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/u_endian.h"
  46 #include "util/xmlpool.h"
  47 #include "main/mtypes.h"
  48 #include "main/framebuffer.h"
  49 #include "main/version.h"
  50 #include "main/debug_output.h"
  51 #include "main/errors.h"
  52 #include "main/macros.h"
  53
  54 const char __dri2ConfigOptions[] =
  55    DRI_CONF_BEGIN
  56       DRI_CONF_SECTION_PERFORMANCE
  57          DRI_CONF_VBLANK_MODE(DRI_CONF_VBLANK_DEF_INTERVAL_1)
  58       DRI_CONF_SECTION_END
  59    DRI_CONF_END;
  60
  61 /*****************************************************************/
  62 /** \name Screen handling functions                              */
  63 /*****************************************************************/
  64 /*@{*/
  65
  66 static void
  67 setupLoaderExtensions(__DRIscreen *psp,
  68                       const __DRIextension **extensions)
  69 {
  70     int i;
  71
  72     for (i = 0; extensions[i]; i++) {
  73         if (strcmp(extensions[i]->name, __DRI_DRI2_LOADER) == 0)
  74             psp->dri2.loader = (__DRIdri2LoaderExtension *) extensions[i];
  75         if (strcmp(extensions[i]->name, __DRI_IMAGE_LOOKUP) == 0)
  76             psp->dri2.image = (__DRIimageLookupExtension *) extensions[i];
  77         if (strcmp(extensions[i]->name, __DRI_USE_INVALIDATE) == 0)
  78             psp->dri2.useInvalidate = (__DRIuseInvalidateExtension *) extensions[i];
  79         if (strcmp(extensions[i]->name, __DRI_BACKGROUND_CALLABLE) == 0)
  80             psp->dri2.backgroundCallable = (__DRIbackgroundCallableExtension *) extensions[i];
  81         if (strcmp(extensions[i]->name, __DRI_SWRAST_LOADER) == 0)
  82             psp->swrast_loader = (__DRIswrastLoaderExtension *) extensions[i];
  83         if (strcmp(extensions[i]->name, __DRI_IMAGE_LOADER) == 0)
  84            psp->image.loader = (__DRIimageLoaderExtension *) extensions[i];
  85         if (strcmp(extensions[i]->name, __DRI_MUTABLE_RENDER_BUFFER_LOADER) == 0)
  86            psp->mutableRenderBuffer.loader = (__DRImutableRenderBufferLoaderExtension *) extensions[i];
  87     }
  88 }
  89
  90 /**
  91  * This pointer determines which driver API we'll use in the case of the
  92  * loader not passing us an explicit driver extensions list (that would,
  93  * itself, contain a pointer to a driver API.)
  94  *
  95  * A driver's driDriverGetExtensions_drivername() can update this pointer to
  96  * what it's returning, and a loader that is ignorant of createNewScreen2()
  97  * will get the correct driver screen created, as long as no other
  98  * driDriverGetExtensions() happened in between the first one and the
  99  * createNewScreen().
 100  *
 101  * This allows the X Server to not require the significant dri_interface.h
 102  * updates for doing createNewScreen2(), which would discourage backporting of
 103  * the X Server patches to support the new loader interface.
 104  */
 105 const struct __DriverAPIRec *globalDriverAPI = &driDriverAPI;
 106
 107 /**
 108  * This is the first entrypoint in the driver called by the DRI driver loader
 109  * after dlopen()ing it.
 110  *
 111  * It's used to create global state for the driver across contexts on the same
 112  * Display.
 113  */
 114 static __DRIscreen *
 115 driCreateNewScreen2(int scrn, int fd,
 116                     const __DRIextension **extensions,
 117                     const __DRIextension **driver_extensions,
 118                     const __DRIconfig ***driver_configs, void *data)
 119 {
 120     static const __DRIextension *emptyExtensionList[] = { NULL };
 121     __DRIscreen *psp;
 122
 123     psp = calloc(1, sizeof(*psp));
 124     if (!psp)
 125         return NULL;
 126
 127     /* By default, use the global driDriverAPI symbol (non-megadrivers). */
 128     psp->driver = globalDriverAPI;
 129
 130     /* If the driver exposes its vtable through its extensions list
 131      * (megadrivers), use that instead.
