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cdd6c482c9
linux/arch/powerpc/kernel/time.c
Ingo Molnar cdd6c482c9 perf: Do the big rename: Performance Counters -> Performance Events 
Bye-bye Performance Counters, welcome Performance Events!

In the past few months the perfcounters subsystem has grown out its
initial role of counting hardware events, and has become (and is
becoming) a much broader generic event enumeration, reporting, logging,
monitoring, analysis facility.

Naming its core object 'perf_counter' and naming the subsystem
'perfcounters' has become more and more of a misnomer. With pending
code like hw-breakpoints support the 'counter' name is less and
less appropriate.

All in one, we've decided to rename the subsystem to 'performance
events' and to propagate this rename through all fields, variables
and API names. (in an ABI compatible fashion)

The word 'event' is also a bit shorter than 'counter' - which makes
it slightly more convenient to write/handle as well.

Thanks goes to Stephane Eranian who first observed this misnomer and
suggested a rename.

User-space tooling and ABI compatibility is not affected - this patch
should be function-invariant. (Also, defconfigs were not touched to
keep the size down.)

This patch has been generated via the following script:

  FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

  sed -i \
    -e 's/PERF_EVENT_/PERF_RECORD_/g' \
    -e 's/PERF_COUNTER/PERF_EVENT/g' \
    -e 's/perf_counter/perf_event/g' \
    -e 's/nb_counters/nb_events/g' \
    -e 's/swcounter/swevent/g' \
    -e 's/tpcounter_event/tp_event/g' \
    $FILES

  for N in $(find . -name perf_counter.[ch]); do
    M=$(echo $N | sed 's/perf_counter/perf_event/g')
    mv $N $M
  done

  FILES=$(find . -name perf_event.*)

  sed -i \
    -e 's/COUNTER_MASK/REG_MASK/g' \
    -e 's/COUNTER/EVENT/g' \
    -e 's/\<event\>/event_id/g' \
    -e 's/counter/event/g' \
    -e 's/Counter/Event/g' \
    $FILES

... to keep it as correct as possible. This script can also be
used by anyone who has pending perfcounters patches - it converts
a Linux kernel tree over to the new naming. We tried to time this
change to the point in time where the amount of pending patches
is the smallest: the end of the merge window.

Namespace clashes were fixed up in a preparatory patch - and some
stylistic fallout will be fixed up in a subsequent patch.

( NOTE: 'counters' are still the proper terminology when we deal
  with hardware registers - and these sed scripts are a bit
  over-eager in renaming them. I've undone some of that, but
  in case there's something left where 'counter' would be
  better than 'event' we can undo that on an individual basis
  instead of touching an otherwise nicely automated patch. )

Suggested-by: Stephane Eranian <eranian@google.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <linux-arch@vger.kernel.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21 14:28:04 +02:00

