src/mesa/drivers/dri/i915/intel_context.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28
  29 #include "main/glheader.h"
  30 #include "main/context.h"
  31 #include "main/extensions.h"
  32 #include "main/fbobject.h"
  33 #include "main/framebuffer.h"
  34 #include "main/imports.h"
  35 #include "main/points.h"
  36 #include "main/renderbuffer.h"
  37
  38 #include "swrast/swrast.h"
  39 #include "swrast_setup/swrast_setup.h"
  40 #include "tnl/tnl.h"
  41 #include "drivers/common/driverfuncs.h"
  42 #include "drivers/common/meta.h"
  43
  44 #include "intel_chipset.h"
  45 #include "intel_buffers.h"
  46 #include "intel_tex.h"
  47 #include "intel_batchbuffer.h"
  48 #include "intel_clear.h"
  49 #include "intel_extensions.h"
  50 #include "intel_pixel.h"
  51 #include "intel_regions.h"
  52 #include "intel_buffer_objects.h"
  53 #include "intel_fbo.h"
  54 #include "intel_bufmgr.h"
  55 #include "intel_screen.h"
  56 #include "intel_mipmap_tree.h"
  57
  58 #include "utils.h"
  59 #include "../glsl/ralloc.h"
  60
  61 int INTEL_DEBUG = (0);
  62
  63 const char *const i915_vendor_string = "Intel Open Source Technology Center";
  64
  65 const char *
  66 i915_get_renderer_string(unsigned deviceID)
  67 {
  68    const char *chipset;
  69    static char buffer[128];
  70
  71    switch (deviceID) {
  72 #undef CHIPSET
  73 #define CHIPSET(id, symbol, str) case id: chipset = str; break;
  74 #include "pci_ids/i915_pci_ids.h"
  75    default:
  76       chipset = "Unknown Intel Chipset";
  77       break;
  78    }
  79
  80    (void) driGetRendererString(buffer, chipset, 0);
  81    return buffer;
  82 }
  83
  84 static const GLubyte *
  85 intelGetString(struct gl_context * ctx, GLenum name)
  86 {
  87    const struct intel_context *const intel = intel_context(ctx);
  88
  89    switch (name) {
  90    case GL_VENDOR:
  91       return (GLubyte *) i915_vendor_string;
  92
  93    case GL_RENDERER:
  94       return
  95          (GLubyte *) i915_get_renderer_string(intel->intelScreen->deviceID);
  96
  97    default:
  98       return NULL;
  99    }
 100 }
 101
 102 static void
 103 intel_flush_front(struct gl_context *ctx)
 104 {
 105    struct intel_context *intel = intel_context(ctx);
 106     __DRIcontext *driContext = intel->driContext;
 107     __DRIdrawable *driDrawable = driContext->driDrawablePriv;
 108     __DRIscreen *const screen = intel->intelScreen->driScrnPriv;
 109
 110     if (intel->front_buffer_dirty && _mesa_is_winsys_fbo(ctx->DrawBuffer)) {
 111       if (screen->dri2.loader->flushFrontBuffer != NULL &&
 112           driDrawable &&
 113           driDrawable->loaderPrivate) {
 114          screen->dri2.loader->flushFrontBuffer(driDrawable,
 115                                                driDrawable->loaderPrivate);
 116
 117          /* We set the dirty bit in intel_prepare_render() if we're
 118           * front buffer rendering once we get there.
