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Commit bb59cfa4 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by Linus Torvalds
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[PATCH] seqlock for xtime 

Add "seqlock" infrastructure for doing low-overhead optimistic reader
locks (writer increments a sequence number, reader verifies that no
writers came in during the critical region, and lots of careful memory
barriers to take care of business).

Make xtime/get_jiffies_64() use this new locking.
parent 62672619
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Showing with 701 additions and 496 deletions
arch/alpha/kernel/time.c
View file @ bb59cfa4
......@@ -44,6 +44,7 @@
#include <asm/hwrpb.h>
#include <linux/mc146818rtc.h>
#include <linux/time.h>
#include <linux/timex.h>
#include "proto.h"
......@@ -51,7 +52,6 @@
u64 jiffies_64;
extern rwlock_t xtime_lock;
extern unsigned long wall_jiffies; /* kernel/timer.c */
static int set_rtc_mmss(unsigned long);
......@@ -106,7 +106,7 @@ void timer_interrupt(int irq, void *dev, struct pt_regs * regs)
alpha_do_profile(regs->pc);
#endif
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
/*
* Calculate how many ticks have passed since the last update,
......@@ -138,7 +138,7 @@ void timer_interrupt(int irq, void *dev, struct pt_regs * regs)
state.last_rtc_update = xtime.tv_sec - (tmp ? 600 : 0);
}
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
}
void
......@@ -395,10 +395,12 @@ time_init(void)
void
do_gettimeofday(struct timeval *tv)
{
unsigned long sec, usec, lost, flags;
unsigned long flags;
unsigned long sec, usec, lost, seq;
unsigned long delta_cycles, delta_usec, partial_tick;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
delta_cycles = rpcc() - state.last_time;
sec = xtime.tv_sec;
......@@ -406,7 +408,7 @@ do_gettimeofday(struct timeval *tv)
partial_tick = state.partial_tick;
lost = jiffies - wall_jiffies;
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
#ifdef CONFIG_SMP
/* Until and unless we figure out how to get cpu cycle counters
......@@ -448,7 +450,7 @@ do_settimeofday(struct timeval *tv)
unsigned long delta_usec;
long sec, usec;
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
/* The offset that is added into time in do_gettimeofday above
must be subtracted out here to keep a coherent view of the
......@@ -479,7 +481,7 @@ do_settimeofday(struct timeval *tv)
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
......
arch/arm/kernel/time.c
View file @ bb59cfa4
......@@ -34,7 +34,6 @@
u64 jiffies_64;
extern rwlock_t xtime_lock;
extern unsigned long wall_jiffies;
/* this needs a better home */
......@@ -148,9 +147,11 @@ static void do_leds(void)
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec, lost;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = gettimeoffset();
lost = jiffies - wall_jiffies;
......@@ -159,7 +160,7 @@ void do_gettimeofday(struct timeval *tv)
sec = xtime.tv_sec;
usec += xtime.tv_nsec / 1000;
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
/* usec may have gone up a lot: be safe */
while (usec >= 1000000) {
......@@ -173,7 +174,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
/*
* This is revolting. We need to set "xtime" correctly. However, the
* value in this location is the value at the most recent update of
......@@ -194,7 +195,7 @@ void do_settimeofday(struct timeval *tv)
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
static struct irqaction timer_irq = {
......
arch/i386/kernel/apm.c
View file @ bb59cfa4
......@@ -215,6 +215,7 @@
#include <linux/miscdevice.h>
#include <linux/apm_bios.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/kernel.h>
......@@ -227,7 +228,6 @@
#include <linux/sysrq.h>
extern rwlock_t xtime_lock;
extern spinlock_t i8253_lock;
extern unsigned long get_cmos_time(void);
extern void machine_real_restart(unsigned char *, int);
......@@ -1264,7 +1264,7 @@ static int suspend(int vetoable)
printk(KERN_CRIT "apm: suspend was vetoed, but suspending anyway.\n");
}
/* serialize with the timer interrupt */
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
/* protect against access to timer chip registers */
spin_lock(&i8253_lock);
......@@ -1276,7 +1276,7 @@ static int suspend(int vetoable)
ignore_normal_resume = 1;
spin_unlock(&i8253_lock);
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
if (err == APM_NO_ERROR)
err = APM_SUCCESS;
......@@ -1301,10 +1301,10 @@ static void standby(void)
int err;
/* serialize with the timer interrupt */
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
/* If needed, notify drivers here */
get_time_diff();
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
err = set_system_power_state(APM_STATE_STANDBY);
if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
......@@ -1393,9 +1393,9 @@ static void check_events(void)
ignore_bounce = 1;
if ((event != APM_NORMAL_RESUME)
|| (ignore_normal_resume == 0)) {
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
set_time();
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
pm_send_all(PM_RESUME, (void *)0);
queue_event(event, NULL);
}
......@@ -1410,9 +1410,9 @@ static void check_events(void)
break;
case APM_UPDATE_TIME:
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
set_time();
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
break;
case APM_CRITICAL_SUSPEND:
......
arch/i386/kernel/i386_ksyms.c
View file @ bb59cfa4
......@@ -15,6 +15,7 @@
#include <linux/string.h>
#include <linux/tty.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <asm/semaphore.h>
#include <asm/processor.h>
......
arch/i386/kernel/time.c
View file @ bb59cfa4
......@@ -70,7 +70,6 @@ u64 jiffies_64;
unsigned long cpu_khz; /* Detected as we calibrate the TSC */
extern rwlock_t xtime_lock;
extern unsigned long wall_jiffies;
spinlock_t rtc_lock = SPIN_LOCK_UNLOCKED;
......@@ -87,10 +86,12 @@ struct timer_opts* timer = &timer_none;
*/
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin(&xtime_lock);
usec = timer->get_offset();
{
unsigned long lost = jiffies - wall_jiffies;
......@@ -99,7 +100,7 @@ void do_gettimeofday(struct timeval *tv)
}
sec = xtime.tv_sec;
usec += (xtime.tv_nsec / 1000);
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry(&xtime_lock, seq));
while (usec >= 1000000) {
usec -= 1000000;
......@@ -112,7 +113,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
/*
* This is revolting. We need to set "xtime" correctly. However, the
* value in this location is the value at the most recent update of
......@@ -133,7 +134,7 @@ void do_settimeofday(struct timeval *tv)
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
/*
......@@ -314,14 +315,14 @@ void timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
* the irq version of write_lock because as just said we have irq
* locally disabled. -arca
*/
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
detect_lost_tick();
timer->mark_offset();
do_timer_interrupt(irq, NULL, regs);
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
}
......
arch/i386/kernel/timers/timer_pit.c
View file @ bb59cfa4
......@@ -76,7 +76,7 @@ static void delay_pit(unsigned long loops)
static unsigned long get_offset_pit(void)
{
int count;
unsigned long flags;
static int count_p = LATCH; /* for the first call after boot */
static unsigned long jiffies_p = 0;
......@@ -85,8 +85,7 @@ static unsigned long get_offset_pit(void)
*/
unsigned long jiffies_t;
/* gets recalled with irq locally disabled */
spin_lock(&i8253_lock);
spin_lock_irqsave(&i8253_lock, flags);
/* timer count may underflow right here */
outb_p(0x00, 0x43); /* latch the count ASAP */
......@@ -108,7 +107,7 @@ static unsigned long get_offset_pit(void)
count = LATCH - 1;
}
spin_unlock(&i8253_lock);
spin_unlock_irqrestore(&i8253_lock, flags);
/*
* avoiding timer inconsistencies (they are rare, but they happen)...
......
arch/ia64/kernel/time.c
View file @ bb59cfa4
......@@ -24,7 +24,6 @@
#include <asm/sal.h>
#include <asm/system.h>
extern rwlock_t xtime_lock;
extern unsigned long wall_jiffies;
extern unsigned long last_time_offset;
......@@ -89,7 +88,7 @@ gettimeoffset (void)
void
do_settimeofday (struct timeval *tv)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
{
/*
* This is revolting. We need to set "xtime" correctly. However, the value
......@@ -112,21 +111,21 @@ do_settimeofday (struct timeval *tv)
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
}
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
void
do_gettimeofday (struct timeval *tv)
{
unsigned long flags, usec, sec, old;
unsigned long seq, usec, sec, old;
read_lock_irqsave(&xtime_lock, flags);
{
do {
seq = read_seqbegin(&xtime_lock);
usec = gettimeoffset();
/*
* Ensure time never goes backwards, even when ITC on different CPUs are
* not perfectly synchronized.
