forked from Minki/linux
963e5d3b76
With some implementations, it is possible that a timer interrupt occurs every few seconds on an offline CPU. In this case, just re-arm the decrementer and return immediately Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
1171 lines
30 KiB
C
1171 lines
30 KiB
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 iSeries, we calibrate the timebase
|
|
* against the Titan chip's clock.)
|
|
* - for astronomical applications: add a new function to get
|
|
* non ambiguous timestamps even around leap seconds. This needs
|
|
* a new timestamp format and a good name.
|
|
*
|
|
* 1997-09-10 Updated NTP code according to technical memorandum Jan '96
|
|
* "A Kernel Model for Precision Timekeeping" by Dave Mills
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/errno.h>
|
|
#include <linux/module.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/param.h>
|
|
#include <linux/string.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/timex.h>
|
|
#include <linux/kernel_stat.h>
|
|
#include <linux/time.h>
|
|
#include <linux/init.h>
|
|
#include <linux/profile.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/security.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/posix-timers.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/irq_work.h>
|
|
#include <asm/trace.h>
|
|
|
|
#include <asm/io.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/nvram.h>
|
|
#include <asm/cache.h>
|
|
#include <asm/machdep.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/time.h>
|
|
#include <asm/prom.h>
|
|
#include <asm/irq.h>
|
|
#include <asm/div64.h>
|
|
#include <asm/smp.h>
|
|
#include <asm/vdso_datapage.h>
|
|
#include <asm/firmware.h>
|
|
#include <asm/cputime.h>
|
|
#ifdef CONFIG_PPC_ISERIES
|
|
#include <asm/iseries/it_lp_queue.h>
|
|
#include <asm/iseries/hv_call_xm.h>
|
|
#endif
|
|
|
|
/* powerpc clocksource/clockevent code */
|
|
|
|
#include <linux/clockchips.h>
|
|
#include <linux/clocksource.h>
|
|
|
|
static cycle_t rtc_read(struct clocksource *);
|
|
static struct clocksource clocksource_rtc = {
|
|
.name = "rtc",
|
|
.rating = 400,
|
|
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
|
|
.mask = CLOCKSOURCE_MASK(64),
|
|
.shift = 22,
|
|
.mult = 0, /* To be filled in */
|
|
.read = rtc_read,
|
|
};
|
|
|
|
static cycle_t timebase_read(struct clocksource *);
|
|
static struct clocksource clocksource_timebase = {
|
|
.name = "timebase",
|
|
.rating = 400,
|
|
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
|
|
.mask = CLOCKSOURCE_MASK(64),
|
|
.shift = 22,
|
|
.mult = 0, /* To be filled in */
|
|
.read = timebase_read,
|
|
};
|
|
|
|
#define DECREMENTER_MAX 0x7fffffff
|
|
|
|
static int decrementer_set_next_event(unsigned long evt,
|
|
struct clock_event_device *dev);
|
|
static void decrementer_set_mode(enum clock_event_mode mode,
|
|
struct clock_event_device *dev);
|
|
|
|
static struct clock_event_device decrementer_clockevent = {
|
|
.name = "decrementer",
|
|
.rating = 200,
|
|
.shift = 0, /* To be filled in */
|
|
.mult = 0, /* To be filled in */
|
|
.irq = 0,
|
|
.set_next_event = decrementer_set_next_event,
|
|
.set_mode = decrementer_set_mode,
|
|
.features = CLOCK_EVT_FEAT_ONESHOT,
|
|
};
|
|
|
|
struct decrementer_clock {
|
|
struct clock_event_device event;
|
|
u64 next_tb;
|
|
};
|
|
|
|
static DEFINE_PER_CPU(struct decrementer_clock, decrementers);
|
|
|
|
#ifdef CONFIG_PPC_ISERIES
|
|
static unsigned long __initdata iSeries_recal_titan;
|
|
static signed long __initdata iSeries_recal_tb;
|
|
|
|
/* Forward declaration is only needed for iSereis compiles */
|
|
static void __init clocksource_init(void);
|
|
#endif
|
|
|
|
#define XSEC_PER_SEC (1024*1024)
|
|
|
|
#ifdef CONFIG_PPC64
|
|
#define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC)
|
|
#else
|
|
/* compute ((xsec << 12) * max) >> 32 */
|
|
#define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max)
|
|
#endif
|
|
|
|
unsigned long tb_ticks_per_jiffy;
|
|
unsigned long tb_ticks_per_usec = 100; /* sane default */
|
|
EXPORT_SYMBOL(tb_ticks_per_usec);
|
|
unsigned long tb_ticks_per_sec;
|
|
EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */
|
|
|
|
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
|
|
/*
|
|
* Factors for converting from cputime_t (timebase ticks) to
|
|
* jiffies, milliseconds, seconds, and clock_t (1/USER_HZ seconds).
