[deliverable/linux.git] / kernel / trace / trace_irqsoff.c

/*
 * trace irqs off criticall timings
 *
 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
 *
 * From code in the latency_tracer, that is:
 *
 *  Copyright (C) 2004-2006 Ingo Molnar
 *  Copyright (C) 2004 William Lee Irwin III
 */
#include <linux/kallsyms.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/ftrace.h>
#include <linux/fs.h>

#include "trace.h"

static struct trace_array		*irqsoff_trace __read_mostly;
static int				tracer_enabled __read_mostly;

static DEFINE_PER_CPU(int, tracing_cpu);

static DEFINE_SPINLOCK(max_trace_lock);

enum {
	TRACER_IRQS_OFF		= (1 << 1),
	TRACER_PREEMPT_OFF	= (1 << 2),
};

static int trace_type __read_mostly;

#ifdef CONFIG_PREEMPT_TRACER
static inline int
preempt_trace(void)
{
	return ((trace_type & TRACER_PREEMPT_OFF) && preempt_count());
}
#else
# define preempt_trace() (0)
#endif

#ifdef CONFIG_IRQSOFF_TRACER
static inline int
irq_trace(void)
{
	return ((trace_type & TRACER_IRQS_OFF) &&
		irqs_disabled());
}
#else
# define irq_trace() (0)
#endif

/*
 * Sequence count - we record it when starting a measurement and
 * skip the latency if the sequence has changed - some other section
 * did a maximum and could disturb our measurement with serial console
 * printouts, etc. Truly coinciding maximum latencies should be rare
 * and what happens together happens separately as well, so this doesnt
 * decrease the validity of the maximum found:
 */
static __cacheline_aligned_in_smp	unsigned long max_sequence;

#ifdef CONFIG_FTRACE
/*
 * irqsoff uses its own tracer function to keep the overhead down:
 */
static void
irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip)
{
	struct trace_array *tr = irqsoff_trace;
	struct trace_array_cpu *data;
	unsigned long flags;
	long disabled;
	int cpu;

	/*
	 * Does not matter if we preempt. We test the flags
	 * afterward, to see if irqs are disabled or not.
	 * If we preempt and get a false positive, the flags
	 * test will fail.
	 */
	cpu = raw_smp_processor_id();
	if (likely(!per_cpu(tracing_cpu, cpu)))
		return;

	local_save_flags(flags);
	/* slight chance to get a false positive on tracing_cpu */
	if (!irqs_disabled_flags(flags))
		return;

	data = tr->data[cpu];
	disabled = atomic_inc_return(&data->disabled);

	if (likely(disabled == 1))
		trace_function(tr, data, ip, parent_ip, flags);

	atomic_dec(&data->disabled);
}

static struct ftrace_ops trace_ops __read_mostly =
{
	.func = irqsoff_tracer_call,
};
#endif /* CONFIG_FTRACE */

/*
 * Should this new latency be reported/recorded?
 */
static int report_latency(cycle_t delta)
{
	if (tracing_thresh) {
		if (delta < tracing_thresh)
			return 0;
	} else {
		if (delta <= tracing_max_latency)
			return 0;
	}
	return 1;
}

static void
check_critical_timing(struct trace_array *tr,
		      struct trace_array_cpu *data,
		      unsigned long parent_ip,
		      int cpu)
{
	unsigned long latency, t0, t1;
	cycle_t T0, T1, delta;
	unsigned long flags;

	/*
	 * usecs conversion is slow so we try to delay the conversion
	 * as long as possible:
	 */
	T0 = data->preempt_timestamp;
	T1 = ftrace_now(cpu);
	delta = T1-T0;

	local_save_flags(flags);

	if (!report_latency(delta))
		goto out;

	spin_lock_irqsave(&max_trace_lock, flags);

