v4.19.13 snapshot.
diff --git a/drivers/oprofile/nmi_timer_int.c b/drivers/oprofile/nmi_timer_int.c
new file mode 100644
index 0000000..f343bd9
--- /dev/null
+++ b/drivers/oprofile/nmi_timer_int.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * @file nmi_timer_int.c
+ *
+ * @remark Copyright 2011 Advanced Micro Devices, Inc.
+ *
+ * @author Robert Richter <robert.richter@amd.com>
+ */
+
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/errno.h>
+#include <linux/oprofile.h>
+#include <linux/perf_event.h>
+
+#ifdef CONFIG_OPROFILE_NMI_TIMER
+
+static DEFINE_PER_CPU(struct perf_event *, nmi_timer_events);
+static int ctr_running;
+
+static struct perf_event_attr nmi_timer_attr = {
+ .type = PERF_TYPE_HARDWARE,
+ .config = PERF_COUNT_HW_CPU_CYCLES,
+ .size = sizeof(struct perf_event_attr),
+ .pinned = 1,
+ .disabled = 1,
+};
+
+static void nmi_timer_callback(struct perf_event *event,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ event->hw.interrupts = 0; /* don't throttle interrupts */
+ oprofile_add_sample(regs, 0);
+}
+
+static int nmi_timer_start_cpu(int cpu)
+{
+ struct perf_event *event = per_cpu(nmi_timer_events, cpu);
+
+ if (!event) {
+ event = perf_event_create_kernel_counter(&nmi_timer_attr, cpu, NULL,
+ nmi_timer_callback, NULL);
+ if (IS_ERR(event))
+ return PTR_ERR(event);
+ per_cpu(nmi_timer_events, cpu) = event;
+ }
+
+ if (event && ctr_running)
+ perf_event_enable(event);
+
+ return 0;
+}
+
+static void nmi_timer_stop_cpu(int cpu)
+{
+ struct perf_event *event = per_cpu(nmi_timer_events, cpu);
+
+ if (event && ctr_running)
+ perf_event_disable(event);
+}
+
+static int nmi_timer_cpu_online(unsigned int cpu)
+{
+ nmi_timer_start_cpu(cpu);
+ return 0;
+}
+static int nmi_timer_cpu_predown(unsigned int cpu)
+{
+ nmi_timer_stop_cpu(cpu);
+ return 0;
+}
+
+static int nmi_timer_start(void)
+{
+ int cpu;
+
+ get_online_cpus();
+ ctr_running = 1;
+ for_each_online_cpu(cpu)
+ nmi_timer_start_cpu(cpu);
+ put_online_cpus();
+
+ return 0;
+}
+
+static void nmi_timer_stop(void)
+{
+ int cpu;
+
+ get_online_cpus();
+ for_each_online_cpu(cpu)
+ nmi_timer_stop_cpu(cpu);
+ ctr_running = 0;
+ put_online_cpus();
+}
+
+static enum cpuhp_state hp_online;
+
+static void nmi_timer_shutdown(void)
+{
+ struct perf_event *event;
+ int cpu;
+
+ cpuhp_remove_state(hp_online);
+ for_each_possible_cpu(cpu) {
+ event = per_cpu(nmi_timer_events, cpu);
+ if (!event)
+ continue;
+ perf_event_disable(event);
+ per_cpu(nmi_timer_events, cpu) = NULL;
+ perf_event_release_kernel(event);
+ }
+}
+
+static int nmi_timer_setup(void)
+{
+ int err;
+ u64 period;
+
+ /* clock cycles per tick: */
+ period = (u64)cpu_khz * 1000;
+ do_div(period, HZ);
+ nmi_timer_attr.sample_period = period;
+
+ err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "oprofile/nmi:online",
+ nmi_timer_cpu_online, nmi_timer_cpu_predown);
+ if (err < 0) {
+ nmi_timer_shutdown();
+ return err;
+ }
+ hp_online = err;
+ return 0;
+}
+
+int __init op_nmi_timer_init(struct oprofile_operations *ops)
+{
+ int err = 0;
+
+ err = nmi_timer_setup();
+ if (err)
+ return err;
+ nmi_timer_shutdown(); /* only check, don't alloc */
+
+ ops->create_files = NULL;
+ ops->setup = nmi_timer_setup;
+ ops->shutdown = nmi_timer_shutdown;
+ ops->start = nmi_timer_start;
+ ops->stop = nmi_timer_stop;
+ ops->cpu_type = "timer";
+
+ printk(KERN_INFO "oprofile: using NMI timer interrupt.\n");
+
+ return 0;
+}
+
+#endif