kernel/syscall/p_online.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 2004 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #include <sys/types.h>
  27 #include <sys/param.h>
  28 #include <sys/var.h>
  29 #include <sys/thread.h>
  30 #include <sys/cpuvar.h>
  31 #include <sys/kstat.h>
  32 #include <sys/uadmin.h>
  33 #include <sys/systm.h>
  34 #include <sys/errno.h>
  35 #include <sys/cmn_err.h>
  36 #include <sys/procset.h>
  37 #include <sys/processor.h>
  38 #include <sys/debug.h>
  39 #include <sys/policy.h>
  40
  41 /*
  42  * CPU state diagram
  43  *
  44  *                   P_SPARE
  45  * P_POWEROFF <---> P_OFFLINE <---> P_ONLINE <---> P_NOINTR
  46  *                  P_FAULTED
  47  */
  48 int
  49 p_online_internal_locked(processorid_t cpun, int new_status, int *old_status)
  50 {
  51         cpu_t   *cp;
  52         int     status;
  53         int     error = 0;
  54         int     flags = 0;
  55
  56         /*
  57          * Try to get a pointer to the requested CPU structure.
  58          */
  59         ASSERT(MUTEX_HELD(&cpu_lock));
  60         if ((cp = cpu_get(cpun)) == NULL) {
  61                 error = EINVAL;
  62                 goto out;
  63         }
  64
  65         if (new_status & P_FORCED)
  66                 flags = CPU_FORCED;
  67         *old_status = status = cpu_get_state(cp); /* get processor status */
  68         new_status &= ~P_FORCED;
  69
  70         /*
  71          * Perform credentials check.
  72          */
  73         switch (new_status) {
  74         case P_STATUS:
  75                 goto out;
  76         case P_ONLINE:
  77         case P_OFFLINE:
  78         case P_NOINTR:
  79         case P_FAULTED:
  80         case P_SPARE:
  81                 if (secpolicy_ponline(CRED()) != 0)
  82                         error = EPERM;
  83                 break;
  84         default:
  85                 error = EINVAL;
  86         }
  87
  88         if (error)
  89                 goto out;
  90
  91         /*
  92          * return 0 if the CPU is already in the desired new state.
  93          */
  94         if (status == new_status)
  95                 goto out;
  96
  97         switch (new_status) {
  98         case P_ONLINE:
  99                 switch (status) {
 100                 case P_POWEROFF:
 101                         /*
 102                          * If CPU is powered off, power it on.
 103                          */
 104                         if (error = cpu_poweron(cp))
 105                                 break;
 106                         ASSERT(cpu_get_state(cp) == P_OFFLINE);
 107                         /* FALLTHROUGH */
 108                 case P_OFFLINE:
 109                 case P_FAULTED:
 110                 case P_SPARE:
 111                         /*
 112                          * If CPU is in one of the offline states,
 113                          * bring it online.
 114                          */
 115                         error = cpu_online(cp);
 116                         break;
 117                 case P_NOINTR:
 118                         cpu_intr_enable(cp);
 119                         break;
 120                 }
 121                 break;
 122
 123         case P_OFFLINE:
 124                 switch (status) {
 125                 case P_NOINTR:
 126                         /*
 127                          * Before we take the CPU offline, we first enable I/O
 128                          * interrupts.
 129                          */
 130                         cpu_intr_enable(cp);
 131                         /* FALLTHROUGH */
 132                 case P_ONLINE:
 133                 case P_FAULTED:
 134                 case P_SPARE:
 135                         /*
 136                          * CPU is online, or in a special offline state.
 137                          * Take it offline.
 138                          */
 139                         error = cpu_offline(cp, flags);
 140                         break;
 141                 case P_POWEROFF:
 142                         /*
 143                          * If CPU is powered off, power it on.
 144                          */
 145                         error = cpu_poweron(cp);
 146                 }
 147                 break;
 148
 149         case P_NOINTR:
 150                 switch (status) {
 151                 case P_POWEROFF:
 152                         /*
 153                          * if CPU is powered off, power it on.
 154                          */
 155                         if (error = cpu_poweron(cp))
 156                                 break;
 157                         ASSERT(cpu_get_state(cp) == P_OFFLINE);
 158                         /* FALLTHROUGH */
 159                 case P_OFFLINE:
 160                 case P_FAULTED:
 161                 case P_SPARE:
 162                         /*
 163                          * First, bring the CPU online.
 164                          */
 165                         if (error = cpu_online(cp))
 166                                 break;
 167                         /* FALLTHROUGH */
 168                 case P_ONLINE:
 169                         /*
 170                          * CPU is now online.  Try to disable interrupts.
 171                          */
 172                         error = cpu_intr_disable(cp);
 173                 }
 174                 break;
 175
 176         case P_FAULTED:
 177                 switch (status) {
 178                 case P_POWEROFF:
 179                         /*
 180                          * If CPU is powered off, power it on.
 181                          */
 182                         if (error = cpu_poweron(cp))
 183                                 break;
 184                         ASSERT(cpu_get_state(cp) == P_OFFLINE);
 185                         /*FALLTHROUGH*/
 186                 case P_OFFLINE:
 187                 case P_SPARE:
 188                 case P_ONLINE:
 189                 case P_NOINTR:
 190                         /*
 191                          * Mark this CPU as faulted.
 192                          */
 193                         error = cpu_faulted(cp, flags);
 194                 }
 195                 break;
 196
 197         case P_SPARE:
 198                 switch (status) {
 199                 case P_POWEROFF:
 200                         /*
 201                          * If CPU is powered off, power it on.
 202                          */
 203                         if (error = cpu_poweron(cp))
 204                                 break;
 205                         ASSERT(cpu_get_state(cp) == P_OFFLINE);
 206                         /*FALLTHROUGH*/
 207                 case P_OFFLINE:
 208                 case P_FAULTED:
 209                 case P_ONLINE:
 210                 case P_NOINTR:
 211                         /*
 212                          * Mark this CPU as a spare.
 213                          */
 214                         error = cpu_spare(cp, flags);
 215                 }
 216                 break;
 217         }
 218 out:
 219         return (error);
 220 }
 221
 222 int
 223 p_online_internal(processorid_t cpun, int new_status, int *old_status)
 224 {
 225         int rc;
 226
 227         mutex_enter(&cpu_lock);         /* protects CPU states */
 228         rc = p_online_internal_locked(cpun, new_status, old_status);
 229         mutex_exit(&cpu_lock);
 230
 231         return (rc);
 232 }
 233
 234 /*
 235  * p_online(2) - get/change processor operational status.
 236  *
 237  *   As noted in os/cpu.c, the P_ONLINE and other state constants are for use
 238  *   only in this system call path and other paths conveying CPU state to
 239  *   userland.  In general, other kernel consumers should be using the accessor
 240  *   functions in kernel/os/cpu.c.
 241  */
 242 int
 243 p_online(processorid_t cpun, int new_status)
 244 {
 245         int ret;
 246         int old_status;
 247
 248         ret = p_online_internal(cpun, new_status, &old_status);
 249         if (ret != 0)
 250                 return (set_errno(ret));
 251         return (old_status);
 252 }