kern_cpu.c revision 1.14
1 /* $NetBSD: kern_cpu.c,v 1.14 2007/11/07 00:23:20 ad 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 1.14 2007/11/07 00:23:20 ad 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 if (ci == curcpu()) 121 ci->ci_data.cpu_onproc = curlwp; 122 else 123 ci->ci_data.cpu_onproc = ci->ci_data.cpu_idlelwp; 124 125 softint_init(ci); 126 xc_init_cpu(ci); 127 pool_cache_cpu_init(ci); 128 TAILQ_INIT(&ci->ci_data.cpu_biodone); 129 ncpu++; 130 ncpuonline++; 131 132 return 0; 133 } 134 135 void 136 cpuctlattach(int dummy) 137 { 138 139 } 140 141 int 142 cpuctl_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l) 143 { 144 CPU_INFO_ITERATOR cii; 145 cpustate_t *cs; 146 struct cpu_info *ci; 147 int error, i; 148 u_int id; 149 150 error = 0; 151 152 mutex_enter(&cpu_lock); 153 switch (cmd) { 154 case IOC_CPU_SETSTATE: 155 error = kauth_authorize_generic(l->l_cred, 156 KAUTH_GENERIC_ISSUSER, NULL); 157 if (error != 0) 158 break; 159 cs = data; 160 if ((ci = cpu_lookup(cs->cs_id)) == NULL) { 161 error = ESRCH; 162 break; 163 } 164 if (!cs->cs_intr) { 165 error = EOPNOTSUPP; 166 break; 167 } 168 error = cpu_setonline(ci, cs->cs_online); 169 break; 170 171 case IOC_CPU_GETSTATE: 172 cs = data; 173 id = cs->cs_id; 174 memset(cs, 0, sizeof(*cs)); 175 cs->cs_id = id; 176 if ((ci = cpu_lookup(id)) == NULL) { 177 error = ESRCH; 178 break; 179 } 180 if ((ci->ci_schedstate.spc_flags & SPCF_OFFLINE) != 0) 181 cs->cs_online = false; 182 else 183 cs->cs_online = true; 184 cs->cs_intr = true; 185 cs->cs_lastmod = ci->ci_schedstate.spc_lastmod; 186 break; 187 188 case IOC_CPU_MAPID: 189 i = 0; 190 for (CPU_INFO_FOREACH(cii, ci)) { 191 if (i++ == *(int *)data) 192 break; 193 } 194 if (ci == NULL) 195 error = ESRCH; 196 else 197 *(int *)data = ci->ci_cpuid; 198 break; 199 200 case IOC_CPU_GETCOUNT: 201 *(int *)data = ncpu; 202 break; 203 204 default: 205 error = ENOTTY; 206 break; 207 } 208 mutex_exit(&cpu_lock); 209 210 return error; 211 } 212 213 struct cpu_info * 214 cpu_lookup(cpuid_t id) 215 { 216 CPU_INFO_ITERATOR cii; 217 struct cpu_info *ci; 218 219 for (CPU_INFO_FOREACH(cii, ci)) { 220 if (ci->ci_cpuid == id) 221 return ci; 222 } 223 224 return NULL; 225 } 226 227 static void 228 cpu_xc_offline(struct cpu_info *ci) 229 { 230 struct schedstate_percpu *spc, *mspc = NULL; 231 struct cpu_info *mci; 232 struct lwp *l; 233 CPU_INFO_ITERATOR cii; 234 int s; 235 236 spc = &ci->ci_schedstate; 237 s = splsched(); 238 spc->spc_flags |= SPCF_OFFLINE; 239 splx(s); 240 241 /* Take the first available CPU for the migration */ 242 for (CPU_INFO_FOREACH(cii, mci)) { 243 mspc = &mci->ci_schedstate; 244 if ((mspc->spc_flags & SPCF_OFFLINE) == 0) 245 break; 246 } 247 KASSERT(mci != NULL); 248 249 /* 250 * Migrate all non-bound threads to the other CPU. 251 * Please note, that this runs from the xcall thread, thus handling 252 * of LSONPROC is not needed. 