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authorTony Breeds <tony@bakeyournoodle.com>2007-09-21 13:26:02 +1000
committerPaul Mackerras <paulus@samba.org>2007-10-03 11:48:42 +1000
commitaa3be5f32db137bc4404f32a24b36fb47d48d260 (patch)
treec1478636bf2025cf9e700c48239418836cb43fbd /arch/powerpc/kernel/time.c
parentdf174e3be88d4352bfcfe20d11adc671d2961c79 (diff)
[POWERPC] Implement {read,update}_persistent_clock
With these functions implemented we cooperate better with the generic timekeeping code. This obsoletes the need for the timer sysdev as a bonus. Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kernel/time.c')
-rw-r--r--arch/powerpc/kernel/time.c85
1 files changed, 26 insertions, 59 deletions
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index d95e68c0a6b..b94e4dffba1 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -73,16 +73,11 @@
#include <asm/iseries/hv_call_xm.h>
#endif
-/* keep track of when we need to update the rtc */
-time_t last_rtc_update;
#ifdef CONFIG_PPC_ISERIES
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. */
-#define DECREMENTER_COUNT_601 (1000000000 / HZ)
-
#define XSEC_PER_SEC (1024*1024)
#ifdef CONFIG_PPC64
@@ -348,39 +343,6 @@ void udelay(unsigned long usecs)
}
EXPORT_SYMBOL(udelay);
-static __inline__ void timer_check_rtc(void)
-{
- /*
- * update the rtc when needed, this should be performed on the
- * right fraction of a second. Half or full second ?
- * Full second works on mk48t59 clocks, others need testing.
- * Note that this update is basically only used through
- * the adjtimex system calls. Setting the HW clock in
- * any other way is a /dev/rtc and userland business.
- * This is still wrong by -0.5/+1.5 jiffies because of the
- * timer interrupt resolution and possible delay, but here we
- * hit a quantization limit which can only be solved by higher
- * resolution timers and decoupling time management from timer
- * interrupts. This is also wrong on the clocks
- * which require being written at the half second boundary.
- * We should have an rtc call that only sets the minutes and
- * seconds like on Intel to avoid problems with non UTC clocks.
- */
- if (ppc_md.set_rtc_time && ntp_synced() &&
- xtime.tv_sec - last_rtc_update >= 659 &&
- abs((xtime.tv_nsec/1000) - (1000000-1000000/HZ)) < 500000/HZ) {
- struct rtc_time tm;
- to_tm(xtime.tv_sec + 1 + timezone_offset, &tm);
- tm.tm_year -= 1900;
- tm.tm_mon -= 1;
- if (ppc_md.set_rtc_time(&tm) == 0)
- last_rtc_update = xtime.tv_sec + 1;
- else
- /* Try again one minute later */
- last_rtc_update += 60;
- }
-}
-
/*
* This version of gettimeofday has microsecond resolution.
*/
@@ -689,7 +651,6 @@ void timer_interrupt(struct pt_regs * regs)
tb_last_jiffy = tb_next_jiffy;
do_timer(1);
timer_recalc_offset(tb_last_jiffy);
- timer_check_rtc();
}
write_sequnlock(&xtime_lock);
}
@@ -801,11 +762,6 @@ int do_settimeofday(struct timespec *tv)
set_normalized_timespec(&xtime, new_sec, new_nsec);
set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
- /* In case of a large backwards jump in time with NTP, we want the
- * clock to be updated as soon as the PLL is again in lock.
- */
- last_rtc_update = new_sec - 658;
-
ntp_clear();
new_xsec = xtime.tv_nsec;
@@ -881,12 +837,35 @@ void __init generic_calibrate_decr(void)
#endif
}
-unsigned long get_boot_time(void)
+int update_persistent_clock(struct timespec now)
+{
+ struct rtc_time tm;
+
+ if (!ppc_md.set_rtc_time)
+ return 0;
+
+ to_tm(now.tv_sec + 1 + timezone_offset, &tm);
+ tm.tm_year -= 1900;
+ tm.tm_mon -= 1;
+
+ return ppc_md.set_rtc_time(&tm);
+}
+
+unsigned long read_persistent_clock(void)
{
struct rtc_time tm;
+ static int first = 1;
+
+ /* XXX this is a litle fragile but will work okay in the short term */
+ if (first) {
+ first = 0;
+ if (ppc_md.time_init)
+ timezone_offset = ppc_md.time_init();
- if (ppc_md.get_boot_time)
- return ppc_md.get_boot_time();
+ /* get_boot_time() isn't guaranteed to be safe to call late */
+ if (ppc_md.get_boot_time)
+ return ppc_md.get_boot_time() -timezone_offset;
+ }
if (!ppc_md.get_rtc_time)
return 0;
ppc_md.get_rtc_time(&tm);
@@ -898,14 +877,10 @@ unsigned long get_boot_time(void)
void __init time_init(void)
{
unsigned long flags;
- unsigned long tm = 0;
struct div_result res;
u64 scale, x;
unsigned shift;
- if (ppc_md.time_init != NULL)
- timezone_offset = ppc_md.time_init();
-
if (__USE_RTC()) {
/* 601 processor: dec counts down by 128 every 128ns */
ppc_tb_freq = 1000000000;
@@ -980,19 +955,14 @@ void __init time_init(void)
/* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
boot_tb = get_tb_or_rtc();
- tm = get_boot_time();
-
write_seqlock_irqsave(&xtime_lock, flags);
/* If platform provided a timezone (pmac), we correct the time */
if (timezone_offset) {
sys_tz.tz_minuteswest = -timezone_offset / 60;
sys_tz.tz_dsttime = 0;
- tm -= timezone_offset;
}
- xtime.tv_sec = tm;
- xtime.tv_nsec = 0;
do_gtod.varp = &do_gtod.vars[0];
do_gtod.var_idx = 0;
do_gtod.varp->tb_orig_stamp = tb_last_jiffy;
@@ -1010,9 +980,6 @@ void __init time_init(void)
time_freq = 0;
- last_rtc_update = xtime.tv_sec;
- set_normalized_timespec(&wall_to_monotonic,
- -xtime.tv_sec, -xtime.tv_nsec);
write_sequnlock_irqrestore(&xtime_lock, flags);
/* Not exact, but the timer interrupt takes care of this */