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-rw-r--r--arch/x86/kernel/tsc_32.c453
1 files changed, 0 insertions, 453 deletions
diff --git a/arch/x86/kernel/tsc_32.c b/arch/x86/kernel/tsc_32.c
deleted file mode 100644
index 068759db63dd..000000000000
--- a/arch/x86/kernel/tsc_32.c
+++ /dev/null
@@ -1,453 +0,0 @@
-#include <linux/sched.h>
-#include <linux/clocksource.h>
-#include <linux/workqueue.h>
-#include <linux/cpufreq.h>
-#include <linux/jiffies.h>
-#include <linux/init.h>
-#include <linux/dmi.h>
-#include <linux/percpu.h>
-
-#include <asm/delay.h>
-#include <asm/tsc.h>
-#include <asm/io.h>
-#include <asm/timer.h>
-
-#include "mach_timer.h"
-
-static int tsc_disabled;
-
-/*
- * On some systems the TSC frequency does not
- * change with the cpu frequency. So we need
- * an extra value to store the TSC freq
- */
-unsigned int tsc_khz;
-EXPORT_SYMBOL_GPL(tsc_khz);
-
-#ifdef CONFIG_X86_TSC
-static int __init tsc_setup(char *str)
-{
- printk(KERN_WARNING "notsc: Kernel compiled with CONFIG_X86_TSC, "
- "cannot disable TSC completely.\n");
- tsc_disabled = 1;
- return 1;
-}
-#else
-/*
- * disable flag for tsc. Takes effect by clearing the TSC cpu flag
- * in cpu/common.c
- */
-static int __init tsc_setup(char *str)
-{
- setup_clear_cpu_cap(X86_FEATURE_TSC);
- return 1;
-}
-#endif
-
-__setup("notsc", tsc_setup);
-
-/*
- * code to mark and check if the TSC is unstable
- * due to cpufreq or due to unsynced TSCs
- */
-static int tsc_unstable;
-
-int check_tsc_unstable(void)
-{
- return tsc_unstable;
-}
-EXPORT_SYMBOL_GPL(check_tsc_unstable);
-
-/* Accelerators for sched_clock()
- * 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 precision, 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!"
- */
-
-DEFINE_PER_CPU(unsigned long, cyc2ns);
-
-static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
-{
- unsigned long long tsc_now, ns_now;
- unsigned long flags, *scale;
-
- local_irq_save(flags);
- sched_clock_idle_sleep_event();
-
- scale = &per_cpu(cyc2ns, cpu);
-
- rdtscll(tsc_now);
- ns_now = __cycles_2_ns(tsc_now);
-
- if (cpu_khz)
- *scale = (NSEC_PER_MSEC << CYC2NS_SCALE_FACTOR)/cpu_khz;
-
- /*
- * Start smoothly with the new frequency:
- */
- sched_clock_idle_wakeup_event(0);
- local_irq_restore(flags);
-}
-
-/*
- * Scheduler clock - returns current time in nanosec units.
- */
-unsigned long long native_sched_clock(void)
-{
- unsigned long long this_offset;
-
- /*
- * Fall back to jiffies if there's no TSC available:
- * ( But note that we still use it if the TSC is marked
- * unstable. We do this because unlike Time Of Day,
- * the scheduler clock tolerates small errors and it's
- * very important for it to be as fast as the platform
- * can achive it. )
- */
- if (unlikely(tsc_disabled))
- /* No locking but a rare wrong value is not a big deal: */
- return (jiffies_64 - INITIAL_JIFFIES) * (1000000000 / HZ);
-
- /* read the Time Stamp Counter: */
- rdtscll(this_offset);
-
- /* return the value in ns */
- return cycles_2_ns(this_offset);
-}
-
-/* We need to define a real function for sched_clock, to override the
- weak default version */
-#ifdef CONFIG_PARAVIRT
-unsigned long long sched_clock(void)
-{
- return paravirt_sched_clock();
-}
-#else
-unsigned long long sched_clock(void)
- __attribute__((alias("native_sched_clock")));
-#endif
-
-unsigned long native_calculate_cpu_khz(void)
-{
- unsigned long long start, end;
- unsigned long count;
- u64 delta64 = (u64)ULLONG_MAX;
- int i;
- unsigned long flags;
-
- local_irq_save(flags);
-
- /* run 3 times to ensure the cache is warm and to get an accurate reading */
- for (i = 0; i < 3; i++) {
- mach_prepare_counter();
- rdtscll(start);
- mach_countup(&count);
- rdtscll(end);
-
- /*
- * Error: ECTCNEVERSET
- * The CTC wasn't reliable: we got a hit on the very first read,
- * or the CPU was so fast/slow that the quotient wouldn't fit in
- * 32 bits..
