Merge tag 'x86_cache_for_v6.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 resource control updates from Borislav Petkov:
 "Carve out the resctrl filesystem-related code into fs/resctrl/ so that
  multiple architectures can share the fs API for manipulating their
  respective hw resource control implementation.

  This is the second step in the work towards sharing the resctrl
  filesystem interface, the next one being plugging ARM's MPAM into the
  aforementioned fs API"

* tag 'x86_cache_for_v6.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
  MAINTAINERS: Add reviewers for fs/resctrl
  x86,fs/resctrl: Move the resctrl filesystem code to live in /fs/resctrl
  x86/resctrl: Always initialise rid field in rdt_resources_all[]
  x86/resctrl: Relax some asm #includes
  x86/resctrl: Prefer alloc(sizeof(*foo)) idiom in rdt_init_fs_context()
  x86/resctrl: Squelch whitespace anomalies in resctrl core code
  x86/resctrl: Move pseudo lock prototypes to include/linux/resctrl.h
  x86/resctrl: Fix types in resctrl_arch_mon_ctx_{alloc,free}() stubs
  x86/resctrl: Move enum resctrl_event_id to resctrl.h
  x86/resctrl: Move the filesystem bits to headers visible to fs/resctrl
  fs/resctrl: Add boiler plate for external resctrl code
  x86/resctrl: Add 'resctrl' to the title of the resctrl documentation
  x86/resctrl: Split trace.h
  x86/resctrl: Expand the width of domid by replacing mon_data_bits
  x86/resctrl: Add end-marker to the resctrl_event_id enum
  x86/resctrl: Move is_mba_sc() out of core.c
  x86/resctrl: Drop __init/__exit on assorted symbols
  x86/resctrl: Resctrl_exit() teardown resctrl but leave the mount point
  x86/resctrl: Check all domains are offline in resctrl_exit()
  x86/resctrl: Rename resctrl_sched_in() to begin with "resctrl_arch_"
  ...

1 files changed, 4353 insertions, 0 deletions

diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
new file mode 100644
index 000000000000..cc37f58b47dd
--- /dev/null
+++ b/fs/resctrl/rdtgroup.c
@@ -0,0 +1,4353 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * User interface for Resource Allocation in Resource Director Technology(RDT)
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Author: Fenghua Yu <fenghua.yu@intel.com>
+ *
+ * More information about RDT be found in the Intel (R) x86 Architecture
+ * Software Developer Manual.
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/cpu.h>
+#include <linux/debugfs.h>
+#include <linux/fs.h>
+#include <linux/fs_parser.h>
+#include <linux/sysfs.h>
+#include <linux/kernfs.h>
+#include <linux/resctrl.h>
+#include <linux/seq_buf.h>
+#include <linux/seq_file.h>
+#include <linux/sched/task.h>
+#include <linux/slab.h>
+#include <linux/user_namespace.h>
+
+#include <uapi/linux/magic.h>
+
+#include "internal.h"
+
+/* Mutex to protect rdtgroup access. */
+DEFINE_MUTEX(rdtgroup_mutex);
+
+static struct kernfs_root *rdt_root;
+
+struct rdtgroup rdtgroup_default;
+
+LIST_HEAD(rdt_all_groups);
+
+/* list of entries for the schemata file */
+LIST_HEAD(resctrl_schema_all);
+
+/*
+ * List of struct mon_data containing private data of event files for use by
+ * rdtgroup_mondata_show(). Protected by rdtgroup_mutex.
+ */
+static LIST_HEAD(mon_data_kn_priv_list);
+
+/* The filesystem can only be mounted once. */
+bool resctrl_mounted;
+
+/* Kernel fs node for "info" directory under root */
+static struct kernfs_node *kn_info;
+
+/* Kernel fs node for "mon_groups" directory under root */
+static struct kernfs_node *kn_mongrp;
+
+/* Kernel fs node for "mon_data" directory under root */
+static struct kernfs_node *kn_mondata;
+
+/*
+ * Used to store the max resource name width to display the schemata names in
+ * a tabular format.
+ */
+int max_name_width;
+
+static struct seq_buf last_cmd_status;
+
+static char last_cmd_status_buf[512];
+
+static int rdtgroup_setup_root(struct rdt_fs_context *ctx);
+
+static void rdtgroup_destroy_root(void);
+
+struct dentry *debugfs_resctrl;
+
+/*
+ * Memory bandwidth monitoring event to use for the default CTRL_MON group
+ * and each new CTRL_MON group created by the user.  Only relevant when
+ * the filesystem is mounted with the "mba_MBps" option so it does not
+ * matter that it remains uninitialized on systems that do not support
+ * the "mba_MBps" option.
+ */
+enum resctrl_event_id mba_mbps_default_event;
+
+static bool resctrl_debug;
+
+void rdt_last_cmd_clear(void)
+{
+	lockdep_assert_held(&rdtgroup_mutex);
+	seq_buf_clear(&last_cmd_status);
+}
+
+void rdt_last_cmd_puts(const char *s)
+{
+	lockdep_assert_held(&rdtgroup_mutex);
+	seq_buf_puts(&last_cmd_status, s);
+}
+
+void rdt_last_cmd_printf(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	lockdep_assert_held(&rdtgroup_mutex);
+	seq_buf_vprintf(&last_cmd_status, fmt, ap);
+	va_end(ap);
+}
+
+void rdt_staged_configs_clear(void)
+{
+	struct rdt_ctrl_domain *dom;
+	struct rdt_resource *r;
+
+	lockdep_assert_held(&rdtgroup_mutex);
+
+	for_each_alloc_capable_rdt_resource(r) {
+		list_for_each_entry(dom, &r->ctrl_domains, hdr.list)
+			memset(dom->staged_config, 0, sizeof(dom->staged_config));
+	}
+}
+
+static bool resctrl_is_mbm_enabled(void)
+{
+	return (resctrl_arch_is_mbm_total_enabled() ||
+		resctrl_arch_is_mbm_local_enabled());
+}
+
+static bool resctrl_is_mbm_event(int e)
+{
+	return (e >= QOS_L3_MBM_TOTAL_EVENT_ID &&
+		e <= QOS_L3_MBM_LOCAL_EVENT_ID);
+}
+
+/*
+ * Trivial allocator for CLOSIDs. Use BITMAP APIs to manipulate a bitmap
+ * of free CLOSIDs.
+ *
+ * Using a global CLOSID across all resources has some advantages and
+ * some drawbacks:
+ * + We can simply set current's closid to assign a task to a resource
+ *   group.
+ * + Context switch code can avoid extra memory references deciding which
+ *   CLOSID to load into the PQR_ASSOC MSR
+ * - We give up some options in configuring resource groups across multi-socket
+ *   systems.
+ * - Our choices on how to configure each resource become progressively more
+ *   limited as the number of resources grows.
+ */
+static unsigned long *closid_free_map;
+
+static int closid_free_map_len;
+
+int closids_supported(void)
+{
+	return closid_free_map_len;
+}
+
+static int closid_init(void)
+{
+	struct resctrl_schema *s;
+	u32 rdt_min_closid = ~0;
+
+	/* Monitor only platforms still call closid_init() */
+	if (list_empty(&resctrl_schema_all))
+		return 0;
+
+	/* Compute rdt_min_closid across all resources */
+	list_for_each_entry(s, &resctrl_schema_all, list)
+		rdt_min_closid = min(rdt_min_closid, s->num_closid);
+
+	closid_free_map = bitmap_alloc(rdt_min_closid, GFP_KERNEL);
+	if (!closid_free_map)
+		return -ENOMEM;
+	bitmap_fill(closid_free_map, rdt_min_closid);
+
+	/* RESCTRL_RESERVED_CLOSID is always reserved for the default group */
+	__clear_bit(RESCTRL_RESERVED_CLOSID, closid_free_map);
+	closid_free_map_len = rdt_min_closid;
+
+	return 0;
+}
+
+static void closid_exit(void)
+{
+	bitmap_free(closid_free_map);
+	closid_free_map = NULL;
+}
+
+static int closid_alloc(void)
+{
+	int cleanest_closid;
+	u32 closid;
+
+	lockdep_assert_held(&rdtgroup_mutex);
+
+	if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID) &&
+	    resctrl_arch_is_llc_occupancy_enabled()) {
+		cleanest_closid = resctrl_find_cleanest_closid();
+		if (cleanest_closid < 0)
+			return cleanest_closid;
+		closid = cleanest_closid;
+	} else {
+		closid = find_first_bit(closid_free_map, closid_free_map_len);
+		if (closid == closid_free_map_len)
+			return -ENOSPC;
+	}
+	__clear_bit(closid, closid_free_map);
+
+	return closid;
+}
+
+void closid_free(int closid)
+{
+	lockdep_assert_held(&rdtgroup_mutex);
+
+	__set_bit(closid, closid_free_map);
+}
+
+/**
+ * closid_allocated - test if provided closid is in use
+ * @closid: closid to be tested
+ *
+ * Return: true if @closid is currently associated with a resource group,
+ * false if @closid is free
+ */
+bool closid_allocated(unsigned int closid)
+{
+	lockdep_assert_held(&rdtgroup_mutex);
+
+	return !test_bit(closid, closid_free_map);
+}
+
+/**
+ * rdtgroup_mode_by_closid - Return mode of resource group with closid
+ * @closid: closid if the resource group
+ *
+ * Each resource group is associated with a @closid. Here the mode
+ * of a resource group can be queried by searching for it using its closid.
+ *
+ * Return: mode as &enum rdtgrp_mode of resource group with closid @closid
+ */
+enum rdtgrp_mode rdtgroup_mode_by_closid(int closid)
+{
+	struct rdtgroup *rdtgrp;
+
+	list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
+		if (rdtgrp->closid == closid)
+			return rdtgrp->mode;
+	}
+
+	return RDT_NUM_MODES;
+}
+
+static const char * const rdt_mode_str[] = {
+	[RDT_MODE_SHAREABLE]		= "shareable",
+	[RDT_MODE_EXCLUSIVE]		= "exclusive",
+	[RDT_MODE_PSEUDO_LOCKSETUP]	= "pseudo-locksetup",
+	[RDT_MODE_PSEUDO_LOCKED]	= "pseudo-locked",
+};
+
+/**
+ * rdtgroup_mode_str - Return the string representation of mode
+ * @mode: the resource group mode as &enum rdtgroup_mode
+ *
+ * Return: string representation of valid mode, "unknown" otherwise
+ */
+static const char *rdtgroup_mode_str(enum rdtgrp_mode mode)
+{
+	if (mode < RDT_MODE_SHAREABLE || mode >= RDT_NUM_MODES)
+		return "unknown";
+
+	return rdt_mode_str[mode];
+}
+
+/* set uid and gid of rdtgroup dirs and files to that of the creator */
+static int rdtgroup_kn_set_ugid(struct kernfs_node *kn)
+{
+	struct iattr iattr = { .ia_valid = ATTR_UID | ATTR_GID,
+				.ia_uid = current_fsuid(),
+				.ia_gid = current_fsgid(), };
+
+	if (uid_eq(iattr.ia_uid, GLOBAL_ROOT_UID) &&
+	    gid_eq(iattr.ia_gid, GLOBAL_ROOT_GID))
+		return 0;
+
+	return kernfs_setattr(kn, &iattr);
+}
+
+static int rdtgroup_add_file(struct kernfs_node *parent_kn, struct rftype *rft)
+{
+	struct kernfs_node *kn;
+	int ret;
+
+	kn = __kernfs_create_file(parent_kn, rft->name, rft->mode,
+				  GLOBAL_ROOT_UID, GLOBAL_ROOT_GID,
+				  0, rft->kf_ops, rft, NULL, NULL);
+	if (IS_ERR(kn))
+		return PTR_ERR(kn);
+
+	ret = rdtgroup_kn_set_ugid(kn);
+	if (ret) {
+		kernfs_remove(kn);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int rdtgroup_seqfile_show(struct seq_file *m, void *arg)
+{
+	struct kernfs_open_file *of = m->private;
+	struct rftype *rft = of->kn->priv;
+
+	if (rft->seq_show)
+		return rft->seq_show(of, m, arg);
+	return 0;
+}
+
+static ssize_t rdtgroup_file_write(struct kernfs_open_file *of, char *buf,
+				   size_t nbytes, loff_t off)
+{
+	struct rftype *rft = of->kn->priv;
+
+	if (rft->write)
+		return rft->write(of, buf, nbytes, off);
+
+	return -EINVAL;
+}
+
+static const struct kernfs_ops rdtgroup_kf_single_ops = {
+	.atomic_write_len	= PAGE_SIZE,
+	.write			= rdtgroup_file_write,
+	.seq_show		= rdtgroup_seqfile_show,
+};
+
+static const struct kernfs_ops kf_mondata_ops = {
+	.atomic_write_len	= PAGE_SIZE,
+	.seq_show		= rdtgroup_mondata_show,
+};
+
+static bool is_cpu_list(struct kernfs_open_file *of)
+{
+	struct rftype *rft = of->kn->priv;
+
+	return rft->flags & RFTYPE_FLAGS_CPUS_LIST;
+}
+
+static int rdtgroup_cpus_show(struct kernfs_open_file *of,
+			      struct seq_file *s, void *v)
+{
+	struct rdtgroup *rdtgrp;
+	struct cpumask *mask;
+	int ret = 0;
+
+	rdtgrp = rdtgroup_kn_lock_live(of->kn);
+
+	if (rdtgrp) {
+		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
+			if (!rdtgrp->plr->d) {
+				rdt_last_cmd_clear();
+				rdt_last_cmd_puts("Cache domain offline\n");
+				ret = -ENODEV;
+			} else {
+				mask = &rdtgrp->plr->d->hdr.cpu_mask;
+				seq_printf(s, is_cpu_list(of) ?
+					   "%*pbl\n" : "%*pb\n",
+					   cpumask_pr_args(mask));
+			}
+		} else {
+			seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n",
+				   cpumask_pr_args(&rdtgrp->cpu_mask));
+		}
+	} else {
+		ret = -ENOENT;
+	}
+	rdtgroup_kn_unlock(of->kn);
+
+	return ret;
+}
+
+/*
+ * Update the PGR_ASSOC MSR on all cpus in @cpu_mask,
+ *
+ * Per task closids/rmids must have been set up before calling this function.
+ * @r may be NULL.
+ */
+static void
+update_closid_rmid(const struct cpumask *cpu_mask, struct rdtgroup *r)
+{
+	struct resctrl_cpu_defaults defaults, *p = NULL;
+
+	if (r) {
+		defaults.closid = r->closid;
+		defaults.rmid = r->mon.rmid;
+		p = &defaults;
+	}
+
+	on_each_cpu_mask(cpu_mask, resctrl_arch_sync_cpu_closid_rmid, p, 1);
+}
+
+static int cpus_mon_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
+			  cpumask_var_t tmpmask)
+{
+	struct rdtgroup *prgrp = rdtgrp->mon.parent, *crgrp;
+	struct list_head *head;
+
+	/* Check whether cpus belong to parent ctrl group */
+	cpumask_andnot(tmpmask, newmask, &prgrp->cpu_mask);
+	if (!cpumask_empty(tmpmask)) {
+		rdt_last_cmd_puts("Can only add CPUs to mongroup that belong to parent\n");
+		return -EINVAL;
+	}
+
+	/* Check whether cpus are dropped from this group */
+	cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
+	if (!cpumask_empty(tmpmask)) {
+		/* Give any dropped cpus to parent rdtgroup */
+		cpumask_or(&prgrp->cpu_mask, &prgrp->cpu_mask, tmpmask);
+		update_closid_rmid(tmpmask, prgrp);
+	}
+
+	/*
+	 * If we added cpus, remove them from previous group that owned them
+	 * and update per-cpu rmid
+	 */
+	cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
+	if (!cpumask_empty(tmpmask)) {
+		head = &prgrp->mon.crdtgrp_list;
+		list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
+			if (crgrp == rdtgrp)
+				continue;
+			cpumask_andnot(&crgrp->cpu_mask, &crgrp->cpu_mask,
+				       tmpmask);
+		}
+		update_closid_rmid(tmpmask, rdtgrp);
+	}
+
+	/* Done pushing/pulling - update this group with new mask */
+	cpumask_copy(&rdtgrp->cpu_mask, newmask);
+
+	return 0;
+}
+
+static void cpumask_rdtgrp_clear(struct rdtgroup *r, struct cpumask *m)
+{
+	struct rdtgroup *crgrp;
+
+	cpumask_andnot(&r->cpu_mask, &r->cpu_mask, m);
+	/* update the child mon group masks as well*/
+	list_for_each_entry(crgrp, &r->mon.crdtgrp_list, mon.crdtgrp_list)
+		cpumask_and(&crgrp->cpu_mask, &r->cpu_mask, &crgrp->cpu_mask);
+}
+
+static int cpus_ctrl_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
+			   cpumask_var_t tmpmask, cpumask_var_t tmpmask1)
+{
+	struct rdtgroup *r, *crgrp;
+	struct list_head *head;
+
+	/* Check whether cpus are dropped from this group */
+	cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
+	if (!cpumask_empty(tmpmask)) {
+		/* Can't drop from default group */
+		if (rdtgrp == &rdtgroup_default) {
+			rdt_last_cmd_puts("Can't drop CPUs from default group\n");
+			return -EINVAL;
+		}
+
+		/* Give any dropped cpus to rdtgroup_default */
+		cpumask_or(&rdtgroup_default.cpu_mask,
+			   &rdtgroup_default.cpu_mask, tmpmask);
+		update_closid_rmid(tmpmask, &rdtgroup_default);
+	}
+
+	/*
+	 * If we added cpus, remove them from previous group and
+	 * the prev group's child groups that owned them
+	 * and update per-cpu closid/rmid.
