[PATCH 0/6] x86_64: Generic timekeeping for x86

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* [PATCH 0/6] x86_64: Generic timekeeping for x86_64
@ 2006-09-07  2:18 john stultz
  2006-09-07  2:18 ` [PATCH 1/6] x86_64: Enable arch-generic vsyscall support john stultz
                   ` (6 more replies)
  0 siblings, 7 replies; 8+ messages in thread
From: john stultz @ 2006-09-07  2:18 UTC (permalink / raw)
  To: ak; +Cc: john stultz, linux-kernel

Hey Andi,
	Just wanted to send this second pass on the x86_64 generic 
timekeeping conversion. It includes a number of changes you suggested, 
however its possible I missed a few things. I've made sure the patchset 
compiles at each stage, and atleast w/ the box I was using it booted 
each step as well.

Still on the TODO:
o See about merging i386/x86-64 hpet.c (maybe driver/char/hpet.c as 
well?)
o 64bit hpet (should be trivial)
o Further cleanups

If anyone else is interested here, my full timekeeping tree can be 
found here: http://sr71.net/~jstultz/tod/

New in the current C6 release:
o x86-64 cleanups
o arch-trivial patch that converts arches w/o inter-tick resolution
o ia64 fixups by Peter Keilty

Let me know if you have any thoughts or comments!

thanks again!
-john

^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH 1/6] x86_64: Enable arch-generic vsyscall support.
  2006-09-07  2:18 [PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
@ 2006-09-07  2:18 ` john stultz
  2006-09-07  2:18 ` [PATCH 2/6] x86_64: hpet_address cleanup john stultz
                   ` (5 subsequent siblings)
  6 siblings, 0 replies; 8+ messages in thread
From: john stultz @ 2006-09-07  2:18 UTC (permalink / raw)
  To: ak; +Cc: john stultz, linux-kernel

Provides generic infrastructure for vsyscall-gtod.

Signed-off-by: John Stultz <johnstul@us.ibm.com>

 include/linux/clocksource.h |    8 ++++++++
 include/linux/time.h        |    1 +
 kernel/timer.c              |    1 +
 3 files changed, 10 insertions(+)

linux-2.6.18-rc6_timeofday-vsyscall-support_C6.patch
============================================
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index d852024..cd4d514 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -46,6 +46,7 @@ typedef u64 cycle_t;
  * @shift:		cycle to nanosecond divisor (power of two)
  * @update_callback:	called when safe to alter clocksource values
  * @is_continuous:	defines if clocksource is free-running.
+ * @vread:		vsyscall based read
  * @cycle_interval:	Used internally by timekeeping core, please ignore.
  * @xtime_interval:	Used internally by timekeeping core, please ignore.
  */
@@ -59,6 +60,7 @@ struct clocksource {
 	u32 shift;
 	int (*update_callback)(void);
 	int is_continuous;
+	cycle_t (*vread)(void);
 
 	/* timekeeping specific data, ignore */
 	cycle_t cycle_last, cycle_interval;
@@ -182,4 +184,10 @@ int clocksource_register(struct clocksou
 void clocksource_reselect(void);
 struct clocksource* clocksource_get_next(void);
 
+#ifdef CONFIG_GENERIC_TIME_VSYSCALL
+extern void update_vsyscall(struct timespec* ts, struct clocksource* c);
+#else
+#define update_vsyscall(now, c) do { } while(0)
+#endif
+
 #endif /* _LINUX_CLOCKSOURCE_H */
diff --git a/include/linux/time.h b/include/linux/time.h
index a5b7399..14e12f0 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -174,6 +174,7 @@ static inline void timespec_add_ns(struc
 	}
 	a->tv_nsec = ns;
 }
+
 #endif /* __KERNEL__ */
 
 #define NFDBITS			__NFDBITS
diff --git a/kernel/timer.c b/kernel/timer.c
index 1d7dd62..a444016 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1165,6 +1165,7 @@ static void update_wall_time(void)
 		clock->xtime_nsec = 0;
 		clocksource_calculate_interval(clock, tick_nsec);
 	}
+	update_vsyscall(&xtime, clock);
 }
 
 /*

^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCH 2/6] x86_64: hpet_address cleanup
  2006-09-07  2:18 [PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
  2006-09-07  2:18 ` [PATCH 1/6] x86_64: Enable arch-generic vsyscall support john stultz
@ 2006-09-07  2:18 ` john stultz
  2006-09-07  2:19 ` [PATCH 3/6] x86_64: Remove apic_runs_main_timer john stultz
                   ` (4 subsequent siblings)
  6 siblings, 0 replies; 8+ messages in thread
From: john stultz @ 2006-09-07  2:18 UTC (permalink / raw)
  To: ak; +Cc: john stultz, linux-kernel

In preparation for supporting generic timekeeping, this patch cleans up 
x86-64's use of vxtime.hpet_address, changing it to just hpet_address 
as is also used in i386. This is necessary since the vxtime structure 
will be going away.

Signed-off-by: John Stultz <johnstul@us.ibm.com>


 arch/i386/kernel/acpi/boot.c |   19 ++++++-------------
 arch/x86_64/kernel/apic.c    |    3 ++-
 arch/x86_64/kernel/time.c    |   34 ++++++++++++++++++----------------
 include/asm-x86_64/hpet.h    |    1 +
 4 files changed, 27 insertions(+), 30 deletions(-)

linux-2.6.18-rc6_timeofday-arch-x86-64-part1_C6.patch
============================================
diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c
index ee003bc..ba6c82d 100644
--- a/arch/i386/kernel/acpi/boot.c
+++ b/arch/i386/kernel/acpi/boot.c
@@ -575,6 +575,7 @@ static int __init acpi_parse_sbf(unsigne
 }
 
 #ifdef CONFIG_HPET_TIMER
+#include <asm/hpet.h>
 
 static int __init acpi_parse_hpet(unsigned long phys, unsigned long size)
 {
@@ -595,21 +596,13 @@ static int __init acpi_parse_hpet(unsign
 		return -1;
 	}
 #ifdef	CONFIG_X86_64
-	vxtime.hpet_address = hpet_tbl->addr.addrl |
+	hpet_address = hpet_tbl->addr.addrl |
 	    ((long)hpet_tbl->addr.addrh << 32);
-
+#else
+	hpet_address = hpet_tbl->addr.addrl;
+#endif
 	printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n",
-	       hpet_tbl->id, vxtime.hpet_address);
-#else				/* X86 */
-	{
-		extern unsigned long hpet_address;
-
-		hpet_address = hpet_tbl->addr.addrl;
-		printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n",
-		       hpet_tbl->id, hpet_address);
-	}
-#endif				/* X86 */
-
+	       hpet_tbl->id, hpet_address);
 	return 0;
 }
 #else
diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c
index 2b8cef0..1b9e3d3 100644
--- a/arch/x86_64/kernel/apic.c
+++ b/arch/x86_64/kernel/apic.c
@@ -36,6 +36,7 @@
 #include <asm/idle.h>
 #include <asm/proto.h>
 #include <asm/timex.h>
+#include <asm/hpet.h>
 
 int apic_verbosity;
 int apic_runs_main_timer;
@@ -727,7 +728,7 @@ static void setup_APIC_timer(unsigned in
 	local_irq_save(flags);
 
 	/* wait for irq slice */
- 	if (vxtime.hpet_address && hpet_use_timer) {
+ 	if (hpet_address && hpet_use_timer) {
  		int trigger = hpet_readl(HPET_T0_CMP);
  		while (hpet_readl(HPET_COUNTER) >= trigger)
  			/* do nothing */ ;
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index 7a9b182..da89e60 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -67,6 +67,7 @@ static int notsc __initdata = 0;
 
 unsigned int cpu_khz;					/* TSC clocks / usec, not used here */
 EXPORT_SYMBOL(cpu_khz);
+unsigned long hpet_address;
 static unsigned long hpet_period;			/* fsecs / HPET clock */
 unsigned long hpet_tick;				/* HPET clocks / interrupt */
 int hpet_use_timer;				/* Use counter of hpet for time keeping, otherwise PIT */
@@ -326,7 +327,7 @@ static noinline void handle_lost_ticks(i
 		       KERN_WARNING "Your time source seems to be instable or "
 		   		"some driver is hogging interupts\n");
 		print_symbol("rip %s\n", regs->rip);
-		if (vxtime.mode == VXTIME_TSC && vxtime.hpet_address) {
+		if (vxtime.mode == VXTIME_TSC && hpet_address) {
 			printk(KERN_WARNING "Falling back to HPET\n");
 			if (hpet_use_timer)
 				vxtime.last = hpet_readl(HPET_T0_CMP) - 
@@ -334,6 +335,7 @@ static noinline void handle_lost_ticks(i
 			else
 				vxtime.last = hpet_readl(HPET_COUNTER);
 			vxtime.mode = VXTIME_HPET;
+			vxtime.hpet_address = hpet_address;
 			do_gettimeoffset = do_gettimeoffset_hpet;
 		}
 		/* else should fall back to PIT, but code missing. */
@@ -364,7 +366,7 @@ void main_timer_handler(struct pt_regs *
 
 	write_seqlock(&xtime_lock);
 
-	if (vxtime.hpet_address)
+	if (hpet_address)
 		offset = hpet_readl(HPET_COUNTER);
 
 	if (hpet_use_timer) {
@@ -734,7 +736,7 @@ static __init int late_hpet_init(void)
 	struct hpet_data	hd;
 	unsigned int 		ntimer;
 
-	if (!vxtime.hpet_address)
+	if (!hpet_address)
         	return 0;
 
 	memset(&hd, 0, sizeof (hd));
@@ -747,7 +749,7 @@ static __init int late_hpet_init(void)
 	 * Register with driver.
 	 * Timer0 and Timer1 is used by platform.
 	 */
-	hd.hd_phys_address = vxtime.hpet_address;
+	hd.hd_phys_address = hpet_address;
 	hd.hd_address = (void __iomem *)fix_to_virt(FIX_HPET_BASE);
 	hd.hd_nirqs = ntimer;
 	hd.hd_flags = HPET_DATA_PLATFORM;
@@ -816,10 +818,10 @@ static int hpet_init(void)
 {
 	unsigned int id;
 
-	if (!vxtime.hpet_address)
+	if (!hpet_address)
 		return -1;
-	set_fixmap_nocache(FIX_HPET_BASE, vxtime.hpet_address);
-	__set_fixmap(VSYSCALL_HPET, vxtime.hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE);
+	set_fixmap_nocache(FIX_HPET_BASE, hpet_address);
+	__set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE);
 
 /*
  * Read the period, compute tick and quotient.
@@ -873,7 +875,7 @@ void __init pit_stop_interrupt(void)
 void __init stop_timer_interrupt(void)
 {
 	char *name;
-	if (vxtime.hpet_address) {
+	if (hpet_address) {
 		name = "HPET";
 		hpet_timer_stop_set_go(0);
 	} else {
@@ -899,8 +901,7 @@ void __init time_init(void)
 	char *gtod;
 
 	if (nohpet)
-		vxtime.hpet_address = 0;
-
+		hpet_address = 0;
 	xtime.tv_sec = get_cmos_time();
 	xtime.tv_nsec = 0;
 
@@ -910,7 +911,7 @@ void __init time_init(void)
 	if (!hpet_init())
                 vxtime_hz = (FSEC_PER_SEC + hpet_period / 2) / hpet_period;
 	else
-		vxtime.hpet_address = 0;
+		hpet_address = 0;
 
 	if (hpet_use_timer) {
 		/* set tick_nsec to use the proper rate for HPET */
@@ -918,7 +919,7 @@ void __init time_init(void)
 		cpu_khz = hpet_calibrate_tsc();
 		timename = "HPET";
 #ifdef CONFIG_X86_PM_TIMER
-	} else if (pmtmr_ioport && !vxtime.hpet_address) {
+	} else if (pmtmr_ioport && !hpet_address) {
 		vxtime_hz = PM_TIMER_FREQUENCY;
 		timename = "PM";
 		pit_init();
@@ -979,18 +980,19 @@ __init static char *time_init_gtod(void)
 
 	if (unsynchronized_tsc())
 		notsc = 1;
-	if (vxtime.hpet_address && notsc) {
+	if (hpet_address && notsc) {
 		timetype = hpet_use_timer ? "HPET" : "PIT/HPET";
 		if (hpet_use_timer)
 			vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
 		else
 			vxtime.last = hpet_readl(HPET_COUNTER);
 		vxtime.mode = VXTIME_HPET;
+		vxtime.hpet_address = hpet_address;
 		do_gettimeoffset = do_gettimeoffset_hpet;
 #ifdef CONFIG_X86_PM_TIMER
 	/* Using PM for gettimeofday is quite slow, but we have no other
 	   choice because the TSC is too unreliable on some systems. */
-	} else if (pmtmr_ioport && !vxtime.hpet_address && notsc) {
+	} else if (pmtmr_ioport && !hpet_address && notsc) {
 		timetype = "PM";
 		do_gettimeoffset = do_gettimeoffset_pm;
 		vxtime.mode = VXTIME_PMTMR;
@@ -1033,7 +1035,7 @@ static int timer_resume(struct sys_devic
 	unsigned long ctime = get_cmos_time();
 	unsigned long sleep_length = (ctime - sleep_start) * HZ;
 
