1 /* 2 * Copyright (c) 2006 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 */ 35 36 #include <sys/types.h> 37 #include <sys/systm.h> 38 #include <sys/kernel.h> 39 #include <sys/systimer.h> 40 #include <sys/sysctl.h> 41 #include <sys/signal.h> 42 #include <sys/interrupt.h> 43 #include <sys/bus.h> 44 #include <sys/time.h> 45 #include <machine/cpu.h> 46 #include <machine/clock.h> 47 #include <machine/globaldata.h> 48 #include <machine/md_var.h> 49 #include <machine/cothread.h> 50 51 #include <sys/thread2.h> 52 53 #include <unistd.h> 54 #include <signal.h> 55 #include <time.h> 56 #include <stdio.h> 57 58 int disable_rtc_set; 59 SYSCTL_INT(_machdep, CPU_DISRTCSET, disable_rtc_set, 60 CTLFLAG_RW, &disable_rtc_set, 0, ""); 61 SYSCTL_INT(_hw, OID_AUTO, tsc_present, CTLFLAG_RD, 62 &tsc_present, 0, "TSC Available"); 63 SYSCTL_INT(_hw, OID_AUTO, tsc_invariant, CTLFLAG_RD, 64 &tsc_invariant, 0, "Invariant TSC"); 65 SYSCTL_INT(_hw, OID_AUTO, tsc_mpsync, CTLFLAG_RD, 66 &tsc_mpsync, 0, "TSC is synchronized across CPUs"); 67 SYSCTL_QUAD(_hw, OID_AUTO, tsc_frequency, CTLFLAG_RD, 68 &tsc_frequency, 0, "TSC Frequency"); 69 70 int adjkerntz; 71 int wall_cmos_clock = 0; 72 SYSCTL_INT(_machdep, CPU_WALLCLOCK, wall_cmos_clock, 73 CTLFLAG_RD, &wall_cmos_clock, 0, ""); 74 75 static cothread_t vktimer_cotd; 76 static int vktimer_running; 77 static sysclock_t vktimer_target; 78 static struct timespec vktimer_ts; 79 static sysclock_t vktimer_reload[MAXCPU]; 80 81 extern int use_precise_timer; 82 83 /* 84 * SYSTIMER IMPLEMENTATION 85 */ 86 static sysclock_t vkernel_timer_get_timecount(void); 87 static void vkernel_timer_construct(struct cputimer *timer, sysclock_t oclock); 88 static void vktimer_thread(cothread_t cotd); 89 90 static struct cputimer vkernel_cputimer = { 91 .next = SLIST_ENTRY_INITIALIZER, 92 .name = "VKERNEL", 93 .pri = CPUTIMER_PRI_VKERNEL, 94 .type = CPUTIMER_VKERNEL, 95 .count = vkernel_timer_get_timecount, 96 .fromhz = cputimer_default_fromhz, 97 .fromus = cputimer_default_fromus, 98 .construct = vkernel_timer_construct, 99 .destruct = cputimer_default_destruct, 100 .freq = 1000000 101 }; 102 103 static void vktimer_intr_reload(struct cputimer_intr *, sysclock_t); 104 static void vktimer_intr_initclock(struct cputimer_intr *, boolean_t); 105 106 static struct cputimer_intr vkernel_cputimer_intr = { 107 .freq = 1000000, 108 .reload = vktimer_intr_reload, 109 .enable = cputimer_intr_default_enable, 110 .config = cputimer_intr_default_config, 111 .restart = cputimer_intr_default_restart, 112 .pmfixup = cputimer_intr_default_pmfixup, 113 .initclock = vktimer_intr_initclock, 114 .pcpuhand = NULL, 115 .next = SLIST_ENTRY_INITIALIZER, 116 .name = "vkernel", 117 .type = CPUTIMER_INTR_VKERNEL, 118 .prio = CPUTIMER_INTR_PRIO_VKERNEL, 119 .caps = CPUTIMER_INTR_CAP_NONE, 120 .priv = NULL 121 }; 122 123 /* 124 * Initialize the systimer subsystem, called