diff options
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r-- | arch/x86/kernel/early_printk.c | 2 | ||||
-rw-r--r-- | arch/x86/kernel/smpboot.c | 16 | ||||
-rw-r--r-- | arch/x86/kernel/tsc.c | 20 |
3 files changed, 32 insertions, 6 deletions
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c index 9d42a52d233..9b9f18b4991 100644 --- a/arch/x86/kernel/early_printk.c +++ b/arch/x86/kernel/early_printk.c @@ -240,7 +240,7 @@ static int __init setup_early_printk(char *buf) if (!strncmp(buf, "xen", 3)) early_console_register(&xenboot_console, keep); #endif -#ifdef CONFIG_EARLY_PRINTK_MRST +#ifdef CONFIG_EARLY_PRINTK_INTEL_MID if (!strncmp(buf, "mrst", 4)) { mrst_early_console_init(); early_console_register(&early_mrst_console, keep); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 79f636bc44c..66d250c00d1 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -207,23 +207,29 @@ static void __cpuinit smp_callin(void) * Need to setup vector mappings before we enable interrupts. */ setup_vector_irq(smp_processor_id()); + + /* + * Save our processor parameters. Note: this information + * is needed for clock calibration. + */ + smp_store_cpu_info(cpuid); + /* * Get our bogomips. + * Update loops_per_jiffy in cpu_data. Previous call to + * smp_store_cpu_info() stored a value that is close but not as + * accurate as the value just calculated. * * Need to enable IRQs because it can take longer and then * the NMI watchdog might kill us. */ local_irq_enable(); calibrate_delay(); + cpu_data(cpuid).loops_per_jiffy = loops_per_jiffy; local_irq_disable(); pr_debug("Stack at about %p\n", &cpuid); /* - * Save our processor parameters - */ - smp_store_cpu_info(cpuid); - - /* * This must be done before setting cpu_online_mask * or calling notify_cpu_starting. */ diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 2c9cf0fd78f..c0dd5b60374 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -995,3 +995,23 @@ void __init tsc_init(void) check_system_tsc_reliable(); } +#ifdef CONFIG_SMP +/* + * If we have a constant TSC and are using the TSC for the delay loop, + * we can skip clock calibration if another cpu in the same socket has already + * been calibrated. This assumes that CONSTANT_TSC applies to all + * cpus in the socket - this should be a safe assumption. + */ +unsigned long __cpuinit calibrate_delay_is_known(void) +{ + int i, cpu = smp_processor_id(); + + if (!tsc_disabled && !cpu_has(&cpu_data(cpu), X86_FEATURE_CONSTANT_TSC)) + return 0; + + for_each_online_cpu(i) + if (cpu_data(i).phys_proc_id == cpu_data(cpu).phys_proc_id) + return cpu_data(i).loops_per_jiffy; + return 0; +} +#endif |