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-rw-r--r--arch/x86/kernel/cpu/resctrl/rdtgroup.c3480
1 files changed, 3480 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
new file mode 100644
index 000000000..15ee89ce8
--- /dev/null
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -0,0 +1,3480 @@
+// 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/cacheinfo.h>
+#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/seq_buf.h>
+#include <linux/seq_file.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/task.h>
+#include <linux/slab.h>
+#include <linux/task_work.h>
+#include <linux/user_namespace.h>
+
+#include <uapi/linux/magic.h>
+
+#include <asm/resctrl.h>
+#include "internal.h"
+
+DEFINE_STATIC_KEY_FALSE(rdt_enable_key);
+DEFINE_STATIC_KEY_FALSE(rdt_mon_enable_key);
+DEFINE_STATIC_KEY_FALSE(rdt_alloc_enable_key);
+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);
+
+/* 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;
+
+static struct seq_buf last_cmd_status;
+static char last_cmd_status_buf[512];
+
+struct dentry *debugfs_resctrl;
+
+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_resource *r;
+ struct rdt_domain *dom;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ for_each_alloc_capable_rdt_resource(r) {
+ list_for_each_entry(dom, &r->domains, list)
+ memset(dom->staged_config, 0, sizeof(dom->staged_config));
+ }
+}
+
+/*
+ * Trivial allocator for CLOSIDs. Since h/w only supports a small number,
+ * we can keep a bitmap of free CLOSIDs in a single integer.
+ *
+ * Using a global CLOSID across all resources has some advantages and
+ * some drawbacks:
+ * + We can simply set "current->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 int closid_free_map;
+static int closid_free_map_len;
+
+int closids_supported(void)
+{
+ return closid_free_map_len;
+}
+
+static void closid_init(void)
+{
+ struct resctrl_schema *s;
+ u32 rdt_min_closid = 32;
+
+ /* 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 = BIT_MASK(rdt_min_closid) - 1;
+
+ /* CLOSID 0 is always reserved for the default group */
+ closid_free_map &= ~1;
+ closid_free_map_len = rdt_min_closid;
+}
+
+static int closid_alloc(void)
+{
+ u32 closid = ffs(closid_free_map);
+
+ if (closid == 0)
+ return -ENOSPC;
+ closid--;
+ closid_free_map &= ~(1 << closid);
+
+ return closid;
+}
+
+void closid_free(int closid)
+{
+ closid_free_map |= 1 << closid;
+}
+
+/**
+ * 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
+ */
+static bool closid_allocated(unsigned int closid)
+{
+ return (closid_free_map & (1 << closid)) == 0;
+}
+
+/**
+ * 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->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;
+}
+
+/*
+ * This is safe against resctrl_sched_in() called from __switch_to()
+ * because __switch_to() is executed with interrupts disabled. A local call
+ * from update_closid_rmid() is protected against __switch_to() because
+ * preemption is disabled.
+ */
+static void update_cpu_closid_rmid(void *info)
+{
+ struct rdtgroup *r = info;
+
+ if (r) {
+ this_cpu_write(pqr_state.default_closid, r->closid);
+ this_cpu_write(pqr_state.default_rmid, r->mon.rmid);
+ }
+
+ /*
+ * We cannot unconditionally write the MSR because the current
+ * executing task might have its own closid selected. Just reuse
+ * the context switch code.
+ */
+ resctrl_sched_in(current);
+}
+
+/*
+ * Update the PGR_ASSOC MSR on all cpus in @cpu_mask,
+ *
+ * Per task closids/rmids must have been set up before calling this function.
