/*

  This file is provided under a dual BSD/GPLv2 license.  When using or
  redistributing this file, you may do so under either license.

  GPL LICENSE SUMMARY

  Copyright(c) 2016 Intel Corporation.

  This program is free software; you can redistribute it and/or modify
  it under the terms of version 2 of the GNU General Public License as
  published by the Free Software Foundation.

  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  Contact Information:
  Intel Corporation, www.intel.com

  BSD LICENSE

  Copyright(c) 2016 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.

*/

/* Copyright (c) 2003-2016 Intel Corporation. All rights reserved. */

#include "psm_user.h"

#define PSMI_MPOOL_ALIGNMENT	64

struct mpool_element {
	union {
		SLIST_ENTRY(mpool_element) me_next;
		mpool_t me_mpool;
	};

	uint32_t me_gen_count;
	uint32_t me_index;
#ifdef PSM_DEBUG
	uint32_t me_isused;
#endif
} __attribute__ ((aligned(16)));

#ifdef PSM_DEBUG
#  define me_mark_used(me)    ((me)->me_isused = 1)
#  define me_mark_unused(me)  ((me)->me_isused = 0)
#else
#  define me_mark_used(me)
#  define me_mark_unused(me)
#endif

struct mpool {
	int mp_type;
	int mp_flags;
	int mp_vector_shift;

	uint32_t mp_elm_vector_size;
	uint32_t mp_elm_offset;
	uint32_t mp_num_obj;
	uint32_t mp_num_obj_inuse;
	uint32_t mp_elm_size;
	uint32_t mp_obj_size;
	uint32_t mp_num_obj_per_chunk;
	uint32_t mp_num_obj_max_total;
	psmi_memtype_t mp_memtype;

	 SLIST_HEAD(, mpool_element) mp_head;
	struct mpool_element **mp_elm_vector;
	struct mpool_element **mp_elm_vector_free;
	non_empty_callback_fn_t mp_non_empty_cb;
	void *mp_non_empty_cb_context;

#ifdef PSM_CUDA
	alloc_dealloc_callback_fn_t mp_alloc_dealloc_cb;
	void *mp_alloc_dealloc_cb_context;
#endif
};

static int psmi_mpool_allocate_chunk(mpool_t);

/**
 * psmi_mpool_create()
 *
 * Create a memory pool and allocates <num_obj_per_chunk> objects of size
 * <obj_size>.  If more memory is needed to accommodate mpool_get()
 * requests, the memory pool will allocate another chunk of
 * <num_obj_per_chunk> objects, until it reaches the maximum number of objects
 * it can allocate.
 *
 * <obj_size>		size of each individual object
 * <num_obj_per_chunk>	number of objects to allocate per chunk (power of two)
 * <num_obj_max_total>	total number of objects that may be allocated
 *			at any given time. Must be a power of two greater than
 *			<num_obj_per_chunk>.
 *
 * <flags>		flags to be applied on the memory pool (ie. memory
 *			alignment)
 *
 * <cb>			callback to be called when the memory pool has some
 *			free objects available again (after running out of them).
 * <context>		context pointer for the callback
 *
 * Return the mpool on success, NULL on failure.
 */
mpool_t
psmi_mpool_create_inner(size_t obj_size, uint32_t num_obj_per_chunk,
			uint32_t num_obj_max_total, int flags,
			psmi_memtype_t statstype,
			non_empty_callback_fn_t cb, void *context)
{
	mpool_t mp;
	int s;
	size_t hdr_size;

	if (!PSMI_POWEROFTWO(num_obj_per_chunk) ||
	    !PSMI_POWEROFTWO(num_obj_max_total) ||
	    num_obj_max_total < num_obj_per_chunk) {
		return NULL;
	}

	mp = psmi_calloc(PSMI_EP_NONE, statstype, 1, sizeof(struct mpool));
	if (mp == NULL) {
		fprintf(stderr,
			"Failed to allocate memory for memory pool: %s\n",
			strerror(errno));
		return NULL;
	}

	for (s = 1; s < num_obj_per_chunk; s <<= 1)
		mp->mp_vector_shift++;

	mp->mp_flags = flags;
	mp->mp_num_obj_per_chunk = num_obj_per_chunk;
	mp->mp_num_obj_max_total = num_obj_max_total;
	mp->mp_non_empty_cb = cb;
	mp->mp_non_empty_cb_context = context;

	mp->mp_memtype = statstype;

