src/mesa/drivers/dri/common/dri_util.c

   1 /*
   2  * (C) Copyright IBM Corporation 2002, 2004
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * on the rights to use, copy, modify, merge, publish, distribute, sub
   9  * license, and/or sell copies of the Software, and to permit persons to whom
  10  * the Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
  20  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  21  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  22  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 /**
  26  * \file dri_util.c
  27  * DRI utility functions.
  28  *
  29  * This module acts as glue between GLX and the actual hardware driver.  A DRI
  30  * driver doesn't really \e have to use any of this - it's optional.  But, some
  31  * useful stuff is done here that otherwise would have to be duplicated in most
  32  * drivers.
  33  *
  34  * Basically, these utility functions take care of some of the dirty details of
  35  * screen initialization, context creation, context binding, DRM setup, etc.
  36  *
  37  * These functions are compiled into each DRI driver so libGL.so knows nothing
  38  * about them.
  39  */
  40
  41
  42 #include <stdbool.h>
  43 #include "dri_util.h"
  44 #include "utils.h"
  45 #include "util/xmlpool.h"
  46 #include "main/mtypes.h"
  47 #include "main/framebuffer.h"
  48 #include "main/version.h"
  49 #include "main/debug_output.h"
  50 #include "main/errors.h"
  51 #include "main/macros.h"
  52
  53 const char __dri2ConfigOptions[] =
  54    DRI_CONF_BEGIN
  55       DRI_CONF_SECTION_PERFORMANCE
  56          DRI_CONF_VBLANK_MODE(DRI_CONF_VBLANK_DEF_INTERVAL_1)
  57       DRI_CONF_SECTION_END
  58    DRI_CONF_END;
  59
  60 /*****************************************************************/
  61 /** \name Screen handling functions                              */
  62 /*****************************************************************/
  63 /*@{*/
  64
  65 static void
  66 setupLoaderExtensions(__DRIscreen *psp,
  67                       const __DRIextension **extensions)
  68 {
  69     int i;
  70
  71     for (i = 0; extensions[i]; i++) {
  72         if (strcmp(extensions[i]->name, __DRI_DRI2_LOADER) == 0)
  73             psp->dri2.loader = (__DRIdri2LoaderExtension *) extensions[i];
  74         if (strcmp(extensions[i]->name, __DRI_IMAGE_LOOKUP) == 0)
  75             psp->dri2.image = (__DRIimageLookupExtension *) extensions[i];
  76         if (strcmp(extensions[i]->name, __DRI_USE_INVALIDATE) == 0)
  77             psp->dri2.useInvalidate = (__DRIuseInvalidateExtension *) extensions[i];
  78         if (strcmp(extensions[i]->name, __DRI_BACKGROUND_CALLABLE) == 0)
  79             psp->dri2.backgroundCallable = (__DRIbackgroundCallableExtension *) extensions[i];
  80         if (strcmp(extensions[i]->name, __DRI_SWRAST_LOADER) == 0)
  81             psp->swrast_loader = (__DRIswrastLoaderExtension *) extensions[i];
  82         if (strcmp(extensions[i]->name, __DRI_IMAGE_LOADER) == 0)
  83            psp->image.loader = (__DRIimageLoaderExtension *) extensions[i];
  84     }
  85 }
  86
  87 /**
  88  * This pointer determines which driver API we'll use in the case of the
  89  * loader not passing us an explicit driver extensions list (that would,
  90  * itself, contain a pointer to a driver API.)
  91  *
  92  * A driver's driDriverGetExtensions_drivername() can update this pointer to
  93  * what it's returning, and a loader that is ignorant of createNewScreen2()
  94  * will get the correct driver screen created, as long as no other
  95  * driDriverGetExtensions() happened in between the first one and the
  96  * createNewScreen().
  97  *
  98  * This allows the X Server to not require the significant dri_interface.h
  99  * updates for doing createNewScreen2(), which would discourage backporting of
 100  * the X Server patches to support the new loader interface.
 101  */
 102 const struct __DriverAPIRec *globalDriverAPI = &driDriverAPI;
 103
 104 /**
 105  * This is the first entrypoint in the driver called by the DRI driver loader
 106  * after dlopen()ing it.
 107  *
 108  * It's used to create global state for the driver across contexts on the same
 109  * Display.
 110  */
 111 static __DRIscreen *
 112 driCreateNewScreen2(int scrn, int fd,
 113                     const __DRIextension **extensions,
 114                     const __DRIextension **driver_extensions,
 115                     const __DRIconfig ***driver_configs, void *data)
 116 {
 117     static const __DRIextension *emptyExtensionList[] = { NULL };
 118     __DRIscreen *psp;
 119
 120     psp = calloc(1, sizeof(*psp));
 121     if (!psp)
 122         return NULL;
 123
 124     /* By default, use the global driDriverAPI symbol (non-megadrivers). */
 125     psp->driver = globalDriverAPI;
 126
 127     /* If the driver exposes its vtable through its extensions list
 128      * (megadrivers), use that instead.
