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authorPaul Mackerras <paulus@samba.org>2005-10-20 09:23:26 +1000
committerPaul Mackerras <paulus@samba.org>2005-10-20 09:23:26 +1000
commitf2783c15007468c14972e2617db51e9affc7fad9 (patch)
tree6c8f57ee8e5cdaeb810a3ccf7f697576a7df7615 /arch/ppc64/kernel
parent03f88e9f7145b03fd0d855918d54a3bf5342ac5e (diff)
powerpc: Merge time.c and asm/time.h.
We now use the merged time.c for both 32-bit and 64-bit compilation with ARCH=powerpc, and for ARCH=ppc64, but not for ARCH=ppc32. This removes setup_default_decr (folds its function into time_init) and moves wakeup_decrementer into time.c. This also makes an asm-powerpc/rtc.h. Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/ppc64/kernel')
-rw-r--r--arch/ppc64/kernel/Makefile2
-rw-r--r--arch/ppc64/kernel/pmac_time.c2
-rw-r--r--arch/ppc64/kernel/setup.c9
-rw-r--r--arch/ppc64/kernel/time.c879
4 files changed, 1 insertions, 891 deletions
diff --git a/arch/ppc64/kernel/Makefile b/arch/ppc64/kernel/Makefile
index 8c9012f0ce6..18f477fa1df 100644
--- a/arch/ppc64/kernel/Makefile
+++ b/arch/ppc64/kernel/Makefile
@@ -12,7 +12,7 @@ obj-y := setup.o entry.o misc.o prom.o
endif
obj-y += irq.o idle.o dma.o \
- time.o signal.o \
+ signal.o \
align.o bitops.o pacaData.o \
udbg.o ioctl32.o \
rtc.o \
diff --git a/arch/ppc64/kernel/pmac_time.c b/arch/ppc64/kernel/pmac_time.c
index c89bfefbbec..56f33511591 100644
--- a/arch/ppc64/kernel/pmac_time.c
+++ b/arch/ppc64/kernel/pmac_time.c
@@ -180,7 +180,5 @@ void __init pmac_calibrate_decr(void)
if (fp == 0)
panic("can't get cpu processor frequency");
ppc_proc_freq = *fp;
-
- setup_default_decr();
}
diff --git a/arch/ppc64/kernel/setup.c b/arch/ppc64/kernel/setup.c
index 776b55b45e1..3e6c1547b71 100644
--- a/arch/ppc64/kernel/setup.c
+++ b/arch/ppc64/kernel/setup.c
@@ -1083,15 +1083,6 @@ void ppc64_terminate_msg(unsigned int src, const char *msg)
printk("[terminate]%04x %s\n", src, msg);
}
-/* This should only be called on processor 0 during calibrate decr */
-void __init setup_default_decr(void)
-{
- struct paca_struct *lpaca = get_paca();
-
- lpaca->default_decr = tb_ticks_per_jiffy;
- lpaca->next_jiffy_update_tb = get_tb() + tb_ticks_per_jiffy;
-}
-
#ifndef CONFIG_PPC_ISERIES
/*
* This function can be used by platforms to "find" legacy serial ports.
diff --git a/arch/ppc64/kernel/time.c b/arch/ppc64/kernel/time.c
deleted file mode 100644
index 7f63755eddf..00000000000
--- a/arch/ppc64/kernel/time.c
+++ /dev/null
@@ -1,879 +0,0 @@
-/*
- *
- * Common time routines among all ppc machines.
- *
- * Written by Cort Dougan (cort@cs.nmt.edu) to merge
- * Paul Mackerras' version and mine for PReP and Pmac.
- * MPC8xx/MBX changes by Dan Malek (dmalek@jlc.net).
- * Converted for 64-bit by Mike Corrigan (mikejc@us.ibm.com)
- *
- * First round of bugfixes by Gabriel Paubert (paubert@iram.es)
- * to make clock more stable (2.4.0-test5). The only thing
- * that this code assumes is that the timebases have been synchronized
- * by firmware on SMP and are never stopped (never do sleep
- * on SMP then, nap and doze are OK).
- *
- * Speeded up do_gettimeofday by getting rid of references to
- * xtime (which required locks for consistency). (mikejc@us.ibm.com)
- *
- * TODO (not necessarily in this file):
- * - improve precision and reproducibility of timebase frequency
- * measurement at boot time. (for iSeries, we calibrate the timebase
- * against the Titan chip's clock.)
