24 Mar
2021
24 Mar
'21
2:30 p.m.
From: Xie XiuQi <xiexiuqi(a)huawei.com>
commit e1b8071e6757590bcbc0284ff9d22768b8e41fc8 openEuler-1.0
hulk inclusion
category: feature
bugzilla: 5510
CVE: NA
Signed-off-by: Xie XiuQi <xiexiuqi(a)huawei.com>
Reviewed-by: Hanjun Guo <guohanjun(a)huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com>
[ Avoid X86 compile fail, change RESCTRL to RESCTRL_ARM64 ]
Signed-off-by: Xin Hao <haoxing990(a)gmail.com>
---
fs/Makefile | 1 +
fs/resctrlfs.c | 930 ++++++++++++++++++++++++++++++++++++++
include/linux/resctrlfs.h | 97 ++++
3 files changed, 1028 insertions(+)
create mode 100644 fs/resctrlfs.c
create mode 100644 include/linux/resctrlfs.h
diff --git a/fs/Makefile b/fs/Makefile
index 28354ea44ed7..6d4b42afba65 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -130,3 +130,4 @@ obj-y += exofs/ # Multiple modules
obj-$(CONFIG_CEPH_FS) += ceph/
obj-$(CONFIG_PSTORE) += pstore/
obj-$(CONFIG_EFIVAR_FS) += efivarfs/
+obj-$(CONFIG_RESCTRL_AARCH64) += resctrlfs.o
diff --git a/fs/resctrlfs.c b/fs/resctrlfs.c
new file mode 100644
index 000000000000..3016dea8c9b7
--- /dev/null
+++ b/fs/resctrlfs.c
@@ -0,0 +1,930 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * User interface for Resource Alloction in Resource Director Technology(RDT)
+ *
+ * Copyright (C) 2016 Intel Corporation
+ *
+ * Author: Fenghua Yu <fenghua.yu(a)intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * 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/fs.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/resctrlfs.h>
+
+#include <uapi/linux/magic.h>
+
+#include <asm/resctrl.h>
+
+DEFINE_STATIC_KEY_FALSE(resctrl_enable_key);
+DEFINE_STATIC_KEY_FALSE(resctrl_mon_enable_key);
+DEFINE_STATIC_KEY_FALSE(resctrl_alloc_enable_key);
+static struct kernfs_root *resctrl_root;
+struct resctrl_group resctrl_group_default;
+LIST_HEAD(resctrl_all_groups);
+
+/* 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;
+
+/* set uid and gid of resctrl_group dirs and files to that of the creator */
+static int resctrl_group_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 resctrl_group_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,
+ 0, rft->kf_ops, rft, NULL, NULL);
+ if (IS_ERR(kn))
+ return PTR_ERR(kn);
+
+ ret = resctrl_group_kn_set_ugid(kn);
+ if (ret) {
+ kernfs_remove(kn);
+ return ret;
+ }
+
+ return 0;
+}
+
+static struct rftype *res_common_files;
+static size_t res_common_files_len;
+
+int register_resctrl_specific_files(struct rftype *files, size_t len)
+{
+ if (res_common_files) {
+ pr_err("Only allowed register specific files once\n");
+ return -EINVAL;
+ }
+
+ if (!files) {
+ pr_err("Invalid input files\n");
+ return -EINVAL;
+ }
+
+ res_common_files = files;
+ res_common_files_len = len;
+
+ return 0;
+}
+
+static int __resctrl_group_add_files(struct kernfs_node *kn, unsigned long fflags,
+ struct rftype *rfts, int len)
+{
+ struct rftype *rft;
+ int ret;
+
+ lockdep_assert_held(&resctrl_group_mutex);
+
+ for (rft = rfts; rft < rfts + len; rft++) {
+ if (rft->enable && !rft->enable(NULL))
+ continue;
+
+ if ((fflags & rft->fflags) == rft->fflags) {
+ ret = resctrl_group_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 int resctrl_group_add_files(struct kernfs_node *kn, unsigned long fflags)
+{
+ int ret;
+
+ if (res_common_files)
+ ret = __resctrl_group_add_files(kn, fflags, res_common_files,
