| /* |
| * Common time routines among all ppc machines. |
| * |
| * Written by Cort Dougan (cort@cs.nmt.edu) to merge |
| * Paul Mackerras' version and mine for PReP and Pmac. |
| * MPC8xx/MBX changes by Dan Malek (dmalek@jlc.net). |
| * Converted for 64-bit by Mike Corrigan (mikejc@us.ibm.com) |
| * |
| * First round of bugfixes by Gabriel Paubert (paubert@iram.es) |
| * to make clock more stable (2.4.0-test5). The only thing |
| * that this code assumes is that the timebases have been synchronized |
| * by firmware on SMP and are never stopped (never do sleep |
| * on SMP then, nap and doze are OK). |
| * |
| * Speeded up do_gettimeofday by getting rid of references to |
| * xtime (which required locks for consistency). (mikejc@us.ibm.com) |
| * |
| * TODO (not necessarily in this file): |
| * - improve precision and reproducibility of timebase frequency |
| * measurement at boot time. |
| * - for astronomical applications: add a new function to get |
| * non ambiguous timestamps even around leap seconds. This needs |
| * a new timestamp format and a good name. |
| * |
| * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 |
| * "A Kernel Model for Precision Timekeeping" by Dave Mills |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #include <linux/errno.h> |
| #include <linux/export.h> |
| #include <linux/sched.h> |
| #include <linux/sched/clock.h> |
| #include <linux/kernel.h> |
| #include <linux/param.h> |
| #include <linux/string.h> |
| #include <linux/mm.h> |
| #include <linux/interrupt.h> |
| #include <linux/timex.h> |
| #include <linux/kernel_stat.h> |
| #include <linux/time.h> |
| #include <linux/clockchips.h> |
| #include <linux/init.h> |
| #include <linux/profile.h> |
| #include <linux/cpu.h> |
| #include <linux/security.h> |
| #include <linux/percpu.h> |
| #include <linux/rtc.h> |
| #include <linux/jiffies.h> |
| #include <linux/posix-timers.h> |
| #include <linux/irq.h> |
| #include <linux/delay.h> |
| #include <linux/irq_work.h> |
| #include <linux/clk-provider.h> |
| #include <linux/suspend.h> |
| #include <linux/sched/cputime.h> |
| #include <linux/processor.h> |
| #include <asm/trace.h> |
| |
| #include <asm/io.h> |
| #include <asm/nvram.h> |
| #include <asm/cache.h> |
| #include <asm/machdep.h> |
| #include <linux/uaccess.h> |
| #include <asm/time.h> |
| #include <asm/prom.h> |
| #include <asm/irq.h> |
| #include <asm/div64.h> |
| #include <asm/smp.h> |
| #include <asm/vdso_datapage.h> |
| #include <asm/firmware.h> |
| #include <asm/asm-prototypes.h> |
| |
| /* powerpc clocksource/clockevent code */ |
| |
| #include <linux/clockchips.h> |
| #include <linux/timekeeper_internal.h> |
| |
| static u64 rtc_read(struct clocksource *); |
| static struct clocksource clocksource_rtc = { |
| .name = "rtc", |
| .rating = 400, |
| .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
| .mask = CLOCKSOURCE_MASK(64), |
| .read = rtc_read, |
| }; |
| |
| static u64 timebase_read(struct clocksource *); |
| static struct clocksource clocksource_timebase = { |
| .name = "timebase", |
| .rating = 400, |
| .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
| .mask = CLOCKSOURCE_MASK(64), |
| .read = timebase_read, |
| }; |
| |
| #define DECREMENTER_DEFAULT_MAX 0x7FFFFFFF |
| u64 decrementer_max = DECREMENTER_DEFAULT_MAX; |
| |
| static int decrementer_set_next_event(unsigned long evt, |
| struct clock_event_device *dev); |
| static int decrementer_shutdown(struct clock_event_device *evt); |
| |
| struct clock_event_device decrementer_clockevent = { |
| .name = "decrementer", |
| .rating = 200, |
| .irq = 0, |
| .set_next_event = decrementer_set_next_event, |
| .set_state_oneshot_stopped = decrementer_shutdown, |