 129      */
 130     if (driver_extensions) {
 131        for (int i = 0; driver_extensions[i]; i++) {
 132           if (strcmp(driver_extensions[i]->name, __DRI_DRIVER_VTABLE) == 0) {
 133              psp->driver =
 134                 ((__DRIDriverVtableExtension *)driver_extensions[i])->vtable;
 135           }
 136        }
 137     }
 138
 139     setupLoaderExtensions(psp, extensions);
 140
 141     psp->loaderPrivate = data;
 142
 143     psp->extensions = emptyExtensionList;
 144     psp->fd = fd;
 145     psp->myNum = scrn;
 146
 147     /* Option parsing before ->InitScreen(), as some options apply there. */
 148     driParseOptionInfo(&psp->optionInfo, __dri2ConfigOptions);
 149     driParseConfigFiles(&psp->optionCache, &psp->optionInfo, psp->myNum, "dri2");
 150
 151     *driver_configs = psp->driver->InitScreen(psp);
 152     if (*driver_configs == NULL) {
 153         free(psp);
 154         return NULL;
 155     }
 156
 157     struct gl_constants consts = { 0 };
 158     gl_api api;
 159     unsigned version;
 160
 161     api = API_OPENGLES2;
 162     if (_mesa_override_gl_version_contextless(&consts, &api, &version))
 163        psp->max_gl_es2_version = version;
 164
 165     api = API_OPENGL_COMPAT;
 166     if (_mesa_override_gl_version_contextless(&consts, &api, &version)) {
 167        psp->max_gl_core_version = version;
 168        if (api == API_OPENGL_COMPAT)
 169           psp->max_gl_compat_version = version;
 170     }
 171
 172     psp->api_mask = 0;
 173     if (psp->max_gl_compat_version > 0)
 174        psp->api_mask |= (1 << __DRI_API_OPENGL);
 175     if (psp->max_gl_core_version > 0)
 176        psp->api_mask |= (1 << __DRI_API_OPENGL_CORE);
 177     if (psp->max_gl_es1_version > 0)
 178        psp->api_mask |= (1 << __DRI_API_GLES);
 179     if (psp->max_gl_es2_version > 0)
 180        psp->api_mask |= (1 << __DRI_API_GLES2);
 181     if (psp->max_gl_es2_version >= 30)
 182        psp->api_mask |= (1 << __DRI_API_GLES3);
 183
 184     return psp;
 185 }
 186
 187 static __DRIscreen *
 188 dri2CreateNewScreen(int scrn, int fd,
 189                     const __DRIextension **extensions,
 190                     const __DRIconfig ***driver_configs, void *data)
 191 {
 192    return driCreateNewScreen2(scrn, fd, extensions, NULL,
 193                                driver_configs, data);
 194 }
 195
 196 /** swrast driver createNewScreen entrypoint. */
 197 static __DRIscreen *
 198 driSWRastCreateNewScreen(int scrn, const __DRIextension **extensions,
 199                          const __DRIconfig ***driver_configs, void *data)
 200 {
 201    return driCreateNewScreen2(scrn, -1, extensions, NULL,
 202                                driver_configs, data);
 203 }
 204
 205 static __DRIscreen *
 206 driSWRastCreateNewScreen2(int scrn, const __DRIextension **extensions,
 207                           const __DRIextension **driver_extensions,
 208                           const __DRIconfig ***driver_configs, void *data)
 209 {
 210    return driCreateNewScreen2(scrn, -1, extensions, driver_extensions,
 211                                driver_configs, data);
 212 }
 213
 214 /**
 215  * Destroy the per-screen private information.
 216  *
 217  * \internal
 218  * This function calls __DriverAPIRec::DestroyScreen on \p screenPrivate, calls
 219  * drmClose(), and finally frees \p screenPrivate.
 220  */
 221 static void driDestroyScreen(__DRIscreen *psp)
 222 {
 223     if (psp) {
 224         /* No interaction with the X-server is possible at this point.  This
 225          * routine is called after XCloseDisplay, so there is no protocol
 226          * stream open to the X-server anymore.
