kern_cpu.c revision 1.13
1 /* $NetBSD: kern_cpu.c,v 1.13 2007/11/06 00:42:41 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 1.13 2007/11/06 00:42:41 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 TAILQ_INIT(&ci->ci_data.cpu_biodone); 128 ncpu++; 129 ncpuonline++; 130 131 return 0; 132 } 133 134 void 135 cpuctlattach(int dummy) 136 { 137 138 } 139 140 int 141 cpuctl_ioctl(dev_t dev, u_long cmd, void *data, int flag, lwp_t *l) 142 { 143 CPU_INFO_ITERATOR cii; 144 cpustate_t *cs; 145 struct cpu_info *ci; 146 int error, i; 147 u_int id; 148 149 error = 0; 150 151 mutex_enter(&cpu_lock); 152 switch (cmd) { 153 case IOC_CPU_SETSTATE: 154 error = kauth_authorize_generic(l->l_cred, 155 KAUTH_GENERIC_ISSUSER, NULL); 156 if (error != 0) 157 break; 158 cs = data; 159 if ((ci = cpu_lookup(cs->cs_id)) == NULL) { 160 error = ESRCH; 161 break; 162 } 163 if (!cs->cs_intr) { 164 error = EOPNOTSUPP; 165 break; 166 } 167 error = cpu_setonline(ci, cs->cs_online); 168 break; 169 170 case IOC_CPU_GETSTATE: 171 cs = data; 172 id = cs->cs_id; 173 memset(cs, 0, sizeof(*cs)); 174 cs->cs_id = id; 175 if ((ci = cpu_lookup(id)) == NULL) { 176 error = ESRCH; 177 break; 178 } 179 if ((ci->ci_schedstate.spc_flags & SPCF_OFFLINE) != 0) 180 cs->cs_online = false; 181 else 182 cs->cs_online = true; 183 cs->cs_intr = true; 184 cs->cs_lastmod = ci->ci_schedstate.spc_lastmod; 185 break; 186 187 case IOC_CPU_MAPID: 188 i = 0; 189 for (CPU_INFO_FOREACH(cii, ci)) { 190 if (i++ == *(int *)data) 191 break; 192 } 193 if (ci == NULL) 194 error = ESRCH; 195 else 196 *(int *)data = ci->ci_cpuid; 197 break; 198 199 case IOC_CPU_GETCOUNT: 200 *(int *)data = ncpu; 201 break; 202 203 default: 204 error = ENOTTY; 205 break; 206 } 207 mutex_exit(&cpu_lock); 208 209 return error; 210 } 211 212 struct cpu_info * 213 cpu_lookup(cpuid_t id) 214 { 215 CPU_INFO_ITERATOR cii; 216 struct cpu_info *ci; 217 218 for (CPU_INFO_FOREACH(cii, ci)) { 219 if (ci->ci_cpuid == id) 220 return ci; 221 } 222 223 return NULL; 224 } 225 226 static void 227 cpu_xc_offline(struct cpu_info *ci) 228 { 229 struct schedstate_percpu *spc, *mspc = NULL; 230 struct cpu_info *mci; 231 struct lwp *l; 232 CPU_INFO_ITERATOR cii; 233 int s; 234 235 spc = &ci->ci_schedstate; 236 s = splsched(); 237 spc->spc_flags |= SPCF_OFFLINE; 238 splx(s); 239 240 /* Take the first available CPU for the migration */ 241 for (CPU_INFO_FOREACH(cii, mci)) { 242 mspc = &mci->ci_schedstate; 243 if ((mspc->spc_flags & SPCF_OFFLINE) == 0) 244 break; 245 } 246 KASSERT(mci != NULL); 247 248 /* 249 * Migrate all non-bound threads to the other CPU. 250 * Please note, that this runs from the xcall thread, thus handling 251 * of LSONPROC is not needed. 