	SLIST_INIT(&mp->mp_head);
	mp->mp_elm_vector_size = num_obj_max_total / num_obj_per_chunk;
	mp->mp_elm_vector =
	    psmi_calloc(PSMI_EP_NONE, statstype, mp->mp_elm_vector_size,
			sizeof(struct mpool_element *));
	if (mp->mp_elm_vector == NULL) {
		fprintf(stderr,
			"Failed to allocate memory for memory pool vector: "
			"%s\n", strerror(errno));
		psmi_free(mp);
		return NULL;
	}

	mp->mp_elm_vector_free = mp->mp_elm_vector;

	if (flags & PSMI_MPOOL_ALIGN) {
		// TBD - this is broken, mp_elm_offset is not
		// used all the places where it needs to be
		// fortunately this flag is not used yet
		psmi_assert_always(0);
		/* User wants its block to start on a PSMI_MPOOL_ALIGNMENT
		 * boundary. */
		hdr_size = PSMI_ALIGNUP(sizeof(struct mpool_element),
					PSMI_MPOOL_ALIGNMENT);
		mp->mp_obj_size = PSMI_ALIGNUP(obj_size, PSMI_MPOOL_ALIGNMENT);
		mp->mp_elm_size = hdr_size + mp->mp_obj_size;
		mp->mp_elm_offset = hdr_size - sizeof(struct mpool_element);
	} else {
		hdr_size = sizeof(struct mpool_element);
		mp->mp_obj_size = PSMI_ALIGNUP(obj_size, 8);
		mp->mp_elm_size = hdr_size + mp->mp_obj_size;
		mp->mp_elm_offset = 0;
	}

	return mp;
}

mpool_t
MOCKABLE(psmi_mpool_create)(size_t obj_size, uint32_t num_obj_per_chunk,
		  uint32_t num_obj_max_total, int flags,
		  psmi_memtype_t statstype, non_empty_callback_fn_t cb,
		  void *context)
{
	mpool_t mp;

	mp = psmi_mpool_create_inner(obj_size, num_obj_per_chunk,
					num_obj_max_total, flags, statstype,
					cb, context);

	if (mp == NULL)
		return NULL;

	if (psmi_mpool_allocate_chunk(mp) != PSM2_OK) {
		psmi_mpool_destroy(mp);
		return NULL;
	}

	return mp;
}
MOCK_DEF_EPILOGUE(psmi_mpool_create);

#ifdef PSM_CUDA
mpool_t
psmi_mpool_create_for_cuda(size_t obj_size, uint32_t num_obj_per_chunk,
			   uint32_t num_obj_max_total, int flags,
			   psmi_memtype_t statstype,
			   non_empty_callback_fn_t cb, void *context,
			   alloc_dealloc_callback_fn_t ad_cb, void *ad_context)
{
	mpool_t mp;

	mp = psmi_mpool_create_inner(obj_size, num_obj_per_chunk,
					num_obj_max_total, flags, statstype,
					cb, context);

	if (mp == NULL)
		return NULL;

	mp->mp_alloc_dealloc_cb = ad_cb;
	mp->mp_alloc_dealloc_cb_context = ad_context;

	if (psmi_mpool_allocate_chunk(mp) != PSM2_OK) {
		psmi_mpool_destroy(mp);
		return NULL;
	}

	return mp;
}
#endif

/**
 * psmi_mpool_get()
 *
 * <mp>	    memory pool
 *
 * Requests an object from the memory pool.
 *
 * Returns NULL if the maximum number of objects has been allocated (refer to
 * <num_obj_max_total> in psmi_mpool_create) or if running out of memory.
 */
void *psmi_mpool_get(mpool_t mp)
{
	struct mpool_element *me;
	void *obj;

	if (SLIST_EMPTY(&mp->mp_head)) {
		if (psmi_mpool_allocate_chunk(mp) != PSM2_OK)
			return NULL;
	}

	me = SLIST_FIRST(&mp->mp_head);
	SLIST_REMOVE_HEAD(&mp->mp_head, me_next);

	psmi_assert(!me->me_isused);
	me_mark_used(me);

	/* store a backpointer to the memory pool */
	me->me_mpool = mp;
	mp->mp_num_obj_inuse++;
	psmi_assert(mp->mp_num_obj_inuse <= mp->mp_num_obj);

	obj = (void *)((uintptr_t) me + sizeof(struct mpool_element));

	return obj;
}

/**
 * psmi_mpool_put()
 *
 * <obj>    object to return to the memory pool
 *
 * Returns an <obj> to the memory pool subsystem.  This object will be re-used
 * to fulfill new psmi_mpool_get() requests.
 */
void psmi_mpool_put(void *obj)
{
	struct mpool_element *me;
	int was_empty;
	mpool_t mp;

	me = (struct mpool_element *)
	    ((uintptr_t) obj - sizeof(struct mpool_element));
	me->me_gen_count++;

	mp = me->me_mpool;

	psmi_assert(mp != NULL);
	psmi_assert(mp->mp_num_obj_inuse >= 0);
	psmi_assert(me->me_isused);
	me_mark_unused(me);

	was_empty = mp->mp_num_obj_inuse == mp->mp_num_obj_max_total;
	SLIST_INSERT_HEAD(&mp->mp_head, me, me_next);

	mp->mp_num_obj_inuse--;