 132      */
 133     if (driver_extensions) {
 134        for (int i = 0; driver_extensions[i]; i++) {
 135           if (strcmp(driver_extensions[i]->name, __DRI_DRIVER_VTABLE) == 0) {
 136              psp->driver =
 137                 ((__DRIDriverVtableExtension *)driver_extensions[i])->vtable;
 138           }
 139        }
 140     }
 141
 142     setupLoaderExtensions(psp, extensions);
 143
 144     psp->loaderPrivate = data;
 145
 146     psp->extensions = emptyExtensionList;
 147     psp->fd = fd;
 148     psp->myNum = scrn;
 149
 150     /* Option parsing before ->InitScreen(), as some options apply there. */
 151     driParseOptionInfo(&psp->optionInfo, __dri2ConfigOptions);
 152     driParseConfigFiles(&psp->optionCache, &psp->optionInfo, psp->myNum,
 153                         "dri2", NULL, NULL, 0);
 154
 155     *driver_configs = psp->driver->InitScreen(psp);
 156     if (*driver_configs == NULL) {
 157         free(psp);
 158         return NULL;
 159     }
 160
 161     struct gl_constants consts = { 0 };
 162     gl_api api;
 163     unsigned version;
 164
 165     api = API_OPENGLES2;
 166     if (_mesa_override_gl_version_contextless(&consts, &api, &version))
 167        psp->max_gl_es2_version = version;
 168
 169     api = API_OPENGL_COMPAT;
 170     if (_mesa_override_gl_version_contextless(&consts, &api, &version)) {
 171        psp->max_gl_core_version = version;
 172        if (api == API_OPENGL_COMPAT)
 173           psp->max_gl_compat_version = version;
 174     }
 175
 176     psp->api_mask = 0;
 177     if (psp->max_gl_compat_version > 0)
 178        psp->api_mask |= (1 << __DRI_API_OPENGL);
 179     if (psp->max_gl_core_version > 0)
 180        psp->api_mask |= (1 << __DRI_API_OPENGL_CORE);
 181     if (psp->max_gl_es1_version > 0)
 182        psp->api_mask |= (1 << __DRI_API_GLES);
 183     if (psp->max_gl_es2_version > 0)
 184        psp->api_mask |= (1 << __DRI_API_GLES2);
 185     if (psp->max_gl_es2_version >= 30)
 186        psp->api_mask |= (1 << __DRI_API_GLES3);
 187
 188     return psp;
 189 }
 190
 191 static __DRIscreen *
 192 dri2CreateNewScreen(int scrn, int fd,
 193                     const __DRIextension **extensions,
 194                     const __DRIconfig ***driver_configs, void *data)
 195 {
 196    return driCreateNewScreen2(scrn, fd, extensions, NULL,
 197                                driver_configs, data);
 198 }
 199
 200 /** swrast driver createNewScreen entrypoint. */
 201 static __DRIscreen *
 202 driSWRastCreateNewScreen(int scrn, const __DRIextension **extensions,
 203                          const __DRIconfig ***driver_configs, void *data)
 204 {
 205    return driCreateNewScreen2(scrn, -1, extensions, NULL,
 206                                driver_configs, data);
 207 }
 208
 209 static __DRIscreen *
 210 driSWRastCreateNewScreen2(int scrn, const __DRIextension **extensions,
 211                           const __DRIextension **driver_extensions,
 212                           const __DRIconfig ***driver_configs, void *data)
 213 {
 214    return driCreateNewScreen2(scrn, -1, extensions, driver_extensions,
 215                                driver_configs, data);
 216 }
 217
 218 /**
 219  * Destroy the per-screen private information.
 220  *
 221  * \internal
 222  * This function calls __DriverAPIRec::DestroyScreen on \p screenPrivate, calls
 223  * drmClose(), and finally frees \p screenPrivate.
 224  */
 225 static void driDestroyScreen(__DRIscreen *psp)
 226 {
 227     if (psp) {
 228         /* No interaction with the X-server is possible at this point.  This
 229          * routine is called after XCloseDisplay, so there is no protocol
 230          * stream open to the X-server anymore.
 231          */
 232
 233         psp->driver->DestroyScreen(psp);
 234
 235         driDestroyOptionCache(&psp->optionCache);
 236         driDestroyOptionInfo(&psp->optionInfo);
 237
 238         free(psp);
 239     }
 240 }
 241
 242 static const __DRIextension **driGetExtensions(__DRIscreen *psp)
 243 {
 244     return psp->extensions;
 245 }
 246
 247 /*@}*/
 248
 249
 250 static bool
 251 validate_context_version(__DRIscreen *screen,
 252                          int mesa_api,
 253                          unsigned major_version,
 254                          unsigned minor_version,
 255                          unsigned *dri_ctx_error)
 256 {
 257    unsigned req_version = 10 * major_version + minor_version;
 258    unsigned max_version = 0;
 259
 260    switch (mesa_api) {
 261    case API_OPENGL_COMPAT:
 262       max_version = screen->max_gl_compat_version;
 263       break;
 264    case API_OPENGL_CORE:
 265       max_version = screen->max_gl_core_version;
 266       break;
