1/* 2 * Copyright (c) 2000-2008 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28/* 29 * @OSF_COPYRIGHT@ 30 */ 31/* 32 * @APPLE_FREE_COPYRIGHT@ 33 */ 34/* 35 * File: timer.c 36 * Purpose: Routines for handling the machine independent timer. 37 */ 38 39#include <mach/mach_types.h> 40 41#include <kern/timer_queue.h> 42#include <kern/timer_call.h> 43#include <kern/clock.h> 44#include <kern/thread.h> 45#include <kern/processor.h> 46#include <kern/macro_help.h> 47#include <kern/spl.h> 48#include <kern/timer_queue.h> 49#include <kern/pms.h> 50 51#include <machine/commpage.h> 52#include <machine/machine_routines.h> 53 54#include <sys/kdebug.h> 55#include <i386/cpu_data.h> 56#include <i386/cpu_topology.h> 57#include <i386/cpu_threads.h> 58 59uint32_t spurious_timers; 60 61/* 62 * Event timer interrupt. 63 * 64 * XXX a drawback of this implementation is that events serviced earlier must not set deadlines 65 * that occur before the entire chain completes. 66 * 67 * XXX a better implementation would use a set of generic callouts and iterate over them 68 */ 69void 70timer_intr(int user_mode, 71 uint64_t rip) 72{ 73 uint64_t abstime; 74 rtclock_timer_t *mytimer; 75 cpu_data_t *pp; 76 int64_t latency; 77 uint64_t pmdeadline; 78 boolean_t timer_processed = FALSE; 79 80 pp = current_cpu_datap(); 81 82 SCHED_STATS_TIMER_POP(current_processor()); 83 84 abstime = mach_absolute_time(); /* Get the time now */ 85 86 /* has a pending clock timer expired? */ 87 mytimer = &pp->rtclock_timer; /* Point to the event timer */ 88 89 if ((timer_processed = ((mytimer->deadline <= abstime) || 90 (abstime >= (mytimer->queue.earliest_soft_deadline))))) { 91 /* 92 * Log interrupt service latency (-ve value expected by tool) 93 * a non-PM event is expected next. 94 * The requested deadline may be earlier than when it was set 95 * - use MAX to avoid reporting bogus latencies. 96 */ 97 latency = (int64_t) (abstime - MAX(mytimer->deadline, 98 mytimer->when_set)); 99 /* Log zero timer latencies when opportunistically processing 100 * coalesced timers. 101 */ 102 if (latency < 0) { 103 TCOAL_DEBUG(0xEEEE0000, abstime, mytimer->queue.earliest_soft_deadline, abstime - mytimer->queue.earliest_soft_deadline, 0, 0); 104 latency = 0; 105 } 106 107 KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, 108 DECR_TRAP_LATENCY | DBG_FUNC_NONE, 109 -latency, 110 ((user_mode != 0) ? rip : VM_KERNEL_UNSLIDE(rip)), 111 user_mode, 0, 0); 112 113 mytimer->has_expired = TRUE; /* Remember that we popped */ 114 mytimer->deadline = timer_queue_expire(&mytimer->queue, abstime); 115 mytimer->has_expired = FALSE; 116 117 /* Get the time again since we ran a bit */ 118 abstime = mach_absolute_time(); 119 mytimer->when_set = abstime; 120 } 121 122 /* is it time for power management state change? */ 123 if ((pmdeadline = pmCPUGetDeadline(pp)) && (pmdeadline <= abstime)) { 124 KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, 125 DECR_PM_DEADLINE | DBG_FUNC_START, 126 0, 0, 0, 0, 0); 127 pmCPUDeadline(pp); 128 KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, 129 DECR_PM_DEADLINE | DBG_FUNC_END, 130 0, 0, 0, 0, 0); 131 timer_processed = TRUE; 132 } 133 134 /* schedule our next deadline */ 135 x86_lcpu()->rtcDeadline = EndOfAllTime; 136 timer_resync_deadlines(); 137 138 if (__improbable(timer_processed == FALSE)) 139 spurious_timers++; 140} 141 142/* 143 * Set the clock deadline. 