 119           */
 120          intel->front_buffer_dirty = false;
 121       }
 122    }
 123 }
 124
 125 static unsigned
 126 intel_bits_per_pixel(const struct intel_renderbuffer *rb)
 127 {
 128    return _mesa_get_format_bytes(intel_rb_format(rb)) * 8;
 129 }
 130
 131 static void
 132 intel_query_dri2_buffers(struct intel_context *intel,
 133                          __DRIdrawable *drawable,
 134                          __DRIbuffer **buffers,
 135                          int *count);
 136
 137 static void
 138 intel_process_dri2_buffer(struct intel_context *intel,
 139                           __DRIdrawable *drawable,
 140                           __DRIbuffer *buffer,
 141                           struct intel_renderbuffer *rb,
 142                           const char *buffer_name);
 143
 144 void
 145 intel_update_renderbuffers(__DRIcontext *context, __DRIdrawable *drawable)
 146 {
 147    struct gl_framebuffer *fb = drawable->driverPrivate;
 148    struct intel_renderbuffer *rb;
 149    struct intel_context *intel = context->driverPrivate;
 150    __DRIbuffer *buffers = NULL;
 151    int i, count;
 152    const char *region_name;
 153
 154    /* Set this up front, so that in case our buffers get invalidated
 155     * while we're getting new buffers, we don't clobber the stamp and
 156     * thus ignore the invalidate. */
 157    drawable->lastStamp = drawable->dri2.stamp;
 158
 159    if (unlikely(INTEL_DEBUG & DEBUG_DRI))
 160       fprintf(stderr, "enter %s, drawable %p\n", __func__, drawable);
 161
 162    intel_query_dri2_buffers(intel, drawable, &buffers, &count);
 163
 164    if (buffers == NULL)
 165       return;
 166
 167    for (i = 0; i < count; i++) {
 168        switch (buffers[i].attachment) {
 169        case __DRI_BUFFER_FRONT_LEFT:
 170            rb = intel_get_renderbuffer(fb, BUFFER_FRONT_LEFT);
 171            region_name = "dri2 front buffer";
 172            break;
 173
 174        case __DRI_BUFFER_FAKE_FRONT_LEFT:
 175            rb = intel_get_renderbuffer(fb, BUFFER_FRONT_LEFT);
 176            region_name = "dri2 fake front buffer";
 177            break;
 178
 179        case __DRI_BUFFER_BACK_LEFT:
 180            rb = intel_get_renderbuffer(fb, BUFFER_BACK_LEFT);
 181            region_name = "dri2 back buffer";
 182            break;
 183
 184        case __DRI_BUFFER_DEPTH:
 185        case __DRI_BUFFER_HIZ:
 186        case __DRI_BUFFER_DEPTH_STENCIL:
 187        case __DRI_BUFFER_STENCIL:
 188        case __DRI_BUFFER_ACCUM:
 189        default:
 190            fprintf(stderr,
 191                    "unhandled buffer attach event, attachment type %d\n",
 192                    buffers[i].attachment);
 193            return;
 194        }
 195
 196        intel_process_dri2_buffer(intel, drawable, &buffers[i], rb, region_name);
 197    }
 198
 199    driUpdateFramebufferSize(&intel->ctx, drawable);
 200 }
 201
 202 /**
 203  * intel_prepare_render should be called anywhere that curent read/drawbuffer
 204  * state is required.
 205  */
 206 void
 207 intel_prepare_render(struct intel_context *intel)
 208 {
 209    __DRIcontext *driContext = intel->driContext;
 210    __DRIdrawable *drawable;
 211
 212    drawable = driContext->driDrawablePriv;
 213    if (drawable && drawable->dri2.stamp != driContext->dri2.draw_stamp) {
 214       if (drawable->lastStamp != drawable->dri2.stamp)
 215          intel_update_renderbuffers(driContext, drawable);
 216       intel_draw_buffer(&intel->ctx);
 217       driContext->dri2.draw_stamp = drawable->dri2.stamp;
 218    }
 219
 220    drawable = driContext->driReadablePriv;
 221    if (drawable && drawable->dri2.stamp != driContext->dri2.read_stamp) {
 222       if (drawable->lastStamp != drawable->dri2.stamp)
 223          intel_update_renderbuffers(driContext, drawable);
 224       driContext->dri2.read_stamp = drawable->dri2.stamp;
 225    }
 226
 227    /* If we're currently rendering to the front buffer, the rendering
 228     * that will happen next will probably dirty the front buffer.  So
 229     * mark it as dirty here.
