diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index 4051f5e2d5fc984e895b8003c8187e65464aefb7..e8fb08f9ea891aface721911a28c01ce82823679 100644
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -37,6 +37,25 @@ extern unsigned int intel_cqm_threshold;
extern bool rdt_alloc_capable;
extern bool rdt_mon_capable;
extern unsigned int rdt_mon_features;
+
+enum rdt_group_type {
+ RDTCTRL_GROUP = 0,
+ RDTMON_GROUP,
+ RDT_NUM_GROUP,
+};
+
+/**
+ * struct mongroup - store mon group's data in resctrl fs.
+ * @parent: parent rdtgrp
+ * @crdtgrp_list: child rdtgroup node list
+ * @rmid: rmid for this rdtgroup
+ */
+struct mongroup {
+ struct rdtgroup *parent;
+ struct list_head crdtgrp_list;
+ u32 rmid;
+};
+
/**
* struct rdtgroup - store rdtgroup's data in resctrl file system.
* @kn: kernfs node
@@ -46,6 +65,9 @@ extern unsigned int rdt_mon_features;
* @flags: status bits
* @waitcount: how many cpus expect to find this
* group when they acquire rdtgroup_mutex
+ * @type: indicates type of this rdtgroup - either
+ * monitor only or ctrl_mon group
+ * @mon: mongroup related data
*/
struct rdtgroup {
struct kernfs_node *kn;
@@ -54,6 +76,8 @@ struct rdtgroup {
struct cpumask cpu_mask;
int flags;
atomic_t waitcount;
+ enum rdt_group_type type;
+ struct mongroup mon;
};
/* rdtgroup.flags */
@@ -306,6 +330,8 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
int rdtgroup_schemata_show(struct kernfs_open_file *of,
struct seq_file *s, void *v);
struct rdt_domain *get_domain_from_cpu(int cpu, struct rdt_resource *r);
+int alloc_rmid(void);
+void free_rmid(u32 rmid);
int rdt_get_mon_l3_config(struct rdt_resource *r);
#endif /* _ASM_X86_INTEL_RDT_H */
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index b3c901a8295e447334bb7f8aa98d2bf837ef1015..bee9f885dd200abcd9ef60c16f980a55d5e848eb 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -758,6 +758,39 @@ static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
return ret;
}
+static int
+mongroup_create_dir(struct kernfs_node *parent_kn, struct rdtgroup *prgrp,
+ char *name, struct kernfs_node **dest_kn)
+{
+ struct kernfs_node *kn;
+ int ret;
+
+ /* create the directory */
+ kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
+ if (IS_ERR(kn))
+ return PTR_ERR(kn);
+
+ if (dest_kn)
+ *dest_kn = kn;
+
+ /*
+ * This extra ref will be put in kernfs_remove() and guarantees
+ * that @rdtgrp->kn is always accessible.
+ */
+ kernfs_get(kn);
+
+ ret = rdtgroup_kn_set_ugid(kn);
+ if (ret)
+ goto out_destroy;
+
+ kernfs_activate(kn);
+
+ return 0;
+
+out_destroy:
+ kernfs_remove(kn);
+ return ret;
+}
static void l3_qos_cfg_update(void *arg)
{
bool *enable = arg;
@@ -1085,7 +1118,7 @@ static struct file_system_type rdt_fs_type = {
static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
struct kernfs_node *prgrp_kn,
const char *name, umode_t mode,
- struct rdtgroup **r)
+ enum rdt_group_type rtype, struct rdtgroup **r)
{
struct rdtgroup *prdtgrp, *rdtgrp;
struct kernfs_node *kn;
@@ -1105,6 +1138,9 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
goto out_unlock;
}
*r = rdtgrp;
+ rdtgrp->mon.parent = prdtgrp;
+ rdtgrp->type = rtype;
+ INIT_LIST_HEAD(&rdtgrp->mon.crdtgrp_list);
/* kernfs creates the directory for rdtgrp */
kn = kernfs_create_dir(parent_kn, name, mode, rdtgrp);
@@ -1127,10 +1163,17 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
goto out_destroy;
files = RFTYPE_BASE | RFTYPE_CTRL;
+ files = RFTYPE_BASE | BIT(RF_CTRLSHIFT + rtype);
ret = rdtgroup_add_files(kn, files);
if (ret)
goto out_destroy;
+ if (rdt_mon_capable) {
+ ret = alloc_rmid();
+ if (ret < 0)
+ goto out_destroy;
+ rdtgrp->mon.rmid = ret;
+ }
kernfs_activate(kn);
/*
@@ -1150,23 +1193,56 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
static void mkdir_rdt_prepare_clean(struct rdtgroup *rgrp)
{
kernfs_remove(rgrp->kn);
+ free_rmid(rgrp->mon.rmid);
kfree(rgrp);
}
+/*
+ * Create a monitor group under "mon_groups" directory of a control
+ * and monitor group(ctrl_mon). This is a resource group
+ * to monitor a subset of tasks and cpus in its parent ctrl_mon group.