+ res_common_files_len);
+
+ return ret;
+}
+
+static int resctrl_group_mkdir_info_resdir(struct resctrl_resource *r, char *name,
+ unsigned long fflags)
+{
+ struct kernfs_node *kn_subdir;
+ int ret;
+
+ kn_subdir = kernfs_create_dir(kn_info, name,
+ kn_info->mode, r);
+ if (IS_ERR(kn_subdir))
+ return PTR_ERR(kn_subdir);
+
+ kernfs_get(kn_subdir);
+ ret = resctrl_group_kn_set_ugid(kn_subdir);
+ if (ret)
+ return ret;
+
+ ret = resctrl_group_add_files(kn_subdir, fflags);
+ if (!ret)
+ kernfs_activate(kn_subdir);
+
+ return ret;
+}
+
+static int resctrl_group_create_info_dir(struct kernfs_node *parent_kn)
+{
+ struct resctrl_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);
+ kernfs_get(kn_info);
+
+ ret = resctrl_group_add_files(kn_info, RF_TOP_INFO);
+ if (ret)
+ goto out_destroy;
+
+ for_each_alloc_enabled_resctrl_resource(r) {
+ fflags = r->fflags | RF_CTRL_INFO;
+ ret = resctrl_group_mkdir_info_resdir(r, r->name, fflags);
+ if (ret)
+ goto out_destroy;
+ }
+
+ for_each_mon_enabled_resctrl_resource(r) {
+ fflags = r->fflags | RF_MON_INFO;
+ sprintf(name, "%s_MON", r->name);
+ ret = resctrl_group_mkdir_info_resdir(r, name, fflags);
+ if (ret)
+ goto out_destroy;
+ }
+
+ /*
+ * This extra ref will be put in kernfs_remove() and guarantees
+ * that @rdtgrp->kn is always accessible.
+ */
+ kernfs_get(kn_info);
+
+ ret = resctrl_group_kn_set_ugid(kn_info);
+ if (ret)
+ goto out_destroy;
+
+ kernfs_activate(kn_info);
+
+ return 0;
+
+out_destroy:
+ kernfs_remove(kn_info);
+ return ret;
+}
+
+/*
+ * We don't allow resctrl_group directories to be created anywhere
+ * except the root directory. Thus when looking for the resctrl_group
+ * structure for a kernfs node we are either looking at a directory,
+ * in which case the resctrl_group structure is pointed at by the "priv"
+ * field, otherwise we have a file, and need only look to the parent
+ * to find the resctrl_group.
+ */
+static struct resctrl_group *kernfs_to_resctrl_group(struct kernfs_node *kn)
+{
+ if (kernfs_type(kn) == KERNFS_DIR) {
+ /*
+ * All the resource directories use "kn->priv"
+ * to point to the "struct resctrl_group" for the
+ * resource. "info" and its subdirectories don't
+ * have resctrl_group 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 resctrl_group *resctrl_group_kn_lock_live(struct kernfs_node *kn)
+{
+ struct resctrl_group *rdtgrp = kernfs_to_resctrl_group(kn);
+
+ if (!rdtgrp)
+ return NULL;
+
+ atomic_inc(&rdtgrp->waitcount);
+ kernfs_break_active_protection(kn);
+
+ mutex_lock(&resctrl_group_mutex);
+
+ /* Was this group deleted while we waited? */
+ if (rdtgrp->flags & RDT_DELETED)
+ return NULL;
+
+ return rdtgrp;
+}
+
+void resctrl_group_kn_unlock(struct kernfs_node *kn)
+{
+ struct resctrl_group *rdtgrp = kernfs_to_resctrl_group(kn);
+
+ if (!rdtgrp)
+ return;
+
+ mutex_unlock(&resctrl_group_mutex);
+
+ if (atomic_dec_and_test(&rdtgrp->waitcount) &&
+ (rdtgrp->flags & RDT_DELETED)) {
+ kernfs_unbreak_active_protection(kn);
+ kernfs_put(rdtgrp->kn);
+ kfree(rdtgrp);
+ } else {
+ kernfs_unbreak_active_protection(kn);
+ }
+}
+
+static struct dentry *resctrl_mount(struct file_system_type *fs_type,
+ int flags, const char *unused_dev_name,
+ void *data)
+{
+ struct dentry *dentry;
+ int ret;
+
+ cpus_read_lock();
+ mutex_lock(&resctrl_group_mutex);
+ /*
+ * resctrl file system can only be mounted once.
