kern_cpu.c revision 1.37
1 /* $NetBSD: kern_cpu.c,v 1.37 2008/10/31 00:36:22 rmind Exp $ */ 2 3 /*- 4 * Copyright (c) 2007, 2008 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /*- 33 * Copyright (c)2007 YAMAMOTO Takashi, 34 * All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 45 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 46 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 47 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 48 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 49 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 50 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 51 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 52 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 53 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 54 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 55 * SUCH DAMAGE. 56 */ 57 58 #include <sys/cdefs.h> 59 __KERNEL_RCSID(0, "$NetBSD: kern_cpu.c,v 1.37 2008/10/31 00:36:22 rmind Exp $"); 60 61 #include <sys/param.h> 62 #include <sys/systm.h> 63 #include <sys/idle.h> 64 #include <sys/sched.h> 65 #include <sys/intr.h> 66 #include <sys/conf.h> 67 #include <sys/cpu.h> 68 #include <sys/cpuio.h> 69 #include <sys/proc.h> 70 #include <sys/percpu.h> 71 #include <sys/kernel.h> 72 #include <sys/kauth.h> 73 #include <sys/xcall.h> 74 #include <sys/pool.h> 75 #include <sys/kmem.h> 76 #include <sys/select.h> 77 #include <sys/namei.h> 78 #include <sys/callout.h> 79 80 #include <uvm/uvm_extern.h> 81 82 void cpuctlattach(int); 83 84 static void cpu_xc_online(struct cpu_info *); 85 static void cpu_xc_offline(struct cpu_info *); 86 87 dev_type_ioctl(cpuctl_ioctl); 88 89 const struct cdevsw cpuctl_cdevsw = { 90 nullopen, nullclose, nullread, nullwrite, cpuctl_ioctl, 91 nullstop, notty, nopoll, nommap, nokqfilter, 92 D_OTHER | D_MPSAFE 93 }; 94 95 kmutex_t cpu_lock; 96 int ncpu; 97 int ncpuonline; 98 bool mp_online; 99 struct cpuqueue cpu_queue = CIRCLEQ_HEAD_INITIALIZER(cpu_queue); 100 101 static struct cpu_info *cpu_infos[MAXCPUS]; 102 103 int 104 mi_cpu_attach(struct cpu_info *ci) 105 { 106 int error; 107 108 ci->ci_index = ncpu; 109 cpu_infos[cpu_index(ci)] = ci; 110 CIRCLEQ_INSERT_TAIL(&cpu_queue, ci, ci_data.cpu_qchain); 111 TAILQ_INIT(&ci->ci_data.cpu_ld_locks); 112 __cpu_simple_lock_init(&ci->ci_data.cpu_ld_lock); 113 114 sched_cpuattach(ci); 115 116 error = create_idle_lwp(ci); 117 if (error != 0) { 118 /* XXX revert sched_cpuattach */ 119 return error; 120 } 121 122 if (ci == curcpu()) 123 ci->ci_data.cpu_onproc = curlwp; 124 else 125 ci->ci_data.cpu_onproc = ci->ci_data.cpu_idlelwp; 126 127 percpu_init_cpu(ci); 128 softint_init(ci); 129 callout_init_cpu(ci); 130 xc_init_cpu(ci); 131 pool_cache_cpu_init(ci); 132 selsysinit(ci); 133 cache_cpu_init(ci); 134 TAILQ_INIT(&ci->ci_data.cpu_biodone); 135 ncpu++; 136 ncpuonline++; 137 138 return 0; 139 } 140 141 void 142 cpuctlattach(int dummy) 143 { 144 145 } 146 147 int 148 cpuctl_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l) 149 { 150 CPU_INFO_ITERATOR cii; 151 cpustate_t *cs; 152 struct cpu_info *ci; 153 int error, i; 154 u_int id; 155 156 error = 0; 157 158 mutex_enter(&cpu_lock); 159 switch (cmd) { 160 case IOC_CPU_SETSTATE: 161 cs = data; 162 error = kauth_authorize_system(l->l_cred, 163 KAUTH_SYSTEM_CPU, KAUTH_REQ_SYSTEM_CPU_SETSTATE, cs, NULL, 164 NULL); 165 if (error != 0) 166 break; 167 if (cs->cs_id >= __arraycount(cpu_infos) || 168 (ci = cpu_lookup(cs->cs_id)) == NULL) { 169 error = ESRCH; 170 break; 171 } 172 if (!cs->cs_intr) { 173 error = EOPNOTSUPP; 174 break; 175 } 176 error = cpu_setstate(ci, cs->cs_online); 177 break; 178 179 case IOC_CPU_GETSTATE: 180 cs = data; 181 id = cs->cs_id; 182 memset(cs, 0, sizeof(*cs)); 183 cs->cs_id = id; 184 if (cs->cs_id >= __arraycount(cpu_infos) || 185 (ci = cpu_lookup(id)) == NULL) { 186 error = ESRCH; 187 break; 188 } 189 if ((ci->ci_schedstate.spc_flags & SPCF_OFFLINE) != 0) 190 cs->cs_online = false; 191 else 192 cs->cs_online = true; 193 cs->cs_intr = true; 