 230     */
 231    if (intel->is_front_buffer_rendering)
 232       intel->front_buffer_dirty = true;
 233
 234    /* Wait for the swapbuffers before the one we just emitted, so we
 235     * don't get too many swaps outstanding for apps that are GPU-heavy
 236     * but not CPU-heavy.
 237     *
 238     * We're using intelDRI2Flush (called from the loader before
 239     * swapbuffer) and glFlush (for front buffer rendering) as the
 240     * indicator that a frame is done and then throttle when we get
 241     * here as we prepare to render the next frame.  At this point for
 242     * round trips for swap/copy and getting new buffers are done and
 243     * we'll spend less time waiting on the GPU.
 244     *
 245     * Unfortunately, we don't have a handle to the batch containing
 246     * the swap, and getting our hands on that doesn't seem worth it,
 247     * so we just us the first batch we emitted after the last swap.
 248     */
 249    if (intel->need_throttle && intel->first_post_swapbuffers_batch) {
 250       if (!intel->disable_throttling)
 251          drm_intel_bo_wait_rendering(intel->first_post_swapbuffers_batch);
 252       drm_intel_bo_unreference(intel->first_post_swapbuffers_batch);
 253       intel->first_post_swapbuffers_batch = NULL;
 254       intel->need_throttle = false;
 255    }
 256 }
 257
 258 static void
 259 intel_noninvalidate_viewport(struct gl_context *ctx, GLint x, GLint y,
 260                              GLsizei w, GLsizei h)
 261 {
 262     struct intel_context *intel = intel_context(ctx);
 263     __DRIcontext *driContext = intel->driContext;
 264
 265     (void) x;
 266     (void) y;
 267     (void) w;
 268     (void) h;
 269
 270     intelCalcViewport(ctx);
 271
 272     if (_mesa_is_winsys_fbo(ctx->DrawBuffer)) {
 273        dri2InvalidateDrawable(driContext->driDrawablePriv);
 274        dri2InvalidateDrawable(driContext->driReadablePriv);
 275     }
 276 }
 277
 278 static void
 279 intel_viewport(struct gl_context *ctx, GLint x, GLint y, GLsizei w, GLsizei h)
 280 {
 281     (void) x;
 282     (void) y;
 283     (void) w;
 284     (void) h;
 285
 286     intelCalcViewport(ctx);
 287 }
 288
 289 static const struct dri_debug_control debug_control[] = {
 290    { "tex",   DEBUG_TEXTURE},
 291    { "state", DEBUG_STATE},
 292    { "blit",  DEBUG_BLIT},
 293    { "mip",   DEBUG_MIPTREE},
 294    { "fall",  DEBUG_PERF},
 295    { "perf",  DEBUG_PERF},
 296    { "bat",   DEBUG_BATCH},
 297    { "pix",   DEBUG_PIXEL},
 298    { "buf",   DEBUG_BUFMGR},
 299    { "reg",   DEBUG_REGION},
 300    { "fbo",   DEBUG_FBO},
 301    { "fs",    DEBUG_WM },
 302    { "sync",  DEBUG_SYNC},
 303    { "dri",   DEBUG_DRI },
 304    { "stats", DEBUG_STATS },
 305    { "wm",    DEBUG_WM },
 306    { "aub",   DEBUG_AUB },
 307    { NULL,    0 }
 308 };
 309
 310
 311 static void
 312 intelInvalidateState(struct gl_context * ctx, GLuint new_state)
 313 {
 314     struct intel_context *intel = intel_context(ctx);
 315
 316     if (ctx->swrast_context)
 317        _swrast_InvalidateState(ctx, new_state);
 318    _vbo_InvalidateState(ctx, new_state);
 319
 320    intel->NewGLState |= new_state;
 321
 322    if (intel->vtbl.invalidate_state)
 323       intel->vtbl.invalidate_state( intel, new_state );
 324 }
 325
 326 void
 327 intel_flush_rendering_to_batch(struct gl_context *ctx)
 328 {
 329    struct intel_context *intel = intel_context(ctx);
 330
 331    if (intel->Fallback)
 332       _swrast_flush(ctx);
 333
 334    INTEL_FIREVERTICES(intel);
 335 }
 336
 337 void
 338 _intel_flush(struct gl_context *ctx, const char *file, int line)
 339 {
 340    struct intel_context *intel = intel_context(ctx);
 341
 342    intel_flush_rendering_to_batch(ctx);
