[mirror_ubuntu-bionic-kernel.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);

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

static int trace_type __read_mostly;

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

#ifdef CONFIG_IRQSOFF_TRACER
static inline int notrace
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 notrace
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))
		ftrace(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 notrace 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 notrace
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, T2, delta;
	unsigned long flags;

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

	local_save_flags(flags);

	if (!report_latency(delta))
		goto out;

	ftrace(tr, data, CALLER_ADDR0, parent_ip, flags);
	/*
	 * Update the timestamp, because the trace entry above
	 * might change it (it can only get larger so the latency
	 * is fair to be reported):
	 */
	T2 = now(cpu);

	delta = T2-T0;

	latency = nsecs_to_usecs(delta);

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

	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);

	if (tracing_thresh)
		printk(KERN_INFO "(%16s-%-5d|#%d): %lu us critical section "
		       "violates %lu us threshold.\n"
		       " => started at timestamp %lu: ",
				current->comm, current->pid,
				raw_smp_processor_id(),
				latency, nsecs_to_usecs(tracing_thresh), t0);
	else
		printk(KERN_INFO "(%16s-%-5d|#%d):"
		       " new %lu us maximum-latency "
		       "critical section.\n => started at timestamp %lu: ",
				current->comm, current->pid,
				raw_smp_processor_id(),
				latency, t0);

	print_symbol(KERN_CONT "<%s>\n", data->critical_start);
	printk(KERN_CONT " =>   ended at timestamp %lu: ", t1);
	print_symbol(KERN_CONT "<%s>\n", data->critical_end);
	dump_stack();
	t1 = nsecs_to_usecs(now(cpu));
	printk(KERN_CONT " =>   dump-end timestamp %lu\n\n", t1);

	max_sequence++;

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

static inline void notrace
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;

	if (__get_cpu_var(tracing_cpu))
		return;

	cpu = raw_smp_processor_id();
	data = tr->data[cpu];

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

	atomic_inc(&data->disabled);

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

	local_save_flags(flags);

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

	__get_cpu_var(tracing_cpu) = 1;

	atomic_dec(&data->disabled);
}

static inline void notrace
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;

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

	if (!tracer_enabled)
		return;

	cpu = raw_smp_processor_id();
	data = tr->data[cpu];

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

	atomic_inc(&data->disabled);
	local_save_flags(flags);
	ftrace(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 notrace start_critical_timings(void)
{
	if (preempt_trace() || irq_trace())
		start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
}

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

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

void notrace 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 notrace trace_hardirqs_on(void)
{
	if (!preempt_trace() && irq_trace())
		stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
}
EXPORT_SYMBOL(trace_hardirqs_on);

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

void notrace 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 notrace 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 notrace trace_preempt_on(unsigned long a0, unsigned long a1)
{
	stop_critical_timing(a0, a1);
}

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

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

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

static void __irqsoff_tracer_init(struct trace_array *tr)
{
	irqsoff_trace = tr;
	/* make sure that the tracer is visibel */
	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 notrace irqsoff_tracer_open(struct trace_iterator *iter)
{
	/* stop the trace while dumping */
	if (iter->tr->ctrl)
		stop_irqsoff_tracer(iter->tr);
}

static void notrace 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,
};
# 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,
};
# 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,
};

