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Diffstat (limited to 'arch/i386/kernel/timers/timer_hpet.c')
-rw-r--r--arch/i386/kernel/timers/timer_hpet.c217
1 files changed, 0 insertions, 217 deletions
diff --git a/arch/i386/kernel/timers/timer_hpet.c b/arch/i386/kernel/timers/timer_hpet.c
deleted file mode 100644
index 17a6fe7166e7..000000000000
--- a/arch/i386/kernel/timers/timer_hpet.c
+++ /dev/null
@@ -1,217 +0,0 @@
-/*
- * This code largely moved from arch/i386/kernel/time.c.
- * See comments there for proper credits.
- */
-
-#include <linux/spinlock.h>
-#include <linux/init.h>
-#include <linux/timex.h>
-#include <linux/errno.h>
-#include <linux/string.h>
-#include <linux/jiffies.h>
-
-#include <asm/timer.h>
-#include <asm/io.h>
-#include <asm/processor.h>
-
-#include "io_ports.h"
-#include "mach_timer.h"
-#include <asm/hpet.h>
-
-static unsigned long hpet_usec_quotient __read_mostly; /* convert hpet clks to usec */
-static unsigned long tsc_hpet_quotient __read_mostly; /* convert tsc to hpet clks */
-static unsigned long hpet_last; /* hpet counter value at last tick*/
-static unsigned long last_tsc_low; /* lsb 32 bits of Time Stamp Counter */
-static unsigned long last_tsc_high; /* msb 32 bits of Time Stamp Counter */
-static unsigned long long monotonic_base;
-static seqlock_t monotonic_lock = SEQLOCK_UNLOCKED;
-
-/* convert from cycles(64bits) => nanoseconds (64bits)
- * basic equation:
- * ns = cycles / (freq / ns_per_sec)
- * ns = cycles * (ns_per_sec / freq)
- * ns = cycles * (10^9 / (cpu_khz * 10^3))
- * ns = cycles * (10^6 / cpu_khz)
- *
- * Then we use scaling math (suggested by george@mvista.com) to get:
- * ns = cycles * (10^6 * SC / cpu_khz) / SC
- * ns = cycles * cyc2ns_scale / SC
- *
- * And since SC is a constant power of two, we can convert the div
- * into a shift.
- *
- * We can use khz divisor instead of mhz to keep a better percision, since
- * cyc2ns_scale is limited to 10^6 * 2^10, which fits in 32 bits.
- * (mathieu.desnoyers@polymtl.ca)
- *
- * -johnstul@us.ibm.com "math is hard, lets go shopping!"
- */
-static unsigned long cyc2ns_scale __read_mostly;
-#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
-
-static inline void set_cyc2ns_scale(unsigned long cpu_khz)
-{
- cyc2ns_scale = (1000000 << CYC2NS_SCALE_FACTOR)/cpu_khz;
-}
-
-static inline unsigned long long cycles_2_ns(unsigned long long cyc)
-{
- return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
-}
-
-static unsigned long long monotonic_clock_hpet(void)
-{
- unsigned long long last_offset, this_offset, base;
- unsigned seq;
-
- /* atomically read monotonic base & last_offset */
- do {
- seq = read_seqbegin(&monotonic_lock);
- last_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
- base = monotonic_base;
- } while (read_seqretry(&monotonic_lock, seq));
-
- /* Read the Time Stamp Counter */
- rdtscll(this_offset);
-
- /* return the value in ns */
- return base + cycles_2_ns(this_offset - last_offset);
-}
-
-static unsigned long get_offset_hpet(void)
-{
- register unsigned long eax, edx;
-
- eax = hpet_readl(HPET_COUNTER);
- eax -= hpet_last; /* hpet delta */
- eax = min(hpet_tick, eax);
- /*
- * Time offset = (hpet delta) * ( usecs per HPET clock )
- * = (hpet delta) * ( usecs per tick / HPET clocks per tick)
- * = (hpet delta) * ( hpet_usec_quotient ) / (2^32)
- *
- * Where,
- * hpet_usec_quotient = (2^32 * usecs per tick)/HPET clocks per tick
- *
- * Using a mull instead of a divl saves some cycles in critical path.
