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

   1 /**
   2  * \file dri_util.c
   3  * DRI utility functions.
   4  *
   5  * This module acts as glue between GLX and the actual hardware driver.  A DRI
   6  * driver doesn't really \e have to use any of this - it's optional.  But, some
   7  * useful stuff is done here that otherwise would have to be duplicated in most
   8  * drivers.
   9  *
  10  * Basically, these utility functions take care of some of the dirty details of
  11  * screen initialization, context creation, context binding, DRM setup, etc.
  12  *
  13  * These functions are compiled into each DRI driver so libGL.so knows nothing
  14  * about them.
  15  */
  16
  17
  18 #include <assert.h>
  19 #include <stdarg.h>
  20 #include <unistd.h>
  21 #include <sys/mman.h>
  22 #include <stdio.h>
  23
  24 #ifndef MAP_FAILED
  25 #define MAP_FAILED ((void *)-1)
  26 #endif
  27
  28 #include "main/imports.h"
  29 #define None 0
  30
  31 #include "dri_util.h"
  32 #include "drm_sarea.h"
  33 #include "utils.h"
  34 #include "xmlpool.h"
  35 #include "../glsl/glsl_parser_extras.h"
  36
  37 PUBLIC const char __dri2ConfigOptions[] =
  38    DRI_CONF_BEGIN
  39       DRI_CONF_SECTION_PERFORMANCE
  40          DRI_CONF_VBLANK_MODE(DRI_CONF_VBLANK_DEF_INTERVAL_1)
  41       DRI_CONF_SECTION_END
  42    DRI_CONF_END;
  43
  44 static const uint __dri2NConfigOptions = 1;
  45
  46 #ifndef GLX_OML_sync_control
  47 typedef GLboolean ( * PFNGLXGETMSCRATEOMLPROC) (__DRIdrawable *drawable, int32_t *numerator, int32_t *denominator);
  48 #endif
  49
  50 static void dri_get_drawable(__DRIdrawable *pdp);
  51 static void dri_put_drawable(__DRIdrawable *pdp);
  52
  53 GLint
  54 driIntersectArea( drm_clip_rect_t rect1, drm_clip_rect_t rect2 )
  55 {
  56    if (rect2.x1 > rect1.x1) rect1.x1 = rect2.x1;
  57    if (rect2.x2 < rect1.x2) rect1.x2 = rect2.x2;
  58    if (rect2.y1 > rect1.y1) rect1.y1 = rect2.y1;
  59    if (rect2.y2 < rect1.y2) rect1.y2 = rect2.y2;
  60
  61    if (rect1.x1 > rect1.x2 || rect1.y1 > rect1.y2) return 0;
  62
  63    return (rect1.x2 - rect1.x1) * (rect1.y2 - rect1.y1);
  64 }
  65
  66 /*****************************************************************/
  67 /** \name Context (un)binding functions                          */
  68 /*****************************************************************/
  69 /*@{*/
  70
  71 /**
  72  * Unbind context.
  73  *
  74  * \param scrn the screen.
  75  * \param gc context.
  76  *
  77  * \return \c GL_TRUE on success, or \c GL_FALSE on failure.
  78  *
  79  * \internal
  80  * This function calls __DriverAPIRec::UnbindContext, and then decrements
  81  * __DRIdrawableRec::refcount which must be non-zero for a successful
  82  * return.
  83  *
  84  * While casting the opaque private pointers associated with the parameters
  85  * into their respective real types it also assures they are not \c NULL.
  86  */
  87 static int driUnbindContext(__DRIcontext *pcp)
  88 {
  89     __DRIscreen *psp;
  90     __DRIdrawable *pdp;
  91     __DRIdrawable *prp;
  92
  93     /*
  94     ** Assume error checking is done properly in glXMakeCurrent before
  95     ** calling driUnbindContext.
