Added MesaLib-7.6

1 files changed, 957 insertions, 0 deletions

diff --git a/mesalib/src/mesa/drivers/dri/common/dri_util.c b/mesalib/src/mesa/drivers/dri/common/dri_util.c
new file mode 100644
index 000000000..e48e10d7c
--- /dev/null
+++ b/mesalib/src/mesa/drivers/dri/common/dri_util.c
@@ -0,0 +1,957 @@
+/**
+ * \file dri_util.c
+ * DRI utility functions.
+ *
+ * This module acts as glue between GLX and the actual hardware driver.  A DRI
+ * driver doesn't really \e have to use any of this - it's optional.  But, some
+ * useful stuff is done here that otherwise would have to be duplicated in most
+ * drivers.
+ * 
+ * Basically, these utility functions take care of some of the dirty details of
+ * screen initialization, context creation, context binding, DRM setup, etc.
+ *
+ * These functions are compiled into each DRI driver so libGL.so knows nothing
+ * about them.
+ */
+
+
+#include <assert.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <stdio.h>
+
+#ifndef MAP_FAILED
+#define MAP_FAILED ((void *)-1)
+#endif
+
+#include "main/imports.h"
+#define None 0
+
+#include "dri_util.h"
+#include "drm_sarea.h"
+#include "utils.h"
+
+#ifndef GLX_OML_sync_control
+typedef GLboolean ( * PFNGLXGETMSCRATEOMLPROC) (__DRIdrawable *drawable, int32_t *numerator, int32_t *denominator);
+#endif
+
+static void dri_get_drawable(__DRIdrawable *pdp);
+static void dri_put_drawable(__DRIdrawable *pdp);
+
+/**
+ * This is just a token extension used to signal that the driver
+ * supports setting a read drawable.
+ */
+const __DRIextension driReadDrawableExtension = {
+    __DRI_READ_DRAWABLE, __DRI_READ_DRAWABLE_VERSION
+};
+
+/**
+ * Print message to \c stderr if the \c LIBGL_DEBUG environment variable
+ * is set. 
+ * 
+ * Is called from the drivers.
+ * 
+ * \param f \c printf like format string.
+ */
+void
+__driUtilMessage(const char *f, ...)
+{
+    va_list args;
+
+    if (getenv("LIBGL_DEBUG")) {
+        fprintf(stderr, "libGL: ");
+        va_start(args, f);
+        vfprintf(stderr, f, args);
+        va_end(args);
+        fprintf(stderr, "\n");
+    }
+}
+
+GLint
+driIntersectArea( drm_clip_rect_t rect1, drm_clip_rect_t rect2 )
+{
+   if (rect2.x1 > rect1.x1) rect1.x1 = rect2.x1;
+   if (rect2.x2 < rect1.x2) rect1.x2 = rect2.x2;
+   if (rect2.y1 > rect1.y1) rect1.y1 = rect2.y1;
+   if (rect2.y2 < rect1.y2) rect1.y2 = rect2.y2;
+
+   if (rect1.x1 > rect1.x2 || rect1.y1 > rect1.y2) return 0;
+
+   return (rect1.x2 - rect1.x1) * (rect1.y2 - rect1.y1);
+}
+
+/*****************************************************************/
+/** \name Context (un)binding functions                          */
+/*****************************************************************/
+/*@{*/
+
+/**
+ * Unbind context.
+ * 
+ * \param scrn the screen.
+ * \param gc context.
+ *
+ * \return \c GL_TRUE on success, or \c GL_FALSE on failure.
+ * 
+ * \internal
+ * This function calls __DriverAPIRec::UnbindContext, and then decrements
+ * __DRIdrawablePrivateRec::refcount which must be non-zero for a successful
+ * return.
+ * 
+ * While casting the opaque private pointers associated with the parameters
+ * into their respective real types it also assures they are not \c NULL. 
+ */
+static int driUnbindContext(__DRIcontext *pcp)
+{
+    __DRIscreen *psp;
+    __DRIdrawable *pdp;
+    __DRIdrawable *prp;
+
+    /*
+    ** Assume error checking is done properly in glXMakeCurrent before
+    ** calling driUnbindContext.
