diff options
Diffstat (limited to 'arch/x86/kernel/tsc_32.c')
| -rw-r--r-- | arch/x86/kernel/tsc_32.c | 188 |
1 files changed, 0 insertions, 188 deletions
diff --git a/arch/x86/kernel/tsc_32.c b/arch/x86/kernel/tsc_32.c deleted file mode 100644 index bbc153d36f84..000000000000 --- a/arch/x86/kernel/tsc_32.c +++ /dev/null @@ -1,188 +0,0 @@ -#include <linux/sched.h> -#include <linux/clocksource.h> -#include <linux/workqueue.h> -#include <linux/delay.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" - -extern int tsc_unstable; -extern int tsc_disabled; - -/* clock source code */ - -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; - u64 lpj; - - if (!cpu_has_tsc || tsc_disabled > 0) - return; - - cpu_khz = calculate_cpu_khz(); - tsc_khz = cpu_khz; - - if (!cpu_khz) { - mark_tsc_unstable("could not calculate TSC khz"); - return; - } - - lpj = ((u64)tsc_khz * 1000); - do_div(lpj, HZ); - lpj_fine = lpj; - - /* now allow native_sched_clock() to use rdtsc */ - tsc_disabled = 0; - - 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(); - clocksource_tsc.mult = clocksource_khz2mult(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); -} |