  96     */
  97
  98     if (pcp == NULL)
  99         return GL_FALSE;
 100
 101     psp = pcp->driScreenPriv;
 102     pdp = pcp->driDrawablePriv;
 103     prp = pcp->driReadablePriv;
 104
 105     /* already unbound */
 106     if (!pdp && !prp)
 107       return GL_TRUE;
 108     /* Let driver unbind drawable from context */
 109     (*psp->DriverAPI.UnbindContext)(pcp);
 110
 111     assert(pdp);
 112     if (pdp->refcount == 0) {
 113         /* ERROR!!! */
 114         return GL_FALSE;
 115     }
 116
 117     dri_put_drawable(pdp);
 118
 119     if (prp != pdp) {
 120         if (prp->refcount == 0) {
 121             /* ERROR!!! */
 122             return GL_FALSE;
 123         }
 124
 125         dri_put_drawable(prp);
 126     }
 127
 128
 129     /* XXX this is disabled so that if we call SwapBuffers on an unbound
 130      * window we can determine the last context bound to the window and
 131      * use that context's lock. (BrianP, 2-Dec-2000)
 132      */
 133     pcp->driDrawablePriv = pcp->driReadablePriv = NULL;
 134
 135     return GL_TRUE;
 136 }
 137
 138 /**
 139  * This function takes both a read buffer and a draw buffer.  This is needed
 140  * for \c glXMakeCurrentReadSGI or GLX 1.3's \c glXMakeContextCurrent
 141  * function.
 142  */
 143 static int driBindContext(__DRIcontext *pcp,
 144                           __DRIdrawable *pdp,
 145                           __DRIdrawable *prp)
 146 {
 147     __DRIscreen *psp = NULL;
 148
 149     /*
 150     ** Assume error checking is done properly in glXMakeCurrent before
 151     ** calling driUnbindContext.
 152     */
 153
 154     if (!pcp)
 155         return GL_FALSE;
 156
 157     /* Bind the drawable to the context */
 158     psp = pcp->driScreenPriv;
 159     pcp->driDrawablePriv = pdp;
 160     pcp->driReadablePriv = prp;
 161     if (pdp) {
 162         pdp->driContextPriv = pcp;
 163         dri_get_drawable(pdp);
 164     }
 165     if (prp && pdp != prp) {
 166         dri_get_drawable(prp);
 167     }
 168
 169     /*
 170     ** Now that we have a context associated with this drawable, we can
 171     ** initialize the drawable information if has not been done before.
 172     */
 173
 174     if (!psp->dri2.enabled) {
 175         if (pdp && !pdp->pStamp) {
 176             DRM_SPINLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
 177             __driUtilUpdateDrawableInfo(pdp);
 178             DRM_SPINUNLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
 179         }
 180         if (prp && pdp != prp && !prp->pStamp) {
 181             DRM_SPINLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
 182             __driUtilUpdateDrawableInfo(prp);
 183             DRM_SPINUNLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
 184         }
 185     }
 186
 187     /* Call device-specific MakeCurrent */
 188     return (*psp->DriverAPI.MakeCurrent)(pcp, pdp, prp);
 189 }
 190
 191 /*@}*/
 192
 193
 194 /*****************************************************************/
 195 /** \name Drawable handling functions                            */
 196 /*****************************************************************/
 197 /*@{*/
 198
 199 /**
 200  * Update private drawable information.
 201  *
 202  * \param pdp pointer to the private drawable information to update.
 203  *
 204  * This function basically updates the __DRIdrawable struct's
 205  * cliprect information by calling \c __DRIinterfaceMethods::getDrawableInfo.
 206  * This is usually called by the DRI_VALIDATE_DRAWABLE_INFO macro which
 207  * compares the __DRIdrwablePrivate pStamp and lastStamp values.  If
 208  * the values are different that means we have to update the clipping
 209  * info.
 210  */
 211 void
 212 __driUtilUpdateDrawableInfo(__DRIdrawable *pdp)
 213 {
 214     __DRIscreen *psp = pdp->driScreenPriv;
 215     __DRIcontext *pcp = pdp->driContextPriv;
 216
 217     if (!pcp
 218         || ((pdp != pcp->driDrawablePriv) && (pdp != pcp->driReadablePriv))) {
 219         /* ERROR!!!
 220          * ...but we must ignore it. There can be many contexts bound to a
 221          * drawable.
 222          */
 223     }
 224
 225     if (pdp->pClipRects) {
 226         free(pdp->pClipRects);
 227         pdp->pClipRects = NULL;
 228     }
 229
 230     if (pdp->pBackClipRects) {
 231         free(pdp->pBackClipRects);
 232         pdp->pBackClipRects = NULL;
 233     }
 234
 235     DRM_SPINUNLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
 236
 237     if (! (*psp->getDrawableInfo->getDrawableInfo)(pdp,
 238                           &pdp->index, &pdp->lastStamp,
 239                           &pdp->x, &pdp->y, &pdp->w, &pdp->h,
 240                           &pdp->numClipRects, &pdp->pClipRects,
 241                           &pdp->backX,
 242                           &pdp->backY,
 243                           &pdp->numBackClipRects,
 244                           &pdp->pBackClipRects,
 245                           pdp->loaderPrivate)) {
 246         /* Error -- eg the window may have been destroyed.  Keep going
 247          * with no cliprects.
