cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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rdtgroup.c (81959B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * User interface for Resource Allocation in Resource Director Technology(RDT)
      4 *
      5 * Copyright (C) 2016 Intel Corporation
      6 *
      7 * Author: Fenghua Yu <fenghua.yu@intel.com>
      8 *
      9 * More information about RDT be found in the Intel (R) x86 Architecture
     10 * Software Developer Manual.
     11 */
     12
     13#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
     14
     15#include <linux/cacheinfo.h>
     16#include <linux/cpu.h>
     17#include <linux/debugfs.h>
     18#include <linux/fs.h>
     19#include <linux/fs_parser.h>
     20#include <linux/sysfs.h>
     21#include <linux/kernfs.h>
     22#include <linux/seq_buf.h>
     23#include <linux/seq_file.h>
     24#include <linux/sched/signal.h>
     25#include <linux/sched/task.h>
     26#include <linux/slab.h>
     27#include <linux/task_work.h>
     28#include <linux/user_namespace.h>
     29
     30#include <uapi/linux/magic.h>
     31
     32#include <asm/resctrl.h>
     33#include "internal.h"
     34
     35DEFINE_STATIC_KEY_FALSE(rdt_enable_key);
     36DEFINE_STATIC_KEY_FALSE(rdt_mon_enable_key);
     37DEFINE_STATIC_KEY_FALSE(rdt_alloc_enable_key);
     38static struct kernfs_root *rdt_root;
     39struct rdtgroup rdtgroup_default;
     40LIST_HEAD(rdt_all_groups);
     41
     42/* list of entries for the schemata file */
     43LIST_HEAD(resctrl_schema_all);
     44
     45/* Kernel fs node for "info" directory under root */
     46static struct kernfs_node *kn_info;
     47
     48/* Kernel fs node for "mon_groups" directory under root */
     49static struct kernfs_node *kn_mongrp;
     50
     51/* Kernel fs node for "mon_data" directory under root */
     52static struct kernfs_node *kn_mondata;
     53
     54static struct seq_buf last_cmd_status;
     55static char last_cmd_status_buf[512];
     56
     57struct dentry *debugfs_resctrl;
     58
     59void rdt_last_cmd_clear(void)
     60{
     61	lockdep_assert_held(&rdtgroup_mutex);
     62	seq_buf_clear(&last_cmd_status);
     63}
     64
     65void rdt_last_cmd_puts(const char *s)
     66{
     67	lockdep_assert_held(&rdtgroup_mutex);
     68	seq_buf_puts(&last_cmd_status, s);
     69}
     70
     71void rdt_last_cmd_printf(const char *fmt, ...)
     72{
     73	va_list ap;
     74
     75	va_start(ap, fmt);
     76	lockdep_assert_held(&rdtgroup_mutex);
     77	seq_buf_vprintf(&last_cmd_status, fmt, ap);
     78	va_end(ap);
     79}
     80
     81/*
     82 * Trivial allocator for CLOSIDs. Since h/w only supports a small number,
     83 * we can keep a bitmap of free CLOSIDs in a single integer.
     84 *
     85 * Using a global CLOSID across all resources has some advantages and
     86 * some drawbacks:
     87 * + We can simply set "current->closid" to assign a task to a resource
     88 *   group.
     89 * + Context switch code can avoid extra memory references deciding which
     90 *   CLOSID to load into the PQR_ASSOC MSR
     91 * - We give up some options in configuring resource groups across multi-socket
     92 *   systems.
     93 * - Our choices on how to configure each resource become progressively more
     94 *   limited as the number of resources grows.
     95 */
     96static int closid_free_map;
     97static int closid_free_map_len;
     98
     99int closids_supported(void)
    100{
    101	return closid_free_map_len;
    102}
    103
    104static void closid_init(void)
    105{
    106	struct resctrl_schema *s;
    107	u32 rdt_min_closid = 32;
    108
    109	/* Compute rdt_min_closid across all resources */
    110	list_for_each_entry(s, &resctrl_schema_all, list)
    111		rdt_min_closid = min(rdt_min_closid, s->num_closid);
    112
    113	closid_free_map = BIT_MASK(rdt_min_closid) - 1;
    114
    115	/* CLOSID 0 is always reserved for the default group */
    116	closid_free_map &= ~1;
    117	closid_free_map_len = rdt_min_closid;
    118}
    119
    120static int closid_alloc(void)
    121{
    122	u32 closid = ffs(closid_free_map);
    123
    124	if (closid == 0)
    125		return -ENOSPC;
    126	closid--;
    127	closid_free_map &= ~(1 << closid);
    128
    129	return closid;
    130}
    131
    132void closid_free(int closid)
    133{
    134	closid_free_map |= 1 << closid;
    135}
    136
    137/**
    138 * closid_allocated - test if provided closid is in use
    139 * @closid: closid to be tested
    140 *
    141 * Return: true if @closid is currently associated with a resource group,
    142 * false if @closid is free
    143 */
    144static bool closid_allocated(unsigned int closid)
    145{
    146	return (closid_free_map & (1 << closid)) == 0;
    147}
    148
    149/**
    150 * rdtgroup_mode_by_closid - Return mode of resource group with closid
    151 * @closid: closid if the resource group
    152 *
    153 * Each resource group is associated with a @closid. Here the mode
    154 * of a resource group can be queried by searching for it using its closid.
    155 *
    156 * Return: mode as &enum rdtgrp_mode of resource group with closid @closid
    157 */
    158enum rdtgrp_mode rdtgroup_mode_by_closid(int closid)
    159{
    160	struct rdtgroup *rdtgrp;
    161
    162	list_for_each_entry(rdtgrp, &rdt_all_groups, rdtgroup_list) {
    163		if (rdtgrp->closid == closid)
    164			return rdtgrp->mode;
    165	}
    166
    167	return RDT_NUM_MODES;
    168}
    169
    170static const char * const rdt_mode_str[] = {
    171	[RDT_MODE_SHAREABLE]		= "shareable",
    172	[RDT_MODE_EXCLUSIVE]		= "exclusive",
    173	[RDT_MODE_PSEUDO_LOCKSETUP]	= "pseudo-locksetup",
    174	[RDT_MODE_PSEUDO_LOCKED]	= "pseudo-locked",
    175};
    176
    177/**
    178 * rdtgroup_mode_str - Return the string representation of mode
    179 * @mode: the resource group mode as &enum rdtgroup_mode
    180 *
    181 * Return: string representation of valid mode, "unknown" otherwise
    182 */
    183static const char *rdtgroup_mode_str(enum rdtgrp_mode mode)
    184{
    185	if (mode < RDT_MODE_SHAREABLE || mode >= RDT_NUM_MODES)
    186		return "unknown";
    187
    188	return rdt_mode_str[mode];
    189}
    190
    191/* set uid and gid of rdtgroup dirs and files to that of the creator */
    192static int rdtgroup_kn_set_ugid(struct kernfs_node *kn)
    193{
    194	struct iattr iattr = { .ia_valid = ATTR_UID | ATTR_GID,
    195				.ia_uid = current_fsuid(),
    196				.ia_gid = current_fsgid(), };
    197
    198	if (uid_eq(iattr.ia_uid, GLOBAL_ROOT_UID) &&
    199	    gid_eq(iattr.ia_gid, GLOBAL_ROOT_GID))
    200		return 0;
    201
    202	return kernfs_setattr(kn, &iattr);
    203}
    204
    205static int rdtgroup_add_file(struct kernfs_node *parent_kn, struct rftype *rft)
    206{
    207	struct kernfs_node *kn;
    208	int ret;
    209
    210	kn = __kernfs_create_file(parent_kn, rft->name, rft->mode,
    211				  GLOBAL_ROOT_UID, GLOBAL_ROOT_GID,
    212				  0, rft->kf_ops, rft, NULL, NULL);
    213	if (IS_ERR(kn))
    214		return PTR_ERR(kn);
    215
    216	ret = rdtgroup_kn_set_ugid(kn);
    217	if (ret) {
    218		kernfs_remove(kn);
    219		return ret;
    220	}
    221
    222	return 0;
    223}
    224
    225static int rdtgroup_seqfile_show(struct seq_file *m, void *arg)
    226{
    227	struct kernfs_open_file *of = m->private;
    228	struct rftype *rft = of->kn->priv;
    229
    230	if (rft->seq_show)
    231		return rft->seq_show(of, m, arg);
    232	return 0;
    233}
    234
    235static ssize_t rdtgroup_file_write(struct kernfs_open_file *of, char *buf,
    236				   size_t nbytes, loff_t off)
    237{
    238	struct rftype *rft = of->kn->priv;
    239
    240	if (rft->write)
    241		return rft->write(of, buf, nbytes, off);
    242
    243	return -EINVAL;
    244}
    245
    246static const struct kernfs_ops rdtgroup_kf_single_ops = {
    247	.atomic_write_len	= PAGE_SIZE,
    248	.write			= rdtgroup_file_write,
    249	.seq_show		= rdtgroup_seqfile_show,
    250};
    251
    252static const struct kernfs_ops kf_mondata_ops = {
    253	.atomic_write_len	= PAGE_SIZE,
    254	.seq_show		= rdtgroup_mondata_show,
    255};
    256
    257static bool is_cpu_list(struct kernfs_open_file *of)
    258{
    259	struct rftype *rft = of->kn->priv;
    260
    261	return rft->flags & RFTYPE_FLAGS_CPUS_LIST;
    262}
    263
    264static int rdtgroup_cpus_show(struct kernfs_open_file *of,
    265			      struct seq_file *s, void *v)
    266{
    267	struct rdtgroup *rdtgrp;
    268	struct cpumask *mask;
    269	int ret = 0;
    270
    271	rdtgrp = rdtgroup_kn_lock_live(of->kn);
    272
    273	if (rdtgrp) {
    274		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
    275			if (!rdtgrp->plr->d) {
    276				rdt_last_cmd_clear();
    277				rdt_last_cmd_puts("Cache domain offline\n");
    278				ret = -ENODEV;
    279			} else {
    280				mask = &rdtgrp->plr->d->cpu_mask;
    281				seq_printf(s, is_cpu_list(of) ?
    282					   "%*pbl\n" : "%*pb\n",
    283					   cpumask_pr_args(mask));
    284			}
    285		} else {
    286			seq_printf(s, is_cpu_list(of) ? "%*pbl\n" : "%*pb\n",
    287				   cpumask_pr_args(&rdtgrp->cpu_mask));
    288		}
    289	} else {
    290		ret = -ENOENT;
    291	}
    292	rdtgroup_kn_unlock(of->kn);
    293
    294	return ret;
    295}
    296
    297/*
    298 * This is safe against resctrl_sched_in() called from __switch_to()
    299 * because __switch_to() is executed with interrupts disabled. A local call
    300 * from update_closid_rmid() is protected against __switch_to() because
    301 * preemption is disabled.
    302 */
    303static void update_cpu_closid_rmid(void *info)
    304{
    305	struct rdtgroup *r = info;
    306
    307	if (r) {
    308		this_cpu_write(pqr_state.default_closid, r->closid);
    309		this_cpu_write(pqr_state.default_rmid, r->mon.rmid);
    310	}
    311
    312	/*
    313	 * We cannot unconditionally write the MSR because the current
    314	 * executing task might have its own closid selected. Just reuse
    315	 * the context switch code.
    316	 */
    317	resctrl_sched_in();
    318}
    319
    320/*
    321 * Update the PGR_ASSOC MSR on all cpus in @cpu_mask,
    322 *
    323 * Per task closids/rmids must have been set up before calling this function.
    324 */
    325static void
    326update_closid_rmid(const struct cpumask *cpu_mask, struct rdtgroup *r)
    327{
    328	int cpu = get_cpu();
    329
    330	if (cpumask_test_cpu(cpu, cpu_mask))
    331		update_cpu_closid_rmid(r);
    332	smp_call_function_many(cpu_mask, update_cpu_closid_rmid, r, 1);
    333	put_cpu();
    334}
    335
    336static int cpus_mon_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
    337			  cpumask_var_t tmpmask)
    338{
    339	struct rdtgroup *prgrp = rdtgrp->mon.parent, *crgrp;
    340	struct list_head *head;
    341
    342	/* Check whether cpus belong to parent ctrl group */
    343	cpumask_andnot(tmpmask, newmask, &prgrp->cpu_mask);
    344	if (!cpumask_empty(tmpmask)) {
    345		rdt_last_cmd_puts("Can only add CPUs to mongroup that belong to parent\n");
    346		return -EINVAL;
    347	}
    348
    349	/* Check whether cpus are dropped from this group */
    350	cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
    351	if (!cpumask_empty(tmpmask)) {
    352		/* Give any dropped cpus to parent rdtgroup */
    353		cpumask_or(&prgrp->cpu_mask, &prgrp->cpu_mask, tmpmask);
    354		update_closid_rmid(tmpmask, prgrp);
    355	}
    356
    357	/*
    358	 * If we added cpus, remove them from previous group that owned them
    359	 * and update per-cpu rmid
    360	 */
    361	cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
    362	if (!cpumask_empty(tmpmask)) {
    363		head = &prgrp->mon.crdtgrp_list;
    364		list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
    365			if (crgrp == rdtgrp)
    366				continue;
    367			cpumask_andnot(&crgrp->cpu_mask, &crgrp->cpu_mask,
    368				       tmpmask);
    369		}
    370		update_closid_rmid(tmpmask, rdtgrp);
    371	}
    372
    373	/* Done pushing/pulling - update this group with new mask */
    374	cpumask_copy(&rdtgrp->cpu_mask, newmask);
    375
    376	return 0;
    377}
    378
    379static void cpumask_rdtgrp_clear(struct rdtgroup *r, struct cpumask *m)
    380{
    381	struct rdtgroup *crgrp;
    382
    383	cpumask_andnot(&r->cpu_mask, &r->cpu_mask, m);
    384	/* update the child mon group masks as well*/
    385	list_for_each_entry(crgrp, &r->mon.crdtgrp_list, mon.crdtgrp_list)
    386		cpumask_and(&crgrp->cpu_mask, &r->cpu_mask, &crgrp->cpu_mask);
    387}
    388
    389static int cpus_ctrl_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
    390			   cpumask_var_t tmpmask, cpumask_var_t tmpmask1)
    391{
    392	struct rdtgroup *r, *crgrp;
    393	struct list_head *head;
    394
    395	/* Check whether cpus are dropped from this group */
    396	cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
    397	if (!cpumask_empty(tmpmask)) {
    398		/* Can't drop from default group */
    399		if (rdtgrp == &rdtgroup_default) {
    400			rdt_last_cmd_puts("Can't drop CPUs from default group\n");
    401			return -EINVAL;
    402		}
    403
    404		/* Give any dropped cpus to rdtgroup_default */
    405		cpumask_or(&rdtgroup_default.cpu_mask,
    406			   &rdtgroup_default.cpu_mask, tmpmask);
    407		update_closid_rmid(tmpmask, &rdtgroup_default);
    408	}
    409
    410	/*
    411	 * If we added cpus, remove them from previous group and
    412	 * the prev group's child groups that owned them
    413	 * and update per-cpu closid/rmid.
