kern_cpu.c revision 1.16
1 /* $NetBSD: kern_cpu.c,v 1.16 2007/12/22 03:26:34 yamt 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 1.16 2007/12/22 03:26:34 yamt 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 static struct cpu_info *cpu_infos[MAXCPUS]; 103 104 int 105 mi_cpu_attach(struct cpu_info *ci) 106 { 107 struct schedstate_percpu *spc = &ci->ci_schedstate; 108 int error; 109 110 ci->ci_index = ncpu; 111 112 mutex_init(&spc->spc_lwplock, MUTEX_DEFAULT, IPL_SCHED); 113 sched_cpuattach(ci); 114 uvm_cpu_attach(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 softint_init(ci); 128 xc_init_cpu(ci); 129 pool_cache_cpu_init(ci); 130 TAILQ_INIT(&ci->ci_data.cpu_biodone); 131 ncpu++; 132 ncpuonline++; 133 cpu_infos[cpu_index(ci)] = ci; 134 135 return 0; 136 } 137 138 void 139 cpuctlattach(int dummy) 140 { 141 142 } 143 144 int 145 cpuctl_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l) 146 { 147 CPU_INFO_ITERATOR cii; 148 cpustate_t *cs; 149 struct cpu_info *ci; 150 int error, i; 151 u_int id; 152 153 error = 0; 154 155 mutex_enter(&cpu_lock); 156 switch (cmd) { 157 case IOC_CPU_SETSTATE: 158 error = kauth_authorize_generic(l->l_cred, 159 KAUTH_GENERIC_ISSUSER, NULL); 160 if (error != 0) 161 break; 162 cs = data; 163 if ((ci = cpu_lookup(cs->cs_id)) == NULL) { 164 error = ESRCH; 165 break; 166 } 167 if (!cs->cs_intr) { 168 error = EOPNOTSUPP; 169 break; 170 } 171 error = cpu_setonline(ci, cs->cs_online); 172 break; 173 174 case IOC_CPU_GETSTATE: 175 cs = data; 176 id = cs->cs_id; 177 memset(cs, 0, sizeof(*cs)); 178 cs->cs_id = id; 179 if ((ci = cpu_lookup(id)) == NULL) { 180 error = ESRCH; 181 break; 182 } 183 if ((ci->ci_schedstate.spc_flags & SPCF_OFFLINE) != 0) 184 cs->cs_online = false; 185 else 186 cs->cs_online = true; 187 cs->cs_intr = true; 188 cs->cs_lastmod = ci->ci_schedstate.spc_lastmod; 189 break; 190 191 case IOC_CPU_MAPID: 192 i = 0; 193 for (CPU_INFO_FOREACH(cii, ci)) { 194 if (i++ == *(int *)data) 195 break; 196 } 197 if (ci == NULL) 198 error = ESRCH; 199 else 200 *(int *)data = ci->ci_cpuid; 201 break; 202 203 case IOC_CPU_GETCOUNT: 204 *(int *)data = ncpu; 205 break; 206 207 default: 208 error = ENOTTY; 209 break; 210 } 211 mutex_exit(&cpu_lock); 212 213 return error; 214 } 215 216 struct cpu_info * 217 cpu_lookup(cpuid_t id) 218 { 219 CPU_INFO_ITERATOR cii; 220 struct cpu_info *ci; 221 222 for (CPU_INFO_FOREACH(cii, ci)) { 223 if (ci->ci_cpuid == id) 224 return ci; 225 } 226 227 return NULL; 228 } 229 230 struct cpu_info * 231 cpu_lookup_byindex(u_int idx) 232 { 233 struct cpu_info *ci = cpu_infos[idx]; 234 235 KASSERT(idx < MAXCPUS); 236 KASSERT(ci == NULL || cpu_index(ci) == idx); 237 238 return ci; 239 } 240 241 static void 242 cpu_xc_offline(struct cpu_info *ci) 243 { 244 struct schedstate_percpu *spc, *mspc = NULL; 245 struct cpu_info *mci; 246 struct lwp *l; 247 CPU_INFO_ITERATOR cii; 248 int s; 249 250 spc = &ci->ci_schedstate; 251 s = splsched(); 252 spc->spc_flags |= SPCF_OFFLINE; 253 splx(s); 254 255 /* Take the first available CPU for the migration */ 256 for (CPU_INFO_FOREACH(cii, mci)) { 257 mspc = &mci->ci_schedstate; 258 if ((mspc->spc_flags & SPCF_OFFLINE) == 0) 259 break; 260 } 261 KASSERT(mci != NULL); 262 263 /* 264 * Migrate all non-bound threads to the other CPU. 265 * Please note, that this runs from the xcall thread, thus handling 266 * of LSONPROC is not needed. 