diff options
Diffstat (limited to 'arch/x86/kernel/irq.c')
| -rw-r--r-- | arch/x86/kernel/irq.c | 136 |
1 files changed, 122 insertions, 14 deletions
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 35fde0107901..9ed29ff10e59 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -22,13 +22,22 @@ #include <asm/desc.h> #include <asm/traps.h> #include <asm/thermal.h> +#include <asm/posted_intr.h> +#include <asm/irq_remapping.h> +#if defined(CONFIG_X86_LOCAL_APIC) || defined(CONFIG_X86_THERMAL_VECTOR) #define CREATE_TRACE_POINTS #include <asm/trace/irq_vectors.h> +#endif DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat); EXPORT_PER_CPU_SYMBOL(irq_stat); +DEFINE_PER_CPU_CACHE_HOT(u16, __softirq_pending); +EXPORT_PER_CPU_SYMBOL(__softirq_pending); + +DEFINE_PER_CPU_CACHE_HOT(struct irq_stack *, hardirq_stack_ptr); + atomic_t irq_err_count; /* @@ -182,6 +191,13 @@ int arch_show_interrupts(struct seq_file *p, int prec) irq_stats(j)->kvm_posted_intr_wakeup_ipis); seq_puts(p, " Posted-interrupt wakeup event\n"); #endif +#ifdef CONFIG_X86_POSTED_MSI + seq_printf(p, "%*s: ", prec, "PMN"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", + irq_stats(j)->posted_msi_notification_count); + seq_puts(p, " Posted MSI notification event\n"); +#endif return 0; } @@ -240,24 +256,16 @@ static __always_inline void handle_irq(struct irq_desc *desc, __handle_irq(desc, regs); } -/* - * common_interrupt() handles all normal device IRQ's (the special SMP - * cross-CPU interrupts have their own entry points). - */ -DEFINE_IDTENTRY_IRQ(common_interrupt) +static __always_inline int call_irq_handler(int vector, struct pt_regs *regs) { - struct pt_regs *old_regs = set_irq_regs(regs); struct irq_desc *desc; - - /* entry code tells RCU that we're not quiescent. Check it. */ - RCU_LOCKDEP_WARN(!rcu_is_watching(), "IRQ failed to wake up RCU"); + int ret = 0; desc = __this_cpu_read(vector_irq[vector]); if (likely(!IS_ERR_OR_NULL(desc))) { handle_irq(desc, regs); } else { - apic_eoi(); - + ret = -EINVAL; if (desc == VECTOR_UNUSED) { pr_emerg_ratelimited("%s: %d.%u No irq handler for vector\n", __func__, smp_processor_id(), @@ -267,6 +275,23 @@ DEFINE_IDTENTRY_IRQ(common_interrupt) } } + return ret; +} + +/* + * common_interrupt() handles all normal device IRQ's (the special SMP + * cross-CPU interrupts have their own entry points). + */ +DEFINE_IDTENTRY_IRQ(common_interrupt) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + + /* entry code tells RCU that we're not quiescent. Check it. */ + RCU_LOCKDEP_WARN(!rcu_is_watching(), "IRQ failed to wake up RCU"); + + if (unlikely(call_irq_handler(vector, regs))) + apic_eoi(); + set_irq_regs(old_regs); } @@ -334,12 +359,96 @@ DEFINE_IDTENTRY_SYSVEC_SIMPLE(sysvec_kvm_posted_intr_nested_ipi) } #endif +#ifdef CONFIG_X86_POSTED_MSI + +/* Posted Interrupt Descriptors for coalesced MSIs to be posted */ +DEFINE_PER_CPU_ALIGNED(struct pi_desc, posted_msi_pi_desc); + +void intel_posted_msi_init(void) +{ + u32 destination; + u32 apic_id; + + this_cpu_write(posted_msi_pi_desc.nv, POSTED_MSI_NOTIFICATION_VECTOR); + + /* + * APIC destination ID is stored in bit 8:15 while in XAPIC mode. + * VT-d spec. CH 9.11 + */ + apic_id = this_cpu_read(x86_cpu_to_apicid); + destination = x2apic_enabled() ? apic_id : apic_id << 8; + this_cpu_write(posted_msi_pi_desc.ndst, destination); +} + +static __always_inline bool handle_pending_pir(unsigned long *pir, struct pt_regs *regs) +{ + unsigned long pir_copy[NR_PIR_WORDS]; + int vec = FIRST_EXTERNAL_VECTOR; + + if (!pi_harvest_pir(pir, pir_copy)) + return false; + + for_each_set_bit_from(vec, pir_copy, FIRST_SYSTEM_VECTOR) + call_irq_handler(vec, regs); + + return true; +} + +/* + * Performance data shows that 3 is good enough to harvest 90+% of the benefit + * on high IRQ rate workload. + */ +#define MAX_POSTED_MSI_COALESCING_LOOP 3 + +/* + * For MSIs that are delivered as posted interrupts, the CPU notifications + * can be coalesced if the MSIs arrive in high frequency bursts. + */ +DEFINE_IDTENTRY_SYSVEC(sysvec_posted_msi_notification) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + struct pi_desc *pid; + int i = 0; + + pid = this_cpu_ptr(&posted_msi_pi_desc); + + inc_irq_stat(posted_msi_notification_count); + irq_enter(); + + /* + * Max coalescing count includes the extra round of handle_pending_pir + * after clearing the outstanding notification bit. Hence, at most + * MAX_POSTED_MSI_COALESCING_LOOP - 1 loops are executed here. + */ + while (++i < MAX_POSTED_MSI_COALESCING_LOOP) { + if (!handle_pending_pir(pid->pir, regs)) + break; + } + + /* + * Clear outstanding notification bit to allow new IRQ notifications, + * do this last to maximize the window of interrupt coalescing. + */ + pi_clear_on(pid); + + /* + * There could be a race of PI notification and the clearing of ON bit, + * process PIR bits one last time such that handling the new interrupts + * are not delayed until the next IRQ. + */ + handle_pending_pir(pid->pir, regs); + + apic_eoi(); + irq_exit(); + set_irq_regs(old_regs); +} +#endif /* X86_POSTED_MSI */ #ifdef CONFIG_HOTPLUG_CPU /* A cpu has been removed from cpu_online_mask. Reset irq affinities. */ void fixup_irqs(void) { - unsigned int irr, vector; + unsigned int vector; struct irq_desc *desc; struct irq_data *data; struct irq_chip *chip; @@ -366,8 +475,7 @@ void fixup_irqs(void) if (IS_ERR_OR_NULL(__this_cpu_read(vector_irq[vector]))) continue; - irr = apic_read(APIC_IRR + (vector / 32 * 0x10)); - if (irr & (1 << (vector % 32))) { + if (is_vector_pending(vector)) { desc = __this_cpu_read(vector_irq[vector]); raw_spin_lock(&desc->lock); |