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// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/ia64/kernel/time.c
*
* Copyright (C) 1998-2003 Hewlett-Packard Co
* Stephane Eranian <eranian@hpl.hp.com>
* David Mosberger <davidm@hpl.hp.com>
* Copyright (C) 1999 Don Dugger <don.dugger@intel.com>
* Copyright (C) 1999-2000 VA Linux Systems
* Copyright (C) 1999-2000 Walt Drummond <drummond@valinux.com>
*/
#include <linux/cpu.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/profile.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/nmi.h>
#include <linux/interrupt.h>
#include <linux/efi.h>
#include <linux/timex.h>
#include <linux/timekeeper_internal.h>
#include <linux/platform_device.h>
#include <linux/sched/cputime.h>
#include <asm/delay.h>
#include <asm/hw_irq.h>
#include <asm/ptrace.h>
#include <asm/sal.h>
#include <asm/sections.h>
#include "fsyscall_gtod_data.h"
static u64 itc_get_cycles(struct clocksource *cs);
struct fsyscall_gtod_data_t fsyscall_gtod_data;
struct itc_jitter_data_t itc_jitter_data;
volatile int time_keeper_id = 0; /* smp_processor_id() of time-keeper */
#ifdef CONFIG_IA64_DEBUG_IRQ
unsigned long last_cli_ip;
EXPORT_SYMBOL(last_cli_ip);
#endif
static struct clocksource clocksource_itc = {
.name = "itc",
.rating = 350,
.read = itc_get_cycles,
.mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static struct clocksource *itc_clocksource;
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
#include <linux/kernel_stat.h>
extern u64 cycle_to_nsec(u64 cyc);
void vtime_flush(struct task_struct *tsk)
{
struct thread_info *ti = task_thread_info(tsk);
u64 delta;
if (ti->utime)
account_user_time(tsk, cycle_to_nsec(ti->utime));
if (ti->gtime)
account_guest_time(tsk, cycle_to_nsec(ti->gtime));
if (ti->idle_time)
account_idle_time(cycle_to_nsec(ti->idle_time));
if (ti->stime) {
delta = cycle_to_nsec(ti->stime);
account_system_index_time(tsk, delta, CPUTIME_SYSTEM);
}
if (ti->hardirq_time) {
delta = cycle_to_nsec(ti->hardirq_time);
account_system_index_time(tsk, delta, CPUTIME_IRQ);
}
if (ti->softirq_time) {
delta = cycle_to_nsec(ti->softirq_time);
account_system_index_time(tsk, delta, CPUTIME_SOFTIRQ);
}
ti->utime = 0;
ti->gtime = 0;
ti->idle_time = 0;
ti->stime = 0;
ti->hardirq_time = 0;
ti->softirq_time = 0;
}
/*
* Called from the context switch with interrupts disabled, to charge all
* accumulated times to the current process, and to prepare accounting on
* the next process.
*/
void arch_vtime_task_switch(struct task_struct *prev)
{
struct thread_info *pi = task_thread_info(prev);
struct thread_info *ni = task_thread_info(current);
ni->ac_stamp = pi->ac_stamp;
ni->ac_stime = ni->ac_utime = 0;
}
/*
* Account time for a transition between system, hard irq or soft irq state.
* Note that this function is called with interrupts enabled.
*/
static __u64 vtime_delta(struct task_struct *tsk)
{
struct thread_info *ti = task_thread_info(tsk);
__u64 now, delta_stime;
WARN_ON_ONCE(!irqs_disabled());
now = ia64_get_itc();
delta_stime = now - ti->ac_stamp;
ti->ac_stamp = now;
return delta_stime;
}
void vtime_account_kernel(struct task_struct *tsk)
{
struct thread_info *ti = task_thread_info(tsk);
__u64 stime = vtime_delta(tsk);
if ((tsk->flags & PF_VCPU) && !irq_count())
ti->gtime += stime;
else if (hardirq_count())
ti->hardirq_time += stime;
else if (in_serving_softirq())
ti->softirq_time += stime;
else
ti->stime += stime;
}
EXPORT_SYMBOL_GPL(vtime_account_kernel);
void vtime_account_idle(struct task_struct *tsk)
{
struct thread_info *ti = task_thread_info(tsk);
ti->idle_time += vtime_delta(tsk);
}
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
static irqreturn_t
timer_interrupt (int irq, void *dev_id)
{
unsigned long new_itm;
if (cpu_is_offline(smp_processor_id())) {
return IRQ_HANDLED;
}
new_itm = local_cpu_data->itm_next;
if (!time_after(ia64_get_itc(), new_itm))
printk(KERN_ERR "Oops: timer tick before it's due (itc=%lx,itm=%lx)\n",
ia64_get_itc(), new_itm);
profile_tick(CPU_PROFILING);
while (1) {
update_process_times(user_mode(get_irq_regs()));
new_itm += local_cpu_data->itm_delta;
if (smp_processor_id() == time_keeper_id)
xtime_update(1);
local_cpu_data->itm_next = new_itm;
if (time_after(new_itm, ia64_get_itc()))
break;
/*
* Allow IPIs to interrupt the timer loop.
