/*
 * Copyright © 2007, 2008 Red Hat, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Soft-
 * ware"), to deal in the Software without restriction, including without
 * limitation the rights to use, copy, modify, merge, publish, distribute,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, provided that the above copyright
 * notice(s) and this permission notice appear in all copies of the Soft-
 * ware and that both the above copyright notice(s) and this permission
 * notice appear in supporting documentation.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL-
 * ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY
 * RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN
 * THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSE-
 * QUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFOR-
 * MANCE OF THIS SOFTWARE.
 *
 * Except as contained in this notice, the name of a copyright holder shall
 * not be used in advertising or otherwise to promote the sale, use or
 * other dealings in this Software without prior written authorization of
 * the copyright holder.
 *
 * Authors:
 *   Kristian Høgsberg (krh@redhat.com)
 */

#ifdef HAVE_XORG_CONFIG_H
#include <xorg-config.h>
#endif

#include <errno.h>
#ifdef WITH_LIBDRM
#include <xf86drm.h>
#endif
#include "xf86Module.h"
#include "list.h"
#include "scrnintstr.h"
#include "windowstr.h"
#include "dixstruct.h"
#include "dri2.h"
#include "xf86VGAarbiter.h"

#include "xf86.h"

CARD8 dri2_major; /* version of DRI2 supported by DDX */
CARD8 dri2_minor;

static DevPrivateKeyRec dri2ScreenPrivateKeyRec;
#define dri2ScreenPrivateKey (&dri2ScreenPrivateKeyRec)

static DevPrivateKeyRec dri2WindowPrivateKeyRec;
#define dri2WindowPrivateKey (&dri2WindowPrivateKeyRec)

static DevPrivateKeyRec dri2PixmapPrivateKeyRec;
#define dri2PixmapPrivateKey (&dri2PixmapPrivateKeyRec)

static RESTYPE       dri2DrawableRes;

typedef struct _DRI2Screen *DRI2ScreenPtr;

typedef struct _DRI2Drawable {
    DRI2ScreenPtr        dri2_screen;
    DrawablePtr		 drawable;
    struct list		 reference_list;
    int			 width;
    int			 height;
    DRI2BufferPtr	*buffers;
    int			 bufferCount;
    unsigned int	 swapsPending;
    ClientPtr		 blockedClient;
    Bool		 blockedOnMsc;
    int			 swap_interval;
    CARD64		 swap_count;
    int64_t		 target_sbc; /* -1 means no SBC wait outstanding */
    CARD64		 last_swap_target; /* most recently queued swap target */
    CARD64		 last_swap_msc; /* msc at completion of most recent swap */
    CARD64		 last_swap_ust; /* ust at completion of most recent swap */
    int			 swap_limit; /* for N-buffering */
    unsigned long	 serialNumber;
} DRI2DrawableRec, *DRI2DrawablePtr;

typedef struct _DRI2Screen {
    ScreenPtr			 screen;
    int				 refcnt;
    unsigned int		 numDrivers;
    const char			**driverNames;
    const char			*deviceName;
    int				 fd;
    unsigned int		 lastSequence;

    DRI2CreateBufferProcPtr	 CreateBuffer;
    DRI2DestroyBufferProcPtr	 DestroyBuffer;
    DRI2CopyRegionProcPtr	 CopyRegion;
    DRI2ScheduleSwapProcPtr	 ScheduleSwap;
    DRI2GetMSCProcPtr		 GetMSC;
    DRI2ScheduleWaitMSCProcPtr	 ScheduleWaitMSC;
    DRI2AuthMagicProcPtr	 AuthMagic;

    HandleExposuresProcPtr       HandleExposures;

    ConfigNotifyProcPtr		 ConfigNotify;
} DRI2ScreenRec;

static DRI2ScreenPtr
DRI2GetScreen(ScreenPtr pScreen)
{
    return dixLookupPrivate(&pScreen->devPrivates, dri2ScreenPrivateKey);
}

static DRI2DrawablePtr
DRI2GetDrawable(DrawablePtr pDraw)
{
    WindowPtr pWin;
    PixmapPtr pPixmap;

    switch (pDraw->type) {
    case DRAWABLE_WINDOW:
	pWin = (WindowPtr) pDraw;
	return dixLookupPrivate(&pWin->devPrivates, dri2WindowPrivateKey);
    case DRAWABLE_PIXMAP:
	pPixmap = (PixmapPtr) pDraw;
	return dixLookupPrivate(&pPixmap->devPrivates, dri2PixmapPrivateKey);
    default:
	return NULL;
    }
}

static unsigned long
DRI2DrawableSerial(DrawablePtr pDraw)
{
    ScreenPtr pScreen = pDraw->pScreen;
    PixmapPtr pPix;

    if (pDraw->type != DRAWABLE_WINDOW)
	return pDraw->serialNumber;

    pPix = pScreen->GetWindowPixmap((WindowPtr)pDraw);
    return pPix->drawable.serialNumber;
}

static DRI2DrawablePtr
DRI2AllocateDrawable(DrawablePtr pDraw)
{
    DRI2ScreenPtr   ds = DRI2GetScreen(pDraw->pScreen);
    DRI2DrawablePtr pPriv;
    CARD64          ust;
    WindowPtr pWin;
    PixmapPtr pPixmap;

