perf/amd/ibs: Advertise zen4_ibs_extensions as pmu capability attribute

PMU driver can advertise certain feature via capability attribute('caps'
sysfs directory) which can be consumed by userspace tools like perf. Add
zen4_ibs_extensions capability attribute for IBS pmus. This attribute
will be enabled when CPUID_Fn8000001B_EAX[11] is set.

With patch on Zen4:

  $ ls /sys/bus/event_source/devices/ibs_op/caps
  zen4_ibs_extensions

Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220509044914.1473-5-ravi.bangoria@amd.com

diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index 2dc8b7ec030a07a7354cbc8c58bb5e0a368e14e2..c251bc44c088d8382b9bfac688e1901f78642bf1 100644 (file)
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c
@@ -537,8 +537,14 @@ static struct attribute_group empty_format_group = {
        .attrs = attrs_empty,
 };
 
+static struct attribute_group empty_caps_group = {
+       .name = "caps",
+       .attrs = attrs_empty,
+};
+
 static const struct attribute_group *empty_attr_groups[] = {
        &empty_format_group,
+       &empty_caps_group,
        NULL,
 };
 
@@ -546,6 +552,7 @@ PMU_FORMAT_ATTR(rand_en,    "config:57");
 PMU_FORMAT_ATTR(cnt_ctl,       "config:19");
 PMU_EVENT_ATTR_STRING(l3missonly, fetch_l3missonly, "config:59");
 PMU_EVENT_ATTR_STRING(l3missonly, op_l3missonly, "config:16");
+PMU_EVENT_ATTR_STRING(zen4_ibs_extensions, zen4_ibs_extensions, "1");
 
 static umode_t
 zen4_ibs_extensions_is_visible(struct kobject *kobj, struct attribute *attr, int i)
@@ -563,6 +570,11 @@ static struct attribute *fetch_l3missonly_attrs[] = {
        NULL,
 };
 
+static struct attribute *zen4_ibs_extensions_attrs[] = {
+       &zen4_ibs_extensions.attr.attr,
+       NULL,
+};
+
 static struct attribute_group group_rand_en = {
        .name = "format",
        .attrs = rand_en_attrs,
@@ -574,13 +586,21 @@ static struct attribute_group group_fetch_l3missonly = {
        .is_visible = zen4_ibs_extensions_is_visible,
 };
 
+static struct attribute_group group_zen4_ibs_extensions = {
+       .name = "caps",
+       .attrs = zen4_ibs_extensions_attrs,
+       .is_visible = zen4_ibs_extensions_is_visible,
+};
+
 static const struct attribute_group *fetch_attr_groups[] = {
        &group_rand_en,
+       &empty_caps_group,
        NULL,
 };
 
 static const struct attribute_group *fetch_attr_update[] = {
        &group_fetch_l3missonly,
+       &group_zen4_ibs_extensions,
        NULL,
 };
 
@@ -615,6 +635,7 @@ static struct attribute_group group_op_l3missonly = {
 static const struct attribute_group *op_attr_update[] = {
        &group_cnt_ctl,
        &group_op_l3missonly,
+       &group_zen4_ibs_extensions,
        NULL,
 };