Release 4.14 arch/powerpc/kernel/time.c

/*
 * 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 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/export.h>
#include <linux/sched.h>
#include <linux/sched/clock.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/clockchips.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/irq_work.h>
#include <linux/clk-provider.h>
#include <linux/suspend.h>
#include <linux/rtc.h>
#include <linux/sched/cputime.h>
#include <linux/processor.h>
#include <asm/trace.h>

#include <asm/io.h>
#include <asm/nvram.h>
#include <asm/cache.h>
#include <asm/machdep.h>
#include <linux/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/asm-prototypes.h>

/* powerpc clocksource/clockevent code */

#include <linux/clockchips.h>
#include <linux/timekeeper_internal.h>

static u64 rtc_read(struct clocksource *);

static struct clocksource clocksource_rtc = {
	.name         = "rtc",
	.rating       = 400,
	.flags        = CLOCK_SOURCE_IS_CONTINUOUS,
	.mask         = CLOCKSOURCE_MASK(64),
	.read         = rtc_read,
};

static u64 timebase_read(struct clocksource *);

static struct clocksource clocksource_timebase = {
	.name         = "timebase",
	.rating       = 400,
	.flags        = CLOCK_SOURCE_IS_CONTINUOUS,
	.mask         = CLOCKSOURCE_MASK(64),
	.read         = timebase_read,
};


#define DECREMENTER_DEFAULT_MAX 0x7FFFFFFF

u64 decrementer_max = DECREMENTER_DEFAULT_MAX;

static int decrementer_set_next_event(unsigned long evt,
				      struct clock_event_device *dev);
static int decrementer_shutdown(struct clock_event_device *evt);


struct clock_event_device decrementer_clockevent = {
	.name			= "decrementer",
	.rating			= 200,
	.irq			= 0,
	.set_next_event		= decrementer_set_next_event,
	.set_state_shutdown	= decrementer_shutdown,
	.tick_resume		= decrementer_shutdown,
	.features		= CLOCK_EVT_FEAT_ONESHOT |
				  CLOCK_EVT_FEAT_C3STOP,
};

EXPORT_SYMBOL(decrementer_clockevent);

DEFINE_PER_CPU(u64, decrementers_next_tb);
static DEFINE_PER_CPU(struct clock_event_device, decrementers);


#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 */


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 u64 boot_tb __read_mostly;

extern struct timezone sys_tz;

static long timezone_offset;


unsigned long ppc_proc_freq;

EXPORT_SYMBOL_GPL(ppc_proc_freq);

unsigned long ppc_tb_freq;

EXPORT_SYMBOL_GPL(ppc_tb_freq);

#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
/*
 * Factor for converting from cputime_t (timebase ticks) to
 * microseconds. This is stored as 0.64 fixed-point binary fraction.
 */

u64 __cputime_usec_factor;

EXPORT_SYMBOL(__cputime_usec_factor);

#ifdef CONFIG_PPC_SPLPAR

void (*dtl_consumer)(struct dtl_entry *, u64);
#endif

#ifdef CONFIG_PPC64

#define get_accounting(tsk)	(&get_paca()->accounting)
#else

#define get_accounting(tsk)	(&task_thread_info(tsk)->accounting)
#endif



static void calc_cputime_factors(void)
{
	struct div_result res;

	div128_by_32(1000000, 0, tb_ticks_per_sec, &res);
	__cputime_usec_factor = res.result_low;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
28
93.33%
1
50.00%
Andreas Schwab
2
6.67%
1
50.00%
Total
30
100.00%
2
100.00%

/*
 * Read the SPURR on systems that have it, otherwise the PURR,
 * or if that doesn't exist return the timebase value passed in.
 */


static unsigned long read_spurr(unsigned long tb)
{
	if (cpu_has_feature(CPU_FTR_SPURR))
		return mfspr(SPRN_SPURR);
	if (cpu_has_feature(CPU_FTR_PURR))
		return mfspr(SPRN_PURR);
	return tb;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
36
90.00%
2
66.67%
Christophe Leroy
4
10.00%
1
33.33%
Total
40
100.00%
3
100.00%