    pPriv = malloc(sizeof *pPriv);
    if (pPriv == NULL)
	return NULL;

    pPriv->dri2_screen = ds;
    pPriv->drawable = pDraw;
    pPriv->width = pDraw->width;
    pPriv->height = pDraw->height;
    pPriv->buffers = NULL;
    pPriv->bufferCount = 0;
    pPriv->swapsPending = 0;
    pPriv->blockedClient = NULL;
    pPriv->blockedOnMsc = FALSE;
    pPriv->swap_count = 0;
    pPriv->target_sbc = -1;
    pPriv->swap_interval = 1;
    /* Initialize last swap target from DDX if possible */
    if (!ds->GetMSC || !(*ds->GetMSC)(pDraw, &ust, &pPriv->last_swap_target))
	pPriv->last_swap_target = 0;

    pPriv->swap_limit = 1; /* default to double buffering */
    pPriv->last_swap_msc = 0;
    pPriv->last_swap_ust = 0;
    list_init(&pPriv->reference_list);
    pPriv->serialNumber = DRI2DrawableSerial(pDraw);

    if (pDraw->type == DRAWABLE_WINDOW) {
	pWin = (WindowPtr) pDraw;
	dixSetPrivate(&pWin->devPrivates, dri2WindowPrivateKey, pPriv);
    } else {
	pPixmap = (PixmapPtr) pDraw;
	dixSetPrivate(&pPixmap->devPrivates, dri2PixmapPrivateKey, pPriv);
    }

    return pPriv;
}

typedef struct DRI2DrawableRefRec {
    XID		  id;
    XID		  dri2_id;
    DRI2InvalidateProcPtr	invalidate;
    void	 *priv;
    struct list	  link;
} DRI2DrawableRefRec, *DRI2DrawableRefPtr;

static DRI2DrawableRefPtr
DRI2LookupDrawableRef(DRI2DrawablePtr pPriv, XID id)
{
    DRI2DrawableRefPtr ref = NULL;

    list_for_each_entry(ref, &pPriv->reference_list, link) {
	if (ref->id == id)
	    return ref;
    }
    
    return NULL;
}

static int
DRI2AddDrawableRef(DRI2DrawablePtr pPriv, XID id, XID dri2_id,
		   DRI2InvalidateProcPtr invalidate, void *priv)
{
    DRI2DrawableRefPtr ref;

    ref = malloc(sizeof *ref);
    if (ref == NULL)
	return BadAlloc;
	
    if (!AddResource(dri2_id, dri2DrawableRes, pPriv)) {
	free(ref);
	return BadAlloc;
    }
    if (!DRI2LookupDrawableRef(pPriv, id))
	if (!AddResource(id, dri2DrawableRes, pPriv)) {
	    FreeResourceByType(dri2_id, dri2DrawableRes, TRUE);
	    free(ref);
	    return BadAlloc;
        }

    ref->id = id;
    ref->dri2_id = dri2_id; 
    ref->invalidate = invalidate;
    ref->priv = priv;
    list_add(&ref->link, &pPriv->reference_list);

    return Success;
}

int
DRI2CreateDrawable(ClientPtr client, DrawablePtr pDraw, XID id,
		   DRI2InvalidateProcPtr invalidate, void *priv)
{
    DRI2DrawablePtr pPriv;
    XID dri2_id;
    int rc;

    pPriv = DRI2GetDrawable(pDraw);
    if (pPriv == NULL)
	pPriv = DRI2AllocateDrawable(pDraw);
    if (pPriv == NULL)
	return BadAlloc;
    
    dri2_id = FakeClientID(client->index);
    rc = DRI2AddDrawableRef(pPriv, id, dri2_id, invalidate, priv);
    if (rc != Success)
	return rc;

    return Success;
}

static int DRI2DrawableGone(pointer p, XID id)
{
    DRI2DrawablePtr pPriv = p;
    DRI2ScreenPtr   ds = pPriv->dri2_screen;
    DRI2DrawableRefPtr ref = NULL, next;
    WindowPtr pWin;
    PixmapPtr pPixmap;
    DrawablePtr pDraw;
    int i;

    list_for_each_entry_safe(ref, next, &pPriv->reference_list, link) {
	if (ref->dri2_id == id) {
	    list_del(&ref->link);
	    /* If this was the last ref under this X drawable XID,
	     * unregister the X drawable resource. */
	    if (!DRI2LookupDrawableRef(pPriv, ref->id))
		FreeResourceByType(ref->id, dri2DrawableRes, TRUE);
	    free(ref);
	    break;
	}

	if (ref->id == id) {
	    list_del(&ref->link);
	    FreeResourceByType(ref->dri2_id, dri2DrawableRes, TRUE);
	    free(ref);
	}
    }

    if (!list_is_empty(&pPriv->reference_list))
	return Success;