194 cs->cs_lastmod = ci->ci_schedstate.spc_lastmod; 195 break; 196 197 case IOC_CPU_MAPID: 198 i = 0; 199 for (CPU_INFO_FOREACH(cii, ci)) { 200 if (i++ == *(int *)data) 201 break; 202 } 203 if (ci == NULL) 204 error = ESRCH; 205 else 206 *(int *)data = ci->ci_cpuid; 207 break; 208 209 case IOC_CPU_GETCOUNT: 210 *(int *)data = ncpu; 211 break; 212 213 default: 214 error = ENOTTY; 215 break; 216 } 217 mutex_exit(&cpu_lock); 218 219 return error; 220 } 221 222 struct cpu_info * 223 cpu_lookup(u_int idx) 224 { 225 struct cpu_info *ci = cpu_infos[idx]; 226 227 KASSERT(idx < __arraycount(cpu_infos)); 228 KASSERT(ci == NULL || cpu_index(ci) == idx); 229 230 return ci; 231 } 232 233 static void 234 cpu_xc_offline(struct cpu_info *ci) 235 { 236 struct schedstate_percpu *spc, *mspc = NULL; 237 struct cpu_info *target_ci; 238 struct lwp *l; 239 CPU_INFO_ITERATOR cii; 240 int s; 241 242 /* 243 * Thread which sent unicast (separate context) is holding 244 * the cpu_lock for us. 245 */ 246 spc = &ci->ci_schedstate; 247 s = splsched(); 248 spc->spc_flags |= SPCF_OFFLINE; 249 splx(s); 250 251 /* Take the first available CPU for the migration */ 252 for (CPU_INFO_FOREACH(cii, target_ci)) { 253 mspc = &target_ci->ci_schedstate; 254 if ((mspc->spc_flags & SPCF_OFFLINE) == 0) 255 break; 256 } 257 KASSERT(target_ci != NULL); 258 259 /* 260 * Migrate all non-bound threads to the other CPU. Note that this 261 * runs from the xcall thread, thus handling of LSONPROC is not needed. 262 */ 263 mutex_enter(proc_lock); 264 LIST_FOREACH(l, &alllwp, l_list) { 265 struct cpu_info *mci; 266 267 lwp_lock(l); 268 if (l->l_cpu != ci || (l->l_pflag & (LP_BOUND | LP_INTR))) { 269 lwp_unlock(l); 270 continue; 271 } 272 /* Normal case - no affinity */ 273 if ((l->l_flag & LW_AFFINITY) == 0) { 274 lwp_migrate(l, target_ci); 275 continue; 276 } 277 /* Affinity is set, find an online CPU in the set */ 278 KASSERT(l->l_affinity != NULL); 279 for (CPU_INFO_FOREACH(cii, mci)) { 280 mspc = &mci->ci_schedstate; 281 if ((mspc->spc_flags & SPCF_OFFLINE) == 0 && 282 kcpuset_isset(cpu_index(mci), l->l_affinity)) 283 break; 284 } 285 if (mci == NULL) { 286 lwp_unlock(l); 287 mutex_exit(proc_lock); 288 goto fail; 289 } 290 lwp_migrate(l, mci); 291 } 292 mutex_exit(proc_lock); 293 294 #ifdef __HAVE_MD_CPU_OFFLINE 295 cpu_offline_md(); 296 #endif 297 return; 298 fail: 299 /* Just unset the SPCF_OFFLINE flag, caller will check */ 300 s = splsched(); 301 spc->spc_flags &= ~SPCF_OFFLINE; 302 splx(s); 303 } 304 305 static void 306 cpu_xc_online(struct cpu_info *ci) 307 { 308 struct schedstate_percpu *spc; 309 int s; 310 311 spc = &ci->ci_schedstate; 312 s = splsched(); 313 spc->spc_flags &= ~SPCF_OFFLINE; 314 splx(s); 315 } 316 317 int 318 cpu_setstate(struct cpu_info *ci, bool online) 319 { 320 struct schedstate_percpu *spc; 321 CPU_INFO_ITERATOR cii; 322 struct cpu_info *ci2; 323 uint64_t where; 324 xcfunc_t func; 325 int nonline; 326 327 spc = &ci->ci_schedstate; 328 329 KASSERT(mutex_owned(&cpu_lock)); 330 331 if (online) { 332 if ((spc->spc_flags & SPCF_OFFLINE) == 0) 333 return 0; 334 func = (xcfunc_t)cpu_xc_online; 335 ncpuonline++; 336 } else { 337 if ((spc->spc_flags & SPCF_OFFLINE) != 0) 338 return 0; 339 nonline = 0; 340 /* 341 * Ensure that at least one CPU within the processor set 342 * stays online. Revisit this later. 343 */ 344 for (CPU_INFO_FOREACH(cii, ci2)) { 345 if ((ci2->ci_schedstate.spc_flags & SPCF_OFFLINE) != 0) 346 continue; 347 if (ci2->ci_schedstate.spc_psid != spc->spc_psid) 348 continue; 349 nonline++; 350 } 351 if (nonline == 1) 352 return EBUSY; 353 func = (xcfunc_t)cpu_xc_offline; 354 ncpuonline--; 355 } 356 357 where = xc_unicast(0, func, ci, NULL, ci); 358 xc_wait(where); 359 if (online) { 360 KASSERT((spc->spc_flags & SPCF_OFFLINE) == 0); 361 } else if ((spc->spc_flags & SPCF_OFFLINE) == 0) { 362 /* If was not set offline, then it is busy */ 363 return EBUSY; 364 } 365 366 spc->spc_lastmod = time_second; 367 return 0; 368 } 369
Indexes created Sun Sep 21 20:09:37 GMT 2025