kern_cpu.c revision 1.12
1 /* $NetBSD: kern_cpu.c,v 1.12 2007/11/05 03:36:14 rmind Exp $ */ 2 3 /*- 4 * Copyright (c) 2007 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Andrew Doran. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /*- 40 * Copyright (c)2007 YAMAMOTO Takashi, 41 * All rights reserved. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 52 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 53 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 55 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 56 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 57 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 58 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 59 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 60 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 62 * SUCH DAMAGE. 63 */ 64 65 #include <sys/cdefs.h> 66 67 __KERNEL_RCSID(0, "$NetBSD: kern_cpu.c,v 1.12 2007/11/05 03:36:14 rmind Exp $"); 68 69 #include <sys/param.h> 70 #include <sys/systm.h> 71 #include <sys/idle.h> 72 #include <sys/sched.h> 73 #include <sys/intr.h> 74 #include <sys/conf.h> 75 #include <sys/cpu.h> 76 #include <sys/cpuio.h> 77 #include <sys/proc.h> 78 #include <sys/kernel.h> 79 #include <sys/kauth.h> 80 #include <sys/xcall.h> 81 #include <sys/pool.h> 82 83 #include <uvm/uvm_extern.h> 84 85 void cpuctlattach(int); 86 87 static void cpu_xc_online(struct cpu_info *); 88 static void cpu_xc_offline(struct cpu_info *); 89 90 dev_type_ioctl(cpuctl_ioctl); 91 92 const struct cdevsw cpuctl_cdevsw = { 93 nullopen, nullclose, nullread, nullwrite, cpuctl_ioctl, 94 nullstop, notty, nopoll, nommap, nokqfilter, 95 D_OTHER | D_MPSAFE 96 }; 97 98 kmutex_t cpu_lock; 99 int ncpu; 100 int ncpuonline; 101 102 int 103 mi_cpu_attach(struct cpu_info *ci) 104 { 105 struct schedstate_percpu *spc = &ci->ci_schedstate; 106 int error; 107 108 ci->ci_index = ncpu; 109 110 mutex_init(&spc->spc_lwplock, MUTEX_SPIN, IPL_SCHED); 111 sched_cpuattach(ci); 112 uvm_cpu_attach(ci); 113 114 error = create_idle_lwp(ci); 115 if (error != 0) { 116 /* XXX revert sched_cpuattach */ 117 return error; 118 } 119 120 softint_init(ci); 121 xc_init_cpu(ci); 122 TAILQ_INIT(&ci->ci_data.cpu_biodone); 123 ncpu++; 124 ncpuonline++; 125 126 return 0; 127 } 128 129 void 130 cpuctlattach(int dummy) 131 { 132 133 } 134 135 int 136 cpuctl_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l) 137 { 138 CPU_INFO_ITERATOR cii; 139 cpustate_t *cs; 140 struct cpu_info *ci; 141 int error, i; 142 u_int id; 143 144 error = 0; 145 146 mutex_enter(&cpu_lock); 147 switch (cmd) { 148 case IOC_CPU_SETSTATE: 149 error = kauth_authorize_generic(l->l_cred, 150 KAUTH_GENERIC_ISSUSER, NULL); 151 if (error != 0) 152 break; 153 cs = data; 154 if ((ci = cpu_lookup(cs->cs_id)) == NULL) { 155 error = ESRCH; 156 break; 157 } 158 if (!cs->cs_intr) { 159 error = EOPNOTSUPP; 160 break; 161 } 162 error = cpu_setonline(ci, cs->cs_online); 163 break; 164 165 case IOC_CPU_GETSTATE: 166 cs = data; 167 id = cs->cs_id; 168 memset(cs, 0, sizeof(*cs)); 169 cs->cs_id = id; 170 if ((ci = cpu_lookup(id)) == NULL) { 171 error = ESRCH; 172 break; 173 } 174 if ((ci->ci_schedstate.spc_flags & SPCF_OFFLINE) != 0) 175 cs->cs_online = false; 176 else 177 cs->cs_online = true; 178 cs->cs_intr = true; 179 cs->cs_lastmod = ci->ci_schedstate.spc_lastmod; 180 break; 181 182 case IOC_CPU_MAPID: 183 i = 0; 184 for (CPU_INFO_FOREACH(cii, ci)) { 185 if (i++ == *(int *)data) 186 break; 187 } 188 if (ci == NULL) 189 error = ESRCH; 190 else 191 *(int *)data = ci->ci_cpuid; 192 break; 193 194 case IOC_CPU_GETCOUNT: 195 *(int *)data = ncpu; 196 break; 197 198 default: 199 error = ENOTTY; 