#ifdef CONFIG_PPC_SPLPAR

/*
 * Scan the dispatch trace log and count up the stolen time.
 * Should be called with interrupts disabled.
 */


static u64 scan_dispatch_log(u64 stop_tb)
{
	u64 i = local_paca->dtl_ridx;
	struct dtl_entry *dtl = local_paca->dtl_curr;
	struct dtl_entry *dtl_end = local_paca->dispatch_log_end;
	struct lppaca *vpa = local_paca->lppaca_ptr;
	u64 tb_delta;
	u64 stolen = 0;
	u64 dtb;

	if (!dtl)
		return 0;

	if (i == be64_to_cpu(vpa->dtl_idx))
		return 0;
	while (i < be64_to_cpu(vpa->dtl_idx)) {
		dtb = be64_to_cpu(dtl->timebase);
		tb_delta = be32_to_cpu(dtl->enqueue_to_dispatch_time) +
			be32_to_cpu(dtl->ready_to_enqueue_time);
		barrier();
		if (i + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx)) {
			/* buffer has overflowed */
			i = be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG;
			dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
			continue;
		}
		if (dtb > stop_tb)
			break;
		if (dtl_consumer)
			dtl_consumer(dtl, i);
		stolen += tb_delta;
		++i;
		++dtl;
		if (dtl == dtl_end)
			dtl = local_paca->dispatch_log;
	}
	local_paca->dtl_ridx = i;
	local_paca->dtl_curr = dtl;
	return stolen;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
158
74.53%
2
33.33%
Anton Blanchard
40
18.87%
3
50.00%
Michael Neuling
14
6.60%
1
16.67%
Total
212
100.00%
6
100.00%

/*
 * Accumulate stolen time by scanning the dispatch trace log.
 * Called on entry from user mode.
 */


void accumulate_stolen_time(void)
{
	u64 sst, ust;
	u8 save_soft_enabled = local_paca->soft_enabled;
	struct cpu_accounting_data *acct = &local_paca->accounting;

	/* We are called early in the exception entry, before
         * soft/hard_enabled are sync'ed to the expected state
         * for the exception. We are hard disabled but the PACA
         * needs to reflect that so various debug stuff doesn't
         * complain
         */
	local_paca->soft_enabled = 0;

	sst = scan_dispatch_log(acct->starttime_user);
	ust = scan_dispatch_log(acct->starttime);
	acct->stime -= sst;
	acct->utime -= ust;
	acct->steal_time += ust + sst;

	local_paca->soft_enabled = save_soft_enabled;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
31
38.75%
2
25.00%
Tejun Heo
20
25.00%
1
12.50%
Christophe Leroy
14
17.50%
1
12.50%
Milton D. Miller II
6
7.50%
1
12.50%
Michael Neuling
5
6.25%
1
12.50%
Frédéric Weisbecker
4
5.00%
2
25.00%
Total
80
100.00%
8
100.00%



static inline u64 calculate_stolen_time(u64 stop_tb)
{
	if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx))
		return scan_dispatch_log(stop_tb);

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
23
67.65%
2
33.33%
Anton Blanchard
4
11.76%
1
16.67%
Frédéric Weisbecker
3
8.82%
1
16.67%
Milton D. Miller II
3
8.82%
1
16.67%
Michael Neuling
1
2.94%
1
16.67%
Total
34
100.00%
6
100.00%

#else /* CONFIG_PPC_SPLPAR */


static inline u64 calculate_stolen_time(u64 stop_tb)
{
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
13
100.00%
2
100.00%
Total
13
100.00%
2
100.00%

