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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"
+#include "xmlpool.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.
+ */
+ return GLX_BAD_CONTEXT;
+ }
+
+ 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.
+ */
+ return GLX_BAD_CONTEXT;
+ }
+ }
+
+ *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 configuration options.
+ */
+
+GLuint driGetDefaultVBlankFlags( const driOptionCache *optionCache )
+{
+ GLuint flags = VBLANK_FLAG_INTERVAL;
+ int vblank_mode;
+
+
+ if ( driCheckOption( optionCache, "vblank_mode", DRI_ENUM ) )
+ vblank_mode = driQueryOptioni( optionCache, "vblank_mode" );
+ else
+ vblank_mode = DRI_CONF_VBLANK_DEF_INTERVAL_1;
+
+ switch (vblank_mode) {
+ case DRI_CONF_VBLANK_NEVER:
+ flags = 0;
+ break;
+ case DRI_CONF_VBLANK_DEF_INTERVAL_0:
+ break;
+ case DRI_CONF_VBLANK_DEF_INTERVAL_1:
+ flags |= VBLANK_FLAG_THROTTLE;
+ break;
+ case DRI_CONF_VBLANK_ALWAYS_SYNC:
+ flags |= VBLANK_FLAG_SYNC;
+ break;
+ }
+
+ return flags;
+}
+
+
+/****************************************************************************/
+/**
+ * Sets the default swap interval when the drawable is first bound to a
+ * direct rendering context.
+ */
+
+void driDrawableInitVBlank( __DRIdrawablePrivate *priv, GLuint flags )
+{
+ if ( priv->pdraw->swap_interval == (unsigned)-1 ) {
+ priv->pdraw->swap_interval = (flags & VBLANK_FLAG_THROTTLE) != 0 ? 1 : 0;
+ }
+}
+
+
+/****************************************************************************/
+/**
+ * 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_INTERVAL |
+ VBLANK_FLAG_THROTTLE |
+ VBLANK_FLAG_SYNC)) == 0 ||
+ (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 ) {
+ interval = priv->pdraw->swap_interval;
+ /* this must have been initialized when the drawable was first bound
+ * to a direct rendering context. */
+ assert ( interval != (unsigned)-1 );
+ }
+ 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;
+}