+ */
+ if (static_branch_unlikely(&resctrl_enable_key)) {
+ dentry = ERR_PTR(-EBUSY);
+ goto out;
+ }
+
+ ret = parse_resctrl_group_fs_options(data);
+ if (ret) {
+ dentry = ERR_PTR(ret);
+ goto out_options;
+ }
+
+ resctrl_id_init();
+
+ ret = resctrl_group_create_info_dir(resctrl_group_default.kn);
+ if (ret) {
+ dentry = ERR_PTR(ret);
+ goto out_options;
+ }
+
+ if (resctrl_mon_capable) {
+ ret = mongroup_create_dir(resctrl_group_default.kn,
+ NULL, "mon_groups",
+ &kn_mongrp);
+ if (ret) {
+ dentry = ERR_PTR(ret);
+ goto out_info;
+ }
+ kernfs_get(kn_mongrp);
+
+ ret = mkdir_mondata_all(resctrl_group_default.kn,
+ &resctrl_group_default, &kn_mondata);
+ if (ret) {
+ dentry = ERR_PTR(ret);
+ goto out_mongrp;
+ }
+ kernfs_get(kn_mondata);
+ resctrl_group_default.mon.mon_data_kn = kn_mondata;
+ }
+
+ dentry = kernfs_mount(fs_type, flags, resctrl_root,
+ RDTGROUP_SUPER_MAGIC, NULL);
+ if (IS_ERR(dentry))
+ goto out_mondata;
+
+ post_resctrl_mount();
+
+ goto out;
+
+out_mondata:
+ if (resctrl_mon_capable)
+ kernfs_remove(kn_mondata);
+out_mongrp:
+ if (resctrl_mon_capable)
+ kernfs_remove(kn_mongrp);
+out_info:
+ kernfs_remove(kn_info);
+out_options:
+ release_resctrl_group_fs_options();
+out:
+ rdt_last_cmd_clear();
+ mutex_unlock(&resctrl_group_mutex);
+ cpus_read_unlock();
+
+ return dentry;
+}
+
+static bool is_closid_match(struct task_struct *t, struct resctrl_group *r)
+{
+ return (resctrl_alloc_capable &&
+ (r->type == RDTCTRL_GROUP) && (t->closid == r->closid));
+}
+
+static bool is_rmid_match(struct task_struct *t, struct resctrl_group *r)
+{
+ return (resctrl_mon_capable &&
+ (r->type == RDTMON_GROUP) && (t->rmid == r->mon.rmid));
+}
+
+/*
+ * 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 resctrl_move_group_tasks(struct resctrl_group *from, struct resctrl_group
*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)) {
+ t->closid = to->closid;
+ t->rmid = to->mon.rmid;
+
+#ifdef CONFIG_SMP
+ /*
+ * This is safe on x86 w/o barriers as the ordering
+ * of writing to task_cpu() and t->on_cpu is
+ * reverse to the reading here. 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 (mask && t->on_cpu)
+ cpumask_set_cpu(task_cpu(t), mask);
+#endif
+ }
+ }
+ read_unlock(&tasklist_lock);
+}
+
+static void free_all_child_rdtgrp(struct resctrl_group *rdtgrp)
+{
+ struct resctrl_group *sentry, *stmp;
+ struct list_head *head;
+
+ head = &rdtgrp->mon.crdtgrp_list;
+ list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) {
+ free_mon_id(sentry->mon.rmid);
+ list_del(&sentry->mon.crdtgrp_list);
+ kfree(sentry);
+ }
+}
+
+/*
+ * Forcibly remove all of subdirectories under root.
