libcfs/include/libcfs/linux/linux-prim.h

   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) 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  * libcfs/include/libcfs/linux/linux-prim.h
  37  *
  38  * Basic library routines.
  39  */
  40
  41 #ifndef __LIBCFS_LINUX_CFS_PRIM_H__
  42 #define __LIBCFS_LINUX_CFS_PRIM_H__
  43
  44 #ifndef __LIBCFS_LIBCFS_H__
  45 #error Do not #include this file directly. #include <libcfs/libcfs.h> instead
  46 #endif
  47
  48 #ifndef __KERNEL__
  49 #error This include is only for kernel use.
  50 #endif
  51
  52 #include <linux/module.h>
  53 #include <linux/init.h>
  54 #include <linux/kernel.h>
  55 #include <linux/version.h>
  56 #include <linux/proc_fs.h>
  57 #include <linux/mm.h>
  58 #include <linux/timer.h>
  59 #include <linux/signal.h>
  60 #include <linux/sched.h>
  61 #include <linux/kthread.h>
  62 #ifdef HAVE_LINUX_RANDOM_H
  63 #include <linux/random.h>
  64 #endif
  65 #ifdef HAVE_UIDGID_HEADER
  66 #include <linux/uidgid.h>
  67 #endif
  68 #include <linux/user_namespace.h>
  69 #include <linux/miscdevice.h>
  70 #include <asm/div64.h>
  71
  72 #include <libcfs/linux/linux-time.h>
  73
  74
  75 /*
  76  * CPU
  77  */
  78 #ifdef for_each_possible_cpu
  79 #define cfs_for_each_possible_cpu(cpu) for_each_possible_cpu(cpu)
  80 #elif defined(for_each_cpu)
  81 #define cfs_for_each_possible_cpu(cpu) for_each_cpu(cpu)
  82 #endif
  83
  84 #ifndef NR_CPUS
  85 #define NR_CPUS                         1
  86 #endif
  87
  88 /*
  89  * Wait Queue
  90  */
  91
  92
  93 #define CFS_DECL_WAITQ(wq)              DECLARE_WAIT_QUEUE_HEAD(wq)
  94
  95 #define LIBCFS_WQITQ_MACROS           1
  96 #define init_waitqueue_entry_current(w)          init_waitqueue_entry(w, current)
  97 #define waitq_wait(w, s)          schedule()
  98 #define waitq_timedwait(w, s, t)  schedule_timeout(t)
  99
 100 #ifndef HAVE___ADD_WAIT_QUEUE_EXCLUSIVE
 101 static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
 102                                               wait_queue_t *wait)
 103 {
 104         wait->flags |= WQ_FLAG_EXCLUSIVE;
 105         __add_wait_queue(q, wait);
 106 }
 107 #endif /* HAVE___ADD_WAIT_QUEUE_EXCLUSIVE */
 108
 109 /**
 110  * wait_queue_t of Linux (version < 2.6.34) is a FIFO list for exclusively
 111  * waiting threads, which is not always desirable because all threads will
 112  * be waken up again and again, even user only needs a few of them to be
 113  * active most time. This is not good for performance because cache can
 114  * be polluted by different threads.
 115  *
 116  * LIFO list can resolve this problem because we always wakeup the most
 117  * recent active thread by default.
 118  *
 119  * NB: please don't call non-exclusive & exclusive wait on the same
 120  * waitq if add_wait_queue_exclusive_head is used.
 121  */
 122 #define add_wait_queue_exclusive_head(waitq, link)                      \
 123 {                                                                       \
 124         unsigned long flags;                                            \
 125                                                                         \
 126         spin_lock_irqsave(&((waitq)->lock), flags);                     \
 127         __add_wait_queue_exclusive(waitq, link);                        \
 128         spin_unlock_irqrestore(&((waitq)->lock), flags);                \
 129 }
 130
 131 #define schedule_timeout_and_set_state(state, timeout)                  \
 132 {                                                                       \
 133         set_current_state(state);                                       \
 134         schedule_timeout(timeout);                                      \
 135 }
 136
 137 /* deschedule for a bit... */
 138 #define cfs_pause(ticks)                                                \
 139 {                                                                       \
 140         set_current_state(TASK_UNINTERRUPTIBLE);                        \
 141         schedule_timeout(ticks);                                        \
 142 }
 143
 144 #define DECL_JOURNAL_DATA           void *journal_info
 145 #define PUSH_JOURNAL                do {    \
 146         journal_info = current->journal_info;   \
 147         current->journal_info = NULL;           \
 148         } while(0)
 149 #define POP_JOURNAL                 do {    \
 150         current->journal_info = journal_info;   \
 151         } while(0)
 152
 153 /* Module interfaces */
 154 #define cfs_module(name, version, init, fini) \
 155         module_init(init);                    \
 156         module_exit(fini)
 157
 158 #endif