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/*
* 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/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/time.h>
#include <linux/init.h>
#include <linux/profile.h>
#include <linux/cpu.h>
#include <linux/security.h>
#include <linux/percpu.h>
#include <linux/rtc.h>
#include <linux/jiffies.h>
#include <linux/posix-timers.h>
#include <linux/irq.h>
#include <linux/delay.h>
#include <linux/perf_event.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/nvram.h>
#include <asm/cache.h>
#include <asm/machdep.h>
#include <asm/uaccess.h>
#include <asm/time.h>
#include <asm/prom.h>
#include <asm/irq.h>
#include <asm/div64.h>
#include <asm/smp.h>
#include <asm/vdso_datapage.h>
#include <asm/firmware.h>
#include <asm/cputime.h>
#ifdef CONFIG_PPC_ISERIES
#include <asm/iseries/it_lp_queue.h>
#include <asm/iseries/hv_call_xm.h>
#endif
/* powerpc clocksource/clockevent code */
#include <linux/clockchips.h>
#include <linux/clocksource.h>
static cycle_t rtc_read(struct clocksource *);
static struct clocksource clocksource_rtc = {
.name = "rtc",
.rating = 400,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.mask = CLOCKSOURCE_MASK(64),
.shift = 22,
.mult = 0, /* To be filled in */
.read = rtc_read,
};
static cycle_t timebase_read(struct clocksource *);
static struct clocksource clocksource_timebase = {
.name = "timebase",
.rating = 400,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.mask = CLOCKSOURCE_MASK(64),
.shift = 22,
.mult = 0, /* To be filled in */
.read = timebase_read,
};
#define DECREMENTER_MAX 0x7fffffff
static int decrementer_set_next_event(unsigned long evt,
struct clock_event_device *dev);
static void decrementer_set_mode(enum clock_event_mode mode,
struct clock_event_device *dev);
static struct clock_event_device decrementer_clockevent = {
.name = "decrementer",
.rating = 200,
.shift = 0, /* To be filled in */
.mult = 0, /* To be filled in */
.irq = 0,
.set_next_event = decrementer_set_next_event,
.set_mode = decrementer_set_mode,
.features = CLOCK_EVT_FEAT_ONESHOT,
};
struct decrementer_clock {
struct clock_event_device event;
u64 next_tb;
};
static DEFINE_PER_CPU(struct decrementer_clock, decrementers);
#ifdef CONFIG_PPC_ISERIES
static unsigned long __initdata iSeries_recal_titan;
static signed long __initdata iSeries_recal_tb;
/* Forward declaration is only needed for iSereis compiles */
static void __init clocksource_init(void);
#endif
#define XSEC_PER_SEC (1024*1024)
#ifdef CONFIG_PPC64
#define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC)
#else
/* compute ((xsec << 12) * max) >> 32 */
#define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max)
#endif
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;
EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */
u64 tb_to_xs;
unsigned tb_to_us;
#define TICKLEN_SCALE NTP_SCALE_SHIFT
static u64 last_tick_len; /* units are ns / 2^TICKLEN_SCALE */
static u64 ticklen_to_xs; /* 0.64 fraction */
/* If last_tick_len corresponds to about 1/HZ seconds, then
last_tick_len << TICKLEN_SHIFT will be about 2^63. */
#define TICKLEN_SHIFT (63 - 30 - TICKLEN_SCALE + SHIFT_HZ)
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL_GPL(rtc_lock);
static u64 tb_to_ns_scale __read_mostly;
static unsigned tb_to_ns_shift __read_mostly;
static unsigned long boot_tb __read_mostly;
extern struct timezone sys_tz;
static long timezone_offset;
unsigned long ppc_proc_freq;
EXPORT_SYMBOL(ppc_proc_freq);
unsigned long ppc_tb_freq;
static u64 tb_last_jiffy __cacheline_aligned_in_smp;
static DEFINE_PER_CPU(u64, last_jiffy);
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
/*
* Factors for converting from cputime_t (timebase ticks) to
* jiffies, milliseconds, seconds, and clock_t (1/USER_HZ seconds).
* These are all stored as 0.64 fixed-point binary fractions.
*/
u64 __cputime_jiffies_factor;