- * - for astronomical applications: add a new function to get
- * non ambiguous timestamps even around leap seconds. This needs
- * a new timestamp format and a good name.
- *
- * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
- * "A Kernel Model for Precision Timekeeping" by Dave Mills
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-
-#include <linux/config.h>
-#include <linux/errno.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/param.h>
-#include <linux/string.h>
-#include <linux/mm.h>
-#include <linux/interrupt.h>
-#include <linux/timex.h>
-#include <linux/kernel_stat.h>
-#include <linux/mc146818rtc.h>
-#include <linux/time.h>
-#include <linux/init.h>
-#include <linux/profile.h>
-#include <linux/cpu.h>
-#include <linux/security.h>
-
-#include <asm/io.h>
-#include <asm/processor.h>
-#include <asm/nvram.h>
-#include <asm/cache.h>
-#include <asm/machdep.h>
-#ifdef CONFIG_PPC_ISERIES
-#include <asm/iSeries/ItLpQueue.h>
-#include <asm/iSeries/HvCallXm.h>
-#endif
-#include <asm/uaccess.h>
-#include <asm/time.h>
-#include <asm/ppcdebug.h>
-#include <asm/prom.h>
-#include <asm/sections.h>
-#include <asm/systemcfg.h>
-#include <asm/firmware.h>
-
-u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;
-
-EXPORT_SYMBOL(jiffies_64);
-
-/* keep track of when we need to update the rtc */
-time_t last_rtc_update;
-extern int piranha_simulator;
-#ifdef CONFIG_PPC_ISERIES
-unsigned long iSeries_recal_titan = 0;
-unsigned long iSeries_recal_tb = 0;
-static unsigned long first_settimeofday = 1;
-#endif
-
-#define XSEC_PER_SEC (1024*1024)
-
-unsigned long tb_ticks_per_jiffy;
-unsigned long tb_ticks_per_usec = 100; /* sane default */
-EXPORT_SYMBOL(tb_ticks_per_usec);
-unsigned long tb_ticks_per_sec;
-unsigned long tb_to_xs;
-unsigned tb_to_us;
-unsigned long processor_freq;
-DEFINE_SPINLOCK(rtc_lock);
-EXPORT_SYMBOL_GPL(rtc_lock);
-
-unsigned long tb_to_ns_scale;
-unsigned long tb_to_ns_shift;
-
-struct gettimeofday_struct do_gtod;
-
-extern unsigned long wall_jiffies;
-extern int smp_tb_synchronized;
-
-extern struct timezone sys_tz;
-
-void ppc_adjtimex(void);
-
-static unsigned adjusting_time = 0;
-
-unsigned long ppc_proc_freq;
-unsigned long ppc_tb_freq;
-
-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 (ntp_synced() &&
- xtime.tv_sec - last_rtc_update >= 659 &&
- abs((xtime.tv_nsec/1000) - (1000000-1000000/HZ)) < 500000/HZ &&
- jiffies - wall_jiffies == 1) {
- struct rtc_time tm;
- to_tm(xtime.tv_sec+1, &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.
- */
-static inline void __do_gettimeofday(struct timeval *tv, unsigned long tb_val)
-{
- unsigned long sec, usec, tb_ticks;
- unsigned long xsec, tb_xsec;
- struct gettimeofday_vars * temp_varp;
- unsigned long temp_tb_to_xs, temp_stamp_xsec;
-
- /*
- * These calculations are faster (gets rid of divides)
- * if done in units of 1/2^20 rather than microseconds.
