
 101         DRM_UNLOCK();
 102         return bit;
 103 }
 104
 105 int drm_ctxbitmap_init(drm_device_t *dev)
 106 {
 107         int i;
 108         int temp;
 109
 110         DRM_LOCK();
 111         dev->ctx_bitmap = malloc(PAGE_SIZE, M_DRM, M_NOWAIT | M_ZERO);
 112         if ( dev->ctx_bitmap == NULL ) {
 113                 DRM_UNLOCK();
 114                 return ENOMEM;
 115         }
 116         dev->context_sareas = NULL;
 117         dev->max_context = -1;
 118         DRM_UNLOCK();
 119
 120         for ( i = 0 ; i < DRM_RESERVED_CONTEXTS ; i++ ) {
 121                 temp = drm_ctxbitmap_next(dev);
 122                 DRM_DEBUG( "drm_ctxbitmap_init : %d\n", temp );
 123         }
 124
 125         return 0;
 126 }
 127
 128 void drm_ctxbitmap_cleanup(drm_device_t *dev)
 129 {
 130         DRM_LOCK();
 131         if (dev->context_sareas != NULL)
 132                 free(dev->context_sareas, M_DRM);
 133         free(dev->ctx_bitmap, M_DRM);
 134         DRM_UNLOCK();
 135 }
 136
 137 /* ================================================================
 138  * Per Context SAREA Support
 139  */
 140
 141 int drm_getsareactx( drm_device_t *dev, void *data, struct drm_file *file_priv )
 142 {
 143         drm_ctx_priv_map_t *request = data;
 144         drm_local_map_t *map;
 145
 146         DRM_LOCK();
 147         if (dev->max_context < 0 ||
 148             request->ctx_id >= (unsigned) dev->max_context) {
 149                 DRM_UNLOCK();
 150                 return EINVAL;
 151         }
 152
 153         map = dev->context_sareas[request->ctx_id];
 154         DRM_UNLOCK();
 155
 156         request->handle = map->handle;
 157
 158         return 0;
 159 }
 160
 161 int drm_setsareactx(drm_device_t *dev, void *data, struct drm_file *file_priv)
 162 {
 163         drm_ctx_priv_map_t *request = data;
 164         drm_local_map_t *map = NULL;
 165
 166         DRM_LOCK();
 167         TAILQ_FOREACH(map, &dev->maplist, link) {
 168                 if (map->handle == request->handle) {
 169                         if (dev->max_context < 0)
 170                                 goto bad;
 171                         if (request->ctx_id >= (unsigned) dev->max_context)
 172                                 goto bad;
 173                         dev->context_sareas[request->ctx_id] = map;
 174                         DRM_UNLOCK();
 175                         return 0;
 176                 }
 177         }
 178
 179 bad:
 180         DRM_UNLOCK();
 181         return EINVAL;
 182 }
 183
 184 /* ================================================================
 185  * The actual DRM context handling routines
 186  */
 187
 188 int drm_context_switch(drm_device_t *dev, int old, int new)
 189 {
 190         if ( test_and_set_bit( 0, &dev->context_flag ) ) {
 191                 DRM_ERROR( "Reentering -- FIXME\n" );
 192                 return EBUSY;
 193         }
 194
 195         DRM_DEBUG( "Context switch from %d to %d\n", old, new );
 196
 197         if ( new == dev->last_context ) {
 198                 clear_bit( 0, &dev->context_flag );
 199                 return 0;
 200         }
 201
 202         return 0;
 203 }
 204
 205 int drm_context_switch_complete(drm_device_t *dev, int new)
 206 {
 207         dev->last_context = new;  /* PRE/POST: This is the _only_ writer. */
 208
 209         if ( !_DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) ) {
 210                 DRM_ERROR( "Lock isn't held after context switch\n" );
 211         }
 212
 213                                 /* If a context switch is ever initiated
 214                                    when the kernel holds the lock, release
 215                                    that lock here. */
 216         clear_bit( 0, &dev->context_flag );
 217
 218         return 0;
 219 }
 220
 221 int drm_resctx(drm_device_t *dev, void *data, struct drm_file *file_priv)
 222 {
 223         drm_ctx_res_t *res = data;
 224         drm_ctx_t ctx;
 225         int i;
 226
 227         if ( res->count >= DRM_RESERVED_CONTEXTS ) {
 228                 bzero(&ctx, sizeof(ctx));
 229                 for ( i = 0 ; i < DRM_RESERVED_CONTEXTS ; i++ ) {
 230                         ctx.handle = i;
 231                         if ( DRM_COPY_TO_USER( &res->contexts[i],
 232                                            &ctx, sizeof(ctx) ) )
 233                                 return EFAULT;
 234                 }
 235         }
 236         res->count = DRM_RESERVED_CONTEXTS;
 237
 238         return 0;
 239 }
 240
 241 int drm_addctx(drm_device_t *dev, void *data, struct drm_file *file_priv)
 242 {
 243         drm_ctx_t *ctx = data;
 244
 245         ctx->handle = drm_ctxbitmap_next(dev);
 246         if ( ctx->handle == DRM_KERNEL_CONTEXT ) {
 247                                 /* Skip kernel's context and get a new one. */
 248                 ctx->handle = drm_ctxbitmap_next(dev);
 249         }
 250         DRM_DEBUG( "%d\n", ctx->handle );
 251         if ( ctx->handle == -1 ) {
 252                 DRM_DEBUG( "Not enough free contexts.\n" );
 253                                 /* Should this return -EBUSY instead? */
 254                 return ENOMEM;
 255         }
 256
 257         if (dev->driver.context_ctor && ctx->handle != DRM_KERNEL_CONTEXT) {
 258                 DRM_LOCK();
 259                 dev->driver.context_ctor(dev, ctx->handle);
 260                 DRM_UNLOCK();
 261         }
 262
 263         return 0;
 264 }
 265
 266 int drm_modctx(drm_device_t *dev, void *data, struct drm_file *file_priv)
 267 {
 268         /* This does nothing */
 269         return 0;
 270 }
 271
 272 int drm_getctx(drm_device_t *dev, void *data, struct drm_file *file_priv)
 273 {
 274         drm_ctx_t *ctx = data;
 275
 276         /* This is 0, because we don't handle any context flags */
 277         ctx->flags = 0;
 278
 279         return 0;
 280 }
 281
 282 int drm_switchctx(drm_device_t *dev, void *data, struct drm_file *file_priv)
 283 {
 284         drm_ctx_t *ctx = data;
 285
 286         DRM_DEBUG( "%d\n", ctx->handle );
 287         return drm_context_switch(dev, dev->last_context, ctx->handle);
 288 }
 289
 290 int drm_newctx(drm_device_t *dev, void *data, struct drm_file *file_priv)
 291 {
 292         drm_ctx_t *ctx = data;
 293
 294         DRM_DEBUG( "%d\n", ctx->handle );
 295         drm_context_switch_complete(dev, ctx->handle);
 296
 297         return 0;
 298 }
 299
 300 int drm_rmctx(drm_device_t *dev, void *data, struct drm_file *file_priv)
 301 {
 302         drm_ctx_t *ctx = data;
 303
 304         DRM_DEBUG( "%d\n", ctx->handle );
 305         if ( ctx->handle != DRM_KERNEL_CONTEXT ) {
 306                 if (dev->driver.context_dtor) {
 307                         DRM_LOCK();
 308                         dev->driver.context_dtor(dev, ctx->handle);
 309                         DRM_UNLOCK();
 310                 }
 311
 312                 drm_ctxbitmap_free(dev, ctx->handle);
 313         }
 314
 315         return 0;
 316 }