ptrace.o time.o ioport.o ldt.o setup.o i8259_64.o sys_x86_64.o \
x8664_ksyms.o i387.o syscall.o vsyscall.o \
setup64.o bootflag.o e820.o reboot.o quirks.o i8237.o \
- pci-dma_64.o pci-nommu.o alternative.o hpet.o tsc.o bugs.o \
+ pci-dma_64.o pci-nommu.o alternative.o hpet_64.o tsc.o bugs.o \
perfctr-watchdog.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
+++ /dev/null
-#include <linux/kernel.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/mc146818rtc.h>
-#include <linux/time.h>
-#include <linux/clocksource.h>
-#include <linux/ioport.h>
-#include <linux/acpi.h>
-#include <linux/hpet.h>
-#include <asm/pgtable.h>
-#include <asm/vsyscall.h>
-#include <asm/timex.h>
-#include <asm/hpet.h>
-
-#define HPET_MASK 0xFFFFFFFF
-#define HPET_SHIFT 22
-
-/* FSEC = 10^-15 NSEC = 10^-9 */
-#define FSEC_PER_NSEC 1000000
-
-int nohpet __initdata;
-
-unsigned long hpet_address;
-unsigned long hpet_period; /* fsecs / HPET clock */
-unsigned long hpet_tick; /* HPET clocks / interrupt */
-
-int hpet_use_timer; /* Use counter of hpet for time keeping,
- * otherwise PIT
- */
-
-#ifdef CONFIG_HPET
-static __init int late_hpet_init(void)
-{
- struct hpet_data hd;
- unsigned int ntimer;
-
- if (!hpet_address)
- return 0;
-
- 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 = (void __iomem *)fix_to_virt(FIX_HPET_BASE);
- 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 *hpet;
- struct hpet_timer *timer;
- int i;
-
- hpet = (struct hpet *) fix_to_virt(FIX_HPET_BASE);
- timer = &hpet->hpet_timers[2];
- for (i = 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);
- return 0;
-}
-fs_initcall(late_hpet_init);
-#endif
-
-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_CFG_LEGACY);
- hpet_writel(cfg, HPET_CFG);
- hpet_writel(0, HPET_COUNTER);
- hpet_writel(0, HPET_COUNTER + 4);
-
-/*
- * Set up timer 0, as periodic with first interrupt to happen at hpet_tick,
- * and period also hpet_tick.
- */
- if (hpet_use_timer) {
- hpet_writel(HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL |
- HPET_TN_32BIT, HPET_T0_CFG);
- hpet_writel(hpet_tick, HPET_T0_CMP); /* next interrupt */
- hpet_writel(hpet_tick, HPET_T0_CMP); /* period */
- cfg |= HPET_CFG_LEGACY;
- }
-/*
- * Go!
- */
-
- cfg |= HPET_CFG_ENABLE;
- hpet_writel(cfg, HPET_CFG);
-
- return 0;
-}
-
-static cycle_t read_hpet(void)
-{
- return (cycle_t)hpet_readl(HPET_COUNTER);
-}
-
-static cycle_t __vsyscall_fn vread_hpet(void)
-{
- return readl((void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0);
-}
-
-struct clocksource clocksource_hpet = {
- .name = "hpet",
- .rating = 250,
- .read = read_hpet,
- .mask = (cycle_t)HPET_MASK,
- .mult = 0, /* set below */
- .shift = HPET_SHIFT,
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
- .vread = vread_hpet,
-};
-
-int __init hpet_arch_init(void)
-{
- unsigned int id;
- u64 tmp;
-
- if (!hpet_address)
- return -1;
- set_fixmap_nocache(FIX_HPET_BASE, hpet_address);
- __set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE);
-
-/*
- * Read the period, compute tick and quotient.
- */
-
- id = hpet_readl(HPET_ID);
-
- if (!(id & HPET_ID_VENDOR) || !(id & HPET_ID_NUMBER))
- return -1;
-
- hpet_period = hpet_readl(HPET_PERIOD);
- if (hpet_period < 100000 || hpet_period > 100000000)
- return -1;
-
- hpet_tick = (FSEC_PER_TICK + hpet_period / 2) / hpet_period;
-
- hpet_use_timer = (id & HPET_ID_LEGSUP);
-
- /*
- * hpet period is in femto seconds per cycle
- * so we need to convert this to ns/cyc units
- * aproximated by mult/2^shift
- *
- * fsec/cyc * 1nsec/1000000fsec = nsec/cyc = mult/2^shift
- * fsec/cyc * 1ns/1000000fsec * 2^shift = mult
- * fsec/cyc * 2^shift * 1nsec/1000000fsec = mult
- * (fsec/cyc << shift)/1000000 = mult
- * (hpet_period << shift)/FSEC_PER_NSEC = mult
- */
- tmp = (u64)hpet_period << HPET_SHIFT;
- do_div(tmp, FSEC_PER_NSEC);
- clocksource_hpet.mult = (u32)tmp;
- clocksource_register(&clocksource_hpet);
-
- return hpet_timer_stop_set_go(hpet_tick);
-}
-
-int hpet_reenable(void)
-{
- return hpet_timer_stop_set_go(hpet_tick);
-}
-
-/*
- * calibrate_tsc() calibrates the processor TSC in a very simple way, comparing
- * it to the HPET timer of known frequency.