- * The conversion to microseconds at the end is done
- * without a divide (and in fact, without a multiply)
- */
- temp_varp = do_gtod.varp;
- tb_ticks = tb_val - temp_varp->tb_orig_stamp;
- temp_tb_to_xs = temp_varp->tb_to_xs;
- temp_stamp_xsec = temp_varp->stamp_xsec;
- tb_xsec = mulhdu( tb_ticks, temp_tb_to_xs );
- xsec = temp_stamp_xsec + tb_xsec;
- sec = xsec / XSEC_PER_SEC;
- xsec -= sec * XSEC_PER_SEC;
- usec = (xsec * USEC_PER_SEC)/XSEC_PER_SEC;
-
- tv->tv_sec = sec;
- tv->tv_usec = usec;
-}
-
-void do_gettimeofday(struct timeval *tv)
-{
- __do_gettimeofday(tv, get_tb());
-}
-
-EXPORT_SYMBOL(do_gettimeofday);
-
-/* Synchronize xtime with do_gettimeofday */
-
-static inline void timer_sync_xtime(unsigned long cur_tb)
-{
- struct timeval my_tv;
-
- __do_gettimeofday(&my_tv, cur_tb);
-
- if (xtime.tv_sec <= my_tv.tv_sec) {
- xtime.tv_sec = my_tv.tv_sec;
- xtime.tv_nsec = my_tv.tv_usec * 1000;
- }
-}
-
-/*
- * When the timebase - tb_orig_stamp gets too big, we do a manipulation
- * between tb_orig_stamp and stamp_xsec. The goal here is to keep the
- * difference tb - tb_orig_stamp small enough to always fit inside a
- * 32 bits number. This is a requirement of our fast 32 bits userland
- * implementation in the vdso. If we "miss" a call to this function
- * (interrupt latency, CPU locked in a spinlock, ...) and we end up
- * with a too big difference, then the vdso will fallback to calling
- * the syscall
- */
-static __inline__ void timer_recalc_offset(unsigned long cur_tb)
-{
- struct gettimeofday_vars * temp_varp;
- unsigned temp_idx;
- unsigned long offset, new_stamp_xsec, new_tb_orig_stamp;
-
- if (((cur_tb - do_gtod.varp->tb_orig_stamp) & 0x80000000u) == 0)
- return;
-
- temp_idx = (do_gtod.var_idx == 0);
- temp_varp = &do_gtod.vars[temp_idx];
-
- new_tb_orig_stamp = cur_tb;
- offset = new_tb_orig_stamp - do_gtod.varp->tb_orig_stamp;
- new_stamp_xsec = do_gtod.varp->stamp_xsec + mulhdu(offset, do_gtod.varp->tb_to_xs);
-
- temp_varp->tb_to_xs = do_gtod.varp->tb_to_xs;
- temp_varp->tb_orig_stamp = new_tb_orig_stamp;
- temp_varp->stamp_xsec = new_stamp_xsec;
- smp_mb();
- do_gtod.varp = temp_varp;
- do_gtod.var_idx = temp_idx;
-
- ++(systemcfg->tb_update_count);
- smp_wmb();
- systemcfg->tb_orig_stamp = new_tb_orig_stamp;
- systemcfg->stamp_xsec = new_stamp_xsec;
- smp_wmb();
- ++(systemcfg->tb_update_count);
-}
-
-#ifdef CONFIG_SMP
-unsigned long profile_pc(struct pt_regs *regs)
-{
- unsigned long pc = instruction_pointer(regs);
-
- if (in_lock_functions(pc))
- return regs->link;
-
- return pc;
-}
-EXPORT_SYMBOL(profile_pc);
-#endif
-
-#ifdef CONFIG_PPC_ISERIES
-
-/*
- * This function recalibrates the timebase based on the 49-bit time-of-day
- * value in the Titan chip. The Titan is much more accurate than the value
- * returned by the service processor for the timebase frequency.