 227          */
 228
 229         psp->driver->DestroyScreen(psp);
 230
 231         driDestroyOptionCache(&psp->optionCache);
 232         driDestroyOptionInfo(&psp->optionInfo);
 233
 234         free(psp);
 235     }
 236 }
 237
 238 static const __DRIextension **driGetExtensions(__DRIscreen *psp)
 239 {
 240     return psp->extensions;
 241 }
 242
 243 /*@}*/
 244
 245
 246 static bool
 247 validate_context_version(__DRIscreen *screen,
 248                          int mesa_api,
 249                          unsigned major_version,
 250                          unsigned minor_version,
 251                          unsigned *dri_ctx_error)
 252 {
 253    unsigned req_version = 10 * major_version + minor_version;
 254    unsigned max_version = 0;
 255
 256    switch (mesa_api) {
 257    case API_OPENGL_COMPAT:
 258       max_version = screen->max_gl_compat_version;
 259       break;
 260    case API_OPENGL_CORE:
 261       max_version = screen->max_gl_core_version;
 262       break;
 263    case API_OPENGLES:
 264       max_version = screen->max_gl_es1_version;
 265       break;
 266    case API_OPENGLES2:
 267       max_version = screen->max_gl_es2_version;
 268       break;
 269    default:
 270       max_version = 0;
 271       break;
 272    }
 273
 274    if (max_version == 0) {
 275       *dri_ctx_error = __DRI_CTX_ERROR_BAD_API;
 276       return false;
 277    } else if (req_version > max_version) {
 278       *dri_ctx_error = __DRI_CTX_ERROR_BAD_VERSION;
 279       return false;
 280    }
 281
 282    return true;
 283 }
 284
 285 /*****************************************************************/
 286 /** \name Context handling functions                             */
 287 /*****************************************************************/
 288 /*@{*/
 289
 290 static __DRIcontext *
 291 driCreateContextAttribs(__DRIscreen *screen, int api,
 292                         const __DRIconfig *config,
 293                         __DRIcontext *shared,
 294                         unsigned num_attribs,
 295                         const uint32_t *attribs,
 296                         unsigned *error,
 297                         void *data)
 298 {
 299     __DRIcontext *context;
 300     const struct gl_config *modes = (config != NULL) ? &config->modes : NULL;
 301     void *shareCtx = (shared != NULL) ? shared->driverPrivate : NULL;
 302     gl_api mesa_api;
 303     struct __DriverContextConfig ctx_config;
 304
 305     ctx_config.major_version = 1;
 306     ctx_config.minor_version = 0;
 307     ctx_config.flags = 0;
 308     ctx_config.attribute_mask = 0;
 309     ctx_config.priority = __DRI_CTX_PRIORITY_MEDIUM;
 310
 311     assert((num_attribs == 0) || (attribs != NULL));
 312
 313     if (!(screen->api_mask & (1 << api))) {
 314         *error = __DRI_CTX_ERROR_BAD_API;
 315         return NULL;
 316     }
 317
 318     switch (api) {
 319     case __DRI_API_OPENGL:
 320         mesa_api = API_OPENGL_COMPAT;
 321         break;
 322     case __DRI_API_GLES:
 323         mesa_api = API_OPENGLES;
 324         break;
 325     case __DRI_API_GLES2:
 326     case __DRI_API_GLES3:
 327         mesa_api = API_OPENGLES2;
 328         break;
 329     case __DRI_API_OPENGL_CORE:
 330         mesa_api = API_OPENGL_CORE;
 331         break;
 332     default:
 333         *error = __DRI_CTX_ERROR_BAD_API;
 334         return NULL;
 335     }
 336
 337     for (unsigned i = 0; i < num_attribs; i++) {
 338         switch (attribs[i * 2]) {
 339         case __DRI_CTX_ATTRIB_MAJOR_VERSION:
 340             ctx_config.major_version = attribs[i * 2 + 1];
 341             break;
 342         case __DRI_CTX_ATTRIB_MINOR_VERSION:
 343             ctx_config.minor_version = attribs[i * 2 + 1];
 344             break;
 345         case __DRI_CTX_ATTRIB_FLAGS:
 346             ctx_config.flags = attribs[i * 2 + 1];
 347             break;
 348         case __DRI_CTX_ATTRIB_RESET_STRATEGY:
 349             if (attribs[i * 2 + 1] != __DRI_CTX_RESET_NO_NOTIFICATION) {
 350                 ctx_config.attribute_mask |=
 351                     __DRIVER_CONTEXT_ATTRIB_RESET_STRATEGY;
 352                 ctx_config.reset_strategy = attribs[i * 2 + 1];
 353             } else {
 354                 ctx_config.attribute_mask &=
 355                     ~__DRIVER_CONTEXT_ATTRIB_RESET_STRATEGY;
 356             }
 357             break;
 358         case __DRI_CTX_ATTRIB_PRIORITY:
 359             ctx_config.attribute_mask |= __DRIVER_CONTEXT_ATTRIB_PRIORITY;
 360             ctx_config.priority = attribs[i * 2 + 1];
 361             break;
 362         case __DRI_CTX_ATTRIB_RELEASE_BEHAVIOR:
 363             if (attribs[i * 2 + 1] != __DRI_CTX_RELEASE_BEHAVIOR_FLUSH) {
 364                 ctx_config.attribute_mask |=
 365                     __DRIVER_CONTEXT_ATTRIB_RELEASE_BEHAVIOR;
 366                 ctx_config.release_behavior = attribs[i * 2 + 1];
 367             } else {
 368                 ctx_config.attribute_mask &=
 369                     ~__DRIVER_CONTEXT_ATTRIB_RELEASE_BEHAVIOR;
 370             }
 371             break;
 372         default:
 373             /* We can't create a context that satisfies the requirements of an
 374              * attribute that we don't understand.  Return failure.
