From 7e69f2b1ead2a4c51c12817f18263ff0e59335a6 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 16 Feb 2007 01:27:42 -0800 Subject: [PATCH] [PATCH] clocksource: Remove the update callback The clocksource code allows direct updates of the rating of a given clocksource now. Change TSC unstable tracking to use this interface and remove the update callback. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Cc: john stultz Cc: Roman Zippel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/tsc.c | 50 +++++++++++++------------------------ include/linux/clocksource.h | 2 -- kernel/timer.c | 2 -- 3 files changed, 17 insertions(+), 37 deletions(-) diff --git a/arch/i386/kernel/tsc.c b/arch/i386/kernel/tsc.c index a37654991788..b4b2be21d1c7 100644 --- a/arch/i386/kernel/tsc.c +++ b/arch/i386/kernel/tsc.c @@ -60,12 +60,6 @@ static inline int check_tsc_unstable(void) return tsc_unstable; } -void mark_tsc_unstable(void) -{ - tsc_unstable = 1; -} -EXPORT_SYMBOL_GPL(mark_tsc_unstable); - /* Accellerators for sched_clock() * convert from cycles(64bits) => nanoseconds (64bits) * basic equation: @@ -295,7 +289,6 @@ core_initcall(cpufreq_tsc); /* clock source code */ static unsigned long current_tsc_khz = 0; -static int tsc_update_callback(void); static cycle_t read_tsc(void) { @@ -313,37 +306,28 @@ static struct clocksource clocksource_tsc = { .mask = CLOCKSOURCE_MASK(64), .mult = 0, /* to be set */ .shift = 22, - .update_callback = tsc_update_callback, .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_MUST_VERIFY, }; -static int tsc_update_callback(void) +void mark_tsc_unstable(void) { - int change = 0; - - /* check to see if we should switch to the safe clocksource: */ - if (clocksource_tsc.rating != 0 && check_tsc_unstable()) { - clocksource_change_rating(&clocksource_tsc, 0); - change = 1; - } - - /* only update if tsc_khz has changed: */ - if (current_tsc_khz != tsc_khz) { - current_tsc_khz = tsc_khz; - clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz, - clocksource_tsc.shift); - change = 1; + if (!tsc_unstable) { + tsc_unstable = 1; + /* Can be called before registration */ + if (clocksource_tsc.mult) + clocksource_change_rating(&clocksource_tsc, 0); + else + clocksource_tsc.rating = 0; } - - return change; } +EXPORT_SYMBOL_GPL(mark_tsc_unstable); static int __init dmi_mark_tsc_unstable(struct dmi_system_id *d) { printk(KERN_NOTICE "%s detected: marking TSC unstable.\n", d->ident); - mark_tsc_unstable(); + tsc_unstable = 1; return 0; } @@ -415,11 +399,12 @@ __cpuinit int unsynchronized_tsc(void) * Intel systems are normally all synchronized. * Exceptions must mark TSC as unstable: */ - if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) - return 0; - - /* assume multi socket systems are not synchronized: */ - return num_possible_cpus() > 1; + 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; } static int __init init_tsc_clocksource(void) @@ -429,8 +414,7 @@ static int __init init_tsc_clocksource(void) /* check blacklist */ dmi_check_system(bad_tsc_dmi_table); - if (unsynchronized_tsc()) /* mark unstable if unsynced */ - mark_tsc_unstable(); + unsynchronized_tsc(); current_tsc_khz = tsc_khz; clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz, clocksource_tsc.shift); diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index 45b0c310ae82..a585a29fe7c4 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -44,7 +44,6 @@ typedef u64 cycle_t; * subtraction of non 64 bit counters * @mult: cycle to nanosecond multiplier * @shift: cycle to nanosecond divisor (power of two) - * @update_callback: called when safe to alter clocksource values * @flags: flags describing special properties * @cycle_interval: Used internally by timekeeping core, please ignore. * @xtime_interval: Used internally by timekeeping core, please ignore. @@ -57,7 +56,6 @@ struct clocksource { cycle_t mask; u32 mult; u32 shift; - int (*update_callback)(void); unsigned long flags; /* timekeeping specific data, ignore */ diff --git a/kernel/timer.c b/kernel/timer.c index 1144ff2c2ea3..4b088fcadb3f 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -848,8 +848,6 @@ static int change_clocksource(void) printk(KERN_INFO "Time: %s clocksource has been installed.\n", clock->name); return 1; - } else if (clock->update_callback) { - return clock->update_callback(); } return 0; } -- 2.34.1