+ */
+static void
+update_closid_rmid(const struct cpumask *cpu_mask, struct rdtgroup *r)
+{
+ int cpu = get_cpu();
+
+ if (cpumask_test_cpu(cpu, cpu_mask))
+ update_cpu_closid_rmid(r);
+ smp_call_function_many(cpu_mask, update_cpu_closid_rmid, r, 1);
+ put_cpu();
+}
+
+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_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 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 ((rdtgrp->type == RDTCTRL_GROUP && tsk->closid == rdtgrp->closid &&
+ tsk->rmid == rdtgrp->mon.rmid) ||
+ (rdtgrp->type == RDTMON_GROUP && tsk->rmid == rdtgrp->mon.rmid &&
+ tsk->closid == rdtgrp->mon.parent->closid))
+ 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 == RDTCTRL_GROUP) {
+ WRITE_ONCE(tsk->closid, rdtgrp->closid);
+ WRITE_ONCE(tsk->rmid, rdtgrp->mon.rmid);
+ } else if (rdtgrp->type == RDTMON_GROUP) {
+ if (rdtgrp->mon.parent->closid == tsk->closid) {
+ WRITE_ONCE(tsk->rmid, rdtgrp->mon.rmid);
+ } else {
+ rdt_last_cmd_puts("Can't move task to different control group\n");
+ return -EINVAL;
+ }
+ }
+
+ /*
+ * 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_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 (rdt_alloc_capable &&
+ (r->type == RDTCTRL_GROUP) && (t->closid == r->closid));
+}
+
+static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r)
+{
+ return (rdt_mon_capable &&
+ (r->type == RDTMON_GROUP) && (t->rmid == 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;
+ int ret = 0;
+ pid_t pid;
+
+ if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0)
+ return -EINVAL;
+ 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;
+ }
+
+ ret = rdtgroup_move_task(pid, rdtgrp, of);
+
+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;
+}
+
+#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 (!static_branch_unlikely(&rdt_enable_key)) {
+ 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 (rdtg->closid != tsk->closid)
+ continue;
+
+ seq_printf(s, "res:%s%s\n", (rdtg == &rdtgroup_default) ? "/" : "",
+ rdtg->kn->name);
+ seq_puts(s, "mon:");
+ list_for_each_entry(crg, &rdtg->mon.crdtgrp_list,
+ mon.crdtgrp_list) {
+ if (tsk->rmid != crg->mon.rmid)
+ continue;
+ seq_printf(s, "%s", crg->kn->name);
+ 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 int rdt_num_closids_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct resctrl_schema *s = of->kn->parent->priv;
+
+ 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 = of->kn->parent->priv;
+ struct rdt_resource *r = s->res;
+
+ seq_printf(seq, "%x\n", r->default_ctrl);
+ return 0;
+}
+
+static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct resctrl_schema *s = of->kn->parent->priv;
+ 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 = of->kn->parent->priv;
+ 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 = of->kn->parent->priv;
+ /*
+ * 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_domain *dom;
+ int i, hwb, swb, excl, psl;
+ enum rdtgrp_mode mode;
+ bool sep = false;
+ u32 ctrl_val;
+
+ mutex_lock(&rdtgroup_mutex);
+ hw_shareable = r->cache.shareable_bits;
+ list_for_each_entry(dom, &r->domains, list) {
+ if (sep)
+ seq_putc(seq, ';');
+ sw_shareable = 0;
+ exclusive = 0;
+ seq_printf(seq, "%d=", dom->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);
+ return 0;
+}
+
+static int rdt_min_bw_show(struct kernfs_open_file *of,
+ struct seq_file *seq, void *v)
+{
+ struct resctrl_schema *s = of->kn->parent->priv;
+ 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 = of->kn->parent->priv;
+
+ 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 = of->kn->parent->priv;
+ struct mon_evt *mevt;
+
+ list_for_each_entry(mevt, &r->evt_list, list)
+ seq_printf(seq, "%s\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 = of->kn->parent->priv;
+ 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 = of->kn->parent->priv;
+ 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 = of->kn->parent->priv;
+ struct rdt_resource *r = s->res;
+
+ if (r->membw.throttle_mode == THREAD_THROTTLE_PER_THREAD)
+ seq_puts(seq, "per-thread\n");
+ else
+ seq_puts(seq, "max\n");
+
+ 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;
+ }
+}
+
+/**
+ * __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.