267 */ 268 mutex_enter(&proclist_lock); 269 270 /* 271 * Note that threads on the runqueue might sleep after this, but 272 * sched_takecpu() would migrate such threads to the appropriate CPU. 273 */ 274 LIST_FOREACH(l, &alllwp, l_list) { 275 lwp_lock(l); 276 if (l->l_cpu == ci && (l->l_stat == LSSLEEP || 277 l->l_stat == LSSTOP || l->l_stat == LSSUSPENDED)) { 278 KASSERT((l->l_flag & LW_RUNNING) == 0); 279 l->l_cpu = mci; 280 } 281 lwp_unlock(l); 282 } 283 284 /* 285 * Runqueues are locked with the global lock if pointers match, 286 * thus hold only one. Otherwise, double-lock the runqueues. 287 */ 288 if (spc->spc_mutex == mspc->spc_mutex) { 289 spc_lock(ci); 290 } else if (ci < mci) { 291 spc_lock(ci); 292 spc_lock(mci); 293 } else { 294 spc_lock(mci); 295 spc_lock(ci); 296 } 297 298 /* Handle LSRUN and LSIDL cases */ 299 LIST_FOREACH(l, &alllwp, l_list) { 300 if (l->l_cpu != ci || (l->l_flag & LW_BOUND)) 301 continue; 302 if (l->l_stat == LSRUN && (l->l_flag & LW_INMEM) != 0) { 303 sched_dequeue(l); 304 l->l_cpu = mci; 305 lwp_setlock(l, mspc->spc_mutex); 306 sched_enqueue(l, false); 307 } else if (l->l_stat == LSRUN || l->l_stat == LSIDL) { 308 l->l_cpu = mci; 309 lwp_setlock(l, mspc->spc_mutex); 310 } 311 } 312 if (spc->spc_mutex == mspc->spc_mutex) { 313 spc_unlock(ci); 314 } else { 315 spc_unlock(ci); 316 spc_unlock(mci); 317 } 318 319 mutex_exit(&proclist_lock); 320 } 321 322 static void 323 cpu_xc_online(struct cpu_info *ci) 324 { 325 struct schedstate_percpu *spc; 326 int s; 327 328 spc = &ci->ci_schedstate; 329 s = splsched(); 330 spc->spc_flags &= ~SPCF_OFFLINE; 331 splx(s); 332 } 333 334 int 335 cpu_setonline(struct cpu_info *ci, bool online) 336 { 337 struct schedstate_percpu *spc; 338 CPU_INFO_ITERATOR cii; 339 struct cpu_info *ci2; 340 uint64_t where; 341 xcfunc_t func; 342 int nonline; 343 344 spc = &ci->ci_schedstate; 345 346 KASSERT(mutex_owned(&cpu_lock)); 347 348 if (online) { 349 if ((spc->spc_flags & SPCF_OFFLINE) == 0) 350 return 0; 351 func = (xcfunc_t)cpu_xc_online; 352 ncpuonline++; 353 } else { 354 if ((spc->spc_flags & SPCF_OFFLINE) != 0) 355 return 0; 356 nonline = 0; 357 for (CPU_INFO_FOREACH(cii, ci2)) { 358 nonline += ((ci2->ci_schedstate.spc_flags & 359 SPCF_OFFLINE) == 0); 360 } 361 if (nonline == 1) 362 return EBUSY; 363 func = (xcfunc_t)cpu_xc_offline; 364 ncpuonline--; 365 } 366 367 where = xc_unicast(0, func, ci, NULL, ci); 368 xc_wait(where); 369 if (online) { 370 KASSERT((spc->spc_flags & SPCF_OFFLINE) == 0); 371 } else { 372 KASSERT(spc->spc_flags & SPCF_OFFLINE); 373 } 374 spc->spc_lastmod = time_second; 375 376 return 0; 377 } 378
Indexes created Wed Sep 24 14:09:57 GMT 2025