path: root/src/mesa/drivers/dri/i915tex/intel_context.c

/**************************************************************************
 * 
 * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
 * All Rights Reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * 
 **************************************************************************/


#include "glheader.h"
#include "context.h"
#include "matrix.h"
#include "simple_list.h"
#include "extensions.h"
#include "framebuffer.h"
#include "imports.h"
#include "points.h"

#include "swrast/swrast.h"
#include "swrast_setup/swrast_setup.h"
#include "tnl/tnl.h"

#include "tnl/t_pipeline.h"
#include "tnl/t_vertex.h"

#include "drivers/common/driverfuncs.h"

#include "intel_screen.h"

#include "i830_dri.h"

#include "intel_buffers.h"
#include "intel_tex.h"
#include "intel_span.h"
#include "intel_tris.h"
#include "intel_ioctl.h"
#include "intel_batchbuffer.h"
#include "intel_blit.h"
#include "intel_pixel.h"
#include "intel_regions.h"
#include "intel_buffer_objects.h"
#include "intel_fbo.h"

#include "drirenderbuffer.h"
#include "vblank.h"
#include "utils.h"
#include "xmlpool.h"            /* for symbolic values of enum-type options */
#ifndef INTEL_DEBUG
int INTEL_DEBUG = (0);
#endif

#define need_GL_ARB_multisample
#define need_GL_ARB_point_parameters
#define need_GL_ARB_texture_compression
#define need_GL_ARB_vertex_buffer_object
#define need_GL_ARB_vertex_program
#define need_GL_ARB_window_pos
#define need_GL_EXT_blend_color
#define need_GL_EXT_blend_equation_separate
#define need_GL_EXT_blend_func_separate
#define need_GL_EXT_blend_minmax
#define need_GL_EXT_cull_vertex
#define need_GL_EXT_fog_coord
#define need_GL_EXT_framebuffer_object
#define need_GL_EXT_multi_draw_arrays
#define need_GL_EXT_secondary_color
#define need_GL_NV_vertex_program
#include "extension_helper.h"


#define DRIVER_DATE                     "20061102"

_glthread_Mutex lockMutex;
static GLboolean lockMutexInit = GL_FALSE;


static const GLubyte *
intelGetString(GLcontext * ctx, GLenum name)
{
   const char *chipset;
   static char buffer[128];

   switch (name) {
   case GL_VENDOR:
      return (GLubyte *) "Tungsten Graphics, Inc";
      break;

   case GL_RENDERER:
      switch (intel_context(ctx)->intelScreen->deviceID) {
      case PCI_CHIP_845_G:
         chipset = "Intel(R) 845G";
         break;
      case PCI_CHIP_I830_M:
         chipset = "Intel(R) 830M";
         break;
      case PCI_CHIP_I855_GM:
         chipset = "Intel(R) 852GM/855GM";
         break;
      case PCI_CHIP_I865_G:
         chipset = "Intel(R) 865G";
         break;
      case PCI_CHIP_I915_G:
         chipset = "Intel(R) 915G";
         break;
      case PCI_CHIP_I915_GM:
         chipset = "Intel(R) 915GM";
         break;
      case PCI_CHIP_I945_G:
         chipset = "Intel(R) 945G";
         break;
      case PCI_CHIP_I945_GM:
         chipset = "Intel(R) 945GM";
         break;
      default:
         chipset = "Unknown Intel Chipset";
         break;
      }

      (void) driGetRendererString(buffer, chipset, DRIVER_DATE, 0);
      return (GLubyte *) buffer;