+ * @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_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_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
+ *
+ * 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 resctrl_schema *s;
+ struct rdt_resource *r;
+ bool has_cache = false;
+ struct rdt_domain *d;
+ u32 ctrl;
+
+ list_for_each_entry(s, &resctrl_schema_all, list) {
+ r = s->res;
+ if (r->rid == RDT_RESOURCE_MBA)
+ continue;
+ has_cache = true;
+ list_for_each_entry(d, &r->domains, 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 (!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_domain *d, unsigned long cbm)
+{
+ struct cpu_cacheinfo *ci;
+ unsigned int size = 0;
+ int num_b, i;
+
+ num_b = bitmap_weight(&cbm, r->cache.cbm_len);
+ ci = get_cpu_cacheinfo(cpumask_any(&d->cpu_mask));
+ for (i = 0; i < ci->num_leaves; i++) {
+ if (ci->info_list[i].level == r->cache_level) {
+ size = ci->info_list[i].size / r->cache.cbm_len * num_b;
+ break;
+ }
+ }
+
+ return size;
+}
+
+/**
+ * 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 rdtgroup *rdtgrp;
+ struct rdt_resource *r;
+ struct rdt_domain *d;
+ 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->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->domains, 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)
+ size = ctrl;
+ else
+ size = rdtgroup_cbm_to_size(r, d, ctrl);
+ }
+ seq_printf(s, "%d=%u", d->id, size);
+ sep = true;
+ }
+ seq_putc(s, '\n');
+ }
+
+out:
+ rdtgroup_kn_unlock(of->kn);
+
+ return ret;
+}
+
+/* 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 = RF_TOP_INFO,
+ },
+ {
+ .name = "num_closids",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_num_closids_show,
+ .fflags = RF_CTRL_INFO,
+ },
+ {
+ .name = "mon_features",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_mon_features_show,
+ .fflags = RF_MON_INFO,
+ },
+ {
+ .name = "num_rmids",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_num_rmids_show,
+ .fflags = RF_MON_INFO,
+ },
+ {
+ .name = "cbm_mask",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_default_ctrl_show,
+ .fflags = RF_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 = RF_CTRL_INFO | RFTYPE_RES_CACHE,
+ },
+ {
+ .name = "shareable_bits",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_shareable_bits_show,
+ .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE,
+ },
+ {
+ .name = "bit_usage",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_bit_usage_show,
+ .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE,
+ },
+ {
+ .name = "min_bandwidth",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_min_bw_show,
+ .fflags = RF_CTRL_INFO | RFTYPE_RES_MB,
+ },
+ {
+ .name = "bandwidth_gran",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_bw_gran_show,
+ .fflags = RF_CTRL_INFO | RFTYPE_RES_MB,
+ },
+ {
+ .name = "delay_linear",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdt_delay_linear_show,
+ .fflags = RF_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 = RF_MON_INFO | RFTYPE_RES_CACHE,
+ },
+ {
+ .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 = "schemata",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .write = rdtgroup_schemata_write,
+ .seq_show = rdtgroup_schemata_show,
+ .fflags = RF_CTRL_BASE,
+ },
+ {
+ .name = "mode",
+ .mode = 0644,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .write = rdtgroup_mode_write,
+ .seq_show = rdtgroup_mode_show,
+ .fflags = RF_CTRL_BASE,
+ },
+ {
+ .name = "size",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdtgroup_size_show,
+ .fflags = RF_CTRL_BASE,
+ },
+
+};
+
+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);
+
+ 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;
+}
+
+void __init thread_throttle_mode_init(void)
+{
+ struct rftype *rft;
+
+ rft = rdtgroup_get_rftype_by_name("thread_throttle_mode");
+ if (!rft)
+ return;
+
+ rft->fflags = RF_CTRL_INFO | RFTYPE_RES_MB;
+}
+
+/**
+ * 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 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, RF_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 = r->fflags | RF_CTRL_INFO;
+ ret = rdtgroup_mkdir_info_resdir(s, s->name, fflags);
+ if (ret)
+ goto out_destroy;
+ }
+
+ for_each_mon_capable_rdt_resource(r) {
+ fflags = r->fflags | RF_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 void l3_qos_cfg_update(void *arg)
+{
+ bool *enable = arg;
+
+ wrmsrl(MSR_IA32_L3_QOS_CFG, *enable ? L3_QOS_CDP_ENABLE : 0ULL);
+}
+
+static void l2_qos_cfg_update(void *arg)
+{
+ bool *enable = arg;
+
+ wrmsrl(MSR_IA32_L2_QOS_CFG, *enable ? L2_QOS_CDP_ENABLE : 0ULL);
+}
+
+static inline bool is_mba_linear(void)
+{
