xref: /xsrc/external/mit/xf86-video-sis/dist/src/sis300_accel.c

/*
 * 2D Acceleration for SiS 530, 620, 300, 540, 630, 730.
 *
 * Copyright (C) 2001-2005 by Thomas Winischhofer, Vienna, Austria
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1) Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2) Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3) The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors:   Thomas Winischhofer <thomas@winischhofer.net>
 *	      Can-Ru Yeou, SiS Inc.
 *
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#if 0
#define DEBUG
#endif

#include "sis.h"
#include "sis_regs.h"

#include "sis300_accel.h"

/* This is the offset to the memory for each head */
#define HEADOFFSET 	(pSiS->dhmOffset)

#ifdef SIS_USE_XAA

#undef STSCE    	/* Use/Don't use ScreenToScreenColorExpand - does not work */

#undef TRAP     	/* Use/Don't use Trapezoid Fills - does not work - XAA provides
		         * illegal trapezoid data (left and right edges cross each other
			 * sometimes) which causes drawing errors. Further, I have not found
			 * out how to draw polygones with a height greater than 127...
                         */
#endif /* XAA */

#ifdef SIS_USE_EXA
extern void SiSScratchSave(ScreenPtr pScreen, ExaOffscreenArea *area);
extern Bool SiSUploadToScreen(PixmapPtr pDst, int x, int y, int w, int h, char *src, int src_pitch);
extern Bool SiSUploadToScratch(PixmapPtr pSrc, PixmapPtr pDst);
extern Bool SiSDownloadFromScreen(PixmapPtr pSrc, int x, int y, int w, int h,
				char *dst, int dst_pitch);
#endif /* EXA */

extern UChar SiSGetCopyROP(int rop);
extern UChar SiSGetPatternROP(int rop);

static void
SiSInitializeAccelerator(ScrnInfoPtr pScrn)
{
#ifdef SIS_USE_XAA
	SISPtr pSiS = SISPTR(pScrn);

	pSiS->DoColorExpand = FALSE;
#endif
}

static void
SiSSync(ScrnInfoPtr pScrn)
{
	SISPtr pSiS = SISPTR(pScrn);

	SiSIdle
}

static void
SiSSyncAccel(ScrnInfoPtr pScrn)
{
	SISPtr pSiS = SISPTR(pScrn);

	if(!pSiS->NoAccel) SiSSync(pScrn);
}

static void
SiSSetupForScreenToScreenCopy(ScrnInfoPtr pScrn,
			int xdir, int ydir, int rop,
			unsigned int planemask, int trans_color)
{
	SISPtr  pSiS = SISPTR(pScrn);

	SiSSetupDSTColorDepth(pSiS->DstColor);
	SiSSetupSRCPitch(pSiS->scrnOffset)
	SiSSetupDSTRect(pSiS->scrnOffset, -1)

	if(trans_color != -1) {
	   SiSSetupROP(0x0A)
	   SiSSetupSRCTrans(trans_color)
	   SiSSetupCMDFlag(TRANSPARENT_BITBLT)
	} else {
	   SiSSetupROP(SiSGetCopyROP(rop))
	}
	if(xdir > 0) {
	   SiSSetupCMDFlag(X_INC)
	}
	if(ydir > 0) {
	   SiSSetupCMDFlag(Y_INC)
	}
}

static void
SiSSubsequentScreenToScreenCopy(ScrnInfoPtr pScrn,
			int src_x, int src_y, int dst_x, int dst_y,
			int width, int height)
{
	SISPtr pSiS = SISPTR(pScrn);
	CARD32 srcbase, dstbase;

	srcbase = dstbase = 0;
	if(src_y >= 2048) {
	   srcbase = pSiS->scrnOffset * src_y;
	   src_y = 0;
	}
	if((dst_y >= pScrn->virtualY) || (dst_y >= 2048)) {
	   dstbase = pSiS->scrnOffset * dst_y;
	   dst_y = 0;
	}
#ifdef SISDUALHEAD
	if(pSiS->VGAEngine != SIS_530_VGA) {
	   srcbase += HEADOFFSET;
	   dstbase += HEADOFFSET;
	}
#endif
	SiSSetupSRCBase(srcbase);
	SiSSetupDSTBase(dstbase);

	if(!(pSiS->CommandReg & X_INC)) {
	   src_x += width-1;
	   dst_x += width-1;
	}
	if(!(pSiS->CommandReg & Y_INC)) {
	   src_y += height-1;
	   dst_y += height-1;
	}
	SiSSetupRect(width, height)
	SiSSetupSRCXY(src_x, src_y)
	SiSSetupDSTXY(dst_x, dst_y)

	SiSDoCMD
}

static void
SiSSetupForSolidFill(ScrnInfoPtr pScrn,
			int color, int rop, unsigned int planemask)
{
	SISPtr pSiS = SISPTR(pScrn);

	if(pSiS->disablecolorkeycurrent) {
	   if((CARD32)color == pSiS->colorKey) {
	      rop = 5;  /* NOOP */
	   }
	}
	SiSSetupPATFG(color)
	SiSSetupDSTRect(pSiS->scrnOffset, -1)
	SiSSetupDSTColorDepth(pSiS->DstColor);
	SiSSetupROP(SiSGetPatternROP(rop))
	/* SiSSetupCMDFlag(PATFG) - is zero */
}

static void
SiSSubsequentSolidFillRect(ScrnInfoPtr pScrn,
			int x, int y, int w, int h)
{
	SISPtr pSiS = SISPTR(pScrn);
	CARD32 dstbase = 0;

	if(y >= 2048) {
	   dstbase = pSiS->scrnOffset * y;
	   y = 0;
	}
#ifdef SISDUALHEAD
        if(pSiS->VGAEngine != SIS_530_VGA) {
	   dstbase += HEADOFFSET;
        }
#endif
	SiSSetupDSTBase(dstbase)
	SiSSetupDSTXY(x,y)
	SiSSetupRect(w,h)
	/* Clear commandReg because Setup can be used for Rect and Trap */
	pSiS->CommandReg &= ~(T_XISMAJORL | T_XISMAJORR |
			      T_L_X_INC | T_L_Y_INC |
			      T_R_X_INC | T_R_Y_INC |
			      TRAPAZOID_FILL);
	SiSSetupCMDFlag(X_INC | Y_INC | BITBLT)

	SiSDoCMD
}

#ifdef SIS_USE_XAA  /* ---------------------------- XAA -------------------------- */

#ifdef SISDUALHEAD
static void
SiSRestoreAccelState(ScrnInfoPtr pScrn)
{
	SISPtr pSiS = SISPTR(pScrn);