 375              */
 376             assert(!"Should not get here.");
 377             *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 378             return NULL;
 379         }
 380     }
 381
 382     /* The specific Mesa driver may not support the GL_ARB_compatibilty
 383      * extension or the compatibility profile.  In that case, we treat an
 384      * API_OPENGL_COMPAT 3.1 as API_OPENGL_CORE. We reject API_OPENGL_COMPAT
 385      * 3.2+ in any case.
 386      */
 387     if (mesa_api == API_OPENGL_COMPAT &&
 388         ctx_config.major_version == 3 && ctx_config.minor_version == 1 &&
 389         screen->max_gl_compat_version < 31)
 390        mesa_api = API_OPENGL_CORE;
 391
 392     if (mesa_api == API_OPENGL_COMPAT
 393         && ((ctx_config.major_version > 3)
 394             || (ctx_config.major_version == 3 &&
 395                 ctx_config.minor_version >= 2))) {
 396        *error = __DRI_CTX_ERROR_BAD_API;
 397        return NULL;
 398     }
 399
 400     /* The latest version of EGL_KHR_create_context spec says:
 401      *
 402      *     "If the EGL_CONTEXT_OPENGL_DEBUG_BIT_KHR flag bit is set in
 403      *     EGL_CONTEXT_FLAGS_KHR, then a <debug context> will be created.
 404      *     [...] This bit is supported for OpenGL and OpenGL ES contexts.
 405      *
 406      * No other EGL_CONTEXT_OPENGL_*_BIT is legal for an ES context.
 407      *
 408      * However, Mesa's EGL layer translates the context attribute
 409      * EGL_CONTEXT_OPENGL_ROBUST_ACCESS into the context flag
 410      * __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS.  That attribute is legal for ES
 411      * (with EGL 1.5 or EGL_EXT_create_context_robustness) and GL (only with
 412      * EGL 1.5).
 413      *
 414      * From the EGL_EXT_create_context_robustness spec:
 415      *
 416      *     This extension is written against the OpenGL ES 2.0 Specification
 417      *     but can apply to OpenGL ES 1.1 and up.
 418      *
 419      * From the EGL 1.5 (2014.08.27) spec, p55:
 420      *
 421      *     If the EGL_CONTEXT_OPENGL_ROBUST_ACCESS attribute is set to
 422      *     EGL_TRUE, a context supporting robust buffer access will be created.
 423      *     OpenGL contexts must support the GL_ARB_robustness extension, or
 424      *     equivalent core API functional- ity. OpenGL ES contexts must support
 425      *     the GL_EXT_robustness extension, or equivalent core API
 426      *     functionality.
 427      */
 428     if (mesa_api != API_OPENGL_COMPAT
 429         && mesa_api != API_OPENGL_CORE
 430         && (ctx_config.flags & ~(__DRI_CTX_FLAG_DEBUG |
 431                                  __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS |
 432                                  __DRI_CTX_FLAG_NO_ERROR))) {
 433         *error = __DRI_CTX_ERROR_BAD_FLAG;
 434         return NULL;
 435     }
 436
 437     /* There are no forward-compatible contexts before OpenGL 3.0.  The
 438      * GLX_ARB_create_context spec says:
 439      *
 440      *     "Forward-compatible contexts are defined only for OpenGL versions
 441      *     3.0 and later."
 442      *
 443      * Forward-looking contexts are supported by silently converting the
 444      * requested API to API_OPENGL_CORE.
 445      *
 446      * In Mesa, a debug context is the same as a regular context.