+	 */
+	cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
+	if (!cpumask_empty(tmpmask)) {
+		list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) {
+			if (r == rdtgrp)
+				continue;
+			cpumask_and(tmpmask1, &r->cpu_mask, tmpmask);
+			if (!cpumask_empty(tmpmask1))
+				cpumask_rdtgrp_clear(r, tmpmask1);
+		}
+		update_closid_rmid(tmpmask, rdtgrp);
+	}
+
+	/* Done pushing/pulling - update this group with new mask */
+	cpumask_copy(&rdtgrp->cpu_mask, newmask);
+
+	/*
+	 * Clear child mon group masks since there is a new parent mask
+	 * now and update the rmid for the cpus the child lost.
+	 */
+	head = &rdtgrp->mon.crdtgrp_list;
+	list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
+		cpumask_and(tmpmask, &rdtgrp->cpu_mask, &crgrp->cpu_mask);
+		update_closid_rmid(tmpmask, rdtgrp);
+		cpumask_clear(&crgrp->cpu_mask);
+	}
+
+	return 0;
+}
+
+static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
+				   char *buf, size_t nbytes, loff_t off)
+{
+	cpumask_var_t tmpmask, newmask, tmpmask1;
+	struct rdtgroup *rdtgrp;
+	int ret;
+
+	if (!buf)
+		return -EINVAL;
+
+	if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
+		return -ENOMEM;
+	if (!zalloc_cpumask_var(&newmask, GFP_KERNEL)) {
+		free_cpumask_var(tmpmask);
+		return -ENOMEM;
+	}
+	if (!zalloc_cpumask_var(&tmpmask1, GFP_KERNEL)) {
+		free_cpumask_var(tmpmask);
+		free_cpumask_var(newmask);
+		return -ENOMEM;
+	}
+
+	rdtgrp = rdtgroup_kn_lock_live(of->kn);
+	if (!rdtgrp) {
+		ret = -ENOENT;
+		goto unlock;
+	}
+
+	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
+	    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+		ret = -EINVAL;
+		rdt_last_cmd_puts("Pseudo-locking in progress\n");
+		goto unlock;
+	}
+
+	if (is_cpu_list(of))
+		ret = cpulist_parse(buf, newmask);
+	else
+		ret = cpumask_parse(buf, newmask);
+
+	if (ret) {
+		rdt_last_cmd_puts("Bad CPU list/mask\n");
+		goto unlock;
+	}
+
+	/* check that user didn't specify any offline cpus */
+	cpumask_andnot(tmpmask, newmask, cpu_online_mask);
+	if (!cpumask_empty(tmpmask)) {
+		ret = -EINVAL;
+		rdt_last_cmd_puts("Can only assign online CPUs\n");
+		goto unlock;
+	}
+
+	if (rdtgrp->type == RDTCTRL_GROUP)
+		ret = cpus_ctrl_write(rdtgrp, newmask, tmpmask, tmpmask1);
+	else if (rdtgrp->type == RDTMON_GROUP)
+		ret = cpus_mon_write(rdtgrp, newmask, tmpmask);
+	else
+		ret = -EINVAL;
+
+unlock:
+	rdtgroup_kn_unlock(of->kn);
+	free_cpumask_var(tmpmask);
+	free_cpumask_var(newmask);
+	free_cpumask_var(tmpmask1);
+
+	return ret ?: nbytes;
+}
+
+/**
+ * rdtgroup_remove - the helper to remove resource group safely
+ * @rdtgrp: resource group to remove
+ *
+ * On resource group creation via a mkdir, an extra kernfs_node reference is
+ * taken to ensure that the rdtgroup structure remains accessible for the
+ * rdtgroup_kn_unlock() calls where it is removed.
+ *
+ * Drop the extra reference here, then free the rdtgroup structure.
+ *
+ * Return: void
+ */
+static void rdtgroup_remove(struct rdtgroup *rdtgrp)
+{
+	kernfs_put(rdtgrp->kn);
+	kfree(rdtgrp);
+}
+
+static void _update_task_closid_rmid(void *task)
+{
+	/*
+	 * If the task is still current on this CPU, update PQR_ASSOC MSR.
+	 * Otherwise, the MSR is updated when the task is scheduled in.
+	 */
+	if (task == current)
+		resctrl_arch_sched_in(task);
+}
+
+static void update_task_closid_rmid(struct task_struct *t)
+{
+	if (IS_ENABLED(CONFIG_SMP) && task_curr(t))
+		smp_call_function_single(task_cpu(t), _update_task_closid_rmid, t, 1);
+	else
+		_update_task_closid_rmid(t);
+}
+
+static bool task_in_rdtgroup(struct task_struct *tsk, struct rdtgroup *rdtgrp)
+{
+	u32 closid, rmid = rdtgrp->mon.rmid;
+
+	if (rdtgrp->type == RDTCTRL_GROUP)
+		closid = rdtgrp->closid;
+	else if (rdtgrp->type == RDTMON_GROUP)
+		closid = rdtgrp->mon.parent->closid;
+	else
+		return false;
+
+	return resctrl_arch_match_closid(tsk, closid) &&
+	       resctrl_arch_match_rmid(tsk, closid, rmid);
+}
+
+static int __rdtgroup_move_task(struct task_struct *tsk,
+				struct rdtgroup *rdtgrp)
+{
+	/* If the task is already in rdtgrp, no need to move the task. */
+	if (task_in_rdtgroup(tsk, rdtgrp))
+		return 0;
+
+	/*
+	 * Set the task's closid/rmid before the PQR_ASSOC MSR can be
+	 * updated by them.
+	 *
+	 * For ctrl_mon groups, move both closid and rmid.
+	 * For monitor groups, can move the tasks only from
+	 * their parent CTRL group.
+	 */
+	if (rdtgrp->type == RDTMON_GROUP &&
+	    !resctrl_arch_match_closid(tsk, rdtgrp->mon.parent->closid)) {
+		rdt_last_cmd_puts("Can't move task to different control group\n");
+		return -EINVAL;
+	}
+
+	if (rdtgrp->type == RDTMON_GROUP)
+		resctrl_arch_set_closid_rmid(tsk, rdtgrp->mon.parent->closid,
+					     rdtgrp->mon.rmid);
+	else
+		resctrl_arch_set_closid_rmid(tsk, rdtgrp->closid,
+					     rdtgrp->mon.rmid);
+
+	/*
+	 * Ensure the task's closid and rmid are written before determining if
+	 * the task is current that will decide if it will be interrupted.
+	 * This pairs with the full barrier between the rq->curr update and
+	 * resctrl_arch_sched_in() during context switch.
+	 */
+	smp_mb();
+
+	/*
+	 * By now, the task's closid and rmid are set. If the task is current
+	 * on a CPU, the PQR_ASSOC MSR needs to be updated to make the resource
+	 * group go into effect. If the task is not current, the MSR will be
+	 * updated when the task is scheduled in.
+	 */
+	update_task_closid_rmid(tsk);
+
+	return 0;
+}
+
+static bool is_closid_match(struct task_struct *t, struct rdtgroup *r)
+{
+	return (resctrl_arch_alloc_capable() && (r->type == RDTCTRL_GROUP) &&
+		resctrl_arch_match_closid(t, r->closid));
+}
+
+static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r)
+{
+	return (resctrl_arch_mon_capable() && (r->type == RDTMON_GROUP) &&
+		resctrl_arch_match_rmid(t, r->mon.parent->closid,
+					r->mon.rmid));
+}
+
+/**
+ * rdtgroup_tasks_assigned - Test if tasks have been assigned to resource group
+ * @r: Resource group
+ *
+ * Return: 1 if tasks have been assigned to @r, 0 otherwise
+ */
+int rdtgroup_tasks_assigned(struct rdtgroup *r)
+{
+	struct task_struct *p, *t;
+	int ret = 0;
+
+	lockdep_assert_held(&rdtgroup_mutex);
+
+	rcu_read_lock();
+	for_each_process_thread(p, t) {
+		if (is_closid_match(t, r) || is_rmid_match(t, r)) {
+			ret = 1;
+			break;
+		}
+	}
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static int rdtgroup_task_write_permission(struct task_struct *task,
+					  struct kernfs_open_file *of)
+{
+	const struct cred *tcred = get_task_cred(task);
+	const struct cred *cred = current_cred();
+	int ret = 0;
+
+	/*
+	 * Even if we're attaching all tasks in the thread group, we only
+	 * need to check permissions on one of them.
+	 */
+	if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) &&
+	    !uid_eq(cred->euid, tcred->uid) &&
+	    !uid_eq(cred->euid, tcred->suid)) {
+		rdt_last_cmd_printf("No permission to move task %d\n", task->pid);
+		ret = -EPERM;
+	}
+
+	put_cred(tcred);
+	return ret;
+}
+
+static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp,
+			      struct kernfs_open_file *of)
+{
+	struct task_struct *tsk;
+	int ret;
+
+	rcu_read_lock();
+	if (pid) {
+		tsk = find_task_by_vpid(pid);
+		if (!tsk) {
+			rcu_read_unlock();
+			rdt_last_cmd_printf("No task %d\n", pid);
+			return -ESRCH;
+		}
+	} else {
+		tsk = current;
+	}
+
+	get_task_struct(tsk);
+	rcu_read_unlock();
+
+	ret = rdtgroup_task_write_permission(tsk, of);
+	if (!ret)
+		ret = __rdtgroup_move_task(tsk, rdtgrp);
+
+	put_task_struct(tsk);
+	return ret;
+}
+
+static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of,
+				    char *buf, size_t nbytes, loff_t off)
+{
+	struct rdtgroup *rdtgrp;
+	char *pid_str;
+	int ret = 0;
+	pid_t pid;
+
+	rdtgrp = rdtgroup_kn_lock_live(of->kn);
+	if (!rdtgrp) {
+		rdtgroup_kn_unlock(of->kn);
+		return -ENOENT;
+	}
+	rdt_last_cmd_clear();
+
+	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
+	    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+		ret = -EINVAL;
+		rdt_last_cmd_puts("Pseudo-locking in progress\n");
+		goto unlock;
+	}
+
+	while (buf && buf[0] != '\0' && buf[0] != '\n') {
+		pid_str = strim(strsep(&buf, ","));
+
+		if (kstrtoint(pid_str, 0, &pid)) {
+			rdt_last_cmd_printf("Task list parsing error pid %s\n", pid_str);
+			ret = -EINVAL;
+			break;
+		}
+
+		if (pid < 0) {
+			rdt_last_cmd_printf("Invalid pid %d\n", pid);
+			ret = -EINVAL;
+			break;
+		}
+
+		ret = rdtgroup_move_task(pid, rdtgrp, of);
+		if (ret) {
+			rdt_last_cmd_printf("Error while processing task %d\n", pid);
+			break;
+		}
+	}
+
+unlock:
+	rdtgroup_kn_unlock(of->kn);
+
+	return ret ?: nbytes;
+}
+
+static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s)
+{
+	struct task_struct *p, *t;
+	pid_t pid;
+
+	rcu_read_lock();
+	for_each_process_thread(p, t) {
+		if (is_closid_match(t, r) || is_rmid_match(t, r)) {
+			pid = task_pid_vnr(t);
+			if (pid)
+				seq_printf(s, "%d\n", pid);
+		}
+	}
+	rcu_read_unlock();
+}
+
+static int rdtgroup_tasks_show(struct kernfs_open_file *of,
+			       struct seq_file *s, void *v)
+{
+	struct rdtgroup *rdtgrp;
+	int ret = 0;
+
+	rdtgrp = rdtgroup_kn_lock_live(of->kn);
+	if (rdtgrp)
+		show_rdt_tasks(rdtgrp, s);
+	else
+		ret = -ENOENT;
+	rdtgroup_kn_unlock(of->kn);
+
+	return ret;
+}
+
+static int rdtgroup_closid_show(struct kernfs_open_file *of,
+				struct seq_file *s, void *v)
+{
+	struct rdtgroup *rdtgrp;
+	int ret = 0;
+
+	rdtgrp = rdtgroup_kn_lock_live(of->kn);
+	if (rdtgrp)
+		seq_printf(s, "%u\n", rdtgrp->closid);
+	else
+		ret = -ENOENT;
+	rdtgroup_kn_unlock(of->kn);
+
+	return ret;
+}
+
+static int rdtgroup_rmid_show(struct kernfs_open_file *of,
+			      struct seq_file *s, void *v)
+{
+	struct rdtgroup *rdtgrp;
+	int ret = 0;
+
+	rdtgrp = rdtgroup_kn_lock_live(of->kn);
+	if (rdtgrp)
+		seq_printf(s, "%u\n", rdtgrp->mon.rmid);
+	else
+		ret = -ENOENT;
+	rdtgroup_kn_unlock(of->kn);
+
+	return ret;
+}
+
+#ifdef CONFIG_PROC_CPU_RESCTRL
+/*
+ * A task can only be part of one resctrl control group and of one monitor
+ * group which is associated to that control group.
+ *
+ * 1)   res:
+ *      mon:
+ *
+ *    resctrl is not available.
+ *
+ * 2)   res:/
+ *      mon:
+ *
+ *    Task is part of the root resctrl control group, and it is not associated
+ *    to any monitor group.
+ *
+ * 3)  res:/
+ *     mon:mon0
+ *
+ *    Task is part of the root resctrl control group and monitor group mon0.
+ *
+ * 4)  res:group0
+ *     mon:
+ *
+ *    Task is part of resctrl control group group0, and it is not associated
+ *    to any monitor group.
+ *
+ * 5) res:group0
+ *    mon:mon1
+ *
+ *    Task is part of resctrl control group group0 and monitor group mon1.
+ */
+int proc_resctrl_show(struct seq_file *s, struct pid_namespace *ns,
+		      struct pid *pid, struct task_struct *tsk)
+{
+	struct rdtgroup *rdtg;
+	int ret = 0;
+
+	mutex_lock(&rdtgroup_mutex);
+
+	/* Return empty if resctrl has not been mounted. */
+	if (!resctrl_mounted) {
+		seq_puts(s, "res:\nmon:\n");
+		goto unlock;
+	}
+
+	list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) {
+		struct rdtgroup *crg;
+
+		/*
+		 * Task information is only relevant for shareable
+		 * and exclusive groups.
+		 */
+		if (rdtg->mode != RDT_MODE_SHAREABLE &&
+		    rdtg->mode != RDT_MODE_EXCLUSIVE)
+			continue;
+
+		if (!resctrl_arch_match_closid(tsk, rdtg->closid))
+			continue;
+
+		seq_printf(s, "res:%s%s\n", (rdtg == &rdtgroup_default) ? "/" : "",
+			   rdt_kn_name(rdtg->kn));
+		seq_puts(s, "mon:");
+		list_for_each_entry(crg, &rdtg->mon.crdtgrp_list,
+				    mon.crdtgrp_list) {
+			if (!resctrl_arch_match_rmid(tsk, crg->mon.parent->closid,
+						     crg->mon.rmid))
+				continue;
+			seq_printf(s, "%s", rdt_kn_name(crg->kn));
+			break;
+		}
+		seq_putc(s, '\n');
+		goto unlock;
+	}
+	/*
+	 * The above search should succeed. Otherwise return
+	 * with an error.
+	 */
+	ret = -ENOENT;
+unlock:
+	mutex_unlock(&rdtgroup_mutex);
+
+	return ret;
+}
+#endif
+
+static int rdt_last_cmd_status_show(struct kernfs_open_file *of,
+				    struct seq_file *seq, void *v)
+{
+	int len;
+
+	mutex_lock(&rdtgroup_mutex);
+	len = seq_buf_used(&last_cmd_status);
+	if (len)
+		seq_printf(seq, "%.*s", len, last_cmd_status_buf);
+	else
+		seq_puts(seq, "ok\n");
+	mutex_unlock(&rdtgroup_mutex);
+	return 0;
+}
+
+static void *rdt_kn_parent_priv(struct kernfs_node *kn)
+{
+	/*
+	 * The parent pointer is only valid within RCU section since it can be
+	 * replaced.
+	 */
+	guard(rcu)();
+	return rcu_dereference(kn->__parent)->priv;
+}
+
+static int rdt_num_closids_show(struct kernfs_open_file *of,
+				struct seq_file *seq, void *v)
+{
+	struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+
+	seq_printf(seq, "%u\n", s->num_closid);
+	return 0;
+}
+
+static int rdt_default_ctrl_show(struct kernfs_open_file *of,
+				 struct seq_file *seq, void *v)
+{
+	struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+	struct rdt_resource *r = s->res;
+
+	seq_printf(seq, "%x\n", resctrl_get_default_ctrl(r));
+	return 0;
+}
+
+static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
+				 struct seq_file *seq, void *v)
+{
+	struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+	struct rdt_resource *r = s->res;
+
+	seq_printf(seq, "%u\n", r->cache.min_cbm_bits);
+	return 0;
+}
+
+static int rdt_shareable_bits_show(struct kernfs_open_file *of,
+				   struct seq_file *seq, void *v)
+{
+	struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+	struct rdt_resource *r = s->res;
+
+	seq_printf(seq, "%x\n", r->cache.shareable_bits);
+	return 0;
+}
+
+/*
+ * rdt_bit_usage_show - Display current usage of resources
+ *
+ * A domain is a shared resource that can now be allocated differently. Here
+ * we display the current regions of the domain as an annotated bitmask.
