[deliverable/linux.git] / arch / x86 / kernel / vmiclock_32.c

/*
 * VMI paravirtual timer support routines.
 *
 * Copyright (C) 2007, VMware, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/cpumask.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>

#include <asm/vmi.h>
#include <asm/vmi_time.h>
#include <asm/arch_hooks.h>
#include <asm/apicdef.h>
#include <asm/apic.h>
#include <asm/timer.h>
#include <asm/i8253.h>
#include <asm/irq_vectors.h>

#define VMI_ONESHOT  (VMI_ALARM_IS_ONESHOT  | VMI_CYCLES_REAL | vmi_get_alarm_wiring())
#define VMI_PERIODIC (VMI_ALARM_IS_PERIODIC | VMI_CYCLES_REAL | vmi_get_alarm_wiring())

static DEFINE_PER_CPU(struct clock_event_device, local_events);

static inline u32 vmi_counter(u32 flags)
{
	/* Given VMI_ONESHOT or VMI_PERIODIC, return the corresponding
	 * cycle counter. */
	return flags & VMI_ALARM_COUNTER_MASK;
}

/* paravirt_ops.get_wallclock = vmi_get_wallclock */
unsigned long vmi_get_wallclock(void)
{
	unsigned long long wallclock;
	wallclock = vmi_timer_ops.get_wallclock(); // nsec
	(void)do_div(wallclock, 1000000000);       // sec

	return wallclock;
}

/* paravirt_ops.set_wallclock = vmi_set_wallclock */
int vmi_set_wallclock(unsigned long now)
{
	return 0;
}

/* paravirt_ops.sched_clock = vmi_sched_clock */
unsigned long long vmi_sched_clock(void)
{
	return cycles_2_ns(vmi_timer_ops.get_cycle_counter(VMI_CYCLES_AVAILABLE));
}

/* paravirt_ops.get_tsc_khz = vmi_tsc_khz */
unsigned long vmi_tsc_khz(void)
{
	unsigned long long khz;
	khz = vmi_timer_ops.get_cycle_frequency();
	(void)do_div(khz, 1000);
	return khz;
}

static inline unsigned int vmi_get_timer_vector(void)
{
#ifdef CONFIG_X86_IO_APIC
	return FIRST_DEVICE_VECTOR;
#else
	return FIRST_EXTERNAL_VECTOR;
#endif
}

/** vmi clockchip */
#ifdef CONFIG_X86_LOCAL_APIC
static unsigned int startup_timer_irq(unsigned int irq)
{
	unsigned long val = apic_read(APIC_LVTT);
	apic_write(APIC_LVTT, vmi_get_timer_vector());

	return (val & APIC_SEND_PENDING);
}

static void mask_timer_irq(unsigned int irq)
{
	unsigned long val = apic_read(APIC_LVTT);
	apic_write(APIC_LVTT, val | APIC_LVT_MASKED);
}

static void unmask_timer_irq(unsigned int irq)
{
	unsigned long val = apic_read(APIC_LVTT);
	apic_write(APIC_LVTT, val & ~APIC_LVT_MASKED);
}

static void ack_timer_irq(unsigned int irq)
{
	ack_APIC_irq();
}

static struct irq_chip vmi_chip __read_mostly = {
	.name 		= "VMI-LOCAL",
	.startup 	= startup_timer_irq,
	.mask	 	= mask_timer_irq,
	.unmask	 	= unmask_timer_irq,
	.ack 		= ack_timer_irq
};
#endif

/** vmi clockevent */
#define VMI_ALARM_WIRED_IRQ0    0x00000000
#define VMI_ALARM_WIRED_LVTT    0x00010000
static int vmi_wiring = VMI_ALARM_WIRED_IRQ0;

static inline int vmi_get_alarm_wiring(void)
{
	return vmi_wiring;
}

static void vmi_timer_set_mode(enum clock_event_mode mode,
			       struct clock_event_device *evt)
{
	cycle_t now, cycles_per_hz;
	BUG_ON(!irqs_disabled());