- */
-
-static void iSeries_tb_recal(void)
-{
- struct div_result divres;
- unsigned long titan, tb;
- tb = get_tb();
- titan = HvCallXm_loadTod();
- if ( iSeries_recal_titan ) {
- unsigned long tb_ticks = tb - iSeries_recal_tb;
- unsigned long titan_usec = (titan - iSeries_recal_titan) >> 12;
- unsigned long new_tb_ticks_per_sec = (tb_ticks * USEC_PER_SEC)/titan_usec;
- unsigned long new_tb_ticks_per_jiffy = (new_tb_ticks_per_sec+(HZ/2))/HZ;
- long tick_diff = new_tb_ticks_per_jiffy - tb_ticks_per_jiffy;
- char sign = '+';
- /* make sure tb_ticks_per_sec and tb_ticks_per_jiffy are consistent */
- new_tb_ticks_per_sec = new_tb_ticks_per_jiffy * HZ;
-
- if ( tick_diff < 0 ) {
- tick_diff = -tick_diff;
- sign = '-';
- }
- if ( tick_diff ) {
- if ( tick_diff < tb_ticks_per_jiffy/25 ) {
- printk( "Titan recalibrate: new tb_ticks_per_jiffy = %lu (%c%ld)\n",
- new_tb_ticks_per_jiffy, sign, tick_diff );
- tb_ticks_per_jiffy = new_tb_ticks_per_jiffy;
- tb_ticks_per_sec = new_tb_ticks_per_sec;
- div128_by_32( XSEC_PER_SEC, 0, tb_ticks_per_sec, &divres );
- do_gtod.tb_ticks_per_sec = tb_ticks_per_sec;
- tb_to_xs = divres.result_low;
- do_gtod.varp->tb_to_xs = tb_to_xs;
- systemcfg->tb_ticks_per_sec = tb_ticks_per_sec;
- systemcfg->tb_to_xs = tb_to_xs;
- }
- else {
- printk( "Titan recalibrate: FAILED (difference > 4 percent)\n"
- " new tb_ticks_per_jiffy = %lu\n"
- " old tb_ticks_per_jiffy = %lu\n",
- new_tb_ticks_per_jiffy, tb_ticks_per_jiffy );
- }
- }
- }
- iSeries_recal_titan = titan;
- iSeries_recal_tb = tb;
-}
-#endif
-
-/*
- * For iSeries shared processors, we have to let the hypervisor
- * set the hardware decrementer. We set a virtual decrementer
- * in the lppaca and call the hypervisor if the virtual
- * decrementer is less than the current value in the hardware
- * decrementer. (almost always the new decrementer value will
- * be greater than the current hardware decementer so the hypervisor
- * call will not be needed)
- */
-
-unsigned long tb_last_stamp __cacheline_aligned_in_smp;
-
-/*
- * timer_interrupt - gets called when the decrementer overflows,
- * with interrupts disabled.
- */
-void timer_interrupt(struct pt_regs * regs)
-{
- int next_dec;
- unsigned long cur_tb;
- struct paca_struct *lpaca = get_paca();
- unsigned long cpu = smp_processor_id();
-
- irq_enter();
-
- profile_tick(CPU_PROFILING, regs);
-
- lpaca->lppaca.int_dword.fields.decr_int = 0;
-
- while (lpaca->next_jiffy_update_tb <= (cur_tb = get_tb())) {
- /*
- * We cannot disable the decrementer, so in the period
- * between this cpu's being marked offline in cpu_online_map
- * and calling stop-self, it is taking timer interrupts.
- * Avoid calling into the scheduler rebalancing code if this
- * is the case.
- */
- if (!cpu_is_offline(cpu))
- update_process_times(user_mode(regs));
- /*
- * No need to check whether cpu is offline here; boot_cpuid
- * should have been fixed up by now.
- */
- if (cpu == boot_cpuid) {
- write_seqlock(&xtime_lock);
- tb_last_stamp = lpaca->next_jiffy_update_tb;
- timer_recalc_offset(lpaca->next_jiffy_update_tb);
- do_timer(regs);
- timer_sync_xtime(lpaca->next_jiffy_update_tb);
- timer_check_rtc();
- write_sequnlock(&xtime_lock);
- if ( adjusting_time && (time_adjust == 0) )
- ppc_adjtimex();
- }
- lpaca->next_jiffy_update_tb += tb_ticks_per_jiffy;
- }
-
- next_dec = lpaca->next_jiffy_update_tb - cur_tb;
- if (next_dec > lpaca->default_decr)
- next_dec = lpaca->default_decr;
- set_dec(next_dec);
-
-#ifdef CONFIG_PPC_ISERIES
- if (hvlpevent_is_pending())
- process_hvlpevents(regs);
-#endif
-
- /* collect purr register values often, for accurate calculations */
- if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
- struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
- cu->current_tb = mfspr(SPRN_PURR);
- }
-
- irq_exit();
-}
-
-/*
- * Scheduler clock - returns current time in nanosec units.
- *
- * Note: mulhdu(a, b) (multiply high double unsigned) returns
- * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b
- * are 64-bit unsigned numbers.