*/
local_irq_enable();
local_irq_disable();
}
do {
/*
* If we're too close to the next clock tick for
* comfort, we increase the safety margin by
* intentionally dropping the next tick(s). We do NOT
* update itm.next because that would force us to call
* xtime_update() which in turn would let our clock run
* too fast (with the potentially devastating effect
* of losing monotony of time).
*/
while (!time_after(new_itm, ia64_get_itc() + local_cpu_data->itm_delta/2))
new_itm += local_cpu_data->itm_delta;
ia64_set_itm(new_itm);
/* double check, in case we got hit by a (slow) PMI: */
} while (time_after_eq(ia64_get_itc(), new_itm));
return IRQ_HANDLED;
}
/*
* Encapsulate access to the itm structure for SMP.
*/
void
ia64_cpu_local_tick (void)
{
int cpu = smp_processor_id();
unsigned long shift = 0, delta;
/* arrange for the cycle counter to generate a timer interrupt: */
ia64_set_itv(IA64_TIMER_VECTOR);
delta = local_cpu_data->itm_delta;
/*
* Stagger the timer tick for each CPU so they don't occur all at (almost) the
* same time:
*/
if (cpu) {
unsigned long hi = 1UL << ia64_fls(cpu);
shift = (2*(cpu - hi) + 1) * delta/hi/2;
}
local_cpu_data->itm_next = ia64_get_itc() + delta + shift;
ia64_set_itm(local_cpu_data->itm_next);
}
static int nojitter;
static int __init nojitter_setup(char *str)
{
nojitter = 1;
printk("Jitter checking for ITC timers disabled\n");
return 1;
}
__setup("nojitter", nojitter_setup);
void ia64_init_itm(void)
{
unsigned long platform_base_freq, itc_freq;
struct pal_freq_ratio itc_ratio, proc_ratio;
long status, platform_base_drift, itc_drift;
/*
* According to SAL v2.6, we need to use a SAL call to determine the platform base
* frequency and then a PAL call to determine the frequency ratio between the ITC
* and the base frequency.
*/
status = ia64_sal_freq_base(SAL_FREQ_BASE_PLATFORM,
&platform_base_freq, &platform_base_drift);
if (status != 0) {
printk(KERN_ERR "SAL_FREQ_BASE_PLATFORM failed: %s\n", ia64_sal_strerror(status));
} else {
status = ia64_pal_freq_ratios(&proc_ratio, NULL, &itc_ratio);
if (status != 0)
printk(KERN_ERR "PAL_FREQ_RATIOS failed with status=%ld\n", status);
}
if (status != 0) {
/* invent "random" values */
printk(KERN_ERR
"SAL/PAL failed to obtain frequency info---inventing reasonable values\n");
platform_base_freq = 100000000;
platform_base_drift = -1; /* no drift info */
itc_ratio.num = 3;
itc_ratio.den = 1;
}
if (platform_base_freq < 40000000) {
printk(KERN_ERR "Platform base frequency %lu bogus---resetting to 75MHz!\n",
platform_base_freq);
platform_base_freq = 75000000;
platform_base_drift = -1;
}
if (!proc_ratio.den)
proc_ratio.den = 1; /* avoid division by zero */
if (!itc_ratio.den)
itc_ratio.den = 1; /* avoid division by zero */
itc_freq = (platform_base_freq*itc_ratio.num)/itc_ratio
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