| .set_state_shutdown = decrementer_shutdown, |
| .tick_resume = decrementer_shutdown, |
| .features = CLOCK_EVT_FEAT_ONESHOT | |
| CLOCK_EVT_FEAT_C3STOP, |
| }; |
| EXPORT_SYMBOL(decrementer_clockevent); |
| |
| DEFINE_PER_CPU(u64, decrementers_next_tb); |
| static DEFINE_PER_CPU(struct clock_event_device, decrementers); |
| |
| #define XSEC_PER_SEC (1024*1024) |
| |
| #ifdef CONFIG_PPC64 |
| #define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC) |
| #else |
| /* compute ((xsec << 12) * max) >> 32 */ |
| #define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max) |
| #endif |
| |
| unsigned long tb_ticks_per_jiffy; |
| unsigned long tb_ticks_per_usec = 100; /* sane default */ |
| EXPORT_SYMBOL(tb_ticks_per_usec); |
| unsigned long tb_ticks_per_sec; |
| EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */ |
| |
| DEFINE_SPINLOCK(rtc_lock); |
| EXPORT_SYMBOL_GPL(rtc_lock); |
| |
| static u64 tb_to_ns_scale __read_mostly; |
| static unsigned tb_to_ns_shift __read_mostly; |
| static u64 boot_tb __read_mostly; |
| |
| extern struct timezone sys_tz; |
| static long timezone_offset; |
| |
| unsigned long ppc_proc_freq; |
| EXPORT_SYMBOL_GPL(ppc_proc_freq); |
| unsigned long ppc_tb_freq; |
| EXPORT_SYMBOL_GPL(ppc_tb_freq); |
| |
| #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE |
| /* |
| * Factor for converting from cputime_t (timebase ticks) to |
| * microseconds. This is stored as 0.64 fixed-point binary fraction. |
| */ |
| u64 __cputime_usec_factor; |
| EXPORT_SYMBOL(__cputime_usec_factor); |
| |
| #ifdef CONFIG_PPC_SPLPAR |
| void (*dtl_consumer)(struct dtl_entry *, u64); |
| #endif |
| |
| static void calc_cputime_factors(void) |
| { |
| struct div_result res; |
| |
| div128_by_32(1000000, 0, tb_ticks_per_sec, &res); |
| __cputime_usec_factor = res.result_low; |
| } |
| |
| /* |
| * Read the SPURR on systems that have it, otherwise the PURR, |
| * or if that doesn't exist return the timebase value passed in. |
| */ |
| static inline unsigned long read_spurr(unsigned long tb) |
| { |
| if (cpu_has_feature(CPU_FTR_SPURR)) |
| return mfspr(SPRN_SPURR); |
| if (cpu_has_feature(CPU_FTR_PURR)) |
| return mfspr(SPRN_PURR); |
| return tb; |
| } |
| |
| #ifdef CONFIG_PPC_SPLPAR |
| |
| /* |
| * Scan the dispatch trace log and count up the stolen time. |
| * Should be called with interrupts disabled. |
| */ |
| static u64 scan_dispatch_log(u64 stop_tb) |
| { |
| u64 i = local_paca->dtl_ridx; |
| struct dtl_entry *dtl = local_paca->dtl_curr; |
| struct dtl_entry *dtl_end = local_paca->dispatch_log_end; |
| struct lppaca *vpa = local_paca->lppaca_ptr; |
| u64 tb_delta; |
| u64 stolen = 0; |
| u64 dtb; |
| |
| if (!dtl) |
| return 0; |
| |
| if (i == be64_to_cpu(vpa->dtl_idx)) |
| return 0; |
| while (i < be64_to_cpu(vpa->dtl_idx)) { |
| dtb = be64_to_cpu(dtl->timebase); |
| tb_delta = be32_to_cpu(dtl->enqueue_to_dispatch_time) + |
| be32_to_cpu(dtl->ready_to_enqueue_time); |
| barrier(); |
| if (i + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx)) { |
| /* buffer has overflowed */ |
| i = be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG; |
| dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG); |
| continue; |
| } |
| if (dtb > stop_tb) |
| break; |
| if (dtl_consumer) |
| dtl_consumer(dtl, i); |
| stolen += tb_delta; |
| ++i; |
| ++dtl; |
| if (dtl == dtl_end) |
| dtl = local_paca->dispatch_log; |
| } |
| local_paca->dtl_ridx = i; |
| local_paca->dtl_curr = dtl; |
| return stolen; |
| } |
| |
| /* |
| * Accumulate stolen time by scanning the dispatch trace log. |
| * Called on entry from user mode. |
| */ |
| void accumulate_stolen_time(void) |
| { |