- */
-unsigned long long sched_clock(void)
-{
- return mulhdu(get_tb(), tb_to_ns_scale) << tb_to_ns_shift;
-}
-
-int do_settimeofday(struct timespec *tv)
-{
- time_t wtm_sec, new_sec = tv->tv_sec;
- long wtm_nsec, new_nsec = tv->tv_nsec;
- unsigned long flags;
- unsigned long delta_xsec;
- long int tb_delta;
- unsigned long new_xsec;
-
- if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
- return -EINVAL;
-
- write_seqlock_irqsave(&xtime_lock, flags);
- /* Updating the RTC is not the job of this code. If the time is
- * stepped under NTP, the RTC will be update after STA_UNSYNC
- * is cleared. Tool like clock/hwclock either copy the RTC
- * to the system time, in which case there is no point in writing
- * 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 ( first_settimeofday ) {
- iSeries_tb_recal();
- first_settimeofday = 0;
- }
-#endif
- tb_delta = tb_ticks_since(tb_last_stamp);
- tb_delta += (jiffies - wall_jiffies) * tb_ticks_per_jiffy;
-
- new_nsec -= tb_delta / tb_ticks_per_usec / 1000;
-
- wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - new_sec);
- wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - new_nsec);
-
- 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();
-
- delta_xsec = mulhdu( (tb_last_stamp-do_gtod.varp->tb_orig_stamp),
- do_gtod.varp->tb_to_xs );
-
- new_xsec = (new_nsec * XSEC_PER_SEC) / NSEC_PER_SEC;
- new_xsec += new_sec * XSEC_PER_SEC;
- if ( new_xsec > delta_xsec ) {
- do_gtod.varp->stamp_xsec = new_xsec - delta_xsec;
- systemcfg->stamp_xsec = new_xsec - delta_xsec;
- }
- else {
- /* This is only for the case where the user is setting the time
- * way back to a time such that the boot time would have been
- * before 1970 ... eg. we booted ten days ago, and we are setting
- * the time to Jan 5, 1970 */
- do_gtod.varp->stamp_xsec = new_xsec;
- do_gtod.varp->tb_orig_stamp = tb_last_stamp;
- systemcfg->stamp_xsec = new_xsec;
- systemcfg->tb_orig_stamp = tb_last_stamp;
- }
-
- systemcfg->tz_minuteswest = sys_tz.tz_minuteswest;
- systemcfg->tz_dsttime = sys_tz.tz_dsttime;
-
- write_sequnlock_irqrestore(&xtime_lock, flags);
- clock_was_set();
- return 0;
-}
-
-EXPORT_SYMBOL(do_settimeofday);
-
-#if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_MAPLE) || defined(CONFIG_PPC_BPA) || defined(CONFIG_PPC_ISERIES)
-void __init generic_calibrate_decr(void)
-{
- struct device_node *cpu;
- struct div_result divres;
- unsigned int *fp;
- int node_found;
-
- /*
- * The cpu node should have a timebase-frequency property
- * to tell us the rate at which the decrementer counts.
- */
- cpu = of_find_node_by_type(NULL, "cpu");
-
- ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
- node_found = 0;
- if (cpu != 0) {
- fp = (unsigned int *)get_property(cpu, "timebase-frequency",
- NULL);
- if (fp != 0) {
- node_found = 1;
- ppc_tb_freq = *fp;
- }
- }
- if (!node_found)
- printk(KERN_ERR "WARNING: Estimating decrementer frequency "
- "(not found)\n");
-
- ppc_proc_freq = DEFAULT_PROC_FREQ;
- node_found = 0;
- if (cpu != 0) {
- fp = (unsigned int *)get_property(cpu, "clock-frequency",
- NULL);
- if (fp != 0) {
- node_found = 1;
- ppc_proc_freq = *fp;
- }
- }
- if (!node_found)
- printk(KERN_ERR "WARNING: Estimating processor frequency "
- "(not found)\n");
-
- of_node_put(cpu);
-
- printk(KERN_INFO "time_init: decrementer frequency = %lu.%.6lu MHz\n",
- ppc_tb_freq/1000000, ppc_tb_freq%1000000);
- printk(KERN_INFO "time_init: processor frequency = %lu.%.6lu MHz\n",
- ppc_proc_freq/1000000, ppc_proc_freq%1000000);
-
- tb_ticks_per_jiffy = ppc_tb_freq / HZ;
- tb_ticks_per_sec = tb_ticks_per_jiffy * HZ;
- tb_ticks_per_usec = ppc_tb_freq / 1000000;
- tb_to_us = mulhwu_scale_factor(ppc_tb_freq, 1000000);
- div128_by_32(1024*1024, 0, tb_ticks_per_sec, &divres);
- tb_to_xs = divres.result_low;
-
- setup_default_decr();
-}
-#endif
-
-void __init time_init(void)
-{
- /* This function is only called on the boot processor */
- unsigned long flags;
- struct rtc_time tm;
- struct div_result res;
- unsigned long scale, shift;
-
- ppc_md.calibrate_decr();
-
- /*
- * Compute scale factor for sched_clock.
