[PATCH v2 3/9] cxl: add common function to enable event trace

[Dave Jiang]

Add a common function for cxl command to enable event tracing for the
instance created. The interested "systems" will be enabled for tracing
as well.

Signed-off-by: Dave Jiang <dave.ji...@intel.com>
---
 cxl/event_trace.c |   21 +++++++++++++++++++++
 cxl/event_trace.h |    1 +
 2 files changed, 22 insertions(+)

diff --git a/cxl/event_trace.c b/cxl/event_trace.c
index 430146ce66f5..ca2fb94f2eba 100644
--- a/cxl/event_trace.c
+++ b/cxl/event_trace.c
@@ -197,3 +197,24 @@ int cxl_parse_events(struct tracefs_instance *inst, struct 
event_ctx *ectx)
        tep_free(tep);
        return rc;
 }
+
+int cxl_event_tracing_enable(struct tracefs_instance *inst, const char *system)
+{
+       int rc;
+       char *path;
+
+       rc = asprintf(&path, "events/%s/enable", system);
+       if (rc == -1)
+               return -errno;
+
+       rc = tracefs_instance_file_write(inst, path, "1");
+       free(path);
+       if (rc == -1)
+               return -errno;
+
+       if (tracefs_trace_is_on(inst))
+               return 0;
+
+       tracefs_trace_on(inst);
+       return 0;
+}
diff --git a/cxl/event_trace.h b/cxl/event_trace.h
index 2fbefa1586d9..1fb905664625 100644
--- a/cxl/event_trace.h
+++ b/cxl/event_trace.h
@@ -17,5 +17,6 @@ struct event_ctx {
 };
 
 int cxl_parse_events(struct tracefs_instance *inst, struct event_ctx *ectx);
+int cxl_event_tracing_enable(struct tracefs_instance *inst, const char 
*system);
 
 #endif