diff options
Diffstat (limited to 'drivers/clocksource/arm_arch_timer.c')
| -rw-r--r-- | drivers/clocksource/arm_arch_timer.c | 62 |
1 files changed, 60 insertions, 2 deletions
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index fbd9ccd5e11..5163ec13429 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -13,12 +13,14 @@ #include <linux/device.h> #include <linux/smp.h> #include <linux/cpu.h> +#include <linux/cpu_pm.h> #include <linux/clockchips.h> #include <linux/interrupt.h> #include <linux/of_irq.h> #include <linux/of_address.h> #include <linux/io.h> #include <linux/slab.h> +#include <linux/sched_clock.h> #include <asm/arch_timer.h> #include <asm/virt.h> @@ -64,6 +66,7 @@ static int arch_timer_ppi[MAX_TIMER_PPI]; static struct clock_event_device __percpu *arch_timer_evt; static bool arch_timer_use_virtual = true; +static bool arch_timer_c3stop; static bool arch_timer_mem_use_virtual; /* @@ -261,7 +264,8 @@ static void __arch_timer_setup(unsigned type, clk->features = CLOCK_EVT_FEAT_ONESHOT; if (type == ARCH_CP15_TIMER) { - clk->features |= CLOCK_EVT_FEAT_C3STOP; + if (arch_timer_c3stop) + clk->features |= CLOCK_EVT_FEAT_C3STOP; clk->name = "arch_sys_timer"; clk->rating = 450; clk->cpumask = cpumask_of(smp_processor_id()); @@ -275,6 +279,7 @@ static void __arch_timer_setup(unsigned type, clk->set_next_event = arch_timer_set_next_event_phys; } } else { + clk->features |= CLOCK_EVT_FEAT_DYNIRQ; clk->name = "arch_mem_timer"; clk->rating = 400; clk->cpumask = cpu_all_mask; @@ -294,6 +299,19 @@ static void __arch_timer_setup(unsigned type, clockevents_config_and_register(clk, arch_timer_rate, 0xf, 0x7fffffff); } +static void arch_timer_configure_evtstream(void) +{ + int evt_stream_div, pos; + + /* Find the closest power of two to the divisor */ + evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ; + pos = fls(evt_stream_div); + if (pos > 1 && !(evt_stream_div & (1 << (pos - 2)))) + pos--; + /* enable event stream */ + arch_timer_evtstrm_enable(min(pos, 15)); +} + static int arch_timer_setup(struct clock_event_device *clk) { __arch_timer_setup(ARCH_CP15_TIMER, clk); @@ -307,6 +325,8 @@ static int arch_timer_setup(struct clock_event_device *clk) } arch_counter_set_user_access(); + if (IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM)) + arch_timer_configure_evtstream(); return 0; } @@ -389,7 +409,7 @@ static struct clocksource clocksource_counter = { .rating = 400, .read = arch_counter_read, .mask = CLOCKSOURCE_MASK(56), - .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_SUSPEND_NONSTOP, }; static struct cyclecounter cyclecounter = { @@ -419,6 +439,9 @@ static void __init arch_counter_register(unsigned type) cyclecounter.mult = clocksource_counter.mult; cyclecounter.shift = clocksource_counter.shift; timecounter_init(&timecounter, &cyclecounter, start_count); + + /* 56 bits minimum, so we assume worst case rollover */ + sched_clock_register(arch_timer_read_counter, 56, arch_timer_rate); } static void arch_timer_stop(struct clock_event_device *clk) @@ -460,6 +483,33 @@ static struct notifier_block arch_timer_cpu_nb = { .notifier_call = arch_timer_cpu_notify, }; +#ifdef CONFIG_CPU_PM +static unsigned int saved_cntkctl; +static int arch_timer_cpu_pm_notify(struct notifier_block *self, + unsigned long action, void *hcpu) +{ + if (action == CPU_PM_ENTER) + saved_cntkctl = arch_timer_get_cntkctl(); + else if (action == CPU_PM_ENTER_FAILED || action == CPU_PM_EXIT) + arch_timer_set_cntkctl(saved_cntkctl); + return NOTIFY_OK; +} + +static struct notifier_block arch_timer_cpu_pm_notifier = { + .notifier_call = arch_timer_cpu_pm_notify, +}; + +static int __init arch_timer_cpu_pm_init(void) +{ + return cpu_pm_register_notifier(&arch_timer_cpu_pm_notifier); +} +#else +static int __init arch_timer_cpu_pm_init(void) +{ + return 0; +} +#endif + static int __init arch_timer_register(void) { int err; @@ -499,11 +549,17 @@ static int __init arch_timer_register(void) if (err) goto out_free_irq; + err = arch_timer_cpu_pm_init(); + if (err) + goto out_unreg_notify; + /* Immediately configure the timer on the boot CPU */ arch_timer_setup(this_cpu_ptr(arch_timer_evt)); return 0; +out_unreg_notify: + unregister_cpu_notifier(&arch_timer_cpu_nb); out_free_irq: if (arch_timer_use_virtual) free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt); @@ -611,6 +667,8 @@ static void __init arch_timer_init(struct device_node *np) } } + arch_timer_c3stop = !of_property_read_bool(np, "always-on"); + arch_timer_register(); arch_timer_common_init(); } |