	switch (mode) {
	case CLOCK_EVT_MODE_ONESHOT:
	case CLOCK_EVT_MODE_RESUME:
		break;
	case CLOCK_EVT_MODE_PERIODIC:
		cycles_per_hz = vmi_timer_ops.get_cycle_frequency();
		(void)do_div(cycles_per_hz, HZ);
		now = vmi_timer_ops.get_cycle_counter(vmi_counter(VMI_PERIODIC));
		vmi_timer_ops.set_alarm(VMI_PERIODIC, now, cycles_per_hz);
		break;
	case CLOCK_EVT_MODE_UNUSED:
	case CLOCK_EVT_MODE_SHUTDOWN:
		switch (evt->mode) {
		case CLOCK_EVT_MODE_ONESHOT:
			vmi_timer_ops.cancel_alarm(VMI_ONESHOT);
			break;
		case CLOCK_EVT_MODE_PERIODIC:
			vmi_timer_ops.cancel_alarm(VMI_PERIODIC);
			break;
		default:
			break;
		}
		break;
	default:
		break;
	}
}

static int vmi_timer_next_event(unsigned long delta,
				struct clock_event_device *evt)
{
	/* Unfortunately, set_next_event interface only passes relative
	 * expiry, but we want absolute expiry.  It'd be better if were
	 * were passed an aboslute expiry, since a bunch of time may
	 * have been stolen between the time the delta is computed and
	 * when we set the alarm below. */
	cycle_t now = vmi_timer_ops.get_cycle_counter(vmi_counter(VMI_ONESHOT));

	BUG_ON(evt->mode != CLOCK_EVT_MODE_ONESHOT);
	vmi_timer_ops.set_alarm(VMI_ONESHOT, now + delta, 0);
	return 0;
}

static struct clock_event_device vmi_clockevent = {
	.name		= "vmi-timer",
	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
	.shift		= 22,
	.set_mode	= vmi_timer_set_mode,
	.set_next_event = vmi_timer_next_event,
	.rating         = 1000,
	.irq		= 0,
};

static irqreturn_t vmi_timer_interrupt(int irq, void *dev_id)
{
	struct clock_event_device *evt = &__get_cpu_var(local_events);
	evt->event_handler(evt);
	return IRQ_HANDLED;
}

static struct irqaction vmi_clock_action  = {
	.name 		= "vmi-timer",
	.handler 	= vmi_timer_interrupt,
	.flags 		= IRQF_DISABLED | IRQF_NOBALANCING,
	.mask 		= CPU_MASK_ALL,
};

static void __devinit vmi_time_init_clockevent(void)
{
	cycle_t cycles_per_msec;
	struct clock_event_device *evt;

	int cpu = smp_processor_id();
	evt = &__get_cpu_var(local_events);

	/* Use cycles_per_msec since div_sc params are 32-bits. */
	cycles_per_msec = vmi_timer_ops.get_cycle_frequency();
	(void)do_div(cycles_per_msec, 1000);

	memcpy(evt, &vmi_clockevent, sizeof(*evt));
	/* Must pick .shift such that .mult fits in 32-bits.  Choosing
	 * .shift to be 22 allows 2^(32-22) cycles per nano-seconds
	 * before overflow. */
	evt->mult = div_sc(cycles_per_msec, NSEC_PER_MSEC, evt->shift);
	/* Upper bound is clockevent's use of ulong for cycle deltas. */
	evt->max_delta_ns = clockevent_delta2ns(ULONG_MAX, evt);
	evt->min_delta_ns = clockevent_delta2ns(1, evt);
	evt->cpumask = cpumask_of(cpu);

	printk(KERN_WARNING "vmi: registering clock event %s. mult=%lu shift=%u\n",
	       evt->name, evt->mult, evt->shift);
	clockevents_register_device(evt);
}

void __init vmi_time_init(void)
{
	unsigned int cpu;
	/* Disable PIT: BIOSes start PIT CH0 with 18.2hz peridic. */
	outb_pit(0x3a, PIT_MODE); /* binary, mode 5, LSB/MSB, ch 0 */

	vmi_time_init_clockevent();
	setup_irq(0, &vmi_clock_action);
	for_each_possible_cpu(cpu)
		per_cpu(vector_irq, cpu)[vmi_get_timer_vector()] = 0;
}