* Ensure time never goes backwards, even when ITC on
* different CPUs are not perfectly synchronized.
*/
do {
old = last_time_offset;
......@@ -138,8 +137,8 @@ do_gettimeofday (struct timeval *tv)
sec = xtime.tv_sec;
usec += xtime.tv_nsec / 1000;
}
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqend(&xtime_lock, seq));
while (usec >= 1000000) {
usec -= 1000000;
......@@ -182,10 +181,10 @@ timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
* another CPU. We need to avoid to SMP race by acquiring the
* xtime_lock.
*/
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
do_timer(regs);
local_cpu_data->itm_next = new_itm;
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
} else
local_cpu_data->itm_next = new_itm;
......
arch/m68k/kernel/time.c
View file @ bb59cfa4
......@@ -22,6 +22,7 @@
#include <asm/machdep.h>
#include <asm/io.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/profile.h>
......@@ -129,25 +130,27 @@ void time_init(void)
mach_sched_init(timer_interrupt);
}
extern rwlock_t xtime_lock;
/*
* This version of gettimeofday has near microsecond resolution.
*/
void do_gettimeofday(struct timeval *tv)
{
extern unsigned long wall_jiffies;
unsigned long flags;
extern unsigned long wall_jiffies;
unsigned long seq;
unsigned long usec, sec, lost;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = mach_gettimeoffset();
lost = jiffies - wall_jiffies;
if (lost)
usec += lost * (1000000/HZ);
sec = xtime.tv_sec;
usec += xtime.tv_nsec/1000;
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
while (usec >= 1000000) {
usec -= 1000000;
......@@ -162,7 +165,7 @@ void do_settimeofday(struct timeval *tv)
{
extern unsigned long wall_jiffies;
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
/* This is revolting. We need to set the xtime.tv_nsec
* correctly. However, the value in this location is
* is value at the last tick.
......@@ -183,5 +186,5 @@ void do_settimeofday(struct timeval *tv)
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
arch/m68knommu/kernel/time.c
View file @ bb59cfa4
......@@ -18,6 +18,7 @@
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/profile.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <asm/machdep.h>
......@@ -126,21 +127,23 @@ void time_init(void)
mach_sched_init(timer_interrupt);
}
extern rwlock_t xtime_lock;
/*
* This version of gettimeofday has near microsecond resolution.
*/
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = mach_gettimeoffset ? mach_gettimeoffset() : 0;
sec = xtime.tv_sec;
usec += (xtime.tv_nsec / 1000);
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
while (usec >= 1000000) {
usec -= 1000000;
......@@ -153,7 +156,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
/* This is revolting. We need to set the xtime.tv_usec
* correctly. However, the value in this location is
* is value at the last tick.
......@@ -174,5 +177,5 @@ void do_settimeofday(struct timeval *tv)
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
arch/mips/au1000/common/time.c
View file @ bb59cfa4
......@@ -27,6 +27,7 @@
#include <linux/config.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
......@@ -44,7 +45,6 @@ unsigned long uart_baud_base;
static unsigned long r4k_offset; /* Amount to increment compare reg each time */
static unsigned long r4k_cur; /* What counter should be at next timer irq */
extern rwlock_t xtime_lock;
#define ALLINTS (IE_IRQ0 | IE_IRQ1 | IE_IRQ2 | IE_IRQ3 | IE_IRQ4 | IE_IRQ5)
......@@ -150,10 +150,10 @@ void __init time_init(void)
set_cp0_status(ALLINTS);
/* Read time from the RTC chipset. */
write_lock_irqsave (&xtime_lock, flags);
write_seqlock_irqsave (&xtime_lock, flags);
xtime.tv_sec = get_mips_time();
xtime.tv_usec = 0;
write_unlock_irqrestore(&xtime_lock, flags);
write_sequnlock_irqrestore(&xtime_lock, flags);
}
/* This is for machines which generate the exact clock. */
......@@ -229,9 +229,12 @@ static unsigned long do_fast_gettimeoffset(void)
void do_gettimeofday(struct timeval *tv)
{
unsigned int flags;
unsigned long flags;
unsigned long seq;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
read_lock_irqsave (&xtime_lock, flags);
*tv = xtime;
tv->tv_usec += do_fast_gettimeoffset();
......@@ -242,7 +245,8 @@ void do_gettimeofday(struct timeval *tv)
if (jiffies - wall_jiffies)
tv->tv_usec += USECS_PER_JIFFY;
read_unlock_irqrestore (&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
if (tv->tv_usec >= 1000000) {
tv->tv_usec -= 1000000;
......@@ -252,7 +256,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq (&xtime_lock);
write_seqlock_irq (&xtime_lock);
/* This is revolting. We need to set the xtime.tv_usec correctly.
* However, the value in this location is is value at the last tick.
......@@ -272,7 +276,7 @@ void do_settimeofday(struct timeval *tv)
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq (&xtime_lock);
write_sequnlock_irq (&xtime_lock);
}
/*
......
arch/mips/baget/time.c
View file @ bb59cfa4
......@@ -11,6 +11,7 @@
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/spinlock.h>
......@@ -23,8 +24,6 @@
#include <asm/baget/baget.h>
extern rwlock_t xtime_lock;
/*
* To have precision clock, we need to fix available clock frequency
*/
......@@ -79,20 +78,21 @@ void __init time_init(void)
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
read_lock_irqsave (&xtime_lock, flags);
do {
seq = read_seqbegin(&xtime_lock);
*tv = xtime;
read_unlock_irqrestore (&xtime_lock, flags);
} while (read_seqretry(&xtime_lock, seq));
}
void do_settimeofday(struct timeval *tv)
{
write_lock_irq (&xtime_lock);
write_seqlock_irq (&xtime_lock);
xtime = *tv;
time_adjust = 0; /* stop active adjtime() */
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq (&xtime_lock);
write_sequnlock_irq (&xtime_lock);
}
arch/mips/dec/time.c
View file @ bb59cfa4
......@@ -15,6 +15,7 @@
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/bcd.h>
......@@ -35,7 +36,6 @@
extern void (*board_time_init)(struct irqaction *irq);
extern volatile unsigned long wall_jiffies;
extern rwlock_t xtime_lock;
/*
* Change this if you have some constant time drift
......@@ -211,8 +211,10 @@ static unsigned long (*do_gettimeoffset) (void) = do_slow_gettimeoffset;
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
*tv = xtime;
tv->tv_usec += do_gettimeoffset();
......@@ -223,7 +225,8 @@ void do_gettimeofday(struct timeval *tv)
if (jiffies - wall_jiffies)
tv->tv_usec += USECS_PER_JIFFY;
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
if (tv->tv_usec >= 1000000) {
tv->tv_usec -= 1000000;
......@@ -233,7 +236,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
/* This is revolting. We need to set the xtime.tv_usec
* correctly. However, the value in this location is
......@@ -254,7 +257,7 @@ void do_settimeofday(struct timeval *tv)
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
/*
......@@ -330,6 +333,7 @@ static inline void
timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
volatile unsigned char dummy;
unsigned long seq;
dummy = CMOS_READ(RTC_REG_C); /* ACK RTC Interrupt */
......@@ -357,7 +361,9 @@ timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
* CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
* called as close as possible to 500 ms before the new second starts.
*/
read_lock(&xtime_lock);
do {
seq = read_seqbegin(&xtime_lock);
if ((time_status & STA_UNSYNC) == 0
&& xtime.tv_sec > last_rtc_update + 660
&& xtime.tv_usec >= 500000 - tick / 2
......@@ -368,12 +374,14 @@ timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
/* do it again in 60 s */
last_rtc_update = xtime.tv_sec - 600;
}
} while (read_seqretry(&xtime_lock, seq));
/* As we return to user mode fire off the other CPU schedulers.. this is
basically because we don't yet share IRQ's around. This message is
rigged to be safe on the 386 - basically it's a hack, so don't look
closely for now.. */
/*smp_message_pass(MSG_ALL_BUT_SELF, MSG_RESCHEDULE, 0L, 0); */
read_unlock(&xtime_lock);
}
static void r4k_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
......@@ -470,10 +478,10 @@ void __init time_init(void)
real_year = CMOS_READ(RTC_DEC_YEAR);
year += real_year - 72 + 2000;
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
xtime.tv_usec = 0;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
if (mips_cpu.options & MIPS_CPU_COUNTER) {
write_32bit_cp0_register(CP0_COUNT, 0);
......
arch/mips/ite-boards/generic/time.c
View file @ bb59cfa4
......@@ -27,6 +27,7 @@
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/spinlock.h>
#include <asm/mipsregs.h>
......@@ -38,7 +39,6 @@
extern void enable_cpu_timer(void);
extern volatile unsigned long wall_jiffies;
extern rwlock_t xtime_lock;
unsigned long missed_heart_beats = 0;
static long last_rtc_update = 0;
......@@ -119,6 +119,8 @@ static int set_rtc_mmss(unsigned long nowtime)
*/
void mips_timer_interrupt(struct pt_regs *regs)
{
unsigned long seq;
if (r4k_offset == 0)
goto null;
......@@ -133,7 +135,10 @@ void mips_timer_interrupt(struct pt_regs *regs)
* within 500ms before the * next second starts,
* thus the following code.
