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

/*
 * h/w branch tracer for x86 based on bts
 *
 * Copyright (C) 2008-2009 Intel Corporation.
 * Markus Metzger <markus.t.metzger@gmail.com>, 2008-2009
 */
#include <linux/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/debugfs.h>
#include <linux/ftrace.h>
#include <linux/module.h>
#include <linux/cpu.h>
#include <linux/smp.h>
#include <linux/fs.h>

#include <asm/ds.h>

#include "trace.h"
#include "trace_output.h"


#define BTS_BUFFER_SIZE (1 << 13)

/*
 * The tracer lock protects the below per-cpu tracer array.
 * It needs to be held to:
 * - start tracing on all cpus
 * - stop tracing on all cpus
 * - start tracing on a single hotplug cpu
 * - stop tracing on a single hotplug cpu
 * - read the trace from all cpus
 * - read the trace from a single cpu
 */
static DEFINE_SPINLOCK(bts_tracer_lock);
static DEFINE_PER_CPU(struct bts_tracer *, tracer);
static DEFINE_PER_CPU(unsigned char[BTS_BUFFER_SIZE], buffer);

#define this_tracer per_cpu(tracer, smp_processor_id())
#define this_buffer per_cpu(buffer, smp_processor_id())

static int trace_hw_branches_enabled __read_mostly;
static int trace_hw_branches_suspended __read_mostly;
static struct trace_array *hw_branch_trace __read_mostly;


/*
 * Initialize the tracer for the current cpu.
 * The argument is ignored.
 *
 * pre: bts_tracer_lock must be locked.
 */
static void bts_trace_init_cpu(void *arg)
{
	if (this_tracer)
		ds_release_bts(this_tracer);

	this_tracer = ds_request_bts(NULL, this_buffer, BTS_BUFFER_SIZE,
				     NULL, (size_t)-1, BTS_KERNEL);
	if (IS_ERR(this_tracer)) {
		this_tracer = NULL;
		return;
	}
}

static int bts_trace_init(struct trace_array *tr)
{
	int cpu, avail;

	spin_lock(&bts_tracer_lock);

	hw_branch_trace = tr;

	on_each_cpu(bts_trace_init_cpu, NULL, 1);

	/* Check on how many cpus we could enable tracing */
	avail = 0;
	for_each_online_cpu(cpu)
		if (per_cpu(tracer, cpu))
			avail++;

	trace_hw_branches_enabled = (avail ? 1 : 0);
	trace_hw_branches_suspended = 0;

	spin_unlock(&bts_tracer_lock);


	/* If we could not enable tracing on a single cpu, we fail. */
	return avail ? 0 : -EOPNOTSUPP;
}

/*
 * Release the tracer for the current cpu.
 * The argument is ignored.
 *
 * pre: bts_tracer_lock must be locked.
 */
static void bts_trace_release_cpu(void *arg)
{
	if (this_tracer) {
		ds_release_bts(this_tracer);
		this_tracer = NULL;
	}
}

static void bts_trace_reset(struct trace_array *tr)
{
	spin_lock(&bts_tracer_lock);

	on_each_cpu(bts_trace_release_cpu, NULL, 1);
	trace_hw_branches_enabled = 0;
	trace_hw_branches_suspended = 0;

	spin_unlock(&bts_tracer_lock);
}

/*
 * Resume tracing on the current cpu.
 * The argument is ignored.
 *
 * pre: bts_tracer_lock must be locked.
 */
static void bts_trace_resume_cpu(void *arg)
{
	if (this_tracer)
		ds_resume_bts(this_tracer);
}

static void bts_trace_start(struct trace_array *tr)
{
	spin_lock(&bts_tracer_lock);

	on_each_cpu(bts_trace_resume_cpu, NULL, 1);
	trace_hw_branches_suspended = 0;

	spin_unlock(&bts_tracer_lock);
}

/*
 * Suspend tracing on the current cpu.
 * The argument is ignored.
 *
 * pre: bts_tracer_lock must be locked.
 */
static void bts_trace_suspend_cpu(void *arg)
{
	if (this_tracer)
		ds_suspend_bts(this_tracer);
}

static void bts_trace_stop(struct trace_array *tr)
{
	spin_lock(&bts_tracer_lock);

	on_each_cpu(bts_trace_suspend_cpu, NULL, 1);
	trace_hw_branches_suspended = 1;