 343
 344    if (intel->batch.used)
 345       _intel_batchbuffer_flush(intel, file, line);
 346 }
 347
 348 static void
 349 intel_glFlush(struct gl_context *ctx)
 350 {
 351    struct intel_context *intel = intel_context(ctx);
 352
 353    intel_flush(ctx);
 354    intel_flush_front(ctx);
 355    if (intel->is_front_buffer_rendering)
 356       intel->need_throttle = true;
 357 }
 358
 359 void
 360 intelFinish(struct gl_context * ctx)
 361 {
 362    struct intel_context *intel = intel_context(ctx);
 363
 364    intel_flush(ctx);
 365    intel_flush_front(ctx);
 366
 367    if (intel->batch.last_bo)
 368       drm_intel_bo_wait_rendering(intel->batch.last_bo);
 369 }
 370
 371 void
 372 intelInitDriverFunctions(struct dd_function_table *functions)
 373 {
 374    _mesa_init_driver_functions(functions);
 375
 376    functions->Flush = intel_glFlush;
 377    functions->Finish = intelFinish;
 378    functions->GetString = intelGetString;
 379    functions->UpdateState = intelInvalidateState;
 380
 381    intelInitTextureFuncs(functions);
 382    intelInitTextureImageFuncs(functions);
 383    intelInitTextureSubImageFuncs(functions);
 384    intelInitTextureCopyImageFuncs(functions);
 385    intelInitClearFuncs(functions);
 386    intelInitBufferFuncs(functions);
 387    intelInitPixelFuncs(functions);
 388    intelInitBufferObjectFuncs(functions);
 389    intel_init_syncobj_functions(functions);
 390 }
 391
 392 bool
 393 intelInitContext(struct intel_context *intel,
 394                  int api,
 395                  unsigned major_version,
 396                  unsigned minor_version,
 397                  const struct gl_config * mesaVis,
 398                  __DRIcontext * driContextPriv,
 399                  void *sharedContextPrivate,
 400                  struct dd_function_table *functions,
 401                  unsigned *dri_ctx_error)
 402 {
 403    struct gl_context *ctx = &intel->ctx;
 404    struct gl_context *shareCtx = (struct gl_context *) sharedContextPrivate;
 405    __DRIscreen *sPriv = driContextPriv->driScreenPriv;
 406    struct intel_screen *intelScreen = sPriv->driverPrivate;
 407    int bo_reuse_mode;
 408    struct gl_config visual;
 409
 410    /* Can't rely on invalidate events, fall back to glViewport hack */
 411    if (!driContextPriv->driScreenPriv->dri2.useInvalidate)
 412       functions->Viewport = intel_noninvalidate_viewport;
 413    else
 414       functions->Viewport = intel_viewport;
 415
 416    if (mesaVis == NULL) {
 417       memset(&visual, 0, sizeof visual);
 418       mesaVis = &visual;
 419    }
 420
 421    intel->intelScreen = intelScreen;
 422
 423    if (!_mesa_initialize_context(&intel->ctx, api, mesaVis, shareCtx,
 424                                  functions)) {
 425       *dri_ctx_error = __DRI_CTX_ERROR_NO_MEMORY;
 426       printf("%s: failed to init mesa context\n", __FUNCTION__);
 427       return false;
 428    }
 429
 430    driContextPriv->driverPrivate = intel;
 431    intel->driContext = driContextPriv;
 432    intel->driFd = sPriv->fd;
 433
 434    intel->gen = intelScreen->gen;
 435
 436    const int devID = intelScreen->deviceID;
 437
 438    intel->is_945 = IS_945(devID);
 439
 440    intel->has_swizzling = intel->intelScreen->hw_has_swizzling;
 441
 442    memset(&ctx->TextureFormatSupported,
 443           0, sizeof(ctx->TextureFormatSupported));
 444
 445    driParseConfigFiles(&intel->optionCache, &intelScreen->optionCache,
 446                        sPriv->myNum, "i915");
 447    intel->maxBatchSize = 4096;
 448
 449    /* Estimate the size of the mappable aperture into the GTT.  There's an
 450     * ioctl to get the whole GTT size, but not one to get the mappable subset.