#endif /* CONFIG_PPC_SPLPAR */

/*
 * Account time for a transition between system, hard irq
 * or soft irq state.
 */


static unsigned long vtime_delta(struct task_struct *tsk,
				 unsigned long *stime_scaled,
				 unsigned long *steal_time)
{
	unsigned long now, nowscaled, deltascaled;
	unsigned long stime;
	unsigned long utime, utime_scaled;
	struct cpu_accounting_data *acct = get_accounting(tsk);

	WARN_ON_ONCE(!irqs_disabled());

	now = mftb();
	nowscaled = read_spurr(now);
	stime = now - acct->starttime;
	acct->starttime = now;
	deltascaled = nowscaled - acct->startspurr;
	acct->startspurr = nowscaled;

	*steal_time = calculate_stolen_time(now);

	utime = acct->utime - acct->utime_sspurr;
	acct->utime_sspurr = acct->utime;

	/*
         * Because we don't read the SPURR on every kernel entry/exit,
         * deltascaled includes both user and system SPURR ticks.
         * Apportion these ticks to system SPURR ticks and user
         * SPURR ticks in the same ratio as the system time (delta)
         * and user time (udelta) values obtained from the timebase
         * over the same interval.  The system ticks get accounted here;
         * the user ticks get saved up in paca->user_time_scaled to be
         * used by account_process_tick.
         */
	*stime_scaled = stime;
	utime_scaled = utime;
	if (deltascaled != stime + utime) {
		if (utime) {
			*stime_scaled = deltascaled * stime / (stime + utime);
			utime_scaled = deltascaled - *stime_scaled;
		} else {
			*stime_scaled = deltascaled;
		}
	}
	acct->utime_scaled += utime_scaled;

	return stime;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
103
55.38%
2
22.22%
Frédéric Weisbecker
52
27.96%
4
44.44%
Christophe Leroy
29
15.59%
1
11.11%
Martin Schwidefsky
1
0.54%
1
11.11%
Nathan T. Lynch
1
0.54%
1
11.11%
Total
186
100.00%
9
100.00%



void vtime_account_system(struct task_struct *tsk)
{
	unsigned long stime, stime_scaled, steal_time;
	struct cpu_accounting_data *acct = get_accounting(tsk);

	stime = vtime_delta(tsk, &stime_scaled, &steal_time);

	stime -= min(stime, steal_time);
	acct->steal_time += steal_time;

	if ((tsk->flags & PF_VCPU) && !irq_count()) {
		acct->gtime += stime;
		acct->utime_scaled += stime_scaled;
	} else {
		if (hardirq_count())
			acct->hardirq_time += stime;
		else if (in_serving_softirq())
			acct->softirq_time += stime;
		else
			acct->stime += stime;

		acct->stime_scaled += stime_scaled;
	}
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Frédéric Weisbecker
106
86.18%
3
37.50%
Paul Mackerras
10
8.13%
2
25.00%
Stanislaw Gruszka
4
3.25%
1
12.50%
Christophe Leroy
2
1.63%
1
12.50%
Martin Schwidefsky
1
0.81%
1
12.50%
Total
123
100.00%
8
100.00%


EXPORT_SYMBOL_GPL(vtime_account_system);



void vtime_account_idle(struct task_struct *tsk)
{
	unsigned long stime, stime_scaled, steal_time;
	struct cpu_accounting_data *acct = get_accounting(tsk);

	stime = vtime_delta(tsk, &stime_scaled, &steal_time);
	acct->idle_time += stime + steal_time;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Frédéric Weisbecker
42
85.71%
3
42.86%
Paul Mackerras
3
6.12%
2
28.57%
Christophe Leroy
2
4.08%
1
14.29%
Martin Schwidefsky
2
4.08%
1
14.29%
Total
49
100.00%
7
100.00%

