usr/src/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 (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #ifndef _SYS_CALLB_H
  27 #define _SYS_CALLB_H
  28
  29 #include <sys/t_lock.h>
  30 #include <sys/thread.h>
  31
  32 #ifdef  __cplusplus
  33 extern "C" {
  34 #endif
  35
  36 /*
  37  * definitions of callback classes (c_class)
  38  *
  39  * Callbacks belong in the same class if (1) their callback routines
  40  * do the same kind of processing (ideally, using the same callback function)
  41  * and (2) they can/should be executed at the same time in a cpr
  42  * suspend/resume operation.
  43  *
  44  * Note: The DAEMON class, in particular, is for stopping kernel threads
  45  * and nothing else.  The CALLB_* macros below should be used to deal
  46  * with kernel threads, and the callback function should be callb_generic_cpr.
  47  * Another idiosyncrasy of the DAEMON class is that if a suspend operation
  48  * fails, some of the callback functions may be called with the RESUME
  49  * code which were never called with SUSPEND.  Not a problem currently,
  50  * but see bug 4201851.
  51  */
  52 #define CB_CL_CPR_DAEMON        0
  53 #define CB_CL_CPR_VM            1
  54 #define CB_CL_CPR_CALLOUT       2
  55 #define CB_CL_CPR_OBP           3
  56 #define CB_CL_CPR_FB            4
  57 #define CB_CL_PANIC             5
  58 #define CB_CL_CPR_RPC           6
  59 #define CB_CL_CPR_PROMPRINTF    7
  60 #define CB_CL_UADMIN            8
  61 #define CB_CL_CPR_PM            9
  62 #define CB_CL_HALT              10
  63 #define CB_CL_CPR_DMA           11
  64 #define CB_CL_CPR_POST_USER     12
  65 #define CB_CL_UADMIN_PRE_VFS    13
  66 #define CB_CL_MDBOOT            CB_CL_UADMIN
  67 #define CB_CL_ENTER_DEBUGGER    14
  68 #define CB_CL_CPR_POST_KERNEL   15
  69 #define CB_CL_CPU_DEEP_IDLE     16
  70 #define NCBCLASS                17 /* CHANGE ME if classes are added/removed */
  71
  72 /*
  73  * CB_CL_CPR_DAEMON class specific definitions are given below:
  74  */
  75
  76 /*
  77  * code for CPR callb_execute_class
  78  */
  79 #define CB_CODE_CPR_CHKPT       0
  80 #define CB_CODE_CPR_RESUME      1
  81
  82 typedef void *          callb_id_t;
  83 /*
  84  * Per kernel thread structure for CPR daemon callbacks.
  85  * Must be protected by either a existing lock in the daemon or
  86  * a new lock created for such a purpose.
  87  */
  88 typedef struct callb_cpr {
  89         kmutex_t        *cc_lockp;      /* lock to protect this struct */
  90         char            cc_events;      /* various events for CPR */
  91         callb_id_t      cc_id;          /* callb id address */
  92         kcondvar_t      cc_callb_cv;    /* cv for callback waiting */
  93         kcondvar_t      cc_stop_cv;     /* cv to checkpoint block */
  94 } callb_cpr_t;
  95
  96 /*
  97  * cc_events definitions
  98  */
  99 #define CALLB_CPR_START         1       /* a checkpoint request's started */
 100 #define CALLB_CPR_SAFE          2       /* thread is safe for CPR */
 101 #define CALLB_CPR_ALWAYS_SAFE   4       /* thread is ALWAYS safe for CPR */
 102
 103 /*
 104  * Used when checking that all kernel threads are stopped.
 105  */
 106 #define CALLB_MAX_RETRY         3       /* when waiting for kthread to sleep */
 107 #define CALLB_THREAD_DELAY      10      /* ticks allowed to reach sleep */
 108 #define CPR_KTHREAD_TIMEOUT_SEC 90      /* secs before callback times out -- */
 109                                         /* due to pwr mgmt of disks, make -- */
 110                                         /* big enough for worst spinup time */
 111
 112 #ifdef  _KERNEL
 113 /*
 114  *
 115  * CALLB_CPR_INIT macro is used by kernel threads to add their entry to
 116  * the callback table and perform other initialization.  It automatically
 117  * adds the thread as being in the callback class CB_CL_CPR_DAEMON.
 118  *
 119  *      cp    - ptr to the callb_cpr_t structure for this kernel thread
 120  *
 121  *      lockp - pointer to mutex protecting the callb_cpr_t stuct
 122  *
 123  *      func  - pointer to the callback function for this kernel thread.