 451     * It turns out it's basically always 256MB, though some ancient hardware
 452     * was smaller.
 453     */
 454    uint32_t gtt_size = 256 * 1024 * 1024;
 455    if (intel->gen == 2)
 456       gtt_size = 128 * 1024 * 1024;
 457
 458    /* We don't want to map two objects such that a memcpy between them would
 459     * just fault one mapping in and then the other over and over forever.  So
 460     * we would need to divide the GTT size by 2.  Additionally, some GTT is
 461     * taken up by things like the framebuffer and the ringbuffer and such, so
 462     * be more conservative.
 463     */
 464    intel->max_gtt_map_object_size = gtt_size / 4;
 465
 466    intel->bufmgr = intelScreen->bufmgr;
 467
 468    bo_reuse_mode = driQueryOptioni(&intel->optionCache, "bo_reuse");
 469    switch (bo_reuse_mode) {
 470    case DRI_CONF_BO_REUSE_DISABLED:
 471       break;
 472    case DRI_CONF_BO_REUSE_ALL:
 473       intel_bufmgr_gem_enable_reuse(intel->bufmgr);
 474       break;
 475    }
 476
 477    ctx->Const.MinLineWidth = 1.0;
 478    ctx->Const.MinLineWidthAA = 1.0;
 479    ctx->Const.MaxLineWidth = 5.0;
 480    ctx->Const.MaxLineWidthAA = 5.0;
 481    ctx->Const.LineWidthGranularity = 0.5;
 482
 483    ctx->Const.MinPointSize = 1.0;
 484    ctx->Const.MinPointSizeAA = 1.0;
 485    ctx->Const.MaxPointSize = 255.0;
 486    ctx->Const.MaxPointSizeAA = 3.0;
 487    ctx->Const.PointSizeGranularity = 1.0;
 488
 489    ctx->Const.StripTextureBorder = GL_TRUE;
 490
 491    /* reinitialize the context point state.
