[PATCH 5/8] perf/x86: Add is_visible attribute_group callback for base events

From: Jiri Olsa
Date: Sat May 04 2019 - 08:53:04 EST


We dont need to pre-filter out unsupported base events,
we can just use its group's is_visible function to do this.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
arch/x86/events/core.c | 52 ++++++++++++------------------------------
1 file changed, 14 insertions(+), 38 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index a43d8d1e8590..1889e45e6742 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1618,42 +1618,6 @@ static struct attribute_group x86_pmu_format_group __ro_after_init = {
.attrs = NULL,
};

-/*
- * Remove all undefined events (x86_pmu.event_map(id) == 0)
- * out of events_attr attributes.
- */
-static void __init filter_events(struct attribute **attrs)
-{
- struct device_attribute *d;
- struct perf_pmu_events_attr *pmu_attr;
- int offset = 0;
- int i, j;
-
- for (i = 0; attrs[i]; i++) {
- d = (struct device_attribute *)attrs[i];
- pmu_attr = container_of(d, struct perf_pmu_events_attr, attr);
- /* str trumps id */
- if (pmu_attr->event_str)
- continue;
- if (x86_pmu.event_map(i + offset))
- continue;
-
- for (j = i; attrs[j]; j++)
- attrs[j] = attrs[j + 1];
-
- /* Check the shifted attr. */
- i--;
-
- /*
- * event_map() is index based, the attrs array is organized
- * by increasing event index. If we shift the events, then
- * we need to compensate for the event_map(), otherwise
- * we are looking up the wrong event in the map
- */
- offset++;
- }
-}
-
/* Merge two pointer arrays */
__init struct attribute **merge_attr(struct attribute **a, struct attribute **b)
{
@@ -1744,9 +1708,23 @@ static struct attribute *events_attr[] = {
NULL,
};

+/*
+ * Remove all undefined events (x86_pmu.event_map(id) == 0)
+ * out of events_attr attributes.
+ */
+static umode_t
+is_visible(struct kobject *kobj, struct attribute *attr, int idx)
+{
+ struct perf_pmu_events_attr *pmu_attr;
+
+ pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr.attr);
+ return pmu_attr->event_str || x86_pmu.event_map(idx) ? attr->mode : 0;
+}
+
static struct attribute_group x86_pmu_events_group __ro_after_init = {
.name = "events",
.attrs = events_attr,
+ .is_visible = is_visible,
};

ssize_t x86_event_sysfs_show(char *page, u64 config, u64 event)
@@ -1852,8 +1830,6 @@ static int __init init_hw_perf_events(void)

if (!x86_pmu.events_sysfs_show)
x86_pmu_events_group.attrs = &empty_attrs;
- else
- filter_events(x86_pmu_events_group.attrs);

if (x86_pmu.attrs) {
struct attribute **tmp;
--
2.20.1