252 */ 253 mutex_enter(&proclist_lock); 254 255 /* 256 * Note that threads on the runqueue might sleep after this, but 257 * sched_takecpu() would migrate such threads to the appropriate CPU. 258 */ 259 LIST_FOREACH(l, &alllwp, l_list) { 260 lwp_lock(l); 261 if (l->l_cpu == ci && (l->l_stat == LSSLEEP || 262 l->l_stat == LSSTOP || l->l_stat == LSSUSPENDED)) { 263 KASSERT((l->l_flag & LW_RUNNING) == 0); 264 l->l_cpu = mci; 265 } 266 lwp_unlock(l); 267 } 268 269 /* 270 * Runqueues are locked with the global lock if pointers match, 271 * thus hold only one. Otherwise, double-lock the runqueues. 272 */ 273 if (spc->spc_mutex == mspc->spc_mutex) { 274 spc_lock(ci); 275 } else if (ci < mci) { 276 spc_lock(ci); 277 spc_lock(mci); 278 } else { 279 spc_lock(mci); 280 spc_lock(ci); 281 } 282 283 /* Handle LSRUN and LSIDL cases */ 284 LIST_FOREACH(l, &alllwp, l_list) { 285 if (l->l_cpu != ci || (l->l_flag & LW_BOUND)) 286 continue; 287 if (l->l_stat == LSRUN && (l->l_flag & LW_INMEM) != 0) { 288 sched_dequeue(l); 289 l->l_cpu = mci; 290 lwp_setlock(l, mspc->spc_mutex); 291 sched_enqueue(l, false); 292 } else if (l->l_stat == LSRUN || l->l_stat == LSIDL) { 293 l->l_cpu = mci; 294 lwp_setlock(l, mspc->spc_mutex); 295 } 296 } 297 if (spc->spc_mutex == mspc->spc_mutex) { 298 spc_unlock(ci); 299 } else { 300 spc_unlock(ci); 301 spc_unlock(mci); 302 } 303 304 mutex_exit(&proclist_lock); 305 } 306 307 static void 308 cpu_xc_online(struct cpu_info *ci) 309 { 310 struct schedstate_percpu *spc; 311 int s; 312 313 spc = &ci->ci_schedstate; 314 s = splsched(); 315 spc->spc_flags &= ~SPCF_OFFLINE; 316 splx(s); 317 } 318 319 int 320 cpu_setonline(struct cpu_info *ci, bool online) 321 { 322 struct schedstate_percpu *spc; 323 CPU_INFO_ITERATOR cii; 324 struct cpu_info *ci2; 325 uint64_t where; 326 xcfunc_t func; 327 int nonline; 328 329 spc = &ci->ci_schedstate; 330 331 KASSERT(mutex_owned(&cpu_lock)); 332 333 if (online) { 334 if ((spc->spc_flags & SPCF_OFFLINE) == 0) 335 return 0; 336 func = (xcfunc_t)cpu_xc_online; 337 ncpuonline++; 338 } else { 339 if ((spc->spc_flags & SPCF_OFFLINE) != 0) 340 return 0; 341 nonline = 0; 342 for (CPU_INFO_FOREACH(cii, ci2)) { 343 nonline += ((ci2->ci_schedstate.spc_flags & 344 SPCF_OFFLINE) == 0); 345 } 346 if (nonline == 1) 347 return EBUSY; 348 func = (xcfunc_t)cpu_xc_offline; 349 ncpuonline--; 350 } 351 352 where = xc_unicast(0, func, ci, NULL, ci); 353 xc_wait(where); 354 if (online) { 355 KASSERT((spc->spc_flags & SPCF_OFFLINE) == 0); 356 } else { 357 KASSERT(spc->spc_flags & SPCF_OFFLINE); 358 } 359 spc->spc_lastmod = time_second; 360 361 return 0; 362 } 363
Indexes created Sun Sep 21 20:09:37 GMT 2025