+    */
+
+    if (pcp == NULL)
+        return GL_FALSE;
+
+    psp = pcp->driScreenPriv;
+    pdp = pcp->driDrawablePriv;
+    prp = pcp->driReadablePriv;
+
+    /* already unbound */
+    if (!pdp && !prp)
+      return GL_TRUE;
+    /* Let driver unbind drawable from context */
+    (*psp->DriverAPI.UnbindContext)(pcp);
+
+    if (pdp->refcount == 0) {
+	/* ERROR!!! */
+	return GL_FALSE;
+    }
+
+    dri_put_drawable(pdp);
+
+    if (prp != pdp) {
+        if (prp->refcount == 0) {
+	    /* ERROR!!! */
+	    return GL_FALSE;
+	}
+
+    	dri_put_drawable(prp);
+    }
+
+
+    /* XXX this is disabled so that if we call SwapBuffers on an unbound
+     * window we can determine the last context bound to the window and
+     * use that context's lock. (BrianP, 2-Dec-2000)
+     */
+    pcp->driDrawablePriv = pcp->driReadablePriv = NULL;
+
+#if 0
+    /* Unbind the drawable */
+    pdp->driContextPriv = &psp->dummyContextPriv;
+#endif
+
+    return GL_TRUE;
+}
+
+/**
+ * This function takes both a read buffer and a draw buffer.  This is needed
+ * for \c glXMakeCurrentReadSGI or GLX 1.3's \c glXMakeContextCurrent
+ * function.
+ */
+static int driBindContext(__DRIcontext *pcp,
+			  __DRIdrawable *pdp,
+			  __DRIdrawable *prp)
+{
+    __DRIscreenPrivate *psp = pcp->driScreenPriv;
+
+    /* Bind the drawable to the context */
+
+    if (pcp) {
+	pcp->driDrawablePriv = pdp;
+	pcp->driReadablePriv = prp;
+	if (pdp) {
+	    pdp->driContextPriv = pcp;
+    	    dri_get_drawable(pdp);
+	}
+	if ( prp && pdp != prp ) {
+    	    dri_get_drawable(prp);
+	}
+    }
+
+    /*
+    ** Now that we have a context associated with this drawable, we can
+    ** initialize the drawable information if has not been done before.
+    */
+
+    if (!psp->dri2.enabled) {
+	if (pdp && !pdp->pStamp) {
+	    DRM_SPINLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
+	    __driUtilUpdateDrawableInfo(pdp);
+	    DRM_SPINUNLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
+	}
+	if (prp && pdp != prp && !prp->pStamp) {
+	    DRM_SPINLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
+	    __driUtilUpdateDrawableInfo(prp);
+	    DRM_SPINUNLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
+        }
+    }
+
+    /* Call device-specific MakeCurrent */
+
+    return (*psp->DriverAPI.MakeCurrent)(pcp, pdp, prp);
+}
+
+/*@}*/
+
+
+/*****************************************************************/
+/** \name Drawable handling functions                            */
+/*****************************************************************/
+/*@{*/
+
+/**
+ * Update private drawable information.
+ *
+ * \param pdp pointer to the private drawable information to update.
+ * 
+ * This function basically updates the __DRIdrawablePrivate struct's
+ * cliprect information by calling \c __DRIinterfaceMethods::getDrawableInfo.
+ * This is usually called by the DRI_VALIDATE_DRAWABLE_INFO macro which
+ * compares the __DRIdrwablePrivate pStamp and lastStamp values.  If
+ * the values are different that means we have to update the clipping
+ * info.
+ */
+void
+__driUtilUpdateDrawableInfo(__DRIdrawablePrivate *pdp)
+{
+    __DRIscreenPrivate *psp = pdp->driScreenPriv;
+    __DRIcontextPrivate *pcp = pdp->driContextPriv;
+    
+    if (!pcp 
+	|| ((pdp != pcp->driDrawablePriv) && (pdp != pcp->driReadablePriv))) {
+	/* ERROR!!! 
+	 * ...but we must ignore it. There can be many contexts bound to a
+	 * drawable.