 248          */
 249         pdp->pStamp = &pdp->lastStamp; /* prevent endless loop */
 250         pdp->numClipRects = 0;
 251         pdp->pClipRects = NULL;
 252         pdp->numBackClipRects = 0;
 253         pdp->pBackClipRects = NULL;
 254     }
 255     else
 256        pdp->pStamp = &(psp->pSAREA->drawableTable[pdp->index].stamp);
 257
 258     DRM_SPINLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
 259 }
 260
 261 /*@}*/
 262
 263 /*****************************************************************/
 264 /** \name GLX callbacks                                          */
 265 /*****************************************************************/
 266 /*@{*/
 267
 268 static void driReportDamage(__DRIdrawable *pdp,
 269                             struct drm_clip_rect *pClipRects, int numClipRects)
 270 {
 271     __DRIscreen *psp = pdp->driScreenPriv;
 272
 273     /* Check that we actually have the new damage report method */
 274     if (psp->damage) {
 275         /* Report the damage.  Currently, all our drivers draw
 276          * directly to the front buffer, so we report the damage there
 277          * rather than to the backing storein (if any).
 278          */
 279         (*psp->damage->reportDamage)(pdp,
 280                                      pdp->x, pdp->y,
 281                                      pClipRects, numClipRects,
 282                                      GL_TRUE, pdp->loaderPrivate);
 283     }
 284 }
 285
 286
 287 /**
 288  * Swap buffers.
 289  *
 290  * \param drawablePrivate opaque pointer to the per-drawable private info.
 291  *
 292  * \internal
 293  * This function calls __DRIdrawable::swapBuffers.
 294  *
 295  * Is called directly from glXSwapBuffers().
 296  */
 297 static void driSwapBuffers(__DRIdrawable *dPriv)
 298 {
 299     __DRIscreen *psp = dPriv->driScreenPriv;
 300     drm_clip_rect_t *rects;
 301     int i;
 302
 303     psp->DriverAPI.SwapBuffers(dPriv);
 304
 305     if (!dPriv->numClipRects)
 306         return;
 307
 308     rects = malloc(sizeof(*rects) * dPriv->numClipRects);
 309
 310     if (!rects)
 311         return;
 312
 313     for (i = 0; i < dPriv->numClipRects; i++) {
 314         rects[i].x1 = dPriv->pClipRects[i].x1 - dPriv->x;
 315         rects[i].y1 = dPriv->pClipRects[i].y1 - dPriv->y;
 316         rects[i].x2 = dPriv->pClipRects[i].x2 - dPriv->x;
 317         rects[i].y2 = dPriv->pClipRects[i].y2 - dPriv->y;
 318     }
 319
 320     driReportDamage(dPriv, rects, dPriv->numClipRects);
 321     free(rects);
 322 }
 323
 324 /**
 325  * This is called via __DRIscreenRec's createNewDrawable pointer.
 326  */
 327 static __DRIdrawable *
 328 driCreateNewDrawable(__DRIscreen *psp, const __DRIconfig *config,
 329                      drm_drawable_t hwDrawable, int renderType,
 330                      const int *attrs, void *data)
 331 {
 332     __DRIdrawable *pdp;
 333
 334     /* Since pbuffers are not yet supported, no drawable attributes are
 335      * supported either.
 336      */
 337     (void) attrs;
 338     (void) renderType;
 339
 340     pdp = malloc(sizeof *pdp);
 341     if (!pdp) {
 342         return NULL;
 343     }
 344
 345     pdp->driContextPriv = NULL;
 346     pdp->loaderPrivate = data;
 347     pdp->hHWDrawable = hwDrawable;
 348     pdp->refcount = 1;
 349     pdp->pStamp = NULL;
 350     pdp->lastStamp = 0;
 351     pdp->index = 0;
 352     pdp->x = 0;
 353     pdp->y = 0;
 354     pdp->w = 0;
 355     pdp->h = 0;
 356     pdp->numClipRects = 0;
 357     pdp->numBackClipRects = 0;
 358     pdp->pClipRects = NULL;
 359     pdp->pBackClipRects = NULL;
 360     pdp->vblSeq = 0;
 361     pdp->vblFlags = 0;
 362
 363     pdp->driScreenPriv = psp;
 364
 365     if (!(*psp->DriverAPI.CreateBuffer)(psp, pdp, &config->modes, 0)) {
 366        free(pdp);
 367        return NULL;
 368     }
 369
 370     pdp->msc_base = 0;
 371
 372     /* This special default value is replaced with the configured
 373      * default value when the drawable is first bound to a direct
 374      * rendering context.