| u64 sst, ust; |
| unsigned long save_irq_soft_mask = irq_soft_mask_return(); |
| struct cpu_accounting_data *acct = &local_paca->accounting; |
| |
| /* We are called early in the exception entry, before |
| * soft/hard_enabled are sync'ed to the expected state |
| * for the exception. We are hard disabled but the PACA |
| * needs to reflect that so various debug stuff doesn't |
| * complain |
| */ |
| irq_soft_mask_set(IRQS_DISABLED); |
| |
| sst = scan_dispatch_log(acct->starttime_user); |
| ust = scan_dispatch_log(acct->starttime); |
| acct->stime -= sst; |
| acct->utime -= ust; |
| acct->steal_time += ust + sst; |
| |
| irq_soft_mask_set(save_irq_soft_mask); |
| } |
| |
| static inline u64 calculate_stolen_time(u64 stop_tb) |
| { |
| if (!firmware_has_feature(FW_FEATURE_SPLPAR)) |
| return 0; |
| |
| if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx)) |
| return scan_dispatch_log(stop_tb); |
| |
| return 0; |
| } |
| |
| #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. |
| */ |
| static unsigned long vtime_delta_scaled(struct cpu_accounting_data *acct, |
| unsigned long now, unsigned long stime) |
| { |
| unsigned long stime_scaled = 0; |
| #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME |
| unsigned long nowscaled, deltascaled; |
| unsigned long utime, utime_scaled; |
| |
| nowscaled = read_spurr(now); |
| deltascaled = nowscaled - acct->startspurr; |
| acct->startspurr = nowscaled; |
| utime = acct->utime - acct->utime_sspurr; |
| acct->utime_sspurr = acct->utime; |
| |
| /* |
| * Because we don't read the SPURR on every kernel entry/exit, |
| * deltascaled includes both user and system SPURR ticks. |
| * Apportion these ticks to system SPURR ticks and user |
| * SPURR ticks in the same ratio as the system time (delta) |
| * and user time (udelta) values obtained from the timebase |
| * over the same interval. The system ticks get accounted here; |
| * the user ticks get saved up in paca->user_time_scaled to be |
| * used by account_process_tick. |
| */ |
| stime_scaled = stime; |
| utime_scaled = utime; |
| if (deltascaled != stime + utime) { |
| if (utime) { |
| stime_scaled = deltascaled * stime / (stime + utime); |
| utime_scaled = deltascaled - stime_scaled; |
| } else { |
| stime_scaled = deltascaled; |
| } |
| } |
| acct->utime_scaled += utime_scaled; |
| #endif |
| |
| return stime_scaled; |
| } |
| |
| static unsigned long vtime_delta(struct task_struct *tsk, |
| unsigned long *stime_scaled, |
| unsigned long *steal_time) |
| { |
| unsigned long now, stime; |
| struct cpu_accounting_data *acct = get_accounting(tsk); |
| |
| WARN_ON_ONCE(!irqs_disabled()); |
| |
| now = mftb(); |
| stime = now - acct->starttime; |
| acct->starttime = now; |
| |
| *stime_scaled = vtime_delta_scaled(acct, now, stime); |
| |
| *steal_time = calculate_stolen_time(now); |
| |
| return stime; |
| } |
| |
| void vtime_account_system(struct task_struct *tsk) |
| { |
| unsigned long stime, stime_scaled, steal_time; |
| struct cpu_accounting_data *acct = get_accounting(tsk); |
| |
| stime = vtime_delta(tsk, &stime_scaled, &steal_time); |
| |
| stime -= min(stime, steal_time); |
| acct->steal_time += steal_time; |
| |
| if ((tsk->flags & PF_VCPU) && !irq_count()) { |
| acct->gtime += stime; |
| #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME |
| acct->utime_scaled += stime_scaled; |
| #endif |
| } else { |
| if (hardirq_count()) |
| acct->hardirq_time += stime; |
| else if (in_serving_softirq()) |
| acct->softirq_time += stime; |
| else |
| acct->stime += stime; |
| |
| #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME |
| acct->stime_scaled += stime_scaled; |
| #endif |
| } |
| } |
