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Commit 1489939f authored by John Stultz's avatar John Stultz Committed by Linus Torvalds
Browse files

[PATCH] time: x86_64: convert x86_64 to use GENERIC_TIME 



This patch converts x86_64 to use the GENERIC_TIME infrastructure and adds
clocksource structures for both TSC and HPET (ACPI PM is shared w/ i386).

[akpm@osdl.org: fix printk timestamps]
[akpm@osdl.org: fix printk ckeanups]
[akpm@osdl.org: hpet build fix]
Signed-off-by: default avatarJohn Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@muc.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c37e7bb5

arch/x86_64/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -24,6 +24,10 @@ config X86 
	bool

	default y



config GENERIC_TIME

	bool

	default y



config ZONE_DMA32

	bool

	default y

arch/x86_64/kernel/apic.c

+1 −1
Original line number Diff line number Diff line
@@ -786,7 +786,7 @@ static void setup_APIC_timer(unsigned int clocks) 
	/* Turn off PIT interrupt if we use APIC timer as main timer.

	   Only works with the PM timer right now

	   TBD fix it for HPET too. */

	if (vxtime.mode == VXTIME_PMTMR &&

	if ((pmtmr_ioport != 0) &&

		smp_processor_id() == boot_cpu_id &&

		apic_runs_main_timer == 1 &&

		!cpu_isset(boot_cpu_id, timer_interrupt_broadcast_ipi_mask)) {

arch/x86_64/kernel/hpet.c

+58 −6
Original line number Diff line number Diff line
@@ -21,12 +21,6 @@ unsigned long hpet_tick; /* HPET clocks / interrupt */ 
int hpet_use_timer;		/* Use counter of hpet for time keeping,

				 * otherwise PIT

				 */

unsigned int do_gettimeoffset_hpet(void)

{

	/* cap counter read to one tick to avoid inconsistencies */

	unsigned long counter = hpet_readl(HPET_COUNTER) - vxtime.last;

	return (min(counter,hpet_tick) * vxtime.quot) >> US_SCALE;

}



#ifdef	CONFIG_HPET

static __init int late_hpet_init(void)
@@ -451,3 +445,61 @@ static int __init nohpet_setup(char *s) 


__setup("nohpet", nohpet_setup);



#define HPET_MASK	0xFFFFFFFF

#define HPET_SHIFT	22



/* FSEC = 10^-15 NSEC = 10^-9 */

#define FSEC_PER_NSEC	1000000



static void *hpet_ptr;



static cycle_t read_hpet(void)

{

	return (cycle_t)readl(hpet_ptr);

}



struct clocksource clocksource_hpet = {

	.name		= "hpet",

	.rating		= 250,

	.read		= read_hpet,

	.mask		= (cycle_t)HPET_MASK,

	.mult		= 0, /* set below */

	.shift		= HPET_SHIFT,

	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,

};



static int __init init_hpet_clocksource(void)

{

	unsigned long hpet_period;

	void __iomem *hpet_base;

	u64 tmp;



	if (!hpet_address)

		return -ENODEV;



	/* calculate the hpet address: */

	hpet_base = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);

	hpet_ptr = hpet_base + HPET_COUNTER;



	/* calculate the frequency: */

	hpet_period = readl(hpet_base + HPET_PERIOD);



	/*

	 * hpet period is in femto seconds per cycle

	 * so we need to convert this to ns/cyc units

	 * aproximated by mult/2^shift

	 *

	 *  fsec/cyc * 1nsec/1000000fsec = nsec/cyc = mult/2^shift

	 *  fsec/cyc * 1ns/1000000fsec * 2^shift = mult

	 *  fsec/cyc * 2^shift * 1nsec/1000000fsec = mult

	 *  (fsec/cyc << shift)/1000000 = mult

	 *  (hpet_period << shift)/FSEC_PER_NSEC = mult

	 */

	tmp = (u64)hpet_period << HPET_SHIFT;

	do_div(tmp, FSEC_PER_NSEC);

	clocksource_hpet.mult = (u32)tmp;



	return clocksource_register(&clocksource_hpet);

}



module_init(init_hpet_clocksource);

arch/x86_64/kernel/pmtimer.c

+0 −58
Original line number Diff line number Diff line
@@ -24,15 +24,6 @@ 
#include <asm/msr.h>

#include <asm/vsyscall.h>



/* The I/O port the PMTMR resides at.

 * The location is detected during setup_arch(),

 * in arch/i386/kernel/acpi/boot.c */

u32 pmtmr_ioport __read_mostly;



/* value of the Power timer at last timer interrupt */

static u32 offset_delay;

static u32 last_pmtmr_tick;



#define ACPI_PM_MASK 0xFFFFFF /* limit it to 24 bits */



static inline u32 cyc2us(u32 cycles)
@@ -48,38 +39,6 @@ static inline u32 cyc2us(u32 cycles) 
	return (cycles >> 10);

}



int pmtimer_mark_offset(void)

{

	static int first_run = 1;

	unsigned long tsc;

	u32 lost;



	u32 tick = inl(pmtmr_ioport);

	u32 delta;



	delta = cyc2us((tick - last_pmtmr_tick) & ACPI_PM_MASK);



	last_pmtmr_tick = tick;

	monotonic_base += delta * NSEC_PER_USEC;



	delta += offset_delay;



	lost = delta / (USEC_PER_SEC / HZ);

	offset_delay = delta % (USEC_PER_SEC / HZ);



	rdtscll(tsc);

	vxtime.last_tsc = tsc - offset_delay * (u64)cpu_khz / 1000;



	/* don't calculate delay for first run,

	   or if we've got less then a tick */

	if (first_run || (lost < 1)) {

		first_run = 0;

		offset_delay = 0;

	}



	return lost - 1;

}



static unsigned pmtimer_wait_tick(void)

{

	u32 a, b;
@@ -101,23 +60,6 @@ void pmtimer_wait(unsigned us) 
	} while (cyc2us(b - a) < us);

}



void pmtimer_resume(void)

{

	last_pmtmr_tick = inl(pmtmr_ioport);

}



unsigned int do_gettimeoffset_pm(void)

{

	u32 now, offset, delta = 0;



	offset = last_pmtmr_tick;

	now = inl(pmtmr_ioport);

	delta = (now - offset) & ACPI_PM_MASK;



	return offset_delay + cyc2us(delta);

}





static int __init nopmtimer_setup(char *s)

{

	pmtmr_ioport = 0;

arch/x86_64/kernel/smpboot.c

+0 −1
Original line number Diff line number Diff line
@@ -982,7 +982,6 @@ void __init smp_cpus_done(unsigned int max_cpus) 
	smp_cleanup_boot();

	setup_ioapic_dest();

	check_nmi_watchdog();

	time_init_gtod();

}



#ifdef CONFIG_HOTPLUG_CPU