	spin_unlock(&bts_tracer_lock);
}

static int __cpuinit bts_hotcpu_handler(struct notifier_block *nfb,
				     unsigned long action, void *hcpu)
{
	unsigned int cpu = (unsigned long)hcpu;

	spin_lock(&bts_tracer_lock);

	if (!trace_hw_branches_enabled)
		goto out;

	switch (action) {
	case CPU_ONLINE:
	case CPU_DOWN_FAILED:
		smp_call_function_single(cpu, bts_trace_init_cpu, NULL, 1);

		if (trace_hw_branches_suspended)
			smp_call_function_single(cpu, bts_trace_suspend_cpu,
						 NULL, 1);
		break;
	case CPU_DOWN_PREPARE:
		smp_call_function_single(cpu, bts_trace_release_cpu, NULL, 1);
		break;
	}

 out:
	spin_unlock(&bts_tracer_lock);
	return NOTIFY_DONE;
}

static struct notifier_block bts_hotcpu_notifier __cpuinitdata = {
	.notifier_call = bts_hotcpu_handler
};

static void bts_trace_print_header(struct seq_file *m)
{
	seq_puts(m, "# CPU#        TO  <-  FROM\n");
}

static enum print_line_t bts_trace_print_line(struct trace_iterator *iter)
{
	struct trace_entry *entry = iter->ent;
	struct trace_seq *seq = &iter->seq;
	struct hw_branch_entry *it;
	unsigned long symflags = TRACE_ITER_SYM_OFFSET;

	trace_assign_type(it, entry);

	if (entry->type == TRACE_HW_BRANCHES) {
		if (trace_seq_printf(seq, "%4d  ", iter->cpu) &&
		    seq_print_ip_sym(seq, it->to, symflags) &&
		    trace_seq_printf(seq, "\t  <-  ") &&
		    seq_print_ip_sym(seq, it->from, symflags) &&
		    trace_seq_printf(seq, "\n"))
			return TRACE_TYPE_HANDLED;
		return TRACE_TYPE_PARTIAL_LINE;;
	}
	return TRACE_TYPE_UNHANDLED;
}

void trace_hw_branch(u64 from, u64 to)
{
	struct trace_array *tr = hw_branch_trace;
	struct ring_buffer_event *event;
	struct hw_branch_entry *entry;
	unsigned long irq1;
	int cpu;

	if (unlikely(!tr))
		return;

	if (unlikely(!trace_hw_branches_enabled))
		return;

	local_irq_save(irq1);
	cpu = raw_smp_processor_id();
	if (atomic_inc_return(&tr->data[cpu]->disabled) != 1)
		goto out;

	event = trace_buffer_lock_reserve(tr, TRACE_HW_BRANCHES,
					  sizeof(*entry), 0, 0);
	if (!event)
		goto out;
	entry	= ring_buffer_event_data(event);
	tracing_generic_entry_update(&entry->ent, 0, from);
	entry->ent.type = TRACE_HW_BRANCHES;
	entry->from = from;
	entry->to   = to;
	trace_buffer_unlock_commit(tr, event, 0, 0);

 out:
	atomic_dec(&tr->data[cpu]->disabled);
	local_irq_restore(irq1);
}

static void trace_bts_at(const struct bts_trace *trace, void *at)
{
	struct bts_struct bts;
	int err = 0;

	WARN_ON_ONCE(!trace->read);
	if (!trace->read)
		return;

	err = trace->read(this_tracer, at, &bts);
	if (err < 0)
		return;

	switch (bts.qualifier) {
	case BTS_BRANCH:
		trace_hw_branch(bts.variant.lbr.from, bts.variant.lbr.to);
		break;
	}
}

/*
 * Collect the trace on the current cpu and write it into the ftrace buffer.
 *
 * pre: bts_tracer_lock must be locked
 */
static void trace_bts_cpu(void *arg)
{
	struct trace_array *tr = (struct trace_array *)arg;
	const struct bts_trace *trace;
	unsigned char *at;

	if (unlikely(!tr))
		return;

	if (unlikely(atomic_read(&tr->data[raw_smp_processor_id()]->disabled)))
		return;

	if (unlikely(!this_tracer))
		return;

	ds_suspend_bts(this_tracer);
	trace = ds_read_bts(this_tracer);
	if (!trace)
		goto out;

	for (at = trace->ds.top; (void *)at < trace->ds.end;
	     at += trace->ds.size)
		trace_bts_at(trace, at);