+ */
+static void rmdir_all_sub(void)
+{
+ struct resctrl_group *rdtgrp, *tmp;
+
+ /* Move all tasks to the default resource group */
+ resctrl_move_group_tasks(NULL, &resctrl_group_default, NULL);
+
+ list_for_each_entry_safe(rdtgrp, tmp, &resctrl_all_groups, resctrl_group_list) {
+ /* Free any child rmids */
+ free_all_child_rdtgrp(rdtgrp);
+
+ /* Remove each resctrl_group other than root */
+ if (rdtgrp == &resctrl_group_default)
+ continue;
+
+ /*
+ * 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(&resctrl_group_default.cpu_mask,
+ &resctrl_group_default.cpu_mask, &rdtgrp->cpu_mask);
+
+ free_mon_id(rdtgrp->mon.rmid);
+
+ kernfs_remove(rdtgrp->kn);
+ list_del(&rdtgrp->resctrl_group_list);
+ kfree(rdtgrp);
+ }
+ /* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */
+ update_closid_rmid(cpu_online_mask, &resctrl_group_default);
+
+ kernfs_remove(kn_info);
+ kernfs_remove(kn_mongrp);
+ kernfs_remove(kn_mondata);
+}
+
+static void resctrl_kill_sb(struct super_block *sb)
+{
+
+ cpus_read_lock();
+ mutex_lock(&resctrl_group_mutex);
+
+ resctrl_resource_reset();
+
+ rmdir_all_sub();
+ static_branch_disable_cpuslocked(&resctrl_alloc_enable_key);
+ static_branch_disable_cpuslocked(&resctrl_mon_enable_key);
+ static_branch_disable_cpuslocked(&resctrl_enable_key);
+ kernfs_kill_sb(sb);
+ mutex_unlock(&resctrl_group_mutex);
+ cpus_read_unlock();
+}
+
+static struct file_system_type resctrl_fs_type = {
+ .name = "resctrl",
+ .mount = resctrl_mount,
+ .kill_sb = resctrl_kill_sb,
+};
+
+static int mkdir_resctrl_prepare(struct kernfs_node *parent_kn,
+ struct kernfs_node *prgrp_kn,
+ const char *name, umode_t mode,
+ enum rdt_group_type rtype, struct resctrl_group **r)
+{
+ struct resctrl_group *prdtgrp, *rdtgrp;
+ struct kernfs_node *kn;
+ uint files = 0;
+ int ret;
+
+ prdtgrp = resctrl_group_kn_lock_live(prgrp_kn);
+ rdt_last_cmd_clear();
+ if (!prdtgrp) {
+ ret = -ENODEV;
+ rdt_last_cmd_puts("directory was removed\n");
+ goto out_unlock;
+ }
+
+ /* allocate the resctrl_group. */
+ 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
+ * resctrl_group_kn_unlock(kn} call below. Take one extra reference
+ * here, which will be dropped inside resctrl_group_kn_unlock().
+ */
+ kernfs_get(kn);
+
+ ret = resctrl_group_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 = resctrl_group_add_files(kn, files);
+ if (ret) {
+ rdt_last_cmd_puts("kernfs fill error\n");
+ goto out_destroy;
+ }
+
+ if (resctrl_mon_capable) {
+ ret = alloc_mon_id();
+ 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 prgrp_kn upon success.
+ */
+ return 0;
+
+out_idfree:
+ free_mon_id(rdtgrp->mon.rmid);
+out_destroy:
+ kernfs_remove(rdtgrp->kn);
+out_free_rgrp:
+ kfree(rdtgrp);
+out_unlock:
+ resctrl_group_kn_unlock(prgrp_kn);
+ return ret;
+}
+
+static void mkdir_resctrl_prepare_clean(struct resctrl_group *rgrp)
+{
+ kernfs_remove(rgrp->kn);
+ free_mon_id(rgrp->mon.rmid);
+ kfree(rgrp);
+}
+
+/*
+ * Create a monitor group under "mon_groups" directory of a control
+ * and monitor group(ctrl_mon). This is a resource group
+ * to monitor a subset of tasks and cpus in its parent ctrl_mon group.
+ */
+static int resctrl_group_mkdir_mon(struct kernfs_node *parent_kn,
+ struct kernfs_node *prgrp_kn,
+ const char *name,
+ umode_t mode)
+{
+ struct resctrl_group *rdtgrp, *prgrp;
+ int ret;
+
+ ret = mkdir_resctrl_prepare(parent_kn, prgrp_kn, name, mode, RDTMON_GROUP,
+ &rdtgrp);
+ if (ret)
+ return ret;
+
+ prgrp = rdtgrp->mon.parent;
+ rdtgrp->closid = prgrp->closid;
+
+ /*
+ * Add the rdtgrp to the list of rdtgrps the parent
+ * ctrl_mon group has to track.