 375      */
 376     pdp->swap_interval = (unsigned)-1;
 377
 378     return pdp;
 379 }
 380
 381
 382 static __DRIdrawable *
 383 dri2CreateNewDrawable(__DRIscreen *screen,
 384                       const __DRIconfig *config,
 385                       void *loaderPrivate)
 386 {
 387     __DRIdrawable *pdraw;
 388
 389     pdraw = driCreateNewDrawable(screen, config, 0, 0, NULL, loaderPrivate);
 390     if (!pdraw)
 391         return NULL;
 392
 393     pdraw->pClipRects = &pdraw->dri2.clipRect;
 394     pdraw->pBackClipRects = &pdraw->dri2.clipRect;
 395
 396     pdraw->pStamp = &pdraw->dri2.stamp;
 397     *pdraw->pStamp = pdraw->lastStamp + 1;
 398
 399     return pdraw;
 400 }
 401
 402 static __DRIbuffer *
 403 dri2AllocateBuffer(__DRIscreen *screen,
 404                    unsigned int attachment, unsigned int format,
 405                    int width, int height)
 406 {
 407     return (*screen->DriverAPI.AllocateBuffer)(screen, attachment, format,
 408                                                width, height);
 409 }
 410
 411 static void
 412 dri2ReleaseBuffer(__DRIscreen *screen, __DRIbuffer *buffer)
 413 {
 414    (*screen->DriverAPI.ReleaseBuffer)(screen, buffer);
 415 }
 416
 417
 418 static int
 419 dri2ConfigQueryb(__DRIscreen *screen, const char *var, GLboolean *val)
 420 {
 421    if (!driCheckOption(&screen->optionCache, var, DRI_BOOL))
 422       return -1;
 423
 424    *val = driQueryOptionb(&screen->optionCache, var);
 425
 426    return 0;
 427 }
 428
 429 static int
 430 dri2ConfigQueryi(__DRIscreen *screen, const char *var, GLint *val)
 431 {
 432    if (!driCheckOption(&screen->optionCache, var, DRI_INT) &&
 433        !driCheckOption(&screen->optionCache, var, DRI_ENUM))
 434       return -1;
 435
 436     *val = driQueryOptioni(&screen->optionCache, var);
 437
 438     return 0;
 439 }
 440
 441 static int
 442 dri2ConfigQueryf(__DRIscreen *screen, const char *var, GLfloat *val)
 443 {
 444    if (!driCheckOption(&screen->optionCache, var, DRI_FLOAT))
 445       return -1;
 446
 447     *val = driQueryOptionf(&screen->optionCache, var);
 448
 449     return 0;
 450 }
 451
 452
 453 static void dri_get_drawable(__DRIdrawable *pdp)
 454 {
 455     pdp->refcount++;
 456 }
 457
 458 static void dri_put_drawable(__DRIdrawable *pdp)
 459 {
 460     __DRIscreen *psp;
 461
 462     if (pdp) {
 463         pdp->refcount--;
 464         if (pdp->refcount)
 465             return;
 466
 467         psp = pdp->driScreenPriv;
 468         (*psp->DriverAPI.DestroyBuffer)(pdp);
 469         if (pdp->pClipRects && pdp->pClipRects != &pdp->dri2.clipRect) {
 470             free(pdp->pClipRects);
 471             pdp->pClipRects = NULL;
 472         }
 473         if (pdp->pBackClipRects && pdp->pClipRects != &pdp->dri2.clipRect) {
 474             free(pdp->pBackClipRects);
 475             pdp->pBackClipRects = NULL;
 476         }
 477         free(pdp);
 478     }
 479 }
 480
 481 static void
 482 driDestroyDrawable(__DRIdrawable *pdp)
 483 {
 484     dri_put_drawable(pdp);
 485 }
 486
 487 /*@}*/
 488
 489
 490 /*****************************************************************/
 491 /** \name Context handling functions                             */
 492 /*****************************************************************/
 493 /*@{*/
 494
 495 /**
 496  * Destroy the per-context private information.