+	 */
+    }
+
+    if (pdp->pClipRects) {
+	_mesa_free(pdp->pClipRects); 
+	pdp->pClipRects = NULL;
+    }
+
+    if (pdp->pBackClipRects) {
+	_mesa_free(pdp->pBackClipRects); 
+	pdp->pBackClipRects = NULL;
+    }
+
+    DRM_SPINUNLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
+
+    if (! (*psp->getDrawableInfo->getDrawableInfo)(pdp,
+			  &pdp->index, &pdp->lastStamp,
+			  &pdp->x, &pdp->y, &pdp->w, &pdp->h,
+			  &pdp->numClipRects, &pdp->pClipRects,
+			  &pdp->backX,
+			  &pdp->backY,
+			  &pdp->numBackClipRects,
+			  &pdp->pBackClipRects,
+			  pdp->loaderPrivate)) {
+	/* Error -- eg the window may have been destroyed.  Keep going
+	 * with no cliprects.
+	 */
+        pdp->pStamp = &pdp->lastStamp; /* prevent endless loop */
+	pdp->numClipRects = 0;
+	pdp->pClipRects = NULL;
+	pdp->numBackClipRects = 0;
+	pdp->pBackClipRects = NULL;
+    }
+    else
+       pdp->pStamp = &(psp->pSAREA->drawableTable[pdp->index].stamp);
+
+    DRM_SPINLOCK(&psp->pSAREA->drawable_lock, psp->drawLockID);
+}
+
+/*@}*/
+
+/*****************************************************************/
+/** \name GLX callbacks                                          */
+/*****************************************************************/
+/*@{*/
+
+static void driReportDamage(__DRIdrawable *pdp,
+			    struct drm_clip_rect *pClipRects, int numClipRects)
+{
+    __DRIscreen *psp = pdp->driScreenPriv;
+
+    /* Check that we actually have the new damage report method */
+    if (psp->damage) {
+	/* Report the damage.  Currently, all our drivers draw
+	 * directly to the front buffer, so we report the damage there
+	 * rather than to the backing storein (if any).
+	 */
+	(*psp->damage->reportDamage)(pdp,
+				     pdp->x, pdp->y,
+				     pClipRects, numClipRects,
+				     GL_TRUE, pdp->loaderPrivate);
+    }
+}
+
+
+/**
+ * Swap buffers.
+ *
+ * \param drawablePrivate opaque pointer to the per-drawable private info.
+ * 
+ * \internal
+ * This function calls __DRIdrawablePrivate::swapBuffers.
+ * 
+ * Is called directly from glXSwapBuffers().
+ */
+static void driSwapBuffers(__DRIdrawable *dPriv)
+{
+    __DRIscreen *psp = dPriv->driScreenPriv;
+    drm_clip_rect_t *rects;
+    int i;
+
+    psp->DriverAPI.SwapBuffers(dPriv);
+
+    if (!dPriv->numClipRects)
+        return;
+
+    rects = _mesa_malloc(sizeof(*rects) * dPriv->numClipRects);
+
+    if (!rects)
+        return;
+
+    for (i = 0; i < dPriv->numClipRects; i++) {
+        rects[i].x1 = dPriv->pClipRects[i].x1 - dPriv->x;
+        rects[i].y1 = dPriv->pClipRects[i].y1 - dPriv->y;
+        rects[i].x2 = dPriv->pClipRects[i].x2 - dPriv->x;
+        rects[i].y2 = dPriv->pClipRects[i].y2 - dPriv->y;
+    }
+
+    driReportDamage(dPriv, rects, dPriv->numClipRects);
+    _mesa_free(rects);
+}
+
+static int driDrawableGetMSC( __DRIscreen *sPriv, __DRIdrawable *dPriv,
+			      int64_t *msc )
+{
+    return sPriv->DriverAPI.GetDrawableMSC(sPriv, dPriv, msc);
+}
+
+
+static int driWaitForMSC(__DRIdrawable *dPriv, int64_t target_msc,
+			 int64_t divisor, int64_t remainder,
+			 int64_t * msc, int64_t * sbc)
+{
+    __DRIswapInfo  sInfo;
+    int  status;
+
+    status = dPriv->driScreenPriv->DriverAPI.WaitForMSC( dPriv, target_msc,
+                                                         divisor, remainder,
+                                                         msc );
+
+    /* GetSwapInfo() may not be provided by the driver if GLX_SGI_video_sync
+     * is supported but GLX_OML_sync_control is not.  Therefore, don't return
+     * an error value if GetSwapInfo() is not implemented.