	/* check if we are still the max latency */
	if (!report_latency(delta))
		goto out_unlock;

	trace_function(tr, data, CALLER_ADDR0, parent_ip, flags);

	latency = nsecs_to_usecs(delta);

	if (data->critical_sequence != max_sequence)
		goto out_unlock;

	tracing_max_latency = delta;
	t0 = nsecs_to_usecs(T0);
	t1 = nsecs_to_usecs(T1);

	data->critical_end = parent_ip;

	update_max_tr_single(tr, current, cpu);

	max_sequence++;

out_unlock:
	spin_unlock_irqrestore(&max_trace_lock, flags);

out:
	data->critical_sequence = max_sequence;
	data->preempt_timestamp = ftrace_now(cpu);
	tracing_reset(tr, cpu);
	trace_function(tr, data, CALLER_ADDR0, parent_ip, flags);
}

static inline void
start_critical_timing(unsigned long ip, unsigned long parent_ip)
{
	int cpu;
	struct trace_array *tr = irqsoff_trace;
	struct trace_array_cpu *data;
	unsigned long flags;

	if (likely(!tracer_enabled))
		return;

	cpu = raw_smp_processor_id();

	if (per_cpu(tracing_cpu, cpu))
		return;

	data = tr->data[cpu];

	if (unlikely(!data) || atomic_read(&data->disabled))
		return;

	atomic_inc(&data->disabled);

	data->critical_sequence = max_sequence;
	data->preempt_timestamp = ftrace_now(cpu);
	data->critical_start = parent_ip ? : ip;
	tracing_reset(tr, cpu);

	local_save_flags(flags);

	trace_function(tr, data, ip, parent_ip, flags);

	per_cpu(tracing_cpu, cpu) = 1;

	atomic_dec(&data->disabled);
}

static inline void
stop_critical_timing(unsigned long ip, unsigned long parent_ip)
{
	int cpu;
	struct trace_array *tr = irqsoff_trace;
	struct trace_array_cpu *data;
	unsigned long flags;

	cpu = raw_smp_processor_id();
	/* Always clear the tracing cpu on stopping the trace */
	if (unlikely(per_cpu(tracing_cpu, cpu)))
		per_cpu(tracing_cpu, cpu) = 0;
	else
		return;

	if (!tracer_enabled)
		return;

	data = tr->data[cpu];

	if (unlikely(!data) ||
	    !data->critical_start || atomic_read(&data->disabled))
		return;

	atomic_inc(&data->disabled);

	local_save_flags(flags);
	trace_function(tr, data, ip, parent_ip, flags);
	check_critical_timing(tr, data, parent_ip ? : ip, cpu);
	data->critical_start = 0;
	atomic_dec(&data->disabled);
}

/* start and stop critical timings used to for stoppage (in idle) */
void start_critical_timings(void)
{
	if (preempt_trace() || irq_trace())
		start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
}
EXPORT_SYMBOL_GPL(start_critical_timings);

void stop_critical_timings(void)
{
	if (preempt_trace() || irq_trace())
		stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
}
EXPORT_SYMBOL_GPL(stop_critical_timings);

#ifdef CONFIG_IRQSOFF_TRACER
#ifdef CONFIG_PROVE_LOCKING
void time_hardirqs_on(unsigned long a0, unsigned long a1)
{
	if (!preempt_trace() && irq_trace())
		stop_critical_timing(a0, a1);
}

void time_hardirqs_off(unsigned long a0, unsigned long a1)
{
	if (!preempt_trace() && irq_trace())
		start_critical_timing(a0, a1);
}

#else /* !CONFIG_PROVE_LOCKING */

/*
 * Stubs:
 */

void early_boot_irqs_off(void)
{
}

void early_boot_irqs_on(void)
{
}

void trace_softirqs_on(unsigned long ip)
{
}

void trace_softirqs_off(unsigned long ip)
{
}

inline void print_irqtrace_events(struct task_struct *curr)
{
}

/*
 * We are only interested in hardirq on/off events:
 */
void trace_hardirqs_on(void)
{
	if (!preempt_trace() && irq_trace())
		stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
}
EXPORT_SYMBOL(trace_hardirqs_on);

void trace_hardirqs_off(void)
{
	if (!preempt_trace() && irq_trace())
		start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
}
EXPORT_SYMBOL(trace_hardirqs_off);

void trace_hardirqs_on_caller(unsigned long caller_addr)
{
	if (!preempt_trace() && irq_trace())
		stop_critical_timing(CALLER_ADDR0, caller_addr);
}
EXPORT_SYMBOL(trace_hardirqs_on_caller);

void trace_hardirqs_off_caller(unsigned long caller_addr)
{
	if (!preempt_trace() && irq_trace())
		start_critical_timing(CALLER_ADDR0, caller_addr);
}
EXPORT_SYMBOL(trace_hardirqs_off_caller);

