3 files changed, 14 insertions, 0 deletions

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 1a6c09af048..5fe0bd57475 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -410,6 +410,9 @@ extern int wakeup_secondary_cpu_via_nmi(int apicid, unsigned long start_eip);
 #endif
 
 #ifdef CONFIG_X86_LOCAL_APIC
+
+DECLARE_PER_CPU(unsigned, icr_read_retry_count);
+
 static inline u32 apic_read(u32 reg)
 {
         return apic->read(reg);
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index f98d84caf94..2942794a9a5 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -79,6 +79,11 @@ DEFINE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid, BAD_APICID);
 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
 
+/*
+ * ICR read retry counter
+ */
+DEFINE_PER_CPU(unsigned, icr_read_retry_count);
+
 #ifdef CONFIG_X86_32
 
 /*
@@ -250,6 +255,7 @@ u32 native_safe_apic_wait_icr_idle(void)
                 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
                 if (!send_status)
                         break;
+                percpu_inc(icr_read_retry_count);
                 udelay(100);
         } while (timeout++ < 1000);
 
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 429e0c92924..4bbf1627905 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -74,6 +74,10 @@ int arch_show_interrupts(struct seq_file *p, int prec)
         for_each_online_cpu(j)
                 seq_printf(p, "%10u ", irq_stats(j)->apic_irq_work_irqs);
         seq_printf(p, "  IRQ work interrupts\n");
+        seq_printf(p, "%*s: ", prec, "RTR");
+        for_each_online_cpu(j)
+                seq_printf(p, "%10u ", per_cpu(icr_read_retry_count, j));
+        seq_printf(p, "  APIC ICR read retries\n");
 #endif
         if (x86_platform_ipi_callback) {
                 seq_printf(p, "%*s: ", prec, "PLT");
@@ -136,6 +140,7 @@ u64 arch_irq_stat_cpu(unsigned int cpu)
         sum += irq_stats(cpu)->irq_spurious_count;
         sum += irq_stats(cpu)->apic_perf_irqs;
         sum += irq_stats(cpu)->apic_irq_work_irqs;
+        sum += per_cpu(icr_read_retry_count, cpu);
 #endif
         if (x86_platform_ipi_callback)
                 sum += irq_stats(cpu)->x86_platform_ipis;