+    */
+    if ( status == 0
+         && dPriv->driScreenPriv->DriverAPI.GetSwapInfo ) {
+        status = dPriv->driScreenPriv->DriverAPI.GetSwapInfo( dPriv, & sInfo );
+        *sbc = sInfo.swap_count;
+    }
+
+    return status;
+}
+
+
+const __DRImediaStreamCounterExtension driMediaStreamCounterExtension = {
+    { __DRI_MEDIA_STREAM_COUNTER, __DRI_MEDIA_STREAM_COUNTER_VERSION },
+    driWaitForMSC,
+    driDrawableGetMSC,
+};
+
+
+static void driCopySubBuffer(__DRIdrawable *dPriv,
+			      int x, int y, int w, int h)
+{
+    drm_clip_rect_t rect;
+
+    rect.x1 = x;
+    rect.y1 = dPriv->h - y - h;
+    rect.x2 = x + w;
+    rect.y2 = rect.y1 + h;
+    driReportDamage(dPriv, &rect, 1);
+
+    dPriv->driScreenPriv->DriverAPI.CopySubBuffer(dPriv, x, y, w, h);
+}
+
+const __DRIcopySubBufferExtension driCopySubBufferExtension = {
+    { __DRI_COPY_SUB_BUFFER, __DRI_COPY_SUB_BUFFER_VERSION },
+    driCopySubBuffer
+};
+
+static void driSetSwapInterval(__DRIdrawable *dPriv, unsigned int interval)
+{
+    dPriv->swap_interval = interval;
+}
+
+static unsigned int driGetSwapInterval(__DRIdrawable *dPriv)
+{
+    return dPriv->swap_interval;
+}
+
+const __DRIswapControlExtension driSwapControlExtension = {
+    { __DRI_SWAP_CONTROL, __DRI_SWAP_CONTROL_VERSION },
+    driSetSwapInterval,
+    driGetSwapInterval
+};
+
+
+/**
+ * This is called via __DRIscreenRec's createNewDrawable pointer.
+ */
+static __DRIdrawable *
+driCreateNewDrawable(__DRIscreen *psp, const __DRIconfig *config,
+		     drm_drawable_t hwDrawable, int renderType,
+		     const int *attrs, void *data)
+{
+    __DRIdrawable *pdp;
+
+    /* Since pbuffers are not yet supported, no drawable attributes are
+     * supported either.
+     */
+    (void) attrs;
+
+    pdp = _mesa_malloc(sizeof *pdp);
+    if (!pdp) {
+	return NULL;
+    }
+
+    pdp->loaderPrivate = data;
+    pdp->hHWDrawable = hwDrawable;
+    pdp->refcount = 1;
+    pdp->pStamp = NULL;
+    pdp->lastStamp = 0;
+    pdp->index = 0;
+    pdp->x = 0;
+    pdp->y = 0;
+    pdp->w = 0;
+    pdp->h = 0;
+    pdp->numClipRects = 0;
+    pdp->numBackClipRects = 0;
+    pdp->pClipRects = NULL;
+    pdp->pBackClipRects = NULL;
+    pdp->vblSeq = 0;
+    pdp->vblFlags = 0;
+
+    pdp->driScreenPriv = psp;
+    pdp->driContextPriv = &psp->dummyContextPriv;
+
+    if (!(*psp->DriverAPI.CreateBuffer)(psp, pdp, &config->modes,
+					renderType == GLX_PIXMAP_BIT)) {
+       _mesa_free(pdp);
+       return NULL;
+    }
+
+    pdp->msc_base = 0;
+
+    /* This special default value is replaced with the configured
+     * default value when the drawable is first bound to a direct
+     * rendering context. 