|
|
* These are all stored as 0.64 fixed-point binary fractions.
|
|
*/
|
|
u64 __cputime_jiffies_factor;
|
|
EXPORT_SYMBOL(__cputime_jiffies_factor);
|
|
u64 __cputime_msec_factor;
|
|
EXPORT_SYMBOL(__cputime_msec_factor);
|
|
u64 __cputime_sec_factor;
|
|
EXPORT_SYMBOL(__cputime_sec_factor);
|
|
u64 __cputime_clockt_factor;
|
|
EXPORT_SYMBOL(__cputime_clockt_factor);
|
|
DEFINE_PER_CPU(unsigned long, cputime_last_delta);
|
|
DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta);
|
|
|
|
cputime_t cputime_one_jiffy;
|
|
|
|
void (*dtl_consumer)(struct dtl_entry *, u64);
|
|
|
|
static void calc_cputime_factors(void)
|
|
{
|
|
struct div_result res;
|
|
|
|
div128_by_32(HZ, 0, tb_ticks_per_sec, &res);
|
|
__cputime_jiffies_factor = res.result_low;
|
|
div128_by_32(1000, 0, tb_ticks_per_sec, &res);
|
|
__cputime_msec_factor = res.result_low;
|
|
div128_by_32(1, 0, tb_ticks_per_sec, &res);
|
|
__cputime_sec_factor = res.result_low;
|
|
div128_by_32(USER_HZ, 0, tb_ticks_per_sec, &res);
|
|
__cputime_clockt_factor = res.result_low;
|
|
}
|
|
|
|
/*
|
|
* Read the SPURR on systems that have it, otherwise the PURR,
|
|
* or if that doesn't exist return the timebase value passed in.
|
|
*/
|
|
static u64 read_spurr(u64 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;
|
|
}
|
|
|
|
#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 (i == vpa->dtl_idx)
|
|
return 0;
|
|
while (i < vpa->dtl_idx) {
|
|
if (dtl_consumer)
|
|
dtl_consumer(dtl, i);
|
|
dtb = dtl->timebase;
|
|
tb_delta = dtl->enqueue_to_dispatch_time +
|
|
dtl->ready_to_enqueue_time;
|
|
barrier();
|
|
if (i + N_DISPATCH_LOG < vpa->dtl_idx) {
|
|
/* buffer has overflowed */
|
|
i = vpa->dtl_idx - N_DISPATCH_LOG;
|
|
dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
|
|
continue;
|
|
}
|
|
if (dtb > stop_tb)
|
|
break;
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
u8 save_hard_enabled = local_paca->hard_enabled;
|
|
|
|
/* 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;
|
|
local_paca->hard_enabled = 0;
|
|
|
|
sst = scan_dispatch_log(local_paca->starttime_user);
|
|
ust = scan_dispatch_log(local_paca->starttime);
|
|
local_paca->system_time -= sst;
|
|
local_paca->user_time -= ust;
|
|
local_paca->stolen_time += ust + sst;
|
|
|
|
local_paca->soft_enabled = save_soft_enabled;
|
|
local_paca->hard_enabled = save_hard_enabled;
|
|
}
|
|
|
|
static inline u64 calculate_stolen_time(u64 stop_tb)
|
|
{
|
|
u64 stolen = 0;
|
|
|
|
if (get_paca()->dtl_ridx != get_paca()->lppaca_ptr->dtl_idx) {
|
|
stolen = scan_dispatch_log(stop_tb);
|
|
get_paca()->system_time -= stolen;
|
|
}
|
|
|
|
stolen += get_paca()->stolen_time;
|
|
get_paca()->stolen_time = 0;
|
|
return stolen;
|
|
}
|
|
|
|
#else /* CONFIG_PPC_SPLPAR */
|
|
static inline u64 calculate_stolen_time(u64 stop_tb)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
#endif /* CONFIG_PPC_SPLPAR */
|
|
|
|
/*
|
|
* Account time for a transition between system, hard irq
|
|
* or soft irq state.