-	if (vxtime.hpet_address)
+	if (hpet_address)
 		hpet_reenable();
 	else
 		i8254_timer_resume();
@@ -1118,7 +1120,7 @@ static unsigned int hpet_t1_cmp; /* cach
 
 int is_hpet_enabled(void)
 {
-	return vxtime.hpet_address != 0;
+	return hpet_address != 0;
 }
 
 /*
diff --git a/include/asm-x86_64/hpet.h b/include/asm-x86_64/hpet.h
index b390984..60d5127 100644
--- a/include/asm-x86_64/hpet.h
+++ b/include/asm-x86_64/hpet.h
@@ -58,6 +58,7 @@ extern int hpet_rtc_timer_init(void);
 extern int apic_is_clustered_box(void);
 
 extern int hpet_use_timer;
+extern unsigned long hpet_address;
 
 #ifdef CONFIG_HPET_EMULATE_RTC
 extern int hpet_mask_rtc_irq_bit(unsigned long bit_mask);

^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCH 3/6] x86_64: Remove apic_runs_main_timer
  2006-09-07  2:18 [PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
  2006-09-07  2:18 ` [PATCH 1/6] x86_64: Enable arch-generic vsyscall support john stultz
  2006-09-07  2:18 ` [PATCH 2/6] x86_64: hpet_address cleanup john stultz
@ 2006-09-07  2:19 ` john stultz
  2006-09-07  2:19 ` [PATCH 4/6] x86_64: Enable CONFIG_GENERIC_TIME john stultz
                   ` (3 subsequent siblings)
  6 siblings, 0 replies; 8+ messages in thread
From: john stultz @ 2006-09-07  2:19 UTC (permalink / raw)
  To: ak; +Cc: john stultz, linux-kernel

Part of the x86-64 cleanup for generic timekeeping. 
Remove apic_runs_main_timer, on request from Andi, since it doesn't 
work on many systems.

Signed-off-by: John Stultz <johnstul@us.ibm.com>

 arch/x86_64/kernel/apic.c |   30 +-----------------------------
 arch/x86_64/kernel/time.c |    2 --
 include/asm-x86_64/apic.h |    1 -
 3 files changed, 1 insertion(+), 32 deletions(-)

linux-2.6.18-rc6_timeofday-arch-x86-64-part2_C6.patch
============================================
diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c
index 1b9e3d3..6173b2f 100644
--- a/arch/x86_64/kernel/apic.c
+++ b/arch/x86_64/kernel/apic.c
@@ -39,7 +39,6 @@
 #include <asm/hpet.h>
 
 int apic_verbosity;
-int apic_runs_main_timer;
 int apic_calibrate_pmtmr __initdata;
 
 int disable_apic_timer __initdata;
@@ -747,16 +746,6 @@ static void setup_APIC_timer(unsigned in
 		} while (c2 - c1 < 300);
 	}
 	__setup_APIC_LVTT(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 &&
-		smp_processor_id() == boot_cpu_id &&
-		apic_runs_main_timer == 1 &&
-		!cpu_isset(boot_cpu_id, timer_interrupt_broadcast_ipi_mask)) {
-		stop_timer_interrupt();
-		apic_runs_main_timer++;
-	}
 	local_irq_restore(flags);
 }
 
@@ -946,8 +935,6 @@ void smp_local_timer_interrupt(struct pt
 #ifdef CONFIG_SMP
 	update_process_times(user_mode(regs));
 #endif
-	if (apic_runs_main_timer > 1 && smp_processor_id() == boot_cpu_id)
-		main_timer_handler(regs);
 	/*
 	 * We take the 'long' return path, and there every subsystem
 	 * grabs the appropriate locks (kernel lock/ irq lock).
@@ -1162,26 +1149,11 @@ static __init int setup_noapictimer(char
 	return 1;
 } 
 
-static __init int setup_apicmaintimer(char *str)
-{
-	apic_runs_main_timer = 1;
-	nohpet = 1;
-	return 1;
-}
-__setup("apicmaintimer", setup_apicmaintimer);
-
-static __init int setup_noapicmaintimer(char *str)
-{
-	apic_runs_main_timer = -1;
-	return 1;
-}
-__setup("noapicmaintimer", setup_noapicmaintimer);
-
 static __init int setup_apicpmtimer(char *s)
 {
 	apic_calibrate_pmtmr = 1;
 	notsc_setup(NULL);
-	return setup_apicmaintimer(NULL);
+	return 1;
 }
 __setup("apicpmtimer", setup_apicpmtimer);
 
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index da89e60..a4aef4e 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -469,8 +469,6 @@ void main_timer_handler(struct pt_regs *
 
 static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 {
-	if (apic_runs_main_timer > 1)
-		return IRQ_HANDLED;
 	main_timer_handler(regs);
 #ifdef CONFIG_X86_LOCAL_APIC
 	if (using_apic_timer)
diff --git a/include/asm-x86_64/apic.h b/include/asm-x86_64/apic.h
index 9c96a0a..06fcdc2 100644
--- a/include/asm-x86_64/apic.h
+++ b/include/asm-x86_64/apic.h
@@ -16,7 +16,6 @@
 #define APIC_DEBUG   2
 
 extern int apic_verbosity;
-extern int apic_runs_main_timer;
 
 /*
  * Define the default level of output to be very little

^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCH 4/6] x86_64: Enable CONFIG_GENERIC_TIME
  2006-09-07  2:18 [PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
                   ` (2 preceding siblings ...)
  2006-09-07  2:19 ` [PATCH 3/6] x86_64: Remove apic_runs_main_timer john stultz
@ 2006-09-07  2:19 ` john stultz
  2006-09-07  2:19 ` [PATCH 5/6] x86_64: Clocksources for x86-64 john stultz
                   ` (2 subsequent siblings)
  6 siblings, 0 replies; 8+ messages in thread
From: john stultz @ 2006-09-07  2:19 UTC (permalink / raw)
  To: ak; +Cc: john stultz, linux-kernel

Enable CONFIG_GENERIC_TIME on x86_64 and remove arch specific 
timekeeping code.

Signed-off-by: John Stultz <johnstul@us.ibm.com>

 arch/x86_64/Kconfig           |    4 
 arch/x86_64/kernel/pmtimer.c  |   58 ------
 arch/x86_64/kernel/time.c     |  354 +-----------------------------------------
 drivers/acpi/processor_idle.c |    1 
 include/asm-x86_64/proto.h    |    1 
 include/asm-x86_64/timex.h    |    2 
 6 files changed, 22 insertions(+), 398 deletions(-)

linux-2.6.18-rc6_timeofday-arch-x86-64-part3_C6.patch
============================================
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 28df7d8..fabb174 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -24,6 +24,10 @@ config X86
 	bool
 	default y
 
+config GENERIC_TIME
+	bool
+	default y
+
 config LOCKDEP_SUPPORT
 	bool
 	default y
diff --git a/arch/x86_64/kernel/pmtimer.c b/arch/x86_64/kernel/pmtimer.c
index 7554458..ae8f912 100644
--- a/arch/x86_64/kernel/pmtimer.c
+++ b/arch/x86_64/kernel/pmtimer.c
@@ -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;
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index a4aef4e..d18230a 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -43,14 +43,9 @@
 #include <asm/apic.h>
 #endif
 
-#ifdef CONFIG_CPU_FREQ
-static void cpufreq_delayed_get(void);
-#endif
 extern void i8254_timer_resume(void);
 extern int using_apic_timer;
 
-static char *time_init_gtod(void);
-
 DEFINE_SPINLOCK(rtc_lock);
 EXPORT_SYMBOL(rtc_lock);
 DEFINE_SPINLOCK(i8253_lock);
@@ -82,108 +77,6 @@ unsigned long __wall_jiffies __section_w
 struct timespec __xtime __section_xtime;
 struct timezone __sys_tz __section_sys_tz;
 
-/*
- * do_gettimeoffset() returns microseconds since last timer interrupt was
- * triggered by hardware. A memory read of HPET is slower than a register read
- * of TSC, but much more reliable. It's also synchronized to the timer
- * interrupt. Note that do_gettimeoffset() may return more than hpet_tick, if a
- * timer interrupt has happened already, but vxtime.trigger wasn't updated yet.
- * This is not a problem, because jiffies hasn't updated either. They are bound
- * together by xtime_lock.
- */
-
-static inline unsigned int do_gettimeoffset_tsc(void)
-{
-	unsigned long t;
-	unsigned long x;
-	t = get_cycles_sync();
-	if (t < vxtime.last_tsc) 
-		t = vxtime.last_tsc; /* hack */
-	x = ((t - vxtime.last_tsc) * vxtime.tsc_quot) >> US_SCALE;
-	return x;
-}
-
-static inline 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;
-}
-
-unsigned int (*do_gettimeoffset)(void) = do_gettimeoffset_tsc;
-
-/*
- * This version of gettimeofday() has microsecond resolution and better than
- * microsecond precision, as we're using at least a 10 MHz (usually 14.31818
- * MHz) HPET timer.
- */
-
-void do_gettimeofday(struct timeval *tv)
-{
-	unsigned long seq, t;
- 	unsigned int sec, usec;
-
-	do {
-		seq = read_seqbegin(&xtime_lock);
-
-		sec = xtime.tv_sec;
-		usec = xtime.tv_nsec / NSEC_PER_USEC;
-
-		/* i386 does some correction here to keep the clock 
-		   monotonous even when ntpd is fixing drift.
-		   But they didn't work for me, there is a non monotonic
-		   clock anyways with ntp.
-		   I dropped all corrections now until a real solution can
-		   be found. Note when you fix it here you need to do the same
-		   in arch/x86_64/kernel/vsyscall.c and export all needed
-		   variables in vmlinux.lds. -AK */ 
-
-		t = (jiffies - wall_jiffies) * USEC_PER_TICK +
-			do_gettimeoffset();
-		usec += t;
-
-	} while (read_seqretry(&xtime_lock, seq));
-
-	tv->tv_sec = sec + usec / USEC_PER_SEC;
-	tv->tv_usec = usec % USEC_PER_SEC;
-}
-
-EXPORT_SYMBOL(do_gettimeofday);
-
-/*
- * settimeofday() first undoes the correction that gettimeofday would do
- * on the time, and then saves it. This is ugly, but has been like this for
- * ages already.
- */
-
-int do_settimeofday(struct timespec *tv)
-{
-	time_t wtm_sec, sec = tv->tv_sec;
-	long wtm_nsec, nsec = tv->tv_nsec;
-
-	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
-		return -EINVAL;
-
-	write_seqlock_irq(&xtime_lock);
-
-	nsec -= do_gettimeoffset() * NSEC_PER_USEC +
-		(jiffies - wall_jiffies) * NSEC_PER_TICK;
-
-	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
-	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
-
-	set_normalized_timespec(&xtime, sec, nsec);
-	set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
-
-	ntp_clear();
-
-	write_sequnlock_irq(&xtime_lock);
-	clock_was_set();
-	return 0;
-}
-
-EXPORT_SYMBOL(do_settimeofday);
-
 unsigned long profile_pc(struct pt_regs *regs)
 {
 	unsigned long pc = instruction_pointer(regs);
@@ -278,85 +171,9 @@ static void set_rtc_mmss(unsigned long n
 }
 