    pDraw = pPriv->drawable;
    if (pDraw->type == DRAWABLE_WINDOW) {
	pWin = (WindowPtr) pDraw;
	dixSetPrivate(&pWin->devPrivates, dri2WindowPrivateKey, NULL);
    } else {
	pPixmap = (PixmapPtr) pDraw;
	dixSetPrivate(&pPixmap->devPrivates, dri2PixmapPrivateKey, NULL);
    }

    if (pPriv->buffers != NULL) {
	for (i = 0; i < pPriv->bufferCount; i++)
	    (*ds->DestroyBuffer)(pDraw, pPriv->buffers[i]);

	free(pPriv->buffers);
    }

    free(pPriv);

    return Success;
}

static int
find_attachment(DRI2DrawablePtr pPriv, unsigned attachment)
{
    int i;

    if (pPriv->buffers == NULL) {
	return -1;
    }

    for (i = 0; i < pPriv->bufferCount; i++) {
	if ((pPriv->buffers[i] != NULL)
	    && (pPriv->buffers[i]->attachment == attachment)) {
	    return i;
	}
    }

    return -1;
}

static Bool
allocate_or_reuse_buffer(DrawablePtr pDraw, DRI2ScreenPtr ds,
			 DRI2DrawablePtr pPriv,
			 unsigned int attachment, unsigned int format,
			 int dimensions_match, DRI2BufferPtr *buffer)
{
    int old_buf = find_attachment(pPriv, attachment);

    if ((old_buf < 0)
	|| !dimensions_match
	|| (pPriv->buffers[old_buf]->format != format)) {
	*buffer = (*ds->CreateBuffer)(pDraw, attachment, format);
	pPriv->serialNumber = DRI2DrawableSerial(pDraw);
	return TRUE;

    } else {
	*buffer = pPriv->buffers[old_buf];
	pPriv->buffers[old_buf] = NULL;
	return FALSE;
    }
}

static void
update_dri2_drawable_buffers(DRI2DrawablePtr pPriv, DrawablePtr pDraw,
			     DRI2BufferPtr *buffers, int *out_count, int *width, int *height)
{
    DRI2ScreenPtr   ds = DRI2GetScreen(pDraw->pScreen);
    int i;

    if (pPriv->buffers != NULL) {
	for (i = 0; i < pPriv->bufferCount; i++) {
	    if (pPriv->buffers[i] != NULL) {
		(*ds->DestroyBuffer)(pDraw, pPriv->buffers[i]);
	    }
	}

	free(pPriv->buffers);
    }

    pPriv->buffers = buffers;
    pPriv->bufferCount = *out_count;
    pPriv->width = pDraw->width;
    pPriv->height = pDraw->height;
    *width = pPriv->width;
    *height = pPriv->height;
}

static DRI2BufferPtr *
do_get_buffers(DrawablePtr pDraw, int *width, int *height,
	       unsigned int *attachments, int count, int *out_count,
	       int has_format)
{
    DRI2ScreenPtr   ds = DRI2GetScreen(pDraw->pScreen);
    DRI2DrawablePtr pPriv = DRI2GetDrawable(pDraw);
    DRI2BufferPtr  *buffers;
    int need_real_front = 0;
    int need_fake_front = 0;
    int have_fake_front = 0;
    int front_format = 0;
    int dimensions_match;
    int buffers_changed = 0;
    int i;

    if (!pPriv) {
	*width = pDraw->width;
	*height = pDraw->height;
	*out_count = 0;
	return NULL;
    }

    dimensions_match = (pDraw->width == pPriv->width)
	&& (pDraw->height == pPriv->height)
	&& (pPriv->serialNumber == DRI2DrawableSerial(pDraw));

    buffers = calloc((count + 1), sizeof(buffers[0]));

    for (i = 0; i < count; i++) {
	const unsigned attachment = *(attachments++);
	const unsigned format = (has_format) ? *(attachments++) : 0;

	if (allocate_or_reuse_buffer(pDraw, ds, pPriv, attachment,
				     format, dimensions_match,
				     &buffers[i]))
		buffers_changed = 1;

	if (buffers[i] == NULL)
	    goto err_out;

	/* If the drawable is a window and the front-buffer is requested,
	 * silently add the fake front-buffer to the list of requested
	 * attachments.  The counting logic in the loop accounts for the case
	 * where the client requests both the fake and real front-buffer.
	 */
	if (attachment == DRI2BufferBackLeft) {
	    need_real_front++;
	    front_format = format;
	}

	if (attachment == DRI2BufferFrontLeft) {
	    need_real_front--;
	    front_format = format;

	    if (pDraw->type == DRAWABLE_WINDOW) {
		need_fake_front++;
	    }
	}

	if (pDraw->type == DRAWABLE_WINDOW) {
	    if (attachment == DRI2BufferFakeFrontLeft) {
		need_fake_front--;
		have_fake_front = 1;
	    }
	}
    }

    if (need_real_front > 0) {
	if (allocate_or_reuse_buffer(pDraw, ds, pPriv, DRI2BufferFrontLeft,
				     front_format, dimensions_match,
				     &buffers[i]))
	    buffers_changed = 1;

	if (buffers[i] == NULL)
	    goto err_out;
	i++;
    }

    if (need_fake_front > 0) {
	if (allocate_or_reuse_buffer(pDraw, ds, pPriv, DRI2BufferFakeFrontLeft,
				     front_format, dimensions_match,
				     &buffers[i]))
	    buffers_changed = 1;

	if (buffers[i] == NULL)
	    goto err_out;

	i++;
	have_fake_front = 1;
    }

    *out_count = i;

    update_dri2_drawable_buffers(pPriv, pDraw, buffers, out_count, width, height);