	for (at = trace->ds.begin; (void *)at < trace->ds.top;
	     at += trace->ds.size)
		trace_bts_at(trace, at);

out:
	ds_resume_bts(this_tracer);
}

static void trace_bts_prepare(struct trace_iterator *iter)
{
	spin_lock(&bts_tracer_lock);

	on_each_cpu(trace_bts_cpu, iter->tr, 1);

	spin_unlock(&bts_tracer_lock);
}

static void trace_bts_close(struct trace_iterator *iter)
{
	tracing_reset_online_cpus(iter->tr);
}

void trace_hw_branch_oops(void)
{
	spin_lock(&bts_tracer_lock);

	if (trace_hw_branches_enabled)
		trace_bts_cpu(hw_branch_trace);

	spin_unlock(&bts_tracer_lock);
}

struct tracer bts_tracer __read_mostly =
{
	.name		= "hw-branch-tracer",
	.init		= bts_trace_init,
	.reset		= bts_trace_reset,
	.print_header	= bts_trace_print_header,
	.print_line	= bts_trace_print_line,
	.start		= bts_trace_start,
	.stop		= bts_trace_stop,
	.open		= trace_bts_prepare,
	.close		= trace_bts_close
};

__init static int init_bts_trace(void)
{
	register_hotcpu_notifier(&bts_hotcpu_notifier);
	return register_tracer(&bts_tracer);
}
device_initcall(init_bts_trace);
Commit	Line	Data
1e9b51c2	1	/*
a93751ca	2	* h/w branch tracer for x86 based on bts
1e9b51c2	3	*
5c5317de MM	4	* Copyright (C) 2008-2009 Intel Corporation.
5c5317de MM	5	* Markus Metzger <markus.t.metzger@gmail.com>, 2008-2009
1e9b51c2	6	*/
2d542cf3 IM	7	#include <linux/spinlock.h>
2d542cf3 IM	8	#include <linux/kallsyms.h>
1e9b51c2 MM	9	#include <linux/debugfs.h>
1e9b51c2 MM	10	#include <linux/ftrace.h>
2d542cf3	11	#include <linux/module.h>
5c5317de MM	12	#include <linux/cpu.h>
5c5317de MM	13	#include <linux/smp.h>
2d542cf3	14	#include <linux/fs.h>
1e9b51c2 MM	15
	16	#include <asm/ds.h>
	17
	18	#include "trace.h"
f0868d1e	19	#include "trace_output.h"
1e9b51c2 MM	20
1e9b51c2 MM	21
ba9372a8	22	#define BTS_BUFFER_SIZE (1 << 13)
1e9b51c2	23
2d542cf3 IM	24	/*
	25	* The tracer lock protects the below per-cpu tracer array.
	26	* It needs to be held to:
	27	* - start tracing on all cpus
	28	* - stop tracing on all cpus
	29	* - start tracing on a single hotplug cpu
	30	* - stop tracing on a single hotplug cpu
	31	* - read the trace from all cpus
	32	* - read the trace from a single cpu
	33	*/
	34	static DEFINE_SPINLOCK(bts_tracer_lock);
1e9b51c2	35	static DEFINE_PER_CPU(struct bts_tracer *, tracer);
ba9372a8	36	static DEFINE_PER_CPU(unsigned char[BTS_BUFFER_SIZE], buffer);
1e9b51c2 MM	37
	38	#define this_tracer per_cpu(tracer, smp_processor_id())
	39	#define this_buffer per_cpu(buffer, smp_processor_id())
	40
ba9372a8 MM	41	static int trace_hw_branches_enabled __read_mostly;
ba9372a8 MM	42	static int trace_hw_branches_suspended __read_mostly;
b1818748	43	static struct trace_array *hw_branch_trace __read_mostly;
1e9b51c2	44
5c5317de MM	45
5c5317de MM	46	/*
ba9372a8	47	* Initialize the tracer for the current cpu.
5c5317de MM	48	* The argument is ignored.
5c5317de MM	49	*
2d542cf3	50	* pre: bts_tracer_lock must be locked.
5c5317de	51	*/
ba9372a8	52	static void bts_trace_init_cpu(void *arg)
1e9b51c2	53	{
a93751ca MM	54	if (this_tracer)
