1 // SPDX-License-Identifier: GPL-2.0-or-later
8  * Converted for 64-bit by Mike Corrigan (mikejc@us.ibm.com)
11  * to make clock more stable (2.4.0-test5). The only thing
20  * - improve precision and reproducibility of timebase frequency
22  * - for astronomical applications: add a new function to get
26  * 1997-09-10  Updated NTP code according to technical memorandum Jan '96
50 #include <linux/posix-timers.h>
82 	.name         = "timebase",
154  * Factor for converting from cputime_t (timebase ticks) to
155  * microseconds. This is stored as 0.64 fixed-point binary fraction.
170  * or if that doesn't exist return the timebase value passed in.
194 	deltascaled = nowscaled - acct->startspurr;  in vtime_delta_scaled()
195 	acct->startspurr = nowscaled;  in vtime_delta_scaled()
196 	utime = acct->utime - acct->utime_sspurr;  in vtime_delta_scaled()
197 	acct->utime_sspurr = acct->utime;  in vtime_delta_scaled()
204 	 * and user time (udelta) values obtained from the timebase  in vtime_delta_scaled()
206 	 * the user ticks get saved up in paca->user_time_scaled to be  in vtime_delta_scaled()
214 			utime_scaled = deltascaled - stime_scaled;  in vtime_delta_scaled()
219 	acct->utime_scaled += utime_scaled;  in vtime_delta_scaled()
234 	stime = now - acct->starttime;  in vtime_delta()
235 	acct->starttime = now;  in vtime_delta()
254 	*stime -= min(*stime, steal_time);  in vtime_delta_kernel()
255 	acct->steal_time += steal_time;  in vtime_delta_kernel()
265 	if (tsk->flags & PF_VCPU) {  in vtime_account_kernel()
266 		acct->gtime += stime;  in vtime_account_kernel()
268 		acct->utime_scaled += stime_scaled;  in vtime_account_kernel()
271 		acct->stime += stime;  in vtime_account_kernel()
273 		acct->stime_scaled += stime_scaled;  in vtime_account_kernel()
285 	acct->idle_time += stime + steal_time;  in vtime_account_idle()
296 	acct->stime_scaled += stime_scaled;  in vtime_account_irq_field()
303 	vtime_account_irq_field(acct, &acct->softirq_time);  in vtime_account_softirq()
309 	vtime_account_irq_field(acct, &acct->hardirq_time);  in vtime_account_hardirq()
316 	if (acct->utime_scaled)  in vtime_flush_scaled()
317 		tsk->utimescaled += cputime_to_nsecs(acct->utime_scaled);  in vtime_flush_scaled()
318 	if (acct->stime_scaled)  in vtime_flush_scaled()
319 		tsk->stimescaled += cputime_to_nsecs(acct->stime_scaled);  in vtime_flush_scaled()
321 	acct->utime_scaled = 0;  in vtime_flush_scaled()
322 	acct->utime_sspurr = 0;  in vtime_flush_scaled()
323 	acct->stime_scaled = 0;  in vtime_flush_scaled()
332  * get_paca()->user_time_scaled is up to date.
338 	if (acct->utime)  in vtime_flush()
339 		account_user_time(tsk, cputime_to_nsecs(acct->utime));  in vtime_flush()
341 	if (acct->gtime)  in vtime_flush()
342 		account_guest_time(tsk, cputime_to_nsecs(acct->gtime));  in vtime_flush()
344 	if (IS_ENABLED(CONFIG_PPC_SPLPAR) && acct->steal_time) {  in vtime_flush()
345 		account_steal_time(cputime_to_nsecs(acct->steal_time));  in vtime_flush()
346 		acct->steal_time = 0;  in vtime_flush()
349 	if (acct->idle_time)  in vtime_flush()
350 		account_idle_time(cputime_to_nsecs(acct->idle_time));  in vtime_flush()
352 	if (acct->stime)  in vtime_flush()
353 		account_system_index_time(tsk, cputime_to_nsecs(acct->stime),  in vtime_flush()
356 	if (acct->hardirq_time)  in vtime_flush()
357 		account_system_index_time(tsk, cputime_to_nsecs(acct->hardirq_time),  in vtime_flush()
359 	if (acct->softirq_time)  in vtime_flush()
360 		account_system_index_time(tsk, cputime_to_nsecs(acct->softirq_time),  in vtime_flush()
365 	acct->utime = 0;  in vtime_flush()
366 	acct->gtime = 0;  in vtime_flush()
367 	acct->idle_time = 0;  in vtime_flush()
368 	acct->stime = 0;  in vtime_flush()
369 	acct->hardirq_time = 0;  in vtime_flush()
370 	acct->softirq_time = 0;  in vtime_flush()
391 		while (mftb() - start < loops)  in __delay()
410 		return regs->link;  in profile_pc()
420  * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
447 #else /* 32-bit */
460 	 * 64-bit code that uses irq soft-mask can just cause an immediate  in arch_irq_work_raise()
466 	 * level manipulations of irq soft-mask state (e.g., trace_hardirqs_on)  in arch_irq_work_raise()
504 		local_paca->irq_happened |= PACA_IRQ_DEC;  in timer_rearm_host_dec()
506 		now = *next_tb - now;  in timer_rearm_host_dec()
516  * timer_interrupt - gets called when the decrementer overflows,
535 	/* Conditionally hard-enable interrupts. */  in DEFINE_INTERRUPT_HANDLER_ASYNC()
570 		evt->event_handler(evt);  in DEFINE_INTERRUPT_HANDLER_ASYNC()
573 		now = *next_tb - now;  in DEFINE_INTERRUPT_HANDLER_ASYNC()
627  * Scheduler clock - returns current time in nanosec units.
