bsd/dev/dtrace/lockstat.c

   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 #include <sys/param.h>
  27 #include <sys/systm.h>
  28 #include <sys/errno.h>
  29 #include <sys/stat.h>
  30 #include <sys/ioctl.h>
  31 #include <sys/conf.h>
  32 #include <sys/fcntl.h>
  33 #include <miscfs/devfs/devfs.h>
  34
  35 #include <sys/dtrace.h>
  36 #include <sys/dtrace_impl.h>
  37
  38 #include <sys/dtrace_glue.h>
  39
  40 #include <sys/lockstat.h>
  41
  42 #include <kern/lock_stat.h>
  43
  44 #include <kern/processor.h>
  45
  46 #define membar_producer dtrace_membar_producer
  47
  48 #define PROBE_ARGS0(a, b, c, d, e) "\000"
  49 #define PROBE_ARGS1(a, b, c, d, e) a "\000"
  50 #define PROBE_ARGS2(a, b, c, d, e) a "\000" b "\000"
  51 #define PROBE_ARGS3(a, b, c, d, e) a "\000" b "\000" c "\000"
  52 #define PROBE_ARGS4(a, b, c, d, e) a "\000" b "\000" c "\000" d "\000"
  53 #define PROBE_ARGS5(a, b, c, d, e) a "\000" b "\000" c "\000" d "\000" e "\000"
  54 #define PROBE_ARGS_(a, b, c, d, e, n, ...) PROBE_ARGS##n(a, b, c, d, e)
  55 #define PROBE_ARGS(...) PROBE_ARGS_(__VA_ARGS__, 5, 4, 3, 2, 1, 0)
  56
  57 #define LOCKSTAT_PROBE(func, name, probe, ...) \
  58         {func, name, probe, DTRACE_IDNONE, PROBE_ARGS(__VA_ARGS__)}
  59
  60 /*
  61  * Hot patch values, x86
  62  */
  63 #if defined(__x86_64__)
  64 #define NOP     0x90
  65 #define RET     0xc3
  66 #define LOCKSTAT_AFRAMES 1
  67 #elif   defined(__arm__)
  68 #define NOP     0xE1A00000
  69 #define BXLR    0xE12FFF1E
  70 #define LOCKSTAT_AFRAMES 2
  71 #elif   defined(__arm64__)
  72 #define NOP     0xD503201F
  73 #define RET     0xD65f03c0
  74 #define LOCKSTAT_AFRAMES 2
  75 #else
  76 #error "not ported to this architecture"
  77 #endif
  78
  79 typedef struct lockstat_probe {
  80         const char      *lsp_func;
  81         const char      *lsp_name;
  82         int             lsp_probe;
  83         dtrace_id_t     lsp_id;
  84         const char      *lsp_args;
  85 } lockstat_probe_t;
  86
  87 lockstat_probe_t lockstat_probes[] =
  88 {
  89 #if defined(__x86_64__)
  90         /* Only provide implemented probes for each architecture  */
  91         LOCKSTAT_PROBE(LS_LCK_MTX_LOCK, LSA_ACQUIRE, LS_LCK_MTX_LOCK_ACQUIRE, "lck_mtx_t"),
  92         LOCKSTAT_PROBE(LS_LCK_MTX_LOCK, LSA_SPIN, LS_LCK_MTX_LOCK_SPIN, "lck_mtx_t", "uint64_t"),
  93         LOCKSTAT_PROBE(LS_LCK_MTX_LOCK, LSA_BLOCK, LS_LCK_MTX_LOCK_BLOCK, "lck_mtx_t", "uint64_t"),
  94         LOCKSTAT_PROBE(LS_LCK_MTX_TRY_LOCK, LSA_ACQUIRE, LS_LCK_MTX_TRY_LOCK_ACQUIRE, "lck_mtx_t"),
  95         LOCKSTAT_PROBE(LS_LCK_MTX_TRY_SPIN_LOCK, LSA_ACQUIRE, LS_LCK_MTX_TRY_SPIN_LOCK_ACQUIRE, "lck_mtx_t"),
  96         LOCKSTAT_PROBE(LS_LCK_MTX_UNLOCK, LSA_RELEASE, LS_LCK_MTX_UNLOCK_RELEASE, "lck_mtx_t"),
