linux-gen: cpu: detect constant_tsc from cpuinfo

INVTSC x86 CPU flag may not be always available with VMs. So, try also to
find 'constant_tsc' flag from /proc/cpuinfo.

Signed-off-by: Matias Elo <matias.elo@nokia.com>
Reviewed-by: Petri Savolainen <petri.savolainen@nokia.com>

4 files changed, 28 insertions, 16 deletions

diff --git a/platform/linux-generic/arch/x86/cpu_flags.c b/platform/linux-generic/arch/x86/cpu_flags.c
index 482c25739..9211df002 100644
--- a/platform/linux-generic/arch/x86/cpu_flags.c
+++ b/platform/linux-generic/arch/x86/cpu_flags.c
@@ -10,9 +10,12 @@
  */
 
 #include "cpu_flags.h"
-#include <odp_debug_internal.h>
+
 #include <odp/api/abi/time_cpu.h>
 
+#include <odp_debug_internal.h>
+#include <odp_global_data.h>
+
 #include <cpuid.h>
 #include <errno.h>
 #include <stdio.h>
@@ -356,7 +359,8 @@ void _odp_cpu_flags_print_all(void)
 
 int _odp_time_cpu_global_freq_is_const(void)
 {
-	if (cpu_get_flag_enabled(RTE_CPUFLAG_INVTSC) > 0)
+	if (odp_global_ro.system_info.cpu_constant_tsc ||
+	    cpu_get_flag_enabled(RTE_CPUFLAG_INVTSC) > 0)
 		return 1;
 
 	_ODP_ERR("WARN: assuming constant TSC based on CPU arch, but could not confirm from CPU "
diff --git a/platform/linux-generic/arch/x86/odp_sysinfo_parse.c b/platform/linux-generic/arch/x86/odp_sysinfo_parse.c
index c74c52045..3cbdb2037 100644
--- a/platform/linux-generic/arch/x86/odp_sysinfo_parse.c
+++ b/platform/linux-generic/arch/x86/odp_sysinfo_parse.c
@@ -1,4 +1,5 @@
 /* Copyright (c) 2016-2018, Linaro Limited
+ * Copyright (c) 2023, Nokia
  * All rights reserved.
  *
  * SPDX-License-Identifier:     BSD-3-Clause
@@ -30,6 +31,11 @@ int _odp_cpuinfo_parser(FILE *file, system_info_t *sysinfo)
 
 	strcpy(sysinfo->cpu_arch_str, "x86");
 	while (fgets(str, sizeof(str), file) != NULL && id < CONFIG_NUM_CPU_IDS) {
+		if (strstr(str, "flags") && strstr(str, "constant_tsc")) {
+			sysinfo->cpu_constant_tsc = 1;
+			continue;
+		}
+
 		pos = strstr(str, "model name");
 		if (pos) {
 			freq_set = false;
diff --git a/platform/linux-generic/include/odp_global_data.h b/platform/linux-generic/include/odp_global_data.h
index d4cc9cda4..67b7572ef 100644
--- a/platform/linux-generic/include/odp_global_data.h
+++ b/platform/linux-generic/include/odp_global_data.h
@@ -1,4 +1,5 @@
 /* Copyright (c) 2013-2018, Linaro Limited
+ * Copyright (c) 2023, Nokia
  * All rights reserved.
  *
  * SPDX-License-Identifier:     BSD-3-Clause
@@ -34,7 +35,8 @@ typedef struct {
 	uint64_t default_cpu_hz;
 	uint64_t page_size;
 	int      cache_line_size;
-	odp_bool_t cpu_hz_static;
+	uint8_t cpu_hz_static;
+	uint8_t cpu_constant_tsc;
 	odp_cpu_arch_t cpu_arch;
 	odp_cpu_arch_isa_t cpu_isa_sw;
 	odp_cpu_arch_isa_t cpu_isa_hw;
diff --git a/platform/linux-generic/odp_init.c b/platform/linux-generic/odp_init.c
index f1aae95bb..e6ea8bc0c 100644
--- a/platform/linux-generic/odp_init.c
+++ b/platform/linux-generic/odp_init.c
@@ -27,8 +27,8 @@ enum init_stage {
 	LIBCONFIG_INIT,
 	CPUMASK_INIT,
 	CPU_CYCLES_INIT,
-	TIME_INIT,
 	SYSINFO_INIT,
+	TIME_INIT,
 	ISHM_INIT,
 	FDSERVER_INIT,
 	GLOBAL_RW_DATA_INIT,
@@ -292,16 +292,16 @@ static int term_global(enum init_stage stage)
 		}
 		/* Fall through */
 
-	case SYSINFO_INIT:
-		if (_odp_system_info_term()) {
-			_ODP_ERR("ODP system info term failed.\n");
+	case TIME_INIT:
+		if (_odp_time_term_global()) {
+			_ODP_ERR("ODP time term failed.\n");
 			rc = -1;
 		}
 		/* Fall through */
 
-	case TIME_INIT:
-		if (_odp_time_term_global()) {
-			_ODP_ERR("ODP time term failed.\n");
+	case SYSINFO_INIT:
+		if (_odp_system_info_term()) {
+			_ODP_ERR("ODP system info term failed.\n");
 			rc = -1;
 		}
 		/* Fall through */
@@ -372,18 +372,18 @@ int odp_init_global(odp_instance_t *instance,
 	}
 	stage = CPU_CYCLES_INIT;
 
-	if (_odp_time_init_global()) {
-		_ODP_ERR("ODP time init failed.\n");
-		goto init_failed;
-	}
-	stage = TIME_INIT;
-
 	if (_odp_system_info_init()) {
 		_ODP_ERR("ODP system_info init failed.\n");
 		goto init_failed;
 	}
 	stage = SYSINFO_INIT;
 
+	if (_odp_time_init_global()) {
+		_ODP_ERR("ODP time init failed.\n");
+		goto init_failed;
+	}
+	stage = TIME_INIT;
+
 	if (_odp_ishm_init_global(params)) {
 		_ODP_ERR("ODP ishm init failed.\n");
 		goto init_failed;