 
-/* monotonic_clock(): returns # of nanoseconds passed since time_init()
- *		Note: This function is required to return accurate
- *		time even in the absence of multiple timer ticks.
- */
-unsigned long long monotonic_clock(void)
-{
-	unsigned long seq;
- 	u32 last_offset, this_offset, offset;
-	unsigned long long base;
-
-	if (vxtime.mode == VXTIME_HPET) {
-		do {
-			seq = read_seqbegin(&xtime_lock);
-
-			last_offset = vxtime.last;
-			base = monotonic_base;
-			this_offset = hpet_readl(HPET_COUNTER);
-		} while (read_seqretry(&xtime_lock, seq));
-		offset = (this_offset - last_offset);
-		offset *= NSEC_PER_TICK / hpet_tick;
-	} else {
-		do {
-			seq = read_seqbegin(&xtime_lock);
-
-			last_offset = vxtime.last_tsc;
-			base = monotonic_base;
-		} while (read_seqretry(&xtime_lock, seq));
-		this_offset = get_cycles_sync();
-		/* FIXME: 1000 or 1000000? */
-		offset = (this_offset - last_offset)*1000 / cpu_khz;
-	}
-	return base + offset;
-}
-EXPORT_SYMBOL(monotonic_clock);
-
-static noinline void handle_lost_ticks(int lost, struct pt_regs *regs)
-{
-	static long lost_count;
-	static int warned;
-	if (report_lost_ticks) {
-		printk(KERN_WARNING "time.c: Lost %d timer tick(s)! ", lost);
-		print_symbol("rip %s)\n", regs->rip);
-	}
-
-	if (lost_count == 1000 && !warned) {
-		printk(KERN_WARNING "warning: many lost ticks.\n"
-		       KERN_WARNING "Your time source seems to be instable or "
-		   		"some driver is hogging interupts\n");
-		print_symbol("rip %s\n", regs->rip);
-		if (vxtime.mode == VXTIME_TSC && hpet_address) {
-			printk(KERN_WARNING "Falling back to HPET\n");
-			if (hpet_use_timer)
-				vxtime.last = hpet_readl(HPET_T0_CMP) - 
-							hpet_tick;
-			else
-				vxtime.last = hpet_readl(HPET_COUNTER);
-			vxtime.mode = VXTIME_HPET;
-			vxtime.hpet_address = hpet_address;
-			do_gettimeoffset = do_gettimeoffset_hpet;
-		}
-		/* else should fall back to PIT, but code missing. */
-		warned = 1;
-	} else
-		lost_count++;
-
-#ifdef CONFIG_CPU_FREQ
-	/* In some cases the CPU can change frequency without us noticing
-	   Give cpufreq a change to catch up. */
-	if ((lost_count+1) % 25 == 0)
-		cpufreq_delayed_get();
-#endif
-}
-
 void main_timer_handler(struct pt_regs *regs)
 {
 	static unsigned long rtc_update = 0;
-	unsigned long tsc;
-	int delay = 0, offset = 0, lost = 0;
-
 /*
  * Here we are in the timer irq handler. We have irqs locally disabled (so we
  * don't need spin_lock_irqsave()) but we don't know if the timer_bh is running
@@ -366,68 +183,6 @@ void main_timer_handler(struct pt_regs *
 
 	write_seqlock(&xtime_lock);
 
-	if (hpet_address)
-		offset = hpet_readl(HPET_COUNTER);
-
-	if (hpet_use_timer) {
-		/* if we're using the hpet timer functionality,
-		 * we can more accurately know the counter value
-		 * when the timer interrupt occured.
-		 */
-		offset = hpet_readl(HPET_T0_CMP) - hpet_tick;
-		delay = hpet_readl(HPET_COUNTER) - offset;
-	} else if (!pmtmr_ioport) {
-		spin_lock(&i8253_lock);
-		outb_p(0x00, 0x43);
-		delay = inb_p(0x40);
-		delay |= inb(0x40) << 8;
-		spin_unlock(&i8253_lock);
-		delay = LATCH - 1 - delay;
-	}
-
-	tsc = get_cycles_sync();
-
-	if (vxtime.mode == VXTIME_HPET) {
-		if (offset - vxtime.last > hpet_tick) {
-			lost = (offset - vxtime.last) / hpet_tick - 1;
-		}
-
-		monotonic_base += 
-			(offset - vxtime.last) * NSEC_PER_TICK / hpet_tick;
-
-		vxtime.last = offset;
-#ifdef CONFIG_X86_PM_TIMER
-	} else if (vxtime.mode == VXTIME_PMTMR) {
-		lost = pmtimer_mark_offset();
-#endif
-	} else {
-		offset = (((tsc - vxtime.last_tsc) *
-			   vxtime.tsc_quot) >> US_SCALE) - USEC_PER_TICK;
-
-		if (offset < 0)
-			offset = 0;
-
-		if (offset > USEC_PER_TICK) {
-			lost = offset / USEC_PER_TICK;
-			offset %= USEC_PER_TICK;
-		}
-
-		/* FIXME: 1000 or 1000000? */
-		monotonic_base += (tsc - vxtime.last_tsc) * 1000000 / cpu_khz;
-
-		vxtime.last_tsc = tsc - vxtime.quot * delay / vxtime.tsc_quot;
-
-		if ((((tsc - vxtime.last_tsc) *
-		      vxtime.tsc_quot) >> US_SCALE) < offset)
-			vxtime.last_tsc = tsc -
-				(((long) offset << US_SCALE) / vxtime.tsc_quot) - 1;
-	}
-
-	if (lost > 0) {
-		handle_lost_ticks(lost, regs);
-		jiffies += lost;
-	}
-
 /*
  * Do the timer stuff.
  */
@@ -493,15 +248,6 @@ unsigned long long sched_clock(void)
 {
 	unsigned long a = 0;
 
-#if 0
-	/* Don't do a HPET read here. Using TSC always is much faster
-	   and HPET may not be mapped yet when the scheduler first runs.
-           Disadvantage is a small drift between CPUs in some configurations,
-	   but that should be tolerable. */
-	if (__vxtime.mode == VXTIME_HPET)
-		return (hpet_readl(HPET_COUNTER) * vxtime.quot) >> US_SCALE;
-#endif
-
 	/* Could do CPU core sync here. Opteron can execute rdtsc speculatively,
 	   which means it is not completely exact and may not be monotonous between
 	   CPUs. But the errors should be too small to matter for scheduling
@@ -511,6 +257,19 @@ unsigned long long sched_clock(void)
 	return cycles_2_ns(a);
 }
 
+static int tsc_unstable;
+
+static inline int check_tsc_unstable(void)
+{
+	return tsc_unstable;
+}
+
+void mark_tsc_unstable(void)
+{
+	tsc_unstable = 1;
+}
+EXPORT_SYMBOL_GPL(mark_tsc_unstable);
+
 static unsigned long get_cmos_time(void)
 {
 	unsigned int year, mon, day, hour, min, sec;
@@ -589,24 +348,6 @@ static void handle_cpufreq_delayed_get(v
 	cpufreq_delayed_issched = 0;
 }
 
-/* if we notice lost ticks, schedule a call to cpufreq_get() as it tries
- * to verify the CPU frequency the timing core thinks the CPU is running
- * at is still correct.
- */
-static void cpufreq_delayed_get(void)
-{
-	static int warned;
-	if (cpufreq_init && !cpufreq_delayed_issched) {
-		cpufreq_delayed_issched = 1;
-		if (!warned) {
-			warned = 1;
-			printk(KERN_DEBUG 
-	"Losing some ticks... checking if CPU frequency changed.\n");
-		}
-		schedule_work(&cpufreq_delayed_get_work);
-	}
-}
-
 static unsigned int  ref_freq = 0;
 static unsigned long loops_per_jiffy_ref = 0;
 
@@ -896,7 +637,6 @@ static struct irqaction irq0 = {
 void __init time_init(void)
 {
 	char *timename;
-	char *gtod;
 
 	if (nohpet)
 		hpet_address = 0;
@@ -906,9 +646,7 @@ void __init time_init(void)
 	set_normalized_timespec(&wall_to_monotonic,
 	                        -xtime.tv_sec, -xtime.tv_nsec);
 
-	if (!hpet_init())
-                vxtime_hz = (FSEC_PER_SEC + hpet_period / 2) / hpet_period;
-	else
+	if (hpet_init())
 		hpet_address = 0;
 
 	if (hpet_use_timer) {
@@ -916,29 +654,14 @@ void __init time_init(void)
 	  	tick_nsec = TICK_NSEC_HPET;
 		cpu_khz = hpet_calibrate_tsc();
 		timename = "HPET";
-#ifdef CONFIG_X86_PM_TIMER
-	} else if (pmtmr_ioport && !hpet_address) {
-		vxtime_hz = PM_TIMER_FREQUENCY;
-		timename = "PM";
-		pit_init();
-		cpu_khz = pit_calibrate_tsc();
-#endif
 	} else {
 		pit_init();
 		cpu_khz = pit_calibrate_tsc();
 		timename = "PIT";
 	}
 
-	vxtime.mode = VXTIME_TSC;
-	gtod = time_init_gtod();
-
-	printk(KERN_INFO "time.c: Using %ld.%06ld MHz WALL %s GTOD %s timer.\n",
-	       vxtime_hz / 1000000, vxtime_hz % 1000000, timename, gtod);
 	printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n",
 		cpu_khz / 1000, cpu_khz % 1000);
-	vxtime.quot = (USEC_PER_SEC << US_SCALE) / vxtime_hz;
-	vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz;
-	vxtime.last_tsc = get_cycles_sync();
 	setup_irq(0, &irq0);
 
 	set_cyc2ns_scale(cpu_khz);
@@ -969,41 +692,6 @@ __cpuinit int unsynchronized_tsc(void)
  	return num_present_cpus() > 1;
 }
 
-/*
- * Decide what mode gettimeofday should use.
- */
-__init static char *time_init_gtod(void)
-{
-	char *timetype;
-
-	if (unsynchronized_tsc())
-		notsc = 1;
-	if (hpet_address && notsc) {
-		timetype = hpet_use_timer ? "HPET" : "PIT/HPET";
-		if (hpet_use_timer)
-			vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
-		else
-			vxtime.last = hpet_readl(HPET_COUNTER);
-		vxtime.mode = VXTIME_HPET;
-		vxtime.hpet_address = hpet_address;
-		do_gettimeoffset = do_gettimeoffset_hpet;
-#ifdef CONFIG_X86_PM_TIMER
-	/* Using PM for gettimeofday is quite slow, but we have no other
-	   choice because the TSC is too unreliable on some systems. */
-	} else if (pmtmr_ioport && !hpet_address && notsc) {
-		timetype = "PM";
-		do_gettimeoffset = do_gettimeoffset_pm;
-		vxtime.mode = VXTIME_PMTMR;
-		sysctl_vsyscall = 0;
-		printk(KERN_INFO "Disabling vsyscall due to use of PM timer\n");
-#endif
-	} else {
-		timetype = hpet_use_timer ? "HPET/TSC" : "PIT/TSC";
-		vxtime.mode = VXTIME_TSC;
-	}
-	return timetype;
-}
-
 __setup("report_lost_ticks", time_setup);
 
 static long clock_cmos_diff;
@@ -1042,21 +730,9 @@ static int timer_resume(struct sys_devic
 	write_seqlock_irqsave(&xtime_lock,flags);
 	xtime.tv_sec = sec;
 	xtime.tv_nsec = 0;
-	if (vxtime.mode == VXTIME_HPET) {
-		if (hpet_use_timer)
-			vxtime.last = hpet_readl(HPET_T0_CMP) - hpet_tick;
-		else
-			vxtime.last = hpet_readl(HPET_COUNTER);
-#ifdef CONFIG_X86_PM_TIMER
-	} else if (vxtime.mode == VXTIME_PMTMR) {
-		pmtimer_resume();
-#endif
-	} else
-		vxtime.last_tsc = get_cycles_sync();
-	write_sequnlock_irqrestore(&xtime_lock,flags);
 	jiffies += sleep_length;
 	wall_jiffies += sleep_length;
-	monotonic_base += sleep_length * (NSEC_PER_SEC/HZ);
+	write_sequnlock_irqrestore(&xtime_lock,flags);
 	touch_softlockup_watchdog();
 	return 0;
 }
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 7106606..415bfa7 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -41,6 +41,7 @@
 
 #include <asm/io.h>
 #include <asm/uaccess.h>
+#include <asm/timex.h>
 
 #include <acpi/acpi_bus.h>
 #include <acpi/processor.h>
diff --git a/include/asm-x86_64/proto.h b/include/asm-x86_64/proto.h
index 038fe1f..716ac55 100644
--- a/include/asm-x86_64/proto.h
+++ b/include/asm-x86_64/proto.h
@@ -47,7 +47,6 @@ extern u32 pmtmr_ioport;
 #else
 #define pmtmr_ioport 0
 #endif
-extern unsigned long long monotonic_base;
 extern int sysctl_vsyscall;
 extern int nohpet;
 extern unsigned long vxtime_hz;
diff --git a/include/asm-x86_64/timex.h b/include/asm-x86_64/timex.h
index b9e5320..40167eb 100644
--- a/include/asm-x86_64/timex.h
+++ b/include/asm-x86_64/timex.h
@@ -41,6 +41,8 @@ static __always_inline cycles_t get_cycl
 
 extern unsigned int cpu_khz;
 
+extern void mark_tsc_unstable(void);
+
 extern int read_current_timer(unsigned long *timer_value);
 #define ARCH_HAS_READ_CURRENT_TIMER	1
 

^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCH 5/6] x86_64: Clocksources for x86-64
  2006-09-07  2:18 [PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
                   ` (3 preceding siblings ...)
  2006-09-07  2:19 ` [PATCH 4/6] x86_64: Enable CONFIG_GENERIC_TIME john stultz
@ 2006-09-07  2:19 ` john stultz
  2006-09-07  2:19 ` [PATCH 6/6] x86_64: GENERIC_TIME based vsyscall code john stultz
  2006-09-09 20:30 ` [PATCH 0/6] x86_64: Generic timekeeping for x86_64 Andi Kleen
  6 siblings, 0 replies; 8+ messages in thread
From: john stultz @ 2006-09-07  2:19 UTC (permalink / raw)
  To: ak; +Cc: john stultz, linux-kernel

Break up HPET and TSC code into their own .c files.
Also add clocksource structures for both.

