perf: Drop the obsolete profile naming for trace events

Drop the obsolete "profile" naming used by perf for trace events.
Perf can now do more than simple events counting, so generalize
the API naming.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>

1 files changed, 165 insertions, 0 deletions

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
new file mode 100644
index 00000000000..f315b12a41d
--- /dev/null
+++ b/kernel/trace/trace_event_perf.c
@@ -0,0 +1,165 @@
+/*
+ * trace event based perf event profiling/tracing
+ *
+ * Copyright (C) 2009 Red Hat Inc, Peter Zijlstra <pzijlstr@redhat.com>
+ * Copyright (C) 2009-2010 Frederic Weisbecker <fweisbec@gmail.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kprobes.h>
+#include "trace.h"
+
+DEFINE_PER_CPU(struct pt_regs, perf_trace_regs);
+
+static char *perf_trace_buf;
+static char *perf_trace_buf_nmi;
+
+typedef typeof(char [PERF_MAX_TRACE_SIZE]) perf_trace_t ;
+
+/* Count the events in use (per event id, not per instance) */
+static int	total_ref_count;
+
+static int perf_trace_event_enable(struct ftrace_event_call *event)
+{
+	char *buf;
+	int ret = -ENOMEM;
+
+	if (event->perf_refcount++ > 0)
+		return 0;
+
+	if (!total_ref_count) {
+		buf = (char *)alloc_percpu(perf_trace_t);
+		if (!buf)
+			goto fail_buf;
+
+		rcu_assign_pointer(perf_trace_buf, buf);
+
+		buf = (char *)alloc_percpu(perf_trace_t);
+		if (!buf)
+			goto fail_buf_nmi;
+
+		rcu_assign_pointer(perf_trace_buf_nmi, buf);
+	}
+
+	ret = event->perf_event_enable(event);
+	if (!ret) {
+		total_ref_count++;
+		return 0;
+	}
+
+fail_buf_nmi:
+	if (!total_ref_count) {
+		free_percpu(perf_trace_buf_nmi);
+		free_percpu(perf_trace_buf);
+		perf_trace_buf_nmi = NULL;
+		perf_trace_buf = NULL;
+	}
+fail_buf:
+	event->perf_refcount--;
+
+	return ret;
+}
+
+int perf_trace_enable(int event_id)
+{
+	struct ftrace_event_call *event;
+	int ret = -EINVAL;
+
+	mutex_lock(&event_mutex);
+	list_for_each_entry(event, &ftrace_events, list) {
+		if (event->id == event_id && event->perf_event_enable &&
+		    try_module_get(event->mod)) {
+			ret = perf_trace_event_enable(event);
+			break;
+		}
+	}
+	mutex_unlock(&event_mutex);
+
+	return ret;
+}
+
+static void perf_trace_event_disable(struct ftrace_event_call *event)
+{
+	char *buf, *nmi_buf;
+
+	if (--event->perf_refcount > 0)
+		return;
+
+	event->perf_event_disable(event);
+
+	if (!--total_ref_count) {
+		buf = perf_trace_buf;
+		rcu_assign_pointer(perf_trace_buf, NULL);
+
+		nmi_buf = perf_trace_buf_nmi;
+		rcu_assign_pointer(perf_trace_buf_nmi, NULL);
+
+		/*
+		 * Ensure every events in profiling have finished before
+		 * releasing the buffers
+		 */
+		synchronize_sched();
+
+		free_percpu(buf);
+		free_percpu(nmi_buf);
+	}
+}
+
+void perf_trace_disable(int event_id)
+{
+	struct ftrace_event_call *event;
+
+	mutex_lock(&event_mutex);
+	list_for_each_entry(event, &ftrace_events, list) {
+		if (event->id == event_id) {
+			perf_trace_event_disable(event);
+			module_put(event->mod);
+			break;
+		}
+	}
+	mutex_unlock(&event_mutex);
+}
+
+__kprobes void *perf_trace_buf_prepare(int size, unsigned short type,
+				       int *rctxp, unsigned long *irq_flags)
+{
+	struct trace_entry *entry;
+	char *trace_buf, *raw_data;
+	int pc, cpu;
+
+	pc = preempt_count();
+
+	/* Protect the per cpu buffer, begin the rcu read side */
+	local_irq_save(*irq_flags);
+
+	*rctxp = perf_swevent_get_recursion_context();
+	if (*rctxp < 0)
+		goto err_recursion;
+
+	cpu = smp_processor_id();
+
+	if (in_nmi())
+		trace_buf = rcu_dereference(perf_trace_buf_nmi);
+	else
+		trace_buf = rcu_dereference(perf_trace_buf);
+
+	if (!trace_buf)
+		goto err;
+
+	raw_data = per_cpu_ptr(trace_buf, cpu);
+
+	/* zero the dead bytes from align to not leak stack to user */
+	*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+
+	entry = (struct trace_entry *)raw_data;
+	tracing_generic_entry_update(entry, *irq_flags, pc);
+	entry->type = type;
+
+	return raw_data;
+err:
+	perf_swevent_put_recursion_context(*rctxp);
+err_recursion:
+	local_irq_restore(*irq_flags);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(perf_trace_buf_prepare);