*/
read_lock(&xtime_lock);
do {
seq = read_seqbegin(&xtime_lock);
if ((time_status & STA_UNSYNC) == 0
&& xtime.tv_sec > last_rtc_update + 660
&& xtime.tv_usec >= 500000 - (tick >> 1)
......@@ -144,7 +149,8 @@ void mips_timer_interrupt(struct pt_regs *regs)
/* do it again in 60 s */
last_rtc_update = xtime.tv_sec - 600;
}
read_unlock(&xtime_lock);
} while (read_seqretry(&xtime_lock, seq));
r4k_cur += r4k_offset;
ack_r4ktimer(r4k_cur);
......@@ -247,10 +253,10 @@ void __init time_init(void)
enable_cpu_timer();
/* Read time from the RTC chipset. */
write_lock_irqsave (&xtime_lock, flags);
write_seqlock_irqsave (&xtime_lock, flags);
xtime.tv_sec = get_mips_time();
xtime.tv_usec = 0;
write_unlock_irqrestore(&xtime_lock, flags);
write_sequnlock_irqrestore(&xtime_lock, flags);
}
/* This is for machines which generate the exact clock. */
......@@ -332,20 +338,24 @@ static unsigned long do_fast_gettimeoffset(void)
void do_gettimeofday(struct timeval *tv)
{
unsigned int flags;
unsigned long flags;
unsigned int seq;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
read_lock_irqsave (&xtime_lock, flags);
*tv = xtime;
tv->tv_usec += do_fast_gettimeoffset();
/*
* xtime is atomically updated in timer_bh. jiffies - wall_jiffies
* xtime is atomically updated in timer_bh.
* jiffies - wall_jiffies
* is nonzero if the timer bottom half hasnt executed yet.
*/
if (jiffies - wall_jiffies)
tv->tv_usec += USECS_PER_JIFFY;
read_unlock_irqrestore (&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
if (tv->tv_usec >= 1000000) {
tv->tv_usec -= 1000000;
......@@ -355,7 +365,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq (&xtime_lock);
write_seqlock_irq (&xtime_lock);
/* This is revolting. We need to set the xtime.tv_usec correctly.
* However, the value in this location is is value at the last tick.
......@@ -375,5 +385,5 @@ void do_settimeofday(struct timeval *tv)
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq (&xtime_lock);
write_sequnlock_irq (&xtime_lock);
}
arch/mips/kernel/sysirix.c
View file @ bb59cfa4
......@@ -13,6 +13,7 @@
#include <linux/slab.h>
#include <linux/swap.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/times.h>
#include <linux/elf.h>
......@@ -615,19 +616,17 @@ asmlinkage int irix_getgid(struct pt_regs *regs)
return current->gid;
}
extern rwlock_t xtime_lock;
asmlinkage int irix_stime(int value)
{
if (!capable(CAP_SYS_TIME))
return -EPERM;
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
xtime.tv_sec = value;
xtime.tv_usec = 0;
time_maxerror = MAXPHASE;
time_esterror = MAXPHASE;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
return 0;
}
......
arch/mips/kernel/time.c
View file @ bb59cfa4
......@@ -37,7 +37,6 @@ u64 jiffies_64;
/*
* forward reference
*/
extern rwlock_t xtime_lock;
extern volatile unsigned long wall_jiffies;
/*
......@@ -63,19 +62,23 @@ int (*rtc_set_time)(unsigned long) = null_rtc_set_time;
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
read_lock_irqsave (&xtime_lock, flags);
*tv = xtime;
tv->tv_usec += do_gettimeoffset();
/*
* xtime is atomically updated in timer_bh. jiffies - wall_jiffies
* xtime is atomically updated in timer_bh.
* jiffies - wall_jiffies
* is nonzero if the timer bottom half hasnt executed yet.
*/
if (jiffies - wall_jiffies)
tv->tv_usec += USECS_PER_JIFFY;
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
read_unlock_irqrestore (&xtime_lock, flags);
if (tv->tv_usec >= 1000000) {
tv->tv_usec -= 1000000;
......@@ -85,7 +88,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq (&xtime_lock);
write_seqlock_irq (&xtime_lock);
/* This is revolting. We need to set the xtime.tv_usec
* correctly. However, the value in this location is
......@@ -105,7 +108,7 @@ void do_settimeofday(struct timeval *tv)
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq (&xtime_lock);
write_sequnlock_irq (&xtime_lock);
}
......@@ -291,6 +294,8 @@ unsigned long calibrate_div64_gettimeoffset(void)
*/
void timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
unsigned long seq;
if (mips_cpu.options & MIPS_CPU_COUNTER) {
unsigned int count;
......@@ -340,7 +345,9 @@ void timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
* CMOS clock accordingly every ~11 minutes. rtc_set_time() has to be
* called as close as possible to 500 ms before the new second starts.
*/
read_lock (&xtime_lock);
do {
seq = read_seqbegin(&xtime_lock);
if ((time_status & STA_UNSYNC) == 0 &&
xtime.tv_sec > last_rtc_update + 660 &&
xtime.tv_usec >= 500000 - ((unsigned) tick) / 2 &&
......@@ -352,7 +359,7 @@ void timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
/* do it again in 60 s */
}
}
read_unlock (&xtime_lock);
} while (read_seqretry(&xtime_lock, seq));
/*
* If jiffies has overflowed in this timer_interrupt we must
......
arch/mips/mips-boards/generic/time.c
View file @ bb59cfa4
......@@ -34,6 +34,7 @@
#include <asm/div64.h>
#include <linux/mc146818rtc.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <asm/mips-boards/generic.h>
......@@ -45,7 +46,6 @@ unsigned long missed_heart_beats = 0;
static unsigned long r4k_offset; /* Amount to increment compare reg each time */
static unsigned long r4k_cur; /* What counter should be at next timer irq */
extern rwlock_t xtime_lock;
#define ALLINTS (IE_IRQ0 | IE_IRQ1 | IE_IRQ2 | IE_IRQ3 | IE_IRQ4 | IE_IRQ5)
......@@ -133,7 +133,9 @@ static int set_rtc_mmss(unsigned long nowtime)
*/
void mips_timer_interrupt(struct pt_regs *regs)
{
unsigned long flags;
int irq = 7;
unsigned long seq;
if (r4k_offset == 0)
goto null;
......@@ -149,7 +151,10 @@ void mips_timer_interrupt(struct pt_regs *regs)
* within 500ms before the * next second starts,
* thus the following code.
*/
read_lock(&xtime_lock);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
if ((time_status & STA_UNSYNC) == 0
&& xtime.tv_sec > last_rtc_update + 660
&& xtime.tv_usec >= 500000 - (tick >> 1)
......@@ -159,7 +164,7 @@ void mips_timer_interrupt(struct pt_regs *regs)
else
/* do it again in 60 s */
last_rtc_update = xtime.tv_sec - 600;
read_unlock(&xtime_lock);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
if ((timer_tick_count++ % HZ) == 0) {
mips_display_message(&display_string[display_count++]);
......@@ -267,10 +272,10 @@ void __init time_init(void)
change_cp0_status(ST0_IM, ALLINTS);
/* Read time from the RTC chipset. */
write_lock_irqsave (&xtime_lock, flags);
write_seqlock_irqsave (&xtime_lock, flags);
xtime.tv_sec = get_mips_time();
xtime.tv_usec = 0;
write_unlock_irqrestore(&xtime_lock, flags);
write_sequnlock_irqrestore(&xtime_lock, flags);
}
/* This is for machines which generate the exact clock. */
......@@ -363,20 +368,24 @@ static unsigned long do_fast_gettimeoffset(void)
void do_gettimeofday(struct timeval *tv)
{
unsigned int flags;
unsigned long flags;
unsigned long seq;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
read_lock_irqsave (&xtime_lock, flags);
*tv = xtime;
tv->tv_usec += do_fast_gettimeoffset();
/*
* xtime is atomically updated in timer_bh. jiffies - wall_jiffies
* xtime is atomically updated in timer_bh.
