x86/resctrl: Make resctrl_arch_get_config() return its value

resctrl_arch_get_config() has no return, but does pass a single value
back via one of its arguments.

Return the value instead.
Suggested-by: NBorislav Petkov <bp@alien8.de>
Signed-off-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210811163831.14917-1-james.morse@arm.com

arch/x86/kernel/cpu/resctrl/ctrlmondata.c

@@ -427,16 +427,15 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
 	return ret ?: nbytes;
 }
 
-void resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d,
-			     u32 closid, enum resctrl_conf_type type, u32 *value)
+u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d,
+			    u32 closid, enum resctrl_conf_type type)
 {
 	struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
 	u32 idx = get_config_index(closid, type);
 
 	if (!is_mba_sc(r))
-		*value = hw_dom->ctrl_val[idx];
-	else
-		*value = hw_dom->mbps_val[idx];
+		return hw_dom->ctrl_val[idx];
+	return hw_dom->mbps_val[idx];
 }
 
 static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int closid)
@@ -451,8 +450,8 @@ static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int clo
 		if (sep)
 			seq_puts(s, ";");
 
-		resctrl_arch_get_config(r, dom, closid, schema->conf_type,
-					&ctrl_val);
+		ctrl_val = resctrl_arch_get_config(r, dom, closid,
+						   schema->conf_type);
 		seq_printf(s, r->format_str, dom->id, max_data_width,
 			   ctrl_val);
 		sep = true;

arch/x86/kernel/cpu/resctrl/monitor.c

@@ -442,7 +442,7 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm)
 	hw_dom_mba = resctrl_to_arch_dom(dom_mba);
 
 	cur_bw = pmbm_data->prev_bw;
-	resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE, &user_bw);
+	user_bw = resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE);
 	delta_bw = pmbm_data->delta_bw;
 	/*
 	 * resctrl_arch_get_config() chooses the mbps/ctrl value to return

arch/x86/kernel/cpu/resctrl/rdtgroup.c

@@ -923,8 +923,8 @@ static int rdt_bit_usage_show(struct kernfs_open_file *of,
 		for (i = 0; i < closids_supported(); i++) {
 			if (!closid_allocated(i))
 				continue;
-			resctrl_arch_get_config(r, dom, i, s->conf_type,
-						&ctrl_val);
+			ctrl_val = resctrl_arch_get_config(r, dom, i,
+							   s->conf_type);
 			mode = rdtgroup_mode_by_closid(i);
 			switch (mode) {
 			case RDT_MODE_SHAREABLE:
@@ -1142,7 +1142,7 @@ static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d
 
 	/* Check for overlap with other resource groups */
 	for (i = 0; i < closids_supported(); i++) {
-		resctrl_arch_get_config(r, d, i, type, (u32 *)&ctrl_b);
+		ctrl_b = resctrl_arch_get_config(r, d, i, type);
 		mode = rdtgroup_mode_by_closid(i);
 		if (closid_allocated(i) && i != closid &&
 		    mode != RDT_MODE_PSEUDO_LOCKSETUP) {
@@ -1222,7 +1222,8 @@ static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp)
 			continue;
 		has_cache = true;
 		list_for_each_entry(d, &r->domains, list) {
-			resctrl_arch_get_config(r, d, closid, s->conf_type, &ctrl);
+			ctrl = resctrl_arch_get_config(r, d, closid,
+						       s->conf_type);
 			if (rdtgroup_cbm_overlaps(s, d, ctrl, closid, false)) {
 				rdt_last_cmd_puts("Schemata overlaps\n");
 				return false;
@@ -1395,8 +1396,9 @@ static int rdtgroup_size_show(struct kernfs_open_file *of,
 			if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
 				size = 0;
 			} else {
-				resctrl_arch_get_config(r, d, rdtgrp->closid,
-							schema->conf_type, &ctrl);
+				ctrl = resctrl_arch_get_config(r, d,
+							       rdtgrp->closid,
+							       schema->conf_type);
 				if (r->rid == RDT_RESOURCE_MBA)
 					size = ctrl;
 				else
@@ -2724,10 +2726,12 @@ static int __init_one_rdt_domain(struct rdt_domain *d, struct resctrl_schema *s,
 			 * with an exclusive group.
 			 */
 			if (resctrl_arch_get_cdp_enabled(r->rid))
-				resctrl_arch_get_config(r, d, i, peer_type, &peer_ctl);
+				peer_ctl = resctrl_arch_get_config(r, d, i,
+								   peer_type);
 			else
 				peer_ctl = 0;
-			resctrl_arch_get_config(r, d, i, s->conf_type, &ctrl_val);
+			ctrl_val = resctrl_arch_get_config(r, d, i,
+							   s->conf_type);
 			used_b |= ctrl_val | peer_ctl;
 			if (mode == RDT_MODE_SHAREABLE)
 				cfg->new_ctrl |= ctrl_val | peer_ctl;

include/linux/resctrl.h

@@ -194,8 +194,7 @@ struct resctrl_schema {
 /* The number of closid supported by this resource regardless of CDP */
 u32 resctrl_arch_get_num_closid(struct rdt_resource *r);
 int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid);
-void resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d,
-			     u32 closid, enum resctrl_conf_type type,
-			     u32 *value);
+u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d,
+			    u32 closid, enum resctrl_conf_type type);
 
 #endif /* _RESCTRL_H */