  97         LOCKSTAT_PROBE(LS_LCK_MTX_EXT_LOCK, LSA_ACQUIRE, LS_LCK_MTX_EXT_LOCK_ACQUIRE, "lck_mtx_t"),
  98         LOCKSTAT_PROBE(LS_LCK_MTX_EXT_LOCK, LSA_SPIN, LS_LCK_MTX_EXT_LOCK_SPIN, "lck_mtx_t", "uint64_t"),
  99         LOCKSTAT_PROBE(LS_LCK_MTX_EXT_LOCK, LSA_BLOCK, LS_LCK_MTX_EXT_LOCK_BLOCK, "lck_mtx_t", "uint64_t"),
 100 //      LOCKSTAT_PROBE(LS_LCK_MTX_EXT_TRY_LOCK, LSA_ACQUIRE, LS_LCK_MTX_TRY_EXT_LOCK_ACQUIRE)
 101         LOCKSTAT_PROBE(LS_LCK_MTX_EXT_UNLOCK, LSA_RELEASE, LS_LCK_MTX_EXT_UNLOCK_RELEASE, "lck_mtx_t"),
 102         LOCKSTAT_PROBE(LS_LCK_MTX_LOCK_SPIN_LOCK, LSA_ACQUIRE, LS_LCK_MTX_LOCK_SPIN_ACQUIRE, "lck_mtx_t"),
 103         // TODO: This should not be a uint64_t !
 104         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_SHARED, LSR_ACQUIRE, LS_LCK_RW_LOCK_SHARED_ACQUIRE, "lck_rw_t", "uint64_t"),
 105         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_SHARED, LSR_BLOCK, LS_LCK_RW_LOCK_SHARED_BLOCK, "lck_rw_t", "uint64_t", "_Bool", "_Bool", "int"),
 106         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_SHARED, LSR_SPIN, LS_LCK_RW_LOCK_SHARED_SPIN, "lck_rw_t", "uint64_t", "_Bool", "_Bool", "int"),
 107         // TODO: This should NOT be a uint64_t
 108         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_EXCL, LSR_ACQUIRE, LS_LCK_RW_LOCK_EXCL_ACQUIRE, "lck_rw_t", "uint64_t"),
 109         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_EXCL, LSR_BLOCK, LS_LCK_RW_LOCK_EXCL_BLOCK, "lck_rw_t", "uint64_t", "_Bool", "_Bool", "int"),
 110         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_EXCL, LSR_SPIN, LS_LCK_RW_LOCK_EXCL_SPIN, "lck_rw_t", "uint64_t", "int"),
 111         LOCKSTAT_PROBE(LS_LCK_RW_DONE, LSR_RELEASE, LS_LCK_RW_DONE_RELEASE, "lck_rw_t", "_Bool"),
 112         // TODO : This should NOT be a uint64_t
 113         LOCKSTAT_PROBE(LS_LCK_RW_TRY_LOCK_SHARED, LSR_ACQUIRE, LS_LCK_RW_TRY_LOCK_SHARED_ACQUIRE, "lck_rw_t", "uint64_t"),
 114         // See above
 115         LOCKSTAT_PROBE(LS_LCK_RW_TRY_LOCK_EXCL, LSR_ACQUIRE, LS_LCK_RW_TRY_LOCK_EXCL_ACQUIRE, "lck_rw_t", "uint64_t"),
 116         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_SHARED_TO_EXCL, LSR_UPGRADE, LS_LCK_RW_LOCK_SHARED_TO_EXCL_UPGRADE, "lck_rw_t", "_Bool"),
 117         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_SHARED_TO_EXCL, LSR_SPIN, LS_LCK_RW_LOCK_SHARED_TO_EXCL_SPIN, "lck_rw_t", "uint64_t"),
 118         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_SHARED_TO_EXCL, LSR_BLOCK, LS_LCK_RW_LOCK_SHARED_TO_EXCL_BLOCK, "lck_rw_t", "uint64_t", "_Bool", "_Bool", "int"),
 119         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_EXCL_TO_SHARED, LSR_DOWNGRADE, LS_LCK_RW_LOCK_EXCL_TO_SHARED_DOWNGRADE, "lck_rw_t"),
 120         //TODO : Separate the probes for the hw_bit from the probe for the normal hw locks
