diff options
Diffstat (limited to 'arch/arm/kernel/arch_timer.c')
-rw-r--r-- | arch/arm/kernel/arch_timer.c | 504 |
1 files changed, 20 insertions, 484 deletions
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index c8ef207..36ebcf4 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -9,516 +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/cputype.h> #include <asm/delay.h> -#include <asm/localtimer.h> -#include <asm/arch_timer.h> -#include <asm/system_info.h> #include <asm/sched_clock.h> -static unsigned long 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. - */ - -#define ARCH_TIMER_CTRL_ENABLE (1 << 0) -#define ARCH_TIMER_CTRL_IT_MASK (1 << 1) -#define ARCH_TIMER_CTRL_IT_STAT (1 << 2) - -#define ARCH_TIMER_REG_CTRL 0 -#define ARCH_TIMER_REG_FREQ 1 -#define ARCH_TIMER_REG_TVAL 2 - -#define ARCH_TIMER_PHYS_ACCESS 0 -#define ARCH_TIMER_VIRT_ACCESS 1 - -/* - * These register accessors are marked inline so the compiler can - * nicely work out which register we want, and chuck away the rest of - * the code. At least it does so with a recent GCC (4.6.3). - */ -static inline void arch_timer_reg_write(const int access, const int reg, u32 val) -{ - if (access == ARCH_TIMER_PHYS_ACCESS) { - switch (reg) { - case ARCH_TIMER_REG_CTRL: - asm volatile("mcr p15, 0, %0, c14, c2, 1" : : "r" (val)); - break; - case ARCH_TIMER_REG_TVAL: - asm volatile("mcr p15, 0, %0, c14, c2, 0" : : "r" (val)); - break; - } - } - - if (access == ARCH_TIMER_VIRT_ACCESS) { - switch (reg) { - case ARCH_TIMER_REG_CTRL: - asm volatile("mcr p15, 0, %0, c14, c3, 1" : : "r" (val)); - break; - case ARCH_TIMER_REG_TVAL: - asm volatile("mcr p15, 0, %0, c14, c3, 0" : : "r" (val)); - break; - } - } - - isb(); -} - -static inline u32 arch_timer_reg_read(const int access, const int reg) -{ - u32 val = 0; - - if (access == ARCH_TIMER_PHYS_ACCESS) { - switch (reg) { - case ARCH_TIMER_REG_CTRL: - asm volatile("mrc p15, 0, %0, c14, c2, 1" : "=r" (val)); - break; - case ARCH_TIMER_REG_TVAL: - asm volatile("mrc p15, 0, %0, c14, c2, 0" : "=r" (val)); - break; - case ARCH_TIMER_REG_FREQ: - asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (val)); - break; - } - } - - if (access == ARCH_TIMER_VIRT_ACCESS) { - switch (reg) { - case ARCH_TIMER_REG_CTRL: - asm volatile("mrc p15, 0, %0, c14, c3, 1" : "=r" (val)); - break; - case ARCH_TIMER_REG_TVAL: - asm volatile("mrc p15, 0, %0, c14, c3, 0" : "=r" (val)); - break; - } - } - - return val; -} - -static inline cycle_t arch_timer_counter_read(const int access) -{ - cycle_t cval = 0; - - if (access == ARCH_TIMER_PHYS_ACCESS) - asm volatile("mrrc p15, 0, %Q0, %R0, c14" : "=r" (cval)); - - if (access == ARCH_TIMER_VIRT_ACCESS) - asm volatile("mrrc p15, 1, %Q0, %R0, c14" : "=r" (cval)); - - return cval; -} - -static inline cycle_t arch_counter_get_cntpct(void) -{ - return arch_timer_counter_read(ARCH_TIMER_PHYS_ACCESS); -} - -static inline cycle_t arch_counter_get_cntvct(void) -{ - return arch_timer_counter_read(ARCH_TIMER_VIRT_ACCESS); -} - -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 = *(struct clock_event_device **)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 = *(struct clock_event_device **)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->set_mode(CLOCK_EVT_MODE_SHUTDOWN, NULL); - - clockevents_config_and_register(clk, arch_timer_rate, - 0xf, 0x7fffffff); - - *__this_cpu_ptr(arch_timer_evt) = clk; - - 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); - } - - return 0; -} - -/* Is the optional system timer available? */ -static int local_timer_is_architected(void) -{ - return (cpu_architecture() >= CPU_ARCH_ARMv7) && - ((read_cpuid_ext(CPUID_EXT_PFR1) >> 16) & 0xf) == 1; -} - -static int arch_timer_available(void) -{ - unsigned long freq; - - if (!local_timer_is_architected()) - return -ENXIO; - - if (arch_timer_rate == 0) { - freq = arch_timer_reg_read(ARCH_TIMER_PHYS_ACCESS, - ARCH_TIMER_REG_FREQ); - - /* 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", - arch_timer_rate / 1000000, (arch_timer_rate / 10000) % 100, - arch_timer_use_virtual ? "virt" : "phys"); - return 0; -} - -static u32 notrace arch_counter_get_cntpct32(void) -{ - cycle_t cnt = arch_counter_get_cntpct(); - - /* - * The sched_clock infrastructure only knows about counters - * with at most 32bits. Forget about the upper 24 bits for the - * time being... - */ - return (u32)cnt; -} - -static u32 notrace arch_counter_get_cntvct32(void) -{ - cycle_t cnt = arch_counter_get_cntvct(); - - /* - * The sched_clock infrastructure only knows about counters - * with at most 32bits. Forget about the upper 24 bits for the - * time being... - */ - return (u32)cnt; -} - -static cycle_t arch_counter_read(struct clocksource *cs) -{ - /* - * Always use the physical counter for the clocksource. - * CNTHCTL.PL1PCTEN must be set to 1. - */ - return arch_counter_get_cntpct(); -} - -static unsigned long arch_timer_read_current_timer(void) +static unsigned long arch_timer_read_counter_long(void) { - return arch_counter_get_cntpct(); + return arch_timer_read_counter(); } -static cycle_t arch_counter_read_cc(const struct cyclecounter *cc) +static u32 arch_timer_read_counter_u32(void) { - /* - * Always use the physical counter for the clocksource. - * CNTHCTL.PL1PCTEN must be set to 1. - */ - return arch_counter_get_cntpct(); + 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 struct local_timer_ops arch_timer_ops __cpuinitdata = { - .setup = arch_timer_setup, - .stop = arch_timer_stop, -}; - -static struct clock_event_device arch_timer_global_evt; +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 = local_timer_register(&arch_timer_ops); - if (err) { - /* - * We couldn't register as a local timer (could be - * because we're on a UP platform, or because some - * other local timer is already present...). Try as a - * global timer instead. - */ - arch_timer_global_evt.cpumask = cpumask_of(0); - err = arch_timer_setup(&arch_timer_global_evt); - } - if (err) - goto out_free_irq; - /* 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; - } - - /* Try to determine the frequency from the device tree or CNTFRQ */ - if (!of_property_read_u32(np, "clock-frequency", &freq)) - arch_timer_rate = freq; - - for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++) - arch_timer_ppi[i] = irq_of_parse_and_map(np, i); + int ret; - /* - * 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; + ret = arch_timer_init(); + if (ret) + return ret; - 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; - } - } + arch_timer_delay_timer_register(); - return arch_timer_register(); + return 0; } int __init arch_timer_sched_clock_init(void) { - u32 (*cnt32)(void); - int err; - - err = arch_timer_available(); - if (err) - return err; - - if (arch_timer_use_virtual) - cnt32 = arch_counter_get_cntvct32; - else - cnt32 = arch_counter_get_cntpct32; + if (arch_timer_get_rate() == 0) + return -ENXIO; - setup_sched_clock(cnt32, 32, arch_timer_rate); + setup_sched_clock(arch_timer_read_counter_u32, + 32, arch_timer_get_rate()); return 0; } |