diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 4 | ||||
| -rw-r--r-- | arch/x86/include/asm/msr-index.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/apic/apic.c | 73 |
3 files changed, 59 insertions, 20 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 9776f068306b..4aa9ca0de63c 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1304,6 +1304,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. lapic [X86-32,APIC] Enable the local APIC even if BIOS disabled it. + lapic= [x86,APIC] "notscdeadline" Do not use TSC deadline + value for LAPIC timer one-shot implementation. Default + back to the programmable timer unit in the LAPIC. + lapic_timer_c2_ok [X86,APIC] trust the local apic timer in C2 power state. diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index 7f0edceb7563..e400cdb2dd65 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -337,6 +337,8 @@ #define MSR_IA32_MISC_ENABLE_TURBO_DISABLE (1ULL << 38) #define MSR_IA32_MISC_ENABLE_IP_PREF_DISABLE (1ULL << 39) +#define MSR_IA32_TSC_DEADLINE 0x000006E0 + /* P4/Xeon+ specific */ #define MSR_IA32_MCG_EAX 0x00000180 #define MSR_IA32_MCG_EBX 0x00000181 diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index b17416e72fbd..b994cc84aa7e 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -90,21 +90,6 @@ EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid); */ DEFINE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid, BAD_APICID); -/* - * Knob to control our willingness to enable the local APIC. - * - * +1=force-enable - */ -static int force_enable_local_apic __initdata; -/* - * APIC command line parameters - */ -static int __init parse_lapic(char *arg) -{ - force_enable_local_apic = 1; - return 0; -} -early_param("lapic", parse_lapic); /* Local APIC was disabled by the BIOS and enabled by the kernel */ static int enabled_via_apicbase; @@ -133,6 +118,25 @@ static inline void imcr_apic_to_pic(void) } #endif +/* + * Knob to control our willingness to enable the local APIC. + * + * +1=force-enable + */ +static int force_enable_local_apic __initdata; +/* + * APIC command line parameters + */ +static int __init parse_lapic(char *arg) +{ + if (config_enabled(CONFIG_X86_32) && !arg) + force_enable_local_apic = 1; + else if (!strncmp(arg, "notscdeadline", 13)) + setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER); + return 0; +} +early_param("lapic", parse_lapic); + #ifdef CONFIG_X86_64 static int apic_calibrate_pmtmr __initdata; static __init int setup_apicpmtimer(char *s) @@ -315,6 +319,7 @@ int lapic_get_maxlvt(void) /* Clock divisor */ #define APIC_DIVISOR 16 +#define TSC_DIVISOR 32 /* * This function sets up the local APIC timer, with a timeout of @@ -333,6 +338,9 @@ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen) lvtt_value = LOCAL_TIMER_VECTOR; if (!oneshot) lvtt_value |= APIC_LVT_TIMER_PERIODIC; + else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) + lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE; + if (!lapic_is_integrated()) lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV); @@ -341,6 +349,11 @@ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen) apic_write(APIC_LVTT, lvtt_value); + if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) { + printk_once(KERN_DEBUG "TSC deadline timer enabled\n"); + return; + } + /* * Divide PICLK by 16 */ @@ -453,6 +466,16 @@ static int lapic_next_event(unsigned long delta, return 0; } +static int lapic_next_deadline(unsigned long delta, + struct clock_event_device *evt) +{ + u64 tsc; + + rdtscll(tsc); + wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR)); + return 0; +} + /* * Setup the lapic timer in periodic or oneshot mode */ @@ -533,7 +556,15 @@ static void __cpuinit setup_APIC_timer(void) memcpy(levt, &lapic_clockevent, sizeof(*levt)); levt->cpumask = cpumask_of(smp_processor_id()); - clockevents_register_device(levt); + if (this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) { + levt->features &= ~(CLOCK_EVT_FEAT_PERIODIC | + CLOCK_EVT_FEAT_DUMMY); + levt->set_next_event = lapic_next_deadline; + clockevents_config_and_register(levt, + (tsc_khz / TSC_DIVISOR) * 1000, + 0xF, ~0UL); + } else + clockevents_register_device(levt); } /* @@ -661,7 +692,9 @@ static int __init calibrate_APIC_clock(void) * in the clockevent structure and return. */ - if (lapic_timer_frequency) { + if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) { + return 0; + } else if (lapic_timer_frequency) { apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n", lapic_timer_frequency); lapic_clockevent.mult = div_sc(lapic_timer_frequency/APIC_DIVISOR, @@ -674,6 +707,9 @@ static int __init calibrate_APIC_clock(void) return 0; } + apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n" + "calibrating APIC timer ...\n"); + local_irq_disable(); /* Replace the global interrupt handler */ @@ -811,9 +847,6 @@ void __init setup_boot_APIC_clock(void) return; } - apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n" - "calibrating APIC timer ...\n"); - if (calibrate_APIC_clock()) { /* No broadcast on UP ! */ if (num_possible_cpus() > 1) |
