/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
- *
- * Copyright (c) 1999-2003 Apple Computer, 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
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * 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
* Please see the License for the specific language governing rights and
* limitations under the License.
*
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*
* @OSF_COPYRIGHT@
#ifndef _KERN_TIMER_H_
#define _KERN_TIMER_H_
-#include <cpus.h>
-#include <stat_time.h>
-
-#include <kern/macro_help.h>
#include <kern/kern_types.h>
-#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 <machine/timer.h>
-
-#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. A check
+ * word on the high portion allows atomic updates.
*/
struct timer {
- unsigned low_bits;
- unsigned high_bits;
- unsigned high_bits_check;
- unsigned tstamp;
-};
-
-typedef struct timer timer_data_t;
-typedef struct timer *timer_t;
-
-/*
- * Mask to check if low_bits is in danger of overflowing
- */
-
-#define TIMER_LOW_FULL 0x80000000
-
-/*
- * Kernel timers and current timer array. [Exported]
- */
-
-extern timer_t current_timer[NCPUS];
-extern timer_data_t kernel_timer[NCPUS];
-
-/*
- * save structure for timer readings. This is used to save timer
- * readings for elapsed time computations.
- */
-
-struct timer_save {
- unsigned low;
- unsigned high;
+ uint64_t tstamp;
+#if defined(__LP64__)
+ uint64_t all_bits;
+#else
+ uint32_t low_bits;
+ uint32_t high_bits;
+ uint32_t high_bits_check;
+#endif
};
-typedef struct timer_save timer_save_data_t, *timer_save_t;
+typedef struct timer timer_data_t, *timer_t;
/*
* Exported kernel interface to timers
*/
-#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);
+/* 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);
-/* Switch to a new timer */
+/* Update the timer and start a new one */
extern void timer_switch(
- timer_t new_timer);
-#endif /* STAT_TIME */
+ timer_t timer,
+ uint64_t tstamp,
+ timer_t new_timer);
-/* Initialize timer module */
-extern void init_timers(void);
+/* Update the thread timer at an event */
+extern void thread_timer_event(
+ uint64_t tstamp,
+ timer_t new_timer);
-/*
- * Initializes a single timer.
- */
+/* Initialize a 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);
+ timer_t timer);
-/* Read thread times */
-extern void thread_read_times(
- thread_t thread,
- time_value_t *user_time_p,
- time_value_t *system_time_p);
+/* Update a saved timer value and return delta to current value */
+extern uint64_t timer_delta(
+ timer_t timer,
+ uint64_t *save);
-/* Compute timer difference */
-extern unsigned timer_delta(
- timer_t timer,
- timer_save_t save);
+/* Advance a timer by a 64 bit value */
+extern void timer_advance(
+ timer_t timer,
+ uint64_t delta);
-#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 */
/*
* Exported hardware interface to timers
*/
-/* 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 */
-
-/*
- * 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().
- */
-#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
+/* Read timer value */
+#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__) */
#endif /* _KERN_TIMER_H_ */
projects / apple / xnu.git / blobdiff