Merge branch 'x86-tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 tracing updates from Ingo Molnar:
 "This tree adds IRQ vector tracepoints that are named after the handler
  and which output the vector #, based on a zero-overhead approach that
  relies on changing the IDT entries, by Seiji Aguchi.

  The new tracepoints look like this:

   # perf list | grep -i irq_vector
    irq_vectors:local_timer_entry                      [Tracepoint event]
    irq_vectors:local_timer_exit                       [Tracepoint event]
    irq_vectors:reschedule_entry                       [Tracepoint event]
    irq_vectors:reschedule_exit                        [Tracepoint event]
    irq_vectors:spurious_apic_entry                    [Tracepoint event]
    irq_vectors:spurious_apic_exit                     [Tracepoint event]
    irq_vectors:error_apic_entry                       [Tracepoint event]
    irq_vectors:error_apic_exit                        [Tracepoint event]
   [...]"

* 'x86-tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/tracing: Add config option checking to the definitions of mce handlers
  trace,x86: Do not call local_irq_save() in load_current_idt()
  trace,x86: Move creation of irq tracepoints from apic.c to irq.c
  x86, trace: Add irq vector tracepoints
  x86: Rename variables for debugging
  x86, trace: Introduce entering/exiting_irq()
  tracing: Add DEFINE_EVENT_FN() macro

1 files changed, 61 insertions, 0 deletions

diff --git a/arch/x86/kernel/tracepoint.c b/arch/x86/kernel/tracepoint.c
new file mode 100644
index 000000000000..4e584a8d6edd
--- /dev/null
+++ b/arch/x86/kernel/tracepoint.c
@@ -0,0 +1,61 @@
+/*
+ * Code for supporting irq vector tracepoints.
+ *
+ * Copyright (C) 2013 Seiji Aguchi <seiji.aguchi@hds.com>
+ *
+ */
+#include <asm/hw_irq.h>
+#include <asm/desc.h>
+#include <linux/atomic.h>
+
+atomic_t trace_idt_ctr = ATOMIC_INIT(0);
+struct desc_ptr trace_idt_descr = { NR_VECTORS * 16 - 1,
+				(unsigned long) trace_idt_table };
+
+#ifndef CONFIG_X86_64
+gate_desc trace_idt_table[NR_VECTORS] __page_aligned_data
+					= { { { { 0, 0 } } }, };
+#endif
+
+static int trace_irq_vector_refcount;
+static DEFINE_MUTEX(irq_vector_mutex);
+
+static void set_trace_idt_ctr(int val)
+{
+	atomic_set(&trace_idt_ctr, val);
+	/* Ensure the trace_idt_ctr is set before sending IPI */
+	wmb();
+}
+
+static void switch_idt(void *arg)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	load_current_idt();
+	local_irq_restore(flags);
+}
+
+void trace_irq_vector_regfunc(void)
+{
+	mutex_lock(&irq_vector_mutex);
+	if (!trace_irq_vector_refcount) {
+		set_trace_idt_ctr(1);
+		smp_call_function(switch_idt, NULL, 0);
+		switch_idt(NULL);
+	}
+	trace_irq_vector_refcount++;
+	mutex_unlock(&irq_vector_mutex);
+}
+
+void trace_irq_vector_unregfunc(void)
+{
+	mutex_lock(&irq_vector_mutex);
+	trace_irq_vector_refcount--;
+	if (!trace_irq_vector_refcount) {
+		set_trace_idt_ctr(0);
+		smp_call_function(switch_idt, NULL, 0);
+		switch_idt(NULL);
+	}
+	mutex_unlock(&irq_vector_mutex);
+}