#endif /* CONFIG_PROVE_LOCKING */
#endif /*  CONFIG_IRQSOFF_TRACER */

#ifdef CONFIG_PREEMPT_TRACER
void trace_preempt_on(unsigned long a0, unsigned long a1)
{
	if (preempt_trace())
		stop_critical_timing(a0, a1);
}

void trace_preempt_off(unsigned long a0, unsigned long a1)
{
	if (preempt_trace())
		start_critical_timing(a0, a1);
}
#endif /* CONFIG_PREEMPT_TRACER */

static void start_irqsoff_tracer(struct trace_array *tr)
{
	register_ftrace_function(&trace_ops);
	tracer_enabled = 1;
}

static void stop_irqsoff_tracer(struct trace_array *tr)
{
	tracer_enabled = 0;
	unregister_ftrace_function(&trace_ops);
}

static void __irqsoff_tracer_init(struct trace_array *tr)
{
	irqsoff_trace = tr;
	/* make sure that the tracer is visible */
	smp_wmb();

	if (tr->ctrl)
		start_irqsoff_tracer(tr);
}

static void irqsoff_tracer_reset(struct trace_array *tr)
{
	if (tr->ctrl)
		stop_irqsoff_tracer(tr);
}

static void irqsoff_tracer_ctrl_update(struct trace_array *tr)
{
	if (tr->ctrl)
		start_irqsoff_tracer(tr);
	else
		stop_irqsoff_tracer(tr);
}

static void irqsoff_tracer_open(struct trace_iterator *iter)
{
	/* stop the trace while dumping */
	if (iter->tr->ctrl)
		stop_irqsoff_tracer(iter->tr);
}

static void irqsoff_tracer_close(struct trace_iterator *iter)
{
	if (iter->tr->ctrl)
		start_irqsoff_tracer(iter->tr);
}

#ifdef CONFIG_IRQSOFF_TRACER
static void irqsoff_tracer_init(struct trace_array *tr)
{
	trace_type = TRACER_IRQS_OFF;

	__irqsoff_tracer_init(tr);
}
static struct tracer irqsoff_tracer __read_mostly =
{
	.name		= "irqsoff",
	.init		= irqsoff_tracer_init,
	.reset		= irqsoff_tracer_reset,
	.open		= irqsoff_tracer_open,
	.close		= irqsoff_tracer_close,
	.ctrl_update	= irqsoff_tracer_ctrl_update,
	.print_max	= 1,
#ifdef CONFIG_FTRACE_SELFTEST
	.selftest    = trace_selftest_startup_irqsoff,
#endif
};
# define register_irqsoff(trace) register_tracer(&trace)
#else
# define register_irqsoff(trace) do { } while (0)
#endif

#ifdef CONFIG_PREEMPT_TRACER
static void preemptoff_tracer_init(struct trace_array *tr)
{
	trace_type = TRACER_PREEMPT_OFF;

	__irqsoff_tracer_init(tr);
}

static struct tracer preemptoff_tracer __read_mostly =
{
	.name		= "preemptoff",
	.init		= preemptoff_tracer_init,
	.reset		= irqsoff_tracer_reset,
	.open		= irqsoff_tracer_open,
	.close		= irqsoff_tracer_close,
	.ctrl_update	= irqsoff_tracer_ctrl_update,
	.print_max	= 1,
#ifdef CONFIG_FTRACE_SELFTEST
	.selftest    = trace_selftest_startup_preemptoff,
#endif
};
# define register_preemptoff(trace) register_tracer(&trace)
#else
# define register_preemptoff(trace) do { } while (0)
#endif

#if defined(CONFIG_IRQSOFF_TRACER) && \
	defined(CONFIG_PREEMPT_TRACER)

static void preemptirqsoff_tracer_init(struct trace_array *tr)
{
	trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;