 447      */
 448     if ((ctx_config.flags & __DRI_CTX_FLAG_FORWARD_COMPATIBLE) != 0) {
 449        mesa_api = API_OPENGL_CORE;
 450     }
 451
 452     const uint32_t allowed_flags = (__DRI_CTX_FLAG_DEBUG
 453                                     | __DRI_CTX_FLAG_FORWARD_COMPATIBLE
 454                                     | __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS
 455                                     | __DRI_CTX_FLAG_NO_ERROR);
 456     if (ctx_config.flags & ~allowed_flags) {
 457         *error = __DRI_CTX_ERROR_UNKNOWN_FLAG;
 458         return NULL;
 459     }
 460
 461     if (!validate_context_version(screen, mesa_api,
 462                                   ctx_config.major_version,
 463                                   ctx_config.minor_version,
 464                                   error))
 465        return NULL;
 466
 467     context = calloc(1, sizeof *context);
 468     if (!context) {
 469         *error = __DRI_CTX_ERROR_NO_MEMORY;
 470         return NULL;
 471     }
 472
 473     context->loaderPrivate = data;
 474
 475     context->driScreenPriv = screen;
 476     context->driDrawablePriv = NULL;
 477     context->driReadablePriv = NULL;
 478
 479     if (!screen->driver->CreateContext(mesa_api, modes, context,
 480                                        &ctx_config, error, shareCtx)) {
 481         free(context);
 482         return NULL;
 483     }
 484
 485     *error = __DRI_CTX_ERROR_SUCCESS;
 486     return context;
 487 }
 488
 489 void
 490 driContextSetFlags(struct gl_context *ctx, uint32_t flags)
 491 {
 492     if ((flags & __DRI_CTX_FLAG_FORWARD_COMPATIBLE) != 0)
 493         ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT;
 494     if ((flags & __DRI_CTX_FLAG_DEBUG) != 0) {
 495        _mesa_set_debug_state_int(ctx, GL_DEBUG_OUTPUT, GL_TRUE);
 496         ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_DEBUG_BIT;
 497     }
 498     if ((flags & __DRI_CTX_FLAG_NO_ERROR) != 0)
 499         ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_NO_ERROR_BIT_KHR;
 500 }
 501
 502 static __DRIcontext *
 503 driCreateNewContextForAPI(__DRIscreen *screen, int api,
 504                           const __DRIconfig *config,
 505                           __DRIcontext *shared, void *data)
 506 {
 507     unsigned error;
 508
 509     return driCreateContextAttribs(screen, api, config, shared, 0, NULL,
 510                                    &error, data);
 511 }
 512
 513 static __DRIcontext *
 514 driCreateNewContext(__DRIscreen *screen, const __DRIconfig *config,
 515                     __DRIcontext *shared, void *data)
 516 {
 517     return driCreateNewContextForAPI(screen, __DRI_API_OPENGL,
 518                                      config, shared, data);
 519 }
 520
 521 /**
 522  * Destroy the per-context private information.
 523  *
 524  * \internal
 525  * This function calls __DriverAPIRec::DestroyContext on \p contextPrivate, calls
 526  * drmDestroyContext(), and finally frees \p contextPrivate.
 527  */
 528 static void
 529 driDestroyContext(__DRIcontext *pcp)
 530 {
 531     if (pcp) {
 532         pcp->driScreenPriv->driver->DestroyContext(pcp);
 533         free(pcp);
 534     }
 535 }
 536
 537 static int
 538 driCopyContext(__DRIcontext *dest, __DRIcontext *src, unsigned long mask)
 539 {
 540     (void) dest;
 541     (void) src;
 542     (void) mask;
 543     return GL_FALSE;
 544 }
 545
 546 /*@}*/
 547
 548
 549 /*****************************************************************/
 550 /** \name Context (un)binding functions                          */
 551 /*****************************************************************/
 552 /*@{*/
 553
 554 static void dri_get_drawable(__DRIdrawable *pdp);
 555 static void dri_put_drawable(__DRIdrawable *pdp);
 556
 557 /**
 558  * This function takes both a read buffer and a draw buffer.  This is needed
 559  * for \c glXMakeCurrentReadSGI or GLX 1.3's \c glXMakeContextCurrent
 560  * function.
 561  */
 562 static int driBindContext(__DRIcontext *pcp,
 563                           __DRIdrawable *pdp,
 564                           __DRIdrawable *prp)
 565 {
 566     /*
 567     ** Assume error checking is done properly in glXMakeCurrent before
 568     ** calling driUnbindContext.
 569     */
 570
 571     if (!pcp)
 572         return GL_FALSE;
 573
 574     /* Bind the drawable to the context */
 575     pcp->driDrawablePriv = pdp;
 576     pcp->driReadablePriv = prp;
 577     if (pdp) {
 578         pdp->driContextPriv = pcp;
 579         dri_get_drawable(pdp);
 580     }
 581     if (prp && pdp != prp) {
 582         dri_get_drawable(prp);
 583     }
 584
 585     return pcp->driScreenPriv->driver->MakeCurrent(pcp, pdp, prp);
 586 }
 587
 588 /**
 589  * Unbind context.
 590  *
 591  * \param scrn the screen.
 592  * \param gc context.
 593  *
 594  * \return \c GL_TRUE on success, or \c GL_FALSE on failure.
 595  *
 596  * \internal
 597  * This function calls __DriverAPIRec::UnbindContext, and then decrements
 598  * __DRIdrawableRec::refcount which must be non-zero for a successful
 599  * return.
 600  *
 601  * While casting the opaque private pointers associated with the parameters
 602  * into their respective real types it also assures they are not \c NULL.
 603  */
 604 static int driUnbindContext(__DRIcontext *pcp)
 605 {
 606     __DRIdrawable *pdp;
 607     __DRIdrawable *prp;
 608
 609     /*
 610     ** Assume error checking is done properly in glXMakeCurrent before
 611     ** calling driUnbindContext.
 612     */
 613
 614     if (pcp == NULL)
 615         return GL_FALSE;
 616
 617     /*
 618     ** Call driUnbindContext before checking for valid drawables
 619     ** to handle surfaceless contexts properly.