+     */
+    pdp->swap_interval = (unsigned)-1;
+
+    return pdp;
+}
+
+
+static __DRIdrawable *
+dri2CreateNewDrawable(__DRIscreen *screen,
+		      const __DRIconfig *config,
+		      void *loaderPrivate)
+{
+    __DRIdrawable *pdraw;
+
+    pdraw = driCreateNewDrawable(screen, config, 0, 0, NULL, loaderPrivate);
+    if (!pdraw)
+    	return NULL;
+
+    pdraw->pClipRects = _mesa_malloc(sizeof *pdraw->pBackClipRects);
+    pdraw->pBackClipRects = _mesa_malloc(sizeof *pdraw->pBackClipRects);
+
+    return pdraw;
+}
+
+static void dri_get_drawable(__DRIdrawable *pdp)
+{
+    pdp->refcount++;
+}
+	
+static void dri_put_drawable(__DRIdrawable *pdp)
+{
+    __DRIscreenPrivate *psp;
+
+    pdp->refcount--;
+    if (pdp->refcount)
+	return;
+
+    if (pdp) {
+	psp = pdp->driScreenPriv;
+        (*psp->DriverAPI.DestroyBuffer)(pdp);
+	if (pdp->pClipRects) {
+	    _mesa_free(pdp->pClipRects);
+	    pdp->pClipRects = NULL;
+	}
+	if (pdp->pBackClipRects) {
+	    _mesa_free(pdp->pBackClipRects);
+	    pdp->pBackClipRects = NULL;
+	}
+	_mesa_free(pdp);
+    }
+}
+
+static void
+driDestroyDrawable(__DRIdrawable *pdp)
+{
+    dri_put_drawable(pdp);
+}
+
+/*@}*/
+
+
+/*****************************************************************/
+/** \name Context handling functions                             */
+/*****************************************************************/
+/*@{*/
+
+/**
+ * Destroy the per-context private information.
+ * 
+ * \internal
+ * This function calls __DriverAPIRec::DestroyContext on \p contextPrivate, calls
+ * drmDestroyContext(), and finally frees \p contextPrivate.
+ */
+static void
+driDestroyContext(__DRIcontext *pcp)
+{
+    if (pcp) {
+	(*pcp->driScreenPriv->DriverAPI.DestroyContext)(pcp);
+	_mesa_free(pcp);
+    }
+}
+
+
+/**
+ * Create the per-drawable private driver information.
+ * 
+ * \param render_type   Type of rendering target.  \c GLX_RGBA is the only
+ *                      type likely to ever be supported for direct-rendering.
+ * \param shared        Context with which to share textures, etc. or NULL
+ *
+ * \returns An opaque pointer to the per-context private information on
+ *          success, or \c NULL on failure.
+ * 
+ * \internal
+ * This function allocates and fills a __DRIcontextPrivateRec structure.  It
+ * performs some device independent initialization and passes all the
+ * relevent information to __DriverAPIRec::CreateContext to create the
+ * context.
+ *
+ */
+static __DRIcontext *
+driCreateNewContext(__DRIscreen *psp, const __DRIconfig *config,
+		    int render_type, __DRIcontext *shared, 
+		    drm_context_t hwContext, void *data)
+{
+    __DRIcontext *pcp;
+    void * const shareCtx = (shared != NULL) ? shared->driverPrivate : NULL;
+
+    pcp = _mesa_malloc(sizeof *pcp);
+    if (!pcp)
+	return NULL;
+
+    pcp->driScreenPriv = psp;
+    pcp->driDrawablePriv = NULL;
+
+    /* When the first context is created for a screen, initialize a "dummy"
+     * context.
+     */
+
+    if (!psp->dri2.enabled && !psp->dummyContextPriv.driScreenPriv) {
+        psp->dummyContextPriv.hHWContext = psp->pSAREA->dummy_context;
+        psp->dummyContextPriv.driScreenPriv = psp;
+        psp->dummyContextPriv.driDrawablePriv = NULL;
+        psp->dummyContextPriv.driverPrivate = NULL;
+	/* No other fields should be used! */
+    }
+
+    pcp->hHWContext = hwContext;
+
+    if ( !(*psp->DriverAPI.CreateContext)(&config->modes, pcp, shareCtx) ) {
+        _mesa_free(pcp);
+        return NULL;
+    }
+
+    return pcp;
+}
+
+
+static __DRIcontext *
+dri2CreateNewContext(__DRIscreen *screen, const __DRIconfig *config,
+		      __DRIcontext *shared, void *data)
+{
+    return driCreateNewContext(screen, config, 0, shared, 0, data);
+}
+
+
+static int
+driCopyContext(__DRIcontext *dest, __DRIcontext *src, unsigned long mask)
+{
+    return GL_FALSE;
+}
+
+/*@}*/
+
+
+/*****************************************************************/
+/** \name Screen handling functions                              */
+/*****************************************************************/
+/*@{*/
+
+/**
+ * Destroy the per-screen private information.
