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  */
  30
  31 /** @file drm_context.c
  32  * Implementation of the context management ioctls.
  33  */
  34
  35 #include "dev/drm/drmP.h"
  36
  37 /* ================================================================
  38  * Context bitmap support
  39  */
  40
  41 void drm_ctxbitmap_free(struct drm_device *dev, int ctx_handle)
  42 {
  43         if (ctx_handle < 0 || ctx_handle >= DRM_MAX_CTXBITMAP ||
  44             dev->ctx_bitmap == NULL) {
  45                 DRM_ERROR("Attempt to free invalid context handle: %d\n",
  46                    ctx_handle);
  47                 return;
  48         }
  49
  50         DRM_LOCK();
  51         clear_bit(ctx_handle, dev->ctx_bitmap);
  52         dev->context_sareas[ctx_handle] = NULL;
  53         DRM_UNLOCK();
  54         return;
  55 }
  56
  57 int drm_ctxbitmap_next(struct drm_device *dev)
  58 {
  59         int bit;
  60
  61         if (dev->ctx_bitmap == NULL)
  62                 return -1;
  63
  64         DRM_LOCK();
  65         bit = find_first_zero_bit(dev->ctx_bitmap, DRM_MAX_CTXBITMAP);
  66         if (bit >= DRM_MAX_CTXBITMAP) {
  67                 DRM_UNLOCK();
  68                 return -1;
  69         }
  70
  71         set_bit(bit, dev->ctx_bitmap);
  72         DRM_DEBUG("drm_ctxbitmap_next bit : %d\n", bit);
  73         if ((bit+1) > dev->max_context) {
  74                 dev->max_context = (bit+1);
  75                 if (dev->context_sareas != NULL) {
  76                         drm_local_map_t **ctx_sareas;
  77
  78                         ctx_sareas = realloc(dev->context_sareas,
  79                             dev->max_context * sizeof(*dev->context_sareas),
  80                             DRM_MEM_SAREA, M_NOWAIT);
  81                         if (ctx_sareas == NULL) {
  82                                 clear_bit(bit, dev->ctx_bitmap);
  83                                 DRM_UNLOCK();
  84                                 return -1;
  85                         }
  86                         dev->context_sareas = ctx_sareas;
  87                         dev->context_sareas[bit] = NULL;
  88                 } else {
  89                         /* max_context == 1 at this point */
  90                         dev->context_sareas = malloc(dev->max_context *
  91                             sizeof(*dev->context_sareas), DRM_MEM_SAREA,
  92                             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(struct drm_device *dev)
 106 {
 107         int i;
 108         int temp;
 109
 110         DRM_LOCK();
 111         dev->ctx_bitmap = malloc(PAGE_SIZE, DRM_MEM_CTXBITMAP,
 112             M_NOWAIT | M_ZERO);
 113         if (dev->ctx_bitmap == NULL) {
 114                 DRM_UNLOCK();
 115                 return ENOMEM;
 116         }
 117         dev->context_sareas = NULL;
 118         dev->max_context = -1;
 119         DRM_UNLOCK();
 120
 121         for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
 122                 temp = drm_ctxbitmap_next(dev);
 123                 DRM_DEBUG("drm_ctxbitmap_init : %d\n", temp);
 124         }
 125
 126         return 0;
 127 }
 128
 129 void drm_ctxbitmap_cleanup(struct drm_device *dev)
 130 {
 131         DRM_LOCK();
 132         if (dev->context_sareas != NULL)
 133                 free(dev->context_sareas, DRM_MEM_SAREA);
 134         free(dev->ctx_bitmap, DRM_MEM_CTXBITMAP);
 135         DRM_UNLOCK();
 136 }
 137
 138 /* ================================================================
 139  * Per Context SAREA Support
 140  */
 141
 142 int drm_getsareactx(struct drm_device *dev, void *data,
 143                     struct drm_file *file_priv)
 144 {
 145         struct drm_ctx_priv_map *request = data;
 146         drm_local_map_t *map;
 147
 148         DRM_LOCK();
 149         if (dev->max_context < 0 ||
 150             request->ctx_id >= (unsigned) dev->max_context) {
 151                 DRM_UNLOCK();
 152                 return EINVAL;
 153         }
 154
 155         map = dev->context_sareas[request->ctx_id];
 156         DRM_UNLOCK();
 157
 158         request->handle = map->handle;
 159
 160         return 0;
 161 }
 162
 163 int drm_setsareactx(struct drm_device *dev, void *data,
 164                     struct drm_file *file_priv)
 165 {
 166         struct drm_ctx_priv_map *request = data;
 167         drm_local_map_t *map = NULL;
 168
 169         DRM_LOCK();
 170         TAILQ_FOREACH(map, &dev->maplist, link) {
 171                 if (map->handle == request->handle) {
 172                         if (dev->max_context < 0)
 173                                 goto bad;
 174                         if (request->ctx_id >= (unsigned) dev->max_context)
