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

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

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();
 }
 

arch/mips/mips-boards/generic/time.c

@@ -75,16 +75,29 @@ static void mips_timer_dispatch (struct pt_regs *regs)
 	do_IRQ (mips_cpu_timer_irq, regs);
 }
 
+extern int null_perf_irq(struct pt_regs *regs);
+
+extern int (*perf_irq)(struct pt_regs *regs);
+
 irqreturn_t mips_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 {
+	int r2 = cpu_has_mips_r2;
 	int cpu = smp_processor_id();
 
 	if (cpu == 0) {
 		/*
-		 * CPU 0 handles the global timer interrupt job and process accounting
-		 * resets count/compare registers to trigger next timer int.
+		 * CPU 0 handles the global timer interrupt job and process
+		 * accounting resets count/compare registers to trigger next
+		 * timer int.
 		 */
-		timer_interrupt(irq, dev_id, regs);
+		if (!r2 || (read_c0_cause() & (1 << 26)))
+			if (perf_irq(regs))
+				goto out;
+
+		/* we keep interrupt disabled all the time */
+		if (!r2 || (read_c0_cause() & (1 << 30)))
+			timer_interrupt(irq, NULL, regs);
+
 		scroll_display_message();
 	} else {
 		/* Everyone else needs to reset the timer int here as
@@ -101,6 +114,7 @@ irqreturn_t mips_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 		local_timer_interrupt (irq, dev_id, regs);
 	}
 
+out:
 	return IRQ_HANDLED;
 }
 

arch/mips/oprofile/op_impl.h

@@ -12,8 +12,8 @@
 
 struct pt_regs;
 
-extern void null_perf_irq(struct pt_regs *regs);
-extern void (*perf_irq)(struct pt_regs *regs);
+extern int null_perf_irq(struct pt_regs *regs);
+extern int (*perf_irq)(struct pt_regs *regs);
 
 /* Per-counter configuration as set via oprofilefs.  */
 struct op_counter_config {

arch/mips/oprofile/op_model_mipsxx.c

@@ -114,11 +114,12 @@ static void mipsxx_cpu_stop(void *args)
 	}
 }
 
-static void mipsxx_perfcount_handler(struct pt_regs *regs)
+static int mipsxx_perfcount_handler(struct pt_regs *regs)
 {
 	unsigned int counters = op_model_mipsxx.num_counters;
 	unsigned int control;
 	unsigned int counter;
+	int handled = 0;
 
 	switch (counters) {
 #define HANDLE_COUNTER(n)						\
@@ -129,12 +130,15 @@ static void mipsxx_perfcount_handler(struct pt_regs *regs)
 		    (counter & M_COUNTER_OVERFLOW)) {			\
 			oprofile_add_sample(regs, n);			\
 			write_c0_perfcntr ## n(reg.counter[n]);		\
+			handled = 1;					\
 		}
 	HANDLE_COUNTER(3)
 	HANDLE_COUNTER(2)
 	HANDLE_COUNTER(1)
 	HANDLE_COUNTER(0)
 	}
+
+	return handled;
 }
 
 #define M_CONFIG1_PC	(1 << 4)