+ * 
+ * \internal
+ * This function calls __DriverAPIRec::DestroyScreen on \p screenPrivate, calls
+ * drmClose(), and finally frees \p screenPrivate.
+ */
+static void driDestroyScreen(__DRIscreen *psp)
+{
+    if (psp) {
+	/* No interaction with the X-server is possible at this point.  This
+	 * routine is called after XCloseDisplay, so there is no protocol
+	 * stream open to the X-server anymore.
+	 */
+
+	if (psp->DriverAPI.DestroyScreen)
+	    (*psp->DriverAPI.DestroyScreen)(psp);
+
+	if (!psp->dri2.enabled) {
+	   (void)drmUnmap((drmAddress)psp->pSAREA, SAREA_MAX);
+	   (void)drmUnmap((drmAddress)psp->pFB, psp->fbSize);
+	   (void)drmCloseOnce(psp->fd);
+	}
+
+	_mesa_free(psp);
+    }
+}
+
+static void
+setupLoaderExtensions(__DRIscreen *psp,
+		      const __DRIextension **extensions)
+{
+    int i;
+
+    for (i = 0; extensions[i]; i++) {
+	if (strcmp(extensions[i]->name, __DRI_GET_DRAWABLE_INFO) == 0)
+	    psp->getDrawableInfo = (__DRIgetDrawableInfoExtension *) extensions[i];
+	if (strcmp(extensions[i]->name, __DRI_DAMAGE) == 0)
+	    psp->damage = (__DRIdamageExtension *) extensions[i];
+	if (strcmp(extensions[i]->name, __DRI_SYSTEM_TIME) == 0)
+	    psp->systemTime = (__DRIsystemTimeExtension *) extensions[i];
+	if (strcmp(extensions[i]->name, __DRI_DRI2_LOADER) == 0)
+	    psp->dri2.loader = (__DRIdri2LoaderExtension *) extensions[i];
+    }
+}
+
+/**
+ * This is the bootstrap function for the driver.  libGL supplies all of the
+ * requisite information about the system, and the driver initializes itself.
+ * This routine also fills in the linked list pointed to by \c driver_modes
+ * with the \c __GLcontextModes that the driver can support for windows or
+ * pbuffers.
+ *
+ * For legacy DRI.
+ * 
+ * \param scrn  Index of the screen
+ * \param ddx_version Version of the 2D DDX.  This may not be meaningful for
+ *                    all drivers.
+ * \param dri_version Version of the "server-side" DRI.
+ * \param drm_version Version of the kernel DRM.
+ * \param frame_buffer Data describing the location and layout of the
+ *                     framebuffer.
+ * \param pSAREA       Pointer the the SAREA.
+ * \param fd           Device handle for the DRM.
+ * \param extensions   ??
+ * \param driver_modes  Returns modes suppoted by the driver
+ * \param loaderPrivate  ??
+ * 
+ * \note There is no need to check the minimum API version in this
+ * function.  Since the name of this function is versioned, it is
+ * impossible for a loader that is too old to even load this driver.
+ */
+static __DRIscreen *
+driCreateNewScreen(int scrn,
+		   const __DRIversion *ddx_version,
+		   const __DRIversion *dri_version,
+		   const __DRIversion *drm_version,
+		   const __DRIframebuffer *frame_buffer,
+		   drmAddress pSAREA, int fd, 
+		   const __DRIextension **extensions,
+		   const __DRIconfig ***driver_modes,
+		   void *loaderPrivate)
+{
+    static const __DRIextension *emptyExtensionList[] = { NULL };
+    __DRIscreen *psp;
+
+    psp = _mesa_calloc(sizeof *psp);
+    if (!psp)
+	return NULL;
+
+    setupLoaderExtensions(psp, extensions);
+
+    /*
+    ** NOT_DONE: This is used by the X server to detect when the client
+    ** has died while holding the drawable lock.  The client sets the
+    ** drawable lock to this value.