	/* We don't need to do anything special here; forcing the
	 * other head to re-read the CmdQueLen is not necessary:
	 * After the Sync in RestoreAccelState(), the real queue
	 * length is always larger than (or at least equal to)
	 * the amount stored in CmdQueueLen of the other head,
	 * so the only thing that might happen is one unnecessary
	 * Sync on the other head. I think we can live with that.
	 */
	pSiS->DoColorExpand = FALSE;
	SiSIdle
}
#endif

/* Trapezoid */
/* This would work better if XAA would provide us with valid trapezoids.
 * In fact, with small trapezoids the left and the right edge often cross
 * each other or result in a line length of 0 which causes drawing errors
 * (filling over whole scanline).
 * Furthermore, I have not found out how to draw trapezoids with a height
 * greater than 127.
 */
#ifdef TRAP
static void
SiSSubsequentSolidFillTrap(ScrnInfoPtr pScrn, int y, int h,
			int left,  int dxL, int dyL, int eL,
			int right, int dxR, int dyR, int eR )
{
	SISPtr pSiS = SISPTR(pScrn);
	CARD32 dstbase;
#if 0
	float kL, kR;
#endif

	dstbase = 0;
	if(y >= 2048) {
	   dstbase=pSiS->scrnOffset*y;
	   y = 0;
	}
#ifdef SISDUALHEAD
	if(pSiS->VGAEngine != SIS_530_VGA) {
	   dstbase += HEADOFFSET;
	}
#endif
	SiSSetupDSTBase(dstbase)
	/* SiSSetupRect(w,h) */

#if 1
	SiSSetupPATFG(0xff0000) /* FOR TESTING */
#endif

	/* Clear CommandReg because SetUp can be used for Rect and Trap */
	pSiS->CommandReg &= ~(T_L_X_INC | T_L_Y_INC |
	                      T_R_X_INC | T_R_Y_INC |
	                      T_XISMAJORL | T_XISMAJORR |
			      BITBLT);

        xf86DrvMsg(0, X_INFO, "Trap (%d %d %d %d) dxL %d dyL %d eL %d   dxR %d dyR %d eR %d\n",
		left, right, y, h, dxL, dyL, eL, dxR, dyR, eR);

	/* Unfortunately, we must check if the right and the left edge
	 * cross each other...  INCOMPLETE (line equation wrong)
	 */
#if 0
	if (dxL == 0) kL = 0;
	else kL = (float)dyL / (float)dxL;
	if (dxR == 0) kR = 0;
	else kR = (float)dyR / (float)dxR;
	xf86DrvMsg(0, X_INFO, "kL %f kR %f!\n", kL, kR);
	if ( (kR != kL) &&
	     (!(kR == 0 && kL == 0)) &&
	     (!(kR <  0 && kL >  0)) ) {
	   xf86DrvMsg(0, X_INFO, "Inside if (%f - %d)\n", ( kL * ( ( ((float)right - (float)left) / (kL - kR) ) - left) + y), h+y);
           if ( ( ( kL * ( ( ((float)right - (float)left) / (kL - kR) ) - (float)left) + (float)y) < (h + y) ) ) {
	     xf86DrvMsg(0, X_INFO, "Cross detected!\n");
	   }
	}
#endif

	/* Determine egde angles */
	if(dxL < 0) { dxL = -dxL; }
	else { SiSSetupCMDFlag(T_L_X_INC) }
	if(dxR < 0) { dxR = -dxR; }
	else { SiSSetupCMDFlag(T_R_X_INC) }

	/* (Y direction always positive - do this anyway) */
	if(dyL < 0) { dyL = -dyL; }
	else { SiSSetupCMDFlag(T_L_Y_INC) }
	if(dyR < 0) { dyR = -dyR; }
	else { SiSSetupCMDFlag(T_R_Y_INC) }

	/* Determine major axis */
	if(dxL >= dyL) {      /* X is major axis */
	   SiSSetupCMDFlag(T_XISMAJORL)
	}
	if(dxR >= dyR) {      /* X is major axis */
	   SiSSetupCMDFlag(T_XISMAJORR)
	}

	/* Set up deltas */
	SiSSetupdL(dxL, dyL)
	SiSSetupdR(dxR, dyR)

#if 0   /* Could it be that this crappy engine can only draw trapezoids up to 127 pixels high? */
	h &= 0x7F;
	if (h == 0) h = 10;
#endif

	/* Set up y, h, left, right */
	SiSSetupYH(y,h)
	SiSSetupLR(left,right)

	/* Set up initial error term */
	SiSSetupEL(eL)
	SiSSetupER(eR)

	SiSSetupCMDFlag(TRAPAZOID_FILL);

	SiSDoCMD
}
#endif

static void
SiSSetupForSolidLine(ScrnInfoPtr pScrn,
			int color, int rop, unsigned int planemask)
{
	SISPtr pSiS = SISPTR(pScrn);

	SiSSetupLineCount(1)
	SiSSetupPATFG(color)
	SiSSetupDSTRect(pSiS->scrnOffset, -1)
	SiSSetupDSTColorDepth(pSiS->DstColor);
	SiSSetupROP(SiSGetPatternROP(rop))
	SiSSetupCMDFlag(PATFG | LINE)
}

static void
SiSSubsequentSolidTwoPointLine(ScrnInfoPtr pScrn,
			int x1, int y1, int x2, int y2, int flags)
{
	SISPtr pSiS = SISPTR(pScrn);
	int    miny, maxy;
	CARD32 dstbase = 0;

	miny = (y1 > y2) ? y2 : y1;
	maxy = (y1 > y2) ? y1 : y2;
	if(maxy >= 2048) {
	   dstbase = pSiS->scrnOffset * miny;
	   y1 -= miny;
	   y2 -= miny;
	}
#ifdef SISDUALHEAD
	if(pSiS->VGAEngine != SIS_530_VGA) {
	   dstbase += HEADOFFSET;
	}
#endif
	SiSSetupDSTBase(dstbase)

	SiSSetupX0Y0(x1,y1)
	SiSSetupX1Y1(x2,y2)
	if(flags & OMIT_LAST) {
	   SiSSetupCMDFlag(NO_LAST_PIXEL)
	} else {
	   pSiS->CommandReg &= ~(NO_LAST_PIXEL);
	}