#ifdef CONFIG_X86_LOCAL_APIC
void __devinit vmi_time_bsp_init(void)
{
	/*
	 * On APIC systems, we want local timers to fire on each cpu.  We do
	 * this by programming LVTT to deliver timer events to the IRQ handler
	 * for IRQ-0, since we can't re-use the APIC local timer handler
	 * without interfering with that code.
	 */
	clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
	local_irq_disable();
#ifdef CONFIG_X86_SMP
	/*
	 * XXX handle_percpu_irq only defined for SMP; we need to switch over
	 * to using it, since this is a local interrupt, which each CPU must
	 * handle individually without locking out or dropping simultaneous
	 * local timers on other CPUs.  We also don't want to trigger the
	 * quirk workaround code for interrupts which gets invoked from
	 * handle_percpu_irq via eoi, so we use our own IRQ chip.
	 */
	set_irq_chip_and_handler_name(0, &vmi_chip, handle_percpu_irq, "lvtt");
#else
	set_irq_chip_and_handler_name(0, &vmi_chip, handle_edge_irq, "lvtt");
#endif
	vmi_wiring = VMI_ALARM_WIRED_LVTT;
	apic_write(APIC_LVTT, vmi_get_timer_vector());
	local_irq_enable();
	clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL);
}

void __devinit vmi_time_ap_init(void)
{
	vmi_time_init_clockevent();
	apic_write(APIC_LVTT, vmi_get_timer_vector());
}
#endif

/** vmi clocksource */

static cycle_t read_real_cycles(void)
{
	return vmi_timer_ops.get_cycle_counter(VMI_CYCLES_REAL);
}

static struct clocksource clocksource_vmi = {
	.name			= "vmi-timer",
	.rating			= 450,
	.read			= read_real_cycles,
	.mask			= CLOCKSOURCE_MASK(64),
	.mult			= 0, /* to be set */
	.shift			= 22,
	.flags			= CLOCK_SOURCE_IS_CONTINUOUS,
};

static int __init init_vmi_clocksource(void)
{
	cycle_t cycles_per_msec;

	if (!vmi_timer_ops.get_cycle_frequency)
		return 0;
	/* Use khz2mult rather than hz2mult since hz arg is only 32-bits. */
	cycles_per_msec = vmi_timer_ops.get_cycle_frequency();
	(void)do_div(cycles_per_msec, 1000);

	/* Note that clocksource.{mult, shift} converts in the opposite direction
	 * as clockevents.  */
	clocksource_vmi.mult = clocksource_khz2mult(cycles_per_msec,
						    clocksource_vmi.shift);

	printk(KERN_WARNING "vmi: registering clock source khz=%lld\n", cycles_per_msec);
	return clocksource_register(&clocksource_vmi);

