Shared dri driver resources

1 files changed, 325 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/common/vblank.c b/src/mesa/drivers/dri/common/vblank.c
new file mode 100644
index 0000000000..e91dd65260
--- /dev/null
+++ b/src/mesa/drivers/dri/common/vblank.c
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+/* -*- mode: c; c-basic-offset: 3 -*- */
+/*
+ * (c) Copyright IBM Corporation 2002
+ * 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
+ * on 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
+ * VA LINUX SYSTEM, IBM AND/OR THEIR 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.
+ *
+ * Authors:
+ *    Ian Romanick <idr@us.ibm.com>
+ */
+/* $XFree86:$ */
+
+#include "glheader.h"
+#include "xf86drm.h"
+#include "mtypes.h"
+#include "macros.h"
+#include "dd.h"
+#include "vblank.h"
+
+
+/****************************************************************************/
+/**
+ * Get the current MSC refresh counter.
+ *
+ * Stores the 64-bit count of vertical refreshes since some (arbitrary)
+ * point in time in \c count.  Unless the value wraps around, which it
+ * may, it will never decrease.
+ *
+ * \warning This function is called from \c glXGetVideoSyncSGI, which expects
+ * a \c count of type \c unsigned (32-bit), and \c glXGetSyncValuesOML, which 
+ * expects a \c count of type \c int64_t (signed 64-bit).  The kernel ioctl 
+ * currently always returns a \c sequence of type \c unsigned.
+ *
+ * \param priv   Pointer to the DRI screen private struct.
+ * \param count  Storage to hold MSC counter.
+ * \return       Zero is returned on success.  A negative errno value
+ *               is returned on failure.
+ */
+int driGetMSC32( __DRIscreenPrivate * priv, int64_t * count )
+{
+   drmVBlank vbl;
+   int ret;
+
+   /* Don't wait for anything.  Just get the current refresh count. */
+
+   vbl.request.type = DRM_VBLANK_RELATIVE;
+   vbl.request.sequence = 0;
+
+   ret = drmWaitVBlank( priv->fd, &vbl );
+   *count = (int64_t)vbl.reply.sequence;
+
+   return ret;
+}
+
+
+/****************************************************************************/
+/**
+ * Wait for a specified refresh count.  This implements most of the
+ * functionality of \c glXWaitForMscOML from the GLX_OML_sync_control spec.
+ * Waits for the \c target_msc refresh.  If that has already passed, it
+ * waits until \f$(MSC \bmod divisor)\f$ is equal to \c remainder.  If 
+ * \c target_msc is 0, use the behavior of glXWaitVideoSyncSGI(), which
+ * omits the initial check against a target MSC value.
+ * 
+ * This function is actually something of a hack.  The problem is that, at
+ * the time of this writing, none of the existing DRM modules support an
+ * ioctl that returns a 64-bit count (at least not on 32-bit platforms).
+ * However, this function exists to support a GLX function that requires
+ * the use of 64-bit counts.  As such, there is a little bit of ugly
+ * hackery at the end of this function to make the 32-bit count act like
+ * a 64-bit count.  There are still some cases where this will break, but
+ * I believe it catches the most common cases.
+ *
+ * The real solution is to provide an ioctl that uses a 64-bit count.
+ *
+ * \param dpy         Pointer to the \c Display.
+ * \param priv        Pointer to the DRI drawable private.
+ * \param target_msc  Desired refresh count to wait for.  A value of 0
+ *                    means to use the glXWaitVideoSyncSGI() behavior.
+ * \param divisor     MSC divisor if \c target_msc is already reached.
+ * \param remainder   Desired MSC remainder if \c target_msc is already
+ *                    reached.
+ * \param msc         Buffer to hold MSC when done waiting.
+ *
+ * \return            Zero on success or \c GLX_BAD_CONTEXT on failure.
