/*
 * multiorder.c: Multi-order radix tree entry testing
 * Copyright (c) 2016 Intel Corporation
 * Author: Ross Zwisler <ross.zwisler@linux.intel.com>
 * Author: Matthew Wilcox <matthew.r.wilcox@intel.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.
 */
#include <linux/radix-tree.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <pthread.h>

#include "test.h"

static int item_insert_order(struct xarray *xa, unsigned long index,
			unsigned order)
{
	XA_STATE_ORDER(xas, xa, index, order);
	struct item *item = item_create(index, order);

	do {
		xas_lock(&xas);
		xas_store(&xas, item);
		xas_unlock(&xas);
	} while (xas_nomem(&xas, GFP_KERNEL));

	if (!xas_error(&xas))
		return 0;

	free(item);
	return xas_error(&xas);
}

void multiorder_iteration(struct xarray *xa)
{
	XA_STATE(xas, xa, 0);
	struct item *item;
	int i, j, err;

#define NUM_ENTRIES 11
	int index[NUM_ENTRIES] = {0, 2, 4, 8, 16, 32, 34, 36, 64, 72, 128};
	int order[NUM_ENTRIES] = {1, 1, 2, 3,  4,  1,  0,  1,  3,  0, 7};

	printv(1, "Multiorder iteration test\n");

	for (i = 0; i < NUM_ENTRIES; i++) {
		err = item_insert_order(xa, index[i], order[i]);
		assert(!err);
	}

	for (j = 0; j < 256; j++) {
		for (i = 0; i < NUM_ENTRIES; i++)
			if (j <= (index[i] | ((1 << order[i]) - 1)))
				break;

		xas_set(&xas, j);
		xas_for_each(&xas, item, ULONG_MAX) {
			int height = order[i] / XA_CHUNK_SHIFT;
			int shift = height * XA_CHUNK_SHIFT;
			unsigned long mask = (1UL << order[i]) - 1;

			assert((xas.xa_index | mask) == (index[i] | mask));
			assert(xas.xa_node->shift == shift);
			assert(!radix_tree_is_internal_node(item));
			assert((item->index | mask) == (index[i] | mask));
			assert(item->order == order[i]);
			i++;
		}
	}

	item_kill_tree(xa);
}

void multiorder_tagged_iteration(struct xarray *xa)
{
	XA_STATE(xas, xa, 0);
	struct item *item;
	int i, j;

#define MT_NUM_ENTRIES 9
	int index[MT_NUM_ENTRIES] = {0, 2, 4, 16, 32, 40, 64, 72, 128};
	int order[MT_NUM_ENTRIES] = {1, 0, 2, 4,  3,  1,  3,  0,   7};

#define TAG_ENTRIES 7
	int tag_index[TAG_ENTRIES] = {0, 4, 16, 40, 64, 72, 128};

	printv(1, "Multiorder tagged iteration test\n");

	for (i = 0; i < MT_NUM_ENTRIES; i++)
		assert(!item_insert_order(xa, index[i], order[i]));

	assert(!xa_marked(xa, XA_MARK_1));

	for (i = 0; i < TAG_ENTRIES; i++)
		xa_set_mark(xa, tag_index[i], XA_MARK_1);

	for (j = 0; j < 256; j++) {
		int k;

		for (i = 0; i < TAG_ENTRIES; i++) {
			for (k = i; index[k] < tag_index[i]; k++)
				;
			if (j <= (index[k] | ((1 << order[k]) - 1)))
				break;
		}

		xas_set(&xas, j);
		xas_for_each_marked(&xas, item, ULONG_MAX, XA_MARK_1) {
			unsigned long mask;
			for (k = i; index[k] < tag_index[i]; k++)
				;
			mask = (1UL << order[k]) - 1;

			assert((xas.xa_index | mask) == (tag_index[i] | mask));
			assert(!xa_is_internal(item));
			assert((item->index | mask) == (tag_index[i] | mask));
			assert(item->order == order[k]);
			i++;
		}
	}

	assert(tag_tagged_items(xa, 0, ULONG_MAX, TAG_ENTRIES, XA_MARK_1,
				XA_MARK_2) == TAG_ENTRIES);

	for (j = 0; j < 256; j++) {
		int mask, k;

		for (i = 0; i < TAG_ENTRIES; i++) {
			for (k = i; index[k] < tag_index[i]; k++)
				;
			if (j <= (index[k] | ((1 << order[k]) - 1)))
				break;
		}

		xas_set(&xas, j);
		xas_for_each_marked(&xas, item, ULONG_MAX, XA_MARK_2) {
			for (k = i; index[k] < tag_index[i]; k++)
				;
			mask = (1 << order[k]) - 1;

			assert((xas.xa_index | mask) == (tag_index[i] | mask));
			assert(!xa_is_internal(item));
			assert((item->index | mask) == (tag_index[i] | mask));
			assert(item->order == order[k]);
			i++;
		}
	}

	assert(tag_tagged_items(xa, 1, ULONG_MAX, MT_NUM_ENTRIES * 2, XA_MARK_1,
				XA_MARK_0) == TAG_ENTRIES);
	i = 0;
	xas_set(&xas, 0);
	xas_for_each_marked(&xas, item, ULONG_MAX, XA_MARK_0) {
		assert(xas.xa_index == tag_index[i]);
		i++;
	}
	assert(i == TAG_ENTRIES);

	item_kill_tree(xa);
}

bool stop_iteration = false;

static void *creator_func(void *ptr)
{
	/* 'order' is set up to ensure we have sibling entries */
	unsigned int order = RADIX_TREE_MAP_SHIFT - 1;
	struct radix_tree_root *tree = ptr;
	int i;

	for (i = 0; i < 10000; i++) {
		item_insert_order(tree, 0, order);
		item_delete_rcu(tree, 0);
	}

	stop_iteration = true;
	return NULL;
}

static void *iterator_func(void *ptr)
{
	XA_STATE(xas, ptr, 0);
	struct item *item;

	while (!stop_iteration) {
		rcu_read_lock();
		xas_for_each(&xas, item, ULONG_MAX) {
			if (xas_retry(&xas, item))
				continue;

			item_sanity(item, xas.xa_index);
		}
		rcu_read_unlock();
	}
	return NULL;
}

static void multiorder_iteration_race(struct xarray *xa)
{
	const int num_threads = sysconf(_SC_NPROCESSORS_ONLN);
	pthread_t worker_thread[num_threads];
	int i;

	pthread_create(&worker_thread[0], NULL, &creator_func, xa);
	for (i = 1; i < num_threads; i++)
		pthread_create(&worker_thread[i], NULL, &iterator_func, xa);

	for (i = 0; i < num_threads; i++)
		pthread_join(worker_thread[i], NULL);

	item_kill_tree(xa);
}

static DEFINE_XARRAY(array);

void multiorder_checks(void)
{
	multiorder_iteration(&array);
	multiorder_tagged_iteration(&array);
	multiorder_iteration_race(&array);

	radix_tree_cpu_dead(0);
}

int __weak main(void)
{
	radix_tree_init();
	multiorder_checks();
	return 0;
}