MIPS: Oprofile: Fixup the loose ends in the plumbing.

    
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 25 insertions, 1 deletions

diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c
index 07e125c027b2..7050b4ffffcd 100644
--- a/arch/mips/kernel/time.c
+++ b/arch/mips/kernel/time.c
@@ -507,14 +507,38 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 	return IRQ_HANDLED;
 }
 
+int null_perf_irq(struct pt_regs *regs)
+{
+	return 0;
+}
+
+int (*perf_irq)(struct pt_regs *regs) = null_perf_irq;
+
+EXPORT_SYMBOL(null_perf_irq);
+EXPORT_SYMBOL(perf_irq);
+
 asmlinkage void ll_timer_interrupt(int irq, struct pt_regs *regs)
 {
+	int r2 = cpu_has_mips_r2;
+
 	irq_enter();
 	kstat_this_cpu.irqs[irq]++;
 
+	/*
+	 * Suckage alert:
+	 * Before R2 of the architecture there was no way to see if a
+	 * performance counter interrupt was pending, so we have to run the
+	 * performance counter interrupt handler anyway.
+	 */
+	if (!r2 || (read_c0_cause() & (1 << 26)))
+		if (perf_irq(regs))
+			goto out;
+
 	/* we keep interrupt disabled all the time */
-	timer_interrupt(irq, NULL, regs);
+	if (!r2 || (read_c0_cause() & (1 << 30)))
+		timer_interrupt(irq, NULL, regs);
 
+out:
 	irq_exit();
 }