[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: Tony Breeds <tony@bakeyournoodle.com>
CC: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 43c687a..66d2db7 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -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 @@
* 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 @@
}
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 @@
* 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;
diff --git a/arch/powerpc/platforms/iseries/setup.c b/arch/powerpc/platforms/iseries/setup.c
index 7f5dcee..13a8b19 100644
--- a/arch/powerpc/platforms/iseries/setup.c
+++ b/arch/powerpc/platforms/iseries/setup.c
@@ -79,8 +79,6 @@
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 @@
{
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
diff --git a/include/asm-powerpc/time.h b/include/asm-powerpc/time.h
index 2d00e13..d7f5ddf 100644
--- a/include/asm-powerpc/time.h
+++ b/include/asm-powerpc/time.h
@@ -240,5 +240,7 @@
#define snapshot_timebases() do { } while (0)
#endif
+extern void iSeries_time_init_early(void);
+
#endif /* __KERNEL__ */
#endif /* __POWERPC_TIME_H */