[PATCH v5 2/8] x86/resctrl: Prepare for different scope for control/monitor operations

[Tony Luck <tony.luck@intel.com>]

Existing resctrl assumes that control and monitor operations on a
resource are performed at the same scope.

Prepare for systems that use different scope (specifically L3 scope
for cache control and NODE scope for cache occupancy and memory
bandwidth monitoring).

Create separate domain lists for control and monitor operations.

No important functional change. But note that errors during
initialization of either control or monitor functions on a domain would
previously result in that domain being excluded from both control and
monitor operations. Now the domains are allocated independently it is
no longer required to disable both control and monitor operations if
either fail.

Signed-off-by: Tony Luck <tony.luck@intel.com>
---
 include/linux/resctrl.h                   |  16 +-
 arch/x86/kernel/cpu/resctrl/internal.h    |   6 +-
 arch/x86/kernel/cpu/resctrl/core.c        | 227 +++++++++++++++-------
 arch/x86/kernel/cpu/resctrl/ctrlmondata.c |   2 +-
 arch/x86/kernel/cpu/resctrl/monitor.c     |   2 +-
 arch/x86/kernel/cpu/resctrl/pseudo_lock.c |   2 +-
 arch/x86/kernel/cpu/resctrl/rdtgroup.c    |  32 +--
 7 files changed, 199 insertions(+), 88 deletions(-)

diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 2db1244ae642..33856943a787 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -155,10 +155,12 @@ enum resctrl_scope {
  * @alloc_capable:	Is allocation available on this machine
  * @mon_capable:	Is monitor feature available on this machine
  * @num_rmid:		Number of RMIDs available
- * @scope:		Scope of this resource
+ * @ctrl_scope:		Scope of this resource for control functions
+ * @mon_scope:		Scope of this resource for monitor functions
  * @cache:		Cache allocation related data
  * @membw:		If the component has bandwidth controls, their properties.
- * @domains:		All domains for this resource
+ * @domains:		Control domains for this resource
+ * @mon_domains:	Monitor domains for this resource
  * @name:		Name to use in "schemata" file.
  * @data_width:		Character width of data when displaying
  * @default_ctrl:	Specifies default cache cbm or memory B/W percent.
@@ -173,10 +175,12 @@ struct rdt_resource {
 	bool			alloc_capable;
 	bool			mon_capable;
 	int			num_rmid;
-	enum resctrl_scope	scope;
+	enum resctrl_scope	ctrl_scope;
+	enum resctrl_scope	mon_scope;
 	struct resctrl_cache	cache;
 	struct resctrl_membw	membw;
 	struct list_head	domains;
+	struct list_head	mondomains;
 	char			*name;
 	int			data_width;
 	u32			default_ctrl;
@@ -222,8 +226,10 @@ int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_domain *d,
 
 u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d,
 			    u32 closid, enum resctrl_conf_type type);
-int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d);
-void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d);
+int resctrl_online_ctrl_domain(struct rdt_resource *r, struct rdt_domain *d);
+int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_domain *d);
+void resctrl_offline_ctrl_domain(struct rdt_resource *r, struct rdt_domain *d);
+void resctrl_offline_mon_domain(struct rdt_resource *r, struct rdt_domain *d);
 
 /**
  * resctrl_arch_rmid_read() - Read the eventid counter corresponding to rmid
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 85ceaf9a31ac..31a5fc3b717f 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -511,8 +511,10 @@ void rdtgroup_kn_unlock(struct kernfs_node *kn);
 int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name);
 int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name,
 			     umode_t mask);
-struct rdt_domain *rdt_find_domain(struct rdt_resource *r, int id,
-				   struct list_head **pos);
+struct rdt_domain *rdt_find_ctrldomain(struct list_head *h, int id,
+				       struct list_head **pos);
+struct rdt_domain *rdt_find_mondomain(struct list_head *h, int id,
+				      struct list_head **pos);
 ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
 				char *buf, size_t nbytes, loff_t off);
 int rdtgroup_schemata_show(struct kernfs_open_file *of,
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 0d3bae523ecb..97f6f9715fdb 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -57,7 +57,7 @@ static void
 mba_wrmsr_amd(struct rdt_domain *d, struct msr_param *m,
 	      struct rdt_resource *r);
 
