[PATCH 7/9] generic timekeeping i386 arch specific changes, part 5
From: john stultz
Date: Wed Aug 10 2005 - 21:23:36 EST
All,
The conversion of i386 to use the generic timekeeping subsystem has
been split into 6 parts. This patch, the fifth of six, converts the i386
arch to use the generic timekeeping subsystem.
It applies on top of my timeofday-arch-i386-part4 patch. This patch is
part the timeofday-arch-i386 patchset, so without the following parts it
is not expected to compile.
thanks
-john
linux-2.6.13-rc6_timeofday-arch-i386-part5_B5.patch
============================================
diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -14,6 +14,10 @@ config X86
486, 586, Pentiums, and various instruction-set-compatible chips by
AMD, Cyrix, and others.
+config GENERICTOD
+ bool
+ default y
+
config MMU
bool
default y
diff --git a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile
--- a/arch/i386/kernel/Makefile
+++ b/arch/i386/kernel/Makefile
@@ -10,7 +10,6 @@ obj-y := process.o semaphore.o signal.o
doublefault.o quirks.o tsc.o
obj-y += cpu/
-obj-y += timers/
obj-$(CONFIG_ACPI_BOOT) += acpi/
obj-$(CONFIG_X86_BIOS_REBOOT) += reboot.o
obj-$(CONFIG_MCA) += mca.o
diff --git a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c
--- a/arch/i386/kernel/time.c
+++ b/arch/i386/kernel/time.c
@@ -46,7 +46,6 @@
#include <linux/bcd.h>
#include <linux/efi.h>
#include <linux/mca.h>
-#include <linux/ntp.h>
#include <asm/io.h>
#include <asm/smp.h>
@@ -57,6 +56,7 @@
#include <asm/uaccess.h>
#include <asm/processor.h>
#include <asm/timer.h>
+#include <asm/timeofday.h>
#include "mach_time.h"
@@ -92,8 +92,6 @@ EXPORT_SYMBOL(rtc_lock);
DEFINE_SPINLOCK(i8253_lock);
EXPORT_SYMBOL(i8253_lock);
-struct timer_opts *cur_timer __read_mostly = &timer_none;
-
/*
* This is a special lock that is owned by the CPU and holds the index
* register we are working with. It is required for NMI access to the
@@ -123,99 +121,19 @@ void rtc_cmos_write(unsigned char val, u
}
EXPORT_SYMBOL(rtc_cmos_write);
-/*
- * This version of gettimeofday has microsecond resolution
- * and better than microsecond precision on fast x86 machines with TSC.
- */
-void do_gettimeofday(struct timeval *tv)
-{
- unsigned long seq;
- unsigned long usec, sec;
- unsigned long max_ntp_tick;
-
- do {
- unsigned long lost;
-
- seq = read_seqbegin(&xtime_lock);
-
- usec = cur_timer->get_offset();
- lost = jiffies - wall_jiffies;
-
- /*
- * If ntp_adjtime_offset is negative then NTP is slowing the clock
- * so make sure not to go into next possible interval.
- * Better to lose some accuracy than have time go backwards..
- */
- if (unlikely(ntp_adjtime_offset < 0)) {
- max_ntp_tick = (USEC_PER_SEC / HZ) - tickadj;
- usec = min(usec, max_ntp_tick);
-
- if (lost)
- usec += lost * max_ntp_tick;
- }
- else if (unlikely(lost))
- usec += lost * (USEC_PER_SEC / HZ);
-
- sec = xtime.tv_sec;
- usec += (xtime.tv_nsec / 1000);
- } while (read_seqretry(&xtime_lock, seq));
-
- while (usec >= 1000000) {
- usec -= 1000000;
- sec++;
- }
-
- tv->tv_sec = sec;
- tv->tv_usec = usec;
-}
-
-EXPORT_SYMBOL(do_gettimeofday);
-
-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);
- /*
- * This is revolting. We need to set "xtime" correctly. However, the
- * value in this location is the value at the most recent update of
- * wall time. Discover what correction gettimeofday() would have
- * made, and then undo it!
