kernel/disp/sysclass.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 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #include <sys/types.h>
  31 #include <sys/param.h>
  32 #include <sys/sysmacros.h>
  33 #include <sys/signal.h>
  34 #include <sys/pcb.h>
  35 #include <sys/user.h>
  36 #include <sys/systm.h>
  37 #include <sys/sysinfo.h>
  38 #include <sys/var.h>
  39 #include <sys/errno.h>
  40 #include <sys/cmn_err.h>
  41 #include <sys/proc.h>
  42 #include <sys/debug.h>
  43 #include <sys/inline.h>
  44 #include <sys/disp.h>
  45 #include <sys/class.h>
  46 #include <sys/kmem.h>
  47 #include <sys/cpuvar.h>
  48 #include <sys/priocntl.h>
  49
  50 /*
  51  * Class specific code for the sys class. There are no
  52  * class specific data structures associated with
  53  * the sys class and the scheduling policy is trivially
  54  * simple. There is no time slicing.
  55  */
  56
  57 pri_t           sys_init(id_t, int, classfuncs_t **);
  58 static int      sys_getclpri(pcpri_t *);
  59 static int      sys_fork(kthread_t *, kthread_t *, void *);
  60 static int      sys_enterclass(kthread_t *, id_t, void *, cred_t *, void *);
  61 static int      sys_canexit(kthread_t *, cred_t *);
  62 static int      sys_nosys();
  63 static int      sys_donice(kthread_t *, cred_t *, int, int *);
  64 static int      sys_doprio(kthread_t *, cred_t *, int, int *);
  65 static void     sys_forkret(kthread_t *, kthread_t *);
  66 static void     sys_nullsys();
  67 static int      sys_alloc(void **, int);
  68
  69 struct classfuncs sys_classfuncs = {
  70         /* messages to class manager */
  71         {
  72                 sys_nosys,      /* admin */
  73                 sys_nosys,      /* getclinfo */
  74                 sys_nosys,      /* parmsin */
  75                 sys_nosys,      /* parmsout */
  76                 sys_nosys,      /* vaparmsin */
  77                 sys_nosys,      /* vaparmsout */
  78                 sys_getclpri,   /* getclpri */
  79                 sys_alloc,
  80                 sys_nullsys,    /* free */
  81         },
  82         /* operations on threads */
  83         {
  84                 sys_enterclass, /* enterclass */
  85                 sys_nullsys,    /* exitclass */
  86                 sys_canexit,
  87                 sys_fork,
  88                 sys_forkret,    /* forkret */
  89                 sys_nullsys,    /* parmsget */
  90                 sys_nosys,      /* parmsset */
  91                 sys_nullsys,    /* stop */
  92                 sys_nullsys,    /* exit */
  93                 sys_nullsys,    /* active */
  94                 sys_nullsys,    /* inactive */
  95                 sys_nullsys,    /* trapret */
  96                 setfrontdq,     /* preempt */
  97                 setbackdq,      /* setrun */
  98                 sys_nullsys,    /* sleep */
  99                 sys_nullsys,    /* tick */
 100                 setbackdq,      /* wakeup */
 101                 sys_donice,
 102                 (pri_t (*)())sys_nosys, /* globpri */
 103                 sys_nullsys,    /* set_process_group */
 104                 sys_nullsys,    /* yield */
 105                 sys_doprio,
 106         }
 107
 108 };
 109
 110
 111 /* ARGSUSED */
 112 pri_t
 113 sys_init(cid, clparmsz, clfuncspp)
 114         id_t            cid;
 115         int             clparmsz;
 116         classfuncs_t    **clfuncspp;
 117 {
 118         *clfuncspp = &sys_classfuncs;
 119         return ((pri_t)v.v_maxsyspri);
 120 }
 121
 122 /*
 123  * Get maximum and minimum priorities enjoyed by sysclass threads
 124  */
 125 static int
 126 sys_getclpri(pcpri_t *pcprip)
 127 {
 128         pcprip->pc_clpmax = maxclsyspri;
 129         pcprip->pc_clpmin = minclsyspri;
 130         return (0);
 131 }
 132
 133 /* ARGSUSED */
 134 static int
 135 sys_enterclass(t, cid, parmsp, reqpcredp, bufp)
 136         kthread_t       *t;
 137         id_t            cid;
 138         void            *parmsp;
 139         cred_t          *reqpcredp;
 140         void            *bufp;
 141 {
 142         return (0);
 143 }
 144
 145 /* ARGSUSED */
 146 static int
 147 sys_canexit(kthread_t *t, cred_t *reqpcredp)
 148 {
 149         return (0);
 150 }
 151
 152 /* ARGSUSED */
 153 static int
 154 sys_fork(t, ct, bufp)
 155         kthread_t *t;
 156         kthread_t *ct;
 157         void    *bufp;
 158 {
 159         /*
 160          * No class specific data structure
 161          */
 162         return (0);
 163 }
 164
 165
 166 /* ARGSUSED */
 167 static void
 168 sys_forkret(t, ct)
 169         kthread_t *t;
 170         kthread_t *ct;
 171 {
 172         register proc_t *pp = ttoproc(t);
 173         register proc_t *cp = ttoproc(ct);
 174
 175         ASSERT(t == curthread);
 176         ASSERT(MUTEX_HELD(&pidlock));
 177
 178         /*
 179          * Grab the child's p_lock before dropping pidlock to ensure
 180          * the process does not disappear before we set it running.
 181          */
 182         mutex_enter(&cp->p_lock);
 183         mutex_exit(&pidlock);
 184         continuelwps(cp);
 185         mutex_exit(&cp->p_lock);
 186
 187         mutex_enter(&pp->p_lock);
 188         continuelwps(pp);
 189         mutex_exit(&pp->p_lock);
 190 }
 191
 192 static int
 193 sys_nosys()
 194 {
 195         return (ENOSYS);
 196 }
 197
 198
 199 static void
 200 sys_nullsys()
 201 {
 202 }
 203
 204 /* ARGSUSED */
 205 static int
 206 sys_donice(kthread_t *t, cred_t *cr, int incr, int *retvalp)
 207 {
 208         return (EINVAL);
 209 }
 210
 211 /* ARGSUSED */
 212 static int
 213 sys_doprio(kthread_t *t, cred_t *cr, int incr, int *retvalp)
 214 {
 215         return (EINVAL);
 216 }
 217
 218 /* ARGSUSED */
 219 static int
 220 sys_alloc(void **p, int flag)
 221 {
 222         *p = NULL;
 223         return (0);
 224 }