-#define domain_init(id) LIST_HEAD_INIT(rdt_resources_all[id].r_resctrl.domains)
+#define domain_init(id, field) LIST_HEAD_INIT(rdt_resources_all[id].r_resctrl.field)
 
 struct rdt_hw_resource rdt_resources_all[] = {
 	[RDT_RESOURCE_L3] =
@@ -65,8 +65,10 @@ struct rdt_hw_resource rdt_resources_all[] = {
 		.r_resctrl = {
 			.rid			= RDT_RESOURCE_L3,
 			.name			= "L3",
-			.scope			= RESCTRL_L3_CACHE,
-			.domains		= domain_init(RDT_RESOURCE_L3),
+			.ctrl_scope		= RESCTRL_L3_CACHE,
+			.mon_scope		= RESCTRL_L3_CACHE,
+			.domains		= domain_init(RDT_RESOURCE_L3, domains),
+			.mondomains		= domain_init(RDT_RESOURCE_L3, mondomains),
 			.parse_ctrlval		= parse_cbm,
 			.format_str		= "%d=%0*x",
 			.fflags			= RFTYPE_RES_CACHE,
@@ -79,8 +81,8 @@ struct rdt_hw_resource rdt_resources_all[] = {
 		.r_resctrl = {
 			.rid			= RDT_RESOURCE_L2,
 			.name			= "L2",
-			.scope			= RESCTRL_L2_CACHE,
-			.domains		= domain_init(RDT_RESOURCE_L2),
+			.ctrl_scope		= RESCTRL_L2_CACHE,
+			.domains		= domain_init(RDT_RESOURCE_L2, domains),
 			.parse_ctrlval		= parse_cbm,
 			.format_str		= "%d=%0*x",
 			.fflags			= RFTYPE_RES_CACHE,
@@ -93,8 +95,8 @@ struct rdt_hw_resource rdt_resources_all[] = {
 		.r_resctrl = {
 			.rid			= RDT_RESOURCE_MBA,
 			.name			= "MB",
-			.scope			= RESCTRL_L3_CACHE,
-			.domains		= domain_init(RDT_RESOURCE_MBA),
+			.ctrl_scope		= RESCTRL_L3_CACHE,
+			.domains		= domain_init(RDT_RESOURCE_MBA, domains),
 			.parse_ctrlval		= parse_bw,
 			.format_str		= "%d=%*u",
 			.fflags			= RFTYPE_RES_MB,
@@ -105,8 +107,8 @@ struct rdt_hw_resource rdt_resources_all[] = {
 		.r_resctrl = {
 			.rid			= RDT_RESOURCE_SMBA,
 			.name			= "SMBA",
-			.scope			= RESCTRL_L3_CACHE,
-			.domains		= domain_init(RDT_RESOURCE_SMBA),
+			.ctrl_scope		= RESCTRL_L3_CACHE,
+			.domains		= domain_init(RDT_RESOURCE_SMBA, domains),
 			.parse_ctrlval		= parse_bw,
 			.format_str		= "%d=%*u",
 			.fflags			= RFTYPE_RES_MB,
@@ -384,15 +386,16 @@ void rdt_ctrl_update(void *arg)
 }
 
 /*
- * rdt_find_domain - Find a domain in a resource that matches input resource id
+ * __rdt_find_domain - Find a domain in either the list of control or
+ * monitor domains that matches input resource id
  *
  * Search resource r's domain list to find the resource id. If the resource
  * id is found in a domain, return the domain. Otherwise, if requested by
  * caller, return the first domain whose id is bigger than the input id.
  * The domain list is sorted by id in ascending order.
  */
-struct rdt_domain *rdt_find_domain(struct rdt_resource *r, int id,
-				   struct list_head **pos)
+static void *__rdt_find_domain(struct list_head *h, int id,
+			       struct list_head **pos)
 {
 	struct rdt_domain *d;
 	struct list_head *l;
@@ -400,7 +403,7 @@ struct rdt_domain *rdt_find_domain(struct rdt_resource *r, int id,
 	if (id < 0)
 		return ERR_PTR(-ENODEV);
 
-	list_for_each(l, &r->domains) {
+	list_for_each(l, h) {
 		d = list_entry(l, struct rdt_domain, list);
 		/* When id is found, return its domain. */
 		if (id == d->id)
@@ -416,6 +419,18 @@ struct rdt_domain *rdt_find_domain(struct rdt_resource *r, int id,
 	return NULL;
 }
 