   default:
      return NULL;
   }
}


/**
 * Extension strings exported by the intel driver.
 *
 * \note
 * It appears that ARB_texture_env_crossbar has "disappeared" compared to the
 * old i830-specific driver.
 */
const struct dri_extension card_extensions[] = {
   {"GL_ARB_multisample", GL_ARB_multisample_functions},
   {"GL_ARB_multitexture", NULL},
   {"GL_ARB_point_parameters", GL_ARB_point_parameters_functions},
   {"GL_ARB_texture_border_clamp", NULL},
   {"GL_ARB_texture_compression", GL_ARB_texture_compression_functions},
   {"GL_ARB_texture_cube_map", NULL},
   {"GL_ARB_texture_env_add", NULL},
   {"GL_ARB_texture_env_combine", NULL},
   {"GL_ARB_texture_env_dot3", NULL},
   {"GL_ARB_texture_mirrored_repeat", NULL},
   {"GL_ARB_texture_rectangle", NULL},
   {"GL_ARB_vertex_buffer_object", GL_ARB_vertex_buffer_object_functions},
   {"GL_ARB_pixel_buffer_object", NULL},
   {"GL_ARB_vertex_program", GL_ARB_vertex_program_functions},
   {"GL_ARB_window_pos", GL_ARB_window_pos_functions},
   {"GL_EXT_blend_color", GL_EXT_blend_color_functions},
   {"GL_EXT_blend_equation_separate",
    GL_EXT_blend_equation_separate_functions},
   {"GL_EXT_blend_func_separate", GL_EXT_blend_func_separate_functions},
   {"GL_EXT_blend_minmax", GL_EXT_blend_minmax_functions},
   {"GL_EXT_blend_subtract", NULL},
   {"GL_EXT_cull_vertex", GL_EXT_cull_vertex_functions},
   {"GL_EXT_fog_coord", GL_EXT_fog_coord_functions},
   {"GL_EXT_framebuffer_object", GL_EXT_framebuffer_object_functions},
   {"GL_EXT_multi_draw_arrays", GL_EXT_multi_draw_arrays_functions},
#if 1                           /* XXX FBO temporary? */
   {"GL_EXT_packed_depth_stencil", NULL},
#endif
   {"GL_EXT_secondary_color", GL_EXT_secondary_color_functions},
   {"GL_EXT_stencil_wrap", NULL},
   {"GL_EXT_texture_edge_clamp", NULL},
   {"GL_EXT_texture_env_combine", NULL},
   {"GL_EXT_texture_env_dot3", NULL},
   {"GL_EXT_texture_filter_anisotropic", NULL},
   {"GL_EXT_texture_lod_bias", NULL},
   {"GL_3DFX_texture_compression_FXT1", NULL},
   {"GL_APPLE_client_storage", NULL},
   {"GL_MESA_pack_invert", NULL},
   {"GL_MESA_ycbcr_texture", NULL},
   {"GL_NV_blend_square", NULL},
   {"GL_NV_vertex_program", GL_NV_vertex_program_functions},
   {"GL_NV_vertex_program1_1", NULL},
/*     { "GL_SGIS_generate_mipmap",           NULL }, */
   {NULL, NULL}
};

extern const struct tnl_pipeline_stage _intel_render_stage;

static const struct tnl_pipeline_stage *intel_pipeline[] = {
   &_tnl_vertex_transform_stage,
   &_tnl_vertex_cull_stage,
   &_tnl_normal_transform_stage,
   &_tnl_lighting_stage,
   &_tnl_fog_coordinate_stage,
   &_tnl_texgen_stage,
   &_tnl_texture_transform_stage,
   &_tnl_point_attenuation_stage,
   &_tnl_arb_vertex_program_stage,
   &_tnl_vertex_program_stage,
#if 1
   &_intel_render_stage,        /* ADD: unclipped rastersetup-to-dma */
#endif
   &_tnl_render_stage,
   0,
};


static const struct dri_debug_control debug_control[] = {
   {"tex", DEBUG_TEXTURE},
   {"state", DEBUG_STATE},
   {"ioctl", DEBUG_IOCTL},
   {"blit", DEBUG_BLIT},
   {"mip", DEBUG_MIPTREE},
   {"fall", DEBUG_FALLBACKS},
   {"verb", DEBUG_VERBOSE},
   {"bat", DEBUG_BATCH},
   {"pix", DEBUG_PIXEL},
   {"buf", DEBUG_BUFMGR},
   {"reg", DEBUG_REGION},
   {"fbo", DEBUG_FBO},
   {"lock", DEBUG_LOCK},
   {NULL, 0}
};


static void
intelInvalidateState(GLcontext * ctx, GLuint new_state)
{
   _swrast_InvalidateState(ctx, new_state);
   _swsetup_InvalidateState(ctx, new_state);
   _vbo_InvalidateState(ctx, new_state);
   _tnl_InvalidateState(ctx, new_state);
   _tnl_invalidate_vertex_state(ctx, new_state);
   intel_context(ctx)->NewGLState |= new_state;
}


void
intelFlush(GLcontext * ctx)
{
   struct intel_context *intel = intel_context(ctx);

   if (intel->Fallback)
      _swrast_flush(ctx);

