kern_cpu.c revision 1.51
1 /* $NetBSD: kern_cpu.c,v 1.51 2011/09/11 14:54:49 jdc Exp $ */ 2 3 /*- 4 * Copyright (c) 2007, 2008, 2009, 2010 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 1.51 2011/09/11 14:54:49 jdc 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 /* 83 * If the port has state that cpu_data is the first thing in cpu_info, 84 * verify the claim is true. This will prevent the from getting out 85 * of sync. 86 */ 87 #ifdef __HAVE_CPU_DATA_FIRST 88 CTASSERT(offsetof(struct cpu_info, ci_data) == 0); 89 #else 90 CTASSERT(offsetof(struct cpu_info, ci_data) != 0); 91 #endif 92 93 void cpuctlattach(int); 94 95 static void cpu_xc_online(struct cpu_info *); 96 static void cpu_xc_offline(struct cpu_info *); 97 98 dev_type_ioctl(cpuctl_ioctl); 99 100 const struct cdevsw cpuctl_cdevsw = { 101 nullopen, nullclose, nullread, nullwrite, cpuctl_ioctl, 102 nullstop, notty, nopoll, nommap, nokqfilter, 103 D_OTHER | D_MPSAFE 104 }; 105 106 kmutex_t cpu_lock __cacheline_aligned; 107 int ncpu __read_mostly; 108 int ncpuonline __read_mostly; 109 bool mp_online __read_mostly; 110 111 kcpuset_t * kcpuset_attached __read_mostly; 112 113 struct cpuqueue cpu_queue __cacheline_aligned 114 = CIRCLEQ_HEAD_INITIALIZER(cpu_queue); 115 116 static struct cpu_info **cpu_infos __read_mostly; 117 118 int 119 mi_cpu_attach(struct cpu_info *ci) 120 { 121 int error; 122 123 KASSERT(maxcpus > 0); 124 125 ci->ci_index = ncpu; 126 CIRCLEQ_INSERT_TAIL(&cpu_queue, ci, ci_data.cpu_qchain); 127 TAILQ_INIT(&ci->ci_data.cpu_ld_locks); 128 __cpu_simple_lock_init(&ci->ci_data.cpu_ld_lock); 129 130 /* This is useful for eg, per-cpu evcnt */ 131 snprintf(ci->ci_data.cpu_name, sizeof(ci->ci_data.cpu_name), "cpu%d", 132 cpu_index(ci)); 133 134 if (__predict_false(cpu_infos == NULL)) { 135 cpu_infos = 136 kmem_zalloc(sizeof(cpu_infos[0]) * maxcpus, KM_SLEEP); 137 kcpuset_create(&kcpuset_attached, true); 138 } 139 cpu_infos[cpu_index(ci)] = ci; 140 kcpuset_set(kcpuset_attached, ci->ci_index); 141 142 sched_cpuattach(ci); 143 144 error = create_idle_lwp(ci); 145 if (error != 0) { 146 /* XXX revert sched_cpuattach */ 147 return error; 148 } 149 150 if (ci == curcpu()) 151 ci->ci_data.cpu_onproc = curlwp; 152 else 153 ci->ci_data.cpu_onproc = ci->ci_data.cpu_idlelwp; 154 155 percpu_init_cpu(ci); 156 softint_init(ci); 157 callout_init_cpu(ci); 158 xc_init_cpu(ci); 159 pool_cache_cpu_init(ci); 160 selsysinit(ci); 161 cache_cpu_init(ci); 162 TAILQ_INIT(&ci->ci_data.cpu_biodone); 163 ncpu++; 164 ncpuonline++; 165 166 return 0; 167 } 168 169 void 170 cpuctlattach(int dummy) 171 { 172 173 KASSERT(cpu_infos != NULL); 174 } 175 176 int 177 cpuctl_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l) 178 { 179 CPU_INFO_ITERATOR cii; 180 cpustate_t *cs; 181 struct cpu_info *ci; 182 int error, i; 183 u_int id; 184 185 error = 0; 186 187 mutex_enter(&cpu_lock); 188 switch (cmd) { 189 case IOC_CPU_SETSTATE: 190 if (error == 0) 191 cs = data; 192 error = kauth_authorize_system(l->l_cred, 193 KAUTH_SYSTEM_CPU, KAUTH_REQ_SYSTEM_CPU_SETSTATE, cs, NULL, 194 NULL); 195 if (error != 0) 196 break; 197 if (cs->cs_id >= maxcpus || 198 (ci = cpu_lookup(cs->cs_id)) == NULL) { 199 error = ESRCH; 200 break; 201 } 202 error = cpu_setintr(ci, cs->cs_intr); 203 error = cpu_setstate(ci, cs->cs_online); 204 break; 205 206 case IOC_CPU_GETSTATE: 207 if (error == 0) 208 cs = data; 209 