 620     */
 621     pcp->driScreenPriv->driver->UnbindContext(pcp);
 622
 623     pdp = pcp->driDrawablePriv;
 624     prp = pcp->driReadablePriv;
 625
 626     /* already unbound */
 627     if (!pdp && !prp)
 628         return GL_TRUE;
 629
 630     assert(pdp);
 631     if (pdp->refcount == 0) {
 632         /* ERROR!!! */
 633         return GL_FALSE;
 634     }
 635
 636     dri_put_drawable(pdp);
 637
 638     if (prp != pdp) {
 639         if (prp->refcount == 0) {
 640             /* ERROR!!! */
 641             return GL_FALSE;
 642         }
 643
 644         dri_put_drawable(prp);
 645     }
 646
 647     pcp->driDrawablePriv = NULL;
 648     pcp->driReadablePriv = NULL;
 649
 650     return GL_TRUE;
 651 }
 652
 653 /*@}*/
 654
 655
 656 static void dri_get_drawable(__DRIdrawable *pdp)
 657 {
 658     pdp->refcount++;
 659 }
 660
 661 static void dri_put_drawable(__DRIdrawable *pdp)
 662 {
 663     if (pdp) {
 664         pdp->refcount--;
 665         if (pdp->refcount)
 666             return;
 667
 668         pdp->driScreenPriv->driver->DestroyBuffer(pdp);
 669         free(pdp);
 670     }
 671 }
 672
 673 static __DRIdrawable *
 674 driCreateNewDrawable(__DRIscreen *screen,
 675                      const __DRIconfig *config,
 676                      void *data)
 677 {
 678     __DRIdrawable *pdraw;
 679
 680     assert(data != NULL);
 681
 682     pdraw = malloc(sizeof *pdraw);
 683     if (!pdraw)
 684         return NULL;
 685
 686     pdraw->loaderPrivate = data;
 687
 688     pdraw->driScreenPriv = screen;
 689     pdraw->driContextPriv = NULL;
 690     pdraw->refcount = 0;
 691     pdraw->lastStamp = 0;
 692     pdraw->w = 0;
 693     pdraw->h = 0;
 694
 695     dri_get_drawable(pdraw);
 696
 697     if (!screen->driver->CreateBuffer(screen, pdraw, &config->modes,
 698                                       GL_FALSE)) {
 699        free(pdraw);
 700        return NULL;
 701     }
 702
 703     pdraw->dri2.stamp = pdraw->lastStamp + 1;
 704
 705     return pdraw;
 706 }
 707
 708 static void
 709 driDestroyDrawable(__DRIdrawable *pdp)
 710 {
 711     /*
 712      * The loader's data structures are going away, even if pdp itself stays
 713      * around for the time being because it is currently bound. This happens
 714      * when a currently bound GLX pixmap is destroyed.
 715      *
 716      * Clear out the pointer back into the loader's data structures to avoid
 717      * accessing an outdated pointer.
 718      */
 719     pdp->loaderPrivate = NULL;
 720
 721     dri_put_drawable(pdp);
 722 }
 723
 724 static __DRIbuffer *
 725 dri2AllocateBuffer(__DRIscreen *screen,
 726                    unsigned int attachment, unsigned int format,
 727                    int width, int height)
 728 {
 729     return screen->driver->AllocateBuffer(screen, attachment, format,
 730                                           width, height);
 731 }
 732
 733 static void
 734 dri2ReleaseBuffer(__DRIscreen *screen, __DRIbuffer *buffer)
 735 {
 736     screen->driver->ReleaseBuffer(screen, buffer);
 737 }
 738
 739
 740 static int
 741 dri2ConfigQueryb(__DRIscreen *screen, const char *var, unsigned char *val)
 742 {
 743    if (!driCheckOption(&screen->optionCache, var, DRI_BOOL))
 744       return -1;
 745
 746    *val = driQueryOptionb(&screen->optionCache, var);
 747
 748    return 0;
 749 }
 750
 751 static int
 752 dri2ConfigQueryi(__DRIscreen *screen, const char *var, int *val)
 753 {
 754    if (!driCheckOption(&screen->optionCache, var, DRI_INT) &&
 755        !driCheckOption(&screen->optionCache, var, DRI_ENUM))
 756       return -1;
 757
 758     *val = driQueryOptioni(&screen->optionCache, var);
 759
 760     return 0;
 761 }
 762
 763 static int
 764 dri2ConfigQueryf(__DRIscreen *screen, const char *var, float *val)
 765 {
 766    if (!driCheckOption(&screen->optionCache, var, DRI_FLOAT))
 767       return -1;
 768
 769     *val = driQueryOptionf(&screen->optionCache, var);
 770
 771     return 0;
 772 }
 773
 774 static unsigned int
 775 driGetAPIMask(__DRIscreen *screen)
 776 {
 777     return screen->api_mask;
 778 }
 779
 780 /**
 781  * swrast swapbuffers entrypoint.