EXPORT_SYMBOL(__cputime_jiffies_factor);
u64 __cputime_msec_factor;
EXPORT_SYMBOL(__cputime_msec_factor);
u64 __cputime_sec_factor;
EXPORT_SYMBOL(__cputime_sec_factor);
u64 __cputime_clockt_factor;
EXPORT_SYMBOL(__cputime_clockt_factor);
DEFINE_PER_CPU(unsigned long, cputime_last_delta);
DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta);
static void calc_cputime_factors(void)
{
struct div_result res;
div128_by_32(HZ, 0, tb_ticks_per_sec, &res);
__cputime_jiffies_factor = res.result_low;
div128_by_32(1000, 0, tb_ticks_per_sec, &res);
__cputime_msec_factor = res.result_low;
div128_by_32(1, 0, tb_ticks_per_sec, &res);
__cputime_sec_factor = res.result_low;
div128_by_32(USER_HZ, 0, tb_ticks_per_sec, &res);
__cputime_clockt_factor = res.result_low;
}
/*
* Read the PURR on systems that have it, otherwise the timebase.
*/
static u64 read_purr(void)
{
if (cpu_has_feature(CPU_FTR_PURR))
return mfspr(SPRN_PURR);
return mftb();
}
/*
* Read the SPURR on systems that have it, otherwise the purr
*/
static u64 read_spurr(u64 purr)
{
/*
* cpus without PURR won't have a SPURR
* We already know the former when we use this, so tell gcc
*/
if (cpu_has_feature(CPU_FTR_PURR) && cpu_has_feature(CPU_FTR_SPURR))
return mfspr(SPRN_SPURR);
return purr;
}
/*
* Account time for a transition between system, hard irq
* or soft irq state.
*/
void account_system_vtime(struct task_struct *tsk)
{
u64 now, nowscaled, delta, deltascaled, sys_time;
unsigned long flags;
local_irq_save(flags);
now = read_purr();
nowscaled = read_spurr(now);
delta = now - get_paca()->startpurr;
deltascaled = nowscaled - get_paca()->startspurr;
get_paca()->startpurr = now;
get_paca()->startspurr = nowscaled;
if (!in_interrupt()) {
/* deltascaled includes both user and system time.
* Hence scale it based on the purr ratio to estimate
* the system time */
sys_time = get_paca()->system_time;
if (get_paca()->user_time)
deltascaled = deltascaled * sys_time /
(sys_time + get_paca()->user_time);
delta += sys_time;
get_paca()->system_time = 0;
}
if (in_irq() || idle_task(smp_processor_id()) != tsk)
account_system_time(tsk, 0, delta, deltascaled);
else
account_idle_time(delta);
per_cpu(cputime_last_delta, smp_processor_id()) = delta;
per_cpu(cputime_scaled_last_delta, smp_processor_id()) = deltascaled;
local_irq_restore(flags);
}
/*
* Transfer the user and system times accumulated in the paca
* by the exception entry and exit code to the generic process
* user and system time records.
* Must be called with interrupts disabled.
*/
void account_process_tick(struct task_struct *tsk, int user_tick)
{
cputime_t utime, utimescaled;
utime = get_paca()->user_time;
get_paca()->user_time = 0;
utimescaled = cputime_to_scaled(utime);
account_user_time(tsk, utime, utimescaled);
}
/*
* Stuff for accounting stolen time.
*/
struct cpu_purr_data {
int initialized; /* thread is running */
u64 tb; /* last TB value read */
u64 purr; /* last PURR value read */
u64 spurr; /* last SPURR value read */
};
/*
* Each entry in the cpu_purr_data array is manipulated only by its
* "owner" cpu -- usually in the timer interrupt but also occasionally
* in process context for cpu online. As long as cpus do not touch
* each others' cpu_purr_data, disabling local interrupts is
* sufficient to serialize accesses.
*/
static DEFINE_PER_CPU(struct cpu_purr_data, cpu_purr_data);
static void snapshot_tb_and_purr(void *data)
{
unsigned long flags;
struct cpu_purr_data *p = &__get_cpu_var(cpu_purr_data);
local_irq_save(flags);
p->tb = get_tb_or_rtc();
p->purr = mfspr(SPRN_PURR);
wmb();
p->initialized = 1;
local_irq_restore(flags);
}
/*
* Called during boot when all cpus have come up.
*/
void snapshot_timebases(void)
{
if (!cpu_has_feature(CPU_FTR_PURR))
return;
on_each_cpu(snapshot_tb_and_purr, NULL, 1);
}
/*
* Must be called with interrupts disabled.
*/
void calculate_steal_time(void)
