diff options
Diffstat (limited to 'arch/x86_64')
| -rw-r--r-- | arch/x86_64/kernel/apic.c | 55 | ||||
| -rw-r--r-- | arch/x86_64/kernel/time.c | 5 |
2 files changed, 58 insertions, 2 deletions
diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c index fa47ae7..40cbd60 100644 --- a/arch/x86_64/kernel/apic.c +++ b/arch/x86_64/kernel/apic.c @@ -25,6 +25,7 @@ #include <linux/mc146818rtc.h> #include <linux/kernel_stat.h> #include <linux/sysdev.h> +#include <linux/module.h> #include <asm/atomic.h> #include <asm/smp.h> @@ -38,6 +39,12 @@ int apic_verbosity; int disable_apic_timer __initdata; +/* + * cpu_mask that denotes the CPUs that needs timer interrupt coming in as + * IPIs in place of local APIC timers + */ +static cpumask_t timer_interrupt_broadcast_ipi_mask; + /* Using APIC to generate smp_local_timer_interrupt? */ int using_apic_timer = 0; @@ -656,9 +663,14 @@ void __init init_apic_mappings(void) static void __setup_APIC_LVTT(unsigned int clocks) { unsigned int lvtt_value, tmp_value, ver; + int cpu = smp_processor_id(); ver = GET_APIC_VERSION(apic_read(APIC_LVR)); lvtt_value = APIC_LVT_TIMER_PERIODIC | LOCAL_TIMER_VECTOR; + + if (cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask)) + lvtt_value |= APIC_LVT_MASKED; + apic_write_around(APIC_LVTT, lvtt_value); /* @@ -781,7 +793,7 @@ void __cpuinit setup_secondary_APIC_clock(void) local_irq_enable(); } -void __cpuinit disable_APIC_timer(void) +void disable_APIC_timer(void) { if (using_apic_timer) { unsigned long v; @@ -793,7 +805,10 @@ void __cpuinit disable_APIC_timer(void) void enable_APIC_timer(void) { - if (using_apic_timer) { + int cpu = smp_processor_id(); + + if (using_apic_timer && + !cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask)) { unsigned long v; v = apic_read(APIC_LVTT); @@ -801,6 +816,42 @@ void enable_APIC_timer(void) } } +void switch_APIC_timer_to_ipi(void *cpumask) +{ + cpumask_t mask = *(cpumask_t *)cpumask; + int cpu = smp_processor_id(); + + if (cpu_isset(cpu, mask) && + !cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask)) { + disable_APIC_timer(); + cpu_set(cpu, timer_interrupt_broadcast_ipi_mask); + } +} +EXPORT_SYMBOL(switch_APIC_timer_to_ipi); + +void smp_send_timer_broadcast_ipi(void) +{ + cpumask_t mask; + + cpus_and(mask, cpu_online_map, timer_interrupt_broadcast_ipi_mask); + if (!cpus_empty(mask)) { + send_IPI_mask(mask, LOCAL_TIMER_VECTOR); + } +} + +void switch_ipi_to_APIC_timer(void *cpumask) +{ + cpumask_t mask = *(cpumask_t *)cpumask; + int cpu = smp_processor_id(); + + if (cpu_isset(cpu, mask) && + cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask)) { + cpu_clear(cpu, timer_interrupt_broadcast_ipi_mask); + enable_APIC_timer(); + } +} +EXPORT_SYMBOL(switch_ipi_to_APIC_timer); + int setup_profiling_timer(unsigned int multiplier) { return -EINVAL; diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c index 43c9fa0..211bf0e 100644 --- a/arch/x86_64/kernel/time.c +++ b/arch/x86_64/kernel/time.c @@ -471,6 +471,11 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) write_sequnlock(&xtime_lock); +#ifdef CONFIG_X86_LOCAL_APIC + if (using_apic_timer) + smp_send_timer_broadcast_ipi(); +#endif + return IRQ_HANDLED; } |