 782  *
 783  * DRI2 implements this inside the loader with only flushes handled by the
 784  * driver.
 785  */
 786 static void
 787 driSwapBuffers(__DRIdrawable *pdp)
 788 {
 789     assert(pdp->driScreenPriv->swrast_loader);
 790
 791     pdp->driScreenPriv->driver->SwapBuffers(pdp);
 792 }
 793
 794 /** Core interface */
 795 const __DRIcoreExtension driCoreExtension = {
 796     .base = { __DRI_CORE, 2 },
 797
 798     .createNewScreen            = NULL,
 799     .destroyScreen              = driDestroyScreen,
 800     .getExtensions              = driGetExtensions,
 801     .getConfigAttrib            = driGetConfigAttrib,
 802     .indexConfigAttrib          = driIndexConfigAttrib,
 803     .createNewDrawable          = NULL,
 804     .destroyDrawable            = driDestroyDrawable,
 805     .swapBuffers                = driSwapBuffers, /* swrast */
 806     .createNewContext           = driCreateNewContext, /* swrast */
 807     .copyContext                = driCopyContext,
 808     .destroyContext             = driDestroyContext,
 809     .bindContext                = driBindContext,
 810     .unbindContext              = driUnbindContext
 811 };
 812
 813 /** DRI2 interface */
 814 const __DRIdri2Extension driDRI2Extension = {
 815     .base = { __DRI_DRI2, 4 },
 816
 817     .createNewScreen            = dri2CreateNewScreen,
 818     .createNewDrawable          = driCreateNewDrawable,
 819     .createNewContext           = driCreateNewContext,
 820     .getAPIMask                 = driGetAPIMask,
 821     .createNewContextForAPI     = driCreateNewContextForAPI,
 822     .allocateBuffer             = dri2AllocateBuffer,
 823     .releaseBuffer              = dri2ReleaseBuffer,
 824     .createContextAttribs       = driCreateContextAttribs,
 825     .createNewScreen2           = driCreateNewScreen2,
 826 };
 827
 828 const __DRIswrastExtension driSWRastExtension = {
 829     .base = { __DRI_SWRAST, 4 },
 830
 831     .createNewScreen            = driSWRastCreateNewScreen,
 832     .createNewDrawable          = driCreateNewDrawable,
 833     .createNewContextForAPI     = driCreateNewContextForAPI,
 834     .createContextAttribs       = driCreateContextAttribs,
 835     .createNewScreen2           = driSWRastCreateNewScreen2,
 836 };
 837
 838 const __DRI2configQueryExtension dri2ConfigQueryExtension = {
 839    .base = { __DRI2_CONFIG_QUERY, 1 },
 840
 841    .configQueryb        = dri2ConfigQueryb,
 842    .configQueryi        = dri2ConfigQueryi,
 843    .configQueryf        = dri2ConfigQueryf,
 844 };
 845
 846 const __DRI2flushControlExtension dri2FlushControlExtension = {
 847    .base = { __DRI2_FLUSH_CONTROL, 1 }
 848 };
 849
 850 void
 851 dri2InvalidateDrawable(__DRIdrawable *drawable)
 852 {
 853     drawable->dri2.stamp++;
 854 }
 855
 856 /**
 857  * Check that the gl_framebuffer associated with dPriv is the right size.
 858  * Resize the gl_framebuffer if needed.
 859  * It's expected that the dPriv->driverPrivate member points to a
 860  * gl_framebuffer object.