	__irqsoff_tracer_init(tr);
}

static struct tracer preemptirqsoff_tracer __read_mostly =
{
	.name		= "preemptirqsoff",
	.init		= preemptirqsoff_tracer_init,
	.reset		= irqsoff_tracer_reset,
	.open		= irqsoff_tracer_open,
	.close		= irqsoff_tracer_close,
	.ctrl_update	= irqsoff_tracer_ctrl_update,
	.print_max	= 1,
#ifdef CONFIG_FTRACE_SELFTEST
	.selftest    = trace_selftest_startup_preemptirqsoff,
#endif
};

# define register_preemptirqsoff(trace) register_tracer(&trace)
#else
# define register_preemptirqsoff(trace) do { } while (0)
#endif

__init static int init_irqsoff_tracer(void)
{
	register_irqsoff(irqsoff_tracer);
	register_preemptoff(preemptoff_tracer);
	register_preemptirqsoff(preemptirqsoff_tracer);

	return 0;
}
device_initcall(init_irqsoff_tracer);
Commit	Line	Data
81d68a96 SR	1	/*
	2	* trace irqs off criticall timings
	3	*
	4	* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
	5	* Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
	6	*
	7	* From code in the latency_tracer, that is:
	8	*
	9	* Copyright (C) 2004-2006 Ingo Molnar
	10	* Copyright (C) 2004 William Lee Irwin III
	11	*/
	12	#include <linux/kallsyms.h>
	13	#include <linux/debugfs.h>
	14	#include <linux/uaccess.h>
	15	#include <linux/module.h>
	16	#include <linux/ftrace.h>
	17	#include <linux/fs.h>
	18
	19	#include "trace.h"
	20
	21	static struct trace_array *irqsoff_trace __read_mostly;
	22	static int tracer_enabled __read_mostly;
	23
6cd8a4bb SR	24	static DEFINE_PER_CPU(int, tracing_cpu);
6cd8a4bb SR	25
89b2f978 SR	26	static DEFINE_SPINLOCK(max_trace_lock);
89b2f978 SR	27
6cd8a4bb SR	28	enum {
	29	TRACER_IRQS_OFF = (1 << 1),
	30	TRACER_PREEMPT_OFF = (1 << 2),
	31	};
	32
	33	static int trace_type __read_mostly;
	34
	35	#ifdef CONFIG_PREEMPT_TRACER
e309b41d	36	static inline int
6cd8a4bb SR	37	preempt_trace(void)
	38	{
	39	return ((trace_type & TRACER_PREEMPT_OFF) && preempt_count());
	40	}
	41	#else
	42	# define preempt_trace() (0)
	43	#endif
	44
	45	#ifdef CONFIG_IRQSOFF_TRACER
e309b41d	46	static inline int
6cd8a4bb SR	47	irq_trace(void)
	48	{
	49	return ((trace_type & TRACER_IRQS_OFF) &&
	50	irqs_disabled());
	51	}
	52	#else
	53	# define irq_trace() (0)
	54	#endif
	55
81d68a96 SR	56	/*
	57	* Sequence count - we record it when starting a measurement and
	58	* skip the latency if the sequence has changed - some other section
	59	* did a maximum and could disturb our measurement with serial console
	60	* printouts, etc. Truly coinciding maximum latencies should be rare
	61	* and what happens together happens separately as well, so this doesnt
	62	* decrease the validity of the maximum found:
	63	*/
	64	static __cacheline_aligned_in_smp unsigned long max_sequence;
	65
	66	#ifdef CONFIG_FTRACE
	67	/*
	68	* irqsoff uses its own tracer function to keep the overhead down:
	69	*/
e309b41d	70	static void
81d68a96 SR	71	irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip)
	72	{
	73	struct trace_array *tr = irqsoff_trace;
	74	struct trace_array_cpu *data;
	75	unsigned long flags;
	76	long disabled;
	77	int cpu;