* jiffies - wall_jiffies
* is nonzero if the timer bottom half hasnt executed yet.
*/
if (jiffies - wall_jiffies)
tv->tv_usec += USECS_PER_JIFFY;
read_unlock_irqrestore (&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
if (tv->tv_usec >= 1000000) {
tv->tv_usec -= 1000000;
......@@ -386,7 +395,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq (&xtime_lock);
write_seqlock_irq (&xtime_lock);
/* This is revolting. We need to set the xtime.tv_usec correctly.
* However, the value in this location is is value at the last tick.
......@@ -406,5 +415,5 @@ void do_settimeofday(struct timeval *tv)
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq (&xtime_lock);
write_sequnlock_irq (&xtime_lock);
}
arch/mips/philips/nino/time.c
View file @ bb59cfa4
......@@ -19,12 +19,12 @@
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/delay.h>
#include <asm/tx3912.h>
extern volatile unsigned long wall_jiffies;
extern rwlock_t xtime_lock;
static struct timeval xbase;
......@@ -62,9 +62,12 @@ void inline readRTC(unsigned long *high, unsigned long *low)
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long high, low;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
// 40 bit RTC, driven by 32khz source:
// +-----------+-----------------------------------------+
// | HHHH.HHHH | LLLL.LLLL.LLLL.LLLL.LMMM.MMMM.MMMM.MMMM |
......@@ -83,8 +86,7 @@ void do_gettimeofday(struct timeval *tv)
*/
if (jiffies - wall_jiffies)
tv->tv_usec += USECS_PER_JIFFY;
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
if (tv->tv_usec >= 1000000) {
tv->tv_usec -= 1000000;
......@@ -94,7 +96,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
/* This is revolting. We need to set the xtime.tv_usec
* correctly. However, the value in this location is
* is value at the last tick.
......@@ -118,7 +120,7 @@ void do_settimeofday(struct timeval *tv)
time_state = TIME_BAD;
time_maxerror = MAXPHASE;
time_esterror = MAXPHASE;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
static int set_rtc_mmss(unsigned long nowtime)
......
arch/mips64/mips-boards/generic/time.c
View file @ bb59cfa4
......@@ -27,6 +27,7 @@
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/spinlock.h>
#include <asm/mipsregs.h>
......@@ -44,7 +45,6 @@ unsigned long missed_heart_beats = 0;
static unsigned long r4k_offset; /* Amount to increment compare reg each time */
static unsigned long r4k_cur; /* What counter should be at next timer irq */
extern rwlock_t xtime_lock;
#define ALLINTS (IE_IRQ0 | IE_IRQ1 | IE_IRQ2 | IE_IRQ3 | IE_IRQ4 | IE_IRQ5)
......@@ -132,6 +132,8 @@ static int set_rtc_mmss(unsigned long nowtime)
*/
void mips_timer_interrupt(struct pt_regs *regs)
{
unsigned long flags;
unsigned long seq;
int irq = 7;
if (r4k_offset == 0)
......@@ -148,7 +150,9 @@ void mips_timer_interrupt(struct pt_regs *regs)
* within 500ms before the * next second starts,
* thus the following code.
*/
read_lock(&xtime_lock);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
if ((time_status & STA_UNSYNC) == 0
&& xtime.tv_sec > last_rtc_update + 660
&& xtime.tv_usec >= 500000 - (tick >> 1)
......@@ -158,7 +162,8 @@ void mips_timer_interrupt(struct pt_regs *regs)
else
/* do it again in 60 s */
last_rtc_update = xtime.tv_sec - 600;
read_unlock(&xtime_lock);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
if ((timer_tick_count++ % HZ) == 0) {
mips_display_message(&display_string[display_count++]);
......@@ -266,10 +271,10 @@ void __init time_init(void)
set_cp0_status(ST0_IM, ALLINTS);
/* Read time from the RTC chipset. */
write_lock_irqsave (&xtime_lock, flags);
write_seqlock_irqsave (&xtime_lock, flags);
xtime.tv_sec = get_mips_time();
xtime.tv_usec = 0;
write_unlock_irqrestore(&xtime_lock, flags);
write_sequnlock_irqrestore(&xtime_lock, flags);
}
/* This is for machines which generate the exact clock. */
......@@ -352,20 +357,25 @@ static unsigned long do_fast_gettimeoffset(void)
void do_gettimeofday(struct timeval *tv)
{
unsigned int flags;
unsigned long flags;
unsigned long seq;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
read_lock_irqsave (&xtime_lock, flags);
*tv = xtime;
tv->tv_usec += do_fast_gettimeoffset();
/*
* xtime is atomically updated in timer_bh. jiffies - wall_jiffies
* xtime is atomically updated in timer_bh.
* jiffies - wall_jiffies
* is nonzero if the timer bottom half hasnt executed yet.
*/
if (jiffies - wall_jiffies)
tv->tv_usec += USECS_PER_JIFFY;
read_unlock_irqrestore (&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
if (tv->tv_usec >= 1000000) {
tv->tv_usec -= 1000000;
......@@ -375,7 +385,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq (&xtime_lock);
write_seqlock_irq (&xtime_lock);
/* This is revolting. We need to set the xtime.tv_usec correctly.
* However, the value in this location is is value at the last tick.
......@@ -395,5 +405,5 @@ void do_settimeofday(struct timeval *tv)
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq (&xtime_lock);
write_sequnlock_irq (&xtime_lock);
}
arch/mips64/sgi-ip22/ip22-timer.c
View file @ bb59cfa4
......@@ -11,6 +11,7 @@
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/time.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/kernel_stat.h>
......@@ -32,8 +33,6 @@
static unsigned long r4k_offset; /* Amount to increment compare reg each time */
static unsigned long r4k_cur; /* What counter should be at next timer irq */
extern rwlock_t xtime_lock;
static inline void ack_r4ktimer(unsigned long newval)
{
write_32bit_cp0_register(CP0_COMPARE, newval);
......@@ -86,7 +85,7 @@ void indy_timer_interrupt(struct pt_regs *regs)
unsigned long count;
int irq = 7;
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
/* Ack timer and compute new compare. */
count = read_32bit_cp0_register(CP0_COUNT);
/* This has races. */
......@@ -116,7 +115,7 @@ void indy_timer_interrupt(struct pt_regs *regs)
/* do it again in 60s */
last_rtc_update = xtime.tv_sec - 600;
}
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
}
static unsigned long dosample(volatile unsigned char *tcwp,
......@@ -224,10 +223,10 @@ void __init indy_timer_init(void)
set_cp0_status(ST0_IM, ALLINTS);
sti();
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
xtime.tv_sec = get_indy_time(); /* Read time from RTC. */
xtime.tv_usec = 0;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
void indy_8254timer_irq(void)
......@@ -243,20 +242,21 @@ void indy_8254timer_irq(void)
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin(&xtime_lock);
*tv = xtime;
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry(&xtime_lock, seq));
}
void do_settimeofday(struct timeval *tv)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
xtime = *tv;
time_adjust = 0; /* stop active adjtime() */
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
arch/mips64/sgi-ip27/ip27-timer.c
View file @ bb59cfa4
......@@ -9,6 +9,7 @@
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/param.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/mm.h>
#include <linux/bcd.h>
......@@ -40,7 +41,6 @@
static unsigned long ct_cur[NR_CPUS]; /* What counter should be at next timer irq */
static long last_rtc_update; /* Last time the rtc clock got updated */
extern rwlock_t xtime_lock;
extern volatile unsigned long wall_jiffies;
......@@ -94,7 +94,7 @@ void rt_timer_interrupt(struct pt_regs *regs)
int cpuA = ((cputoslice(cpu)) == 0);
int irq = 7; /* XXX Assign number */
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
again:
LOCAL_HUB_S(cpuA ? PI_RT_PEND_A : PI_RT_PEND_B, 0); /* Ack */
......@@ -145,7 +145,7 @@ void rt_timer_interrupt(struct pt_regs *regs)
}
}
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
if (softirq_pending(cpu))
do_softirq();
......@@ -162,8 +162,11 @@ void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long usec, sec;
unsigned long seq;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
read_lock_irqsave(&xtime_lock, flags);
usec = do_gettimeoffset();
{
unsigned long lost = jiffies - wall_jiffies;
......@@ -172,7 +175,7 @@ void do_gettimeofday(struct timeval *tv)
}
sec = xtime.tv_sec;
usec += xtime.tv_usec;
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
while (usec >= 1000000) {
usec -= 1000000;
......@@ -185,7 +188,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
tv->tv_usec -= do_gettimeoffset();
tv->tv_usec -= (jiffies - wall_jiffies) * (1000000 / HZ);
......@@ -199,7 +202,7 @@ void do_settimeofday(struct timeval *tv)
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
/* Includes for ioc3_init(). */
......