 267    case API_OPENGLES:
 268       max_version = screen->max_gl_es1_version;
 269       break;
 270    case API_OPENGLES2:
 271       max_version = screen->max_gl_es2_version;
 272       break;
 273    default:
 274       max_version = 0;
 275       break;
 276    }
 277
 278    if (max_version == 0) {
 279       *dri_ctx_error = __DRI_CTX_ERROR_BAD_API;
 280       return false;
 281    } else if (req_version > max_version) {
 282       *dri_ctx_error = __DRI_CTX_ERROR_BAD_VERSION;
 283       return false;
 284    }
 285
 286    return true;
 287 }
 288
 289 /*****************************************************************/
 290 /** \name Context handling functions                             */
 291 /*****************************************************************/
 292 /*@{*/
 293
 294 static __DRIcontext *
 295 driCreateContextAttribs(__DRIscreen *screen, int api,
 296                         const __DRIconfig *config,
 297                         __DRIcontext *shared,
 298                         unsigned num_attribs,
 299                         const uint32_t *attribs,
 300                         unsigned *error,
 301                         void *data)
 302 {
 303     __DRIcontext *context;
 304     const struct gl_config *modes = (config != NULL) ? &config->modes : NULL;
 305     void *shareCtx = (shared != NULL) ? shared->driverPrivate : NULL;
 306     gl_api mesa_api;
 307     struct __DriverContextConfig ctx_config;
 308
 309     ctx_config.major_version = 1;
 310     ctx_config.minor_version = 0;
 311     ctx_config.flags = 0;
 312     ctx_config.attribute_mask = 0;
 313     ctx_config.priority = __DRI_CTX_PRIORITY_MEDIUM;
 314
 315     assert((num_attribs == 0) || (attribs != NULL));
 316
 317     if (!(screen->api_mask & (1 << api))) {
 318         *error = __DRI_CTX_ERROR_BAD_API;
 319         return NULL;
 320     }
 321
 322     switch (api) {
 323     case __DRI_API_OPENGL:
 324         mesa_api = API_OPENGL_COMPAT;
 325         break;
 326     case __DRI_API_GLES:
 327         mesa_api = API_OPENGLES;
 328         break;
 329     case __DRI_API_GLES2:
 330     case __DRI_API_GLES3:
 331         mesa_api = API_OPENGLES2;
 332         break;
 333     case __DRI_API_OPENGL_CORE:
 334         mesa_api = API_OPENGL_CORE;
 335         break;
 336     default:
 337         *error = __DRI_CTX_ERROR_BAD_API;
 338         return NULL;
 339     }
 340
 341     for (unsigned i = 0; i < num_attribs; i++) {
 342         switch (attribs[i * 2]) {
 343         case __DRI_CTX_ATTRIB_MAJOR_VERSION:
 344             ctx_config.major_version = attribs[i * 2 + 1];
 345             break;
 346         case __DRI_CTX_ATTRIB_MINOR_VERSION:
 347             ctx_config.minor_version = attribs[i * 2 + 1];
 348             break;
 349         case __DRI_CTX_ATTRIB_FLAGS:
 350             ctx_config.flags = attribs[i * 2 + 1];
 351             break;
 352         case __DRI_CTX_ATTRIB_RESET_STRATEGY:
 353             if (attribs[i * 2 + 1] != __DRI_CTX_RESET_NO_NOTIFICATION) {
 354                 ctx_config.attribute_mask |=
 355                     __DRIVER_CONTEXT_ATTRIB_RESET_STRATEGY;
 356                 ctx_config.reset_strategy = attribs[i * 2 + 1];
 357             } else {
 358                 ctx_config.attribute_mask &=
 359                     ~__DRIVER_CONTEXT_ATTRIB_RESET_STRATEGY;
 360             }
 361             break;
 362         case __DRI_CTX_ATTRIB_PRIORITY:
 363             ctx_config.attribute_mask |= __DRIVER_CONTEXT_ATTRIB_PRIORITY;
 364             ctx_config.priority = attribs[i * 2 + 1];
 365             break;
 366         case __DRI_CTX_ATTRIB_RELEASE_BEHAVIOR:
 367             if (attribs[i * 2 + 1] != __DRI_CTX_RELEASE_BEHAVIOR_FLUSH) {
 368                 ctx_config.attribute_mask |=
 369                     __DRIVER_CONTEXT_ATTRIB_RELEASE_BEHAVIOR;
 370                 ctx_config.release_behavior = attribs[i * 2 + 1];
 371             } else {
 372                 ctx_config.attribute_mask &=
 373                     ~__DRIVER_CONTEXT_ATTRIB_RELEASE_BEHAVIOR;
 374             }
 375             break;
 376         default:
 377             /* We can't create a context that satisfies the requirements of an
 378              * attribute that we don't understand.  Return failure.
 379              */
 380             assert(!"Should not get here.");
 381             *error = __DRI_CTX_ERROR_UNKNOWN_ATTRIBUTE;
 382             return NULL;
 383         }
 384     }
 385
 386     /* The specific Mesa driver may not support the GL_ARB_compatibilty
 387      * extension or the compatibility profile.  In that case, we treat an
 388      * API_OPENGL_COMPAT 3.1 as API_OPENGL_CORE. We reject API_OPENGL_COMPAT
 389      * 3.2+ in any case.
