/*

 * Copyright (c) 2016-2017, Intel Corporation

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 *  * Redistributions of source code must retain the above copyright notice,

 *    this list of conditions and the following disclaimer.

 *  * 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.

 *  * Neither the name of Intel Corporation nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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.

 */

#include "pt_block_cache.h"

#include <stdlib.h>

#include <string.h>

struct pt_block_cache *pt_bcache_alloc(uint64_t nentries)

{

	struct pt_block_cache *bcache;

	uint64_t size;

	if (!nentries || (UINT32_MAX < nentries))

		return NULL;

	size = sizeof(*bcache) + (nentries * sizeof(struct pt_bcache_entry));

	if (SIZE_MAX < size)

		return NULL;

	bcache = malloc((size_t) size);

	if (!bcache)

		return NULL;

	memset(bcache, 0, (size_t) size);

	bcache->nentries = (uint32_t) nentries;

	return bcache;

}

void pt_bcache_free(struct pt_block_cache *bcache)

{

	free(bcache);

}

int pt_bcache_add(struct pt_block_cache *bcache, uint64_t index,

		  struct pt_bcache_entry bce)

{

	if (!bcache)

		return -pte_internal;

	if (bcache->nentries <= index)

		return -pte_internal;

	/* We rely on guaranteed atomic operations as specified in section 8.1.1

	 * in Volume 3A of the Intel(R) Software Developer's Manual at

	 * http://www.intel.com/sdm.

	 */

	bcache->entry[(uint32_t) index] = bce;

	return 0;

}

int pt_bcache_lookup(struct pt_bcache_entry *bce,

		     const struct pt_block_cache *bcache, uint64_t index)

{

	if (!bce || !bcache)

		return -pte_internal;

	if (bcache->nentries <= index)

		return -pte_internal;

	/* We rely on guaranteed atomic operations as specified in section 8.1.1

	 * in Volume 3A of the Intel(R) Software Developer's Manual at

	 * http://www.intel.com/sdm.

	 */

	*bce = bcache->entry[(uint32_t) index];

	return 0;

}