diff options
Diffstat (limited to 'arch/i386/kernel')
| -rw-r--r-- | arch/i386/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/i386/kernel/apic.c | 291 | ||||
| -rw-r--r-- | arch/i386/kernel/hpet.c | 496 | ||||
| -rw-r--r-- | arch/i386/kernel/i8253.c | 96 | ||||
| -rw-r--r-- | arch/i386/kernel/i8259.c | 6 | ||||
| -rw-r--r-- | arch/i386/kernel/smpboot.c | 5 | ||||
| -rw-r--r-- | arch/i386/kernel/time.c | 70 | ||||
| -rw-r--r-- | arch/i386/kernel/time_hpet.c | 497 |
8 files changed, 717 insertions, 745 deletions
diff --git a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile index c2b3b79dc43..4ae3dcf1d2f 100644 --- a/arch/i386/kernel/Makefile +++ b/arch/i386/kernel/Makefile @@ -32,7 +32,6 @@ obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_MODULES) += module.o obj-y += sysenter.o vsyscall.o obj-$(CONFIG_ACPI_SRAT) += srat.o -obj-$(CONFIG_HPET_TIMER) += time_hpet.o obj-$(CONFIG_EFI) += efi.o efi_stub.o obj-$(CONFIG_DOUBLEFAULT) += doublefault.o obj-$(CONFIG_VM86) += vm86.o diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c index b56448f214a..e98b5c750bd 100644 --- a/arch/i386/kernel/apic.c +++ b/arch/i386/kernel/apic.c @@ -25,6 +25,7 @@ #include <linux/kernel_stat.h> #include <linux/sysdev.h> #include <linux/cpu.h> +#include <linux/clockchips.h> #include <linux/module.h> #include <asm/atomic.h> @@ -52,28 +53,44 @@ #endif /* - * cpu_mask that denotes the CPUs that needs timer interrupt coming in as - * IPIs in place of local APIC timers - */ -static cpumask_t timer_bcast_ipi; - -/* * Knob to control our willingness to enable the local APIC. * * -1=force-disable, +1=force-enable */ static int enable_local_apic __initdata = 0; +/* Enable local APIC timer for highres/dyntick on UP */ +static int enable_local_apic_timer __initdata = 0; + /* * Debug level, exported for io_apic.c */ int apic_verbosity; -static void apic_pm_activate(void); +static unsigned int calibration_result; +static int lapic_next_event(unsigned long delta, + struct clock_event_device *evt); +static void lapic_timer_setup(enum clock_event_mode mode, + struct clock_event_device *evt); +static void lapic_timer_broadcast(cpumask_t mask); +static void apic_pm_activate(void); -/* Using APIC to generate smp_local_timer_interrupt? */ -int using_apic_timer __read_mostly = 0; +/* + * The local apic timer can be used for any function which is CPU local. + */ +static struct clock_event_device lapic_clockevent = { + .name = "lapic", + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT + | CLOCK_EVT_FEAT_C3STOP, + .shift = 32, + .set_mode = lapic_timer_setup, + .set_next_event = lapic_next_event, + .broadcast = lapic_timer_broadcast, + .rating = 100, + .irq = -1, +}; +static DEFINE_PER_CPU(struct clock_event_device, lapic_events); /* Local APIC was disabled by the BIOS and enabled by the kernel */ static int enabled_via_apicbase; @@ -152,6 +169,11 @@ int lapic_get_maxlvt(void) */ /* + * FIXME: Move this to i8253.h. There is no need to keep the access to + * the PIT scattered all around the place -tglx + */ + +/* * The timer chip is already set up at HZ interrupts per second here, * but we do not accept timer interrupts yet. We only allow the BP * to calibrate. @@ -209,16 +231,17 @@ void (*wait_timer_tick)(void) __devinitdata = wait_8254_wraparound; #define APIC_DIVISOR 16 -static void __setup_APIC_LVTT(unsigned int clocks) +static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen) { unsigned int lvtt_value, tmp_value; - int cpu = smp_processor_id(); - lvtt_value = APIC_LVT_TIMER_PERIODIC | LOCAL_TIMER_VECTOR; + lvtt_value = LOCAL_TIMER_VECTOR; + if (!oneshot) + lvtt_value |= APIC_LVT_TIMER_PERIODIC; if (!lapic_is_integrated()) lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV); - if (cpu_isset(cpu, timer_bcast_ipi)) + if (!irqen) lvtt_value |= APIC_LVT_MASKED; apic_write_around(APIC_LVTT, lvtt_value); @@ -231,31 +254,80 @@ static void __setup_APIC_LVTT(unsigned int clocks) & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) | APIC_TDR_DIV_16); - apic_write_around(APIC_TMICT, clocks/APIC_DIVISOR); + if (!oneshot) + apic_write_around(APIC_TMICT, clocks/APIC_DIVISOR); +} + +/* + * Program the next event, relative to now + */ +static int lapic_next_event(unsigned long delta, + struct clock_event_device *evt) +{ + apic_write_around(APIC_TMICT, delta); + return 0; } -static void __devinit setup_APIC_timer(unsigned int clocks) +/* + * Setup the lapic timer in periodic or oneshot mode + */ +static void lapic_timer_setup(enum clock_event_mode mode, + struct clock_event_device *evt) { unsigned long flags; + unsigned int v; local_irq_save(flags); - /* - * Wait for IRQ0's slice: - */ - wait_timer_tick(); - - __setup_APIC_LVTT(clocks); + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + case CLOCK_EVT_MODE_ONESHOT: + __setup_APIC_LVTT(calibration_result, + mode != CLOCK_EVT_MODE_PERIODIC, 1); + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + v = apic_read(APIC_LVTT); + v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR); + apic_write_around(APIC_LVTT, v); + break; + } local_irq_restore(flags); } /* + * Local APIC timer broadcast function + */ +static void lapic_timer_broadcast(cpumask_t mask) +{ +#ifdef CONFIG_SMP + send_IPI_mask(mask, LOCAL_TIMER_VECTOR); +#endif +} + +/* + * Setup the local APIC timer for this CPU. Copy the initilized values + * of the boot CPU and register the clock event in the framework. + */ +static void __devinit setup_APIC_timer(void) +{ + struct clock_event_device *levt = &__get_cpu_var(lapic_events); + + memcpy(levt, &lapic_clockevent, sizeof(*levt)); + levt->cpumask = cpumask_of_cpu(smp_processor_id()); + + clockevents_register_device(levt); +} + +/* * In this function we calibrate