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("bit : %d\n", bit);
  73         if ((bit+1) > dev->max_context) {
  74                 drm_local_map_t **ctx_sareas;
  75                 int max_ctx = (bit+1);
  76
  77                 ctx_sareas = realloc(dev->context_sareas,
  78                     max_ctx * sizeof(*dev->context_sareas),
  79                     DRM_MEM_SAREA, M_NOWAIT);
  80                 if (ctx_sareas == NULL) {
  81                         clear_bit(bit, dev->ctx_bitmap);
  82                         DRM_DEBUG("failed to allocate bit : %d\n", bit);
  83                         DRM_UNLOCK();
  84                         return -1;
  85                 }
  86                 dev->max_context = max_ctx;
  87                 dev->context_sareas = ctx_sareas;
  88                 dev->context_sareas[bit] = NULL;
  89         }
  90         DRM_UNLOCK();
  91         return bit;
  92 }
  93
  94 int drm_ctxbitmap_init(struct drm_device *dev)
  95 {
  96         int i;
  97         int temp;
  98
  99         DRM_LOCK();
 100         dev->ctx_bitmap = malloc(PAGE_SIZE, DRM_MEM_CTXBITMAP,
 101             M_NOWAIT | M_ZERO);
 102         if (dev->ctx_bitmap == NULL) {
 103                 DRM_UNLOCK();
 104                 return ENOMEM;
 105         }
 106         dev->context_sareas = NULL;
 107         dev->max_context = -1;
 108         DRM_UNLOCK();
 109
 110         for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
 111                 temp = drm_ctxbitmap_next(dev);
 112                 DRM_DEBUG("drm_ctxbitmap_init : %d\n", temp);
 113         }
 114
 115         return 0;
 116 }
 117
 118 void drm_ctxbitmap_cleanup(struct drm_device *dev)
 119 {
 120         DRM_LOCK();
 121         if (dev->context_sareas != NULL)
 122                 free(dev->context_sareas, DRM_MEM_SAREA);
 123         free(dev->ctx_bitmap, DRM_MEM_CTXBITMAP);
 124         DRM_UNLOCK();
 125 }
 126
 127 /* ================================================================
 128  * Per Context SAREA Support
 129  */
 130
 131 int drm_getsareactx(struct drm_device *dev, void *data,
 132                     struct drm_file *file_priv)
 133 {
 134         struct drm_ctx_priv_map *request = data;
 135         drm_local_map_t *map;
 136
 137         DRM_LOCK();
 138         if (dev->max_context < 0 ||
 139             request->ctx_id >= (unsigned) dev->max_context) {
 140                 DRM_UNLOCK();
 141                 return EINVAL;
 142         }
 143
 144         map = dev->context_sareas[request->ctx_id];
 145         DRM_UNLOCK();
 146
 147         request->handle = map->handle;
 148
 149         return 0;
 150 }
 151
 152 int drm_setsareactx(struct drm_device *dev, void *data,
 153                     struct drm_file *file_priv)
 154 {
 155         struct drm_ctx_priv_map *request = data;
 156         drm_local_map_t *map = NULL;
 157
 158         DRM_LOCK();
 159         TAILQ_FOREACH(map, &dev->maplist, link) {
 160                 if (map->handle == request->handle) {
 161                         if (dev->max_context < 0)
 162                                 goto bad;
 163                         if (request->ctx_id >= (unsigned) dev->max_context)
 164                                 goto bad;
 165                         dev->context_sareas[request->ctx_id] = map;
 166                         DRM_UNLOCK();
 167                         return 0;
 168                 }
 169         }
 170
 171 bad:
 172         DRM_UNLOCK();
 173         return EINVAL;
 174 }
 175
 176 /* ================================================================
 177  * The actual DRM context handling routines
 178  */
 179
 180 int drm_context_switch(struct drm_device *dev, int old, int new)
 181 {
 182         if (test_and_set_bit(0, &dev->context_flag)) {
 183                 DRM_ERROR("Reentering -- FIXME\n");
 184                 return EBUSY;
 185         }
 186
 187         DRM_DEBUG("Context switch from %d to %d\n", old, new);