+ */
+ list_add_tail(&rdtgrp->mon.crdtgrp_list, &prgrp->mon.crdtgrp_list);
+
+ resctrl_group_kn_unlock(prgrp_kn);
+ return ret;
+}
+
+/*
+ * These are resctrl_groups created under the root directory. Can be used
+ * to allocate and monitor resources.
+ */
+static int resctrl_group_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
+ struct kernfs_node *prgrp_kn,
+ const char *name, umode_t mode)
+{
+ struct resctrl_group *rdtgrp;
+ struct kernfs_node *kn;
+ u32 closid;
+ int ret;
+
+ ret = mkdir_resctrl_prepare(parent_kn, prgrp_kn, name, mode, RDTCTRL_GROUP,
+ &rdtgrp);
+ if (ret)
+ return ret;
+
+ kn = rdtgrp->kn;
+ ret = resctrl_id_alloc();
+ if (ret < 0) {
+ rdt_last_cmd_puts("out of CLOSIDs\n");
+ goto out_common_fail;
+ }
+ closid = ret;
+ ret = 0;
+
+ rdtgrp->closid = closid;
+ list_add(&rdtgrp->resctrl_group_list, &resctrl_all_groups);
+
+ if (resctrl_mon_capable) {
+ /*
+ * Create an empty mon_groups directory to hold the subset
+ * of tasks and cpus to monitor.
+ */
+ ret = mongroup_create_dir(kn, NULL, "mon_groups", NULL);
+ if (ret) {
+ rdt_last_cmd_puts("kernfs subdir error\n");
+ goto out_id_free;
+ }
+ }
+
+ goto out_unlock;
+
+out_id_free:
+ resctrl_id_free(closid);
+ list_del(&rdtgrp->resctrl_group_list);
+out_common_fail:
+ mkdir_resctrl_prepare_clean(rdtgrp);
+out_unlock:
+ resctrl_group_kn_unlock(prgrp_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 resctrl_group_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_alloc_capable && parent_kn == resctrl_group_default.kn)
+ return resctrl_group_mkdir_ctrl_mon(parent_kn, parent_kn, name, mode);
+
+ /*
+ * If RDT monitoring is supported and the parent directory is a valid
+ * "mon_groups" directory, add a monitoring subdirectory.
+ */
+ if (resctrl_mon_capable && is_mon_groups(parent_kn, name))
+ return resctrl_group_mkdir_mon(parent_kn, parent_kn->parent, name, mode);
+
+ return -EPERM;
+}
+
+static void resctrl_group_rm_mon(struct resctrl_group *rdtgrp,
+ cpumask_var_t tmpmask)
+{
+ struct resctrl_group *prdtgrp = rdtgrp->mon.parent;
+ int cpu;
+
+ /* Give any tasks back to the parent group */
+ resctrl_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_mon_id(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);
+}
+
+static int resctrl_group_rmdir_mon(struct kernfs_node *kn, struct resctrl_group *rdtgrp,
+ cpumask_var_t tmpmask)
+{
+ resctrl_group_rm_mon(rdtgrp, tmpmask);
+
+ /*
+ * one extra hold on this, will drop when we kfree(rdtgrp)
+ * in resctrl_group_kn_unlock()
+ */
+ kernfs_get(kn);
+ kernfs_remove(rdtgrp->kn);
+
+ return 0;
+}
+
+static void resctrl_group_rm_ctrl(struct resctrl_group *rdtgrp, cpumask_var_t tmpmask)
+{
+ int cpu;
+
+ /* Give any tasks back to the default group */
+ resctrl_move_group_tasks(rdtgrp, &resctrl_group_default, tmpmask);
+
+ /* Give any CPUs back to the default group */
+ cpumask_or(&resctrl_group_default.cpu_mask,
+ &resctrl_group_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) = resctrl_group_default.closid;
+ per_cpu(pqr_state.default_rmid, cpu) = resctrl_group_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);
+
+ rdtgrp->flags = RDT_DELETED;
+ resctrl_id_free(rdtgrp->closid);
+ free_mon_id(rdtgrp->mon.rmid);
+
+ /*
+ * Free all the child monitor group rmids.