	78
361943ad SR	79	/*
	80	* Does not matter if we preempt. We test the flags
	81	* afterward, to see if irqs are disabled or not.
	82	* If we preempt and get a false positive, the flags
	83	* test will fail.
	84	*/
	85	cpu = raw_smp_processor_id();
	86	if (likely(!per_cpu(tracing_cpu, cpu)))
81d68a96 SR	87	return;
	88
	89	local_save_flags(flags);
361943ad SR	90	/* slight chance to get a false positive on tracing_cpu */
	91	if (!irqs_disabled_flags(flags))
	92	return;
81d68a96	93
81d68a96 SR	94	data = tr->data[cpu];
	95	disabled = atomic_inc_return(&data->disabled);
	96
	97	if (likely(disabled == 1))
6fb44b71	98	trace_function(tr, data, ip, parent_ip, flags);
81d68a96 SR	99
	100	atomic_dec(&data->disabled);
	101	}
	102
	103	static struct ftrace_ops trace_ops __read_mostly =
	104	{
	105	.func = irqsoff_tracer_call,
	106	};
	107	#endif /* CONFIG_FTRACE */
	108
	109	/*
	110	* Should this new latency be reported/recorded?
	111	*/
e309b41d	112	static int report_latency(cycle_t delta)
81d68a96 SR	113	{
	114	if (tracing_thresh) {
	115	if (delta < tracing_thresh)
	116	return 0;
	117	} else {
	118	if (delta <= tracing_max_latency)
	119	return 0;
	120	}
	121	return 1;
	122	}
	123
e309b41d	124	static void
81d68a96 SR	125	check_critical_timing(struct trace_array *tr,
	126	struct trace_array_cpu *data,
	127	unsigned long parent_ip,
	128	int cpu)
	129	{
	130	unsigned long latency, t0, t1;
89b2f978	131	cycle_t T0, T1, delta;
81d68a96 SR	132	unsigned long flags;
	133
	134	/*
	135	* usecs conversion is slow so we try to delay the conversion
	136	* as long as possible:
	137	*/
	138	T0 = data->preempt_timestamp;
750ed1a4	139	T1 = ftrace_now(cpu);
81d68a96 SR	140	delta = T1-T0;
	141
	142	local_save_flags(flags);
	143
	144	if (!report_latency(delta))
	145	goto out;
	146
c7aafc54	147	spin_lock_irqsave(&max_trace_lock, flags);
81d68a96	148
89b2f978 SR	149	/* check if we are still the max latency */
	150	if (!report_latency(delta))
	151	goto out_unlock;
	152
6fb44b71	153	trace_function(tr, data, CALLER_ADDR0, parent_ip, flags);
81d68a96 SR	154
	155	latency = nsecs_to_usecs(delta);
	156
	157	if (data->critical_sequence != max_sequence)
89b2f978	158	goto out_unlock;
81d68a96 SR	159
	160	tracing_max_latency = delta;
	161	t0 = nsecs_to_usecs(T0);
	162	t1 = nsecs_to_usecs(T1);
	163
	164	data->critical_end = parent_ip;
	165
	166	update_max_tr_single(tr, current, cpu);
	167
81d68a96 SR	168	max_sequence++;
81d68a96 SR	169
89b2f978	170	out_unlock:
c7aafc54	171	spin_unlock_irqrestore(&max_trace_lock, flags);
89b2f978	172
81d68a96 SR	173	out:
81d68a96 SR	174	data->critical_sequence = max_sequence;
750ed1a4	175	data->preempt_timestamp = ftrace_now(cpu);
3928a8a2	176	tracing_reset(tr, cpu);
6fb44b71	177	trace_function(tr, data, CALLER_ADDR0, parent_ip, flags);
81d68a96 SR	178	}
81d68a96 SR	179
e309b41d	180	static inline void
81d68a96 SR	181	start_critical_timing(unsigned long ip, unsigned long parent_ip)
	182	{
	183	int cpu;
	184	struct trace_array *tr = irqsoff_trace;
	185	struct trace_array_cpu *data;