Signed-off-by: John Stultz <johnstul@us.ibm.com>

 arch/x86_64/kernel/Makefile |    2 
 arch/x86_64/kernel/hpet.c   |  469 +++++++++++++++++++++++++++++++++++++
 arch/x86_64/kernel/time.c   |  557 --------------------------------------------
 arch/x86_64/kernel/tsc.c    |  222 +++++++++++++++++
 include/asm-x86_64/hpet.h   |    6 
 include/asm-x86_64/timex.h  |    2 
 6 files changed, 705 insertions(+), 553 deletions(-)

linux-2.6.18-rc6_timeofday-arch-x86-64-part4_C6.patch
============================================
diff --git a/arch/x86_64/kernel/Makefile b/arch/x86_64/kernel/Makefile
index b5aaeaf..5834f49 100644
--- a/arch/x86_64/kernel/Makefile
+++ b/arch/x86_64/kernel/Makefile
@@ -8,7 +8,7 @@ obj-y	:= process.o signal.o entry.o trap
 		ptrace.o time.o ioport.o ldt.o setup.o i8259.o sys_x86_64.o \
 		x8664_ksyms.o i387.o syscall.o vsyscall.o \
 		setup64.o bootflag.o e820.o reboot.o quirks.o i8237.o \
-		pci-dma.o pci-nommu.o alternative.o
+		pci-dma.o pci-nommu.o alternative.o hpet.o tsc.o
 
 obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
 obj-$(CONFIG_X86_MCE)         += mce.o
diff --git a/arch/x86_64/kernel/hpet.c b/arch/x86_64/kernel/hpet.c
new file mode 100644
index 0000000..8ac58a8
--- /dev/null
+++ b/arch/x86_64/kernel/hpet.c
@@ -0,0 +1,469 @@
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/mc146818rtc.h>
+#include <linux/time.h>
+#include <linux/clocksource.h>
+#include <linux/ioport.h>
+#include <linux/acpi.h>
+#include <linux/hpet.h>
+#include <asm/timex.h>
+#include <asm/hpet.h>
+
+int nohpet __initdata = 0;
+
+unsigned long hpet_address;
+static unsigned long hpet_period;			/* fsecs / HPET clock */
+unsigned long hpet_tick;				/* HPET clocks / interrupt */
+int hpet_use_timer;				/* Use counter of hpet for time keeping, otherwise PIT */
+
+#define FSEC_PER_TICK (FSEC_PER_SEC / HZ)
+
+/*
+ * calibrate_tsc() calibrates the processor TSC in a very simple way, comparing
+ * it to the HPET timer of known frequency.
+ */
+
+#define TICK_COUNT 100000000
+
+unsigned int __init hpet_calibrate_tsc(void)
+{
+	int tsc_start, hpet_start;
+	int tsc_now, hpet_now;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	local_irq_disable();
+
+	hpet_start = hpet_readl(HPET_COUNTER);
+	rdtscl(tsc_start);
+
+	do {
+		local_irq_disable();
+		hpet_now = hpet_readl(HPET_COUNTER);
+		tsc_now = get_cycles_sync();
+		local_irq_restore(flags);
+	} while ((tsc_now - tsc_start) < TICK_COUNT &&
+		 (hpet_now - hpet_start) < TICK_COUNT);
+
+	return (tsc_now - tsc_start) * 1000000000L
+		/ ((hpet_now - hpet_start) * hpet_period / 1000);
+}
+
+
+
+#ifdef	CONFIG_HPET
+static __init int late_hpet_init(void)
+{
+	struct hpet_data	hd;
+	unsigned int 		ntimer;
+
+	if (!hpet_address)
+        	return 0;
+
+	memset(&hd, 0, sizeof (hd));
+
+	ntimer = hpet_readl(HPET_ID);
+	ntimer = (ntimer & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT;
+	ntimer++;
+
+	/*
+	 * Register with driver.
+	 * Timer0 and Timer1 is used by platform.
+	 */
+	hd.hd_phys_address = hpet_address;
+	hd.hd_address = (void __iomem *)fix_to_virt(FIX_HPET_BASE);
+	hd.hd_nirqs = ntimer;
+	hd.hd_flags = HPET_DATA_PLATFORM;
+	hpet_reserve_timer(&hd, 0);
+#ifdef	CONFIG_HPET_EMULATE_RTC
+	hpet_reserve_timer(&hd, 1);
+#endif
+	hd.hd_irq[0] = HPET_LEGACY_8254;
+	hd.hd_irq[1] = HPET_LEGACY_RTC;
+	if (ntimer > 2) {
+		struct hpet		*hpet;
+		struct hpet_timer	*timer;
+		int			i;
+
+		hpet = (struct hpet *) fix_to_virt(FIX_HPET_BASE);
+		timer = &hpet->hpet_timers[2];
+		for (i = 2; i < ntimer; timer++, i++)
+			hd.hd_irq[i] = (timer->hpet_config &
+					Tn_INT_ROUTE_CNF_MASK) >>
+				Tn_INT_ROUTE_CNF_SHIFT;
+
+	}
+
+	hpet_alloc(&hd);
+	return 0;
+}
+fs_initcall(late_hpet_init);
+#endif
+
+static int hpet_timer_stop_set_go(unsigned long tick)
+{
+	unsigned int cfg;
+
+/*
+ * Stop the timers and reset the main counter.
+ */
+
+	cfg = hpet_readl(HPET_CFG);
+	cfg &= ~(HPET_CFG_ENABLE | HPET_CFG_LEGACY);
+	hpet_writel(cfg, HPET_CFG);
+	hpet_writel(0, HPET_COUNTER);
+	hpet_writel(0, HPET_COUNTER + 4);
+
+/*
+ * Set up timer 0, as periodic with first interrupt to happen at hpet_tick,
+ * and period also hpet_tick.
+ */
+	if (hpet_use_timer) {
+		hpet_writel(HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL |
+		    HPET_TN_32BIT, HPET_T0_CFG);
+		hpet_writel(hpet_tick, HPET_T0_CMP); /* next interrupt */
+		hpet_writel(hpet_tick, HPET_T0_CMP); /* period */
+		cfg |= HPET_CFG_LEGACY;
+	}
+/*
+ * Go!
+ */
+
+	cfg |= HPET_CFG_ENABLE;
+	hpet_writel(cfg, HPET_CFG);
+
+	return 0;
+}
+
+int hpet_arch_init(void)
+{
+	unsigned int id;
+
+	if (!hpet_address)
+		return -1;
+	set_fixmap_nocache(FIX_HPET_BASE, hpet_address);
+	__set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE);
+
+/*
+ * Read the period, compute tick and quotient.
+ */
+
+	id = hpet_readl(HPET_ID);
+
+	if (!(id & HPET_ID_VENDOR) || !(id & HPET_ID_NUMBER))
+		return -1;
+
+	hpet_period = hpet_readl(HPET_PERIOD);
+	if (hpet_period < 100000 || hpet_period > 100000000)
+		return -1;
+
+	hpet_tick = (FSEC_PER_TICK + hpet_period / 2) / hpet_period;
+
+	hpet_use_timer = (id & HPET_ID_LEGSUP);
+
+	return hpet_timer_stop_set_go(hpet_tick);
+}
+
+int hpet_reenable(void)
+{
+	return hpet_timer_stop_set_go(hpet_tick);
+}
+
+int hpet_stop(void)
+{
+	return hpet_timer_stop_set_go(0);
+}
+
+#ifdef CONFIG_HPET_EMULATE_RTC
+/* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET
+ * is enabled, we support RTC interrupt functionality in software.
+ * RTC has 3 kinds of interrupts:
+ * 1) Update Interrupt - generate an interrupt, every sec, when RTC clock
+ *    is updated
+ * 2) Alarm Interrupt - generate an interrupt at a specific time of day
+ * 3) Periodic Interrupt - generate periodic interrupt, with frequencies
+ *    2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2)
+ * (1) and (2) above are implemented using polling at a frequency of
+ * 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt
+ * overhead. (DEFAULT_RTC_INT_FREQ)
+ * For (3), we use interrupts at 64Hz or user specified periodic
+ * frequency, whichever is higher.
+ */
+#include <linux/rtc.h>
+
+#define DEFAULT_RTC_INT_FREQ 	64
+#define RTC_NUM_INTS 		1
+
+static unsigned long UIE_on;
+static unsigned long prev_update_sec;
+
+static unsigned long AIE_on;
+static struct rtc_time alarm_time;
+
+static unsigned long PIE_on;
+static unsigned long PIE_freq = DEFAULT_RTC_INT_FREQ;
+static unsigned long PIE_count;
+
+static unsigned long hpet_rtc_int_freq; /* RTC interrupt frequency */
+static unsigned int hpet_t1_cmp; /* cached comparator register */
+
+int is_hpet_enabled(void)
+{
+	return hpet_address != 0;
+}
+
+/*
+ * Timer 1 for RTC, we do not use periodic interrupt feature,
+ * even if HPET supports periodic interrupts on Timer 1.
+ * The reason being, to set up a periodic interrupt in HPET, we need to
+ * stop the main counter. And if we do that everytime someone diables/enables
+ * RTC, we will have adverse effect on main kernel timer running on Timer 0.
+ * So, for the time being, simulate the periodic interrupt in software.
+ *
+ * hpet_rtc_timer_init() is called for the first time and during subsequent
+ * interuppts reinit happens through hpet_rtc_timer_reinit().
+ */
+int hpet_rtc_timer_init(void)
+{
+	unsigned int cfg, cnt;
+	unsigned long flags;
+
+	if (!is_hpet_enabled())
+		return 0;
+	/*
+	 * Set the counter 1 and enable the interrupts.
+	 */
+	if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ))
+		hpet_rtc_int_freq = PIE_freq;
+	else
+		hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
+
+	local_irq_save(flags);
+	cnt = hpet_readl(HPET_COUNTER);
+	cnt += ((hpet_tick*HZ)/hpet_rtc_int_freq);
+	hpet_writel(cnt, HPET_T1_CMP);
+	hpet_t1_cmp = cnt;
+	local_irq_restore(flags);
+
+	cfg = hpet_readl(HPET_T1_CFG);
+	cfg &= ~HPET_TN_PERIODIC;
+	cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
+	hpet_writel(cfg, HPET_T1_CFG);
+
+	return 1;
+}
+
+static void hpet_rtc_timer_reinit(void)
+{
+	unsigned int cfg, cnt;
+
+	if (unlikely(!(PIE_on | AIE_on | UIE_on))) {
+		cfg = hpet_readl(HPET_T1_CFG);
+		cfg &= ~HPET_TN_ENABLE;
+		hpet_writel(cfg, HPET_T1_CFG);
+		return;
+	}
+
+	if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ))
+		hpet_rtc_int_freq = PIE_freq;
+	else
+		hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
+
+	/* It is more accurate to use the comparator value than current count.*/
+	cnt = hpet_t1_cmp;
+	cnt += hpet_tick*HZ/hpet_rtc_int_freq;
+	hpet_writel(cnt, HPET_T1_CMP);
+	hpet_t1_cmp = cnt;
+}
+
+/*
+ * The functions below are called from rtc driver.
+ * Return 0 if HPET is not being used.
+ * Otherwise do the necessary changes and return 1.
+ */
+int hpet_mask_rtc_irq_bit(unsigned long bit_mask)
+{
+	if (!is_hpet_enabled())
+		return 0;
+
+	if (bit_mask & RTC_UIE)
+		UIE_on = 0;
+	if (bit_mask & RTC_PIE)
+		PIE_on = 0;
+	if (bit_mask & RTC_AIE)
+		AIE_on = 0;
+
+	return 1;
+}
+
+int hpet_set_rtc_irq_bit(unsigned long bit_mask)
+{
+	int timer_init_reqd = 0;
+
+	if (!is_hpet_enabled())
+		return 0;
+
+	if (!(PIE_on | AIE_on | UIE_on))
+		timer_init_reqd = 1;
+
+	if (bit_mask & RTC_UIE) {
+		UIE_on = 1;
+	}
+	if (bit_mask & RTC_PIE) {
+		PIE_on = 1;
+		PIE_count = 0;
+	}
+	if (bit_mask & RTC_AIE) {
+		AIE_on = 1;
+	}
+
+	if (timer_init_reqd)
+		hpet_rtc_timer_init();
+
+	return 1;
+}
+
+int hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec)
+{
+	if (!is_hpet_enabled())
+		return 0;
+
+	alarm_time.tm_hour = hrs;
+	alarm_time.tm_min = min;
+	alarm_time.tm_sec = sec;
+
+	return 1;
+}
+
+int hpet_set_periodic_freq(unsigned long freq)
+{
+	if (!is_hpet_enabled())
+		return 0;
+
+	PIE_freq = freq;
+	PIE_count = 0;
+
+	return 1;
+}
+
+int hpet_rtc_dropped_irq(void)
+{
+	if (!is_hpet_enabled())
+		return 0;
+
+	return 1;
+}
+
+irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	struct rtc_time curr_time;
+	unsigned long rtc_int_flag = 0;
+	int call_rtc_interrupt = 0;
+
+	hpet_rtc_timer_reinit();
+
+	if (UIE_on | AIE_on) {
+		rtc_get_rtc_time(&curr_time);
+	}
+	if (UIE_on) {
+		if (curr_time.tm_sec != prev_update_sec) {
+			/* Set update int info, call real rtc int routine */
+			call_rtc_interrupt = 1;
+			rtc_int_flag = RTC_UF;
+			prev_update_sec = curr_time.tm_sec;
+		}
+	}
+	if (PIE_on) {
+		PIE_count++;
+		if (PIE_count >= hpet_rtc_int_freq/PIE_freq) {
+			/* Set periodic int info, call real rtc int routine */
+			call_rtc_interrupt = 1;
+			rtc_int_flag |= RTC_PF;
+			PIE_count = 0;
+		}
+	}
+	if (AIE_on) {
+		if ((curr_time.tm_sec == alarm_time.tm_sec) &&
+		    (curr_time.tm_min == alarm_time.tm_min) &&
+		    (curr_time.tm_hour == alarm_time.tm_hour)) {
+			/* Set alarm int info, call real rtc int routine */
+			call_rtc_interrupt = 1;
+			rtc_int_flag |= RTC_AF;
+		}
+	}
+	if (call_rtc_interrupt) {
+		rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
+		rtc_interrupt(rtc_int_flag, dev_id, regs);
+	}
+	return IRQ_HANDLED;
+}
+#endif
+
+static int __init nohpet_setup(char *s)
+{
+	nohpet = 1;
+	return 1;
+}
+
+__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,
+	.is_continuous	= 1,
+};
+
+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 =
+		(void __iomem*)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);
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index d18230a..aafcd2f 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -39,6 +39,7 @@
 #include <asm/sections.h>
 #include <linux/cpufreq.h>
 #include <linux/hpet.h>
+#include <linux/clocksource.h>
 #ifdef CONFIG_X86_LOCAL_APIC
 #include <asm/apic.h>
 #endif
@@ -50,22 +51,10 @@ DEFINE_SPINLOCK(rtc_lock);
 EXPORT_SYMBOL(rtc_lock);
 DEFINE_SPINLOCK(i8253_lock);
 