|
|
*/
|
|
void account_system_vtime(struct task_struct *tsk)
|
|
{
|
|
u64 now, nowscaled, delta, deltascaled;
|
|
unsigned long flags;
|
|
u64 stolen, udelta, sys_scaled, user_scaled;
|
|
|
|
local_irq_save(flags);
|
|
now = mftb();
|
|
nowscaled = read_spurr(now);
|
|
get_paca()->system_time += now - get_paca()->starttime;
|
|
get_paca()->starttime = now;
|
|
deltascaled = nowscaled - get_paca()->startspurr;
|
|
get_paca()->startspurr = nowscaled;
|
|
|
|
stolen = calculate_stolen_time(now);
|
|
|
|
delta = get_paca()->system_time;
|
|
get_paca()->system_time = 0;
|
|
udelta = get_paca()->user_time - get_paca()->utime_sspurr;
|
|
get_paca()->utime_sspurr = get_paca()->user_time;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
sys_scaled = delta;
|
|
user_scaled = udelta;
|
|
if (deltascaled != delta + udelta) {
|
|
if (udelta) {
|
|
sys_scaled = deltascaled * delta / (delta + udelta);
|
|
user_scaled = deltascaled - sys_scaled;
|
|
} else {
|
|
sys_scaled = deltascaled;
|
|
}
|
|
}
|
|
get_paca()->user_time_scaled += user_scaled;
|
|
|
|
if (in_interrupt() || idle_task(smp_processor_id()) != tsk) {
|
|
account_system_time(tsk, 0, delta, sys_scaled);
|
|
if (stolen)
|
|
account_steal_time(stolen);
|
|
} else {
|
|
account_idle_time(delta + stolen);
|
|
}
|
|
local_irq_restore(flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(account_system_vtime);
|
|
|
|
/*
|
|
* Transfer the user and system times accumulated in the paca
|
|
* by the exception entry and exit code to the generic process
|
|
* user and system time records.
|
|
* Must be called with interrupts disabled.
|
|
* Assumes that account_system_vtime() has been called recently
|
|
* (i.e. since the last entry from usermode) so that
|
|
* get_paca()->user_time_scaled is up to date.
|
|
*/
|
|
void account_process_tick(struct task_struct *tsk, int user_tick)
|
|
{
|
|
cputime_t utime, utimescaled;
|
|
|
|
utime = get_paca()->user_time;
|
|
utimescaled = get_paca()->user_time_scaled;
|
|
get_paca()->user_time = 0;
|
|
get_paca()->user_time_scaled = 0;
|
|
get_paca()->utime_sspurr = 0;
|
|
account_user_time(tsk, utime, utimescaled);
|
|
}
|
|
|
|
#else /* ! CONFIG_VIRT_CPU_ACCOUNTING */
|
|
#define calc_cputime_factors()
|
|
#endif
|
|
|
|
void __delay(unsigned long loops)
|
|
{
|
|
unsigned long start;
|
|
int diff;
|
|
|
|
if (__USE_RTC()) {
|
|
start = get_rtcl();
|
|
do {
|
|
/* the RTCL register wraps at 1000000000 */
|
|
diff = get_rtcl() - start;
|
|
if (diff < 0)
|
|
diff += 1000000000;
|
|
} while (diff < loops);
|
|
} else {
|
|
start = get_tbl();
|
|
while (get_tbl() - start < loops)
|
|
HMT_low();
|
|
HMT_medium();
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(__delay);
|
|
|
|
void udelay(unsigned long usecs)
|
|
{
|
|
__delay(tb_ticks_per_usec * usecs);
|
|
}
|
|
EXPORT_SYMBOL(udelay);
|
|
|
|
#ifdef CONFIG_SMP
|
|
unsigned long profile_pc(struct pt_regs *regs)
|
|
{
|
|
unsigned long pc = instruction_pointer(regs);
|
|
|
|
if (in_lock_functions(pc))
|
|
return regs->link;
|
|
|
|
return pc;
|
|
}
|
|
EXPORT_SYMBOL(profile_pc);
|
|
#endif
|
|
|
|
#ifdef CONFIG_PPC_ISERIES
|
|
|
|
/*
|
|
* This function recalibrates the timebase based on the 49-bit time-of-day
|
|
* value in the Titan chip. The Titan is much more accurate than the value
|
|
* returned by the service processor for the timebase frequency.
