timer: prefer TSC to HPET

[dpdk.git] / lib / librte_eal / common / include / rte_cycles.h

diff --git a/lib/librte_eal/common/include/rte_cycles.h b/lib/librte_eal/common/include/rte_cycles.h
index 14a7c1b..a490905 100644 (file)
--- a/lib/librte_eal/common/include/rte_cycles.h
+++ b/lib/librte_eal/common/include/rte_cycles.h
@@ -76,6 +76,7 @@ extern "C" {
 #endif
 
 #include <stdint.h>
+#include <rte_debug.h>
 
 #ifdef RTE_LIBRTE_EAL_VMWARE_TSC_MAP_SUPPORT
 /** Global switch to use VMWARE mapping of TSC instead of RDTSC */
@@ -83,6 +84,15 @@ extern int rte_cycles_vmware_tsc_map;
 #include <rte_branch_prediction.h>
 #endif
 
+#define MS_PER_S 1000
+#define US_PER_S 1000000
+#define NS_PER_S 1000000000
+
+enum timer_source {
+       EAL_TIMER_TSC = 0,
+       EAL_TIMER_HPET
+};
+extern enum timer_source eal_timer_source;
 
 /**
  * Read the TSC register.
@@ -118,11 +128,30 @@ rte_rdtsc(void)
        return tsc.tsc_64;
 }
 
+/**
+ * Get the measured frequency of the RDTSC counter
+ *
+ * @return
+ *   The TSC frequency for this lcore
+ */
+uint64_t
+rte_get_tsc_hz(void);
+
+/**
+ * Return the number of TSC cycles since boot
+ *
+  * @return
+ *   the number of cycles
+ */
+static inline uint64_t
+rte_get_tsc_cycles(void) { return rte_rdtsc(); }
+
+#ifdef RTE_LIBEAL_USE_HPET
 /**
  * Return the number of HPET cycles since boot
  *
  * This counter is global for all execution units. The number of
- * cycles in one second can be retrived using rte_get_hpet_hz().
+ * cycles in one second can be retrieved using rte_get_hpet_hz().
  *
  * @return
  *   the number of cycles
@@ -131,7 +160,7 @@ uint64_t
 rte_get_hpet_cycles(void);
 
 /**
- * Get the number of cycles in one second.
+ * Get the number of HPET cycles in one second.
  *
  * @return
  *   The number of cycles in one second.
@@ -139,6 +168,63 @@ rte_get_hpet_cycles(void);
 uint64_t
 rte_get_hpet_hz(void);
 
+/**
+ * Initialise the HPET for use. This must be called before the rte_get_hpet_hz
+ * and rte_get_hpet_cycles APIs are called. If this function does not succeed,
+ * then the HPET functions are unavailable and should not be called.
+ *
+ * @param make_default
+ *     If set, the hpet timer becomes the default timer whose values are
+ *     returned by the rte_get_timer_hz/cycles API calls
+ *
+ * @return
+ *     0 on success,
+ *     -1 on error, and the make_default parameter is ignored.
+ */
+int rte_eal_hpet_init(int make_default);
+
+#endif
+
+/**
+ * Get the number of cycles since boot from the default timer.
+ *
+ * @return
+ *   The number of cycles
+ */
+static inline uint64_t
+rte_get_timer_cycles(void)
+{
+       switch(eal_timer_source) {
+       case EAL_TIMER_TSC:
+               return rte_rdtsc();
+       case EAL_TIMER_HPET:
+#ifdef RTE_LIBEAL_USE_HPET
+               return rte_get_hpet_cycles();
+#endif
+       default: rte_panic("Invalid timer source specified\n");
+       }
+}
+
+/**
+ * Get the number of cycles in one second for the default timer.
+ *
+ * @return
+ *   The number of cycles in one second.
+ */
+static inline uint64_t
+rte_get_timer_hz(void)
+{
+       switch(eal_timer_source) {
+       case EAL_TIMER_TSC:
+               return rte_get_tsc_hz();
+       case EAL_TIMER_HPET:
+#ifdef RTE_LIBEAL_USE_HPET
+               return rte_get_hpet_hz();
+#endif
+       default: rte_panic("Invalid timer source specified\n");
+       }
+}
+
 /**
  * Wait at least us microseconds.
  *