   INTEL_FIREVERTICES(intel);

   if (intel->batch->map != intel->batch->ptr)
      intel_batchbuffer_flush(intel->batch);

   /* XXX: Need to do an MI_FLUSH here.
    */
}


/**
 * Check if we need to rotate/warp the front color buffer to the
 * rotated screen.  We generally need to do this when we get a glFlush
 * or glFinish after drawing to the front color buffer.
 */
static void
intelCheckFrontRotate(GLcontext * ctx)
{
   struct intel_context *intel = intel_context(ctx);
   if (intel->ctx.DrawBuffer->_ColorDrawBufferMask[0] ==
       BUFFER_BIT_FRONT_LEFT) {
      intelScreenPrivate *screen = intel->intelScreen;
      if (screen->current_rotation != 0) {
         __DRIdrawablePrivate *dPriv = intel->driDrawable;
         intelRotateWindow(intel, dPriv, BUFFER_BIT_FRONT_LEFT);
      }
   }
}


/**
 * Called via glFlush.
 */
static void
intelglFlush(GLcontext * ctx)
{
   intelFlush(ctx);
   intelCheckFrontRotate(ctx);
}

void
intelFinish(GLcontext * ctx)
{
   struct intel_context *intel = intel_context(ctx);
   intelFlush(ctx);
   if (intel->batch->last_fence) {
      driFenceFinish(intel->batch->last_fence,
                     0, GL_FALSE);
      driFenceUnReference(intel->batch->last_fence);
      intel->batch->last_fence = NULL;
   }
   intelCheckFrontRotate(ctx);
}


void
intelInitDriverFunctions(struct dd_function_table *functions)
{
   _mesa_init_driver_functions(functions);

   functions->Flush = intelglFlush;
   functions->Finish = intelFinish;
   functions->GetString = intelGetString;
   functions->UpdateState = intelInvalidateState;
   functions->CopyColorTable = _swrast_CopyColorTable;
   functions->CopyColorSubTable = _swrast_CopyColorSubTable;
   functions->CopyConvolutionFilter1D = _swrast_CopyConvolutionFilter1D;
   functions->CopyConvolutionFilter2D = _swrast_CopyConvolutionFilter2D;

   intelInitTextureFuncs(functions);
   intelInitPixelFuncs(functions);
   intelInitStateFuncs(functions);
   intelInitBufferFuncs(functions);
}


GLboolean
intelInitContext(struct intel_context *intel,
                 const __GLcontextModes * mesaVis,
                 __DRIcontextPrivate * driContextPriv,
                 void *sharedContextPrivate,
                 struct dd_function_table *functions)
{
   GLcontext *ctx = &intel->ctx;
   GLcontext *shareCtx = (GLcontext *) sharedContextPrivate;
   __DRIscreenPrivate *sPriv = driContextPriv->driScreenPriv;
   intelScreenPrivate *intelScreen = (intelScreenPrivate *) sPriv->private;
   drmI830Sarea *saPriv = (drmI830Sarea *)
      (((GLubyte *) sPriv->pSAREA) + intelScreen->sarea_priv_offset);
   int fthrottle_mode;

   if (!_mesa_initialize_context(&intel->ctx,
                                 mesaVis, shareCtx,
                                 functions, (void *) intel))
      return GL_FALSE;

   driContextPriv->driverPrivate = intel;
   intel->intelScreen = intelScreen;
   intel->driScreen = sPriv;
   intel->sarea = saPriv;

   intel->width = intelScreen->width;
   intel->height = intelScreen->height;
   intel->current_rotation = intelScreen->current_rotation;

   if (!lockMutexInit) {
      lockMutexInit = GL_TRUE;
      _glthread_INIT_MUTEX(lockMutex);
   }

   driParseConfigFiles(&intel->optionCache, &intelScreen->optionCache,
                       intel->driScreen->myNum, "i915");

   ctx->Const.MaxTextureMaxAnisotropy = 2.0;

   /* This doesn't yet catch all non-conformant rendering, but it's a
    * start.
    */
   if (getenv("INTEL_STRICT_CONFORMANCE")) {
      intel->strict_conformance = 1;
   }

   ctx->Const.MinLineWidth = 1.0;
   ctx->Const.MinLineWidthAA = 1.0;
   ctx->Const.MaxLineWidth = 3.0;
   ctx->Const.MaxLineWidthAA = 3.0;
   ctx->Const.LineWidthGranularity = 1.0;

   ctx->Const.MinPointSize = 1.0;
   ctx->Const.MinPointSizeAA = 1.0;
   ctx->Const.MaxPointSize = 255.0;
   ctx->Const.MaxPointSizeAA = 3.0;
   ctx->Const.PointSizeGranularity = 1.0;