/*
 * Account the whole cputime accumulated in the paca
 * Must be called with interrupts disabled.
 * Assumes that vtime_account_system/idle() has been called
 * recently (i.e. since the last entry from usermode) so that
 * get_paca()->user_time_scaled is up to date.
 */


void vtime_flush(struct task_struct *tsk)
{
	struct cpu_accounting_data *acct = get_accounting(tsk);

	if (acct->utime)
		account_user_time(tsk, cputime_to_nsecs(acct->utime));

	if (acct->utime_scaled)
		tsk->utimescaled += cputime_to_nsecs(acct->utime_scaled);

	if (acct->gtime)
		account_guest_time(tsk, cputime_to_nsecs(acct->gtime));

	if (acct->steal_time)
		account_steal_time(cputime_to_nsecs(acct->steal_time));

	if (acct->idle_time)
		account_idle_time(cputime_to_nsecs(acct->idle_time));

	if (acct->stime)
		account_system_index_time(tsk, cputime_to_nsecs(acct->stime),
					  CPUTIME_SYSTEM);
	if (acct->stime_scaled)
		tsk->stimescaled += cputime_to_nsecs(acct->stime_scaled);

	if (acct->hardirq_time)
		account_system_index_time(tsk, cputime_to_nsecs(acct->hardirq_time),
					  CPUTIME_IRQ);
	if (acct->softirq_time)
		account_system_index_time(tsk, cputime_to_nsecs(acct->softirq_time),
					  CPUTIME_SOFTIRQ);

	acct->utime = 0;
	acct->utime_scaled = 0;
	acct->utime_sspurr = 0;
	acct->gtime = 0;
	acct->steal_time = 0;
	acct->idle_time = 0;
	acct->stime = 0;
	acct->stime_scaled = 0;
	acct->hardirq_time = 0;
	acct->softirq_time = 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Frédéric Weisbecker
196
80.99%
8
57.14%
Paul Mackerras
27
11.16%
2
14.29%
Christophe Leroy
15
6.20%
1
7.14%
Stanislaw Gruszka
2
0.83%
1
7.14%
Stephen Rothwell
1
0.41%
1
7.14%
Nathan T. Lynch
1
0.41%
1
7.14%
Total
242
100.00%
14
100.00%

#ifdef CONFIG_PPC32
/*
 * Called from the context switch with interrupts disabled, to charge all
 * accumulated times to the current process, and to prepare accounting on
 * the next process.
 */


void arch_vtime_task_switch(struct task_struct *prev)
{
	struct cpu_accounting_data *acct = get_accounting(current);

	acct->starttime = get_accounting(prev)->starttime;
	acct->startspurr = get_accounting(prev)->startspurr;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Christophe Leroy
33
78.57%
1
50.00%
Frédéric Weisbecker
9
21.43%
1
50.00%
Total
42
100.00%
2
100.00%

#endif /* CONFIG_PPC32 */

#else /* ! CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */

#define calc_cputime_factors()
#endif



void __delay(unsigned long loops)
{
	unsigned long start;
	int diff;

	spin_begin();
	if (__USE_RTC()) {
		start = get_rtcl();
		do {
			/* the RTCL register wraps at 1000000000 */
			diff = get_rtcl() - start;
			if (diff < 0)
				diff += 1000000000;
			spin_cpu_relax();
		} while (diff < loops);
	} else {
		start = get_tbl();
		while (get_tbl() - start < loops)
			spin_cpu_relax();
	}
	spin_end();
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
76
89.41%
1
50.00%
Nicholas Piggin
9
10.59%
1
50.00%
Total
85
100.00%
2
100.00%


EXPORT_SYMBOL(__delay);



void udelay(unsigned long usecs)
{
	__delay(tb_ticks_per_usec * usecs);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
16
100.00%
1
100.00%
Total
16
100.00%
1
100.00%


EXPORT_SYMBOL(udelay);

#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;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Zwane Mwaikambo
14
40.00%
1
20.00%
Tony Breeds
11
31.43%
1
20.00%
Anton Blanchard
8
22.86%
2
40.00%
Paul Mackerras
2
5.71%
1
20.00%
Total
35
100.00%
5
100.00%