 121         LOCKSTAT_PROBE(LS_LCK_SPIN_LOCK, LSS_ACQUIRE, LS_LCK_SPIN_LOCK_ACQUIRE, "hw_lock_t"),
 122         LOCKSTAT_PROBE(LS_LCK_SPIN_LOCK, LSS_SPIN, LS_LCK_SPIN_LOCK_SPIN, "hw_lock_t", "uint64_t", "uint64_t"),
 123         LOCKSTAT_PROBE(LS_LCK_SPIN_UNLOCK, LSS_RELEASE, LS_LCK_SPIN_UNLOCK_RELEASE, "hw_lock_t"),
 124 #elif defined(__arm__) || defined(__arm64__)
 125         LOCKSTAT_PROBE(LS_LCK_MTX_LOCK, LSA_ACQUIRE, LS_LCK_MTX_LOCK_ACQUIRE, "lck_mtx_t"),
 126 //      LOCKSTAT_PROBE(LS_LCK_MTX_LOCK, LSA_SPIN, LS_LCK_MTX_LOCK_SPIN, "lck_mtx_t", "uint64_t"),
 127         LOCKSTAT_PROBE(LS_LCK_MTX_LOCK, LSA_BLOCK, LS_LCK_MTX_LOCK_BLOCK, "lck_mtx_t", "uint64_t"),
 128         LOCKSTAT_PROBE(LS_LCK_MTX_TRY_LOCK, LSA_ACQUIRE, LS_LCK_MTX_TRY_LOCK_ACQUIRE, "lck_mtx_t"),
 129 //      LOCKSTAT_PROBE(LS_LCK_MTX_TRY_SPIN_LOCK, LSA_ACQUIRE, LS_LCK_MTX_TRY_SPIN_LOCK_ACQUIRE, "lck_mtx_t"),
 130         LOCKSTAT_PROBE(LS_LCK_MTX_UNLOCK, LSA_RELEASE, LS_LCK_MTX_UNLOCK_RELEASE, "lck_mtx_t"),
 131         LOCKSTAT_PROBE(LS_LCK_MTX_EXT_LOCK, LSA_ACQUIRE, LS_LCK_MTX_EXT_LOCK_ACQUIRE, "lck_mtx_t"),
 132 //      LOCKSTAT_PROBE(LS_LCK_MTX_EXT_LOCK, LSA_SPIN, LS_LCK_MTX_EXT_LOCK_SPIN, "lck_mtx_t", "uint64_t"),
 133         LOCKSTAT_PROBE(LS_LCK_MTX_EXT_LOCK, LSA_BLOCK, LS_LCK_MTX_EXT_LOCK_BLOCK, "lck_mtx_t", "uint64_t"),
 134 //      LOCKSTAT_PROBE(LS_LCK_MTX_EXT_TRY_LOCK, LSA_ACQUIRE, LS_LCK_MTX_TRY_EXT_LOCK_ACQUIRE)
 135 //      LOCKSTAT_PROBE(LS_LCK_MTX_EXT_UNLOCK, LSA_RELEASE, LS_LCK_MTX_EXT_UNLOCK_RELEASE, "lck_mtx_t"),
 136 //      LOCKSTAT_PROBE(LS_LCK_MTX_LOCK_SPIN_LOCK, LSA_ACQUIRE, LS_LCK_MTX_LOCK_SPIN_ACQUIRE, "lck_mtx_t"),
 137         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_SHARED, LSR_ACQUIRE, LS_LCK_RW_LOCK_SHARED_ACQUIRE, "lck_rw_t", "uint64_t"),
 138         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_SHARED, LSR_BLOCK, LS_LCK_RW_LOCK_SHARED_BLOCK, "lck_rw_t", "uint64_t", "_Bool", "_Bool", "int"),
 139         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_SHARED, LSR_SPIN, LS_LCK_RW_LOCK_SHARED_SPIN, "lck_rw_t", "uint64_t", "_Bool", "_Bool", "int"),
 140         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_EXCL, LSR_ACQUIRE, LS_LCK_RW_LOCK_EXCL_ACQUIRE, "lck_rw_t", "uint64_t"),
 141         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_EXCL, LSR_BLOCK, LS_LCK_RW_LOCK_EXCL_BLOCK, "lck_rw_t", "uint64_t", "_Bool", "_Bool", "int"),
 142         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_EXCL, LSR_SPIN, LS_LCK_RW_LOCK_EXCL_SPIN, "lck_rw_t", "uint64_t", "int"),
 143         LOCKSTAT_PROBE(LS_LCK_RW_DONE, LSR_RELEASE, LS_LCK_RW_DONE_RELEASE, "lck_rw_t", "_Bool"),
 144         // TODO : This should NOT be a uint64_t
 145         LOCKSTAT_PROBE(LS_LCK_RW_TRY_LOCK_SHARED, LSR_ACQUIRE, LS_LCK_RW_TRY_LOCK_SHARED_ACQUIRE, "lck_rw_t", "uint64_t"),
 146         // See above
