usr/src/uts/common/os/unix_bb.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, 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 (c) 1997 by Sun Microsystems, Inc.
  24  * All rights reserved.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 /*
  30  * Kernel Basic Block Profiling - profiling initialization hooks
  31  */
  32
  33 #include <sys/param.h>
  34 #include <sys/types.h>
  35 #include <sys/t_lock.h>
  36 #include <sys/cpuvar.h>
  37 #include <sys/systm.h>
  38 #include <sys/spl.h>
  39 #include <sys/unix_bb_info.h>
  40
  41 #ifdef KCOV
  42
  43 /*
  44  * routines to do kernel basic block coverage.
  45  */
  46
  47 struct bb_info  *unix_bb_list;
  48 lock_t          unix_bb_lock;
  49
  50 /*
  51  *  There is the potential that we will be called by any C routine.
  52  *  So we avoid calling any C routines from here, as we'll get
  53  *  a recursive call.
  54  *  Also, we wish to avoid a deadlock due to being called by
  55  *  an interrupt handler, so we lock at the NMI level.
  56  *  Of course, that leaves the possibility that we'll
  57  *  be called from an NMI handler.  If the lock is available,
  58  *  fine, otherwise, if we're on the interrupt stack at the
  59  *  NMI level, we just return.
  60  *
  61  *  We will probably get another chance to add the bb_info structure
  62  *  to the list, since the bb_info structure is for the entire object file.
  63  */
  64 #ifdef  KCOV_TEST
  65 int             unix_bb_a, unix_bb_b, unix_bb_c;
  66 int             unix_bb_d, unix_bb_e, unix_bb_f, unix_bb_g;
  67 processorid_t   bb_last_who;
  68 char            *bb_last_where;
  69 #endif
  70
  71 void
  72 __bb_init_func(struct bb_info *bb)
  73 {
  74         u_short s;
  75
  76 /*
  77  *      a = c + g
  78  *      b = c + d
  79  *      a = c + e
  80  *      e = g
  81  *
  82  *      a->b->c
  83  *      a->b->d->e->g
  84  *      a->b->d->e->f->g
  85  *      a->e->g
  86  *      a->e->f->g
  87  */
  88
  89         /*
  90          *  Raise the pil and try to get the lock.
  91          */
  92         s = spl8();
  93 #ifdef  KCOV_TEST
  94         unix_bb_a++;
  95 #endif
  96
  97         if (!lock_try(&unix_bb_lock)) {
  98                 /*
  99                  *  If we're on the interrrupt stack, we just return
 100                  *  in case it's an NMI and we're looking at a deadlock
 101                  *  situation.  Otherwise, we use lock_set_spl()
 102                  */
 103 #ifdef  KCOV_TEST
 104                 unix_bb_b++;
 105 #endif
 106                 if (CPU_ON_INTR(CPU)) {
 107 #ifdef  KCOV_TEST
 108                         unix_bb_c++;
 109 #endif
 110                         splx(s);
 111                         return;
 112                 }
 113 #ifdef  KCOV_TEST
 114                 unix_bb_d++;
 115 #endif
 116                 splx(s);
 117                 lock_set_spl(&unix_bb_lock, ipltospl(NMI_LEVEL), &s);
 118         }
 119
 120 #ifdef  KCOV_TEST
 121         bb_last_who = CPU->cpu_id;
 122         bb_last_where = bb->bb_filename;
 123         unix_bb_e++;
 124 #endif
 125         /*
 126          *  We've got the lock.  If we have not been initialized, add us
 127          *  to the list and set the initialized flag.
 128          */
 129 #ifdef  KCOV_TEST
 130         if (bb->bb_next == 0) {
 131                 unix_bb_f++;
 132 #else
 133         if (bb->bb_initflag == 0) {
 134                 bb->bb_initflag = 1;
 135 #endif
 136                 bb->bb_next = unix_bb_list;
 137                 unix_bb_list = bb;
 138         }
 139
 140 #ifdef  KCOV_TEST
 141         unix_bb_g++;
 142 #endif
 143         lock_clear_splx(&unix_bb_lock, s);
 144 }
 145 #endif /* KCOV */