drivers/scsi/isci/timers.c

   1 /*
   2  * This file is provided under a dual BSD/GPLv2 license.  When using or
   3  * redistributing this file, you may do so under either license.
   4  *
   5  * GPL LICENSE SUMMARY
   6  *
   7  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of version 2 of the GNU General Public License as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  21  * The full GNU General Public License is included in this distribution
  22  * in the file called LICENSE.GPL.
  23  *
  24  * BSD LICENSE
  25  *
  26  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
  27  * All rights reserved.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  *
  33  *   * Redistributions of source code must retain the above copyright
  34  *     notice, this list of conditions and the following disclaimer.
  35  *   * Redistributions in binary form must reproduce the above copyright
  36  *     notice, this list of conditions and the following disclaimer in
  37  *     the documentation and/or other materials provided with the
  38  *     distribution.
  39  *   * Neither the name of Intel Corporation nor the names of its
  40  *     contributors may be used to endorse or promote products derived
  41  *     from this software without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  44  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  45  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  46  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  47  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  48  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  49  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  50  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  51  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  52  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  53  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  54  */
  55
  56 #include "isci.h"
  57 #include "timers.h"
  58
  59 /**
  60  * isci_timer_list_construct() - This method contrucst the SCI Timer List
  61  *    object used by the SCI Module class. The construction process involves
  62  *    creating isci_timer objects and adding them to the SCI Timer List
  63  *    object's list member. The number of isci_timer objects is determined by
  64  *    the timer_list_size parameter.
  65  * @ihost: container of the timer list
  66  *
  67  * This method returns an error code indicating sucess or failure. The user
  68  * should check for possible memory allocation error return otherwise, a zero
  69  * indicates success.
  70  */
  71 int isci_timer_list_construct(struct isci_host *ihost)
  72 {
  73         struct isci_timer *itimer;
  74         int i, err = 0;
  75
  76         INIT_LIST_HEAD(&ihost->timers);
  77         for (i = 0; i < SCI_MAX_TIMER_COUNT; i++) {
  78                 itimer = devm_kzalloc(&ihost->pdev->dev, sizeof(*itimer), GFP_KERNEL);
  79
  80                 if (!itimer) {
  81                         err = -ENOMEM;
  82                         break;
  83                 }
  84                 init_timer(&itimer->timer);
  85                 itimer->used = 0;
  86                 itimer->stopped = 1;
  87                 list_add(&itimer->node, &ihost->timers);
  88         }
  89
  90         return err;
  91 }
  92
  93 /**
  94  * isci_timer_list_destroy() - This method destroys the SCI Timer List object
  95  *    used by the SCI Module class. The destruction  process involves freeing
  96  *    memory allocated for isci_timer objects on the SCI Timer List object's
  97  *    timers list_head member. If any isci_timer objects are mark as "in use",
  98  *    they are not freed and the function returns an error code of -EBUSY.
  99  * @ihost: container of the list to be destroyed
 100  */
 101 void isci_timer_list_destroy(struct isci_host *ihost)
 102 {
 103         struct isci_timer *timer;
 104         LIST_HEAD(list);
 105
 106         spin_lock_irq(&ihost->scic_lock);
 107         list_splice_init(&ihost->timers, &list);
 108         spin_unlock_irq(&ihost->scic_lock);
 109
 110         list_for_each_entry(timer, &list, node)
 111                 del_timer_sync(&timer->timer);
 112 }
 113
 114 /**
 115  * This method pulls an isci_timer object off of the list for the SCI Timer
 116  *    List object specified, marks the isci_timer as "in use" and initializes
 117  *    it with user callback function and cookie data. The timer is not start at
 118  *    this time, just reserved for the user.
 119  * @isci_timer_list: This parameter points to the SCI Timer List from which the
 120  *    timer is reserved.
 121  * @cookie: This parameter specifies a piece of information that the user must
 122  *    retain.  This cookie is to be supplied by the user anytime a timeout
 123  *    occurs for the created timer.
 124  * @timer_callback: This parameter specifies the callback method to be invoked
 125  *    whenever the timer expires.
 126  *
 127  * This method returns a pointer to an isci_timer object reserved from the SCI
 128  * Timer List.  The pointer will be utilized for all further interactions
 129  * relating to this timer.
