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Subject[PATCH -mm 4/5][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).

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

arch/x86_64/Kconfig | 4
arch/x86_64/kernel/apic.c | 2
arch/x86_64/kernel/hpet.c | 65 ++++++++
arch/x86_64/kernel/pmtimer.c | 58 -------
arch/x86_64/kernel/smpboot.c | 1
arch/x86_64/kernel/time.c | 301 -----------------------------------------
arch/x86_64/kernel/tsc.c | 108 ++++++++------
drivers/char/hangcheck-timer.c | 2
include/asm-x86_64/proto.h | 2
include/asm-x86_64/timex.h | 5
10 files changed, 137 insertions(+), 411 deletions(-)
linux-2.6.20-rc1_timeofday-arch-x86-64-generic-time-conversion_C7.patch
============================================
Index: 2.6-mm/arch/x86_64/Kconfig
===================================================================
--- 2.6-mm.orig/arch/x86_64/Kconfig 2006-12-20 12:19:26.000000000 -0800
+++ 2.6-mm/arch/x86_64/Kconfig 2006-12-20 12:24:10.000000000 -0800
@@ -24,6 +24,10 @@ config X86
bool
default y

+config GENERIC_TIME
+ bool
+ default y
+
config ZONE_DMA32
bool
default y
Index: 2.6-mm/arch/x86_64/kernel/apic.c
===================================================================
--- 2.6-mm.orig/arch/x86_64/kernel/apic.c 2006-12-20 12:20:01.000000000 -0800
+++ 2.6-mm/arch/x86_64/kernel/apic.c 2006-12-20 12:24:10.000000000 -0800
@@ -785,7 +785,7 @@ static void setup_APIC_timer(unsigned in
/* 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)) {
Index: 2.6-mm/arch/x86_64/kernel/hpet.c
===================================================================
--- 2.6-mm.orig/arch/x86_64/kernel/hpet.c 2006-12-20 12:23:00.000000000 -0800
+++ 2.6-mm/arch/x86_64/kernel/hpet.c 2006-12-20 12:24:10.000000000 -0800
@@ -21,12 +21,6 @@ unsigned long hpet_tick; /* HPET clocks
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)
@@ -436,3 +430,62 @@ 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,
+ .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);
Index: 2.6-mm/arch/x86_64/kernel/pmtimer.c
===================================================================
--- 2.6-mm.orig/arch/x86_64/kernel/pmtimer.c 2006-12-20 12:18:18.000000000 -0800
+++ 2.6-mm/arch/x86_64/kernel/pmtimer.c 2006-12-20 12:24:10.000000000 -0800
@@ -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;
Index: 2.6-mm/arch/x86_64/kernel/smpboot.c
===================================================================
--- 2.6-mm.orig/arch/x86_64/kernel/smpboot.c 2006-12-20 12:19:26.000000000 -0800
+++ 2.6-mm/arch/x86_64/kernel/smpboot.c 2006-12-20 12:24:10.000000000 -0800
@@ -1181,7 +1181,6 @@ void __init smp_cpus_done(unsigned int m
smp_cleanup_boot();
setup_ioapic_dest();
check_nmi_watchdog();
- time_init_gtod();
}

#ifdef CONFIG_HOTPLUG_CPU
Index: 2.6-mm/arch/x86_64/kernel/time.c
===================================================================
--- 2.6-mm.orig/arch/x86_64/kernel/time.c 2006-12-20 12:23:54.000000000 -0800
+++ 2.6-mm/arch/x86_64/kernel/time.c 2006-12-20 12:29:59.000000000 -0800
@@ -44,9 +44,6 @@
#include <asm/apic.h>
#include <asm/hpet.h>

-#ifdef CONFIG_CPU_FREQ
-extern void cpufreq_delayed_get(void);
-#endif
extern void i8254_timer_resume(void);
extern int using_apic_timer;

@@ -57,8 +54,6 @@ EXPORT_SYMBOL(rtc_lock);
DEFINE_SPINLOCK(i8253_lock);

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 */

@@ -66,76 +61,6 @@ volatile unsigned long __jiffies __secti
struct timespec __xtime __section_xtime;
struct timezone __sys_tz __section_sys_tz;

-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;
- 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 */
- usec += do_gettimeoffset();
-
- } 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;
-
- 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);
@@ -225,85 +150,9 @@ 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.
- */
-extern unsigned long long cycles_2_ns(unsigned long long cyc);
-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();
- offset = cycles_2_ns(this_offset - last_offset);
- }
- return base + offset;
-}
-EXPORT_SYMBOL(monotonic_clock);
-
-static noinline void handle_lost_ticks(int lost)
-{
- 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", get_irq_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", get_irq_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(void)
{
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
@@ -313,72 +162,11 @@ void main_timer_handler(void)

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;
- }
-
- monotonic_base += cycles_2_ns(tsc - vxtime.last_tsc);
-
- 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);
- else
- lost = 0;
-
/*
* Do the timer stuff.
*/

- do_timer(lost + 1);
+ do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(get_irq_regs()));
#endif
@@ -537,12 +325,6 @@ void __init stop_timer_interrupt(void)
printk(KERN_INFO "timer: %s interrupt stopped.\n", name);
}

-int __init time_setup(char *str)
-{
- report_lost_ticks = 1;
- return 1;
-}
-
static struct irqaction irq0 = {
timer_interrupt, IRQF_DISABLED, CPU_MASK_NONE, "timer", NULL, NULL
};
@@ -557,9 +339,7 @@ void __init time_init(void)
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);