arch/parisc/kernel/sys_parisc32.c
View file @ bb59cfa4
......@@ -20,6 +20,7 @@
#include <linux/resource.h>
#include <linux/times.h>
#include <linux/utsname.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
......@@ -2361,13 +2362,14 @@ asmlinkage int sys32_sysinfo(struct sysinfo32 *info)
{
struct sysinfo val;
int err;
extern rwlock_t xtime_lock;
unsigned long seq;
/* We don't need a memset here because we copy the
* struct to userspace once element at a time.
*/
read_lock_irq(&xtime_lock);
do {
seq = read_seqbegin(&xtime_lock);
val.uptime = jiffies / HZ;
val.loads[0] = avenrun[0] << (SI_LOAD_SHIFT - FSHIFT);
......@@ -2375,7 +2377,8 @@ asmlinkage int sys32_sysinfo(struct sysinfo32 *info)
val.loads[2] = avenrun[2] << (SI_LOAD_SHIFT - FSHIFT);
val.procs = nr_threads;
read_unlock_irq(&xtime_lock);
} while (read_seqretry(&xtime_lock, seq));
si_meminfo(&val);
si_swapinfo(&val);
......
arch/parisc/kernel/time.c
View file @ bb59cfa4
......@@ -36,7 +36,6 @@ u64 jiffies_64;
/* xtime and wall_jiffies keep wall-clock time */
extern unsigned long wall_jiffies;
extern rwlock_t xtime_lock;
static long clocktick; /* timer cycles per tick */
static long halftick;
......@@ -115,9 +114,9 @@ void timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
smp_do_timer(regs);
#endif
if (cpu == 0) {
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
do_timer(regs);
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
}
}
......@@ -172,16 +171,14 @@ gettimeoffset (void)
void
do_gettimeofday (struct timeval *tv)
{
unsigned long flags, usec, sec;
unsigned long flags, seq, usec, sec;
read_lock_irqsave(&xtime_lock, flags);
{
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = gettimeoffset();
sec = xtime.tv_sec;
usec += (xtime.tv_nsec / 1000);
}
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
while (usec >= 1000000) {
usec -= 1000000;
......@@ -195,7 +192,7 @@ do_gettimeofday (struct timeval *tv)
void
do_settimeofday (struct timeval *tv)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
{
/*
* This is revolting. We need to set "xtime"
......@@ -219,7 +216,7 @@ do_settimeofday (struct timeval *tv)
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
}
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
......@@ -241,10 +238,10 @@ void __init time_init(void)
mtctl(next_tick, 16);
if(pdc_tod_read(&tod_data) == 0) {
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
xtime.tv_sec = tod_data.tod_sec;
xtime.tv_nsec = tod_data.tod_usec * 1000;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
} else {
printk(KERN_ERR "Error reading tod clock\n");
xtime.tv_sec = 0;
......
arch/ppc/kernel/time.c
View file @ bb59cfa4
......@@ -76,7 +76,6 @@ extern struct timezone sys_tz;
/* keep track of when we need to update the rtc */
time_t last_rtc_update;
extern rwlock_t xtime_lock;
/* The decrementer counts down by 128 every 128ns on a 601. */
#define DECREMENTER_COUNT_601 (1000000000 / HZ)
......@@ -161,7 +160,7 @@ void timer_interrupt(struct pt_regs * regs)
continue;
/* We are in an interrupt, no need to save/restore flags */
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
tb_last_stamp = jiffy_stamp;
do_timer(regs);
......@@ -191,7 +190,7 @@ void timer_interrupt(struct pt_regs * regs)
/* Try again one minute later */
last_rtc_update += 60;
}
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
}
if ( !disarm_decr[smp_processor_id()] )
set_dec(next_dec);
......@@ -213,9 +212,11 @@ void timer_interrupt(struct pt_regs * regs)
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned delta, lost_ticks, usec, sec;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
sec = xtime.tv_sec;
usec = (xtime.tv_nsec / 1000);
delta = tb_ticks_since(tb_last_stamp);
......@@ -227,7 +228,7 @@ void do_gettimeofday(struct timeval *tv)
delta = 0;
#endif /* CONFIG_SMP */
lost_ticks = jiffies - wall_jiffies;
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
usec += mulhwu(tb_to_us, tb_ticks_per_jiffy * lost_ticks + delta);
while (usec >= 1000000) {
......@@ -243,7 +244,7 @@ void do_settimeofday(struct timeval *tv)
unsigned long flags;
int tb_delta, new_usec, new_sec;
write_lock_irqsave(&xtime_lock, flags);
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
......@@ -283,7 +284,7 @@ void do_settimeofday(struct timeval *tv)
time_state = TIME_ERROR; /* p. 24, (a) */
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irqrestore(&xtime_lock, flags);
write_sequnlock_irqrestore(&xtime_lock, flags);
}
/* This function is only called on the boot processor */
......
arch/ppc/platforms/pmac_time.c
View file @ bb59cfa4
......@@ -15,6 +15,7 @@
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/adb.h>
#include <linux/cuda.h>
#include <linux/pmu.h>
......@@ -29,8 +30,6 @@
#include <asm/time.h>
#include <asm/nvram.h>
extern rwlock_t xtime_lock;
/* Apparently the RTC stores seconds since 1 Jan 1904 */
#define RTC_OFFSET 2082844800
......@@ -215,19 +214,21 @@ time_sleep_notify(struct pmu_sleep_notifier *self, int when)
{
static unsigned long time_diff;
unsigned long flags;
unsigned long seq;
switch (when) {
case PBOOK_SLEEP_NOW:
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
time_diff = xtime.tv_sec - pmac_get_rtc_time();
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
break;
case PBOOK_WAKE:
write_lock_irqsave(&xtime_lock, flags);
write_seqlock_irqsave(&xtime_lock, flags);
xtime.tv_sec = pmac_get_rtc_time() + time_diff;
xtime.tv_nsec = 0;
last_rtc_update = xtime.tv_sec;
write_unlock_irqrestore(&xtime_lock, flags);
write_sequnlock_irqrestore(&xtime_lock, flags);
break;
}
return PBOOK_SLEEP_OK;
......
arch/ppc64/kernel/time.c
View file @ bb59cfa4
......@@ -69,7 +69,6 @@ u64 jiffies_64;
/* keep track of when we need to update the rtc */
time_t last_rtc_update;
extern rwlock_t xtime_lock;
extern int piranha_simulator;
#ifdef CONFIG_PPC_ISERIES
unsigned long iSeries_recal_titan = 0;
......@@ -284,12 +283,12 @@ int timer_interrupt(struct pt_regs * regs)
smp_local_timer_interrupt(regs);
#endif
if (cpu == boot_cpuid) {
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
tb_last_stamp = lpaca->next_jiffy_update_tb;
do_timer(regs);
timer_sync_xtime( cur_tb );
timer_check_rtc();
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
if ( adjusting_time && (time_adjust == 0) )
ppc_adjtimex();
}
......@@ -348,7 +347,7 @@ void do_settimeofday(struct timeval *tv)
long int tb_delta, new_usec, new_sec;
unsigned long new_xsec;
write_lock_irqsave(&xtime_lock, flags);
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
......@@ -399,7 +398,7 @@ void do_settimeofday(struct timeval *tv)
do_gtod.tb_orig_stamp = tb_last_stamp;
}
write_unlock_irqrestore(&xtime_lock, flags);
write_sequnlock_irqrestore(&xtime_lock, flags);
}
/*
......@@ -465,7 +464,7 @@ void __init time_init(void)
#endif
ppc_md.get_boot_time(&tm);
write_lock_irqsave(&xtime_lock, flags);
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();
......@@ -484,7 +483,7 @@ void __init time_init(void)
xtime.tv_nsec = 0;
last_rtc_update = xtime.tv_sec;
write_unlock_irqrestore(&xtime_lock, flags);
write_sequnlock_irqrestore(&xtime_lock, flags);
/* Not exact, but the timer interrupt takes care of this */
set_dec(tb_ticks_per_jiffy);
......@@ -587,7 +586,7 @@ void ppc_adjtimex(void)
new_tb_to_xs = divres.result_low;
new_xsec = mulhdu( tb_ticks, new_tb_to_xs );
write_lock_irqsave( &xtime_lock, flags );
write_seqlock_irqsave( &xtime_lock, flags );
old_xsec = mulhdu( tb_ticks, do_gtod.varp->tb_to_xs );
new_stamp_xsec = do_gtod.varp->stamp_xsec + old_xsec - new_xsec;
......@@ -609,7 +608,7 @@ void ppc_adjtimex(void)
do_gtod.varp = temp_varp;
do_gtod.var_idx = temp_idx;
write_unlock_irqrestore( &xtime_lock, flags );
write_sequnlock_irqrestore( &xtime_lock, flags );
}
......
