diff options
Diffstat (limited to 'arch/arm/kernel/arch_timer.c')
| -rw-r--r-- | arch/arm/kernel/arch_timer.c | 386 | 
1 files changed, 18 insertions, 368 deletions
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index 94f503394c5..36ebcf4b516 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -9,402 +9,52 @@   * published by the Free Software Foundation.   */  #include <linux/init.h> -#include <linux/kernel.h> -#include <linux/delay.h> -#include <linux/device.h> -#include <linux/smp.h> -#include <linux/cpu.h> -#include <linux/jiffies.h> -#include <linux/clockchips.h> -#include <linux/interrupt.h> -#include <linux/of_irq.h> -#include <linux/io.h> +#include <linux/types.h>  #include <asm/delay.h> -#include <asm/arch_timer.h>  #include <asm/sched_clock.h> -static u32 arch_timer_rate; +#include <clocksource/arm_arch_timer.h> -enum ppi_nr { -	PHYS_SECURE_PPI, -	PHYS_NONSECURE_PPI, -	VIRT_PPI, -	HYP_PPI, -	MAX_TIMER_PPI -}; - -static int arch_timer_ppi[MAX_TIMER_PPI]; - -static struct clock_event_device __percpu *arch_timer_evt; -static struct delay_timer arch_delay_timer; - -static bool arch_timer_use_virtual = true; - -/* - * Architected system timer support. - */ - -static irqreturn_t inline timer_handler(const int access, -					struct clock_event_device *evt) -{ -	unsigned long ctrl; -	ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL); -	if (ctrl & ARCH_TIMER_CTRL_IT_STAT) { -		ctrl |= ARCH_TIMER_CTRL_IT_MASK; -		arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl); -		evt->event_handler(evt); -		return IRQ_HANDLED; -	} - -	return IRQ_NONE; -} - -static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id) -{ -	struct clock_event_device *evt = dev_id; - -	return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt); -} - -static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id) -{ -	struct clock_event_device *evt = dev_id; - -	return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt); -} - -static inline void timer_set_mode(const int access, int mode) -{ -	unsigned long ctrl; -	switch (mode) { -	case CLOCK_EVT_MODE_UNUSED: -	case CLOCK_EVT_MODE_SHUTDOWN: -		ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL); -		ctrl &= ~ARCH_TIMER_CTRL_ENABLE; -		arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl); -		break; -	default: -		break; -	} -} - -static void arch_timer_set_mode_virt(enum clock_event_mode mode, -				     struct clock_event_device *clk) -{ -	timer_set_mode(ARCH_TIMER_VIRT_ACCESS, mode); -} - -static void arch_timer_set_mode_phys(enum clock_event_mode mode, -				     struct clock_event_device *clk) -{ -	timer_set_mode(ARCH_TIMER_PHYS_ACCESS, mode); -} - -static inline void set_next_event(const int access, unsigned long evt) -{ -	unsigned long ctrl; -	ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL); -	ctrl |= ARCH_TIMER_CTRL_ENABLE; -	ctrl &= ~ARCH_TIMER_CTRL_IT_MASK; -	arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt); -	arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl); -} - -static int arch_timer_set_next_event_virt(unsigned long evt, -					  struct clock_event_device *unused) -{ -	set_next_event(ARCH_TIMER_VIRT_ACCESS, evt); -	return 0; -} - -static int arch_timer_set_next_event_phys(unsigned long evt, -					  struct clock_event_device *unused) -{ -	set_next_event(ARCH_TIMER_PHYS_ACCESS, evt); -	return 0; -} - -static int __cpuinit arch_timer_setup(struct clock_event_device *clk) -{ -	clk->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP; -	clk->name = "arch_sys_timer"; -	clk->rating = 450; -	if (arch_timer_use_virtual) { -		clk->irq = arch_timer_ppi[VIRT_PPI]; -		clk->set_mode = arch_timer_set_mode_virt; -		clk->set_next_event = arch_timer_set_next_event_virt; -	} else { -		clk->irq = arch_timer_ppi[PHYS_SECURE_PPI]; -		clk->set_mode = arch_timer_set_mode_phys; -		clk->set_next_event = arch_timer_set_next_event_phys; -	} - -	clk->cpumask = cpumask_of(smp_processor_id()); - -	clk->set_mode(CLOCK_EVT_MODE_SHUTDOWN, NULL); - -	clockevents_config_and_register(clk, arch_timer_rate, -					0xf, 0x7fffffff); - -	if (arch_timer_use_virtual) -		enable_percpu_irq(arch_timer_ppi[VIRT_PPI], 0); -	else { -		enable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI], 0); -		if (arch_timer_ppi[PHYS_NONSECURE_PPI]) -			enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0); -	} - -	arch_counter_set_user_access(); - -	return 0; -} - -static int arch_timer_available(void) -{ -	u32 freq; - -	if (arch_timer_rate == 0) { -		freq = arch_timer_get_cntfrq(); - -		/* Check the timer frequency. */ -		if (freq == 0) { -			pr_warn("Architected timer frequency not available\n"); -			return -EINVAL; -		} - -		arch_timer_rate = freq; -	} - -	pr_info_once("Architected local timer running at %lu.%02luMHz (%s).\n", -		     (unsigned long)arch_timer_rate / 1000000, -		     (unsigned long)(arch_timer_rate / 10000) % 100, -		     arch_timer_use_virtual ? "virt" : "phys"); -	return 0; -} - -/* - * Some external users of arch_timer_read_counter (e.g. sched_clock) may try to - * call it before it has been initialised. Rather than incur a performance - * penalty checking for initialisation, provide a default implementation that - * won't lead to time appearing to jump backwards. - */ -static u64 arch_timer_read_zero(void) -{ -	return 0; -} - -u64 (*arch_timer_read_counter)(void) = arch_timer_read_zero; - -static u32 arch_timer_read_counter32(void) -{ -	return arch_timer_read_counter(); -} - -static cycle_t arch_counter_read(struct clocksource *cs) +static unsigned long arch_timer_read_counter_long(void)  {  	return arch_timer_read_counter();  } -static unsigned long arch_timer_read_current_timer(void) +static u32 arch_timer_read_counter_u32(void)  {  	return arch_timer_read_counter();  } -static cycle_t arch_counter_read_cc(const struct cyclecounter *cc) -{ -	return arch_timer_read_counter(); -} - -static struct clocksource clocksource_counter = { -	.name	= "arch_sys_counter", -	.rating	= 400, -	.read	= arch_counter_read, -	.mask	= CLOCKSOURCE_MASK(56), -	.flags	= CLOCK_SOURCE_IS_CONTINUOUS, -}; - -static struct cyclecounter cyclecounter = { -	.read	= arch_counter_read_cc, -	.mask	= CLOCKSOURCE_MASK(56), -}; - -static struct timecounter timecounter; - -struct timecounter *arch_timer_get_timecounter(void) -{ -	return &timecounter; -} - -static void __cpuinit arch_timer_stop(struct clock_event_device *clk) -{ -	pr_debug("arch_timer_teardown disable IRQ%d cpu #%d\n", -		 clk->irq, smp_processor_id()); - -	if (arch_timer_use_virtual) -		disable_percpu_irq(arch_timer_ppi[VIRT_PPI]); -	else { -		disable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI]); -		if (arch_timer_ppi[PHYS_NONSECURE_PPI]) -			disable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI]); -	} - -	clk->set_mode(CLOCK_EVT_MODE_UNUSED, clk); -} - -static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self, -					   unsigned long action, void *hcpu) -{ -	struct clock_event_device *evt = this_cpu_ptr(arch_timer_evt); - -	switch (action & ~CPU_TASKS_FROZEN) { -	case CPU_STARTING: -		arch_timer_setup(evt); -		break; -	case CPU_DYING: -		arch_timer_stop(evt); -		break; -	} - -	return NOTIFY_OK; -} - -static struct notifier_block arch_timer_cpu_nb __cpuinitdata = { -	.notifier_call = arch_timer_cpu_notify, -}; +static struct delay_timer arch_delay_timer; -static int __init arch_timer_register(void) +static void __init arch_timer_delay_timer_register(void)  { -	int err; -	int ppi; - -	err = arch_timer_available(); -	if (err) -		goto out; - -	