rv: Add scpd, snep and sncid per-cpu monitors

Add 3 per-cpu monitors as part of the sched model:

* scpd: schedule called with preemption disabled
    Monitor to ensure schedule is called with preemption disabled
* snep: schedule does not enable preempt
    Monitor to ensure schedule does not enable preempt
* sncid: schedule not called with interrupt disabled
    Monitor to ensure schedule is not called with interrupt disabled

To: Ingo Molnar <mingo@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Kacur <jkacur@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Link: https://lore.kernel.org/20250305140406.350227-6-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

kernel/trace/rv/Kconfig

@@ -31,6 +31,9 @@ source "kernel/trace/rv/monitors/sched/Kconfig"
 source "kernel/trace/rv/monitors/tss/Kconfig"
 source "kernel/trace/rv/monitors/sco/Kconfig"
 source "kernel/trace/rv/monitors/snroc/Kconfig"
+source "kernel/trace/rv/monitors/scpd/Kconfig"
+source "kernel/trace/rv/monitors/snep/Kconfig"
+source "kernel/trace/rv/monitors/sncid/Kconfig"
 # Add new monitors here
 
 config RV_REACTORS

kernel/trace/rv/Makefile

@@ -9,6 +9,9 @@ obj-$(CONFIG_RV_MON_SCHED) += monitors/sched/sched.o
 obj-$(CONFIG_RV_MON_TSS) += monitors/tss/tss.o
 obj-$(CONFIG_RV_MON_SCO) += monitors/sco/sco.o
 obj-$(CONFIG_RV_MON_SNROC) += monitors/snroc/snroc.o
+obj-$(CONFIG_RV_MON_SCPD) += monitors/scpd/scpd.o
+obj-$(CONFIG_RV_MON_SNEP) += monitors/snep/snep.o
+obj-$(CONFIG_RV_MON_SNCID) += monitors/sncid/sncid.o
 # Add new monitors here
 obj-$(CONFIG_RV_REACTORS) += rv_reactors.o
 obj-$(CONFIG_RV_REACT_PRINTK) += reactor_printk.o

kernel/trace/rv/monitors/scpd/Kconfig

@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+config RV_MON_SCPD
+	depends on RV
+	depends on PREEMPT_TRACER
+	depends on RV_MON_SCHED
+	default y
+	select DA_MON_EVENTS_IMPLICIT
+	bool "scpd monitor"
+	help
+	  Monitor to ensure schedule is called with preemption disabled.
+	  This monitor is part of the sched monitors collection.
+
+	  For further information, see:
+	    Documentation/trace/rv/monitor_sched.rst

kernel/trace/rv/monitors/scpd/scpd.c

@@ -0,0 +1,96 @@
+// 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>
+#include <rv/da_monitor.h>
+
+#define MODULE_NAME "scpd"
+
+#include <trace/events/sched.h>
+#include <trace/events/preemptirq.h>
+#include <rv_trace.h>
+#include <monitors/sched/sched.h>
+
+#include "scpd.h"
+
+static struct rv_monitor rv_scpd;
+DECLARE_DA_MON_PER_CPU(scpd, unsigned char);
+
+static void handle_preempt_disable(void *data, unsigned long ip, unsigned long parent_ip)
+{
+	da_handle_event_scpd(preempt_disable_scpd);
+}
+
+static void handle_preempt_enable(void *data, unsigned long ip, unsigned long parent_ip)
+{
+	da_handle_start_event_scpd(preempt_enable_scpd);
+}
+
+static void handle_schedule_entry(void *data, bool preempt, unsigned long ip)
+{
+	da_handle_event_scpd(schedule_entry_scpd);
+}
+
+static void handle_schedule_exit(void *data, bool is_switch, unsigned long ip)
+{
+	da_handle_event_scpd(schedule_exit_scpd);
+}
+
+static int enable_scpd(void)
+{
+	int retval;
+
+	retval = da_monitor_init_scpd();
+	if (retval)
+		return retval;
+
+	rv_attach_trace_probe("scpd", preempt_disable, handle_preempt_disable);
+	rv_attach_trace_probe("scpd", preempt_enable, handle_preempt_enable);
+	rv_attach_trace_probe("scpd", sched_entry_tp, handle_schedule_entry);
+	rv_attach_trace_probe("scpd", sched_exit_tp, handle_schedule_exit);
+
+	return 0;
+}
+
+static void disable_scpd(void)
+{
+	rv_scpd.enabled = 0;
+
+	rv_detach_trace_probe("scpd", preempt_disable, handle_preempt_disable);
+	rv_detach_trace_probe("scpd", preempt_enable, handle_preempt_enable);
+	rv_detach_trace_probe("scpd", sched_entry_tp, handle_schedule_entry);
+	rv_detach_trace_probe("scpd", sched_exit_tp, handle_schedule_exit);
+
+	da_monitor_destroy_scpd();
+}
+
+static struct rv_monitor rv_scpd = {
+	.name = "scpd",
+	.description = "schedule called with preemption disabled.",
+	.enable = enable_scpd,
+	.disable = disable_scpd,
+	.reset = da_monitor_reset_all_scpd,
+	.enabled = 0,
+};
+
+static int __init register_scpd(void)
+{
+	rv_register_monitor(&rv_scpd, &rv_sched);
+	return 0;
+}
+
+static void __exit unregister_scpd(void)
+{
+	rv_unregister_monitor(&rv_scpd);
+}
+
+module_init(register_scpd);
+module_exit(unregister_scpd);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Gabriele Monaco <gmonaco@redhat.com>");
+MODULE_DESCRIPTION("scpd: schedule called with preemption disabled.");