+struct rdt_domain *rdt_find_ctrldomain(struct list_head *h, int id,
+				       struct list_head **pos)
+{
+	return __rdt_find_domain(h, id, pos);
+}
+
+struct rdt_domain *rdt_find_mondomain(struct list_head *h, int id,
+				      struct list_head **pos)
+{
+	return __rdt_find_domain(h, id, pos);
+}
+
 static void setup_default_ctrlval(struct rdt_resource *r, u32 *dc)
 {
 	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
@@ -431,10 +446,15 @@ static void setup_default_ctrlval(struct rdt_resource *r, u32 *dc)
 }
 
 static void domain_free(struct rdt_hw_domain *hw_dom)
+{
+	kfree(hw_dom->ctrl_val);
+	kfree(hw_dom);
+}
+
+static void mondomain_free(struct rdt_hw_domain *hw_dom)
 {
 	kfree(hw_dom->arch_mbm_total);
 	kfree(hw_dom->arch_mbm_local);
-	kfree(hw_dom->ctrl_val);
 	kfree(hw_dom);
 }
 
@@ -502,6 +522,93 @@ static int get_domain_id_from_scope(int cpu, enum resctrl_scope scope)
 	return -1;
 }
 
+static void domain_add_cpu_ctrl(int cpu, struct rdt_resource *r)
+{
+	int id = get_domain_id_from_scope(cpu, r->ctrl_scope);
+	struct list_head *add_pos = NULL;
+	struct rdt_hw_domain *hw_dom;
+	struct rdt_domain *d;
+	int err;
+
+	d = rdt_find_ctrldomain(&r->domains, id, &add_pos);
+	if (IS_ERR(d)) {
+		pr_warn("Couldn't find scope id=%d for CPU %d\n", id, cpu);
+		return;
+	}
+
+	if (d) {
+		cpumask_set_cpu(cpu, &d->cpu_mask);
+		if (r->cache.arch_has_per_cpu_cfg)
+			rdt_domain_reconfigure_cdp(r);
+		return;
+	}
+
+	hw_dom = kzalloc_node(sizeof(*hw_dom), GFP_KERNEL, cpu_to_node(cpu));
+	if (!hw_dom)
+		return;
+
+	d = &hw_dom->d_resctrl;
+	d->id = id;
+	cpumask_set_cpu(cpu, &d->cpu_mask);
+
+	rdt_domain_reconfigure_cdp(r);
+
+	if (domain_setup_ctrlval(r, d)) {
+		domain_free(hw_dom);
+		return;
+	}
+
+	list_add_tail(&d->list, add_pos);
+
+	err = resctrl_online_ctrl_domain(r, d);
+	if (err) {
+		list_del(&d->list);
+		domain_free(hw_dom);
+	}
+}
+
+static void domain_add_cpu_mon(int cpu, struct rdt_resource *r)
+{
+	int id = get_domain_id_from_scope(cpu, r->mon_scope);
+	struct rdt_hw_domain *hw_mondom;
+	struct list_head *add_pos = NULL;
+	struct rdt_domain *d;
+	int err;
+
+	d = rdt_find_mondomain(&r->mondomains, id, &add_pos);
+	if (IS_ERR(d)) {
+		pr_warn("Couldn't find scope id=%d for CPU %d\n", id, cpu);
+		return;
+	}
+
+	if (d) {
+		cpumask_set_cpu(cpu, &d->cpu_mask);
+
+		return;
+	}
+
+	hw_mondom = kzalloc_node(sizeof(*hw_mondom), GFP_KERNEL, cpu_to_node(cpu));
+	if (!hw_mondom)
+		return;
+
+	d = &hw_mondom->d_resctrl;
+	d->id = id;
+	cpumask_set_cpu(cpu, &d->cpu_mask);
+
+	if (arch_domain_mbm_alloc(r->num_rmid, hw_mondom)) {
+		mondomain_free(hw_mondom);
+		return;
+	}
+
+	list_add_tail(&d->list, add_pos);
+
+	err = resctrl_online_mon_domain(r, d);
+	if (err) {
+		list_del(&d->list);
+		mondomain_free(hw_mondom);
+	}
+}
+
 /*
  * domain_add_cpu - Add a cpu to a resource's domain list.
  *
@@ -517,70 +624,28 @@ static int get_domain_id_from_scope(int cpu, enum resctrl_scope scope)
  */
 static void domain_add_cpu(int cpu, struct rdt_resource *r)
 {
-	int id = get_domain_id_from_scope(cpu, r->scope);
-	struct list_head *add_pos = NULL;
-	struct rdt_hw_domain *hw_dom;
-	struct rdt_domain *d;
-	int err;
-
-	d = rdt_find_domain(r, id, &add_pos);
-	if (IS_ERR(d)) {
-		pr_warn("Couldn't find cache id for CPU %d\n", cpu);
-		return;
-	}
-
-	if (d) {
-		cpumask_set_cpu(cpu, &d->cpu_mask);
-		if (r->cache.arch_has_per_cpu_cfg)
-			rdt_domain_reconfigure_cdp(r);
-		return;
-	}
-
-	hw_dom = kzalloc_node(sizeof(*hw_dom), GFP_KERNEL, cpu_to_node(cpu));
-	if (!hw_dom)
-		return;
-
-	d = &hw_dom->d_resctrl;
-	d->id = id;
-	cpumask_set_cpu(cpu, &d->cpu_mask);
-
-	rdt_domain_reconfigure_cdp(r);
-
-	if (r->alloc_capable && domain_setup_ctrlval(r, d)) {
-		domain_free(hw_dom);
-		return;
-	}
-
-	if (r->mon_capable && arch_domain_mbm_alloc(r->num_rmid, hw_dom)) {
-		domain_free(hw_dom);
-		return;
-	}
-
-	list_add_tail(&d->list, add_pos);
-
-	err = resctrl_online_domain(r, d);
-	if (err) {
-		list_del(&d->list);
-		domain_free(hw_dom);
-	}
+	if (r->alloc_capable)
+		domain_add_cpu_ctrl(cpu, r);
+	if (r->mon_capable)
+		domain_add_cpu_mon(cpu, r);
 }
 