-int nohpet __initdata = 0;
-static int notsc __initdata = 0;
-
 #define USEC_PER_TICK (USEC_PER_SEC / HZ)
 #define NSEC_PER_TICK (NSEC_PER_SEC / HZ)
-#define FSEC_PER_TICK (FSEC_PER_SEC / HZ)
 
-#define NS_SCALE	10 /* 2^10, carefully chosen */
-#define US_SCALE	32 /* 2^32, arbitralrily chosen */
 
-unsigned int cpu_khz;					/* TSC clocks / usec, not used here */
-EXPORT_SYMBOL(cpu_khz);
-unsigned long hpet_address;
-static unsigned long hpet_period;			/* fsecs / HPET clock */
-unsigned long hpet_tick;				/* HPET clocks / interrupt */
-int hpet_use_timer;				/* Use counter of hpet for time keeping, otherwise PIT */
 unsigned long vxtime_hz = PIT_TICK_RATE;
 int report_lost_ticks;				/* command line option */
 unsigned long long monotonic_base;
@@ -232,43 +221,6 @@ static irqreturn_t timer_interrupt(int i
 	return IRQ_HANDLED;
 }
 
-static unsigned int cyc2ns_scale __read_mostly;
-
-static inline void set_cyc2ns_scale(unsigned long cpu_khz)
-{
-	cyc2ns_scale = (NSEC_PER_MSEC << NS_SCALE) / cpu_khz;
-}
-
-static inline unsigned long long cycles_2_ns(unsigned long long cyc)
-{
-	return (cyc * cyc2ns_scale) >> NS_SCALE;
-}
-
-unsigned long long sched_clock(void)
-{
-	unsigned long a = 0;
-
-	/* Could do CPU core sync here. Opteron can execute rdtsc speculatively,
-	   which means it is not completely exact and may not be monotonous between
-	   CPUs. But the errors should be too small to matter for scheduling
-	   purposes. */
-
-	rdtscll(a);
-	return cycles_2_ns(a);
-}
-
-static int tsc_unstable;
-
-static inline int check_tsc_unstable(void)
-{
-	return tsc_unstable;
-}
-
-void mark_tsc_unstable(void)
-{
-	tsc_unstable = 1;
-}
-EXPORT_SYMBOL_GPL(mark_tsc_unstable);
 
 static unsigned long get_cmos_time(void)
 {
@@ -321,124 +273,6 @@ static unsigned long get_cmos_time(void)
 	return mktime(year, mon, day, hour, min, sec);
 }
 
-#ifdef CONFIG_CPU_FREQ
-
-/* Frequency scaling support. Adjust the TSC based timer when the cpu frequency
-   changes.
-   
-   RED-PEN: On SMP we assume all CPUs run with the same frequency.  It's
-   not that important because current Opteron setups do not support
-   scaling on SMP anyroads.
-
-   Should fix up last_tsc too. Currently gettimeofday in the
-   first tick after the change will be slightly wrong. */
-
-#include <linux/workqueue.h>
-
-static unsigned int cpufreq_delayed_issched = 0;
-static unsigned int cpufreq_init = 0;
-static struct work_struct cpufreq_delayed_get_work;
-
-static void handle_cpufreq_delayed_get(void *v)
-{
-	unsigned int cpu;
-	for_each_online_cpu(cpu) {
-		cpufreq_get(cpu);
-	}
-	cpufreq_delayed_issched = 0;
-}
-
-static unsigned int  ref_freq = 0;
-static unsigned long loops_per_jiffy_ref = 0;
-
-static unsigned long cpu_khz_ref = 0;
-
-static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
-				 void *data)
-{
-        struct cpufreq_freqs *freq = data;
-	unsigned long *lpj, dummy;
-
-	if (cpu_has(&cpu_data[freq->cpu], X86_FEATURE_CONSTANT_TSC))
-		return 0;
-
-	lpj = &dummy;
-	if (!(freq->flags & CPUFREQ_CONST_LOOPS))
-#ifdef CONFIG_SMP
-		lpj = &cpu_data[freq->cpu].loops_per_jiffy;
-#else
-		lpj = &boot_cpu_data.loops_per_jiffy;
-#endif
-
-	if (!ref_freq) {
-		ref_freq = freq->old;
-		loops_per_jiffy_ref = *lpj;
-		cpu_khz_ref = cpu_khz;
-	}
-        if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
-            (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
-	    (val == CPUFREQ_RESUMECHANGE)) {
-                *lpj =
-		cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new);
-
-		cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new);
-		if (!(freq->flags & CPUFREQ_CONST_LOOPS))
-			vxtime.tsc_quot = (USEC_PER_MSEC << US_SCALE) / cpu_khz;
-	}
-	
-	set_cyc2ns_scale(cpu_khz_ref);
-
-	return 0;
-}
- 
-static struct notifier_block time_cpufreq_notifier_block = {
-         .notifier_call  = time_cpufreq_notifier
-};
-
-static int __init cpufreq_tsc(void)
-{
-	INIT_WORK(&cpufreq_delayed_get_work, handle_cpufreq_delayed_get, NULL);
-	if (!cpufreq_register_notifier(&time_cpufreq_notifier_block,
-				       CPUFREQ_TRANSITION_NOTIFIER))
-		cpufreq_init = 1;
-	return 0;
-}
-
-core_initcall(cpufreq_tsc);
-
-#endif
-
-/*
- * calibrate_tsc() calibrates the processor TSC in a very simple way, comparing
- * it to the HPET timer of known frequency.
- */
-
-#define TICK_COUNT 100000000
-
-static unsigned int __init hpet_calibrate_tsc(void)
-{
-	int tsc_start, hpet_start;
-	int tsc_now, hpet_now;
-	unsigned long flags;
-
-	local_irq_save(flags);
-	local_irq_disable();
-
-	hpet_start = hpet_readl(HPET_COUNTER);
-	rdtscl(tsc_start);
-
-	do {
-		local_irq_disable();
-		hpet_now = hpet_readl(HPET_COUNTER);
-		tsc_now = get_cycles_sync();
-		local_irq_restore(flags);
-	} while ((tsc_now - tsc_start) < TICK_COUNT &&
-		 (hpet_now - hpet_start) < TICK_COUNT);
-
-	return (tsc_now - tsc_start) * 1000000000L
-		/ ((hpet_now - hpet_start) * hpet_period / 1000);
-}
-
 
 /*
  * pit_calibrate_tsc() uses the speaker output (channel 2) of
@@ -469,124 +303,6 @@ static unsigned int __init pit_calibrate
 	return (end - start) / 50;
 }
 
-#ifdef	CONFIG_HPET
-static __init int late_hpet_init(void)
-{
-	struct hpet_data	hd;
-	unsigned int 		ntimer;
-
-	if (!hpet_address)
-        	return 0;
-
-	memset(&hd, 0, sizeof (hd));
-
-	ntimer = hpet_readl(HPET_ID);
-	ntimer = (ntimer & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT;
-	ntimer++;
-
-	/*
-	 * Register with driver.
-	 * Timer0 and Timer1 is used by platform.
-	 */
-	hd.hd_phys_address = hpet_address;
-	hd.hd_address = (void __iomem *)fix_to_virt(FIX_HPET_BASE);
-	hd.hd_nirqs = ntimer;
-	hd.hd_flags = HPET_DATA_PLATFORM;
-	hpet_reserve_timer(&hd, 0);
-#ifdef	CONFIG_HPET_EMULATE_RTC
-	hpet_reserve_timer(&hd, 1);
-#endif
-	hd.hd_irq[0] = HPET_LEGACY_8254;
-	hd.hd_irq[1] = HPET_LEGACY_RTC;
-	if (ntimer > 2) {
-		struct hpet		*hpet;
-		struct hpet_timer	*timer;
-		int			i;
-
-		hpet = (struct hpet *) fix_to_virt(FIX_HPET_BASE);
-		timer = &hpet->hpet_timers[2];
-		for (i = 2; i < ntimer; timer++, i++)
-			hd.hd_irq[i] = (timer->hpet_config &
-					Tn_INT_ROUTE_CNF_MASK) >>
-				Tn_INT_ROUTE_CNF_SHIFT;
-
-	}
-
-	hpet_alloc(&hd);
-	return 0;
-}
-fs_initcall(late_hpet_init);
-#endif
-
-static int hpet_timer_stop_set_go(unsigned long tick)
-{
-	unsigned int cfg;
-
-/*
- * Stop the timers and reset the main counter.
- */
-
-	cfg = hpet_readl(HPET_CFG);
-	cfg &= ~(HPET_CFG_ENABLE | HPET_CFG_LEGACY);
-	hpet_writel(cfg, HPET_CFG);
-	hpet_writel(0, HPET_COUNTER);
-	hpet_writel(0, HPET_COUNTER + 4);
-
-/*
- * Set up timer 0, as periodic with first interrupt to happen at hpet_tick,
- * and period also hpet_tick.
- */
-	if (hpet_use_timer) {
-		hpet_writel(HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL |
-		    HPET_TN_32BIT, HPET_T0_CFG);
-		hpet_writel(hpet_tick, HPET_T0_CMP); /* next interrupt */
-		hpet_writel(hpet_tick, HPET_T0_CMP); /* period */
-		cfg |= HPET_CFG_LEGACY;
-	}
-/*
- * Go!
- */
-
-	cfg |= HPET_CFG_ENABLE;
-	hpet_writel(cfg, HPET_CFG);
-
-	return 0;
-}
-
-static int hpet_init(void)
-{
-	unsigned int id;
-
-	if (!hpet_address)
-		return -1;
-	set_fixmap_nocache(FIX_HPET_BASE, hpet_address);
-	__set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE);
-
-/*
- * Read the period, compute tick and quotient.
- */
-
-	id = hpet_readl(HPET_ID);
-
-	if (!(id & HPET_ID_VENDOR) || !(id & HPET_ID_NUMBER))
-		return -1;
-
-	hpet_period = hpet_readl(HPET_PERIOD);
-	if (hpet_period < 100000 || hpet_period > 100000000)
-		return -1;
-
-	hpet_tick = (FSEC_PER_TICK + hpet_period / 2) / hpet_period;
-
-	hpet_use_timer = (id & HPET_ID_LEGSUP);
-
-	return hpet_timer_stop_set_go(hpet_tick);
-}
-
-static int hpet_reenable(void)
-{
-	return hpet_timer_stop_set_go(hpet_tick);
-}
-
 #define PIT_MODE 0x43
 #define PIT_CH0  0x40
 