    414	 */
    415	cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
    416	if (!cpumask_empty(tmpmask)) {
    417		list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) {
    418			if (r == rdtgrp)
    419				continue;
    420			cpumask_and(tmpmask1, &r->cpu_mask, tmpmask);
    421			if (!cpumask_empty(tmpmask1))
    422				cpumask_rdtgrp_clear(r, tmpmask1);
    423		}
    424		update_closid_rmid(tmpmask, rdtgrp);
    425	}
    426
    427	/* Done pushing/pulling - update this group with new mask */
    428	cpumask_copy(&rdtgrp->cpu_mask, newmask);
    429
    430	/*
    431	 * Clear child mon group masks since there is a new parent mask
    432	 * now and update the rmid for the cpus the child lost.
    433	 */
    434	head = &rdtgrp->mon.crdtgrp_list;
    435	list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
    436		cpumask_and(tmpmask, &rdtgrp->cpu_mask, &crgrp->cpu_mask);
    437		update_closid_rmid(tmpmask, rdtgrp);
    438		cpumask_clear(&crgrp->cpu_mask);
    439	}
    440
    441	return 0;
    442}
    443
    444static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
    445				   char *buf, size_t nbytes, loff_t off)
    446{
    447	cpumask_var_t tmpmask, newmask, tmpmask1;
    448	struct rdtgroup *rdtgrp;
    449	int ret;
    450
    451	if (!buf)
    452		return -EINVAL;
    453
    454	if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
    455		return -ENOMEM;
    456	if (!zalloc_cpumask_var(&newmask, GFP_KERNEL)) {
    457		free_cpumask_var(tmpmask);
    458		return -ENOMEM;
    459	}
    460	if (!zalloc_cpumask_var(&tmpmask1, GFP_KERNEL)) {
    461		free_cpumask_var(tmpmask);
    462		free_cpumask_var(newmask);
    463		return -ENOMEM;
    464	}
    465
    466	rdtgrp = rdtgroup_kn_lock_live(of->kn);
    467	if (!rdtgrp) {
    468		ret = -ENOENT;
    469		goto unlock;
    470	}
    471
    472	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
    473	    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
    474		ret = -EINVAL;
    475		rdt_last_cmd_puts("Pseudo-locking in progress\n");
    476		goto unlock;
    477	}
    478
    479	if (is_cpu_list(of))
    480		ret = cpulist_parse(buf, newmask);
    481	else
    482		ret = cpumask_parse(buf, newmask);
    483
    484	if (ret) {
    485		rdt_last_cmd_puts("Bad CPU list/mask\n");
    486		goto unlock;
    487	}
    488
    489	/* check that user didn't specify any offline cpus */
    490	cpumask_andnot(tmpmask, newmask, cpu_online_mask);
    491	if (!cpumask_empty(tmpmask)) {
    492		ret = -EINVAL;
    493		rdt_last_cmd_puts("Can only assign online CPUs\n");
    494		goto unlock;
    495	}
    496
    497	if (rdtgrp->type == RDTCTRL_GROUP)
    498		ret = cpus_ctrl_write(rdtgrp, newmask, tmpmask, tmpmask1);
    499	else if (rdtgrp->type == RDTMON_GROUP)
    500		ret = cpus_mon_write(rdtgrp, newmask, tmpmask);
    501	else
    502		ret = -EINVAL;
    503
    504unlock:
    505	rdtgroup_kn_unlock(of->kn);
    506	free_cpumask_var(tmpmask);
    507	free_cpumask_var(newmask);
    508	free_cpumask_var(tmpmask1);
    509
    510	return ret ?: nbytes;
    511}
    512
    513/**
    514 * rdtgroup_remove - the helper to remove resource group safely
    515 * @rdtgrp: resource group to remove
    516 *
    517 * On resource group creation via a mkdir, an extra kernfs_node reference is
    518 * taken to ensure that the rdtgroup structure remains accessible for the
    519 * rdtgroup_kn_unlock() calls where it is removed.
    520 *
    521 * Drop the extra reference here, then free the rdtgroup structure.
    522 *
    523 * Return: void
    524 */
    525static void rdtgroup_remove(struct rdtgroup *rdtgrp)
    526{
    527	kernfs_put(rdtgrp->kn);
    528	kfree(rdtgrp);
    529}
    530
    531static void _update_task_closid_rmid(void *task)
    532{
    533	/*
    534	 * If the task is still current on this CPU, update PQR_ASSOC MSR.
    535	 * Otherwise, the MSR is updated when the task is scheduled in.
    536	 */
    537	if (task == current)
    538		resctrl_sched_in();
    539}
    540
    541static void update_task_closid_rmid(struct task_struct *t)
    542{
    543	if (IS_ENABLED(CONFIG_SMP) && task_curr(t))
    544		smp_call_function_single(task_cpu(t), _update_task_closid_rmid, t, 1);
    545	else
    546		_update_task_closid_rmid(t);
    547}
    548
    549static int __rdtgroup_move_task(struct task_struct *tsk,
    550				struct rdtgroup *rdtgrp)
    551{
    552	/* If the task is already in rdtgrp, no need to move the task. */
    553	if ((rdtgrp->type == RDTCTRL_GROUP && tsk->closid == rdtgrp->closid &&
    554	     tsk->rmid == rdtgrp->mon.rmid) ||
    555	    (rdtgrp->type == RDTMON_GROUP && tsk->rmid == rdtgrp->mon.rmid &&
    556	     tsk->closid == rdtgrp->mon.parent->closid))
    557		return 0;
    558
    559	/*
    560	 * Set the task's closid/rmid before the PQR_ASSOC MSR can be
    561	 * updated by them.
    562	 *
    563	 * For ctrl_mon groups, move both closid and rmid.
    564	 * For monitor groups, can move the tasks only from
    565	 * their parent CTRL group.
    566	 */
    567
    568	if (rdtgrp->type == RDTCTRL_GROUP) {
    569		WRITE_ONCE(tsk->closid, rdtgrp->closid);
    570		WRITE_ONCE(tsk->rmid, rdtgrp->mon.rmid);
    571	} else if (rdtgrp->type == RDTMON_GROUP) {
    572		if (rdtgrp->mon.parent->closid == tsk->closid) {
    573			WRITE_ONCE(tsk->rmid, rdtgrp->mon.rmid);
    574		} else {
    575			rdt_last_cmd_puts("Can't move task to different control group\n");
    576			return -EINVAL;
    577		}
    578	}
    579
    580	/*
    581	 * Ensure the task's closid and rmid are written before determining if
    582	 * the task is current that will decide if it will be interrupted.
    583	 */
    584	barrier();
    585
    586	/*
    587	 * By now, the task's closid and rmid are set. If the task is current
    588	 * on a CPU, the PQR_ASSOC MSR needs to be updated to make the resource
    589	 * group go into effect. If the task is not current, the MSR will be
    590	 * updated when the task is scheduled in.
    591	 */
    592	update_task_closid_rmid(tsk);
    593
    594	return 0;
    595}
    596
    597static bool is_closid_match(struct task_struct *t, struct rdtgroup *r)
    598{
    599	return (rdt_alloc_capable &&
    600	       (r->type == RDTCTRL_GROUP) && (t->closid == r->closid));
    601}
    602
    603static bool is_rmid_match(struct task_struct *t, struct rdtgroup *r)
    604{
    605	return (rdt_mon_capable &&
    606	       (r->type == RDTMON_GROUP) && (t->rmid == r->mon.rmid));
    607}
    608
    609/**
    610 * rdtgroup_tasks_assigned - Test if tasks have been assigned to resource group
    611 * @r: Resource group
    612 *
    613 * Return: 1 if tasks have been assigned to @r, 0 otherwise
    614 */
    615int rdtgroup_tasks_assigned(struct rdtgroup *r)
    616{
    617	struct task_struct *p, *t;
    618	int ret = 0;
    619
    620	lockdep_assert_held(&rdtgroup_mutex);
    621
    622	rcu_read_lock();
    623	for_each_process_thread(p, t) {
    624		if (is_closid_match(t, r) || is_rmid_match(t, r)) {
    625			ret = 1;
    626			break;
    627		}
    628	}
    629	rcu_read_unlock();
    630
    631	return ret;
    632}
    633
    634static int rdtgroup_task_write_permission(struct task_struct *task,
    635					  struct kernfs_open_file *of)
    636{
    637	const struct cred *tcred = get_task_cred(task);
    638	const struct cred *cred = current_cred();
    639	int ret = 0;
    640
    641	/*
    642	 * Even if we're attaching all tasks in the thread group, we only
    643	 * need to check permissions on one of them.
    644	 */
    645	if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) &&
    646	    !uid_eq(cred->euid, tcred->uid) &&
    647	    !uid_eq(cred->euid, tcred->suid)) {
    648		rdt_last_cmd_printf("No permission to move task %d\n", task->pid);
    649		ret = -EPERM;
    650	}
    651
    652	put_cred(tcred);
    653	return ret;
    654}
    655
    656static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp,
    657			      struct kernfs_open_file *of)
    658{
    659	struct task_struct *tsk;
    660	int ret;
    661
    662	rcu_read_lock();
    663	if (pid) {
    664		tsk = find_task_by_vpid(pid);
    665		if (!tsk) {
    666			rcu_read_unlock();
    667			rdt_last_cmd_printf("No task %d\n", pid);
    668			return -ESRCH;
    669		}
    670	} else {
    671		tsk = current;
    672	}
    673
    674	get_task_struct(tsk);
    675	rcu_read_unlock();
    676
    677	ret = rdtgroup_task_write_permission(tsk, of);
    678	if (!ret)
    679		ret = __rdtgroup_move_task(tsk, rdtgrp);
    680
    681	put_task_struct(tsk);
    682	return ret;
    683}
    684
    685static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of,
    686				    char *buf, size_t nbytes, loff_t off)
    687{
    688	struct rdtgroup *rdtgrp;
    689	int ret = 0;
    690	pid_t pid;
    691
    692	if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0)
    693		return -EINVAL;
    694	rdtgrp = rdtgroup_kn_lock_live(of->kn);
    695	if (!rdtgrp) {
    696		rdtgroup_kn_unlock(of->kn);
    697		return -ENOENT;
    698	}
    699	rdt_last_cmd_clear();
    700
    701	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED ||
    702	    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
    703		ret = -EINVAL;
    704		rdt_last_cmd_puts("Pseudo-locking in progress\n");
    705		goto unlock;
    706	}
    707
    708	ret = rdtgroup_move_task(pid, rdtgrp, of);
    709
    710unlock:
    711	rdtgroup_kn_unlock(of->kn);
    712
    713	return ret ?: nbytes;
    714}
    715
    716static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s)
    717{
    718	struct task_struct *p, *t;
    719
    720	rcu_read_lock();
    721	for_each_process_thread(p, t) {
    722		if (is_closid_match(t, r) || is_rmid_match(t, r))
    723			seq_printf(s, "%d\n", t->pid);
    724	}
    725	rcu_read_unlock();
    726}
    727
    728static int rdtgroup_tasks_show(struct kernfs_open_file *of,
    729			       struct seq_file *s, void *v)
    730{
    731	struct rdtgroup *rdtgrp;
    732	int ret = 0;
    733
    734	rdtgrp = rdtgroup_kn_lock_live(of->kn);
    735	if (rdtgrp)
    736		show_rdt_tasks(rdtgrp, s);
    737	else
    738		ret = -ENOENT;
    739	rdtgroup_kn_unlock(of->kn);
    740
    741	return ret;
    742}
    743
    744#ifdef CONFIG_PROC_CPU_RESCTRL
    745
    746/*
    747 * A task can only be part of one resctrl control group and of one monitor
    748 * group which is associated to that control group.