APIC bus clocks to the external * timer. Unfortunately we cannot use jiffies and the timer irq * to calibrate, since some later bootup code depends on getting * the first irq? Ugh. * + * TODO: Fix this rather than saying "Ugh" -tglx + * * We want to do the calibration only once since we * want to have local timer irqs syncron. CPUs connected * by the same APIC bus have the very same bus frequency. @@ -278,7 +350,7 @@ static int __init calibrate_APIC_clock(void) * value into the APIC clock, we just want to get the * counter running for calibration. */ - __setup_APIC_LVTT(1000000000); + __setup_APIC_LVTT(1000000000, 0, 0); /* * The timer chip counts down to zero. Let's wait @@ -315,6 +387,17 @@ static int __init calibrate_APIC_clock(void) result = (tt1-tt2)*APIC_DIVISOR/LOOPS; + /* Calculate the scaled math multiplication factor */ + lapic_clockevent.mult = div_sc(tt1-tt2, TICK_NSEC * LOOPS, 32); + lapic_clockevent.max_delta_ns = + clockevent_delta2ns(0x7FFFFF, &lapic_clockevent); + lapic_clockevent.min_delta_ns = + clockevent_delta2ns(0xF, &lapic_clockevent); + + apic_printk(APIC_VERBOSE, "..... tt1-tt2 %ld\n", tt1 - tt2); + apic_printk(APIC_VERBOSE, "..... mult: %ld\n", lapic_clockevent.mult); + apic_printk(APIC_VERBOSE, "..... calibration result: %ld\n", result); + if (cpu_has_tsc) apic_printk(APIC_VERBOSE, "..... CPU clock speed is " "%ld.%04ld MHz.\n", @@ -329,13 +412,10 @@ static int __init calibrate_APIC_clock(void) return result; } -static unsigned int calibration_result; - void __init setup_boot_APIC_clock(void) { unsigned long flags; apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"); - using_apic_timer = 1; local_irq_save(flags); @@ -343,97 +423,47 @@ void __init setup_boot_APIC_clock(void) /* * Now set up the timer for real. */ - setup_APIC_timer(calibration_result); + setup_APIC_timer(); local_irq_restore(flags); } void __devinit setup_secondary_APIC_clock(void) { - setup_APIC_timer(calibration_result); -} - -void disable_APIC_timer(void) -{ - if (using_apic_timer) { - unsigned long v; - - v = apic_read(APIC_LVTT); - /* - * When an illegal vector value (0-15) is written to an LVT - * entry and delivery mode is Fixed, the APIC may signal an - * illegal vector error, with out regard to whether the mask - * bit is set or whether an interrupt is actually seen on - * input. - * - * Boot sequence might call this function when the LVTT has - * '0' vector value. So make sure vector field is set to - * valid value. - */ - v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR); - apic_write_around(APIC_LVTT, v); - } -} - -void enable_APIC_timer(void) -{ - int cpu = smp_processor_id(); - - if (using_apic_timer && !cpu_isset(cpu, timer_bcast_ipi)) { - unsigned long v; - - v = apic_read(APIC_LVTT); - apic_write_around(APIC_LVTT, v & ~APIC_LVT_MASKED); - } -} - -void switch_APIC_timer_to_ipi(void *cpumask) -{ - cpumask_t mask = *(cpumask_t *)cpumask; - int cpu = smp_processor_id(); - - if (cpu_isset(cpu, mask) && - !cpu_isset(cpu, timer_bcast_ipi)) { - disable_APIC_timer(); - cpu_set(cpu, timer_bcast_ipi); - } -} -EXPORT_SYMBOL(switch_APIC_timer_to_ipi); - -void switch_ipi_to_APIC_timer(void *cpumask) -{ - cpumask_t mask = *(cpumask_t *)cpumask; - int cpu = smp_processor_id(); - - if (cpu_isset(cpu, mask) && - cpu_isset(cpu, timer_bcast_ipi)) { - cpu_clear(cpu, timer_bcast_ipi); - enable_APIC_timer(); - } + setup_APIC_timer(); } -EXPORT_SYMBOL(switch_ipi_to_APIC_timer); /* - * Local timer interrupt handler. It does both profiling and - * process statistics/rescheduling. + * The guts of the apic timer interrupt */ -inline void smp_local_timer_interrupt(void) +static void local_apic_timer_interrupt(void) { - profile_tick(CPU_PROFILING); -#ifdef CONFIG_SMP - update_process_times(user_mode_vm(get_irq_regs())); -#endif + int cpu = smp_processor_id(); + struct clock_event_device *evt = &per_cpu(lapic_events, cpu); /* - * We take the 'long' return path, and there every subsystem - * grabs the apropriate locks (kernel lock/ irq lock). + * Normally we should not be here till LAPIC has been + * initialized but in some cases like kdump, its possible that + * there is a pending LAPIC timer interrupt from previous + * kernel's context and is delivered in new kernel the moment + * interrupts are enabled. * - * we might want to decouple profiling from the 'long path', - * and do the profiling totally in assembly. - * - * Currently this isn't too much of an issue (performance wise), - * we can take more than 100K local irqs per second on a 100 MHz P5. + * Interrupts are enabled early and LAPIC is setup much later, + * hence its possible that when we get here evt->event_handler + * is NULL. Check for event_handler being NULL and discard + * the interrupt as spurious. */ + if (!evt->event_handler) { + printk(KERN_WARNING + "Spurious LAPIC timer interrupt on cpu %d\n", cpu); + /* Switch it off */ + lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt); + return; + } + + per_cpu(irq_stat, cpu).apic_timer_irqs++; + + evt->event_handler(evt); } /* @@ -445,15 +475,9 @@ inline void smp_local_timer_interrupt(void) * interrupt as well. Thus we cannot inline the local irq ... ] */ -fastcall void smp_apic_timer_interrupt(struct pt_regs *regs) +void fastcall smp_apic_timer_interrupt(struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); - int cpu = smp_processor_id(); - - /* - * the NMI deadlock-detector uses this. - */ - per_cpu(irq_stat, cpu).apic_timer_irqs++; /* * NOTE! We'd better ACK the irq immediately, @@ -467,41 +491,10 @@ fastcall void smp_apic_timer_interrupt(struct pt_regs *regs) */ exit_idle(); irq_enter(); - smp_local_timer_interrupt(); + local_apic_timer_interrupt(); irq_exit(); - set_irq_regs(old_regs); -} -#ifndef CONFIG_SMP -static void up_apic_timer_interrupt_call(void) -{ - int cpu = smp_processor_id(); - - /* - * the NMI deadlock-detector uses this. - */ - per_cpu(irq_stat, cpu).apic_timer_irqs++; - - smp_local_timer_interrupt(); -} -#endif - -void smp_send_timer_broadcast_ipi(void) -{ - cpumask_t mask; - - cpus_and(mask, cpu_online_map, timer_bcast_ipi); - if (!cpus_empty(mask)) { -#ifdef CONFIG_SMP - send_IPI_mask(mask, LOCAL_TIMER_VECTOR); -#else - /* - * We can directly call the apic timer interrupt handler - * in UP case. Minus all irq related functions - */ - up_apic_timer_interrupt_call(); -#endif - } + set_irq_regs(old_regs); } int setup_profiling_timer(unsigned int multiplier) @@ -914,6 +907,11 @@ void __devinit setup_local_APIC(void) printk(KERN_INFO "No ESR for 82489DX.