+ */
+ free_all_child_rdtgrp(rdtgrp);
+
+ list_del(&rdtgrp->resctrl_group_list);
+}
+
+static int resctrl_group_rmdir_ctrl(struct kernfs_node *kn, struct resctrl_group
*rdtgrp,
+ cpumask_var_t tmpmask)
+{
+ resctrl_group_rm_ctrl(rdtgrp, tmpmask);
+
+ /*
+ * one extra hold on this, will drop when we kfree(rdtgrp)
+ * in resctrl_group_kn_unlock()
+ */
+ kernfs_get(kn);
+ kernfs_remove(rdtgrp->kn);
+
+ return 0;
+}
+
+static int resctrl_group_rmdir(struct kernfs_node *kn)
+{
+ struct kernfs_node *parent_kn = kn->parent;
+ struct resctrl_group *rdtgrp;
+ cpumask_var_t tmpmask;
+ int ret = 0;
+
+ if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
+ return -ENOMEM;
+
+ rdtgrp = resctrl_group_kn_lock_live(kn);
+ if (!rdtgrp) {
+ ret = -EPERM;
+ goto out;
+ }
+
+ /*
+ * If the resctrl_group is a ctrl_mon group and parent directory
+ * is the root directory, remove the ctrl_mon group.
+ *
+ * If the resctrl_group is a mon group and parent directory
+ * is a valid "mon_groups" directory, remove the mon group.
+ */
+ if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == resctrl_group_default.kn)
+ ret = resctrl_group_rmdir_ctrl(kn, rdtgrp, tmpmask);
+ else if (rdtgrp->type == RDTMON_GROUP &&
+ is_mon_groups(parent_kn, kn->name))
+ ret = resctrl_group_rmdir_mon(kn, rdtgrp, tmpmask);
+ else
+ ret = -EPERM;
+
+out:
+ resctrl_group_kn_unlock(kn);
+ free_cpumask_var(tmpmask);
+ return ret;
+}
+
+static int resctrl_group_show_options(struct seq_file *seq, struct kernfs_root *kf)
+{
+ return __resctrl_group_show_options(seq);
+}
+
+static struct kernfs_syscall_ops resctrl_group_kf_syscall_ops = {
+ .mkdir = resctrl_group_mkdir,
+ .rmdir = resctrl_group_rmdir,
+ .show_options = resctrl_group_show_options,
+};
+
+static void resctrl_group_default_init(struct resctrl_group *r)
+{
+ r->closid = 0;
+ r->mon.rmid = 0;
+ r->type = RDTCTRL_GROUP;
+}
+
+static int __init resctrl_group_setup_root(void)
+{
+ int ret;
+
+ resctrl_root = kernfs_create_root(&resctrl_group_kf_syscall_ops,
+ KERNFS_ROOT_CREATE_DEACTIVATED,
+ &resctrl_group_default);
+ if (IS_ERR(resctrl_root))
+ return PTR_ERR(resctrl_root);
+
+ mutex_lock(&resctrl_group_mutex);
+
+ resctrl_group_default_init(&resctrl_group_default);
+ INIT_LIST_HEAD(&resctrl_group_default.mon.crdtgrp_list);
+
+ list_add(&resctrl_group_default.resctrl_group_list, &resctrl_all_groups);
+
+ ret = resctrl_group_add_files(resctrl_root->kn, RF_CTRL_BASE);
+ if (ret) {
+ kernfs_destroy_root(resctrl_root);
+ goto out;
+ }
+
+ resctrl_group_default.kn = resctrl_root->kn;
+ kernfs_activate(resctrl_group_default.kn);
+
+out:
+ mutex_unlock(&resctrl_group_mutex);
+
+ return ret;
+}
+
+/*
+ * resctrl_group_init - resctrl_group initialization
+ *
+ * Setup resctrl file system including set up root, create mount point,
+ * register resctrl_group filesystem, and initialize files under root directory.
