X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/8ad349bb6ed4a0be06e34c92be0d98b92e078db4..HEAD:/osfmk/kern/timer.h diff --git a/osfmk/kern/timer.h b/osfmk/kern/timer.h index c9096cb99..eeb8eebdb 100644 --- a/osfmk/kern/timer.h +++ b/osfmk/kern/timer.h @@ -1,151 +1,163 @@ /* - * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2007 Apple Inc. All rights reserved. * - * @APPLE_LICENSE_OSREFERENCE_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. + * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * - * Please obtain a copy of the License at - * http://www.opensource.apple.com/apsl/ and read it before using this - * file. + * 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. * - * 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, QUIET ENJOYMENT OR NON-INFRINGEMENT. - * Please see the License for the specific language governing rights and + * 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, QUIET ENJOYMENT OR NON-INFRINGEMENT. + * Please see the License for the specific language governing rights and * limitations under the License. * - * @APPLE_LICENSE_OSREFERENCE_HEADER_END@ + * @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. */ - -struct timer { - uint32_t low_bits; - uint32_t high_bits; - uint32_t high_bits_check; -#if !STAT_TIME - uint32_t tstamp; -#endif /* STAT_TIME */ -}; - -typedef struct timer timer_data_t, *timer_t; +extern int precise_user_kernel_time; /* - * Exported kernel interface to timers + * 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) -#if STAT_TIME - -#include - -/* Advance a timer by the specified amount */ -#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_switch(tstamp, new_timer) -#define timer_event(tstamp, new_timer) - -#else /* STAT_TIME */ - -/* Update the current timer and start a new one */ -extern void timer_switch( - uint32_t tstamp, - timer_t new_timer); - -#define TIMER_BUMP(timer, ticks) +/* + * Definitions for high resolution timers. + */ -#endif /* STAT_TIME */ +#if __LP64__ +#define TIMER_ALIGNMENT +#else +#define TIMER_ALIGNMENT __attribute__((packed, aligned(4))) +#endif -/* Initialize a timer */ -extern void timer_init( - timer_t timer); +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; -/* Update a saved timer value and return delta to current value */ -extern uint64_t timer_delta( - timer_t timer, - uint64_t *save); +/* + * Initialize the `timer`. + */ +void timer_init(timer_t timer); /* - * Exported hardware interface to timers + * Start the `timer` at time `tstamp`. */ +void timer_start(timer_t timer, uint64_t tstamp); -/* Read timer value */ -extern uint64_t timer_grab( - timer_t timer); +/* + * Stop the `timer` and update it with time `tstamp`. + */ +void timer_stop(timer_t timer, uint64_t tstamp); -/* Update timer value */ -extern void timer_update( - timer_t timer, - uint32_t new_high, - uint32_t new_low); +/* + * Update the `timer` at time `tstamp`, leaving it running. + */ +void timer_update(timer_t timer, uint64_t tstamp); -#if !STAT_TIME +/* + * 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 current timer at an event */ -extern void timer_event( - uint32_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); -#endif /* STAT_TIME */ +/* + * 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); -#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_ */