[dpdk-dev] [PATCH v2 04/16] eal/arm: cpu cycle operations for ARM
Jan Viktorin
viktorin at rehivetech.com
Mon Oct 26 17:37:26 CET 2015
From: Vlastimil Kosar <kosar at rehivetech.com>
ARM architecture doesn't have a suitable source of CPU cycles. This
patch uses clock_gettime instead. The implementation should be improved
in the future.
Signed-off-by: Vlastimil Kosar <kosar at rehivetech.com>
Signed-off-by: Jan Viktorin <viktorin at rehivetech.com>
---
.../common/include/arch/arm/rte_cycles.h | 85 ++++++++++++++++++++++
1 file changed, 85 insertions(+)
create mode 100644 lib/librte_eal/common/include/arch/arm/rte_cycles.h
diff --git a/lib/librte_eal/common/include/arch/arm/rte_cycles.h b/lib/librte_eal/common/include/arch/arm/rte_cycles.h
new file mode 100644
index 0000000..ff66ae2
--- /dev/null
+++ b/lib/librte_eal/common/include/arch/arm/rte_cycles.h
@@ -0,0 +1,85 @@
+/*
+ * BSD LICENSE
+ *
+ * Copyright(c) 2015 RehiveTech. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of RehiveTech nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _RTE_CYCLES_ARM_H_
+#define _RTE_CYCLES_ARM_H_
+
+/* ARM v7 does not have suitable source of clock signals. The only clock counter
+ available in the core is 32 bit wide. Therefore it is unsuitable as the
+ counter overlaps every few seconds and probably is not accessible by
+ userspace programs. Therefore we use clock_gettime(CLOCK_MONOTONIC_RAW) to
+ simulate counter running at 1GHz.
+*/
+
+#include <time.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "generic/rte_cycles.h"
+
+/**
+ * Read the time base register.
+ *
+ * @return
+ * The time base for this lcore.
+ */
+static inline uint64_t
+rte_rdtsc(void)
+{
+ struct timespec val;
+ uint64_t v;
+
+ while (clock_gettime(CLOCK_MONOTONIC_RAW, &val) != 0)
+ /* no body */;
+
+ v = (uint64_t) val.tv_sec * 1000000000LL;
+ v += (uint64_t) val.tv_nsec;
+ return v;
+}
+
+static inline uint64_t
+rte_rdtsc_precise(void)
+{
+ rte_mb();
+ return rte_rdtsc();
+}
+
+static inline uint64_t
+rte_get_tsc_cycles(void) { return rte_rdtsc(); }
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTE_CYCLES_ARM_H_ */
--
2.6.1
More information about the dev
mailing list