144 */ 145void timer_set_deadline(uint64_t deadline) 146{ 147 rtclock_timer_t *mytimer; 148 spl_t s; 149 cpu_data_t *pp; 150 151 s = splclock(); /* no interruptions */ 152 pp = current_cpu_datap(); 153 154 mytimer = &pp->rtclock_timer; /* Point to the timer itself */ 155 mytimer->deadline = deadline; /* Set new expiration time */ 156 mytimer->when_set = mach_absolute_time(); 157 158 timer_resync_deadlines(); 159 160 splx(s); 161} 162 163/* 164 * Re-evaluate the outstanding deadlines and select the most proximate. 165 * 166 * Should be called at splclock. 167 */ 168void 169timer_resync_deadlines(void) 170{ 171 uint64_t deadline = EndOfAllTime; 172 uint64_t pmdeadline; 173 rtclock_timer_t *mytimer; 174 spl_t s = splclock(); 175 cpu_data_t *pp; 176 uint32_t decr; 177 178 pp = current_cpu_datap(); 179 if (!pp->cpu_running) 180 /* There's really nothing to do if this processor is down */ 181 return; 182 183 /* 184 * If we have a clock timer set, pick that. 185 */ 186 mytimer = &pp->rtclock_timer; 187 if (!mytimer->has_expired && 188 0 < mytimer->deadline && mytimer->deadline < EndOfAllTime) 189 deadline = mytimer->deadline; 190 191 /* 192 * If we have a power management deadline, see if that's earlier. 193 */ 194 pmdeadline = pmCPUGetDeadline(pp); 195 if (0 < pmdeadline && pmdeadline < deadline) 196 deadline = pmdeadline; 197 198 /* 199 * Go and set the "pop" event. 200 */ 201 decr = (uint32_t) setPop(deadline); 202 203 /* Record non-PM deadline for latency tool */ 204 if (decr != 0 && deadline != pmdeadline) { 205 KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, 206 DECR_SET_DEADLINE | DBG_FUNC_NONE, 207 decr, 2, 208 deadline, 209 mytimer->queue.count, 0); 210 } 211 splx(s); 212} 213 214void 215timer_queue_expire_local( 216__unused void *arg) 217{ 218 rtclock_timer_t *mytimer; 219 uint64_t abstime; 220 cpu_data_t *pp; 221 222 pp = current_cpu_datap(); 223 224 mytimer = &pp->rtclock_timer; 225 abstime = mach_absolute_time(); 226 227 mytimer->has_expired = TRUE; 228 mytimer->deadline = timer_queue_expire(&mytimer->queue, abstime); 229 mytimer->has_expired = FALSE; 230 mytimer->when_set = mach_absolute_time(); 231 232 timer_resync_deadlines(); 233} 234 235void 236timer_queue_expire_rescan( 237__unused void *arg) 238{ 239 rtclock_timer_t *mytimer; 240 uint64_t abstime; 241 cpu_data_t *pp; 242 243 assert(ml_get_interrupts_enabled() == FALSE); 244 pp = current_cpu_datap(); 245 246 mytimer = &pp->rtclock_timer; 247 abstime = mach_absolute_time(); 248 249 mytimer->has_expired = TRUE; 250 mytimer->deadline = timer_queue_expire_with_options(&mytimer->queue, abstime, TRUE); 251 mytimer->has_expired = FALSE; 252 mytimer->when_set = mach_absolute_time(); 253 254 timer_resync_deadlines(); 255} 256 257#define TIMER_RESORT_THRESHOLD_ABSTIME (50 * NSEC_PER_MSEC) 258 259#if TCOAL_PRIO_STATS 260int32_t nc_tcl, rt_tcl, bg_tcl, kt_tcl, fp_tcl, ts_tcl, qos_tcl; 261#define TCOAL_PRIO_STAT(x) (x++) 262#else 263#define TCOAL_PRIO_STAT(x) 264#endif 265 266boolean_t 267timer_resort_threshold(uint64_t skew) { 268 if (skew >= TIMER_RESORT_THRESHOLD_ABSTIME) 269 return TRUE; 270 else 271 return FALSE; 272} 273 274/* 275 * Return the local timer queue for a running processor 276 * else return the boot processor's timer queue. 277 */ 278mpqueue_head_t * 279timer_queue_assign( 280 uint64_t deadline) 281{ 282 cpu_data_t *cdp = current_cpu_datap(); 283 mpqueue_head_t *queue; 284 285 if (cdp->cpu_running) { 286 queue = &cdp->rtclock_timer.queue; 287 288 if (deadline < cdp->rtclock_timer.deadline) 289 timer_set_deadline(deadline); 290 } 291 else 292 queue = &cpu_datap(master_cpu)->rtclock_timer.queue; 293 294 return (queue); 295} 296 297void 298timer_queue_cancel( 299 mpqueue_head_t *queue, 300 uint64_t deadline, 301 uint64_t new_deadline) 302{ 303 if (queue == ¤t_cpu_datap()->rtclock_timer.queue) { 304 if (deadline < new_deadline) 305 timer_set_deadline(new_deadline); 306 } 307} 308 309/* 310 * timer_queue_migrate_cpu() is called from the Power-Management kext 311 * when a logical processor goes idle (in a deep C-state) with a distant 312 * deadline so that it's timer queue can be moved to another processor. 