	SiSDoCMD
}

static void
SiSSubsequentSolidHorzVertLine(ScrnInfoPtr pScrn,
			int x, int y, int len, int dir)
{
	SISPtr pSiS = SISPTR(pScrn);
	CARD32 dstbase = 0;

	len--; /* starting point is included! */

	if((y >= 2048) || ((dir != DEGREES_0) && ((y + len) >= 2048))) {
	   dstbase = pSiS->scrnOffset * y;
	   y = 0;
	}
#ifdef SISDUALHEAD
	if(pSiS->VGAEngine != SIS_530_VGA) {
	   dstbase += HEADOFFSET;
	}
#endif
	SiSSetupDSTBase(dstbase)

	SiSSetupX0Y0(x,y)
	if(dir == DEGREES_0) {
	   SiSSetupX1Y1(x + len, y);
	} else {
	   SiSSetupX1Y1(x, y + len);
	}

	SiSDoCMD
}

static void
SiSSetupForDashedLine(ScrnInfoPtr pScrn,
			int fg, int bg, int rop, unsigned int planemask,
			int length, UChar *pattern)
{
	SISPtr pSiS = SISPTR(pScrn);

	SiSSetupLineCount(1)
	SiSSetupDSTRect(pSiS->scrnOffset, -1)
	SiSSetupDSTColorDepth(pSiS->DstColor);
	SiSSetupStyleLow(*pattern)
	SiSSetupStyleHigh(*(pattern+4))
	SiSSetupStylePeriod(length-1);
	SiSSetupROP(SiSGetPatternROP(rop))
	SiSSetupPATFG(fg)
	SiSSetupCMDFlag(LINE | LINE_STYLE)
	if(bg != -1) {
	   SiSSetupPATBG(bg)
	} else {
	   SiSSetupCMDFlag(TRANSPARENT);
	}
}

static void
SiSSubsequentDashedTwoPointLine(ScrnInfoPtr pScrn,
			int x1, int y1, int x2, int y2,
			int flags, int phase)
{
	SISPtr pSiS = SISPTR(pScrn);
	int    miny, maxy;
	CARD32 dstbase = 0;

	miny = (y1 > y2) ? y2 : y1;
	maxy = (y1 > y2) ? y1 : y2;
	if(maxy >= 2048) {
	   dstbase = pSiS->scrnOffset * miny;
	   y1 -= miny;
	   y2 -= miny;
	}
#ifdef SISDUALHEAD
	if(pSiS->VGAEngine != SIS_530_VGA) {
	   dstbase += HEADOFFSET;
	}
#endif
	SiSSetupDSTBase(dstbase)

	SiSSetupX0Y0(x1,y1)
	SiSSetupX1Y1(x2,y2)
	if(flags & OMIT_LAST) {
	   SiSSetupCMDFlag(NO_LAST_PIXEL)
	} else {
	   pSiS->CommandReg &= ~(NO_LAST_PIXEL);
	}

	SiSDoCMD
}

static void
SiSSetupForMonoPatternFill(ScrnInfoPtr pScrn,
			int patx, int paty, int fg, int bg,
			int rop, unsigned int planemask)
{
	SISPtr pSiS = SISPTR(pScrn);

	SiSSetupDSTRect(pSiS->scrnOffset, -1)
	SiSSetupDSTColorDepth(pSiS->DstColor);
	SiSSetupMONOPAT(patx,paty)
	SiSSetupPATFG(fg)
	SiSSetupROP(SiSGetPatternROP(rop))
	SiSSetupCMDFlag(PATMONO)
	if(bg != -1) {
	   SiSSetupPATBG(bg)
	} else {
	   SiSSetupCMDFlag(TRANSPARENT)
	}
}

static void
SiSSubsequentMonoPatternFill(ScrnInfoPtr pScrn,
			int patx, int paty,
			int x, int y, int w, int h)
{
	SISPtr pSiS = SISPTR(pScrn);
	CARD32 dstbase = 0;

	if(y >= 2048) {
	   dstbase = pSiS->scrnOffset * y;
	   y = 0;
	}
#ifdef SISDUALHEAD
	if(pSiS->VGAEngine != SIS_530_VGA) {
	   dstbase += HEADOFFSET;
	}
#endif
	SiSSetupDSTBase(dstbase)
	SiSSetupDSTXY(x, y)
	SiSSetupRect(w, h)
	/* Clear commandReg because Setup can be used for Rect and Trap */
	pSiS->CommandReg &= ~(T_XISMAJORL | T_XISMAJORR |
	                      T_L_X_INC | T_L_Y_INC |
	                      T_R_X_INC | T_R_Y_INC |
	                      TRAPAZOID_FILL);
	SiSSetupCMDFlag(X_INC | Y_INC)

	SiSDoCMD
}

/* Trapezoid */
#ifdef TRAP
static void
SiSSubsequentMonoPatternFillTrap(ScrnInfoPtr pScrn,
			int patx, int paty,
			int y, int h,
			int left, int dxL, int dyL, int eL,
			int right, int dxR, int dyR, int eR )
{
	SISPtr pSiS = SISPTR(pScrn);
	CARD32 dstbase = 0;

	if(y >= 2048) {
	   dstbase = pSiS->scrnOffset * y;
	   y = 0;
	}
#ifdef SISDUALHEAD
	if(pSiS->VGAEngine != SIS_530_VGA) {
	   dstbase += HEADOFFSET;
	}
#endif
	SiSSetupDSTBase(dstbase)

	/* Clear CommandReg because SetUp can be used for Rect and Trap */
	pSiS->CommandReg &= ~(T_XISMAJORL | T_XISMAJORR |
			      T_L_X_INC | T_L_Y_INC |
			      T_R_X_INC | T_R_Y_INC |
			      BITBLT);

	if(dxL < 0) { dxL = -dxL;  }
	else { SiSSetupCMDFlag(T_L_X_INC) }
	if(dxR < 0) { dxR = -dxR; }
	else { SiSSetupCMDFlag(T_R_X_INC) }

	if(dyL < 0) { dyL = -dyL; }
	else { SiSSetupCMDFlag(T_L_Y_INC) }
	if(dyR < 0) { dyR = -dyR; }
	else { SiSSetupCMDFlag(T_R_Y_INC) }

	/* Determine major axis */
	if(dxL >= dyL) {      /* X is major axis */
	   SiSSetupCMDFlag(T_XISMAJORL)
	}
	if(dxR >= dyR) {      /* X is major axis */
	   SiSSetupCMDFlag(T_XISMAJORR)
	}

	SiSSetupYH(y,h)
	SiSSetupLR(left,right)

	SiSSetupdL(dxL, dyL)
	SiSSetupdR(dxR, dyR)

	SiSSetupEL(eL)
	SiSSetupER(eR)

