1 files changed, 36 insertions, 21 deletions

diff --git a/arch/mips/mips-boards/generic/time.c b/arch/mips/mips-boards/generic/time.c
index 557bf961f36..de5798e1e01 100644
--- a/arch/mips/mips-boards/generic/time.c
+++ b/arch/mips/mips-boards/generic/time.c
@@ -92,10 +92,9 @@ extern int (*perf_irq)(struct pt_regs *regs);
 irqreturn_t mips_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 {
         int cpu = smp_processor_id();
-        int r2 = cpu_has_mips_r2;
 
 #ifdef CONFIG_MIPS_MT_SMTC
-        /*
+        /*
          *  In an SMTC system, one Count/Compare set exists per VPE.
          *  Which TC within a VPE gets the interrupt is essentially
          *  random - we only know that it shouldn't be one with
@@ -108,29 +107,46 @@ irqreturn_t mips_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
          *  the general MIPS timer_interrupt routine.
          */
 
+        int vpflags;
+
         /*
-         * DVPE is necessary so long as cross-VPE interrupts
-         * are done via read-modify-write of Cause register.
+         * We could be here due to timer interrupt,
+         * perf counter overflow, or both.
          */
-        int vpflags = dvpe();
-        write_c0_compare (read_c0_count() - 1);
-        clear_c0_cause(CPUCTR_IMASKBIT);
-        evpe(vpflags);
-
-        if (cpu_data[cpu].vpe_id == 0) {
-                timer_interrupt(irq, dev_id, regs);
-                scroll_display_message();
-        } else
-                write_c0_compare (read_c0_count() + ( mips_hpt_frequency/HZ));
-        smtc_timer_broadcast(cpu_data[cpu].vpe_id);
+        if (read_c0_cause() & (1 << 26))
+                perf_irq(regs);
 
-        if (cpu != 0)
+        if (read_c0_cause() & (1 << 30)) {
+                /* If timer interrupt, make it de-assert */
+                write_c0_compare (read_c0_count() - 1);
                 /*
-                 * Other CPUs should do profiling and process accounting
+                 * DVPE is necessary so long as cross-VPE interrupts
+                 * are done via read-modify-write of Cause register.
                  */
-                local_timer_interrupt(irq, dev_id, regs);
-
+                vpflags = dvpe();
+                clear_c0_cause(CPUCTR_IMASKBIT);
+                evpe(vpflags);
+                /*
+                 * There are things we only want to do once per tick
+                 * in an "MP" system.   One TC of each VPE will take
+                 * the actual timer interrupt.  The others will get
+                 * timer broadcast IPIs. We use whoever it is that takes
+                 * the tick on VPE 0 to run the full timer_interrupt().
+                 */
+                if (cpu_data[cpu].vpe_id == 0) {
+                                timer_interrupt(irq, NULL, regs);
+                                smtc_timer_broadcast(cpu_data[cpu].vpe_id);
+                                scroll_display_message();
+                } else {
+                        write_c0_compare(read_c0_count() +
+                                         (mips_hpt_frequency/HZ));
+                        local_timer_interrupt(irq, dev_id, regs);
+                        smtc_timer_broadcast(cpu_data[cpu].vpe_id);
+                }
+        }
 #else /* CONFIG_MIPS_MT_SMTC */
+        int r2 = cpu_has_mips_r2;
+
         if (cpu == 0) {
                 /*
                  * CPU 0 handles the global timer interrupt job and process
@@ -161,9 +177,8 @@ irqreturn_t mips_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
                  */
                 local_timer_interrupt(irq, dev_id, regs);
         }
-#endif /* CONFIG_MIPS_MT_SMTC */
-
 out:
+#endif /* CONFIG_MIPS_MT_SMTC */
         return IRQ_HANDLED;
 }