- */
- nsec -= cur_timer->get_offset() * NSEC_PER_USEC;
- nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
-
- 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);
-
static int set_rtc_mmss(unsigned long nowtime)
{
int retval;
-
- WARN_ON(irqs_disabled());
+ unsigned long flags;
/* gets recalled with irq locally disabled */
- spin_lock_irq(&rtc_lock);
+ /* XXX - does irqsave resolve this? -johnstul */
+ spin_lock_irqsave(&rtc_lock, flags);
if (efi_enabled)
retval = efi_set_rtc_mmss(nowtime);
else
retval = mach_set_rtc_mmss(nowtime);
- spin_unlock_irq(&rtc_lock);
+ spin_unlock_irqrestore(&rtc_lock, flags);
return retval;
}
@@ -223,16 +141,6 @@ static int set_rtc_mmss(unsigned long no
int timer_ack;
-/* 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)
-{
- return cur_timer->monotonic_clock();
-}
-EXPORT_SYMBOL(monotonic_clock);
-
#if defined(CONFIG_SMP) && defined(CONFIG_FRAME_POINTER)
unsigned long profile_pc(struct pt_regs *regs)
{
@@ -247,12 +155,21 @@ EXPORT_SYMBOL(profile_pc);
#endif
/*
- * timer_interrupt() needs to keep up the real-time clock,
- * as well as call the "do_timer()" routine every clocktick
+ * This is the same as the above, except we _also_ save the current
+ * Time Stamp Counter value at the time of the timer interrupt, so that
+ * we later on can estimate the time of day more exactly.
*/
-static inline void do_timer_interrupt(int irq, void *dev_id,
- struct pt_regs *regs)
+irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
+ /*
+ * Here we are in the timer irq handler. We just have irqs locally
+ * disabled but we don't know if the timer_bh is running on the other
+ * CPU. We need to avoid to SMP race with it. NOTE: we don' t need
+ * the irq version of write_lock because as just said we have irq
+ * locally disabled. -arca
+ */
+ write_seqlock(&xtime_lock);
+
#ifdef CONFIG_X86_IO_APIC
if (timer_ack) {
/*
@@ -285,27 +202,6 @@ static inline void do_timer_interrupt(in
irq = inb_p( 0x61 ); /* read the current state */
outb_p( irq|0x80, 0x61 ); /* reset the IRQ */
}
-}
-
-/*
- * This is the same as the above, except we _also_ save the current
- * Time Stamp Counter value at the time of the timer interrupt, so that
- * we later on can estimate the time of day more exactly.
- */
-irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
-{
- /*
- * Here we are in the timer irq handler. We just have irqs locally
- * disabled but we don't know if the timer_bh is running on the other
- * CPU. We need to avoid to SMP race with it. NOTE: we don' t need
- * the irq version of write_lock because as just said we have irq
- * locally disabled. -arca
- */
- write_seqlock(&xtime_lock);
-
- cur_timer->mark_offset();
-
- do_timer_interrupt(irq, NULL, regs);
write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
@@ -329,55 +225,34 @@ unsigned long get_cmos_time(void)
}
EXPORT_SYMBOL(get_cmos_time);
-static void sync_cmos_clock(unsigned long dummy);
-
-static struct timer_list sync_cmos_timer =
- TIMER_INITIALIZER(sync_cmos_clock, 0, 0);
-
-static void sync_cmos_clock(unsigned long dummy)
+/* arch specific timeofday hooks */
+nsec_t read_persistent_clock(void)
{
- struct timeval now, next;
- int fail = 1;
+ return (nsec_t)get_cmos_time() * NSEC_PER_SEC;
+}
+void sync_persistent_clock(struct timespec ts)
+{
+ static unsigned long last_rtc_update;
/*
* If we have an externally synchronized Linux clock, then update
* CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
* called as close as possible to 500 ms before the new second starts.