}
module_init(init_vmi_clocksource);
Commit	Line	Data
e0bb8643 ZA	1	/*
	2	* VMI paravirtual timer support routines.
	3	*
	4	* Copyright (C) 2007, VMware, Inc.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful, but
	12	* WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
	14	* NON INFRINGEMENT. See the GNU General Public License for more
	15	* details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to the Free Software
	19	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	20	*
	21	*/
	22
	23	#include <linux/smp.h>
	24	#include <linux/interrupt.h>
	25	#include <linux/cpumask.h>
	26	#include <linux/clocksource.h>
	27	#include <linux/clockchips.h>
	28
	29	#include <asm/vmi.h>
	30	#include <asm/vmi_time.h>
	31	#include <asm/arch_hooks.h>
	32	#include <asm/apicdef.h>
	33	#include <asm/apic.h>
	34	#include <asm/timer.h>
a2900975	35	#include <asm/i8253.h>
9b7dc567	36	#include <asm/irq_vectors.h>
e0bb8643 ZA	37
	38	#define VMI_ONESHOT (VMI_ALARM_IS_ONESHOT \| VMI_CYCLES_REAL \| vmi_get_alarm_wiring())
	39	#define VMI_PERIODIC (VMI_ALARM_IS_PERIODIC \| VMI_CYCLES_REAL \| vmi_get_alarm_wiring())
	40
	41	static DEFINE_PER_CPU(struct clock_event_device, local_events);
	42
	43	static inline u32 vmi_counter(u32 flags)
	44	{
	45	/* Given VMI_ONESHOT or VMI_PERIODIC, return the corresponding
	46	* cycle counter. */
	47	return flags & VMI_ALARM_COUNTER_MASK;
	48	}
	49
	50	/* paravirt_ops.get_wallclock = vmi_get_wallclock */
	51	unsigned long vmi_get_wallclock(void)
	52	{
	53	unsigned long long wallclock;
	54	wallclock = vmi_timer_ops.get_wallclock(); // nsec
	55	(void)do_div(wallclock, 1000000000); // sec
	56
	57	return wallclock;
	58	}
	59
	60	/* paravirt_ops.set_wallclock = vmi_set_wallclock */
	61	int vmi_set_wallclock(unsigned long now)
	62	{
	63	return 0;
	64	}
	65
688340ea JF	66	/* paravirt_ops.sched_clock = vmi_sched_clock */
688340ea JF	67	unsigned long long vmi_sched_clock(void)
e0bb8643	68	{
688340ea	69	return cycles_2_ns(vmi_timer_ops.get_cycle_counter(VMI_CYCLES_AVAILABLE));
e0bb8643 ZA	70	}
e0bb8643 ZA	71
e93ef949 AK	72	/* paravirt_ops.get_tsc_khz = vmi_tsc_khz */
e93ef949 AK	73	unsigned long vmi_tsc_khz(void)
e0bb8643 ZA	74	{
	75	unsigned long long khz;
	76	khz = vmi_timer_ops.get_cycle_frequency();
	77	(void)do_div(khz, 1000);
	78	return khz;
	79	}
	80
	81	static inline unsigned int vmi_get_timer_vector(void)
	82	{
	83	#ifdef CONFIG_X86_IO_APIC
	84	return FIRST_DEVICE_VECTOR;
	85	#else
	86	return FIRST_EXTERNAL_VECTOR;
	87	#endif
	88	}
	89
	90	/** vmi clockchip */
	91	#ifdef CONFIG_X86_LOCAL_APIC
	92	static unsigned int startup_timer_irq(unsigned int irq)
	93	{
	94	unsigned long val = apic_read(APIC_LVTT);
	95	apic_write(APIC_LVTT, vmi_get_timer_vector());
	96
	97	return (val & APIC_SEND_PENDING);
	98	}
	99
	100	static void mask_timer_irq(unsigned int irq)
	101	{
	102	unsigned long val = apic_read(APIC_LVTT);
	103	apic_write(APIC_LVTT, val \| APIC_LVT_MASKED);
	104	}
	105
	106	static void unmask_timer_irq(unsigned int irq)
	107	{
	108	unsigned long val = apic_read(APIC_LVTT);
	109	apic_write(APIC_LVTT, val & ~APIC_LVT_MASKED);
	110	}
	111
	112	static void ack_timer_irq(unsigned int irq)
	113	{
	114	ack_APIC_irq();
	115	}
	116
	117	static struct irq_chip vmi_chip __read_mostly = {
	118	.name = "VMI-LOCAL",
	119	.startup = startup_timer_irq,
	120	.mask = mask_timer_irq,