+ *
+ * Return: 0 on success or -errno
+ */
+int __init resctrl_group_init(void)
+{
+ int ret = 0;
+
+ ret = resctrl_group_setup_root();
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_mount_point(fs_kobj, "resctrl");
+ if (ret)
+ goto cleanup_root;
+
+ ret = register_filesystem(&resctrl_fs_type);
+ if (ret)
+ goto cleanup_mountpoint;
+
+ return 0;
+
+cleanup_mountpoint:
+ sysfs_remove_mount_point(fs_kobj, "resctrl");
+cleanup_root:
+ kernfs_destroy_root(resctrl_root);
+
+ return ret;
+}
diff --git a/include/linux/resctrlfs.h b/include/linux/resctrlfs.h
new file mode 100644
index 000000000000..4eeac66dbd25
--- /dev/null
+++ b/include/linux/resctrlfs.h
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _RESCTRLFS_H
+#define _RESCTRLFS_H
+
+#include <linux/sched.h>
+#include <linux/kernfs.h>
+#include <linux/jump_label.h>
+
+#include <linux/seq_buf.h>
+#include <linux/seq_file.h>
+
+struct resctrl_resource {
+ int rid;
+ bool alloc_enabled;
+ bool mon_enabled;
+ bool alloc_capable;
+ bool mon_capable;
+ char *name;
+ struct list_head domains;
+ struct list_head evt_list;
+ unsigned long fflags;
+
+ void *res;
+};
+
+DECLARE_STATIC_KEY_FALSE(resctrl_enable_key);
+
+/* rftype.flags */
+#define RFTYPE_FLAGS_CPUS_LIST 1
+
+/*
+ * Define the file type flags for base and info directories.
+ */
+#define RFTYPE_INFO BIT(0)
+#define RFTYPE_BASE BIT(1)
+#define RF_CTRLSHIFT 4
+#define RF_MONSHIFT 5
+#define RF_TOPSHIFT 6
+#define RFTYPE_CTRL BIT(RF_CTRLSHIFT)
+#define RFTYPE_MON BIT(RF_MONSHIFT)
+#define RFTYPE_TOP BIT(RF_TOPSHIFT)
+#define RFTYPE_RES_SMMU BIT(7)
+#define RFTYPE_RES_CACHE BIT(8)
+#define RFTYPE_RES_MB BIT(9)
+#define RFTYPE_RES_MC BIT(10)
+#define RF_CTRL_INFO (RFTYPE_INFO | RFTYPE_CTRL)
+#define RF_MON_INFO (RFTYPE_INFO | RFTYPE_MON)
+#define RF_TOP_INFO (RFTYPE_INFO | RFTYPE_TOP)
+#define RF_CTRL_BASE (RFTYPE_BASE | RFTYPE_CTRL)
+
+/* List of all resource groups */
+extern struct list_head resctrl_all_groups;
+
+/**
+ * struct rftype - describe each file in the resctrl file system
+ * @name: File name
+ * @mode: Access mode
+ * @kf_ops: File operations
+ * @flags: File specific RFTYPE_FLAGS_* flags
+ * @fflags: File specific RF_* or RFTYPE_* flags
+ * @seq_show: Show content of the file
+ * @write: Write to the file
+ */
+struct rftype {
+ char *name;
+ umode_t mode;
+ struct kernfs_ops *kf_ops;
+ unsigned long flags;
+ unsigned long fflags;
+
+ bool (*enable)(void *arg);
+
+ int (*seq_show)(struct kernfs_open_file *of,
+ struct seq_file *sf, void *v);
+ /*
+ * write() is the generic write callback which maps directly to
+ * kernfs write operation and overrides all other operations.
+ * Maximum write size is determined by ->max_write_len.
+ */
+ ssize_t (*write)(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off);
+};
+
+DECLARE_STATIC_KEY_FALSE(resctrl_alloc_enable_key);
+extern struct rdtgroup resctrl_group_default;
+
+int __init resctrl_group_init(void);
+
+int register_resctrl_specific_files(struct rftype *files, size_t len);
+extern struct kernfs_ops resctrl_group_kf_single_ops;
+
+extern struct rdtgroup *resctrl_group_kn_lock_live(struct kernfs_node *kn);
+void resctrl_group_kn_unlock(struct kernfs_node *kn);
+
+void post_resctrl_mount(void);
+
+#endif
--
2.31.0