+ * For each domain of this resource its allocation bitmask
+ * is annotated as below to indicate the current usage of the corresponding bit:
+ *   0 - currently unused
+ *   X - currently available for sharing and used by software and hardware
+ *   H - currently used by hardware only but available for software use
+ *   S - currently used and shareable by software only
+ *   E - currently used exclusively by one resource group
+ *   P - currently pseudo-locked by one resource group
+ */
+static int rdt_bit_usage_show(struct kernfs_open_file *of,
+			      struct seq_file *seq, void *v)
+{
+	struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+	/*
+	 * Use unsigned long even though only 32 bits are used to ensure
+	 * test_bit() is used safely.
+	 */
+	unsigned long sw_shareable = 0, hw_shareable = 0;
+	unsigned long exclusive = 0, pseudo_locked = 0;
+	struct rdt_resource *r = s->res;
+	struct rdt_ctrl_domain *dom;
+	int i, hwb, swb, excl, psl;
+	enum rdtgrp_mode mode;
+	bool sep = false;
+	u32 ctrl_val;
+
+	cpus_read_lock();
+	mutex_lock(&rdtgroup_mutex);
+	hw_shareable = r->cache.shareable_bits;
+	list_for_each_entry(dom, &r->ctrl_domains, hdr.list) {
+		if (sep)
+			seq_putc(seq, ';');
+		sw_shareable = 0;
+		exclusive = 0;
+		seq_printf(seq, "%d=", dom->hdr.id);
+		for (i = 0; i < closids_supported(); i++) {
+			if (!closid_allocated(i))
+				continue;
+			ctrl_val = resctrl_arch_get_config(r, dom, i,
+							   s->conf_type);
+			mode = rdtgroup_mode_by_closid(i);
+			switch (mode) {
+			case RDT_MODE_SHAREABLE:
+				sw_shareable |= ctrl_val;
+				break;
+			case RDT_MODE_EXCLUSIVE:
+				exclusive |= ctrl_val;
+				break;
+			case RDT_MODE_PSEUDO_LOCKSETUP:
+			/*
+			 * RDT_MODE_PSEUDO_LOCKSETUP is possible
+			 * here but not included since the CBM
+			 * associated with this CLOSID in this mode
+			 * is not initialized and no task or cpu can be
+			 * assigned this CLOSID.
+			 */
+				break;
+			case RDT_MODE_PSEUDO_LOCKED:
+			case RDT_NUM_MODES:
+				WARN(1,
+				     "invalid mode for closid %d\n", i);
+				break;
+			}
+		}
+		for (i = r->cache.cbm_len - 1; i >= 0; i--) {
+			pseudo_locked = dom->plr ? dom->plr->cbm : 0;
+			hwb = test_bit(i, &hw_shareable);
+			swb = test_bit(i, &sw_shareable);
+			excl = test_bit(i, &exclusive);
+			psl = test_bit(i, &pseudo_locked);
+			if (hwb && swb)
+				seq_putc(seq, 'X');
+			else if (hwb && !swb)
+				seq_putc(seq, 'H');
+			else if (!hwb && swb)
+				seq_putc(seq, 'S');
+			else if (excl)
+				seq_putc(seq, 'E');
+			else if (psl)
+				seq_putc(seq, 'P');
+			else /* Unused bits remain */
+				seq_putc(seq, '0');
+		}
+		sep = true;
+	}
+	seq_putc(seq, '\n');
+	mutex_unlock(&rdtgroup_mutex);
+	cpus_read_unlock();
+	return 0;
+}
+
+static int rdt_min_bw_show(struct kernfs_open_file *of,
+			   struct seq_file *seq, void *v)
+{
+	struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+	struct rdt_resource *r = s->res;
+
+	seq_printf(seq, "%u\n", r->membw.min_bw);
+	return 0;
+}
+
+static int rdt_num_rmids_show(struct kernfs_open_file *of,
+			      struct seq_file *seq, void *v)
+{
+	struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+
+	seq_printf(seq, "%d\n", r->num_rmid);
+
+	return 0;
+}
+
+static int rdt_mon_features_show(struct kernfs_open_file *of,
+				 struct seq_file *seq, void *v)
+{
+	struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+	struct mon_evt *mevt;
+
+	list_for_each_entry(mevt, &r->evt_list, list) {
+		seq_printf(seq, "%s\n", mevt->name);
+		if (mevt->configurable)
+			seq_printf(seq, "%s_config\n", mevt->name);
+	}
+
+	return 0;
+}
+
+static int rdt_bw_gran_show(struct kernfs_open_file *of,
+			    struct seq_file *seq, void *v)
+{
+	struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+	struct rdt_resource *r = s->res;
+
+	seq_printf(seq, "%u\n", r->membw.bw_gran);
+	return 0;
+}
+
+static int rdt_delay_linear_show(struct kernfs_open_file *of,
+				 struct seq_file *seq, void *v)
+{
+	struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+	struct rdt_resource *r = s->res;
+
+	seq_printf(seq, "%u\n", r->membw.delay_linear);
+	return 0;
+}
+
+static int max_threshold_occ_show(struct kernfs_open_file *of,
+				  struct seq_file *seq, void *v)
+{
+	seq_printf(seq, "%u\n", resctrl_rmid_realloc_threshold);
+
+	return 0;
+}
+
+static int rdt_thread_throttle_mode_show(struct kernfs_open_file *of,
+					 struct seq_file *seq, void *v)
+{
+	struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+	struct rdt_resource *r = s->res;
+
+	switch (r->membw.throttle_mode) {
+	case THREAD_THROTTLE_PER_THREAD:
+		seq_puts(seq, "per-thread\n");
+		return 0;
+	case THREAD_THROTTLE_MAX:
+		seq_puts(seq, "max\n");
+		return 0;
+	case THREAD_THROTTLE_UNDEFINED:
+		seq_puts(seq, "undefined\n");
+		return 0;
+	}
+
+	WARN_ON_ONCE(1);
+
+	return 0;
+}
+
+static ssize_t max_threshold_occ_write(struct kernfs_open_file *of,
+				       char *buf, size_t nbytes, loff_t off)
+{
+	unsigned int bytes;
+	int ret;
+
+	ret = kstrtouint(buf, 0, &bytes);
+	if (ret)
+		return ret;
+
+	if (bytes > resctrl_rmid_realloc_limit)
+		return -EINVAL;
+
+	resctrl_rmid_realloc_threshold = resctrl_arch_round_mon_val(bytes);
+
+	return nbytes;
+}
+
+/*
+ * rdtgroup_mode_show - Display mode of this resource group
+ */
+static int rdtgroup_mode_show(struct kernfs_open_file *of,
+			      struct seq_file *s, void *v)
+{
+	struct rdtgroup *rdtgrp;
+
+	rdtgrp = rdtgroup_kn_lock_live(of->kn);
+	if (!rdtgrp) {
+		rdtgroup_kn_unlock(of->kn);
+		return -ENOENT;
+	}
+
+	seq_printf(s, "%s\n", rdtgroup_mode_str(rdtgrp->mode));
+
+	rdtgroup_kn_unlock(of->kn);
+	return 0;
+}
+
+static enum resctrl_conf_type resctrl_peer_type(enum resctrl_conf_type my_type)
+{
+	switch (my_type) {
+	case CDP_CODE:
+		return CDP_DATA;
+	case CDP_DATA:
+		return CDP_CODE;
+	default:
+	case CDP_NONE:
+		return CDP_NONE;
+	}
+}
+
+static int rdt_has_sparse_bitmasks_show(struct kernfs_open_file *of,
+					struct seq_file *seq, void *v)
+{
+	struct resctrl_schema *s = rdt_kn_parent_priv(of->kn);
+	struct rdt_resource *r = s->res;
+
+	seq_printf(seq, "%u\n", r->cache.arch_has_sparse_bitmasks);
+
+	return 0;
+}
+
+/**
+ * __rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other
+ * @r: Resource to which domain instance @d belongs.
+ * @d: The domain instance for which @closid is being tested.
+ * @cbm: Capacity bitmask being tested.
+ * @closid: Intended closid for @cbm.
+ * @type: CDP type of @r.
+ * @exclusive: Only check if overlaps with exclusive resource groups
+ *
+ * Checks if provided @cbm intended to be used for @closid on domain
+ * @d overlaps with any other closids or other hardware usage associated
+ * with this domain. If @exclusive is true then only overlaps with
+ * resource groups in exclusive mode will be considered. If @exclusive
+ * is false then overlaps with any resource group or hardware entities
+ * will be considered.
+ *
+ * @cbm is unsigned long, even if only 32 bits are used, to make the
+ * bitmap functions work correctly.
+ *
+ * Return: false if CBM does not overlap, true if it does.
+ */
+static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_ctrl_domain *d,
+				    unsigned long cbm, int closid,
+				    enum resctrl_conf_type type, bool exclusive)
+{
+	enum rdtgrp_mode mode;
+	unsigned long ctrl_b;
+	int i;
+
+	/* Check for any overlap with regions used by hardware directly */
+	if (!exclusive) {
+		ctrl_b = r->cache.shareable_bits;
+		if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len))
+			return true;
+	}
+
+	/* Check for overlap with other resource groups */
+	for (i = 0; i < closids_supported(); i++) {
+		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) {
+			if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) {
+				if (exclusive) {
+					if (mode == RDT_MODE_EXCLUSIVE)
+						return true;
+					continue;
+				}
+				return true;
+			}
+		}
+	}
+
+	return false;
+}
+
+/**
+ * rdtgroup_cbm_overlaps - Does CBM overlap with other use of hardware
+ * @s: Schema for the resource to which domain instance @d belongs.
+ * @d: The domain instance for which @closid is being tested.
+ * @cbm: Capacity bitmask being tested.
+ * @closid: Intended closid for @cbm.
+ * @exclusive: Only check if overlaps with exclusive resource groups
+ *
+ * Resources that can be allocated using a CBM can use the CBM to control
+ * the overlap of these allocations. rdtgroup_cmb_overlaps() is the test
+ * for overlap. Overlap test is not limited to the specific resource for
+ * which the CBM is intended though - when dealing with CDP resources that
+ * share the underlying hardware the overlap check should be performed on
+ * the CDP resource sharing the hardware also.
+ *
+ * Refer to description of __rdtgroup_cbm_overlaps() for the details of the
+ * overlap test.
+ *
+ * Return: true if CBM overlap detected, false if there is no overlap
+ */
+bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_ctrl_domain *d,
+			   unsigned long cbm, int closid, bool exclusive)
+{
+	enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type);
+	struct rdt_resource *r = s->res;
+
+	if (__rdtgroup_cbm_overlaps(r, d, cbm, closid, s->conf_type,
+				    exclusive))
+		return true;
+
+	if (!resctrl_arch_get_cdp_enabled(r->rid))
+		return false;
+	return  __rdtgroup_cbm_overlaps(r, d, cbm, closid, peer_type, exclusive);
+}
+
+/**
+ * rdtgroup_mode_test_exclusive - Test if this resource group can be exclusive
+ * @rdtgrp: Resource group identified through its closid.
+ *
+ * An exclusive resource group implies that there should be no sharing of
+ * its allocated resources. At the time this group is considered to be
+ * exclusive this test can determine if its current schemata supports this
+ * setting by testing for overlap with all other resource groups.
+ *
+ * Return: true if resource group can be exclusive, false if there is overlap
+ * with allocations of other resource groups and thus this resource group
+ * cannot be exclusive.
+ */
+static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp)
+{
+	int closid = rdtgrp->closid;
+	struct rdt_ctrl_domain *d;
+	struct resctrl_schema *s;
+	struct rdt_resource *r;
+	bool has_cache = false;
+	u32 ctrl;
+
+	/* Walking r->domains, ensure it can't race with cpuhp */
+	lockdep_assert_cpus_held();
+
+	list_for_each_entry(s, &resctrl_schema_all, list) {
+		r = s->res;
+		if (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA)
+			continue;
+		has_cache = true;
+		list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
+			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;
+			}
+		}
+	}
+
+	if (!has_cache) {
+		rdt_last_cmd_puts("Cannot be exclusive without CAT/CDP\n");
+		return false;
+	}
+
+	return true;
+}
+
+/*
+ * rdtgroup_mode_write - Modify the resource group's mode
+ */
+static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of,
+				   char *buf, size_t nbytes, loff_t off)
+{
+	struct rdtgroup *rdtgrp;
+	enum rdtgrp_mode mode;
+	int ret = 0;
+
+	/* Valid input requires a trailing newline */
+	if (nbytes == 0 || buf[nbytes - 1] != '\n')
+		return -EINVAL;
+	buf[nbytes - 1] = '\0';
+
+	rdtgrp = rdtgroup_kn_lock_live(of->kn);
+	if (!rdtgrp) {
+		rdtgroup_kn_unlock(of->kn);
+		return -ENOENT;
+	}
+
+	rdt_last_cmd_clear();
+
+	mode = rdtgrp->mode;
+
+	if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) ||
+	    (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE) ||
+	    (!strcmp(buf, "pseudo-locksetup") &&
+	     mode == RDT_MODE_PSEUDO_LOCKSETUP) ||
+	    (!strcmp(buf, "pseudo-locked") && mode == RDT_MODE_PSEUDO_LOCKED))
+		goto out;
+
+	if (mode == RDT_MODE_PSEUDO_LOCKED) {
+		rdt_last_cmd_puts("Cannot change pseudo-locked group\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (!strcmp(buf, "shareable")) {
+		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+			ret = rdtgroup_locksetup_exit(rdtgrp);
+			if (ret)
+				goto out;
+		}
+		rdtgrp->mode = RDT_MODE_SHAREABLE;
+	} else if (!strcmp(buf, "exclusive")) {
+		if (!rdtgroup_mode_test_exclusive(rdtgrp)) {
+			ret = -EINVAL;
+			goto out;
+		}
+		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+			ret = rdtgroup_locksetup_exit(rdtgrp);
+			if (ret)
+				goto out;
+		}
+		rdtgrp->mode = RDT_MODE_EXCLUSIVE;
+	} else if (IS_ENABLED(CONFIG_RESCTRL_FS_PSEUDO_LOCK) &&
+		   !strcmp(buf, "pseudo-locksetup")) {
+		ret = rdtgroup_locksetup_enter(rdtgrp);
+		if (ret)
+			goto out;
+		rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP;
+	} else {
+		rdt_last_cmd_puts("Unknown or unsupported mode\n");
+		ret = -EINVAL;
+	}
+
+out:
+	rdtgroup_kn_unlock(of->kn);
+	return ret ?: nbytes;
+}
+
+/**
+ * rdtgroup_cbm_to_size - Translate CBM to size in bytes
+ * @r: RDT resource to which @d belongs.
+ * @d: RDT domain instance.
+ * @cbm: bitmask for which the size should be computed.
+ *
+ * The bitmask provided associated with the RDT domain instance @d will be
+ * translated into how many bytes it represents. The size in bytes is
+ * computed by first dividing the total cache size by the CBM length to
+ * determine how many bytes each bit in the bitmask represents. The result
+ * is multiplied with the number of bits set in the bitmask.
+ *
+ * @cbm is unsigned long, even if only 32 bits are used to make the
+ * bitmap functions work correctly.
+ */
+unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r,
+				  struct rdt_ctrl_domain *d, unsigned long cbm)
+{
+	unsigned int size = 0;
+	struct cacheinfo *ci;
+	int num_b;
+
+	if (WARN_ON_ONCE(r->ctrl_scope != RESCTRL_L2_CACHE && r->ctrl_scope != RESCTRL_L3_CACHE))
+		return size;
+
+	num_b = bitmap_weight(&cbm, r->cache.cbm_len);
+	ci = get_cpu_cacheinfo_level(cpumask_any(&d->hdr.cpu_mask), r->ctrl_scope);
+	if (ci)
+		size = ci->size / r->cache.cbm_len * num_b;
+
+	return size;
+}
+
+bool is_mba_sc(struct rdt_resource *r)
+{
+	if (!r)
+		r = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
+
+	/*
+	 * The software controller support is only applicable to MBA resource.
+	 * Make sure to check for resource type.
+	 */
+	if (r->rid != RDT_RESOURCE_MBA)
+		return false;
+
+	return r->membw.mba_sc;
+}
+
+/*
+ * rdtgroup_size_show - Display size in bytes of allocated regions
+ *
+ * The "size" file mirrors the layout of the "schemata" file, printing the
+ * size in bytes of each region instead of the capacity bitmask.