   /* reinitialize the context point state.
    * It depend on constants in __GLcontextRec::Const
    */
   _mesa_init_point(ctx);

   ctx->Const.MaxColorAttachments = 4;  /* XXX FBO: review this */

   /* Initialize the software rasterizer and helper modules. */
   _swrast_CreateContext(ctx);
   _vbo_CreateContext(ctx);
   _tnl_CreateContext(ctx);
   _swsetup_CreateContext(ctx);

   /* Install the customized pipeline: */
   _tnl_destroy_pipeline(ctx);
   _tnl_install_pipeline(ctx, intel_pipeline);

   /* Configure swrast to match hardware characteristics: */
   _swrast_allow_pixel_fog(ctx, GL_FALSE);
   _swrast_allow_vertex_fog(ctx, GL_TRUE);

   /* Dri stuff */
   intel->hHWContext = driContextPriv->hHWContext;
   intel->driFd = sPriv->fd;
   intel->driHwLock = (drmLock *) & sPriv->pSAREA->lock;

   intel->hw_stipple = 1;

   /* XXX FBO: this doesn't seem to be used anywhere */
   switch (mesaVis->depthBits) {
   case 0:                     /* what to do in this case? */
   case 16:
      intel->polygon_offset_scale = 1.0 / 0xffff;
      break;
   case 24:
      intel->polygon_offset_scale = 2.0 / 0xffffff;     /* req'd to pass glean */
      break;
   default:
      assert(0);
      break;
   }

   /* Initialize swrast, tnl driver tables: */
   intelInitSpanFuncs(ctx);
   intelInitTriFuncs(ctx);


   intel->RenderIndex = ~0;

   fthrottle_mode = driQueryOptioni(&intel->optionCache, "fthrottle_mode");
   intel->iw.irq_seq = -1;
   intel->irqsEmitted = 0;

   intel->do_irqs = (intel->intelScreen->irq_active &&
                     fthrottle_mode == DRI_CONF_FTHROTTLE_IRQS);

   intel->do_usleeps = (fthrottle_mode == DRI_CONF_FTHROTTLE_USLEEPS);

   _math_matrix_ctr(&intel->ViewportMatrix);

   /* Disable imaging extension until convolution is working in
    * teximage paths:
    */
   driInitExtensions(ctx, card_extensions,
/* 		      GL_TRUE, */
                     GL_FALSE);


   intel->batch = intel_batchbuffer_alloc(intel);
   intel->last_swap_fence = NULL;
   intel->first_swap_fence = NULL;

   intel_bufferobj_init(intel);
   intel_fbo_init(intel);

   if (intel->ctx.Mesa_DXTn) {
      _mesa_enable_extension(ctx, "GL_EXT_texture_compression_s3tc");
      _mesa_enable_extension(ctx, "GL_S3_s3tc");
   }
   else if (driQueryOptionb(&intel->optionCache, "force_s3tc_enable")) {
      _mesa_enable_extension(ctx, "GL_EXT_texture_compression_s3tc");
   }

   intel->prim.primitive = ~0;


#if DO_DEBUG
   INTEL_DEBUG = driParseDebugString(getenv("INTEL_DEBUG"), debug_control);
#endif

   if (getenv("INTEL_NO_RAST")) {
      fprintf(stderr, "disabling 3D rasterization\n");
      FALLBACK(intel, INTEL_FALLBACK_USER, 1);
   }

   return GL_TRUE;
}

void
intelDestroyContext(__DRIcontextPrivate * driContextPriv)
{
   struct intel_context *intel =
      (struct intel_context *) driContextPriv->driverPrivate;

   assert(intel);               /* should never be null */
   if (intel) {
      GLboolean release_texture_heaps;

      INTEL_FIREVERTICES(intel);

      intel->vtbl.destroy(intel);

      release_texture_heaps = (intel->ctx.Shared->RefCount == 1);
      _swsetup_DestroyContext(&intel->ctx);
      _tnl_DestroyContext(&intel->ctx);
      _vbo_DestroyContext(&intel->ctx);

