[apple/xnu.git] / osfmk / i386 / rtclock_native.c

/*
 * 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 <platforms.h>
#include <mach_kdb.h>

#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/etimer.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);
	}
	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;

	if (deadline > 0) {
		/*
		 * Convert to TSC
		 */
		delta = deadline_to_decrementer(deadline, now);
		set = now + delta;
		delta_tsc = tmrCvt(delta, tscFCvtn2t);
		lapic_set_tsc_deadline_timer(tsc + delta_tsc);
	} else {
		lapic_set_tsc_deadline_timer(0);
	}
	
	KERNEL_DEBUG_CONSTANT(
		DECR_SET_TSC_DEADLINE | DBG_FUNC_NONE,
		now, deadline,
		tsc, lapic_get_tsc_deadline_timer(),
		0);

	return set;
} 

/*
 * Definitions for timer operations table
 */

rtc_timer_t	rtc_timer_lapic  = {
	rtc_lapic_config_timer,
	rtc_lapic_set_timer
};

rtc_timer_t	rtc_timer_tsc_deadline  = {
	rtc_lapic_config_tsc_deadline_timer,
	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);
}
Commit	Line	Data
6d2010ae	1	/*
ebb1b9f4	2	* Copyright (c) 2000-2011 Apple Inc. All rights reserved.
6d2010ae A	3	*
	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
	25	*
	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
	27	*/
	28	/*
	29	* @OSF_COPYRIGHT@
	30	*/
	31
	32	#include <platforms.h>
	33	#include <mach_kdb.h>
	34
	35	#include <mach/mach_types.h>
	36
	37	#include <architecture/i386/pio.h>
	38	#include <i386/machine_cpu.h>
	39	#include <i386/cpuid.h>
	40	#include <i386/cpu_threads.h>
	41	#include <i386/mp.h>
	42	#include <i386/machine_routines.h>
	43	#include <i386/pal_routines.h>
	44	#include <i386/proc_reg.h>
	45	#include <i386/misc_protos.h>
	46	#include <i386/lapic.h>
	47	#include <pexpert/pexpert.h>
	48	#include <machine/limits.h>
	49	#include <sys/kdebug.h>
	50	#include <i386/tsc.h>
	51	#include <i386/rtclock_protos.h>
	52	#include <i386/pal_routines.h>
	53	#include <kern/etimer.h>
	54
	55	static uint64_t rtc_decrementer_min;
	56	static uint64_t rtc_decrementer_max;
	57
	58	static uint64_t
	59	deadline_to_decrementer(
	60	uint64_t deadline,
	61	uint64_t now)
	62	{
	63	uint64_t delta;
	64
	65	if (deadline <= now)
	66	return rtc_decrementer_min;
67	else {
68	delta = deadline - now;
69	return MIN(MAX(rtc_decrementer_min,delta),rtc_decrementer_max);
70	}
71	}
72
6d2010ae A	73
	74	/*
	75	* Regular local APIC timer case:
	76	*/
	77	static void
	78	rtc_lapic_config_timer(void)
	79	{
	80	lapic_config_timer(TRUE, one_shot, divide_by_1);
	81	}
	82	static uint64_t
	83	rtc_lapic_set_timer(uint64_t deadline, uint64_t now)
	84	{
	85	uint64_t count;
	86	uint64_t set = 0;
	87
	88	if (deadline > 0) {
	89	/*
	90	* Convert delta to bus ticks
	91	* - time now is not relevant
	92	*/
	93	count = deadline_to_decrementer(deadline, now);
	94	set = now + count;
	95	lapic_set_timer_fast((uint32_t) tmrCvt(count, busFCvtn2t));
	96	} else {
	97	lapic_set_timer(FALSE, one_shot, divide_by_1, 0);
	98	}
	99	return set;
	100	}
	101
	102	/*
	103	* TSC-deadline timer case:
	104	*/
	105	static void
	106	rtc_lapic_config_tsc_deadline_timer(void)
	107	{
	108	lapic_config_tsc_deadline_timer();
	109	}
	110	static uint64_t
	111	rtc_lapic_set_tsc_deadline_timer(uint64_t deadline, uint64_t now)
	112	{
ebb1b9f4 A	113	uint64_t delta;
	114	uint64_t delta_tsc;
	115	uint64_t tsc = rdtsc64();
	116	uint64_t set = 0;
6d2010ae A	117
	118	if (deadline > 0) {
	119	/*
	120	* Convert to TSC
	121	*/
ebb1b9f4 A	122	delta = deadline_to_decrementer(deadline, now);
	123	set = now + delta;
	124	delta_tsc = tmrCvt(delta, tscFCvtn2t);
	125	lapic_set_tsc_deadline_timer(tsc + delta_tsc);
6d2010ae A	126	} else {
	127	lapic_set_tsc_deadline_timer(0);
	128	}
	129
	130	KERNEL_DEBUG_CONSTANT(
	131	DECR_SET_TSC_DEADLINE \| DBG_FUNC_NONE,
	132	now, deadline,
ebb1b9f4	133	tsc, lapic_get_tsc_deadline_timer(),
6d2010ae A	134	0);
	135
	136	return set;
	137	}
	138
	139	/*
	140	* Definitions for timer operations table
	141	*/
	142
	143	rtc_timer_t rtc_timer_lapic = {
	144	rtc_lapic_config_timer,
	145	rtc_lapic_set_timer
	146	};
	147
	148	rtc_timer_t rtc_timer_tsc_deadline = {
	149	rtc_lapic_config_tsc_deadline_timer,
	150	rtc_lapic_set_tsc_deadline_timer
	151	};
	152
	153	rtc_timer_t rtc_timer = &rtc_timer_lapic; / defaults to LAPIC timer */
	154
	155	/*
	156	* rtc_timer_init() is called at startup on the boot processor only.
	157	*/
	158	void
	159	rtc_timer_init(void)
	160	{
	161	int TSC_deadline_timer = 0;
	162
	163	/* See whether we can use the local apic in TSC-deadline mode */
	164	if ((cpuid_features() & CPUID_FEATURE_TSCTMR)) {
	165	TSC_deadline_timer = 1;
	166	PE_parse_boot_argn("TSC_deadline_timer", &TSC_deadline_timer,
	167	sizeof(TSC_deadline_timer));
	168	printf("TSC Deadline Timer supported %s enabled\n",
	169	TSC_deadline_timer ? "and" : "but not");
	170	}
	171
	172	if (TSC_deadline_timer) {
	173	rtc_timer = &rtc_timer_tsc_deadline;
	174	rtc_decrementer_max = UINT64_MAX; /* effectively none */
	175	/*
	176	* The min could be as low as 1nsec,
	177	* but we're being conservative for now and making it the same
	178	* as for the local apic timer.
	179	*/
	180	rtc_decrementer_min = 1NSEC_PER_USEC; / 1 usec */
	181	} else {
	182	/*
	183	* Compute the longest interval using LAPIC timer.
	184	*/
	185	rtc_decrementer_max = tmrCvt(0x7fffffffULL, busFCvtt2n);
	186	kprintf("maxDec: %lld\n", rtc_decrementer_max);
	187	rtc_decrementer_min = 1NSEC_PER_USEC; / 1 usec */
	188	}
	189
	190	/* Point LAPIC interrupts to hardclock() */
	191	lapic_set_timer_func((i386_intr_func_t) rtclock_intr);
	192	}