+    */
+    psp->drawLockID = 1;
+
+    psp->drm_version = *drm_version;
+    psp->ddx_version = *ddx_version;
+    psp->dri_version = *dri_version;
+
+    psp->pSAREA = pSAREA;
+    psp->lock = (drmLock *) &psp->pSAREA->lock;
+
+    psp->pFB = frame_buffer->base;
+    psp->fbSize = frame_buffer->size;
+    psp->fbStride = frame_buffer->stride;
+    psp->fbWidth = frame_buffer->width;
+    psp->fbHeight = frame_buffer->height;
+    psp->devPrivSize = frame_buffer->dev_priv_size;
+    psp->pDevPriv = frame_buffer->dev_priv;
+    psp->fbBPP = psp->fbStride * 8 / frame_buffer->width;
+
+    psp->extensions = emptyExtensionList;
+    psp->fd = fd;
+    psp->myNum = scrn;
+    psp->dri2.enabled = GL_FALSE;
+
+    /*
+    ** Do not init dummy context here; actual initialization will be
+    ** done when the first DRI context is created.  Init screen priv ptr
+    ** to NULL to let CreateContext routine that it needs to be inited.
+    */
+    psp->dummyContextPriv.driScreenPriv = NULL;
+
+    psp->DriverAPI = driDriverAPI;
+
+    *driver_modes = driDriverAPI.InitScreen(psp);
+    if (*driver_modes == NULL) {
+	_mesa_free(psp);
+	return NULL;
+    }
+
+    return psp;
+}
+
+/**
+ * DRI2
+ */
+static __DRIscreen *
+dri2CreateNewScreen(int scrn, int fd,
+		    const __DRIextension **extensions,
+		    const __DRIconfig ***driver_configs, void *data)
+{
+    static const __DRIextension *emptyExtensionList[] = { NULL };
+    __DRIscreen *psp;
+    drmVersionPtr version;
+
+    if (driDriverAPI.InitScreen2 == NULL)
+        return NULL;
+
+    psp = _mesa_calloc(sizeof(*psp));
+    if (!psp)
+	return NULL;
+
+    setupLoaderExtensions(psp, extensions);
+
+    version = drmGetVersion(fd);
+    if (version) {
+	psp->drm_version.major = version->version_major;
+	psp->drm_version.minor = version->version_minor;
+	psp->drm_version.patch = version->version_patchlevel;
+	drmFreeVersion(version);
+    }
+
+    psp->extensions = emptyExtensionList;
+    psp->fd = fd;
+    psp->myNum = scrn;
+    psp->dri2.enabled = GL_TRUE;
+
+    psp->DriverAPI = driDriverAPI;
+    *driver_configs = driDriverAPI.InitScreen2(psp);
+    if (*driver_configs == NULL) {
+	_mesa_free(psp);
+	return NULL;
+    }
+
+    psp->DriverAPI = driDriverAPI;
+
+    return psp;
+}
+
+static const __DRIextension **driGetExtensions(__DRIscreen *psp)
+{
+    return psp->extensions;
+}
+
+/** Core interface */
+const __DRIcoreExtension driCoreExtension = {
+    { __DRI_CORE, __DRI_CORE_VERSION },
+    NULL,
+    driDestroyScreen,
+    driGetExtensions,
+    driGetConfigAttrib,
+    driIndexConfigAttrib,
+    NULL,
+    driDestroyDrawable,
+    driSwapBuffers,
+    NULL,
+    driCopyContext,
+    driDestroyContext,
+    driBindContext,
+    driUnbindContext
+};
+
+/** Legacy DRI interface */
+const __DRIlegacyExtension driLegacyExtension = {
+    { __DRI_LEGACY, __DRI_LEGACY_VERSION },
+    driCreateNewScreen,
+    driCreateNewDrawable,
+    driCreateNewContext,
+};
+
+/** Legacy DRI interface */
+const __DRIdri2Extension driDRI2Extension = {
+    { __DRI_DRI2, __DRI_DRI2_VERSION },
+    dri2CreateNewScreen,
+    dri2CreateNewDrawable,
+    dri2CreateNewContext,
+};
+
+/* This is the table of extensions that the loader will dlsym() for. */
+PUBLIC const __DRIextension *__driDriverExtensions[] = {
+    &driCoreExtension.base,
+    &driLegacyExtension.base,
+    &driDRI2Extension.base,
+    NULL