	SiSSetupCMDFlag(TRAPAZOID_FILL);

	SiSDoCMD
}
#endif

/* ------ Screen To Screen Color Expand ------------------------------- */

/* The hareware does not seem to support this the way we need it */

#ifdef STSCE
static void
SiSSetupForScreenToScreenColorExpand(ScrnInfoPtr pScrn,
			int fg, int bg,
			int rop, unsigned int planemask)
{
	SISPtr pSiS = SISPTR(pScrn);

	SiSSetupDSTColorDepth(pSiS->DstColor)
	SiSSetupDSTRect(pSiS->scrnOffset, -1)
	SiSSetupROP(SiSGetCopyROP(rop))
	SiSSetupSRCFG(fg)
	/* SiSSetupSRCXY(0,0) */

	if(bg == -1) {
	   SiSSetupCMDFlag(TRANSPARENT | ENCOLOREXP | X_INC |
				Y_INC | SRCVIDEO);
	} else {
	   SiSSetupSRCBG(bg);
	   SiSSetupCMDFlag(ENCOLOREXP | X_INC | Y_INC |
				SRCVIDEO);
	};
}
#endif

/* This method blits in a single task; this does not seem to work
 * because the hardware does not use the source pitch as scanline
 * offset but only to calculate pattern address from source X and Y.
 * XAA provides the pattern bitmap with scrnOffset (displayWidth * bpp/8)
 * offset, but this does not seem to be supported by the hardware.
 */
#ifdef STSCE

/* For testing, these are the methods: (use only one at a time!) */

#undef npitch		/* Normal: Use srcx/y as srcx/y, use scrnOffset as source pitch
			 * This would work if the hareware used the source pitch for
			 * incrementing the source address after each scanline - but
			 * it doesn't do this! The first line of the area is correctly
			 * color expanded, but since the source pitch is ignored and
			 * the source address not incremented correctly, the following
			 * lines are color expanded with any bit pattern that is left
			 * in the unused space of the source bitmap (which is organized
			 * with the depth of the screen framebuffer hence with a pitch
			 * of scrnOffset).
			 */

#undef pitchdw		/* Use source pitch "displayWidth / 8" instead
			 * of scrnOffset (=displayWidth * bpp / 8)
			 * This can't work, because the pitch of the source
			 * bitmap is scrnoffset!
			 */

#define nopitch		/* Calculate srcbase with srcx and srcy, set the
			 * pitch to scrnOffset (which IS the correct pitch
			 * for the source bitmap) and set srcx and srcy both
			 * to 0.
			 * This would work if the hareware used the source pitch for
			 * incrementing the source address after each scanline - but
			 * it doesn't do this! Again: The first line of the area is
			 * correctly color expanded, but since the source pitch is
			 * ignored for scanline address incremention, the following
			 * lines are not correctly color expanded.
			 * WHATEVER I write to source pitch is ignored!
			 */

static void
SiSSubsequentScreenToScreenColorExpand(ScrnInfoPtr pScrn,
			int x, int y, int w, int h,
			int srcx, int srcy, int skipleft)
{
	SISPtr pSiS = SISPTR(pScrn);
        CARD32 srcbase, dstbase;
#if 0
	int _x0, _y0, _x1, _y1;
#endif
#ifdef pitchdw
	int newsrcx, newsrcy;

	/* srcx and srcy are provided based on a scrnOffset pitch ( = displayWidth * bpp / 8 )
	 * We recalulate srcx and srcy based on pitch = displayWidth / 8
	 */
        newsrcy = ((pSiS->scrnOffset * srcy) + (srcx * ((pScrn->bitsPerPixel+7)/8))) /
					  (pScrn->displayWidth/8);
        newsrcx = ((pSiS->scrnOffset * srcy) + (srcx * ((pScrn->bitsPerPixel+7)/8))) %
					  (pScrn->displayWidth/8);
#endif
	xf86DrvMsg(0, X_INFO, "Sub ScreenToScreen ColorExp(%d,%d, %d,%d, %d,%d, %d)\n",
					x, y, w, h, srcx, srcy, skipleft);

	srcbase = dstbase = 0;

#ifdef pitchdw
	if(newsrcy >= 2048) {
	   srcbase = (pScrn->displayWidth / 8) * newsrcy;
	   newsrcy = 0;
	}
#endif
#ifdef nopitch
	srcbase = (pSiS->scrnOffset * srcy) + (srcx * ((pScrn->bitsPerPixel+7)/8));
#endif
#ifdef npitch
	if(srcy >= 2048) {
	   srcbase = pSiS->scrnOffset * srcy;
	   srcy = 0;
	}
#endif
	if(y >= 2048) {
	   dstbase = pSiS->scrnOffset * y;
	   y = 0;
	}
#ifdef SISDUALHEAD
	if(pSiS->VGAEngine != SIS_530_VGA) {
	   srcbase += HEADOFFSET;
	   dstbase += HEADOFFSET;
	}
#endif
	SiSSetupSRCBase(srcbase)
	SiSSetupDSTBase(dstbase)

#ifdef pitchdw
	SiSSetupSRCPitch(pScrn->displayWidth/8)
#endif
#ifdef nopitch
	SiSSetupSRCPitch(pSiS->scrnOffset)
	/* SiSSetupSRCPitch(100) */ /* For test - has NO effect WHATSOEVER */
#endif
#ifdef npitch
	SiSSetupSRCPitch(pSiS->scrnOffset)
#endif

	SiSSetupRect(w,h)

#if 0   /* How do I implement the offset? Not this way, that's for sure.. */
	if (skipleft > 0) {
		_x0 = x+skipleft;
		_y0 = y;
		_x1 = x+w;
		_y1 = y+h;
		SiSSetupClipLT(_x0, _y0);
		SiSSetupClipRB(_x1, _y1);
		SiSSetupCMDFlag(CLIPENABLE);
	}
#endif
#ifdef pitchdw
	SiSSetupSRCXY(newsrcx, newsrcy)
#endif
#ifdef nopitch
	SiSSetupSRCXY(0,0)
#endif
#ifdef npitch
	SiSSetupSRCXY(srcx, srcy)
#endif

	SiSSetupDSTXY(x,y)

	SiSDoCMD
}
#endif

/* ----- CPU To Screen Color Expand (scanline-wise) ----------------- */

/* We do it using the indirect method */

static void
SiSSetupForScanlineCPUToScreenColorExpandFill(ScrnInfoPtr pScrn,
			int fg, int bg, int rop, unsigned int planemask)
{
	SISPtr pSiS=SISPTR(pScrn);