631  * are 64-bit unsigned numbers.
635 	return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;  in sched_clock()
642  * Running clock - attempts to give a view of time passing for a virtualised
650 	 * timebase into the VTB when it takes a guest off the CPU, reading the  in running_clock()
658 		return mulhdu(get_vtb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;  in running_clock()
666 	return local_clock() - kcpustat_this_cpu->cpustat[CPUTIME_STEAL];  in running_clock()
676 	/* The cpu node should have timebase and clock frequency properties */  in get_freq()
702 	 * The watchdog may have already been enabled by u-boot. So leave  in start_cpu_decrementer()
715 	if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) &&  in generic_calibrate_decr()
716 	    !get_freq("timebase-frequency", 1, &ppc_tb_freq)) {  in generic_calibrate_decr()
718 		printk(KERN_ERR "WARNING: Estimating decrementer frequency "  in generic_calibrate_decr()
724 	if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) &&  in generic_calibrate_decr()
725 	    !get_freq("clock-frequency", 1, &ppc_proc_freq)) {  in generic_calibrate_decr()
727 		printk(KERN_ERR "WARNING: Estimating processor frequency "  in generic_calibrate_decr()
737 		return -ENODEV;  in update_persistent_clock64()
749 	ts->tv_nsec = 0;  in __read_persistent_clock()
758 			ts->tv_sec = ppc_md.get_boot_time() - timezone_offset;  in __read_persistent_clock()
763 		ts->tv_sec = 0;  in __read_persistent_clock()
768 	ts->tv_sec = rtc_tm_to_time64(&tm);  in __read_persistent_clock()
776 	if (ts->tv_sec < 0) {  in read_persistent_clock64()
777 		ts->tv_sec = 0;  in read_persistent_clock64()
778 		ts->tv_nsec = 0;  in read_persistent_clock64()
795 		       clock->name);  in clocksource_init()
800 	       clock->name, clock->mult, clock->shift);  in clocksource_init()
825 	dec->cpumask = cpumask_of(cpu);  in register_decrementer_clockevent()
830 		    dec->name, dec->mult, dec->shift, cpu);  in register_decrementer_clockevent()
833 	decrementer_clockevent.mult = dec->mult;  in register_decrementer_clockevent()
834 	decrementer_clockevent.shift = dec->shift;  in register_decrementer_clockevent()
864 	if (of_property_read_u32(cpu, "ibm,dec-bits", &bits) == 0) {  in set_decrementer_max()
866 			pr_warn("time_init: firmware supplied invalid ibm,dec-bits");  in set_decrementer_max()
871 		decrementer_max = (1ul << (bits - 1)) - 1;  in set_decrementer_max()
907 	/* Normal PowerPC with timebase register */  in time_init()
909 	printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n",  in time_init()
911 	printk(KERN_DEBUG "time_init: processor frequency   = %lu.%.6lu MHz\n",  in time_init()
922 	 * which is the timebase frequency.  in time_init()
924 	 * the 128-bit result as a 64.64 fixed-point number.  in time_init()
937 	/* Save the current timebase to pretty up CONFIG_PRINTK_TIME */  in time_init()
942 		sys_tz.tz_minuteswest = -timezone_offset / 60;  in time_init()
946 	vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;  in time_init()
968  * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
984 	ra = ((u64)(a - (w * divisor)) << 32) + b;  in div128_by_32()
995 	dr->result_high = ((u64)w << 32) + x;  in div128_by_32()
996 	dr->result_low  = ((u64)y << 32) + z;  in div128_by_32()
1000 /* We don't need to calibrate delay, we use the CPU timebase for that */
1019 		return -EOPNOTSUPP;  in rtc_generic_set_time()
1022 		return -EOPNOTSUPP;  in rtc_generic_set_time()
1037 		return -ENODEV;  in rtc_init()
1039 	pdev = platform_device_register_data(NULL, "rtc-generic", -1,  in rtc_init()