On Tue, Sep 11, 2007 at 05:49:17PM +1000, Tony Breeds wrote:
> With these functions implemented we cooperate better with the generic
> timekeeping code. This obsoletes the need for the timer sysdev as a bonus.
Looks fine, there is still the problem that most PPC RTC
seem to prefer update on the second boundary instead of
the half second used by Wintel clones.
>
> Signed-off-by: Tony Breeds <[EMAIL PROTECTED]>
>
> ---
>
> * Compile tested for arch/powerpc/configs/*_defconfig
> * Booted on pSeries, iSeries, Cell and PS3
> * Really needs booting on powermac and a quad G5 (hint hint)
> * Should remove arch/powerpc/sysdev/timer.c at the same time.
Realistically this can only be tested with a running ntp
process which locks to a server.
>
> arch/powerpc/Kconfig | 3 +
> arch/powerpc/kernel/time.c | 58 ++++++++++-------------------------
> arch/powerpc/sysdev/Makefile | 5 ---
> 3 files changed, 20 insertions(+), 46 deletions(-)
>
> Index: working/arch/powerpc/Kconfig
> ===================================================================
> --- working.orig/arch/powerpc/Kconfig
> +++ working/arch/powerpc/Kconfig
> @@ -21,6 +21,9 @@ config MMU
> bool
> default y
>
> +config GENERIC_CMOS_UPDATE
> + def_bool y
> +
> config GENERIC_HARDIRQS
> bool
> default y
> Index: working/arch/powerpc/kernel/time.c
> ===================================================================
> --- working.orig/arch/powerpc/kernel/time.c
> +++ working/arch/powerpc/kernel/time.c
> @@ -74,16 +74,11 @@
> #endif
> #include <asm/smp.h>
>
> -/* 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
> @@ -349,38 +344,7 @@ 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.
> @@ -688,7 +652,6 @@ void timer_interrupt(struct pt_regs * re
> tb_last_jiffy = tb_next_jiffy;
> do_timer(1);
> timer_recalc_offset(tb_last_jiffy);
> - timer_check_rtc();
> }
> write_sequnlock(&xtime_lock);
> }
> @@ -800,11 +763,6 @@ 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;
> @@ -880,12 +838,36 @@ 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;
> + unsigned long time = 0;
> +
> + 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 (system_state != SYSTEM_RUNNING && 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);
> @@ -897,14 +879,10 @@ 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;
> @@ -979,19 +957,14 @@ void __init time_init(void)
> /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
> boot_tb = get_tb();
>
> - 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;
> @@ -1009,9 +982,6 @@ 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 */
> Index: working/arch/powerpc/sysdev/Makefile
> ===================================================================
> --- working.orig/arch/powerpc/sysdev/Makefile
> +++ working/arch/powerpc/sysdev/Makefile
> @@ -20,11 +20,6 @@ obj-$(CONFIG_MV64X60) += $(mv64x60-y) m
> obj-$(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
>
>
> Yours Tony
>
> linux.conf.au http://linux.conf.au/ || http://lca2008.linux.org.au/
> Jan 28 - Feb 02 2008 The Australian Linux Technical Conference!
>
> _______________________________________________
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> Linuxppc-dev@ozlabs.org
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