    749 *
    750 * 1)   res:
    751 *      mon:
    752 *
    753 *    resctrl is not available.
    754 *
    755 * 2)   res:/
    756 *      mon:
    757 *
    758 *    Task is part of the root resctrl control group, and it is not associated
    759 *    to any monitor group.
    760 *
    761 * 3)  res:/
    762 *     mon:mon0
    763 *
    764 *    Task is part of the root resctrl control group and monitor group mon0.
    765 *
    766 * 4)  res:group0
    767 *     mon:
    768 *
    769 *    Task is part of resctrl control group group0, and it is not associated
    770 *    to any monitor group.
    771 *
    772 * 5) res:group0
    773 *    mon:mon1
    774 *
    775 *    Task is part of resctrl control group group0 and monitor group mon1.
    776 */
    777int proc_resctrl_show(struct seq_file *s, struct pid_namespace *ns,
    778		      struct pid *pid, struct task_struct *tsk)
    779{
    780	struct rdtgroup *rdtg;
    781	int ret = 0;
    782
    783	mutex_lock(&rdtgroup_mutex);
    784
    785	/* Return empty if resctrl has not been mounted. */
    786	if (!static_branch_unlikely(&rdt_enable_key)) {
    787		seq_puts(s, "res:\nmon:\n");
    788		goto unlock;
    789	}
    790
    791	list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) {
    792		struct rdtgroup *crg;
    793
    794		/*
    795		 * Task information is only relevant for shareable
    796		 * and exclusive groups.
    797		 */
    798		if (rdtg->mode != RDT_MODE_SHAREABLE &&
    799		    rdtg->mode != RDT_MODE_EXCLUSIVE)
    800			continue;
    801
    802		if (rdtg->closid != tsk->closid)
    803			continue;
    804
    805		seq_printf(s, "res:%s%s\n", (rdtg == &rdtgroup_default) ? "/" : "",
    806			   rdtg->kn->name);
    807		seq_puts(s, "mon:");
    808		list_for_each_entry(crg, &rdtg->mon.crdtgrp_list,
    809				    mon.crdtgrp_list) {
    810			if (tsk->rmid != crg->mon.rmid)
    811				continue;
    812			seq_printf(s, "%s", crg->kn->name);
    813			break;
    814		}
    815		seq_putc(s, '\n');
    816		goto unlock;
    817	}
    818	/*
    819	 * The above search should succeed. Otherwise return
    820	 * with an error.
    821	 */
    822	ret = -ENOENT;
    823unlock:
    824	mutex_unlock(&rdtgroup_mutex);
    825
    826	return ret;
    827}
    828#endif
    829
    830static int rdt_last_cmd_status_show(struct kernfs_open_file *of,
    831				    struct seq_file *seq, void *v)
    832{
    833	int len;
    834
    835	mutex_lock(&rdtgroup_mutex);
    836	len = seq_buf_used(&last_cmd_status);
    837	if (len)
    838		seq_printf(seq, "%.*s", len, last_cmd_status_buf);
    839	else
    840		seq_puts(seq, "ok\n");
    841	mutex_unlock(&rdtgroup_mutex);
    842	return 0;
    843}
    844
    845static int rdt_num_closids_show(struct kernfs_open_file *of,
    846				struct seq_file *seq, void *v)
    847{
    848	struct resctrl_schema *s = of->kn->parent->priv;
    849
    850	seq_printf(seq, "%u\n", s->num_closid);
    851	return 0;
    852}
    853
    854static int rdt_default_ctrl_show(struct kernfs_open_file *of,
    855			     struct seq_file *seq, void *v)
    856{
    857	struct resctrl_schema *s = of->kn->parent->priv;
    858	struct rdt_resource *r = s->res;
    859
    860	seq_printf(seq, "%x\n", r->default_ctrl);
    861	return 0;
    862}
    863
    864static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
    865			     struct seq_file *seq, void *v)
    866{
    867	struct resctrl_schema *s = of->kn->parent->priv;
    868	struct rdt_resource *r = s->res;
    869
    870	seq_printf(seq, "%u\n", r->cache.min_cbm_bits);
    871	return 0;
    872}
    873
    874static int rdt_shareable_bits_show(struct kernfs_open_file *of,
    875				   struct seq_file *seq, void *v)
    876{
    877	struct resctrl_schema *s = of->kn->parent->priv;
    878	struct rdt_resource *r = s->res;
    879
    880	seq_printf(seq, "%x\n", r->cache.shareable_bits);
    881	return 0;
    882}
    883
    884/**
    885 * rdt_bit_usage_show - Display current usage of resources
    886 *
    887 * A domain is a shared resource that can now be allocated differently. Here
    888 * we display the current regions of the domain as an annotated bitmask.
    889 * For each domain of this resource its allocation bitmask
    890 * is annotated as below to indicate the current usage of the corresponding bit:
    891 *   0 - currently unused
    892 *   X - currently available for sharing and used by software and hardware
    893 *   H - currently used by hardware only but available for software use
    894 *   S - currently used and shareable by software only
    895 *   E - currently used exclusively by one resource group
    896 *   P - currently pseudo-locked by one resource group
    897 */
    898static int rdt_bit_usage_show(struct kernfs_open_file *of,
    899			      struct seq_file *seq, void *v)
    900{
    901	struct resctrl_schema *s = of->kn->parent->priv;
    902	/*
    903	 * Use unsigned long even though only 32 bits are used to ensure
    904	 * test_bit() is used safely.
    905	 */
    906	unsigned long sw_shareable = 0, hw_shareable = 0;
    907	unsigned long exclusive = 0, pseudo_locked = 0;
    908	struct rdt_resource *r = s->res;
    909	struct rdt_domain *dom;
    910	int i, hwb, swb, excl, psl;
    911	enum rdtgrp_mode mode;
    912	bool sep = false;
    913	u32 ctrl_val;
    914
    915	mutex_lock(&rdtgroup_mutex);
    916	hw_shareable = r->cache.shareable_bits;
    917	list_for_each_entry(dom, &r->domains, list) {
    918		if (sep)
    919			seq_putc(seq, ';');
    920		sw_shareable = 0;
    921		exclusive = 0;
    922		seq_printf(seq, "%d=", dom->id);
    923		for (i = 0; i < closids_supported(); i++) {
    924			if (!closid_allocated(i))
    925				continue;
    926			ctrl_val = resctrl_arch_get_config(r, dom, i,
    927							   s->conf_type);
    928			mode = rdtgroup_mode_by_closid(i);
    929			switch (mode) {
    930			case RDT_MODE_SHAREABLE:
    931				sw_shareable |= ctrl_val;
    932				break;
    933			case RDT_MODE_EXCLUSIVE:
    934				exclusive |= ctrl_val;
    935				break;
    936			case RDT_MODE_PSEUDO_LOCKSETUP:
    937			/*
    938			 * RDT_MODE_PSEUDO_LOCKSETUP is possible
    939			 * here but not included since the CBM
    940			 * associated with this CLOSID in this mode
    941			 * is not initialized and no task or cpu can be
    942			 * assigned this CLOSID.
    943			 */
    944				break;
    945			case RDT_MODE_PSEUDO_LOCKED:
    946			case RDT_NUM_MODES:
    947				WARN(1,
    948				     "invalid mode for closid %d\n", i);
    949				break;
    950			}
    951		}
    952		for (i = r->cache.cbm_len - 1; i >= 0; i--) {
    953			pseudo_locked = dom->plr ? dom->plr->cbm : 0;
    954			hwb = test_bit(i, &hw_shareable);
    955			swb = test_bit(i, &sw_shareable);
    956			excl = test_bit(i, &exclusive);
    957			psl = test_bit(i, &pseudo_locked);
    958			if (hwb && swb)
    959				seq_putc(seq, 'X');
    960			else if (hwb && !swb)
    961				seq_putc(seq, 'H');
    962			else if (!hwb && swb)
    963				seq_putc(seq, 'S');
    964			else if (excl)
    965				seq_putc(seq, 'E');
    966			else if (psl)
    967				seq_putc(seq, 'P');
    968			else /* Unused bits remain */
    969				seq_putc(seq, '0');
    970		}
    971		sep = true;
    972	}
    973	seq_putc(seq, '\n');
    974	mutex_unlock(&rdtgroup_mutex);
    975	return 0;
    976}
    977
    978static int rdt_min_bw_show(struct kernfs_open_file *of,
    979			     struct seq_file *seq, void *v)
    980{
    981	struct resctrl_schema *s = of->kn->parent->priv;
    982	struct rdt_resource *r = s->res;
    983
    984	seq_printf(seq, "%u\n", r->membw.min_bw);
    985	return 0;
    986}
    987
    988static int rdt_num_rmids_show(struct kernfs_open_file *of,
    989			      struct seq_file *seq, void *v)
    990{
    991	struct rdt_resource *r = of->kn->parent->priv;
    992
    993	seq_printf(seq, "%d\n", r->num_rmid);
    994
    995	return 0;
    996}
    997
    998static int rdt_mon_features_show(struct kernfs_open_file *of,
    999				 struct seq_file *seq, void *v)
   1000{
   1001	struct rdt_resource *r = of->kn->parent->priv;
   1002	struct mon_evt *mevt;
   1003
   1004	list_for_each_entry(mevt, &r->evt_list, list)
   1005		seq_printf(seq, "%s\n", mevt->name);
   1006
   1007	return 0;
   1008}
   1009
   1010static int rdt_bw_gran_show(struct kernfs_open_file *of,
   1011			     struct seq_file *seq, void *v)
   1012{
   1013	struct resctrl_schema *s = of->kn->parent->priv;
   1014	struct rdt_resource *r = s->res;
   1015
   1016	seq_printf(seq, "%u\n", r->membw.bw_gran);
   1017	return 0;
   1018}
   1019
   1020static int rdt_delay_linear_show(struct kernfs_open_file *of,
   1021			     struct seq_file *seq, void *v)
   1022{
   1023	struct resctrl_schema *s = of->kn->parent->priv;
   1024	struct rdt_resource *r = s->res;
   1025
   1026	seq_printf(seq, "%u\n", r->membw.delay_linear);
   1027	return 0;
   1028}
   1029
   1030static int max_threshold_occ_show(struct kernfs_open_file *of,
   1031				  struct seq_file *seq, void *v)
   1032{
   1033	struct rdt_resource *r = of->kn->parent->priv;
   1034	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
   1035
   1036	seq_printf(seq, "%u\n", resctrl_cqm_threshold * hw_res->mon_scale);
   1037
   1038	return 0;
   1039}
   1040
   1041static int rdt_thread_throttle_mode_show(struct kernfs_open_file *of,
   1042					 struct seq_file *seq, void *v)
   1043{
   1044	struct resctrl_schema *s = of->kn->parent->priv;
   1045	struct rdt_resource *r = s->res;
   1046
   1047	if (r->membw.throttle_mode == THREAD_THROTTLE_PER_THREAD)
   1048		seq_puts(seq, "per-thread\n");
   1049	else
   1050		seq_puts(seq, "max\n");
   1051
   1052	return 0;
   1053}
   1054
   1055static ssize_t max_threshold_occ_write(struct kernfs_open_file *of,
   1056				       char *buf, size_t nbytes, loff_t off)
   1057{
   1058	struct rdt_hw_resource *hw_res;
   1059	unsigned int bytes;
   1060	int ret;
   1061
   1062	ret = kstrtouint(buf, 0, &bytes);
   1063	if (ret)
   1064		return ret;
   1065
   1066	if (bytes > (boot_cpu_data.x86_cache_size * 1024))
   1067		return -EINVAL;
   1068
   1069	hw_res = resctrl_to_arch_res(of->kn->parent->priv);
   1070	resctrl_cqm_threshold = bytes / hw_res->mon_scale;
   1071
   1072	return nbytes;
   1073}
   1074
   1075/*
   1076 * rdtgroup_mode_show - Display mode of this resource group
   1077 */
   1078static int rdtgroup_mode_show(struct kernfs_open_file *of,
   1079			      struct seq_file *s, void *v)
   1080{
   1081	struct rdtgroup *rdtgrp;
   1082
   1083	rdtgrp = rdtgroup_kn_lock_live(of->kn);
   1084	if (!rdtgrp) {
   1085		rdtgroup_kn_unlock(of->kn);
   1086		return -ENOENT;
   1087	}
   1088
   1089	seq_printf(s, "%s\n", rdtgroup_mode_str(rdtgrp->mode));
   1090
   1091	rdtgroup_kn_unlock(of->kn);
   1092	return 0;
   1093}
   1094
   1095static enum resctrl_conf_type resctrl_peer_type(enum resctrl_conf_type my_type)
   1096{
   1097	switch (my_type) {
   1098	case CDP_CODE:
   1099		return CDP_DATA;
   1100	case CDP_DATA:
   1101		return CDP_CODE;
   1102	default:
   1103	case CDP_NONE:
   1104		return CDP_NONE;
   1105	}
   1106}
   1107
   1108/**
   1109 * __rdtgroup_cbm_overlaps - Does CBM for intended closid overlap with other
   1110 * @r: Resource to which domain instance @d belongs.
   1111 * @d: The domain instance for which @closid is being tested.
   1112 * @cbm: Capacity bitmask being tested.