|
|
*/
|
|
|
|
static int __init iSeries_tb_recal(void)
|
|
{
|
|
unsigned long titan, tb;
|
|
|
|
/* Make sure we only run on iSeries */
|
|
if (!firmware_has_feature(FW_FEATURE_ISERIES))
|
|
return -ENODEV;
|
|
|
|
tb = get_tb();
|
|
titan = HvCallXm_loadTod();
|
|
if ( iSeries_recal_titan ) {
|
|
unsigned long tb_ticks = tb - iSeries_recal_tb;
|
|
unsigned long titan_usec = (titan - iSeries_recal_titan) >> 12;
|
|
unsigned long new_tb_ticks_per_sec = (tb_ticks * USEC_PER_SEC)/titan_usec;
|
|
unsigned long new_tb_ticks_per_jiffy =
|
|
DIV_ROUND_CLOSEST(new_tb_ticks_per_sec, HZ);
|
|
long tick_diff = new_tb_ticks_per_jiffy - tb_ticks_per_jiffy;
|
|
char sign = '+';
|
|
/* make sure tb_ticks_per_sec and tb_ticks_per_jiffy are consistent */
|
|
new_tb_ticks_per_sec = new_tb_ticks_per_jiffy * HZ;
|
|
|
|
if ( tick_diff < 0 ) {
|
|
tick_diff = -tick_diff;
|
|
sign = '-';
|
|
}
|
|
if ( tick_diff ) {
|
|
if ( tick_diff < tb_ticks_per_jiffy/25 ) {
|
|
printk( "Titan recalibrate: new tb_ticks_per_jiffy = %lu (%c%ld)\n",
|
|
new_tb_ticks_per_jiffy, sign, tick_diff );
|
|
tb_ticks_per_jiffy = new_tb_ticks_per_jiffy;
|
|
tb_ticks_per_sec = new_tb_ticks_per_sec;
|
|
calc_cputime_factors();
|
|
vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
|
|
setup_cputime_one_jiffy();
|
|
}
|
|
else {
|
|
printk( "Titan recalibrate: FAILED (difference > 4 percent)\n"
|
|
" new tb_ticks_per_jiffy = %lu\n"
|
|
" old tb_ticks_per_jiffy = %lu\n",
|
|
new_tb_ticks_per_jiffy, tb_ticks_per_jiffy );
|
|
}
|
|
}
|
|
}
|
|
iSeries_recal_titan = titan;
|
|
iSeries_recal_tb = tb;
|
|
|
|
/* Called here as now we know accurate values for the timebase */
|
|
clocksource_init();
|
|
return 0;
|
|
}
|
|
late_initcall(iSeries_tb_recal);
|
|
|
|
/* Called from platform early init */
|
|
void __init iSeries_time_init_early(void)
|
|
{
|
|
iSeries_recal_tb = get_tb();
|
|
iSeries_recal_titan = HvCallXm_loadTod();
|
|
}
|
|
#endif /* CONFIG_PPC_ISERIES */
|
|
|
|
#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;
|
|
}
|
|
|
|
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)));
|
|
}
|
|
|
|
static inline void clear_irq_work_pending(void)
|
|
{
|
|
asm volatile("stb %0,%1(13)" : :
|
|
"r" (0),
|
|
"i" (offsetof(struct paca_struct, irq_work_pending)));
|
|
}
|
|
|
|
#else /* 32-bit */
|
|
|
|
DEFINE_PER_CPU(u8, irq_work_pending);
|
|
|
|
#define set_irq_work_pending_flag() __get_cpu_var(irq_work_pending) = 1
|
|
#define test_irq_work_pending() __get_cpu_var(irq_work_pending)
|
|
#define clear_irq_work_pending() __get_cpu_var(irq_work_pending) = 0
|
|
|
|
#endif /* 32 vs 64 bit */
|
|
|
|
void set_irq_work_pending(void)
|
|
{
|
|
preempt_disable();
|
|
set_irq_work_pending_flag();
|
|
set_dec(1);
|
|
preempt_enable();
|
|
}
|
|
|
|
#else /* CONFIG_IRQ_WORK */
|
|
|
|
#define test_irq_work_pending() 0
|
|
#define clear_irq_work_pending()
|
|
|
|
#endif /* CONFIG_IRQ_WORK */
|
|
|
|
/*
|
|
* For iSeries shared processors, we have to let the hypervisor
|
|
* set the hardware decrementer. We set a virtual decrementer
|
|
* in the lppaca and call the hypervisor if the virtual
|
|
* decrementer is less than the current value in the hardware
|
|
* decrementer. (almost always the new decrementer value will
|
|
* be greater than the current hardware decementer so the hypervisor
|
|
* call will not be needed)
|
|
*/
|
|
|
|
/*
|
|
* timer_interrupt - gets called when the decrementer overflows,
|
|
* with interrupts disabled.
|
|
*/
|
|
void timer_interrupt(struct pt_regs * regs)
|
|
{
|
|
struct pt_regs *old_regs;
|
|
struct decrementer_clock *decrementer = &__get_cpu_var(decrementers);
|
|
struct clock_event_device *evt = &decrementer->event;
|
|
u64 now;
|
|
|
|
/* Ensure a positive value is written to the decrementer, or else
|
|
* some CPUs will continue to take decrementer exceptions.