- */
-
-#define TICK_COUNT 100000000
-#define SMI_THRESHOLD 50000
-#define MAX_TRIES 5
-
-/*
- * Some platforms take periodic SMI interrupts with 5ms duration. Make sure none
- * occurs between the reads of the hpet & TSC.
- */
-static void __init read_hpet_tsc(int *hpet, int *tsc)
-{
- int tsc1, tsc2, hpet1, i;
-
- for (i = 0; i < MAX_TRIES; i++) {
- tsc1 = get_cycles_sync();
- hpet1 = hpet_readl(HPET_COUNTER);
- tsc2 = get_cycles_sync();
- if ((tsc2 - tsc1) < SMI_THRESHOLD)
- break;
- }
- *hpet = hpet1;
- *tsc = tsc2;
-}
-
-unsigned int __init hpet_calibrate_tsc(void)
-{
- int tsc_start, hpet_start;
- int tsc_now, hpet_now;
- unsigned long flags;
-
- local_irq_save(flags);
-
- read_hpet_tsc(&hpet_start, &tsc_start);
-
- do {
- local_irq_disable();
- read_hpet_tsc(&hpet_now, &tsc_now);
- local_irq_restore(flags);
- } while ((tsc_now - tsc_start) < TICK_COUNT &&
- (hpet_now - hpet_start) < TICK_COUNT);
-
- return (tsc_now - tsc_start) * 1000000000L
- / ((hpet_now - hpet_start) * hpet_period / 1000);
-}
-
-#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/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 */
-
-int is_hpet_enabled(void)
-{
- return hpet_address != 0;
-}
-
-/*
- * 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;
-
- if (printk_ratelimit())
- 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
-
-static int __init nohpet_setup(char *s)
-{
- nohpet = 1;
- return 1;
-}
-
-__setup("nohpet", nohpet_setup);
--- /dev/null
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/mc146818rtc.h>
+#include <linux/time.h>
+#include <linux/clocksource.h>
+#include <linux/ioport.h>
+#include <linux/acpi.h>
+#include <linux/hpet.h>
+#include <asm/pgtable.h>
+#include <asm/vsyscall.h>
+#include <asm/timex.h>
+#include <asm/hpet.h>
+
+#define HPET_MASK 0xFFFFFFFF
+#define HPET_SHIFT 22
+
+/* FSEC = 10^-15 NSEC = 10^-9 */
+#define FSEC_PER_NSEC 1000000
+
+int nohpet __initdata;
+
+unsigned long hpet_address;
+unsigned long hpet_period; /* fsecs / HPET clock */
+unsigned long hpet_tick; /* HPET clocks / interrupt */
+
+int hpet_use_timer; /* Use counter of hpet for time keeping,
+ * otherwise PIT
+ */
+
+#ifdef CONFIG_HPET
+static __init int late_hpet_init(void)
+{
+ struct hpet_data hd;
+ unsigned int ntimer;
+
+ if (!hpet_address)
+ return 0;
+
+ 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 = (void __iomem *)fix_to_virt(FIX_HPET_BASE);
+ 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 *hpet;
+ struct hpet_timer *timer;
+ int i;
+
+ hpet = (struct hpet *) fix_to_virt(FIX_HPET_BASE);
+ timer = &hpet->hpet_timers[2];
+ for (i = 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);
+ return 0;
+}
+fs_initcall(late_hpet_init);
+#endif
+
+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_CFG_LEGACY);
+ hpet_writel(cfg, HPET_CFG);
+ hpet_writel(0, HPET_COUNTER);
+ hpet_writel(0, HPET_COUNTER + 4);
+
+/*
+ * Set up timer 0, as periodic with first interrupt to happen at hpet_tick,
+ * and period also hpet_tick.
+ */
+ if (hpet_use_timer) {
+ hpet_writel(HPET_TN_ENABLE | HPET_TN_PERIODIC | HPET_TN_SETVAL |
+ HPET_TN_32BIT, HPET_T0_CFG);
+ hpet_writel(hpet_tick, HPET_T0_CMP); /* next interrupt */
+ hpet_writel(hpet_tick, HPET_T0_CMP); /* period */
+ cfg |= HPET_CFG_LEGACY;
+ }
+/*
+ * Go!