 390      */
 391     if (mesa_api == API_OPENGL_COMPAT &&
 392         ctx_config.major_version == 3 && ctx_config.minor_version == 1 &&
 393         screen->max_gl_compat_version < 31)
 394        mesa_api = API_OPENGL_CORE;
 395
 396     /* The latest version of EGL_KHR_create_context spec says:
 397      *
 398      *     "If the EGL_CONTEXT_OPENGL_DEBUG_BIT_KHR flag bit is set in
 399      *     EGL_CONTEXT_FLAGS_KHR, then a <debug context> will be created.
 400      *     [...] This bit is supported for OpenGL and OpenGL ES contexts.
 401      *
 402      * No other EGL_CONTEXT_OPENGL_*_BIT is legal for an ES context.
 403      *
 404      * However, Mesa's EGL layer translates the context attribute
 405      * EGL_CONTEXT_OPENGL_ROBUST_ACCESS into the context flag
 406      * __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS.  That attribute is legal for ES
 407      * (with EGL 1.5 or EGL_EXT_create_context_robustness) and GL (only with
 408      * EGL 1.5).
 409      *
 410      * From the EGL_EXT_create_context_robustness spec:
 411      *
 412      *     This extension is written against the OpenGL ES 2.0 Specification
 413      *     but can apply to OpenGL ES 1.1 and up.
 414      *
 415      * From the EGL 1.5 (2014.08.27) spec, p55:
 416      *
 417      *     If the EGL_CONTEXT_OPENGL_ROBUST_ACCESS attribute is set to
 418      *     EGL_TRUE, a context supporting robust buffer access will be created.
 419      *     OpenGL contexts must support the GL_ARB_robustness extension, or
 420      *     equivalent core API functional- ity. OpenGL ES contexts must support
 421      *     the GL_EXT_robustness extension, or equivalent core API
 422      *     functionality.
 423      */
 424     if (mesa_api != API_OPENGL_COMPAT
 425         && mesa_api != API_OPENGL_CORE
 426         && (ctx_config.flags & ~(__DRI_CTX_FLAG_DEBUG |
 427                                  __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS |
 428                                  __DRI_CTX_FLAG_NO_ERROR))) {
 429         *error = __DRI_CTX_ERROR_BAD_FLAG;
 430         return NULL;
 431     }
 432
 433     /* There are no forward-compatible contexts before OpenGL 3.0.  The
 434      * GLX_ARB_create_context spec says:
 435      *
 436      *     "Forward-compatible contexts are defined only for OpenGL versions
 437      *     3.0 and later."
 438      *
 439      * Forward-looking contexts are supported by silently converting the
 440      * requested API to API_OPENGL_CORE.
 441      *
 442      * In Mesa, a debug context is the same as a regular context.
 443      */
 444     if ((ctx_config.flags & __DRI_CTX_FLAG_FORWARD_COMPATIBLE) != 0) {
 445        mesa_api = API_OPENGL_CORE;
 446     }
 447
 448     const uint32_t allowed_flags = (__DRI_CTX_FLAG_DEBUG
 449                                     | __DRI_CTX_FLAG_FORWARD_COMPATIBLE
 450                                     | __DRI_CTX_FLAG_ROBUST_BUFFER_ACCESS
 451                                     | __DRI_CTX_FLAG_NO_ERROR);
 452     if (ctx_config.flags & ~allowed_flags) {
 453         *error = __DRI_CTX_ERROR_UNKNOWN_FLAG;
 454         return NULL;
 455     }
 456
 457     if (!validate_context_version(screen, mesa_api,
 458                                   ctx_config.major_version,
 459                                   ctx_config.minor_version,
 460                                   error))
 461        return NULL;
 462
 463     context = calloc(1, sizeof *context);
 464     if (!context) {
 465         *error = __DRI_CTX_ERROR_NO_MEMORY;
 466         return NULL;
 467     }
 468
 469     context->loaderPrivate = data;
 470
 471     context->driScreenPriv = screen;
 472     context->driDrawablePriv = NULL;
 473     context->driReadablePriv = NULL;
 474
 475     if (!screen->driver->CreateContext(mesa_api, modes, context,
 476                                        &ctx_config, error, shareCtx)) {
 477         free(context);
 478         return NULL;
 479     }
 480
 481     *error = __DRI_CTX_ERROR_SUCCESS;
 482     return context;
 483 }
 484
 485 void
 486 driContextSetFlags(struct gl_context *ctx, uint32_t flags)
 487 {
 488     if ((flags & __DRI_CTX_FLAG_FORWARD_COMPATIBLE) != 0)
 489         ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT;
 490     if ((flags & __DRI_CTX_FLAG_DEBUG) != 0) {
 491        _mesa_set_debug_state_int(ctx, GL_DEBUG_OUTPUT, GL_TRUE);
 492         ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_DEBUG_BIT;
 493     }
 494     if ((flags & __DRI_CTX_FLAG_NO_ERROR) != 0)
 495         ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_NO_ERROR_BIT_KHR;
 496 }
 497
 498 static __DRIcontext *
 499 driCreateNewContextForAPI(__DRIscreen *screen, int api,
 500                           const __DRIconfig *config,
 501                           __DRIcontext *shared, void *data)
 502 {
 503     unsigned error;
 504
 505     return driCreateContextAttribs(screen, api, config, shared, 0, NULL,
 506                                    &error, data);
 507 }
 508
 509 static __DRIcontext *
 510 driCreateNewContext(__DRIscreen *screen, const __DRIconfig *config,
 511                     __DRIcontext *shared, void *data)
 512 {
 513     return driCreateNewContextForAPI(screen, __DRI_API_OPENGL,
 514                                      config, shared, data);
 515 }
 516
 517 /**
 518  * Destroy the per-context private information.