arch/s390/kernel/time.c
View file @ bb59cfa4
......@@ -52,7 +52,6 @@ static ext_int_info_t ext_int_info_timer;
static uint64_t xtime_cc;
static uint64_t init_timer_cc;
extern rwlock_t xtime_lock;
extern unsigned long wall_jiffies;
void tod_to_timeval(__u64 todval, struct timespec *xtime)
......@@ -83,12 +82,15 @@ static inline unsigned long do_gettimeoffset(void)
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
sec = xtime.tv_sec;
usec = xtime.tv_nsec / 1000 + do_gettimeoffset();
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
while (usec >= 1000000) {
usec -= 1000000;
......@@ -102,7 +104,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
/* This is revolting. We need to set the xtime.tv_nsec
* correctly. However, the value in this location is
* is value at the last tick.
......@@ -122,7 +124,7 @@ void do_settimeofday(struct timeval *tv)
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
static inline __u32 div64_32(__u64 dividend, __u32 divisor)
......@@ -166,7 +168,7 @@ static void do_comparator_interrupt(struct pt_regs *regs, __u16 error_code)
* Do not rely on the boot cpu to do the calls to do_timer.
* Spread it over all cpus instead.
*/
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
if (S390_lowcore.jiffy_timer > xtime_cc) {
__u32 xticks;
......@@ -181,7 +183,7 @@ static void do_comparator_interrupt(struct pt_regs *regs, __u16 error_code)
while (xticks--)
do_timer(regs);
}
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
while (ticks--)
update_process_times(user_mode(regs));
#else
......
arch/s390x/kernel/time.c
View file @ bb59cfa4
......@@ -51,7 +51,6 @@ static ext_int_info_t ext_int_info_timer;
static uint64_t xtime_cc;
static uint64_t init_timer_cc;
extern rwlock_t xtime_lock;
extern unsigned long wall_jiffies;
void tod_to_timeval(__u64 todval, struct timespec *xtime)
......@@ -78,12 +77,14 @@ static inline unsigned long do_gettimeoffset(void)
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
sec = xtime.tv_sec;
usec = xtime.tv_nsec + do_gettimeoffset();
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
while (usec >= 1000000) {
usec -= 1000000;
......@@ -97,7 +98,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
/* This is revolting. We need to set the xtime.tv_usec
* correctly. However, the value in this location is
* is value at the last tick.
......@@ -117,7 +118,7 @@ void do_settimeofday(struct timeval *tv)
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
/*
......@@ -152,7 +153,7 @@ static void do_comparator_interrupt(struct pt_regs *regs, __u16 error_code)
* Do not rely on the boot cpu to do the calls to do_timer.
* Spread it over all cpus instead.
*/
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
if (S390_lowcore.jiffy_timer > xtime_cc) {
__u32 xticks;
......@@ -167,7 +168,7 @@ static void do_comparator_interrupt(struct pt_regs *regs, __u16 error_code)
while (xticks--)
do_timer(regs);
}
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
while (ticks--)
update_process_times(user_mode(regs));
#else
......
arch/sh/kernel/time.c
View file @ bb59cfa4
......@@ -72,7 +72,6 @@
u64 jiffies_64;
extern rwlock_t xtime_lock;
extern unsigned long wall_jiffies;
#define TICK_SIZE tick
......@@ -128,9 +127,11 @@ static unsigned long do_gettimeoffset(void)
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = do_gettimeoffset();
{
unsigned long lost = jiffies - wall_jiffies;
......@@ -139,7 +140,7 @@ void do_gettimeofday(struct timeval *tv)
}
sec = xtime.tv_sec;
usec += xtime.tv_usec;
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
while (usec >= 1000000) {
usec -= 1000000;
......@@ -152,7 +153,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
/*
* This is revolting. We need to set "xtime" correctly. However, the
* value in this location is the value at the most recent update of
......@@ -172,7 +173,7 @@ void do_settimeofday(struct timeval *tv)
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
/* last time the RTC clock got updated */
......@@ -231,9 +232,9 @@ static void timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
* the irq version of write_lock because as just said we have irq
* locally disabled. -arca
*/
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
do_timer_interrupt(irq, NULL, regs);
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
}
static unsigned int __init get_timer_frequency(void)
......
arch/sparc/kernel/pcic.c
View file @ bb59cfa4
......@@ -25,6 +25,7 @@
#include <linux/ctype.h>
#include <linux/pci.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/interrupt.h>
......@@ -34,8 +35,6 @@
#include <asm/timer.h>
#include <asm/uaccess.h>
extern rwlock_t xtime_lock;
#ifndef CONFIG_PCI
asmlinkage int sys_pciconfig_read(unsigned long bus,
......@@ -739,10 +738,10 @@ static void pcic_clear_clock_irq(void)
static void pcic_timer_handler (int irq, void *h, struct pt_regs *regs)
{
write_lock(&xtime_lock); /* Dummy, to show that we remember */
write_seqlock(&xtime_lock); /* Dummy, to show that we remember */
pcic_clear_clock_irq();
do_timer(regs);
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
}
#define USECS_PER_JIFFY 10000 /* We have 100HZ "standard" timer for sparc */
......@@ -795,9 +794,11 @@ extern unsigned long wall_jiffies;
static void pci_do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = do_gettimeoffset();
{
unsigned long lost = jiffies - wall_jiffies;
......@@ -806,7 +807,7 @@ static void pci_do_gettimeofday(struct timeval *tv)
}
sec = xtime.tv_sec;
usec += (xtime.tv_nsec / 1000);
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
while (usec >= 1000000) {
usec -= 1000000;
......
arch/sparc/kernel/time.c
View file @ bb59cfa4
......@@ -23,6 +23,7 @@
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/init.h>
#include <linux/pci.h>
......@@ -42,8 +43,6 @@
#include <asm/page.h>
#include <asm/pcic.h>
extern rwlock_t xtime_lock;
extern unsigned long wall_jiffies;
u64 jiffies_64;
......@@ -131,7 +130,7 @@ void timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
#endif
/* Protect counter clear so that do_gettimeoffset works */
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
#ifdef CONFIG_SUN4
if((idprom->id_machtype == (SM_SUN4 | SM_4_260)) ||
(idprom->id_machtype == (SM_SUN4 | SM_4_110))) {
......@@ -155,7 +154,7 @@ void timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
else
last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
}
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
}
/* Kick start a stopped clock (procedure from the Sun NVRAM/hostid FAQ). */
......@@ -470,9 +469,11 @@ extern __inline__ unsigned long do_gettimeoffset(void)
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = do_gettimeoffset();
{
unsigned long lost = jiffies - wall_jiffies;
......@@ -481,7 +482,7 @@ void do_gettimeofday(struct timeval *tv)
}
sec = xtime.tv_sec;
usec += (xtime.tv_nsec / 1000);
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
while (usec >= 1000000) {
usec -= 1000000;
......@@ -494,9 +495,9 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
bus_do_settimeofday(tv);
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
static void sbus_do_settimeofday(struct timeval *tv)
......
arch/sparc64/kernel/time.c
View file @ bb59cfa4
......@@ -17,6 +17,7 @@
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/init.h>
#include <linux/ioport.h>
......@@ -37,8 +38,6 @@
#include <asm/isa.h>
#include <asm/starfire.h>
extern rwlock_t xtime_lock;
spinlock_t mostek_lock = SPIN_LOCK_UNLOCKED;
spinlock_t rtc_lock = SPIN_LOCK_UNLOCKED;
unsigned long mstk48t02_regs = 0UL;
......@@ -134,7 +133,7 @@ static void timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
unsigned long ticks, pstate;
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
do {
#ifndef CONFIG_SMP
......@@ -196,13 +195,13 @@ static void timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
timer_check_rtc();
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
}
#ifdef CONFIG_SMP
void timer_tick_interrupt(struct pt_regs *regs)
{
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
do_timer(regs);
......@@ -225,7 +224,7 @@ void timer_tick_interrupt(struct pt_regs *regs)
timer_check_rtc();
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
}
#endif
......@@ -665,7 +664,7 @@ void do_settimeofday(struct timeval *tv)
if (this_is_starfire)
return;
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
/*
* This is revolting. We need to set "xtime" correctly. However, the
* value in this location is the value at the most recent update of
......@@ -686,7 +685,7 @@ void do_settimeofday(struct timeval *tv)
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
/* Ok, my cute asm atomicity trick doesn't work anymore.