 147         LOCKSTAT_PROBE(LS_LCK_RW_TRY_LOCK_EXCL, LSR_ACQUIRE, LS_LCK_RW_TRY_LOCK_EXCL_ACQUIRE, "lck_rw_t", "uint64_t"),
 148         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_SHARED_TO_EXCL, LSR_UPGRADE, LS_LCK_RW_LOCK_SHARED_TO_EXCL_UPGRADE, "lck_rw_t", "_Bool"),
 149         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_SHARED_TO_EXCL, LSR_SPIN, LS_LCK_RW_LOCK_SHARED_TO_EXCL_SPIN, "lck_rw_t", "uint64_t"),
 150         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_SHARED_TO_EXCL, LSR_BLOCK, LS_LCK_RW_LOCK_SHARED_TO_EXCL_BLOCK, "lck_rw_t", "uint64_t", "_Bool", "_Bool", "int"),
 151         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_EXCL_TO_SHARED, LSR_DOWNGRADE, LS_LCK_RW_LOCK_EXCL_TO_SHARED_DOWNGRADE, "lck_rw_t"),
 152         //TODO : Separate the probes for the hw_bit from the probe for the normal hw locks
 153         LOCKSTAT_PROBE(LS_LCK_SPIN_LOCK, LSS_ACQUIRE, LS_LCK_SPIN_LOCK_ACQUIRE, "hw_lock_t"),
 154         LOCKSTAT_PROBE(LS_LCK_SPIN_LOCK, LSS_SPIN, LS_LCK_SPIN_LOCK_SPIN, "hw_lock_t", "uint64_t", "uint64_t"),
 155         LOCKSTAT_PROBE(LS_LCK_SPIN_UNLOCK, LSS_RELEASE, LS_LCK_SPIN_UNLOCK_RELEASE, "hw_lock_t"),
 156 #endif
 157         /* Interlock measurements would be nice, but later */
 158
 159 #ifdef  LATER
 160         LOCKSTAT_PROBE(LS_LCK_RW_LOCK_EXCL_TO_SHARED, LSA_ILK_SPIN, LS_LCK_RW_LOCK_EXCL_TO_SHARED_ILK_SPIN),
 161         LOCKSTAT_PROBE(LS_LCK_MTX_LOCK, LSA_ILK_SPIN, LS_LCK_MTX_LOCK_ILK_SPIN),
 162         LOCKSTAT_PROBE(LS_LCK_MTX_EXT_LOCK, LSA_ILK_SPIN, LS_LCK_MTX_EXT_LOCK_ILK_SPIN),
 163         LOCKSTAT_PROBE(LS_LCK_RW_TRY_LOCK_EXCL, LSA_ILK_SPIN, LS_LCK_RW_TRY_LOCK_EXCL_ILK_SPIN),
 164         LOCKSTAT_PROBE(LS_LCK_RW_TRY_LOCK_SHARED, LSA_SPIN, LS_LCK_RW_TRY_LOCK_SHARED_SPIN)
 165 #endif
 166
 167         {
 168                 NULL, NULL, 0, 0, NULL
 169         }
 170 };
 171
 172 dtrace_id_t lockstat_probemap[LS_NPROBES];
 173 void (*lockstat_probe)(dtrace_id_t, uint64_t, uint64_t,
 174     uint64_t, uint64_t, uint64_t);
 175
 176 static dtrace_provider_id_t lockstat_id;
 177
 178 /*ARGSUSED*/
 179 static int
 180 lockstat_enable(void *arg, dtrace_id_t id, void *parg)
 181 {
 182 #pragma unused(arg) /* __APPLE__ */
 183
 184         lockstat_probe_t *probe = parg;
 185
 186         ASSERT(!lockstat_probemap[probe->lsp_probe]);
 187
 188         lockstat_probemap[probe->lsp_probe] = id;
 189         membar_producer();
 190
 191         membar_producer();
 192         return 0;
 193 }
 194
 195 /*ARGSUSED*/
 196 static void
 197 lockstat_disable(void *arg, dtrace_id_t id, void *parg)
 198 {
 199 #pragma unused(arg, id) /* __APPLE__ */
 200
 201         lockstat_probe_t *probe = parg;
 202         int i;
 203
 204         ASSERT(lockstat_probemap[probe->lsp_probe]);
 205
 206         lockstat_probemap[probe->lsp_probe] = 0;