| EXPORT_SYMBOL_GPL(vtime_account_system); |
| |
| void vtime_account_idle(struct task_struct *tsk) |
| { |
| unsigned long stime, stime_scaled, steal_time; |
| struct cpu_accounting_data *acct = get_accounting(tsk); |
| |
| stime = vtime_delta(tsk, &stime_scaled, &steal_time); |
| acct->idle_time += stime + steal_time; |
| } |
| |
| static void vtime_flush_scaled(struct task_struct *tsk, |
| struct cpu_accounting_data *acct) |
| { |
| #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME |
| if (acct->utime_scaled) |
| tsk->utimescaled += cputime_to_nsecs(acct->utime_scaled); |
| if (acct->stime_scaled) |
| tsk->stimescaled += cputime_to_nsecs(acct->stime_scaled); |
| |
| acct->utime_scaled = 0; |
| acct->utime_sspurr = 0; |
| acct->stime_scaled = 0; |
| #endif |
| } |
| |
| /* |
| * Account the whole cputime accumulated in the paca |
| * Must be called with interrupts disabled. |
| * Assumes that vtime_account_system/idle() has been called |
| * recently (i.e. since the last entry from usermode) so that |
| * get_paca()->user_time_scaled is up to date. |
| */ |
| void vtime_flush(struct task_struct *tsk) |
| { |
| struct cpu_accounting_data *acct = get_accounting(tsk); |
| |
| if (acct->utime) |
| account_user_time(tsk, cputime_to_nsecs(acct->utime)); |
| |
| if (acct->gtime) |
| account_guest_time(tsk, cputime_to_nsecs(acct->gtime)); |
| |
| if (IS_ENABLED(CONFIG_PPC_SPLPAR) && acct->steal_time) { |
| account_steal_time(cputime_to_nsecs(acct->steal_time)); |
| acct->steal_time = 0; |
| } |
| |
| if (acct->idle_time) |
| account_idle_time(cputime_to_nsecs(acct->idle_time)); |
| |
| if (acct->stime) |
| account_system_index_time(tsk, cputime_to_nsecs(acct->stime), |
| CPUTIME_SYSTEM); |
| |
| if (acct->hardirq_time) |
| account_system_index_time(tsk, cputime_to_nsecs(acct->hardirq_time), |
| CPUTIME_IRQ); |
| if (acct->softirq_time) |
| account_system_index_time(tsk, cputime_to_nsecs(acct->softirq_time), |
| CPUTIME_SOFTIRQ); |
| |
| vtime_flush_scaled(tsk, acct); |
| |
| acct->utime = 0; |
| acct->gtime = 0; |
| acct->idle_time = 0; |
| acct->stime = 0; |
| acct->hardirq_time = 0; |
| acct->softirq_time = 0; |
| } |
| |
| #else /* ! CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */ |
| #define calc_cputime_factors() |
| #endif |
| |
| void __delay(unsigned long loops) |
| { |
| unsigned long start; |
| int diff; |
| |
| spin_begin(); |
| if (__USE_RTC()) { |
| start = get_rtcl(); |
| do { |
| /* the RTCL register wraps at 1000000000 */ |
| diff = get_rtcl() - start; |
| if (diff < 0) |
| diff += 1000000000; |
| spin_cpu_relax(); |
| } while (diff < loops); |
| } else { |
| start = get_tbl(); |
| while (get_tbl() - start < loops) |
| spin_cpu_relax(); |
| } |
| spin_end(); |
| } |
| 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_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))); |
| } |
| |
| void arch_irq_work_raise(void) |
| { |
| preempt_disable(); |
| set_irq_work_pending_flag(); |
| /* |
| * Non-nmi code running with interrupts disabled will replay |
| * irq_happened before it re-enables interrupts, so setthe |
| * decrementer there instead of causing a hardware exception |
| * which would immediately hit the masked interrupt handler |
| * and have the net effect of setting the decrementer in |
| * irq_happened. |
| * |
| * NMI interrupts can not check this when they return, so the |
| * decrementer hardware exception is raised, which will fire |
| * when interrupts are next enabled. |
| * |
| * BookE does not support this yet, it must audit all NMI |
| * interrupt handlers to ensure they call nmi_enter() so this |
| * check would be correct. |
| */ |
