x86/irq: Get rid of duplicated trace_x86_platform_ipi() code

Two NOP5s are really a good tradeoff vs. the unholy IDT switching mess,
which duplicates code all over the place.

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/20170828064956.907209383@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/hw_irq.h

@@ -48,7 +48,6 @@ extern asmlinkage void call_function_single_interrupt(void);
 
 #ifdef CONFIG_TRACING
 /* Interrupt handlers registered during init_IRQ */
-extern void trace_x86_platform_ipi(void);
 extern void trace_error_interrupt(void);
 extern void trace_irq_work_interrupt(void);
 extern void trace_spurious_interrupt(void);
@@ -58,6 +57,7 @@ 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_x86_platform_ipi	x86_platform_ipi
 #define trace_apic_timer_interrupt	apic_timer_interrupt
 #define trace_irq_move_cleanup_interrupt  irq_move_cleanup_interrupt
 #define trace_reboot_interrupt  reboot_interrupt

arch/x86/kernel/irq.c

@@ -262,20 +262,16 @@ __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 /*
  * Handler for X86_PLATFORM_IPI_VECTOR.
  */
-void __smp_x86_platform_ipi(void)
-{
-	inc_irq_stat(x86_platform_ipis);
-
-	if (x86_platform_ipi_callback)
-		x86_platform_ipi_callback();
-}
-
 __visible void __irq_entry smp_x86_platform_ipi(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
 
 	entering_ack_irq();
-	__smp_x86_platform_ipi();
+	trace_x86_platform_ipi_entry(X86_PLATFORM_IPI_VECTOR);
+	inc_irq_stat(x86_platform_ipis);
+	if (x86_platform_ipi_callback)
+		x86_platform_ipi_callback();
+	trace_x86_platform_ipi_exit(X86_PLATFORM_IPI_VECTOR);
 	exiting_irq();
 	set_irq_regs(old_regs);
 }
@@ -334,17 +330,6 @@ __visible void smp_kvm_posted_intr_nested_ipi(struct pt_regs *regs)
 }
 #endif
 
-__visible void __irq_entry smp_trace_x86_platform_ipi(struct pt_regs *regs)
-{
-	struct pt_regs *old_regs = set_irq_regs(regs);
-
-	entering_ack_irq();
-	trace_x86_platform_ipi_entry(X86_PLATFORM_IPI_VECTOR);
-	__smp_x86_platform_ipi();
-	trace_x86_platform_ipi_exit(X86_PLATFORM_IPI_VECTOR);
-	exiting_irq();
-	set_irq_regs(old_regs);
-}
 
 #ifdef CONFIG_HOTPLUG_CPU