{
u64 tb, purr;
s64 stolen;
struct cpu_purr_data *pme;
pme = &__get_cpu_var(cpu_purr_data);
if (!pme->initialized)
return; /* !CPU_FTR_PURR or early in early boot */
tb = mftb();
purr = mfspr(SPRN_PURR);
stolen = (tb - pme->tb) - (purr - pme->purr);
if (stolen > 0) {
if (idle_task(smp_processor_id()) != current)
account_steal_time(stolen);
else
account_idle_time(stolen);
}
pme->tb = tb;
pme->purr = purr;
}
#ifdef CONFIG_PPC_SPLPAR
/*
* Must be called before the cpu is added to the online map when
* a cpu is being brought up at runtime.
*/
static void snapshot_purr(void)
{
struct cpu_purr_data *pme;
unsigned long flags;
if (!cpu_has_feature(CPU_FTR_PURR))
return;
local_irq_save(flags);
pme = &__get_cpu_var(cpu_purr_data);
pme->tb = mftb();
pme->purr = mfspr(SPRN_PURR);
pme->initialized = 1;
local_irq_restore(flags);
}
#endif /* CONFIG_PPC_SPLPAR */
#else /* ! CONFIG_VIRT_CPU_ACCOUNTING */
#define calc_cputime_factors()
#define calculate_steal_time() do { } while (0)
#endif
#if !(defined(CONFIG_VIRT_CPU_ACCOUNTING) && defined(CONFIG_PPC_SPLPAR))
#define snapshot_purr() do { } while (0)
#endif
/*
* Called when a cpu comes up after the system has finished booting,
* i.e. as a result of a hotplug cpu action.
*/
void snapshot_timebase(void)
{
__get_cpu_var(last_jiffy) = get_tb_or_rtc();
snapshot_purr();
}
void __delay(unsigned long loops)
{
unsigned long start;
int diff;
if (__USE_RTC()) {
start = get_rtcl();
do {
/* the RTCL register wraps at 1000000000 */
diff = get_rtcl() - start;
if (diff < 0)
diff += 1000000000;
} while (diff < loops);
} else {
start = get_tbl();
while (get_tbl() - start < loops)
HMT_low();
HMT_medium();
}
}
EXPORT_SYMBOL(__delay);
void udelay(unsigned long usecs)
{
__delay(tb_ticks_per_usec * usecs);
}
EXPORT_SYMBOL(udelay);
static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec,
u64 new_tb_to_xs)
{
/*
* tb_update_count is used to allow the userspace 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.
* We expect the caller to have done the first increment of
* vdso_data->tb_update_count already.
*/
vdso_data->tb_orig_stamp = new_tb_stamp;
vdso_data->stamp_xsec = new_stamp_xsec;
vdso_data->tb_to_xs = new_tb_to_xs;
vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec;
vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec;
vdso_data->stamp_xtime = xtime;
smp_wmb();
++(vdso_data->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 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 ) {
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 =
DIV_ROUND_CLOSEST(new_tb_ticks_per_sec, 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;
calc_cputime_factors();
div128_by_32( XSEC_PER_SEC, 0, tb_ticks_per_sec, &divres );
tb_to_xs = divres.result_low;
vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
vdso_data->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;
/* Called here as now we know accurate values for the timebase */
clocksource_init();
return 0;
}
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 */
#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_PPC32)
DEFINE_PER_CPU(u8, perf_event_pending);
void set_perf_event_pending(void)
{
get_cpu_var(perf_event_pending) = 1;
set_dec(1);
put_cpu_var(perf_event_pending);
}
#define test_perf_event_pending() __get_cpu_var(perf_event_pending)
#define clear_perf_event_pending() __get_cpu_var(perf_event_pending) = 0
#else /* CONFIG_PERF_EVENTS && CONFIG_PPC32 */
#define test_perf_event_pending() 0
#define clear_perf_event_pending()
#endif /* CONFIG_PERF_EVENTS && CONFIG_PPC32 */
/*
* 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)
*/
/*
* timer_interrupt - gets called when the decrementer overflows,
* with interrupts disabled.
*/
void timer_interrupt(struct pt_regs * regs)
{
struct pt_regs *old_regs;
struct decrementer_clock *decrementer = &__get_cpu_var(decrementers);