 492     * It depend on constants in __struct gl_contextRec::Const
 493     */
 494    _mesa_init_point(ctx);
 495
 496    ctx->Const.MaxRenderbufferSize = 2048;
 497
 498    _swrast_CreateContext(ctx);
 499    _vbo_CreateContext(ctx);
 500    if (ctx->swrast_context) {
 501       _tnl_CreateContext(ctx);
 502       _swsetup_CreateContext(ctx);
 503
 504       /* Configure swrast to match hardware characteristics: */
 505       _swrast_allow_pixel_fog(ctx, false);
 506       _swrast_allow_vertex_fog(ctx, true);
 507    }
 508
 509    _mesa_meta_init(ctx);
 510
 511    intel->hw_stencil = mesaVis->stencilBits && mesaVis->depthBits == 24;
 512    intel->hw_stipple = 1;
 513
 514    intel->RenderIndex = ~0;
 515
 516    intelInitExtensions(ctx);
 517
 518    INTEL_DEBUG = driParseDebugString(getenv("INTEL_DEBUG"), debug_control);
 519    if (INTEL_DEBUG & DEBUG_BUFMGR)
 520       dri_bufmgr_set_debug(intel->bufmgr, true);
 521    if (INTEL_DEBUG & DEBUG_PERF)
 522       intel->perf_debug = true;
 523
 524    if (INTEL_DEBUG & DEBUG_AUB)
 525       drm_intel_bufmgr_gem_set_aub_dump(intel->bufmgr, true);
 526
 527    intel_batchbuffer_init(intel);
 528
 529    intel_fbo_init(intel);
 530
 531    intel->use_early_z = driQueryOptionb(&intel->optionCache, "early_z");
 532
 533    intel->prim.primitive = ~0;
 534
 535    /* Force all software fallbacks */
 536    if (driQueryOptionb(&intel->optionCache, "no_rast")) {
 537       fprintf(stderr, "disabling 3D rasterization\n");
 538       intel->no_rast = 1;
 539    }
 540
 541    if (driQueryOptionb(&intel->optionCache, "always_flush_batch")) {
 542       fprintf(stderr, "flushing batchbuffer before/after each draw call\n");
 543       intel->always_flush_batch = 1;
 544    }
 545
 546    if (driQueryOptionb(&intel->optionCache, "always_flush_cache")) {
 547       fprintf(stderr, "flushing GPU caches before/after each draw call\n");
 548       intel->always_flush_cache = 1;
 549    }
 550
 551    if (driQueryOptionb(&intel->optionCache, "disable_throttling")) {
 552       fprintf(stderr, "disabling flush throttling\n");
 553       intel->disable_throttling = 1;
 554    }
 555
 556    return true;
 557 }
 558
 559 void
 560 intelDestroyContext(__DRIcontext * driContextPriv)
 561 {
 562    struct intel_context *intel =
 563       (struct intel_context *) driContextPriv->driverPrivate;
 564    struct gl_context *ctx = &intel->ctx;
 565
 566    assert(intel);               /* should never be null */
 567    if (intel) {
 568       INTEL_FIREVERTICES(intel);
 569
 570       /* Dump a final BMP in case the application doesn't call SwapBuffers */
 571       if (INTEL_DEBUG & DEBUG_AUB) {
 572          intel_batchbuffer_flush(intel);
 573          aub_dump_bmp(&intel->ctx);
 574       }
 575
 576       _mesa_meta_free(&intel->ctx);
 577
 578       intel->vtbl.destroy(intel);
 579
 580       if (ctx->swrast_context) {
 581          _swsetup_DestroyContext(&intel->ctx);
 582          _tnl_DestroyContext(&intel->ctx);
 583       }
 584       _vbo_DestroyContext(&intel->ctx);
 585
 586       if (ctx->swrast_context)
 587          _swrast_DestroyContext(&intel->ctx);
 588       intel->Fallback = 0x0;      /* don't call _swrast_Flush later */
 589
 590       intel_batchbuffer_free(intel);
 591
 592       free(intel->prim.vb);
 593       intel->prim.vb = NULL;
 594       drm_intel_bo_unreference(intel->prim.vb_bo);
 595       intel->prim.vb_bo = NULL;
 596       drm_intel_bo_unreference(intel->first_post_swapbuffers_batch);
 597       intel->first_post_swapbuffers_batch = NULL;
 598
 599       driDestroyOptionCache(&intel->optionCache);
 600
 601       /* free the Mesa context */
 602       _mesa_free_context_data(&intel->ctx);
 603
 604       _math_matrix_dtr(&intel->ViewportMatrix);
 605
 606       ralloc_free(intel);
 607       driContextPriv->driverPrivate = NULL;
 608    }
 609 }
 610
 611 GLboolean
 612 intelUnbindContext(__DRIcontext * driContextPriv)
 613 {
 614    /* Unset current context and dispath table */
 615    _mesa_make_current(NULL, NULL, NULL);
 616
 617    return true;
 618 }
 619
 620 GLboolean
 621 intelMakeCurrent(__DRIcontext * driContextPriv,
 622                  __DRIdrawable * driDrawPriv,
 623                  __DRIdrawable * driReadPriv)
 624 {
 625    struct intel_context *intel;
 626    GET_CURRENT_CONTEXT(curCtx);
 627
 628    if (driContextPriv)
 629       intel = (struct intel_context *) driContextPriv->driverPrivate;
 630    else
 631       intel = NULL;
 632
 633    /* According to the glXMakeCurrent() man page: "Pending commands to
 634     * the previous context, if any, are flushed before it is released."
