external/cddl/osnet/dist/uts/common/sys/callb.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #ifndef _SYS_CALLB_H
  28 #define _SYS_CALLB_H
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #include <sys/t_lock.h>
  33 #include <sys/thread.h>
  34
  35 #ifdef  __cplusplus
  36 extern "C" {
  37 #endif
  38
  39 /*
  40  * definitions of callback classes (c_class)
  41  *
  42  * Callbacks belong in the same class if (1) their callback routines
  43  * do the same kind of processing (ideally, using the same callback function)
  44  * and (2) they can/should be executed at the same time in a cpr
  45  * suspend/resume operation.
  46  *
  47  * Note: The DAEMON class, in particular, is for stopping kernel threads
  48  * and nothing else.  The CALLB_* macros below should be used to deal
  49  * with kernel threads, and the callback function should be callb_generic_cpr.
  50  * Another idiosyncrasy of the DAEMON class is that if a suspend operation
  51  * fails, some of the callback functions may be called with the RESUME
  52  * code which were never called with SUSPEND.  Not a problem currently,
  53  * but see bug 4201851.
  54  */
  55 #define CB_CL_CPR_DAEMON        0
  56 #define CB_CL_CPR_VM            1
  57 #define CB_CL_CPR_CALLOUT       2
  58 #define CB_CL_CPR_OBP           3
  59 #define CB_CL_CPR_FB            4
  60 #define CB_CL_PANIC             5
  61 #define CB_CL_CPR_RPC           6
  62 #define CB_CL_CPR_PROMPRINTF    7
  63 #define CB_CL_UADMIN            8
  64 #define CB_CL_CPR_PM            9
  65 #define CB_CL_HALT              10
  66 #define CB_CL_CPR_DMA           11
  67 #define CB_CL_CPR_POST_USER     12
  68 #define CB_CL_UADMIN_PRE_VFS    13
  69 #define CB_CL_MDBOOT            CB_CL_UADMIN
  70 #define CB_CL_ENTER_DEBUGGER    14
  71 #define CB_CL_CPR_POST_KERNEL   15
  72 #define NCBCLASS                16 /* CHANGE ME if classes are added/removed */
  73
  74 /*
  75  * CB_CL_CPR_DAEMON class specific definitions are given below:
  76  */
  77
  78 /*
  79  * code for CPR callb_execute_class
  80  */
  81 #define CB_CODE_CPR_CHKPT       0
  82 #define CB_CODE_CPR_RESUME      1
  83
  84 typedef void *          callb_id_t;
  85 /*
  86  * Per kernel thread structure for CPR daemon callbacks.
  87  * Must be protected by either a existing lock in the daemon or
  88  * a new lock created for such a purpose.
  89  */
  90 typedef struct callb_cpr {
  91         kmutex_t        *cc_lockp;      /* lock to protect this struct */
  92         char            cc_events;      /* various events for CPR */
  93         callb_id_t      cc_id;          /* callb id address */
  94         kcondvar_t      cc_callb_cv;    /* cv for callback waiting */
  95         kcondvar_t      cc_stop_cv;     /* cv to checkpoint block */
  96 } callb_cpr_t;
  97
  98 /*
  99  * cc_events definitions
 100  */
 101 #define CALLB_CPR_START         1       /* a checkpoint request's started */
 102 #define CALLB_CPR_SAFE          2       /* thread is safe for CPR */
 103 #define CALLB_CPR_ALWAYS_SAFE   4       /* thread is ALWAYS safe for CPR */
 104
 105 /*
 106  * Used when checking that all kernel threads are stopped.
 107  */
 108 #define CALLB_MAX_RETRY         3       /* when waiting for kthread to sleep */
 109 #define CALLB_THREAD_DELAY      10      /* ticks allowed to reach sleep */
 110 #define CPR_KTHREAD_TIMEOUT_SEC 90      /* secs before callback times out -- */
 111                                         /* due to pwr mgmt of disks, make -- */
 112                                         /* big enough for worst spinup time */
 113
 114 #ifdef  _KERNEL
 115 /*
 116  *
 117  * CALLB_CPR_INIT macro is used by kernel threads to add their entry to
 118  * the callback table and perform other initialization.  It automatically
 119  * adds the thread as being in the callback class CB_CL_CPR_DAEMON.
 120  *
 121  *      cp    - ptr to the callb_cpr_t structure for this kernel thread
 122  *
 123  *      lockp - pointer to mutex protecting the callb_cpr_t stuct
 124  *
 125  *      func  - pointer to the callback function for this kernel thread.