   1113 * @closid: Intended closid for @cbm.
   1114 * @exclusive: Only check if overlaps with exclusive resource groups
   1115 *
   1116 * Checks if provided @cbm intended to be used for @closid on domain
   1117 * @d overlaps with any other closids or other hardware usage associated
   1118 * with this domain. If @exclusive is true then only overlaps with
   1119 * resource groups in exclusive mode will be considered. If @exclusive
   1120 * is false then overlaps with any resource group or hardware entities
   1121 * will be considered.
   1122 *
   1123 * @cbm is unsigned long, even if only 32 bits are used, to make the
   1124 * bitmap functions work correctly.
   1125 *
   1126 * Return: false if CBM does not overlap, true if it does.
   1127 */
   1128static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d,
   1129				    unsigned long cbm, int closid,
   1130				    enum resctrl_conf_type type, bool exclusive)
   1131{
   1132	enum rdtgrp_mode mode;
   1133	unsigned long ctrl_b;
   1134	int i;
   1135
   1136	/* Check for any overlap with regions used by hardware directly */
   1137	if (!exclusive) {
   1138		ctrl_b = r->cache.shareable_bits;
   1139		if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len))
   1140			return true;
   1141	}
   1142
   1143	/* Check for overlap with other resource groups */
   1144	for (i = 0; i < closids_supported(); i++) {
   1145		ctrl_b = resctrl_arch_get_config(r, d, i, type);
   1146		mode = rdtgroup_mode_by_closid(i);
   1147		if (closid_allocated(i) && i != closid &&
   1148		    mode != RDT_MODE_PSEUDO_LOCKSETUP) {
   1149			if (bitmap_intersects(&cbm, &ctrl_b, r->cache.cbm_len)) {
   1150				if (exclusive) {
   1151					if (mode == RDT_MODE_EXCLUSIVE)
   1152						return true;
   1153					continue;
   1154				}
   1155				return true;
   1156			}
   1157		}
   1158	}
   1159
   1160	return false;
   1161}
   1162
   1163/**
   1164 * rdtgroup_cbm_overlaps - Does CBM overlap with other use of hardware
   1165 * @s: Schema for the resource to which domain instance @d belongs.
   1166 * @d: The domain instance for which @closid is being tested.
   1167 * @cbm: Capacity bitmask being tested.
   1168 * @closid: Intended closid for @cbm.
   1169 * @exclusive: Only check if overlaps with exclusive resource groups
   1170 *
   1171 * Resources that can be allocated using a CBM can use the CBM to control
   1172 * the overlap of these allocations. rdtgroup_cmb_overlaps() is the test
   1173 * for overlap. Overlap test is not limited to the specific resource for
   1174 * which the CBM is intended though - when dealing with CDP resources that
   1175 * share the underlying hardware the overlap check should be performed on
   1176 * the CDP resource sharing the hardware also.
   1177 *
   1178 * Refer to description of __rdtgroup_cbm_overlaps() for the details of the
   1179 * overlap test.
   1180 *
   1181 * Return: true if CBM overlap detected, false if there is no overlap
   1182 */
   1183bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_domain *d,
   1184			   unsigned long cbm, int closid, bool exclusive)
   1185{
   1186	enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type);
   1187	struct rdt_resource *r = s->res;
   1188
   1189	if (__rdtgroup_cbm_overlaps(r, d, cbm, closid, s->conf_type,
   1190				    exclusive))
   1191		return true;
   1192
   1193	if (!resctrl_arch_get_cdp_enabled(r->rid))
   1194		return false;
   1195	return  __rdtgroup_cbm_overlaps(r, d, cbm, closid, peer_type, exclusive);
   1196}
   1197
   1198/**
   1199 * rdtgroup_mode_test_exclusive - Test if this resource group can be exclusive
   1200 *
   1201 * An exclusive resource group implies that there should be no sharing of
   1202 * its allocated resources. At the time this group is considered to be
   1203 * exclusive this test can determine if its current schemata supports this
   1204 * setting by testing for overlap with all other resource groups.
   1205 *
   1206 * Return: true if resource group can be exclusive, false if there is overlap
   1207 * with allocations of other resource groups and thus this resource group
   1208 * cannot be exclusive.
   1209 */
   1210static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp)
   1211{
   1212	int closid = rdtgrp->closid;
   1213	struct resctrl_schema *s;
   1214	struct rdt_resource *r;
   1215	bool has_cache = false;
   1216	struct rdt_domain *d;
   1217	u32 ctrl;
   1218
   1219	list_for_each_entry(s, &resctrl_schema_all, list) {
   1220		r = s->res;
   1221		if (r->rid == RDT_RESOURCE_MBA)
   1222			continue;
   1223		has_cache = true;
   1224		list_for_each_entry(d, &r->domains, list) {
   1225			ctrl = resctrl_arch_get_config(r, d, closid,
   1226						       s->conf_type);
   1227			if (rdtgroup_cbm_overlaps(s, d, ctrl, closid, false)) {
   1228				rdt_last_cmd_puts("Schemata overlaps\n");
   1229				return false;
   1230			}
   1231		}
   1232	}
   1233
   1234	if (!has_cache) {
   1235		rdt_last_cmd_puts("Cannot be exclusive without CAT/CDP\n");
   1236		return false;
   1237	}
   1238
   1239	return true;
   1240}
   1241
   1242/**
   1243 * rdtgroup_mode_write - Modify the resource group's mode
   1244 *
   1245 */
   1246static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of,
   1247				   char *buf, size_t nbytes, loff_t off)
   1248{
   1249	struct rdtgroup *rdtgrp;
   1250	enum rdtgrp_mode mode;
   1251	int ret = 0;
   1252
   1253	/* Valid input requires a trailing newline */
   1254	if (nbytes == 0 || buf[nbytes - 1] != '\n')
   1255		return -EINVAL;
   1256	buf[nbytes - 1] = '\0';
   1257
   1258	rdtgrp = rdtgroup_kn_lock_live(of->kn);
   1259	if (!rdtgrp) {
   1260		rdtgroup_kn_unlock(of->kn);
   1261		return -ENOENT;
   1262	}
   1263
   1264	rdt_last_cmd_clear();
   1265
   1266	mode = rdtgrp->mode;
   1267
   1268	if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) ||
   1269	    (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE) ||
   1270	    (!strcmp(buf, "pseudo-locksetup") &&
   1271	     mode == RDT_MODE_PSEUDO_LOCKSETUP) ||
   1272	    (!strcmp(buf, "pseudo-locked") && mode == RDT_MODE_PSEUDO_LOCKED))
   1273		goto out;
   1274
   1275	if (mode == RDT_MODE_PSEUDO_LOCKED) {
   1276		rdt_last_cmd_puts("Cannot change pseudo-locked group\n");
   1277		ret = -EINVAL;
   1278		goto out;
   1279	}
   1280
   1281	if (!strcmp(buf, "shareable")) {
   1282		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
   1283			ret = rdtgroup_locksetup_exit(rdtgrp);
   1284			if (ret)
   1285				goto out;
   1286		}
   1287		rdtgrp->mode = RDT_MODE_SHAREABLE;
   1288	} else if (!strcmp(buf, "exclusive")) {
   1289		if (!rdtgroup_mode_test_exclusive(rdtgrp)) {
   1290			ret = -EINVAL;
   1291			goto out;
   1292		}
   1293		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
   1294			ret = rdtgroup_locksetup_exit(rdtgrp);
   1295			if (ret)
   1296				goto out;
   1297		}
   1298		rdtgrp->mode = RDT_MODE_EXCLUSIVE;
   1299	} else if (!strcmp(buf, "pseudo-locksetup")) {
   1300		ret = rdtgroup_locksetup_enter(rdtgrp);
   1301		if (ret)
   1302			goto out;
   1303		rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP;
   1304	} else {
   1305		rdt_last_cmd_puts("Unknown or unsupported mode\n");
   1306		ret = -EINVAL;
   1307	}
   1308
   1309out:
   1310	rdtgroup_kn_unlock(of->kn);
   1311	return ret ?: nbytes;
   1312}
   1313
   1314/**
   1315 * rdtgroup_cbm_to_size - Translate CBM to size in bytes
   1316 * @r: RDT resource to which @d belongs.
   1317 * @d: RDT domain instance.
   1318 * @cbm: bitmask for which the size should be computed.
   1319 *
   1320 * The bitmask provided associated with the RDT domain instance @d will be
   1321 * translated into how many bytes it represents. The size in bytes is
   1322 * computed by first dividing the total cache size by the CBM length to
   1323 * determine how many bytes each bit in the bitmask represents. The result
   1324 * is multiplied with the number of bits set in the bitmask.
   1325 *
   1326 * @cbm is unsigned long, even if only 32 bits are used to make the
   1327 * bitmap functions work correctly.
   1328 */
   1329unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r,
   1330				  struct rdt_domain *d, unsigned long cbm)
   1331{
   1332	struct cpu_cacheinfo *ci;
   1333	unsigned int size = 0;
   1334	int num_b, i;
   1335
   1336	num_b = bitmap_weight(&cbm, r->cache.cbm_len);
   1337	ci = get_cpu_cacheinfo(cpumask_any(&d->cpu_mask));
   1338	for (i = 0; i < ci->num_leaves; i++) {
   1339		if (ci->info_list[i].level == r->cache_level) {
   1340			size = ci->info_list[i].size / r->cache.cbm_len * num_b;
   1341			break;
   1342		}
   1343	}
   1344
   1345	return size;
   1346}
   1347
   1348/**
   1349 * rdtgroup_size_show - Display size in bytes of allocated regions
   1350 *
   1351 * The "size" file mirrors the layout of the "schemata" file, printing the
   1352 * size in bytes of each region instead of the capacity bitmask.
   1353 *
   1354 */
   1355static int rdtgroup_size_show(struct kernfs_open_file *of,
   1356			      struct seq_file *s, void *v)
   1357{
   1358	struct resctrl_schema *schema;
   1359	struct rdtgroup *rdtgrp;
   1360	struct rdt_resource *r;
   1361	struct rdt_domain *d;
   1362	unsigned int size;
   1363	int ret = 0;
   1364	bool sep;
   1365	u32 ctrl;
   1366
   1367	rdtgrp = rdtgroup_kn_lock_live(of->kn);
   1368	if (!rdtgrp) {
   1369		rdtgroup_kn_unlock(of->kn);
   1370		return -ENOENT;
   1371	}
   1372
   1373	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
   1374		if (!rdtgrp->plr->d) {
   1375			rdt_last_cmd_clear();
   1376			rdt_last_cmd_puts("Cache domain offline\n");
   1377			ret = -ENODEV;
   1378		} else {
   1379			seq_printf(s, "%*s:", max_name_width,
   1380				   rdtgrp->plr->s->name);
   1381			size = rdtgroup_cbm_to_size(rdtgrp->plr->s->res,
   1382						    rdtgrp->plr->d,
   1383						    rdtgrp->plr->cbm);
   1384			seq_printf(s, "%d=%u\n", rdtgrp->plr->d->id, size);
   1385		}
   1386		goto out;
   1387	}
   1388
   1389	list_for_each_entry(schema, &resctrl_schema_all, list) {
   1390		r = schema->res;
   1391		sep = false;
   1392		seq_printf(s, "%*s:", max_name_width, schema->name);
   1393		list_for_each_entry(d, &r->domains, list) {
   1394			if (sep)
   1395				seq_putc(s, ';');
   1396			if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
   1397				size = 0;
   1398			} else {
   1399				ctrl = resctrl_arch_get_config(r, d,
   1400							       rdtgrp->closid,
   1401							       schema->conf_type);
   1402				if (r->rid == RDT_RESOURCE_MBA)
   1403					size = ctrl;
   1404				else
   1405					size = rdtgroup_cbm_to_size(r, d, ctrl);
   1406			}
   1407			seq_printf(s, "%d=%u", d->id, size);
   1408			sep = true;
   1409		}
   1410		seq_putc(s, '\n');
   1411	}
   1412
   1413out:
   1414	rdtgroup_kn_unlock(of->kn);
   1415
   1416	return ret;
   1417}
   1418
   1419/* rdtgroup information files for one cache resource. */
   1420static struct rftype res_common_files[] = {
   1421	{
   1422		.name		= "last_cmd_status",
   1423		.mode		= 0444,
   1424		.kf_ops		= &rdtgroup_kf_single_ops,
   1425		.seq_show	= rdt_last_cmd_status_show,
   1426		.fflags		= RF_TOP_INFO,
   1427	},
   1428	{
   1429		.name		= "num_closids",
   1430		.mode		= 0444,
   1431		.kf_ops		= &rdtgroup_kf_single_ops,
   1432		.seq_show	= rdt_num_closids_show,
   1433		.fflags		= RF_CTRL_INFO,
   1434	},
   1435	{
   1436		.name		= "mon_features",
   1437		.mode		= 0444,
   1438		.kf_ops		= &rdtgroup_kf_single_ops,
   1439		.seq_show	= rdt_mon_features_show,
   1440		.fflags		= RF_MON_INFO,
   1441	},
   1442	{
   1443		.name		= "num_rmids",
   1444		.mode		= 0444,
   1445		.kf_ops		= &rdtgroup_kf_single_ops,
   1446		.seq_show	= rdt_num_rmids_show,
   1447		.fflags		= RF_MON_INFO,
   1448	},
   1449	{
   1450		.name		= "cbm_mask",
   1451		.mode		= 0444,
   1452		.kf_ops		= &rdtgroup_kf_single_ops,
   1453		.seq_show	= rdt_default_ctrl_show,
   1454		.fflags		= RF_CTRL_INFO | RFTYPE_RES_CACHE,
   1455	},
   1456	{
   1457		.name		= "min_cbm_bits",
   1458		.mode		= 0444,
   1459		.kf_ops		= &rdtgroup_kf_single_ops,
   1460		.seq_show	= rdt_min_cbm_bits_show,
   1461		.fflags		= RF_CTRL_INFO | RFTYPE_RES_CACHE,
   1462	},
   1463	{
   1464		.name		= "shareable_bits",
   1465		.mode		= 0444,
   1466		.kf_ops		= &rdtgroup_kf_single_ops,
   1467		.seq_show	= rdt_shareable_bits_show,
   1468		.fflags		= RF_CTRL_INFO | RFTYPE_RES_CACHE,
   1469	},
   1470	{
   1471		.name		= "bit_usage",
   1472		.mode		= 0444,
   1473		.kf_ops		= &rdtgroup_kf_single_ops,
   1474		.seq_show	= rdt_bit_usage_show,
   1475		.fflags		= RF_CTRL_INFO | RFTYPE_RES_CACHE,
   1476	},
   1477	{
   1478		.name		= "min_bandwidth",
   1479		.mode		= 0444,
   1480		.kf_ops		= &rdtgroup_kf_single_ops,
   1481		.seq_show	= rdt_min_bw_show,
   1482		.fflags		= RF_CTRL_INFO | RFTYPE_RES_MB,
   1483	},
   1484	{
   1485		.name		= "bandwidth_gran",
   1486		.mode		= 0444,
   1487		.kf_ops		= &rdtgroup_kf_single_ops,
   1488		.seq_show	= rdt_bw_gran_show,
   1489		.fflags		= RF_CTRL_INFO | RFTYPE_RES_MB,
   1490	},
   1491	{
   1492		.name		= "delay_linear",
   1493		.mode		= 0444,
   1494		.kf_ops		= &rdtgroup_kf_single_ops,
   1495		.seq_show	= rdt_delay_linear_show,
   1496		.fflags		= RF_CTRL_INFO | RFTYPE_RES_MB,
   1497	},
   1498	/*
   1499	 * Platform specific which (if any) capabilities are provided by
   1500	 * thread_throttle_mode. Defer "fflags" initialization to platform
   1501	 * discovery.
