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[POWERPC] Move iSeries_tb_recal into its own late_initcall.

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Currently iSeries will recalibrate the cputime_factors in the first
settimeofday() call.

It seems the reason for doing this is to ensure a resaonable time delta after
time_init().  On current kernels (with udev), this call is made 40-60 seconds
into the boot process, by moving it to a late initcall it is called
approximately 5 seconds after time_init() is called.  This is sufficient to
recalibrate the timebase.

Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
CC: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Tony Breeds
2007-06-22 16:54:30 +10:00
committed by Paul Mackerras
parent a5c631b174
commit 71712b4553
3 changed files with 23 additions and 15 deletions
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30
arch/powerpc/kernel/time.c
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@@ -77,9 +77,8 @@
/* keep track of when we need to update the rtc */
time_t last_rtc_update;
#ifdef CONFIG_PPC_ISERIES
unsigned long iSeries_recal_titan = 0;
unsigned long iSeries_recal_tb = 0;
static unsigned long first_settimeofday = 1;
static unsigned long __initdata iSeries_recal_titan;
static signed long __initdata iSeries_recal_tb;
#endif
/* The decrementer counts down by 128 every 128ns on a 601. */
@@ -556,10 +555,15 @@ EXPORT_SYMBOL(profile_pc);
* returned by the service processor for the timebase frequency.
*/
static void iSeries_tb_recal(void)
static int __init iSeries_tb_recal(void)
{
struct div_result divres;
unsigned long titan, tb;
/* Make sure we only run on iSeries */
if (!firmware_has_feature(FW_FEATURE_ISERIES))
return -ENODEV;
tb = get_tb();
titan = HvCallXm_loadTod();
if ( iSeries_recal_titan ) {
@@ -600,8 +604,18 @@ static void iSeries_tb_recal(void)
}
iSeries_recal_titan = titan;
iSeries_recal_tb = tb;
return 0;
}
#endif
late_initcall(iSeries_tb_recal);
/* Called from platform early init */
void __init iSeries_time_init_early(void)
{
iSeries_recal_tb = get_tb();
iSeries_recal_titan = HvCallXm_loadTod();
}
#endif /* CONFIG_PPC_ISERIES */
/*
* For iSeries shared processors, we have to let the hypervisor
@@ -765,12 +779,6 @@ int do_settimeofday(struct timespec *tv)
* to the RTC again, or write to the RTC but then they don't call
* settimeofday to perform this operation.
*/
#ifdef CONFIG_PPC_ISERIES
if (firmware_has_feature(FW_FEATURE_ISERIES) && first_settimeofday) {
iSeries_tb_recal();
first_settimeofday = 0;
}
#endif
/* Make userspace gettimeofday spin until we're done. */
++vdso_data->tb_update_count;