| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Vikas Shivappa | 3541 | 29.01% | 23 | 19.49% |
| Reinette Chatre | 3236 | 26.51% | 44 | 37.29% |
| Fenghua Yu | 3091 | 25.32% | 12 | 10.17% |
| Tony Luck | 1066 | 8.73% | 6 | 5.08% |
| David Howells | 420 | 3.44% | 1 | 0.85% |
| Xiaochen Shen | 277 | 2.27% | 9 | 7.63% |
| Chen Yu | 206 | 1.69% | 1 | 0.85% |
| Shaohua Li | 108 | 0.88% | 2 | 1.69% |
| Jithu Joseph | 81 | 0.66% | 1 | 0.85% |
| Jiri Olsa | 59 | 0.48% | 2 | 1.69% |
| James Morse | 57 | 0.47% | 2 | 1.69% |
| Babu Moger | 23 | 0.19% | 4 | 3.39% |
| Shakeel Butt | 15 | 0.12% | 1 | 0.85% |
| Dmitry Torokhov | 8 | 0.07% | 1 | 0.85% |
| Thomas Gleixner | 6 | 0.05% | 3 | 2.54% |
| Ingo Molnar | 4 | 0.03% | 2 | 1.69% |
| Wang Hui | 4 | 0.03% | 1 | 0.85% |
| Dan Carpenter | 4 | 0.03% | 1 | 0.85% |
| Michel Lespinasse | 1 | 0.01% | 1 | 0.85% |
| Al Viro | 1 | 0.01% | 1 | 0.85% |
| Total | 12208 | 118 |
// SPDX-License-Identifier: GPL-2.0-only /* * User interface for Resource Alloction 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); /* 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); } /* * 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 rdt_resource *r; int rdt_min_closid = 32; /* Compute rdt_min_closid across all resources */ for_each_alloc_enabled_rdt_resource(r) rdt_min_closid = min(rdt_min_closid, r->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 struct kernfs_ops rdtgroup_kf_single_ops = { .atomic_write_len = PAGE_SIZE, .write = rdtgroup_file_write, .seq_show = rdtgroup_seqfile_show, }; static 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 proteced 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(); } /* * 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_weight(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_weight(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_weight(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_weight(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_weight(tmpmask)) { list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) { if (r == rdtgrp) continue; cpumask_and(tmpmask1, &r->cpu_mask, tmpmask); if (cpumask_weight(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_weight(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; } struct task_move_callback { struct callback_head work; struct rdtgroup *rdtgrp; }; static void move_myself(struct callback_head *head) { struct task_move_callback *callback; struct rdtgroup *rdtgrp; callback = container_of(head, struct task_move_callback, work); rdtgrp = callback->rdtgrp; /* * If resource group was deleted before this task work callback * was invoked, then assign the task to root group and free the * resource group. */ if (atomic_dec_and_test(&rdtgrp->waitcount) && (rdtgrp->flags & RDT_DELETED)) { current->closid = 0; current->rmid = 0; kfree(rdtgrp); } if (unlikely(current->flags & PF_EXITING)) goto out; preempt_disable(); /* update PQR_ASSOC MSR to make resource group go into effect */ resctrl_sched_in(); preempt_enable(); out: kfree(callback); } static int __rdtgroup_move_task(struct task_struct *tsk, struct rdtgroup *rdtgrp) { struct task_move_callback *callback; int ret; callback = kzalloc(sizeof(*callback), GFP_KERNEL); if (!callback) return -ENOMEM; callback->work.func = move_myself; callback->rdtgrp = rdtgrp; /* * Take a refcount, so rdtgrp cannot be freed before the * callback has been invoked. */ atomic_inc(&rdtgrp->waitcount); ret = task_work_add(tsk, &callback->work, true); if (ret) { /* * Task is exiting. Drop the refcount and free the callback. * No need to check the refcount as the group cannot be * deleted before the write function unlocks rdtgroup_mutex. */ atomic_dec(&rdtgrp->waitcount); kfree(callback); rdt_last_cmd_puts("Task exited\n"); } else { /* * 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) { tsk->closid = rdtgrp->closid; tsk->rmid = rdtgrp->mon.rmid; } else if (rdtgrp->type == RDTMON_GROUP) { if (rdtgrp->mon.parent->closid == tsk->closid) { tsk->rmid = rdtgrp->mon.rmid; } else { rdt_last_cmd_puts("Can't move task to different control group\n"); ret = -EINVAL; } } } return ret; } /** * 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 ((r->type == RDTCTRL_GROUP && t->closid == r->closid) || (r->type == RDTMON_GROUP && t->rmid == r->mon.rmid)) { 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; rcu_read_lock(); for_each_process_thread(p, t) { if ((r->type == RDTCTRL_GROUP && t->closid == r->closid) || (r->type == RDTMON_GROUP && t->rmid == r->mon.rmid)) seq_printf(s, "%d\n", t->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 rdt_resource *r = of->kn->parent->priv; seq_printf(seq, "%d\n", r->num_closid); return 0; } static int rdt_default_ctrl_show(struct kernfs_open_file *of, struct seq_file *seq, void *v) { struct rdt_resource *r = of->kn->parent->priv; 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 rdt_resource *r = of->kn->parent->priv; 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 rdt_resource *r = of->kn->parent->priv; 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 rdt_resource *r = 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_domain *dom; int i, hwb, swb, excl, psl; enum rdtgrp_mode mode; bool sep = false; u32 *ctrl; mutex_lock(&rdtgroup_mutex); hw_shareable = r->cache.shareable_bits; list_for_each_entry(dom, &r->domains, list) { if (sep) seq_putc(seq, ';'); ctrl = dom->ctrl_val; sw_shareable = 0; exclusive = 0; seq_printf(seq, "%d=", dom->id); for (i = 0; i < closids_supported(); i++, ctrl++) { if (!closid_allocated(i)) continue; mode = rdtgroup_mode_by_closid(i); switch (mode) { case RDT_MODE_SHAREABLE: sw_shareable |= *ctrl; break; case RDT_MODE_EXCLUSIVE: exclusive |= *ctrl; 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 rdt_resource *r = of->kn->parent->priv; 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 rdt_resource *r = of->kn->parent->priv; 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 rdt_resource *r = of->kn->parent->priv; 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) { struct rdt_resource *r = of->kn->parent->priv; seq_printf(seq, "%u\n", resctrl_cqm_threshold * r->mon_scale); return 0; } static ssize_t max_threshold_occ_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { struct rdt_resource *r = of->kn->parent->priv; unsigned int bytes; int ret; ret = kstrtouint(buf, 0, &bytes); if (ret) return ret; if (bytes > (boot_cpu_data.x86_cache_size * 1024)) return -EINVAL; resctrl_cqm_threshold = bytes / r->mon_scale; 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; } /** * rdt_cdp_peer_get - Retrieve CDP peer if it exists * @r: RDT resource to which RDT domain @d belongs * @d: Cache instance for which a CDP peer is requested * @r_cdp: RDT resource that shares hardware with @r (RDT resource peer) * Used to return the result. * @d_cdp: RDT domain that shares hardware with @d (RDT domain peer) * Used to return the result. * * RDT resources are managed independently and by extension the RDT domains * (RDT resource instances) are managed independently also. The Code and * Data Prioritization (CDP) RDT resources, while managed independently, * could refer to the same underlying hardware. For example, * RDT_RESOURCE_L2CODE and RDT_RESOURCE_L2DATA both refer to the L2 cache. * * When provided with an RDT resource @r and an instance of that RDT * resource @d rdt_cdp_peer_get() will return if there is a peer RDT * resource and the exact instance that shares the same hardware. * * Return: 0 if a CDP peer was found, <0 on error or if no CDP peer exists. * If a CDP peer was found, @r_cdp will point to the peer RDT resource * and @d_cdp will point to the peer RDT domain. */ static int rdt_cdp_peer_get(struct rdt_resource *r, struct rdt_domain *d, struct rdt_resource **r_cdp, struct rdt_domain **d_cdp) { struct rdt_resource *_r_cdp = NULL; struct rdt_domain *_d_cdp = NULL; int ret = 0; switch (r->rid) { case RDT_RESOURCE_L3DATA: _r_cdp = &rdt_resources_all[RDT_RESOURCE_L3CODE]; break; case RDT_RESOURCE_L3CODE: _r_cdp = &rdt_resources_all[RDT_RESOURCE_L3DATA]; break; case RDT_RESOURCE_L2DATA: _r_cdp = &rdt_resources_all[RDT_RESOURCE_L2CODE]; break; case RDT_RESOURCE_L2CODE: _r_cdp = &rdt_resources_all[RDT_RESOURCE_L2DATA]; break; default: ret = -ENOENT; goto out; } /* * When a new CPU comes online and CDP is enabled then the new * RDT domains (if any) associated with both CDP RDT resources * are added in the same CPU online routine while the * rdtgroup_mutex is held. It should thus not happen for one * RDT domain to exist and be associated with its RDT CDP * resource but there is no RDT domain associated with the * peer RDT CDP resource. Hence the WARN. */ _d_cdp = rdt_find_domain(_r_cdp, d->id, NULL); if (WARN_ON(IS_ERR_OR_NULL(_d_cdp))) { _r_cdp = NULL; _d_cdp = NULL; ret = -EINVAL; } out: *r_cdp = _r_cdp; *d_cdp = _d_cdp; return ret; } /** * __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, bool exclusive) { enum rdtgrp_mode mode; unsigned long ctrl_b; u32 *ctrl; 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 */ ctrl = d->ctrl_val; for (i = 0; i < closids_supported(); i++, ctrl++) { ctrl_b = *ctrl; 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 * @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 * * 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 rdt_resource *r, struct rdt_domain *d, unsigned long cbm, int closid, bool exclusive) { struct rdt_resource *r_cdp; struct rdt_domain *d_cdp; if (__rdtgroup_cbm_overlaps(r, d, cbm, closid, exclusive)) return true; if (rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp) < 0) return false; return __rdtgroup_cbm_overlaps(r_cdp, d_cdp, cbm, closid, 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 rdt_resource *r; bool has_cache = false; struct rdt_domain *d; for_each_alloc_enabled_rdt_resource(r) { if (r->rid == RDT_RESOURCE_MBA) continue; has_cache = true; list_for_each_entry(d, &r->domains, list) { if (rdtgroup_cbm_overlaps(r, d, d->ctrl_val[closid], rdtgrp->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 rdtgroup *rdtgrp; struct rdt_resource *r; struct rdt_domain *d; unsigned int size; int ret = 0; 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->r->name); size = rdtgroup_cbm_to_size(rdtgrp->plr->r, rdtgrp->plr->d, rdtgrp->plr->cbm); seq_printf(s, "%d=%u\n", rdtgrp->plr->d->id, size); } goto out; } for_each_alloc_enabled_rdt_resource(r) { sep = false; seq_printf(s, "%*s:", max_name_width, r->name); list_for_each_entry(d, &r->domains, list) { if (sep) seq_putc(s, ';'); if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { size = 0; } else { ctrl = (!is_mba_sc(r) ? d->ctrl_val[rdtgrp->closid] : d->mbps_val[rdtgrp->closid]); 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, }, { .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 ((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; } /** * 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(struct rdt_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 = 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 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); kernfs_get(kn_info); ret = rdtgroup_add_files(kn_info, RF_TOP_INFO); if (ret) goto out_destroy; for_each_alloc_enabled_rdt_resource(r) { fflags = r->fflags | RF_CTRL_INFO; ret = rdtgroup_mkdir_info_resdir(r, r->name, fflags); if (ret) goto out_destroy; } for_each_mon_enabled_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; } /* * This extra ref will be put in kernfs_remove() and guarantees * that @rdtgrp->kn is always accessible. */ kernfs_get(kn_info); 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; /* * This extra ref will be put in kernfs_remove() and guarantees * that @rdtgrp->kn is always accessible. */ kernfs_get(kn); ret = rdtgroup_kn_set_ugid(kn); if (ret) goto out_destroy; kernfs_activate(kn); return 0; out_destroy: kernfs_remove(kn); return ret; } static void l3_qos_cfg_update(void *arg) { bool *enable = arg; 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].