+};
+
+static int
+driFrameTracking(__DRIdrawable *drawable, GLboolean enable)
+{
+    return GLX_BAD_CONTEXT;
+}
+
+static int
+driQueryFrameTracking(__DRIdrawable *dpriv,
+		      int64_t * sbc, int64_t * missedFrames,
+		      float * lastMissedUsage, float * usage)
+{
+   __DRIswapInfo   sInfo;
+   int             status;
+   int64_t         ust;
+   __DRIscreenPrivate *psp = dpriv->driScreenPriv;
+
+   status = dpriv->driScreenPriv->DriverAPI.GetSwapInfo( dpriv, & sInfo );
+   if ( status == 0 ) {
+      *sbc = sInfo.swap_count;
+      *missedFrames = sInfo.swap_missed_count;
+      *lastMissedUsage = sInfo.swap_missed_usage;
+
+      (*psp->systemTime->getUST)( & ust );
+      *usage = driCalculateSwapUsage( dpriv, sInfo.swap_ust, ust );
+   }
+
+   return status;
+}
+
+const __DRIframeTrackingExtension driFrameTrackingExtension = {
+    { __DRI_FRAME_TRACKING, __DRI_FRAME_TRACKING_VERSION },
+    driFrameTracking,
+    driQueryFrameTracking    
+};
+
+/**
+ * Calculate amount of swap interval used between GLX buffer swaps.
+ * 
+ * The usage value, on the range [0,max], is the fraction of total swap
+ * interval time used between GLX buffer swaps is calculated.
+ *
+ *            \f$p = t_d / (i * t_r)\f$
+ * 
+ * Where \f$t_d\f$ is the time since the last GLX buffer swap, \f$i\f$ is the
+ * swap interval (as set by \c glXSwapIntervalSGI), and \f$t_r\f$ time
+ * required for a single vertical refresh period (as returned by \c
+ * glXGetMscRateOML).
+ * 
+ * See the documentation for the GLX_MESA_swap_frame_usage extension for more
+ * details.
+ *
+ * \param   dPriv  Pointer to the private drawable structure.
+ * \return  If less than a single swap interval time period was required
+ *          between GLX buffer swaps, a number greater than 0 and less than
+ *          1.0 is returned.  If exactly one swap interval time period is
+ *          required, 1.0 is returned, and if more than one is required then
+ *          a number greater than 1.0 will be returned.
+ *
+ * \sa glXSwapIntervalSGI glXGetMscRateOML
+ * 
+ * \todo Instead of caching the \c glXGetMscRateOML function pointer, would it
+ *       be possible to cache the sync rate?
+ */
+float
+driCalculateSwapUsage( __DRIdrawablePrivate *dPriv, int64_t last_swap_ust,
+		       int64_t current_ust )
+{
+   int32_t   n;
+   int32_t   d;
+   int       interval;
+   float     usage = 1.0;
+   __DRIscreenPrivate *psp = dPriv->driScreenPriv;
+
+   if ( (*psp->systemTime->getMSCRate)(dPriv, &n, &d, dPriv->loaderPrivate) ) {
+      interval = (dPriv->swap_interval != 0) ? dPriv->swap_interval : 1;
+
+
+      /* We want to calculate
+       * (current_UST - last_swap_UST) / (interval * us_per_refresh).  We get
+       * current_UST by calling __glXGetUST.  last_swap_UST is stored in
+       * dPriv->swap_ust.  interval has already been calculated.
+       *
+       * The only tricky part is us_per_refresh.  us_per_refresh is
+       * 1000000 / MSC_rate.  We know the MSC_rate is n / d.  We can flip it
+       * around and say us_per_refresh = 1000000 * d / n.  Since this goes in
+       * the denominator of the final calculation, we calculate
+       * (interval * 1000000 * d) and move n into the numerator.
+       */
+
+      usage = (current_ust - last_swap_ust);
+      usage *= n;
+      usage /= (interval * d);
+      usage /= 1000000.0;
+   }
+   
+   return usage;
+}
+
+/*@}*/