| if (IS_ENABLED(CONFIG_BOOKE) || !irqs_disabled() || in_nmi()) { |
| set_dec(1); |
| } else { |
| hard_irq_disable(); |
| local_paca->irq_happened |= PACA_IRQ_DEC; |
| } |
| preempt_enable(); |
| } |
| |
| #else /* 32-bit */ |
| |
| DEFINE_PER_CPU(u8, irq_work_pending); |
| |
| #define set_irq_work_pending_flag() __this_cpu_write(irq_work_pending, 1) |
| #define test_irq_work_pending() __this_cpu_read(irq_work_pending) |
| #define clear_irq_work_pending() __this_cpu_write(irq_work_pending, 0) |
| |
| void arch_irq_work_raise(void) |
| { |
| preempt_disable(); |
| set_irq_work_pending_flag(); |
| set_dec(1); |
| preempt_enable(); |
| } |
| |
| #endif /* 32 vs 64 bit */ |
| |
| #else /* CONFIG_IRQ_WORK */ |
| |
| #define test_irq_work_pending() 0 |
| #define clear_irq_work_pending() |
| |
| #endif /* CONFIG_IRQ_WORK */ |
| |
| /* |
| * timer_interrupt - gets called when the decrementer overflows, |
| * with interrupts disabled. |
| */ |
| void timer_interrupt(struct pt_regs *regs) |
| { |
| struct clock_event_device *evt = this_cpu_ptr(&decrementers); |
| u64 *next_tb = this_cpu_ptr(&decrementers_next_tb); |
| struct pt_regs *old_regs; |
| u64 now; |
| |
| /* Some implementations of hotplug will get timer interrupts while |
| * offline, just ignore these and we also need to set |
| * decrementers_next_tb as MAX to make sure __check_irq_replay |
| * don't replay timer interrupt when return, otherwise we'll trap |
| * here infinitely :( |
| */ |
| if (unlikely(!cpu_online(smp_processor_id()))) { |
| *next_tb = ~(u64)0; |
| set_dec(decrementer_max); |
| return; |
| } |
| |
| /* Ensure a positive value is written to the decrementer, or else |
| * some CPUs will continue to take decrementer exceptions. When the |
| * PPC_WATCHDOG (decrementer based) is configured, keep this at most |
| * 31 bits, which is about 4 seconds on most systems, which gives |
| * the watchdog a chance of catching timer interrupt hard lockups. |
| */ |
| if (IS_ENABLED(CONFIG_PPC_WATCHDOG)) |
| set_dec(0x7fffffff); |
| else |
| set_dec(decrementer_max); |
| |
| /* Conditionally hard-enable interrupts now that the DEC has been |
| * bumped to its maximum value |
| */ |
| may_hard_irq_enable(); |
| |
| |
| #if defined(CONFIG_PPC32) && defined(CONFIG_PPC_PMAC) |
| if (atomic_read(&ppc_n_lost_interrupts) != 0) |
| do_IRQ(regs); |
| #endif |
| |
| old_regs = set_irq_regs(regs); |
| irq_enter(); |
| trace_timer_interrupt_entry(regs); |
| |
| if (test_irq_work_pending()) { |
| clear_irq_work_pending(); |
| irq_work_run(); |
| } |
| |
| now = get_tb_or_rtc(); |
| if (now >= *next_tb) { |
| *next_tb = ~(u64)0; |
| if (evt->event_handler) |
| evt->event_handler(evt); |
| __this_cpu_inc(irq_stat.timer_irqs_event); |
| } else { |
| now = *next_tb - now; |
| if (now <= decrementer_max) |
| set_dec(now); |
| /* We may have raced with new irq work */ |
| if (test_irq_work_pending()) |
| set_dec(1); |
| __this_cpu_inc(irq_stat.timer_irqs_others); |
| } |
| |
| trace_timer_interrupt_exit(regs); |
| irq_exit(); |
| set_irq_regs(old_regs); |
| } |
| EXPORT_SYMBOL(timer_interrupt); |
| |
| #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST |
| void timer_broadcast_interrupt(void) |
| { |
| u64 *next_tb = this_cpu_ptr(&decrementers_next_tb); |
| |
| *next_tb = ~(u64)0; |
| tick_receive_broadcast(); |
| __this_cpu_inc(irq_stat.broadcast_irqs_event); |
| } |
| #endif |
| |
| /* |
| * Hypervisor decrementer interrupts shouldn't occur but are sometimes |
| * left pending on exit from a KVM guest. We don't need to do anything |
| * to clear them, as they are edge-triggered. |
| */ |
| void hdec_interrupt(struct pt_regs *regs) |
| { |
| } |
| |
| #ifdef CONFIG_SUSPEND |
