linux-gen: time: change to non-zero startup time

Time does not have to start from zero anymore. Optimize time stamp
performance by returning the counter value directly. Implemented
the new startup time function.

Signed-off-by: Petri Savolainen <petri.savolainen@nokia.com>
Reviewed-by: Janne Peltonen <janne.peltonen@nokia.com>

5 files changed, 69 insertions, 19 deletions

diff --git a/platform/linux-generic/arch/common/odp/api/abi/time_cpu_inlines.h b/platform/linux-generic/arch/common/odp/api/abi/time_cpu_inlines.h
index c154c5f1a..553114666 100644
--- a/platform/linux-generic/arch/common/odp/api/abi/time_cpu_inlines.h
+++ b/platform/linux-generic/arch/common/odp/api/abi/time_cpu_inlines.h
@@ -21,8 +21,9 @@ extern "C" {
 #define _ODP_TIME_GIGA_HZ  1000000000ULL
 
 typedef struct _odp_time_global_t {
-	uint64_t start_time;
 	uint64_t freq_hz;
+	uint64_t start_time;
+	uint64_t start_time_ns;
 
 } _odp_time_global_t;
 
@@ -32,7 +33,7 @@ static inline odp_time_t _odp_time_cur(void)
 {
 	odp_time_t time;
 
-	time.count = _odp_time_cpu_global() - _odp_time_glob.start_time;
+	time.count = _odp_time_cpu_global();
 	return time;
 }
 
@@ -40,7 +41,7 @@ static inline odp_time_t _odp_time_cur_strict(void)
 {
 	odp_time_t time;
 
-	time.count = _odp_time_cpu_global_strict() - _odp_time_glob.start_time;
+	time.count = _odp_time_cpu_global_strict();
 	return time;
 }
 
@@ -86,6 +87,12 @@ static inline uint64_t _odp_time_res(void)
 	return _odp_time_glob.freq_hz;
 }
 
+static inline void _odp_time_startup(odp_time_startup_t *startup)
+{
+	startup->global.count = _odp_time_glob.start_time;
+	startup->global_ns    = _odp_time_glob.start_time_ns;
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/platform/linux-generic/arch/common/odp_time_cpu.c b/platform/linux-generic/arch/common/odp_time_cpu.c
index bbfe82e21..3c392de0c 100644
--- a/platform/linux-generic/arch/common/odp_time_cpu.c
+++ b/platform/linux-generic/arch/common/odp_time_cpu.c
@@ -17,6 +17,8 @@
 #include <stdint.h>
 #include <string.h>
 
+#define YEAR_IN_SEC (365 * 24 * 3600)
+
 #include <odp/visibility_begin.h>
 
 _odp_time_global_t _odp_time_glob;
@@ -25,6 +27,8 @@ _odp_time_global_t _odp_time_glob;
 
 int _odp_time_init_global(void)
 {
+	uint64_t count, diff, years;
+	odp_time_t time;
 	_odp_time_global_t *global = &_odp_time_glob;
 
 	memset(global, 0, sizeof(_odp_time_global_t));
@@ -38,7 +42,29 @@ int _odp_time_init_global(void)
 
 	_ODP_PRINT("HW time counter freq: %" PRIu64 " hz\n\n", global->freq_hz);
 
-	global->start_time = _odp_time_cpu_global();
+	count = _odp_time_cpu_global();
+	time.count = count;
+	global->start_time = count;
+	global->start_time_ns = _odp_time_to_ns(time);
+
+	/* Make sure that counters will not wrap */
+	diff = UINT64_MAX - count;
+	years = (diff / global->freq_hz) / YEAR_IN_SEC;
+
+	if (years < 10) {
+		_ODP_ERR("Time counter would wrap in 10 years: %" PRIu64 "\n", count);
+		return -1;
+	}
+
+	diff = UINT64_MAX - global->start_time_ns;
+	years = (diff / ODP_TIME_SEC_IN_NS) / YEAR_IN_SEC;
+
+	if (years < 10) {
+		_ODP_ERR("Time in nsec would wrap in 10 years: %" PRIu64 "\n",
+			 global->start_time_ns);
+		return -1;
+	}
+
 	return 0;
 }
 
diff --git a/platform/linux-generic/arch/default/odp/api/abi/time_inlines.h b/platform/linux-generic/arch/default/odp/api/abi/time_inlines.h
index b38e52dac..ed0ffdb3f 100644
--- a/platform/linux-generic/arch/default/odp/api/abi/time_inlines.h
+++ b/platform/linux-generic/arch/default/odp/api/abi/time_inlines.h
@@ -18,6 +18,7 @@ extern "C" {
 
 odp_time_t _odp_time_cur(void);
 uint64_t _odp_time_res(void);
+void _odp_time_startup(odp_time_startup_t *startup);
 
 static inline odp_time_t _odp_time_cur_strict(void)
 {
diff --git a/platform/linux-generic/arch/default/odp_time.c b/platform/linux-generic/arch/default/odp_time.c
index 919a3ba68..664a5deae 100644
--- a/platform/linux-generic/arch/default/odp_time.c
+++ b/platform/linux-generic/arch/default/odp_time.c
@@ -16,31 +16,24 @@
 #include <odp_debug_internal.h>
 #include <odp_init_internal.h>
 