	186	unsigned long flags;
	187
	188	if (likely(!tracer_enabled))
	189	return;
	190
c5f888ca SR	191	cpu = raw_smp_processor_id();
	192
	193	if (per_cpu(tracing_cpu, cpu))
6cd8a4bb SR	194	return;
6cd8a4bb SR	195
81d68a96 SR	196	data = tr->data[cpu];
81d68a96 SR	197
c5f888ca	198	if (unlikely(!data) \|\| atomic_read(&data->disabled))
81d68a96 SR	199	return;
	200
	201	atomic_inc(&data->disabled);
	202
	203	data->critical_sequence = max_sequence;
750ed1a4	204	data->preempt_timestamp = ftrace_now(cpu);
6cd8a4bb	205	data->critical_start = parent_ip ? : ip;
3928a8a2	206	tracing_reset(tr, cpu);
81d68a96 SR	207
81d68a96 SR	208	local_save_flags(flags);
6cd8a4bb	209
6fb44b71	210	trace_function(tr, data, ip, parent_ip, flags);
81d68a96	211
c5f888ca	212	per_cpu(tracing_cpu, cpu) = 1;
6cd8a4bb	213
81d68a96 SR	214	atomic_dec(&data->disabled);
	215	}
	216
e309b41d	217	static inline void
81d68a96 SR	218	stop_critical_timing(unsigned long ip, unsigned long parent_ip)
	219	{
	220	int cpu;
	221	struct trace_array *tr = irqsoff_trace;
	222	struct trace_array_cpu *data;
	223	unsigned long flags;
	224
c5f888ca	225	cpu = raw_smp_processor_id();
6cd8a4bb	226	/* Always clear the tracing cpu on stopping the trace */
c5f888ca SR	227	if (unlikely(per_cpu(tracing_cpu, cpu)))
c5f888ca SR	228	per_cpu(tracing_cpu, cpu) = 0;
6cd8a4bb SR	229	else
	230	return;
	231
	232	if (!tracer_enabled)
81d68a96 SR	233	return;
81d68a96 SR	234
81d68a96 SR	235	data = tr->data[cpu];
81d68a96 SR	236
3928a8a2	237	if (unlikely(!data) \|\|
81d68a96 SR	238	!data->critical_start \|\| atomic_read(&data->disabled))
	239	return;
	240
	241	atomic_inc(&data->disabled);
c5f888ca	242
81d68a96	243	local_save_flags(flags);
6fb44b71	244	trace_function(tr, data, ip, parent_ip, flags);
6cd8a4bb	245	check_critical_timing(tr, data, parent_ip ? : ip, cpu);
81d68a96 SR	246	data->critical_start = 0;
	247	atomic_dec(&data->disabled);
	248	}
	249
6cd8a4bb	250	/* start and stop critical timings used to for stoppage (in idle) */
e309b41d	251	void start_critical_timings(void)
81d68a96	252	{
6cd8a4bb	253	if (preempt_trace() \|\| irq_trace())
81d68a96 SR	254	start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
81d68a96 SR	255	}
1fe37104	256	EXPORT_SYMBOL_GPL(start_critical_timings);
81d68a96	257
e309b41d	258	void stop_critical_timings(void)
81d68a96	259	{
6cd8a4bb	260	if (preempt_trace() \|\| irq_trace())
81d68a96 SR	261	stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
81d68a96 SR	262	}
1fe37104	263	EXPORT_SYMBOL_GPL(stop_critical_timings);
81d68a96	264
6cd8a4bb	265	#ifdef CONFIG_IRQSOFF_TRACER
81d68a96	266	#ifdef CONFIG_PROVE_LOCKING
e309b41d	267	void time_hardirqs_on(unsigned long a0, unsigned long a1)
81d68a96	268	{
6cd8a4bb	269	if (!preempt_trace() && irq_trace())
81d68a96 SR	270	stop_critical_timing(a0, a1);
	271	}
	272
e309b41d	273	void time_hardirqs_off(unsigned long a0, unsigned long a1)
81d68a96	274	{
6cd8a4bb	275	if (!preempt_trace() && irq_trace())
81d68a96 SR	276	start_critical_timing(a0, a1);
	277	}
	278
	279	#else /* !CONFIG_PROVE_LOCKING */
	280