+ return rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl.membw.delay_linear;
+}
+
+static int set_cache_qos_cfg(int level, bool enable)
+{
+ void (*update)(void *arg);
+ struct rdt_resource *r_l;
+ cpumask_var_t cpu_mask;
+ struct rdt_domain *d;
+ int cpu;
+
+ if (level == RDT_RESOURCE_L3)
+ update = l3_qos_cfg_update;
+ else if (level == RDT_RESOURCE_L2)
+ update = l2_qos_cfg_update;
+ else
+ return -EINVAL;
+
+ if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
+ return -ENOMEM;
+
+ r_l = &rdt_resources_all[level].r_resctrl;
+ list_for_each_entry(d, &r_l->domains, list) {
+ if (r_l->cache.arch_has_per_cpu_cfg)
+ /* Pick all the CPUs in the domain instance */
+ for_each_cpu(cpu, &d->cpu_mask)
+ cpumask_set_cpu(cpu, cpu_mask);
+ else
+ /* Pick one CPU from each domain instance to update MSR */
+ cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
+ }
+ cpu = get_cpu();
+ /* Update QOS_CFG MSR on this cpu if it's in cpu_mask. */
+ if (cpumask_test_cpu(cpu, cpu_mask))
+ update(&enable);
+ /* Update QOS_CFG MSR on all other cpus in cpu_mask. */
+ smp_call_function_many(cpu_mask, update, &enable, 1);
+ put_cpu();
+
+ free_cpumask_var(cpu_mask);
+
+ return 0;
+}
+
+/* Restore the qos cfg state when a domain comes online */
+void rdt_domain_reconfigure_cdp(struct rdt_resource *r)
+{
+ struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
+
+ if (!r->cdp_capable)
+ return;
+
+ if (r->rid == RDT_RESOURCE_L2)
+ l2_qos_cfg_update(&hw_res->cdp_enabled);
+
+ if (r->rid == RDT_RESOURCE_L3)
+ l3_qos_cfg_update(&hw_res->cdp_enabled);
+}
+
+static int mba_sc_domain_allocate(struct rdt_resource *r, struct rdt_domain *d)
+{
+ u32 num_closid = resctrl_arch_get_num_closid(r);
+ int cpu = cpumask_any(&d->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_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.
+ */
+static bool supports_mba_mbps(void)
+{
+ struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl;
+
+ return (is_mbm_local_enabled() &&
+ r->alloc_capable && is_mba_linear());
+}
+
+/*
+ * 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 = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl;
+ u32 num_closid = resctrl_arch_get_num_closid(r);
+ struct rdt_domain *d;
+ int i;
+
+ if (!supports_mba_mbps() || mba_sc == is_mba_sc(r))
+ return -EINVAL;
+
+ r->membw.mba_sc = mba_sc;
+
+ list_for_each_entry(d, &r->domains, list) {
+ for (i = 0; i < num_closid; i++)
+ d->mbps_val[i] = MBA_MAX_MBPS;
+ }
+
+ return 0;
+}
+
+static int cdp_enable(int level)
+{
+ struct rdt_resource *r_l = &rdt_resources_all[level].r_resctrl;
+ int ret;
+
+ if (!r_l->alloc_capable)
+ return -EINVAL;
+
+ ret = set_cache_qos_cfg(level, true);
+ if (!ret)
+ rdt_resources_all[level].cdp_enabled = true;
+
+ return ret;
+}
+
+static void cdp_disable(int level)
+{
+ struct rdt_hw_resource *r_hw = &rdt_resources_all[level];
+
+ if (r_hw->cdp_enabled) {
+ set_cache_qos_cfg(level, false);
+ r_hw->cdp_enabled = false;
+ }
+}
+
+int resctrl_arch_set_cdp_enabled(enum resctrl_res_level l, bool enable)
+{
+ struct rdt_hw_resource *hw_res = &rdt_resources_all[l];
+
+ if (!hw_res->r_resctrl.cdp_capable)
+ return -EINVAL;
+
+ if (enable)
+ return cdp_enable(l);
+
+ cdp_disable(l);
+
+ return 0;
+}
+
+static void cdp_disable_all(void)
+{
+ if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3))
+ resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);
+ if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2))
+ resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);
+}
+
+/*
+ * 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 || kn->parent == kn_info)
+ return NULL;
+ else
+ return kn->priv;
+ } else {
+ return kn->parent->priv;
+ }
+}
+
+struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn)
+{
+ struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn);
+
+ if (!rdtgrp)
+ return NULL;
+
+ atomic_inc(&rdtgrp->waitcount);
+ kernfs_break_active_protection(kn);
+
+ 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);
+
+ 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);
+ }
+}
+
+static int mkdir_mondata_all(struct kernfs_node *parent_kn,
+ struct rdtgroup *prgrp,
+ struct kernfs_node **mon_data_kn);
+
+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 && ctx->enable_cdpl3)
+ ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, true);
+
+ if (!ret && ctx->enable_mba_mbps)
+ ret = set_mba_sc(true);
+
+ 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;
+
+ 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);
+ struct rdt_domain *dom;
+ struct rdt_resource *r;
+ int ret;
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+ /*
+ * resctrl file system can only be mounted once.
