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
  66 #include <linux/miscdevice.h>
  67 #include <libcfs/linux/portals_compat25.h>
  68 #include <asm/div64.h>
  69
  70 #include <libcfs/linux/linux-time.h>
  71
  72
  73 /*
  74  * CPU
  75  */
  76 #ifdef for_each_possible_cpu
  77 #define cfs_for_each_possible_cpu(cpu) for_each_possible_cpu(cpu)
  78 #elif defined(for_each_cpu)
  79 #define cfs_for_each_possible_cpu(cpu) for_each_cpu(cpu)
  80 #endif
  81
  82 #ifndef NR_CPUS
  83 #define NR_CPUS                         1
  84 #endif
  85
  86 #define DECLARE_PROC_HANDLER(name)                      \
  87 static int                                              \
  88 LL_PROC_PROTO(name)                                     \
  89 {                                                       \
  90         return proc_call_handler(table->data, write,    \
  91                                  ppos, buffer, lenp,    \
  92                                  __##name);             \
  93 }
  94
  95 /*
  96  * Proc file system APIs
  97  */
  98 typedef read_proc_t                     cfs_read_proc_t;
  99 typedef write_proc_t                    cfs_write_proc_t;
 100 typedef struct proc_dir_entry           cfs_proc_dir_entry_t;
 101 #define cfs_create_proc_entry(n, m, p)  create_proc_entry(n, m, p)
 102 #define cfs_free_proc_entry(e)          free_proc_entry(e)
 103 #define cfs_remove_proc_entry(n, e)     remove_proc_entry(n, e)
 104
 105 /*
 106  * Wait Queue
 107  */
 108
 109
 110 #define CFS_DECL_WAITQ(wq)              DECLARE_WAIT_QUEUE_HEAD(wq)
 111
 112 #define LIBCFS_WQITQ_MACROS           1
 113 #define init_waitqueue_entry_current(w)          init_waitqueue_entry(w, current)
 114 #define waitq_wait(w, s)          schedule()
 115 #define waitq_timedwait(w, s, t)  schedule_timeout(t)
 116
 117 #ifndef HAVE___ADD_WAIT_QUEUE_EXCLUSIVE
 118 static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
 119                                               wait_queue_t *wait)
 120 {
 121         wait->flags |= WQ_FLAG_EXCLUSIVE;
 122         __add_wait_queue(q, wait);
 123 }
 124 #endif /* HAVE___ADD_WAIT_QUEUE_EXCLUSIVE */
 125
 126 /**
 127  * wait_queue_t of Linux (version < 2.6.34) is a FIFO list for exclusively
 128  * waiting threads, which is not always desirable because all threads will
 129  * be waken up again and again, even user only needs a few of them to be
 130  * active most time. This is not good for performance because cache can
 131  * be polluted by different threads.
 132  *
 133  * LIFO list can resolve this problem because we always wakeup the most
 134  * recent active thread by default.
 135  *
 136  * NB: please don't call non-exclusive & exclusive wait on the same
 137  * waitq if add_wait_queue_exclusive_head is used.
 138  */
 139 #define add_wait_queue_exclusive_head(waitq, link)                      \
 140 {                                                                       \
 141         unsigned long flags;                                            \
 142                                                                         \
 143         spin_lock_irqsave(&((waitq)->lock), flags);                     \
 144         __add_wait_queue_exclusive(waitq, link);                        \
 145         spin_unlock_irqrestore(&((waitq)->lock), flags);                \
 146 }
 147
 148 #define schedule_timeout_and_set_state(state, timeout)                  \
 149 {                                                                       \
 150         set_current_state(state);                                       \
 151         schedule_timeout(timeout);                                      \
 152 }
 153
 154 /* deschedule for a bit... */
 155 #define cfs_pause(ticks)                                                \
 156 {                                                                       \
 157         set_current_state(TASK_UNINTERRUPTIBLE);                        \
 158         schedule_timeout(ticks);                                        \
 159 }
 160
 161 #define DECL_JOURNAL_DATA           void *journal_info
 162 #define PUSH_JOURNAL                do {    \
 163         journal_info = current->journal_info;   \
 164         current->journal_info = NULL;           \
 165         } while(0)
 166 #define POP_JOURNAL                 do {    \
 167         current->journal_info = journal_info;   \
 168         } while(0)
 169
 170 /* Module interfaces */
 171 #define cfs_module(name, version, init, fini) \
 172         module_init(init);                    \
 173         module_exit(fini)
 174
 175 #endif