 497  *
 498  * \internal
 499  * This function calls __DriverAPIRec::DestroyContext on \p contextPrivate, calls
 500  * drmDestroyContext(), and finally frees \p contextPrivate.
 501  */
 502 static void
 503 driDestroyContext(__DRIcontext *pcp)
 504 {
 505     if (pcp) {
 506         (*pcp->driScreenPriv->DriverAPI.DestroyContext)(pcp);
 507         free(pcp);
 508     }
 509 }
 510
 511
 512 /**
 513  * Create the per-drawable private driver information.
 514  *
 515  * \param render_type   Type of rendering target.  \c GLX_RGBA_TYPE is the only
 516  *                      type likely to ever be supported for direct-rendering.
 517  *                      However, \c GLX_RGBA_FLOAT_TYPE_ARB may eventually be
 518  *                      supported by some drivers.
 519  * \param shared        Context with which to share textures, etc. or NULL
 520  *
 521  * \returns An opaque pointer to the per-context private information on
 522  *          success, or \c NULL on failure.
 523  *
 524  * \internal
 525  * This function allocates and fills a __DRIcontextRec structure.  It
 526  * performs some device independent initialization and passes all the
 527  * relevent information to __DriverAPIRec::CreateContext to create the
 528  * context.
 529  *
 530  */
 531 static __DRIcontext *
 532 driCreateNewContext(__DRIscreen *psp, const __DRIconfig *config,
 533                     int render_type, __DRIcontext *shared,
 534                     drm_context_t hwContext, void *data)
 535 {
 536     __DRIcontext *pcp;
 537     void * const shareCtx = (shared != NULL) ? shared->driverPrivate : NULL;
 538
 539     (void) render_type;
 540
 541     pcp = malloc(sizeof *pcp);
 542     if (!pcp)
 543         return NULL;
 544
 545     pcp->driScreenPriv = psp;
 546     pcp->driDrawablePriv = NULL;
 547     pcp->loaderPrivate = data;
 548
 549     pcp->dri2.draw_stamp = 0;
 550     pcp->dri2.read_stamp = 0;
 551
 552     pcp->hHWContext = hwContext;
 553
 554     if ( !(*psp->DriverAPI.CreateContext)(API_OPENGL,
 555                                           &config->modes, pcp, shareCtx) ) {
 556         free(pcp);
 557         return NULL;
 558     }
 559
 560     return pcp;
 561 }
 562
 563 static unsigned int
 564 dri2GetAPIMask(__DRIscreen *screen)
 565 {
 566     return screen->api_mask;
 567 }
 568
 569 static __DRIcontext *
 570 dri2CreateNewContextForAPI(__DRIscreen *screen, int api,
 571                            const __DRIconfig *config,
 572                            __DRIcontext *shared, void *data)
 573 {
 574     __DRIcontext *context;
 575     const struct gl_config *modes = (config != NULL) ? &config->modes : NULL;
 576     void *shareCtx = (shared != NULL) ? shared->driverPrivate : NULL;
 577     gl_api mesa_api;
 578
 579     if (!(screen->api_mask & (1 << api)))
 580         return NULL;
 581
 582     switch (api) {
 583     case __DRI_API_OPENGL:
 584             mesa_api = API_OPENGL;
 585             break;
 586     case __DRI_API_GLES:
 587             mesa_api = API_OPENGLES;
 588             break;
 589     case __DRI_API_GLES2:
 590             mesa_api = API_OPENGLES2;
 591             break;
 592     default:
 593             return NULL;
 594     }
 595
 596     context = malloc(sizeof *context);
 597     if (!context)
 598         return NULL;
 599
 600     context->driScreenPriv = screen;
 601     context->driDrawablePriv = NULL;
 602     context->loaderPrivate = data;
 603
 604     if (!(*screen->DriverAPI.CreateContext)(mesa_api, modes,
 605                                             context, shareCtx) ) {
 606         free(context);
 607         return NULL;
 608     }
 609
 610     return context;
 611 }
 612
 613
 614 static __DRIcontext *
 615 dri2CreateNewContext(__DRIscreen *screen, const __DRIconfig *config,
 616                       __DRIcontext *shared, void *data)
 617 {
 618    return dri2CreateNewContextForAPI(screen, __DRI_API_OPENGL,
 619                                      config, shared, data);
 620 }
 621
 622 static int
 623 driCopyContext(__DRIcontext *dest, __DRIcontext *src, unsigned long mask)
 624 {
 625     (void) dest;
 626     (void) src;
 627     (void) mask;
 628     return GL_FALSE;
 629 }
 630
 631 /*@}*/
 632
 633
 634 /*****************************************************************/
 635 /** \name Screen handling functions                              */
 636 /*****************************************************************/
 637 /*@{*/
 638
 639 /**
 640  * Destroy the per-screen private information.
