diff --git a/fs/Makefile b/fs/Makefile index 293733f61594bc073fcd98ed94bb19fd8a93da21..04aa2a165404ce0c7c8edbd32ddb73f27d951ce0 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -128,3 +128,4 @@ obj-y += exofs/ # Multiple modules obj-$(CONFIG_CEPH_FS) += ceph/ obj-$(CONFIG_PSTORE) += pstore/ obj-$(CONFIG_EFIVAR_FS) += efivarfs/ +obj-$(CONFIG_RESCTRL) += resctrlfs.o diff --git a/fs/resctrlfs.c b/fs/resctrlfs.c new file mode 100644 index 0000000000000000000000000000000000000000..71da1f900dd8f4ac06b7aee9923b20ea72a7b8e8 --- /dev/null +++ b/fs/resctrlfs.c @@ -0,0 +1,929 @@ +/* + * User interface for Resource Alloction in Resource Director Technology(RDT) + * + * Copyright (C) 2016 Intel Corporation + * + * Author: Fenghua Yu + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include + +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 0000000000000000000000000000000000000000..6650f8c7672a044cf758310ea49f3585f32c6d0f --- /dev/null +++ b/include/linux/resctrlfs.h @@ -0,0 +1,96 @@ +#ifndef _RESCTRLFS_H +#define _RESCTRLFS_H + +#include +#include +#include + +#include +#include + +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 /* _RESCTRLFS_H */