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/**
 *   BSD LICENSE
 * 
 *   Copyright(c) 2010-2012 Intel Corporation. All rights reserved.
 *   All rights reserved.
 * 
 *   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.
 * 
 *  version: DPDK.L.1.2.3-3
 */

#include <stdint.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>

#include <sys/queue.h>
#include <rte_memory.h>
#include <rte_memzone.h>
#include <rte_tailq.h>
#include <rte_eal.h>
#include <rte_hash_crc.h>
#include <rte_malloc.h>
#include <rte_common.h>
#include <rte_per_lcore.h>
#include <rte_errno.h>
#include <rte_string_fns.h>
#include <rte_cpuflags.h>
#include <rte_log.h>

#include "rte_fbk_hash.h"
#include "rte_jhash.h"
#include "rte_hash_crc.h"

TAILQ_HEAD(rte_fbk_hash_list, rte_fbk_hash_table);

/* global list of fbk_hashes (used for debug/dump) */
static struct rte_fbk_hash_list *fbk_hash_list = NULL;

/* macro to prevent duplication of list creation check code */
#define CHECK_FBK_HASH_LIST_CREATED() do { \
	if (fbk_hash_list == NULL) \
		if ((fbk_hash_list = RTE_TAILQ_RESERVE("RTE_FBK_HASH", \
				rte_fbk_hash_list)) == NULL){ \
			rte_errno = E_RTE_NO_TAILQ; \
			return NULL; \
		} \
} while (0)


/**
 * Performs a lookup for an existing hash table, and returns a pointer to
 * the table if found.
 *
 * @param name
 *   Name of the hash table to find
 *
 * @return
 *   pointer to hash table structure or NULL on error.
 */
struct rte_fbk_hash_table *
rte_fbk_hash_find_existing(const char *name)
{
	struct rte_fbk_hash_table *h;

	/* check that we have an initialised tail queue */
	CHECK_FBK_HASH_LIST_CREATED();

	TAILQ_FOREACH(h, fbk_hash_list, next) {
		if (strncmp(name, h->name, RTE_FBK_HASH_NAMESIZE) == 0)
			break;
	}
	if (h == NULL)
		rte_errno = ENOENT;
	return h;
}

/**
 * Create a new hash table for use with four byte keys.
 *
 * @param params
 *   Parameters used in creation of hash table.
 *
 * @return
 *   Pointer to hash table structure that is used in future hash table
 *   operations, or NULL on error.
 */
struct rte_fbk_hash_table *
rte_fbk_hash_create(const struct rte_fbk_hash_params *params)
{
	struct rte_fbk_hash_table *ht;
	char hash_name[RTE_FBK_HASH_NAMESIZE];
	const uint32_t mem_size =
			sizeof(*ht) + (sizeof(ht->t[0]) * params->entries);
	uint32_t i;

	/* check that we have access to create things in shared memory. */
	if (rte_eal_process_type() == RTE_PROC_SECONDARY){
		rte_errno = E_RTE_SECONDARY;
		return NULL;
	}

	/* check that we have an initialised tail queue */
	CHECK_FBK_HASH_LIST_CREATED();

	/* Error checking of parameters. */
	if ((!rte_is_power_of_2(params->entries)) ||
			(!rte_is_power_of_2(params->entries_per_bucket)) ||
			(params->entries == 0) ||
			(params->entries_per_bucket == 0) ||
			(params->entries_per_bucket > params->entries) ||
			(params->entries > RTE_FBK_HASH_ENTRIES_MAX) ||
			(params->entries_per_bucket > RTE_FBK_HASH_ENTRIES_MAX)){
		rte_errno = EINVAL;
		return NULL;
	}

	rte_snprintf(hash_name, sizeof(hash_name), "FBK_%s", params->name);

	/* Allocate memory for table. */
#if defined(RTE_LIBRTE_HASH_USE_MEMZONE)
	const struct rte_memzone *mz;
	mz = rte_memzone_reserve(hash_name, mem_size, params->socket_id, 0);
	if (mz == NULL)
		return NULL;
	ht = (struct rte_fbk_hash_table *)mz->addr;
#else
	ht = (struct rte_fbk_hash_table *)rte_malloc(hash_name, mem_size, 0);
	if (ht == NULL)
		return NULL;
#endif
	memset(ht, 0, mem_size);

	/* Set up hash table context. */
	rte_snprintf(ht->name, sizeof(ht->name), "%s", params->name);
	ht->entries = params->entries;
	ht->entries_per_bucket = params->entries_per_bucket;
	ht->used_entries = 0;
	ht->bucket_mask = (params->entries / params->entries_per_bucket) - 1;
	for (ht->bucket_shift = 0, i = 1;
	    (params->entries_per_bucket & i) == 0;
	    ht->bucket_shift++, i <<= 1)
		; /* empty loop body */

	if (params->hash_func != NULL) {
		ht->hash_func = params->hash_func;
		ht->init_val = params->init_val;
	}
	else {
		ht->hash_func = RTE_FBK_HASH_FUNC_DEFAULT;
		ht->init_val = RTE_FBK_HASH_INIT_VAL_DEFAULT;
	}

	if (ht->hash_func == rte_hash_crc_4byte &&
			!rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE4_2)) {
		RTE_LOG(WARNING, HASH, "CRC32 instruction requires SSE4.2, "
				"which is not supported on this system. "
				"Falling back to software hash\n.");
		ht->hash_func = rte_jhash_1word;
	}

	TAILQ_INSERT_TAIL(fbk_hash_list, ht, next);
	return ht;
}

/**
 * Free all memory used by a hash table.
 *
 * @param ht
 *   Hash table to deallocate.
 */
void
rte_fbk_hash_free(struct rte_fbk_hash_table *ht)
{
	if (ht == NULL)
		return;
	/* No way to deallocate memzones - but can de-allocate from malloc */
#if !defined(RTE_LIBRTE_HASH_USE_MEMZONE)
	TAILQ_REMOVE(fbk_hash_list, ht, next);
	rte_free(ht);
#endif
	RTE_SET_USED(ht);
	return;
}