# 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);
	25
	26	enum {
	27	TRACER_IRQS_OFF = (1 << 1),
	28	TRACER_PREEMPT_OFF = (1 << 2),
	29	};
	30
	31	static int trace_type __read_mostly;
	32
	33	#ifdef CONFIG_PREEMPT_TRACER
	34	static inline int notrace
	35	preempt_trace(void)
	36	{
	37	return ((trace_type & TRACER_PREEMPT_OFF) && preempt_count());
	38	}
	39	#else
	40	# define preempt_trace() (0)
	41	#endif
	42
	43	#ifdef CONFIG_IRQSOFF_TRACER
	44	static inline int notrace
	45	irq_trace(void)
	46	{
	47	return ((trace_type & TRACER_IRQS_OFF) &&
	48	irqs_disabled());
	49	}
	50	#else
	51	# define irq_trace() (0)
	52	#endif
	53
81d68a96 SR	54	/*
	55	* Sequence count - we record it when starting a measurement and
	56	* skip the latency if the sequence has changed - some other section
	57	* did a maximum and could disturb our measurement with serial console
	58	* printouts, etc. Truly coinciding maximum latencies should be rare
	59	* and what happens together happens separately as well, so this doesnt
	60	* decrease the validity of the maximum found:
	61	*/
	62	static __cacheline_aligned_in_smp unsigned long max_sequence;
	63
	64	#ifdef CONFIG_FTRACE
	65	/*
	66	* irqsoff uses its own tracer function to keep the overhead down:
	67	*/
	68	static void notrace
	69	irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip)
	70	{
	71	struct trace_array *tr = irqsoff_trace;
	72	struct trace_array_cpu *data;
	73	unsigned long flags;
	74	long disabled;
	75	int cpu;
	76
361943ad SR	77	/*
	78	* Does not matter if we preempt. We test the flags
	79	* afterward, to see if irqs are disabled or not.
	80	* If we preempt and get a false positive, the flags
	81	* test will fail.
	82	*/
	83	cpu = raw_smp_processor_id();
	84	if (likely(!per_cpu(tracing_cpu, cpu)))
81d68a96 SR	85	return;
	86
	87	local_save_flags(flags);
361943ad SR	88	/* slight chance to get a false positive on tracing_cpu */
	89	if (!irqs_disabled_flags(flags))
	90	return;
81d68a96	91
81d68a96 SR	92	data = tr->data[cpu];
	93	disabled = atomic_inc_return(&data->disabled);
	94
	95	if (likely(disabled == 1))
	96	ftrace(tr, data, ip, parent_ip, flags);
	97
	98	atomic_dec(&data->disabled);
	99	}
	100
	101	static struct ftrace_ops trace_ops __read_mostly =
	102	{
	103	.func = irqsoff_tracer_call,
	104	};
	105	#endif /* CONFIG_FTRACE */
	106
	107	/*
	108	* Should this new latency be reported/recorded?
	109	*/
	110	static int notrace report_latency(cycle_t delta)
	111	{
	112	if (tracing_thresh) {
	113	if (delta < tracing_thresh)
	114	return 0;
	115	} else {
	116	if (delta <= tracing_max_latency)
	117	return 0;
	118	}
	119	return 1;
	120	}
	121
	122	static void notrace
	123	check_critical_timing(struct trace_array *tr,
	124	struct trace_array_cpu *data,
	125	unsigned long parent_ip,
	126	int cpu)
	127	{
	128	unsigned long latency, t0, t1;
	129	cycle_t T0, T1, T2, delta;
	130	unsigned long flags;
	131
	132	/*
	133	* usecs conversion is slow so we try to delay the conversion
	134	* as long as possible:
	135	*/
	136	T0 = data->preempt_timestamp;
	137	T1 = now(cpu);
	138	delta = T1-T0;
	139
	140	local_save_flags(flags);
	141
	142	if (!report_latency(delta))
	143	goto out;
	144
	145	ftrace(tr, data, CALLER_ADDR0, parent_ip, flags);
	146	/*
