diff options
| -rw-r--r-- | arch/x86/kernel/time_64.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/tsc_32.c | 5 | ||||
| -rw-r--r-- | include/linux/delay.h | 1 | ||||
| -rw-r--r-- | init/calibrate.c | 36 |
4 files changed, 27 insertions, 17 deletions
diff --git a/arch/x86/kernel/time_64.c b/arch/x86/kernel/time_64.c index c737849..12b4a71 100644 --- a/arch/x86/kernel/time_64.c +++ b/arch/x86/kernel/time_64.c @@ -123,6 +123,8 @@ void __init time_init(void) (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)) cpu_khz = calculate_cpu_khz(); + lpj_tsc = ((unsigned long)tsc_khz * 1000)/HZ; + if (unsynchronized_tsc()) mark_tsc_unstable("TSCs unsynchronized"); diff --git a/arch/x86/kernel/tsc_32.c b/arch/x86/kernel/tsc_32.c index 068759d..be72903 100644 --- a/arch/x86/kernel/tsc_32.c +++ b/arch/x86/kernel/tsc_32.c @@ -401,6 +401,7 @@ static inline void check_geode_tsc_reliable(void) { } void __init tsc_init(void) { int cpu; + u64 lpj; if (!cpu_has_tsc || tsc_disabled) { /* Disable the TSC in case of !cpu_has_tsc */ @@ -421,6 +422,10 @@ void __init tsc_init(void) return; } + lpj = ((u64)tsc_khz * 1000); + do_div(lpj, HZ); + lpj_tsc = lpj; + printk("Detected %lu.%03lu MHz processor.\n", (unsigned long)cpu_khz / 1000, (unsigned long)cpu_khz % 1000); diff --git a/include/linux/delay.h b/include/linux/delay.h index 54552d2..01aec60 100644 --- a/include/linux/delay.h +++ b/include/linux/delay.h @@ -41,6 +41,7 @@ static inline void ndelay(unsigned long x) #define ndelay(x) ndelay(x) #endif +extern unsigned long lpj_tsc; void calibrate_delay(void); void msleep(unsigned int msecs); unsigned long msleep_interruptible(unsigned int msecs); diff --git a/init/calibrate.c b/init/calibrate.c index ecb3822..8628697 100644 --- a/init/calibrate.c +++ b/init/calibrate.c @@ -8,7 +8,9 @@ #include <linux/delay.h> #include <linux/init.h> #include <linux/timex.h> +#include <linux/smp.h> +unsigned long lpj_tsc; unsigned long preset_lpj; static int __init lpj_setup(char *str) { @@ -108,6 +110,10 @@ static unsigned long __cpuinit calibrate_delay_direct(void) {return 0;} * This is the number of bits of precision for the loops_per_jiffy. Each * bit takes on average 1.5/HZ seconds. This (like the original) is a little * better than 1% + * For the boot cpu we can skip the delay calibration and assign it a value + * calculated based on the tsc frequency. + * For the rest of the CPUs we cannot assume that the tsc frequency is same as + * the cpu frequency, hence do the calibration for those. */ #define LPS_PREC 8 @@ -118,20 +124,20 @@ void __cpuinit calibrate_delay(void) if (preset_lpj) { loops_per_jiffy = preset_lpj; - printk("Calibrating delay loop (skipped)... " - "%lu.%02lu BogoMIPS preset\n", - loops_per_jiffy/(500000/HZ), - (loops_per_jiffy/(5000/HZ)) % 100); + printk(KERN_INFO + "Calibrating delay loop (skipped) preset value.. "); + } else if ((smp_processor_id() == 0) && lpj_tsc) { + loops_per_jiffy = lpj_tsc; + printk(KERN_INFO + "Calibrating delay loop (skipped), " + "using tsc calculated value.. "); } else if ((loops_per_jiffy = calibrate_delay_direct()) != 0) { - printk("Calibrating delay using timer specific routine.. "); - printk("%lu.%02lu BogoMIPS (lpj=%lu)\n", - loops_per_jiffy/(500000/HZ), - (loops_per_jiffy/(5000/HZ)) % 100, - loops_per_jiffy); + printk(KERN_INFO + "Calibrating delay using timer specific routine.. "); } else { loops_per_jiffy = (1<<12); - printk(KERN_DEBUG "Calibrating delay loop... "); + printk(KERN_INFO "Calibrating delay loop... "); while ((loops_per_jiffy <<= 1) != 0) { /* wait for "start of" clock tick */ ticks = jiffies; @@ -161,12 +167,8 @@ void __cpuinit calibrate_delay(void) if (jiffies != ticks) /* longer than 1 tick */ loops_per_jiffy &= ~loopbit; } - - /* Round the value and print it */ - printk("%lu.%02lu BogoMIPS (lpj=%lu)\n", - loops_per_jiffy/(500000/HZ), - (loops_per_jiffy/(5000/HZ)) % 100, - loops_per_jiffy); } - + printk(KERN_INFO "%lu.%02lu BogoMIPS (lpj=%lu)\n", + loops_per_jiffy/(500000/HZ), + (loops_per_jiffy/(5000/HZ)) % 100, loops_per_jiffy); } |