        /* Make sure that current CPU-driven BitBlt buffer stage is 0
	 * This is required!!! (Otherwise -> drawing errors)
	 */
	while((SIS_MMIO_IN16(pSiS->IOBase, 0x8242) & 0x1F00) != 0) {} /* WDR: == 0x10 */

	SiSSetupSRCXY(0,0);
	SiSSetupROP(SiSGetCopyROP(rop));
	SiSSetupSRCFG(fg);
	SiSSetupDSTRect(pSiS->scrnOffset, -1);
	SiSSetupDSTColorDepth(pSiS->DstColor);
	if(bg == -1) {
	   SiSSetupCMDFlag(TRANSPARENT |
			   ENCOLOREXP |
			   X_INC | Y_INC |
			   SRCCPUBLITBUF);
	} else {
	   SiSSetupSRCBG(bg);
	   SiSSetupCMDFlag(ENCOLOREXP |
			   X_INC | Y_INC |
			   SRCCPUBLITBUF);
	}
}


static void
SiSSubsequentScanlineCPUToScreenColorExpandFill(
			ScrnInfoPtr pScrn, int x, int y, int w,
			int h, int skipleft)
{
	SISPtr pSiS = SISPTR(pScrn);
	int    _x0, _y0, _x1, _y1;
	CARD32 dstbase = 0;

	if((y >= 2048) || ((y + h) >= 2048)) {
	   dstbase = pSiS->scrnOffset * y;
	   y = 0;
	}
#ifdef SISDUALHEAD
	if(pSiS->VGAEngine != SIS_530_VGA) {
	   dstbase += HEADOFFSET;
	}
#endif

	/* Wait until there is no color expansion command in queue
	 * (This solves the OpenOffice.org window-move bug)
	 * Added Idle-check - bit 23 is set sometimes, although
	 * engine is actually idle!
	 * Update: Bit 23 is not reliable. After heavy 3D engine
	 * action, this bit never gets cleared again. So do
	 * SiSIdle instead.
	 */
	if((SIS_MMIO_IN16(pSiS->IOBase, 0x8242) & 0xe000) != 0xe000) {
           /* while ((SIS_MMIO_IN16(pSiS->IOBase, 0x8242) & 0x0080) != 0) {} */
	   SiSIdle
	}

	SiSSetupDSTBase(dstbase)

	if(skipleft > 0) {
	   _x0 = x + skipleft;
	   _y0 = y;
	   _x1 = x + w;
	   _y1 = y + h;
	   SiSSetupClipLT(_x0, _y0);
	   SiSSetupClipRB(_x1, _y1);
	   SiSSetupCMDFlag(CLIPENABLE);
	} else {
	   pSiS->CommandReg &= (~CLIPENABLE);
	}

	SiSSetupRect(w, 1);
        SiSSetupSRCPitch(((((w + 7) / 8) + 3) >> 2) * 4);
	pSiS->xcurrent = x;
	pSiS->ycurrent = y;
}

static void
SiSSubsequentColorExpandScanline(ScrnInfoPtr pScrn, int bufno)
{
	SISPtr pSiS=SISPTR(pScrn);
#if 0
	int newhead,bltbufstage,newtail;
#endif
	CARD32 cbo;

	cbo = pSiS->ColorExpandBufferScreenOffset[bufno];
#ifdef SISDUALHEAD
	if(pSiS->VGAEngine != SIS_530_VGA) {
	   cbo += HEADOFFSET;
	}
#endif

	/* Wait until there is no color expansion command in queue
	 * (This solves the GTK-big-font bug)
	 * Added Idle-check - bit 23 is set sometimes, although
	 * engine is actually idle!
	 * Update: Bit 23 is not reliable. After heavy 3D engine
	 * action, this bit never gets cleared again. So do
	 * SiSIdle instead.
	 */
	if((SIS_MMIO_IN16(pSiS->IOBase, 0x8242) & 0xe000) != 0xe000) {
	   /* while ((SIS_MMIO_IN16(pSiS->IOBase, 0x8242) & 0x0080) != 0) {} */
	   SiSIdle
	}

	SiSSetupSRCBase(cbo);

	SiSSetupDSTXY(pSiS->xcurrent, pSiS->ycurrent);

	SiSDoCMD

	pSiS->ycurrent++;

	if(pSiS->VGAEngine == SIS_530_VGA) {
	   while(SIS_MMIO_IN8(pSiS->IOBase, 0x8242) & 0x80) {}
	}
}

#endif /* XAA */

#ifdef SIS_USE_EXA  /* ---------------------------- EXA -------------------------- */

static const unsigned short dstcol[] = { 0x0000, 0x8000, 0xc000 };

static void
SiSEXASync(ScreenPtr pScreen, int marker)
{
	SISPtr pSiS = SISPTR(xf86ScreenToScrn(pScreen));

	SiSIdle
}

static Bool
SiSPrepareSolid(PixmapPtr pPixmap, int alu, Pixel planemask, Pixel fg)
{
	ScrnInfoPtr pScrn = xf86ScreenToScrn(pPixmap->drawable.pScreen);
	SISPtr pSiS = SISPTR(pScrn);
	CARD32 dstbase;

	/* Planemask not supported */
	if((planemask & ((1 << pPixmap->drawable.depth) - 1)) !=
				(1 << pPixmap->drawable.depth) - 1) {
	   return FALSE;
	}

	/* Since the 530/620 have no "dest color depth" register, I
	 * assume that the 2D engine reads the current color depth
	 * from the DAC.... FIXME ? */
	if(pSiS->VGAEngine == SIS_530_VGA) {
	   if(pPixmap->drawable.bitsPerPixel != pSiS->CurrentLayout.bitsPerPixel)
	      return FALSE;
	} else if((pPixmap->drawable.bitsPerPixel != 8)  &&
		  (pPixmap->drawable.bitsPerPixel != 16) &&
		  (pPixmap->drawable.bitsPerPixel != 32))
	   return FALSE;

	if(pSiS->disablecolorkeycurrent) {
	   if((CARD32)fg == pSiS->colorKey) {
	      alu = 5;  /* NOOP */
	   }
	}

	/* Check that the pitch matches the hardware's requirements. Should
	 * never be a problem due to pixmapPitchAlign and fbScreenInit.
	 */
	if(exaGetPixmapPitch(pPixmap) & 3)
	   return FALSE;

	dstbase = (CARD32)exaGetPixmapOffset(pPixmap) + HEADOFFSET;