\n"); } + /* Disable the local apic timer */ + value = apic_read(APIC_LVTT); + value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR); + apic_write_around(APIC_LVTT, value); + setup_apic_nmi_watchdog(NULL); apic_pm_activate(); } @@ -1128,6 +1126,13 @@ static int __init parse_nolapic(char *arg) } early_param("nolapic", parse_nolapic); +static int __init apic_enable_lapic_timer(char *str) +{ + enable_local_apic_timer = 1; + return 0; +} +early_param("lapictimer", apic_enable_lapic_timer); + static int __init apic_set_verbosity(char *str) { if (strcmp("debug", str) == 0) @@ -1147,7 +1152,7 @@ __setup("apic=", apic_set_verbosity); /* * This interrupt should _never_ happen with our APIC/SMP architecture */ -fastcall void smp_spurious_interrupt(struct pt_regs *regs) +void smp_spurious_interrupt(struct pt_regs *regs) { unsigned long v; @@ -1171,7 +1176,7 @@ fastcall void smp_spurious_interrupt(struct pt_regs *regs) /* * This interrupt should never happen with our APIC/SMP architecture */ -fastcall void smp_error_interrupt(struct pt_regs *regs) +void smp_error_interrupt(struct pt_regs *regs) { unsigned long v, v1; diff --git a/arch/i386/kernel/hpet.c b/arch/i386/kernel/hpet.c index 7d2739fff3a..e1006b7acc9 100644 --- a/arch/i386/kernel/hpet.c +++ b/arch/i386/kernel/hpet.c @@ -1,4 +1,5 @@ #include <linux/clocksource.h> +#include <linux/clockchips.h> #include <linux/errno.h> #include <linux/hpet.h> #include <linux/init.h> @@ -6,17 +7,278 @@ #include <asm/hpet.h> #include <asm/io.h> +extern struct clock_event_device *global_clock_event; + #define HPET_MASK CLOCKSOURCE_MASK(32) #define HPET_SHIFT 22 /* FSEC = 10^-15 NSEC = 10^-9 */ #define FSEC_PER_NSEC 1000000 -static void __iomem *hpet_ptr; +/* + * HPET address is set in acpi/boot.c, when an ACPI entry exists + */ +unsigned long hpet_address; +static void __iomem * hpet_virt_address; + +static inline unsigned long hpet_readl(unsigned long a) +{ + return readl(hpet_virt_address + a); +} + +static inline void hpet_writel(unsigned long d, unsigned long a) +{ + writel(d, hpet_virt_address + a); +} + +/* + * HPET command line enable / disable + */ +static int boot_hpet_disable; + +static int __init hpet_setup(char* str) +{ + if (str) { + if (!strncmp("disable", str, 7)) + boot_hpet_disable = 1; + } + return 1; +} +__setup("hpet=", hpet_setup); + +static inline int is_hpet_capable(void) +{ + return (!boot_hpet_disable && hpet_address); +} + +/* + * HPET timer interrupt enable / disable + */ +static int hpet_legacy_int_enabled; + +/** + * is_hpet_enabled - check whether the hpet timer interrupt is enabled + */ +int is_hpet_enabled(void) +{ + return is_hpet_capable() && hpet_legacy_int_enabled; +} + +/* + * When the hpet driver (/dev/hpet) is enabled, we need to reserve + * timer 0 and timer 1 in case of RTC emulation. + */ +#ifdef CONFIG_HPET +static void hpet_reserve_platform_timers(unsigned long id) +{ + struct hpet __iomem *hpet = hpet_virt_address; + struct hpet_timer __iomem *timer = &hpet->hpet_timers[2]; + unsigned int nrtimers, i; + struct hpet_data hd; + + nrtimers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1; + + memset(&hd, 0, sizeof (hd)); + hd.hd_phys_address = hpet_address; + hd.hd_address = hpet_virt_address; + hd.hd_nirqs = nrtimers; + hd.hd_flags = HPET_DATA_PLATFORM; + hpet_reserve_timer(&hd, 0); + +#ifdef CONFIG_HPET_EMULATE_RTC + hpet_reserve_timer(&hd, 1); +#endif + + hd.hd_irq[0] = HPET_LEGACY_8254; + hd.hd_irq[1] = HPET_LEGACY_RTC; + + for (i = 2; i < nrtimers; timer++, i++) + hd.hd_irq[i] = (timer->hpet_config & Tn_INT_ROUTE_CNF_MASK) >> + Tn_INT_ROUTE_CNF_SHIFT; + + hpet_alloc(&hd); + +} +#else +static void hpet_reserve_platform_timers(unsigned long id) { } +#endif + +/* + * Common hpet info + */ +static unsigned long hpet_period; + +static void hpet_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt); +static int hpet_next_event(unsigned long delta, + struct clock_event_device *evt); + +/* + * The hpet clock event device + */ +static struct clock_event_device hpet_clockevent = { + .name = "hpet", + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .set_mode = hpet_set_mode, + .set_next_event = hpet_next_event, + .shift = 32, + .irq = 0, +}; + +static void hpet_start_counter(void) +{ + unsigned long cfg = hpet_readl(HPET_CFG); + + cfg &= ~HPET_CFG_ENABLE; + hpet_writel(cfg, HPET_CFG); + hpet_writel(0, HPET_COUNTER); + hpet_writel(0, HPET_COUNTER + 4); + cfg |= HPET_CFG_ENABLE; + hpet_writel(cfg, HPET_CFG); +} + +static void hpet_enable_int(void) +{ + unsigned long cfg = hpet_readl(HPET_CFG); + + cfg |= HPET_CFG_LEGACY; + hpet_writel(cfg, HPET_CFG); + hpet_legacy_int_enabled = 1; +} + +static void hpet_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + unsigned long cfg, cmp, now; + uint64_t delta; + + switch(mode) { + case CLOCK_EVT_MODE_PERIODIC: + delta = ((uint64_t)(NSEC_PER_SEC/HZ)) * hpet_clockevent.mult; + delta >>= hpet_clockevent.shift; + now = hpet_readl(HPET_COUNTER); + cmp = now + (unsigned long) delta; + cfg = hpet_readl(HPET_T0_CFG); + cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC | + HPET_TN_SETVAL | HPET_TN_32BIT; + hpet_writel(cfg, HPET_T0_CFG); + /* + * The first write after writing TN_SETVAL to the + * config register sets the counter value, the second + * write sets the period. + */ + hpet_writel(cmp, HPET_T0_CMP); + udelay(1); + hpet_writel((unsigned long) delta, HPET_T0_CMP); + break; + + case CLOCK_EVT_MODE_ONESHOT: + cfg = hpet_readl(HPET_T0_CFG); + cfg &= ~HPET_TN_PERIODIC; + cfg |= HPET_TN_ENABLE | HPET_TN_32BIT; + hpet_writel(cfg, HPET_T0_CFG); + break; + + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + cfg = hpet_readl(HPET_T0_CFG); + cfg &= ~HPET_TN_ENABLE; + hpet_writel(cfg, HPET_T0_CFG); + break; + } +} + +static int hpet_next_event(unsigned long delta, + struct clock_event_device *evt) +{ + unsigned long cnt; + + cnt = hpet_readl(HPET_COUNTER); + cnt += delta; + hpet_writel(cnt, HPET_T0_CMP); + + return ((long)(hpet_readl(HPET_COUNTER) - cnt ) > 0); +} + +/* + * Try to setup the HPET timer + */ +int __init hpet_enable(void) +{ + unsigned long id; + uint64_t hpet_freq; + + if (!is_hpet_capable()) + return 0; + + hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE); + + /* + * Read the period and check for a sane value: + */ + hpet_period = hpet_readl(HPET_PERIOD); + if (hpet_period < HPET_MIN_PERIOD || hpet_period > HPET_MAX_PERIOD) + goto out_nohpet; + + /* + * The period is a femto seconds value. We need to calculate the + * scaled math multiplication factor for nanosecond to hpet tick + * conversion. + */ + hpet_freq = 1000000000000000ULL; + do_div(hpet_freq, hpet_period); + hpet_clockevent.mult = div_sc((unsigned long) hpet_freq, + NSEC_PER_SEC, 32); + /* Calculate the min / max delta */ + hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF, + &hpet_clockevent); + hpet_clockevent.min_delta_ns = clockevent_delta2ns(0x30, + &hpet_clockevent); + + /* + * Read the HPET ID register to retrieve the IRQ routing + * information and the number of channels + */ + id = hpet_readl(HPET_ID); + +#ifdef CONFIG_HPET_EMULATE_RTC + /* + * The legacy routing mode needs at least two channels, tick timer + * and the rtc emulation channel. + */ + if (!(id & HPET_ID_NUMBER)) + goto out_nohpet; +#endif + + /* Start the counter */ + hpet_start_counter(); + + if (id & HPET_ID_LEGSUP) { + hpet_enable_int(); + hpet_reserve_platform_timers(id); + /* + * Start hpet with the boot cpu mask and make it + * global after the IO_APIC has been initialized. + */ + hpet_clockevent.cpumask =cpumask_of_cpu(0); + clockevents_register_device(&hpet_clockevent); + global_clock_event = &hpet_clockevent; + return 1; + } + return 0; +out_nohpet: + iounmap(hpet_virt_address); + hpet_virt_address = NULL; + return 0; +} + +/* + * Clock source related code + */ static cycle_t read_hpet(void) { - return (cycle_t)readl(hpet_ptr); + return (cycle_t)hpet_readl(HPET_COUNTER); } static struct clocksource clocksource_hpet = { @@ -24,28 +286,17 @@ static struct clocksource clocksource_hpet = { .rating = 250, .read = read_hpet, .mask = HPET_MASK, - .mult = 0, /* set below */ .shift = HPET_SHIFT, .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; static int __init init_hpet_clocksource(void) { - unsigned long hpet_period; - void __iomem* hpet_base; u64 tmp; - int err; - if (!is_hpet_enabled()) + if (!hpet_virt_address) return -ENODEV; - /* calculate the hpet address: */ - hpet_base = ioremap_nocache(hpet_address, HPET_MMAP_SIZE); - hpet_ptr = hpet_base + HPET_COUNTER; - - /* calculate the frequency: */ - hpet_period = readl(hpet_base + HPET_PERIOD); - /* * hpet period is in femto seconds per cycle * so we need to convert this to ns/cyc units @@ -61,11 +312,218 @@ static int __init init_hpet_clocksource(void) do_div(tmp, FSEC_PER_NSEC); clocksource_hpet.mult = (u32)tmp; - err = clocksource_register(&clocksource_hpet); - if (err) - iounmap(hpet_base); - - return err; + return clocksource_register(&clocksource_hpet); } module_init(init_hpet_clocksource); + +#ifdef CONFIG_HPET_EMULATE_RTC + +/* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET + * is enabled, we support RTC interrupt functionality in software. + * RTC has 3 kinds of interrupts: + * 1) Update Interrupt - generate an interrupt, every sec, when RTC clock + * is updated + * 2) Alarm Interrupt - generate an interrupt at a specific time of day + * 3) Periodic Interrupt - generate periodic interrupt, with frequencies + * 2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2) + * (1) and (2) above are implemented using polling at a frequency of + * 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt + * overhead. (DEFAULT_RTC_INT_FREQ) + * For (3), we use interrupts at 64Hz or user specified periodic + * frequency, whichever is higher. + */ +#include <linux/mc146818rtc.h> +#include <linux/rtc.h> + +#define DEFAULT_RTC_INT_FREQ 64 +#define DEFAULT_RTC_SHIFT 6 +#define RTC_NUM_INTS 1 + +static unsigned long hpet_rtc_flags; +static unsigned long hpet_prev_update_sec; +static struct rtc_time hpet_alarm_time; +static unsigned long hpet_pie_count; +static unsigned long hpet_t1_cmp; +static unsigned long hpet_default_delta; +static unsigned long hpet_pie_delta; +static unsigned long hpet_pie_limit; + +/* + * Timer 1 for RTC emulation. We use one shot mode, as periodic mode + * is not supported by all HPET implementations for timer 1. + * + * hpet_rtc_timer_init() is called when the rtc is initialized. + */ +int hpet_rtc_timer_init(void) +{ + unsigned long cfg, cnt, delta, flags; + + if (!is_hpet_enabled()) + return 0; + + if (!hpet_default_delta) { + uint64_t