Imported Upstream version 16.04

[deb_dpdk.git] / lib / librte_eal / common / include / arch / arm / rte_cycles_32.h

diff --git a/lib/librte_eal/common/include/arch/arm/rte_cycles_32.h b/lib/librte_eal/common/include/arch/arm/rte_cycles_32.h
new file mode 100644 (file)
index 0000000..9c1be71
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+++ b/lib/librte_eal/common/include/arch/arm/rte_cycles_32.h
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+/*
+ *   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_ARM32_H_
+#define _RTE_CYCLES_ARM32_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.
+ */
+#ifndef RTE_ARM_EAL_RDTSC_USE_PMU
+
+/**
+ * This call is easily portable to any ARM architecture, however,
+ * it may be damn slow and inprecise for some tasks.
+ */
+static inline uint64_t
+__rte_rdtsc_syscall(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;
+}
+#define rte_rdtsc __rte_rdtsc_syscall
+
+#else
+
+/**
+ * This function requires to configure the PMCCNTR and enable
+ * userspace access to it:
+ *
+ *      asm volatile("mcr p15, 0, %0, c9, c14, 0" : : "r"(1));
+ *      asm volatile("mcr p15, 0, %0, c9, c12, 0" : : "r"(29));
+ *      asm volatile("mcr p15, 0, %0, c9, c12, 1" : : "r"(0x8000000f));
+ *
+ * which is possible only from the priviledged mode (kernel space).
+ */
+static inline uint64_t
+__rte_rdtsc_pmccntr(void)
+{
+       unsigned tsc;
+       uint64_t final_tsc;
+
+       /* Read PMCCNTR */
+       asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r"(tsc));
+       /* 1 tick = 64 clocks */
+       final_tsc = ((uint64_t)tsc) << 6;
+
+       return (uint64_t)final_tsc;
+}
+#define rte_rdtsc __rte_rdtsc_pmccntr
+
+#endif /* RTE_ARM_EAL_RDTSC_USE_PMU */
+
+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_ARM32_H_ */