- * The calibrate_decr() function has set tb_ticks_per_sec,
- * which is the timebase frequency.
- * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret
- * the 128-bit result as a 64.64 fixed-point number.
- * We then shift that number right until it is less than 1.0,
- * giving us the scale factor and shift count to use in
- * sched_clock().
- */
- div128_by_32(1000000000, 0, tb_ticks_per_sec, &res);
- scale = res.result_low;
- for (shift = 0; res.result_high != 0; ++shift) {
- scale = (scale >> 1) | (res.result_high << 63);
- res.result_high >>= 1;
- }
- tb_to_ns_scale = scale;
- tb_to_ns_shift = shift;
-
-#ifdef CONFIG_PPC_ISERIES
- if (!piranha_simulator)
-#endif
- ppc_md.get_boot_time(&tm);
-
- write_seqlock_irqsave(&xtime_lock, flags);
- xtime.tv_sec = mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
- tm.tm_hour, tm.tm_min, tm.tm_sec);
- tb_last_stamp = get_tb();
- do_gtod.varp = &do_gtod.vars[0];
- do_gtod.var_idx = 0;
- do_gtod.varp->tb_orig_stamp = tb_last_stamp;
- get_paca()->next_jiffy_update_tb = tb_last_stamp + tb_ticks_per_jiffy;
- do_gtod.varp->stamp_xsec = xtime.tv_sec * XSEC_PER_SEC;
- do_gtod.tb_ticks_per_sec = tb_ticks_per_sec;
- do_gtod.varp->tb_to_xs = tb_to_xs;
- do_gtod.tb_to_us = tb_to_us;
- systemcfg->tb_orig_stamp = tb_last_stamp;
- systemcfg->tb_update_count = 0;
- systemcfg->tb_ticks_per_sec = tb_ticks_per_sec;
- systemcfg->stamp_xsec = xtime.tv_sec * XSEC_PER_SEC;
- systemcfg->tb_to_xs = tb_to_xs;
-
- time_freq = 0;
-
- xtime.tv_nsec = 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 */
- set_dec(tb_ticks_per_jiffy);
-}
-
-/*
- * After adjtimex is called, adjust the conversion of tb ticks
- * to microseconds to keep do_gettimeofday synchronized
- * with ntpd.
- *
- * Use the time_adjust, time_freq and time_offset computed by adjtimex to
- * adjust the frequency.
- */
-
-/* #define DEBUG_PPC_ADJTIMEX 1 */
-
-void ppc_adjtimex(void)
-{
- unsigned long den, new_tb_ticks_per_sec, tb_ticks, old_xsec, new_tb_to_xs, new_xsec, new_stamp_xsec;
- unsigned long tb_ticks_per_sec_delta;
- long delta_freq, ltemp;
- struct div_result divres;
- unsigned long flags;
- struct gettimeofday_vars * temp_varp;
- unsigned temp_idx;
- long singleshot_ppm = 0;
-
- /* Compute parts per million frequency adjustment to accomplish the time adjustment
- implied by time_offset to be applied over the elapsed time indicated by time_constant.