id = cs->cs_id; 210 memset(cs, 0, sizeof(*cs)); 211 cs->cs_id = id; 212 if (cs->cs_id >= maxcpus || 213 (ci = cpu_lookup(id)) == NULL) { 214 error = ESRCH; 215 break; 216 } 217 if ((ci->ci_schedstate.spc_flags & SPCF_OFFLINE) != 0) 218 cs->cs_online = false; 219 else 220 cs->cs_online = true; 221 if ((ci->ci_schedstate.spc_flags & SPCF_NOINTR) != 0) 222 cs->cs_intr = false; 223 else 224 cs->cs_intr = true; 225 cs->cs_lastmod = (int32_t)ci->ci_schedstate.spc_lastmod; 226 cs->cs_lastmodhi = (int32_t) 227 (ci->ci_schedstate.spc_lastmod >> 32); 228 cs->cs_intrcnt = cpu_intr_count(ci) + 1; 229 cs->cs_hwid = ci->ci_cpuid; 230 break; 231 232 case IOC_CPU_MAPID: 233 i = 0; 234 for (CPU_INFO_FOREACH(cii, ci)) { 235 if (i++ == *(int *)data) 236 break; 237 } 238 if (ci == NULL) 239 error = ESRCH; 240 else 241 *(int *)data = cpu_index(ci); 242 break; 243 244 case IOC_CPU_GETCOUNT: 245 *(int *)data = ncpu; 246 break; 247 248 default: 249 error = ENOTTY; 250 break; 251 } 252 mutex_exit(&cpu_lock); 253 254 return error; 255 } 256 257 struct cpu_info * 258 cpu_lookup(u_int idx) 259 { 260 struct cpu_info *ci; 261 262 KASSERT(idx < maxcpus); 263 264 if (__predict_false(cpu_infos == NULL)) { 265 KASSERT(idx == 0); 266 return curcpu(); 267 } 268 269 ci = cpu_infos[idx]; 270 KASSERT(ci == NULL || cpu_index(ci) == idx); 271 272 return ci; 273 } 274 275 static void 276 cpu_xc_offline(struct cpu_info *ci) 277 { 278 struct schedstate_percpu *spc, *mspc = NULL; 279 struct cpu_info *target_ci; 280 struct lwp *l; 281 CPU_INFO_ITERATOR cii; 282 int s; 283 284 /* 285 * Thread that made the cross call (separate context) holds 286 * cpu_lock on our behalf. 287 */ 288 spc = &ci->ci_schedstate; 289 s = splsched(); 290 spc->spc_flags |= SPCF_OFFLINE; 291 splx(s); 292 293 /* Take the first available CPU for the migration. */ 294 for (CPU_INFO_FOREACH(cii, target_ci)) { 295 mspc = &target_ci->ci_schedstate; 296 if ((mspc->spc_flags & SPCF_OFFLINE) == 0) 297 break; 298 } 299 KASSERT(target_ci != NULL); 300 301 /* 302 * Migrate all non-bound threads to the other CPU. Note that this 303 * runs from the xcall thread, thus handling of LSONPROC is not needed. 304 */ 305 mutex_enter(proc_lock); 306 LIST_FOREACH(l, &alllwp, l_list) { 307 struct cpu_info *mci; 308 309 lwp_lock(l); 310 if (l->l_cpu != ci || (l->l_pflag & (LP_BOUND | LP_INTR))) { 311 lwp_unlock(l); 312 continue; 313 } 314 /* Regular case - no affinity. */ 315 if (l->l_affinity == NULL) { 316 lwp_migrate(l, target_ci); 317 continue; 318 } 319 /* Affinity is set, find an online CPU in the set. */ 320 for (CPU_INFO_FOREACH(cii, mci)) { 321 mspc = &mci->ci_schedstate; 322 if ((mspc->spc_flags & SPCF_OFFLINE) == 0 && 323 kcpuset_isset(l->l_affinity, cpu_index(mci))) 324 break; 325 } 326 if (mci == NULL) { 327 lwp_unlock(l); 328 mutex_exit(proc_lock); 329 goto fail; 330 } 331 lwp_migrate(l, mci); 332 } 333 mutex_exit(proc_lock); 334 335 #ifdef __HAVE_MD_CPU_OFFLINE 336 cpu_offline_md(); 337 #endif 338 return; 339 fail: 340 /* Just unset the SPCF_OFFLINE flag, caller will check */ 341 s = splsched(); 342 spc->spc_flags &= ~SPCF_OFFLINE; 343 splx(s); 344 } 345 346 static void 347 cpu_xc_online(struct cpu_info *ci) 348 { 349 struct schedstate_percpu *spc; 350 int s; 351 352 spc = &ci->ci_schedstate; 353 s = splsched(); 354 spc->spc_flags &= ~SPCF_OFFLINE; 355 splx(s); 356 } 357 358 int 359 cpu_setstate(struct