+ */
+ if (static_branch_unlikely(&rdt_enable_key)) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ ret = rdt_enable_ctx(ctx);
+ if (ret < 0)
+ goto out_cdp;
+
+ ret = schemata_list_create();
+ if (ret) {
+ schemata_list_destroy();
+ goto out_mba;
+ }
+
+ closid_init();
+
+ ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
+ if (ret < 0)
+ goto out_schemata_free;
+
+ if (rdt_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 (rdt_alloc_capable)
+ static_branch_enable_cpuslocked(&rdt_alloc_enable_key);
+ if (rdt_mon_capable)
+ static_branch_enable_cpuslocked(&rdt_mon_enable_key);
+
+ if (rdt_alloc_capable || rdt_mon_capable)
+ static_branch_enable_cpuslocked(&rdt_enable_key);
+
+ if (is_mbm_enabled()) {
+ r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
+ list_for_each_entry(dom, &r->domains, list)
+ mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL);
+ }
+
+ goto out;
+
+out_psl:
+ rdt_pseudo_lock_release();
+out_mondata:
+ if (rdt_mon_capable)
+ kernfs_remove(kn_mondata);
+out_mongrp:
+ if (rdt_mon_capable)
+ kernfs_remove(kn_mongrp);
+out_info:
+ kernfs_remove(kn_info);
+out_schemata_free:
+ schemata_list_destroy();
+out_mba:
+ if (ctx->enable_mba_mbps)
+ set_mba_sc(false);
+out_cdp:
+ cdp_disable_all();
+out:
+ rdt_last_cmd_clear();
+ mutex_unlock(&rdtgroup_mutex);
+ cpus_read_unlock();
+ return ret;
+}
+
+enum rdt_param {
+ Opt_cdp,
+ Opt_cdpl2,
+ Opt_mba_mbps,
+ 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),
+ {}
+};
+
+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;
+ 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:
+ if (!supports_mba_mbps())
+ return -EINVAL;
+ ctx->enable_mba_mbps = 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(struct rdt_fs_context), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->kfc.root = rdt_root;
+ 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;
+}
+
+static int reset_all_ctrls(struct rdt_resource *r)
+{
+ struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
+ struct rdt_hw_domain *hw_dom;
+ struct msr_param msr_param;
+ cpumask_var_t cpu_mask;
+ struct rdt_domain *d;
+ int i, cpu;
+
+ if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
+ return -ENOMEM;
+
+ msr_param.res = r;
+ msr_param.low = 0;
+ msr_param.high = hw_res->num_closid;
+
+ /*
+ * Disable resource control for this resource by setting all
+ * CBMs in all domains to the maximum mask value. Pick one CPU
+ * from each domain to update the MSRs below.
+ */
+ list_for_each_entry(d, &r->domains, list) {
+ hw_dom = resctrl_to_arch_dom(d);
+ cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
+
+ for (i = 0; i < hw_res->num_closid; i++)
+ hw_dom->ctrl_val[i] = r->default_ctrl;
+ }
+ cpu = get_cpu();
+ /* Update CBM on this cpu if it's in cpu_mask. */
+ if (cpumask_test_cpu(cpu, cpu_mask))
+ rdt_ctrl_update(&msr_param);
+ /* Update CBM on all other cpus in cpu_mask. */
+ smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1);
+ put_cpu();
+
+ free_cpumask_var(cpu_mask);
+
+ 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)) {
+ WRITE_ONCE(t->closid, to->closid);
+ WRITE_ONCE(t->rmid, 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_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->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->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);
+}
+
+static void rdt_kill_sb(struct super_block *sb)
+{
+ struct rdt_resource *r;
+
+ cpus_read_lock();
+ mutex_lock(&rdtgroup_mutex);
+
+ set_mba_sc(false);
+
+ /*Put everything back to default values. */
+ for_each_alloc_capable_rdt_resource(r)
+ reset_all_ctrls(r);
+ cdp_disable_all();
+ rmdir_all_sub();
+ rdt_pseudo_lock_release();
+ rdtgroup_default.mode = RDT_MODE_SHAREABLE;
+ schemata_list_destroy();
+ static_branch_disable_cpuslocked(&rdt_alloc_enable_key);
+ static_branch_disable_cpuslocked(&rdt_mon_enable_key);
+ static_branch_disable_cpuslocked(&rdt_enable_key);
+ 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;
+}
+
+/*
+ * Remove all subdirectories of mon_data of ctrl_mon groups
+ * and monitor groups with given domain id.
