drivers/staging/lustre/lustre/libcfs/linux/linux-prim.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2011, 2012, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  */
  36
  37 #define DEBUG_SUBSYSTEM S_LNET
  38 #include <linux/module.h>
  39 #include <linux/kernel.h>
  40 #include <linux/fs_struct.h>
  41 #include <linux/sched.h>
  42
  43 #include <linux/libcfs/libcfs.h>
  44
  45 #if defined(CONFIG_KGDB)
  46 #include <asm/kgdb.h>
  47 #endif
  48
  49 /**
  50  * wait_queue_t of Linux (version < 2.6.34) is a FIFO list for exclusively
  51  * waiting threads, which is not always desirable because all threads will
  52  * be waken up again and again, even user only needs a few of them to be
  53  * active most time. This is not good for performance because cache can
  54  * be polluted by different threads.
  55  *
  56  * LIFO list can resolve this problem because we always wakeup the most
  57  * recent active thread by default.
  58  *
  59  * NB: please don't call non-exclusive & exclusive wait on the same
  60  * waitq if add_wait_queue_exclusive_head is used.
  61  */
  62 void
  63 add_wait_queue_exclusive_head(wait_queue_head_t *waitq, wait_queue_t *link)
  64 {
  65         unsigned long flags;
  66
  67         spin_lock_irqsave(&waitq->lock, flags);
  68         __add_wait_queue_exclusive(waitq, link);
  69         spin_unlock_irqrestore(&waitq->lock, flags);
  70 }
  71 EXPORT_SYMBOL(add_wait_queue_exclusive_head);
  72
  73 void cfs_init_timer(struct timer_list *t)
  74 {
  75         init_timer(t);
  76 }
  77 EXPORT_SYMBOL(cfs_init_timer);
  78
  79 void cfs_timer_init(struct timer_list *t, cfs_timer_func_t *func, void *arg)
  80 {
  81         init_timer(t);
  82         t->function = func;
  83         t->data = (unsigned long)arg;
  84 }
  85 EXPORT_SYMBOL(cfs_timer_init);
  86
  87 void cfs_timer_done(struct timer_list *t)
  88 {
  89         return;
  90 }
  91 EXPORT_SYMBOL(cfs_timer_done);
  92
  93 void cfs_timer_arm(struct timer_list *t, cfs_time_t deadline)
  94 {
  95         mod_timer(t, deadline);
  96 }
  97 EXPORT_SYMBOL(cfs_timer_arm);
  98
  99 void cfs_timer_disarm(struct timer_list *t)
 100 {
 101         del_timer(t);
 102 }
 103 EXPORT_SYMBOL(cfs_timer_disarm);
 104
 105 int  cfs_timer_is_armed(struct timer_list *t)
 106 {
 107         return timer_pending(t);
 108 }
 109 EXPORT_SYMBOL(cfs_timer_is_armed);
 110
 111 cfs_time_t cfs_timer_deadline(struct timer_list *t)
 112 {
 113         return t->expires;
 114 }
 115 EXPORT_SYMBOL(cfs_timer_deadline);
 116
 117 void cfs_enter_debugger(void)
 118 {
 119 #if defined(CONFIG_KGDB)
 120 //      BREAKPOINT();
 121 #else
 122         /* nothing */
 123 #endif
 124 }
 125
 126
 127 sigset_t
 128 cfs_block_allsigs(void)
 129 {
 130         unsigned long     flags;
 131         sigset_t        old;
 132
 133         SIGNAL_MASK_LOCK(current, flags);
 134         old = current->blocked;
 135         sigfillset(&current->blocked);
 136         recalc_sigpending();
 137         SIGNAL_MASK_UNLOCK(current, flags);
 138
 139         return old;
 140 }
 141
 142 sigset_t cfs_block_sigs(unsigned long sigs)
 143 {
 144         unsigned long  flags;
 145         sigset_t        old;
 146
 147         SIGNAL_MASK_LOCK(current, flags);
 148         old = current->blocked;
 149         sigaddsetmask(&current->blocked, sigs);
 150         recalc_sigpending();
 151         SIGNAL_MASK_UNLOCK(current, flags);
 152         return old;
 153 }
 154
 155 /* Block all signals except for the @sigs */
 156 sigset_t cfs_block_sigsinv(unsigned long sigs)
 157 {
 158         unsigned long flags;
 159         sigset_t old;
 160
 161         SIGNAL_MASK_LOCK(current, flags);
 162         old = current->blocked;
 163         sigaddsetmask(&current->blocked, ~sigs);
 164         recalc_sigpending();
 165         SIGNAL_MASK_UNLOCK(current, flags);
 166
 167         return old;
 168 }
 169
 170 void
 171 cfs_restore_sigs (sigset_t old)
 172 {
 173         unsigned long  flags;
 174
 175         SIGNAL_MASK_LOCK(current, flags);
 176         current->blocked = old;
 177         recalc_sigpending();
 178         SIGNAL_MASK_UNLOCK(current, flags);
 179 }
 180
 181 int
 182 cfs_signal_pending(void)
 183 {
 184         return signal_pending(current);
 185 }
 186
 187 void
 188 cfs_clear_sigpending(void)
 189 {
 190         unsigned long flags;
 191
 192         SIGNAL_MASK_LOCK(current, flags);
 193         clear_tsk_thread_flag(current, TIF_SIGPENDING);
 194         SIGNAL_MASK_UNLOCK(current, flags);
 195 }
 196
 197 int
 198 libcfs_arch_init(void)
 199 {
 200         return 0;
 201 }
 202
 203 void
 204 libcfs_arch_cleanup(void)
 205 {
 206         return;
 207 }
 208
 209 EXPORT_SYMBOL(libcfs_arch_init);
 210 EXPORT_SYMBOL(libcfs_arch_cleanup);
 211 EXPORT_SYMBOL(cfs_enter_debugger);
 212 EXPORT_SYMBOL(cfs_block_allsigs);
 213 EXPORT_SYMBOL(cfs_block_sigs);
 214 EXPORT_SYMBOL(cfs_block_sigsinv);
 215 EXPORT_SYMBOL(cfs_restore_sigs);
 216 EXPORT_SYMBOL(cfs_signal_pending);
 217 EXPORT_SYMBOL(cfs_clear_sigpending);