sys/dev/smartpqi/smartpqi_tag.c

   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 /* $FreeBSD$ */
  28
  29 #include "smartpqi_includes.h"
  30
  31 #ifndef LOCKFREE_STACK
  32
  33 /*
  34  * Function used to release the tag from taglist.
  35  */
  36 void 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  */
  58 uint32_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  */
  83 int 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
 121 err_lock:
 122     os_mem_free(softs, (char *)taglist->elem_array,
 123         (taglist->max_elem * sizeof(uint32_t)));
 124         taglist->elem_array = NULL;
 125 err_out:
 126         DBG_FUNC("OUT failed\n");
 127         return ret;
 128 }
 129
 130 /*
 131  * Destroy circular queue implementation of tag list.
 132  */
 133 void 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  */
 153 int 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;
 183 err_out:
 184         DBG_FUNC("Failed OUT\n");
 185         return ret;
 186 }
 187
 188 /*
 189  * Destroy circular queue implementation of tag list.
 190  */
 191 void 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  */
 208 void 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  */
 244 uint32_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 */