- */
- if (count <= 1)
- continue;
-
- /* cpu freq too slow: */
- if ((end - start) <= CALIBRATE_TIME_MSEC)
- continue;
-
- /*
- * We want the minimum time of all runs in case one of them
- * is inaccurate due to SMI or other delay
- */
- delta64 = min(delta64, (end - start));
- }
-
- /* cpu freq too fast (or every run was bad): */
- if (delta64 > (1ULL<<32))
- goto err;
-
- delta64 += CALIBRATE_TIME_MSEC/2; /* round for do_div */
- do_div(delta64,CALIBRATE_TIME_MSEC);
-
- local_irq_restore(flags);
- return (unsigned long)delta64;
-err:
- local_irq_restore(flags);
- return 0;
-}
-
-int recalibrate_cpu_khz(void)
-{
-#ifndef CONFIG_SMP
- unsigned long cpu_khz_old = cpu_khz;
-
- if (cpu_has_tsc) {
- cpu_khz = calculate_cpu_khz();
- tsc_khz = cpu_khz;
- cpu_data(0).loops_per_jiffy =
- cpufreq_scale(cpu_data(0).loops_per_jiffy,
- cpu_khz_old, cpu_khz);
- return 0;
- } else
- return -ENODEV;
-#else
- return -ENODEV;
-#endif
-}
-
-EXPORT_SYMBOL(recalibrate_cpu_khz);
-
-#ifdef CONFIG_CPU_FREQ
-
-/*
- * if the CPU frequency is scaled, TSC-based delays will need a different
- * loops_per_jiffy value to function properly.
- */
-static unsigned int ref_freq;
-static unsigned long loops_per_jiffy_ref;
-static unsigned long cpu_khz_ref;
-
-static int
-time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data)
-{
- struct cpufreq_freqs *freq = data;
-
- if (!ref_freq) {
- if (!freq->old){
- ref_freq = freq->new;
- return 0;
- }
- ref_freq = freq->old;
- loops_per_jiffy_ref = cpu_data(freq->cpu).loops_per_jiffy;
- cpu_khz_ref = cpu_khz;
- }
-
- if ((val == CPUFREQ_PRECHANGE && freq->old < freq->new) ||
- (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
- (val == CPUFREQ_RESUMECHANGE)) {
- if (!(freq->flags & CPUFREQ_CONST_LOOPS))
- cpu_data(freq->cpu).loops_per_jiffy =
- cpufreq_scale(loops_per_jiffy_ref,
- ref_freq, freq->new);
-
- if (cpu_khz) {
-
- if (num_online_cpus() == 1)
- cpu_khz = cpufreq_scale(cpu_khz_ref,
- ref_freq, freq->new);
- if (!(freq->flags & CPUFREQ_CONST_LOOPS)) {
- tsc_khz = cpu_khz;
- set_cyc2ns_scale(cpu_khz, freq->cpu);
- /*
- * TSC based sched_clock turns
- * to junk w/ cpufreq
- */
- mark_tsc_unstable("cpufreq changes");
- }
- }
- }
-
- return 0;
-}
-
-static struct notifier_block time_cpufreq_notifier_block = {
- .notifier_call = time_cpufreq_notifier
-};
-
-static int __init cpufreq_tsc(void)
-{
- return cpufreq_register_notifier(&time_cpufreq_notifier_block,
- CPUFREQ_TRANSITION_NOTIFIER);
-}
-core_initcall(cpufreq_tsc);
-
-#endif
-
-/* clock source code */
-
-static unsigned long current_tsc_khz;
-static struct clocksource clocksource_tsc;
-
-/*
- * We compare the TSC to the cycle_last value in the clocksource
- * structure to avoid a nasty time-warp issue. This can be observed in
- * a very small window right after one CPU updated cycle_last under
- * xtime lock and the other CPU reads a TSC value which is smaller
- * than the cycle_last reference value due to a TSC which is slighty
- * behind. This delta is nowhere else observable, but in that case it
- * results in a forward time jump in the range of hours due to the
- * unsigned delta calculation of the time keeping core code, which is
- * necessary to support wrapping clocksources like pm timer.
- */
-static cycle_t read_tsc(void)
-{
- cycle_t ret;
-
- rdtscll(ret);
-
- return ret >= clocksource_tsc.cycle_last ?