| static void generic_suspend_disable_irqs(void) |
| { |
| /* Disable the decrementer, so that it doesn't interfere |
| * with suspending. |
| */ |
| |
| set_dec(decrementer_max); |
| local_irq_disable(); |
| set_dec(decrementer_max); |
| } |
| |
| 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 |
| |
| unsigned long long tb_to_ns(unsigned long long ticks) |
| { |
| return mulhdu(ticks, tb_to_ns_scale) << tb_to_ns_shift; |
| } |
| EXPORT_SYMBOL_GPL(tb_to_ns); |
| |
| /* |
| * Scheduler clock - returns current time in nanosec units. |
| * |
| * Note: mulhdu(a, b) (multiply high double unsigned) returns |
| * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b |
| * are 64-bit unsigned numbers. |
| */ |
| notrace unsigned long long sched_clock(void) |
| { |
| if (__USE_RTC()) |
| return get_rtc(); |
| return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift; |
| } |
| |
| |
| #ifdef CONFIG_PPC_PSERIES |
| |
| /* |
| * Running clock - attempts to give a view of time passing for a virtualised |
| * kernels. |
| * Uses the VTB register if available otherwise a next best guess. |
| */ |
| unsigned long long running_clock(void) |
| { |
| /* |
| * Don't read the VTB as a host since KVM does not switch in host |
| * timebase into the VTB when it takes a guest off the CPU, reading the |
| * VTB would result in reading 'last switched out' guest VTB. |
| * |
| * Host kernels are often compiled with CONFIG_PPC_PSERIES checked, it |
| * would be unsafe to rely only on the #ifdef above. |
| */ |
| if (firmware_has_feature(FW_FEATURE_LPAR) && |
| cpu_has_feature(CPU_FTR_ARCH_207S)) |
| return mulhdu(get_vtb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift; |
| |
| /* |
| * This is a next best approximation without a VTB. |
| * On a host which is running bare metal there should never be any stolen |
| * time and on a host which doesn't do any virtualisation TB *should* equal |
| * VTB so it makes no difference anyway. |
| */ |
| return local_clock() - kcpustat_this_cpu->cpustat[CPUTIME_STEAL]; |
| } |
| #endif |
| |
| static int __init get_freq(char *name, int cells, unsigned long *val) |
| { |
| struct device_node *cpu; |
| const __be32 *fp; |
| int found = 0; |
| |
| /* The cpu node should have timebase and clock frequency properties */ |
| cpu = of_find_node_by_type(NULL, "cpu"); |
| |
| if (cpu) { |
| fp = of_get_property(cpu, name, NULL); |
| if (fp) { |
| found = 1; |
| *val = of_read_ulong(fp, cells); |
| } |
| |
| of_node_put(cpu); |
| } |
| |
| return found; |
| } |
| |
| static void start_cpu_decrementer(void) |
| { |
| #if defined(CONFIG_BOOKE) || defined(CONFIG_40x) |
| unsigned int tcr; |
| |
| /* Clear any pending timer interrupts */ |
| mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS); |
| |
| tcr = mfspr(SPRN_TCR); |
| /* |
| * The watchdog may have already been enabled by u-boot. So leave |
| * TRC[WP] (Watchdog Period) alone. |
| */ |
| tcr &= TCR_WP_MASK; /* Clear all bits except for TCR[WP] */ |
| tcr |= TCR_DIE; /* Enable decrementer */ |
| mtspr(SPRN_TCR, tcr); |
| #endif |
| } |
| |
| 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_clock64(struct timespec64 now) |
| { |
| struct rtc_time tm; |
| |
| if (!ppc_md.set_rtc_time) |
| return -ENODEV; |
| |
| rtc_time64_to_tm(now.tv_sec + 1 + timezone_offset, &tm); |
| |
| return ppc_md.set_rtc_time(&tm); |
| } |
| |
| static void __read_persistent_clock(struct timespec64 *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 = rtc_tm_to_time64(&tm); |
| } |
| |
| void read_persistent_clock64(struct timespec64 *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 notrace u64 rtc_read(struct clocksource *cs) |
| { |
| return (u64)get_rtc(); |