-static void domain_remove_cpu(int cpu, struct rdt_resource *r)
+static void domain_remove_cpu_ctrl(int cpu, struct rdt_resource *r)
 {
-	int id = get_domain_id_from_scope(cpu, r->scope);
+	int id = get_domain_id_from_scope(cpu, r->ctrl_scope);
 	struct rdt_hw_domain *hw_dom;
 	struct rdt_domain *d;
 
-	d = rdt_find_domain(r, id, NULL);
+	d = rdt_find_ctrldomain(&r->domains, id, NULL);
 	if (IS_ERR_OR_NULL(d)) {
-		pr_warn("Couldn't find cache id for CPU %d\n", cpu);
+		pr_warn("Couldn't find scope id=%d for CPU %d\n", id, cpu);
 		return;
 	}
 	hw_dom = resctrl_to_arch_dom(d);
 
 	cpumask_clear_cpu(cpu, &d->cpu_mask);
 	if (cpumask_empty(&d->cpu_mask)) {
-		resctrl_offline_domain(r, d);
+		resctrl_offline_ctrl_domain(r, d);
 		list_del(&d->list);
 
 		/*
@@ -593,6 +658,30 @@ static void domain_remove_cpu(int cpu, struct rdt_resource *r)
 
 		return;
 	}
+}
+
+static void domain_remove_cpu_mon(int cpu, struct rdt_resource *r)
+{
+	int id = get_domain_id_from_scope(cpu, r->mon_scope);
+	struct rdt_hw_domain *hw_mondom;
+	struct rdt_domain *d;
+
+	d = rdt_find_mondomain(&r->mondomains, id, NULL);
+	if (IS_ERR_OR_NULL(d)) {
+		pr_warn("Couldn't find scope id=%d for CPU %d\n", id, cpu);
+		return;
+	}
+	hw_mondom = resctrl_to_arch_dom(d);
+
+	cpumask_clear_cpu(cpu, &d->cpu_mask);
+	if (cpumask_empty(&d->cpu_mask)) {
+		resctrl_offline_mon_domain(r, d);
+		list_del(&d->list);
+
+		mondomain_free(hw_mondom);
+
+		return;
+	}
 
 	if (r == &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl) {
 		if (is_mbm_enabled() && cpu == d->mbm_work_cpu) {
@@ -607,6 +696,14 @@ static void domain_remove_cpu(int cpu, struct rdt_resource *r)
 	}
 }
 
+static void domain_remove_cpu(int cpu, struct rdt_resource *r)
+{
+	if (r->alloc_capable)
+		domain_remove_cpu_ctrl(cpu, r);
+	if (r->mon_capable)
+		domain_remove_cpu_mon(cpu, r);
+}
+
 static void clear_closid_rmid(int cpu)
 {
 	struct resctrl_pqr_state *state = this_cpu_ptr(&pqr_state);
diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
index b44c487727d4..468c1815edfd 100644
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -560,7 +560,7 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg)
 	evtid = md.u.evtid;
 
