x86/apic: Remove the duplicated tracing versions of interrupts

The error and the spurious interrupt are really rare events and not at all
performance sensitive: two NOP5s can be tolerated when tracing is disabled.

Remove the complication.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170828064956.986009402@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/hw_irq.h

@@ -48,15 +48,15 @@ extern asmlinkage void call_function_single_interrupt(void);
 
 #ifdef CONFIG_TRACING
 /* Interrupt handlers registered during init_IRQ */
-extern void trace_error_interrupt(void);
 extern void trace_irq_work_interrupt(void);
-extern void trace_spurious_interrupt(void);
 extern void trace_thermal_interrupt(void);
 extern void trace_reschedule_interrupt(void);
 extern void trace_threshold_interrupt(void);
 extern void trace_deferred_error_interrupt(void);
 extern void trace_call_function_interrupt(void);
 extern void trace_call_function_single_interrupt(void);
+#define trace_error_interrupt error_interrupt
+#define trace_spurious_interrupt spurious_interrupt
 #define trace_x86_platform_ipi	x86_platform_ipi
 #define trace_apic_timer_interrupt	apic_timer_interrupt
 #define trace_irq_move_cleanup_interrupt  irq_move_cleanup_interrupt

arch/x86/kernel/apic/apic.c

@@ -1899,10 +1899,14 @@ void __init register_lapic_address(unsigned long address)
 /*
  * This interrupt should _never_ happen with our APIC/SMP architecture
  */
-static void __smp_spurious_interrupt(u8 vector)
+__visible void __irq_entry smp_spurious_interrupt(struct pt_regs *regs)
 {
+	u8 vector = ~regs->orig_ax;
 	u32 v;
 
+	entering_irq();
+	trace_spurious_apic_entry(vector);
+
 	/*
 	 * Check if this really is a spurious interrupt and ACK it
 	 * if it is a vectored one.  Just in case...
@@ -1917,22 +1921,7 @@ static void __smp_spurious_interrupt(u8 vector)
 	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
 	pr_info("spurious APIC interrupt through vector %02x on CPU#%d, "
 		"should never happen.\n", vector, smp_processor_id());
-}
 
-__visible void __irq_entry smp_spurious_interrupt(struct pt_regs *regs)
-{
-	entering_irq();
-	__smp_spurious_interrupt(~regs->orig_ax);
-	exiting_irq();
-}
-
-__visible void __irq_entry smp_trace_spurious_interrupt(struct pt_regs *regs)
-{
-	u8 vector = ~regs->orig_ax;
-
-	entering_irq();
-	trace_spurious_apic_entry(vector);
-	__smp_spurious_interrupt(vector);
 	trace_spurious_apic_exit(vector);
 	exiting_irq();
 }
@@ -1940,10 +1929,8 @@ __visible void __irq_entry smp_trace_spurious_interrupt(struct pt_regs *regs)
 /*
  * This interrupt should never happen with our APIC/SMP architecture
  */
-static void __smp_error_interrupt(struct pt_regs *regs)
+__visible void __irq_entry smp_error_interrupt(struct pt_regs *regs)
 {
-	u32 v;
-	u32 i = 0;
 	static const char * const error_interrupt_reason[] = {
 		"Send CS error",		/* APIC Error Bit 0 */
 		"Receive CS error",		/* APIC Error Bit 1 */
@@ -1954,6 +1941,10 @@ static void __smp_error_interrupt(struct pt_regs *regs)
 		"Received illegal vector",	/* APIC Error Bit 6 */
 		"Illegal register address",	/* APIC Error Bit 7 */
 	};
+	u32 v, i = 0;
+
+	entering_irq();
+	trace_error_apic_entry(ERROR_APIC_VECTOR);
 
 	/* First tickle the hardware, only then report what went on. -- REW */
 	if (lapic_get_maxlvt() > 3)	/* Due to the Pentium erratum 3AP. */
@@ -1975,20 +1966,6 @@ static void __smp_error_interrupt(struct pt_regs *regs)
 
 	apic_printk(APIC_DEBUG, KERN_CONT "\n");
 
-}
-
-__visible void __irq_entry smp_error_interrupt(struct pt_regs *regs)
-{
-	entering_irq();
-	__smp_error_interrupt(regs);
-	exiting_irq();
-}
-
-__visible void __irq_entry smp_trace_error_interrupt(struct pt_regs *regs)
-{
-	entering_irq();
-	trace_error_apic_entry(ERROR_APIC_VECTOR);
-	__smp_error_interrupt(regs);
 	trace_error_apic_exit(ERROR_APIC_VECTOR);
 	exiting_irq();
 }