clc; + + clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC; + clc >>= hpet_clockevent.shift + DEFAULT_RTC_SHIFT; + hpet_default_delta = (unsigned long) clc; + } + + if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit) + delta = hpet_default_delta; + else + delta = hpet_pie_delta; + + local_irq_save(flags); + + cnt = delta + hpet_readl(HPET_COUNTER); + hpet_writel(cnt, HPET_T1_CMP); + hpet_t1_cmp = cnt; + + cfg = hpet_readl(HPET_T1_CFG); + cfg &= ~HPET_TN_PERIODIC; + cfg |= HPET_TN_ENABLE | HPET_TN_32BIT; + hpet_writel(cfg, HPET_T1_CFG); + + local_irq_restore(flags); + + return 1; +} + +/* + * The functions below are called from rtc driver. + * Return 0 if HPET is not being used. + * Otherwise do the necessary changes and return 1. + */ +int hpet_mask_rtc_irq_bit(unsigned long bit_mask) +{ + if (!is_hpet_enabled()) + return 0; + + hpet_rtc_flags &= ~bit_mask; + return 1; +} + +int hpet_set_rtc_irq_bit(unsigned long bit_mask) +{ + unsigned long oldbits = hpet_rtc_flags; + + if (!is_hpet_enabled()) + return 0; + + hpet_rtc_flags |= bit_mask; + + if (!oldbits) + hpet_rtc_timer_init(); + + return 1; +} + +int hpet_set_alarm_time(unsigned char hrs, unsigned char min, + unsigned char sec) +{ + if (!is_hpet_enabled()) + return 0; + + hpet_alarm_time.tm_hour = hrs; + hpet_alarm_time.tm_min = min; + hpet_alarm_time.tm_sec = sec; + + return 1; +} + +int hpet_set_periodic_freq(unsigned long freq) +{ + uint64_t clc; + + if (!is_hpet_enabled()) + return 0; + + if (freq <= DEFAULT_RTC_INT_FREQ) + hpet_pie_limit = DEFAULT_RTC_INT_FREQ / freq; + else { + clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC; + do_div(clc, freq); + clc >>= hpet_clockevent.shift; + hpet_pie_delta = (unsigned long) clc; + } + return 1; +} + +int hpet_rtc_dropped_irq(void) +{ + return is_hpet_enabled(); +} + +static void hpet_rtc_timer_reinit(void) +{ + unsigned long cfg, delta; + int lost_ints = -1; + + if (unlikely(!hpet_rtc_flags)) { + cfg = hpet_readl(HPET_T1_CFG); + cfg &= ~HPET_TN_ENABLE; + hpet_writel(cfg, HPET_T1_CFG); + return; + } + + if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit) + delta = hpet_default_delta; + else + delta = hpet_pie_delta; + + /* + * Increment the comparator value until we are ahead of the + * current count. + */ + do { + hpet_t1_cmp += delta; + hpet_writel(hpet_t1_cmp, HPET_T1_CMP); + lost_ints++; + } while ((long)(hpet_readl(HPET_COUNTER) - hpet_t1_cmp) > 0); + + if (lost_ints) { + if (hpet_rtc_flags & RTC_PIE) + hpet_pie_count += lost_ints; + if (printk_ratelimit()) + printk(KERN_WARNING "rtc: lost %d interrupts\n", + lost_ints); + } +} + +irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id) +{ + struct rtc_time curr_time; + unsigned long rtc_int_flag = 0; + + hpet_rtc_timer_reinit(); + + if (hpet_rtc_flags & (RTC_UIE | RTC_AIE)) + rtc_get_rtc_time(&curr_time); + + if (hpet_rtc_flags & RTC_UIE && + curr_time.tm_sec != hpet_prev_update_sec) { + rtc_int_flag = RTC_UF; + hpet_prev_update_sec = curr_time.tm_sec; + } + + if (hpet_rtc_flags & RTC_PIE && + ++hpet_pie_count >= hpet_pie_limit) { + rtc_int_flag |= RTC_PF; + hpet_pie_count = 0; + } + + if (hpet_rtc_flags & RTC_PIE && + (curr_time.tm_sec == hpet_alarm_time.tm_sec) && + (curr_time.tm_min == hpet_alarm_time.tm_min) && + (curr_time.tm_hour == hpet_alarm_time.tm_hour)) + rtc_int_flag |= RTC_AF; + + if (rtc_int_flag) { + rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8)); + rtc_interrupt(rtc_int_flag, dev_id); + } + return IRQ_HANDLED; +} +#endif diff --git a/arch/i386/kernel/i8253.c b/arch/i386/kernel/i8253.c index 9a0060b92e3..a6bc7bb3883 100644 --- a/arch/i386/kernel/i8253.c +++ b/arch/i386/kernel/i8253.c @@ -2,7 +2,7 @@ * i8253.c 8253/PIT functions * */ -#include <linux/clocksource.h> +#include <linux/clockchips.h> #include <linux/spinlock.h> #include <linux/jiffies.h> #include <linux/sysdev.h> @@ -19,17 +19,97 @@ DEFINE_SPINLOCK(i8253_lock); EXPORT_SYMBOL(i8253_lock); -void setup_pit_timer(void) +/* + * HPET replaces the PIT, when enabled. So we need to know, which of + * the two timers is used + */ +struct clock_event_device *global_clock_event; + +/* + * Initialize the PIT timer. + * + * This is also called after resume to bring the PIT into operation again. + */ +static void init_pit_timer(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + unsigned long flags; + + spin_lock_irqsave(&i8253_lock, flags); + + switch(mode) { + case CLOCK_EVT_MODE_PERIODIC: + /* binary, mode 2, LSB/MSB, ch 0 */ + outb_p(0x34, PIT_MODE); + udelay(10); + outb_p(LATCH & 0xff , PIT_CH0); /* LSB */ + udelay(10); + outb(LATCH >> 8 , PIT_CH0); /* MSB */ + break; + + case CLOCK_EVT_MODE_ONESHOT: + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_UNUSED: + /* One shot setup */ + outb_p(0x38, PIT_MODE); + udelay(10); + break; + } + spin_unlock_irqrestore(&i8253_lock, flags); +} + +/* + * Program the next event in oneshot mode + * + * Delta is given in PIT ticks + */ +static int pit_next_event(unsigned long delta, struct clock_event_device *evt) { unsigned long flags; spin_lock_irqsave(&i8253_lock, flags); - outb_p(0x34,PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */ - udelay(10); - outb_p(LATCH & 0xff , PIT_CH0); /* LSB */ - udelay(10); - outb(LATCH >> 8 , PIT_CH0); /* MSB */ + outb_p(delta & 0xff , PIT_CH0); /* LSB */ + outb(delta >> 8 , PIT_CH0); /* MSB */ spin_unlock_irqrestore(&i8253_lock, flags); + + return 0; +} + +/* + * On UP the PIT can serve all of the possible timer functions. On SMP systems + * it can be solely used for the global tick. + * + * The profiling and update capabilites are switched off once the local apic is + * registered. This mechanism replaces the previous #ifdef LOCAL_APIC - + * !using_apic_timer decisions in do_timer_interrupt_hook() + */ +struct clock_event_device pit_clockevent = { + .name = "pit", + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .set_mode = init_pit_timer, + .set_next_event = pit_next_event, + .shift = 32, + .irq = 0, +}; + +/* + * Initialize the conversion factor and the min/max deltas of the clock event + * structure and register the clock event source with the framework. + */ +void __init setup_pit_timer(void) +{ + /* + * Start pit with the boot cpu mask and make it global after the + * IO_APIC has been initialized. + */ + pit_clockevent.cpumask = cpumask_of_cpu(0); + pit_clockevent.