 519  *
 520  * \internal
 521  * This function calls __DriverAPIRec::DestroyContext on \p contextPrivate, calls
 522  * drmDestroyContext(), and finally frees \p contextPrivate.
 523  */
 524 static void
 525 driDestroyContext(__DRIcontext *pcp)
 526 {
 527     if (pcp) {
 528         pcp->driScreenPriv->driver->DestroyContext(pcp);
 529         free(pcp);
 530     }
 531 }
 532
 533 static int
 534 driCopyContext(__DRIcontext *dest, __DRIcontext *src, unsigned long mask)
 535 {
 536     (void) dest;
 537     (void) src;
 538     (void) mask;
 539     return GL_FALSE;
 540 }
 541
 542 /*@}*/
 543
 544
 545 /*****************************************************************/
 546 /** \name Context (un)binding functions                          */
 547 /*****************************************************************/
 548 /*@{*/
 549
 550 static void dri_get_drawable(__DRIdrawable *pdp);
 551 static void dri_put_drawable(__DRIdrawable *pdp);
 552
 553 /**
 554  * This function takes both a read buffer and a draw buffer.  This is needed
 555  * for \c glXMakeCurrentReadSGI or GLX 1.3's \c glXMakeContextCurrent
 556  * function.
 557  */
 558 static int driBindContext(__DRIcontext *pcp,
 559                           __DRIdrawable *pdp,
 560                           __DRIdrawable *prp)
 561 {
 562     /*
 563     ** Assume error checking is done properly in glXMakeCurrent before
 564     ** calling driUnbindContext.
 565     */
 566
 567     if (!pcp)
 568         return GL_FALSE;
 569
 570     /* Bind the drawable to the context */
 571     pcp->driDrawablePriv = pdp;
 572     pcp->driReadablePriv = prp;
 573     if (pdp) {
 574         pdp->driContextPriv = pcp;
 575         dri_get_drawable(pdp);
 576     }
 577     if (prp && pdp != prp) {
 578         dri_get_drawable(prp);
 579     }
 580
 581     return pcp->driScreenPriv->driver->MakeCurrent(pcp, pdp, prp);
 582 }
 583
 584 /**
 585  * Unbind context.
 586  *
 587  * \param scrn the screen.
 588  * \param gc context.
 589  *
 590  * \return \c GL_TRUE on success, or \c GL_FALSE on failure.
 591  *
 592  * \internal
 593  * This function calls __DriverAPIRec::UnbindContext, and then decrements
 594  * __DRIdrawableRec::refcount which must be non-zero for a successful
 595  * return.
 596  *
 597  * While casting the opaque private pointers associated with the parameters
 598  * into their respective real types it also assures they are not \c NULL.
 599  */
 600 static int driUnbindContext(__DRIcontext *pcp)
 601 {
 602     __DRIdrawable *pdp;
 603     __DRIdrawable *prp;
 604
 605     /*
 606     ** Assume error checking is done properly in glXMakeCurrent before
 607     ** calling driUnbindContext.
 608     */
 609
 610     if (pcp == NULL)
 611         return GL_FALSE;
 612
 613     /*
 614     ** Call driUnbindContext before checking for valid drawables
 615     ** to handle surfaceless contexts properly.