+ */
+
+ cfg |= HPET_CFG_ENABLE;
+ hpet_writel(cfg, HPET_CFG);
+
+ return 0;
+}
+
+static cycle_t read_hpet(void)
+{
+ return (cycle_t)hpet_readl(HPET_COUNTER);
+}
+
+static cycle_t __vsyscall_fn vread_hpet(void)
+{
+ return readl((void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0);
+}
+
+struct clocksource clocksource_hpet = {
+ .name = "hpet",
+ .rating = 250,
+ .read = read_hpet,
+ .mask = (cycle_t)HPET_MASK,
+ .mult = 0, /* set below */
+ .shift = HPET_SHIFT,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+ .vread = vread_hpet,
+};
+
+int __init hpet_arch_init(void)
+{
+ unsigned int id;
+ u64 tmp;
+
+ if (!hpet_address)
+ return -1;
+ set_fixmap_nocache(FIX_HPET_BASE, hpet_address);
+ __set_fixmap(VSYSCALL_HPET, hpet_address, PAGE_KERNEL_VSYSCALL_NOCACHE);
+
+/*
+ * Read the period, compute tick and quotient.
+ */
+
+ id = hpet_readl(HPET_ID);
+
+ if (!(id & HPET_ID_VENDOR) || !(id & HPET_ID_NUMBER))
+ return -1;
+
+ hpet_period = hpet_readl(HPET_PERIOD);
+ if (hpet_period < 100000 || hpet_period > 100000000)
+ return -1;
+
+ hpet_tick = (FSEC_PER_TICK + hpet_period / 2) / hpet_period;
+
+ hpet_use_timer = (id & HPET_ID_LEGSUP);
+
+ /*
+ * hpet period is in femto seconds per cycle
+ * so we need to convert this to ns/cyc units
+ * aproximated by mult/2^shift
+ *
+ * fsec/cyc * 1nsec/1000000fsec = nsec/cyc = mult/2^shift
+ * fsec/cyc * 1ns/1000000fsec * 2^shift = mult
+ * fsec/cyc * 2^shift * 1nsec/1000000fsec = mult
+ * (fsec/cyc << shift)/1000000 = mult
+ * (hpet_period << shift)/FSEC_PER_NSEC = mult
+ */
+ tmp = (u64)hpet_period << HPET_SHIFT;
+ do_div(tmp, FSEC_PER_NSEC);
+ clocksource_hpet.mult = (u32)tmp;
+ clocksource_register(&clocksource_hpet);
+
+ return hpet_timer_stop_set_go(hpet_tick);
+}
+
+int hpet_reenable(void)
+{
+ return hpet_timer_stop_set_go(hpet_tick);
+}
+
+/*
+ * calibrate_tsc() calibrates the processor TSC in a very simple way, comparing
+ * it to the HPET timer of known frequency.
+ */
+
+#define TICK_COUNT 100000000
+#define SMI_THRESHOLD 50000
+#define MAX_TRIES 5
+
+/*
+ * Some platforms take periodic SMI interrupts with 5ms duration. Make sure none
+ * occurs between the reads of the hpet & TSC.
+ */
+static void __init read_hpet_tsc(int *hpet, int *tsc)
+{
+ int tsc1, tsc2, hpet1, i;
+
+ for (i = 0; i < MAX_TRIES; i++) {
+ tsc1 = get_cycles_sync();
+ hpet1 = hpet_readl(HPET_COUNTER);
+ tsc2 = get_cycles_sync();
+ if ((tsc2 - tsc1) < SMI_THRESHOLD)
+ break;
+ }
+ *hpet = hpet1;
+ *tsc = tsc2;
+}
+
+unsigned int __init hpet_calibrate_tsc(void)
+{
+ int tsc_start, hpet_start;
+ int tsc_now, hpet_now;
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ read_hpet_tsc(&hpet_start, &tsc_start);
+
+ do {
+ local_irq_disable();
+ read_hpet_tsc(&hpet_now, &tsc_now);
+ local_irq_restore(flags);
+ } while ((tsc_now - tsc_start) < TICK_COUNT &&
+ (hpet_now - hpet_start) < TICK_COUNT);
+
+ return (tsc_now - tsc_start) * 1000000000L
+ / ((hpet_now - hpet_start) * hpet_period / 1000);
+}
+
+#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/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 */
+
+int is_hpet_enabled(void)
+{
+ return hpet_address != 0;
+}
+
+/*
+ * 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;
+
+ if (printk_ratelimit())
+ 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
+
+static int __init nohpet_setup(char *s)
+{
+ nohpet = 1;
+ return 1;
+}
+
+__setup("nohpet", nohpet_setup);
projects / firefly-linux-kernel-4.4.55.git / commitdiff