+ */
+
+int driWaitForMSC32( __DRIdrawablePrivate *priv,
+		     int64_t target_msc, int64_t divisor, int64_t remainder,
+		     int64_t * msc )
+{
+   drmVBlank vbl;
+
+
+   if ( divisor != 0 ) {
+      unsigned int target = (unsigned int)target_msc;
+      unsigned int next = target;
+      unsigned int r;
+      int dont_wait = (target_msc == 0);
+
+      do {
+         /* dont_wait means we're using the glXWaitVideoSyncSGI() behavior.
+          * The first time around, just get the current count and proceed 
+          * to the test for (MSC % divisor) == remainder.
+          */
+         vbl.request.type = dont_wait ? DRM_VBLANK_RELATIVE :
+                                        DRM_VBLANK_ABSOLUTE;
+         vbl.request.sequence = next;
+
+	 if ( drmWaitVBlank( priv->driScreenPriv->fd, &vbl ) != 0 ) {
+	    /* FIXME: This doesn't seem like the right thing to return here.
+	     */
+#ifndef _SOLO
+	    return GLX_BAD_CONTEXT;
+#else
+	    return -1;
+#endif
+	 }
+
+         dont_wait = 0;
+         if (target_msc != 0 && vbl.reply.sequence == target)
+            break;
+
+         /* Assuming the wait-done test fails, the next refresh to wait for
+          * will be one that satisfies (MSC % divisor) == remainder.  The
+          * value (MSC - (MSC % divisor) + remainder) is the refresh value 
+          * closest to the current value that would satisfy the equation.  
+          * If this refresh has already happened, we add divisor to obtain 
+          * the next refresh after the current one that will satisfy it.
+          */
+         r = (vbl.reply.sequence % (unsigned int)divisor);
+         next = (vbl.reply.sequence - r + (unsigned int)remainder);
+         if (next <= vbl.reply.sequence) next += (unsigned int)divisor;
+
+      } while ( r != (unsigned int)remainder );
+   }
+   else {
+      /* If the \c divisor is zero, just wait until the MSC is greater
+       * than or equal to \c target_msc.
+       */
+
+      vbl.request.type = DRM_VBLANK_ABSOLUTE;
+      vbl.request.sequence = target_msc;
+
+      if ( drmWaitVBlank( priv->driScreenPriv->fd, &vbl ) != 0 ) {
+	 /* FIXME: This doesn't seem like the right thing to return here.
+	  */
+#ifndef _SOLO
+	    return GLX_BAD_CONTEXT;
+#else
+	    return -1;
+#endif
+      }
+   }
+
+   *msc  = (target_msc & 0xffffffff00000000LL);
+   *msc |= vbl.reply.sequence;
+   if ( *msc < target_msc ) {
+      *msc += 0x0000000100000000LL;
+   }
+
+   return 0;
+}
+
+
+/****************************************************************************/
+/**
+ * Gets a set of default vertical-blank-wait flags based on the internal GLX
+ * API version and several environment variables.
+ */
+
+GLuint driGetDefaultVBlankFlags( void )
+{
+   GLuint  flags = 0;
+
+
+   flags |= (driCompareGLXAPIVersion( 20030317 ) >= 0) 
+       ? VBLANK_FLAG_INTERVAL : 0;
+   flags |= (getenv("LIBGL_SYNC_REFRESH") != NULL)
+       ? VBLANK_FLAG_SYNC : 0;
+   flags |= (getenv("LIBGL_THROTTLE_REFRESH") != NULL)
+       ? VBLANK_FLAG_THROTTLE : 0;
+
+   return flags;
+}
+
+
+/****************************************************************************/
+/**
+ * Wrapper to call \c drmWaitVBlank.  The main purpose of this function is to
+ * wrap the error message logging.  The error message should only be logged
+ * the first time the \c drmWaitVBlank fails.  If \c drmWaitVBlank is
+ * successful, \c vbl_seq will be set the sequence value in the reply.
+ *
+ * \param vbl      Pointer to drmVBlank packet desribing how to wait.
+ * \param vbl_seq  Location to store the current refresh counter.
+ * \param fd       File descriptor use to call into the DRM.
+ * \return         Zero on success or -1 on failure.