- * This code is run on a timer. If the clock is set, that timer
- * may not expire at the correct time. Thus, we adjust...
*/
- if (!ntp_synced())
- /*
- * Not synced, exit, do not restart a timer (if one is
- * running, let it run out).
- */
+ if (ts.tv_sec <= last_rtc_update + 660)
return;
- do_gettimeofday(&now);
- if (now.tv_usec >= USEC_AFTER - ((unsigned) TICK_SIZE) / 2 &&
- now.tv_usec <= USEC_BEFORE + ((unsigned) TICK_SIZE) / 2)
- fail = set_rtc_mmss(now.tv_sec);
-
- next.tv_usec = USEC_AFTER - now.tv_usec;
- if (next.tv_usec <= 0)
- next.tv_usec += USEC_PER_SEC;
-
- if (!fail)
- next.tv_sec = 659;
- else
- next.tv_sec = 0;
-
- if (next.tv_usec >= USEC_PER_SEC) {
- next.tv_sec++;
- next.tv_usec -= USEC_PER_SEC;
+ if((ts.tv_nsec / 1000) >= USEC_AFTER - ((unsigned) TICK_SIZE) / 2 &&
+ (ts.tv_nsec / 1000) <= USEC_BEFORE + ((unsigned) TICK_SIZE) / 2) {
+ /* horrible...FIXME */
+ if (set_rtc_mmss(ts.tv_sec) == 0)
+ last_rtc_update = ts.tv_sec;
+ else
+ last_rtc_update = ts.tv_sec - 600; /* do it again in 60 s */
}
- mod_timer(&sync_cmos_timer, jiffies + timeval_to_jiffies(&next));
}
-void notify_arch_cmos_timer(void)
-{
- mod_timer(&sync_cmos_timer, jiffies + 1);
-}
+
static long clock_cmos_diff, sleep_start;
@@ -394,7 +269,6 @@ static int timer_suspend(struct sys_devi
static int timer_resume(struct sys_device *dev)
{
- unsigned long flags;
unsigned long sec;
unsigned long sleep_length;
@@ -404,10 +278,6 @@ static int timer_resume(struct sys_devic
#endif
sec = get_cmos_time() + clock_cmos_diff;
sleep_length = (get_cmos_time() - sleep_start) * HZ;
- write_seqlock_irqsave(&xtime_lock, flags);
- xtime.tv_sec = sec;
- xtime.tv_nsec = 0;
- write_sequnlock_irqrestore(&xtime_lock, flags);
jiffies += sleep_length;
wall_jiffies += sleep_length;
return 0;
@@ -441,17 +311,10 @@ extern void (*late_time_init)(void);
/* Duplicate of time_init() below, with hpet_enable part added */
static void __init hpet_time_init(void)
{
- xtime.tv_sec = get_cmos_time();
- xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
- set_normalized_timespec(&wall_to_monotonic,
- -xtime.tv_sec, -xtime.tv_nsec);
-
if ((hpet_enable() >= 0) && hpet_use_timer) {
printk("Using HPET for base-timer\n");
}
- cur_timer = select_timer();
- printk(KERN_INFO "Using %s for high-res timesource\n",cur_timer->name);
time_init_hook();
}
@@ -469,13 +332,5 @@ void __init time_init(void)
return;
}
#endif
- xtime.tv_sec = get_cmos_time();
- xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
- set_normalized_timespec(&wall_to_monotonic,
- -xtime.tv_sec, -xtime.tv_nsec);
-
- cur_timer = select_timer();
- printk(KERN_INFO "Using %s for high-res timesource\n",cur_timer->name);
-
time_init_hook();
}
diff --git a/arch/i386/lib/delay.c b/arch/i386/lib/delay.c
--- a/arch/i386/lib/delay.c
+++ b/arch/i386/lib/delay.c
@@ -13,6 +13,7 @@
#include <linux/config.h>
#include <linux/sched.h>
#include <linux/delay.h>
+#include <linux/timeofday.h>
#include <linux/module.h>
#include <asm/processor.h>
#include <asm/delay.h>
@@ -22,11 +23,20 @@
#include <asm/smp.h>
#endif
-extern struct timer_opts* timer;
-
+/* XXX - For now just use a simple loop delay
+ * This has cpufreq issues, but so did the old method.