|
|
*/
|
|
set_dec(DECREMENTER_MAX);
|
|
|
|
/* Some implementations of hotplug will get timer interrupts while
|
|
* offline, just ignore these
|
|
*/
|
|
if (!cpu_online(smp_processor_id()))
|
|
return;
|
|
|
|
trace_timer_interrupt_entry(regs);
|
|
|
|
__get_cpu_var(irq_stat).timer_irqs++;
|
|
|
|
#if defined(CONFIG_PPC32) && defined(CONFIG_PMAC)
|
|
if (atomic_read(&ppc_n_lost_interrupts) != 0)
|
|
do_IRQ(regs);
|
|
#endif
|
|
|
|
old_regs = set_irq_regs(regs);
|
|
irq_enter();
|
|
|
|
if (test_irq_work_pending()) {
|
|
clear_irq_work_pending();
|
|
irq_work_run();
|
|
}
|
|
|
|
#ifdef CONFIG_PPC_ISERIES
|
|
if (firmware_has_feature(FW_FEATURE_ISERIES))
|
|
get_lppaca()->int_dword.fields.decr_int = 0;
|
|
#endif
|
|
|
|
now = get_tb_or_rtc();
|
|
if (now >= decrementer->next_tb) {
|
|
decrementer->next_tb = ~(u64)0;
|
|
if (evt->event_handler)
|
|
evt->event_handler(evt);
|
|
} else {
|
|
now = decrementer->next_tb - now;
|
|
if (now <= DECREMENTER_MAX)
|
|
set_dec((int)now);
|
|
}
|
|
|
|
#ifdef CONFIG_PPC_ISERIES
|
|
if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending())
|
|
process_hvlpevents();
|
|
#endif
|
|
|
|
#ifdef CONFIG_PPC64
|
|
/* collect purr register values often, for accurate calculations */
|
|
if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
|
|
struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
|
|
cu->current_tb = mfspr(SPRN_PURR);
|
|
}
|
|
#endif
|
|
|
|
irq_exit();
|
|
set_irq_regs(old_regs);
|
|
|
|
trace_timer_interrupt_exit(regs);
|
|
}
|
|
|
|
#ifdef CONFIG_SUSPEND
|
|
static void generic_suspend_disable_irqs(void)
|
|
{
|
|
/* Disable the decrementer, so that it doesn't interfere
|
|
* with suspending.
|
|
*/
|
|
|
|
set_dec(0x7fffffff);
|
|
local_irq_disable();
|
|
set_dec(0x7fffffff);
|
|
}
|
|
|
|
static void generic_suspend_enable_irqs(void)
|
|
{
|
|
local_irq_enable();
|
|
}
|
|
|
|
/* Overrides the weak version in kernel/power/main.c */
|
|
void arch_suspend_disable_irqs(void)
|
|
{
|
|
if (ppc_md.suspend_disable_irqs)
|
|
ppc_md.suspend_disable_irqs();
|
|
generic_suspend_disable_irqs();
|
|
}
|
|
|
|
/* Overrides the weak version in kernel/power/main.c */
|
|
void arch_suspend_enable_irqs(void)
|
|
{
|
|
generic_suspend_enable_irqs();
|
|
if (ppc_md.suspend_enable_irqs)
|
|
ppc_md.suspend_enable_irqs();
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Scheduler clock - returns current time in nanosec units.
|
|
*
|
|
* Note: mulhdu(a, b) (multiply high double unsigned) returns
|
|
* the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b
|
|
* are 64-bit unsigned numbers.
|
|
*/
|
|
unsigned long long sched_clock(void)
|
|
{
|
|
if (__USE_RTC())
|
|
return get_rtc();
|
|
return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
|
|
}
|
|
|
|
static int __init get_freq(char *name, int cells, unsigned long *val)
|
|
{
|
|
struct device_node *cpu;
|
|
const unsigned int *fp;
|
|
int found = 0;
|
|
|
|
/* The cpu node should have timebase and clock frequency properties */
|
|
cpu = of_find_node_by_type(NULL, "cpu");
|
|
|
|
if (cpu) {
|
|
fp = of_get_property(cpu, name, NULL);
|
|
if (fp) {
|
|
found = 1;
|
|
*val = of_read_ulong(fp, cells);
|
|
}
|
|
|
|
of_node_put(cpu);
|
|
}
|
|
|
|
return found;
|
|
}
|
|
|
|
/* should become __cpuinit when secondary_cpu_time_init also is */
|
|
void start_cpu_decrementer(void)
|
|
{
|
|
#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
|
|
/* Clear any pending timer interrupts */
|
|
mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS);
|
|
|
|
/* Enable decrementer interrupt */
|
|
mtspr(SPRN_TCR, TCR_DIE);
|
|
#endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */
|
|
}
|
|
|
|
void __init generic_calibrate_decr(void)
|
|
{
|
|
ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
|
|
|
|
if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) &&
|
|
!get_freq("timebase-frequency", 1, &ppc_tb_freq)) {
|
|
|
|
printk(KERN_ERR "WARNING: Estimating decrementer frequency "
|
|
"(not found)\n");
|
|
}
|
|
|
|
ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */
|
|
|
|
if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) &&
|
|
!get_freq("clock-frequency", 1, &ppc_proc_freq)) {
|
|
|
|
printk(KERN_ERR "WARNING: Estimating processor frequency "
|
|
"(not found)\n");
|
|
}
|
|
}
|
|
|
|
int update_persistent_clock(struct timespec now)
|
|
{
|
|
struct rtc_time tm;
|
|
|
|
if (!ppc_md.set_rtc_time)
|
|
return 0;
|
|
|
|
to_tm(now.tv_sec + 1 + timezone_offset, &tm);
|
|
tm.tm_year -= 1900;
|
|
tm.tm_mon -= 1;
|
|
|
|
return ppc_md.set_rtc_time(&tm);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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) {
|
|
ts->tv_sec = 0;
|
|
ts->tv_nsec = 0;
|
|
}
|
|
|
|
}
|
|
|
|
/* clocksource code */
|
|
static cycle_t rtc_read(struct clocksource *cs)
|
|
{
|
|
return (cycle_t)get_rtc();
|
|
}
|
|
|
|
static cycle_t timebase_read(struct clocksource *cs)
|
|
{
|
|
return (cycle_t)get_tb();
|
|
}
|
|
|
|
void update_vsyscall(struct timespec *wall_time, struct timespec *wtm,
|
|
struct clocksource *clock, u32 mult)
|
|
{
|
|
u64 new_tb_to_xs, new_stamp_xsec;
|
|
u32 frac_sec;
|
|
|
|
if (clock != &clocksource_timebase)
|
|
return;
|
|
|
|
/* Make userspace gettimeofday spin until we're done. */
|
|
++vdso_data->tb_update_count;
|
|
smp_mb();
|
|
|
|
/* XXX this assumes clock->shift == 22 */
|
|
/* 4611686018 ~= 2^(20+64-22) / 1e9 */
|
|
new_tb_to_xs = (u64) mult * 4611686018ULL;
|
|
new_stamp_xsec = (u64) wall_time->tv_nsec * XSEC_PER_SEC;
|
|
do_div(new_stamp_xsec, 1000000000);
|
|
new_stamp_xsec += (u64) wall_time->tv_sec * XSEC_PER_SEC;
|
|
|
|
BUG_ON(wall_time->tv_nsec >= NSEC_PER_SEC);
|
|
/* this is tv_nsec / 1e9 as a 0.32 fraction */
|
|
frac_sec = ((u64) wall_time->tv_nsec * 18446744073ULL) >> 32;
|
|
|
|
/*
|
|
* tb_update_count is used to allow the userspace gettimeofday code
|
|
* to assure itself that it sees a consistent view of the tb_to_xs and
|
|
* stamp_xsec variables. It reads the tb_update_count, then reads
|
|
* tb_to_xs and stamp_xsec and then reads tb_update_count again. If
|
|
* the two values of tb_update_count match and are even then the
|
|
* tb_to_xs and stamp_xsec values are consistent. If not, then it
|
|
* loops back and reads them again until this criteria is met.
|
|
* We expect the caller to have done the first increment of
|
|
* vdso_data->tb_update_count already.
|
|
*/
|
|
vdso_data->tb_orig_stamp = clock->cycle_last;
|
|
vdso_data->stamp_xsec = new_stamp_xsec;
|
|
vdso_data->tb_to_xs = new_tb_to_xs;
|
|
vdso_data->wtom_clock_sec = wtm->tv_sec;
|
|
vdso_data->wtom_clock_nsec = wtm->tv_nsec;
|
|
vdso_data->stamp_xtime = *wall_time;
|
|
vdso_data->stamp_sec_fraction = frac_sec;
|
|
smp_wmb();
|
|
++(vdso_data->tb_update_count);
|
|
}
|
|
|
|
void update_vsyscall_tz(void)
|
|
{
|
|
/* Make userspace gettimeofday spin until we're done. */
|
|
++vdso_data->tb_update_count;
|
|
smp_mb();
|
|
vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
|
|
vdso_data->tz_dsttime = sys_tz.tz_dsttime;
|
|
smp_mb();
|
|
++vdso_data->tb_update_count;
|
|
}
|
|
|
|
static void __init clocksource_init(void)
|
|
{
|
|
struct clocksource *clock;
|
|
|
|
if (__USE_RTC())
|
|
clock = &clocksource_rtc;
|
|
else
|
|
clock = &clocksource_timebase;