 616     */
 617     pcp->driScreenPriv->driver->UnbindContext(pcp);
 618
 619     pdp = pcp->driDrawablePriv;
 620     prp = pcp->driReadablePriv;
 621
 622     /* already unbound */
 623     if (!pdp && !prp)
 624         return GL_TRUE;
 625
 626     assert(pdp);
 627     if (pdp->refcount == 0) {
 628         /* ERROR!!! */
 629         return GL_FALSE;
 630     }
 631
 632     dri_put_drawable(pdp);
 633
 634     if (prp != pdp) {
 635         if (prp->refcount == 0) {
 636             /* ERROR!!! */
 637             return GL_FALSE;
 638         }
 639
 640         dri_put_drawable(prp);
 641     }
 642
 643     pcp->driDrawablePriv = NULL;
 644     pcp->driReadablePriv = NULL;
 645
 646     return GL_TRUE;
 647 }
 648
 649 /*@}*/
 650
 651
 652 static void dri_get_drawable(__DRIdrawable *pdp)
 653 {
 654     pdp->refcount++;
 655 }
 656
 657 static void dri_put_drawable(__DRIdrawable *pdp)
 658 {
 659     if (pdp) {
 660         pdp->refcount--;
 661         if (pdp->refcount)
 662             return;
 663
 664         pdp->driScreenPriv->driver->DestroyBuffer(pdp);
 665         free(pdp);
 666     }
 667 }
 668
 669 static __DRIdrawable *
 670 driCreateNewDrawable(__DRIscreen *screen,
 671                      const __DRIconfig *config,
 672                      void *data)
 673 {
 674     __DRIdrawable *pdraw;
 675
 676     assert(data != NULL);
 677
 678     pdraw = malloc(sizeof *pdraw);
 679     if (!pdraw)
 680         return NULL;
 681
 682     pdraw->loaderPrivate = data;
 683
 684     pdraw->driScreenPriv = screen;
 685     pdraw->driContextPriv = NULL;
 686     pdraw->refcount = 0;
 687     pdraw->lastStamp = 0;
 688     pdraw->w = 0;
 689     pdraw->h = 0;
 690
 691     dri_get_drawable(pdraw);
 692
 693     if (!screen->driver->CreateBuffer(screen, pdraw, &config->modes,
 694                                       GL_FALSE)) {
 695        free(pdraw);
 696        return NULL;
 697     }
 698
 699     pdraw->dri2.stamp = pdraw->lastStamp + 1;
 700
 701     return pdraw;
 702 }
 703
 704 static void
 705 driDestroyDrawable(__DRIdrawable *pdp)
 706 {
 707     /*
 708      * The loader's data structures are going away, even if pdp itself stays
 709      * around for the time being because it is currently bound. This happens
 710      * when a currently bound GLX pixmap is destroyed.
 711      *
 712      * Clear out the pointer back into the loader's data structures to avoid
 713      * accessing an outdated pointer.
 714      */
 715     pdp->loaderPrivate = NULL;
 716
 717     dri_put_drawable(pdp);
 718 }
 719
 720 static __DRIbuffer *
 721 dri2AllocateBuffer(__DRIscreen *screen,
 722                    unsigned int attachment, unsigned int format,
 723                    int width, int height)
 724 {
 725     return screen->driver->AllocateBuffer(screen, attachment, format,
 726                                           width, height);
 727 }
 728
 729 static void
 730 dri2ReleaseBuffer(__DRIscreen *screen, __DRIbuffer *buffer)
 731 {
 732     screen->driver->ReleaseBuffer(screen, buffer);
 733 }
 734
 735
 736 static int
 737 dri2ConfigQueryb(__DRIscreen *screen, const char *var, unsigned char *val)
 738 {
 739    if (!driCheckOption(&screen->optionCache, var, DRI_BOOL))
 740       return -1;
 741
 742    *val = driQueryOptionb(&screen->optionCache, var);
 743
 744    return 0;
 745 }
 746
 747 static int
 748 dri2ConfigQueryi(__DRIscreen *screen, const char *var, int *val)
 749 {
 750    if (!driCheckOption(&screen->optionCache, var, DRI_INT) &&
 751        !driCheckOption(&screen->optionCache, var, DRI_ENUM))
 752       return -1;
 753
 754     *val = driQueryOptioni(&screen->optionCache, var);
 755
 756     return 0;
 757 }
 758
 759 static int
 760 dri2ConfigQueryf(__DRIscreen *screen, const char *var, float *val)
 761 {
 762    if (!driCheckOption(&screen->optionCache, var, DRI_FLOAT))
 763       return -1;
 764
 765     *val = driQueryOptionf(&screen->optionCache, var);
 766
 767     return 0;
 768 }
 769
 770 static unsigned int
 771 driGetAPIMask(__DRIscreen *screen)
 772 {
 773     return screen->api_mask;
 774 }
 775
 776 /**
 777  * swrast swapbuffers entrypoint.
 778  *
 779  * DRI2 implements this inside the loader with only flushes handled by the
 780  * driver.