 207         membar_producer();
 208
 209         /*
 210          * See if we have any probes left enabled.
 211          */
 212         for (i = 0; i < LS_NPROBES; i++) {
 213                 if (lockstat_probemap[i]) {
 214                         /*
 215                          * This probe is still enabled.  We don't need to deal
 216                          * with waiting for all threads to be out of the
 217                          * lockstat critical sections; just return.
 218                          */
 219                         return;
 220                 }
 221         }
 222 }
 223
 224 /*ARGSUSED*/
 225 static void
 226 lockstat_provide(void *arg, const dtrace_probedesc_t *desc)
 227 {
 228 #pragma unused(arg, desc) /* __APPLE__ */
 229
 230         int i = 0;
 231
 232         for (i = 0; lockstat_probes[i].lsp_func != NULL; i++) {
 233                 lockstat_probe_t *probe = &lockstat_probes[i];
 234
 235                 if (dtrace_probe_lookup(lockstat_id, "mach_kernel",
 236                     probe->lsp_func, probe->lsp_name) != 0) {
 237                         continue;
 238                 }
 239
 240                 ASSERT(!probe->lsp_id);
 241                 probe->lsp_id = dtrace_probe_create(lockstat_id,
 242                     "mach_kernel", probe->lsp_func, probe->lsp_name,
 243                     LOCKSTAT_AFRAMES, probe);
 244         }
 245 }
 246
 247
 248 /*ARGSUSED*/
 249 static void
 250 lockstat_destroy(void *arg, dtrace_id_t id, void *parg)
 251 {
 252 #pragma unused(arg, id) /* __APPLE__ */
 253
 254         lockstat_probe_t *probe = parg;
 255
 256         ASSERT(!lockstat_probemap[probe->lsp_probe]);
 257         probe->lsp_id = 0;
 258 }
 259
 260 static void
 261 lockstat_getargdesc(void *arg, dtrace_id_t id, void *parg, dtrace_argdesc_t *desc)
 262 {
 263 #pragma unused(arg, id)
 264         lockstat_probe_t *probe = parg;
 265         const char* argdesc = probe->lsp_args;
 266         int narg = 0;
 267
 268         desc->dtargd_native[0] = '\0';
 269         desc->dtargd_xlate[0] = '\0';
 270
 271         while (argdesc[0] != '\0') {
 272                 if (narg == desc->dtargd_ndx) {
 273                         strlcpy(desc->dtargd_native, argdesc, DTRACE_ARGTYPELEN);
 274                         return;
 275                 }
 276                 argdesc += strlen(argdesc) + 1;
 277                 narg++;
 278         }
 279
 280         desc->dtargd_ndx = DTRACE_ARGNONE;
 281 }
 282
 283 static dtrace_pattr_t lockstat_attr = {
 284         { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
 285         { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
 286         { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
 287         { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
