eal/armv8: implement arch-specific TSC freq query

Use cntvct_el0 system register to get the system counter frequency.

If the system is configured with RTE_ARM_EAL_RDTSC_USE_PMU then
return 0(let the common code calibrate the tsc frequency).

Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Acked-by: Jianbo Liu <jianbo.liu@linaro.org>

diff --git a/lib/librte_eal/common/arch/arm/rte_cycles.c b/lib/librte_eal/common/arch/arm/rte_cycles.c
index 851fd02..3e31e5b 100644 (file)
--- a/lib/librte_eal/common/arch/arm/rte_cycles.c
+++ b/lib/librte_eal/common/arch/arm/rte_cycles.c
@@ -1,7 +1,45 @@
+/*
+ *   BSD LICENSE
+ *
+ *   Copyright (C) Cavium, Inc. 2015.
+ *
+ *   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 Cavium, Inc 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.
+ */
+
 #include "eal_private.h"
 
 uint64_t
 get_tsc_freq_arch(void)
 {
+#if defined RTE_ARCH_ARM64 && !defined RTE_ARM_EAL_RDTSC_USE_PMU
+       uint64_t freq;
+       asm volatile("mrs %0, cntfrq_el0" : "=r" (freq));
+       return freq;
+#else
        return 0;
+#endif
 }