mpam: update monitor rmid and group configuration

ascend inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4L735
CVE: NA

-------------------------------------------------

When group rmid changes, as introduced by 6bbf2791b ("mpam: Add
support for group rmid modify") the sysfs monitor data file rmid
needs to update as well. This add support for updating rmid for
monitoring, and then resync the group configuration. When update
failed, roll back to the previous rmid.
Signed-off-by: NXingang Wang <wangxingang5@huawei.com>
Reviewed-by: NWang ShaoBo <bobo.shaobowang@huawei.com>
Reviewed-by: NWeilong Chen <chenweilong@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/arm64/include/asm/resctrl.h

@@ -162,6 +162,7 @@ struct rdtgroup {
 	atomic_t        waitcount;
 	enum rdt_group_type type;
 	struct mongroup     mon;
+	int                 resync;
 };
 
 enum resctrl_ctrl_type {

arch/arm64/kernel/mpam/mpam_ctrlmon.c

@@ -185,6 +185,55 @@ resctrl_dom_ctrl_config(bool cdp_both_ctrl, struct resctrl_resource *r,
 	}
 }
 
+/**
+ * Resync resctrl group domain ctrls, use rdtgrp->resync to indicate
+ * whether the resync procedure will be called. When resync==1, all
+ * domain ctrls of this group be synchronized again. This happens
+ * when rmid of this group is changed, and all configurations need to
+ * be remapped again accordingly.
+ */
+static void resctrl_group_resync_domain_ctrls(struct rdtgroup *rdtgrp,
+			struct resctrl_resource *r, struct rdt_domain *dom)
+{
+	int i;
+	int staged_start, staged_end;
+	struct resctrl_staged_config *cfg;
+	struct sd_closid closid;
+	struct list_head *head;
+	struct rdtgroup *entry;
+	struct msr_param para;
+	bool cdp_both_ctrl;
+
+	cfg = dom->staged_cfg;
+	para.closid = &closid;
+
+	staged_start = (r->cdp_enable) ? CDP_CODE : CDP_BOTH;
+	staged_end = (r->cdp_enable) ? CDP_DATA : CDP_BOTH;
+
+	for (i = staged_start; i <= staged_end; i++) {
+		cdp_both_ctrl = cfg[i].cdp_both_ctrl;
+		/*
+		 * for ctrl group configuration, hw_closid of cfg[i] equals
+		 * to rdtgrp->closid.intpartid.
+		 */
+		closid.intpartid = hw_closid_val(cfg[i].hw_closid);
+		resctrl_cdp_mpamid_map_val(rdtgrp->closid.reqpartid,
+				cfg[i].conf_type, closid.reqpartid);
+		resctrl_dom_ctrl_config(cdp_both_ctrl, r, dom, &para);
+
+		/*
+		 * we should synchronize all child mon groups'
+		 * configuration from this ctrl rdtgrp
+		 */
+		head = &rdtgrp->mon.crdtgrp_list;
+		list_for_each_entry(entry, head, mon.crdtgrp_list) {
+			resctrl_cdp_mpamid_map_val(entry->closid.reqpartid,
+					cfg[i].conf_type, closid.reqpartid);
+			resctrl_dom_ctrl_config(cdp_both_ctrl, r, dom, &para);
+		}
+	}
+}
+
 static void resctrl_group_update_domain_ctrls(struct rdtgroup *rdtgrp,
 			struct resctrl_resource *r, struct rdt_domain *dom)
 {
@@ -247,8 +296,12 @@ static int resctrl_group_update_domains(struct rdtgroup *rdtgrp,
 {
 	struct rdt_domain *d;
 
-	list_for_each_entry(d, &r->domains, list)
-		resctrl_group_update_domain_ctrls(rdtgrp, r, d);
+	list_for_each_entry(d, &r->domains, list) {
+		if (rdtgrp->resync)
+			resctrl_group_resync_domain_ctrls(rdtgrp, r, d);
+		else
+			resctrl_group_update_domain_ctrls(rdtgrp, r, d);
+	}
 
 	return 0;
 }
@@ -663,20 +716,31 @@ static int resctrl_mkdir_mondata_dom(struct kernfs_node *parent_kn,
 
 	md.u.cdp_both_mon = s->cdp_mc_both;
 
+	if (!parent_kn) {
+		pr_err("%s: error parent_kn null\n", __func__);
+		return -EINVAL;
+	}
+
 	snprintf(name, sizeof(name), "mon_%s_%02d", s->name, d->id);
-	kn = __kernfs_create_file(parent_kn, name, 0444,
-				  GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 0,
-				  &kf_mondata_ops, md.priv, NULL, NULL);
-	if (IS_ERR(kn))
-		return PTR_ERR(kn);
-
-	ret = resctrl_group_kn_set_ugid(kn);
-	if (ret) {
-		pr_info("%s: create name %s, error ret %d\n", __func__, name, ret);
-		kernfs_remove(kn);
-		return ret;
+	kn = kernfs_find_and_get(parent_kn, name);
+	if (!kn) {
+		kn = __kernfs_create_file(parent_kn, name, 0444,
+					  GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 0,
+					  &kf_mondata_ops, md.priv, NULL, NULL);
+		if (IS_ERR(kn))
+			return PTR_ERR(kn);
+
+		ret = resctrl_group_kn_set_ugid(kn);
+		if (ret) {
+			pr_info("%s: create name %s, error ret %d\n",
+					__func__, name, ret);
+			kernfs_remove(kn);
+			return ret;
+		}
 	}
 
+	kn->priv = md.priv;
+
 	/* Could we remove the MATCH_* param ? */
 	rr->mon_write(d, md.priv);
 
@@ -954,5 +1018,8 @@ int resctrl_update_groups_config(struct rdtgroup *rdtgrp)
 		}
 	}
 
+	/* after resync all configurations, restore resync to 0 */
+	rdtgrp->resync = 0;
+
 	return ret;
 }

arch/arm64/kernel/mpam/mpam_resctrl.c

@@ -1882,6 +1882,21 @@ static ssize_t resctrl_group_rmid_write(struct kernfs_open_file *of,
 	rdtgrp->closid.reqpartid = partid;
 	rdtgrp->mon.rmid = rmid;
 
+	/* update rmid for mondata */
+	ret = resctrl_mkdir_mondata_all_subdir(rdtgrp->mon.mon_data_kn, rdtgrp);
+	if (ret) {
+		rdt_last_cmd_puts("update rmid for mondata failed\n");
+		goto rollback;
+	}
+
+	/* resync groups configuration */
+	rdtgrp->resync = 1;
+	ret = resctrl_update_groups_config(rdtgrp);
+	if (ret) {
+		rdt_last_cmd_puts("update groups config failed\n");
+		goto rollback;
+	}
+
 	read_lock(&tasklist_lock);
 	for_each_process_thread(p, t) {
 		if (t->closid == rdtgrp->closid.intpartid) {
@@ -1908,6 +1923,12 @@ static ssize_t resctrl_group_rmid_write(struct kernfs_open_file *of,
 	rdtgrp->mon.rmid = old_rmid;
 	rdtgrp->closid.reqpartid = old_reqpartid;
 
+	/* the old rmid is valid, so mkdir mondata here won't fail */
+	resctrl_mkdir_mondata_all_subdir(rdtgrp->mon.mon_data_kn, rdtgrp);
+
+	rdtgrp->resync = 1;
+	WARN_ON_ONCE(resctrl_update_groups_config(rdtgrp));
+
 	read_lock(&tasklist_lock);
 	for_each_process_thread(p, t) {
 		if (t->closid == rdtgrp->closid.intpartid)