	281	/*
	282	* Stubs:
	283	*/
	284
	285	void early_boot_irqs_off(void)
	286	{
	287	}
	288
	289	void early_boot_irqs_on(void)
	290	{
	291	}
	292
	293	void trace_softirqs_on(unsigned long ip)
	294	{
	295	}
	296
	297	void trace_softirqs_off(unsigned long ip)
	298	{
	299	}
	300
e309b41d	301	inline void print_irqtrace_events(struct task_struct *curr)
81d68a96 SR	302	{
	303	}
	304
	305	/*
	306	* We are only interested in hardirq on/off events:
	307	*/
e309b41d	308	void trace_hardirqs_on(void)
81d68a96	309	{
6cd8a4bb	310	if (!preempt_trace() && irq_trace())
81d68a96 SR	311	stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
	312	}
	313	EXPORT_SYMBOL(trace_hardirqs_on);
	314
e309b41d	315	void trace_hardirqs_off(void)
81d68a96	316	{
6cd8a4bb	317	if (!preempt_trace() && irq_trace())
81d68a96 SR	318	start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
	319	}
	320	EXPORT_SYMBOL(trace_hardirqs_off);
	321
e309b41d	322	void trace_hardirqs_on_caller(unsigned long caller_addr)
81d68a96	323	{
6cd8a4bb	324	if (!preempt_trace() && irq_trace())
81d68a96 SR	325	stop_critical_timing(CALLER_ADDR0, caller_addr);
	326	}
	327	EXPORT_SYMBOL(trace_hardirqs_on_caller);
	328
e309b41d	329	void trace_hardirqs_off_caller(unsigned long caller_addr)
81d68a96	330	{
6cd8a4bb	331	if (!preempt_trace() && irq_trace())
81d68a96 SR	332	start_critical_timing(CALLER_ADDR0, caller_addr);
	333	}
	334	EXPORT_SYMBOL(trace_hardirqs_off_caller);
	335
	336	#endif /* CONFIG_PROVE_LOCKING */
6cd8a4bb SR	337	#endif /* CONFIG_IRQSOFF_TRACER */
	338
	339	#ifdef CONFIG_PREEMPT_TRACER
e309b41d	340	void trace_preempt_on(unsigned long a0, unsigned long a1)
6cd8a4bb	341	{
1e01cb0c SR	342	if (preempt_trace())
1e01cb0c SR	343	stop_critical_timing(a0, a1);
6cd8a4bb SR	344	}
6cd8a4bb SR	345
e309b41d	346	void trace_preempt_off(unsigned long a0, unsigned long a1)
6cd8a4bb	347	{
1e01cb0c SR	348	if (preempt_trace())
1e01cb0c SR	349	start_critical_timing(a0, a1);
6cd8a4bb SR	350	}
6cd8a4bb SR	351	#endif /* CONFIG_PREEMPT_TRACER */
81d68a96 SR	352
	353	static void start_irqsoff_tracer(struct trace_array *tr)
	354	{
81d68a96	355	register_ftrace_function(&trace_ops);
89b2f978	356	tracer_enabled = 1;
81d68a96 SR	357	}
	358
	359	static void stop_irqsoff_tracer(struct trace_array *tr)
	360	{
81d68a96	361	tracer_enabled = 0;
89b2f978	362	unregister_ftrace_function(&trace_ops);
81d68a96 SR	363	}
81d68a96 SR	364
6cd8a4bb	365	static void __irqsoff_tracer_init(struct trace_array *tr)
81d68a96 SR	366	{
81d68a96 SR	367	irqsoff_trace = tr;
c5f888ca	368	/* make sure that the tracer is visible */
81d68a96 SR	369	smp_wmb();
	370
	371	if (tr->ctrl)
	372	start_irqsoff_tracer(tr);
	373	}
	374
	375	static void irqsoff_tracer_reset(struct trace_array *tr)
	376	{
	377	if (tr->ctrl)
	378	stop_irqsoff_tracer(tr);
	379	}
	380
	381	static void irqsoff_tracer_ctrl_update(struct trace_array *tr)
	382	{
	383	if (tr->ctrl)
	384	start_irqsoff_tracer(tr);
	385	else
	386	stop_irqsoff_tracer(tr);
	387	}
	388
e309b41d	389	static void irqsoff_tracer_open(struct trace_iterator *iter)