 641  *
 642  * \internal
 643  * This function calls __DriverAPIRec::DestroyScreen on \p screenPrivate, calls
 644  * drmClose(), and finally frees \p screenPrivate.
 645  */
 646 static void driDestroyScreen(__DRIscreen *psp)
 647 {
 648     if (psp) {
 649         /* No interaction with the X-server is possible at this point.  This
 650          * routine is called after XCloseDisplay, so there is no protocol
 651          * stream open to the X-server anymore.
 652          */
 653
 654        _mesa_destroy_shader_compiler();
 655
 656         if (psp->DriverAPI.DestroyScreen)
 657             (*psp->DriverAPI.DestroyScreen)(psp);
 658
 659         if (!psp->dri2.enabled) {
 660            (void)drmUnmap((drmAddress)psp->pSAREA, SAREA_MAX);
 661            (void)drmUnmap((drmAddress)psp->pFB, psp->fbSize);
 662            (void)drmCloseOnce(psp->fd);
 663         } else {
 664            driDestroyOptionCache(&psp->optionCache);
 665            driDestroyOptionInfo(&psp->optionInfo);
 666         }
 667
 668         free(psp);
 669     }
 670 }
 671
 672 static void
 673 setupLoaderExtensions(__DRIscreen *psp,
 674                       const __DRIextension **extensions)
 675 {
 676     int i;
 677
 678     for (i = 0; extensions[i]; i++) {
 679         if (strcmp(extensions[i]->name, __DRI_GET_DRAWABLE_INFO) == 0)
 680             psp->getDrawableInfo = (__DRIgetDrawableInfoExtension *) extensions[i];
 681         if (strcmp(extensions[i]->name, __DRI_DAMAGE) == 0)
 682             psp->damage = (__DRIdamageExtension *) extensions[i];
 683         if (strcmp(extensions[i]->name, __DRI_SYSTEM_TIME) == 0)
 684             psp->systemTime = (__DRIsystemTimeExtension *) extensions[i];
 685         if (strcmp(extensions[i]->name, __DRI_DRI2_LOADER) == 0)
 686             psp->dri2.loader = (__DRIdri2LoaderExtension *) extensions[i];
 687         if (strcmp(extensions[i]->name, __DRI_IMAGE_LOOKUP) == 0)
 688             psp->dri2.image = (__DRIimageLookupExtension *) extensions[i];
 689         if (strcmp(extensions[i]->name, __DRI_USE_INVALIDATE) == 0)
 690             psp->dri2.useInvalidate = (__DRIuseInvalidateExtension *) extensions[i];
 691     }
 692 }
 693
 694 /**
 695  * This is the bootstrap function for the driver.  libGL supplies all of the
 696  * requisite information about the system, and the driver initializes itself.
 697  * This routine also fills in the linked list pointed to by \c driver_modes
 698  * with the \c struct gl_config that the driver can support for windows or
 699  * pbuffers.
 700  *
 701  * For legacy DRI.
 702  *
 703  * \param scrn  Index of the screen
 704  * \param ddx_version Version of the 2D DDX.  This may not be meaningful for
 705  *                    all drivers.
 706  * \param dri_version Version of the "server-side" DRI.
 707  * \param drm_version Version of the kernel DRM.
 708  * \param frame_buffer Data describing the location and layout of the
 709  *                     framebuffer.
 710  * \param pSAREA       Pointer to the SAREA.
 711  * \param fd           Device handle for the DRM.
 712  * \param extensions   ??
 713  * \param driver_modes  Returns modes suppoted by the driver
 714  * \param loaderPrivate  ??
 715  *
 716  * \note There is no need to check the minimum API version in this
 717  * function.  Since the name of this function is versioned, it is
 718  * impossible for a loader that is too old to even load this driver.