- ret : clocksource_tsc.cycle_last;
-}
-
-static struct clocksource clocksource_tsc = {
- .name = "tsc",
- .rating = 300,
- .read = read_tsc,
- .mask = CLOCKSOURCE_MASK(64),
- .mult = 0, /* to be set */
- .shift = 22,
- .flags = CLOCK_SOURCE_IS_CONTINUOUS |
- CLOCK_SOURCE_MUST_VERIFY,
-};
-
-void mark_tsc_unstable(char *reason)
-{
- if (!tsc_unstable) {
- tsc_unstable = 1;
- printk("Marking TSC unstable due to: %s.\n", reason);
- /* Can be called before registration */
- if (clocksource_tsc.mult)
- clocksource_change_rating(&clocksource_tsc, 0);
- else
- clocksource_tsc.rating = 0;
- }
-}
-EXPORT_SYMBOL_GPL(mark_tsc_unstable);
-
-static int __init dmi_mark_tsc_unstable(const struct dmi_system_id *d)
-{
- printk(KERN_NOTICE "%s detected: marking TSC unstable.\n",
- d->ident);
- tsc_unstable = 1;
- return 0;
-}
-
-/* List of systems that have known TSC problems */
-static struct dmi_system_id __initdata bad_tsc_dmi_table[] = {
- {
- .callback = dmi_mark_tsc_unstable,
- .ident = "IBM Thinkpad 380XD",
- .matches = {
- DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
- DMI_MATCH(DMI_BOARD_NAME, "2635FA0"),
- },
- },
- {}
-};
-
-/*
- * Make an educated guess if the TSC is trustworthy and synchronized
- * over all CPUs.
- */
-__cpuinit int unsynchronized_tsc(void)
-{
- if (!cpu_has_tsc || tsc_unstable)
- return 1;
-
- /* Anything with constant TSC should be synchronized */
- if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
- return 0;
-
- /*
- * Intel systems are normally all synchronized.
- * Exceptions must mark TSC as unstable:
- */
- if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) {
- /* assume multi socket systems are not synchronized: */
- if (num_possible_cpus() > 1)
- tsc_unstable = 1;
- }
- return tsc_unstable;
-}
-
-/*
- * Geode_LX - the OLPC CPU has a possibly a very reliable TSC
- */
-#ifdef CONFIG_MGEODE_LX
-/* RTSC counts during suspend */
-#define RTSC_SUSP 0x100
-
-static void __init check_geode_tsc_reliable(void)
-{
- unsigned long res_low, res_high;
-
- rdmsr_safe(MSR_GEODE_BUSCONT_CONF0, &res_low, &res_high);
- if (res_low & RTSC_SUSP)
- clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY;
-}
-#else
-static inline void check_geode_tsc_reliable(void) { }
-#endif
-
-
-void __init tsc_init(void)
-{
- int cpu;
-
- if (!cpu_has_tsc || tsc_disabled) {
- /* Disable the TSC in case of !cpu_has_tsc */
- tsc_disabled = 1;
- return;
- }
-
- cpu_khz = calculate_cpu_khz();
- tsc_khz = cpu_khz;
-
- if (!cpu_khz) {
- mark_tsc_unstable("could not calculate TSC khz");
- /*
- * We need to disable the TSC completely in this case
- * to prevent sched_clock() from using it.
- */
- tsc_disabled = 1;
- return;
- }
-
- printk("Detected %lu.%03lu MHz processor.\n",
- (unsigned long)cpu_khz / 1000,
- (unsigned long)cpu_khz % 1000);
-
- /*
- * Secondary CPUs do not run through tsc_init(), so set up
- * all the scale factors for all CPUs, assuming the same
- * speed as the bootup CPU. (cpufreq notifiers will fix this
- * up if their speed diverges)
- */
- for_each_possible_cpu(cpu)
- set_cyc2ns_scale(cpu_khz, cpu);
-
- use_tsc_delay();
-
- /* Check and install the TSC clocksource */
- dmi_check_system(bad_tsc_dmi_table);
-
- unsynchronized_tsc();
- check_geode_tsc_reliable();
- current_tsc_khz = tsc_khz;
- clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
- clocksource_tsc.shift);
- /* lower the rating if we already know its unstable: */
- if (check_tsc_unstable()) {
- clocksource_tsc.rating = 0;
- clocksource_tsc.flags &= ~CLOCK_SOURCE_IS_CONTINUOUS;
- }
- clocksource_register(&clocksource_tsc);
-}
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