 635     * But only flush if we're actually changing contexts.
 636     */
 637    if (intel_context(curCtx) && intel_context(curCtx) != intel) {
 638       _mesa_flush(curCtx);
 639    }
 640
 641    if (driContextPriv) {
 642       struct gl_context *ctx = &intel->ctx;
 643       struct gl_framebuffer *fb, *readFb;
 644
 645       if (driDrawPriv == NULL && driReadPriv == NULL) {
 646          fb = _mesa_get_incomplete_framebuffer();
 647          readFb = _mesa_get_incomplete_framebuffer();
 648       } else {
 649          fb = driDrawPriv->driverPrivate;
 650          readFb = driReadPriv->driverPrivate;
 651          driContextPriv->dri2.draw_stamp = driDrawPriv->dri2.stamp - 1;
 652          driContextPriv->dri2.read_stamp = driReadPriv->dri2.stamp - 1;
 653       }
 654
 655       intel_prepare_render(intel);
 656       _mesa_make_current(ctx, fb, readFb);
 657
 658       /* We do this in intel_prepare_render() too, but intel->ctx.DrawBuffer
 659        * is NULL at that point.  We can't call _mesa_makecurrent()
 660        * first, since we need the buffer size for the initial
 661        * viewport.  So just call intel_draw_buffer() again here. */
 662       intel_draw_buffer(ctx);
 663    }
 664    else {
 665       _mesa_make_current(NULL, NULL, NULL);
 666    }
 667
 668    return true;
 669 }
 670
 671 /**
 672  * \brief Query DRI2 to obtain a DRIdrawable's buffers.
 673  *
 674  * To determine which DRI buffers to request, examine the renderbuffers
 675  * attached to the drawable's framebuffer. Then request the buffers with
 676  * DRI2GetBuffers() or DRI2GetBuffersWithFormat().
 677  *
 678  * This is called from intel_update_renderbuffers().
 679  *
 680  * \param drawable      Drawable whose buffers are queried.
 681  * \param buffers       [out] List of buffers returned by DRI2 query.
 682  * \param buffer_count  [out] Number of buffers returned.
 683  *
 684  * \see intel_update_renderbuffers()
 685  * \see DRI2GetBuffers()
 686  * \see DRI2GetBuffersWithFormat()
 687  */
 688 static void
 689 intel_query_dri2_buffers(struct intel_context *intel,
 690                          __DRIdrawable *drawable,
 691                          __DRIbuffer **buffers,
 692                          int *buffer_count)
 693 {
 694    __DRIscreen *screen = intel->intelScreen->driScrnPriv;
 695    struct gl_framebuffer *fb = drawable->driverPrivate;
 696    int i = 0;
 697    unsigned attachments[8];
 698
 699    struct intel_renderbuffer *front_rb;
 700    struct intel_renderbuffer *back_rb;
 701
 702    front_rb = intel_get_renderbuffer(fb, BUFFER_FRONT_LEFT);
 703    back_rb = intel_get_renderbuffer(fb, BUFFER_BACK_LEFT);
 704
 705    memset(attachments, 0, sizeof(attachments));
 706    if ((intel->is_front_buffer_rendering ||
 707         intel->is_front_buffer_reading ||
 708         !back_rb) && front_rb) {
 709       /* If a fake front buffer is in use, then querying for
 710        * __DRI_BUFFER_FRONT_LEFT will cause the server to copy the image from
 711        * the real front buffer to the fake front buffer.  So before doing the
 712        * query, we need to make sure all the pending drawing has landed in the
 713        * real front buffer.