|
|
|
|
clock->mult = clocksource_hz2mult(tb_ticks_per_sec, clock->shift);
|
|
|
|
if (clocksource_register(clock)) {
|
|
printk(KERN_ERR "clocksource: %s is already registered\n",
|
|
clock->name);
|
|
return;
|
|
}
|
|
|
|
printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n",
|
|
clock->name, clock->mult, clock->shift);
|
|
}
|
|
|
|
static int decrementer_set_next_event(unsigned long evt,
|
|
struct clock_event_device *dev)
|
|
{
|
|
__get_cpu_var(decrementers).next_tb = get_tb_or_rtc() + evt;
|
|
set_dec(evt);
|
|
return 0;
|
|
}
|
|
|
|
static void decrementer_set_mode(enum clock_event_mode mode,
|
|
struct clock_event_device *dev)
|
|
{
|
|
if (mode != CLOCK_EVT_MODE_ONESHOT)
|
|
decrementer_set_next_event(DECREMENTER_MAX, dev);
|
|
}
|
|
|
|
static inline uint64_t div_sc64(unsigned long ticks, unsigned long nsec,
|
|
int shift)
|
|
{
|
|
uint64_t tmp = ((uint64_t)ticks) << shift;
|
|
|
|
do_div(tmp, nsec);
|
|
return tmp;
|
|
}
|
|
|
|
static void __init setup_clockevent_multiplier(unsigned long hz)
|
|
{
|
|
u64 mult, shift = 32;
|
|
|
|
while (1) {
|
|
mult = div_sc64(hz, NSEC_PER_SEC, shift);
|
|
if (mult && (mult >> 32UL) == 0UL)
|
|
break;
|
|
|
|
shift--;
|
|
}
|
|
|
|
decrementer_clockevent.shift = shift;
|
|
decrementer_clockevent.mult = mult;
|
|
}
|
|
|
|
static void register_decrementer_clockevent(int cpu)
|
|
{
|
|
struct clock_event_device *dec = &per_cpu(decrementers, cpu).event;
|
|
|
|
*dec = decrementer_clockevent;
|
|
dec->cpumask = cpumask_of(cpu);
|
|
|
|
printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
|
|
dec->name, dec->mult, dec->shift, cpu);
|
|
|
|
clockevents_register_device(dec);
|
|
}
|
|
|
|
static void __init init_decrementer_clockevent(void)
|
|
{
|
|
int cpu = smp_processor_id();
|
|
|
|
setup_clockevent_multiplier(ppc_tb_freq);
|
|
decrementer_clockevent.max_delta_ns =
|
|
clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent);
|
|
decrementer_clockevent.min_delta_ns =
|
|
clockevent_delta2ns(2, &decrementer_clockevent);
|
|
|
|
register_decrementer_clockevent(cpu);
|
|
}
|
|
|
|
void secondary_cpu_time_init(void)
|
|
{
|
|
/* Start the decrementer on CPUs that have manual control
|
|
* such as BookE
|
|
*/
|
|
start_cpu_decrementer();
|
|
|
|
/* FIME: Should make unrelatred change to move snapshot_timebase
|
|
* call here ! */
|
|
register_decrementer_clockevent(smp_processor_id());
|
|
}
|
|
|
|
/* This function is only called on the boot processor */
|
|
void __init time_init(void)
|
|
{
|
|
struct div_result res;
|
|
u64 scale;
|
|
unsigned shift;
|
|
|
|
if (__USE_RTC()) {
|
|
/* 601 processor: dec counts down by 128 every 128ns */
|
|
ppc_tb_freq = 1000000000;
|
|
} else {
|
|
/* Normal PowerPC with timebase register */
|
|
ppc_md.calibrate_decr();
|
|
printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n",
|
|
ppc_tb_freq / 1000000, ppc_tb_freq % 1000000);
|
|
printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n",
|
|
ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
|
|
}
|
|
|
|
tb_ticks_per_jiffy = ppc_tb_freq / HZ;
|
|
tb_ticks_per_sec = ppc_tb_freq;
|
|
tb_ticks_per_usec = ppc_tb_freq / 1000000;
|
|
calc_cputime_factors();
|
|
setup_cputime_one_jiffy();
|
|
|
|
/*
|
|
* Compute scale factor for sched_clock.
|
|
* The calibrate_decr() function has set tb_ticks_per_sec,
|
|
* which is the timebase frequency.
|
|
* We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret
|
|
* the 128-bit result as a 64.64 fixed-point number.
|
|
* We then shift that number right until it is less than 1.0,
|
|
* giving us the scale factor and shift count to use in
|
|
* sched_clock().