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC, 32); + pit_clockevent.max_delta_ns = + clockevent_delta2ns(0x7FFF, &pit_clockevent); + pit_clockevent.min_delta_ns = + clockevent_delta2ns(0xF, &pit_clockevent); + clockevents_register_device(&pit_clockevent); + global_clock_event = &pit_clockevent; } /* @@ -46,7 +126,7 @@ static cycle_t pit_read(void) static u32 old_jifs; spin_lock_irqsave(&i8253_lock, flags); - /* + /* * Although our caller may have the read side of xtime_lock, * this is now a seqlock, and we are cheating in this routine * by having side effects on state that we cannot undo if diff --git a/arch/i386/kernel/i8259.c b/arch/i386/kernel/i8259.c index c8d45821c78..255b1af9a05 100644 --- a/arch/i386/kernel/i8259.c +++ b/arch/i386/kernel/i8259.c @@ -410,12 +410,6 @@ void __init native_init_IRQ(void) intr_init_hook(); /* - * Set the clock to HZ Hz, we already have a valid - * vector now: - */ - setup_pit_timer(); - - /* * External FPU? Set up irq13 if so, for * original braindamaged IBM FERR coupling. */ diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c index 6cdd941fc2f..48bfcaa13ec 100644 --- a/arch/i386/kernel/smpboot.c +++ b/arch/i386/kernel/smpboot.c @@ -287,9 +287,7 @@ static void __cpuinit smp_callin(void) /* * Save our processor parameters */ - smp_store_cpu_info(cpuid); - - disable_APIC_timer(); + smp_store_cpu_info(cpuid); /* * Allow the master to continue. @@ -408,7 +406,6 @@ static void __cpuinit start_secondary(void *unused) enable_NMI_through_LVT0(NULL); enable_8259A_irq(0); } - enable_APIC_timer(); /* * low-memory mappings have been cleared, flush them from * the local TLBs too. diff --git a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c index 044c17572ee..a5350059557 100644 --- a/arch/i386/kernel/time.c +++ b/arch/i386/kernel/time.c @@ -159,15 +159,6 @@ EXPORT_SYMBOL(profile_pc); */ irqreturn_t timer_interrupt(int irq, void *dev_id) { - /* - * Here we are in the timer irq handler. We just have irqs locally - * disabled but we don't know if the timer_bh is running on the other - * CPU. We need to avoid to SMP race with it. NOTE: we don' t need - * the irq version of write_lock because as just said we have irq - * locally disabled. -arca - */ - write_seqlock(&xtime_lock); - #ifdef CONFIG_X86_IO_APIC if (timer_ack) { /* @@ -186,7 +177,6 @@ irqreturn_t timer_interrupt(int irq, void *dev_id) do_timer_interrupt_hook(); - if (MCA_bus) { /* The PS/2 uses level-triggered interrupts. You can't turn them off, nor would you want to (any attempt to @@ -201,13 +191,6 @@ irqreturn_t timer_interrupt(int irq, void *dev_id) outb_p( irq_v|0x80, 0x61 ); /* reset the IRQ */ } - write_sequnlock(&xtime_lock); - -#ifdef CONFIG_X86_LOCAL_APIC - if (using_apic_timer) - smp_send_timer_broadcast_ipi(); -#endif - return IRQ_HANDLED; } @@ -277,63 +260,16 @@ void notify_arch_cmos_timer(void) mod_timer(&sync_cmos_timer, jiffies + 1); } -static int timer_resume(struct sys_device *dev) -{ -#ifdef CONFIG_HPET_TIMER - if (is_hpet_enabled()) - hpet_reenable(); -#endif - setup_pit_timer(); - touch_softlockup_watchdog(); - return 0; -} - -static struct sysdev_class timer_sysclass = { - .resume = timer_resume, - set_kset_name("timer"), -}; - - -/* XXX this driverfs stuff should probably go elsewhere later -john */ -static struct sys_device device_timer = { - .id = 0, - .cls = &timer_sysclass, -}; - -static int time_init_device(void) -{ - int error = sysdev_class_register(&timer_sysclass); - if (!error) - error = sysdev_register(&device_timer); - return error; -} - -device_initcall(time_init_device); - -#ifdef CONFIG_HPET_TIMER extern void (*late_time_init)(void); /* Duplicate of time_init() below, with hpet_enable part added */ static void __init hpet_time_init(void) { - if ((hpet_enable() >= 0) && hpet_use_timer) { - printk("Using HPET for base-timer\n"); - } - + if (!hpet_enable()) + setup_pit_timer(); do_time_init(); } -#endif void __init time_init(void) { -#ifdef CONFIG_HPET_TIMER - if (is_hpet_capable()) { - /* - * HPET initialization needs to do memory-mapped io. So, let - * us do a late initialization after mem_init(). - */ - late_time_init = hpet_time_init; - return; - } -#endif - do_time_init(); + late_time_init = hpet_time_init; } diff --git a/arch/i386/kernel/time_hpet.c b/arch/i386/kernel/time_hpet.c deleted file mode 100644 index 1e4702dfcd0..00000000000 --- a/arch/i386/kernel/time_hpet.c +++ /dev/null @@ -1,497 +0,0 @@ -/* - * linux/arch/i386/kernel/time_hpet.c - * This code largely copied from arch/x86_64/kernel/time.c - * See that file for credits. - * - * 2003-06-30 Venkatesh Pallipadi - Additional changes for HPET support - */ - -#include <linux/errno.h> -#include <linux/kernel.h> -#include <linux/param.h> -#include <linux/string.h> -#include <linux/init.h> -#include <linux/smp.h> - -#include <asm/timer.h> -#include <asm/fixmap.h> -#include <asm/apic.h> - -#include <linux/timex.h> - -#include <asm/hpet.h> -#include <linux/hpet.h> - -static unsigned long hpet_period; /* fsecs / HPET clock */ -unsigned long hpet_tick; /* hpet clks count per tick */ -unsigned long