	SiSSetupPATFG(fg)
	SiSSetupDSTRect(exaGetPixmapPitch(pPixmap), -1)
	SiSSetupDSTColorDepth(dstcol[pPixmap->drawable.bitsPerPixel >> 4]);
	SiSSetupROP(SiSGetPatternROP(alu))
	SiSSetupDSTBase(dstbase)
	/* SiSSetupCMDFlag(PATFG) - is zero */

	return TRUE;
}

static void
SiSSolid(PixmapPtr pPixmap, int x1, int y1, int x2, int y2)
{
	ScrnInfoPtr pScrn = xf86ScreenToScrn(pPixmap->drawable.pScreen);
	SISPtr pSiS = SISPTR(pScrn);

	SiSSetupDSTXY(x1, y1)
	SiSSetupRect(x2-x1, y2-y1)

	SiSSetupCMDFlag(X_INC | Y_INC | BITBLT)

	SiSDoCMD
}

static void
SiSDoneSolid(PixmapPtr pPixmap)
{
}

static Bool
SiSPrepareCopy(PixmapPtr pSrcPixmap, PixmapPtr pDstPixmap, int xdir, int ydir,
					int alu, Pixel planemask)
{
	ScrnInfoPtr pScrn = xf86ScreenToScrn(pDstPixmap->drawable.pScreen);
	SISPtr pSiS = SISPTR(pScrn);
	CARD32 srcbase, dstbase;

	/* Planemask not supported */
	if((planemask & ((1 << pSrcPixmap->drawable.depth) - 1)) !=
				(1 << pSrcPixmap->drawable.depth) - 1) {
	   return FALSE;
	}

	/* Since the 530/620 have no "dest color depth" register, I
	 * assume that the 2D engine reads the current color depth
	 * from the DAC.... FIXME ? */
	if(pSiS->VGAEngine == SIS_530_VGA) {
	   if(pDstPixmap->drawable.bitsPerPixel != pSiS->CurrentLayout.bitsPerPixel)
	      return FALSE;
	} else if((pDstPixmap->drawable.bitsPerPixel != 8)  &&
		  (pDstPixmap->drawable.bitsPerPixel != 16) &&
		  (pDstPixmap->drawable.bitsPerPixel != 32))
	   return FALSE;

	/* Check that the pitch matches the hardware's requirements. Should
	 * never be a problem due to pixmapPitchAlign and fbScreenInit.
	 */
	if(exaGetPixmapPitch(pSrcPixmap) & 3)
	   return FALSE;
	if(exaGetPixmapPitch(pDstPixmap) & 3)
	   return FALSE;

	SiSSetupDSTColorDepth(dstcol[pDstPixmap->drawable.bitsPerPixel >> 4]);
	SiSSetupSRCPitch(exaGetPixmapPitch(pSrcPixmap))
	SiSSetupDSTRect(exaGetPixmapPitch(pDstPixmap), -1)

	SiSSetupROP(SiSGetCopyROP(alu))

	if(xdir >= 0) {
	   SiSSetupCMDFlag(X_INC)
	}
	if(ydir >= 0) {
	   SiSSetupCMDFlag(Y_INC)
	}

	srcbase = (CARD32)exaGetPixmapOffset(pSrcPixmap) + HEADOFFSET;

	dstbase = (CARD32)exaGetPixmapOffset(pDstPixmap) + HEADOFFSET;

	SiSSetupSRCBase(srcbase);
	SiSSetupDSTBase(dstbase);

	return TRUE;
}

static void
SiSCopy(PixmapPtr pDstPixmap, int srcX, int srcY, int dstX, int dstY, int width, int height)
{
	ScrnInfoPtr pScrn = xf86ScreenToScrn(pDstPixmap->drawable.pScreen);
	SISPtr pSiS = SISPTR(pScrn);

	if(!(pSiS->CommandReg & X_INC))  {
	   srcX += width-1;
	   dstX += width-1;
	}
	if(!(pSiS->CommandReg & Y_INC))  {
	   srcY += height-1;
	   dstY += height-1;
	}
	SiSSetupRect(width, height)
	SiSSetupSRCXY(srcX, srcY)
	SiSSetupDSTXY(dstX, dstY)

	SiSDoCMD
}

static void
SiSDoneCopy(PixmapPtr pDstPixmap)
{
}

#endif /* EXA */

/* For DGA usage */

static void
SiSDGAFillRect(ScrnInfoPtr pScrn, int x, int y, int w, int h, int color)
{
	SiSSetupForSolidFill(pScrn, color, GXcopy, ~0);
	SiSSubsequentSolidFillRect(pScrn, x, y, w, h);
}

static void
SiSDGABlitRect(ScrnInfoPtr pScrn, int srcx, int srcy, int dstx, int dsty, int w, int h, int color)
{
	int xdir = ((srcx < dstx) && (srcy == dsty)) ? -1 : 1;
	int ydir = (srcy < dsty) ? -1 : 1;

	SiSSetupForScreenToScreenCopy(pScrn, xdir, ydir, GXcopy, (CARD32)~0, color);
	SiSSubsequentScreenToScreenCopy(pScrn, srcx, srcy, dstx, dsty, w, h);
}

/* Initialisation */

Bool
SiS300AccelInit(ScreenPtr pScreen)
{
	ScrnInfoPtr     pScrn = xf86ScreenToScrn(pScreen);
	SISPtr          pSiS = SISPTR(pScrn);
#ifdef SIS_USE_XAA
	XAAInfoRecPtr   infoPtr = NULL;
	UChar           *AvailBufBase;
	int		topFB, reservedFbSize, usableFbSize, i;
	BoxRec          Avail;
#endif /* XAA */

	pSiS->ColorExpandBufferNumber = 0;
	pSiS->PerColorExpandBufferSize = 0;
	pSiS->RenderAccelArray = NULL;
#ifdef SIS_USE_XAA
	pSiS->AccelInfoPtr = NULL;
#endif
#ifdef SIS_USE_EXA
	pSiS->EXADriverPtr = NULL;
	pSiS->exa_scratch = NULL;
#endif

	if((pScrn->bitsPerPixel != 8)  &&
	   (pScrn->bitsPerPixel != 16) &&
	   (pScrn->bitsPerPixel != 32)) {
	   pSiS->NoAccel = TRUE;
	}

	if(!pSiS->NoAccel) {
#ifdef SIS_USE_XAA
	   if(!pSiS->useEXA) {
	      pSiS->AccelInfoPtr = infoPtr = XAACreateInfoRec();
	      if(!infoPtr) pSiS->NoAccel = TRUE;
	   }
#endif
#ifdef SIS_USE_EXA
	   if(pSiS->useEXA) {
	      if(!(pSiS->EXADriverPtr = exaDriverAlloc())) {
		 pSiS->NoAccel = TRUE;
		 pSiS->NoXvideo = TRUE; /* No fbmem manager -> no xv */
	      }
	   }
#endif
	}

	if(!pSiS->NoAccel) {

	   SiSInitializeAccelerator(pScrn);

	   pSiS->InitAccel = SiSInitializeAccelerator;
	   pSiS->SyncAccel = SiSSyncAccel;
	   pSiS->FillRect  = SiSDGAFillRect;
	   pSiS->BlitRect  = SiSDGABlitRect;

