ARM timer support

2 files changed, 60 insertions, 0 deletions

diff --git a/include/litmus/clock.h b/include/litmus/clock.h
new file mode 100644
index 000000000000..f8de7a3dfb5a
--- /dev/null
+++ b/include/litmus/clock.h
@@ -0,0 +1,48 @@
+#ifndef _LITMUS_CLOCK_H_
+#define _LITMUS_CLOCK_H_
+
+#if defined(CONFIG_EXYNOS_MCT)
+
+/*
+ * Only used if we are using the EXYNOS MCT clock.
+ */
+
+#include <linux/clocksource.h>
+extern struct clocksource mct_frc;
+
+static inline cycles_t mct_frc_read(void)
+{
+        cycle_t cycles = mct_frc.read(&mct_frc);
+        return cycles;
+}
+
+static inline s64 litmus_cycles_to_ns(cycles_t cycles)
+{
+        return clocksource_cyc2ns(cycles, mct_frc.mult, mct_frc.shift);
+}
+
+#define litmus_get_cycles mct_frc_read
+
+#elif defined(CONFIG_CPU_V7) && !defined(CONFIG_HW_PERF_EVENTS)
+
+#include <asm/timex.h>
+
+static inline cycles_t v7_get_cycles (void)
+{
+        u32 value;
+        /* read CCNT register */
+        asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r"(value));
+        return value;
+}
+
+#define litmus_get_cycles v7_get_cycles
+
+#else
+#include <asm/timex.h>
+
+#define litmus_get_cycles get_cycles
+
+#endif
+
+#endif
+
diff --git a/include/litmus/feather_trace.h b/include/litmus/feather_trace.h
index dbeca46c01f5..cc4396e7fbe4 100644
--- a/include/litmus/feather_trace.h
+++ b/include/litmus/feather_trace.h
@@ -38,11 +38,23 @@ static inline void ft_atomic_dec(int *val)
 /* provide default implementation */
 #include <linux/timex.h> /* for get_cycles() */
 
+#if defined(CONFIG_CPU_V7) && !defined(CONFIG_HW_PERF_EVENTS)   
+
+#include <litmus/clock.h> /* for litmus_get_cycles() */
+static inline unsigned long long ft_timestamp(void)
+{
+        return (unsigned long long)litmus_get_cycles();
+}
+
+#else
+
 static inline unsigned long long ft_timestamp(void)
 {
         return get_cycles();
 }
 
+#endif
+
 #define feather_callback
 
 #define MAX_EVENTS 1024