 781  */
 782 static void
 783 driSwapBuffers(__DRIdrawable *pdp)
 784 {
 785     assert(pdp->driScreenPriv->swrast_loader);
 786
 787     pdp->driScreenPriv->driver->SwapBuffers(pdp);
 788 }
 789
 790 /** Core interface */
 791 const __DRIcoreExtension driCoreExtension = {
 792     .base = { __DRI_CORE, 2 },
 793
 794     .createNewScreen            = NULL,
 795     .destroyScreen              = driDestroyScreen,
 796     .getExtensions              = driGetExtensions,
 797     .getConfigAttrib            = driGetConfigAttrib,
 798     .indexConfigAttrib          = driIndexConfigAttrib,
 799     .createNewDrawable          = NULL,
 800     .destroyDrawable            = driDestroyDrawable,
 801     .swapBuffers                = driSwapBuffers, /* swrast */
 802     .createNewContext           = driCreateNewContext, /* swrast */
 803     .copyContext                = driCopyContext,
 804     .destroyContext             = driDestroyContext,
 805     .bindContext                = driBindContext,
 806     .unbindContext              = driUnbindContext
 807 };
 808
 809 /** DRI2 interface */
 810 const __DRIdri2Extension driDRI2Extension = {
 811     .base = { __DRI_DRI2, 4 },
 812
 813     .createNewScreen            = dri2CreateNewScreen,
 814     .createNewDrawable          = driCreateNewDrawable,
 815     .createNewContext           = driCreateNewContext,
 816     .getAPIMask                 = driGetAPIMask,
 817     .createNewContextForAPI     = driCreateNewContextForAPI,
 818     .allocateBuffer             = dri2AllocateBuffer,
 819     .releaseBuffer              = dri2ReleaseBuffer,
 820     .createContextAttribs       = driCreateContextAttribs,
 821     .createNewScreen2           = driCreateNewScreen2,
 822 };
 823
 824 const __DRIswrastExtension driSWRastExtension = {
 825     .base = { __DRI_SWRAST, 4 },
 826
 827     .createNewScreen            = driSWRastCreateNewScreen,
 828     .createNewDrawable          = driCreateNewDrawable,
 829     .createNewContextForAPI     = driCreateNewContextForAPI,
 830     .createContextAttribs       = driCreateContextAttribs,
 831     .createNewScreen2           = driSWRastCreateNewScreen2,
 832 };
 833
 834 const __DRI2configQueryExtension dri2ConfigQueryExtension = {
 835    .base = { __DRI2_CONFIG_QUERY, 1 },
 836
 837    .configQueryb        = dri2ConfigQueryb,
 838    .configQueryi        = dri2ConfigQueryi,
 839    .configQueryf        = dri2ConfigQueryf,
 840 };
 841
 842 const __DRI2flushControlExtension dri2FlushControlExtension = {
 843    .base = { __DRI2_FLUSH_CONTROL, 1 }
 844 };
 845
 846 void
 847 dri2InvalidateDrawable(__DRIdrawable *drawable)
 848 {
 849     drawable->dri2.stamp++;
 850 }
 851
 852 /**
 853  * Check that the gl_framebuffer associated with dPriv is the right size.
 854  * Resize the gl_framebuffer if needed.
 855  * It's expected that the dPriv->driverPrivate member points to a
 856  * gl_framebuffer object.
 857  */
 858 void
 859 driUpdateFramebufferSize(struct gl_context *ctx, const __DRIdrawable *dPriv)
 860 {
 861    struct gl_framebuffer *fb = (struct gl_framebuffer *) dPriv->driverPrivate;
 862    if (fb && (dPriv->w != fb->Width || dPriv->h != fb->Height)) {
 863       _mesa_resize_framebuffer(ctx, fb, dPriv->w, dPriv->h);
 864       /* if the driver needs the hw lock for ResizeBuffers, the drawable
 865          might have changed again by now */
 866       assert(fb->Width == dPriv->w);
 867       assert(fb->Height == dPriv->h);
 868    }
 869 }
 870
 871 /*
 872  * Note: the first match is returned, which is important for formats like
 873  * __DRI_IMAGE_FORMAT_R8 which maps to both MESA_FORMAT_{R,L}_UNORM8
 874  */
 875 static const struct {
 876    uint32_t    image_format;
 877    mesa_format mesa_format;
 878 } format_mapping[] = {
 879    {
 880       .image_format = __DRI_IMAGE_FORMAT_RGB565,
 881       .mesa_format  =        MESA_FORMAT_B5G6R5_UNORM,
 882    },
 883    {
 884       .image_format = __DRI_IMAGE_FORMAT_ARGB1555,
 885       .mesa_format  =        MESA_FORMAT_B5G5R5A1_UNORM,
 886    },
 887    {
 888       .image_format = __DRI_IMAGE_FORMAT_XRGB8888,
 889       .mesa_format  =        MESA_FORMAT_B8G8R8X8_UNORM,
 890    },
 891    {
 892       .image_format = __DRI_IMAGE_FORMAT_ABGR16161616F,