	147	* Update the timestamp, because the trace entry above
	148	* might change it (it can only get larger so the latency
	149	* is fair to be reported):
	150	*/
	151	T2 = now(cpu);
	152
	153	delta = T2-T0;
	154
	155	latency = nsecs_to_usecs(delta);
156
157	if (data->critical_sequence != max_sequence)
158	goto out;
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
168	if (tracing_thresh)
169	printk(KERN_INFO "(%16s-%-5d\|#%d): %lu us critical section "
170	"violates %lu us threshold.\n"
171	" => started at timestamp %lu: ",
172	current->comm, current->pid,
173	raw_smp_processor_id(),
174	latency, nsecs_to_usecs(tracing_thresh), t0);
175	else
176	printk(KERN_INFO "(%16s-%-5d\|#%d):"
177	" new %lu us maximum-latency "
178	"critical section.\n => started at timestamp %lu: ",
179	current->comm, current->pid,
180	raw_smp_processor_id(),
181	latency, t0);
182
183	print_symbol(KERN_CONT "<%s>\n", data->critical_start);
184	printk(KERN_CONT " => ended at timestamp %lu: ", t1);
185	print_symbol(KERN_CONT "<%s>\n", data->critical_end);
186	dump_stack();
187	t1 = nsecs_to_usecs(now(cpu));
188	printk(KERN_CONT " => dump-end timestamp %lu\n\n", t1);
189
190	max_sequence++;
191
192	out:
193	data->critical_sequence = max_sequence;
194	data->preempt_timestamp = now(cpu);
195	tracing_reset(data);
196	ftrace(tr, data, CALLER_ADDR0, parent_ip, flags);
197	}
198
199	static inline void notrace
200	start_critical_timing(unsigned long ip, unsigned long parent_ip)
201	{
202	int cpu;
203	struct trace_array *tr = irqsoff_trace;
204	struct trace_array_cpu *data;
205	unsigned long flags;
206
207	if (likely(!tracer_enabled))
208	return;
209
6cd8a4bb SR	210	if (__get_cpu_var(tracing_cpu))
	211	return;
	212
81d68a96 SR	213	cpu = raw_smp_processor_id();
	214	data = tr->data[cpu];
	215
	216	if (unlikely(!data) \|\| unlikely(!data->trace) \|\|
6cd8a4bb	217	atomic_read(&data->disabled))
81d68a96 SR	218	return;
	219
	220	atomic_inc(&data->disabled);
	221
	222	data->critical_sequence = max_sequence;
	223	data->preempt_timestamp = now(cpu);
6cd8a4bb	224	data->critical_start = parent_ip ? : ip;
81d68a96 SR	225	tracing_reset(data);
	226
	227	local_save_flags(flags);
6cd8a4bb	228
81d68a96 SR	229	ftrace(tr, data, ip, parent_ip, flags);
81d68a96 SR	230
6cd8a4bb SR	231	__get_cpu_var(tracing_cpu) = 1;
6cd8a4bb SR	232
81d68a96 SR	233	atomic_dec(&data->disabled);
	234	}
	235
	236	static inline void notrace
	237	stop_critical_timing(unsigned long ip, unsigned long parent_ip)
	238	{
	239	int cpu;
	240	struct trace_array *tr = irqsoff_trace;
	241	struct trace_array_cpu *data;
	242	unsigned long flags;
	243
6cd8a4bb SR	244	/* Always clear the tracing cpu on stopping the trace */
	245	if (unlikely(__get_cpu_var(tracing_cpu)))
	246	__get_cpu_var(tracing_cpu) = 0;
	247	else
	248	return;
	249
	250	if (!tracer_enabled)
81d68a96 SR	251	return;
	252
	253	cpu = raw_smp_processor_id();
	254	data = tr->data[cpu];
	255
	256	if (unlikely(!data) \|\| unlikely(!data->trace) \|\|
	257	!data->critical_start \|\| atomic_read(&data->disabled))
	258	return;
	259
	260	atomic_inc(&data->disabled);
	261	local_save_flags(flags);
	262	ftrace(tr, data, ip, parent_ip, flags);
6cd8a4bb	263	check_critical_timing(tr, data, parent_ip ? : ip, cpu);