......@@ -696,9 +695,11 @@ void do_settimeofday(struct timeval *tv)
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long seq;
unsigned long usec, sec;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
usec = do_gettimeoffset();
{
unsigned long lost = jiffies - wall_jiffies;
......@@ -707,7 +708,7 @@ void do_gettimeofday(struct timeval *tv)
}
sec = xtime.tv_sec;
usec += (xtime.tv_nsec / 1000);
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
while (usec >= 1000000) {
usec -= 1000000;
......
arch/um/kernel/time_kern.c
View file @ bb59cfa4
......@@ -7,6 +7,7 @@
#include "linux/unistd.h"
#include "linux/stddef.h"
#include "linux/spinlock.h"
#include "linux/time.h"
#include "linux/sched.h"
#include "linux/interrupt.h"
#include "linux/init.h"
......@@ -21,8 +22,6 @@
u64 jiffies_64;
extern rwlock_t xtime_lock;
int hz(void)
{
return(HZ);
......@@ -57,9 +56,9 @@ void boot_timer_handler(int sig)
void um_timer(int irq, void *dev, struct pt_regs *regs)
{
do_timer(regs);
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
timer();
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
}
long um_time(int * tloc)
......
arch/v850/kernel/time.c
View file @ bb59cfa4
......@@ -17,6 +17,7 @@
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/profile.h>
......@@ -107,8 +108,6 @@ static void timer_interrupt (int irq, void *dummy, struct pt_regs *regs)
#endif /* 0 */
}
extern rwlock_t xtime_lock;
/*
* This version of gettimeofday has near microsecond resolution.
*/
......@@ -120,8 +119,11 @@ void do_gettimeofday (struct timeval *tv)
#endif
unsigned long flags;
unsigned long usec, sec;
unsigned long seq;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
read_lock_irqsave (&xtime_lock, flags);
#if 0
usec = mach_gettimeoffset ? mach_gettimeoffset () : 0;
#else
......@@ -134,7 +136,7 @@ void do_gettimeofday (struct timeval *tv)
#endif
sec = xtime.tv_sec;
usec += xtime.tv_nsec / 1000;
read_unlock_irqrestore (&xtime_lock, flags);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
while (usec >= 1000000) {
usec -= 1000000;
......@@ -147,7 +149,7 @@ void do_gettimeofday (struct timeval *tv)
void do_settimeofday (struct timeval *tv)
{
write_lock_irq (&xtime_lock);
write_seqlock_irq (&xtime_lock);
/* This is revolting. We need to set the xtime.tv_nsec
* correctly. However, the value in this location is
......@@ -172,7 +174,7 @@ void do_settimeofday (struct timeval *tv)
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq (&xtime_lock);
write_sequnlock_irq (&xtime_lock);
}
static int timer_dev_id;
......
arch/x86_64/kernel/time.c
View file @ bb59cfa4
......@@ -18,6 +18,7 @@
#include <linux/init.h>
#include <linux/mc146818rtc.h>
#include <linux/irq.h>
#include <linux/time.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/device.h>
......@@ -27,7 +28,6 @@
u64 jiffies_64;
extern rwlock_t xtime_lock;
spinlock_t rtc_lock = SPIN_LOCK_UNLOCKED;
unsigned int cpu_khz; /* TSC clocks / usec, not used here */
......@@ -70,11 +70,12 @@ inline unsigned int do_gettimeoffset(void)
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags, t;
unsigned long flags, t, seq;
unsigned int sec, usec;
read_lock_irqsave(&xtime_lock, flags);
spin_lock(&time_offset_lock);
spin_lock_irqsave(&time_offset_lock, flags);
do {
seq = read_seqbegin(&xtime_lock);
sec = xtime.tv_sec;
usec = xtime.tv_nsec / 1000;
......@@ -83,8 +84,8 @@ void do_gettimeofday(struct timeval *tv)
if (t > timeoffset) timeoffset = t;
usec += timeoffset;
spin_unlock(&time_offset_lock);
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry(&xtime_lock, seq));
spin_unlock_irqrestore(&time_offset_lock, flags);
tv->tv_sec = sec + usec / 1000000;
tv->tv_usec = usec % 1000000;
......@@ -98,7 +99,7 @@ void do_gettimeofday(struct timeval *tv)
void do_settimeofday(struct timeval *tv)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
vxtime_lock();
tv->tv_usec -= do_gettimeoffset() +
......@@ -118,7 +119,7 @@ void do_settimeofday(struct timeval *tv)
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
/*
......@@ -201,7 +202,7 @@ static void timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
* variables, because both do_timer() and us change them -arca+vojtech
*/
write_lock(&xtime_lock);
write_seqlock(&xtime_lock);
vxtime_lock();
{
......@@ -251,7 +252,7 @@ static void timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
}
vxtime_unlock();
write_unlock(&xtime_lock);
write_sequnlock(&xtime_lock);
}
unsigned long get_cmos_time(void)
......
include/linux/jiffies.h
View file @ bb59cfa4
......@@ -3,6 +3,7 @@
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/seqlock.h>
#include <asm/system.h>
#include <asm/param.h> /* for HZ */
......@@ -17,13 +18,15 @@ extern unsigned long volatile jiffies;
static inline u64 get_jiffies_64(void)
{
#if BITS_PER_LONG < 64
extern rwlock_t xtime_lock;
unsigned long flags;
extern seqlock_t xtime_lock;
unsigned long seq;
u64 tmp;
read_lock_irqsave(&xtime_lock, flags);
do {
seq = read_seqbegin(&xtime_lock);
tmp = jiffies_64;
read_unlock_irqrestore(&xtime_lock, flags);
} while (read_seqretry(&xtime_lock, seq));
return tmp;
#else
return (u64)jiffies;
......
include/linux/seqlock.h 0 → 100644
View file @ bb59cfa4
#ifndef __LINUX_SEQLOCK_H
#define __LINUX_SEQLOCK_H
/*
* Reader/writer consistent mechanism without starving writers. This type of
* lock for data where the reader wants a consitent set of information
* and is willing to retry if the information changes. Readers never
* block but they may have to retry if a writer is in
* progress. Writers do not wait for readers.
*
* This is not as cache friendly as brlock. Also, this will not work
* for data that contains pointers, because any writer could
* invalidate a pointer that a reader was following.
*
* Expected reader usage:
* do {
* seq = read_seqbegin(&foo);
* ...
* } while (read_seqretry(&foo, seq));
*
*
* On non-SMP the spin locks disappear but the writer still needs
* to increment the sequence variables because an interrupt routine could
* change the state of the data.
*
* Based on x86_64 vsyscall gettimeofday
* by Keith Owens and Andrea Arcangeli
*/
#include <linux/config.h>
#include <linux/spinlock.h>
#include <linux/preempt.h>
typedef struct {
unsigned sequence;
spinlock_t lock;
} seqlock_t;
/*
* These macros triggered gcc-3.x compile-time problems. We think these are
* OK now. Be cautious.
*/
#define SEQLOCK_UNLOCKED { 0, SPIN_LOCK_UNLOCKED }
#define seqlock_init(x) do { *(x) = (seqlock_t) SEQLOCK_UNLOCKED; } while (0)
/* Lock out other writers and update the count.
* Acts like a normal spin_lock/unlock.
* Don't need preempt_disable() because that is in the spin_lock already.