cpu_info *ci, bool online) 360 { 361 struct schedstate_percpu *spc; 362 CPU_INFO_ITERATOR cii; 363 struct cpu_info *ci2; 364 uint64_t where; 365 xcfunc_t func; 366 int nonline; 367 368 spc = &ci->ci_schedstate; 369 370 KASSERT(mutex_owned(&cpu_lock)); 371 372 if (online) { 373 if ((spc->spc_flags & SPCF_OFFLINE) == 0) 374 return 0; 375 func = (xcfunc_t)cpu_xc_online; 376 ncpuonline++; 377 } else { 378 if ((spc->spc_flags & SPCF_OFFLINE) != 0) 379 return 0; 380 nonline = 0; 381 /* 382 * Ensure that at least one CPU within the processor set 383 * stays online. Revisit this later. 384 */ 385 for (CPU_INFO_FOREACH(cii, ci2)) { 386 if ((ci2->ci_schedstate.spc_flags & SPCF_OFFLINE) != 0) 387 continue; 388 if (ci2->ci_schedstate.spc_psid != spc->spc_psid) 389 continue; 390 nonline++; 391 } 392 if (nonline == 1) 393 return EBUSY; 394 func = (xcfunc_t)cpu_xc_offline; 395 ncpuonline--; 396 } 397 398 where = xc_unicast(0, func, ci, NULL, ci); 399 xc_wait(where); 400 if (online) { 401 KASSERT((spc->spc_flags & SPCF_OFFLINE) == 0); 402 } else if ((spc->spc_flags & SPCF_OFFLINE) == 0) { 403 /* If was not set offline, then it is busy */ 404 return EBUSY; 405 } 406 407 spc->spc_lastmod = time_second; 408 return 0; 409 } 410 411 #ifdef __HAVE_INTR_CONTROL 412 static void 413 cpu_xc_intr(struct cpu_info *ci) 414 { 415 struct schedstate_percpu *spc; 416 int s; 417 418 spc = &ci->ci_schedstate; 419 s = splsched(); 420 spc->spc_flags &= ~SPCF_NOINTR; 421 splx(s); 422 } 423 424 static void 425 cpu_xc_nointr(struct cpu_info *ci) 426 { 427 struct schedstate_percpu *spc; 428 int s; 429 430 spc = &ci->ci_schedstate; 431 s = splsched(); 432 spc->spc_flags |= SPCF_NOINTR; 433 splx(s); 434 } 435 436 int 437 cpu_setintr(struct cpu_info *ci, bool intr) 438 { 439 struct schedstate_percpu *spc; 440 CPU_INFO_ITERATOR cii; 441 struct cpu_info *ci2; 442 uint64_t where; 443 xcfunc_t func; 444 int nintr; 445 446 spc = &ci->ci_schedstate; 447 448 KASSERT(mutex_owned(&cpu_lock)); 449 450 if (intr) { 451 if ((spc->spc_flags & SPCF_NOINTR) == 0) 452 return 0; 453 func = (xcfunc_t)cpu_xc_intr; 454 } else { 455 if ((spc->spc_flags & SPCF_NOINTR) != 0) 456 return 0; 457 /* 458 * Ensure that at least one CPU within the system 459 * is handing device interrupts. 460 */ 461 nintr = 0; 462 for (CPU_INFO_FOREACH(cii, ci2)) { 463 if ((ci2->ci_schedstate.spc_flags & SPCF_NOINTR) != 0) 464 continue; 465 if (ci2 == ci) 466 continue; 467 nintr++; 468 } 469 if (nintr == 0) 470 return EBUSY; 471 func = (xcfunc_t)cpu_xc_nointr; 472 } 473 474 where = xc_unicast(0, func, ci, NULL, ci); 475 xc_wait(where); 476 if (intr) { 477 KASSERT((spc->spc_flags & SPCF_NOINTR) == 0); 478 } else if ((spc->spc_flags & SPCF_NOINTR) == 0) { 479 /* If was not set offline, then it is busy */ 480 return EBUSY; 481 } 482 483 /* Direct interrupts away from the CPU and record the change. */ 484 cpu_intr_redistribute(); 485 spc->spc_lastmod = time_second; 486 return 0; 487 } 488 #else /* __HAVE_INTR_CONTROL */ 489 int 490 cpu_setintr(struct cpu_info *ci, bool intr) 491 { 492 493 return EOPNOTSUPP; 494 } 495 496 u_int 497 cpu_intr_count(struct cpu_info *ci) 498 { 499 500 return 0; /* 0 == "don't know" */ 501 } 502 #endif /* __HAVE_INTR_CONTROL */ 503 504 bool 505 cpu_softintr_p(void) 506 { 507 508 return (curlwp->l_pflag & LP_INTR) != 0; 509 } 510
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