 188
 189         if (new == dev->last_context) {
 190                 clear_bit(0, &dev->context_flag);
 191                 return 0;
 192         }
 193
 194         return 0;
 195 }
 196
 197 int drm_context_switch_complete(struct drm_device *dev, int new)
 198 {
 199         dev->last_context = new;  /* PRE/POST: This is the _only_ writer. */
 200
 201         if (!_DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock)) {
 202                 DRM_ERROR("Lock isn't held after context switch\n");
 203         }
 204
 205         /* If a context switch is ever initiated
 206            when the kernel holds the lock, release
 207            that lock here. */
 208         clear_bit(0, &dev->context_flag);
 209
 210         return 0;
 211 }
 212
 213 int drm_resctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
 214 {
 215         struct drm_ctx_res *res = data;
 216         struct drm_ctx ctx;
 217         int i;
 218
 219         if (res->count >= DRM_RESERVED_CONTEXTS) {
 220                 bzero(&ctx, sizeof(ctx));
 221                 for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
 222                         ctx.handle = i;
 223                         if (DRM_COPY_TO_USER(&res->contexts[i],
 224                             &ctx, sizeof(ctx)))
 225                                 return EFAULT;
 226                 }
 227         }
 228         res->count = DRM_RESERVED_CONTEXTS;
 229
 230         return 0;
 231 }
 232
 233 int drm_addctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
 234 {
 235         struct drm_ctx *ctx = data;
 236
 237         ctx->handle = drm_ctxbitmap_next(dev);
 238         if (ctx->handle == DRM_KERNEL_CONTEXT) {
 239                 /* Skip kernel's context and get a new one. */
 240                 ctx->handle = drm_ctxbitmap_next(dev);
 241         }
 242         DRM_DEBUG("%d\n", ctx->handle);
 243         if (ctx->handle == -1) {
 244                 DRM_DEBUG("Not enough free contexts.\n");
 245                 /* Should this return -EBUSY instead? */
 246                 return ENOMEM;
 247         }
 248
 249         if (dev->driver->context_ctor && ctx->handle != DRM_KERNEL_CONTEXT) {
 250                 DRM_LOCK();
 251                 dev->driver->context_ctor(dev, ctx->handle);
 252                 DRM_UNLOCK();
 253         }
 254
 255         return 0;
 256 }
 257
 258 int drm_modctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
 259 {
 260         /* This does nothing */
 261         return 0;
 262 }
 263
 264 int drm_getctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
 265 {
 266         struct drm_ctx *ctx = data;
 267
 268         /* This is 0, because we don't handle any context flags */
 269         ctx->flags = 0;
 270
 271         return 0;
 272 }
 273
 274 int drm_switchctx(struct drm_device *dev, void *data,
 275                   struct drm_file *file_priv)
 276 {
 277         struct drm_ctx *ctx = data;
 278
 279         DRM_DEBUG("%d\n", ctx->handle);
 280         return drm_context_switch(dev, dev->last_context, ctx->handle);
 281 }
 282
 283 int drm_newctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
 284 {
 285         struct drm_ctx *ctx = data;
 286
 287         DRM_DEBUG("%d\n", ctx->handle);
 288         drm_context_switch_complete(dev, ctx->handle);
 289
 290         return 0;
 291 }
 292
 293 int drm_rmctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
 294 {
 295         struct drm_ctx *ctx = data;
 296
 297         DRM_DEBUG("%d\n", ctx->handle);
 298         if (ctx->handle != DRM_KERNEL_CONTEXT) {
 299                 if (dev->driver->context_dtor) {
 300                         DRM_LOCK();
 301                         dev->driver->context_dtor(dev, ctx->handle);
 302                         DRM_UNLOCK();
 303                 }
 304
 305                 drm_ctxbitmap_free(dev, ctx->handle);
 306         }
 307
 308         return 0;
 309 }