#ifdef SIS_USE_XAA	/* ----------------------- XAA ----------------------- */
	   if(!pSiS->useEXA) {

	      infoPtr->Flags = LINEAR_FRAMEBUFFER |
			       OFFSCREEN_PIXMAPS |
			       PIXMAP_CACHE;

	      /* sync */
	      infoPtr->Sync = SiSSync;

	      /* Although SiS states that the 300 series supports a
	       * virtual screen of 4096x4096, the 2D accelerator
	       * does not seem to know that. If the destination bitmap
	       * pitch is > 8192 (which easily happens in 32bpp mode),
	       * the accelerator engine collapses.
	       * TODO: Find out about the 530 and 620
	       */

	      if(pSiS->scrnOffset < 8192) {

		 /* screen to screen copy */
		 infoPtr->SetupForScreenToScreenCopy = SiSSetupForScreenToScreenCopy;
		 infoPtr->SubsequentScreenToScreenCopy = SiSSubsequentScreenToScreenCopy;
		 infoPtr->ScreenToScreenCopyFlags = NO_PLANEMASK |
						    TRANSPARENCY_GXCOPY_ONLY;

		 /* solid fills */
		 infoPtr->SetupForSolidFill = SiSSetupForSolidFill;
		 infoPtr->SubsequentSolidFillRect = SiSSubsequentSolidFillRect;
#ifdef TRAP
		 infoPtr->SubsequentSolidFillTrap = SiSSubsequentSolidFillTrap;
#endif
		 infoPtr->SolidFillFlags = NO_PLANEMASK;

		 /* solid line */
	         infoPtr->SetupForSolidLine = SiSSetupForSolidLine;
		 infoPtr->SubsequentSolidTwoPointLine = SiSSubsequentSolidTwoPointLine;
		 infoPtr->SubsequentSolidHorVertLine = SiSSubsequentSolidHorzVertLine;
		 infoPtr->SolidLineFlags = NO_PLANEMASK;

		 /* dashed line */
		 infoPtr->SetupForDashedLine = SiSSetupForDashedLine;
		 infoPtr->SubsequentDashedTwoPointLine = SiSSubsequentDashedTwoPointLine;
		 infoPtr->DashPatternMaxLength = 64;
		 infoPtr->DashedLineFlags = NO_PLANEMASK |
					    LINE_PATTERN_MSBFIRST_LSBJUSTIFIED;

		 /* 8x8 mono pattern fill */
		 infoPtr->SetupForMono8x8PatternFill = SiSSetupForMonoPatternFill;
		 infoPtr->SubsequentMono8x8PatternFillRect = SiSSubsequentMonoPatternFill;
#ifdef TRAP
		 infoPtr->SubsequentMono8x8PatternFillTrap = SiSSubsequentMonoPatternFillTrap;
#endif
		 infoPtr->Mono8x8PatternFillFlags = NO_PLANEMASK |
						    HARDWARE_PATTERN_SCREEN_ORIGIN |
						    HARDWARE_PATTERN_PROGRAMMED_BITS |
						    /* NO_TRANSPARENCY | */
						    BIT_ORDER_IN_BYTE_MSBFIRST ;

#ifdef STSCE
		 /* Screen To Screen Color Expand */
		 /* The hardware does support this the way we need it */
		 infoPtr->SetupForScreenToScreenColorExpandFill =
				SiSSetupForScreenToScreenColorExpand;
		 infoPtr->SubsequentScreenToScreenColorExpandFill =
				SiSSubsequentScreenToScreenColorExpand;
		 infoPtr->ScreenToScreenColorExpandFillFlags = NO_PLANEMASK |
							       BIT_ORDER_IN_BYTE_MSBFIRST ;
#endif

		 /* per-scanline color expansion (using indirect method) */
		 if(pSiS->VGAEngine == SIS_530_VGA) {
		    pSiS->ColorExpandBufferNumber = 4;
		    pSiS->ColorExpandBufferCountMask = 0x03;
		 } else {
		    pSiS->ColorExpandBufferNumber = 16;
		    pSiS->ColorExpandBufferCountMask = 0x0F;
		 }

		 pSiS->PerColorExpandBufferSize = ((pScrn->virtualX + 31)/32) * 4;
		 infoPtr->NumScanlineColorExpandBuffers = pSiS->ColorExpandBufferNumber;
		 infoPtr->ScanlineColorExpandBuffers = (UChar **)&pSiS->ColorExpandBufferAddr[0];

		 infoPtr->SetupForScanlineCPUToScreenColorExpandFill =
					SiSSetupForScanlineCPUToScreenColorExpandFill;
		 infoPtr->SubsequentScanlineCPUToScreenColorExpandFill =
					SiSSubsequentScanlineCPUToScreenColorExpandFill;
		 infoPtr->SubsequentColorExpandScanline =
					SiSSubsequentColorExpandScanline;
		 infoPtr->ScanlineCPUToScreenColorExpandFillFlags = NO_PLANEMASK |
								    CPU_TRANSFER_PAD_DWORD |
								    SCANLINE_PAD_DWORD |
								    BIT_ORDER_IN_BYTE_MSBFIRST |
								    LEFT_EDGE_CLIPPING;
	      } else {

		 xf86DrvMsg(pScrn->scrnIndex, X_WARNING,
			"Virtual screen width too large for accelerator engine\n");
		 xf86DrvMsg(pScrn->scrnIndex, X_WARNING,
			"\t2D acceleration and Xv disabled\n");
		 pSiS->NoXvideo = TRUE;

	      }

#ifdef SISDUALHEAD
	      if(pSiS->DualHeadMode) {
		 infoPtr->RestoreAccelState = SiSRestoreAccelState;
	      }
#endif
	   } /* !exa */
#endif /* XAA */