 126  *              It has the prototype boolean_t <func>(void *arg, int code)
 127  *              where: arg      - ptr to the callb_cpr_t structure
 128  *                     code     - not used for this type of callback
 129  *              returns: B_TRUE if successful; B_FALSE if unsuccessful.
 130  *
 131  *      name  - a string giving the name of the kernel thread
 132  *
 133  * Note: lockp is the lock to protect the callb_cpr_t (cp) structure
 134  * later on.  No lock held is needed for this initialization.
 135  */
 136 #define CALLB_CPR_INIT(cp, lockp, func, name)   {                       \
 137                 bzero((caddr_t)(cp), sizeof (callb_cpr_t));             \
 138                 (cp)->cc_lockp = lockp;                                 \
 139                 (cp)->cc_id = callb_add(func, (void *)(cp),             \
 140                         CB_CL_CPR_DAEMON, name);                        \
 141         }
 142
 143 #ifndef __lock_lint
 144 #define CALLB_CPR_ASSERT(cp)    ASSERT(MUTEX_HELD((cp)->cc_lockp));
 145 #else
 146 #define CALLB_CPR_ASSERT(cp)
 147 #endif
 148 /*
 149  * Some threads (like the idle threads) do not adhere to the callback
 150  * protocol and are always considered safe.  Such threads must never exit.
 151  * They register their presence by calling this macro during their
 152  * initialization.
 153  *
 154  * Args:
 155  *      t       - thread pointer of the client kernel thread
 156  *      name    - a string giving the name of the kernel thread
 157  */
 158 #define CALLB_CPR_INIT_SAFE(t, name) {                                  \
 159                 (void) callb_add_thread(callb_generic_cpr_safe,         \
 160                 (void *) &callb_cprinfo_safe, CB_CL_CPR_DAEMON,         \
 161                     name, t);                                           \
 162         }
 163 /*
 164  * The lock to protect cp's content must be held before
 165  * calling the following two macros.
 166  *
 167  * Any code region between CALLB_CPR_SAFE_BEGIN and CALLB_CPR_SAFE_END
 168  * is safe for checkpoint/resume.
 169  */
 170 #define CALLB_CPR_SAFE_BEGIN(cp) {                      \
 171                 CALLB_CPR_ASSERT(cp)                    \
 172                 (cp)->cc_events |= CALLB_CPR_SAFE;      \
 173                 if ((cp)->cc_events & CALLB_CPR_START)  \
 174                         cv_signal(&(cp)->cc_callb_cv);  \
 175         }
 176 #define CALLB_CPR_SAFE_END(cp, lockp) {                         \
 177                 CALLB_CPR_ASSERT(cp)                            \
 178                 while ((cp)->cc_events & CALLB_CPR_START)       \
 179                         cv_wait(&(cp)->cc_stop_cv, lockp);      \
 180                 (cp)->cc_events &= ~CALLB_CPR_SAFE;             \
 181         }
 182 /*
 183  * cv_destroy is nop right now but may be needed in the future.
 184  */
 185 #define CALLB_CPR_EXIT(cp) {                            \
 186                 CALLB_CPR_ASSERT(cp)                    \
 187                 (cp)->cc_events |= CALLB_CPR_SAFE;      \
 188                 if ((cp)->cc_events & CALLB_CPR_START)  \
 189                         cv_signal(&(cp)->cc_callb_cv);  \
 190                 mutex_exit((cp)->cc_lockp);             \
 191                 (void) callb_delete((cp)->cc_id);       \
 192                 cv_destroy(&(cp)->cc_callb_cv);         \
 193                 cv_destroy(&(cp)->cc_stop_cv);          \
 194         }
 195
 196 extern callb_cpr_t callb_cprinfo_safe;
 197 extern void     callb_init(void);
 198 extern callb_id_t callb_add(boolean_t  (*)(void *, int), void *, int, char *);
 199 extern callb_id_t callb_add_thread(boolean_t (*)(void *, int),
 200     void *, int, char *, kthread_id_t);
 201 extern int      callb_delete(callb_id_t);
 202 extern void     callb_execute(callb_id_t, int);
 203 extern void     *callb_execute_class(int, int);
 204 extern boolean_t callb_generic_cpr(void *, int);
 205 extern boolean_t callb_generic_cpr_safe(void *, int);
 206 extern boolean_t callb_is_stopped(kthread_id_t, caddr_t *);
 207 extern void     callb_lock_table(void);
 208 extern void     callb_unlock_table(void);
 209 #endif
 210
 211 #ifdef  __cplusplus
 212 }
 213 #endif
 214
 215 #endif  /* _SYS_CALLB_H */