   1502	 */
   1503	{
   1504		.name		= "thread_throttle_mode",
   1505		.mode		= 0444,
   1506		.kf_ops		= &rdtgroup_kf_single_ops,
   1507		.seq_show	= rdt_thread_throttle_mode_show,
   1508	},
   1509	{
   1510		.name		= "max_threshold_occupancy",
   1511		.mode		= 0644,
   1512		.kf_ops		= &rdtgroup_kf_single_ops,
   1513		.write		= max_threshold_occ_write,
   1514		.seq_show	= max_threshold_occ_show,
   1515		.fflags		= RF_MON_INFO | RFTYPE_RES_CACHE,
   1516	},
   1517	{
   1518		.name		= "cpus",
   1519		.mode		= 0644,
   1520		.kf_ops		= &rdtgroup_kf_single_ops,
   1521		.write		= rdtgroup_cpus_write,
   1522		.seq_show	= rdtgroup_cpus_show,
   1523		.fflags		= RFTYPE_BASE,
   1524	},
   1525	{
   1526		.name		= "cpus_list",
   1527		.mode		= 0644,
   1528		.kf_ops		= &rdtgroup_kf_single_ops,
   1529		.write		= rdtgroup_cpus_write,
   1530		.seq_show	= rdtgroup_cpus_show,
   1531		.flags		= RFTYPE_FLAGS_CPUS_LIST,
   1532		.fflags		= RFTYPE_BASE,
   1533	},
   1534	{
   1535		.name		= "tasks",
   1536		.mode		= 0644,
   1537		.kf_ops		= &rdtgroup_kf_single_ops,
   1538		.write		= rdtgroup_tasks_write,
   1539		.seq_show	= rdtgroup_tasks_show,
   1540		.fflags		= RFTYPE_BASE,
   1541	},
   1542	{
   1543		.name		= "schemata",
   1544		.mode		= 0644,
   1545		.kf_ops		= &rdtgroup_kf_single_ops,
   1546		.write		= rdtgroup_schemata_write,
   1547		.seq_show	= rdtgroup_schemata_show,
   1548		.fflags		= RF_CTRL_BASE,
   1549	},
   1550	{
   1551		.name		= "mode",
   1552		.mode		= 0644,
   1553		.kf_ops		= &rdtgroup_kf_single_ops,
   1554		.write		= rdtgroup_mode_write,
   1555		.seq_show	= rdtgroup_mode_show,
   1556		.fflags		= RF_CTRL_BASE,
   1557	},
   1558	{
   1559		.name		= "size",
   1560		.mode		= 0444,
   1561		.kf_ops		= &rdtgroup_kf_single_ops,
   1562		.seq_show	= rdtgroup_size_show,
   1563		.fflags		= RF_CTRL_BASE,
   1564	},
   1565
   1566};
   1567
   1568static int rdtgroup_add_files(struct kernfs_node *kn, unsigned long fflags)
   1569{
   1570	struct rftype *rfts, *rft;
   1571	int ret, len;
   1572
   1573	rfts = res_common_files;
   1574	len = ARRAY_SIZE(res_common_files);
   1575
   1576	lockdep_assert_held(&rdtgroup_mutex);
   1577
   1578	for (rft = rfts; rft < rfts + len; rft++) {
   1579		if (rft->fflags && ((fflags & rft->fflags) == rft->fflags)) {
   1580			ret = rdtgroup_add_file(kn, rft);
   1581			if (ret)
   1582				goto error;
   1583		}
   1584	}
   1585
   1586	return 0;
   1587error:
   1588	pr_warn("Failed to add %s, err=%d\n", rft->name, ret);
   1589	while (--rft >= rfts) {
   1590		if ((fflags & rft->fflags) == rft->fflags)
   1591			kernfs_remove_by_name(kn, rft->name);
   1592	}
   1593	return ret;
   1594}
   1595
   1596static struct rftype *rdtgroup_get_rftype_by_name(const char *name)
   1597{
   1598	struct rftype *rfts, *rft;
   1599	int len;
   1600
   1601	rfts = res_common_files;
   1602	len = ARRAY_SIZE(res_common_files);
   1603
   1604	for (rft = rfts; rft < rfts + len; rft++) {
   1605		if (!strcmp(rft->name, name))
   1606			return rft;
   1607	}
   1608
   1609	return NULL;
   1610}
   1611
   1612void __init thread_throttle_mode_init(void)
   1613{
   1614	struct rftype *rft;
   1615
   1616	rft = rdtgroup_get_rftype_by_name("thread_throttle_mode");
   1617	if (!rft)
   1618		return;
   1619
   1620	rft->fflags = RF_CTRL_INFO | RFTYPE_RES_MB;
   1621}
   1622
   1623/**
   1624 * rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file
   1625 * @r: The resource group with which the file is associated.
   1626 * @name: Name of the file
   1627 *
   1628 * The permissions of named resctrl file, directory, or link are modified
   1629 * to not allow read, write, or execute by any user.
   1630 *
   1631 * WARNING: This function is intended to communicate to the user that the
   1632 * resctrl file has been locked down - that it is not relevant to the
   1633 * particular state the system finds itself in. It should not be relied
   1634 * on to protect from user access because after the file's permissions
   1635 * are restricted the user can still change the permissions using chmod
   1636 * from the command line.
   1637 *
   1638 * Return: 0 on success, <0 on failure.
   1639 */
   1640int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name)
   1641{
   1642	struct iattr iattr = {.ia_valid = ATTR_MODE,};
   1643	struct kernfs_node *kn;
   1644	int ret = 0;
   1645
   1646	kn = kernfs_find_and_get_ns(r->kn, name, NULL);
   1647	if (!kn)
   1648		return -ENOENT;
   1649
   1650	switch (kernfs_type(kn)) {
   1651	case KERNFS_DIR:
   1652		iattr.ia_mode = S_IFDIR;
   1653		break;
   1654	case KERNFS_FILE:
   1655		iattr.ia_mode = S_IFREG;
   1656		break;
   1657	case KERNFS_LINK:
   1658		iattr.ia_mode = S_IFLNK;
   1659		break;
   1660	}
   1661
   1662	ret = kernfs_setattr(kn, &iattr);
   1663	kernfs_put(kn);
   1664	return ret;
   1665}
   1666
   1667/**
   1668 * rdtgroup_kn_mode_restore - Restore user access to named resctrl file
   1669 * @r: The resource group with which the file is associated.
   1670 * @name: Name of the file
   1671 * @mask: Mask of permissions that should be restored
   1672 *
   1673 * Restore the permissions of the named file. If @name is a directory the
   1674 * permissions of its parent will be used.
   1675 *
   1676 * Return: 0 on success, <0 on failure.
   1677 */
   1678int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name,
   1679			     umode_t mask)
   1680{
   1681	struct iattr iattr = {.ia_valid = ATTR_MODE,};
   1682	struct kernfs_node *kn, *parent;
   1683	struct rftype *rfts, *rft;
   1684	int ret, len;
   1685
   1686	rfts = res_common_files;
   1687	len = ARRAY_SIZE(res_common_files);
   1688
   1689	for (rft = rfts; rft < rfts + len; rft++) {
   1690		if (!strcmp(rft->name, name))
   1691			iattr.ia_mode = rft->mode & mask;
   1692	}
   1693
   1694	kn = kernfs_find_and_get_ns(r->kn, name, NULL);
   1695	if (!kn)
   1696		return -ENOENT;
   1697
   1698	switch (kernfs_type(kn)) {
   1699	case KERNFS_DIR:
   1700		parent = kernfs_get_parent(kn);
   1701		if (parent) {
   1702			iattr.ia_mode |= parent->mode;
   1703			kernfs_put(parent);
   1704		}
   1705		iattr.ia_mode |= S_IFDIR;
   1706		break;
   1707	case KERNFS_FILE:
   1708		iattr.ia_mode |= S_IFREG;
   1709		break;
   1710	case KERNFS_LINK:
   1711		iattr.ia_mode |= S_IFLNK;
   1712		break;
   1713	}
   1714
   1715	ret = kernfs_setattr(kn, &iattr);
   1716	kernfs_put(kn);
   1717	return ret;
   1718}
   1719
   1720static int rdtgroup_mkdir_info_resdir(void *priv, char *name,
   1721				      unsigned long fflags)
   1722{
   1723	struct kernfs_node *kn_subdir;
   1724	int ret;
   1725
   1726	kn_subdir = kernfs_create_dir(kn_info, name,
   1727				      kn_info->mode, priv);
   1728	if (IS_ERR(kn_subdir))
   1729		return PTR_ERR(kn_subdir);
   1730
   1731	ret = rdtgroup_kn_set_ugid(kn_subdir);
   1732	if (ret)
   1733		return ret;
   1734
   1735	ret = rdtgroup_add_files(kn_subdir, fflags);
   1736	if (!ret)
   1737		kernfs_activate(kn_subdir);
   1738
   1739	return ret;
   1740}
   1741
   1742static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
   1743{
   1744	struct resctrl_schema *s;
   1745	struct rdt_resource *r;
   1746	unsigned long fflags;
   1747	char name[32];
   1748	int ret;
   1749
   1750	/* create the directory */
   1751	kn_info = kernfs_create_dir(parent_kn, "info", parent_kn->mode, NULL);
   1752	if (IS_ERR(kn_info))
   1753		return PTR_ERR(kn_info);
   1754
   1755	ret = rdtgroup_add_files(kn_info, RF_TOP_INFO);
   1756	if (ret)
   1757		goto out_destroy;
   1758
   1759	/* loop over enabled controls, these are all alloc_enabled */
   1760	list_for_each_entry(s, &resctrl_schema_all, list) {
   1761		r = s->res;
   1762		fflags =  r->fflags | RF_CTRL_INFO;
   1763		ret = rdtgroup_mkdir_info_resdir(s, s->name, fflags);
   1764		if (ret)
   1765			goto out_destroy;
   1766	}
   1767
   1768	for_each_mon_enabled_rdt_resource(r) {
   1769		fflags =  r->fflags | RF_MON_INFO;
   1770		sprintf(name, "%s_MON", r->name);
   1771		ret = rdtgroup_mkdir_info_resdir(r, name, fflags);
   1772		if (ret)
   1773			goto out_destroy;
   1774	}
   1775
   1776	ret = rdtgroup_kn_set_ugid(kn_info);
   1777	if (ret)
   1778		goto out_destroy;
   1779
   1780	kernfs_activate(kn_info);
   1781
   1782	return 0;
   1783
   1784out_destroy:
   1785	kernfs_remove(kn_info);
   1786	return ret;
   1787}
   1788
   1789static int
   1790mongroup_create_dir(struct kernfs_node *parent_kn, struct rdtgroup *prgrp,
   1791		    char *name, struct kernfs_node **dest_kn)
   1792{
   1793	struct kernfs_node *kn;
   1794	int ret;
   1795
   1796	/* create the directory */
   1797	kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
   1798	if (IS_ERR(kn))
   1799		return PTR_ERR(kn);
   1800
   1801	if (dest_kn)
   1802		*dest_kn = kn;
   1803
   1804	ret = rdtgroup_kn_set_ugid(kn);
   1805	if (ret)
   1806		goto out_destroy;
   1807
   1808	kernfs_activate(kn);
   1809
   1810	return 0;
   1811
   1812out_destroy:
   1813	kernfs_remove(kn);
   1814	return ret;
   1815}
   1816
   1817static void l3_qos_cfg_update(void *arg)
   1818{
   1819	bool *enable = arg;
   1820
   1821	wrmsrl(MSR_IA32_L3_QOS_CFG, *enable ? L3_QOS_CDP_ENABLE : 0ULL);
   1822}
   1823
   1824static void l2_qos_cfg_update(void *arg)
   1825{
   1826	bool *enable = arg;
   1827
   1828	wrmsrl(MSR_IA32_L2_QOS_CFG, *enable ? L2_QOS_CDP_ENABLE : 0ULL);
   1829}
   1830
   1831static inline bool is_mba_linear(void)
   1832{
   1833	return rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl.membw.delay_linear;
   1834}
   1835
   1836static int set_cache_qos_cfg(int level, bool enable)
   1837{
   1838	void (*update)(void *arg);
   1839	struct rdt_resource *r_l;
   1840	cpumask_var_t cpu_mask;
   1841	struct rdt_domain *d;
   1842	int cpu;
   1843
   1844	if (level == RDT_RESOURCE_L3)
   1845		update = l3_qos_cfg_update;
   1846	else if (level == RDT_RESOURCE_L2)
   1847		update = l2_qos_cfg_update;
   1848	else
   1849		return -EINVAL;
   1850
   1851	if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
   1852		return -ENOMEM;
   1853
   1854	r_l = &rdt_resources_all[level].r_resctrl;
   1855	list_for_each_entry(d, &r_l->domains, list) {
   1856		if (r_l->cache.arch_has_per_cpu_cfg)
   1857			/* Pick all the CPUs in the domain instance */
   1858			for_each_cpu(cpu, &d->cpu_mask)
   1859				cpumask_set_cpu(cpu, cpu_mask);
   1860		else
   1861			/* Pick one CPU from each domain instance to update MSR */
   1862			cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
   1863	}
   1864	cpu = get_cpu();
   1865	/* Update QOS_CFG MSR on this cpu if it's in cpu_mask. */
   1866	if (cpumask_test_cpu(cpu, cpu_mask))
   1867		update(&enable);
   1868	/* Update QOS_CFG MSR on all other cpus in cpu_mask. */
   1869	smp_call_function_many(cpu_mask, update, &enable, 1);
   1870	put_cpu();
   1871
   1872	free_cpumask_var(cpu_mask);
   1873
   1874	return 0;
   1875}
   1876
   1877/* Restore the qos cfg state when a domain comes online */
   1878void rdt_domain_reconfigure_cdp(struct rdt_resource *r)
   1879{
   1880	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
   1881
   1882	if (!r->cdp_capable)
   1883		return;
   1884
   1885	if (r->rid == RDT_RESOURCE_L2)
   1886		l2_qos_cfg_update(&hw_res->cdp_enabled);
   1887
   1888	if (r->rid == RDT_RESOURCE_L3)
   1889		l3_qos_cfg_update(&hw_res->cdp_enabled);
   1890}
   1891
   1892/*
   1893 * Enable or disable the MBA software controller
   1894 * which helps user specify bandwidth in MBps.