#ifdef SIS_USE_EXA	/* ----------------------- EXA ----------------------- */
	   if(pSiS->useEXA) {

	      pSiS->EXADriverPtr->exa_major = 2;
	      pSiS->EXADriverPtr->exa_minor = 0;

	      if(pSiS->scrnOffset < 8192) {

		 /* data */
		 pSiS->EXADriverPtr->memoryBase = pSiS->FbBase;
		 pSiS->EXADriverPtr->memorySize = pSiS->maxxfbmem;
		 pSiS->EXADriverPtr->offScreenBase = pScrn->virtualX * pScrn->virtualY
						* ((pScrn->bitsPerPixel + 7) / 8);
		 if(pSiS->EXADriverPtr->memorySize > pSiS->EXADriverPtr->offScreenBase) {
		    pSiS->EXADriverPtr->flags = EXA_OFFSCREEN_PIXMAPS;
		 } else {
		    pSiS->NoXvideo = TRUE;
		    xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
			"Not enough video RAM for offscreen memory manager. Xv disabled\n");
		 }
		 pSiS->EXADriverPtr->pixmapOffsetAlign = 16;	/* src/dst: double quad word boundary */
		 pSiS->EXADriverPtr->pixmapPitchAlign = 4;		/* pitch:   double word boundary      */
		 if(pSiS->VGAEngine == SIS_300_VGA) {
		    pSiS->EXADriverPtr->maxX = 4095;
		    pSiS->EXADriverPtr->maxY = 4095;
		 } else {
		    pSiS->EXADriverPtr->maxX = 2047;
		    pSiS->EXADriverPtr->maxY = 2047;
		 }

		 /* Sync */
		 pSiS->EXADriverPtr->WaitMarker = SiSEXASync;

		 /* Solid fill */
		 pSiS->EXADriverPtr->PrepareSolid = SiSPrepareSolid;
		 pSiS->EXADriverPtr->Solid = SiSSolid;
		 pSiS->EXADriverPtr->DoneSolid = SiSDoneSolid;

		 /* Copy */
		 pSiS->EXADriverPtr->PrepareCopy = SiSPrepareCopy;
		 pSiS->EXADriverPtr->Copy = SiSCopy;
		 pSiS->EXADriverPtr->DoneCopy = SiSDoneCopy;

		 /* Composite not supported */

		 /* Upload, download to/from Screen */
		 pSiS->EXADriverPtr->UploadToScreen = SiSUploadToScreen;
		 pSiS->EXADriverPtr->DownloadFromScreen = SiSDownloadFromScreen;

	      } else {

		 xf86DrvMsg(pScrn->scrnIndex, X_WARNING,
			"Virtual screen width too large for accelerator engine\n");
		 xf86DrvMsg(pScrn->scrnIndex, X_WARNING,
			"\t2D acceleration and Xv disabled\n");
		 pSiS->NoAccel = TRUE;
		 pSiS->NoXvideo = TRUE; /* No fbmem manager -> no xv */

	      }

	   }
#endif /* EXA */


	}  /* NoAccel */

	/* Init framebuffer memory manager */

	/* Layout: (Sizes do not reflect correct proportions)
	 * |--------------++++++++++++++++++++^************==========~~~~~~~~~~~~|
	 *   UsableFbSize  ColorExpandBuffers | DRI-Heap  |  HWCursor  TurboQueue   300/310/325 series
	 * |--------------++++++++++++++++++++|  ====================~~~~~~~~~~~~|
	 *   UsableFbSize  ColorExpandBuffers |        TurboQueue     HWCursor      530/620
	 *                                  topFB
	 */

#ifdef SIS_USE_XAA
	if(!pSiS->useEXA) {

	   topFB = pSiS->maxxfbmem;

	   reservedFbSize = pSiS->ColorExpandBufferNumber * pSiS->PerColorExpandBufferSize;

	   usableFbSize = topFB - reservedFbSize;

	   AvailBufBase = pSiS->FbBase + usableFbSize;
	   for(i = 0; i < pSiS->ColorExpandBufferNumber; i++) {
	      pSiS->ColorExpandBufferAddr[i] = AvailBufBase +
				i * pSiS->PerColorExpandBufferSize;
	      pSiS->ColorExpandBufferScreenOffset[i] = usableFbSize +
				i * pSiS->PerColorExpandBufferSize;
	   }

	   Avail.x1 = 0;
	   Avail.y1 = 0;
	   Avail.x2 = pScrn->displayWidth;
	   Avail.y2 = (usableFbSize / (pScrn->displayWidth * pScrn->bitsPerPixel/8)) - 1;

	   if(Avail.y2 < 0)  Avail.y2 = 32767;

	   if(Avail.y2 < pScrn->currentMode->VDisplay) {
	      xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
			"Not enough video RAM for accelerator. At least "
			"%dKB needed, %dKB available\n",
			((((pScrn->displayWidth * pScrn->bitsPerPixel/8)   /* +8 for make it sure */
		     		* pScrn->currentMode->VDisplay) + reservedFbSize) / 1024) + 8,
			pSiS->maxxfbmem/1024);
	      pSiS->NoAccel = TRUE;
	      pSiS->NoXvideo = TRUE;
	      XAADestroyInfoRec(pSiS->AccelInfoPtr);
	      pSiS->AccelInfoPtr = NULL;
	      return FALSE;
	   }

	   xf86DrvMsg(pScrn->scrnIndex, X_INFO,
			"Framebuffer from (%d,%d) to (%d,%d)\n",
			Avail.x1, Avail.y1, Avail.x2 - 1, Avail.y2 - 1);

	   xf86InitFBManager(pScreen, &Avail);

	   if(!pSiS->NoAccel) {
	      return XAAInit(pScreen, infoPtr);
	   }
	} /* !exa */
#endif /* XAA */

#ifdef SIS_USE_EXA
        if(pSiS->useEXA) {

	   if(!pSiS->NoAccel) {

	      if(!exaDriverInit(pScreen, pSiS->EXADriverPtr)) {
		 pSiS->NoAccel = TRUE;
		 pSiS->NoXvideo = TRUE; /* No fbmem manager -> no xv */
		 return FALSE;
	      }

	      /* Reserve locked offscreen scratch area of 128K for glyph data */
	      pSiS->exa_scratch = exaOffscreenAlloc(pScreen, 128 * 1024, 16, TRUE,
						SiSScratchSave, pSiS);
	      if(pSiS->exa_scratch) {
		 pSiS->exa_scratch_next = pSiS->exa_scratch->offset;
		 pSiS->EXADriverPtr->UploadToScratch = SiSUploadToScratch;
	      }

	   } else {

	      pSiS->NoXvideo = TRUE; /* No fbmem manager -> no xv */

	   }

	}
#endif /* EXA */

	return TRUE;
}