 719  */
 720 static __DRIscreen *
 721 driCreateNewScreen(int scrn,
 722                    const __DRIversion *ddx_version,
 723                    const __DRIversion *dri_version,
 724                    const __DRIversion *drm_version,
 725                    const __DRIframebuffer *frame_buffer,
 726                    drmAddress pSAREA, int fd,
 727                    const __DRIextension **extensions,
 728                    const __DRIconfig ***driver_modes,
 729                    void *loaderPrivate)
 730 {
 731     static const __DRIextension *emptyExtensionList[] = { NULL };
 732     __DRIscreen *psp;
 733
 734     (void) loaderPrivate;
 735
 736     if (driDriverAPI.InitScreen == NULL) {
 737         __driUtilMessage("driver does not support DRI1");
 738         return NULL;
 739     }
 740
 741     psp = calloc(1, sizeof *psp);
 742     if (!psp)
 743         return NULL;
 744
 745     setupLoaderExtensions(psp, extensions);
 746
 747     /*
 748     ** NOT_DONE: This is used by the X server to detect when the client
 749     ** has died while holding the drawable lock.  The client sets the
 750     ** drawable lock to this value.
 751     */
 752     psp->drawLockID = 1;
 753
 754     psp->drm_version = *drm_version;
 755     psp->ddx_version = *ddx_version;
 756     psp->dri_version = *dri_version;
 757
 758     psp->pSAREA = pSAREA;
 759     psp->lock = (drmLock *) &psp->pSAREA->lock;
 760
 761     psp->pFB = frame_buffer->base;
 762     psp->fbSize = frame_buffer->size;
 763     psp->fbStride = frame_buffer->stride;
 764     psp->fbWidth = frame_buffer->width;
 765     psp->fbHeight = frame_buffer->height;
 766     psp->devPrivSize = frame_buffer->dev_priv_size;
 767     psp->pDevPriv = frame_buffer->dev_priv;
 768     psp->fbBPP = psp->fbStride * 8 / frame_buffer->width;
 769
 770     psp->extensions = emptyExtensionList;
 771     psp->fd = fd;
 772     psp->myNum = scrn;
 773     psp->dri2.enabled = GL_FALSE;
 774
 775     psp->DriverAPI = driDriverAPI;
 776     psp->api_mask = (1 << __DRI_API_OPENGL);
 777
 778     *driver_modes = driDriverAPI.InitScreen(psp);
 779     if (*driver_modes == NULL) {
 780         free(psp);
 781         return NULL;
 782     }
 783
 784     return psp;
 785 }
 786
 787 /**
 788  * DRI2
 789  */
 790 static __DRIscreen *
 791 dri2CreateNewScreen(int scrn, int fd,
 792                     const __DRIextension **extensions,
 793                     const __DRIconfig ***driver_configs, void *data)
 794 {
 795     static const __DRIextension *emptyExtensionList[] = { NULL };
 796     __DRIscreen *psp;
 797     drmVersionPtr version;
 798
 799     if (driDriverAPI.InitScreen2 == NULL)
 800         return NULL;
 801
 802     psp = calloc(1, sizeof(*psp));
 803     if (!psp)
 804         return NULL;
 805
 806     setupLoaderExtensions(psp, extensions);
 807
 808     version = drmGetVersion(fd);
 809     if (version) {
 810         psp->drm_version.major = version->version_major;
 811         psp->drm_version.minor = version->version_minor;
 812         psp->drm_version.patch = version->version_patchlevel;
 813         drmFreeVersion(version);
 814     }
 815
 816     psp->extensions = emptyExtensionList;
 817     psp->fd = fd;
 818     psp->myNum = scrn;
 819     psp->dri2.enabled = GL_TRUE;
 820
 821     psp->DriverAPI = driDriverAPI;
 822     psp->api_mask = (1 << __DRI_API_OPENGL);
 823     *driver_configs = driDriverAPI.InitScreen2(psp);
 824     if (*driver_configs == NULL) {
 825         free(psp);
 826         return NULL;
 827     }
 828
 829     psp->DriverAPI = driDriverAPI;
 830     psp->loaderPrivate = data;
 831
 832     driParseOptionInfo(&psp->optionInfo, __dri2ConfigOptions,
 833                        __dri2NConfigOptions);
 834     driParseConfigFiles(&psp->optionCache, &psp->optionInfo, psp->myNum,
 835                         "dri2");
 836
 837     return psp;
 838 }
 839