	/* tell the user that memory is available */
	if (mp->mp_non_empty_cb && was_empty)
		mp->mp_non_empty_cb(mp->mp_non_empty_cb_context);
}

/**
 * psmi_mpool_get_obj_index()
 *
 * <obj>    object in the memory pool
 *
 * Returns the index of the <obj> in the memory pool.
 */

int psmi_mpool_get_obj_index(void *obj)
{
	struct mpool_element *me = (struct mpool_element *)
	    ((uintptr_t) obj - sizeof(struct mpool_element));

	return me->me_index;
}

/**
 * psmi_mpool_get_obj_gen_count()
 *
 * <obj>    object in the memory pool
 *
 * Returns the generation count of the <obj>.
 */
uint32_t psmi_mpool_get_obj_gen_count(void *obj)
{
	struct mpool_element *me = (struct mpool_element *)
	    ((uintptr_t) obj - sizeof(struct mpool_element));

	return me->me_gen_count;
}

/**
 * psmi_mpool_get_obj_index_gen_count()
 *
 * <obj>    object in the memory pool
 *
 * Returns the index of the <obj> in <index>.
 * Returns the generation count of the <obj> in <gen_count>.
 */
int
psmi_mpool_get_obj_index_gen_count(void *obj, uint32_t *index,
				   uint32_t *gen_count)
{
	struct mpool_element *me = (struct mpool_element *)
	    ((uintptr_t) obj - sizeof(struct mpool_element));

	*index = me->me_index;
	*gen_count = me->me_gen_count;
	return 0;
}

/**
 * psmi_mpool_find_obj_by_index()
 *
 * <mp>	    memory pool
 * <index>  index of the object
 *
 * Returns the object located at <index> in the memory pool or NULL if the
 * <index> is invalid.
 */
void *psmi_mpool_find_obj_by_index(mpool_t mp, int index)
{
	struct mpool_element *me;

	if_pf(index < 0 || index >= mp->mp_num_obj)
	    return NULL;

	me = (struct mpool_element *)
	    ((uintptr_t) mp->mp_elm_vector[index >> mp->mp_vector_shift] +
	     (index & (mp->mp_num_obj_per_chunk - 1)) * mp->mp_elm_size +
	     mp->mp_elm_offset);

	/* If this mpool doesn't require generation counts, it's illegal to find a
	 * freed object */
#ifdef PSM_DEBUG
	if (mp->mp_flags & PSMI_MPOOL_NOGENERATION)
		psmi_assert(!me->me_isused);
#endif

	return (void *)((uintptr_t) me + sizeof(struct mpool_element));
}

#ifdef PSM_CUDA
/**
 * psmi_mpool_chunk_dealloc()
 * <mp>	    memory pool
 * <i>	    index
 * Calls the dealloc function on each element in the chunk.
 */
void psmi_mpool_chunk_dealloc(mpool_t mp, int idx)
{
	int j;
	for (j = 0; j < mp->mp_num_obj_per_chunk; j++)
		mp->mp_alloc_dealloc_cb(0 /* is not alloc */,
					mp->mp_alloc_dealloc_cb_context,
					((void *) mp->mp_elm_vector[idx]) +
					j * mp->mp_elm_size +
					sizeof(struct mpool_element));
}
#endif
/**
 * psmi_mpool_destroy()
 *
 * <mp>	    memory pool
 *
 * Destroy a previously allocated memory pool and reclaim its associated
 * memory.  The behavior is undefined if some objects have not been returned
 * to the memory pool with psmi_mpool_put().
 */
void psmi_mpool_destroy(mpool_t mp)
{
	int i = 0;
	size_t nbytes = mp->mp_num_obj * mp->mp_elm_size;

	for (i = 0; i < mp->mp_elm_vector_size; i++) {
		if (mp->mp_elm_vector[i]) {
#ifdef PSM_CUDA
			if (mp->mp_alloc_dealloc_cb)
				psmi_mpool_chunk_dealloc(mp, i);
#endif
			psmi_free(mp->mp_elm_vector[i]);
		}
	}
	psmi_free(mp->mp_elm_vector);
	nbytes += mp->mp_elm_vector_size * sizeof(struct mpool_element *);
	psmi_free(mp);
	nbytes += sizeof(struct mpool);
}

