arm_mpam: resctrl: Call resctrl_init() on platforms that can support resctrl

Now that MPAM links against resctrl, call resctrl_init() to register the
filesystem and setup resctrl's structures.

Tested-by: Gavin Shan <gshan@redhat.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Zeng Heng <zengheng4@huawei.com>
Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com>
Tested-by: Jesse Chick <jessechick@os.amperecomputing.com>
Reviewed-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Co-developed-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>

1 files changed, 62 insertions, 1 deletions

diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c
index 777ecdc2d0f8..a9938006d0e6 100644
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c
@@ -69,6 +69,12 @@ static bool cdp_enabled;
 static bool cacheinfo_ready;
 static DECLARE_WAIT_QUEUE_HEAD(wait_cacheinfo_ready);
 
+/*
+ * If resctrl_init() succeeded, resctrl_exit() can be used to remove support
+ * for the filesystem in the event of an error.
+ */
+static bool resctrl_enabled;
+
 bool resctrl_arch_alloc_capable(void)
 {
 	struct mpam_resctrl_res *res;
@@ -360,6 +366,9 @@ static int resctrl_arch_mon_ctx_alloc_no_wait(enum resctrl_event_id evtid)
 {
 	struct mpam_resctrl_mon *mon = &mpam_resctrl_counters[evtid];
 
+	if (!mpam_is_enabled())
+		return -EINVAL;
+
 	if (!mon->class)
 		return -EINVAL;
 
@@ -402,6 +411,9 @@ static void resctrl_arch_mon_ctx_free_no_wait(enum resctrl_event_id evtid,
 {
 	struct mpam_resctrl_mon *mon = &mpam_resctrl_counters[evtid];
 
+	if (!mpam_is_enabled())
+		return;
+
 	if (!mon->class)
 		return;
 
@@ -488,6 +500,9 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain_hdr *hdr,
 
 	resctrl_arch_rmid_read_context_check();
 
+	if (!mpam_is_enabled())
+		return -EINVAL;
+
 	if (eventid >= QOS_NUM_EVENTS || !mon->class)
 		return -EINVAL;
 
@@ -1162,6 +1177,9 @@ int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_ctrl_domain *d,
 	lockdep_assert_cpus_held();
 	lockdep_assert_irqs_enabled();
 
+	if (!mpam_is_enabled())
+		return -EINVAL;
+
 	/*
 	 * No need to check the CPU as mpam_apply_config() doesn't care, and
 	 * resctrl_arch_update_domains() relies on this.
@@ -1227,6 +1245,9 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid)
 	lockdep_assert_cpus_held();
 	lockdep_assert_irqs_enabled();
 
+	if (!mpam_is_enabled())
+		return -EINVAL;
+
 	list_for_each_entry_rcu(d, &r->ctrl_domains, hdr.list) {
 		for (enum resctrl_conf_type t = 0; t < CDP_NUM_TYPES; t++) {
 			struct resctrl_staged_config *cfg = &d->staged_config[t];
@@ -1619,7 +1640,11 @@ int mpam_resctrl_setup(void)
 		return -EOPNOTSUPP;
 	}
 
-	/* TODO: call resctrl_init() */
+	err = resctrl_init();
+	if (err)
+		return err;
+
+	WRITE_ONCE(resctrl_enabled, true);
 
 	return 0;
 
@@ -1629,6 +1654,42 @@ internal_error:
 	return err;
 }
 
+void mpam_resctrl_exit(void)
+{
+	if (!READ_ONCE(resctrl_enabled))
+		return;
+
+	WRITE_ONCE(resctrl_enabled, false);
+	resctrl_exit();
+}
+
+/*
+ * The driver is detaching an MSC from this class, if resctrl was using it,
+ * pull on resctrl_exit().
+ */
+void mpam_resctrl_teardown_class(struct mpam_class *class)
+{
+	struct mpam_resctrl_res *res;
+	enum resctrl_res_level rid;
+	struct mpam_resctrl_mon *mon;
+	enum resctrl_event_id eventid;
+
+	might_sleep();
+
+	for_each_mpam_resctrl_control(res, rid) {
+		if (res->class == class) {
+			res->class = NULL;
+			break;
+		}
+	}
+	for_each_mpam_resctrl_mon(mon, eventid) {
+		if (mon->class == class) {
+			mon->class = NULL;
+			break;
+		}
+	}
+}
+
 static int __init __cacheinfo_ready(void)
 {
 	cacheinfo_ready = true;