arm64/mpam: Set per-cpu's closid to none zero for cdp

hulk inclusion
category: feature
feature: ARM MPAM support
bugzilla: 48265
CVE: NA

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

Sometimes monitoring will have such anomalies:

e.g.
    > cd /sys/fs/resctrl/ && grep . mon_data/*
      mon_data/mon_L3CODE_00:14336
      mon_data/mon_L3CODE_01:344064
      mon_data/mon_L3CODE_02:2048
      mon_data/mon_L3CODE_03:27648
      mon_data/mon_L3DATA_00:0  #L3DATA's monitoring data always be 0
      mon_data/mon_L3DATA_01:0
      mon_data/mon_L3DATA_02:0
      mon_data/mon_L3DATA_03:0
      mon_data/mon_MB_00:392
      mon_data/mon_MB_01:552
      mon_data/mon_MB_02:160
      mon_data/mon_MB_03:0

If cdp on, tasks in resctrl default group with closid=0 and rmid=0 don't
know how to fill proper partid_i/pmg_i and partid_d/pmg_d into MPAMx_ELx
sysregs by mpam_sched_in() called by __switch_to(), it's because current
cpu's default closid and rmid are also equal to 0 and to make the operation
modifying configuration passed.

Update per cpu default closid of none-zero value, call update_closid_rmid()
to update each cpu's mpam proper MPAMx_ELx sysregs for setting partid and
pmg when mounting resctrl sysfs, it looks like a practical method.
Signed-off-by: NWang ShaoBo <bobo.shaobowang@huawei.com>
Reviewed-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: NCheng Jian <cj.chengjian@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

fs/resctrlfs.c

@@ -324,6 +324,28 @@ static int mkdir_mondata_all(struct kernfs_node *parent_kn,
 	return ret;
 }
 
+static void resctrl_cdp_update_cpus_state(struct resctrl_group *r)
+{
+	int cpu;
+
+	/*
+     * If cdp on, tasks in resctrl default group with closid=0
+	 * and rmid=0 don't know how to fill proper partid_i/pmg_i
+	 * and partid_d/pmg_d into MPAMx_ELx sysregs by mpam_sched_in()
+	 * called by __switch_to(), it's because current cpu's default
+	 * closid and rmid are also equal to 0 and to make the operation
+	 * modifying configuration passed. Update per cpu default closid
+	 * of none-zero value, call update_closid_rmid() to update each
+	 * cpu's mpam proper MPAMx_ELx sysregs for setting partid and
+	 * pmg when mounting resctrl sysfs, it looks like a practical
+	 * method.
+	 */
+	for_each_cpu(cpu, &r->cpu_mask)
+		per_cpu(pqr_state.default_closid, cpu) = ~0;
+
+	update_closid_rmid(&r->cpu_mask, NULL);
+}
+
 static int resctrl_get_tree(struct fs_context *fc)
 {
 	int ret;
@@ -381,6 +403,8 @@ static int resctrl_get_tree(struct fs_context *fc)
 	if (ret < 0)
 		goto out_mondata;
 
+	resctrl_cdp_update_cpus_state(&resctrl_group_default);
+
 	post_resctrl_mount();
 
 	goto out;