/* Copyright (c) 2008 Advanced Micro Devices, Inc.
 *
 * 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 the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, 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 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 NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS 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.
 *
 * Neither the name of the Advanced Micro Devices, Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 */

#include "xf86.h"
#include "geode.h"
#include "cim/cim_regs.h"

#define ALIGN(x,y)   (((x) + (y) - 1) / (y) * (y))
#define LX_CB_PITCH   544

/* Geode offscreen memory allocation functions.  This is
   overengineered for the simple hardware that we have, but
   there are multiple functions that may want to independently
   allocate and free memory (crtc->shadow_alloc and Xv).  This
   provides a semi-robust mechanism for doing that.
*/

/* Return the number of free bytes */

unsigned int
GeodeOffscreenFreeSize(GeodeRec * pGeode)
{
    GeodeMemPtr ptr = pGeode->offscreenList;

    if (ptr == NULL)
	return pGeode->offscreenSize;

    for (; ptr->next; ptr = ptr->next) ;
    return pGeode->offscreenSize - (ptr->offset + ptr->size);
}

void
GeodeFreeOffscreen(GeodeRec * pGeode, GeodeMemPtr ptr)
{
    /* There is a clear memory leak here, but
     * but it is unlikely that the first block of
     * "allocated" memory is going to be released
     * individually.
     */

    if (ptr->prev == NULL)
	pGeode->offscreenList = ptr->next;
    else
	ptr->prev->next = ptr->next;

    if (ptr->next)
	ptr->next->prev = ptr->prev;

    xfree(ptr);
}

/* Allocate the "rest" of the offscreen memory - this is for
   situations where we have very little video memory, and we
   want to take as much of it as we can for EXA
*/

static GeodeMemPtr
GeodeAllocRemainder(GeodeRec * pGeode)
{
    GeodeMemPtr nptr, ptr = pGeode->offscreenList;

    if (!pGeode->offscreenList) {
	pGeode->offscreenList = xcalloc(1, sizeof(*nptr));
	pGeode->offscreenList->offset = pGeode->offscreenStart;
	pGeode->offscreenList->size = pGeode->offscreenSize;
	pGeode->offscreenList->next = NULL;
	pGeode->offscreenList->prev = NULL;

	return pGeode->offscreenList;
    }

    /* Go to the end of the list of allocated stuff */
    for (; ptr->next; ptr = ptr->next) ;

    nptr = xcalloc(1, sizeof(*nptr));
    nptr->offset = ptr->offset + ptr->size;
    nptr->size = pGeode->offscreenSize - nptr->offset;
    nptr->next = ptr->next;
    nptr->prev = ptr;
    ptr->next = nptr;

    return nptr;
}

/* Allocate 'size' bytes of offscreen memory.
*/

GeodeMemPtr
GeodeAllocOffscreen(GeodeRec * pGeode, int size, int align)
{
    GeodeMemPtr ptr = pGeode->offscreenList;
    GeodeMemPtr nptr;

    unsigned int offset;

    if (!pGeode->offscreenList) {

	if (size > pGeode->offscreenSize)
	    return NULL;

	offset = ALIGN(pGeode->offscreenStart, align);

	pGeode->offscreenList = xcalloc(1, sizeof(*nptr));
	pGeode->offscreenList->offset = offset;
	pGeode->offscreenList->size = size;
	pGeode->offscreenList->next = NULL;

	return pGeode->offscreenList;
    }

    while (ptr) {
	unsigned int gap;

	if (ptr->next == NULL)
	    gap = pGeode->offscreenSize;

	else
	    gap = ptr->next->offset;

	gap = gap - (ptr->offset + ptr->size);
	gap = ALIGN(gap, align);

	if (size < gap) {
	    offset = ptr->offset + ptr->size;
	    offset = ALIGN(ptr->offset + ptr->size, align);

	    nptr = xcalloc(1, sizeof(*nptr));
	    nptr->offset = offset;
	    nptr->size = size;
	    nptr->next = ptr->next;
	    nptr->prev = ptr;
	    ptr->next = nptr;

	    return nptr;
	}

	ptr = ptr->next;
    }

    return NULL;
}

/* Carve out the space for the visible screen, and carve out
   the usual suspects that need offscreen memory
*/

#define MAX(a,b) ((a) > (b) ? (a) : (b))

void
LXInitOffscreen(ScrnInfoPtr pScrni)
{
    GeodeRec *pGeode = GEODEPTR(pScrni);
    unsigned int fbavail;
    GeodeMemPtr ptr;