EXPORT_SYMBOL(profile_pc);
#endif

#ifdef CONFIG_IRQ_WORK

/*
 * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
 */
#ifdef CONFIG_PPC64


static inline unsigned long test_irq_work_pending(void)
{
	unsigned long x;

	asm volatile("lbz %0,%1(13)"
                : "=r" (x)
                : "i" (offsetof(struct paca_struct, irq_work_pending)));
	return x;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
18
90.00%
2
66.67%
Peter Zijlstra
2
10.00%
1
33.33%
Total
20
100.00%
3
100.00%



static inline void set_irq_work_pending_flag(void)
{
	asm volatile("stb %0,%1(13)" : :
                "r" (1),
                "i" (offsetof(struct paca_struct, irq_work_pending)));
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
10
83.33%
2
66.67%
Peter Zijlstra
2
16.67%
1
33.33%
Total
12
100.00%
3
100.00%



static inline void clear_irq_work_pending(void)
{
	asm volatile("stb %0,%1(13)" : :
                "r" (0),
                "i" (offsetof(struct paca_struct, irq_work_pending)));
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
10
83.33%
1
50.00%
Peter Zijlstra
2
16.67%
1
50.00%
Total
12
100.00%
2
100.00%

#else /* 32-bit */

DEFINE_PER_CPU(u8, irq_work_pending);


#define set_irq_work_pending_flag()	__this_cpu_write(irq_work_pending, 1)

#define test_irq_work_pending()		__this_cpu_read(irq_work_pending)

#define clear_irq_work_pending()	__this_cpu_write(irq_work_pending, 0)

#endif /* 32 vs 64 bit */



void arch_irq_work_raise(void)
{
	preempt_disable();
	set_irq_work_pending_flag();
	set_dec(1);
	preempt_enable();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
19
90.48%
1
33.33%
Peter Zijlstra
2
9.52%
2
66.67%
Total
21
100.00%
3
100.00%

#else  /* CONFIG_IRQ_WORK */


#define test_irq_work_pending()	0

#define clear_irq_work_pending()

#endif /* CONFIG_IRQ_WORK */



static void __timer_interrupt(void)
{
	struct pt_regs *regs = get_irq_regs();
	u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
	struct clock_event_device *evt = this_cpu_ptr(&decrementers);
	u64 now;

	trace_timer_interrupt_entry(regs);

	if (test_irq_work_pending()) {
		clear_irq_work_pending();
		irq_work_run();
	}

	now = get_tb_or_rtc();
	if (now >= *next_tb) {
		*next_tb = ~(u64)0;
		if (evt->event_handler)
			evt->event_handler(evt);
		__this_cpu_inc(irq_stat.timer_irqs_event);
	} else {
		now = *next_tb - now;
		if (now <= decrementer_max)
			set_dec(now);
		/* We may have raced with new irq work */
		if (test_irq_work_pending())
			set_dec(1);
		__this_cpu_inc(irq_stat.timer_irqs_others);
	}

#ifdef CONFIG_PPC64
	/* collect purr register values often, for accurate calculations */
	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
		struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array);
		cu->current_tb = mfspr(SPRN_PURR);
	}
#endif

	trace_timer_interrupt_exit(regs);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
83
46.11%
5
22.73%
Anton Blanchard
21
11.67%
4
18.18%
Tony Breeds
12
6.67%
1
4.55%
Benjamin Herrenschmidt
11
6.11%
1
4.55%
Fan Du
10
5.56%
1
4.55%
Li Zhong
10
5.56%
1
4.55%
Christoph Lameter
10
5.56%
1
4.55%
Preeti U. Murthy
7
3.89%
1
4.55%
David Howells
4
2.22%
1
4.55%
Stephen Rothwell
3
1.67%
1
4.55%
Peter Zijlstra
3
1.67%
1
4.55%
Milton D. Miller II
3
1.67%
1
4.55%
Nathan T. Lynch
1
0.56%
1
4.55%
Oliver O'Halloran
1
0.56%
1
4.55%
Kumar Gala
1
0.56%
1
4.55%
Total
180
100.00%
22
100.00%

