1/*-
2 * Copyright (c) 2018 Microsemi Corporation.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/* $FreeBSD: stable/11/sys/dev/smartpqi/smartpqi_tag.c 333019 2018-04-26 16:59:06Z sbruno $ */
28
29#include "smartpqi_includes.h"
30
31#ifndef LOCKFREE_STACK
32
33/*
34 * Function used to release the tag from taglist.
35 */
36void pqisrc_put_tag(pqi_taglist_t *taglist, uint32_t elem)
37{
38
39	OS_ACQUIRE_SPINLOCK(&(taglist->lock));
40	/*DBG_FUNC("IN\n");*/
41
42	ASSERT(taglist->num_elem < taglist->max_elem);
43
44	if (taglist->num_elem < taglist->max_elem) {
45		taglist->elem_array[taglist->tail] = elem;
46		taglist->num_elem++;
47		taglist->tail = (taglist->tail + 1) % taglist->max_elem;
48	}
49
50	OS_RELEASE_SPINLOCK(&taglist->lock);
51
52	/*DBG_FUNC("OUT\n");*/
53}
54
55/*
56 * Function used to get an unoccupied tag from the tag list.
57 */
58uint32_t pqisrc_get_tag(pqi_taglist_t *taglist)
59{
60	uint32_t elem = INVALID_ELEM;
61
62	/*DBG_FUNC("IN\n");*/
63
64	OS_ACQUIRE_SPINLOCK(&taglist->lock);
65
66	ASSERT(taglist->num_elem > 0);
67
68	if (taglist->num_elem > 0) {
69		elem = taglist->elem_array[taglist->head];
70		taglist->num_elem--;
71		taglist->head = (taglist->head + 1) % taglist->max_elem;
72	}
73
74	OS_RELEASE_SPINLOCK(&taglist->lock);
75
76	/*DBG_FUNC("OUT got %d\n", elem);*/
77	return elem;
78}
79
80/*
81 * Initialize circular queue implementation of tag list.
82 */
83int pqisrc_init_taglist(pqisrc_softstate_t *softs, pqi_taglist_t *taglist,
84				uint32_t max_elem)
85{
86	int ret = PQI_STATUS_SUCCESS;
87	int i = 0;
88
89	DBG_FUNC("IN\n");
90
91	taglist->max_elem = max_elem;
92	taglist->num_elem = 0;
93	taglist->head = 0;
94	taglist->tail = 0;
95	taglist->elem_array = os_mem_alloc(softs,
96			(max_elem * sizeof(uint32_t)));
97	if (!(taglist->elem_array)) {
98		DBG_FUNC("Unable to allocate memory for taglist\n");
99		ret = PQI_STATUS_FAILURE;
100		goto err_out;
101	}
102
103    	os_strlcpy(taglist->lockname, "tag_lock",  LOCKNAME_SIZE);
104    	ret = os_init_spinlock(softs, &taglist->lock, taglist->lockname);
105    	if(ret){
106        	DBG_ERR("tag lock initialization failed\n");
107        	taglist->lockcreated=false;
108        	goto err_lock;
109	}
110    	taglist->lockcreated = true;
111
112	/* indices 1 to max_elem are considered as valid tags */
113	for (i=1; i <= max_elem; i++) {
114		softs->rcb[i].tag = INVALID_ELEM;
115		pqisrc_put_tag(taglist, i);
116	}
117
118	DBG_FUNC("OUT\n");
119	return ret;
120
121err_lock:
122    os_mem_free(softs, (char *)taglist->elem_array,
123        (taglist->max_elem * sizeof(uint32_t)));
124	taglist->elem_array = NULL;
125err_out:
126	DBG_FUNC("OUT failed\n");
127	return ret;
128}
129
130/*
131 * Destroy circular queue implementation of tag list.
132 */
133void pqisrc_destroy_taglist(pqisrc_softstate_t *softs, pqi_taglist_t *taglist)
134{
135	DBG_FUNC("IN\n");
136	os_mem_free(softs, (char *)taglist->elem_array,
137		(taglist->max_elem * sizeof(uint32_t)));
138	taglist->elem_array = NULL;
139
140    	if(taglist->lockcreated==true){
141        	os_uninit_spinlock(&taglist->lock);
142        	taglist->lockcreated = false;
143    	}
144
145	DBG_FUNC("OUT\n");
146}
147
148#else /* LOCKFREE_STACK */
149
150/*
151 * Initialize circular queue implementation of tag list.