 893       .mesa_format  =        MESA_FORMAT_RGBA_FLOAT16,
 894    },
 895    {
 896       .image_format = __DRI_IMAGE_FORMAT_XBGR16161616F,
 897       .mesa_format  =        MESA_FORMAT_RGBX_FLOAT16,
 898    },
 899    {
 900       .image_format = __DRI_IMAGE_FORMAT_ARGB2101010,
 901       .mesa_format  =        MESA_FORMAT_B10G10R10A2_UNORM,
 902    },
 903    {
 904       .image_format = __DRI_IMAGE_FORMAT_XRGB2101010,
 905       .mesa_format  =        MESA_FORMAT_B10G10R10X2_UNORM,
 906    },
 907    {
 908       .image_format = __DRI_IMAGE_FORMAT_ABGR2101010,
 909       .mesa_format  =        MESA_FORMAT_R10G10B10A2_UNORM,
 910    },
 911    {
 912       .image_format = __DRI_IMAGE_FORMAT_XBGR2101010,
 913       .mesa_format  =        MESA_FORMAT_R10G10B10X2_UNORM,
 914    },
 915    {
 916       .image_format = __DRI_IMAGE_FORMAT_ARGB8888,
 917       .mesa_format  =        MESA_FORMAT_B8G8R8A8_UNORM,
 918    },
 919    {
 920       .image_format = __DRI_IMAGE_FORMAT_ABGR8888,
 921       .mesa_format  =        MESA_FORMAT_R8G8B8A8_UNORM,
 922    },
 923    {
 924       .image_format = __DRI_IMAGE_FORMAT_XBGR8888,
 925       .mesa_format  =        MESA_FORMAT_R8G8B8X8_UNORM,
 926    },
 927    {
 928       .image_format = __DRI_IMAGE_FORMAT_R8,
 929       .mesa_format  =        MESA_FORMAT_R_UNORM8,
 930    },
 931    {
 932       .image_format = __DRI_IMAGE_FORMAT_R8,
 933       .mesa_format  =        MESA_FORMAT_L_UNORM8,
 934    },
 935 #if PIPE_ARCH_LITTLE_ENDIAN
 936    {
 937       .image_format = __DRI_IMAGE_FORMAT_GR88,
 938       .mesa_format  =        MESA_FORMAT_RG_UNORM8,
 939    },
 940    {
 941       .image_format = __DRI_IMAGE_FORMAT_GR88,
 942       .mesa_format  =        MESA_FORMAT_LA_UNORM8,
 943    },
 944 #endif
 945    {
 946       .image_format = __DRI_IMAGE_FORMAT_SABGR8,
 947       .mesa_format  =        MESA_FORMAT_R8G8B8A8_SRGB,
 948    },
 949    {
 950       .image_format = __DRI_IMAGE_FORMAT_SARGB8,
 951       .mesa_format  =        MESA_FORMAT_B8G8R8A8_SRGB,
 952    },
 953    {
 954       .image_format = __DRI_IMAGE_FORMAT_R16,
 955       .mesa_format  =        MESA_FORMAT_R_UNORM16,
 956    },
 957    {
 958       .image_format = __DRI_IMAGE_FORMAT_R16,
 959       .mesa_format  =        MESA_FORMAT_L_UNORM16,
 960    },
 961 #if PIPE_ARCH_LITTLE_ENDIAN
 962    {
 963       .image_format = __DRI_IMAGE_FORMAT_GR1616,
 964       .mesa_format  =        MESA_FORMAT_RG_UNORM16,
 965    },
 966    {
 967       .image_format = __DRI_IMAGE_FORMAT_GR1616,
 968       .mesa_format  =        MESA_FORMAT_LA_UNORM16,
 969    },
 970 #endif
 971 };
 972
 973 uint32_t
 974 driGLFormatToImageFormat(mesa_format format)
 975 {
 976    for (size_t i = 0; i < ARRAY_SIZE(format_mapping); i++)
 977       if (format_mapping[i].mesa_format == format)
 978          return format_mapping[i].image_format;
 979
 980    return __DRI_IMAGE_FORMAT_NONE;
 981 }
 982
 983 mesa_format
 984 driImageFormatToGLFormat(uint32_t image_format)
 985 {
 986    for (size_t i = 0; i < ARRAY_SIZE(format_mapping); i++)
 987       if (format_mapping[i].image_format == image_format)
 988          return format_mapping[i].mesa_format;
 989
 990    return MESA_FORMAT_NONE;
 991 }
 992
 993 /** Image driver interface */
 994 const __DRIimageDriverExtension driImageDriverExtension = {
 995     .base = { __DRI_IMAGE_DRIVER, 1 },
 996
 997     .createNewScreen2           = driCreateNewScreen2,
 998     .createNewDrawable          = driCreateNewDrawable,
 999     .getAPIMask                 = driGetAPIMask,
1000     .createContextAttribs       = driCreateContextAttribs,
1001 };
1002
1003 /* swrast copy sub buffer entrypoint. */
1004 static void driCopySubBuffer(__DRIdrawable *pdp, int x, int y,
1005                              int w, int h)
1006 {
1007     assert(pdp->driScreenPriv->swrast_loader);
1008
1009     pdp->driScreenPriv->driver->CopySubBuffer(pdp, x, y, w, h);
1010 }
1011
1012 /* for swrast only */
1013 const __DRIcopySubBufferExtension driCopySubBufferExtension = {
1014    .base = { __DRI_COPY_SUB_BUFFER, 1 },
1015
1016    .copySubBuffer               = driCopySubBuffer,
1017 };
1018
1019 const __DRInoErrorExtension dri2NoErrorExtension = {
1020    .base = { __DRI2_NO_ERROR, 1 },
1021 };