    /* If the client is getting a fake front-buffer, pre-fill it with the
     * contents of the real front-buffer.  This ensures correct operation of
     * applications that call glXWaitX before calling glDrawBuffer.
     */
    if (have_fake_front && buffers_changed) {
	BoxRec box;
	RegionRec region;

	box.x1 = 0;
	box.y1 = 0;
	box.x2 = pPriv->width;
	box.y2 = pPriv->height;
	RegionInit(&region, &box, 0);

	DRI2CopyRegion(pDraw, &region, DRI2BufferFakeFrontLeft,
		       DRI2BufferFrontLeft);
    }

    return pPriv->buffers;

err_out:

    *out_count = 0;

    for (i = 0; i < count; i++) {
	    if (buffers[i] != NULL)
		    (*ds->DestroyBuffer)(pDraw, buffers[i]);
    }

    free(buffers);
    buffers = NULL;

    update_dri2_drawable_buffers(pPriv, pDraw, buffers, out_count, width, height);

    return buffers;
}

DRI2BufferPtr *
DRI2GetBuffers(DrawablePtr pDraw, int *width, int *height,
	       unsigned int *attachments, int count, int *out_count)
{
    return do_get_buffers(pDraw, width, height, attachments, count,
			  out_count, FALSE);
}

DRI2BufferPtr *
DRI2GetBuffersWithFormat(DrawablePtr pDraw, int *width, int *height,
			 unsigned int *attachments, int count, int *out_count)
{
    return do_get_buffers(pDraw, width, height, attachments, count,
			  out_count, TRUE);
}

static void
DRI2InvalidateDrawable(DrawablePtr pDraw)
{
    DRI2DrawablePtr pPriv = DRI2GetDrawable(pDraw);
    DRI2DrawableRefPtr ref = NULL;

    if (!pPriv)
        return;

    list_for_each_entry(ref, &pPriv->reference_list, link)
	ref->invalidate(pDraw, ref->priv);
}

/*
 * In the direct rendered case, we throttle the clients that have more
 * than their share of outstanding swaps (and thus busy buffers) when a
 * new GetBuffers request is received.  In the AIGLX case, we allow the
 * client to get the new buffers, but throttle when the next GLX request
 * comes in (see __glXDRIcontextWait()).
 */
Bool
DRI2ThrottleClient(ClientPtr client, DrawablePtr pDraw)
{
    DRI2DrawablePtr pPriv;

    pPriv = DRI2GetDrawable(pDraw);
    if (pPriv == NULL)
	return FALSE;

    /* Throttle to swap limit */
    if ((pPriv->swapsPending >= pPriv->swap_limit) &&
	!pPriv->blockedClient) {
	ResetCurrentRequest(client);
	client->sequence--;
	IgnoreClient(client);
	pPriv->blockedClient = client;
	return TRUE;
    }

    return FALSE;
}

static void
__DRI2BlockClient(ClientPtr client, DRI2DrawablePtr pPriv)
{
    if (pPriv->blockedClient == NULL) {
	IgnoreClient(client);
	pPriv->blockedClient = client;
    }
}

void
DRI2BlockClient(ClientPtr client, DrawablePtr pDraw)
{
    DRI2DrawablePtr pPriv;

    pPriv = DRI2GetDrawable(pDraw);
    if (pPriv == NULL)
	return;

    __DRI2BlockClient(client, pPriv);
    pPriv->blockedOnMsc = TRUE;
}

int
DRI2CopyRegion(DrawablePtr pDraw, RegionPtr pRegion,
	       unsigned int dest, unsigned int src)
{
    DRI2ScreenPtr   ds = DRI2GetScreen(pDraw->pScreen);
    DRI2DrawablePtr pPriv;
    DRI2BufferPtr   pDestBuffer, pSrcBuffer;
    int		    i;

    pPriv = DRI2GetDrawable(pDraw);
    if (pPriv == NULL)
	return BadDrawable;

    pDestBuffer = NULL;
    pSrcBuffer = NULL;
    for (i = 0; i < pPriv->bufferCount; i++)
    {
	if (pPriv->buffers[i]->attachment == dest)
	    pDestBuffer = (DRI2BufferPtr) pPriv->buffers[i];
	if (pPriv->buffers[i]->attachment == src)
	    pSrcBuffer = (DRI2BufferPtr) pPriv->buffers[i];
    }
    if (pSrcBuffer == NULL || pDestBuffer == NULL)
	return BadValue;