	55	ds_release_bts(this_tracer);
	56
ba9372a8 MM	57	this_tracer = ds_request_bts(NULL, this_buffer, BTS_BUFFER_SIZE,
ba9372a8 MM	58	NULL, (size_t)-1, BTS_KERNEL);
1e9b51c2 MM	59	if (IS_ERR(this_tracer)) {
	60	this_tracer = NULL;
	61	return;
	62	}
1e9b51c2 MM	63	}
1e9b51c2 MM	64
ba9372a8	65	static int bts_trace_init(struct trace_array *tr)
1e9b51c2	66	{
ba9372a8 MM	67	int cpu, avail;
ba9372a8 MM	68
2d542cf3	69	spin_lock(&bts_tracer_lock);
1e9b51c2	70
ba9372a8 MM	71	hw_branch_trace = tr;
	72
	73	on_each_cpu(bts_trace_init_cpu, NULL, 1);
	74
	75	/* Check on how many cpus we could enable tracing */
	76	avail = 0;
	77	for_each_online_cpu(cpu)
	78	if (per_cpu(tracer, cpu))
	79	avail++;
	80
	81	trace_hw_branches_enabled = (avail ? 1 : 0);
	82	trace_hw_branches_suspended = 0;
1e9b51c2	83
2d542cf3	84	spin_unlock(&bts_tracer_lock);
ba9372a8 MM	85
	86
	87	/* If we could not enable tracing on a single cpu, we fail. */
	88	return avail ? 0 : -EOPNOTSUPP;
1e9b51c2 MM	89	}
1e9b51c2 MM	90
5c5317de	91	/*
ba9372a8	92	* Release the tracer for the current cpu.
5c5317de MM	93	* The argument is ignored.
5c5317de MM	94	*
2d542cf3	95	* pre: bts_tracer_lock must be locked.
5c5317de	96	*/
ba9372a8	97	static void bts_trace_release_cpu(void *arg)
1e9b51c2 MM	98	{
1e9b51c2 MM	99	if (this_tracer) {
1e9b51c2 MM	100	ds_release_bts(this_tracer);
	101	this_tracer = NULL;
	102	}
	103	}
	104
ba9372a8	105	static void bts_trace_reset(struct trace_array *tr)
1e9b51c2	106	{
2d542cf3	107	spin_lock(&bts_tracer_lock);
5c5317de	108
ba9372a8	109	on_each_cpu(bts_trace_release_cpu, NULL, 1);
5c5317de	110	trace_hw_branches_enabled = 0;
ba9372a8 MM	111	trace_hw_branches_suspended = 0;
	112
	113	spin_unlock(&bts_tracer_lock);
	114	}
	115
	116	/*
	117	* Resume tracing on the current cpu.
	118	* The argument is ignored.
	119	*
	120	* pre: bts_tracer_lock must be locked.
	121	*/
	122	static void bts_trace_resume_cpu(void *arg)
	123	{
	124	if (this_tracer)
	125	ds_resume_bts(this_tracer);
	126	}
	127
	128	static void bts_trace_start(struct trace_array *tr)
	129	{
	130	spin_lock(&bts_tracer_lock);
	131
	132	on_each_cpu(bts_trace_resume_cpu, NULL, 1);
	133	trace_hw_branches_suspended = 0;
	134
	135	spin_unlock(&bts_tracer_lock);
	136	}
	137
	138	/*
	139	* Suspend tracing on the current cpu.
	140	* The argument is ignored.
	141	*
	142	* pre: bts_tracer_lock must be locked.
	143	*/
	144	static void bts_trace_suspend_cpu(void *arg)
	145	{
	146	if (this_tracer)
	147	ds_suspend_bts(this_tracer);
	148	}
	149
	150	static void bts_trace_stop(struct trace_array *tr)
	151	{
	152	spin_lock(&bts_tracer_lock);
	153
	154	on_each_cpu(bts_trace_suspend_cpu, NULL, 1);
	155	trace_hw_branches_suspended = 1;
1e9b51c2	156
2d542cf3	157	spin_unlock(&bts_tracer_lock);
5c5317de MM	158	}
	159
	160	static int __cpuinit bts_hotcpu_handler(struct notifier_block *nfb,
	161	unsigned long action, void *hcpu)
	162	{
	163	unsigned int cpu = (unsigned long)hcpu;
	164
2d542cf3	165	spin_lock(&bts_tracer_lock);
5c5317de MM	166