152 */
153int pqisrc_init_taglist(pqisrc_softstate_t *softs, lockless_stack_t *stack,
154				uint32_t max_elem)
155{
156	int ret = PQI_STATUS_SUCCESS;
157	int index = 0;
158
159	DBG_FUNC("IN\n");
160
161	/* indices 1 to max_elem are considered as valid tags */
162	stack->num_elements = max_elem + 1;
163	stack->head.data = 0;
164	DBG_INFO("Stack head address :%p\n",&stack->head);
165
166	/*Allocate memory for stack*/
167	stack->next_index_array = (uint32_t*)os_mem_alloc(softs,
168		(stack->num_elements * sizeof(uint32_t)));
169	if (!(stack->next_index_array)) {
170		DBG_ERR("Unable to allocate memory for stack\n");
171		ret = PQI_STATUS_FAILURE;
172		goto err_out;
173	}
174
175	/* push all the entries to the stack */
176	for (index = 1; index < stack->num_elements ; index++) {
177		softs->rcb[index].tag = INVALID_ELEM;
178		pqisrc_put_tag(stack, index);
179	}
180
181	DBG_FUNC("OUT\n");
182	return ret;
183err_out:
184	DBG_FUNC("Failed OUT\n");
185	return ret;
186}
187
188/*
189 * Destroy circular queue implementation of tag list.
190 */
191void pqisrc_destroy_taglist(pqisrc_softstate_t *softs, lockless_stack_t *stack)
192{
193	DBG_FUNC("IN\n");
194
195	/* de-allocate stack memory */
196	if (stack->next_index_array) {
197		os_mem_free(softs,(char*)stack->next_index_array,
198			(stack->num_elements * sizeof(uint32_t)));
199		stack->next_index_array = NULL;
200	}
201
202	DBG_FUNC("OUT\n");
203}
204
205/*
206 * Function used to release the tag from taglist.
207 */
208void pqisrc_put_tag(lockless_stack_t *stack, uint32_t index)
209{
210   	union head_list cur_head, new_head;
211
212	DBG_FUNC("IN\n");
213 	DBG_INFO("push tag :%d\n",index);
214
215	if ( index >= stack->num_elements ) {
216		ASSERT(false);
217 		DBG_ERR("Pushed Invalid index\n"); /* stack full */
218		return;
219	}
220
221	if ( stack->next_index_array[index] != 0) {
222 		ASSERT(false);
223		DBG_ERR("Index already present as tag in the stack\n");
224		return;
225	}
226
227	do {
228		cur_head = stack->head;
229		/* increment seq_no */
230 		new_head.top.seq_no = cur_head.top.seq_no + 1;
231		/* update the index at the top of the stack with the new index */
232		new_head.top.index = index;
233		/* Create a link to the previous index */
234		stack->next_index_array[index] = cur_head.top.index;
235	}while(OS_ATOMIC64_CAS(&stack->head.data,cur_head.data,new_head.data)
236		!= cur_head.data);
237 	DBG_FUNC("OUT\n");
238 	return;
239}
240
241/*
242 * Function used to get an unoccupied tag from the tag list.
243 */
244uint32_t pqisrc_get_tag(lockless_stack_t *stack)
245{
246	union head_list cur_head, new_head;
247
248	DBG_FUNC("IN\n");
249	do {
250		cur_head = stack->head;
251		if (cur_head.top.index == 0)    /* stack empty */
252			return INVALID_ELEM;
253		/* increment seq_no field */
254		new_head.top.seq_no = cur_head.top.seq_no + 1;
255		/* update the index at the top of the stack with the next index */
256		new_head.top.index = stack->next_index_array[cur_head.top.index];
257	}while(OS_ATOMIC64_CAS(&stack->head.data,cur_head.data,new_head.data)
258        	!= cur_head.data);
259 	stack->next_index_array[cur_head.top.index] = 0;
260
261	DBG_INFO("pop tag: %d\n",cur_head.top.index);
262 	DBG_FUNC("OUT\n");
263	return cur_head.top.index; /*tag*/
264}
265#endif /* LOCKFREE_STACK */
266