| } |
| |
| static notrace u64 timebase_read(struct clocksource *cs) |
| { |
| return (u64)get_tb(); |
| } |
| |
| |
| void update_vsyscall(struct timekeeper *tk) |
| { |
| struct timespec xt; |
| struct clocksource *clock = tk->tkr_mono.clock; |
| u32 mult = tk->tkr_mono.mult; |
| u32 shift = tk->tkr_mono.shift; |
| u64 cycle_last = tk->tkr_mono.cycle_last; |
| u64 new_tb_to_xs, new_stamp_xsec; |
| u64 frac_sec; |
| |
| if (clock != &clocksource_timebase) |
| return; |
| |
| xt.tv_sec = tk->xtime_sec; |
| xt.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); |
| |
| /* Make userspace gettimeofday spin until we're done. */ |
| ++vdso_data->tb_update_count; |
| smp_mb(); |
| |
| /* |
| * This computes ((2^20 / 1e9) * mult) >> shift as a |
| * 0.64 fixed-point fraction. |
| * The computation in the else clause below won't overflow |
| * (as long as the timebase frequency is >= 1.049 MHz) |
| * but loses precision because we lose the low bits of the constant |
| * in the shift. Note that 19342813113834067 ~= 2^(20+64) / 1e9. |
| * For a shift of 24 the error is about 0.5e-9, or about 0.5ns |
| * over a second. (Shift values are usually 22, 23 or 24.) |
| * For high frequency clocks such as the 512MHz timebase clock |
| * on POWER[6789], the mult value is small (e.g. 32768000) |
| * and so we can shift the constant by 16 initially |
| * (295147905179 ~= 2^(20+64-16) / 1e9) and then do the |
| * remaining shifts after the multiplication, which gives a |
| * more accurate result (e.g. with mult = 32768000, shift = 24, |
| * the error is only about 1.2e-12, or 0.7ns over 10 minutes). |
| */ |
| if (mult <= 62500000 && clock->shift >= 16) |
| new_tb_to_xs = ((u64) mult * 295147905179ULL) >> (clock->shift - 16); |
| else |
| new_tb_to_xs = (u64) mult * (19342813113834067ULL >> clock->shift); |
| |
| /* |
| * Compute the fractional second in units of 2^-32 seconds. |
| * The fractional second is tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift |
| * in nanoseconds, so multiplying that by 2^32 / 1e9 gives |
| * it in units of 2^-32 seconds. |
| * We assume shift <= 32 because clocks_calc_mult_shift() |
| * generates shift values in the range 0 - 32. |
| */ |
| frac_sec = tk->tkr_mono.xtime_nsec << (32 - shift); |
| do_div(frac_sec, NSEC_PER_SEC); |
| |
| /* |
| * Work out new stamp_xsec value for any legacy users of systemcfg. |
| * stamp_xsec is in units of 2^-20 seconds. |
| */ |
| new_stamp_xsec = frac_sec >> 12; |
| new_stamp_xsec += tk->xtime_sec * XSEC_PER_SEC; |
| |
| /* |
| * 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. |
| */ |
| vdso_data->tb_orig_stamp = cycle_last; |
| vdso_data->stamp_xsec = new_stamp_xsec; |
| vdso_data->tb_to_xs = new_tb_to_xs; |
| vdso_data->wtom_clock_sec = tk->wall_to_monotonic.tv_sec; |
| vdso_data->wtom_clock_nsec = tk->wall_to_monotonic.tv_nsec; |
| vdso_data->stamp_xtime = xt; |
| vdso_data->stamp_sec_fraction = frac_sec; |
| smp_wmb(); |
| ++(vdso_data->tb_update_count); |
| } |
| |
| void update_vsyscall_tz(void) |
| { |
| vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; |
| vdso_data->tz_dsttime = sys_tz.tz_dsttime; |
| } |
| |
| static void __init clocksource_init(void) |
| { |
| struct clocksource *clock; |
| |
| if (__USE_RTC()) |
| clock = &clocksource_rtc; |
| else |
| clock = &clocksource_timebase; |
| |
| if (clocksource_register_hz(clock, tb_ticks_per_sec)) { |
| 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) |
| { |
| __this_cpu_write(decrementers_next_tb, get_tb_or_rtc() + evt); |
| set_dec(evt); |
| |
| /* We may have raced with new irq work */ |
| if (test_irq_work_pending()) |
| set_dec(1); |
| |
| return 0; |
| } |
| |