	167	if (!trace_hw_branches_enabled)
	168	goto out;
	169
	170	switch (action) {
	171	case CPU_ONLINE:
	172	case CPU_DOWN_FAILED:
ba9372a8 MM	173	smp_call_function_single(cpu, bts_trace_init_cpu, NULL, 1);
	174
	175	if (trace_hw_branches_suspended)
	176	smp_call_function_single(cpu, bts_trace_suspend_cpu,
	177	NULL, 1);
5c5317de MM	178	break;
5c5317de MM	179	case CPU_DOWN_PREPARE:
ba9372a8	180	smp_call_function_single(cpu, bts_trace_release_cpu, NULL, 1);
5c5317de MM	181	break;
	182	}
	183
	184	out:
2d542cf3	185	spin_unlock(&bts_tracer_lock);
5c5317de	186	return NOTIFY_DONE;
1e9b51c2 MM	187	}
1e9b51c2 MM	188
5c5317de MM	189	static struct notifier_block bts_hotcpu_notifier __cpuinitdata = {
	190	.notifier_call = bts_hotcpu_handler
	191	};
	192
1e9b51c2 MM	193	static void bts_trace_print_header(struct seq_file *m)
1e9b51c2 MM	194	{
11edda06	195	seq_puts(m, "# CPU# TO <- FROM\n");
1e9b51c2 MM	196	}
	197
	198	static enum print_line_t bts_trace_print_line(struct trace_iterator *iter)
	199	{
	200	struct trace_entry *entry = iter->ent;
	201	struct trace_seq *seq = &iter->seq;
a93751ca	202	struct hw_branch_entry *it;
11edda06	203	unsigned long symflags = TRACE_ITER_SYM_OFFSET;
1e9b51c2 MM	204
	205	trace_assign_type(it, entry);
	206
a93751ca	207	if (entry->type == TRACE_HW_BRANCHES) {
1830b52d	208	if (trace_seq_printf(seq, "%4d ", iter->cpu) &&
11edda06 MM	209	seq_print_ip_sym(seq, it->to, symflags) &&
	210	trace_seq_printf(seq, "\t <- ") &&
	211	seq_print_ip_sym(seq, it->from, symflags) &&
a93751ca MM	212	trace_seq_printf(seq, "\n"))
	213	return TRACE_TYPE_HANDLED;
	214	return TRACE_TYPE_PARTIAL_LINE;;
1e9b51c2 MM	215	}
	216	return TRACE_TYPE_UNHANDLED;
	217	}
	218
b1818748	219	void trace_hw_branch(u64 from, u64 to)
1e9b51c2	220	{
b1818748	221	struct trace_array *tr = hw_branch_trace;
1e9b51c2	222	struct ring_buffer_event *event;
a93751ca	223	struct hw_branch_entry *entry;
0a987751	224	unsigned long irq1;
5c5317de	225	int cpu;
1e9b51c2	226
5c5317de MM	227	if (unlikely(!tr))
	228	return;
	229
	230	if (unlikely(!trace_hw_branches_enabled))
1e9b51c2	231	return;
5c5317de MM	232
	233	local_irq_save(irq1);
	234	cpu = raw_smp_processor_id();
	235	if (atomic_inc_return(&tr->data[cpu]->disabled) != 1)
	236	goto out;
	237
51a763dd ACM	238	event = trace_buffer_lock_reserve(tr, TRACE_HW_BRANCHES,
51a763dd ACM	239	sizeof(*entry), 0, 0);
5c5317de MM	240	if (!event)
5c5317de MM	241	goto out;
1e9b51c2 MM	242	entry = ring_buffer_event_data(event);
1e9b51c2 MM	243	tracing_generic_entry_update(&entry->ent, 0, from);
a93751ca	244	entry->ent.type = TRACE_HW_BRANCHES;
1e9b51c2 MM	245	entry->from = from;
1e9b51c2 MM	246	entry->to = to;
51a763dd	247	trace_buffer_unlock_commit(tr, event, 0, 0);
5c5317de MM	248
	249	out:
	250	atomic_dec(&tr->data[cpu]->disabled);
	251	local_irq_restore(irq1);
1e9b51c2 MM	252	}
1e9b51c2 MM	253
b1818748	254	static void trace_bts_at(const struct bts_trace trace, void at)
1e9b51c2	255	{
a93751ca MM	256	struct bts_struct bts;
a93751ca MM	257	int err = 0;
1e9b51c2	258