   1895 * MBA software controller is supported only if
   1896 * MBM is supported and MBA is in linear scale.
   1897 */
   1898static int set_mba_sc(bool mba_sc)
   1899{
   1900	struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl;
   1901	struct rdt_hw_domain *hw_dom;
   1902	struct rdt_domain *d;
   1903
   1904	if (!is_mbm_enabled() || !is_mba_linear() ||
   1905	    mba_sc == is_mba_sc(r))
   1906		return -EINVAL;
   1907
   1908	r->membw.mba_sc = mba_sc;
   1909	list_for_each_entry(d, &r->domains, list) {
   1910		hw_dom = resctrl_to_arch_dom(d);
   1911		setup_default_ctrlval(r, hw_dom->ctrl_val, hw_dom->mbps_val);
   1912	}
   1913
   1914	return 0;
   1915}
   1916
   1917static int cdp_enable(int level)
   1918{
   1919	struct rdt_resource *r_l = &rdt_resources_all[level].r_resctrl;
   1920	int ret;
   1921
   1922	if (!r_l->alloc_capable)
   1923		return -EINVAL;
   1924
   1925	ret = set_cache_qos_cfg(level, true);
   1926	if (!ret)
   1927		rdt_resources_all[level].cdp_enabled = true;
   1928
   1929	return ret;
   1930}
   1931
   1932static void cdp_disable(int level)
   1933{
   1934	struct rdt_hw_resource *r_hw = &rdt_resources_all[level];
   1935
   1936	if (r_hw->cdp_enabled) {
   1937		set_cache_qos_cfg(level, false);
   1938		r_hw->cdp_enabled = false;
   1939	}
   1940}
   1941
   1942int resctrl_arch_set_cdp_enabled(enum resctrl_res_level l, bool enable)
   1943{
   1944	struct rdt_hw_resource *hw_res = &rdt_resources_all[l];
   1945
   1946	if (!hw_res->r_resctrl.cdp_capable)
   1947		return -EINVAL;
   1948
   1949	if (enable)
   1950		return cdp_enable(l);
   1951
   1952	cdp_disable(l);
   1953
   1954	return 0;
   1955}
   1956
   1957static void cdp_disable_all(void)
   1958{
   1959	if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3))
   1960		resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);
   1961	if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2))
   1962		resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);
   1963}
   1964
   1965/*
   1966 * We don't allow rdtgroup directories to be created anywhere
   1967 * except the root directory. Thus when looking for the rdtgroup
   1968 * structure for a kernfs node we are either looking at a directory,
   1969 * in which case the rdtgroup structure is pointed at by the "priv"
   1970 * field, otherwise we have a file, and need only look to the parent
   1971 * to find the rdtgroup.
   1972 */
   1973static struct rdtgroup *kernfs_to_rdtgroup(struct kernfs_node *kn)
   1974{
   1975	if (kernfs_type(kn) == KERNFS_DIR) {
   1976		/*
   1977		 * All the resource directories use "kn->priv"
   1978		 * to point to the "struct rdtgroup" for the
   1979		 * resource. "info" and its subdirectories don't
   1980		 * have rdtgroup structures, so return NULL here.
   1981		 */
   1982		if (kn == kn_info || kn->parent == kn_info)
   1983			return NULL;
   1984		else
   1985			return kn->priv;
   1986	} else {
   1987		return kn->parent->priv;
   1988	}
   1989}
   1990
   1991struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn)
   1992{
   1993	struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn);
   1994
   1995	if (!rdtgrp)
   1996		return NULL;
   1997
   1998	atomic_inc(&rdtgrp->waitcount);
   1999	kernfs_break_active_protection(kn);
   2000
   2001	mutex_lock(&rdtgroup_mutex);
   2002
   2003	/* Was this group deleted while we waited? */
   2004	if (rdtgrp->flags & RDT_DELETED)
   2005		return NULL;
   2006
   2007	return rdtgrp;
   2008}
   2009
   2010void rdtgroup_kn_unlock(struct kernfs_node *kn)
   2011{
   2012	struct rdtgroup *rdtgrp = kernfs_to_rdtgroup(kn);
   2013
   2014	if (!rdtgrp)
   2015		return;
   2016
   2017	mutex_unlock(&rdtgroup_mutex);
   2018
   2019	if (atomic_dec_and_test(&rdtgrp->waitcount) &&
   2020	    (rdtgrp->flags & RDT_DELETED)) {
   2021		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
   2022		    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
   2023			rdtgroup_pseudo_lock_remove(rdtgrp);
   2024		kernfs_unbreak_active_protection(kn);
   2025		rdtgroup_remove(rdtgrp);
   2026	} else {
   2027		kernfs_unbreak_active_protection(kn);
   2028	}
   2029}
   2030
   2031static int mkdir_mondata_all(struct kernfs_node *parent_kn,
   2032			     struct rdtgroup *prgrp,
   2033			     struct kernfs_node **mon_data_kn);
   2034
   2035static int rdt_enable_ctx(struct rdt_fs_context *ctx)
   2036{
   2037	int ret = 0;
   2038
   2039	if (ctx->enable_cdpl2)
   2040		ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, true);
   2041
   2042	if (!ret && ctx->enable_cdpl3)
   2043		ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, true);
   2044
   2045	if (!ret && ctx->enable_mba_mbps)
   2046		ret = set_mba_sc(true);
   2047
   2048	return ret;
   2049}
   2050
   2051static int schemata_list_add(struct rdt_resource *r, enum resctrl_conf_type type)
   2052{
   2053	struct resctrl_schema *s;
   2054	const char *suffix = "";
   2055	int ret, cl;
   2056
   2057	s = kzalloc(sizeof(*s), GFP_KERNEL);
   2058	if (!s)
   2059		return -ENOMEM;
   2060
   2061	s->res = r;
   2062	s->num_closid = resctrl_arch_get_num_closid(r);
   2063	if (resctrl_arch_get_cdp_enabled(r->rid))
   2064		s->num_closid /= 2;
   2065
   2066	s->conf_type = type;
   2067	switch (type) {
   2068	case CDP_CODE:
   2069		suffix = "CODE";
   2070		break;
   2071	case CDP_DATA:
   2072		suffix = "DATA";
   2073		break;
   2074	case CDP_NONE:
   2075		suffix = "";
   2076		break;
   2077	}
   2078
   2079	ret = snprintf(s->name, sizeof(s->name), "%s%s", r->name, suffix);
   2080	if (ret >= sizeof(s->name)) {
   2081		kfree(s);
   2082		return -EINVAL;
   2083	}
   2084
   2085	cl = strlen(s->name);
   2086
   2087	/*
   2088	 * If CDP is supported by this resource, but not enabled,
   2089	 * include the suffix. This ensures the tabular format of the
   2090	 * schemata file does not change between mounts of the filesystem.
   2091	 */
   2092	if (r->cdp_capable && !resctrl_arch_get_cdp_enabled(r->rid))
   2093		cl += 4;
   2094
   2095	if (cl > max_name_width)
   2096		max_name_width = cl;
   2097
   2098	INIT_LIST_HEAD(&s->list);
   2099	list_add(&s->list, &resctrl_schema_all);
   2100
   2101	return 0;
   2102}
   2103
   2104static int schemata_list_create(void)
   2105{
   2106	struct rdt_resource *r;
   2107	int ret = 0;
   2108
   2109	for_each_alloc_enabled_rdt_resource(r) {
   2110		if (resctrl_arch_get_cdp_enabled(r->rid)) {
   2111			ret = schemata_list_add(r, CDP_CODE);
   2112			if (ret)
   2113				break;
   2114
   2115			ret = schemata_list_add(r, CDP_DATA);
   2116		} else {
   2117			ret = schemata_list_add(r, CDP_NONE);
   2118		}
   2119
   2120		if (ret)
   2121			break;
   2122	}
   2123
   2124	return ret;
   2125}
   2126
   2127static void schemata_list_destroy(void)
   2128{
   2129	struct resctrl_schema *s, *tmp;
   2130
   2131	list_for_each_entry_safe(s, tmp, &resctrl_schema_all, list) {
   2132		list_del(&s->list);
   2133		kfree(s);
   2134	}
   2135}
   2136
   2137static int rdt_get_tree(struct fs_context *fc)
   2138{
   2139	struct rdt_fs_context *ctx = rdt_fc2context(fc);
   2140	struct rdt_domain *dom;
   2141	struct rdt_resource *r;
   2142	int ret;
   2143
   2144	cpus_read_lock();
   2145	mutex_lock(&rdtgroup_mutex);
   2146	/*
   2147	 * resctrl file system can only be mounted once.