 714        */
 715       intel_flush(&intel->ctx);
 716       intel_flush_front(&intel->ctx);
 717
 718       attachments[i++] = __DRI_BUFFER_FRONT_LEFT;
 719       attachments[i++] = intel_bits_per_pixel(front_rb);
 720    } else if (front_rb && intel->front_buffer_dirty) {
 721       /* We have pending front buffer rendering, but we aren't querying for a
 722        * front buffer.  If the front buffer we have is a fake front buffer,
 723        * the X server is going to throw it away when it processes the query.
 724        * So before doing the query, make sure all the pending drawing has
 725        * landed in the real front buffer.
 726        */
 727       intel_flush(&intel->ctx);
 728       intel_flush_front(&intel->ctx);
 729    }
 730
 731    if (back_rb) {
 732       attachments[i++] = __DRI_BUFFER_BACK_LEFT;
 733       attachments[i++] = intel_bits_per_pixel(back_rb);
 734    }
 735
 736    assert(i <= ARRAY_SIZE(attachments));
 737
 738    *buffers = screen->dri2.loader->getBuffersWithFormat(drawable,
 739                                                         &drawable->w,
 740                                                         &drawable->h,
 741                                                         attachments, i / 2,
 742                                                         buffer_count,
 743                                                         drawable->loaderPrivate);
 744 }
 745
 746 /**
 747  * \brief Assign a DRI buffer's DRM region to a renderbuffer.
 748  *
 749  * This is called from intel_update_renderbuffers().
 750  *
 751  * \par Note:
 752  *    DRI buffers whose attachment point is DRI2BufferStencil or
 753  *    DRI2BufferDepthStencil are handled as special cases.
 754  *
 755  * \param buffer_name is a human readable name, such as "dri2 front buffer",
 756  *        that is passed to intel_region_alloc_for_handle().
 757  *
 758  * \see intel_update_renderbuffers()
 759  * \see intel_region_alloc_for_handle()
 760  */
 761 static void
 762 intel_process_dri2_buffer(struct intel_context *intel,
 763                           __DRIdrawable *drawable,
 764                           __DRIbuffer *buffer,
 765                           struct intel_renderbuffer *rb,
 766                           const char *buffer_name)
 767 {
 768    struct intel_region *region = NULL;
 769
 770    if (!rb)
 771       return;
 772
 773    /* We try to avoid closing and reopening the same BO name, because the first
 774     * use of a mapping of the buffer involves a bunch of page faulting which is
 775     * moderately expensive.
 776     */
 777    if (rb->mt &&
 778        rb->mt->region &&
 779        rb->mt->region->name == buffer->name)
 780       return;
 781
 782    if (unlikely(INTEL_DEBUG & DEBUG_DRI)) {
 783       fprintf(stderr,
 784               "attaching buffer %d, at %d, cpp %d, pitch %d\n",
 785               buffer->name, buffer->attachment,
 786               buffer->cpp, buffer->pitch);
 787    }
 788
 789    intel_miptree_release(&rb->mt);
 790    region = intel_region_alloc_for_handle(intel->intelScreen,
 791                                           buffer->cpp,
 792                                           drawable->w,
 793                                           drawable->h,
 794                                           buffer->pitch,
 795                                           buffer->name,
 796                                           buffer_name);
 797    if (!region)
 798       return;
 799
 800    rb->mt = intel_miptree_create_for_dri2_buffer(intel,
 801                                                  buffer->attachment,
 802                                                  intel_rb_format(rb),
 803                                                  region);
 804    intel_region_release(&region);
 805 }