313 * This target processor should be the least idle (most busy) -- 314 * currently this is the primary processor for the calling thread's package. 315 * Locking restrictions demand that the target cpu must be the boot cpu. 316 */ 317uint32_t 318timer_queue_migrate_cpu(int target_cpu) 319{ 320 cpu_data_t *target_cdp = cpu_datap(target_cpu); 321 cpu_data_t *cdp = current_cpu_datap(); 322 int ntimers_moved; 323 324 assert(!ml_get_interrupts_enabled()); 325 assert(target_cpu != cdp->cpu_number); 326 assert(target_cpu == master_cpu); 327 328 KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, 329 DECR_TIMER_MIGRATE | DBG_FUNC_START, 330 target_cpu, 331 cdp->rtclock_timer.deadline, (cdp->rtclock_timer.deadline >>32), 332 0, 0); 333 334 /* 335 * Move timer requests from the local queue to the target processor's. 336 * The return value is the number of requests moved. If this is 0, 337 * it indicates that the first (i.e. earliest) timer is earlier than 338 * the earliest for the target processor. Since this would force a 339 * resync, the move of this and all later requests is aborted. 340 */ 341 ntimers_moved = timer_queue_migrate(&cdp->rtclock_timer.queue, 342 &target_cdp->rtclock_timer.queue); 343 344 /* 345 * Assuming we moved stuff, clear local deadline. 346 */ 347 if (ntimers_moved > 0) { 348 cdp->rtclock_timer.deadline = EndOfAllTime; 349 setPop(EndOfAllTime); 350 } 351 352 KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, 353 DECR_TIMER_MIGRATE | DBG_FUNC_END, 354 target_cpu, ntimers_moved, 0, 0, 0); 355 356 return ntimers_moved; 357} 358 359mpqueue_head_t * 360timer_queue_cpu(int cpu) 361{ 362 return &cpu_datap(cpu)->rtclock_timer.queue; 363} 364 365void 366timer_call_cpu(int cpu, void (*fn)(void *), void *arg) 367{ 368 mp_cpus_call(cpu_to_cpumask(cpu), SYNC, fn, arg); 369} 370 371void 372timer_call_nosync_cpu(int cpu, void (*fn)(void *), void *arg) 373{ 374 /* XXX Needs error checking and retry */ 375 mp_cpus_call(cpu_to_cpumask(cpu), NOSYNC, fn, arg); 376} 377 378 379static timer_coalescing_priority_params_ns_t tcoal_prio_params_init = 380{ 381 .idle_entry_timer_processing_hdeadline_threshold_ns = 5000ULL * NSEC_PER_USEC, 382 .interrupt_timer_coalescing_ilat_threshold_ns = 30ULL * NSEC_PER_USEC, 383 .timer_resort_threshold_ns = 50 * NSEC_PER_MSEC, 384 .timer_coalesce_rt_shift = 0, 385 .timer_coalesce_bg_shift = -5, 386 .timer_coalesce_kt_shift = 3, 387 .timer_coalesce_fp_shift = 3, 388 .timer_coalesce_ts_shift = 3, 389 .timer_coalesce_rt_ns_max = 0ULL, 390 .timer_coalesce_bg_ns_max = 100 * NSEC_PER_MSEC, 391 .timer_coalesce_kt_ns_max = 1 * NSEC_PER_MSEC, 392 .timer_coalesce_fp_ns_max = 1 * NSEC_PER_MSEC, 393 .timer_coalesce_ts_ns_max = 1 * NSEC_PER_MSEC, 394 .latency_qos_scale = {3, 2, 1, -2, -15, -15}, 395 .latency_qos_ns_max ={1 * NSEC_PER_MSEC, 5 * NSEC_PER_MSEC, 20 * NSEC_PER_MSEC, 396 75 * NSEC_PER_MSEC, 10000 * NSEC_PER_MSEC, 10000 * NSEC_PER_MSEC}, 397 .latency_tier_rate_limited = {FALSE, FALSE, FALSE, FALSE, TRUE, TRUE}, 398}; 399 400timer_coalescing_priority_params_ns_t * timer_call_get_priority_params(void) 401{ 402 return &tcoal_prio_params_init; 403} 404