| static int decrementer_shutdown(struct clock_event_device *dev) |
| { |
| decrementer_set_next_event(decrementer_max, dev); |
| return 0; |
| } |
| |
| static void register_decrementer_clockevent(int cpu) |
| { |
| struct clock_event_device *dec = &per_cpu(decrementers, cpu); |
| |
| *dec = decrementer_clockevent; |
| dec->cpumask = cpumask_of(cpu); |
| |
| clockevents_config_and_register(dec, ppc_tb_freq, 2, decrementer_max); |
| |
| printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n", |
| dec->name, dec->mult, dec->shift, cpu); |
| |
| /* Set values for KVM, see kvm_emulate_dec() */ |
| decrementer_clockevent.mult = dec->mult; |
| decrementer_clockevent.shift = dec->shift; |
| } |
| |
| static void enable_large_decrementer(void) |
| { |
| if (!cpu_has_feature(CPU_FTR_ARCH_300)) |
| return; |
| |
| if (decrementer_max <= DECREMENTER_DEFAULT_MAX) |
| return; |
| |
| /* |
| * If we're running as the hypervisor we need to enable the LD manually |
| * otherwise firmware should have done it for us. |
| */ |
| if (cpu_has_feature(CPU_FTR_HVMODE)) |
| mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_LD); |
| } |
| |
| static void __init set_decrementer_max(void) |
| { |
| struct device_node *cpu; |
| u32 bits = 32; |
| |
| /* Prior to ISAv3 the decrementer is always 32 bit */ |
| if (!cpu_has_feature(CPU_FTR_ARCH_300)) |
| return; |
| |
| cpu = of_find_node_by_type(NULL, "cpu"); |
| |
| if (of_property_read_u32(cpu, "ibm,dec-bits", &bits) == 0) { |
| if (bits > 64 || bits < 32) { |
| pr_warn("time_init: firmware supplied invalid ibm,dec-bits"); |
| bits = 32; |
| } |
| |
| /* calculate the signed maximum given this many bits */ |
| decrementer_max = (1ul << (bits - 1)) - 1; |
| } |
| |
| of_node_put(cpu); |
| |
| pr_info("time_init: %u bit decrementer (max: %llx)\n", |
| bits, decrementer_max); |
| } |
| |
| static void __init init_decrementer_clockevent(void) |
| { |
| register_decrementer_clockevent(smp_processor_id()); |
| } |
| |
| void secondary_cpu_time_init(void) |
| { |
| /* Enable and test the large decrementer for this cpu */ |
| enable_large_decrementer(); |
| |
| /* 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(); |
| |
| /* |
| * 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; |
| |
| /* initialise and enable the large decrementer (if we have one) */ |
| set_decrementer_max(); |
| enable_large_decrementer(); |
| |
| /* Start the decrementer on CPUs that have manual control |
| * such as BookE |
| */ |
| start_cpu_decrementer(); |
| |
| /* Register the clocksource */ |
| clocksource_init(); |
| |
| init_decrementer_clockevent(); |
| tick_setup_hrtimer_broadcast(); |
| |
| #ifdef CONFIG_COMMON_CLK |
| of_clk_init(NULL); |
| #endif |
| } |
| |
| /* |
| * 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; |
| } |
| |
| #if IS_ENABLED(CONFIG_RTC_DRV_GENERIC) |
| static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm) |
| { |
| ppc_md.get_rtc_time(tm); |
| return 0; |
| } |
| |
| static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm) |
| { |
| if (!ppc_md.set_rtc_time) |
| return -EOPNOTSUPP; |
| |
| if (ppc_md.set_rtc_time(tm) < 0) |
| return -EOPNOTSUPP; |
| |
| return 0; |
| } |
| |
| static const struct rtc_class_ops rtc_generic_ops = { |
| .read_time = rtc_generic_get_time, |
| .set_time = rtc_generic_set_time, |
| }; |
| |
| static int __init rtc_init(void) |
| { |
| struct platform_device *pdev; |
| |
| if (!ppc_md.get_rtc_time) |
| return -ENODEV; |
| |
| pdev = platform_device_register_data(NULL, "rtc-generic", -1, |
| &rtc_generic_ops, |
| sizeof(rtc_generic_ops)); |
| |
| return PTR_ERR_OR_ZERO(pdev); |
| } |
| |
| device_initcall(rtc_init); |
| #endif |