+ */
+static int rdtgroup_size_show(struct kernfs_open_file *of,
+			      struct seq_file *s, void *v)
+{
+	struct resctrl_schema *schema;
+	enum resctrl_conf_type type;
+	struct rdt_ctrl_domain *d;
+	struct rdtgroup *rdtgrp;
+	struct rdt_resource *r;
+	unsigned int size;
+	int ret = 0;
+	u32 closid;
+	bool sep;
+	u32 ctrl;
+
+	rdtgrp = rdtgroup_kn_lock_live(of->kn);
+	if (!rdtgrp) {
+		rdtgroup_kn_unlock(of->kn);
+		return -ENOENT;
+	}
+
+	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
+		if (!rdtgrp->plr->d) {
+			rdt_last_cmd_clear();
+			rdt_last_cmd_puts("Cache domain offline\n");
+			ret = -ENODEV;
+		} else {
+			seq_printf(s, "%*s:", max_name_width,
+				   rdtgrp->plr->s->name);
+			size = rdtgroup_cbm_to_size(rdtgrp->plr->s->res,
+						    rdtgrp->plr->d,
+						    rdtgrp->plr->cbm);
+			seq_printf(s, "%d=%u\n", rdtgrp->plr->d->hdr.id, size);
+		}
+		goto out;
+	}
+
+	closid = rdtgrp->closid;
+
+	list_for_each_entry(schema, &resctrl_schema_all, list) {
+		r = schema->res;
+		type = schema->conf_type;
+		sep = false;
+		seq_printf(s, "%*s:", max_name_width, schema->name);
+		list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
+			if (sep)
+				seq_putc(s, ';');
+			if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
+				size = 0;
+			} else {
+				if (is_mba_sc(r))
+					ctrl = d->mbps_val[closid];
+				else
+					ctrl = resctrl_arch_get_config(r, d,
+								       closid,
+								       type);
+				if (r->rid == RDT_RESOURCE_MBA ||
+				    r->rid == RDT_RESOURCE_SMBA)
+					size = ctrl;
+				else
+					size = rdtgroup_cbm_to_size(r, d, ctrl);
+			}
+			seq_printf(s, "%d=%u", d->hdr.id, size);
+			sep = true;
+		}
+		seq_putc(s, '\n');
+	}
+
+out:
+	rdtgroup_kn_unlock(of->kn);
+
+	return ret;
+}
+
+static void mondata_config_read(struct resctrl_mon_config_info *mon_info)
+{
+	smp_call_function_any(&mon_info->d->hdr.cpu_mask,
+			      resctrl_arch_mon_event_config_read, mon_info, 1);
+}
+
+static int mbm_config_show(struct seq_file *s, struct rdt_resource *r, u32 evtid)
+{
+	struct resctrl_mon_config_info mon_info;
+	struct rdt_mon_domain *dom;
+	bool sep = false;
+
+	cpus_read_lock();
+	mutex_lock(&rdtgroup_mutex);
+
+	list_for_each_entry(dom, &r->mon_domains, hdr.list) {
+		if (sep)
+			seq_puts(s, ";");
+
+		memset(&mon_info, 0, sizeof(struct resctrl_mon_config_info));
+		mon_info.r = r;
+		mon_info.d = dom;
+		mon_info.evtid = evtid;
+		mondata_config_read(&mon_info);
+
+		seq_printf(s, "%d=0x%02x", dom->hdr.id, mon_info.mon_config);
+		sep = true;
+	}
+	seq_puts(s, "\n");
+
+	mutex_unlock(&rdtgroup_mutex);
+	cpus_read_unlock();
+
+	return 0;
+}
+
+static int mbm_total_bytes_config_show(struct kernfs_open_file *of,
+				       struct seq_file *seq, void *v)
+{
+	struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+
+	mbm_config_show(seq, r, QOS_L3_MBM_TOTAL_EVENT_ID);
+
+	return 0;
+}
+
+static int mbm_local_bytes_config_show(struct kernfs_open_file *of,
+				       struct seq_file *seq, void *v)
+{
+	struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+
+	mbm_config_show(seq, r, QOS_L3_MBM_LOCAL_EVENT_ID);
+
+	return 0;
+}
+
+static void mbm_config_write_domain(struct rdt_resource *r,
+				    struct rdt_mon_domain *d, u32 evtid, u32 val)
+{
+	struct resctrl_mon_config_info mon_info = {0};
+
+	/*
+	 * Read the current config value first. If both are the same then
+	 * no need to write it again.
+	 */
+	mon_info.r = r;
+	mon_info.d = d;
+	mon_info.evtid = evtid;
+	mondata_config_read(&mon_info);
+	if (mon_info.mon_config == val)
+		return;
+
+	mon_info.mon_config = val;
+
+	/*
+	 * Update MSR_IA32_EVT_CFG_BASE MSR on one of the CPUs in the
+	 * domain. The MSRs offset from MSR MSR_IA32_EVT_CFG_BASE
+	 * are scoped at the domain level. Writing any of these MSRs
+	 * on one CPU is observed by all the CPUs in the domain.
+	 */
+	smp_call_function_any(&d->hdr.cpu_mask, resctrl_arch_mon_event_config_write,
+			      &mon_info, 1);
+
+	/*
+	 * When an Event Configuration is changed, the bandwidth counters
+	 * for all RMIDs and Events will be cleared by the hardware. The
+	 * hardware also sets MSR_IA32_QM_CTR.Unavailable (bit 62) for
+	 * every RMID on the next read to any event for every RMID.
+	 * Subsequent reads will have MSR_IA32_QM_CTR.Unavailable (bit 62)
+	 * cleared while it is tracked by the hardware. Clear the
+	 * mbm_local and mbm_total counts for all the RMIDs.
+	 */
+	resctrl_arch_reset_rmid_all(r, d);
+}
+
+static int mon_config_write(struct rdt_resource *r, char *tok, u32 evtid)
+{
+	char *dom_str = NULL, *id_str;
+	unsigned long dom_id, val;
+	struct rdt_mon_domain *d;
+
+	/* Walking r->domains, ensure it can't race with cpuhp */
+	lockdep_assert_cpus_held();
+
+next:
+	if (!tok || tok[0] == '\0')
+		return 0;
+
+	/* Start processing the strings for each domain */
+	dom_str = strim(strsep(&tok, ";"));
+	id_str = strsep(&dom_str, "=");
+
+	if (!id_str || kstrtoul(id_str, 10, &dom_id)) {
+		rdt_last_cmd_puts("Missing '=' or non-numeric domain id\n");
+		return -EINVAL;
+	}
+
+	if (!dom_str || kstrtoul(dom_str, 16, &val)) {
+		rdt_last_cmd_puts("Non-numeric event configuration value\n");
+		return -EINVAL;
+	}
+
+	/* Value from user cannot be more than the supported set of events */
+	if ((val & r->mbm_cfg_mask) != val) {
+		rdt_last_cmd_printf("Invalid event configuration: max valid mask is 0x%02x\n",
+				    r->mbm_cfg_mask);
+		return -EINVAL;
+	}
+
+	list_for_each_entry(d, &r->mon_domains, hdr.list) {
+		if (d->hdr.id == dom_id) {
+			mbm_config_write_domain(r, d, evtid, val);
+			goto next;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static ssize_t mbm_total_bytes_config_write(struct kernfs_open_file *of,
+					    char *buf, size_t nbytes,
+					    loff_t off)
+{
+	struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+	int ret;
+
+	/* Valid input requires a trailing newline */
+	if (nbytes == 0 || buf[nbytes - 1] != '\n')
+		return -EINVAL;
+
+	cpus_read_lock();
+	mutex_lock(&rdtgroup_mutex);
+
+	rdt_last_cmd_clear();
+
+	buf[nbytes - 1] = '\0';
+
+	ret = mon_config_write(r, buf, QOS_L3_MBM_TOTAL_EVENT_ID);
+
+	mutex_unlock(&rdtgroup_mutex);
+	cpus_read_unlock();
+
+	return ret ?: nbytes;
+}
+
+static ssize_t mbm_local_bytes_config_write(struct kernfs_open_file *of,
+					    char *buf, size_t nbytes,
+					    loff_t off)
+{
+	struct rdt_resource *r = rdt_kn_parent_priv(of->kn);
+	int ret;
+
+	/* Valid input requires a trailing newline */
+	if (nbytes == 0 || buf[nbytes - 1] != '\n')
+		return -EINVAL;
+
+	cpus_read_lock();
+	mutex_lock(&rdtgroup_mutex);
+
+	rdt_last_cmd_clear();
+
+	buf[nbytes - 1] = '\0';
+
+	ret = mon_config_write(r, buf, QOS_L3_MBM_LOCAL_EVENT_ID);
+
+	mutex_unlock(&rdtgroup_mutex);
+	cpus_read_unlock();
+
+	return ret ?: nbytes;
+}
+
+/* rdtgroup information files for one cache resource. */
+static struct rftype res_common_files[] = {
+	{
+		.name		= "last_cmd_status",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_last_cmd_status_show,
+		.fflags		= RFTYPE_TOP_INFO,
+	},
+	{
+		.name		= "num_closids",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_num_closids_show,
+		.fflags		= RFTYPE_CTRL_INFO,
+	},
+	{
+		.name		= "mon_features",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_mon_features_show,
+		.fflags		= RFTYPE_MON_INFO,
+	},
+	{
+		.name		= "num_rmids",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_num_rmids_show,
+		.fflags		= RFTYPE_MON_INFO,
+	},
+	{
+		.name		= "cbm_mask",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_default_ctrl_show,
+		.fflags		= RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
+	},
+	{
+		.name		= "min_cbm_bits",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_min_cbm_bits_show,
+		.fflags		= RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
+	},
+	{
+		.name		= "shareable_bits",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_shareable_bits_show,
+		.fflags		= RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
+	},
+	{
+		.name		= "bit_usage",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_bit_usage_show,
+		.fflags		= RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
+	},
+	{
+		.name		= "min_bandwidth",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_min_bw_show,
+		.fflags		= RFTYPE_CTRL_INFO | RFTYPE_RES_MB,
+	},
+	{
+		.name		= "bandwidth_gran",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_bw_gran_show,
+		.fflags		= RFTYPE_CTRL_INFO | RFTYPE_RES_MB,
+	},
+	{
+		.name		= "delay_linear",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_delay_linear_show,
+		.fflags		= RFTYPE_CTRL_INFO | RFTYPE_RES_MB,
+	},
+	/*
+	 * Platform specific which (if any) capabilities are provided by
+	 * thread_throttle_mode. Defer "fflags" initialization to platform
+	 * discovery.
+	 */
+	{
+		.name		= "thread_throttle_mode",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_thread_throttle_mode_show,
+	},
+	{
+		.name		= "max_threshold_occupancy",
+		.mode		= 0644,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.write		= max_threshold_occ_write,
+		.seq_show	= max_threshold_occ_show,
+		.fflags		= RFTYPE_MON_INFO | RFTYPE_RES_CACHE,
+	},
+	{
+		.name		= "mbm_total_bytes_config",
+		.mode		= 0644,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= mbm_total_bytes_config_show,
+		.write		= mbm_total_bytes_config_write,
+	},
+	{
+		.name		= "mbm_local_bytes_config",
+		.mode		= 0644,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= mbm_local_bytes_config_show,
+		.write		= mbm_local_bytes_config_write,
+	},
+	{
+		.name		= "cpus",
+		.mode		= 0644,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.write		= rdtgroup_cpus_write,
+		.seq_show	= rdtgroup_cpus_show,
+		.fflags		= RFTYPE_BASE,
+	},
+	{
+		.name		= "cpus_list",
+		.mode		= 0644,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.write		= rdtgroup_cpus_write,
+		.seq_show	= rdtgroup_cpus_show,
+		.flags		= RFTYPE_FLAGS_CPUS_LIST,
+		.fflags		= RFTYPE_BASE,
+	},
+	{
+		.name		= "tasks",
+		.mode		= 0644,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.write		= rdtgroup_tasks_write,
+		.seq_show	= rdtgroup_tasks_show,
+		.fflags		= RFTYPE_BASE,
+	},
+	{
+		.name		= "mon_hw_id",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdtgroup_rmid_show,
+		.fflags		= RFTYPE_MON_BASE | RFTYPE_DEBUG,
+	},
+	{
+		.name		= "schemata",
+		.mode		= 0644,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.write		= rdtgroup_schemata_write,
+		.seq_show	= rdtgroup_schemata_show,
+		.fflags		= RFTYPE_CTRL_BASE,
+	},
+	{
+		.name		= "mba_MBps_event",
+		.mode		= 0644,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.write		= rdtgroup_mba_mbps_event_write,
+		.seq_show	= rdtgroup_mba_mbps_event_show,
+	},
+	{
+		.name		= "mode",
+		.mode		= 0644,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.write		= rdtgroup_mode_write,
+		.seq_show	= rdtgroup_mode_show,
+		.fflags		= RFTYPE_CTRL_BASE,
+	},
+	{
+		.name		= "size",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdtgroup_size_show,
+		.fflags		= RFTYPE_CTRL_BASE,
+	},
+	{
+		.name		= "sparse_masks",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_has_sparse_bitmasks_show,
+		.fflags		= RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
+	},
+	{
+		.name		= "ctrl_hw_id",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdtgroup_closid_show,
+		.fflags		= RFTYPE_CTRL_BASE | RFTYPE_DEBUG,
+	},
+};
+
+static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags)
+{
+	struct rftype *rfts, *rft;
+	int ret, len;
+
+	rfts = res_common_files;
+	len = ARRAY_SIZE(res_common_files);
+
+	lockdep_assert_held(&rdtgroup_mutex);
+
+	if (resctrl_debug)
+		fflags |= RFTYPE_DEBUG;
+
+	for (rft = rfts; rft < rfts + len; rft++) {
+		if (rft->fflags && ((fflags & rft->fflags) == rft->fflags)) {
+			ret = rdtgroup_add_file(kn, rft);
+			if (ret)
+				goto error;
+		}
+	}
+
+	return 0;
+error:
+	pr_warn("Failed to add %s, err=%d\n", rft->name, ret);
+	while (--rft >= rfts) {
+		if ((fflags & rft->fflags) == rft->fflags)
+			kernfs_remove_by_name(kn, rft->name);
+	}
+	return ret;
+}
+
+static struct rftype *rdtgroup_get_rftype_by_name(const char *name)
+{
+	struct rftype *rfts, *rft;
+	int len;
+
+	rfts = res_common_files;
+	len = ARRAY_SIZE(res_common_files);
+
+	for (rft = rfts; rft < rfts + len; rft++) {
+		if (!strcmp(rft->name, name))
+			return rft;
+	}
+
+	return NULL;
+}
+
+static void thread_throttle_mode_init(void)
+{
+	enum membw_throttle_mode throttle_mode = THREAD_THROTTLE_UNDEFINED;
+	struct rdt_resource *r_mba, *r_smba;
+
+	r_mba = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
+	if (r_mba->alloc_capable &&
+	    r_mba->membw.throttle_mode != THREAD_THROTTLE_UNDEFINED)
+		throttle_mode = r_mba->membw.throttle_mode;
+
+	r_smba = resctrl_arch_get_resource(RDT_RESOURCE_SMBA);
+	if (r_smba->alloc_capable &&
+	    r_smba->membw.throttle_mode != THREAD_THROTTLE_UNDEFINED)
+		throttle_mode = r_smba->membw.throttle_mode;
+
+	if (throttle_mode == THREAD_THROTTLE_UNDEFINED)
+		return;
+
+	resctrl_file_fflags_init("thread_throttle_mode",
+				 RFTYPE_CTRL_INFO | RFTYPE_RES_MB);
+}
+
+void resctrl_file_fflags_init(const char *config, unsigned long fflags)
+{
+	struct rftype *rft;
+
+	rft = rdtgroup_get_rftype_by_name(config);
+	if (rft)
+		rft->fflags = fflags;
+}
+
+/**
+ * rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file
+ * @r: The resource group with which the file is associated.
+ * @name: Name of the file
+ *
+ * The permissions of named resctrl file, directory, or link are modified
+ * to not allow read, write, or execute by any user.
+ *
+ * WARNING: This function is intended to communicate to the user that the
+ * resctrl file has been locked down - that it is not relevant to the
+ * particular state the system finds itself in. It should not be relied
+ * on to protect from user access because after the file's permissions
+ * are restricted the user can still change the permissions using chmod
+ * from the command line.
+ *
+ * Return: 0 on success, <0 on failure.
+ */
+int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name)
+{
+	struct iattr iattr = {.ia_valid = ATTR_MODE,};
+	struct kernfs_node *kn;
+	int ret = 0;
+
+	kn = kernfs_find_and_get_ns(r->kn, name, NULL);
+	if (!kn)
+		return -ENOENT;
+
+	switch (kernfs_type(kn)) {
+	case KERNFS_DIR:
+		iattr.ia_mode = S_IFDIR;
+		break;
+	case KERNFS_FILE:
+		iattr.ia_mode = S_IFREG;
+		break;
+	case KERNFS_LINK:
+		iattr.ia_mode = S_IFLNK;
+		break;
+	}
+
+	ret = kernfs_setattr(kn, &iattr);
+	kernfs_put(kn);
+	return ret;
+}
+
+/**
+ * rdtgroup_kn_mode_restore - Restore user access to named resctrl file
+ * @r: The resource group with which the file is associated.
+ * @name: Name of the file
+ * @mask: Mask of permissions that should be restored
+ *
+ * Restore the permissions of the named file. If @name is a directory the
+ * permissions of its parent will be used.
+ *
+ * Return: 0 on success, <0 on failure.