+ */
void __delay(unsigned long loops)
{
- cur_timer->delay(loops);
+ int d0;
+ __asm__ __volatile__(
+ "\tjmp 1f\n"
+ ".align 16\n"
+ "1:\tjmp 2f\n"
+ ".align 16\n"
+ "2:\tdecl %0\n\tjns 2b"
+ :"=&a" (d0)
+ :"0" (loops));
}
inline void __const_udelay(unsigned long xloops)
diff --git a/include/asm-i386/timeofday.h b/include/asm-i386/timeofday.h
new file mode 100644
--- /dev/null
+++ b/include/asm-i386/timeofday.h
@@ -0,0 +1,4 @@
+#ifndef _ASM_I386_TIMEOFDAY_H
+#define _ASM_I386_TIMEOFDAY_H
+#include <asm-generic/timeofday.h>
+#endif
diff --git a/include/asm-i386/timer.h b/include/asm-i386/timer.h
--- a/include/asm-i386/timer.h
+++ b/include/asm-i386/timer.h
@@ -2,66 +2,11 @@
#define _ASMi386_TIMER_H
#include <linux/init.h>
-/**
- * struct timer_ops - used to define a timer source
- *
- * @name: name of the timer.
- * @init: Probes and initializes the timer. Takes clock= override
- * string as an argument. Returns 0 on success, anything else
- * on failure.
- * @mark_offset: called by the timer interrupt.
- * @get_offset: called by gettimeofday(). Returns the number of microseconds
- * since the last timer interupt.
- * @monotonic_clock: returns the number of nanoseconds since the init of the
- * timer.
- * @delay: delays this many clock cycles.
- */
-struct timer_opts {
- char* name;
- void (*mark_offset)(void);
- unsigned long (*get_offset)(void);
- unsigned long long (*monotonic_clock)(void);
- void (*delay)(unsigned long);
- unsigned long (*read_timer)(void);
-};
-
-struct init_timer_opts {
- int (*init)(char *override);
- struct timer_opts *opts;
-};
-
#define TICK_SIZE (tick_nsec / 1000)
-
-extern struct timer_opts* __init select_timer(void);
-extern void clock_fallback(void);
void setup_pit_timer(void);
-
/* Modifiers for buggy PIT handling */
-
extern int pit_latch_buggy;
-
-extern struct timer_opts *cur_timer;
extern int timer_ack;
-
-/* list of externed timers */
-extern struct timer_opts timer_none;
-extern struct timer_opts timer_pit;
-extern struct init_timer_opts timer_pit_init;
-extern struct init_timer_opts timer_tsc_init;
-#ifdef CONFIG_X86_CYCLONE_TIMER
-extern struct init_timer_opts timer_cyclone_init;
-#endif
-
-extern unsigned long calibrate_tsc(void);
-extern unsigned long read_timer_tsc(void);
-extern void init_cpu_khz(void);
extern int recalibrate_cpu_khz(void);
-#ifdef CONFIG_HPET_TIMER
-extern struct init_timer_opts timer_hpet_init;
-extern unsigned long calibrate_tsc_hpet(unsigned long *tsc_hpet_quotient_ptr);
-#endif
-#ifdef CONFIG_X86_PM_TIMER
-extern struct init_timer_opts timer_pmtmr_init;
-#endif
#endif
-
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