- Use SHIFT_USEC to get it into the same units as time_freq. */
- if ( time_offset < 0 ) {
- ltemp = -time_offset;
- ltemp <<= SHIFT_USEC - SHIFT_UPDATE;
- ltemp >>= SHIFT_KG + time_constant;
- ltemp = -ltemp;
- }
- else {
- ltemp = time_offset;
- ltemp <<= SHIFT_USEC - SHIFT_UPDATE;
- ltemp >>= SHIFT_KG + time_constant;
- }
-
- /* If there is a single shot time adjustment in progress */
- if ( time_adjust ) {
-#ifdef DEBUG_PPC_ADJTIMEX
- printk("ppc_adjtimex: ");
- if ( adjusting_time == 0 )
- printk("starting ");
- printk("single shot time_adjust = %ld\n", time_adjust);
-#endif
-
- adjusting_time = 1;
-
- /* Compute parts per million frequency adjustment to match time_adjust */
- singleshot_ppm = tickadj * HZ;
- /*
- * The adjustment should be tickadj*HZ to match the code in
- * linux/kernel/timer.c, but experiments show that this is too
- * large. 3/4 of tickadj*HZ seems about right
- */
- singleshot_ppm -= singleshot_ppm / 4;
- /* Use SHIFT_USEC to get it into the same units as time_freq */
- singleshot_ppm <<= SHIFT_USEC;
- if ( time_adjust < 0 )
- singleshot_ppm = -singleshot_ppm;
- }
- else {
-#ifdef DEBUG_PPC_ADJTIMEX
- if ( adjusting_time )
- printk("ppc_adjtimex: ending single shot time_adjust\n");
-#endif
- adjusting_time = 0;
- }
-
- /* Add up all of the frequency adjustments */
- delta_freq = time_freq + ltemp + singleshot_ppm;
-
- /* Compute a new value for tb_ticks_per_sec based on the frequency adjustment */
- den = 1000000 * (1 << (SHIFT_USEC - 8));
- if ( delta_freq < 0 ) {
- tb_ticks_per_sec_delta = ( tb_ticks_per_sec * ( (-delta_freq) >> (SHIFT_USEC - 8))) / den;
- new_tb_ticks_per_sec = tb_ticks_per_sec + tb_ticks_per_sec_delta;
- }
- else {
- tb_ticks_per_sec_delta = ( tb_ticks_per_sec * ( delta_freq >> (SHIFT_USEC - 8))) / den;
- new_tb_ticks_per_sec = tb_ticks_per_sec - tb_ticks_per_sec_delta;
- }
-
-#ifdef DEBUG_PPC_ADJTIMEX
- printk("ppc_adjtimex: ltemp = %ld, time_freq = %ld, singleshot_ppm = %ld\n", ltemp, time_freq, singleshot_ppm);
- printk("ppc_adjtimex: tb_ticks_per_sec - base = %ld new = %ld\n", tb_ticks_per_sec, new_tb_ticks_per_sec);
-#endif
-
- /* Compute a new value of tb_to_xs (used to convert tb to microseconds and a new value of
- stamp_xsec which is the time (in 1/2^20 second units) corresponding to tb_orig_stamp. This
- new value of stamp_xsec compensates for the change in frequency (implied by the new tb_to_xs)
- which guarantees that the current time remains the same */
- write_seqlock_irqsave( &xtime_lock, flags );
- tb_ticks = get_tb() - do_gtod.varp->tb_orig_stamp;
- div128_by_32( 1024*1024, 0, new_tb_ticks_per_sec, &divres );
- new_tb_to_xs = divres.result_low;
- new_xsec = mulhdu( tb_ticks, new_tb_to_xs );
-
- old_xsec = mulhdu( tb_ticks, do_gtod.varp->tb_to_xs );
- new_stamp_xsec = do_gtod.varp->stamp_xsec + old_xsec - new_xsec;
-
- /* There are two copies of tb_to_xs and stamp_xsec so that no lock is needed to access and use these
- values in do_gettimeofday. We alternate the copies and as long as a reasonable time elapses between
- changes, there will never be inconsistent values. ntpd has a minimum of one minute between updates */
-
- temp_idx = (do_gtod.var_idx == 0);
- temp_varp = &do_gtod.vars[temp_idx];
-
- temp_varp->tb_to_xs = new_tb_to_xs;
- temp_varp->stamp_xsec = new_stamp_xsec;
- temp_varp->tb_orig_stamp = do_gtod.varp->tb_orig_stamp;
- smp_mb();
- do_gtod.varp = temp_varp;
- do_gtod.var_idx = temp_idx;
-
- /*
- * tb_update_count is used to allow the problem state gettimeofday code
- * to assure itself that it sees a consistent view of the tb_to_xs and
- * stamp_xsec variables. It reads the tb_update_count, then reads
- * tb_to_xs and stamp_xsec and then reads tb_update_count again. If
- * the two values of tb_update_count match and are even then the
- * tb_to_xs and stamp_xsec values are consistent. If not, then it
- * loops back and reads them again until this criteria is met.