@@ -616,7 +332,7 @@ void __init stop_timer_interrupt(void)
 	char *name;
 	if (hpet_address) {
 		name = "HPET";
-		hpet_timer_stop_set_go(0);
+		hpet_stop();
 	} else {
 		name = "PIT";
 		pit_stop_interrupt();
@@ -646,7 +362,7 @@ void __init time_init(void)
 	set_normalized_timespec(&wall_to_monotonic,
 	                        -xtime.tv_sec, -xtime.tv_nsec);
 
-	if (hpet_init())
+	if (hpet_arch_init())
 		hpet_address = 0;
 
 	if (hpet_use_timer) {
@@ -660,6 +376,9 @@ void __init time_init(void)
 		timename = "PIT";
 	}
 
+	if (unsynchronized_tsc())
+		mark_tsc_unstable();
+
 	printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n",
 		cpu_khz / 1000, cpu_khz % 1000);
 	setup_irq(0, &irq0);
@@ -667,30 +386,6 @@ void __init time_init(void)
 	set_cyc2ns_scale(cpu_khz);
 }
 
-/*
- * Make an educated guess if the TSC is trustworthy and synchronized
- * over all CPUs.
- */
-__cpuinit int unsynchronized_tsc(void)
-{
-#ifdef CONFIG_SMP
-	if (apic_is_clustered_box())
-		return 1;
-#endif
-	/* Most intel systems have synchronized TSCs except for
-	   multi node systems */
- 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) {
-#ifdef CONFIG_ACPI
-		/* But TSC doesn't tick in C3 so don't use it there */
-		if (acpi_fadt.length > 0 && acpi_fadt.plvl3_lat < 100)
-			return 1;
-#endif
- 		return 0;
-	}
-
- 	/* Assume multi socket systems are not synchronized */
- 	return num_present_cpus() > 1;
-}
 
 __setup("report_lost_ticks", time_setup);
 
@@ -759,243 +454,3 @@ static int time_init_device(void)
 
 device_initcall(time_init_device);
 
-#ifdef CONFIG_HPET_EMULATE_RTC
-/* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET
- * is enabled, we support RTC interrupt functionality in software.
- * RTC has 3 kinds of interrupts:
- * 1) Update Interrupt - generate an interrupt, every sec, when RTC clock
- *    is updated
- * 2) Alarm Interrupt - generate an interrupt at a specific time of day
- * 3) Periodic Interrupt - generate periodic interrupt, with frequencies
- *    2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2)
- * (1) and (2) above are implemented using polling at a frequency of
- * 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt
- * overhead. (DEFAULT_RTC_INT_FREQ)
- * For (3), we use interrupts at 64Hz or user specified periodic
- * frequency, whichever is higher.
- */
-#include <linux/rtc.h>
-
-#define DEFAULT_RTC_INT_FREQ 	64
-#define RTC_NUM_INTS 		1
-
-static unsigned long UIE_on;
-static unsigned long prev_update_sec;
-
-static unsigned long AIE_on;
-static struct rtc_time alarm_time;
-
-static unsigned long PIE_on;
-static unsigned long PIE_freq = DEFAULT_RTC_INT_FREQ;
-static unsigned long PIE_count;
-
-static unsigned long hpet_rtc_int_freq; /* RTC interrupt frequency */
-static unsigned int hpet_t1_cmp; /* cached comparator register */
-
-int is_hpet_enabled(void)
-{
-	return hpet_address != 0;
-}
-
-/*
- * Timer 1 for RTC, we do not use periodic interrupt feature,
- * even if HPET supports periodic interrupts on Timer 1.
- * The reason being, to set up a periodic interrupt in HPET, we need to
- * stop the main counter. And if we do that everytime someone diables/enables
- * RTC, we will have adverse effect on main kernel timer running on Timer 0.
- * So, for the time being, simulate the periodic interrupt in software.
- *
- * hpet_rtc_timer_init() is called for the first time and during subsequent
- * interuppts reinit happens through hpet_rtc_timer_reinit().
- */
-int hpet_rtc_timer_init(void)
-{
-	unsigned int cfg, cnt;
-	unsigned long flags;
-
-	if (!is_hpet_enabled())
-		return 0;
-	/*
-	 * Set the counter 1 and enable the interrupts.
-	 */
-	if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ))
-		hpet_rtc_int_freq = PIE_freq;
-	else
-		hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
-
-	local_irq_save(flags);
-	cnt = hpet_readl(HPET_COUNTER);
-	cnt += ((hpet_tick*HZ)/hpet_rtc_int_freq);
-	hpet_writel(cnt, HPET_T1_CMP);
-	hpet_t1_cmp = cnt;
-	local_irq_restore(flags);
-
-	cfg = hpet_readl(HPET_T1_CFG);
-	cfg &= ~HPET_TN_PERIODIC;
-	cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
-	hpet_writel(cfg, HPET_T1_CFG);
-
-	return 1;
-}
-
-static void hpet_rtc_timer_reinit(void)
-{
-	unsigned int cfg, cnt;
-
-	if (unlikely(!(PIE_on | AIE_on | UIE_on))) {
-		cfg = hpet_readl(HPET_T1_CFG);
-		cfg &= ~HPET_TN_ENABLE;
-		hpet_writel(cfg, HPET_T1_CFG);
-		return;
-	}
-
-	if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ))
-		hpet_rtc_int_freq = PIE_freq;
-	else
-		hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
-
-	/* It is more accurate to use the comparator value than current count.*/
-	cnt = hpet_t1_cmp;
-	cnt += hpet_tick*HZ/hpet_rtc_int_freq;
-	hpet_writel(cnt, HPET_T1_CMP);
-	hpet_t1_cmp = cnt;
-}
-
-/*
- * The functions below are called from rtc driver.
- * Return 0 if HPET is not being used.
- * Otherwise do the necessary changes and return 1.
- */
-int hpet_mask_rtc_irq_bit(unsigned long bit_mask)
-{
-	if (!is_hpet_enabled())
-		return 0;
-
-	if (bit_mask & RTC_UIE)
-		UIE_on = 0;
-	if (bit_mask & RTC_PIE)
-		PIE_on = 0;
-	if (bit_mask & RTC_AIE)
-		AIE_on = 0;
-
-	return 1;
-}
-
-int hpet_set_rtc_irq_bit(unsigned long bit_mask)
-{
-	int timer_init_reqd = 0;
-
-	if (!is_hpet_enabled())
-		return 0;
-
-	if (!(PIE_on | AIE_on | UIE_on))
-		timer_init_reqd = 1;
-
-	if (bit_mask & RTC_UIE) {
-		UIE_on = 1;
-	}
-	if (bit_mask & RTC_PIE) {
-		PIE_on = 1;
-		PIE_count = 0;
-	}
-	if (bit_mask & RTC_AIE) {
-		AIE_on = 1;
-	}
-
-	if (timer_init_reqd)
-		hpet_rtc_timer_init();
-
-	return 1;
-}
-
-int hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec)
-{
-	if (!is_hpet_enabled())
-		return 0;
-
-	alarm_time.tm_hour = hrs;
-	alarm_time.tm_min = min;
-	alarm_time.tm_sec = sec;
-
-	return 1;
-}
-
-int hpet_set_periodic_freq(unsigned long freq)
-{
-	if (!is_hpet_enabled())
-		return 0;
-
-	PIE_freq = freq;
-	PIE_count = 0;
-
-	return 1;
-}
-
-int hpet_rtc_dropped_irq(void)
-{
-	if (!is_hpet_enabled())
-		return 0;
-
-	return 1;
-}
-
-irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
-{
-	struct rtc_time curr_time;
-	unsigned long rtc_int_flag = 0;
-	int call_rtc_interrupt = 0;
-
-	hpet_rtc_timer_reinit();
-
-	if (UIE_on | AIE_on) {
-		rtc_get_rtc_time(&curr_time);
-	}
-	if (UIE_on) {
-		if (curr_time.tm_sec != prev_update_sec) {
-			/* Set update int info, call real rtc int routine */
-			call_rtc_interrupt = 1;
-			rtc_int_flag = RTC_UF;
-			prev_update_sec = curr_time.tm_sec;
-		}
-	}
-	if (PIE_on) {
-		PIE_count++;
-		if (PIE_count >= hpet_rtc_int_freq/PIE_freq) {
-			/* Set periodic int info, call real rtc int routine */
-			call_rtc_interrupt = 1;
-			rtc_int_flag |= RTC_PF;
-			PIE_count = 0;
-		}
-	}
-	if (AIE_on) {
-		if ((curr_time.tm_sec == alarm_time.tm_sec) &&
-		    (curr_time.tm_min == alarm_time.tm_min) &&
-		    (curr_time.tm_hour == alarm_time.tm_hour)) {
-			/* Set alarm int info, call real rtc int routine */
-			call_rtc_interrupt = 1;
-			rtc_int_flag |= RTC_AF;
-		}
-	}
-	if (call_rtc_interrupt) {
-		rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
-		rtc_interrupt(rtc_int_flag, dev_id, regs);
-	}
-	return IRQ_HANDLED;
-}
-#endif
-
-static int __init nohpet_setup(char *s) 
-{ 
-	nohpet = 1;
-	return 1;
-} 
-
-__setup("nohpet", nohpet_setup);
-
-int __init notsc_setup(char *s)
-{
-	notsc = 1;
-	return 1;
-}
-
-__setup("notsc", notsc_setup);
diff --git a/arch/x86_64/kernel/tsc.c b/arch/x86_64/kernel/tsc.c
new file mode 100644
index 0000000..f662183
--- /dev/null
+++ b/arch/x86_64/kernel/tsc.c
@@ -0,0 +1,222 @@
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/clocksource.h>
+#include <linux/time.h>
+#include <linux/acpi.h>
+#include <linux/cpufreq.h>
+
+#include <asm/timex.h>
+
+#define NS_SCALE	10 /* 2^10, carefully chosen */
+#define US_SCALE	32 /* 2^32, arbitralrily chosen */
+
+static int notsc __initdata = 0;
+
+unsigned int cpu_khz;					/* TSC clocks / usec, not used here */
+EXPORT_SYMBOL(cpu_khz);
+
+static unsigned int cyc2ns_scale __read_mostly;
+
+void set_cyc2ns_scale(unsigned long khz)
+{
+	cyc2ns_scale = (NSEC_PER_MSEC << NS_SCALE) / khz;
+}
+
+static inline unsigned long long cycles_2_ns(unsigned long long cyc)
+{
+	return (cyc * cyc2ns_scale) >> NS_SCALE;
+}
+
+unsigned long long sched_clock(void)
+{
+	unsigned long a = 0;
+
+	/* Could do CPU core sync here. Opteron can execute rdtsc speculatively,
+	   which means it is not completely exact and may not be monotonous between
+	   CPUs. But the errors should be too small to matter for scheduling
+	   purposes. */
+
+	rdtscll(a);
+	return cycles_2_ns(a);
+}
+
+static int tsc_unstable;
+
+static inline int check_tsc_unstable(void)
+{
+	return tsc_unstable;
+}
+
+void mark_tsc_unstable(void)
+{
+	tsc_unstable = 1;
+}
+EXPORT_SYMBOL_GPL(mark_tsc_unstable);
+
+#ifdef CONFIG_CPU_FREQ
+
+/* Frequency scaling support. Adjust the TSC based timer when the cpu frequency
+   changes.
+
+   RED-PEN: On SMP we assume all CPUs run with the same frequency.  It's
+   not that important because current Opteron setups do not support
+   scaling on SMP anyroads.
+
+   Should fix up last_tsc too. Currently gettimeofday in the
+   first tick after the change will be slightly wrong. */
+
+#include <linux/workqueue.h>
+
+static unsigned int cpufreq_delayed_issched = 0;
+static unsigned int cpufreq_init = 0;
+static struct work_struct cpufreq_delayed_get_work;
+
+static void handle_cpufreq_delayed_get(void *v)
+{
+	unsigned int cpu;
+	for_each_online_cpu(cpu) {
+		cpufreq_get(cpu);
+	}
+	cpufreq_delayed_issched = 0;
+}
+
+static unsigned int  ref_freq = 0;
+static unsigned long loops_per_jiffy_ref = 0;
+
+static unsigned long cpu_khz_ref = 0;
+
+static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
+				 void *data)
+{
+        struct cpufreq_freqs *freq = data;
+	unsigned long *lpj, dummy;
+
+	if (cpu_has(&cpu_data[freq->cpu], X86_FEATURE_CONSTANT_TSC))
+		return 0;
+
+	lpj = &dummy;
+	if (!(freq->flags & CPUFREQ_CONST_LOOPS))
+#ifdef CONFIG_SMP
+		lpj = &cpu_data[freq->cpu].loops_per_jiffy;
+#else
+		lpj = &boot_cpu_data.loops_per_jiffy;
+#endif
+
+	if (!ref_freq) {
+		ref_freq = freq->old;
+		loops_per_jiffy_ref = *lpj;
+		cpu_khz_ref = cpu_khz;
+	}
+        if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
+            (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
+	    (val == CPUFREQ_RESUMECHANGE)) {
+                *lpj =
+		cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new);
+
+		cpu_khz = cpufreq_scale(cpu_khz_ref, ref_freq, freq->new);
+		if (!(freq->flags & CPUFREQ_CONST_LOOPS))
+			mark_tsc_unstable();
+	}
+
+	set_cyc2ns_scale(cpu_khz_ref);
+
+	return 0;
+}
+
+static struct notifier_block time_cpufreq_notifier_block = {
+	.notifier_call  = time_cpufreq_notifier
+};
+
+static int __init cpufreq_tsc(void)
+{
+	INIT_WORK(&cpufreq_delayed_get_work, handle_cpufreq_delayed_get, NULL);
+	if (!cpufreq_register_notifier(&time_cpufreq_notifier_block,
+				       CPUFREQ_TRANSITION_NOTIFIER))
+		cpufreq_init = 1;
+	return 0;
+}
+
+core_initcall(cpufreq_tsc);
+
+#endif
+/*
+ * Make an educated guess if the TSC is trustworthy and synchronized
+ * over all CPUs.
+ */
+__cpuinit int unsynchronized_tsc(void)
+{
+#ifdef CONFIG_SMP
+	if (apic_is_clustered_box())
+		return 1;
+#endif
+	/* Most intel systems have synchronized TSCs except for
+	   multi node systems */
+ 	if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) {
+#ifdef CONFIG_ACPI
+		/* But TSC doesn't tick in C3 so don't use it there */
+		if (acpi_fadt.length > 0 && acpi_fadt.plvl3_lat < 100)
+			return 1;
+#endif
+ 		return 0;
+	}
+
+ 	/* Assume multi socket systems are not synchronized */
+ 	return num_present_cpus() > 1;
+}
+
+int __init notsc_setup(char *s)
+{
+	notsc = 1;
+	return 1;
+}
+
+__setup("notsc", notsc_setup);
+
+
+/* clock source code: */
+
+static int tsc_update_callback(void);
+
+static cycle_t read_tsc(void)
+{
+	cycle_t ret = (cycle_t)get_cycles_sync();
+	return ret;
+}
+
+static struct clocksource clocksource_tsc = {
+	.name			= "tsc",
+	.rating			= 300,
+	.read			= read_tsc,
+	.mask			= (cycle_t)-1,
+	.mult			= 0, /* to be set */
+	.shift			= 22,
+	.update_callback	= tsc_update_callback,
+	.is_continuous		= 1,
+};
+
+static int tsc_update_callback(void)
+{
+	int change = 0;
+
+	/* check to see if we should switch to the safe clocksource: */
+	if (clocksource_tsc.rating != 50 && check_tsc_unstable()) {
+		clocksource_tsc.rating = 50;
+		clocksource_reselect();
+		change = 1;
+	}
+	return change;
+}
+
+static int __init init_tsc_clocksource(void)
+{
+	if (!notsc) {
+		clocksource_tsc.mult = clocksource_khz2mult(cpu_khz,
+							clocksource_tsc.shift);
+		return clocksource_register(&clocksource_tsc);
+	}
+	return 0;
+}
+
+module_init(init_tsc_clocksource);
diff --git a/include/asm-x86_64/hpet.h b/include/asm-x86_64/hpet.h
index 60d5127..c10d4e4 100644
--- a/include/asm-x86_64/hpet.h
+++ b/include/asm-x86_64/hpet.h
@@ -60,6 +60,12 @@ extern int apic_is_clustered_box(void);
 extern int hpet_use_timer;
 extern unsigned long hpet_address;
 
