4 files changed, 49 insertions, 7 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();
 }
 
diff --git a/arch/mips/mips-boards/generic/time.c b/arch/mips/mips-boards/generic/time.c
index 2830f656fe2f..93f3bf2c2b22 100644
--- a/arch/mips/mips-boards/generic/time.c
+++ b/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;
 }
 
diff --git a/arch/mips/oprofile/op_impl.h b/arch/mips/oprofile/op_impl.h
index f0121557047d..5cfce7d87a4d 100644
--- a/arch/mips/oprofile/op_impl.h
+++ b/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 {
diff --git a/arch/mips/oprofile/op_model_mipsxx.c b/arch/mips/oprofile/op_model_mipsxx.c
index d36b64dfcb2f..a4a4aa99ab03 100644
--- a/arch/mips/oprofile/op_model_mipsxx.c
+++ b/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)