- */
- ++(systemcfg->tb_update_count);
- smp_wmb();
- systemcfg->tb_to_xs = new_tb_to_xs;
- systemcfg->stamp_xsec = new_stamp_xsec;
- smp_wmb();
- ++(systemcfg->tb_update_count);
-
- write_sequnlock_irqrestore( &xtime_lock, flags );
-
-}
-
-
-#define TICK_SIZE tick
-#define FEBRUARY 2
-#define STARTOFTIME 1970
-#define SECDAY 86400L
-#define SECYR (SECDAY * 365)
-#define leapyear(year) ((year) % 4 == 0)
-#define days_in_year(a) (leapyear(a) ? 366 : 365)
-#define days_in_month(a) (month_days[(a) - 1])
-
-static int month_days[12] = {
- 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
-};
-
-/*
- * This only works for the Gregorian calendar - i.e. after 1752 (in the UK)
- */
-void GregorianDay(struct rtc_time * tm)
-{
- int leapsToDate;
- int lastYear;
- int day;
- int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
-
- lastYear=tm->tm_year-1;
-
- /*
- * Number of leap corrections to apply up to end of last year
- */
- leapsToDate = lastYear/4 - lastYear/100 + lastYear/400;
-
- /*
- * This year is a leap year if it is divisible by 4 except when it is
- * divisible by 100 unless it is divisible by 400
- *
- * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 will be
- */
- if((tm->tm_year%4==0) &&
- ((tm->tm_year%100!=0) || (tm->tm_year%400==0)) &&
- (tm->tm_mon>2))
- {
- /*
- * We are past Feb. 29 in a leap year
- */
- day=1;
- }
- else
- {
- day=0;
- }
-
- day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] +
- tm->tm_mday;
-
- tm->tm_wday=day%7;
-}
-
-void to_tm(int tim, struct rtc_time * tm)
-{
- register int i;
- register long hms, day;
-
- day = tim / SECDAY;
- hms = tim % SECDAY;
-
- /* Hours, minutes, seconds are easy */
- tm->tm_hour = hms / 3600;
- tm->tm_min = (hms % 3600) / 60;
- tm->tm_sec = (hms % 3600) % 60;
-
- /* Number of years in days */
- for (i = STARTOFTIME; day >= days_in_year(i); i++)
- day -= days_in_year(i);
- tm->tm_year = i;
-
- /* Number of months in days left */
- if (leapyear(tm->tm_year))
- days_in_month(FEBRUARY) = 29;
- for (i = 1; day >= days_in_month(i); i++)
- day -= days_in_month(i);
- days_in_month(FEBRUARY) = 28;
- tm->tm_mon = i;
-
- /* Days are what is left over (+1) from all that. */
- tm->tm_mday = day + 1;
-
- /*
- * Determine the day of week
- */
- GregorianDay(tm);
-}
-
-/* Auxiliary function to compute scaling factors */
-/* Actually the choice of a timebase running at 1/4 the of the bus
- * frequency giving resolution of a few tens of nanoseconds is quite nice.
- * It makes this computation very precise (27-28 bits typically) which
- * is optimistic considering the stability of most processor clock
- * oscillators and the precision with which the timebase frequency
- * is measured but does not harm.
- */
-unsigned mulhwu_scale_factor(unsigned inscale, unsigned outscale) {
- unsigned mlt=0, tmp, err;
- /* No concern for performance, it's done once: use a stupid
- * but safe and compact method to find the multiplier.
- */
-
- for (tmp = 1U<<31; tmp != 0; tmp >>= 1) {
- if (mulhwu(inscale, mlt|tmp) < outscale) mlt|=tmp;
- }
-
- /* We might still be off by 1 for the best approximation.
- * A side effect of this is that if outscale is too large
- * the returned value will be zero.
- * Many corner cases have been checked and seem to work,
- * some might have been forgotten in the test however.
- */
-
- err = inscale*(mlt+1);
- if (err <= inscale/2) mlt++;
- return mlt;
- }
-
-/*
- * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
- * result.
- */
-
-void div128_by_32( unsigned long dividend_high, unsigned long dividend_low,
- unsigned divisor, struct div_result *dr )
-{
- unsigned long a,b,c,d, w,x,y,z, ra,rb,rc;
-
- a = dividend_high >> 32;
- b = dividend_high & 0xffffffff;
- c = dividend_low >> 32;
- d = dividend_low & 0xffffffff;
-
- w = a/divisor;
- ra = (a - (w * divisor)) << 32;
-
- x = (ra + b)/divisor;
- rb = ((ra + b) - (x * divisor)) << 32;
-
- y = (rb + c)/divisor;
- rc = ((rb + b) - (y * divisor)) << 32;
-
- z = (rc + d)/divisor;
-
- dr->result_high = (w << 32) + x;
- dr->result_low = (y << 32) + z;
-
-}
-