81d68a96 SR	264	data->critical_start = 0;
	265	atomic_dec(&data->disabled);
	266	}
	267
6cd8a4bb	268	/* start and stop critical timings used to for stoppage (in idle) */
81d68a96 SR	269	void notrace start_critical_timings(void)
81d68a96 SR	270	{
6cd8a4bb	271	if (preempt_trace() \|\| irq_trace())
81d68a96 SR	272	start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
	273	}
	274
	275	void notrace stop_critical_timings(void)
	276	{
6cd8a4bb	277	if (preempt_trace() \|\| irq_trace())
81d68a96 SR	278	stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
	279	}
	280
6cd8a4bb	281	#ifdef CONFIG_IRQSOFF_TRACER
81d68a96 SR	282	#ifdef CONFIG_PROVE_LOCKING
	283	void notrace time_hardirqs_on(unsigned long a0, unsigned long a1)
	284	{
6cd8a4bb	285	if (!preempt_trace() && irq_trace())
81d68a96 SR	286	stop_critical_timing(a0, a1);
	287	}
	288
	289	void notrace time_hardirqs_off(unsigned long a0, unsigned long a1)
	290	{
6cd8a4bb	291	if (!preempt_trace() && irq_trace())
81d68a96 SR	292	start_critical_timing(a0, a1);
	293	}
	294
	295	#else /* !CONFIG_PROVE_LOCKING */
	296
	297	/*
	298	* Stubs:
	299	*/
	300
	301	void early_boot_irqs_off(void)
	302	{
	303	}
	304
	305	void early_boot_irqs_on(void)
	306	{
	307	}
	308
	309	void trace_softirqs_on(unsigned long ip)
	310	{
	311	}
	312
	313	void trace_softirqs_off(unsigned long ip)
	314	{
	315	}
	316
	317	inline void print_irqtrace_events(struct task_struct *curr)
	318	{
	319	}
	320
	321	/*
	322	* We are only interested in hardirq on/off events:
	323	*/
	324	void notrace trace_hardirqs_on(void)
	325	{
6cd8a4bb	326	if (!preempt_trace() && irq_trace())
81d68a96 SR	327	stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
	328	}
	329	EXPORT_SYMBOL(trace_hardirqs_on);
	330
	331	void notrace trace_hardirqs_off(void)
	332	{
6cd8a4bb	333	if (!preempt_trace() && irq_trace())
81d68a96 SR	334	start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
	335	}
	336	EXPORT_SYMBOL(trace_hardirqs_off);
	337
	338	void notrace trace_hardirqs_on_caller(unsigned long caller_addr)
	339	{
6cd8a4bb	340	if (!preempt_trace() && irq_trace())
81d68a96 SR	341	stop_critical_timing(CALLER_ADDR0, caller_addr);
	342	}
	343	EXPORT_SYMBOL(trace_hardirqs_on_caller);
	344
	345	void notrace trace_hardirqs_off_caller(unsigned long caller_addr)
	346	{
6cd8a4bb	347	if (!preempt_trace() && irq_trace())
81d68a96 SR	348	start_critical_timing(CALLER_ADDR0, caller_addr);
	349	}
	350	EXPORT_SYMBOL(trace_hardirqs_off_caller);
	351
	352	#endif /* CONFIG_PROVE_LOCKING */
6cd8a4bb SR	353	#endif /* CONFIG_IRQSOFF_TRACER */
	354
	355	#ifdef CONFIG_PREEMPT_TRACER
	356	void notrace trace_preempt_on(unsigned long a0, unsigned long a1)
	357	{
	358	stop_critical_timing(a0, a1);
	359	}
	360
	361	void notrace trace_preempt_off(unsigned long a0, unsigned long a1)
	362	{
	363	start_critical_timing(a0, a1);
	364	}
	365	#endif /* CONFIG_PREEMPT_TRACER */
81d68a96 SR	366
	367	static void start_irqsoff_tracer(struct trace_array *tr)
	368	{
	369	tracer_enabled = 1;
	370	register_ftrace_function(&trace_ops);
	371	}
	372
	373	static void stop_irqsoff_tracer(struct trace_array *tr)
	374	{
	375	unregister_ftrace_function(&trace_ops);
	376	tracer_enabled = 0;
	377	}
	378
6cd8a4bb	379	static void __irqsoff_tracer_init(struct trace_array *tr)
