X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/1c79356b52d46aa6b508fb032f5ae709b1f2897b..HEAD:/osfmk/kern/timer.h diff --git a/osfmk/kern/timer.h b/osfmk/kern/timer.h index c55f093da..eeb8eebdb 100644 --- a/osfmk/kern/timer.h +++ b/osfmk/kern/timer.h @@ -1,228 +1,163 @@ /* - * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2007 Apple Inc. All rights reserved. * - * @APPLE_LICENSE_HEADER_START@ - * - * The contents of this file constitute Original Code as defined in and - * are subject to the Apple Public Source License Version 1.1 (the - * "License"). You may not use this file except in compliance with the - * License. Please obtain a copy of the License at - * http://www.apple.com/publicsource and read it before using this file. - * - * This Original Code and all software distributed under the License are - * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ + * + * This file contains Original Code and/or Modifications of Original Code + * as defined in and that are subject to the Apple Public Source License + * Version 2.0 (the 'License'). You may not use this file except in + * compliance with the License. The rights granted to you under the License + * may not be used to create, or enable the creation or redistribution of, + * unlawful or unlicensed copies of an Apple operating system, or to + * circumvent, violate, or enable the circumvention or violation of, any + * terms of an Apple operating system software license agreement. + * + * Please obtain a copy of the License at + * http://www.opensource.apple.com/apsl/ and read it before using this file. + * + * The Original Code and all software distributed under the License are + * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the - * License for the specific language governing rights and limitations - * under the License. - * - * @APPLE_LICENSE_HEADER_END@ + * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. + * Please see the License for the specific language governing rights and + * limitations under the License. + * + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * @OSF_COPYRIGHT@ */ -/* +/* * Mach Operating System * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University * All Rights Reserved. - * + * * Permission to use, copy, modify and distribute this software and its * documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. - * + * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. - * + * * Carnegie Mellon requests users of this software to return to - * + * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 - * + * * any improvements or extensions that they make and grant Carnegie Mellon * the rights to redistribute these changes. */ /* */ -#ifndef _KERN_TIMER_H_ +#ifndef _KERN_TIMER_H_ #define _KERN_TIMER_H_ -#include -#include - -#include #include -#if STAT_TIME /* - * Statistical timer definitions - use microseconds in timer, seconds - * in high unit field. No adjustment needed to convert to time_value_t - * as a result. Service timers once an hour. + * Some platforms have very expensive timebase routines. An optimization + * is to avoid switching timers on kernel exit/entry, which results in all + * time billed to the system timer. However, when exposed to userspace, + * we report as user time to indicate that work was done on behalf of + * userspace. + * + * Although this policy is implemented as a global variable, we snapshot it + * at key points in the thread structure (when the thread is locked and + * executing in the kernel) to avoid imbalances. */ +extern int precise_user_kernel_time; -#define TIMER_RATE 1000000 -#define TIMER_HIGH_UNIT TIMER_RATE -#undef TIMER_ADJUST - -#else /* STAT_TIME */ /* - * Machine dependent definitions based on hardware support. + * thread must be locked, or be the current executing thread, so that + * it doesn't transition from user to kernel while updating the + * thread-local value (or in kernel debugger context). In the future, + * we make take into account task-level or thread-level policy. */ - -#include - -#endif /* STAT_TIME */ +#define use_precise_user_kernel_time(thread) (precise_user_kernel_time) /* - * Definitions for accurate timers. high_bits_check is a copy of - * high_bits that allows reader to verify that values read are ok. + * Definitions for high resolution timers. */ -struct timer { - unsigned low_bits; - unsigned high_bits; - unsigned high_bits_check; - unsigned tstamp; -}; +#if __LP64__ +#define TIMER_ALIGNMENT +#else +#define TIMER_ALIGNMENT __attribute__((packed, aligned(4))) +#endif -typedef struct timer timer_data_t; -typedef struct timer *timer_t; +struct timer { + uint64_t tstamp; +#if defined(__LP64__) + uint64_t all_bits; +#else /* defined(__LP64__) */ + /* A check word on the high portion allows atomic updates. */ + uint32_t low_bits; + uint32_t high_bits; + uint32_t high_bits_check; +#endif /* !defined(__LP64__) */ +} TIMER_ALIGNMENT; + +typedef struct timer timer_data_t, *timer_t; /* - * Mask to check if low_bits is in danger of overflowing + * Initialize the `timer`. */ - -#define TIMER_LOW_FULL 0x80000000 +void timer_init(timer_t timer); /* - * Kernel timers and current timer array. [Exported] + * Start the `timer` at time `tstamp`. */ - -extern timer_t current_timer[NCPUS]; -extern timer_data_t kernel_timer[NCPUS]; +void timer_start(timer_t timer, uint64_t tstamp); /* - * save structure for timer readings. This is used to save timer - * readings for elapsed time computations. + * Stop the `timer` and update it with time `tstamp`. */ - -struct timer_save { - unsigned low; - unsigned high; -}; - -typedef struct timer_save timer_save_data_t, *timer_save_t; +void timer_stop(timer_t timer, uint64_t tstamp); /* - * Exported kernel interface to timers + * Update the `timer` at time `tstamp`, leaving it running. */ - -#if STAT_TIME -#define start_timer(timer) -#define timer_switch(timer) -#else /* STAT_TIME */ -/* Start timer for this cpu */ -extern void start_timer( - timer_t timer); - -/* Switch to a new timer */ -extern void timer_switch( - timer_t new_timer); -#endif /* STAT_TIME */ - -/* Initialize timer module */ -extern void init_timers(void); +void timer_update(timer_t timer, uint64_t tstamp); /* - * Initializes a single timer. + * Update the `timer` with time `tstamp` and start `new_timer`. */ -extern void timer_init( - timer_t this_timer); - -/* Normalize timer value */ -extern void timer_normalize( - timer_t timer); - -/* Read value of timer into tv */ -extern void timer_read( - timer_t timer, - time_value_t *tv); - -/* Read thread times */ -extern void thread_read_times( - thread_t thread, - time_value_t *user_time_p, - time_value_t *system_time_p); - -/* Compute timer difference */ -extern unsigned timer_delta( - timer_t timer, - timer_save_t save); - -#if STAT_TIME -/* - * Macro to bump timer values. - */ -#define timer_bump(timer, usec) \ -MACRO_BEGIN \ - (timer)->low_bits += usec; \ - if ((timer)->low_bits & TIMER_LOW_FULL) { \ - timer_normalize(timer); \ - } \ -MACRO_END - -#else /* STAT_TIME */ +void timer_switch(timer_t timer, uint64_t tstamp, timer_t new_timer); + /* - * Exported hardware interface to timers + * Update the thread timer at an "event," like a context switch, at time + * `tstamp`. This stops the current timer and starts the `new_timer` running. + * + * Must be called with interrupts disabled. */ -/* Time trap entry */ -extern void time_trap_uentry( - unsigned ts); - -/* Time trap exit */ -extern void time_trap_uexit( - unsigned ts); - -/* Time interrupt entry */ -extern timer_t time_int_entry( - unsigned ts, - timer_t new_timer); - -/* Time interrrupt exit */ -extern void time_int_exit( - unsigned ts, - timer_t old_timer); - -#endif /* STAT_TIME */ +void processor_timer_switch_thread(uint64_t tstamp, timer_t new_timer); /* - * TIMER_DELTA finds the difference between a timer and a saved value, - * and updates the saved value. Look at high_bits check field after - * reading low because that's the first written by a normalize - * operation; this isn't necessary for current usage because - * this macro is only used when the timer can't be normalized: - * thread is not running, or running thread calls it on itself at - * splsched(). + * Return the difference between the `timer` and a previous value pointed to by + * `prev_in_cur_out`. Store the current value of the timer to + * `prev_in_cur_out`. */ +uint64_t timer_delta(timer_t timer, uint64_t *prev_in_cur_out); -#define TIMER_DELTA(timer, save, result) \ -MACRO_BEGIN \ - register unsigned temp; \ - \ - temp = (timer).low_bits; \ - if ((save).high != (timer).high_bits_check) { \ - result += timer_delta(&(timer), &(save)); \ - } \ - else { \ - result += temp - (save).low; \ - (save).low = temp; \ - } \ -MACRO_END - -#endif /* _KERN_TIMER_H_ */ +/* + * Read the accumulated time of `timer`. + */ +#if defined(__LP64__) +static inline +uint64_t +timer_grab(timer_t timer) +{ + return timer->all_bits; +} +#else /* defined(__LP64__) */ +uint64_t timer_grab(timer_t timer); +#endif /* !defined(__LP64__) */ + +#endif /* _KERN_TIMER_H_ */