+ */
+static void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
+ unsigned int dom_id)
+{
+ struct rdtgroup *prgrp, *crgrp;
+ char name[32];
+
+ list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
+ sprintf(name, "mon_%s_%02d", r->name, dom_id);
+ kernfs_remove_by_name(prgrp->mon.mon_data_kn, name);
+
+ list_for_each_entry(crgrp, &prgrp->mon.crdtgrp_list, mon.crdtgrp_list)
+ kernfs_remove_by_name(crgrp->mon.mon_data_kn, name);
+ }
+}
+
+static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
+ struct rdt_domain *d,
+ struct rdt_resource *r, struct rdtgroup *prgrp)
+{
+ union mon_data_bits priv;
+ struct kernfs_node *kn;
+ struct mon_evt *mevt;
+ struct rmid_read rr;
+ char name[32];
+ int ret;
+
+ sprintf(name, "mon_%s_%02d", r->name, d->id);
+ /* create the directory */
+ 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;
+
+ if (WARN_ON(list_empty(&r->evt_list))) {
+ ret = -EPERM;
+ goto out_destroy;
+ }
+
+ priv.u.rid = r->rid;
+ priv.u.domid = d->id;
+ list_for_each_entry(mevt, &r->evt_list, list) {
+ priv.u.evtid = mevt->evtid;
+ ret = mon_addfile(kn, mevt->name, priv.priv);
+ if (ret)
+ goto out_destroy;
+
+ if (is_mbm_event(mevt->evtid))
+ mon_event_read(&rr, r, d, prgrp, mevt->evtid, true);
+ }
+ 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_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_domain *dom;
+ int ret;
+
+ list_for_each_entry(dom, &r->domains, 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_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->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_domain *d;
+ int ret;
+
+ list_for_each_entry(d, &s->res->domains, 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_domain *d;
+
+ list_for_each_entry(d, &r->domains, list) {
+ if (is_mba_sc(r)) {
+ d->mbps_val[closid] = MBA_MAX_MBPS;
+ continue;
+ }
+
+ cfg = &d->staged_config[CDP_NONE];
+ cfg->new_ctrl = r->default_ctrl;
+ 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) {
+ 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(struct kernfs_node *parent_kn,
+ const char *name, umode_t mode,
+ enum rdt_group_type rtype, struct rdtgroup **r)
+{
+ struct rdtgroup *prdtgrp, *rdtgrp;
+ struct kernfs_node *kn;
+ uint files = 0;
+ int ret;
+
+ prdtgrp = rdtgroup_kn_lock_live(parent_kn);
+ if (!prdtgrp) {
+ ret = -ENODEV;
+ 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;
+ }
+
+ files = RFTYPE_BASE | BIT(RF_CTRLSHIFT + rtype);
+ ret = rdtgroup_add_files(kn, files);
+ if (ret) {
+ rdt_last_cmd_puts("kernfs fill error\n");
+ goto out_destroy;
+ }
+
+ if (rdt_mon_capable) {
+ ret = alloc_rmid();
+ if (ret < 0) {
+ rdt_last_cmd_puts("Out of RMIDs\n");
+ goto out_destroy;
+ }
+ rdtgrp->mon.rmid = ret;
+
+ ret = mkdir_mondata_all(kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
+ if (ret) {
+ rdt_last_cmd_puts("kernfs subdir error\n");
+ goto out_idfree;
+ }
+ }
+ kernfs_activate(kn);
+
+ /*
+ * The caller unlocks the parent_kn upon success.
+ */
+ return 0;
+
+out_idfree:
+ free_rmid(rdtgrp->mon.rmid);
+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);
+ free_rmid(rgrp->mon.rmid);
+ 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;
+
+ /*
+ * Add the rdtgrp to the list of rdtgrps the parent
+ * ctrl_mon group has to track.
+ */
+ list_add_tail(&rdtgrp->mon.crdtgrp_list, &prgrp->mon.crdtgrp_list);
+
+ rdtgroup_kn_unlock(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 = rdtgroup_init_alloc(rdtgrp);
+ if (ret < 0)
+ goto out_id_free;
+
+ list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups);
+
+ if (rdt_mon_capable) {
+ /*
+ * Create an empty mon_groups directory to hold the subset
+ * of tasks and cpus to monitor.