    (*ds->CopyRegion)(pDraw, pRegion, pDestBuffer, pSrcBuffer);

    return Success;
}

/* Can this drawable be page flipped? */
Bool
DRI2CanFlip(DrawablePtr pDraw)
{
    ScreenPtr pScreen = pDraw->pScreen;
    WindowPtr pWin, pRoot;
    PixmapPtr pWinPixmap, pRootPixmap;

    if (pDraw->type == DRAWABLE_PIXMAP)
	return TRUE;

    pRoot = pScreen->root;
    pRootPixmap = pScreen->GetWindowPixmap(pRoot);

    pWin = (WindowPtr) pDraw;
    pWinPixmap = pScreen->GetWindowPixmap(pWin);
    if (pRootPixmap != pWinPixmap)
	return FALSE;
    if (!RegionEqual(&pWin->clipList, &pRoot->winSize))
	return FALSE;

    /* Does the window match the pixmap exactly? */
    if (pDraw->x != 0 ||
	pDraw->y != 0 ||
#ifdef COMPOSITE
	pDraw->x != pWinPixmap->screen_x ||
	pDraw->y != pWinPixmap->screen_y ||
#endif
	pDraw->width != pWinPixmap->drawable.width ||
	pDraw->height != pWinPixmap->drawable.height)
	return FALSE;

    return TRUE;
}

/* Can we do a pixmap exchange instead of a blit? */
Bool
DRI2CanExchange(DrawablePtr pDraw)
{
    return FALSE;
}

void
DRI2WaitMSCComplete(ClientPtr client, DrawablePtr pDraw, int frame,
		    unsigned int tv_sec, unsigned int tv_usec)
{
    DRI2DrawablePtr pPriv;

    pPriv = DRI2GetDrawable(pDraw);
    if (pPriv == NULL)
	return;

    ProcDRI2WaitMSCReply(client, ((CARD64)tv_sec * 1000000) + tv_usec,
			 frame, pPriv->swap_count);

    if (pPriv->blockedClient)
	AttendClient(pPriv->blockedClient);

    pPriv->blockedClient = NULL;
    pPriv->blockedOnMsc = FALSE;
}

static void
DRI2WakeClient(ClientPtr client, DrawablePtr pDraw, int frame,
	       unsigned int tv_sec, unsigned int tv_usec)
{
    ScreenPtr	    pScreen = pDraw->pScreen;
    DRI2DrawablePtr pPriv;

    pPriv = DRI2GetDrawable(pDraw);
    if (pPriv == NULL) {
        xf86DrvMsg(pScreen->myNum, X_ERROR,
		   "[DRI2] %s: bad drawable\n", __func__);
	return;
    }

    /*
     * Swap completed.
     * Wake the client iff:
     *   - it was waiting on SBC
     *   - was blocked due to GLX make current
     *   - was blocked due to swap throttling
     *   - is not blocked due to an MSC wait
     */
    if (pPriv->target_sbc != -1 &&
	pPriv->target_sbc <= pPriv->swap_count) {
	ProcDRI2WaitMSCReply(client, ((CARD64)tv_sec * 1000000) + tv_usec,
			     frame, pPriv->swap_count);
	pPriv->target_sbc = -1;

	AttendClient(pPriv->blockedClient);
	pPriv->blockedClient = NULL;
    } else if (pPriv->target_sbc == -1 && !pPriv->blockedOnMsc) {
	if (pPriv->blockedClient) {
	    AttendClient(pPriv->blockedClient);
	    pPriv->blockedClient = NULL;
	}
    }
}

void
DRI2SwapComplete(ClientPtr client, DrawablePtr pDraw, int frame,
		   unsigned int tv_sec, unsigned int tv_usec, int type,
		   DRI2SwapEventPtr swap_complete, void *swap_data)
{
    ScreenPtr	    pScreen = pDraw->pScreen;
    DRI2DrawablePtr pPriv;
    CARD64          ust = 0;
    BoxRec          box;
    RegionRec       region;

    pPriv = DRI2GetDrawable(pDraw);
    if (pPriv == NULL) {
        xf86DrvMsg(pScreen->myNum, X_ERROR,
		   "[DRI2] %s: bad drawable\n", __func__);
	return;
    }

    pPriv->swapsPending--;
    pPriv->swap_count++;

    box.x1 = 0;
    box.y1 = 0;
    box.x2 = pDraw->width;
    box.y2 = pDraw->height;
    RegionInit(&region, &box, 0);
    DRI2CopyRegion(pDraw, &region, DRI2BufferFakeFrontLeft,
		   DRI2BufferFrontLeft);

    ust = ((CARD64)tv_sec * 1000000) + tv_usec;
    if (swap_complete)
	swap_complete(client, swap_data, type, ust, frame, pPriv->swap_count);

    pPriv->last_swap_msc = frame;
    pPriv->last_swap_ust = ust;

    DRI2WakeClient(client, pDraw, frame, tv_sec, tv_usec);
}

Bool
DRI2WaitSwap(ClientPtr client, DrawablePtr pDrawable)
{
    DRI2DrawablePtr pPriv = DRI2GetDrawable(pDrawable);

