first commit for chrg

rt-thread/components/drivers/ktime/src/risc-v/virt64/cputimer.c

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2006-2023, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2023-07-10     xqyjlj       The first version.
+ */
+
+#include "ktime.h"
+
+static volatile unsigned long _init_cnt = 0;
+
+rt_uint64_t rt_ktime_cputimer_getres(void)
+{
+    return ((1000ULL * 1000 * 1000) * RT_KTIME_RESMUL) / CPUTIME_TIMER_FREQ;
+}
+
+unsigned long rt_ktime_cputimer_getfrq(void)
+{
+    return CPUTIME_TIMER_FREQ;
+}
+
+unsigned long rt_ktime_cputimer_getcnt(void)
+{
+    unsigned long time_elapsed;
+    __asm__ __volatile__("rdtime %0" : "=r"(time_elapsed));
+    return time_elapsed - _init_cnt;
+}
+
+unsigned long rt_ktime_cputimer_getstep(void)
+{
+    return rt_ktime_cputimer_getfrq() / RT_TICK_PER_SECOND;
+}
+
+void rt_ktime_cputimer_init(void)
+{
+    __asm__ __volatile__("rdtime %0" : "=r"(_init_cnt));
+}