+ */
+ ret = mongroup_create_dir(kn, rdtgrp, "mon_groups", NULL);
+ if (ret) {
+ rdt_last_cmd_puts("kernfs subdir error\n");
+ goto out_del_list;
+ }
+ }
+
+ goto out_unlock;
+
+out_del_list:
+ list_del(&rdtgrp->rdtgroup_list);
+out_id_free:
+ closid_free(closid);
+out_common_fail:
+ mkdir_rdt_prepare_clean(rdtgrp);
+out_unlock:
+ rdtgroup_kn_unlock(parent_kn);
+ return ret;
+}
+
+/*
+ * We allow creating mon groups only with in a directory called "mon_groups"
+ * which is present in every ctrl_mon group. Check if this is a valid
+ * "mon_groups" directory.
+ *
+ * 1. The directory should be named "mon_groups".
+ * 2. The mon group itself should "not" be named "mon_groups".
+ * This makes sure "mon_groups" directory always has a ctrl_mon group
+ * as parent.
+ */
+static bool is_mon_groups(struct kernfs_node *kn, const char *name)
+{
+ return (!strcmp(kn->name, "mon_groups") &&
+ strcmp(name, "mon_groups"));
+}
+
+static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
+ umode_t mode)
+{
+ /* 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 (rdt_alloc_capable && parent_kn == rdtgroup_default.kn)
+ return rdtgroup_mkdir_ctrl_mon(parent_kn, name, mode);
+
+ /*
+ * If RDT monitoring is supported and the parent directory is a valid
+ * "mon_groups" directory, add a monitoring subdirectory.
+ */
+ if (rdt_mon_capable && is_mon_groups(parent_kn, name))
+ return rdtgroup_mkdir_mon(parent_kn, name, mode);
+
+ return -EPERM;
+}
+
+static int rdtgroup_rmdir_mon(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask)
+{
+ struct rdtgroup *prdtgrp = rdtgrp->mon.parent;
+ int cpu;
+
+ /* Give any tasks back to the parent group */
+ rdt_move_group_tasks(rdtgrp, prdtgrp, tmpmask);
+
+ /* Update per cpu rmid of the moved CPUs first */
+ for_each_cpu(cpu, &rdtgrp->cpu_mask)
+ per_cpu(pqr_state.default_rmid, cpu) = prdtgrp->mon.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->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)
+{
+ 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 */
+ for_each_cpu(cpu, &rdtgrp->cpu_mask) {
+ per_cpu(pqr_state.default_closid, cpu) = rdtgroup_default.closid;
+ per_cpu(pqr_state.default_rmid, cpu) = rdtgroup_default.mon.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);
+
+ closid_free(rdtgrp->closid);
+ free_rmid(rdtgrp->mon.rmid);
+
+ rdtgroup_ctrl_remove(rdtgrp);
+
+ /*
+ * Free all the child monitor group rmids.
+ */
+ free_all_child_rdtgrp(rdtgrp);
+
+ return 0;
+}
+
+static int rdtgroup_rmdir(struct kernfs_node *kn)
+{
+ struct kernfs_node *parent_kn = kn->parent;
+ 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;
+ }
+
+ /*
+ * 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, kn->name)) {
+ ret = rdtgroup_rmdir_mon(rdtgrp, tmpmask);
+ } else {
+ ret = -EPERM;
+ }
+
+out:
+ rdtgroup_kn_unlock(kn);
+ free_cpumask_var(tmpmask);
+ 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(&rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl))
+ seq_puts(seq, ",mba_MBps");
+
+ return 0;
+}
+
+static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = {
+ .mkdir = rdtgroup_mkdir,
+ .rmdir = rdtgroup_rmdir,
+ .show_options = rdtgroup_show_options,
+};
+
+static int __init rdtgroup_setup_root(void)
+{
+ int ret;
+
+ 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);
+
+ mutex_lock(&rdtgroup_mutex);
+
+ rdtgroup_default.closid = 0;
+ rdtgroup_default.mon.rmid = 0;
+ rdtgroup_default.type = RDTCTRL_GROUP;
+ INIT_LIST_HEAD(&rdtgroup_default.mon.crdtgrp_list);
+
+ list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups);
+
+ ret = rdtgroup_add_files(kernfs_root_to_node(rdt_root), RF_CTRL_BASE);
+ if (ret) {
+ kernfs_destroy_root(rdt_root);
+ goto out;
+ }
+
+ rdtgroup_default.kn = kernfs_root_to_node(rdt_root);
+ kernfs_activate(rdtgroup_default.kn);
+
+out:
+ mutex_unlock(&rdtgroup_mutex);
+
+ return ret;
+}
+
+static void domain_destroy_mon_state(struct rdt_domain *d)
+{
+ bitmap_free(d->rmid_busy_llc);
+ kfree(d->mbm_total);
+ kfree(d->mbm_local);
+}
+
+void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d)
+{
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA)
+ mba_sc_domain_destroy(r, d);
+
+ if (!r->mon_capable)
+ return;
+
+ /*
+ * If resctrl is mounted, remove all the
+ * per domain monitor data directories.