 861  */
 862 void
 863 driUpdateFramebufferSize(struct gl_context *ctx, const __DRIdrawable *dPriv)
 864 {
 865    struct gl_framebuffer *fb = (struct gl_framebuffer *) dPriv->driverPrivate;
 866    if (fb && (dPriv->w != fb->Width || dPriv->h != fb->Height)) {
 867       _mesa_resize_framebuffer(ctx, fb, dPriv->w, dPriv->h);
 868       /* if the driver needs the hw lock for ResizeBuffers, the drawable
 869          might have changed again by now */
 870       assert(fb->Width == dPriv->w);
 871       assert(fb->Height == dPriv->h);
 872    }
 873 }
 874
 875 uint32_t
 876 driGLFormatToImageFormat(mesa_format format)
 877 {
 878    switch (format) {
 879    case MESA_FORMAT_B5G6R5_UNORM:
 880       return __DRI_IMAGE_FORMAT_RGB565;
 881    case MESA_FORMAT_B5G5R5A1_UNORM:
 882       return __DRI_IMAGE_FORMAT_ARGB1555;
 883    case MESA_FORMAT_B8G8R8X8_UNORM:
 884       return __DRI_IMAGE_FORMAT_XRGB8888;
 885    case MESA_FORMAT_B10G10R10A2_UNORM:
 886       return __DRI_IMAGE_FORMAT_ARGB2101010;
 887    case MESA_FORMAT_B10G10R10X2_UNORM:
 888       return __DRI_IMAGE_FORMAT_XRGB2101010;
 889    case MESA_FORMAT_B8G8R8A8_UNORM:
 890       return __DRI_IMAGE_FORMAT_ARGB8888;
 891    case MESA_FORMAT_R8G8B8A8_UNORM:
 892       return __DRI_IMAGE_FORMAT_ABGR8888;
 893    case MESA_FORMAT_R8G8B8X8_UNORM:
 894       return __DRI_IMAGE_FORMAT_XBGR8888;
 895    case MESA_FORMAT_L_UNORM8:
 896    case MESA_FORMAT_R_UNORM8:
 897       return __DRI_IMAGE_FORMAT_R8;
 898    case MESA_FORMAT_L8A8_UNORM:
 899    case MESA_FORMAT_R8G8_UNORM:
 900       return __DRI_IMAGE_FORMAT_GR88;
 901    case MESA_FORMAT_NONE:
 902       return __DRI_IMAGE_FORMAT_NONE;
 903    case MESA_FORMAT_R8G8B8A8_SRGB:
 904       return __DRI_IMAGE_FORMAT_SABGR8;
 905    case MESA_FORMAT_B8G8R8A8_SRGB:
 906       return __DRI_IMAGE_FORMAT_SARGB8;
 907    default:
 908       return 0;
 909    }
 910 }
 911
 912 mesa_format
 913 driImageFormatToGLFormat(uint32_t image_format)
 914 {
 915    switch (image_format) {
 916    case __DRI_IMAGE_FORMAT_RGB565:
 917       return MESA_FORMAT_B5G6R5_UNORM;
 918    case __DRI_IMAGE_FORMAT_ARGB1555:
 919       return MESA_FORMAT_B5G5R5A1_UNORM;
 920    case __DRI_IMAGE_FORMAT_XRGB8888:
 921       return MESA_FORMAT_B8G8R8X8_UNORM;
 922    case __DRI_IMAGE_FORMAT_ARGB2101010:
 923       return MESA_FORMAT_B10G10R10A2_UNORM;
 924    case __DRI_IMAGE_FORMAT_XRGB2101010:
 925       return MESA_FORMAT_B10G10R10X2_UNORM;
 926    case __DRI_IMAGE_FORMAT_ARGB8888:
 927       return MESA_FORMAT_B8G8R8A8_UNORM;
 928    case __DRI_IMAGE_FORMAT_ABGR8888:
 929       return MESA_FORMAT_R8G8B8A8_UNORM;
 930    case __DRI_IMAGE_FORMAT_XBGR8888:
 931       return MESA_FORMAT_R8G8B8X8_UNORM;
 932    case __DRI_IMAGE_FORMAT_R8:
 933       return MESA_FORMAT_R_UNORM8;
 934    case __DRI_IMAGE_FORMAT_R16:
 935       return MESA_FORMAT_R_UNORM16;
 936    case __DRI_IMAGE_FORMAT_GR88:
 937       return MESA_FORMAT_R8G8_UNORM;
 938    case __DRI_IMAGE_FORMAT_GR1616:
 939       return MESA_FORMAT_R16G16_UNORM;
 940    case __DRI_IMAGE_FORMAT_SARGB8:
 941       return MESA_FORMAT_B8G8R8A8_SRGB;
 942    case __DRI_IMAGE_FORMAT_SABGR8:
 943       return MESA_FORMAT_R8G8B8A8_SRGB;
 944    case __DRI_IMAGE_FORMAT_NONE:
 945       return MESA_FORMAT_NONE;
 946    default:
 947       return MESA_FORMAT_NONE;
 948    }
 949 }
 950
 951 /** Image driver interface */
 952 const __DRIimageDriverExtension driImageDriverExtension = {
 953     .base = { __DRI_IMAGE_DRIVER, 1 },
 954
 955     .createNewScreen2           = driCreateNewScreen2,
 956     .createNewDrawable          = driCreateNewDrawable,
 957     .getAPIMask                 = driGetAPIMask,
 958     .createContextAttribs       = driCreateContextAttribs,
 959 };
 960
 961 /* swrast copy sub buffer entrypoint. */
 962 static void driCopySubBuffer(__DRIdrawable *pdp, int x, int y,
 963                              int w, int h)
 964 {
 965     assert(pdp->driScreenPriv->swrast_loader);
 966
 967     pdp->driScreenPriv->driver->CopySubBuffer(pdp, x, y, w, h);
 968 }
 969
 970 /* for swrast only */
 971 const __DRIcopySubBufferExtension driCopySubBufferExtension = {
 972    .base = { __DRI_COPY_SUB_BUFFER, 1 },
 973
 974    .copySubBuffer               = driCopySubBuffer,
 975 };
 976
 977 const __DRInoErrorExtension dri2NoErrorExtension = {
 978    .base = { __DRI2_NO_ERROR, 1 },
 979 };