- */
- ASM_MUL64_REG(eax, edx, hpet_usec_quotient, eax);
-
- /* our adjusted time offset in microseconds */
- return edx;
-}
-
-static void mark_offset_hpet(void)
-{
- unsigned long long this_offset, last_offset;
- unsigned long offset;
-
- write_seqlock(&monotonic_lock);
- last_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
- rdtsc(last_tsc_low, last_tsc_high);
-
- if (hpet_use_timer)
- offset = hpet_readl(HPET_T0_CMP) - hpet_tick;
- else
- offset = hpet_readl(HPET_COUNTER);
- if (unlikely(((offset - hpet_last) >= (2*hpet_tick)) && (hpet_last != 0))) {
- int lost_ticks = ((offset - hpet_last) / hpet_tick) - 1;
- jiffies_64 += lost_ticks;
- }
- hpet_last = offset;
-
- /* update the monotonic base value */
- this_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
- monotonic_base += cycles_2_ns(this_offset - last_offset);
- write_sequnlock(&monotonic_lock);
-}
-
-static void delay_hpet(unsigned long loops)
-{
- unsigned long hpet_start, hpet_end;
- unsigned long eax;
-
- /* loops is the number of cpu cycles. Convert it to hpet clocks */
- ASM_MUL64_REG(eax, loops, tsc_hpet_quotient, loops);
-
- hpet_start = hpet_readl(HPET_COUNTER);
- do {
- rep_nop();
- hpet_end = hpet_readl(HPET_COUNTER);
- } while ((hpet_end - hpet_start) < (loops));
-}
-
-static struct timer_opts timer_hpet;
-
-static int __init init_hpet(char* override)
-{
- unsigned long result, remain;
-
- /* check clock override */
- if (override[0] && strncmp(override,"hpet",4))
- return -ENODEV;
-
- if (!is_hpet_enabled())
- return -ENODEV;
-
- printk("Using HPET for gettimeofday\n");
- if (cpu_has_tsc) {
- unsigned long tsc_quotient = calibrate_tsc_hpet(&tsc_hpet_quotient);
- if (tsc_quotient) {
- /* report CPU clock rate in Hz.
- * The formula is (10^6 * 2^32) / (2^32 * 1 / (clocks/us)) =
- * clock/second. Our precision is about 100 ppm.
- */
- { unsigned long eax=0, edx=1000;
- ASM_DIV64_REG(cpu_khz, edx, tsc_quotient,
- eax, edx);
- printk("Detected %u.%03u MHz processor.\n",
- cpu_khz / 1000, cpu_khz % 1000);
- }
- set_cyc2ns_scale(cpu_khz);
- }
- /* set this only when cpu_has_tsc */
- timer_hpet.read_timer = read_timer_tsc;
- }
-
- /*
- * Math to calculate hpet to usec multiplier
- * Look for the comments at get_offset_hpet()
- */
- ASM_DIV64_REG(result, remain, hpet_tick, 0, KERNEL_TICK_USEC);
- if (remain > (hpet_tick >> 1))
- result++; /* rounding the result */
- hpet_usec_quotient = result;
-
- return 0;
-}
-
-static int hpet_resume(void)
-{
- write_seqlock(&monotonic_lock);
- /* Assume this is the last mark offset time */
- rdtsc(last_tsc_low, last_tsc_high);
-
- if (hpet_use_timer)
- hpet_last = hpet_readl(HPET_T0_CMP) - hpet_tick;
- else
- hpet_last = hpet_readl(HPET_COUNTER);
- write_sequnlock(&monotonic_lock);
- return 0;
-}
-/************************************************************/
-
-/* tsc timer_opts struct */
-static struct timer_opts timer_hpet __read_mostly = {
- .name = "hpet",
- .mark_offset = mark_offset_hpet,
- .get_offset = get_offset_hpet,
- .monotonic_clock = monotonic_clock_hpet,
- .delay = delay_hpet,
- .resume = hpet_resume,
-};
-
-struct init_timer_opts __initdata timer_hpet_init = {
- .init = init_hpet,
- .opts = &timer_hpet,
-};