kernel/trace/rv/monitors/scpd/scpd.h

@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Automatically generated C representation of scpd automaton
+ * For further information about this format, see kernel documentation:
+ *   Documentation/trace/rv/deterministic_automata.rst
+ */
+
+enum states_scpd {
+	cant_sched_scpd = 0,
+	can_sched_scpd,
+	state_max_scpd
+};
+
+#define INVALID_STATE state_max_scpd
+
+enum events_scpd {
+	preempt_disable_scpd = 0,
+	preempt_enable_scpd,
+	schedule_entry_scpd,
+	schedule_exit_scpd,
+	event_max_scpd
+};
+
+struct automaton_scpd {
+	char *state_names[state_max_scpd];
+	char *event_names[event_max_scpd];
+	unsigned char function[state_max_scpd][event_max_scpd];
+	unsigned char initial_state;
+	bool final_states[state_max_scpd];
+};
+
+static const struct automaton_scpd automaton_scpd = {
+	.state_names = {
+		"cant_sched",
+		"can_sched"
+	},
+	.event_names = {
+		"preempt_disable",
+		"preempt_enable",
+		"schedule_entry",
+		"schedule_exit"
+	},
+	.function = {
+		{     can_sched_scpd,     INVALID_STATE,     INVALID_STATE,     INVALID_STATE },
+		{     INVALID_STATE,    cant_sched_scpd,     can_sched_scpd,     can_sched_scpd },
+	},
+	.initial_state = cant_sched_scpd,
+	.final_states = { 1, 0 },
+};

kernel/trace/rv/monitors/scpd/scpd_trace.h

@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Snippet to be included in rv_trace.h
+ */
+
+#ifdef CONFIG_RV_MON_SCPD
+DEFINE_EVENT(event_da_monitor, event_scpd,
+	     TP_PROTO(char *state, char *event, char *next_state, bool final_state),
+	     TP_ARGS(state, event, next_state, final_state));
+
+DEFINE_EVENT(error_da_monitor, error_scpd,
+	     TP_PROTO(char *state, char *event),
+	     TP_ARGS(state, event));
+#endif /* CONFIG_RV_MON_SCPD */

kernel/trace/rv/monitors/sncid/Kconfig

@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+config RV_MON_SNCID
+	depends on RV
+	depends on IRQSOFF_TRACER
+	depends on RV_MON_SCHED
+	default y
+	select DA_MON_EVENTS_IMPLICIT
+	bool "sncid monitor"
+	help
+	  Monitor to ensure schedule is not called with interrupt disabled.
+	  This monitor is part of the sched monitors collection.
+
+	  For further information, see:
+	    Documentation/trace/rv/monitor_sched.rst

