diff options
Diffstat (limited to 'arch/ia64/kernel')
| -rw-r--r-- | arch/ia64/kernel/irq_ia64.c | 27 | ||||
| -rw-r--r-- | arch/ia64/kernel/smp.c | 68 |
2 files changed, 90 insertions, 5 deletions
diff --git a/arch/ia64/kernel/irq_ia64.c b/arch/ia64/kernel/irq_ia64.c index 456f57b087c..9a5f41be760 100644 --- a/arch/ia64/kernel/irq_ia64.c +++ b/arch/ia64/kernel/irq_ia64.c @@ -39,6 +39,7 @@ #include <asm/machvec.h> #include <asm/pgtable.h> #include <asm/system.h> +#include <asm/tlbflush.h> #ifdef CONFIG_PERFMON # include <asm/perfmon.h> @@ -127,8 +128,10 @@ void destroy_irq(unsigned int irq) #ifdef CONFIG_SMP # define IS_RESCHEDULE(vec) (vec == IA64_IPI_RESCHEDULE) +# define IS_LOCAL_TLB_FLUSH(vec) (vec == IA64_IPI_LOCAL_TLB_FLUSH) #else # define IS_RESCHEDULE(vec) (0) +# define IS_LOCAL_TLB_FLUSH(vec) (0) #endif /* * That's where the IVT branches when we get an external @@ -180,8 +183,11 @@ ia64_handle_irq (ia64_vector vector, struct pt_regs *regs) saved_tpr = ia64_getreg(_IA64_REG_CR_TPR); ia64_srlz_d(); while (vector != IA64_SPURIOUS_INT_VECTOR) { - if (unlikely(IS_RESCHEDULE(vector))) - kstat_this_cpu.irqs[vector]++; + if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) { + smp_local_flush_tlb(); + kstat_this_cpu.irqs[vector]++; + } else if (unlikely(IS_RESCHEDULE(vector))) + kstat_this_cpu.irqs[vector]++; else { ia64_setreg(_IA64_REG_CR_TPR, vector); ia64_srlz_d(); @@ -227,8 +233,11 @@ void ia64_process_pending_intr(void) * Perform normal interrupt style processing */ while (vector != IA64_SPURIOUS_INT_VECTOR) { - if (unlikely(IS_RESCHEDULE(vector))) - kstat_this_cpu.irqs[vector]++; + if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) { + smp_local_flush_tlb(); + kstat_this_cpu.irqs[vector]++; + } else if (unlikely(IS_RESCHEDULE(vector))) + kstat_this_cpu.irqs[vector]++; else { struct pt_regs *old_regs = set_irq_regs(NULL); @@ -260,12 +269,12 @@ void ia64_process_pending_intr(void) #ifdef CONFIG_SMP -extern irqreturn_t handle_IPI (int irq, void *dev_id); static irqreturn_t dummy_handler (int irq, void *dev_id) { BUG(); } +extern irqreturn_t handle_IPI (int irq, void *dev_id); static struct irqaction ipi_irqaction = { .handler = handle_IPI, @@ -278,6 +287,13 @@ static struct irqaction resched_irqaction = { .flags = IRQF_DISABLED, .name = "resched" }; + +static struct irqaction tlb_irqaction = { + .handler = dummy_handler, + .flags = SA_INTERRUPT, + .name = "tlb_flush" +}; + #endif void @@ -303,6 +319,7 @@ init_IRQ (void) #ifdef CONFIG_SMP register_percpu_irq(IA64_IPI_VECTOR, &ipi_irqaction); register_percpu_irq(IA64_IPI_RESCHEDULE, &resched_irqaction); + register_percpu_irq(IA64_IPI_LOCAL_TLB_FLUSH, &tlb_irqaction); #endif #ifdef CONFIG_PERFMON pfm_init_percpu(); diff --git a/arch/ia64/kernel/smp.c b/arch/ia64/kernel/smp.c index 55ddd809b02..221de380456 100644 --- a/arch/ia64/kernel/smp.c +++ b/arch/ia64/kernel/smp.c @@ -50,6 +50,18 @@ #include <asm/mca.h> /* + * Note: alignment of 4 entries/cacheline was empirically determined + * to be a good tradeoff between hot cachelines & spreading the array + * across too many cacheline. + */ +static struct local_tlb_flush_counts { + unsigned int count; +} __attribute__((__aligned__(32))) local_tlb_flush_counts[NR_CPUS]; + +static DEFINE_PER_CPU(unsigned int, shadow_flush_counts[NR_CPUS]) ____cacheline_aligned; + + +/* * Structure and data for smp_call_function(). This is designed to minimise static memory * requirements. It also looks cleaner. */ @@ -248,6 +260,62 @@ smp_send_reschedule (int cpu) platform_send_ipi(cpu, IA64_IPI_RESCHEDULE, IA64_IPI_DM_INT, 0); } +/* + * Called with preeemption disabled. + */ +static void +smp_send_local_flush_tlb (int cpu) +{ + platform_send_ipi(cpu, IA64_IPI_LOCAL_TLB_FLUSH, IA64_IPI_DM_INT, 0); +} + +void +smp_local_flush_tlb(void) +{ + /* + * Use atomic ops. Otherwise, the load/increment/store sequence from + * a "++" operation can have the line stolen between the load & store. + * The overhead of the atomic op in negligible in this case & offers + * significant benefit for the brief periods where lots of cpus + * are simultaneously flushing TLBs. + */ + ia64_fetchadd(1, &local_tlb_flush_counts[smp_processor_id()].count, acq); + local_flush_tlb_all(); +} + +#define FLUSH_DELAY 5 /* Usec backoff to eliminate excessive cacheline bouncing */ + +void +smp_flush_tlb_cpumask(cpumask_t xcpumask) +{ + unsigned int *counts = __ia64_per_cpu_var(shadow_flush_counts); + cpumask_t cpumask = xcpumask; + int mycpu, cpu, flush_mycpu = 0; + + preempt_disable(); + mycpu = smp_processor_id(); + + for_each_cpu_mask(cpu, cpumask) + counts[cpu] = local_tlb_flush_counts[cpu].count; + + mb(); + for_each_cpu_mask(cpu, cpumask) { + if (cpu == mycpu) + flush_mycpu = 1; + else + smp_send_local_flush_tlb(cpu); + } + + if (flush_mycpu) + smp_local_flush_tlb(); + + for_each_cpu_mask(cpu, cpumask) + while(counts[cpu] == local_tlb_flush_counts[cpu].count) + udelay(FLUSH_DELAY); + + preempt_enable(); +} + void smp_flush_tlb_all (void) { |