/*
* Copyright (c) 2000-2011 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
* 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, 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@
*/
#include <mach/mach_types.h>
#include <architecture/i386/pio.h>
#include <i386/machine_cpu.h>
#include <i386/cpuid.h>
#include <i386/cpu_threads.h>
#include <i386/mp.h>
#include <i386/machine_routines.h>
#include <i386/pal_routines.h>
#include <i386/proc_reg.h>
#include <i386/misc_protos.h>
#include <i386/lapic.h>
#include <pexpert/pexpert.h>
#include <machine/limits.h>
#include <sys/kdebug.h>
#include <i386/tsc.h>
#include <i386/rtclock_protos.h>
#include <i386/pal_routines.h>
#include <kern/timer_queue.h>
static uint64_t rtc_decrementer_min;
static uint64_t rtc_decrementer_max;
static uint64_t
deadline_to_decrementer(
uint64_t deadline,
uint64_t now)
{
uint64_t delta;
if (deadline <= now) {
return rtc_decrementer_min;
} else {
delta = deadline - now;
return MIN(MAX(rtc_decrementer_min, delta), rtc_decrementer_max);
}
}
/*
* Regular local APIC timer case:
*/
static void
rtc_lapic_config_timer(void)
{
lapic_config_timer(TRUE, one_shot, divide_by_1);
}
static uint64_t
rtc_lapic_set_timer(uint64_t deadline, uint64_t now)
{
uint64_t count;
uint64_t set = 0;
if (deadline > 0) {
/*
* Convert delta to bus ticks
* - time now is not relevant
*/
count = deadline_to_decrementer(deadline, now);
set = now + count;
lapic_set_timer_fast((uint32_t) tmrCvt(count, busFCvtn2t));
} else {
lapic_set_timer(FALSE, one_shot, divide_by_1, 0);
}
KERNEL_DEBUG_CONSTANT(
DECR_SET_APIC_DEADLINE | DBG_FUNC_NONE,
now, deadline,
set, LAPIC_READ(TIMER_CURRENT_COUNT),
0);
return set;
}
/*
* TSC-deadline timer case:
*/
static void
rtc_lapic_config_tsc_deadline_timer(void)
{
lapic_config_tsc_deadline_timer();
}
static uint64_t
rtc_lapic_set_tsc_deadline_timer(uint64_t deadline, uint64_t now)
{
uint64_t delta;
uint64_t delta_tsc;
uint64_t tsc = rdtsc64();
uint64_t set = 0;
uint64_t dead_tsc;
if (deadline > 0) {
/*
* Convert to TSC
*/
delta = deadline_to_decrementer(deadline, now);
set = now + delta;
delta_tsc = tmrCvt(delta, tscFCvtn2t);
dead_tsc = tsc + delta_tsc;
} else {
dead_tsc = 0;
}
lapic_set_tsc_deadline_timer(dead_tsc);
KERNEL_DEBUG_CONSTANT(
DECR_SET_TSC_DEADLINE | DBG_FUNC_NONE,
now, deadline,
tsc, dead_tsc,
0);
return set;
}
/*
* Definitions for timer operations table
*/
rtc_timer_t rtc_timer_lapic = {
.rtc_config = rtc_lapic_config_timer,
.rtc_set = rtc_lapic_set_timer,
};
rtc_timer_t rtc_timer_tsc_deadline = {
.rtc_config = rtc_lapic_config_tsc_deadline_timer,
.rtc_set = rtc_lapic_set_tsc_deadline_timer,
};
rtc_timer_t *rtc_timer = &rtc_timer_lapic; /* defaults to LAPIC timer */
/*
* rtc_timer_init() is called at startup on the boot processor only.
*/
void
rtc_timer_init(void)
{
int TSC_deadline_timer = 0;
/* See whether we can use the local apic in TSC-deadline mode */
if ((cpuid_features() & CPUID_FEATURE_TSCTMR)) {
TSC_deadline_timer = 1;
PE_parse_boot_argn("TSC_deadline_timer", &TSC_deadline_timer,
sizeof(TSC_deadline_timer));
printf("TSC Deadline Timer supported %s enabled\n",
TSC_deadline_timer ? "and" : "but not");
}
if (TSC_deadline_timer) {
rtc_timer = &rtc_timer_tsc_deadline;
rtc_decrementer_max = UINT64_MAX; /* effectively none */
/*
* The min could be as low as 1nsec,
* but we're being conservative for now and making it the same
* as for the local apic timer.
*/
rtc_decrementer_min = 1 * NSEC_PER_USEC; /* 1 usec */
} else {
/*
* Compute the longest interval using LAPIC timer.
*/
rtc_decrementer_max = tmrCvt(0x7fffffffULL, busFCvtt2n);
kprintf("maxDec: %lld\n", rtc_decrementer_max);
rtc_decrementer_min = 1 * NSEC_PER_USEC; /* 1 usec */
}
/* Point LAPIC interrupts to hardclock() */
lapic_set_timer_func((i386_intr_func_t) rtclock_intr);
}