+ */
+int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name,
+			     umode_t mask)
+{
+	struct iattr iattr = {.ia_valid = ATTR_MODE,};
+	struct kernfs_node *kn, *parent;
+	struct rftype *rfts, *rft;
+	int ret, len;
+
+	rfts = res_common_files;
+	len = ARRAY_SIZE(res_common_files);
+
+	for (rft = rfts; rft < rfts + len; rft++) {
+		if (!strcmp(rft->name, name))
+			iattr.ia_mode = rft->mode & mask;
+	}
+
+	kn = kernfs_find_and_get_ns(r->kn, name, NULL);
+	if (!kn)
+		return -ENOENT;
+
+	switch (kernfs_type(kn)) {
+	case KERNFS_DIR:
+		parent = kernfs_get_parent(kn);
+		if (parent) {
+			iattr.ia_mode |= parent->mode;
+			kernfs_put(parent);
+		}
+		iattr.ia_mode |= S_IFDIR;
+		break;
+	case KERNFS_FILE:
+		iattr.ia_mode |= S_IFREG;
+		break;
+	case KERNFS_LINK:
+		iattr.ia_mode |= S_IFLNK;
+		break;
+	}
+
+	ret = kernfs_setattr(kn, &iattr);
+	kernfs_put(kn);
+	return ret;
+}
+
+static int rdtgroup_mkdir_info_resdir(void *priv, char *name,
+				      unsigned long fflags)
+{
+	struct kernfs_node *kn_subdir;
+	int ret;
+
+	kn_subdir = kernfs_create_dir(kn_info, name,
+				      kn_info->mode, priv);
+	if (IS_ERR(kn_subdir))
+		return PTR_ERR(kn_subdir);
+
+	ret = rdtgroup_kn_set_ugid(kn_subdir);
+	if (ret)
+		return ret;
+
+	ret = rdtgroup_add_files(kn_subdir, fflags);
+	if (!ret)
+		kernfs_activate(kn_subdir);
+
+	return ret;
+}
+
+static unsigned long fflags_from_resource(struct rdt_resource *r)
+{
+	switch (r->rid) {
+	case RDT_RESOURCE_L3:
+	case RDT_RESOURCE_L2:
+		return RFTYPE_RES_CACHE;
+	case RDT_RESOURCE_MBA:
+	case RDT_RESOURCE_SMBA:
+		return RFTYPE_RES_MB;
+	}
+
+	return WARN_ON_ONCE(1);
+}
+
+static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
+{
+	struct resctrl_schema *s;
+	struct rdt_resource *r;
+	unsigned long fflags;
+	char name[32];
+	int ret;
+
+	/* create the directory */
+	kn_info = kernfs_create_dir(parent_kn, "info", parent_kn->mode, NULL);
+	if (IS_ERR(kn_info))
+		return PTR_ERR(kn_info);
+
+	ret = rdtgroup_add_files(kn_info, RFTYPE_TOP_INFO);
+	if (ret)
+		goto out_destroy;
+
+	/* loop over enabled controls, these are all alloc_capable */
+	list_for_each_entry(s, &resctrl_schema_all, list) {
+		r = s->res;
+		fflags = fflags_from_resource(r) | RFTYPE_CTRL_INFO;
+		ret = rdtgroup_mkdir_info_resdir(s, s->name, fflags);
+		if (ret)
+			goto out_destroy;
+	}
+
+	for_each_mon_capable_rdt_resource(r) {
+		fflags = fflags_from_resource(r) | RFTYPE_MON_INFO;
+		sprintf(name, "%s_MON", r->name);
+		ret = rdtgroup_mkdir_info_resdir(r, name, fflags);
+		if (ret)
+			goto out_destroy;
+	}
+
+	ret = rdtgroup_kn_set_ugid(kn_info);
+	if (ret)
+		goto out_destroy;
+
+	kernfs_activate(kn_info);
+
+	return 0;
+
+out_destroy:
+	kernfs_remove(kn_info);
+	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;
+
+	ret = rdtgroup_kn_set_ugid(kn);
+	if (ret)
+		goto out_destroy;
+
+	kernfs_activate(kn);
+
+	return 0;
+
+out_destroy:
+	kernfs_remove(kn);
+	return ret;
+}
+
+static inline bool is_mba_linear(void)
+{
+	return resctrl_arch_get_resource(RDT_RESOURCE_MBA)->membw.delay_linear;
+}
+
+static int mba_sc_domain_allocate(struct rdt_resource *r, struct rdt_ctrl_domain *d)
+{
+	u32 num_closid = resctrl_arch_get_num_closid(r);
+	int cpu = cpumask_any(&d->hdr.cpu_mask);
+	int i;
+
+	d->mbps_val = kcalloc_node(num_closid, sizeof(*d->mbps_val),
+				   GFP_KERNEL, cpu_to_node(cpu));
+	if (!d->mbps_val)
+		return -ENOMEM;
+
+	for (i = 0; i < num_closid; i++)
+		d->mbps_val[i] = MBA_MAX_MBPS;
+
+	return 0;
+}
+
+static void mba_sc_domain_destroy(struct rdt_resource *r,
+				  struct rdt_ctrl_domain *d)
+{
+	kfree(d->mbps_val);
+	d->mbps_val = NULL;
+}
+
+/*
+ * MBA software controller is supported only if
+ * MBM is supported and MBA is in linear scale,
+ * and the MBM monitor scope is the same as MBA
+ * control scope.
+ */
+static bool supports_mba_mbps(void)
+{
+	struct rdt_resource *rmbm = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+	struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
+
+	return (resctrl_is_mbm_enabled() &&
+		r->alloc_capable && is_mba_linear() &&
+		r->ctrl_scope == rmbm->mon_scope);
+}
+
+/*
+ * Enable or disable the MBA software controller
+ * which helps user specify bandwidth in MBps.
+ */
+static int set_mba_sc(bool mba_sc)
+{
+	struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_MBA);
+	u32 num_closid = resctrl_arch_get_num_closid(r);
+	struct rdt_ctrl_domain *d;
+	unsigned long fflags;
+	int i;
+
+	if (!supports_mba_mbps() || mba_sc == is_mba_sc(r))
+		return -EINVAL;
+
+	r->membw.mba_sc = mba_sc;
+
+	rdtgroup_default.mba_mbps_event = mba_mbps_default_event;
+
+	list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
+		for (i = 0; i < num_closid; i++)
+			d->mbps_val[i] = MBA_MAX_MBPS;
+	}
+
+	fflags = mba_sc ? RFTYPE_CTRL_BASE | RFTYPE_MON_BASE : 0;
+	resctrl_file_fflags_init("mba_MBps_event", fflags);
+
+	return 0;
+}
+
+/*
+ * We don't allow rdtgroup directories to be created anywhere
+ * except the root directory. Thus when looking for the rdtgroup
+ * structure for a kernfs node we are either looking at a directory,
+ * in which case the rdtgroup structure is pointed at by the "priv"
+ * field, otherwise we have a file, and need only look to the parent
+ * to find the rdtgroup.
+ */
+static struct rdtgroup *kernfs_to_rdtgroup(struct kernfs_node *kn)
+{
+	if (kernfs_type(kn) == KERNFS_DIR) {
+		/*
+		 * All the resource directories use "kn->priv"
+		 * to point to the "struct rdtgroup" for the
+		 * resource. "info" and its subdirectories don't
+		 * have rdtgroup structures, so return NULL here.
+		 */
+		if (kn == kn_info ||
+		    rcu_access_pointer(kn->__parent) == kn_info)
+			return NULL;
+		else
+			return kn->priv;
+	} else {
+		return rdt_kn_parent_priv(kn);
+	}
+}
+
+static void rdtgroup_kn_get(struct rdtgroup *rdtgrp, struct kernfs_node *kn)
+{
+	atomic_inc(&rdtgrp->waitcount);
+	kernfs_break_active_protection(kn);
+}
+
+static void rdtgroup_kn_put(struct rdtgroup *rdtgrp, struct kernfs_node *kn)
+{
+	if (atomic_dec_and_test(&rdtgrp->waitcount) &&
+	    (rdtgrp->flags & RDT_DELETED)) {
+		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
+		    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
+			rdtgroup_pseudo_lock_remove(rdtgrp);
+		kernfs_unbreak_active_protection(kn);
+		rdtgroup_remove(rdtgrp);
+	} else {
+		kernfs_unbreak_active_protection(kn);
+	}
+}
+
+struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn)
+{
+	struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn);
+
+	if (!rdtgrp)
+		return NULL;
+
+	rdtgroup_kn_get(rdtgrp, kn);
+
+	cpus_read_lock();
+	mutex_lock(&rdtgroup_mutex);
+
+	/* Was this group deleted while we waited? */
+	if (rdtgrp->flags & RDT_DELETED)
+		return NULL;
+
+	return rdtgrp;
+}
+
+void rdtgroup_kn_unlock(struct kernfs_node *kn)
+{
+	struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn);
+
+	if (!rdtgrp)
+		return;
+
+	mutex_unlock(&rdtgroup_mutex);
+	cpus_read_unlock();
+
+	rdtgroup_kn_put(rdtgrp, kn);
+}
+
+static int mkdir_mondata_all(struct kernfs_node *parent_kn,
+			     struct rdtgroup *prgrp,
+			     struct kernfs_node **mon_data_kn);
+
+static void rdt_disable_ctx(void)
+{
+	resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);
+	resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);
+	set_mba_sc(false);
+
+	resctrl_debug = false;
+}
+
+static int rdt_enable_ctx(struct rdt_fs_context *ctx)
+{
+	int ret = 0;
+
+	if (ctx->enable_cdpl2) {
+		ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, true);
+		if (ret)
+			goto out_done;
+	}
+
+	if (ctx->enable_cdpl3) {
+		ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, true);
+		if (ret)
+			goto out_cdpl2;
+	}
+
+	if (ctx->enable_mba_mbps) {
+		ret = set_mba_sc(true);
+		if (ret)
+			goto out_cdpl3;
+	}
+
+	if (ctx->enable_debug)
+		resctrl_debug = true;
+
+	return 0;
+
+out_cdpl3:
+	resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);
+out_cdpl2:
+	resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);
+out_done:
+	return ret;
+}
+
+static int schemata_list_add(struct rdt_resource *r, enum resctrl_conf_type type)
+{
+	struct resctrl_schema *s;
+	const char *suffix = "";
+	int ret, cl;
+
+	s = kzalloc(sizeof(*s), GFP_KERNEL);
+	if (!s)
+		return -ENOMEM;
+
+	s->res = r;
+	s->num_closid = resctrl_arch_get_num_closid(r);
+	if (resctrl_arch_get_cdp_enabled(r->rid))
+		s->num_closid /= 2;
+
+	s->conf_type = type;
+	switch (type) {
+	case CDP_CODE:
+		suffix = "CODE";
+		break;
+	case CDP_DATA:
+		suffix = "DATA";
+		break;
+	case CDP_NONE:
+		suffix = "";
+		break;
+	}
+
+	ret = snprintf(s->name, sizeof(s->name), "%s%s", r->name, suffix);
+	if (ret >= sizeof(s->name)) {
+		kfree(s);
+		return -EINVAL;
+	}
+
+	cl = strlen(s->name);
+
+	/*
+	 * If CDP is supported by this resource, but not enabled,
+	 * include the suffix. This ensures the tabular format of the
+	 * schemata file does not change between mounts of the filesystem.
+	 */
+	if (r->cdp_capable && !resctrl_arch_get_cdp_enabled(r->rid))
+		cl += 4;
+
+	if (cl > max_name_width)
+		max_name_width = cl;
+
+	switch (r->schema_fmt) {
+	case RESCTRL_SCHEMA_BITMAP:
+		s->fmt_str = "%d=%x";
+		break;
+	case RESCTRL_SCHEMA_RANGE:
+		s->fmt_str = "%d=%u";
+		break;
+	}
+
+	if (WARN_ON_ONCE(!s->fmt_str)) {
+		kfree(s);
+		return -EINVAL;
+	}
+
+	INIT_LIST_HEAD(&s->list);
+	list_add(&s->list, &resctrl_schema_all);
+
+	return 0;
+}
+
+static int schemata_list_create(void)
+{
+	struct rdt_resource *r;
+	int ret = 0;
+
+	for_each_alloc_capable_rdt_resource(r) {
+		if (resctrl_arch_get_cdp_enabled(r->rid)) {
+			ret = schemata_list_add(r, CDP_CODE);
+			if (ret)
+				break;
+
+			ret = schemata_list_add(r, CDP_DATA);
+		} else {
+			ret = schemata_list_add(r, CDP_NONE);
+		}
+
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
+static void schemata_list_destroy(void)
+{
+	struct resctrl_schema *s, *tmp;
+
+	list_for_each_entry_safe(s, tmp, &resctrl_schema_all, list) {
+		list_del(&s->list);
+		kfree(s);
+	}
+}
+
+static int rdt_get_tree(struct fs_context *fc)
+{
+	struct rdt_fs_context *ctx = rdt_fc2context(fc);
+	unsigned long flags = RFTYPE_CTRL_BASE;
+	struct rdt_mon_domain *dom;
+	struct rdt_resource *r;
+	int ret;
+
+	cpus_read_lock();
+	mutex_lock(&rdtgroup_mutex);
+	/*
+	 * resctrl file system can only be mounted once.
+	 */
+	if (resctrl_mounted) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	ret = rdtgroup_setup_root(ctx);
+	if (ret)
+		goto out;
+
+	ret = rdt_enable_ctx(ctx);
+	if (ret)
+		goto out_root;
+
+	ret = schemata_list_create();
+	if (ret) {
+		schemata_list_destroy();
+		goto out_ctx;
+	}
+
+	ret = closid_init();
+	if (ret)
+		goto out_schemata_free;
+
+	if (resctrl_arch_mon_capable())
+		flags |= RFTYPE_MON;
+
+	ret = rdtgroup_add_files(rdtgroup_default.kn, flags);
+	if (ret)
+		goto out_closid_exit;
+
+	kernfs_activate(rdtgroup_default.kn);
+
+	ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
+	if (ret < 0)
+		goto out_closid_exit;
+
+	if (resctrl_arch_mon_capable()) {
+		ret = mongroup_create_dir(rdtgroup_default.kn,
+					  &rdtgroup_default, "mon_groups",
+					  &kn_mongrp);
+		if (ret < 0)
+			goto out_info;
+
+		ret = mkdir_mondata_all(rdtgroup_default.kn,
+					&rdtgroup_default, &kn_mondata);
+		if (ret < 0)
+			goto out_mongrp;
+		rdtgroup_default.mon.mon_data_kn = kn_mondata;
+	}
+
+	ret = rdt_pseudo_lock_init();
+	if (ret)
+		goto out_mondata;
+
+	ret = kernfs_get_tree(fc);
+	if (ret < 0)
+		goto out_psl;
+
+	if (resctrl_arch_alloc_capable())
+		resctrl_arch_enable_alloc();
+	if (resctrl_arch_mon_capable())
+		resctrl_arch_enable_mon();
+
+	if (resctrl_arch_alloc_capable() || resctrl_arch_mon_capable())
+		resctrl_mounted = true;
+
+	if (resctrl_is_mbm_enabled()) {
+		r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+		list_for_each_entry(dom, &r->mon_domains, hdr.list)
+			mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL,
+						   RESCTRL_PICK_ANY_CPU);
+	}
+
+	goto out;
+
+out_psl:
+	rdt_pseudo_lock_release();
+out_mondata:
+	if (resctrl_arch_mon_capable())
+		kernfs_remove(kn_mondata);
+out_mongrp:
+	if (resctrl_arch_mon_capable())
+		kernfs_remove(kn_mongrp);
+out_info:
+	kernfs_remove(kn_info);
+out_closid_exit:
+	closid_exit();
+out_schemata_free:
+	schemata_list_destroy();
+out_ctx:
+	rdt_disable_ctx();
+out_root:
+	rdtgroup_destroy_root();
+out:
+	rdt_last_cmd_clear();
+	mutex_unlock(&rdtgroup_mutex);
+	cpus_read_unlock();
+	return ret;
+}
+
+enum rdt_param {
+	Opt_cdp,
+	Opt_cdpl2,
+	Opt_mba_mbps,
+	Opt_debug,
+	nr__rdt_params
+};
+
+static const struct fs_parameter_spec rdt_fs_parameters[] = {
+	fsparam_flag("cdp",		Opt_cdp),
+	fsparam_flag("cdpl2",		Opt_cdpl2),
+	fsparam_flag("mba_MBps",	Opt_mba_mbps),
+	fsparam_flag("debug",		Opt_debug),
+	{}
+};
+
+static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct rdt_fs_context *ctx = rdt_fc2context(fc);
+	struct fs_parse_result result;
+	const char *msg;
+	int opt;
+
+	opt = fs_parse(fc, rdt_fs_parameters, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_cdp:
+		ctx->enable_cdpl3 = true;
+		return 0;
+	case Opt_cdpl2:
+		ctx->enable_cdpl2 = true;
+		return 0;
+	case Opt_mba_mbps:
+		msg = "mba_MBps requires MBM and linear scale MBA at L3 scope";
+		if (!supports_mba_mbps())
+			return invalfc(fc, msg);
+		ctx->enable_mba_mbps = true;
+		return 0;
+	case Opt_debug:
+		ctx->enable_debug = true;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static void rdt_fs_context_free(struct fs_context *fc)
+{
+	struct rdt_fs_context *ctx = rdt_fc2context(fc);
+
+	kernfs_free_fs_context(fc);
+	kfree(ctx);
+}
+
+static const struct fs_context_operations rdt_fs_context_ops = {
+	.free		= rdt_fs_context_free,
+	.parse_param	= rdt_parse_param,
+	.get_tree	= rdt_get_tree,
+};
+
+static int rdt_init_fs_context(struct fs_context *fc)
+{
+	struct rdt_fs_context *ctx;
+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->kfc.magic = RDTGROUP_SUPER_MAGIC;
+	fc->fs_private = &ctx->kfc;
+	fc->ops = &rdt_fs_context_ops;
+	put_user_ns(fc->user_ns);
+	fc->user_ns = get_user_ns(&init_user_ns);
+	fc->global = true;
+	return 0;
+}
+
+/*
+ * Move tasks from one to the other group. If @from is NULL, then all tasks
+ * in the systems are moved unconditionally (used for teardown).
