kern/clock: new module

1 files changed, 99 insertions, 0 deletions

diff --git a/kern/clock.c b/kern/clock.c
new file mode 100644
index 00000000..d8af3f4c
--- /dev/null
+++ b/kern/clock.c
@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2017 Richard Braun.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+
+#include <kern/atomic.h>
+#include <kern/clock.h>
+#include <kern/clock_i.h>
+#include <kern/init.h>
+#include <kern/llsync.h>
+#include <kern/percpu.h>
+#include <kern/sref.h>
+#include <kern/syscnt.h>
+#include <kern/thread.h>
+#include <kern/work.h>
+#include <machine/boot.h>
+#include <machine/cpu.h>
+
+struct clock_cpu_data {
+    struct syscnt sc_tick_intrs;
+};
+
+static struct clock_cpu_data clock_cpu_data __percpu;
+
+union clock_global_time clock_global_time;
+
+static inline void __init
+clock_cpu_data_init(struct clock_cpu_data *cpu_data, unsigned int cpu)
+{
+    char name[SYSCNT_NAME_SIZE];
+
+    snprintf(name, sizeof(name), "clock_tick_intrs/%u", cpu);
+    syscnt_register(&cpu_data->sc_tick_intrs, name);
+}
+
+static int __init
+clock_setup(void)
+{
+    for (unsigned int cpu = 0; cpu < cpu_count(); cpu++) {
+        clock_cpu_data_init(percpu_ptr(clock_cpu_data, cpu), cpu);
+    }
+
+    return 0;
+}
+
+INIT_OP_DEFINE(clock_setup,
+               INIT_OP_DEP(boot_setup_intr, true),
+               INIT_OP_DEP(cpu_mp_probe, true),
+               INIT_OP_DEP(syscnt_setup, true));
+
+void clock_tick_intr(void)
+{
+    struct clock_cpu_data *cpu_data;
+
+    assert(!cpu_intr_enabled());
+    assert(!thread_preempt_enabled());
+
+    if (cpu_id() == 0) {
+#ifdef ATOMIC_HAVE_64B_OPS
+
+        atomic_add(&clock_global_time.ticks, 1, ATOMIC_RELAXED);
+
+#else /* ATOMIC_HAVE_64B_OPS */
+
+        union clock_global_time t;
+
+        t.ticks = clock_global_time.ticks;
+        t.ticks++;
+
+        atomic_store(&clock_global_time.high2, t.high1, ATOMIC_RELAXED);
+        atomic_store_release(&clock_global_time.low, t.low);
+        atomic_store_release(&clock_global_time.high1, t.high1);
+
+#endif /* ATOMIC_HAVE_64B_OPS */
+    }
+
+    llsync_report_periodic_event();
+    sref_report_periodic_event();
+    work_report_periodic_event();
+    thread_report_periodic_event();
+
+    cpu_data = cpu_local_ptr(clock_cpu_data);
+    syscnt_inc(&cpu_data->sc_tick_intrs);
+}