	121	.unmask = unmask_timer_irq,
	122	.ack = ack_timer_irq
	123	};
	124	#endif
	125
	126	/** vmi clockevent */
	127	#define VMI_ALARM_WIRED_IRQ0 0x00000000
	128	#define VMI_ALARM_WIRED_LVTT 0x00010000
	129	static int vmi_wiring = VMI_ALARM_WIRED_IRQ0;
	130
	131	static inline int vmi_get_alarm_wiring(void)
	132	{
	133	return vmi_wiring;
	134	}
	135
	136	static void vmi_timer_set_mode(enum clock_event_mode mode,
	137	struct clock_event_device *evt)
138	{
139	cycle_t now, cycles_per_hz;
140	BUG_ON(!irqs_disabled());
141
142	switch (mode) {
143	case CLOCK_EVT_MODE_ONESHOT:
18de5bc4	144	case CLOCK_EVT_MODE_RESUME:
e0bb8643 ZA	145	break;
	146	case CLOCK_EVT_MODE_PERIODIC:
	147	cycles_per_hz = vmi_timer_ops.get_cycle_frequency();
	148	(void)do_div(cycles_per_hz, HZ);
	149	now = vmi_timer_ops.get_cycle_counter(vmi_counter(VMI_PERIODIC));
	150	vmi_timer_ops.set_alarm(VMI_PERIODIC, now, cycles_per_hz);
	151	break;
	152	case CLOCK_EVT_MODE_UNUSED:
	153	case CLOCK_EVT_MODE_SHUTDOWN:
	154	switch (evt->mode) {
	155	case CLOCK_EVT_MODE_ONESHOT:
	156	vmi_timer_ops.cancel_alarm(VMI_ONESHOT);
	157	break;
	158	case CLOCK_EVT_MODE_PERIODIC:
	159	vmi_timer_ops.cancel_alarm(VMI_PERIODIC);
	160	break;
	161	default:
	162	break;
	163	}
	164	break;
	165	default:
	166	break;
	167	}
	168	}
	169
	170	static int vmi_timer_next_event(unsigned long delta,
	171	struct clock_event_device *evt)
	172	{
	173	/* Unfortunately, set_next_event interface only passes relative
	174	* expiry, but we want absolute expiry. It'd be better if were
	175	* were passed an aboslute expiry, since a bunch of time may
	176	* have been stolen between the time the delta is computed and
	177	* when we set the alarm below. */
	178	cycle_t now = vmi_timer_ops.get_cycle_counter(vmi_counter(VMI_ONESHOT));
	179
	180	BUG_ON(evt->mode != CLOCK_EVT_MODE_ONESHOT);
	181	vmi_timer_ops.set_alarm(VMI_ONESHOT, now + delta, 0);
	182	return 0;
	183	}
	184
	185	static struct clock_event_device vmi_clockevent = {
	186	.name = "vmi-timer",
	187	.features = CLOCK_EVT_FEAT_PERIODIC \| CLOCK_EVT_FEAT_ONESHOT,
	188	.shift = 22,
	189	.set_mode = vmi_timer_set_mode,
	190	.set_next_event = vmi_timer_next_event,
	191	.rating = 1000,
	192	.irq = 0,
	193	};
	194
	195	static irqreturn_t vmi_timer_interrupt(int irq, void *dev_id)
	196	{
	197	struct clock_event_device *evt = &__get_cpu_var(local_events);
	198	evt->event_handler(evt);
	199	return IRQ_HANDLED;
	200	}
	201
	202	static struct irqaction vmi_clock_action = {
	203	.name = "vmi-timer",
	204	.handler = vmi_timer_interrupt,
	205	.flags = IRQF_DISABLED \| IRQF_NOBALANCING,
	206	.mask = CPU_MASK_ALL,
	207	};
	208
209	static void __devinit vmi_time_init_clockevent(void)
210	{
211	cycle_t cycles_per_msec;
212	struct clock_event_device *evt;
213
214	int cpu = smp_processor_id();
215	evt = &__get_cpu_var(local_events);
216
217	/* Use cycles_per_msec since div_sc params are 32-bits. */
218	cycles_per_msec = vmi_timer_ops.get_cycle_frequency();
219	(void)do_div(cycles_per_msec, 1000);
220
221	memcpy(evt, &vmi_clockevent, sizeof(*evt));
222	/* Must pick .shift such that .mult fits in 32-bits. Choosing
223	* .shift to be 22 allows 2^(32-22) cycles per nano-seconds
224	* before overflow. */
225	evt->mult = div_sc(cycles_per_msec, NSEC_PER_MSEC, evt->shift);
226	/* Upper bound is clockevent's use of ulong for cycle deltas. */