 	r = &rdt_resources_all[resid].r_resctrl;
-	d = rdt_find_domain(r, domid, NULL);
+	d = rdt_find_mondomain(&r->mondomains, domid, NULL);
 	if (IS_ERR_OR_NULL(d)) {
 		ret = -ENOENT;
 		goto out;
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index ded1fc7cb7cb..66beca785535 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -340,7 +340,7 @@ static void add_rmid_to_limbo(struct rmid_entry *entry)
 
 	entry->busy = 0;
 	cpu = get_cpu();
-	list_for_each_entry(d, &r->domains, list) {
+	list_for_each_entry(d, &r->mondomains, list) {
 		if (cpumask_test_cpu(cpu, &d->cpu_mask)) {
 			err = resctrl_arch_rmid_read(r, d, entry->rmid,
 						     QOS_L3_OCCUP_EVENT_ID,
diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
index e79324676f57..be8b5f28e638 100644
--- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
+++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
@@ -297,7 +297,7 @@ static int pseudo_lock_region_init(struct pseudo_lock_region *plr)
 
 	plr->size = rdtgroup_cbm_to_size(plr->s->res, plr->d, plr->cbm);
 
-	switch (plr->s->res->scope) {
+	switch (plr->s->res->ctrl_scope) {
 	case RESCTRL_L3_CACHE:
 		cache_level = 3;
 		break;
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index f510414bf6ce..f2aec39c49df 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1346,7 +1346,7 @@ unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r,
 	int cache_level;
 	int num_b, i;
 
-	switch (r->scope) {
+	switch (r->ctrl_scope) {
 	case RESCTRL_L3_CACHE:
 		cache_level = 3;
 		break;
@@ -1509,7 +1509,7 @@ static int mbm_config_show(struct seq_file *s, struct rdt_resource *r, u32 evtid
 
 	mutex_lock(&rdtgroup_mutex);
 
-	list_for_each_entry(dom, &r->domains, list) {
+	list_for_each_entry(dom, &r->mondomains, list) {
 		if (sep)
 			seq_puts(s, ";");
 
@@ -1632,7 +1632,7 @@ static int mon_config_write(struct rdt_resource *r, char *tok, u32 evtid)
 		return -EINVAL;
 	}
 
-	list_for_each_entry(d, &r->domains, list) {
+	list_for_each_entry(d, &r->mondomains, list) {
 		if (d->id == dom_id) {
 			ret = mbm_config_write_domain(r, d, evtid, val);
 			if (ret)
@@ -2538,7 +2538,7 @@ static int rdt_get_tree(struct fs_context *fc)
 
 	if (is_mbm_enabled()) {
 		r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
-		list_for_each_entry(dom, &r->domains, list)
+		list_for_each_entry(dom, &r->mondomains, list)
 			mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL);
 	}
 
@@ -2932,7 +2932,7 @@ static int mkdir_mondata_subdir_alldom(struct kernfs_node *parent_kn,
 	struct rdt_domain *dom;
 	int ret;
 
-	list_for_each_entry(dom, &r->domains, list) {
+	list_for_each_entry(dom, &r->mondomains, list) {
 		ret = mkdir_mondata_subdir(parent_kn, dom, r, prgrp);
 		if (ret)
 			return ret;
@@ -3721,15 +3721,17 @@ static void domain_destroy_mon_state(struct rdt_domain *d)
 	kfree(d->mbm_local);
 }
 
-void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d)
+void resctrl_offline_ctrl_domain(struct rdt_resource *r, struct rdt_domain *d)
 {
 	lockdep_assert_held(&rdtgroup_mutex);
 
 	if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA)
 		mba_sc_domain_destroy(r, d);
+}
 
-	if (!r->mon_capable)
-		return;
+void resctrl_offline_mon_domain(struct rdt_resource *r, struct rdt_domain *d)
+{
+	lockdep_assert_held(&rdtgroup_mutex);
 
 	/*
 	 * If resctrl is mounted, remove all the
@@ -3786,18 +3788,22 @@ static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_domain *d)
 	return 0;
 }
 
-int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d)
+int resctrl_online_ctrl_domain(struct rdt_resource *r, struct rdt_domain *d)
 {
-	int err;
-
 	lockdep_assert_held(&rdtgroup_mutex);
 
 	if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA)
 		/* RDT_RESOURCE_MBA is never mon_capable */
 		return mba_sc_domain_allocate(r, d);
 
-	if (!r->mon_capable)
-		return 0;
+	return 0;
+}
+
+int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_domain *d)
+{
+	int err;
+
+	lockdep_assert_held(&rdtgroup_mutex);
 
 	err = domain_setup_mon_state(r, d);
 	if (err)
-- 
2.41.0