- if (!hpet_arch_init())
- vxtime_hz = (FSEC_PER_SEC + hpet_period / 2) / hpet_period;
- else
+ if (hpet_arch_init())
hpet_address = 0;

if (hpet_use_timer) {
@@ -567,82 +347,25 @@ 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;
- 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();
- set_cyc2ns_scale(cpu_khz);
- setup_irq(0, &irq0);
-
-#ifndef CONFIG_SMP
- time_init_gtod();
-#endif
-}
-
-/*
- * Decide what mode gettimeofday should use.
- */
-void time_init_gtod(void)
-{
- char *timetype;
-
if (unsynchronized_tsc())
- notsc = 1;
+ mark_tsc_unstable();

if (cpu_has(&boot_cpu_data, X86_FEATURE_RDTSCP))
vgetcpu_mode = VGETCPU_RDTSCP;
else
vgetcpu_mode = VGETCPU_LSL;

- 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;
- }
-
- printk(KERN_INFO "time.c: Using %ld.%06ld MHz WALL %s GTOD %s timer.\n",
- vxtime_hz / 1000000, vxtime_hz % 1000000, timename, timetype);
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();
-
- set_cyc2ns_scale(cpu_khz);
+ setup_irq(0, &irq0);
}

-__setup("report_lost_ticks", time_setup);

static long clock_cmos_diff;
static unsigned long sleep_start;
@@ -688,20 +411,8 @@ 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;
- monotonic_base += sleep_length * (NSEC_PER_SEC/HZ);
+ write_sequnlock_irqrestore(&xtime_lock,flags);
touch_softlockup_watchdog();
return 0;
}
Index: 2.6-mm/arch/x86_64/kernel/tsc.c
===================================================================
--- 2.6-mm.orig/arch/x86_64/kernel/tsc.c 2006-12-20 12:21:16.000000000 -0800
+++ 2.6-mm/arch/x86_64/kernel/tsc.c 2006-12-20 12:24:10.000000000 -0800
@@ -9,32 +9,11 @@

#include <asm/timex.h>

-int notsc __initdata = 0;
+static int notsc __initdata = 0;

unsigned int cpu_khz; /* TSC clocks / usec, not used here */
EXPORT_SYMBOL(cpu_khz);

-/*
- * 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.
- */
-
-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 unsigned int cyc2ns_scale __read_mostly;

void set_cyc2ns_scale(unsigned long khz)
@@ -42,7 +21,7 @@ void set_cyc2ns_scale(unsigned long khz)
cyc2ns_scale = (NSEC_PER_MSEC << NS_SCALE) / khz;
}

-unsigned long long cycles_2_ns(unsigned long long cyc)
+static unsigned long long cycles_2_ns(unsigned long long cyc)
{
return (cyc * cyc2ns_scale) >> NS_SCALE;
}
@@ -61,6 +40,19 @@ 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);
+
#ifdef CONFIG_CPU_FREQ

/* Frequency scaling support. Adjust the TSC based timer when the cpu frequency
@@ -89,24 +81,6 @@ static void handle_cpufreq_delayed_get(s
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.
- */
-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;

@@ -142,7 +116,7 @@ static int time_cpufreq_notifier(struct

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;
+ mark_tsc_unstable();
}

set_cyc2ns_scale(cpu_khz_ref);
@@ -207,3 +181,53 @@ int __init notsc_setup(char *s)
}

__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);
+ if (check_tsc_unstable())
+ clocksource_tsc.rating = 50;
+
+ return clocksource_register(&clocksource_tsc);
+ }
+ return 0;
+}
+
+module_init(init_tsc_clocksource);
Index: 2.6-mm/drivers/char/hangcheck-timer.c
===================================================================
--- 2.6-mm.orig/drivers/char/hangcheck-timer.c 2006-12-20 12:18:53.000000000 -0800
+++ 2.6-mm/drivers/char/hangcheck-timer.c 2006-12-20 12:24:10.000000000 -0800
@@ -117,7 +117,7 @@ __setup("hcheck_reboot", hangcheck_parse
__setup("hcheck_dump_tasks", hangcheck_parse_dump_tasks);
#endif /* not MODULE */

-#if defined(CONFIG_X86_64) || defined(CONFIG_S390)
+#if defined(CONFIG_S390)
# define HAVE_MONOTONIC
# define TIMER_FREQ 1000000000ULL
#elif defined(CONFIG_IA64)
Index: 2.6-mm/include/asm-x86_64/proto.h
===================================================================
--- 2.6-mm.orig/include/asm-x86_64/proto.h 2006-12-20 12:19:27.000000000 -0800
+++ 2.6-mm/include/asm-x86_64/proto.h 2006-12-20 12:24:10.000000000 -0800
@@ -45,11 +45,9 @@ 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;
-extern void time_init_gtod(void);

extern void early_printk(const char *fmt, ...) __attribute__((format(printf,1,2)));

Index: 2.6-mm/include/asm-x86_64/timex.h
===================================================================
--- 2.6-mm.orig/include/asm-x86_64/timex.h 2006-12-20 12:20:12.000000000 -0800
+++ 2.6-mm/include/asm-x86_64/timex.h 2006-12-20 12:24:10.000000000 -0800
@@ -52,9 +52,6 @@ extern int read_current_timer(unsigned l
#define US_SCALE 32 /* 2^32, arbitralrily chosen */

extern struct vxtime_data vxtime;
-
-extern unsigned int do_gettimeoffset_hpet(void);
-extern unsigned int do_gettimeoffset_tsc(void);
+extern void mark_tsc_unstable(void);
extern void set_cyc2ns_scale(unsigned long khz);
-extern int notsc;
#endif
-
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