   2148	 */
   2149	if (static_branch_unlikely(&rdt_enable_key)) {
   2150		ret = -EBUSY;
   2151		goto out;
   2152	}
   2153
   2154	ret = rdt_enable_ctx(ctx);
   2155	if (ret < 0)
   2156		goto out_cdp;
   2157
   2158	ret = schemata_list_create();
   2159	if (ret) {
   2160		schemata_list_destroy();
   2161		goto out_mba;
   2162	}
   2163
   2164	closid_init();
   2165
   2166	ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
   2167	if (ret < 0)
   2168		goto out_schemata_free;
   2169
   2170	if (rdt_mon_capable) {
   2171		ret = mongroup_create_dir(rdtgroup_default.kn,
   2172					  &rdtgroup_default, "mon_groups",
   2173					  &kn_mongrp);
   2174		if (ret < 0)
   2175			goto out_info;
   2176
   2177		ret = mkdir_mondata_all(rdtgroup_default.kn,
   2178					&rdtgroup_default, &kn_mondata);
   2179		if (ret < 0)
   2180			goto out_mongrp;
   2181		rdtgroup_default.mon.mon_data_kn = kn_mondata;
   2182	}
   2183
   2184	ret = rdt_pseudo_lock_init();
   2185	if (ret)
   2186		goto out_mondata;
   2187
   2188	ret = kernfs_get_tree(fc);
   2189	if (ret < 0)
   2190		goto out_psl;
   2191
   2192	if (rdt_alloc_capable)
   2193		static_branch_enable_cpuslocked(&rdt_alloc_enable_key);
   2194	if (rdt_mon_capable)
   2195		static_branch_enable_cpuslocked(&rdt_mon_enable_key);
   2196
   2197	if (rdt_alloc_capable || rdt_mon_capable)
   2198		static_branch_enable_cpuslocked(&rdt_enable_key);
   2199
   2200	if (is_mbm_enabled()) {
   2201		r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
   2202		list_for_each_entry(dom, &r->domains, list)
   2203			mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL);
   2204	}
   2205
   2206	goto out;
   2207
   2208out_psl:
   2209	rdt_pseudo_lock_release();
   2210out_mondata:
   2211	if (rdt_mon_capable)
   2212		kernfs_remove(kn_mondata);
   2213out_mongrp:
   2214	if (rdt_mon_capable)
   2215		kernfs_remove(kn_mongrp);
   2216out_info:
   2217	kernfs_remove(kn_info);
   2218out_schemata_free:
   2219	schemata_list_destroy();
   2220out_mba:
   2221	if (ctx->enable_mba_mbps)
   2222		set_mba_sc(false);
   2223out_cdp:
   2224	cdp_disable_all();
   2225out:
   2226	rdt_last_cmd_clear();
   2227	mutex_unlock(&rdtgroup_mutex);
   2228	cpus_read_unlock();
   2229	return ret;
   2230}
   2231
   2232enum rdt_param {
   2233	Opt_cdp,
   2234	Opt_cdpl2,
   2235	Opt_mba_mbps,
   2236	nr__rdt_params
   2237};
   2238
   2239static const struct fs_parameter_spec rdt_fs_parameters[] = {
   2240	fsparam_flag("cdp",		Opt_cdp),
   2241	fsparam_flag("cdpl2",		Opt_cdpl2),
   2242	fsparam_flag("mba_MBps",	Opt_mba_mbps),
   2243	{}
   2244};
   2245
   2246static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param)
   2247{
   2248	struct rdt_fs_context *ctx = rdt_fc2context(fc);
   2249	struct fs_parse_result result;
   2250	int opt;
   2251
   2252	opt = fs_parse(fc, rdt_fs_parameters, param, &result);
   2253	if (opt < 0)
   2254		return opt;
   2255
   2256	switch (opt) {
   2257	case Opt_cdp:
   2258		ctx->enable_cdpl3 = true;
   2259		return 0;
   2260	case Opt_cdpl2:
   2261		ctx->enable_cdpl2 = true;
   2262		return 0;
   2263	case Opt_mba_mbps:
   2264		if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
   2265			return -EINVAL;
   2266		ctx->enable_mba_mbps = true;
   2267		return 0;
   2268	}
   2269
   2270	return -EINVAL;
   2271}
   2272
   2273static void rdt_fs_context_free(struct fs_context *fc)
   2274{
   2275	struct rdt_fs_context *ctx = rdt_fc2context(fc);
   2276
   2277	kernfs_free_fs_context(fc);
   2278	kfree(ctx);
   2279}
   2280
   2281static const struct fs_context_operations rdt_fs_context_ops = {
   2282	.free		= rdt_fs_context_free,
   2283	.parse_param	= rdt_parse_param,
   2284	.get_tree	= rdt_get_tree,
   2285};
   2286
   2287static int rdt_init_fs_context(struct fs_context *fc)
   2288{
   2289	struct rdt_fs_context *ctx;
   2290
   2291	ctx = kzalloc(sizeof(struct rdt_fs_context), GFP_KERNEL);
   2292	if (!ctx)
   2293		return -ENOMEM;
   2294
   2295	ctx->kfc.root = rdt_root;
   2296	ctx->kfc.magic = RDTGROUP_SUPER_MAGIC;
   2297	fc->fs_private = &ctx->kfc;
   2298	fc->ops = &rdt_fs_context_ops;
   2299	put_user_ns(fc->user_ns);
   2300	fc->user_ns = get_user_ns(&init_user_ns);
   2301	fc->global = true;
   2302	return 0;
   2303}
   2304
   2305static int reset_all_ctrls(struct rdt_resource *r)
   2306{
   2307	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
   2308	struct rdt_hw_domain *hw_dom;
   2309	struct msr_param msr_param;
   2310	cpumask_var_t cpu_mask;
   2311	struct rdt_domain *d;
   2312	int i, cpu;
   2313
   2314	if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
   2315		return -ENOMEM;
   2316
   2317	msr_param.res = r;
   2318	msr_param.low = 0;
   2319	msr_param.high = hw_res->num_closid;
   2320
   2321	/*
   2322	 * Disable resource control for this resource by setting all
   2323	 * CBMs in all domains to the maximum mask value. Pick one CPU
   2324	 * from each domain to update the MSRs below.
   2325	 */
   2326	list_for_each_entry(d, &r->domains, list) {
   2327		hw_dom = resctrl_to_arch_dom(d);
   2328		cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
   2329
   2330		for (i = 0; i < hw_res->num_closid; i++)
   2331			hw_dom->ctrl_val[i] = r->default_ctrl;
   2332	}
   2333	cpu = get_cpu();
   2334	/* Update CBM on this cpu if it's in cpu_mask. */
   2335	if (cpumask_test_cpu(cpu, cpu_mask))
   2336		rdt_ctrl_update(&msr_param);
   2337	/* Update CBM on all other cpus in cpu_mask. */
   2338	smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1);
   2339	put_cpu();
   2340
   2341	free_cpumask_var(cpu_mask);
   2342
   2343	return 0;
   2344}
   2345
   2346/*
   2347 * Move tasks from one to the other group. If @from is NULL, then all tasks
   2348 * in the systems are moved unconditionally (used for teardown).
   2349 *
   2350 * If @mask is not NULL the cpus on which moved tasks are running are set
   2351 * in that mask so the update smp function call is restricted to affected
   2352 * cpus.
   2353 */
   2354static void rdt_move_group_tasks(struct rdtgroup *from, struct rdtgroup *to,
   2355				 struct cpumask *mask)
   2356{
   2357	struct task_struct *p, *t;
   2358
   2359	read_lock(&tasklist_lock);
   2360	for_each_process_thread(p, t) {
   2361		if (!from || is_closid_match(t, from) ||
   2362		    is_rmid_match(t, from)) {
   2363			WRITE_ONCE(t->closid, to->closid);
   2364			WRITE_ONCE(t->rmid, to->mon.rmid);
   2365
   2366			/*
   2367			 * If the task is on a CPU, set the CPU in the mask.
   2368			 * The detection is inaccurate as tasks might move or
   2369			 * schedule before the smp function call takes place.
   2370			 * In such a case the function call is pointless, but
   2371			 * there is no other side effect.
   2372			 */
   2373			if (IS_ENABLED(CONFIG_SMP) && mask && task_curr(t))
   2374				cpumask_set_cpu(task_cpu(t), mask);
   2375		}
   2376	}
   2377	read_unlock(&tasklist_lock);
   2378}
   2379
   2380static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp)
   2381{
   2382	struct rdtgroup *sentry, *stmp;
   2383	struct list_head *head;
   2384
   2385	head = &rdtgrp->mon.crdtgrp_list;
   2386	list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) {
   2387		free_rmid(sentry->mon.rmid);
   2388		list_del(&sentry->mon.crdtgrp_list);
   2389
   2390		if (atomic_read(&sentry->waitcount) != 0)
   2391			sentry->flags = RDT_DELETED;
   2392		else
   2393			rdtgroup_remove(sentry);
   2394	}
   2395}
   2396
   2397/*
   2398 * Forcibly remove all of subdirectories under root.
   2399 */
   2400static void rmdir_all_sub(void)
   2401{
   2402	struct rdtgroup *rdtgrp, *tmp;
   2403
   2404	/* Move all tasks to the default resource group */
   2405	rdt_move_group_tasks(NULL, &rdtgroup_default, NULL);
   2406
   2407	list_for_each_entry_safe(rdtgrp, tmp, &rdt_all_groups, rdtgroup_list) {
   2408		/* Free any child rmids */
   2409		free_all_child_rdtgrp(rdtgrp);
   2410
   2411		/* Remove each rdtgroup other than root */
   2412		if (rdtgrp == &rdtgroup_default)
   2413			continue;
   2414
   2415		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
   2416		    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)
   2417			rdtgroup_pseudo_lock_remove(rdtgrp);
   2418
   2419		/*
   2420		 * Give any CPUs back to the default group. We cannot copy
   2421		 * cpu_online_mask because a CPU might have executed the
   2422		 * offline callback already, but is still marked online.
   2423		 */
   2424		cpumask_or(&rdtgroup_default.cpu_mask,
   2425			   &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask);
   2426
   2427		free_rmid(rdtgrp->mon.rmid);
   2428
   2429		kernfs_remove(rdtgrp->kn);
   2430		list_del(&rdtgrp->rdtgroup_list);
   2431
   2432		if (atomic_read(&rdtgrp->waitcount) != 0)
   2433			rdtgrp->flags = RDT_DELETED;
   2434		else
   2435			rdtgroup_remove(rdtgrp);
   2436	}
   2437	/* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */
   2438	update_closid_rmid(cpu_online_mask, &rdtgroup_default);
   2439
   2440	kernfs_remove(kn_info);
   2441	kernfs_remove(kn_mongrp);
   2442	kernfs_remove(kn_mondata);
   2443}
   2444
   2445static void rdt_kill_sb(struct super_block *sb)
   2446{
   2447	struct rdt_resource *r;
   2448
   2449	cpus_read_lock();
   2450	mutex_lock(&rdtgroup_mutex);
   2451
   2452	set_mba_sc(false);
   2453
   2454	/*Put everything back to default values. */
   2455	for_each_alloc_enabled_rdt_resource(r)
   2456		reset_all_ctrls(r);
   2457	cdp_disable_all();
   2458	rmdir_all_sub();
   2459	rdt_pseudo_lock_release();
   2460	rdtgroup_default.mode = RDT_MODE_SHAREABLE;
   2461	schemata_list_destroy();
   2462	static_branch_disable_cpuslocked(&rdt_alloc_enable_key);
   2463	static_branch_disable_cpuslocked(&rdt_mon_enable_key);
   2464	static_branch_disable_cpuslocked(&rdt_enable_key);
   2465	kernfs_kill_sb(sb);
   2466	mutex_unlock(&rdtgroup_mutex);
   2467	cpus_read_unlock();
   2468}
   2469
   2470static struct file_system_type rdt_fs_type = {
   2471	.name			= "resctrl",
   2472	.init_fs_context	= rdt_init_fs_context,
   2473	.parameters		= rdt_fs_parameters,
   2474	.kill_sb		= rdt_kill_sb,
   2475};
   2476
   2477static int mon_addfile(struct kernfs_node *parent_kn, const char *name,
   2478		       void *priv)
   2479{
   2480	struct kernfs_node *kn;
   2481	int ret = 0;
   2482
   2483	kn = __kernfs_create_file(parent_kn, name, 0444,
   2484				  GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 0,
   2485				  &kf_mondata_ops, priv, NULL, NULL);
   2486	if (IS_ERR(kn))
   2487		return PTR_ERR(kn);
   2488
   2489	ret = rdtgroup_kn_set_ugid(kn);
   2490	if (ret) {
   2491		kernfs_remove(kn);
   2492		return ret;
   2493	}
   2494
   2495	return ret;
   2496}
   2497
   2498/*
   2499 * Remove all subdirectories of mon_data of ctrl_mon groups
   2500 * and monitor groups with given domain id.
   2501 */
   2502void rmdir_mondata_subdir_allrdtgrp(struct rdt_resource *r, unsigned int dom_id)
   2503{
   2504	struct rdtgroup *prgrp, *crgrp;
   2505	char name[32];
   2506
   2507	if (!r->mon_enabled)
   2508		return;
   2509
   2510	list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
   2511		sprintf(name, "mon_%s_%02d", r->name, dom_id);
   2512		kernfs_remove_by_name(prgrp->mon.mon_data_kn, name);
   2513
   2514		list_for_each_entry(crgrp, &prgrp->mon.crdtgrp_list, mon.crdtgrp_list)
   2515			kernfs_remove_by_name(crgrp->mon.mon_data_kn, name);
   2516	}
   2517}
   2518
   2519static int mkdir_mondata_subdir(struct kernfs_node *parent_kn,
   2520				struct rdt_domain *d,
   2521				struct rdt_resource *r, struct rdtgroup *prgrp)
   2522{
   2523	union mon_data_bits priv;
   2524	struct kernfs_node *kn;
   2525	struct mon_evt *mevt;
   2526	struct rmid_read rr;
   2527	char name[32];
   2528	int ret;
   2529
   2530	sprintf(name, "mon_%s_%02d", r->name, d->id);
   2531	/* create the directory */
   2532	kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, prgrp);
   2533	if (IS_ERR(kn))
   2534		return PTR_ERR(kn);
   2535
   2536	ret = rdtgroup_kn_set_ugid(kn);
   2537	if (ret)
   2538		goto out_destroy;
   2539
   2540	if (WARN_ON(list_empty(&r->evt_list))) {
   2541		ret = -EPERM;
   2542		goto out_destroy;
   2543	}
   2544
   2545	priv.u.rid = r->rid;
   2546	priv.u.domid = d->id;
   2547	list_for_each_entry(mevt, &r->evt_list, list) {
   2548		priv.u.evtid = mevt->evtid;
   2549		ret = mon_addfile(kn, mevt->name, priv.priv);
   2550		if (ret)
   2551			goto out_destroy;
   2552
   2553		if (is_mbm_event(mevt->evtid))
   2554			mon_event_read(&rr, r, d, prgrp, mevt->evtid, true);
   2555	}
   2556	kernfs_activate(kn);
   2557	return 0;
   2558
   2559out_destroy:
   2560	kernfs_remove(kn);
   2561	return ret;
   2562}
   2563
   2564/*
   2565 * Add all subdirectories of mon_data for "ctrl_mon" groups
   2566 * and "monitor" groups with given domain id.