      _swrast_DestroyContext(&intel->ctx);
      intel->Fallback = 0;      /* don't call _swrast_Flush later */

      intel_batchbuffer_free(intel->batch);

      if (intel->last_swap_fence) {
	 driFenceFinish(intel->last_swap_fence, DRM_FENCE_TYPE_EXE, GL_TRUE);
	 driFenceUnReference(intel->last_swap_fence);
	 intel->last_swap_fence = NULL;
      }
      if (intel->first_swap_fence) {
	 driFenceFinish(intel->first_swap_fence, DRM_FENCE_TYPE_EXE, GL_TRUE);
	 driFenceUnReference(intel->first_swap_fence);
	 intel->first_swap_fence = NULL;
      }


      if (release_texture_heaps) {
         /* This share group is about to go away, free our private
          * texture object data.
          */
         if (INTEL_DEBUG & DEBUG_TEXTURE)
            fprintf(stderr, "do something to free texture heaps\n");
      }

      /* free the Mesa context */
      _mesa_free_context_data(&intel->ctx);
   }
}

GLboolean
intelUnbindContext(__DRIcontextPrivate * driContextPriv)
{
   return GL_TRUE;
}

GLboolean
intelMakeCurrent(__DRIcontextPrivate * driContextPriv,
                 __DRIdrawablePrivate * driDrawPriv,
                 __DRIdrawablePrivate * driReadPriv)
{

   if (driContextPriv) {
      struct intel_context *intel =
         (struct intel_context *) driContextPriv->driverPrivate;
      struct intel_framebuffer *intel_fb =
	 (struct intel_framebuffer *) driDrawPriv->driverPrivate;
      GLframebuffer *readFb = (GLframebuffer *) driReadPriv->driverPrivate;


      /* XXX FBO temporary fix-ups! */
      /* if the renderbuffers don't have regions, init them from the context */
      {
         struct intel_renderbuffer *irbDepth
            = intel_get_renderbuffer(&intel_fb->Base, BUFFER_DEPTH);
         struct intel_renderbuffer *irbStencil
            = intel_get_renderbuffer(&intel_fb->Base, BUFFER_STENCIL);

         if (intel_fb->color_rb[0] && !intel_fb->color_rb[0]->region) {
            intel_region_reference(&intel_fb->color_rb[0]->region,
				   intel->intelScreen->front_region);
         }
         if (intel_fb->color_rb[1] && !intel_fb->color_rb[1]->region) {
            intel_region_reference(&intel_fb->color_rb[1]->region,
				   intel->intelScreen->back_region);
         }
         if (intel_fb->color_rb[2] && !intel_fb->color_rb[2]->region) {
            intel_region_reference(&intel_fb->color_rb[2]->region,
				   intel->intelScreen->third_region);
         }
         if (irbDepth && !irbDepth->region) {
            intel_region_reference(&irbDepth->region, intel->intelScreen->depth_region);
         }
         if (irbStencil && !irbStencil->region) {
            intel_region_reference(&irbStencil->region, intel->intelScreen->depth_region);
         }
      }

      /* set GLframebuffer size to match window, if needed */
      driUpdateFramebufferSize(&intel->ctx, driDrawPriv);

      if (driReadPriv != driDrawPriv) {
	 driUpdateFramebufferSize(&intel->ctx, driReadPriv);
      }

      _mesa_make_current(&intel->ctx, &intel_fb->Base, readFb);

      /* The drawbuffer won't always be updated by _mesa_make_current: 
       */
      if (intel->ctx.DrawBuffer == &intel_fb->Base) {

	 if (intel->driDrawable != driDrawPriv) {
	    intel_fb->vblank_flags = (intel->intelScreen->irq_active != 0)
	       ? driGetDefaultVBlankFlags(&intel->optionCache)
	       : VBLANK_FLAG_NO_IRQ;
	    (*dri_interface->getUST) (&intel_fb->swap_ust);
	    driDrawableInitVBlank(driDrawPriv, intel_fb->vblank_flags,
				  &intel_fb->vbl_seq);
	    intel->driDrawable = driDrawPriv;
	    intelWindowMoved(intel);
	 }

	 intel_draw_buffer(&intel->ctx, &intel_fb->Base);
      }
   }
   else {
      _mesa_make_current(NULL, NULL, NULL);
   }

   return GL_TRUE;
}

static void
intelContendedLock(struct intel_context *intel, GLuint flags)
{
   __DRIdrawablePrivate *dPriv = intel->driDrawable;
   __DRIscreenPrivate *sPriv = intel->driScreen;
   intelScreenPrivate *intelScreen = (intelScreenPrivate *) sPriv->private;
   drmI830Sarea *sarea = intel->sarea;

   drmGetLock(intel->driFd, intel->hHWContext, flags);

   if (INTEL_DEBUG & DEBUG_LOCK)
      _mesa_printf("%s - got contended lock\n", __progname);