    /* If we're currently waiting for a swap on this drawable, reset
     * the request and suspend the client.  We only support one
     * blocked client per drawable. */
    if (pPriv &&
	pPriv->swapsPending &&
	pPriv->blockedClient == NULL) {
	ResetCurrentRequest(client);
	client->sequence--;
	__DRI2BlockClient(client, pPriv);
	return TRUE;
    }

    return FALSE;
}

int
DRI2SwapBuffers(ClientPtr client, DrawablePtr pDraw, CARD64 target_msc,
		CARD64 divisor, CARD64 remainder, CARD64 *swap_target,
		DRI2SwapEventPtr func, void *data)
{
    ScreenPtr       pScreen = pDraw->pScreen;
    DRI2ScreenPtr   ds = DRI2GetScreen(pDraw->pScreen);
    DRI2DrawablePtr pPriv;
    DRI2BufferPtr   pDestBuffer = NULL, pSrcBuffer = NULL;
    int             ret, i;
    CARD64          ust, current_msc;

    pPriv = DRI2GetDrawable(pDraw);
    if (pPriv == NULL) {
        xf86DrvMsg(pScreen->myNum, X_ERROR,
		   "[DRI2] %s: bad drawable\n", __func__);
	return BadDrawable;
    }

    for (i = 0; i < pPriv->bufferCount; i++) {
	if (pPriv->buffers[i]->attachment == DRI2BufferFrontLeft)
	    pDestBuffer = (DRI2BufferPtr) pPriv->buffers[i];
	if (pPriv->buffers[i]->attachment == DRI2BufferBackLeft)
	    pSrcBuffer = (DRI2BufferPtr) pPriv->buffers[i];
    }
    if (pSrcBuffer == NULL || pDestBuffer == NULL) {
        xf86DrvMsg(pScreen->myNum, X_ERROR,
		   "[DRI2] %s: drawable has no back or front?\n", __func__);
	return BadDrawable;
    }

    /* Old DDX or no swap interval, just blit */
    if (!ds->ScheduleSwap || !pPriv->swap_interval) {
	BoxRec box;
	RegionRec region;

	box.x1 = 0;
	box.y1 = 0;
	box.x2 = pDraw->width;
	box.y2 = pDraw->height;
	RegionInit(&region, &box, 0);

	pPriv->swapsPending++;

	(*ds->CopyRegion)(pDraw, &region, pDestBuffer, pSrcBuffer);
	DRI2SwapComplete(client, pDraw, target_msc, 0, 0, DRI2_BLIT_COMPLETE,
			 func, data);
	return Success;
    }

    /*
     * In the simple glXSwapBuffers case, all params will be 0, and we just
     * need to schedule a swap for the last swap target + the swap interval.
     */
    if (target_msc == 0 && divisor == 0 && remainder == 0) {
	/* If the current vblank count of the drawable's crtc is lower
	 * than the count stored in last_swap_target from a previous swap
	 * then reinitialize last_swap_target to the current crtc's msc,
	 * otherwise the swap will hang. This will happen if the drawable
	 * is moved to a crtc with a lower refresh rate, or a crtc that just
	 * got enabled.
	 */
	if (ds->GetMSC) {
	    if (!(*ds->GetMSC)(pDraw, &ust, &current_msc))
		pPriv->last_swap_target = 0;

	    if (current_msc < pPriv->last_swap_target)
		pPriv->last_swap_target = current_msc;

	}

	/*
	 * Swap target for this swap is last swap target + swap interval since
	 * we have to account for the current swap count, interval, and the
	 * number of pending swaps.
	 */
	*swap_target = pPriv->last_swap_target + pPriv->swap_interval;

    } else {
	/* glXSwapBuffersMscOML could have a 0 target_msc, honor it */
	*swap_target = target_msc;
    }

    pPriv->swapsPending++;
    ret = (*ds->ScheduleSwap)(client, pDraw, pDestBuffer, pSrcBuffer,
			      swap_target, divisor, remainder, func, data);
    if (!ret) {
	pPriv->swapsPending--; /* didn't schedule */
        xf86DrvMsg(pScreen->myNum, X_ERROR,
		   "[DRI2] %s: driver failed to schedule swap\n", __func__);
	return BadDrawable;
    }

    pPriv->last_swap_target = *swap_target;

    /* According to spec, return expected swapbuffers count SBC after this swap
     * will complete.
     */
    *swap_target = pPriv->swap_count + pPriv->swapsPending;

    DRI2InvalidateDrawable(pDraw);

    return Success;
}

void
DRI2SwapInterval(DrawablePtr pDrawable, int interval)
{
    ScreenPtr       pScreen = pDrawable->pScreen;
    DRI2DrawablePtr pPriv = DRI2GetDrawable(pDrawable);

    if (pPriv == NULL) {
        xf86DrvMsg(pScreen->myNum, X_ERROR,
		   "[DRI2] %s: bad drawable\n", __func__);
	return;
    }

    /* fixme: check against arbitrary max? */
    pPriv->swap_interval = interval;
}

int
DRI2GetMSC(DrawablePtr pDraw, CARD64 *ust, CARD64 *msc, CARD64 *sbc)
{
    ScreenPtr pScreen = pDraw->pScreen;
    DRI2ScreenPtr ds = DRI2GetScreen(pDraw->pScreen);
    DRI2DrawablePtr pPriv;
    Bool ret;

    pPriv = DRI2GetDrawable(pDraw);
    if (pPriv == NULL) {
        xf86DrvMsg(pScreen->myNum, X_ERROR,
		   "[DRI2] %s: bad drawable\n", __func__);
	return BadDrawable;
    }

    if (!ds->GetMSC) {
	*ust = 0;
	*msc = 0;
	*sbc = pPriv->swap_count;
	return Success;
    }

