Commit 71712b45 authored by Tony Breeds's avatar Tony Breeds Committed by Paul Mackerras
Browse files

[POWERPC] Move iSeries_tb_recal into its own late_initcall. 



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: default avatarTony Breeds <tony@bakeyournoodle.com>
CC: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent a5c631b1

arch/powerpc/kernel/time.c

+19 −11
Original line number Diff line number Diff line
@@ -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;

arch/powerpc/platforms/iseries/setup.c

+2 −4
Original line number Diff line number Diff line
@@ -79,8 +79,6 @@ extern void iSeries_pci_final_fixup(void); 
static void iSeries_pci_final_fixup(void) { }

#endif



extern unsigned long iSeries_recal_tb;

extern unsigned long iSeries_recal_titan;



struct MemoryBlock {

	unsigned long absStart;
@@ -292,8 +290,8 @@ static void __init iSeries_init_early(void) 
{

	DBG(" -> iSeries_init_early()\n");



	iSeries_recal_tb = get_tb();

	iSeries_recal_titan = HvCallXm_loadTod();

	/* Snapshot the timebase, for use in later recalibration */

	iSeries_time_init_early();



	/*

	 * Initialize the DMA/TCE management

include/asm-powerpc/time.h

+2 −0
Original line number Diff line number Diff line
@@ -240,5 +240,7 @@ extern void snapshot_timebases(void); 
#define snapshot_timebases()			do { } while (0)

#endif



extern void iSeries_time_init_early(void);



#endif /* __KERNEL__ */

#endif /* __POWERPC_TIME_H */