struct clock_event_device *evt = &decrementer->event;
u64 now;
/* Ensure a positive value is written to the decrementer, or else
* some CPUs will continuue to take decrementer exceptions */
set_dec(DECREMENTER_MAX);
#ifdef CONFIG_PPC32
if (test_perf_event_pending()) {
clear_perf_event_pending();
perf_event_do_pending();
}
if (atomic_read(&ppc_n_lost_interrupts) != 0)
do_IRQ(regs);
#endif
now = get_tb_or_rtc();
if (now < decrementer->next_tb) {
/* not time for this event yet */
now = decrementer->next_tb - now;
if (now <= DECREMENTER_MAX)
set_dec((int)now);
return;
}
old_regs = set_irq_regs(regs);
irq_enter();
calculate_steal_time();
#ifdef CONFIG_PPC_ISERIES
if (firmware_has_feature(FW_FEATURE_ISERIES))
get_lppaca()->int_dword.fields.decr_int = 0;
#endif
if (evt->event_handler)
evt->event_handler(evt);
#ifdef CONFIG_PPC_ISERIES
if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending())
process_hvlpevents();
#endif
#ifdef CONFIG_PPC64
/* 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);
}
#endif
irq_exit();
set_irq_regs(old_regs);
}
void wakeup_decrementer(void)
{
unsigned long ticks;
/*
* The timebase gets saved on sleep and restored on wakeup,
* so all we need to do is to reset the decrementer.
*/
ticks = tb_ticks_since(__get_cpu_var(last_jiffy));
if (ticks < tb_ticks_per_jiffy)
ticks = tb_ticks_per_jiffy - ticks;
else
ticks = 1;
set_dec(ticks);
}
#ifdef CONFIG_SUSPEND
void generic_suspend_disable_irqs(void)
{
preempt_disable();
/* Disable the decrementer, so that it doesn't interfere
* with suspending.
*/
set_dec(0x7fffffff);
local_irq_disable();
set_dec(0x7fffffff);
}
void generic_suspend_enable_irqs(void)
{
wakeup_decrementer();
local_irq_enable();
preempt_enable();
}
/* Overrides the weak version in kernel/power/main.c */
void arch_suspend_disable_irqs(void)
{
if (ppc_md.suspend_disable_irqs)
ppc_md.suspend_disable_irqs();
generic_suspend_disable_irqs();
}
/* Overrides the weak version in kernel/power/main.c */
void arch_suspend_enable_irqs(void)
{
generic_suspend_enable_irqs();
if (ppc_md.suspend_enable_irqs)
ppc_md.suspend_enable_irqs();
}
#endif
#ifdef CONFIG_SMP
void __init smp_space_timers(unsigned int max_cpus)
{
int i;
u64 previous_tb = per_cpu(last_jiffy, boot_cpuid);
/* make sure tb > per_cpu(last_jiffy, cpu) for all cpus always */
previous_tb -= tb_ticks_per_jiffy;
for_each_possible_cpu(i) {
if (i == boot_cpuid)
continue;
per_cpu(last_jiffy, i) = previous_tb;
}
}
#endif
/*
* 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)
{
if (__USE_RTC())
return get_rtc();
return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
}
static int __init get_freq(char *name, int cells, unsigned long *val)
{
struct device_node *cpu;
const unsigned int *fp;
int found = 0;
/* The cpu node should have timebase and clock frequency properties */
cpu = of_find_node_by_type(NULL, "cpu");
if (cpu) {
fp = of_get_property(cpu, name, NULL);
if (fp) {
found = 1;
*val = of_read_ulong(fp, cells);
}
of_node_put(cpu);
}
return found;
}
/* should become __cpuinit when secondary_cpu_time_init also is */
void start_cpu_decrementer(void)
{
#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
/* Clear any pending timer interrupts */
mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS);
/* Enable decrementer interrupt */
mtspr(SPRN_TCR, TCR_DIE);
#endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */
}
void __init generic_calibrate_decr(void)
{
ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) &&
!get_freq("timebase-frequency", 1, &ppc_tb_freq)) {
printk(KERN_ERR "WARNING: Estimating decrementer frequency "
"(not found)\n");
}
ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */
if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) &&
!get_freq("clock-frequency", 1, &ppc_proc_freq)) {
printk(KERN_ERR "WARNING: Estimating processor frequency "
"(not found)\n");
}
}