 175                                 goto bad;
 176                         dev->context_sareas[request->ctx_id] = map;
 177                         DRM_UNLOCK();
 178                         return 0;
 179                 }
 180         }
 181
 182 bad:
 183         DRM_UNLOCK();
 184         return EINVAL;
 185 }
 186
 187 /* ================================================================
 188  * The actual DRM context handling routines
 189  */
 190
 191 int drm_context_switch(struct drm_device *dev, int old, int new)
 192 {
 193         if (test_and_set_bit(0, &dev->context_flag)) {
 194                 DRM_ERROR("Reentering -- FIXME\n");
 195                 return EBUSY;
 196         }
 197
 198         DRM_DEBUG("Context switch from %d to %d\n", old, new);
 199
 200         if (new == dev->last_context) {
 201                 clear_bit(0, &dev->context_flag);
 202                 return 0;
 203         }
 204
 205         return 0;
 206 }
 207
 208 int drm_context_switch_complete(struct drm_device *dev, int new)
 209 {
 210         dev->last_context = new;  /* PRE/POST: This is the _only_ writer. */
 211
 212         if (!_DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock)) {
 213                 DRM_ERROR("Lock isn't held after context switch\n");
 214         }
 215
 216         /* If a context switch is ever initiated
 217            when the kernel holds the lock, release
 218            that lock here. */
 219         clear_bit(0, &dev->context_flag);
 220
 221         return 0;
 222 }
 223
 224 int drm_resctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
 225 {
 226         struct drm_ctx_res *res = data;
 227         struct drm_ctx ctx;
 228         int i;
 229
 230         if (res->count >= DRM_RESERVED_CONTEXTS) {
 231                 bzero(&ctx, sizeof(ctx));
 232                 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
 233                         ctx.handle = i;
 234                         if (DRM_COPY_TO_USER(&res->contexts[i],
 235                             &ctx, sizeof(ctx)))
 236                                 return EFAULT;
 237                 }
 238         }
 239         res->count = DRM_RESERVED_CONTEXTS;
 240
 241         return 0;
 242 }
 243
 244 int drm_addctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
 245 {
 246         struct drm_ctx *ctx = data;
 247
 248         ctx->handle = drm_ctxbitmap_next(dev);
 249         if (ctx->handle == DRM_KERNEL_CONTEXT) {
 250                 /* Skip kernel's context and get a new one. */
 251                 ctx->handle = drm_ctxbitmap_next(dev);
 252         }
 253         DRM_DEBUG("%d\n", ctx->handle);
 254         if (ctx->handle == -1) {
 255                 DRM_DEBUG("Not enough free contexts.\n");
 256                 /* Should this return -EBUSY instead? */
 257                 return ENOMEM;
 258         }
 259
 260         if (dev->driver->context_ctor && ctx->handle != DRM_KERNEL_CONTEXT) {
 261                 DRM_LOCK();
 262                 dev->driver->context_ctor(dev, ctx->handle);
 263                 DRM_UNLOCK();
 264         }
 265
 266         return 0;
 267 }
 268
 269 int drm_modctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
 270 {
 271         /* This does nothing */
 272         return 0;
 273 }
 274
 275 int drm_getctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
 276 {
 277         struct drm_ctx *ctx = data;
 278
 279         /* This is 0, because we don't handle any context flags */
 280         ctx->flags = 0;
 281
 282         return 0;
 283 }
 284
 285 int drm_switchctx(struct drm_device *dev, void *data,
 286                   struct drm_file *file_priv)
 287 {
 288         struct drm_ctx *ctx = data;
 289
 290         DRM_DEBUG("%d\n", ctx->handle);
 291         return drm_context_switch(dev, dev->last_context, ctx->handle);
 292 }
 293
 294 int drm_newctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
 295 {
 296         struct drm_ctx *ctx = data;
 297
 298         DRM_DEBUG("%d\n", ctx->handle);
 299         drm_context_switch_complete(dev, ctx->handle);
 300
 301         return 0;
 302 }
 303
 304 int drm_rmctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
 305 {
 306         struct drm_ctx *ctx = data;
 307
 308         DRM_DEBUG("%d\n", ctx->handle);
 309         if (ctx->handle != DRM_KERNEL_CONTEXT) {
 310                 if (dev->driver->context_dtor) {
 311                         DRM_LOCK();
 312                         dev->driver->context_dtor(dev, ctx->handle);
 313                         DRM_UNLOCK();
 314                 }
 315
 316                 drm_ctxbitmap_free(dev, ctx->handle);
 317         }
 318
 319         return 0;
 320 }