 130  */
 131
 132 static void timer_function(unsigned long data)
 133 {
 134
 135         struct isci_timer *timer = (struct isci_timer *)data;
 136         struct isci_host *isci_host = timer->isci_host;
 137         unsigned long flags;
 138
 139         dev_dbg(&isci_host->pdev->dev,
 140                 "%s: isci_timer = %p\n", __func__, timer);
 141
 142         if (isci_stopped == isci_host_get_state(isci_host)) {
 143                 timer->stopped = 1;
 144                 return;
 145         }
 146
 147         spin_lock_irqsave(&isci_host->scic_lock, flags);
 148
 149         if (!timer->stopped) {
 150                 timer->stopped = 1;
 151                 timer->timer_callback(timer->cb_param);
 152         }
 153
 154         spin_unlock_irqrestore(&isci_host->scic_lock, flags);
 155 }
 156
 157
 158 struct isci_timer *isci_timer_create(struct isci_host *ihost, void *cb_param,
 159                                      void (*timer_callback)(void *))
 160 {
 161         struct timer_list *timer;
 162         struct isci_timer *isci_timer;
 163         struct list_head *list = &ihost->timers;
 164
 165         WARN_ONCE(!spin_is_locked(&ihost->scic_lock),
 166                   "%s: unlocked!\n", __func__);
 167
 168         if (WARN_ONCE(list_empty(list), "%s: timer pool empty\n", __func__))
 169                 return NULL;
 170
 171         isci_timer = list_entry(list->next, struct isci_timer, node);
 172
 173         isci_timer->used = 1;
 174         isci_timer->stopped = 1;
 175         /* FIXME: what!? we recycle the timer, rather than take it off
 176          * the free list?
 177          */
 178         list_move_tail(&isci_timer->node, list);
 179
 180         timer = &isci_timer->timer;
 181         timer->data = (unsigned long)isci_timer;
 182         timer->function = timer_function;
 183         isci_timer->cb_param = cb_param;
 184         isci_timer->timer_callback = timer_callback;
 185         isci_timer->isci_host = ihost;
 186
 187         dev_dbg(&ihost->pdev->dev,
 188                 "%s: isci_timer = %p\n", __func__, isci_timer);
 189
 190         return isci_timer;
 191 }
 192
 193 /* isci_del_timer() - This method frees the isci_timer, marking it "free to
 194  *    use", then places its back at the head of the timers list for the SCI
 195  *    Timer List object specified.
 196  */
 197 void isci_del_timer(struct isci_host *ihost, struct isci_timer *isci_timer)
 198 {
 199         struct list_head *list = &ihost->timers;
 200
 201         WARN_ONCE(!spin_is_locked(&ihost->scic_lock),
 202                   "%s unlocked!\n", __func__);
 203
 204         dev_dbg(&isci_timer->isci_host->pdev->dev,
 205                 "%s: isci_timer = %p\n", __func__, isci_timer);
 206
 207         isci_timer->used = 0;
 208         list_move(&isci_timer->node, list);
 209         del_timer(&isci_timer->timer);
 210         isci_timer->stopped = 1;
 211 }
 212
 213 /**
 214  * isci_timer_start() - This method starts the specified isci_timer, with the
 215  *    specified timeout value.
 216  * @isci_timer: This parameter specifies the timer to be started.
 217  * @timeout: This parameter specifies the timeout, in milliseconds, after which
 218  *    the associated callback function will be called.
 219  *
 220  */
 221 void isci_timer_start(struct isci_timer *isci_timer, unsigned long tmo)
 222 {
 223         struct timer_list *timer = &isci_timer->timer;
 224
 225         dev_dbg(&isci_timer->isci_host->pdev->dev,
 226                 "%s: isci_timer = %p\n", __func__, isci_timer);
 227
 228         isci_timer->stopped = 0;
 229         mod_timer(timer, jiffies + msecs_to_jiffies(tmo));
 230 }
 231
 232 /**
 233  * isci_timer_stop() - This method stops the supplied isci_timer.
 234  * @isci_timer: This parameter specifies the isci_timer to be stopped.
 235  *
 236  */
 237 void isci_timer_stop(struct isci_timer *isci_timer)
 238 {
 239         dev_dbg(&isci_timer->isci_host->pdev->dev,
 240                 "%s: isci_timer = %p\n", __func__, isci_timer);
 241
 242         isci_timer->stopped = 1;
 243         del_timer(&isci_timer->timer);
 244 }