from MI code in early boot. 125 */ 126 static void 127 cpu_initclocks(void *arg __unused) 128 { 129 kprintf("initclocks\n"); 130 cputimer_intr_register(&vkernel_cputimer_intr); 131 cputimer_intr_select(&vkernel_cputimer_intr, 0); 132 133 cputimer_register(&vkernel_cputimer); 134 cputimer_select(&vkernel_cputimer, 0); 135 } 136 SYSINIT(clocksvk, SI_BOOT2_CLOCKREG, SI_ORDER_FIRST, cpu_initclocks, NULL); 137 138 /* 139 * Constructor to initialize timer->base and get an initial count. 140 */ 141 static void 142 vkernel_timer_construct(struct cputimer *timer, sysclock_t oclock) 143 { 144 timer->base = 0; 145 timer->base = oclock - vkernel_timer_get_timecount(); 146 } 147 148 /* 149 * Get the current counter, with 2's complement rollover. 150 * 151 * NOTE! MPSAFE, possibly no critical section 152 */ 153 static sysclock_t 154 vkernel_timer_get_timecount(void) 155 { 156 struct timespec ts; 157 sysclock_t count; 158 159 if (use_precise_timer) 160 clock_gettime(CLOCK_MONOTONIC_PRECISE, &ts); 161 else 162 clock_gettime(CLOCK_MONOTONIC_FAST, &ts); 163 count = ts.tv_nsec / 1000; 164 count += ts.tv_sec * 1000000; 165 166 return count; 167 } 168 169 /* 170 * Initialize the interrupt for our core systimer. Use the kqueue timer 171 * support functions. 172 */ 173 static void 174 vktimer_intr_initclock(struct cputimer_intr *cti __unused, 175 boolean_t selected __unused) 176 { 177 vktimer_target = vkernel_timer_get_timecount(); 178 179 vktimer_ts.tv_nsec = 1000000000 / 20; 180 vktimer_cotd = cothread_create(vktimer_thread, NULL, NULL, "vktimer"); 181 while (vktimer_running == 0) 182 usleep(1000000 / 10); 183 #if 0 184 KKASSERT(kqueue_timer_info == NULL); 185 kqueue_timer_info = kqueue_add_timer(vktimer_intr, NULL); 186 #endif 187 } 188 189 /* 190 * 191 */ 192 static void 193 vktimer_sigint(int signo) 194 { 195 /* do nothing, just interrupt */ 196 } 197 198 static sysclock_t 199 vktimer_gettick_us(void) 200 { 201 struct clockinfo info; 202 int mib[] = { CTL_KERN, KERN_CLOCKRATE }; 203 size_t len = sizeof(info); 204 205 if (sysctl(mib, NELEM(mib), &info, &len, NULL, 0) != 0 || 206 len != sizeof(info)) { 207 /* Assume 10 milliseconds (== 100hz) */ 208 return 1000000 / 100; 209 } else if (info.tick < 999999) { 210 return info.tick; 211 } else { 212 /* Assume 10 milliseconds (== 100hz) */ 213 return 1000000 / 100; 214 } 215 } 216 217 static void 218 vktimer_thread(cothread_t cotd) 219 { 220 struct sigaction sa; 221 globaldata_t gscan; 222 sysclock_t ticklength_us; 223 224 bzero(&sa, sizeof(sa)); 225 sa.sa_handler = vktimer_sigint; 226 sa.sa_flags |= SA_NODEFER; 227 sigemptyset(&sa.sa_mask); 228 sigaction(SIGINT, &sa, NULL); 229 230 ticklength_us = vktimer_gettick_us(); 231 vktimer_running = 1; 232 while (vktimer_cotd == NULL) 233 usleep(1000000 / 10); 234 235 for (;;) { 236 sysclock_t curtime; 237 sysclock_t reload; 238 ssysclock_t delta; 239 int n; 240 241 /* 242 * Sleep 243 */ 244 cothread_sleep(cotd, &vktimer_ts); 245 246 rescan: 247 curtime = vkernel_timer_get_timecount(); 248 reload = 999999; 249 250 /* 251 * Reset the target 252 */ 253 for (n = 0; n < ncpus; ++n) { 254 gscan = globaldata_find(n); 255 delta = vktimer_reload[n] - curtime; 256 if (delta <= 0 && TAILQ_FIRST(&gscan->gd_systimerq)) 257 pthread_kill(ap_tids[n], SIGURG); 258 if (delta > 0 && reload > delta) 259 reload = delta; 260 } 261 reload += curtime; 262 vktimer_target = reload; 263 264 /* 265 * Check for races 266 */ 267 reload -= curtime; 268 for (n = 0; n < ncpus; ++n) { 269 gscan = globaldata_find(n); 270 delta = vktimer_reload[n] - curtime; 271 if (delta > 0 && reload > delta) 272 goto rescan; 273 } 274 if (!use_precise_timer && reload < ticklength_us / 10) { 275 /* 276 * Avoid pointless short sleeps, when we only measure 277 * the current time at tick precision. 278 */ 279 reload = ticklength_us / 10; 280 } 281 vktimer_ts.tv_nsec = reload * 1000; 282 } 283 } 284 285 /* 286 * Reload the interrupt for our core systimer. Because the caller's 287 * reload calculation can be negatively indexed, we need a minimal 288 * check to ensure that a reasonable reload value is selected. 289 */ 290 static void 291 vktimer_intr_reload(struct cputimer_intr *cti __unused, sysclock_t reload) 292 { 293 if (reload >= 1000000) /* uS */ 294 reload = 1000000; 295 reload += vkernel_timer_get_timecount(); 296 vktimer_reload[mycpu->gd_cpuid] = reload; 297 if (vktimer_cotd && (ssysclock_t)(reload - vktimer_target) < 0) { 298 while ((sysclock_t)(reload - vktimer_target) < 0) 299 reload = atomic_swap_int(&vktimer_target, reload); 300 cothread_wakeup(vktimer_cotd, &vktimer_ts); 301 } 302 } 303 304 /* 305 * pcpu clock interrupt (hard interrupt) 306 */ 307 void 308 vktimer_intr(struct intrframe *frame) 309 { 310 struct globaldata *gd = mycpu; 311 sysclock_t sysclock_count; 312 313 sysclock_count = sys_cputimer->count(); 314 ++gd->gd_cnt.v_timer; 315 systimer_intr(&sysclock_count, 0, frame); 316 } 317 318 /* 319 * Initialize the time of day register, based on the time base which is, e.g. 320 * from a filesystem. 321 */ 322 void 323 inittodr(time_t base) 324 { 325 struct timespec ts; 326 struct timeval tv; 327 328 gettimeofday(&tv, NULL); 329 ts.tv_sec = tv.tv_sec; 330 ts.tv_nsec = tv.tv_usec * 1000; 331 set_timeofday(&ts); 332 } 333 334 /* 335 * Write system time back to the RTC 336 */ 337 void 338 resettodr(void) 339 { 340 } 341 342 /* 343 * We need to enter a critical section to prevent signals from recursing 344 * into pthreads. 345 */ 346 void 347 DELAY(int usec) 348 { 349 crit_enter(); 350 usleep(usec); 351 crit_exit(); 352 } 353 354 void 355 DRIVERSLEEP(int usec) 356 { 357 if (mycpu->gd_intr_nesting_level) 358 DELAY(usec); 359 else if (1000000 / usec >= hz) 360 tsleep(DRIVERSLEEP, 0, "DELAY", 1000000 / usec / hz + 1); 361 else 362 DELAY(usec); 363 } 364