/*
 * timer_interrupt - gets called when the decrementer overflows,
 * with interrupts disabled.
 */


void timer_interrupt(struct pt_regs * regs)
{
	struct pt_regs *old_regs;
	u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);

	/* Ensure a positive value is written to the decrementer, or else
         * some CPUs will continue to take decrementer exceptions.
         */
	set_dec(decrementer_max);

	/* Some implementations of hotplug will get timer interrupts while
         * offline, just ignore these and we also need to set
         * decrementers_next_tb as MAX to make sure __check_irq_replay
         * don't replay timer interrupt when return, otherwise we'll trap
         * here infinitely :(
         */
	if (!cpu_online(smp_processor_id())) {
		*next_tb = ~(u64)0;
		return;
	}

	/* Conditionally hard-enable interrupts now that the DEC has been
         * bumped to its maximum value
         */
	may_hard_irq_enable();


#if defined(CONFIG_PPC32) && defined(CONFIG_PPC_PMAC)
	if (atomic_read(&ppc_n_lost_interrupts) != 0)
		do_IRQ(regs);
#endif

	old_regs = set_irq_regs(regs);
	irq_enter();

	__timer_interrupt();
	irq_exit();
	set_irq_regs(old_regs);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Preeti U. Murthy
93
87.74%
1
14.29%
David Howells
5
4.72%
1
14.29%
Anton Blanchard
4
3.77%
2
28.57%
Christoph Lameter
2
1.89%
1
14.29%
Oliver O'Halloran
1
0.94%
1
14.29%
Paul Bolle
1
0.94%
1
14.29%
Total
106
100.00%
7
100.00%


EXPORT_SYMBOL(timer_interrupt);

/*
 * Hypervisor decrementer interrupts shouldn't occur but are sometimes
 * left pending on exit from a KVM guest.  We don't need to do anything
 * to clear them, as they are edge-triggered.
 */


void hdec_interrupt(struct pt_regs *regs)
{
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
9
100.00%
1
100.00%
Total
9
100.00%
1
100.00%

#ifdef CONFIG_SUSPEND


static void generic_suspend_disable_irqs(void)
{
	/* Disable the decrementer, so that it doesn't interfere
         * with suspending.
         */

	set_dec(decrementer_max);
	local_irq_disable();
	set_dec(decrementer_max);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Scott Wood
19
86.36%
1
33.33%
Oliver O'Halloran
2
9.09%
1
33.33%
Paul Mackerras
1
4.55%
1
33.33%
Total
22
100.00%
3
100.00%



static void generic_suspend_enable_irqs(void)
{
	local_irq_enable();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Scott Wood
10
90.91%
1
50.00%
Paul Mackerras
1
9.09%
1
50.00%
Total
11
100.00%
2
100.00%

/* 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();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Scott Wood
21
100.00%
1
100.00%
Total
21
100.00%
1
100.00%

/* 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();
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Scott Wood
21
100.00%
1
100.00%
Total
21
100.00%
1
100.00%

#endif



unsigned long long tb_to_ns(unsigned long long ticks)
{
	return mulhdu(ticks, tb_to_ns_scale) << tb_to_ns_shift;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
22
100.00%
1
100.00%
Total
22
100.00%
1
100.00%


EXPORT_SYMBOL_GPL(tb_to_ns);