hpet_address; /* hpet memory map physical address */ -int hpet_use_timer; - -static int use_hpet; /* can be used for runtime check of hpet */ -static int boot_hpet_disable; /* boottime override for HPET timer */ -static void __iomem * hpet_virt_address; /* hpet kernel virtual address */ - -#define FSEC_TO_USEC (1000000000UL) - -int hpet_readl(unsigned long a) -{ - return readl(hpet_virt_address + a); -} - -static void hpet_writel(unsigned long d, unsigned long a) -{ - writel(d, hpet_virt_address + a); -} - -#ifdef CONFIG_X86_LOCAL_APIC -/* - * HPET counters dont wrap around on every tick. They just change the - * comparator value and continue. Next tick can be caught by checking - * for a change in the comparator value. Used in apic.c. - */ -static void __devinit wait_hpet_tick(void) -{ - unsigned int start_cmp_val, end_cmp_val; - - start_cmp_val = hpet_readl(HPET_T0_CMP); - do { - end_cmp_val = hpet_readl(HPET_T0_CMP); - } while (start_cmp_val == end_cmp_val); -} -#endif - -static int hpet_timer_stop_set_go(unsigned long tick) -{ - unsigned int cfg; - - /* - * Stop the timers and reset the main counter. - */ - cfg = hpet_readl(HPET_CFG); - cfg &= ~HPET_CFG_ENABLE; - hpet_writel(cfg, HPET_CFG); - hpet_writel(0, HPET_COUNTER); - hpet_writel(0, HPET_COUNTER + 4); - - if (hpet_use_timer) { - /* - * Set up timer 0, as periodic with first interrupt to happen at - * hpet_tick, and period also hpet_tick. - */ - cfg = hpet_readl(HPET_T0_CFG); - cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC | - HPET_TN_SETVAL | HPET_TN_32BIT; - hpet_writel(cfg, HPET_T0_CFG); - - /* - * The first write after writing TN_SETVAL to the config register sets - * the counter value, the second write sets the threshold. - */ - hpet_writel(tick, HPET_T0_CMP); - hpet_writel(tick, HPET_T0_CMP); - } - /* - * Go! - */ - cfg = hpet_readl(HPET_CFG); - if (hpet_use_timer) - cfg |= HPET_CFG_LEGACY; - cfg |= HPET_CFG_ENABLE; - hpet_writel(cfg, HPET_CFG); - - return 0; -} - -/* - * Check whether HPET was found by ACPI boot parse. If yes setup HPET - * counter 0 for kernel base timer. - */ -int __init hpet_enable(void) -{ - unsigned int id; - unsigned long tick_fsec_low, tick_fsec_high; /* tick in femto sec */ - unsigned long hpet_tick_rem; - - if (boot_hpet_disable) - return -1; - - if (!hpet_address) { - return -1; - } - hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE); - /* - * Read the period, compute tick and quotient. - */ - id = hpet_readl(HPET_ID); - - /* - * We are checking for value '1' or more in number field if - * CONFIG_HPET_EMULATE_RTC is set because we will need an - * additional timer for RTC emulation. - * However, we can do with one timer otherwise using the - * the single HPET timer for system time. - */ -#ifdef CONFIG_HPET_EMULATE_RTC - if (!(id & HPET_ID_NUMBER)) { - iounmap(hpet_virt_address); - hpet_virt_address = NULL; - return -1; - } -#endif - - - hpet_period = hpet_readl(HPET_PERIOD); - if ((hpet_period < HPET_MIN_PERIOD) || (hpet_period > HPET_MAX_PERIOD)) { - iounmap(hpet_virt_address); - hpet_virt_address = NULL; - return -1; - } - - /* - * 64 bit math - * First changing tick into fsec - * Then 64 bit div to find number of hpet clk per tick - */ - ASM_MUL64_REG(tick_fsec_low, tick_fsec_high, - KERNEL_TICK_USEC, FSEC_TO_USEC); - ASM_DIV64_REG(hpet_tick, hpet_tick_rem, - hpet_period, tick_fsec_low, tick_fsec_high); - - if (hpet_tick_rem > (hpet_period >> 1)) - hpet_tick++; /* rounding the result */ - - hpet_use_timer = id & HPET_ID_LEGSUP; - - if (hpet_timer_stop_set_go(hpet_tick)) { - iounmap(hpet_virt_address); - hpet_virt_address = NULL; - return -1; - } - - use_hpet = 1; - -#ifdef CONFIG_HPET - { - struct hpet_data hd; - unsigned int ntimer; - - memset(&hd, 0, sizeof (hd)); - - ntimer = hpet_readl(HPET_ID); - ntimer = (ntimer & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT; - ntimer++; - - /* - * Register with driver. - * Timer0 and Timer1 is used by platform. - */ - hd.hd_phys_address = hpet_address; - hd.hd_address = hpet_virt_address; - hd.hd_nirqs = ntimer; - hd.hd_flags = HPET_DATA_PLATFORM; - hpet_reserve_timer(&hd, 0); -#ifdef CONFIG_HPET_EMULATE_RTC - hpet_reserve_timer(&hd, 1); -#endif - hd.hd_irq[0] = HPET_LEGACY_8254; - hd.hd_irq[1] = HPET_LEGACY_RTC; - if (ntimer > 2) { - struct hpet __iomem *hpet; - struct hpet_timer __iomem *timer; - int i; - - hpet = hpet_virt_address; - - for (i = 2, timer = &hpet->hpet_timers[2]; i < ntimer; - timer++, i++) - hd.hd_irq[i] = (timer->hpet_config & - Tn_INT_ROUTE_CNF_MASK) >> - Tn_INT_ROUTE_CNF_SHIFT; - - } - - hpet_alloc(&hd); - } -#endif - -#ifdef CONFIG_X86_LOCAL_APIC - if (hpet_use_timer) - wait_timer_tick = wait_hpet_tick; -#endif - return 0; -} - -int hpet_reenable(void) -{ - return hpet_timer_stop_set_go(hpet_tick); -} - -int is_hpet_enabled(void) -{ - return use_hpet; -} - -int is_hpet_capable(void) -{ - if (!boot_hpet_disable && hpet_address) - return 1; - return 0; -} - -static int __init hpet_setup(char* str) -{ - if (str) { - if (!strncmp("disable", str, 7)) - boot_hpet_disable = 1; - } - return 1; -} - -__setup("hpet=", hpet_setup); - -#ifdef CONFIG_HPET_EMULATE_RTC -/* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET - * is enabled, we support RTC interrupt functionality in software. - * RTC has 3 kinds of interrupts: - * 1) Update Interrupt - generate an interrupt, every sec, when RTC clock - * is updated - * 2) Alarm Interrupt - generate an interrupt at a specific time of day - * 3) Periodic Interrupt - generate periodic interrupt, with frequencies - * 2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2) - * (1) and (2) above are implemented using polling at a frequency of - * 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt - * overhead. (DEFAULT_RTC_INT_FREQ) - * For (3), we use interrupts at 64Hz or user specified periodic - * frequency, whichever is higher. - */ -#include <linux/mc146818rtc.h> -#include <linux/rtc.h> - -#define DEFAULT_RTC_INT_FREQ 64 -#define RTC_NUM_INTS 1 - -static unsigned long UIE_on; -static unsigned long prev_update_sec; - -static unsigned long AIE_on; -static struct rtc_time alarm_time; - -static unsigned long PIE_on; -static unsigned long PIE_freq = DEFAULT_RTC_INT_FREQ; -static unsigned long PIE_count; - -static unsigned long hpet_rtc_int_freq; /* RTC interrupt frequency */ -static unsigned int hpet_t1_cmp; /* cached comparator register */ - -/* - * Timer 1 for RTC, we do not use periodic interrupt feature, - * even if HPET supports periodic interrupts on Timer 1. - * The reason being, to set up a periodic interrupt in HPET, we need to - * stop the main counter. And if we do that everytime someone diables/enables - * RTC, we will have adverse effect on main kernel timer running on Timer 0. - * So, for the time being, simulate the periodic interrupt in software. - * - * hpet_rtc_timer_init() is called for the first time and during subsequent - * interuppts reinit happens through hpet_rtc_timer_reinit(). - */ -int hpet_rtc_timer_init(void) -{ - unsigned int cfg, cnt; - unsigned long flags; - - if (!is_hpet_enabled()) - return 0; - /* - * Set the counter 1 and enable the interrupts. - */ - if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ)) - hpet_rtc_int_freq = PIE_freq; - else - hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ; - - local_irq_save(flags); - - cnt = hpet_readl(HPET_COUNTER); - cnt += ((hpet_tick*HZ)/hpet_rtc_int_freq); - hpet_writel(cnt, HPET_T1_CMP); - hpet_t1_cmp = cnt; - - cfg = hpet_readl(HPET_T1_CFG); - cfg &= ~HPET_TN_PERIODIC; - cfg |= HPET_TN_ENABLE | HPET_TN_32BIT; - hpet_writel(cfg, HPET_T1_CFG); - - local_irq_restore(flags); - - return 1; -} - -static void hpet_rtc_timer_reinit(void) -{ - unsigned int cfg, cnt, ticks_per_int, lost_ints; - - if (unlikely(!(PIE_on | AIE_on | UIE_on))) { - cfg = hpet_readl(HPET_T1_CFG); - cfg &= ~HPET_TN_ENABLE; - hpet_writel(cfg, HPET_T1_CFG); - return; - } - - if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ)) - hpet_rtc_int_freq = PIE_freq; - else - hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ; - - /* It is more accurate to use the comparator value than current count.*/ - ticks_per_int = hpet_tick * HZ / hpet_rtc_int_freq; - hpet_t1_cmp += ticks_per_int; - hpet_writel(hpet_t1_cmp, HPET_T1_CMP); - - /* - * If the interrupt handler was delayed too long, the write above tries - * to schedule the next interrupt in the past and the hardware would - * not interrupt until the counter had wrapped around. - * So we have to check that the comparator wasn't set to a past time. - */ - cnt = hpet_readl(HPET_COUNTER); - if (unlikely((int)(cnt - hpet_t1_cmp) > 0)) { - lost_ints = (cnt - hpet_t1_cmp) / ticks_per_int + 1; - /* Make sure that, even with the time needed to execute - * this code, the next scheduled interrupt has been moved - * back to the future: */ - lost_ints++; - - hpet_t1_cmp += lost_ints * ticks_per_int; - hpet_writel(hpet_t1_cmp, HPET_T1_CMP); - - if (PIE_on) - PIE_count += lost_ints; - - printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n", - hpet_rtc_int_freq); - } -} - -/* - * The functions below are called from rtc driver. - * Return 0 if HPET is not being used. - * Otherwise do the necessary changes and return 1. - */ -int hpet_mask_rtc_irq_bit(unsigned long bit_mask) -{ - if (!is_hpet_enabled()) - return 0; - - if (bit_mask & RTC_UIE) - UIE_on = 0; - if (bit_mask & RTC_PIE) - PIE_on = 0; - if (bit_mask & RTC_AIE) - AIE_on = 0; - - return 1; -} - -int hpet_set_rtc_irq_bit(unsigned long bit_mask) -{ - int timer_init_reqd = 0; - - if (!is_hpet_enabled()) - return 0; - - if (!(PIE_on | AIE_on | UIE_on)) - timer_init_reqd = 1; - - if (bit_mask & RTC_UIE) { - UIE_on = 1; - } - if (bit_mask & RTC_PIE) { - PIE_on = 1; - PIE_count = 0; - } - if (bit_mask & RTC_AIE) { - AIE_on = 1; - } - - if (timer_init_reqd) - hpet_rtc_timer_init(); - - return 1; -} - -int hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec) -{ - if (!is_hpet_enabled()) - return 0; - - alarm_time.tm_hour = hrs; - alarm_time.tm_min = min; - alarm_time.tm_sec = sec; - - return 1; -} - -int hpet_set_periodic_freq(unsigned long freq) -{ - if (!is_hpet_enabled()) - return 0; - - PIE_freq = freq; - PIE_count = 0; - - return 1; -} - -int hpet_rtc_dropped_irq(void) -{ - if (!is_hpet_enabled()) - return 0; - - return 1; -} - -irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id) -{ - struct rtc_time curr_time; - unsigned long rtc_int_flag = 0; - int call_rtc_interrupt = 0; - - hpet_rtc_timer_reinit(); - - if (UIE_on | AIE_on) { - rtc_get_rtc_time(&curr_time); - } - if (UIE_on) { - if (curr_time.tm_sec != prev_update_sec) { - /* Set update int info, call real rtc int routine */ - call_rtc_interrupt = 1; - rtc_int_flag = RTC_UF; - prev_update_sec = curr_time.tm_sec; - } - } - if (PIE_on) { - PIE_count++; - if (PIE_count >= hpet_rtc_int_freq/PIE_freq) { - /* Set periodic int info, call real rtc int routine */ - call_rtc_interrupt = 1; - rtc_int_flag |= RTC_PF; - PIE_count = 0; - } - } - if (AIE_on) { - if ((curr_time.tm_sec == alarm_time.tm_sec) && - (curr_time.tm_min == alarm_time.tm_min) && - (curr_time.tm_hour == alarm_time.tm_hour)) { - /* Set alarm int info, call real rtc int routine */ - call_rtc_interrupt = 1; - rtc_int_flag |= RTC_AF; - } - } - if (call_rtc_interrupt) { - rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8)); - rtc_interrupt(rtc_int_flag, dev_id); - } - return IRQ_HANDLED; -} -#endif - |