arch_timer_evt = alloc_percpu(struct clock_event_device); -	if (!arch_timer_evt) { -		err = -ENOMEM; -		goto out; -	} - -	clocksource_register_hz(&clocksource_counter, arch_timer_rate); -	cyclecounter.mult = clocksource_counter.mult; -	cyclecounter.shift = clocksource_counter.shift; -	timecounter_init(&timecounter, &cyclecounter, -			 arch_counter_get_cntpct()); - -	if (arch_timer_use_virtual) { -		ppi = arch_timer_ppi[VIRT_PPI]; -		err = request_percpu_irq(ppi, arch_timer_handler_virt, -					 "arch_timer", arch_timer_evt); -	} else { -		ppi = arch_timer_ppi[PHYS_SECURE_PPI]; -		err = request_percpu_irq(ppi, arch_timer_handler_phys, -					 "arch_timer", arch_timer_evt); -		if (!err && arch_timer_ppi[PHYS_NONSECURE_PPI]) { -			ppi = arch_timer_ppi[PHYS_NONSECURE_PPI]; -			err = request_percpu_irq(ppi, arch_timer_handler_phys, -						 "arch_timer", arch_timer_evt); -			if (err) -				free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI], -						arch_timer_evt); -		} -	} - -	if (err) { -		pr_err("arch_timer: can't register interrupt %d (%d)\n", -		       ppi, err); -		goto out_free; -	} - -	err = register_cpu_notifier(&arch_timer_cpu_nb); -	if (err) -		goto out_free_irq; - -	/* Immediately configure the timer on the boot CPU */ -	arch_timer_setup(this_cpu_ptr(arch_timer_evt)); -  	/* Use the architected timer for the delay loop. */ -	arch_delay_timer.read_current_timer = &arch_timer_read_current_timer; -	arch_delay_timer.freq = arch_timer_rate; +	arch_delay_timer.read_current_timer = arch_timer_read_counter_long; +	arch_delay_timer.freq = arch_timer_get_rate();  	register_current_timer_delay(&arch_delay_timer); -	return 0; - -out_free_irq: -	if (arch_timer_use_virtual) -		free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt); -	else { -		free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI], -				arch_timer_evt); -		if (arch_timer_ppi[PHYS_NONSECURE_PPI]) -			free_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], -					arch_timer_evt); -	} - -out_free: -	free_percpu(arch_timer_evt); -out: -	return err;  } -static const struct of_device_id arch_timer_of_match[] __initconst = { -	{ .compatible	= "arm,armv7-timer",	}, -	{}, -}; -  int __init arch_timer_of_register(void)  { -	struct device_node *np; -	u32 freq; -	int i; - -	np = of_find_matching_node(NULL, arch_timer_of_match); -	if (!np) { -		pr_err("arch_timer: can't find DT node\n"); -		return -ENODEV; -	} +	int ret; -	/* Try to determine the frequency from the device tree or CNTFRQ */ -	if (!of_property_read_u32(np, "clock-frequency", &freq)) -		arch_timer_rate = freq; +	ret = arch_timer_init(); +	if (ret) +		return ret; -	for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++) -		arch_timer_ppi[i] = irq_of_parse_and_map(np, i); +	arch_timer_delay_timer_register(); -	of_node_put(np); - -	/* -	 * If no interrupt provided for virtual timer, we'll have to -	 * stick to the physical timer. It'd better be accessible... -	 */ -	if (!arch_timer_ppi[VIRT_PPI]) { -		arch_timer_use_virtual = false; - -		if (!arch_timer_ppi[PHYS_SECURE_PPI] || -		    !arch_timer_ppi[PHYS_NONSECURE_PPI]) { -			pr_warn("arch_timer: No interrupt available, giving up\n"); -			return -EINVAL; -		} -	} - -	if (arch_timer_use_virtual) -		arch_timer_read_counter = arch_counter_get_cntvct; -	else -		arch_timer_read_counter = arch_counter_get_cntpct; - -	return arch_timer_register(); +	return 0;  }  int __init arch_timer_sched_clock_init(void)  { -	int err; - -	err = arch_timer_available(); -	if (err) -		return err; +	if (arch_timer_get_rate() == 0) +		return -ENXIO; -	setup_sched_clock(arch_timer_read_counter32, -			  32, arch_timer_rate); +	setup_sched_clock(arch_timer_read_counter_u32, +			  32, arch_timer_get_rate());  	return 0;  }  |