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]; list_for_each_entry(d, &r_l->domains, list) { /* 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) { if (!r->alloc_capable) return; if (r == &rdt_resources_all[RDT_RESOURCE_L2DATA]) l2_qos_cfg_update(&r->alloc_enabled); if (r == &rdt_resources_all[RDT_RESOURCE_L3DATA]) l3_qos_cfg_update(&r->alloc_enabled); } /* * Enable or disable the MBA software controller * which helps user specify bandwidth in MBps. * MBA software controller is supported only if * MBM is supported and MBA is in linear scale. */ static int set_mba_sc(bool mba_sc) { struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_MBA]; struct rdt_domain *d; if (!is_mbm_enabled() || !is_mba_linear() || mba_sc == is_mba_sc(r)) return -EINVAL; r->membw.mba_sc = mba_sc; list_for_each_entry(d, &r->domains, list) setup_default_ctrlval(r, d->ctrl_val, d->mbps_val); return 0; } static int cdp_enable(int level, int data_type, int code_type) { struct rdt_resource *r_ldata = &rdt_resources_all[data_type]; struct rdt_resource *r_lcode = &rdt_resources_all[code_type]; struct rdt_resource *r_l = &rdt_resources_all[level]; int ret; if (!r_l->alloc_capable || !r_ldata->alloc_capable || !r_lcode->alloc_capable) return -EINVAL; ret = set_cache_qos_cfg(level, true); if (!ret) { r_l->alloc_enabled = false; r_ldata->alloc_enabled = true; r_lcode->alloc_enabled = true; } return ret; } static int cdpl3_enable(void) { return cdp_enable(RDT_RESOURCE_L3, RDT_RESOURCE_L3DATA, RDT_RESOURCE_L3CODE); } static int cdpl2_enable(void) { return cdp_enable(RDT_RESOURCE_L2, RDT_RESOURCE_L2DATA, RDT_RESOURCE_L2CODE); } static void cdp_disable(int level, int data_type, int code_type) { struct rdt_resource *r = &rdt_resources_all[level]; r->alloc_enabled = r->alloc_capable; if (rdt_resources_all[data_type].alloc_enabled) { rdt_resources_all[data_type].alloc_enabled = false; rdt_resources_all[code_type].alloc_enabled = false; set_cache_qos_cfg(level, false); } } static void cdpl3_disable(void) { cdp_disable(RDT_RESOURCE_L3, RDT_RESOURCE_L3DATA, RDT_RESOURCE_L3CODE); } static void cdpl2_disable(void) { cdp_disable(RDT_RESOURCE_L2, RDT_RESOURCE_L2DATA, RDT_RESOURCE_L2CODE); } static void cdp_disable_all(void) { if (rdt_resources_all[RDT_RESOURCE_L3DATA].alloc_enabled) cdpl3_disable(); if (rdt_resources_all[RDT_RESOURCE_L2DATA].alloc_enabled) cdpl2_disable(); } /* * 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); kernfs_put(rdtgrp->kn); kfree(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 = cdpl2_enable(); if (!ret && ctx->enable_cdpl3) ret = cdpl3_enable(); if (!ret && ctx->enable_mba_mbps) ret = set_mba_sc(true); return ret; } 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; closid_init(); ret = rdtgroup_create_info_dir(rdtgroup_default.kn); if (ret < 0) goto out_mba; if (rdt_mon_capable) { ret = mongroup_create_dir(rdtgroup_default.kn, &rdtgroup_default, "mon_groups", &kn_mongrp); if (ret < 0) goto out_info; kernfs_get(kn_mongrp); ret = mkdir_mondata_all(rdtgroup_default.kn, &rdtgroup_default, &kn_mondata); if (ret < 0) goto out_mongrp; kernfs_get(kn_mondata); 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]; 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_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 (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) 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 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 = r->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) { cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask); for (i = 0; i < r->num_closid; i++) d->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; } 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)); } /* * 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)) { 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 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 kfree(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 kfree(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_enabled_rdt_resource(r) reset_all_ctrls(r); cdp_disable_all(); rmdir_all_sub(); rdt_pseudo_lock_release(); rdtgroup_default.mode = RDT_MODE_SHAREABLE; 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. */ void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, unsigned int dom_id) { struct rdtgroup *prgrp, *crgrp; char name[32]; if (!r->mon_enabled) return; 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); /* * This extra ref will be put in kernfs_remove() and guarantees * that kn is always accessible. */ kernfs_get(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. */ 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; if (!r->mon_enabled) return; 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 whic 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_enabled_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 