/**
 * psmi_mpool_get_max_obj()
 *
 * <mp>	    memory pool
 *
 * Returns the num-obj-per-chunk
 * Returns the num-obj-max-total
 */
void
MOCKABLE(psmi_mpool_get_obj_info)(mpool_t mp, uint32_t *num_obj_per_chunk,
			uint32_t *num_obj_max_total)
{
	*num_obj_per_chunk = mp->mp_num_obj_per_chunk;
	*num_obj_max_total = mp->mp_num_obj_max_total;
	return;
}
MOCK_DEF_EPILOGUE(psmi_mpool_get_obj_info);

static int psmi_mpool_allocate_chunk(mpool_t mp)
{
	struct mpool_element *elm;
	void *chunk;
	uint32_t i = 0, num_to_allocate;

	num_to_allocate =
	    mp->mp_num_obj + mp->mp_num_obj_per_chunk >
	    mp->mp_num_obj_max_total ? 0 : mp->mp_num_obj_per_chunk;

	psmi_assert(mp->mp_num_obj + num_to_allocate <=
		    mp->mp_num_obj_max_total);

	if (num_to_allocate == 0)
		return PSM2_NO_MEMORY;

#ifdef PSM_CUDA
	if (mp->mp_alloc_dealloc_cb)
		chunk = psmi_calloc(PSMI_EP_NONE, mp->mp_memtype,
				    num_to_allocate, mp->mp_elm_size);
	else
		chunk = psmi_malloc(PSMI_EP_NONE, mp->mp_memtype,
				    num_to_allocate * mp->mp_elm_size);
#else
	chunk = psmi_malloc(PSMI_EP_NONE, mp->mp_memtype,
			    num_to_allocate * mp->mp_elm_size);
#endif
	if (chunk == NULL) {
		fprintf(stderr,
			"Failed to allocate memory for memory pool chunk: %s\n",
			strerror(errno));
		return PSM2_NO_MEMORY;
	}

	for (i = 0; i < num_to_allocate; i++) {
#ifdef PSM_CUDA
		if (mp->mp_alloc_dealloc_cb)
			mp->mp_alloc_dealloc_cb(1 /* is alloc */,
						mp->mp_alloc_dealloc_cb_context,
						chunk + i * mp->mp_elm_size +
						sizeof(struct mpool_element));
#endif
		elm = (struct mpool_element *)((uintptr_t) chunk +
					       i * mp->mp_elm_size +
					       mp->mp_elm_offset);
		elm->me_gen_count = 0;
		elm->me_index = mp->mp_num_obj + i;
#ifdef PSM_DEBUG
		elm->me_isused = 0;
#endif
		SLIST_INSERT_HEAD(&mp->mp_head, elm, me_next);
#if 0
		fprintf(stderr, "chunk%ld i=%d elm=%p user=%p next=%p\n",
			(long)(mp->mp_elm_vector_free - mp->mp_elm_vector),
			(int)i, elm,
			(void *)((uintptr_t) elm +
				 sizeof(struct mpool_element)), SLIST_NEXT(elm,
									   me_next));
#endif
	}

	psmi_assert((uintptr_t) mp->mp_elm_vector_free
		    < ((uintptr_t) mp->mp_elm_vector) + mp->mp_elm_vector_size
		    * sizeof(struct mpool_element *));

	mp->mp_elm_vector_free[0] = chunk;
	mp->mp_elm_vector_free++;
	mp->mp_num_obj += num_to_allocate;

	return PSM2_OK;
}

#if 0
void psmi_mpool_dump(mpool_t mp)
{
	int i, j;
	struct mpool_element *me;

	fprintf(stderr, "Memory pool %p has %d elements per chunk.\n",
		mp, mp->mp_num_obj_per_chunk);
	for (i = 0; i < mp->mp_elm_vector_size; i++) {
		if (mp->mp_elm_vector[i] != NULL) {
			fprintf(stderr, "===========================\n");
			fprintf(stderr, "mpool chunk #%d\n", i);

			for (j = 0, me = mp->mp_elm_vector[i];
			     j < mp->mp_num_obj_per_chunk;
			     j++, me = (struct mpool_element *)
			     ((uintptr_t) me + mp->mp_elm_size)) {
				fprintf(stderr,
					"obj=%p index=%d gen_count=%d\n",
					(void *)((uintptr_t) me +
						 sizeof(struct mpool_element)),
					me->me_index, me->me_gen_count);
			}
			fprintf(stderr, "===========================\n");
		}
	}
}
#endif