 288         { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
 289 };
 290
 291 static dtrace_pops_t lockstat_pops = {
 292         .dtps_provide =         lockstat_provide,
 293         .dtps_provide_module =  NULL,
 294         .dtps_enable =          lockstat_enable,
 295         .dtps_disable =         lockstat_disable,
 296         .dtps_suspend =         NULL,
 297         .dtps_resume =          NULL,
 298         .dtps_getargdesc =      lockstat_getargdesc,
 299         .dtps_getargval =       NULL,
 300         .dtps_usermode =        NULL,
 301         .dtps_destroy =         lockstat_destroy
 302 };
 303
 304 static int
 305 lockstat_attach(dev_info_t *devi)
 306 {
 307         if (ddi_create_minor_node(devi, "lockstat", S_IFCHR, 0,
 308             DDI_PSEUDO, 0) == DDI_FAILURE ||
 309             dtrace_register("lockstat", &lockstat_attr, DTRACE_PRIV_KERNEL,
 310             NULL, &lockstat_pops, NULL, &lockstat_id) != 0) {
 311                 ddi_remove_minor_node(devi, NULL);
 312                 return DDI_FAILURE;
 313         }
 314
 315         lockstat_probe = dtrace_probe;
 316         membar_producer();
 317
 318         return DDI_SUCCESS;
 319 }
 320
 321 d_open_t _lockstat_open;
 322
 323 int
 324 _lockstat_open(dev_t dev, int flags, int devtype, struct proc *p)
 325 {
 326 #pragma unused(dev,flags,devtype,p)
 327         return 0;
 328 }
 329
 330 #define LOCKSTAT_MAJOR  -24 /* let the kernel pick the device number */
 331
 332 /*
 333  * A struct describing which functions will get invoked for certain
 334  * actions.
 335  */
 336 static struct cdevsw lockstat_cdevsw =
 337 {
 338         _lockstat_open,         /* open */
 339         eno_opcl,                       /* close */
 340         eno_rdwrt,                      /* read */
 341         eno_rdwrt,                      /* write */
 342         eno_ioctl,                      /* ioctl */
 343         (stop_fcn_t *)nulldev, /* stop */
 344         (reset_fcn_t *)nulldev, /* reset */
 345         NULL,                           /* tty's */
 346         eno_select,                     /* select */
 347         eno_mmap,                       /* mmap */
 348         eno_strat,                      /* strategy */
 349         eno_getc,                       /* getc */
 350         eno_putc,                       /* putc */
 351         0                                       /* type */
 352 };
 353
 354 void lockstat_init( void );
 355
 356 void
 357 lockstat_init( void )
 358 {
 359         int majdevno = cdevsw_add(LOCKSTAT_MAJOR, &lockstat_cdevsw);
 360
 361         if (majdevno < 0) {
 362                 printf("lockstat_init: failed to allocate a major number!\n");
 363                 return;
 364         }
 365
 366         lockstat_attach((dev_info_t*)(uintptr_t)majdevno);
 367 }
 368 #undef LOCKSTAT_MAJOR