227	evt->max_delta_ns = clockevent_delta2ns(ULONG_MAX, evt);
228	evt->min_delta_ns = clockevent_delta2ns(1, evt);
320ab2b0	229	evt->cpumask = cpumask_of(cpu);
e0bb8643 ZA	230
	231	printk(KERN_WARNING "vmi: registering clock event %s. mult=%lu shift=%u\n",
	232	evt->name, evt->mult, evt->shift);
	233	clockevents_register_device(evt);
	234	}
	235
	236	void __init vmi_time_init(void)
	237	{
2699574b	238	unsigned int cpu;
e0bb8643	239	/* Disable PIT: BIOSes start PIT CH0 with 18.2hz peridic. */
466eed22	240	outb_pit(0x3a, PIT_MODE); /* binary, mode 5, LSB/MSB, ch 0 */
e0bb8643 ZA	241
	242	vmi_time_init_clockevent();
	243	setup_irq(0, &vmi_clock_action);
2699574b AK	244	for_each_possible_cpu(cpu)
2699574b AK	245	per_cpu(vector_irq, cpu)[vmi_get_timer_vector()] = 0;
e0bb8643 ZA	246	}
	247
	248	#ifdef CONFIG_X86_LOCAL_APIC
	249	void __devinit vmi_time_bsp_init(void)
	250	{
	251	/*
	252	* On APIC systems, we want local timers to fire on each cpu. We do
	253	* this by programming LVTT to deliver timer events to the IRQ handler
	254	* for IRQ-0, since we can't re-use the APIC local timer handler
	255	* without interfering with that code.
	256	*/
	257	clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
	258	local_irq_disable();
	259	#ifdef CONFIG_X86_SMP
	260	/*
	261	* XXX handle_percpu_irq only defined for SMP; we need to switch over
	262	* to using it, since this is a local interrupt, which each CPU must
	263	* handle individually without locking out or dropping simultaneous
	264	* local timers on other CPUs. We also don't want to trigger the
	265	* quirk workaround code for interrupts which gets invoked from
	266	* handle_percpu_irq via eoi, so we use our own IRQ chip.
	267	*/
	268	set_irq_chip_and_handler_name(0, &vmi_chip, handle_percpu_irq, "lvtt");
	269	#else
	270	set_irq_chip_and_handler_name(0, &vmi_chip, handle_edge_irq, "lvtt");
	271	#endif
	272	vmi_wiring = VMI_ALARM_WIRED_LVTT;
	273	apic_write(APIC_LVTT, vmi_get_timer_vector());
	274	local_irq_enable();
	275	clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL);
	276	}
	277
	278	void __devinit vmi_time_ap_init(void)
	279	{
	280	vmi_time_init_clockevent();
	281	apic_write(APIC_LVTT, vmi_get_timer_vector());
	282	}
	283	#endif
	284
	285	/** vmi clocksource */
	286
	287	static cycle_t read_real_cycles(void)
	288	{
	289	return vmi_timer_ops.get_cycle_counter(VMI_CYCLES_REAL);
	290	}
	291
	292	static struct clocksource clocksource_vmi = {
	293	.name = "vmi-timer",
	294	.rating = 450,
	295	.read = read_real_cycles,
	296	.mask = CLOCKSOURCE_MASK(64),
	297	.mult = 0, /* to be set */
	298	.shift = 22,
	299	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
	300	};
	301
	302	static int __init init_vmi_clocksource(void)
	303	{
	304	cycle_t cycles_per_msec;
	305
	306	if (!vmi_timer_ops.get_cycle_frequency)
	307	return 0;
	308	/* Use khz2mult rather than hz2mult since hz arg is only 32-bits. */
	309	cycles_per_msec = vmi_timer_ops.get_cycle_frequency();
310	(void)do_div(cycles_per_msec, 1000);
311
312	/* Note that clocksource.{mult, shift} converts in the opposite direction
313	* as clockevents. */
314	clocksource_vmi.mult = clocksource_khz2mult(cycles_per_msec,
315	clocksource_vmi.shift);
316
317	printk(KERN_WARNING "vmi: registering clock source khz=%lld\n", cycles_per_msec);
318	return clocksource_register(&clocksource_vmi);
319
320	}
321	module_init(init_vmi_clocksource);