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);
}
void read_persistent_clock(struct timespec *ts)
{
struct rtc_time tm;
static int first = 1;
ts->tv_nsec = 0;
/* 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) {
ts->tv_sec = ppc_md.get_boot_time() - timezone_offset;
return;
}
}
if (!ppc_md.get_rtc_time) {
ts->tv_sec = 0;
return;
}
ppc_md.get_rtc_time(&tm);
ts->tv_sec = mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec);
}
/* clocksource code */
static cycle_t rtc_read(struct clocksource *cs)
{
return (cycle_t)get_rtc();
}
static cycle_t timebase_read(struct clocksource *cs)
{
return (cycle_t)get_tb();
}
void update_vsyscall(struct timespec *wall_time, struct clocksource *clock)
{
u64 t2x, stamp_xsec;
if (clock != &clocksource_timebase)
return;
/* Make userspace gettimeofday spin until we're done. */
++vdso_data->tb_update_count;
smp_mb();
/* XXX this assumes clock->shift == 22 */
/* 4611686018 ~= 2^(20+64-22) / 1e9 */
t2x = (u64) clock->mult * 4611686018ULL;
stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC;
do_div(stamp_xsec, 1000000000);
stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC;
update_gtod(clock->cycle_last, stamp_xsec, t2x);
}
void update_vsyscall_tz(void)
{
/* Make userspace gettimeofday spin until we're done. */
++vdso_data->tb_update_count;
smp_mb();
vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
vdso_data->tz_dsttime = sys_tz.tz_dsttime;
smp_mb();
++vdso_data->tb_update_count;
}
static void __init clocksource_init(void)
{
struct clocksource *clock;
if (__USE_RTC())
clock = &clocksource_rtc;
else
clock = &clocksource_timebase;
clock->mult = clocksource_hz2mult(tb_ticks_per_sec, clock->shift);
if (clocksource_register(clock)) {
printk(KERN_ERR "clocksource: %s is already registered\n",
clock->name);
return;
}
printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n",
clock->name, clock->mult, clock->shift);
}
static int decrementer_set_next_event(unsigned long evt,
struct clock_event_device *dev)
{
__get_cpu_var(decrementers).next_tb = get_tb_or_rtc() + evt;
set_dec(evt);
return 0;
}
static void decrementer_set_mode(enum clock_event_mode mode,
struct clock_event_device *dev)
{
if (mode != CLOCK_EVT_MODE_ONESHOT)
decrementer_set_next_event(DECREMENTER_MAX, dev);
}
static void __init setup_clockevent_multiplier(unsigned long hz)
{
u64 mult, shift = 32;
while (1) {
mult = div_sc(hz, NSEC_PER_SEC, shift);
if (mult && (mult >> 32UL) == 0UL)
break;
shift--;
}
decrementer_clockevent.shift = shift;
decrementer_clockevent.mult = mult;
}
static void register_decrementer_clockevent(int cpu)
{
struct clock_event_device *dec = &per_cpu(decrementers, cpu).event;
*dec = decrementer_clockevent;
dec->cpumask = cpumask_of(cpu);
printk(KERN_DEBUG "clockevent: %s mult[%lx] shift[%d] cpu[%d]\n",
dec->name, dec->mult, dec->shift, cpu);
clockevents_register_device(dec);
}
static void __init init_decrementer_clockevent(void)
{
int cpu = smp_processor_id();
setup_clockevent_multiplier(ppc_tb_freq);
decrementer_clockevent.max_delta_ns =
clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent);
decrementer_clockevent.min_delta_ns =
clockevent_delta2ns(2, &decrementer_clockevent);
register_decrementer_clockevent(cpu);
}
void secondary_cpu_time_init(void)
{
/* Start the decrementer on CPUs that have manual control
* such as BookE
*/
start_cpu_decrementer();
/* FIME: Should make unrelatred change to move snapshot_timebase
* call here ! */
register_decrementer_clockevent(smp_processor_id());
}
/* This function is only called on the boot processor */
void __init time_init(void)
{
unsigned long flags;
struct div_result res;
u64 scale, x;
unsigned shift;
if (__USE_RTC()) {
/* 601 processor: dec counts down by 128 every 128ns */
ppc_tb_freq = 1000000000;
tb_last_jiffy = get_rtcl();
} else {
/* Normal PowerPC with timebase register */
ppc_md.calibrate_decr();
printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n",
ppc_tb_freq / 1000000, ppc_tb_freq % 1000000);
printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n",
ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
tb_last_jiffy = get_tb();
}
tb_ticks_per_jiffy = ppc_tb_freq / HZ;
tb_ticks_per_sec = ppc_tb_freq;
tb_ticks_per_usec = ppc_tb_freq / 1000000;
tb_to_us = mulhwu_scale_factor(ppc_tb_freq, 1000000);
calc_cputime_factors();
/*
* Calculate the length of each tick in ns. It will not be
* exactly 1e9/HZ unless ppc_tb_freq is divisible by HZ.
* We compute 1e9 * tb_ticks_per_jiffy / ppc_tb_freq,
* rounded up.
*/
x = (u64) NSEC_PER_SEC * tb_ticks_per_jiffy + ppc_tb_freq - 1;
do_div(x, ppc_tb_freq);
tick_nsec = x;
last_tick_len = x << TICKLEN_SCALE;
/*
* Compute ticklen_to_xs, which is a factor which gets multiplied
* by (last_tick_len << TICKLEN_SHIFT) to get a tb_to_xs value.
* It is computed as:
* ticklen_to_xs = 2^N / (tb_ticks_per_jiffy * 1e9)
* where N = 64 + 20 - TICKLEN_SCALE - TICKLEN_SHIFT
* which turns out to be N = 51 - SHIFT_HZ.
* This gives the result as a 0.64 fixed-point fraction.
* That value is reduced by an offset amounting to 1 xsec per
* 2^31 timebase ticks to avoid problems with time going backwards
* by 1 xsec when we do timer_recalc_offset due to losing the
* fractional xsec. That offset is equal to ppc_tb_freq/2^51
* since there are 2^20 xsec in a second.
*/
div128_by_32((1ULL << 51) - ppc_tb_freq, 0,
tb_ticks_per_jiffy << SHIFT_HZ, &res);
div128_by_32(res.result_high, res.result_low, NSEC_PER_SEC, &res);
ticklen_to_xs = res.result_low;
/* Compute tb_to_xs from tick_nsec */
tb_to_xs = mulhdu(last_tick_len << TICKLEN_SHIFT, ticklen_to_xs);
/*
* 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;
/* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
boot_tb = get_tb_or_rtc();
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;
}
vdso_data->tb_orig_stamp = tb_last_jiffy;
vdso_data->tb_update_count = 0;
vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
vdso_data->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC;
vdso_data->tb_to_xs = tb_to_xs;
write_sequnlock_irqrestore(&xtime_lock, flags);
/* Start the decrementer on CPUs that have manual control
* such as BookE
*/
start_cpu_decrementer();
/* Register the clocksource, if we're not running on iSeries */
if (!firmware_has_feature(FW_FEATURE_ISERIES))
clocksource_init();
init_decrementer_clockevent();
}
#define FEBRUARY 2
#define STARTOFTIME 1970
#define SECDAY 86400L
#define SECYR (SECDAY * 365)
#define leapyear(year) ((year) % 4 == 0 && \
((year) % 100 != 0 || (year) % 400 == 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 was
*/
day = tm->tm_mon > 2 && leapyear(tm->tm_year);
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(u64 dividend_high, u64 dividend_low,
unsigned divisor, struct div_result *dr)
{
unsigned long a, b, c, d;
unsigned long w, x, y, z;
u64 ra, rb, rc;
a = dividend_high >> 32;
b = dividend_high & 0xffffffff;
c = dividend_low >> 32;
d = dividend_low & 0xffffffff;
w = a / divisor;
ra = ((u64)(a - (w * divisor)) << 32) + b;
rb = ((u64) do_div(ra, divisor) << 32) + c;
x = ra;
rc = ((u64) do_div(rb, divisor) << 32) + d;
y = rb;
do_div(rc, divisor);
z = rc;
dr->result_high = ((u64)w << 32) + x;
dr->result_low = ((u64)y << 32) + z;
}
/* We don't need to calibrate delay, we use the CPU timebase for that */
void calibrate_delay(void)
{
/* Some generic code (such as spinlock debug) use loops_per_jiffy
* as the number of __delay(1) in a jiffy, so make it so
*/
loops_per_jiffy = tb_ticks_per_jiffy;
}
static int __init rtc_init(void)
{
struct platform_device *pdev;
if (!ppc_md.get_rtc_time)
return -ENODEV;
pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0);
if (IS_ERR(pdev))
return PTR_ERR(pdev);
return 0;
}
module_init(rtc_init);
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