+ *
+ * If @mask is not NULL the cpus on which moved tasks are running are set
+ * in that mask so the update smp function call is restricted to affected
+ * cpus.
+ */
+static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to,
+				 struct cpumask *mask)
+{
+	struct task_struct *p, *t;
+
+	read_lock(&tasklist_lock);
+	for_each_process_thread(p, t) {
+		if (!from || is_closid_match(t, from) ||
+		    is_rmid_match(t, from)) {
+			resctrl_arch_set_closid_rmid(t, to->closid,
+						     to->mon.rmid);
+
+			/*
+			 * Order the closid/rmid stores above before the loads
+			 * in task_curr(). This pairs with the full barrier
+			 * between the rq->curr update and
+			 * resctrl_arch_sched_in() during context switch.
+			 */
+			smp_mb();
+
+			/*
+			 * If the task is on a CPU, set the CPU in the mask.
+			 * The detection is inaccurate as tasks might move or
+			 * schedule before the smp function call takes place.
+			 * In such a case the function call is pointless, but
+			 * there is no other side effect.
+			 */
+			if (IS_ENABLED(CONFIG_SMP) && mask && task_curr(t))
+				cpumask_set_cpu(task_cpu(t), mask);
+		}
+	}
+	read_unlock(&tasklist_lock);
+}
+
+static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp)
+{
+	struct rdtgroup *sentry, *stmp;
+	struct list_head *head;
+
+	head = &rdtgrp->mon.crdtgrp_list;
+	list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) {
+		free_rmid(sentry->closid, sentry->mon.rmid);
+		list_del(&sentry->mon.crdtgrp_list);
+
+		if (atomic_read(&sentry->waitcount) != 0)
+			sentry->flags = RDT_DELETED;
+		else
+			rdtgroup_remove(sentry);
+	}
+}
+
+/*
+ * Forcibly remove all of subdirectories under root.
+ */
+static void rmdir_all_sub(void)
+{
+	struct rdtgroup *rdtgrp, *tmp;
+
+	/* Move all tasks to the default resource group */
+	rdt_move_group_tasks(NULL, &rdtgroup_default, NULL);
+
+	list_for_each_entry_safe(rdtgrp, tmp, &rdt_all_groups, rdtgroup_list) {
+		/* Free any child rmids */
+		free_all_child_rdtgrp(rdtgrp);
+
+		/* Remove each rdtgroup other than root */
+		if (rdtgrp == &rdtgroup_default)
+			continue;
+
+		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
+		    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
+			rdtgroup_pseudo_lock_remove(rdtgrp);
+
+		/*
+		 * Give any CPUs back to the default group. We cannot copy
+		 * cpu_online_mask because a CPU might have executed the
+		 * offline callback already, but is still marked online.
+		 */
+		cpumask_or(&rdtgroup_default.cpu_mask,
+			   &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask);
+
+		free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
+
+		kernfs_remove(rdtgrp->kn);
+		list_del(&rdtgrp->rdtgroup_list);
+
+		if (atomic_read(&rdtgrp->waitcount) != 0)
+			rdtgrp->flags = RDT_DELETED;
+		else
+			rdtgroup_remove(rdtgrp);
+	}
+	/* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */
+	update_closid_rmid(cpu_online_mask, &rdtgroup_default);
+
+	kernfs_remove(kn_info);
+	kernfs_remove(kn_mongrp);
+	kernfs_remove(kn_mondata);
+}
+
+/**
+ * mon_get_kn_priv() - Get the mon_data priv data for this event.
+ *
+ * The same values are used across the mon_data directories of all control and
+ * monitor groups for the same event in the same domain. Keep a list of
+ * allocated structures and re-use an existing one with the same values for
+ * @rid, @domid, etc.
+ *
+ * @rid:    The resource id for the event file being created.
+ * @domid:  The domain id for the event file being created.
+ * @mevt:   The type of event file being created.
+ * @do_sum: Whether SNC summing monitors are being created.
+ */
+static struct mon_data *mon_get_kn_priv(enum resctrl_res_level rid, int domid,
+					struct mon_evt *mevt,
+					bool do_sum)
+{
+	struct mon_data *priv;
+
+	lockdep_assert_held(&rdtgroup_mutex);
+
+	list_for_each_entry(priv, &mon_data_kn_priv_list, list) {
+		if (priv->rid == rid && priv->domid == domid &&
+		    priv->sum == do_sum && priv->evtid == mevt->evtid)
+			return priv;
+	}
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return NULL;
+
+	priv->rid = rid;
+	priv->domid = domid;
+	priv->sum = do_sum;
+	priv->evtid = mevt->evtid;
+	list_add_tail(&priv->list, &mon_data_kn_priv_list);
+
+	return priv;
+}
+
+/**
+ * mon_put_kn_priv() - Free all allocated mon_data structures.
+ *
+ * Called when resctrl file system is unmounted.
+ */
+static void mon_put_kn_priv(void)
+{
+	struct mon_data *priv, *tmp;
+
+	lockdep_assert_held(&rdtgroup_mutex);
+
+	list_for_each_entry_safe(priv, tmp, &mon_data_kn_priv_list, list) {
+		list_del(&priv->list);
+		kfree(priv);
+	}
+}
+
+static void resctrl_fs_teardown(void)
+{
+	lockdep_assert_held(&rdtgroup_mutex);
+
+	/* Cleared by rdtgroup_destroy_root() */
+	if (!rdtgroup_default.kn)
+		return;
+
+	rmdir_all_sub();
+	mon_put_kn_priv();
+	rdt_pseudo_lock_release();
+	rdtgroup_default.mode = RDT_MODE_SHAREABLE;
+	closid_exit();
+	schemata_list_destroy();
+	rdtgroup_destroy_root();
+}
+
+static void rdt_kill_sb(struct super_block *sb)
+{
+	struct rdt_resource *r;
+
+	cpus_read_lock();
+	mutex_lock(&rdtgroup_mutex);
+
+	rdt_disable_ctx();
+
+	/* Put everything back to default values. */
+	for_each_alloc_capable_rdt_resource(r)
+		resctrl_arch_reset_all_ctrls(r);
+
+	resctrl_fs_teardown();
+	if (resctrl_arch_alloc_capable())
+		resctrl_arch_disable_alloc();
+	if (resctrl_arch_mon_capable())
+		resctrl_arch_disable_mon();
+	resctrl_mounted = false;
+	kernfs_kill_sb(sb);
+	mutex_unlock(&rdtgroup_mutex);
+	cpus_read_unlock();
+}
+
+static struct file_system_type rdt_fs_type = {
+	.name			= "resctrl",
+	.init_fs_context	= rdt_init_fs_context,
+	.parameters		= rdt_fs_parameters,
+	.kill_sb		= rdt_kill_sb,
+};
+
+static int mon_addfile(struct kernfs_node *parent_kn, const char *name,
+		       void *priv)
+{
+	struct kernfs_node *kn;
+	int ret = 0;
+
+	kn = __kernfs_create_file(parent_kn, name, 0444,
+				  GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 0,
+				  &kf_mondata_ops, priv, NULL, NULL);
+	if (IS_ERR(kn))
+		return PTR_ERR(kn);
+
+	ret = rdtgroup_kn_set_ugid(kn);
+	if (ret) {
+		kernfs_remove(kn);
+		return ret;
+	}
+
+	return ret;
+}
+
+static void mon_rmdir_one_subdir(struct kernfs_node *pkn, char *name, char *subname)
+{
+	struct kernfs_node *kn;
+
+	kn = kernfs_find_and_get(pkn, name);
+	if (!kn)
+		return;
+	kernfs_put(kn);
+
+	if (kn->dir.subdirs <= 1)
+		kernfs_remove(kn);
+	else
+		kernfs_remove_by_name(kn, subname);
+}
+
+/*
+ * Remove all subdirectories of mon_data of ctrl_mon groups
+ * and monitor groups for the given domain.
+ * Remove files and directories containing "sum" of domain data
+ * when last domain being summed is removed.
+ */
+static void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
+					   struct rdt_mon_domain *d)
+{
+	struct rdtgroup *prgrp, *crgrp;
+	char subname[32];
+	bool snc_mode;
+	char name[32];
+
+	snc_mode = r->mon_scope == RESCTRL_L3_NODE;
+	sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id);
+	if (snc_mode)
+		sprintf(subname, "mon_sub_%s_%02d", r->name, d->hdr.id);
+
+	list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
+		mon_rmdir_one_subdir(prgrp->mon.mon_data_kn, name, subname);
+
+		list_for_each_entry(crgrp, &prgrp->mon.crdtgrp_list, mon.crdtgrp_list)
+			mon_rmdir_one_subdir(crgrp->mon.mon_data_kn, name, subname);
+	}
+}
+
+static int mon_add_all_files(struct kernfs_node *kn, struct rdt_mon_domain *d,
+			     struct rdt_resource *r, struct rdtgroup *prgrp,
+			     bool do_sum)
+{
+	struct rmid_read rr = {0};
+	struct mon_data *priv;
+	struct mon_evt *mevt;
+	int ret, domid;
+
+	if (WARN_ON(list_empty(&r->evt_list)))
+		return -EPERM;
+
+	list_for_each_entry(mevt, &r->evt_list, list) {
+		domid = do_sum ? d->ci->id : d->hdr.id;
+		priv = mon_get_kn_priv(r->rid, domid, mevt, do_sum);
+		if (WARN_ON_ONCE(!priv))
+			return -EINVAL;
+
+		ret = mon_addfile(kn, mevt->name, priv);
+		if (ret)
+			return ret;
+
+		if (!do_sum && resctrl_is_mbm_event(mevt->evtid))
+			mon_event_read(&rr, r, d, prgrp, &d->hdr.cpu_mask, mevt->evtid, true);
+	}
+
+	return 0;
+}
+
+static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
+				struct rdt_mon_domain *d,
+				struct rdt_resource *r, struct rdtgroup *prgrp)
+{
+	struct kernfs_node *kn, *ckn;
+	char name[32];
+	bool snc_mode;
+	int ret = 0;
+
+	lockdep_assert_held(&rdtgroup_mutex);
+
+	snc_mode = r->mon_scope == RESCTRL_L3_NODE;
+	sprintf(name, "mon_%s_%02d", r->name, snc_mode ? d->ci->id : d->hdr.id);
+	kn = kernfs_find_and_get(parent_kn, name);
+	if (kn) {
+		/*
+		 * rdtgroup_mutex will prevent this directory from being
+		 * removed. No need to keep this hold.
+		 */
+		kernfs_put(kn);
+	} else {
+		kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
+		if (IS_ERR(kn))
+			return PTR_ERR(kn);
+
+		ret = rdtgroup_kn_set_ugid(kn);
+		if (ret)
+			goto out_destroy;
+		ret = mon_add_all_files(kn, d, r, prgrp, snc_mode);
+		if (ret)
+			goto out_destroy;
+	}
+
+	if (snc_mode) {
+		sprintf(name, "mon_sub_%s_%02d", r->name, d->hdr.id);
+		ckn = kernfs_create_dir(kn, name, parent_kn->mode, prgrp);
+		if (IS_ERR(ckn)) {
+			ret = -EINVAL;
+			goto out_destroy;
+		}
+
+		ret = rdtgroup_kn_set_ugid(ckn);
+		if (ret)
+			goto out_destroy;
+
+		ret = mon_add_all_files(ckn, d, r, prgrp, false);
+		if (ret)
+			goto out_destroy;
+	}
+
+	kernfs_activate(kn);
+	return 0;
+
+out_destroy:
+	kernfs_remove(kn);
+	return ret;
+}
+
+/*
+ * Add all subdirectories of mon_data for "ctrl_mon" groups
+ * and "monitor" groups with given domain id.
+ */
+static void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
+					   struct rdt_mon_domain *d)
+{
+	struct kernfs_node *parent_kn;
+	struct rdtgroup *prgrp, *crgrp;
+	struct list_head *head;
+
+	list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
+		parent_kn = prgrp->mon.mon_data_kn;
+		mkdir_mondata_subdir(parent_kn, d, r, prgrp);
+
+		head = &prgrp->mon.crdtgrp_list;
+		list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
+			parent_kn = crgrp->mon.mon_data_kn;
+			mkdir_mondata_subdir(parent_kn, d, r, crgrp);
+		}
+	}
+}
+
+static int mkdir_mondata_subdir_alldom(struct kernfs_node *parent_kn,
+				       struct rdt_resource *r,
+				       struct rdtgroup *prgrp)
+{
+	struct rdt_mon_domain *dom;
+	int ret;
+
+	/* Walking r->domains, ensure it can't race with cpuhp */
+	lockdep_assert_cpus_held();
+
+	list_for_each_entry(dom, &r->mon_domains, hdr.list) {
+		ret = mkdir_mondata_subdir(parent_kn, dom, r, prgrp);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/*
+ * This creates a directory mon_data which contains the monitored data.
+ *
+ * mon_data has one directory for each domain which are named
+ * in the format mon_<domain_name>_<domain_id>. For ex: A mon_data
+ * with L3 domain looks as below:
+ * ./mon_data:
+ * mon_L3_00
+ * mon_L3_01
+ * mon_L3_02
+ * ...
+ *
+ * Each domain directory has one file per event:
+ * ./mon_L3_00/:
+ * llc_occupancy
+ *
+ */
+static int mkdir_mondata_all(struct kernfs_node *parent_kn,
+			     struct rdtgroup *prgrp,
+			     struct kernfs_node **dest_kn)
+{
+	struct rdt_resource *r;
+	struct kernfs_node *kn;
+	int ret;
+
+	/*
+	 * Create the mon_data directory first.
+	 */
+	ret = mongroup_create_dir(parent_kn, prgrp, "mon_data", &kn);
+	if (ret)
+		return ret;
+
+	if (dest_kn)
+		*dest_kn = kn;
+
+	/*
+	 * Create the subdirectories for each domain. Note that all events
+	 * in a domain like L3 are grouped into a resource whose domain is L3
+	 */
+	for_each_mon_capable_rdt_resource(r) {
+		ret = mkdir_mondata_subdir_alldom(kn, r, prgrp);
+		if (ret)
+			goto out_destroy;
+	}
+
+	return 0;
+
+out_destroy:
+	kernfs_remove(kn);
+	return ret;
+}
+
+/**
+ * cbm_ensure_valid - Enforce validity on provided CBM
+ * @_val:	Candidate CBM
+ * @r:		RDT resource to which the CBM belongs
+ *
+ * The provided CBM represents all cache portions available for use. This
+ * may be represented by a bitmap that does not consist of contiguous ones
+ * and thus be an invalid CBM.
+ * Here the provided CBM is forced to be a valid CBM by only considering
+ * the first set of contiguous bits as valid and clearing all bits.
+ * The intention here is to provide a valid default CBM with which a new
+ * resource group is initialized. The user can follow this with a
+ * modification to the CBM if the default does not satisfy the
+ * requirements.
+ */
+static u32 cbm_ensure_valid(u32 _val, struct rdt_resource *r)
+{
+	unsigned int cbm_len = r->cache.cbm_len;
+	unsigned long first_bit, zero_bit;
+	unsigned long val = _val;
+
+	if (!val)
+		return 0;
+
+	first_bit = find_first_bit(&val, cbm_len);
+	zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
+
+	/* Clear any remaining bits to ensure contiguous region */
+	bitmap_clear(&val, zero_bit, cbm_len - zero_bit);
+	return (u32)val;
+}
+
+/*
+ * Initialize cache resources per RDT domain
+ *
+ * Set the RDT domain up to start off with all usable allocations. That is,
+ * all shareable and unused bits. All-zero CBM is invalid.
+ */
+static int __init_one_rdt_domain(struct rdt_ctrl_domain *d, struct resctrl_schema *s,
+				 u32 closid)
+{
+	enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type);
+	enum resctrl_conf_type t = s->conf_type;
+	struct resctrl_staged_config *cfg;
+	struct rdt_resource *r = s->res;
+	u32 used_b = 0, unused_b = 0;
+	unsigned long tmp_cbm;
+	enum rdtgrp_mode mode;
+	u32 peer_ctl, ctrl_val;
+	int i;
+
+	cfg = &d->staged_config[t];
+	cfg->have_new_ctrl = false;
+	cfg->new_ctrl = r->cache.shareable_bits;
+	used_b = r->cache.shareable_bits;
+	for (i = 0; i < closids_supported(); i++) {
+		if (closid_allocated(i) && i != closid) {
+			mode = rdtgroup_mode_by_closid(i);
+			if (mode == RDT_MODE_PSEUDO_LOCKSETUP)
+				/*
+				 * ctrl values for locksetup aren't relevant
+				 * until the schemata is written, and the mode
+				 * becomes RDT_MODE_PSEUDO_LOCKED.
