1 files changed, 136 insertions, 0 deletions
diff --git a/kernel/trace/rv/monitors/nrp/nrp.c b/kernel/trace/rv/monitors/nrp/nrp.c
new file mode 100644
index 000000000000..4b5646a70094
--- /dev/null
+++ b/kernel/trace/rv/monitors/nrp/nrp.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ftrace.h>
+#include <linux/tracepoint.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/rv.h>
+#include <rv/instrumentation.h>
+
+#define MODULE_NAME "nrp"
+
+#include <trace/events/irq.h>
+#include <trace/events/sched.h>
+#include <rv_trace.h>
+#include <monitors/sched/sched.h>
+
+#define RV_MON_TYPE RV_MON_PER_TASK
+#include "nrp.h"
+#include <rv/da_monitor.h>
+
+#ifdef CONFIG_X86_LOCAL_APIC
+#include <asm/trace/irq_vectors.h>
+
+static void handle_vector_irq_entry(void *data, int vector)
+{
+	da_handle_event(current, irq_entry_nrp);
+}
+
+static void attach_vector_irq(void)
+{
+	rv_attach_trace_probe("nrp", local_timer_entry, handle_vector_irq_entry);
+	if (IS_ENABLED(CONFIG_IRQ_WORK))
+		rv_attach_trace_probe("nrp", irq_work_entry, handle_vector_irq_entry);
+	if (IS_ENABLED(CONFIG_SMP)) {
+		rv_attach_trace_probe("nrp", reschedule_entry, handle_vector_irq_entry);
+		rv_attach_trace_probe("nrp", call_function_entry, handle_vector_irq_entry);
+		rv_attach_trace_probe("nrp", call_function_single_entry, handle_vector_irq_entry);
+	}
+}
+
+static void detach_vector_irq(void)
+{
+	rv_detach_trace_probe("nrp", local_timer_entry, handle_vector_irq_entry);
+	if (IS_ENABLED(CONFIG_IRQ_WORK))
+		rv_detach_trace_probe("nrp", irq_work_entry, handle_vector_irq_entry);
+	if (IS_ENABLED(CONFIG_SMP)) {
+		rv_detach_trace_probe("nrp", reschedule_entry, handle_vector_irq_entry);
+		rv_detach_trace_probe("nrp", call_function_entry, handle_vector_irq_entry);
+		rv_detach_trace_probe("nrp", call_function_single_entry, handle_vector_irq_entry);
+	}
+}
+
+#else
+/* We assume irq_entry tracepoints are sufficient on other architectures */
+static void attach_vector_irq(void) { }
+static void detach_vector_irq(void) { }
+#endif
+
+static void handle_irq_entry(void *data, int irq, struct irqaction *action)
+{
+	da_handle_event(current, irq_entry_nrp);
+}
+
+static void handle_sched_need_resched(void *data, struct task_struct *tsk,
+				      int cpu, int tif)
+{
+	/*
+	 * Although need_resched leads to both the rescheduling and preempt_irq
+	 * states, it is safer to start the monitor always in preempt_irq,
+	 * which may not mirror the system state but makes the monitor simpler,
+	 */
+	if (tif == TIF_NEED_RESCHED)
+		da_handle_start_event(tsk, sched_need_resched_nrp);
+}
+
+static void handle_schedule_entry(void *data, bool preempt)
+{
+	if (preempt)
+		da_handle_event(current, schedule_entry_preempt_nrp);
+	else
+		da_handle_event(current, schedule_entry_nrp);
+}
+
+static int enable_nrp(void)
+{
+	int retval;
+
+	retval = da_monitor_init();
+	if (retval)
+		return retval;
+
+	rv_attach_trace_probe("nrp", irq_handler_entry, handle_irq_entry);
+	rv_attach_trace_probe("nrp", sched_set_need_resched_tp, handle_sched_need_resched);
+	rv_attach_trace_probe("nrp", sched_entry_tp, handle_schedule_entry);
+	attach_vector_irq();
+
+	return 0;
+}
+
+static void disable_nrp(void)
+{
+	rv_this.enabled = 0;
+
+	rv_detach_trace_probe("nrp", irq_handler_entry, handle_irq_entry);
+	rv_detach_trace_probe("nrp", sched_set_need_resched_tp, handle_sched_need_resched);
+	rv_detach_trace_probe("nrp", sched_entry_tp, handle_schedule_entry);
+	detach_vector_irq();
+
+	da_monitor_destroy();
+}
+
+static struct rv_monitor rv_this = {
+	.name = "nrp",
+	.description = "need resched preempts.",
+	.enable = enable_nrp,
+	.disable = disable_nrp,
+	.reset = da_monitor_reset_all,
+	.enabled = 0,
+};
+
+static int __init register_nrp(void)
+{
+	return rv_register_monitor(&rv_this, &rv_sched);
+}
+
+static void __exit unregister_nrp(void)
+{
+	rv_unregister_monitor(&rv_this);
+}
+
+module_init(register_nrp);
+module_exit(unregister_nrp);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Gabriele Monaco <gmonaco@redhat.com>");
+MODULE_DESCRIPTION("nrp: need resched preempts.");