/**
* json_events - Read JSON event file from disk and call event callback.
* @fn: File name to read or NULL for default.
* @func: Callback to call for each event
* @data: Abstract pointer to pass to func.
*
* The callback gets the data pointer, the event name, the event
* in perf format and a description passed.
*
* Call func with each event in the json file
* Return: -1 on failure, otherwise 0.
*/
int json_events(const char *fn,
int (*func)(void *data, char *name, char *event, char *desc, char *pmu),
void *data)
{
int err = -EIO;
size_t size;
jsmntok_t *tokens, *tok;
int i, j, len;
char *map;
char buf[128];
const char *orig_fn = fn;
if (!fn)
fn = json_default_name("-core");
tokens = parse_json(fn, &map, &size, &len);
if (!tokens)
return -EIO;
EXPECT(tokens->type == JSMN_ARRAY, tokens, "expected top level array");
tok = tokens + 1;
for (i = 0; i < tokens->size; i++) {
char *event = NULL, *desc = NULL, *name = NULL;
char *pmu = NULL;
char *filter = NULL;
unsigned long long eventcode = 0;
struct msrmap *msr = NULL;
jsmntok_t *msrval = NULL;
jsmntok_t *precise = NULL;
jsmntok_t *obj = tok++;
EXPECT(obj->type == JSMN_OBJECT, obj, "expected object");
for (j = 0; j < obj->size; j += 2) {
jsmntok_t *field, *val;
int nz;
field = tok + j;
EXPECT(field->type == JSMN_STRING, tok + j,
"Expected field name");
val = tok + j + 1;
EXPECT(val->type == JSMN_STRING, tok + j + 1,
"Expected string value");
nz = !json_streq(map, val, "0");
if (match_field(map, field, nz, &event, val)) {
/* ok */
} else if (json_streq(map, field, "EventCode")) {
char *code = NULL;
addfield(map, &code, "", "", val);
eventcode |= strtoul(code, NULL, 0);
free(code);
} else if (json_streq(map, field, "ExtSel")) {
char *code = NULL;
addfield(map, &code, "", "", val);
eventcode |= strtoul(code, NULL, 0) << 21;
free(code);
} else if (json_streq(map, field, "EventName")) {
addfield(map, &name, "", "", val);
} else if (json_streq(map, field, "BriefDescription")) {
addfield(map, &desc, "", "", val);
fixdesc(desc);
} else if (json_streq(map, field, "PEBS") && nz && desc &&
!strstr(desc, "(Precise Event)")) {
precise = val;
} else if (json_streq(map, field, "MSRIndex") && nz) {
msr = lookup_msr(map, val);
} else if (json_streq(map, field, "MSRValue")) {
msrval = val;
} else if (json_streq(map, field, "Errata") &&
!json_streq(map, val, "null")) {
addfield(map, &desc, ". ",
" Spec update: ", val);
} else if (json_streq(map, field, "Data_LA") && nz) {
addfield(map, &desc, ". ",
" Supports address when precise",
NULL);
} else if (json_streq(map, field, "Unit")) {
const char *ppmu;
char *s;
ppmu = field_to_perf(unit_to_pmu, map, val);
if (ppmu) {
pmu = strdup(ppmu);
} else {
addfield(map, &pmu, "", "", val);
for (s = pmu; *s; s++)
*s = tolower(*s);
}
addfield(map, &desc, ". ", "Unit: ", NULL);
addfield(map, &desc, "", pmu, NULL);
} else if (json_streq(map, field, "Filter")) {
addfield(map, &filter, "", "", val);
}
/* ignore unknown fields */
}
if (precise) {
if (json_streq(map, precise, "2"))
addfield(map, &desc, " ", "(Must be precise)",
NULL);
else
addfield(map, &desc, " ",
"(Precise event)", NULL);
}
snprintf(buf, sizeof buf, "event=%#llx", eventcode);
addfield(map, &event, ",", buf, NULL);
if (filter)
addfield(map, &event, ",", filter, NULL);
if (msr != NULL)
addfield(map, &event, ",", msr->pname, msrval);
if (!pmu)
pmu = strdup("cpu");
err = -EIO;
if (name && event) {
fixname(name);
err = func(data, name, event, desc, pmu);
}
free(event);
free(desc);
free(name);
free(pmu);
free(filter);
if (err)
break;
tok += j;
}
EXPECT(tok - tokens == len, tok, "unexpected objects at end");
err = 0;
out_free:
free_json(map, size, tokens);
if (!orig_fn && !err) {
fn = json_default_name("-uncore");
err = json_events(fn, func, data);
/* Ignore open error */
if (err == -EIO)
return 0;
}
if (!orig_fn)
free((char *)fn);
return err;
}
/**
* read_events - Read JSON performance counter event list
* @fn: File name to read. NULL to chose default location.
*
* Read the JSON event list fn. The other functions in the library
* automatically read the default event list for the current CPU,
* but calling this explicitly is useful to chose a specific one.
*
* Return: -1 on failure, otherwise 0.
*/
int read_events(char *fn)
{
if (eventlist)
free_events();
return json_events(NULL, collect_events, NULL);
}