+ */
+ if (static_branch_unlikely(&rdt_mon_enable_key))
+ rmdir_mondata_subdir_allrdtgrp(r, d->id);
+
+ if (is_mbm_enabled())
+ cancel_delayed_work(&d->mbm_over);
+ if (is_llc_occupancy_enabled() && has_busy_rmid(r, 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);
+}
+
+static int domain_setup_mon_state(struct rdt_resource *r, struct rdt_domain *d)
+{
+ size_t tsize;
+
+ if (is_llc_occupancy_enabled()) {
+ d->rmid_busy_llc = bitmap_zalloc(r->num_rmid, GFP_KERNEL);
+ if (!d->rmid_busy_llc)
+ return -ENOMEM;
+ }
+ if (is_mbm_total_enabled()) {
+ tsize = sizeof(*d->mbm_total);
+ d->mbm_total = kcalloc(r->num_rmid, tsize, GFP_KERNEL);
+ if (!d->mbm_total) {
+ bitmap_free(d->rmid_busy_llc);
+ return -ENOMEM;
+ }
+ }
+ if (is_mbm_local_enabled()) {
+ tsize = sizeof(*d->mbm_local);
+ d->mbm_local = kcalloc(r->num_rmid, tsize, GFP_KERNEL);
+ if (!d->mbm_local) {
+ bitmap_free(d->rmid_busy_llc);
+ kfree(d->mbm_total);
+ return -ENOMEM;
+ }
+ }
+
+ return 0;
+}
+
+int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d)
+{
+ int err;
+
+ lockdep_assert_held(&rdtgroup_mutex);
+
+ if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA)
+ /* RDT_RESOURCE_MBA is never mon_capable */
+ return mba_sc_domain_allocate(r, d);
+
+ if (!r->mon_capable)
+ return 0;
+
+ err = domain_setup_mon_state(r, d);
+ if (err)
+ return err;
+
+ if (is_mbm_enabled()) {
+ INIT_DELAYED_WORK(&d->mbm_over, mbm_handle_overflow);
+ mbm_setup_overflow_handler(d, MBM_OVERFLOW_INTERVAL);
+ }
+
+ if (is_llc_occupancy_enabled())
+ INIT_DELAYED_WORK(&d->cqm_limbo, cqm_handle_limbo);
+
+ /* If resctrl is mounted, add per domain monitor data directories. */
+ if (static_branch_unlikely(&rdt_mon_enable_key))
+ mkdir_mondata_subdir_allrdtgrp(r, d);
+
+ return 0;
+}
+
+/*
+ * rdtgroup_init - rdtgroup initialization
+ *
+ * Setup resctrl file system including set up root, create mount point,
+ * register rdtgroup filesystem, and initialize files under root directory.
+ *
+ * Return: 0 on success or -errno
+ */
+int __init rdtgroup_init(void)
+{
+ int ret = 0;
+
+ seq_buf_init(&last_cmd_status, last_cmd_status_buf,
+ sizeof(last_cmd_status_buf));
+
+ ret = rdtgroup_setup_root();
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_mount_point(fs_kobj, "resctrl");
+ if (ret)
+ goto cleanup_root;
+
+ 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");
+cleanup_root:
+ kernfs_destroy_root(rdt_root);
+
+ return ret;
+}
+
+void __exit rdtgroup_exit(void)
+{
+ debugfs_remove_recursive(debugfs_resctrl);
+ unregister_filesystem(&rdt_fs_type);
+ sysfs_remove_mount_point(fs_kobj, "resctrl");
+ kernfs_destroy_root(rdt_root);
+}