    /*
     * Spec needs to be updated to include unmapped or redirected
     * drawables
     */

    ret = (*ds->GetMSC)(pDraw, ust, msc);
    if (!ret)
	return BadDrawable;

    *sbc = pPriv->swap_count;

    return Success;
}

int
DRI2WaitMSC(ClientPtr client, DrawablePtr pDraw, CARD64 target_msc,
	    CARD64 divisor, CARD64 remainder)
{
    DRI2ScreenPtr ds = DRI2GetScreen(pDraw->pScreen);
    DRI2DrawablePtr pPriv;
    Bool ret;

    pPriv = DRI2GetDrawable(pDraw);
    if (pPriv == NULL)
	return BadDrawable;

    /* Old DDX just completes immediately */
    if (!ds->ScheduleWaitMSC) {
	DRI2WaitMSCComplete(client, pDraw, target_msc, 0, 0);

	return Success;
    }

    ret = (*ds->ScheduleWaitMSC)(client, pDraw, target_msc, divisor, remainder);
    if (!ret)
	return BadDrawable;

    return Success;
}

int
DRI2WaitSBC(ClientPtr client, DrawablePtr pDraw, CARD64 target_sbc)
{
    DRI2DrawablePtr pPriv;

    pPriv = DRI2GetDrawable(pDraw);
    if (pPriv == NULL)
	return BadDrawable;

    /* target_sbc == 0 means to block until all pending swaps are
     * finished. Recalculate target_sbc to get that behaviour.
     */
    if (target_sbc == 0)
        target_sbc = pPriv->swap_count + pPriv->swapsPending;

    /* If current swap count already >= target_sbc, reply and
     * return immediately with (ust, msc, sbc) triplet of
     * most recent completed swap.
     */
    if (pPriv->swap_count >= target_sbc) {
        ProcDRI2WaitMSCReply(client, pPriv->last_swap_ust,
                             pPriv->last_swap_msc, pPriv->swap_count);
        return Success;
    }

    pPriv->target_sbc = target_sbc;
    __DRI2BlockClient(client, pPriv);

    return Success;
}

Bool
DRI2HasSwapControl(ScreenPtr pScreen)
{
    DRI2ScreenPtr ds = DRI2GetScreen(pScreen);

    return ds->ScheduleSwap && ds->GetMSC;
}

Bool
DRI2Connect(ScreenPtr pScreen, unsigned int driverType, int *fd,
	    const char **driverName, const char **deviceName)
{
    DRI2ScreenPtr ds;

    if (!dixPrivateKeyRegistered(dri2ScreenPrivateKey))
	return FALSE;

    ds = DRI2GetScreen(pScreen);
    if (ds == NULL || driverType >= ds->numDrivers ||
	    !ds->driverNames[driverType])
	return FALSE;

    *fd = ds->fd;
    *driverName = ds->driverNames[driverType];
    *deviceName = ds->deviceName;

    return TRUE;
}

Bool
DRI2Authenticate(ScreenPtr pScreen, uint32_t magic)
{
    DRI2ScreenPtr ds = DRI2GetScreen(pScreen);

    if (ds == NULL || (*ds->AuthMagic)(ds->fd, magic))
        return FALSE;

    return TRUE;
}

static int
DRI2ConfigNotify(WindowPtr pWin, int x, int y, int w, int h, int bw,
		 WindowPtr pSib)
{
    DrawablePtr pDraw = (DrawablePtr)pWin;
    ScreenPtr pScreen = pDraw->pScreen;
    DRI2ScreenPtr ds = DRI2GetScreen(pScreen);
    DRI2DrawablePtr dd = DRI2GetDrawable(pDraw);
    int ret;

    if (ds->ConfigNotify) {
	pScreen->ConfigNotify = ds->ConfigNotify;

	ret = (*pScreen->ConfigNotify)(pWin, x, y, w, h, bw, pSib);

	ds->ConfigNotify = pScreen->ConfigNotify;
	pScreen->ConfigNotify = DRI2ConfigNotify;
	if (ret)
	    return ret;
    }

    if (!dd || (dd->width == w && dd->height == h))
	return Success;