/*
 * 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.
 */


notrace 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;
}


Contributors
Person
Tokens
Prop
Commits
CommitProp
Tony Breeds
14
43.75%
1
16.67%
Andrew Morton
9
28.12%
2
33.33%
Anton Blanchard
4
12.50%
1
16.67%
Paul Mackerras
4
12.50%
1
16.67%
Santosh Sivaraj
1
3.12%
1
16.67%
Total
32
100.00%
6
100.00%

#ifdef CONFIG_PPC_PSERIES

/*
 * Running clock - attempts to give a view of time passing for a virtualised
 * kernels.
 * Uses the VTB register if available otherwise a next best guess.
 */


unsigned long long running_clock(void)
{
	/*
         * Don't read the VTB as a host since KVM does not switch in host
         * timebase into the VTB when it takes a guest off the CPU, reading the
         * VTB would result in reading 'last switched out' guest VTB.
         *
         * Host kernels are often compiled with CONFIG_PPC_PSERIES checked, it
         * would be unsafe to rely only on the #ifdef above.
         */
	if (firmware_has_feature(FW_FEATURE_LPAR) &&
	    cpu_has_feature(CPU_FTR_ARCH_207S))
		return mulhdu(get_vtb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;

	/*
         * This is a next best approximation without a VTB.
         * On a host which is running bare metal there should never be any stolen
         * time and on a host which doesn't do any virtualisation TB *should* equal
         * VTB so it makes no difference anyway.
         */
	return local_clock() - kcpustat_this_cpu->cpustat[CPUTIME_STEAL];
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Cyril Bur
47
100.00%
1
100.00%
Total
47
100.00%
1
100.00%

#endif



static int __init get_freq(char *name, int cells, unsigned long *val)
{
	struct device_node *cpu;
	const __be32 *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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Arnd Bergmann
49
55.06%
1
16.67%
Anton Blanchard
33
37.08%
2
33.33%
Paul Mackerras
5
5.62%
1
16.67%
Stephen Rothwell
1
1.12%
1
16.67%
Jeremy Kerr
1
1.12%
1
16.67%
Total
89
100.00%
6
100.00%



static void start_cpu_decrementer(void)
{
#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
	unsigned int tcr;

	/* Clear any pending timer interrupts */
	mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS);

	tcr = mfspr(SPRN_TCR);
	/*
         * The watchdog may have already been enabled by u-boot. So leave
         * TRC[WP] (Watchdog Period) alone.
         */
	tcr &= TCR_WP_MASK;	/* Clear all bits except for TCR[WP] */
	tcr |= TCR_DIE;		/* Enable decrementer */
	mtspr(SPRN_TCR, tcr);
#endif
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Benjamin Herrenschmidt
40
62.50%
1
33.33%
Ivan Mikhaylov
23
35.94%
1
33.33%
Anton Blanchard
1
1.56%
1
33.33%
Total
64
100.00%
3
100.00%



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");
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Anton Blanchard
57
67.86%
1
50.00%
Arnd Bergmann
27
32.14%
1
50.00%
Total
84
100.00%
2
100.00%



int update_persistent_clock(struct timespec now)
{
	struct rtc_time tm;

	if (!ppc_md.set_rtc_time)
		return -ENODEV;

	to_tm(now.tv_sec + 1 + timezone_offset, &tm);
	tm.tm_year -= 1900;
	tm.tm_mon -= 1;

	return ppc_md.set_rtc_time(&tm);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Tony Breeds
57
96.61%
1
50.00%
Jason Gunthorpe
2
3.39%
1
50.00%
Total
59
100.00%
2
100.00%



static 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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Paul Mackerras
64
48.85%
1
20.00%
Tony Breeds
33
25.19%
1
20.00%
Martin Schwidefsky
32
24.43%
2
40.00%
Benjamin Herrenschmidt
2
1.53%
1
20.00%
Total
131
100.00%
5
100.00%



void read_persistent_clock(struct timespec *ts)
{
	__read_persistent_clock(ts);

	/* Sanitize it in case real time clock is set below EPOCH */
	if (ts->tv_sec < 0)