+ */
+static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn,
+ struct kernfs_node *prgrp_kn,
+ const char *name,
+ umode_t mode)
+{
+ struct rdtgroup *rdtgrp, *prgrp;
+ int ret;
+
+ ret = mkdir_rdt_prepare(parent_kn, prgrp_kn, name, mode, RDTMON_GROUP,
+ &rdtgrp);
+ if (ret)
+ return ret;
+
+ prgrp = rdtgrp->mon.parent;
+ rdtgrp->closid = prgrp->closid;
+
+ /*
+ * Add the rdtgrp to the list of rdtgrps the parent
+ * ctrl_mon group has to track.
+ */
+ list_add_tail(&rdtgrp->mon.crdtgrp_list, &prgrp->mon.crdtgrp_list);
+
+ rdtgroup_kn_unlock(prgrp_kn);
+ return ret;
+}
+
/*
* These are rdtgroups created under the root directory. Can be used
- * to allocate resources.
+ * to allocate and monitor resources.
*/
-static int rdtgroup_mkdir_ctrl(struct kernfs_node *parent_kn,
- struct kernfs_node *prgrp_kn,
- const char *name, umode_t mode)
+static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
+ struct kernfs_node *prgrp_kn,
+ const char *name, umode_t mode)
{
struct rdtgroup *rdtgrp;
struct kernfs_node *kn;
u32 closid;
int ret;
- ret = mkdir_rdt_prepare(parent_kn, prgrp_kn, name, mode, &rdtgrp);
+ ret = mkdir_rdt_prepare(parent_kn, prgrp_kn, name, mode, RDTCTRL_GROUP,
+ &rdtgrp);
if (ret)
return ret;
@@ -1179,8 +1255,21 @@ static int rdtgroup_mkdir_ctrl(struct kernfs_node *parent_kn,
rdtgrp->closid = closid;
list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups);
+ if (rdt_mon_capable) {
+ /*
+ * Create an empty mon_groups directory to hold the subset
+ * of tasks and cpus to monitor.
+ */
+ ret = mongroup_create_dir(kn, NULL, "mon_groups", NULL);
+ if (ret)
+ goto out_id_free;
+ }
+
goto out_unlock;
+out_id_free:
+ closid_free(closid);
+ list_del(&rdtgrp->rdtgroup_list);
out_common_fail:
mkdir_rdt_prepare_clean(rdtgrp);
out_unlock:
@@ -1188,6 +1277,22 @@ static int rdtgroup_mkdir_ctrl(struct kernfs_node *parent_kn,
return ret;
}
+/*
+ * We allow creating mon groups only with in a directory called "mon_groups"
+ * which is present in every ctrl_mon group. Check if this is a valid
+ * "mon_groups" directory.
+ *
+ * 1. The directory should be named "mon_groups".
+ * 2. The mon group itself should "not" be named "mon_groups".
+ * This makes sure "mon_groups" directory always has a ctrl_mon group
+ * as parent.
+ */
+static bool is_mon_groups(struct kernfs_node *kn, const char *name)
+{
+ return (!strcmp(kn->name, "mon_groups") &&
+ strcmp(name, "mon_groups"));
+}
+
static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
umode_t mode)
{
@@ -1197,10 +1302,18 @@ static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
/*
* If the parent directory is the root directory and RDT
- * allocation is supported, add a control rdtgroup.
+ * allocation is supported, add a control and monitoring
+ * subdirectory
*/
if (rdt_alloc_capable && parent_kn == rdtgroup_default.kn)
- return rdtgroup_mkdir_ctrl(parent_kn, parent_kn, name, mode);
+ return rdtgroup_mkdir_ctrl_mon(parent_kn, parent_kn, name, mode);
+
+ /*
+ * If RDT monitoring is supported and the parent directory is a valid
+ * "mon_groups" directory, add a monitoring subdirectory.
+ */
+ if (rdt_mon_capable && is_mon_groups(parent_kn, name))
+ return rdtgroup_mkdir_mon(parent_kn, parent_kn->parent, name, mode);
return -EPERM;
}
@@ -1280,6 +1393,10 @@ static int __init rdtgroup_setup_root(void)
mutex_lock(&rdtgroup_mutex);
rdtgroup_default.closid = 0;
+ rdtgroup_default.mon.rmid = 0;
+ rdtgroup_default.type = RDTCTRL_GROUP;
+ INIT_LIST_HEAD(&rdtgroup_default.mon.crdtgrp_list);
+
list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups);
ret = rdtgroup_add_files(rdt_root->kn, RF_CTRL_BASE);