|
|
*/
|
|
div128_by_32(1000000000, 0, tb_ticks_per_sec, &res);
|
|
scale = res.result_low;
|
|
for (shift = 0; res.result_high != 0; ++shift) {
|
|
scale = (scale >> 1) | (res.result_high << 63);
|
|
res.result_high >>= 1;
|
|
}
|
|
tb_to_ns_scale = scale;
|
|
tb_to_ns_shift = shift;
|
|
/* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
|
|
boot_tb = get_tb_or_rtc();
|
|
|
|
/* If platform provided a timezone (pmac), we correct the time */
|
|
if (timezone_offset) {
|
|
sys_tz.tz_minuteswest = -timezone_offset / 60;
|
|
sys_tz.tz_dsttime = 0;
|
|
}
|
|
|
|
vdso_data->tb_update_count = 0;
|
|
vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
|
|
|
|
/* Start the decrementer on CPUs that have manual control
|
|
* such as BookE
|
|
*/
|
|
start_cpu_decrementer();
|
|
|
|
/* Register the clocksource, if we're not running on iSeries */
|
|
if (!firmware_has_feature(FW_FEATURE_ISERIES))
|
|
clocksource_init();
|
|
|
|
init_decrementer_clockevent();
|
|
}
|
|
|
|
|
|
#define FEBRUARY 2
|
|
#define STARTOFTIME 1970
|
|
#define SECDAY 86400L
|
|
#define SECYR (SECDAY * 365)
|
|
#define leapyear(year) ((year) % 4 == 0 && \
|
|
((year) % 100 != 0 || (year) % 400 == 0))
|
|
#define days_in_year(a) (leapyear(a) ? 366 : 365)
|
|
#define days_in_month(a) (month_days[(a) - 1])
|
|
|
|
static int month_days[12] = {
|
|
31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
|
|
};
|
|
|
|
/*
|
|
* This only works for the Gregorian calendar - i.e. after 1752 (in the UK)
|
|
*/
|
|
void GregorianDay(struct rtc_time * tm)
|
|
{
|
|
int leapsToDate;
|
|
int lastYear;
|
|
int day;
|
|
int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
|
|
|
|
lastYear = tm->tm_year - 1;
|
|
|
|
/*
|
|
* Number of leap corrections to apply up to end of last year
|
|
*/
|
|
leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400;
|
|
|
|
/*
|
|
* This year is a leap year if it is divisible by 4 except when it is
|
|
* divisible by 100 unless it is divisible by 400
|
|
*
|
|
* e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was
|
|
*/
|
|
day = tm->tm_mon > 2 && leapyear(tm->tm_year);
|
|
|
|
day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] +
|
|
tm->tm_mday;
|
|
|
|
tm->tm_wday = day % 7;
|
|
}
|
|
|
|
void to_tm(int tim, struct rtc_time * tm)
|
|
{
|
|
register int i;
|
|
register long hms, day;
|
|
|
|
day = tim / SECDAY;
|
|
hms = tim % SECDAY;
|
|
|
|
/* Hours, minutes, seconds are easy */
|
|
tm->tm_hour = hms / 3600;
|
|
tm->tm_min = (hms % 3600) / 60;
|
|
tm->tm_sec = (hms % 3600) % 60;
|
|
|
|
/* Number of years in days */
|
|
for (i = STARTOFTIME; day >= days_in_year(i); i++)
|
|
day -= days_in_year(i);
|
|
tm->tm_year = i;
|
|
|
|
/* Number of months in days left */
|
|
if (leapyear(tm->tm_year))
|
|
days_in_month(FEBRUARY) = 29;
|
|
for (i = 1; day >= days_in_month(i); i++)
|
|
day -= days_in_month(i);
|
|
days_in_month(FEBRUARY) = 28;
|
|
tm->tm_mon = i;
|
|
|
|
/* Days are what is left over (+1) from all that. */
|
|
tm->tm_mday = day + 1;
|
|
|
|
/*
|
|
* Determine the day of week
|
|
*/
|
|
GregorianDay(tm);
|
|
}
|
|
|
|
/*
|
|
* Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
|
|
* result.
|
|
*/
|
|
void div128_by_32(u64 dividend_high, u64 dividend_low,
|
|
unsigned divisor, struct div_result *dr)
|
|
{
|
|
unsigned long a, b, c, d;
|
|
unsigned long w, x, y, z;
|
|
u64 ra, rb, rc;
|
|
|
|
a = dividend_high >> 32;
|
|
b = dividend_high & 0xffffffff;
|
|
c = dividend_low >> 32;
|
|
d = dividend_low & 0xffffffff;
|
|
|
|
w = a / divisor;
|
|
ra = ((u64)(a - (w * divisor)) << 32) + b;
|
|
|
|
rb = ((u64) do_div(ra, divisor) << 32) + c;
|
|
x = ra;
|
|
|
|
rc = ((u64) do_div(rb, divisor) << 32) + d;
|
|
y = rb;
|
|
|
|
do_div(rc, divisor);
|
|
z = rc;
|
|
|
|
dr->result_high = ((u64)w << 32) + x;
|
|
dr->result_low = ((u64)y << 32) + z;
|
|
|
|
}
|
|
|
|
/* We don't need to calibrate delay, we use the CPU timebase for that */
|
|
void calibrate_delay(void)
|
|
{
|
|
/* Some generic code (such as spinlock debug) use loops_per_jiffy
|
|
* as the number of __delay(1) in a jiffy, so make it so
|
|
*/
|
|
loops_per_jiffy = tb_ticks_per_jiffy;
|
|
}
|
|
|
|
static int __init rtc_init(void)
|
|
{
|
|
struct platform_device *pdev;
|
|
|
|
if (!ppc_md.get_rtc_time)
|
|
return -ENODEV;
|
|
|
|
pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0);
|
|
if (IS_ERR(pdev))
|
|
return PTR_ERR(pdev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
module_init(rtc_init);
|