200 break; 201 } 202 mutex_exit(&cpu_lock); 203 204 return error; 205 } 206 207 struct cpu_info * 208 cpu_lookup(cpuid_t id) 209 { 210 CPU_INFO_ITERATOR cii; 211 struct cpu_info *ci; 212 213 for (CPU_INFO_FOREACH(cii, ci)) { 214 if (ci->ci_cpuid == id) 215 return ci; 216 } 217 218 return NULL; 219 } 220 221 static void 222 cpu_xc_offline(struct cpu_info *ci) 223 { 224 struct schedstate_percpu *spc, *mspc = NULL; 225 struct cpu_info *mci; 226 struct lwp *l; 227 CPU_INFO_ITERATOR cii; 228 int s; 229 230 spc = &ci->ci_schedstate; 231 s = splsched(); 232 spc->spc_flags |= SPCF_OFFLINE; 233 splx(s); 234 235 /* Take the first available CPU for the migration */ 236 for (CPU_INFO_FOREACH(cii, mci)) { 237 mspc = &mci->ci_schedstate; 238 if ((mspc->spc_flags & SPCF_OFFLINE) == 0) 239 break; 240 } 241 KASSERT(mci != NULL); 242 243 /* 244 * Migrate all non-bound threads to the other CPU. 245 * Please note, that this runs from the xcall thread, thus handling 246 * of LSONPROC is not needed. 247 */ 248 mutex_enter(&proclist_lock); 249 250 /* 251 * Note that threads on the runqueue might sleep after this, but 252 * sched_takecpu() would migrate such threads to the appropriate CPU. 253 */ 254 LIST_FOREACH(l, &alllwp, l_list) { 255 lwp_lock(l); 256 if (l->l_cpu == ci && (l->l_stat == LSSLEEP || 257 l->l_stat == LSSTOP || l->l_stat == LSSUSPENDED)) { 258 KASSERT((l->l_flag & LW_RUNNING) == 0); 259 l->l_cpu = mci; 260 } 261 lwp_unlock(l); 262 } 263 264 /* 265 * Runqueues are locked with the global lock if pointers match, 266 * thus hold only one. Otherwise, double-lock the runqueues. 267 */ 268 if (spc->spc_mutex == mspc->spc_mutex) { 269 spc_lock(ci); 270 } else if (ci < mci) { 271 spc_lock(ci); 272 spc_lock(mci); 273 } else { 274 spc_lock(mci); 275 spc_lock(ci); 276 } 277 278 /* Handle LSRUN and LSIDL cases */ 279 LIST_FOREACH(l, &alllwp, l_list) { 280 if (l->l_cpu != ci || (l->l_flag & LW_BOUND)) 281 continue; 282 if (l->l_stat == LSRUN && (l->l_flag & LW_INMEM) != 0) { 283 sched_dequeue(l); 284 l->l_cpu = mci; 285 lwp_setlock(l, mspc->spc_mutex); 286 sched_enqueue(l, false); 287 } else if (l->l_stat == LSRUN || l->l_stat == LSIDL) { 288 l->l_cpu = mci; 289 lwp_setlock(l, mspc->spc_mutex); 290 } 291 } 292 if (spc->spc_mutex == mspc->spc_mutex) { 293 spc_unlock(ci); 294 } else { 295 spc_unlock(ci); 296 spc_unlock(mci); 297 } 298 299 mutex_exit(&proclist_lock); 300 } 301 302 static void 303 cpu_xc_online(struct cpu_info *ci) 304 { 305 struct schedstate_percpu *spc; 306 int s; 307 308 spc = &ci->ci_schedstate; 309 s = splsched(); 310 spc->spc_flags &= ~SPCF_OFFLINE; 311 splx(s); 312 } 313 314 int 315 cpu_setonline(struct cpu_info *ci, bool online) 316 { 317 struct schedstate_percpu *spc; 318 CPU_INFO_ITERATOR cii; 319 struct cpu_info *ci2; 320 uint64_t where; 321 xcfunc_t func; 322 int nonline; 323 324 spc = &ci->ci_schedstate; 325 326 KASSERT(mutex_owned(&cpu_lock)); 327 328 if (online) { 329 if ((spc->spc_flags & SPCF_OFFLINE) == 0) 330 return 0; 331 func = (xcfunc_t)cpu_xc_online; 332 ncpuonline++; 333 } else { 334 if ((spc->spc_flags & SPCF_OFFLINE) != 0) 335 return 0; 336 nonline = 0; 337 for (CPU_INFO_FOREACH(cii, ci2)) { 338 nonline += ((ci2->ci_schedstate.spc_flags & 339 SPCF_OFFLINE) == 0); 340 } 341 if (nonline == 1) 342 return EBUSY; 343 func = (xcfunc_t)cpu_xc_offline; 344 ncpuonline--; 345 } 346 347 where = xc_unicast(0, func, ci, NULL, ci); 348 xc_wait(where); 349 if (online) { 350 KASSERT((spc->spc_flags & SPCF_OFFLINE) == 0); 351 } else { 352 KASSERT(spc->spc_flags & SPCF_OFFLINE); 353 } 354 spc->spc_lastmod = time_second; 355 356 return 0; 357 } 358
Indexes created Tue Sep 23 02:09:52 GMT 2025