   /* If the window moved, may need to set a new cliprect now.
    *
    * NOTE: This releases and regains the hw lock, so all state
    * checking must be done *after* this call:
    */
   if (dPriv)
      DRI_VALIDATE_DRAWABLE_INFO(sPriv, dPriv);

   if (sarea->width != intelScreen->width ||
       sarea->height != intelScreen->height ||
       sarea->rotation != intelScreen->current_rotation) {

      intelUpdateScreenRotation(sPriv, sarea);
   }

   if (sarea->width != intel->width ||
       sarea->height != intel->height ||
       sarea->rotation != intel->current_rotation) {
      
      void *batchMap = intel->batch->map;
      
      /*
       * FIXME: Really only need to do this when drawing to a
       * common back- or front buffer.
       */

      /*
       * This will drop the outstanding batchbuffer on the floor
       */

      if (batchMap != NULL) {
	 driBOUnmap(intel->batch->buffer);
	 intel->batch->map = NULL;
      }

      intel_batchbuffer_reset(intel->batch);

      if (batchMap == NULL) {
	 driBOUnmap(intel->batch->buffer);
	 intel->batch->map = NULL;
      }

      /* lose all primitives */
      intel->prim.primitive = ~0;
      intel->prim.start_ptr = 0;
      intel->prim.flush = 0;

      /* re-emit all state */
      intel->vtbl.lost_hardware(intel);

      /* force window update */
      intel->lastStamp = 0;

      intel->width = sarea->width;
      intel->height = sarea->height;
      intel->current_rotation = sarea->rotation;
   }

   /* Drawable changed?
    */
   if (dPriv && intel->lastStamp != dPriv->lastStamp) {
      intelWindowMoved(intel);
      intel->lastStamp = dPriv->lastStamp;
   }
}



/* Lock the hardware and validate our state.  
 */
void LOCK_HARDWARE( struct intel_context *intel )
{
    char __ret=0;
    struct intel_framebuffer *intel_fb = NULL;
    struct intel_renderbuffer *intel_rb = NULL;
    _glthread_LOCK_MUTEX(lockMutex);
    assert(!intel->locked);

    if (intel->driDrawable) {
       intel_fb = intel->driDrawable->driverPrivate;

       if (intel_fb)
	  intel_rb =
	     intel_get_renderbuffer(&intel_fb->Base,
				    intel_fb->Base._ColorDrawBufferMask[0] ==
				    BUFFER_BIT_FRONT_LEFT ? BUFFER_FRONT_LEFT :
				    BUFFER_BACK_LEFT);
    }

    if (intel_rb && (intel_fb->vbl_waited - intel_rb->vbl_pending) > (1<<23)) {
	drmVBlank vbl;

	vbl.request.type = DRM_VBLANK_ABSOLUTE;

	if ( intel_fb->vblank_flags & VBLANK_FLAG_SECONDARY ) {
	    vbl.request.type |= DRM_VBLANK_SECONDARY;
	}

	vbl.request.sequence = intel_rb->vbl_pending;
	drmWaitVBlank(intel->driFd, &vbl);
	intel_fb->vbl_waited = vbl.reply.sequence;
    }

    DRM_CAS(intel->driHwLock, intel->hHWContext,
        (DRM_LOCK_HELD|intel->hHWContext), __ret);

    if (__ret)
        intelContendedLock( intel, 0 );

    if (INTEL_DEBUG & DEBUG_LOCK)
      _mesa_printf("%s - locked\n", __progname);

    intel->locked = 1;
}


  /* Unlock the hardware using the global current context 
   */
void UNLOCK_HARDWARE( struct intel_context *intel )
{
   intel->locked = 0;

   DRM_UNLOCK(intel->driFd, intel->driHwLock, intel->hHWContext);

   _glthread_UNLOCK_MUTEX(lockMutex);

   if (INTEL_DEBUG & DEBUG_LOCK)
      _mesa_printf("%s - unlocked\n", __progname);
}