+#include <inttypes.h>
 #include <stdint.h>
 #include <string.h>
 #include <time.h>
 
+#define YEAR_IN_SEC (365 * 24 * 3600)
+
 typedef struct _odp_time_global_t {
 	struct timespec start_time;
+	uint64_t start_time_ns;
 
 } _odp_time_global_t;
 
 _odp_time_global_t _odp_time_glob;
 
-static inline uint64_t time_diff_nsec(struct timespec *t2, struct timespec *t1)
+static inline uint64_t time_nsec(struct timespec *t)
 {
-	struct timespec diff;
-	uint64_t nsec;
-
-	diff.tv_sec  = t2->tv_sec  - t1->tv_sec;
-	diff.tv_nsec = t2->tv_nsec - t1->tv_nsec;
-
-	if (diff.tv_nsec < 0) {
-		diff.tv_nsec += ODP_TIME_SEC_IN_NS;
-		diff.tv_sec  -= 1;
-	}
-
-	nsec = (diff.tv_sec * ODP_TIME_SEC_IN_NS) + diff.tv_nsec;
+	uint64_t nsec = (t->tv_sec * ODP_TIME_SEC_IN_NS) + t->tv_nsec;
 
 	return nsec;
 }
@@ -52,13 +45,12 @@ odp_time_t _odp_time_cur(void)
 	int ret;
 	odp_time_t time;
 	struct timespec sys_time;
-	struct timespec *start_time = &_odp_time_glob.start_time;
 
 	ret = clock_gettime(CLOCK_MONOTONIC_RAW, &sys_time);
 	if (odp_unlikely(ret != 0))
 		_ODP_ABORT("clock_gettime() failed\n");
 
-	time.nsec = time_diff_nsec(&sys_time, start_time);
+	time.nsec = time_nsec(&sys_time);
 
 	return time;
 }
@@ -75,11 +67,18 @@ uint64_t _odp_time_res(void)
 	return ODP_TIME_SEC_IN_NS / (uint64_t)tres.tv_nsec;
 }
 
+void _odp_time_startup(odp_time_startup_t *startup)
+{
+	startup->global.nsec = _odp_time_glob.start_time_ns;
+	startup->global_ns   = _odp_time_glob.start_time_ns;
+}
+
 #include <odp/visibility_end.h>
 
 int _odp_time_init_global(void)
 {
 	struct timespec *start_time;
+	uint64_t diff, years;
 	int ret = 0;
 	_odp_time_global_t *global = &_odp_time_glob;
 
@@ -93,6 +92,17 @@ int _odp_time_init_global(void)
 	if (ret)
 		_ODP_ERR("clock_gettime() failed: %d\n", ret);
 
+	global->start_time_ns = time_nsec(start_time);
+
+	diff = UINT64_MAX - global->start_time_ns;
+	years = (diff / ODP_TIME_SEC_IN_NS) / YEAR_IN_SEC;
+
+	if (years < 10) {
+		_ODP_ERR("Time in nsec would wrap in 10 years: %" PRIu64 "\n",
+			 global->start_time_ns);
+		return -1;
+	}
+
 	return ret;
 }
 
diff --git a/platform/linux-generic/include/odp/api/plat/time_inlines.h b/platform/linux-generic/include/odp/api/plat/time_inlines.h
index 76c9276d3..8ead06f7b 100644
--- a/platform/linux-generic/include/odp/api/plat/time_inlines.h
+++ b/platform/linux-generic/include/odp/api/plat/time_inlines.h
@@ -46,6 +46,7 @@
 
 	#define odp_time_wait_ns __odp_time_wait_ns
 	#define odp_time_wait_until __odp_time_wait_until
+	#define odp_time_startup __odp_time_startup
 #else
 	#define _ODP_INLINE
 #endif
@@ -180,6 +181,11 @@ _ODP_INLINE void odp_time_wait_ns(uint64_t ns)
 	odp_time_wait_until(end_time);
 }
 
+_ODP_INLINE void odp_time_startup(odp_time_startup_t *startup)
+{
+	_odp_time_startup(startup);
+}
+
 /** @endcond */
 
 #endif