81d68a96 SR	390	{
	391	/* stop the trace while dumping */
	392	if (iter->tr->ctrl)
	393	stop_irqsoff_tracer(iter->tr);
	394	}
	395
e309b41d	396	static void irqsoff_tracer_close(struct trace_iterator *iter)
81d68a96 SR	397	{
	398	if (iter->tr->ctrl)
	399	start_irqsoff_tracer(iter->tr);
	400	}
	401
6cd8a4bb SR	402	#ifdef CONFIG_IRQSOFF_TRACER
	403	static void irqsoff_tracer_init(struct trace_array *tr)
	404	{
	405	trace_type = TRACER_IRQS_OFF;
	406
	407	__irqsoff_tracer_init(tr);
	408	}
81d68a96 SR	409	static struct tracer irqsoff_tracer __read_mostly =
	410	{
	411	.name = "irqsoff",
	412	.init = irqsoff_tracer_init,
	413	.reset = irqsoff_tracer_reset,
	414	.open = irqsoff_tracer_open,
	415	.close = irqsoff_tracer_close,
	416	.ctrl_update = irqsoff_tracer_ctrl_update,
	417	.print_max = 1,
60a11774 SR	418	#ifdef CONFIG_FTRACE_SELFTEST
	419	.selftest = trace_selftest_startup_irqsoff,
	420	#endif
81d68a96	421	};
6cd8a4bb SR	422	# define register_irqsoff(trace) register_tracer(&trace)
	423	#else
	424	# define register_irqsoff(trace) do { } while (0)
	425	#endif
	426
	427	#ifdef CONFIG_PREEMPT_TRACER
	428	static void preemptoff_tracer_init(struct trace_array *tr)
	429	{
	430	trace_type = TRACER_PREEMPT_OFF;
	431
	432	__irqsoff_tracer_init(tr);
	433	}
	434
	435	static struct tracer preemptoff_tracer __read_mostly =
	436	{
	437	.name = "preemptoff",
	438	.init = preemptoff_tracer_init,
	439	.reset = irqsoff_tracer_reset,
	440	.open = irqsoff_tracer_open,
	441	.close = irqsoff_tracer_close,
	442	.ctrl_update = irqsoff_tracer_ctrl_update,
	443	.print_max = 1,
60a11774 SR	444	#ifdef CONFIG_FTRACE_SELFTEST
	445	.selftest = trace_selftest_startup_preemptoff,
	446	#endif
6cd8a4bb SR	447	};
	448	# define register_preemptoff(trace) register_tracer(&trace)
	449	#else
	450	# define register_preemptoff(trace) do { } while (0)
	451	#endif
	452
	453	#if defined(CONFIG_IRQSOFF_TRACER) && \
	454	defined(CONFIG_PREEMPT_TRACER)
	455
	456	static void preemptirqsoff_tracer_init(struct trace_array *tr)
	457	{
	458	trace_type = TRACER_IRQS_OFF \| TRACER_PREEMPT_OFF;
	459
	460	__irqsoff_tracer_init(tr);
	461	}
	462
	463	static struct tracer preemptirqsoff_tracer __read_mostly =
	464	{
	465	.name = "preemptirqsoff",
	466	.init = preemptirqsoff_tracer_init,
	467	.reset = irqsoff_tracer_reset,
	468	.open = irqsoff_tracer_open,
	469	.close = irqsoff_tracer_close,
	470	.ctrl_update = irqsoff_tracer_ctrl_update,
	471	.print_max = 1,
60a11774 SR	472	#ifdef CONFIG_FTRACE_SELFTEST
	473	.selftest = trace_selftest_startup_preemptirqsoff,
	474	#endif
6cd8a4bb SR	475	};
	476
	477	# define register_preemptirqsoff(trace) register_tracer(&trace)
	478	#else
	479	# define register_preemptirqsoff(trace) do { } while (0)
	480	#endif
81d68a96 SR	481
	482	__init static int init_irqsoff_tracer(void)
	483	{
6cd8a4bb SR	484	register_irqsoff(irqsoff_tracer);
	485	register_preemptoff(preemptoff_tracer);
	486	register_preemptirqsoff(preemptirqsoff_tracer);
81d68a96 SR	487
	488	return 0;
	489	}
	490	device_initcall(init_irqsoff_tracer);