 124  *              It has the prototype boolean_t <func>(void *arg, int code)
 125  *              where: arg      - ptr to the callb_cpr_t structure
 126  *                     code     - not used for this type of callback
 127  *              returns: B_TRUE if successful; B_FALSE if unsuccessful.
 128  *
 129  *      name  - a string giving the name of the kernel thread
 130  *
 131  * Note: lockp is the lock to protect the callb_cpr_t (cp) structure
 132  * later on.  No lock held is needed for this initialization.
 133  */
 134 #define CALLB_CPR_INIT(cp, lockp, func, name)   {                       \
 135                 bzero((caddr_t)(cp), sizeof (callb_cpr_t));             \
 136                 (cp)->cc_lockp = lockp;                                 \
 137                 (cp)->cc_id = callb_add(func, (void *)(cp),             \
 138                         CB_CL_CPR_DAEMON, name);                        \
 139         }
 140
 141 #ifndef __lock_lint
 142 #define CALLB_CPR_ASSERT(cp)    ASSERT(MUTEX_HELD((cp)->cc_lockp));
 143 #else
 144 #define CALLB_CPR_ASSERT(cp)
 145 #endif
 146 /*
 147  * Some threads (like the idle threads) do not adhere to the callback
 148  * protocol and are always considered safe.  Such threads must never exit.
 149  * They register their presence by calling this macro during their
 150  * initialization.
 151  *
 152  * Args:
 153  *      t       - thread pointer of the client kernel thread
 154  *      name    - a string giving the name of the kernel thread
 155  */
 156 #define CALLB_CPR_INIT_SAFE(t, name) {                                  \
 157                 (void) callb_add_thread(callb_generic_cpr_safe,         \
 158                 (void *) &callb_cprinfo_safe, CB_CL_CPR_DAEMON,         \
 159                     name, t);                                           \
 160         }
 161 /*
 162  * The lock to protect cp's content must be held before
 163  * calling the following two macros.
 164  *
 165  * Any code region between CALLB_CPR_SAFE_BEGIN and CALLB_CPR_SAFE_END
 166  * is safe for checkpoint/resume.
 167  */
 168 #define CALLB_CPR_SAFE_BEGIN(cp) {                      \
 169                 CALLB_CPR_ASSERT(cp)                    \
 170                 (cp)->cc_events |= CALLB_CPR_SAFE;      \
 171                 if ((cp)->cc_events & CALLB_CPR_START)  \
 172                         cv_signal(&(cp)->cc_callb_cv);  \
 173         }
 174 #define CALLB_CPR_SAFE_END(cp, lockp) {                         \
 175                 CALLB_CPR_ASSERT(cp)                            \
 176                 while ((cp)->cc_events & CALLB_CPR_START)       \
 177                         cv_wait(&(cp)->cc_stop_cv, lockp);      \
 178                 (cp)->cc_events &= ~CALLB_CPR_SAFE;             \
 179         }
 180 /*
 181  * cv_destroy is nop right now but may be needed in the future.
 182  */
 183 #define CALLB_CPR_EXIT(cp) {                            \
 184                 CALLB_CPR_ASSERT(cp)                    \
 185                 (cp)->cc_events |= CALLB_CPR_SAFE;      \
 186                 if ((cp)->cc_events & CALLB_CPR_START)  \
 187                         cv_signal(&(cp)->cc_callb_cv);  \
 188                 mutex_exit((cp)->cc_lockp);             \
 189                 (void) callb_delete((cp)->cc_id);       \
 190                 cv_destroy(&(cp)->cc_callb_cv);         \
 191                 cv_destroy(&(cp)->cc_stop_cv);          \
 192         }
 193
 194 extern callb_cpr_t callb_cprinfo_safe;
 195 extern void     callb_init(void);
 196 extern callb_id_t callb_add(boolean_t  (*)(void *, int), void *, int, char *);
 197 extern callb_id_t callb_add_thread(boolean_t (*)(void *, int),
 198     void *, int, char *, kthread_id_t);
 199 extern int      callb_delete(callb_id_t);
 200 extern void     callb_execute(callb_id_t, int);
 201 extern void     *callb_execute_class(int, int);
 202 extern boolean_t callb_generic_cpr(void *, int);
 203 extern boolean_t callb_generic_cpr_safe(void *, int);
 204 extern boolean_t callb_is_stopped(kthread_id_t, caddr_t *);
 205 extern void     callb_lock_table(void);
 206 extern void     callb_unlock_table(void);
 207 #endif
 208
 209 #ifdef  __cplusplus
 210 }
 211 #endif
 212
 213 #endif  /* _SYS_CALLB_H */