+extern int hpet_reenable(void);
+extern int hpet_arch_init(void);
+extern int hpet_stop(void);
+extern unsigned int hpet_calibrate_tsc(void);
+
+
 #ifdef CONFIG_HPET_EMULATE_RTC
 extern int hpet_mask_rtc_irq_bit(unsigned long bit_mask);
 extern int hpet_set_rtc_irq_bit(unsigned long bit_mask);
diff --git a/include/asm-x86_64/timex.h b/include/asm-x86_64/timex.h
index 40167eb..c5165cd 100644
--- a/include/asm-x86_64/timex.h
+++ b/include/asm-x86_64/timex.h
@@ -42,7 +42,7 @@ static __always_inline cycles_t get_cycl
 extern unsigned int cpu_khz;
 
 extern void mark_tsc_unstable(void);
-
+extern void set_cyc2ns_scale(unsigned long khz);
 extern int read_current_timer(unsigned long *timer_value);
 #define ARCH_HAS_READ_CURRENT_TIMER	1
 

^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCH 6/6] x86_64: GENERIC_TIME based vsyscall code
  2006-09-07  2:18 [PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
                   ` (4 preceding siblings ...)
  2006-09-07  2:19 ` [PATCH 5/6] x86_64: Clocksources for x86-64 john stultz
@ 2006-09-07  2:19 ` john stultz
  2006-09-09 20:30 ` [PATCH 0/6] x86_64: Generic timekeeping for x86_64 Andi Kleen
  6 siblings, 0 replies; 8+ messages in thread
From: john stultz @ 2006-09-07  2:19 UTC (permalink / raw)
  To: ak; +Cc: john stultz, linux-kernel

Re-enable vsyscall gettimeofday using the generic clocksource 
infrastructure.

Signed-off-by: John Stultz <johnstul@us.ibm.com>

 arch/x86_64/Kconfig              |    4 +
 arch/x86_64/kernel/hpet.c        |    6 ++
 arch/x86_64/kernel/time.c        |    9 ---
 arch/x86_64/kernel/tsc.c         |    7 ++
 arch/x86_64/kernel/vmlinux.lds.S |   24 +-------
 arch/x86_64/kernel/vsyscall.c    |  111 ++++++++++++++++++++++-----------------
 include/asm-x86_64/proto.h       |    2 
 include/asm-x86_64/timex.h       |    2 
 include/asm-x86_64/vsyscall.h    |   39 +------------
 9 files changed, 92 insertions(+), 112 deletions(-)

linux-2.6.18-rc6_timeofday-arch-x86-64-part5_C6.patch
============================================
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index fabb174..6167ce2 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -28,6 +28,10 @@ config GENERIC_TIME
 	bool
 	default y
 
+config GENERIC_TIME_VSYSCALL
+	bool
+	default y
+
 config LOCKDEP_SUPPORT
 	bool
 	default y
diff --git a/arch/x86_64/kernel/hpet.c b/arch/x86_64/kernel/hpet.c
index 8ac58a8..97be615 100644
--- a/arch/x86_64/kernel/hpet.c
+++ b/arch/x86_64/kernel/hpet.c
@@ -421,6 +421,11 @@ static cycle_t read_hpet(void)
 	return (cycle_t)readl(hpet_ptr);
 }
 
+static cycle_t __vsyscall_fn vread_hpet(void)
+{
+	return (cycle_t)readl((void *)fix_to_virt(VSYSCALL_HPET) + 0xf0);
+}
+
 struct clocksource clocksource_hpet = {
 	.name		= "hpet",
 	.rating		= 250,
@@ -429,6 +434,7 @@ struct clocksource clocksource_hpet = {
 	.mult		= 0, /* set below */
 	.shift		= HPET_SHIFT,
 	.is_continuous	= 1,
+	.vread		= vread_hpet,
 };
 
 static int __init init_hpet_clocksource(void)
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index aafcd2f..afa2f7f 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -55,16 +55,9 @@ DEFINE_SPINLOCK(i8253_lock);
 #define NSEC_PER_TICK (NSEC_PER_SEC / HZ)
 
 
-unsigned long vxtime_hz = PIT_TICK_RATE;
 int report_lost_ticks;				/* command line option */
-unsigned long long monotonic_base;
 
-struct vxtime_data __vxtime __section_vxtime;	/* for vsyscalls */
-
-volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES;
-unsigned long __wall_jiffies __section_wall_jiffies = INITIAL_JIFFIES;
-struct timespec __xtime __section_xtime;
-struct timezone __sys_tz __section_sys_tz;
+volatile unsigned long jiffies  = INITIAL_JIFFIES;
 
 unsigned long profile_pc(struct pt_regs *regs)
 {
diff --git a/arch/x86_64/kernel/tsc.c b/arch/x86_64/kernel/tsc.c
index f662183..5c55a51 100644
--- a/arch/x86_64/kernel/tsc.c
+++ b/arch/x86_64/kernel/tsc.c
@@ -185,6 +185,12 @@ static cycle_t read_tsc(void)
 	return ret;
 }
 
+static cycle_t __vsyscall_fn vread_tsc(void)
+{
+	cycle_t ret = (cycle_t)get_cycles_sync();
+	return ret;
+}
+
 static struct clocksource clocksource_tsc = {
 	.name			= "tsc",
 	.rating			= 300,
@@ -194,6 +200,7 @@ static struct clocksource clocksource_ts
 	.shift			= 22,
 	.update_callback	= tsc_update_callback,
 	.is_continuous		= 1,
+	.vread			= vread_tsc,
 };
 
 static int tsc_update_callback(void)
diff --git a/arch/x86_64/kernel/vmlinux.lds.S b/arch/x86_64/kernel/vmlinux.lds.S
index 7c4de31..9e7c048 100644
--- a/arch/x86_64/kernel/vmlinux.lds.S
+++ b/arch/x86_64/kernel/vmlinux.lds.S
@@ -93,27 +93,11 @@ SECTIONS
   __vsyscall_0 = VSYSCALL_VIRT_ADDR;
 
   . = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
-  .xtime_lock : AT(VLOAD(.xtime_lock)) { *(.xtime_lock) }
-  xtime_lock = VVIRT(.xtime_lock);
-
-  .vxtime : AT(VLOAD(.vxtime)) { *(.vxtime) }
-  vxtime = VVIRT(.vxtime);
-
-  .wall_jiffies : AT(VLOAD(.wall_jiffies)) { *(.wall_jiffies) }
-  wall_jiffies = VVIRT(.wall_jiffies);
-
-  .sys_tz : AT(VLOAD(.sys_tz)) { *(.sys_tz) }
-  sys_tz = VVIRT(.sys_tz);
-
-  .sysctl_vsyscall : AT(VLOAD(.sysctl_vsyscall)) { *(.sysctl_vsyscall) }
-  sysctl_vsyscall = VVIRT(.sysctl_vsyscall);
-
-  .xtime : AT(VLOAD(.xtime)) { *(.xtime) }
-  xtime = VVIRT(.xtime);
-
+  .vsyscall_fn : AT(VLOAD(.vsyscall_fn)) { *(.vsyscall_fn) }
   . = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
-  .jiffies : AT(VLOAD(.jiffies)) { *(.jiffies) }
-  jiffies = VVIRT(.jiffies);
+  .vsyscall_gtod_data : AT(VLOAD(.vsyscall_gtod_data)) { *(.vsyscall_gtod_data) }
+  vsyscall_gtod_data = VVIRT(.vsyscall_gtod_data);
+
 
   .vsyscall_1 ADDR(.vsyscall_0) + 1024: AT(VLOAD(.vsyscall_1)) { *(.vsyscall_1) }
   .vsyscall_2 ADDR(.vsyscall_0) + 2048: AT(VLOAD(.vsyscall_2)) { *(.vsyscall_2) }
diff --git a/arch/x86_64/kernel/vsyscall.c b/arch/x86_64/kernel/vsyscall.c
index f603037..02b6325 100644
--- a/arch/x86_64/kernel/vsyscall.c
+++ b/arch/x86_64/kernel/vsyscall.c
@@ -26,65 +26,50 @@
 #include <linux/seqlock.h>
 #include <linux/jiffies.h>
 #include <linux/sysctl.h>
+#include <linux/clocksource.h>
 