 840 static const __DRIextension **driGetExtensions(__DRIscreen *psp)
 841 {
 842     return psp->extensions;
 843 }
 844
 845 /** Core interface */
 846 const __DRIcoreExtension driCoreExtension = {
 847     { __DRI_CORE, __DRI_CORE_VERSION },
 848     NULL,
 849     driDestroyScreen,
 850     driGetExtensions,
 851     driGetConfigAttrib,
 852     driIndexConfigAttrib,
 853     NULL,
 854     driDestroyDrawable,
 855     driSwapBuffers,
 856     NULL,
 857     driCopyContext,
 858     driDestroyContext,
 859     driBindContext,
 860     driUnbindContext
 861 };
 862
 863 /** DRI2 interface */
 864 const __DRIdri2Extension driDRI2Extension = {
 865     { __DRI_DRI2, __DRI_DRI2_VERSION },
 866     dri2CreateNewScreen,
 867     dri2CreateNewDrawable,
 868     dri2CreateNewContext,
 869     dri2GetAPIMask,
 870     dri2CreateNewContextForAPI,
 871     dri2AllocateBuffer,
 872     dri2ReleaseBuffer
 873 };
 874
 875 const __DRI2configQueryExtension dri2ConfigQueryExtension = {
 876    { __DRI2_CONFIG_QUERY, __DRI2_CONFIG_QUERY_VERSION },
 877    dri2ConfigQueryb,
 878    dri2ConfigQueryi,
 879    dri2ConfigQueryf,
 880 };
 881
 882 /**
 883  * Calculate amount of swap interval used between GLX buffer swaps.
 884  *
 885  * The usage value, on the range [0,max], is the fraction of total swap
 886  * interval time used between GLX buffer swaps is calculated.
 887  *
 888  *            \f$p = t_d / (i * t_r)\f$
 889  *
 890  * Where \f$t_d\f$ is the time since the last GLX buffer swap, \f$i\f$ is the
 891  * swap interval (as set by \c glXSwapIntervalSGI), and \f$t_r\f$ time
 892  * required for a single vertical refresh period (as returned by \c
 893  * glXGetMscRateOML).
 894  *
 895  * See the documentation for the GLX_MESA_swap_frame_usage extension for more
 896  * details.
 897  *
 898  * \param   dPriv  Pointer to the private drawable structure.
 899  * \return  If less than a single swap interval time period was required
 900  *          between GLX buffer swaps, a number greater than 0 and less than
 901  *          1.0 is returned.  If exactly one swap interval time period is
 902  *          required, 1.0 is returned, and if more than one is required then
 903  *          a number greater than 1.0 will be returned.
 904  *
 905  * \sa glXSwapIntervalSGI glXGetMscRateOML
 906  *
 907  * \todo Instead of caching the \c glXGetMscRateOML function pointer, would it
 908  *       be possible to cache the sync rate?
 909  */
 910 float
 911 driCalculateSwapUsage( __DRIdrawable *dPriv, int64_t last_swap_ust,
 912                        int64_t current_ust )
 913 {
 914    int32_t   n;
 915    int32_t   d;
 916    int       interval;
 917    float     usage = 1.0;
 918    __DRIscreen *psp = dPriv->driScreenPriv;
 919
 920    if ( (*psp->systemTime->getMSCRate)(dPriv, &n, &d, dPriv->loaderPrivate) ) {
 921       interval = (dPriv->swap_interval != 0) ? dPriv->swap_interval : 1;
 922
 923
 924       /* We want to calculate
 925        * (current_UST - last_swap_UST) / (interval * us_per_refresh).  We get
 926        * current_UST by calling __glXGetUST.  last_swap_UST is stored in
 927        * dPriv->swap_ust.  interval has already been calculated.
 928        *
 929        * The only tricky part is us_per_refresh.  us_per_refresh is
 930        * 1000000 / MSC_rate.  We know the MSC_rate is n / d.  We can flip it
 931        * around and say us_per_refresh = 1000000 * d / n.  Since this goes in
 932        * the denominator of the final calculation, we calculate
 933        * (interval * 1000000 * d) and move n into the numerator.
 934        */
 935
 936       usage = (current_ust - last_swap_ust);
 937       usage *= n;
 938       usage /= (interval * d);
 939       usage /= 1000000.0;
 940    }
 941
 942    return usage;
 943 }
 944
 945 void
 946 dri2InvalidateDrawable(__DRIdrawable *drawable)
 947 {
 948     drawable->dri2.stamp++;
 949 }
 950
 951 /*@}*/