rdt_resource *r, u32 closid) { struct rdt_resource *r_cdp = NULL; struct rdt_domain *d_cdp = NULL; u32 used_b = 0, unused_b = 0; unsigned long tmp_cbm; enum rdtgrp_mode mode; u32 peer_ctl, *ctrl; int i; rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp); d->have_new_ctrl = false; d->new_ctrl = r->cache.shareable_bits; used_b = r->cache.shareable_bits; ctrl = d->ctrl_val; for (i = 0; i < closids_supported(); i++, ctrl++) { 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 (d_cdp) peer_ctl = d_cdp->ctrl_val[i]; else peer_ctl = 0; used_b |= *ctrl | peer_ctl; if (mode == RDT_MODE_SHAREABLE) d->new_ctrl |= *ctrl | 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; d->new_ctrl |= unused_b; /* * Force the initial CBM to be valid, user can * modify the CBM based on system availability. */ d->new_ctrl = cbm_ensure_valid(d->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 = d->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", r->name, d->id); return -ENOSPC; } d->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 rdt_resource *r, u32 closid) { struct rdt_domain *d; int ret; list_for_each_entry(d, &r->domains, list) { ret = __init_one_rdt_domain(d, r, closid); if (ret < 0) return ret; } return 0; } /* Initialize MBA resource with default values. */ static void rdtgroup_init_mba(struct rdt_resource *r) { struct rdt_domain *d; list_for_each_entry(d, &r->domains, list) { d->new_ctrl = is_mba_sc(r) ? MBA_MAX_MBPS : r->default_ctrl; d->have_new_ctrl = true; } } /* Initialize the RDT group's allocations. */ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp) { struct rdt_resource *r; int ret; for_each_alloc_enabled_rdt_resource(r) { if (r->rid == RDT_RESOURCE_MBA) { rdtgroup_init_mba(r); } else { ret = rdtgroup_init_cat(r, rdtgrp->closid); if (ret < 0) return ret; } ret = update_domains(r, rdtgrp->closid); if (ret < 0) { rdt_last_cmd_puts("Failed to initialize allocations\n"); return ret; } } rdtgrp->mode = RDT_MODE_SHAREABLE; return 0; } 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 below. Take one extra reference * here, which will be dropped inside rdtgroup_kn_unlock(). */ 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_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); kfree(rgrp); } /* * Create a monitor group under "mon_groups" directory of a control * and monitor group(ctrl_mon). This is a resource group * to monitor a subset of tasks and cpus in its parent ctrl_mon group. */ static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn, 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 kernfs_node *kn, 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); /* * one extra hold on this, will drop when we kfree(rdtgrp) * in rdtgroup_kn_unlock() */ kernfs_get(kn); kernfs_remove(rdtgrp->kn); return 0; } static int rdtgroup_ctrl_remove(struct kernfs_node *kn, struct rdtgroup *rdtgrp) { rdtgrp->flags = RDT_DELETED; list_del(&rdtgrp->rdtgroup_list); /* * one extra hold on this, will drop when we kfree(rdtgrp) * in rdtgroup_kn_unlock() */ kernfs_get(kn); kernfs_remove(rdtgrp->kn); return 0; } static int rdtgroup_rmdir_ctrl(struct kernfs_node *kn, 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(kn, 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(kn, rdtgrp); } else { ret = rdtgroup_rmdir_ctrl(kn, rdtgrp, tmpmask); } } else if (rdtgrp->type == RDTMON_GROUP && is_mon_groups(parent_kn, kn->name)) { ret = rdtgroup_rmdir_mon(kn, 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 (rdt_resources_all[RDT_RESOURCE_L3DATA].alloc_enabled) seq_puts(seq, ",cdp"); if (rdt_resources_all[RDT_RESOURCE_L2DATA].alloc_enabled) seq_puts(seq, ",cdpl2"); if (is_mba_sc(&rdt_resources_all[RDT_RESOURCE_MBA])) 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(rdt_root->kn, RF_CTRL_BASE); if (ret) { kernfs_destroy_root(rdt_root); goto out; } rdtgroup_default.kn = rdt_root->kn; kernfs_activate(rdtgroup_default.kn); out: mutex_unlock(&rdtgroup_mutex); return ret; } /* * 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_mount() is because rdt_mount() 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); }
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