    /* The scratch buffer is always used */
    fbavail = pGeode->FBAvail - GP3_SCRATCH_BUFFER_SIZE;

    pGeode->displaySize = MAX(pScrni->virtualX, pScrni->virtualY)
	* pGeode->Pitch;

    pGeode->offscreenStart = pGeode->displaySize;
    pGeode->offscreenSize = fbavail - pGeode->displaySize;

    /* Allocate the usual memory suspects */
    if (pGeode->tryCompression) {
	int size = pScrni->virtualY * LX_CB_PITCH;

	/* The compression buffer needs to be 16 byte aligned */
	ptr = GeodeAllocOffscreen(pGeode, size, 16);

	if (ptr != NULL) {
	    pGeode->CBData.compression_offset = ptr->offset;
	    pGeode->CBData.size = LX_CB_PITCH;
	    pGeode->CBData.pitch = LX_CB_PITCH;

	    pGeode->Compression = TRUE;
	} else {
	    xf86DrvMsg(pScrni->scrnIndex, X_ERROR,
		"Not enough memory for compression\n");
	    pGeode->Compression = FALSE;
	}
    }

    if (pGeode->tryHWCursor) {
	ptr = GeodeAllocOffscreen(pGeode, 1024, 4);
	if (ptr != NULL) {
	    pGeode->CursorStartOffset = ptr->offset;
	    pGeode->HWCursor = TRUE;
	} else {
	    xf86DrvMsg(pScrni->scrnIndex, X_ERROR,
		"Not enough memory for the hardware cursor\n");
	    pGeode->HWCursor = FALSE;
	}
    }

    if (!pGeode->NoAccel && pGeode->pExa) {
	int size;

	/* Try to get the scratch buffer for blending */
	pGeode->exaBfrOffset = 0;

	if (pGeode->exaBfrSz > 0) {
	    ptr = GeodeAllocOffscreen(pGeode, pGeode->exaBfrSz, 4);
	    if (ptr != NULL)
		pGeode->exaBfrOffset = ptr->offset;
	}

	pGeode->pExa->offScreenBase = 0;
	pGeode->pExa->memorySize = 0;

	/* In a break from the previous behavior, we will
	 * allocate 3 screens worth of offscreen memory.
	 * (that means, 3 * y * (x * bpp) - not the compressed
	 * pitch if it is enabled). */

	/* FIXME:  Make this configurable */

	size = 3 * (pScrni->virtualY *
	    ((pScrni->virtualX + 3) & ~3) * (pScrni->bitsPerPixel >> 3));

	ptr = GeodeAllocOffscreen(pGeode, size, 4);

	if (ptr == NULL) {
	    /* If we couldn't allocate what we wanted,
	     * then allocate whats left */

	    ptr = GeodeAllocRemainder(pGeode);
	}

	if (ptr != NULL) {
	    pGeode->pExa->offScreenBase = ptr->offset;
	    pGeode->pExa->memorySize = ptr->offset + ptr->size;
	}
    }

    /* Show the memory map for diagnostic purposes */

    xf86DrvMsg(pScrni->scrnIndex, X_INFO, "LX video memory:\n");
    xf86DrvMsg(pScrni->scrnIndex, X_INFO, " Display: 0x%x bytes\n",
	pGeode->displaySize);

    if (pGeode->Compression)
	xf86DrvMsg(pScrni->scrnIndex, X_INFO, " Compression: 0x%x bytes\n",
	    pScrni->virtualY * LX_CB_PITCH);

    if (pGeode->HWCursor)
	xf86DrvMsg(pScrni->scrnIndex, X_INFO, " Cursor: 0x400 bytes\n");

    if (pGeode->pExa->offScreenBase)
	xf86DrvMsg(pScrni->scrnIndex, X_INFO, " EXA: 0x%x bytes\n",
	    pGeode->pExa->memorySize - pGeode->pExa->offScreenBase);

    xf86DrvMsg(pScrni->scrnIndex, X_INFO, " FREE: 0x%x bytes\n",
	GeodeOffscreenFreeSize(pGeode));
}

/* Called as we go down, so blitz everybody */

void
GeodeCloseOffscreen(ScrnInfoPtr pScrni)
{
    GeodeRec *pGeode = GEODEPTR(pScrni);
    GeodeMemPtr ptr = pGeode->offscreenList;
    GeodeMemPtr nptr;

    while (ptr) {
	nptr = ptr->next;
	xfree(ptr);
	ptr = nptr;
    }

    pGeode->offscreenList = NULL;
}