*/
static inline void write_seqlock(seqlock_t *sl)
{
spin_lock(&sl->lock);
++sl->sequence;
smp_wmb();
}
static inline void write_sequnlock(seqlock_t *sl)
{
smp_wmb();
sl->sequence++;
spin_unlock(&sl->lock);
}
static inline int write_tryseqlock(seqlock_t *sl)
{
int ret = spin_trylock(&sl->lock);
if (ret) {
++sl->sequence;
smp_wmb();
}
return ret;
}
/* Start of read calculation -- fetch last complete writer token */
static inline unsigned read_seqbegin(const seqlock_t *sl)
{
unsigned ret = sl->sequence;
smp_rmb();
return ret;
}
/* Test if reader processed invalid data.
* If initial values is odd,
* then writer had already started when section was entered
* If sequence value changed
* then writer changed data while in section
*
* Using xor saves one conditional branch.
*/
static inline int read_seqretry(const seqlock_t *sl, unsigned iv)
{
smp_rmb();
return (iv & 1) | (sl->sequence ^ iv);
}
/*
* Possible sw/hw IRQ protected versions of the interfaces.
*/
#define write_seqlock_irqsave(lock, flags) \
do { local_irq_save(flags); write_seqlock(lock); } while (0)
#define write_seqlock_irq(lock) \
do { local_irq_disable(); write_seqlock(lock); } while (0)
#define write_seqlock_bh(lock) \
do { local_bh_disable(); write_seqlock(lock); } while (0)
#define write_sequnlock_irqrestore(lock, flags) \
do { write_sequnlock(lock); local_irq_restore(flags); } while(0)
#define write_sequnlock_irq(lock) \
do { write_sequnlock(lock); local_irq_enable(); } while(0)
#define write_sequnlock_bh(lock) \
do { write_sequnlock(lock); local_bh_enable(); } while(0)
#define read_seqbegin_irqsave(lock, flags) \
({ local_irq_save(flags); read_seqbegin(lock); })
#define read_seqretry_irqrestore(lock, iv, flags) \
({int ret = read_seqretry(&(lock)->seq, iv); \
local_irq_restore(flags); \
ret; \
})
#endif /* __LINUX_SEQLOCK_H */
include/linux/time.h
View file @ bb59cfa4
......@@ -25,6 +25,7 @@ struct timezone {
#ifdef __KERNEL__
#include <linux/spinlock.h>
#include <linux/seqlock.h>
/*
* Change timeval to jiffies, trying to avoid the
......@@ -120,7 +121,7 @@ mktime (unsigned int year, unsigned int mon,
}
extern struct timespec xtime;
extern rwlock_t xtime_lock;
extern seqlock_t xtime_lock;
static inline unsigned long get_seconds(void)
{
......
kernel/ksyms.c
View file @ bb59cfa4
......@@ -55,6 +55,7 @@
#include <linux/dnotify.h>
#include <linux/mount.h>
#include <linux/ptrace.h>
#include <linux/time.h>
#include <asm/checksum.h>
#if defined(CONFIG_PROC_FS)
......@@ -485,6 +486,7 @@ EXPORT_SYMBOL(kernel_flag);
EXPORT_SYMBOL(jiffies);
EXPORT_SYMBOL(jiffies_64);
EXPORT_SYMBOL(xtime);
EXPORT_SYMBOL(xtime_lock);
EXPORT_SYMBOL(do_gettimeofday);
EXPORT_SYMBOL(do_settimeofday);
#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
......
kernel/time.c
View file @ bb59cfa4
......@@ -36,9 +36,6 @@
*/
struct timezone sys_tz;
/* The xtime_lock is not only serializing the xtime read/writes but it's also
serializing all accesses to the global NTP variables now. */
extern rwlock_t xtime_lock;
extern unsigned long last_time_offset;
#if !defined(__alpha__) && !defined(__ia64__)
......@@ -80,7 +77,7 @@ asmlinkage long sys_stime(int * tptr)
return -EPERM;
if (get_user(value, tptr))
return -EFAULT;
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
xtime.tv_sec = value;
xtime.tv_nsec = 0;
last_time_offset = 0;
......@@ -88,7 +85,7 @@ asmlinkage long sys_stime(int * tptr)
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
return 0;
}
......@@ -96,13 +93,13 @@ asmlinkage long sys_stime(int * tptr)
asmlinkage long sys_gettimeofday(struct timeval *tv, struct timezone *tz)
{
if (tv) {
if (likely(tv != NULL)) {
struct timeval ktv;
do_gettimeofday(&ktv);
if (copy_to_user(tv, &ktv, sizeof(ktv)))
return -EFAULT;
}
if (tz) {
if (unlikely(tz != NULL)) {
if (copy_to_user(tz, &sys_tz, sizeof(sys_tz)))
return -EFAULT;
}
......@@ -127,10 +124,10 @@ asmlinkage long sys_gettimeofday(struct timeval *tv, struct timezone *tz)
*/
inline static void warp_clock(void)
{
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
xtime.tv_sec += sys_tz.tz_minuteswest * 60;
last_time_offset = 0;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
}
/*
......@@ -235,7 +232,7 @@ int do_adjtimex(struct timex *txc)
txc->tick > 1100000/USER_HZ)
return -EINVAL;
write_lock_irq(&xtime_lock);
write_seqlock_irq(&xtime_lock);
result = time_state; /* mostly `TIME_OK' */
/* Save for later - semantics of adjtime is to return old value */
......@@ -386,7 +383,7 @@ leave: if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0
txc->errcnt = pps_errcnt;
txc->stbcnt = pps_stbcnt;
last_time_offset = 0;
write_unlock_irq(&xtime_lock);
write_sequnlock_irq(&xtime_lock);
do_gettimeofday(&txc->time);
return(result);
}
......@@ -409,9 +406,13 @@ asmlinkage long sys_adjtimex(struct timex *txc_p)
struct timespec current_kernel_time(void)
{
struct timespec now;
unsigned long flags;
read_lock_irqsave(&xtime_lock,flags);
unsigned long seq;
do {
seq = read_seqbegin(&xtime_lock);
now = xtime;
read_unlock_irqrestore(&xtime_lock,flags);
} while (read_seqretry(&xtime_lock, seq));
return now;
}
kernel/timer.c
View file @ bb59cfa4
......@@ -26,6 +26,7 @@
#include <linux/mm.h>
#include <linux/notifier.h>
#include <linux/thread_info.h>
#include <linux/time.h>
#include <linux/jiffies.h>
#include <asm/uaccess.h>
......@@ -760,7 +761,7 @@ unsigned long wall_jiffies;
* This read-write spinlock protects us from races in SMP while
* playing with xtime and avenrun.
*/
rwlock_t xtime_lock __cacheline_aligned_in_smp = RW_LOCK_UNLOCKED;
seqlock_t xtime_lock __cacheline_aligned_in_smp = SEQLOCK_UNLOCKED;
unsigned long last_time_offset;
/*
......@@ -801,7 +802,7 @@ static inline void update_times(void)
/*
* The 64-bit jiffies value is not atomic - you MUST NOT read it
* without holding read_lock_irq(&xtime_lock).
* without sampling the sequence number in xtime_lock.
* jiffies is defined in the linker script...
*/
......@@ -1090,10 +1091,13 @@ asmlinkage long sys_sysinfo(struct sysinfo *info)
u64 uptime;
unsigned long mem_total, sav_total;
unsigned int mem_unit, bitcount;
unsigned long seq;
memset((char *)&val, 0, sizeof(struct sysinfo));
read_lock_irq(&xtime_lock);
do {
seq = read_seqbegin(&xtime_lock);
uptime = jiffies_64;
do_div(uptime, HZ);
val.uptime = (unsigned long) uptime;
......@@ -1103,7 +1107,7 @@ asmlinkage long sys_sysinfo(struct sysinfo *info)
val.loads[2] = avenrun[2] << (SI_LOAD_SHIFT - FSHIFT);
val.procs = nr_threads;
read_unlock_irq(&xtime_lock);
} while (read_seqretry(&xtime_lock, seq));
si_meminfo(&val);
si_swapinfo(&val);
......@@ -1148,7 +1152,7 @@ asmlinkage long sys_sysinfo(struct sysinfo *info)
val.totalhigh <<= bitcount;
val.freehigh <<= bitcount;
out:
out:
if (copy_to_user(info, &val, sizeof(struct sysinfo)))
return -EFAULT;
......
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