253 */ 254 mutex_enter(&proclist_lock); 255 256 /* 257 * Note that threads on the runqueue might sleep after this, but 258 * sched_takecpu() would migrate such threads to the appropriate CPU. 259 */ 260 LIST_FOREACH(l, &alllwp, l_list) { 261 lwp_lock(l); 262 if (l->l_cpu == ci && (l->l_stat == LSSLEEP || 263 l->l_stat == LSSTOP || l->l_stat == LSSUSPENDED)) { 264 KASSERT((l->l_flag & LW_RUNNING) == 0); 265 l->l_cpu = mci; 266 } 267 lwp_unlock(l); 268 } 269 270 /* 271 * Runqueues are locked with the global lock if pointers match, 272 * thus hold only one. Otherwise, double-lock the runqueues. 273 */ 274 if (spc->spc_mutex == mspc->spc_mutex) { 275 spc_lock(ci); 276 } else if (ci < mci) { 277 spc_lock(ci); 278 spc_lock(mci); 279 } else { 280 spc_lock(mci); 281 spc_lock(ci); 282 } 283 284 /* Handle LSRUN and LSIDL cases */ 285 LIST_FOREACH(l, &alllwp, l_list) { 286 if (l->l_cpu != ci || (l->l_flag & LW_BOUND)) 287 continue; 288 if (l->l_stat == LSRUN && (l->l_flag & LW_INMEM) != 0) { 289 sched_dequeue(l); 290 l->l_cpu = mci; 291 lwp_setlock(l, mspc->spc_mutex); 292 sched_enqueue(l, false); 293 } else if (l->l_stat == LSRUN || l->l_stat == LSIDL) { 294 l->l_cpu = mci; 295 lwp_setlock(l, mspc->spc_mutex); 296 } 297 } 298 if (spc->spc_mutex == mspc->spc_mutex) { 299 spc_unlock(ci); 300 } else { 301 spc_unlock(ci); 302 spc_unlock(mci); 303 } 304 305 mutex_exit(&proclist_lock); 306 } 307 308 static void 309 cpu_xc_online(struct cpu_info *ci) 310 { 311 struct schedstate_percpu *spc; 312 int s; 313 314 spc = &ci->ci_schedstate; 315 s = splsched(); 316 spc->spc_flags &= ~SPCF_OFFLINE; 317 splx(s); 318 } 319 320 int 321 cpu_setonline(struct cpu_info *ci, bool online) 322 { 323 struct schedstate_percpu *spc; 324 CPU_INFO_ITERATOR cii; 325 struct cpu_info *ci2; 326 uint64_t where; 327 xcfunc_t func; 328 int nonline; 329 330 spc = &ci->ci_schedstate; 331 332 KASSERT(mutex_owned(&cpu_lock)); 333 334 if (online) { 335 if ((spc->spc_flags & SPCF_OFFLINE) == 0) 336 return 0; 337 func = (xcfunc_t)cpu_xc_online; 338 ncpuonline++; 339 } else { 340 if ((spc->spc_flags & SPCF_OFFLINE) != 0) 341 return 0; 342 nonline = 0; 343 for (CPU_INFO_FOREACH(cii, ci2)) { 344 nonline += ((ci2->ci_schedstate.spc_flags & 345 SPCF_OFFLINE) == 0); 346 } 347 if (nonline == 1) 348 return EBUSY; 349 func = (xcfunc_t)cpu_xc_offline; 350 ncpuonline--; 351 } 352 353 where = xc_unicast(0, func, ci, NULL, ci); 354 xc_wait(where); 355 if (online) { 356 KASSERT((spc->spc_flags & SPCF_OFFLINE) == 0); 357 } else { 358 KASSERT(spc->spc_flags & SPCF_OFFLINE); 359 } 360 spc->spc_lastmod = time_second; 361 362 return 0; 363 } 364
Indexes created Sun Sep 21 20:09:37 GMT 2025