81d68a96 SR	380	{
	381	irqsoff_trace = tr;
	382	/* make sure that the tracer is visibel */
	383	smp_wmb();
	384
	385	if (tr->ctrl)
	386	start_irqsoff_tracer(tr);
	387	}
	388
	389	static void irqsoff_tracer_reset(struct trace_array *tr)
	390	{
	391	if (tr->ctrl)
	392	stop_irqsoff_tracer(tr);
	393	}
	394
	395	static void irqsoff_tracer_ctrl_update(struct trace_array *tr)
	396	{
	397	if (tr->ctrl)
	398	start_irqsoff_tracer(tr);
	399	else
	400	stop_irqsoff_tracer(tr);
	401	}
	402
	403	static void notrace irqsoff_tracer_open(struct trace_iterator *iter)
	404	{
	405	/* stop the trace while dumping */
	406	if (iter->tr->ctrl)
	407	stop_irqsoff_tracer(iter->tr);
	408	}
	409
	410	static void notrace irqsoff_tracer_close(struct trace_iterator *iter)
	411	{
	412	if (iter->tr->ctrl)
	413	start_irqsoff_tracer(iter->tr);
	414	}
	415
6cd8a4bb SR	416	#ifdef CONFIG_IRQSOFF_TRACER
	417	static void irqsoff_tracer_init(struct trace_array *tr)
	418	{
	419	trace_type = TRACER_IRQS_OFF;
	420
	421	__irqsoff_tracer_init(tr);
	422	}
81d68a96 SR	423	static struct tracer irqsoff_tracer __read_mostly =
	424	{
	425	.name = "irqsoff",
	426	.init = irqsoff_tracer_init,
	427	.reset = irqsoff_tracer_reset,
	428	.open = irqsoff_tracer_open,
	429	.close = irqsoff_tracer_close,
	430	.ctrl_update = irqsoff_tracer_ctrl_update,
	431	.print_max = 1,
	432	};
6cd8a4bb SR	433	# define register_irqsoff(trace) register_tracer(&trace)
	434	#else
	435	# define register_irqsoff(trace) do { } while (0)
	436	#endif
	437
	438	#ifdef CONFIG_PREEMPT_TRACER
	439	static void preemptoff_tracer_init(struct trace_array *tr)
	440	{
	441	trace_type = TRACER_PREEMPT_OFF;
	442
	443	__irqsoff_tracer_init(tr);
	444	}
	445
	446	static struct tracer preemptoff_tracer __read_mostly =
	447	{
	448	.name = "preemptoff",
	449	.init = preemptoff_tracer_init,
	450	.reset = irqsoff_tracer_reset,
	451	.open = irqsoff_tracer_open,
	452	.close = irqsoff_tracer_close,
	453	.ctrl_update = irqsoff_tracer_ctrl_update,
	454	.print_max = 1,
	455	};
	456	# define register_preemptoff(trace) register_tracer(&trace)
	457	#else
	458	# define register_preemptoff(trace) do { } while (0)
	459	#endif
	460
	461	#if defined(CONFIG_IRQSOFF_TRACER) && \
	462	defined(CONFIG_PREEMPT_TRACER)
	463
	464	static void preemptirqsoff_tracer_init(struct trace_array *tr)
	465	{
	466	trace_type = TRACER_IRQS_OFF \| TRACER_PREEMPT_OFF;
	467
	468	__irqsoff_tracer_init(tr);
	469	}
	470
	471	static struct tracer preemptirqsoff_tracer __read_mostly =
	472	{
	473	.name = "preemptirqsoff",
	474	.init = preemptirqsoff_tracer_init,
	475	.reset = irqsoff_tracer_reset,
	476	.open = irqsoff_tracer_open,
	477	.close = irqsoff_tracer_close,
	478	.ctrl_update = irqsoff_tracer_ctrl_update,
	479	.print_max = 1,
	480	};
	481
	482	# define register_preemptirqsoff(trace) register_tracer(&trace)
	483	#else
	484	# define register_preemptirqsoff(trace) do { } while (0)
	485	#endif
81d68a96 SR	486
	487	__init static int init_irqsoff_tracer(void)
	488	{
6cd8a4bb SR	489	register_irqsoff(irqsoff_tracer);
	490	register_preemptoff(preemptoff_tracer);
	491	register_preemptirqsoff(preemptirqsoff_tracer);
81d68a96 SR	492
	493	return 0;
	494	}
	495	device_initcall(init_irqsoff_tracer);