+				 */
+				continue;
+			/*
+			 * If CDP is active include peer domain's
+			 * usage to ensure there is no overlap
+			 * with an exclusive group.
+			 */
+			if (resctrl_arch_get_cdp_enabled(r->rid))
+				peer_ctl = resctrl_arch_get_config(r, d, i,
+								   peer_type);
+			else
+				peer_ctl = 0;
+			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;
+		}
+	}
+	if (d->plr && d->plr->cbm > 0)
+		used_b |= d->plr->cbm;
+	unused_b = used_b ^ (BIT_MASK(r->cache.cbm_len) - 1);
+	unused_b &= BIT_MASK(r->cache.cbm_len) - 1;
+	cfg->new_ctrl |= unused_b;
+	/*
+	 * Force the initial CBM to be valid, user can
+	 * modify the CBM based on system availability.
+	 */
+	cfg->new_ctrl = cbm_ensure_valid(cfg->new_ctrl, r);
+	/*
+	 * Assign the u32 CBM to an unsigned long to ensure that
+	 * bitmap_weight() does not access out-of-bound memory.
+	 */
+	tmp_cbm = cfg->new_ctrl;
+	if (bitmap_weight(&tmp_cbm, r->cache.cbm_len) < r->cache.min_cbm_bits) {
+		rdt_last_cmd_printf("No space on %s:%d\n", s->name, d->hdr.id);
+		return -ENOSPC;
+	}
+	cfg->have_new_ctrl = true;
+
+	return 0;
+}
+
+/*
+ * Initialize cache resources with default values.
+ *
+ * A new RDT group is being created on an allocation capable (CAT)
+ * supporting system. Set this group up to start off with all usable
+ * allocations.
+ *
+ * If there are no more shareable bits available on any domain then
+ * the entire allocation will fail.
+ */
+static int rdtgroup_init_cat(struct resctrl_schema *s, u32 closid)
+{
+	struct rdt_ctrl_domain *d;
+	int ret;
+
+	list_for_each_entry(d, &s->res->ctrl_domains, hdr.list) {
+		ret = __init_one_rdt_domain(d, s, closid);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+/* Initialize MBA resource with default values. */
+static void rdtgroup_init_mba(struct rdt_resource *r, u32 closid)
+{
+	struct resctrl_staged_config *cfg;
+	struct rdt_ctrl_domain *d;
+
+	list_for_each_entry(d, &r->ctrl_domains, hdr.list) {
+		if (is_mba_sc(r)) {
+			d->mbps_val[closid] = MBA_MAX_MBPS;
+			continue;
+		}
+
+		cfg = &d->staged_config[CDP_NONE];
+		cfg->new_ctrl = resctrl_get_default_ctrl(r);
+		cfg->have_new_ctrl = true;
+	}
+}
+
+/* Initialize the RDT group's allocations. */
+static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
+{
+	struct resctrl_schema *s;
+	struct rdt_resource *r;
+	int ret = 0;
+
+	rdt_staged_configs_clear();
+
+	list_for_each_entry(s, &resctrl_schema_all, list) {
+		r = s->res;
+		if (r->rid == RDT_RESOURCE_MBA ||
+		    r->rid == RDT_RESOURCE_SMBA) {
+			rdtgroup_init_mba(r, rdtgrp->closid);
+			if (is_mba_sc(r))
+				continue;
+		} else {
+			ret = rdtgroup_init_cat(s, rdtgrp->closid);
+			if (ret < 0)
+				goto out;
+		}
+
+		ret = resctrl_arch_update_domains(r, rdtgrp->closid);
+		if (ret < 0) {
+			rdt_last_cmd_puts("Failed to initialize allocations\n");
+			goto out;
+		}
+	}
+
+	rdtgrp->mode = RDT_MODE_SHAREABLE;
+
+out:
+	rdt_staged_configs_clear();
+	return ret;
+}
+
+static int mkdir_rdt_prepare_rmid_alloc(struct rdtgroup *rdtgrp)
+{
+	int ret;
+
+	if (!resctrl_arch_mon_capable())
+		return 0;
+
+	ret = alloc_rmid(rdtgrp->closid);
+	if (ret < 0) {
+		rdt_last_cmd_puts("Out of RMIDs\n");
+		return ret;
+	}
+	rdtgrp->mon.rmid = ret;
+
+	ret = mkdir_mondata_all(rdtgrp->kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
+	if (ret) {
+		rdt_last_cmd_puts("kernfs subdir error\n");
+		free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void mkdir_rdt_prepare_rmid_free(struct rdtgroup *rgrp)
+{
+	if (resctrl_arch_mon_capable())
+		free_rmid(rgrp->closid, rgrp->mon.rmid);
+}
+
+/*
+ * 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(rdt_kn_name(kn), "mon_groups") &&
+		strcmp(name, "mon_groups"));
+}
+
+static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
+			     const char *name, umode_t mode,
+			     enum rdt_group_type rtype, struct rdtgroup **r)
+{
+	struct rdtgroup *prdtgrp, *rdtgrp;
+	unsigned long files = 0;
+	struct kernfs_node *kn;
+	int ret;
+
+	prdtgrp = rdtgroup_kn_lock_live(parent_kn);
+	if (!prdtgrp) {
+		ret = -ENODEV;
+		goto out_unlock;
+	}
+
+	/*
+	 * Check that the parent directory for a monitor group is a "mon_groups"
+	 * directory.
+	 */
+	if (rtype == RDTMON_GROUP && !is_mon_groups(parent_kn, name)) {
+		ret = -EPERM;
+		goto out_unlock;
+	}
+
+	if (rtype == RDTMON_GROUP &&
+	    (prdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
+	     prdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)) {
+		ret = -EINVAL;
+		rdt_last_cmd_puts("Pseudo-locking in progress\n");
+		goto out_unlock;
+	}
+
+	/* allocate the rdtgroup. */
+	rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL);
+	if (!rdtgrp) {
+		ret = -ENOSPC;
+		rdt_last_cmd_puts("Kernel out of memory\n");
+		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);
+	if (IS_ERR(kn)) {
+		ret = PTR_ERR(kn);
+		rdt_last_cmd_puts("kernfs create error\n");
+		goto out_free_rgrp;
+	}
+	rdtgrp->kn = kn;
+
+	/*
+	 * kernfs_remove() will drop the reference count on "kn" which
+	 * will free it. But we still need it to stick around for the
+	 * rdtgroup_kn_unlock(kn) call. Take one extra reference here,
+	 * which will be dropped by kernfs_put() in rdtgroup_remove().
+	 */
+	kernfs_get(kn);
+
+	ret = rdtgroup_kn_set_ugid(kn);
+	if (ret) {
+		rdt_last_cmd_puts("kernfs perm error\n");
+		goto out_destroy;
+	}
+
+	if (rtype == RDTCTRL_GROUP) {
+		files = RFTYPE_BASE | RFTYPE_CTRL;
+		if (resctrl_arch_mon_capable())
+			files |= RFTYPE_MON;
+	} else {
+		files = RFTYPE_BASE | RFTYPE_MON;
+	}
+
+	ret = rdtgroup_add_files(kn, files);
+	if (ret) {
+		rdt_last_cmd_puts("kernfs fill error\n");
+		goto out_destroy;
+	}
+
+	/*
+	 * The caller unlocks the parent_kn upon success.
+	 */
+	return 0;
+
+out_destroy:
+	kernfs_put(rdtgrp->kn);
+	kernfs_remove(rdtgrp->kn);
+out_free_rgrp:
+	kfree(rdtgrp);
+out_unlock:
+	rdtgroup_kn_unlock(parent_kn);
+	return ret;
+}
+
+static void mkdir_rdt_prepare_clean(struct rdtgroup *rgrp)
+{
+	kernfs_remove(rgrp->kn);
+	rdtgroup_remove(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,
+			      const char *name, umode_t mode)
+{
+	struct rdtgroup *rdtgrp, *prgrp;
+	int ret;
+
+	ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTMON_GROUP, &rdtgrp);
+	if (ret)
+		return ret;
+
+	prgrp = rdtgrp->mon.parent;
+	rdtgrp->closid = prgrp->closid;
+
+	ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp);
+	if (ret) {
+		mkdir_rdt_prepare_clean(rdtgrp);
+		goto out_unlock;
+	}
+
+	kernfs_activate(rdtgrp->kn);
+
+	/*
+	 * 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);
+
+out_unlock:
+	rdtgroup_kn_unlock(parent_kn);
+	return ret;
+}
+
+/*
+ * These are rdtgroups created under the root directory. Can be used
+ * to allocate and monitor resources.
+ */
+static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
+				   const char *name, umode_t mode)
+{
+	struct rdtgroup *rdtgrp;
+	struct kernfs_node *kn;
+	u32 closid;
+	int ret;
+
+	ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTCTRL_GROUP, &rdtgrp);
+	if (ret)
+		return ret;
+
+	kn = rdtgrp->kn;
+	ret = closid_alloc();
+	if (ret < 0) {
+		rdt_last_cmd_puts("Out of CLOSIDs\n");
+		goto out_common_fail;
+	}
+	closid = ret;
+	ret = 0;
+
+	rdtgrp->closid = closid;
+
+	ret = mkdir_rdt_prepare_rmid_alloc(rdtgrp);
+	if (ret)
+		goto out_closid_free;
+
+	kernfs_activate(rdtgrp->kn);
+
+	ret = rdtgroup_init_alloc(rdtgrp);
+	if (ret < 0)
+		goto out_rmid_free;
+
+	list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups);
+
+	if (resctrl_arch_mon_capable()) {
+		/*
+		 * Create an empty mon_groups directory to hold the subset
+		 * of tasks and cpus to monitor.
+		 */
+		ret = mongroup_create_dir(kn, rdtgrp, "mon_groups", NULL);
+		if (ret) {
+			rdt_last_cmd_puts("kernfs subdir error\n");
+			goto out_del_list;
+		}
+		if (is_mba_sc(NULL))
+			rdtgrp->mba_mbps_event = mba_mbps_default_event;
+	}
+
+	goto out_unlock;
+
+out_del_list:
+	list_del(&rdtgrp->rdtgroup_list);
+out_rmid_free:
+	mkdir_rdt_prepare_rmid_free(rdtgrp);
+out_closid_free:
+	closid_free(closid);
+out_common_fail:
+	mkdir_rdt_prepare_clean(rdtgrp);
+out_unlock:
+	rdtgroup_kn_unlock(parent_kn);
+	return ret;
+}
+
+static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
+			  umode_t mode)
+{
+	/* Do not accept '\n' to avoid unparsable situation. */
+	if (strchr(name, '\n'))
+		return -EINVAL;
+
+	/*
+	 * If the parent directory is the root directory and RDT
+	 * allocation is supported, add a control and monitoring
+	 * subdirectory
+	 */
+	if (resctrl_arch_alloc_capable() && parent_kn == rdtgroup_default.kn)
+		return rdtgroup_mkdir_ctrl_mon(parent_kn, name, mode);
+
+	/* Else, attempt to add a monitoring subdirectory. */
+	if (resctrl_arch_mon_capable())
+		return rdtgroup_mkdir_mon(parent_kn, name, mode);
+
+	return -EPERM;
+}
+
+static int rdtgroup_rmdir_mon(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask)
+{
+	struct rdtgroup *prdtgrp = rdtgrp->mon.parent;
+	u32 closid, rmid;
+	int cpu;
+
+	/* Give any tasks back to the parent group */
+	rdt_move_group_tasks(rdtgrp, prdtgrp, tmpmask);
+
+	/*
+	 * Update per cpu closid/rmid of the moved CPUs first.
+	 * Note: the closid will not change, but the arch code still needs it.
+	 */
+	closid = prdtgrp->closid;
+	rmid = prdtgrp->mon.rmid;
+	for_each_cpu(cpu, &rdtgrp->cpu_mask)
+		resctrl_arch_set_cpu_default_closid_rmid(cpu, closid, rmid);
+
+	/*
+	 * Update the MSR on moved CPUs and CPUs which have moved
+	 * task running on them.
+	 */
+	cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
+	update_closid_rmid(tmpmask, NULL);
+
+	rdtgrp->flags = RDT_DELETED;
+	free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
+
+	/*
+	 * Remove the rdtgrp from the parent ctrl_mon group's list
+	 */
+	WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list));
+	list_del(&rdtgrp->mon.crdtgrp_list);
+
+	kernfs_remove(rdtgrp->kn);
+
+	return 0;
+}
+
+static int rdtgroup_ctrl_remove(struct rdtgroup *rdtgrp)
+{
+	rdtgrp->flags = RDT_DELETED;
+	list_del(&rdtgrp->rdtgroup_list);
+
+	kernfs_remove(rdtgrp->kn);
+	return 0;
+}
+
+static int rdtgroup_rmdir_ctrl(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask)
+{
+	u32 closid, rmid;
+	int cpu;
+
+	/* Give any tasks back to the default group */
+	rdt_move_group_tasks(rdtgrp, &rdtgroup_default, tmpmask);
+
+	/* Give any CPUs back to the default group */
+	cpumask_or(&rdtgroup_default.cpu_mask,
+		   &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask);
+
+	/* Update per cpu closid and rmid of the moved CPUs first */
+	closid = rdtgroup_default.closid;
+	rmid = rdtgroup_default.mon.rmid;
+	for_each_cpu(cpu, &rdtgrp->cpu_mask)
+		resctrl_arch_set_cpu_default_closid_rmid(cpu, closid, rmid);
+
+	/*
+	 * Update the MSR on moved CPUs and CPUs which have moved
+	 * task running on them.
+	 */
+	cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
+	update_closid_rmid(tmpmask, NULL);
+
+	free_rmid(rdtgrp->closid, rdtgrp->mon.rmid);
+	closid_free(rdtgrp->closid);
+
+	rdtgroup_ctrl_remove(rdtgrp);
+
+	/*
+	 * Free all the child monitor group rmids.
+	 */
+	free_all_child_rdtgrp(rdtgrp);
+
+	return 0;
+}
+
+static struct kernfs_node *rdt_kn_parent(struct kernfs_node *kn)
+{
+	/*
+	 * Valid within the RCU section it was obtained or while rdtgroup_mutex
+	 * is held.
+	 */
+	return rcu_dereference_check(kn->__parent, lockdep_is_held(&rdtgroup_mutex));
+}
+
+static int rdtgroup_rmdir(struct kernfs_node *kn)
+{
+	struct kernfs_node *parent_kn;
+	struct rdtgroup *rdtgrp;
+	cpumask_var_t tmpmask;
+	int ret = 0;
+
+	if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
+		return -ENOMEM;
+
+	rdtgrp = rdtgroup_kn_lock_live(kn);
+	if (!rdtgrp) {
+		ret = -EPERM;
+		goto out;
+	}
+	parent_kn = rdt_kn_parent(kn);
+
+	/*
+	 * If the rdtgroup is a ctrl_mon group and parent directory
+	 * is the root directory, remove the ctrl_mon group.
+	 *
+	 * If the rdtgroup is a mon group and parent directory
+	 * is a valid "mon_groups" directory, remove the mon group.
+	 */
+	if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn &&
+	    rdtgrp != &rdtgroup_default) {
+		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
+		    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
+			ret = rdtgroup_ctrl_remove(rdtgrp);
+		} else {
+			ret = rdtgroup_rmdir_ctrl(rdtgrp, tmpmask);
+		}
+	} else if (rdtgrp->type == RDTMON_GROUP &&
+		 is_mon_groups(parent_kn, rdt_kn_name(kn))) {
+		ret = rdtgroup_rmdir_mon(rdtgrp, tmpmask);
+	} else {
+		ret = -EPERM;
+	}
+
+out:
+	rdtgroup_kn_unlock(kn);
+	free_cpumask_var(tmpmask);
+	return ret;
+}
+
+/**
+ * mongrp_reparent() - replace parent CTRL_MON group of a MON group
+ * @rdtgrp:		the MON group whose parent should be replaced
+ * @new_prdtgrp:	replacement parent CTRL_MON group for @rdtgrp
+ * @cpus:		cpumask provided by the caller for use during this call
+ *
+ * Replaces the parent CTRL_MON group for a MON group, resulting in all member
+ * tasks' CLOSID immediately changing to that of the new parent group.
+ * Monitoring data for the group is unaffected by this operation.
