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[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>
This commit is contained in:
Tony Breeds 2007-09-21 13:26:02 +10:00 committed by Paul Mackerras
parent df174e3be8
commit aa3be5f32d
4 changed files with 29 additions and 145 deletions
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3
arch/powerpc/Kconfig
View File

@ -26,6 +26,9 @@ config MMU
bool
default y
config GENERIC_CMOS_UPDATE
def_bool y
config GENERIC_HARDIRQS
bool
default y

85
arch/powerpc/kernel/time.c
View File

@ -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.get_boot_time)
return ppc_md.get_boot_time();
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();
/* 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 */

5
arch/powerpc/sysdev/Makefile
View File

@ -21,11 +21,6 @@ obj-$(CONFIG_MV64X60) += $(mv64x60-y) mv64x60_pic.o mv64x60_dev.o \
obj-$(CONFIG_RTC_DRV_CMOS) += rtc_cmos_setup.o
obj-$(CONFIG_AXON_RAM) += axonram.o
# contains only the suspend handler for time
ifeq ($(CONFIG_RTC_CLASS),)
obj-$(CONFIG_PM) += timer.o
endif
ifeq ($(CONFIG_PPC_MERGE),y)
obj-$(CONFIG_PPC_INDIRECT_PCI) += indirect_pci.o
obj-$(CONFIG_PPC_I8259) += i8259.o

81
arch/powerpc/sysdev/timer.c
View File

@ -1,81 +0,0 @@
/*
* Common code to keep time when machine suspends.
*
* Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
*
* GPLv2
*/
#include <linux/time.h>
#include <linux/sysdev.h>
#include <asm/rtc.h>
static unsigned long suspend_rtc_time;
/*
* Reset the time after a sleep.
*/
static int timer_resume(struct sys_device *dev)
{
struct timeval tv;
struct timespec ts;
struct rtc_time cur_rtc_tm;
unsigned long cur_rtc_time, diff;
/* get current RTC time and convert to seconds */
get_rtc_time(&cur_rtc_tm);
cur_rtc_time = mktime(cur_rtc_tm.tm_year + 1900,
cur_rtc_tm.tm_mon + 1,
cur_rtc_tm.tm_mday,
cur_rtc_tm.tm_hour,
cur_rtc_tm.tm_min,
cur_rtc_tm.tm_sec);
diff = cur_rtc_time - suspend_rtc_time;
/* adjust time of day by seconds that elapsed while
* we were suspended */
do_gettimeofday(&tv);
ts.tv_sec = tv.tv_sec + diff;
ts.tv_nsec = tv.tv_usec * NSEC_PER_USEC;
do_settimeofday(&ts);
return 0;
}
static int timer_suspend(struct sys_device *dev, pm_message_t state)
{
struct rtc_time suspend_rtc_tm;
WARN_ON(!ppc_md.get_rtc_time);
get_rtc_time(&suspend_rtc_tm);
suspend_rtc_time = mktime(suspend_rtc_tm.tm_year + 1900,
suspend_rtc_tm.tm_mon + 1,
suspend_rtc_tm.tm_mday,
suspend_rtc_tm.tm_hour,
suspend_rtc_tm.tm_min,
suspend_rtc_tm.tm_sec);
return 0;
}
static struct sysdev_class timer_sysclass = {
.resume = timer_resume,
.suspend = timer_suspend,
set_kset_name("timer"),
};
static struct sys_device device_timer = {
.id = 0,
.cls = &timer_sysclass,
};
static int time_init_device(void)
{
int error = sysdev_class_register(&timer_sysclass);
if (!error)
error = sysdev_register(&device_timer);
return error;
}
device_initcall(time_init_device);