[Feature] add GA346 baseline version
Change-Id: Ic62933698569507dcf98240cdf5d9931ae34348f
diff --git a/src/kernel/linux/v4.19/samples/bpf/lathist_kern.c b/src/kernel/linux/v4.19/samples/bpf/lathist_kern.c
new file mode 100644
index 0000000..18fa088
--- /dev/null
+++ b/src/kernel/linux/v4.19/samples/bpf/lathist_kern.c
@@ -0,0 +1,99 @@
+/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2015 BMW Car IT GmbH
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/version.h>
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include "bpf_helpers.h"
+
+#define MAX_ENTRIES 20
+#define MAX_CPU 4
+
+/* We need to stick to static allocated memory (an array instead of
+ * hash table) because managing dynamic memory from the
+ * trace_preempt_[on|off] tracepoints hooks is not supported.
+ */
+
+struct bpf_map_def SEC("maps") my_map = {
+ .type = BPF_MAP_TYPE_ARRAY,
+ .key_size = sizeof(int),
+ .value_size = sizeof(u64),
+ .max_entries = MAX_CPU,
+};
+
+SEC("kprobe/trace_preempt_off")
+int bpf_prog1(struct pt_regs *ctx)
+{
+ int cpu = bpf_get_smp_processor_id();
+ u64 *ts = bpf_map_lookup_elem(&my_map, &cpu);
+
+ if (ts)
+ *ts = bpf_ktime_get_ns();
+
+ return 0;
+}
+
+static unsigned int log2(unsigned int v)
+{
+ unsigned int r;
+ unsigned int shift;
+
+ r = (v > 0xFFFF) << 4; v >>= r;
+ shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
+ shift = (v > 0xF) << 2; v >>= shift; r |= shift;
+ shift = (v > 0x3) << 1; v >>= shift; r |= shift;
+ r |= (v >> 1);
+
+ return r;
+}
+
+static unsigned int log2l(unsigned long v)
+{
+ unsigned int hi = v >> 32;
+
+ if (hi)
+ return log2(hi) + 32;
+ else
+ return log2(v);
+}
+
+struct bpf_map_def SEC("maps") my_lat = {
+ .type = BPF_MAP_TYPE_ARRAY,
+ .key_size = sizeof(int),
+ .value_size = sizeof(long),
+ .max_entries = MAX_CPU * MAX_ENTRIES,
+};
+
+SEC("kprobe/trace_preempt_on")
+int bpf_prog2(struct pt_regs *ctx)
+{
+ u64 *ts, cur_ts, delta;
+ int key, cpu;
+ long *val;
+
+ cpu = bpf_get_smp_processor_id();
+ ts = bpf_map_lookup_elem(&my_map, &cpu);
+ if (!ts)
+ return 0;
+
+ cur_ts = bpf_ktime_get_ns();
+ delta = log2l(cur_ts - *ts);
+
+ if (delta > MAX_ENTRIES - 1)
+ delta = MAX_ENTRIES - 1;
+
+ key = cpu * MAX_ENTRIES + delta;
+ val = bpf_map_lookup_elem(&my_lat, &key);
+ if (val)
+ __sync_fetch_and_add((long *)val, 1);
+
+ return 0;
+
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;