+ */
+static void mongrp_reparent(struct rdtgroup *rdtgrp,
+			    struct rdtgroup *new_prdtgrp,
+			    cpumask_var_t cpus)
+{
+	struct rdtgroup *prdtgrp = rdtgrp->mon.parent;
+
+	WARN_ON(rdtgrp->type != RDTMON_GROUP);
+	WARN_ON(new_prdtgrp->type != RDTCTRL_GROUP);
+
+	/* Nothing to do when simply renaming a MON group. */
+	if (prdtgrp == new_prdtgrp)
+		return;
+
+	WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list));
+	list_move_tail(&rdtgrp->mon.crdtgrp_list,
+		       &new_prdtgrp->mon.crdtgrp_list);
+
+	rdtgrp->mon.parent = new_prdtgrp;
+	rdtgrp->closid = new_prdtgrp->closid;
+
+	/* Propagate updated closid to all tasks in this group. */
+	rdt_move_group_tasks(rdtgrp, rdtgrp, cpus);
+
+	update_closid_rmid(cpus, NULL);
+}
+
+static int rdtgroup_rename(struct kernfs_node *kn,
+			   struct kernfs_node *new_parent, const char *new_name)
+{
+	struct kernfs_node *kn_parent;
+	struct rdtgroup *new_prdtgrp;
+	struct rdtgroup *rdtgrp;
+	cpumask_var_t tmpmask;
+	int ret;
+
+	rdtgrp = kernfs_to_rdtgroup(kn);
+	new_prdtgrp = kernfs_to_rdtgroup(new_parent);
+	if (!rdtgrp || !new_prdtgrp)
+		return -ENOENT;
+
+	/* Release both kernfs active_refs before obtaining rdtgroup mutex. */
+	rdtgroup_kn_get(rdtgrp, kn);
+	rdtgroup_kn_get(new_prdtgrp, new_parent);
+
+	mutex_lock(&rdtgroup_mutex);
+
+	rdt_last_cmd_clear();
+
+	/*
+	 * Don't allow kernfs_to_rdtgroup() to return a parent rdtgroup if
+	 * either kernfs_node is a file.
+	 */
+	if (kernfs_type(kn) != KERNFS_DIR ||
+	    kernfs_type(new_parent) != KERNFS_DIR) {
+		rdt_last_cmd_puts("Source and destination must be directories");
+		ret = -EPERM;
+		goto out;
+	}
+
+	if ((rdtgrp->flags & RDT_DELETED) || (new_prdtgrp->flags & RDT_DELETED)) {
+		ret = -ENOENT;
+		goto out;
+	}
+
+	kn_parent = rdt_kn_parent(kn);
+	if (rdtgrp->type != RDTMON_GROUP || !kn_parent ||
+	    !is_mon_groups(kn_parent, rdt_kn_name(kn))) {
+		rdt_last_cmd_puts("Source must be a MON group\n");
+		ret = -EPERM;
+		goto out;
+	}
+
+	if (!is_mon_groups(new_parent, new_name)) {
+		rdt_last_cmd_puts("Destination must be a mon_groups subdirectory\n");
+		ret = -EPERM;
+		goto out;
+	}
+
+	/*
+	 * If the MON group is monitoring CPUs, the CPUs must be assigned to the
+	 * current parent CTRL_MON group and therefore cannot be assigned to
+	 * the new parent, making the move illegal.
+	 */
+	if (!cpumask_empty(&rdtgrp->cpu_mask) &&
+	    rdtgrp->mon.parent != new_prdtgrp) {
+		rdt_last_cmd_puts("Cannot move a MON group that monitors CPUs\n");
+		ret = -EPERM;
+		goto out;
+	}
+
+	/*
+	 * Allocate the cpumask for use in mongrp_reparent() to avoid the
+	 * possibility of failing to allocate it after kernfs_rename() has
+	 * succeeded.
+	 */
+	if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/*
+	 * Perform all input validation and allocations needed to ensure
+	 * mongrp_reparent() will succeed before calling kernfs_rename(),
+	 * otherwise it would be necessary to revert this call if
+	 * mongrp_reparent() failed.
+	 */
+	ret = kernfs_rename(kn, new_parent, new_name);
+	if (!ret)
+		mongrp_reparent(rdtgrp, new_prdtgrp, tmpmask);
+
+	free_cpumask_var(tmpmask);
+
+out:
+	mutex_unlock(&rdtgroup_mutex);
+	rdtgroup_kn_put(rdtgrp, kn);
+	rdtgroup_kn_put(new_prdtgrp, new_parent);
+	return ret;
+}
+
+static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf)
+{
+	if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3))
+		seq_puts(seq, ",cdp");
+
+	if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2))
+		seq_puts(seq, ",cdpl2");
+
+	if (is_mba_sc(resctrl_arch_get_resource(RDT_RESOURCE_MBA)))
+		seq_puts(seq, ",mba_MBps");
+
+	if (resctrl_debug)
+		seq_puts(seq, ",debug");
+
+	return 0;
+}
+
+static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = {
+	.mkdir		= rdtgroup_mkdir,
+	.rmdir		= rdtgroup_rmdir,
+	.rename		= rdtgroup_rename,
+	.show_options	= rdtgroup_show_options,
+};
+
+static int rdtgroup_setup_root(struct rdt_fs_context *ctx)
+{
+	rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops,
+				      KERNFS_ROOT_CREATE_DEACTIVATED |
+				      KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK,
+				      &rdtgroup_default);
+	if (IS_ERR(rdt_root))
+		return PTR_ERR(rdt_root);
+
+	ctx->kfc.root = rdt_root;
+	rdtgroup_default.kn = kernfs_root_to_node(rdt_root);
+
+	return 0;
+}
+
+static void rdtgroup_destroy_root(void)
+{
+	lockdep_assert_held(&rdtgroup_mutex);
+
+	kernfs_destroy_root(rdt_root);
+	rdtgroup_default.kn = NULL;
+}
+
+static void rdtgroup_setup_default(void)
+{
+	mutex_lock(&rdtgroup_mutex);
+
+	rdtgroup_default.closid = RESCTRL_RESERVED_CLOSID;
+	rdtgroup_default.mon.rmid = RESCTRL_RESERVED_RMID;
+	rdtgroup_default.type = RDTCTRL_GROUP;
+	INIT_LIST_HEAD(&rdtgroup_default.mon.crdtgrp_list);
+
+	list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups);
+
+	mutex_unlock(&rdtgroup_mutex);
+}
+
+static void domain_destroy_mon_state(struct rdt_mon_domain *d)
+{
+	bitmap_free(d->rmid_busy_llc);
+	kfree(d->mbm_total);
+	kfree(d->mbm_local);
+}
+
+void resctrl_offline_ctrl_domain(struct rdt_resource *r, struct rdt_ctrl_domain *d)
+{
+	mutex_lock(&rdtgroup_mutex);
+
+	if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA)
+		mba_sc_domain_destroy(r, d);
+
+	mutex_unlock(&rdtgroup_mutex);
+}
+
+void resctrl_offline_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d)
+{
+	mutex_lock(&rdtgroup_mutex);
+
+	/*
+	 * If resctrl is mounted, remove all the
+	 * per domain monitor data directories.
+	 */
+	if (resctrl_mounted && resctrl_arch_mon_capable())
+		rmdir_mondata_subdir_allrdtgrp(r, d);
+
+	if (resctrl_is_mbm_enabled())
+		cancel_delayed_work(&d->mbm_over);
+	if (resctrl_arch_is_llc_occupancy_enabled() && has_busy_rmid(d)) {
+		/*
+		 * When a package is going down, forcefully
+		 * decrement rmid->ebusy. There is no way to know
+		 * that the L3 was flushed and hence may lead to
+		 * incorrect counts in rare scenarios, but leaving
+		 * the RMID as busy creates RMID leaks if the
+		 * package never comes back.
+		 */
+		__check_limbo(d, true);
+		cancel_delayed_work(&d->cqm_limbo);
+	}
+
+	domain_destroy_mon_state(d);
+
+	mutex_unlock(&rdtgroup_mutex);
+}
+
+/**
+ * domain_setup_mon_state() -  Initialise domain monitoring structures.
+ * @r:	The resource for the newly online domain.
+ * @d:	The newly online domain.
+ *
+ * Allocate monitor resources that belong to this domain.
+ * Called when the first CPU of a domain comes online, regardless of whether
+ * the filesystem is mounted.
+ * During boot this may be called before global allocations have been made by
+ * resctrl_mon_resource_init().
+ *
+ * Returns 0 for success, or -ENOMEM.
+ */
+static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_mon_domain *d)
+{
+	u32 idx_limit = resctrl_arch_system_num_rmid_idx();
+	size_t tsize;
+
+	if (resctrl_arch_is_llc_occupancy_enabled()) {
+		d->rmid_busy_llc = bitmap_zalloc(idx_limit, GFP_KERNEL);
+		if (!d->rmid_busy_llc)
+			return -ENOMEM;
+	}
+	if (resctrl_arch_is_mbm_total_enabled()) {
+		tsize = sizeof(*d->mbm_total);
+		d->mbm_total = kcalloc(idx_limit, tsize, GFP_KERNEL);
+		if (!d->mbm_total) {
+			bitmap_free(d->rmid_busy_llc);
+			return -ENOMEM;
+		}
+	}
+	if (resctrl_arch_is_mbm_local_enabled()) {
+		tsize = sizeof(*d->mbm_local);
+		d->mbm_local = kcalloc(idx_limit, tsize, GFP_KERNEL);
+		if (!d->mbm_local) {
+			bitmap_free(d->rmid_busy_llc);
+			kfree(d->mbm_total);
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+int resctrl_online_ctrl_domain(struct rdt_resource *r, struct rdt_ctrl_domain *d)
+{
+	int err = 0;
+
+	mutex_lock(&rdtgroup_mutex);
+
+	if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA) {
+		/* RDT_RESOURCE_MBA is never mon_capable */
+		err = mba_sc_domain_allocate(r, d);
+	}
+
+	mutex_unlock(&rdtgroup_mutex);
+
+	return err;
+}
+
+int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d)
+{
+	int err;
+
+	mutex_lock(&rdtgroup_mutex);
+
+	err = domain_setup_mon_state(r, d);
+	if (err)
+		goto out_unlock;
+
+	if (resctrl_is_mbm_enabled()) {
+		INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow);
+		mbm_setup_overflow_handler(d, MBM_OVERFLOW_INTERVAL,
+					   RESCTRL_PICK_ANY_CPU);
+	}
+
+	if (resctrl_arch_is_llc_occupancy_enabled())
+		INIT_DELAYED_WORK(&d->cqm_limbo, cqm_handle_limbo);
+
+	/*
+	 * If the filesystem is not mounted then only the default resource group
+	 * exists. Creation of its directories is deferred until mount time
+	 * by rdt_get_tree() calling mkdir_mondata_all().
+	 * If resctrl is mounted, add per domain monitor data directories.
+	 */
+	if (resctrl_mounted && resctrl_arch_mon_capable())
+		mkdir_mondata_subdir_allrdtgrp(r, d);
+
+out_unlock:
+	mutex_unlock(&rdtgroup_mutex);
+
+	return err;
+}
+
+void resctrl_online_cpu(unsigned int cpu)
+{
+	mutex_lock(&rdtgroup_mutex);
+	/* The CPU is set in default rdtgroup after online. */
+	cpumask_set_cpu(cpu, &rdtgroup_default.cpu_mask);
+	mutex_unlock(&rdtgroup_mutex);
+}
+
+static void clear_childcpus(struct rdtgroup *r, unsigned int cpu)
+{
+	struct rdtgroup *cr;
+
+	list_for_each_entry(cr, &r->mon.crdtgrp_list, mon.crdtgrp_list) {
+		if (cpumask_test_and_clear_cpu(cpu, &cr->cpu_mask))
+			break;
+	}
+}
+
+static struct rdt_mon_domain *get_mon_domain_from_cpu(int cpu,
+						      struct rdt_resource *r)
+{
+	struct rdt_mon_domain *d;
+
+	lockdep_assert_cpus_held();
+
+	list_for_each_entry(d, &r->mon_domains, hdr.list) {
+		/* Find the domain that contains this CPU */
+		if (cpumask_test_cpu(cpu, &d->hdr.cpu_mask))
+			return d;
+	}
+
+	return NULL;
+}
+
+void resctrl_offline_cpu(unsigned int cpu)
+{
+	struct rdt_resource *l3 = resctrl_arch_get_resource(RDT_RESOURCE_L3);
+	struct rdt_mon_domain *d;
+	struct rdtgroup *rdtgrp;
+
+	mutex_lock(&rdtgroup_mutex);
+	list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
+		if (cpumask_test_and_clear_cpu(cpu, &rdtgrp->cpu_mask)) {
+			clear_childcpus(rdtgrp, cpu);
+			break;
+		}
+	}
+
+	if (!l3->mon_capable)
+		goto out_unlock;
+
+	d = get_mon_domain_from_cpu(cpu, l3);
+	if (d) {
+		if (resctrl_is_mbm_enabled() && cpu == d->mbm_work_cpu) {
+			cancel_delayed_work(&d->mbm_over);
+			mbm_setup_overflow_handler(d, 0, cpu);
+		}
+		if (resctrl_arch_is_llc_occupancy_enabled() &&
+		    cpu == d->cqm_work_cpu && has_busy_rmid(d)) {
+			cancel_delayed_work(&d->cqm_limbo);
+			cqm_setup_limbo_handler(d, 0, cpu);
+		}
+	}
+
+out_unlock:
+	mutex_unlock(&rdtgroup_mutex);
+}
+
+/*
+ * resctrl_init - resctrl filesystem initialization
+ *
+ * Setup resctrl file system including set up root, create mount point,
+ * register resctrl filesystem, and initialize files under root directory.
+ *
+ * Return: 0 on success or -errno
+ */
+int resctrl_init(void)
+{
+	int ret = 0;
+
+	seq_buf_init(&last_cmd_status, last_cmd_status_buf,
+		     sizeof(last_cmd_status_buf));
+
+	rdtgroup_setup_default();
+
+	thread_throttle_mode_init();
+
+	ret = resctrl_mon_resource_init();
+	if (ret)
+		return ret;
+
+	ret = sysfs_create_mount_point(fs_kobj, "resctrl");
+	if (ret) {
+		resctrl_mon_resource_exit();
+		return ret;
+	}
+
+	ret = register_filesystem(&rdt_fs_type);
+	if (ret)
+		goto cleanup_mountpoint;
+
+	/*
+	 * Adding the resctrl debugfs directory here may not be ideal since
+	 * it would let the resctrl debugfs directory appear on the debugfs
+	 * filesystem before the resctrl filesystem is mounted.
+	 * It may also be ok since that would enable debugging of RDT before
+	 * resctrl is mounted.
+	 * The reason why the debugfs directory is created here and not in
+	 * rdt_get_tree() is because rdt_get_tree() takes rdtgroup_mutex and
+	 * during the debugfs directory creation also &sb->s_type->i_mutex_key
+	 * (the lockdep class of inode->i_rwsem). Other filesystem
+	 * interactions (eg. SyS_getdents) have the lock ordering:
+	 * &sb->s_type->i_mutex_key --> &mm->mmap_lock
+	 * During mmap(), called with &mm->mmap_lock, the rdtgroup_mutex
+	 * is taken, thus creating dependency:
+	 * &mm->mmap_lock --> rdtgroup_mutex for the latter that can cause
+	 * issues considering the other two lock dependencies.
+	 * By creating the debugfs directory here we avoid a dependency
+	 * that may cause deadlock (even though file operations cannot
+	 * occur until the filesystem is mounted, but I do not know how to
+	 * tell lockdep that).
+	 */
+	debugfs_resctrl = debugfs_create_dir("resctrl", NULL);
+
+	return 0;
+
+cleanup_mountpoint:
+	sysfs_remove_mount_point(fs_kobj, "resctrl");
+	resctrl_mon_resource_exit();
+
+	return ret;
+}
+
+static bool resctrl_online_domains_exist(void)
+{
+	struct rdt_resource *r;
+
+	/*
+	 * Only walk capable resources to allow resctrl_arch_get_resource()
+	 * to return dummy 'not capable' resources.
+	 */
+	for_each_alloc_capable_rdt_resource(r) {
+		if (!list_empty(&r->ctrl_domains))
+			return true;
+	}
+
+	for_each_mon_capable_rdt_resource(r) {
+		if (!list_empty(&r->mon_domains))
+			return true;
+	}
+
+	return false;
+}
+
+/**
+ * resctrl_exit() - Remove the resctrl filesystem and free resources.
+ *
+ * Called by the architecture code in response to a fatal error.
+ * Removes resctrl files and structures from kernfs to prevent further
+ * configuration.
+ *
+ * When called by the architecture code, all CPUs and resctrl domains must be
+ * offline. This ensures the limbo and overflow handlers are not scheduled to
+ * run, meaning the data structures they access can be freed by
+ * resctrl_mon_resource_exit().
+ *
+ * After resctrl_exit() returns, the architecture code should return an
+ * error from all resctrl_arch_ functions that can do this.
+ * resctrl_arch_get_resource() must continue to return struct rdt_resources
+ * with the correct rid field to ensure the filesystem can be unmounted.
+ */
+void resctrl_exit(void)
+{
+	cpus_read_lock();
+	WARN_ON_ONCE(resctrl_online_domains_exist());
+
+	mutex_lock(&rdtgroup_mutex);
+	resctrl_fs_teardown();
+	mutex_unlock(&rdtgroup_mutex);
+
+	cpus_read_unlock();
+
+	debugfs_remove_recursive(debugfs_resctrl);
+	debugfs_resctrl = NULL;
+	unregister_filesystem(&rdt_fs_type);
+
+	/*
+	 * Do not remove the sysfs mount point added by resctrl_init() so that
+	 * it can be used to umount resctrl.
+	 */
+
+	resctrl_mon_resource_exit();
+}