/*

 * GLX Hardware Device Driver common code

 * Copyright (C) 1999 Wittawat Yamwong

 *

 * 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

 * WITTAWAT YAMWONG, OR ANY OTHER CONTRIBUTORS 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.

 *

 */

#include <stdlib.h>

#include <assert.h>

#include "xf86drm.h"

#include "libdrm_macros.h"

#include "mm.h"

drm_private void mmDumpMemInfo(const struct mem_block *heap)

{

	drmMsg("Memory heap %p:\n", (void *)heap);

	if (heap == 0) {

		drmMsg("  heap == 0\n");

	} else {

		const struct mem_block *p;

		for (p = heap->next; p != heap; p = p->next) {

			drmMsg("  Offset:%08x, Size:%08x, %c%c\n", p->ofs,

			       p->size, p->free ? 'F' : '.',

			       p->reserved ? 'R' : '.');

		}

		drmMsg("\nFree list:\n");

		for (p = heap->next_free; p != heap; p = p->next_free) {

			drmMsg(" FREE Offset:%08x, Size:%08x, %c%c\n", p->ofs,

			       p->size, p->free ? 'F' : '.',

			       p->reserved ? 'R' : '.');

		}

	}

	drmMsg("End of memory blocks\n");

}

drm_private struct mem_block *mmInit(int ofs, int size)

{

	struct mem_block *heap, *block;

	if (size <= 0)

		return NULL;

	heap = (struct mem_block *)calloc(1, sizeof(struct mem_block));

	if (!heap)

		return NULL;

	block = (struct mem_block *)calloc(1, sizeof(struct mem_block));

	if (!block) {

		free(heap);

		return NULL;

	}

	heap->next = block;

	heap->prev = block;

	heap->next_free = block;

	heap->prev_free = block;

	block->heap = heap;

	block->next = heap;

	block->prev = heap;

	block->next_free = heap;

	block->prev_free = heap;

	block->ofs = ofs;

	block->size = size;

	block->free = 1;

	return heap;

}

static struct mem_block *SliceBlock(struct mem_block *p,

				    int startofs, int size,

				    int reserved, int alignment)

{

	struct mem_block *newblock;

	/* break left  [p, newblock, p->next], then p = newblock */

	if (startofs > p->ofs) {

		newblock =

		    (struct mem_block *)calloc(1, sizeof(struct mem_block));

		if (!newblock)

			return NULL;

		newblock->ofs = startofs;

		newblock->size = p->size - (startofs - p->ofs);

		newblock->free = 1;

		newblock->heap = p->heap;

		newblock->next = p->next;

		newblock->prev = p;

		p->next->prev = newblock;

		p->next = newblock;

		newblock->next_free = p->next_free;

		newblock->prev_free = p;

		p->next_free->prev_free = newblock;

		p->next_free = newblock;

		p->size -= newblock->size;

		p = newblock;

	}

	/* break right, also [p, newblock, p->next] */

	if (size < p->size) {

		newblock =

		    (struct mem_block *)calloc(1, sizeof(struct mem_block));

		if (!newblock)

			return NULL;

		newblock->ofs = startofs + size;

		newblock->size = p->size - size;

		newblock->free = 1;

		newblock->heap = p->heap;

		newblock->next = p->next;

		newblock->prev = p;

		p->next->prev = newblock;

		p->next = newblock;

		newblock->next_free = p->next_free;

		newblock->prev_free = p;

		p->next_free->prev_free = newblock;

		p->next_free = newblock;

		p->size = size;

	}

	/* p = middle block */

	p->free = 0;

	/* Remove p from the free list: 

	 */

	p->next_free->prev_free = p->prev_free;

	p->prev_free->next_free = p->next_free;

	p->next_free = 0;

	p->prev_free = 0;

	p->reserved = reserved;

	return p;

}

drm_private struct mem_block *mmAllocMem(struct mem_block *heap, int size,

					 int align2, int startSearch)

{

	struct mem_block *p;

	const int mask = (1 << align2) - 1;

	int startofs = 0;

	int endofs;

	if (!heap || align2 < 0 || size <= 0)

		return NULL;

	for (p = heap->next_free; p != heap; p = p->next_free) {

		assert(p->free);

		startofs = (p->ofs + mask) & ~mask;

		if (startofs < startSearch) {

			startofs = startSearch;

		}

		endofs = startofs + size;

		if (endofs <= (p->ofs + p->size))

			break;

	}

	if (p == heap)

		return NULL;

	assert(p->free);

	p = SliceBlock(p, startofs, size, 0, mask + 1);

	return p;

}

static int Join2Blocks(struct mem_block *p)

{

	/* XXX there should be some assertions here */

	/* NOTE: heap->free == 0 */

	if (p->free && p->next->free) {

		struct mem_block *q = p->next;

		assert(p->ofs + p->size == q->ofs);

		p->size += q->size;

		p->next = q->next;

		q->next->prev = p;

		q->next_free->prev_free = q->prev_free;

		q->prev_free->next_free = q->next_free;

		free(q);

		return 1;

	}

	return 0;

}

drm_private int mmFreeMem(struct mem_block *b)

{

	if (!b)

		return 0;

	if (b->free) {

		drmMsg("block already free\n");

		return -1;

	}

	if (b->reserved) {

		drmMsg("block is reserved\n");

		return -1;

	}

	b->free = 1;

	b->next_free = b->heap->next_free;

	b->prev_free = b->heap;

	b->next_free->prev_free = b;

	b->prev_free->next_free = b;

	Join2Blocks(b);

	if (b->prev != b->heap)

		Join2Blocks(b->prev);

	return 0;

}

drm_private void mmDestroy(struct mem_block *heap)

{

	struct mem_block *p;

	if (!heap)

		return;

	for (p = heap->next; p != heap;) {

		struct mem_block *next = p->next;

		free(p);

		p = next;

	}

	free(heap);

}