kernel/trace/rv/monitors/sncid/sncid.c

@@ -0,0 +1,96 @@
+// 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>
+#include <rv/da_monitor.h>
+
+#define MODULE_NAME "sncid"
+
+#include <trace/events/sched.h>
+#include <trace/events/preemptirq.h>
+#include <rv_trace.h>
+#include <monitors/sched/sched.h>
+
+#include "sncid.h"
+
+static struct rv_monitor rv_sncid;
+DECLARE_DA_MON_PER_CPU(sncid, unsigned char);
+
+static void handle_irq_disable(void *data, unsigned long ip, unsigned long parent_ip)
+{
+	da_handle_event_sncid(irq_disable_sncid);
+}
+
+static void handle_irq_enable(void *data, unsigned long ip, unsigned long parent_ip)
+{
+	da_handle_start_event_sncid(irq_enable_sncid);
+}
+
+static void handle_schedule_entry(void *data, bool preempt, unsigned long ip)
+{
+	da_handle_start_event_sncid(schedule_entry_sncid);
+}
+
+static void handle_schedule_exit(void *data, bool is_switch, unsigned long ip)
+{
+	da_handle_start_event_sncid(schedule_exit_sncid);
+}
+
+static int enable_sncid(void)
+{
+	int retval;
+
+	retval = da_monitor_init_sncid();
+	if (retval)
+		return retval;
+
+	rv_attach_trace_probe("sncid", irq_disable, handle_irq_disable);
+	rv_attach_trace_probe("sncid", irq_enable, handle_irq_enable);
+	rv_attach_trace_probe("sncid", sched_entry_tp, handle_schedule_entry);
+	rv_attach_trace_probe("sncid", sched_exit_tp, handle_schedule_exit);
+
+	return 0;
+}
+
+static void disable_sncid(void)
+{
+	rv_sncid.enabled = 0;
+
+	rv_detach_trace_probe("sncid", irq_disable, handle_irq_disable);
+	rv_detach_trace_probe("sncid", irq_enable, handle_irq_enable);
+	rv_detach_trace_probe("sncid", sched_entry_tp, handle_schedule_entry);
+	rv_detach_trace_probe("sncid", sched_exit_tp, handle_schedule_exit);
+
+	da_monitor_destroy_sncid();
+}
+
+static struct rv_monitor rv_sncid = {
+	.name = "sncid",
+	.description = "schedule not called with interrupt disabled.",
+	.enable = enable_sncid,
+	.disable = disable_sncid,
+	.reset = da_monitor_reset_all_sncid,
+	.enabled = 0,
+};
+
+static int __init register_sncid(void)
+{
+	rv_register_monitor(&rv_sncid, &rv_sched);
+	return 0;
+}
+
+static void __exit unregister_sncid(void)
+{
+	rv_unregister_monitor(&rv_sncid);
+}
+
+module_init(register_sncid);
+module_exit(unregister_sncid);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Gabriele Monaco <gmonaco@redhat.com>");
+MODULE_DESCRIPTION("sncid: schedule not called with interrupt disabled.");

kernel/trace/rv/monitors/sncid/sncid.h

@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Automatically generated C representation of sncid automaton
+ * For further information about this format, see kernel documentation:
+ *   Documentation/trace/rv/deterministic_automata.rst
+ */
+
+enum states_sncid {
+	can_sched_sncid = 0,
+	cant_sched_sncid,
+	state_max_sncid
+};
+
+#define INVALID_STATE state_max_sncid
+
+enum events_sncid {
+	irq_disable_sncid = 0,
+	irq_enable_sncid,
+	schedule_entry_sncid,
+	schedule_exit_sncid,
+	event_max_sncid
+};
+
+struct automaton_sncid {
+	char *state_names[state_max_sncid];
+	char *event_names[event_max_sncid];
+	unsigned char function[state_max_sncid][event_max_sncid];
+	unsigned char initial_state;
+	bool final_states[state_max_sncid];
+};
+
+static const struct automaton_sncid automaton_sncid = {
+	.state_names = {
+		"can_sched",
+		"cant_sched"
+	},
+	.event_names = {
+		"irq_disable",
+		"irq_enable",
+		"schedule_entry",
+		"schedule_exit"
+	},
+	.function = {
+		{ cant_sched_sncid,   INVALID_STATE, can_sched_sncid, can_sched_sncid },
+		{    INVALID_STATE, can_sched_sncid,   INVALID_STATE,   INVALID_STATE },
+	},
+	.initial_state = can_sched_sncid,
+	.final_states = { 1, 0 },
+};

kernel/trace/rv/monitors/sncid/sncid_trace.h

@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Snippet to be included in rv_trace.h
+ */
+
+#ifdef CONFIG_RV_MON_SNCID
+DEFINE_EVENT(event_da_monitor, event_sncid,
+	     TP_PROTO(char *state, char *event, char *next_state, bool final_state),
+	     TP_ARGS(state, event, next_state, final_state));
+
+DEFINE_EVENT(error_da_monitor, error_sncid,
+	     TP_PROTO(char *state, char *event),
+	     TP_ARGS(state, event));
+#endif /* CONFIG_RV_MON_SNCID */

kernel/trace/rv/monitors/snep/Kconfig

@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+config RV_MON_SNEP
+	depends on RV
+	depends on PREEMPT_TRACER
+	depends on RV_MON_SCHED
+	default y
+	select DA_MON_EVENTS_IMPLICIT
+	bool "snep monitor"
+	help
+	  Monitor to ensure schedule does not enable preempt.
+	  This monitor is part of the sched monitors collection.
+
+	  For further information, see:
+	    Documentation/trace/rv/monitor_sched.rst