    DRI2InvalidateDrawable(pDraw);
    return Success;
}

Bool
DRI2ScreenInit(ScreenPtr pScreen, DRI2InfoPtr info)
{
    DRI2ScreenPtr ds;
    const char* driverTypeNames[] = {
	"DRI", /* DRI2DriverDRI */
	"VDPAU", /* DRI2DriverVDPAU */
    };
    unsigned int i;
    CARD8 cur_minor;

    if (info->version < 3)
	return FALSE;

    if (!xf86VGAarbiterAllowDRI(pScreen)) {
        xf86DrvMsg(pScreen->myNum, X_WARNING,
                  "[DRI2] Direct rendering is not supported when VGA arb is necessary for the device\n");
        return FALSE;
    }

    if (!dixRegisterPrivateKey(&dri2ScreenPrivateKeyRec, PRIVATE_SCREEN, 0))
	return FALSE;

    if (!dixRegisterPrivateKey(&dri2WindowPrivateKeyRec, PRIVATE_WINDOW, 0))
	return FALSE;

    if (!dixRegisterPrivateKey(&dri2PixmapPrivateKeyRec, PRIVATE_PIXMAP, 0))
	return FALSE;

    ds = calloc(1, sizeof *ds);
    if (!ds)
	return FALSE;

    ds->screen         = pScreen;
    ds->fd	       = info->fd;
    ds->deviceName     = info->deviceName;
    dri2_major         = 1;

    ds->CreateBuffer   = info->CreateBuffer;
    ds->DestroyBuffer  = info->DestroyBuffer;
    ds->CopyRegion     = info->CopyRegion;

    if (info->version >= 4) {
	ds->ScheduleSwap = info->ScheduleSwap;
	ds->ScheduleWaitMSC = info->ScheduleWaitMSC;
	ds->GetMSC = info->GetMSC;
	cur_minor = 3;
    } else {
	cur_minor = 1;
    }

    if (info->version >= 5) {
        ds->AuthMagic = info->AuthMagic;
    }

    /*
     * if the driver doesn't provide an AuthMagic function or the info struct
     * version is too low, it relies on the old method (using libdrm) or fail
     */
    if (!ds->AuthMagic)
#ifdef WITH_LIBDRM
        ds->AuthMagic = drmAuthMagic;
#else
        goto err_out;
#endif

    /* Initialize minor if needed and set to minimum provied by DDX */
    if (!dri2_minor || dri2_minor > cur_minor)
	dri2_minor = cur_minor;

    if (info->version == 3 || info->numDrivers == 0) {
	/* Driver too old: use the old-style driverName field */
	ds->numDrivers = 1;
	ds->driverNames = malloc(sizeof(*ds->driverNames));
	if (!ds->driverNames)
	    goto err_out;
	ds->driverNames[0] = info->driverName;
    } else {
	ds->numDrivers = info->numDrivers;
	ds->driverNames = malloc(info->numDrivers * sizeof(*ds->driverNames));
	if (!ds->driverNames)
		goto err_out;
	memcpy(ds->driverNames, info->driverNames,
	       info->numDrivers * sizeof(*ds->driverNames));
    }

    dixSetPrivate(&pScreen->devPrivates, dri2ScreenPrivateKey, ds);

    ds->ConfigNotify = pScreen->ConfigNotify;
    pScreen->ConfigNotify = DRI2ConfigNotify;

    xf86DrvMsg(pScreen->myNum, X_INFO, "[DRI2] Setup complete\n");
    for (i = 0; i < sizeof(driverTypeNames) / sizeof(driverTypeNames[0]); i++) {
	if (i < ds->numDrivers && ds->driverNames[i]) {
	    xf86DrvMsg(pScreen->myNum, X_INFO, "[DRI2]   %s driver: %s\n",
		       driverTypeNames[i], ds->driverNames[i]);
	}
    }

    return TRUE;

err_out:
    xf86DrvMsg(pScreen->myNum, X_WARNING,
            "[DRI2] Initialization failed for info version %d.\n", info->version);
    free(ds);
    return FALSE;
}

void
DRI2CloseScreen(ScreenPtr pScreen)
{
    DRI2ScreenPtr ds = DRI2GetScreen(pScreen);

    free(ds->driverNames);
    free(ds);
    dixSetPrivate(&pScreen->devPrivates, dri2ScreenPrivateKey, NULL);
}

extern ExtensionModule dri2ExtensionModule;
extern Bool DRI2ModuleSetup(void);

/* Called by InitExtensions() */
Bool
DRI2ModuleSetup(void)
{
    dri2DrawableRes = CreateNewResourceType(DRI2DrawableGone, "DRI2Drawable");
    if (!dri2DrawableRes)
	return FALSE;

    return TRUE;
}

static pointer
DRI2Setup(pointer module, pointer opts, int *errmaj, int *errmin)
{
    static Bool setupDone = FALSE;

    if (!setupDone)
    {
	setupDone = TRUE;
	LoadExtension(&dri2ExtensionModule, FALSE);
    }
    else
    {
	if (errmaj)
	    *errmaj = LDR_ONCEONLY;
    }

    return (pointer) 1;
}

static XF86ModuleVersionInfo DRI2VersRec =
{
    "dri2",
    MODULEVENDORSTRING,
    MODINFOSTRING1,
    MODINFOSTRING2,
    XORG_VERSION_CURRENT,
    1, 2, 0,
    ABI_CLASS_EXTENSION,
    ABI_EXTENSION_VERSION,
    MOD_CLASS_NONE,
    { 0, 0, 0, 0 }
};

_X_EXPORT XF86ModuleData dri2ModuleData = { &DRI2VersRec, DRI2Setup, NULL };

void
DRI2Version(int *major, int *minor)
{
    if (major != NULL)
	*major = DRI2VersRec.majorversion;

    if (minor != NULL)
	*minor = DRI2VersRec.minorversion;
}