+ */
+
+static int do_wait( drmVBlank * vbl, GLuint * vbl_seq, int fd )
+{
+   int   ret;
+
+
+   ret = drmWaitVBlank( fd, vbl );
+   if ( ret != 0 ) {
+      static GLboolean first_time = GL_TRUE;
+
+      if ( first_time ) {
+	 fprintf(stderr, 
+		 "%s: drmWaitVBlank returned %d, IRQs don't seem to be"
+		 " working correctly.\nTry running with LIBGL_THROTTLE_REFRESH"
+		 " and LIBL_SYNC_REFRESH unset.\n", __FUNCTION__, ret);
+	 first_time = GL_FALSE;
+      }
+
+      return -1;
+   }
+
+   *vbl_seq = vbl->reply.sequence;
+   return 0;
+}
+
+
+/****************************************************************************/
+/**
+ * Waits for the vertical blank for use with glXSwapBuffers.
+ * 
+ * \param vbl_seq  Vertical blank sequence number (MSC) after the last buffer
+ *                 swap.  Updated after this wait.
+ * \param flags    \c VBLANK_FLAG bits that control how long to wait.
+ * \param missed_deadline  Set to \c GL_TRUE if the MSC after waiting is later
+ *                 than the "target" based on \c flags.  The idea is that if
+ *                 \c missed_deadline is set, then the application is not 
+ *                 achieving its desired framerate.
+ * \return         Zero on success, -1 on error.
+ */
+
+int
+driWaitForVBlank( const  __DRIdrawablePrivate *priv, GLuint * vbl_seq,
+		  GLuint flags, GLboolean * missed_deadline )
+{
+   drmVBlank vbl;
+   unsigned   original_seq;
+   unsigned   deadline;
+   unsigned   interval;
+
+
+   *missed_deadline = GL_FALSE;
+   if ( (flags & VBLANK_FLAG_NO_IRQ) != 0 ) {
+      return 0;
+   }
+
+
+   /* VBLANK_FLAG_SYNC means to wait for at least one vertical blank.  If
+    * that flag is not set, do a fake wait for zero vertical blanking
+    * periods so that we can get the current MSC.
+    *
+    * VBLANK_FLAG_INTERVAL and VBLANK_FLAG_THROTTLE mean to wait for at
+    * least one vertical blank since the last wait.  Since do_wait modifies
+    * vbl_seq, we have to save the original value of vbl_seq for the
+    * VBLANK_FLAG_INTERVAL / VBLANK_FLAG_THROTTLE calculation later.
+    */
+
+   original_seq = *vbl_seq;
+
+   vbl.request.sequence = ((flags & VBLANK_FLAG_SYNC) != 0) ? 1 : 0;
+   vbl.request.type = DRM_VBLANK_RELATIVE;
+      
+   if ( do_wait( & vbl, vbl_seq, priv->driScreenPriv->fd ) != 0 ) {
+      return -1;
+   }
+
+	
+   vbl.request.type = DRM_VBLANK_ABSOLUTE;
+
+   if ( (flags & VBLANK_FLAG_INTERVAL) != 0 ) {
+#ifndef _SOLO
+      interval = priv->pdraw->swap_interval;
+#else
+      interval = 0;
+#endif
+   }
+   else if ( (flags & VBLANK_FLAG_THROTTLE) != 0 ) {
+      interval = 1;
+   }
+   else {
+      interval = 0;
+   }
+
+
+   /* Wait until the next vertical blank.  If the interval is zero, then
+    * the deadline is one vertical blank after the previous wait.
+    */
+
+   vbl.request.sequence = original_seq + interval;
+   if ( *vbl_seq < vbl.request.sequence ) {
+      if ( do_wait( & vbl, vbl_seq, priv->driScreenPriv->fd ) != 0 ) {
+	 return -1;
+      }
+   }
+
+   deadline = original_seq + ((interval == 0) ? 1 : interval);
+   *missed_deadline = ( *vbl_seq > deadline );
+
+   return 0;
+}