a93751ca MM	259	WARN_ON_ONCE(!trace->read);
a93751ca MM	260	if (!trace->read)
1e9b51c2 MM	261	return;
1e9b51c2 MM	262
a93751ca MM	263	err = trace->read(this_tracer, at, &bts);
	264	if (err < 0)
	265	return;
1e9b51c2	266
a93751ca MM	267	switch (bts.qualifier) {
a93751ca MM	268	case BTS_BRANCH:
b1818748	269	trace_hw_branch(bts.variant.lbr.from, bts.variant.lbr.to);
a93751ca MM	270	break;
a93751ca MM	271	}
1e9b51c2 MM	272	}
1e9b51c2 MM	273
5c5317de MM	274	/*
	275	* Collect the trace on the current cpu and write it into the ftrace buffer.
	276	*
2d542cf3	277	* pre: bts_tracer_lock must be locked
5c5317de	278	*/
1e9b51c2 MM	279	static void trace_bts_cpu(void *arg)
1e9b51c2 MM	280	{
ba9372a8	281	struct trace_array tr = (struct trace_array )arg;
a93751ca MM	282	const struct bts_trace *trace;
a93751ca MM	283	unsigned char *at;
1e9b51c2	284
b1818748	285	if (unlikely(!tr))
1e9b51c2 MM	286	return;
1e9b51c2 MM	287
5c5317de MM	288	if (unlikely(atomic_read(&tr->data[raw_smp_processor_id()]->disabled)))
	289	return;
	290
b1818748 MM	291	if (unlikely(!this_tracer))
	292	return;
	293
a93751ca MM	294	ds_suspend_bts(this_tracer);
	295	trace = ds_read_bts(this_tracer);
	296	if (!trace)
1e9b51c2 MM	297	goto out;
1e9b51c2 MM	298
a93751ca MM	299	for (at = trace->ds.top; (void *)at < trace->ds.end;
a93751ca MM	300	at += trace->ds.size)
b1818748	301	trace_bts_at(trace, at);
1e9b51c2	302
a93751ca MM	303	for (at = trace->ds.begin; (void *)at < trace->ds.top;
a93751ca MM	304	at += trace->ds.size)
b1818748	305	trace_bts_at(trace, at);
1e9b51c2 MM	306
1e9b51c2 MM	307	out:
a93751ca	308	ds_resume_bts(this_tracer);
1e9b51c2 MM	309	}
	310
	311	static void trace_bts_prepare(struct trace_iterator *iter)
	312	{
2d542cf3	313	spin_lock(&bts_tracer_lock);
5c5317de MM	314
5c5317de MM	315	on_each_cpu(trace_bts_cpu, iter->tr, 1);
1e9b51c2	316
2d542cf3	317	spin_unlock(&bts_tracer_lock);
1e9b51c2 MM	318	}
1e9b51c2 MM	319
e23b8ad8 MM	320	static void trace_bts_close(struct trace_iterator *iter)
	321	{
	322	tracing_reset_online_cpus(iter->tr);
	323	}
	324
b1818748 MM	325	void trace_hw_branch_oops(void)
b1818748 MM	326	{
2d542cf3	327	spin_lock(&bts_tracer_lock);
b1818748	328
ba9372a8 MM	329	if (trace_hw_branches_enabled)
ba9372a8 MM	330	trace_bts_cpu(hw_branch_trace);
b1818748	331
2d542cf3	332	spin_unlock(&bts_tracer_lock);
b1818748 MM	333	}
b1818748 MM	334
1e9b51c2 MM	335	struct tracer bts_tracer __read_mostly =
1e9b51c2 MM	336	{
a93751ca	337	.name = "hw-branch-tracer",
1e9b51c2	338	.init = bts_trace_init,
5c5317de	339	.reset = bts_trace_reset,
1e9b51c2 MM	340	.print_header = bts_trace_print_header,
	341	.print_line = bts_trace_print_line,
	342	.start = bts_trace_start,
	343	.stop = bts_trace_stop,
e23b8ad8 MM	344	.open = trace_bts_prepare,
e23b8ad8 MM	345	.close = trace_bts_close
1e9b51c2 MM	346	};
	347
	348	__init static int init_bts_trace(void)
	349	{
5e01cb69	350	register_hotcpu_notifier(&bts_hotcpu_notifier);
1e9b51c2 MM	351	return register_tracer(&bts_tracer);
	352	}
	353	device_initcall(init_bts_trace);