/* * ring buffer based C-state tracer * * Arjan van de Ven <arjan@linux.intel.com> * Copyright (C) 2008 Intel Corporation * * Much is borrowed from trace_boot.c which is * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com> * */ #include <linux/init.h>#include <linux/debugfs.h>#include <trace/power.h>#include <linux/kallsyms.h>#include <linux/module.h> #include "trace.h"#include "trace_output.h" static struct trace_array *power_trace;static int __read_mostly trace_power_enabled; static void probe_power_start(struct power_trace *it, unsigned int type,				unsigned int level){	if (!trace_power_enabled)		return; 	memset(it, 0, sizeof(struct power_trace));	it->state = level;	it->type = type;	it->stamp = ktime_get();}  static void probe_power_end(struct power_trace *it){	struct ring_buffer_event *event;	struct trace_power *entry;	struct trace_array_cpu *data;	struct trace_array *tr = power_trace; 	if (!trace_power_enabled)		return; 	preempt_disable();	it->end = ktime_get();	data = tr->data[smp_processor_id()]; 	event = trace_buffer_lock_reserve(tr, TRACE_POWER,					  sizeof(*entry), 0, 0);	if (!event)		goto out;	entry	= ring_buffer_event_data(event);	entry->state_data = *it;	trace_buffer_unlock_commit(tr, event, 0, 0); out:	preempt_enable();} static void probe_power_mark(struct power_trace *it, unsigned int type,				unsigned int level){	struct ring_buffer_event *event;	struct trace_power *entry;	struct trace_array_cpu *data;	struct trace_array *tr = power_trace; 	if (!trace_power_enabled)		return; 	memset(it, 0, sizeof(struct power_trace));	it->state = level;	it->type = type;	it->stamp = ktime_get();	preempt_disable();	it->end = it->stamp;	data = tr->data[smp_processor_id()]; 	event = trace_buffer_lock_reserve(tr, TRACE_POWER,					  sizeof(*entry), 0, 0);	if (!event)		goto out;	entry	= ring_buffer_event_data(event);	entry->state_data = *it;	trace_buffer_unlock_commit(tr, event, 0, 0); out:	preempt_enable();} static int tracing_power_register(void){	int ret; 	ret = register_trace_power_start(probe_power_start);	if (ret) {		pr_info("power trace: Couldn't activate tracepoint"			" probe to trace_power_start\n");		return ret;	}	ret = register_trace_power_end(probe_power_end);	if (ret) {		pr_info("power trace: Couldn't activate tracepoint"			" probe to trace_power_end\n");		goto fail_start;	}	ret = register_trace_power_mark(probe_power_mark);	if (ret) {		pr_info("power trace: Couldn't activate tracepoint"			" probe to trace_power_mark\n");		goto fail_end;	}	return ret;fail_end:	unregister_trace_power_end(probe_power_end);fail_start:	unregister_trace_power_start(probe_power_start);	return ret;} static void start_power_trace(struct trace_array *tr){	trace_power_enabled = 1;} static void stop_power_trace(struct trace_array *tr){	trace_power_enabled = 0;} static void power_trace_reset(struct trace_array *tr){	trace_power_enabled = 0;	unregister_trace_power_start(probe_power_start);	unregister_trace_power_end(probe_power_end);	unregister_trace_power_mark(probe_power_mark);}  static int power_trace_init(struct trace_array *tr){	int cpu;	power_trace = tr; 	trace_power_enabled = 1;	tracing_power_register(); 	for_each_cpu(cpu, cpu_possible_mask)		tracing_reset(tr, cpu);	return 0;} static enum print_line_t power_print_line(struct trace_iterator *iter){	int ret = 0;	struct trace_entry *entry = iter->ent;	struct trace_power *field ;	struct power_trace *it;	struct trace_seq *s = &iter->seq;	struct timespec stamp;	struct timespec duration; 	trace_assign_type(field, entry);	it = &field->state_data;	stamp = ktime_to_timespec(it->stamp);	duration = ktime_to_timespec(ktime_sub(it->end, it->stamp)); 	if (entry->type == TRACE_POWER) {		if (it->type == POWER_CSTATE)			ret = trace_seq_printf(s, "[%5ld.%09ld] CSTATE: Going to C%i on cpu %i for %ld.%09ld\n",					  stamp.tv_sec,					  stamp.tv_nsec,					  it->state, iter->cpu,					  duration.tv_sec,					  duration.tv_nsec);		if (it->type == POWER_PSTATE)			ret = trace_seq_printf(s, "[%5ld.%09ld] PSTATE: Going to P%i on cpu %i\n",					  stamp.tv_sec,					  stamp.tv_nsec,					  it->state, iter->cpu);		if (!ret)			return TRACE_TYPE_PARTIAL_LINE;		return TRACE_TYPE_HANDLED;	}	return TRACE_TYPE_UNHANDLED;} static void power_print_header(struct seq_file *s){	seq_puts(s, "#   TIMESTAMP      STATE  EVENT\n");	seq_puts(s, "#       |            |      |\n");} static struct tracer power_tracer __read_mostly ={	.name		= "power",	.init		= power_trace_init,	.start		= start_power_trace,	.stop		= stop_power_trace,	.reset		= power_trace_reset,	.print_line	= power_print_line,	.print_header	= power_print_header,}; static int init_power_trace(void){	return register_tracer(&power_tracer);}device_initcall(init_power_trace);