X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/b0d623f7f2ae71ed96e60569f61f9a9a27016e80..HEAD:/osfmk/kern/timer.h diff --git a/osfmk/kern/timer.h b/osfmk/kern/timer.h index abbfcb5e3..eeb8eebdb 100644 --- a/osfmk/kern/timer.h +++ b/osfmk/kern/timer.h @@ -2,7 +2,7 @@ * Copyright (c) 2000-2007 Apple Inc. All rights reserved. * * @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 @@ -11,10 +11,10 @@ * 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, @@ -22,154 +22,142 @@ * 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 /* - * Definitions for high resolution timers. A check - * word on the high portion allows atomic updates. + * 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; -struct timer { -#if !STAT_TIME - uint64_t tstamp; -#endif /* STAT_TIME */ -#if defined(__LP64__) - uint64_t all_bits; +/* + * 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. + */ +#define use_precise_user_kernel_time(thread) (precise_user_kernel_time) + +/* + * Definitions for high resolution timers. + */ + +#if __LP64__ +#define TIMER_ALIGNMENT #else - uint32_t low_bits; - uint32_t high_bits; - uint32_t high_bits_check; +#define TIMER_ALIGNMENT __attribute__((packed, aligned(4))) #endif -}; -typedef struct timer timer_data_t, *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; /* - * Exported kernel interface to timers + * Initialize the `timer`. */ +void timer_init(timer_t timer); -#if STAT_TIME - -#include - -/* Advance a timer by a 32 bit value */ -#define TIMER_BUMP(timer, ticks) \ -MACRO_BEGIN \ - uint32_t old_low, low; \ - \ - old_low = (timer)->low_bits; \ - low = old_low + (ticks); \ - if (low < old_low) \ - timer_update((timer), (timer)->high_bits + 1, low); \ - else \ - (timer)->low_bits = low; \ -MACRO_END - -#define timer_start(timer, tstamp) -#define timer_stop(timer, tstamp) -#define timer_switch(timer, tstamp, new_timer) -#define thread_timer_event(tstamp, new_timer) - -#else /* STAT_TIME */ - -#define TIMER_BUMP(timer, ticks) - -/* Start a timer by setting the timestamp */ -extern void timer_start( - timer_t timer, - uint64_t tstamp); - -/* Stop a timer by updating from the timestamp */ -extern void timer_stop( - timer_t timer, - uint64_t tstamp); - -/* Update the timer and start a new one */ -extern void timer_switch( - timer_t timer, - uint64_t tstamp, - timer_t new_timer); - -/* Update the thread timer at an event */ -extern void thread_timer_event( - uint64_t tstamp, - timer_t new_timer); - -#endif /* STAT_TIME */ - -/* Initialize a timer */ -extern void timer_init( - timer_t timer); - -/* Update a saved timer value and return delta to current value */ -extern uint64_t timer_delta( - timer_t timer, - uint64_t *save); - -/* Advance a timer by a 64 bit value */ -extern void timer_advance( - timer_t timer, - uint64_t delta); +/* + * Start the `timer` at time `tstamp`. + */ +void timer_start(timer_t timer, uint64_t tstamp); + +/* + * Stop the `timer` and update it with time `tstamp`. + */ +void timer_stop(timer_t timer, uint64_t tstamp); /* - * Exported hardware interface to timers + * Update the `timer` at time `tstamp`, leaving it running. */ +void timer_update(timer_t timer, uint64_t tstamp); -/* Read timer value */ -#if defined(__LP64__) -static inline uint64_t timer_grab( - timer_t timer) +/* + * Update the `timer` with time `tstamp` and start `new_timer`. + */ +void timer_switch(timer_t timer, uint64_t tstamp, timer_t new_timer); + +/* + * 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. + */ +void processor_timer_switch_thread(uint64_t tstamp, timer_t new_timer); + +/* + * 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); + +/* + * Read the accumulated time of `timer`. + */ +#if defined(__LP64__) +static inline +uint64_t +timer_grab(timer_t timer) { return timer->all_bits; } -#else -extern uint64_t timer_grab( - timer_t timer); - -/* Update timer value */ -extern void timer_update( - timer_t timer, - uint32_t new_high, - uint32_t new_low); -#endif /* defined(__LP64__) */ +#else /* defined(__LP64__) */ +uint64_t timer_grab(timer_t timer); +#endif /* !defined(__LP64__) */ -#endif /* _KERN_TIMER_H_ */ +#endif /* _KERN_TIMER_H_ */