 #include <asm/vsyscall.h>
 #include <asm/pgtable.h>
 #include <asm/page.h>
+#include <asm/unistd.h>
 #include <asm/fixmap.h>
 #include <asm/errno.h>
 #include <asm/io.h>
 
 #define __vsyscall(nr) __attribute__ ((unused,__section__(".vsyscall_" #nr)))
 
-int __sysctl_vsyscall __section_sysctl_vsyscall = 1;
-seqlock_t __xtime_lock __section_xtime_lock = SEQLOCK_UNLOCKED;
-
-#include <asm/unistd.h>
-
-static __always_inline void timeval_normalize(struct timeval * tv)
-{
-	time_t __sec;
+struct vsyscall_gtod_data_t {
+	seqlock_t lock;
+	int sysctl_enabled;
+	struct timeval wall_time_tv;
+	struct timezone sys_tz;
+	cycle_t offset_base;
+	struct clocksource clock;
+};
 
-	__sec = tv->tv_usec / 1000000;
-	if (__sec) {
-		tv->tv_usec %= 1000000;
-		tv->tv_sec += __sec;
-	}
-}
+struct vsyscall_gtod_data_t __vsyscall_gtod_data __section_vsyscall_gtod_data =  {
+	.lock = SEQLOCK_UNLOCKED,
+	.sysctl_enabled = 1,
+};
 
-static __always_inline void do_vgettimeofday(struct timeval * tv)
+void update_vsyscall(struct timespec* wall_time, struct clocksource* clock)
 {
-	long sequence, t;
-	unsigned long sec, usec;
+	unsigned long flags;
 
-	do {
-		sequence = read_seqbegin(&__xtime_lock);
-		
-		sec = __xtime.tv_sec;
-		usec = (__xtime.tv_nsec / 1000) +
-			(__jiffies - __wall_jiffies) * (1000000 / HZ);
-
-		if (__vxtime.mode != VXTIME_HPET) {
-			t = get_cycles_sync();
-			if (t < __vxtime.last_tsc)
-				t = __vxtime.last_tsc;
-			usec += ((t - __vxtime.last_tsc) *
-				 __vxtime.tsc_quot) >> 32;
-			/* See comment in x86_64 do_gettimeofday. */
-		} else {
-			usec += ((readl((void *)fix_to_virt(VSYSCALL_HPET) + 0xf0) -
-				  __vxtime.last) * __vxtime.quot) >> 32;
-		}
-	} while (read_seqretry(&__xtime_lock, sequence));
+	write_seqlock_irqsave(&vsyscall_gtod_data.lock, flags);
+	/* copy vsyscall data */
+	vsyscall_gtod_data.clock = *clock;
+	vsyscall_gtod_data.wall_time_tv.tv_sec = wall_time->tv_sec;
+	vsyscall_gtod_data.wall_time_tv.tv_usec = wall_time->tv_nsec/1000;
+	vsyscall_gtod_data.sys_tz = sys_tz;
 
-	tv->tv_sec = sec + usec / 1000000;
-	tv->tv_usec = usec % 1000000;
+	write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags);
 }
 
 /* RED-PEN may want to readd seq locking, but then the variable should be write-once. */
 static __always_inline void do_get_tz(struct timezone * tz)
 {
-	*tz = __sys_tz;
+	*tz = __vsyscall_gtod_data.sys_tz;
 }
 
 static __always_inline int gettimeofday(struct timeval *tv, struct timezone *tz)
@@ -105,10 +90,44 @@ static __always_inline long time_syscall
 	return secs;
 }
 
+static __always_inline void do_vgettimeofday(struct timeval * tv)
+{
+	cycle_t now, base, mask, cycle_delta;
+	unsigned long seq, mult, shift, nsec_delta;
+	cycle_t (*vread)(void);
+	do {
+		seq = read_seqbegin(&__vsyscall_gtod_data.lock);
+
+		vread = __vsyscall_gtod_data.clock.vread;
+		if (unlikely(!__vsyscall_gtod_data.sysctl_enabled || !vread)) {
+			gettimeofday(tv,0);
+			return;
+		}
+		now = vread();
+		base = __vsyscall_gtod_data.clock.cycle_last;
+		mask = __vsyscall_gtod_data.clock.mask;
+		mult = __vsyscall_gtod_data.clock.mult;
+		shift = __vsyscall_gtod_data.clock.shift;
+
+		*tv = __vsyscall_gtod_data.wall_time_tv;
+
+	} while (read_seqretry(&__vsyscall_gtod_data.lock, seq));
+
+	/* calculate interval: */
+	cycle_delta = (now - base) & mask;
+	/* convert to nsecs: */
+	nsec_delta = (cycle_delta * mult) >> shift;
+
+	/* convert to usecs and add to timespec: */
+	tv->tv_usec += nsec_delta / NSEC_PER_USEC;
+	while (tv->tv_usec > USEC_PER_SEC) {
+		tv->tv_sec += 1;
+		tv->tv_usec -= USEC_PER_SEC;
+	}
+}
+
 int __vsyscall(0) vgettimeofday(struct timeval * tv, struct timezone * tz)
 {
-	if (!__sysctl_vsyscall)
-		return gettimeofday(tv,tz);
 	if (tv)
 		do_vgettimeofday(tv);
 	if (tz)
@@ -120,11 +139,11 @@ int __vsyscall(0) vgettimeofday(struct t
  * unlikely */
 time_t __vsyscall(1) vtime(time_t *t)
 {
-	if (!__sysctl_vsyscall)
+	if (unlikely(!__vsyscall_gtod_data.sysctl_enabled))
 		return time_syscall(t);
 	else if (t)
-		*t = __xtime.tv_sec;		
-	return __xtime.tv_sec;
+		*t = __vsyscall_gtod_data.wall_time_tv.tv_sec;
+	return __vsyscall_gtod_data.wall_time_tv.tv_sec;
 }
 
 long __vsyscall(2) venosys_0(void)
@@ -163,7 +182,7 @@ static int vsyscall_sysctl_change(ctl_ta
 		ret = -ENOMEM;
 		goto out;
 	}
-	if (!sysctl_vsyscall) {
+	if (!vsyscall_gtod_data.sysctl_enabled) {
 		*map1 = SYSCALL;
 		*map2 = SYSCALL;
 	} else {
@@ -186,7 +205,7 @@ static int vsyscall_sysctl_nostrat(ctl_t
 
 static ctl_table kernel_table2[] = {
 	{ .ctl_name = 99, .procname = "vsyscall64",
-	  .data = &sysctl_vsyscall, .maxlen = sizeof(int), .mode = 0644,
+	  .data = &vsyscall_gtod_data.sysctl_enabled, .maxlen = sizeof(int), .mode = 0644,
 	  .strategy = vsyscall_sysctl_nostrat,
 	  .proc_handler = vsyscall_sysctl_change },
 	{ 0, }
diff --git a/include/asm-x86_64/proto.h b/include/asm-x86_64/proto.h
index 716ac55..33d1a19 100644
--- a/include/asm-x86_64/proto.h
+++ b/include/asm-x86_64/proto.h
@@ -47,9 +47,7 @@ extern u32 pmtmr_ioport;
 #else
 #define pmtmr_ioport 0
 #endif
-extern int sysctl_vsyscall;
 extern int nohpet;
-extern unsigned long vxtime_hz;
 
 extern int numa_setup(char *opt);
 
diff --git a/include/asm-x86_64/timex.h b/include/asm-x86_64/timex.h
index c5165cd..372bdc6 100644
--- a/include/asm-x86_64/timex.h
+++ b/include/asm-x86_64/timex.h
@@ -46,6 +46,4 @@ extern void set_cyc2ns_scale(unsigned lo
 extern int read_current_timer(unsigned long *timer_value);
 #define ARCH_HAS_READ_CURRENT_TIMER	1
 
-extern struct vxtime_data vxtime;
-
 #endif
diff --git a/include/asm-x86_64/vsyscall.h b/include/asm-x86_64/vsyscall.h
index a85e16f..b8f7ab4 100644
--- a/include/asm-x86_64/vsyscall.h
+++ b/include/asm-x86_64/vsyscall.h
@@ -15,48 +15,19 @@ enum vsyscall_num {
 
 #ifdef __KERNEL__
 
-#define __section_vxtime __attribute__ ((unused, __section__ (".vxtime"), aligned(16)))
-#define __section_wall_jiffies __attribute__ ((unused, __section__ (".wall_jiffies"), aligned(16)))
-#define __section_jiffies __attribute__ ((unused, __section__ (".jiffies"), aligned(16)))
-#define __section_sys_tz __attribute__ ((unused, __section__ (".sys_tz"), aligned(16)))
-#define __section_sysctl_vsyscall __attribute__ ((unused, __section__ (".sysctl_vsyscall"), aligned(16)))
-#define __section_xtime __attribute__ ((unused, __section__ (".xtime"), aligned(16)))
-#define __section_xtime_lock __attribute__ ((unused, __section__ (".xtime_lock"), aligned(16)))
-
-#define VXTIME_TSC	1
-#define VXTIME_HPET	2
-#define VXTIME_PMTMR	3
-
-struct vxtime_data {
-	long hpet_address;	/* HPET base address */
-	int last;
-	unsigned long last_tsc;
-	long quot;
-	long tsc_quot;
-	int mode;
-};
+/* Definitions for CONFIG_GENERIC_TIME definitions */
+#define __section_vsyscall_gtod_data __attribute__ ((unused, __section__ (".vsyscall_gtod_data"),aligned(16)))
+#define __vsyscall_fn __attribute__ ((unused,__section__(".vsyscall_fn")))
+
 
 #define hpet_readl(a)           readl((const void __iomem *)fix_to_virt(FIX_HPET_BASE) + a)
 #define hpet_writel(d,a)        writel(d, (void __iomem *)fix_to_virt(FIX_HPET_BASE) + a)
 
-/* vsyscall space (readonly) */
-extern struct vxtime_data __vxtime;
-extern struct timespec __xtime;
-extern volatile unsigned long __jiffies;
-extern unsigned long __wall_jiffies;
-extern struct timezone __sys_tz;
-extern seqlock_t __xtime_lock;
-
 /* kernel space (writeable) */
-extern struct vxtime_data vxtime;
 extern unsigned long wall_jiffies;
 extern struct timezone sys_tz;
-extern int sysctl_vsyscall;
 extern seqlock_t xtime_lock;
-
-extern int sysctl_vsyscall;
-
-#define ARCH_HAVE_XTIME_LOCK 1
+extern struct vsyscall_gtod_data_t vsyscall_gtod_data;
 
 #endif /* __KERNEL__ */
 

^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCH 0/6] x86_64: Generic timekeeping for x86_64
  2006-09-07  2:18 [PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
                   ` (5 preceding siblings ...)
  2006-09-07  2:19 ` [PATCH 6/6] x86_64: GENERIC_TIME based vsyscall code john stultz
@ 2006-09-09 20:30 ` Andi Kleen
  6 siblings, 0 replies; 8+ messages in thread
From: Andi Kleen @ 2006-09-09 20:30 UTC (permalink / raw)
  To: john stultz; +Cc: linux-kernel

On Thursday 07 September 2006 04:18, john stultz wrote:
> Hey Andi,
> 	Just wanted to send this second pass on the x86_64 generic
> timekeeping conversion. It includes a number of changes you suggested,
> however its possible I missed a few things. I've made sure the patchset
> compiles at each stage, and atleast w/ the box I was using it booted
> each step as well.

Looks all reasonable from a quick look.
I assume it will clash with the recent patch to remove wall_jiffies use,
but that should be easy to fix.

How does the performance of the user space gettimeofday look
compared to the old code in TSC mode?

BTW I got some experimental code to put clock_gettime into
user space too, but that can be later merged I guess.

-Andi
 

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2006-09-09 21:44 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2006-09-07  2:18 [PATCH 0/6] x86_64: Generic timekeeping for x86_64 john stultz
2006-09-07  2:18 ` [PATCH 1/6] x86_64: Enable arch-generic vsyscall support john stultz
2006-09-07  2:18 ` [PATCH 2/6] x86_64: hpet_address cleanup john stultz
2006-09-07  2:19 ` [PATCH 3/6] x86_64: Remove apic_runs_main_timer john stultz
2006-09-07  2:19 ` [PATCH 4/6] x86_64: Enable CONFIG_GENERIC_TIME john stultz
2006-09-07  2:19 ` [PATCH 5/6] x86_64: Clocksources for x86-64 john stultz
2006-09-07  2:19 ` [PATCH 6/6] x86_64: GENERIC_TIME based vsyscall code john stultz
2006-09-09 20:30 ` [PATCH 0/6] x86_64: Generic timekeeping for x86_64 Andi Kleen

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