   2567 */
   2568void mkdir_mondata_subdir_allrdtgrp(struct rdt_resource *r,
   2569				    struct rdt_domain *d)
   2570{
   2571	struct kernfs_node *parent_kn;
   2572	struct rdtgroup *prgrp, *crgrp;
   2573	struct list_head *head;
   2574
   2575	if (!r->mon_enabled)
   2576		return;
   2577
   2578	list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
   2579		parent_kn = prgrp->mon.mon_data_kn;
   2580		mkdir_mondata_subdir(parent_kn, d, r, prgrp);
   2581
   2582		head = &prgrp->mon.crdtgrp_list;
   2583		list_for_each_entry(crgrp, head, mon.crdtgrp_list) {
   2584			parent_kn = crgrp->mon.mon_data_kn;
   2585			mkdir_mondata_subdir(parent_kn, d, r, crgrp);
   2586		}
   2587	}
   2588}
   2589
   2590static int mkdir_mondata_subdir_alldom(struct kernfs_node *parent_kn,
   2591				       struct rdt_resource *r,
   2592				       struct rdtgroup *prgrp)
   2593{
   2594	struct rdt_domain *dom;
   2595	int ret;
   2596
   2597	list_for_each_entry(dom, &r->domains, list) {
   2598		ret = mkdir_mondata_subdir(parent_kn, dom, r, prgrp);
   2599		if (ret)
   2600			return ret;
   2601	}
   2602
   2603	return 0;
   2604}
   2605
   2606/*
   2607 * This creates a directory mon_data which contains the monitored data.
   2608 *
   2609 * mon_data has one directory for each domain which are named
   2610 * in the format mon_<domain_name>_<domain_id>. For ex: A mon_data
   2611 * with L3 domain looks as below:
   2612 * ./mon_data:
   2613 * mon_L3_00
   2614 * mon_L3_01
   2615 * mon_L3_02
   2616 * ...
   2617 *
   2618 * Each domain directory has one file per event:
   2619 * ./mon_L3_00/:
   2620 * llc_occupancy
   2621 *
   2622 */
   2623static int mkdir_mondata_all(struct kernfs_node *parent_kn,
   2624			     struct rdtgroup *prgrp,
   2625			     struct kernfs_node **dest_kn)
   2626{
   2627	struct rdt_resource *r;
   2628	struct kernfs_node *kn;
   2629	int ret;
   2630
   2631	/*
   2632	 * Create the mon_data directory first.
   2633	 */
   2634	ret = mongroup_create_dir(parent_kn, prgrp, "mon_data", &kn);
   2635	if (ret)
   2636		return ret;
   2637
   2638	if (dest_kn)
   2639		*dest_kn = kn;
   2640
   2641	/*
   2642	 * Create the subdirectories for each domain. Note that all events
   2643	 * in a domain like L3 are grouped into a resource whose domain is L3
   2644	 */
   2645	for_each_mon_enabled_rdt_resource(r) {
   2646		ret = mkdir_mondata_subdir_alldom(kn, r, prgrp);
   2647		if (ret)
   2648			goto out_destroy;
   2649	}
   2650
   2651	return 0;
   2652
   2653out_destroy:
   2654	kernfs_remove(kn);
   2655	return ret;
   2656}
   2657
   2658/**
   2659 * cbm_ensure_valid - Enforce validity on provided CBM
   2660 * @_val:	Candidate CBM
   2661 * @r:		RDT resource to which the CBM belongs
   2662 *
   2663 * The provided CBM represents all cache portions available for use. This
   2664 * may be represented by a bitmap that does not consist of contiguous ones
   2665 * and thus be an invalid CBM.
   2666 * Here the provided CBM is forced to be a valid CBM by only considering
   2667 * the first set of contiguous bits as valid and clearing all bits.
   2668 * The intention here is to provide a valid default CBM with which a new
   2669 * resource group is initialized. The user can follow this with a
   2670 * modification to the CBM if the default does not satisfy the
   2671 * requirements.
   2672 */
   2673static u32 cbm_ensure_valid(u32 _val, struct rdt_resource *r)
   2674{
   2675	unsigned int cbm_len = r->cache.cbm_len;
   2676	unsigned long first_bit, zero_bit;
   2677	unsigned long val = _val;
   2678
   2679	if (!val)
   2680		return 0;
   2681
   2682	first_bit = find_first_bit(&val, cbm_len);
   2683	zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
   2684
   2685	/* Clear any remaining bits to ensure contiguous region */
   2686	bitmap_clear(&val, zero_bit, cbm_len - zero_bit);
   2687	return (u32)val;
   2688}
   2689
   2690/*
   2691 * Initialize cache resources per RDT domain
   2692 *
   2693 * Set the RDT domain up to start off with all usable allocations. That is,
   2694 * all shareable and unused bits. All-zero CBM is invalid.
   2695 */
   2696static int __init_one_rdt_domain(struct rdt_domain *d, struct resctrl_schema *s,
   2697				 u32 closid)
   2698{
   2699	enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type);
   2700	enum resctrl_conf_type t = s->conf_type;
   2701	struct resctrl_staged_config *cfg;
   2702	struct rdt_resource *r = s->res;
   2703	u32 used_b = 0, unused_b = 0;
   2704	unsigned long tmp_cbm;
   2705	enum rdtgrp_mode mode;
   2706	u32 peer_ctl, ctrl_val;
   2707	int i;
   2708
   2709	cfg = &d->staged_config[t];
   2710	cfg->have_new_ctrl = false;
   2711	cfg->new_ctrl = r->cache.shareable_bits;
   2712	used_b = r->cache.shareable_bits;
   2713	for (i = 0; i < closids_supported(); i++) {
   2714		if (closid_allocated(i) && i != closid) {
   2715			mode = rdtgroup_mode_by_closid(i);
   2716			if (mode == RDT_MODE_PSEUDO_LOCKSETUP)
   2717				/*
   2718				 * ctrl values for locksetup aren't relevant
   2719				 * until the schemata is written, and the mode
   2720				 * becomes RDT_MODE_PSEUDO_LOCKED.
   2721				 */
   2722				continue;
   2723			/*
   2724			 * If CDP is active include peer domain's
   2725			 * usage to ensure there is no overlap
   2726			 * with an exclusive group.
   2727			 */
   2728			if (resctrl_arch_get_cdp_enabled(r->rid))
   2729				peer_ctl = resctrl_arch_get_config(r, d, i,
   2730								   peer_type);
   2731			else
   2732				peer_ctl = 0;
   2733			ctrl_val = resctrl_arch_get_config(r, d, i,
   2734							   s->conf_type);
   2735			used_b |= ctrl_val | peer_ctl;
   2736			if (mode == RDT_MODE_SHAREABLE)
   2737				cfg->new_ctrl |= ctrl_val | peer_ctl;
   2738		}
   2739	}
   2740	if (d->plr && d->plr->cbm > 0)
   2741		used_b |= d->plr->cbm;
   2742	unused_b = used_b ^ (BIT_MASK(r->cache.cbm_len) - 1);
   2743	unused_b &= BIT_MASK(r->cache.cbm_len) - 1;
   2744	cfg->new_ctrl |= unused_b;
   2745	/*
   2746	 * Force the initial CBM to be valid, user can
   2747	 * modify the CBM based on system availability.
   2748	 */
   2749	cfg->new_ctrl = cbm_ensure_valid(cfg->new_ctrl, r);
   2750	/*
   2751	 * Assign the u32 CBM to an unsigned long to ensure that
   2752	 * bitmap_weight() does not access out-of-bound memory.
   2753	 */
   2754	tmp_cbm = cfg->new_ctrl;
   2755	if (bitmap_weight(&tmp_cbm, r->cache.cbm_len) < r->cache.min_cbm_bits) {
   2756		rdt_last_cmd_printf("No space on %s:%d\n", s->name, d->id);
   2757		return -ENOSPC;
   2758	}
   2759	cfg->have_new_ctrl = true;
   2760
   2761	return 0;
   2762}
   2763
   2764/*
   2765 * Initialize cache resources with default values.
   2766 *
   2767 * A new RDT group is being created on an allocation capable (CAT)
   2768 * supporting system. Set this group up to start off with all usable
   2769 * allocations.
   2770 *
   2771 * If there are no more shareable bits available on any domain then
   2772 * the entire allocation will fail.
   2773 */
   2774static int rdtgroup_init_cat(struct resctrl_schema *s, u32 closid)
   2775{
   2776	struct rdt_domain *d;
   2777	int ret;
   2778
   2779	list_for_each_entry(d, &s->res->domains, list) {
   2780		ret = __init_one_rdt_domain(d, s, closid);
   2781		if (ret < 0)
   2782			return ret;
   2783	}
   2784
   2785	return 0;
   2786}
   2787
   2788/* Initialize MBA resource with default values. */
   2789static void rdtgroup_init_mba(struct rdt_resource *r)
   2790{
   2791	struct resctrl_staged_config *cfg;
   2792	struct rdt_domain *d;
   2793
   2794	list_for_each_entry(d, &r->domains, list) {
   2795		cfg = &d->staged_config[CDP_NONE];
   2796		cfg->new_ctrl = is_mba_sc(r) ? MBA_MAX_MBPS : r->default_ctrl;
   2797		cfg->have_new_ctrl = true;
   2798	}
   2799}
   2800
   2801/* Initialize the RDT group's allocations. */
   2802static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
   2803{
   2804	struct resctrl_schema *s;
   2805	struct rdt_resource *r;
   2806	int ret;
   2807
   2808	list_for_each_entry(s, &resctrl_schema_all, list) {
   2809		r = s->res;
   2810		if (r->rid == RDT_RESOURCE_MBA) {
   2811			rdtgroup_init_mba(r);
   2812		} else {
   2813			ret = rdtgroup_init_cat(s, rdtgrp->closid);
   2814			if (ret < 0)
   2815				return ret;
   2816		}
   2817
   2818		ret = resctrl_arch_update_domains(r, rdtgrp->closid);
   2819		if (ret < 0) {
   2820			rdt_last_cmd_puts("Failed to initialize allocations\n");
   2821			return ret;
   2822		}
   2823
   2824	}
   2825
   2826	rdtgrp->mode = RDT_MODE_SHAREABLE;
   2827
   2828	return 0;
   2829}
   2830
   2831static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
   2832			     const char *name, umode_t mode,
   2833			     enum rdt_group_type rtype, struct rdtgroup **r)
   2834{
   2835	struct rdtgroup *prdtgrp, *rdtgrp;
   2836	struct kernfs_node *kn;
   2837	uint files = 0;
   2838	int ret;
   2839
   2840	prdtgrp = rdtgroup_kn_lock_live(parent_kn);
   2841	if (!prdtgrp) {
   2842		ret = -ENODEV;
   2843		goto out_unlock;
   2844	}
   2845
   2846	if (rtype == RDTMON_GROUP &&
   2847	    (prdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
   2848	     prdtgrp->mode == RDT_MODE_PSEUDO_LOCKED)) {
   2849		ret = -EINVAL;
   2850		rdt_last_cmd_puts("Pseudo-locking in progress\n");
   2851		goto out_unlock;
   2852	}
   2853
   2854	/* allocate the rdtgroup. */
   2855	rdtgrp = kzalloc(sizeof(*rdtgrp), GFP_KERNEL);
   2856	if (!rdtgrp) {
   2857		ret = -ENOSPC;
   2858		rdt_last_cmd_puts("Kernel out of memory\n");
   2859		goto out_unlock;
   2860	}
   2861	*r = rdtgrp;
   2862	rdtgrp->mon.parent = prdtgrp;
   2863	rdtgrp->type = rtype;
   2864	INIT_LIST_HEAD(&rdtgrp->mon.crdtgrp_list);
   2865
   2866	/* kernfs creates the directory for rdtgrp */
   2867	kn = kernfs_create_dir(parent_kn, name, mode, rdtgrp);
   2868	if (IS_ERR(kn)) {
   2869		ret = PTR_ERR(kn);
   2870		rdt_last_cmd_puts("kernfs create error\n");
   2871		goto out_free_rgrp;
   2872	}
   2873	rdtgrp->kn = kn;
   2874
   2875	/*
   2876	 * kernfs_remove() will drop the reference count on "kn" which
   2877	 * will free it. But we still need it to stick around for the
   2878	 * rdtgroup_kn_unlock(kn) call. Take one extra reference here,
   2879	 * which will be dropped by kernfs_put() in rdtgroup_remove().
   2880	 */
   2881	kernfs_get(kn);
   2882
   2883	ret = rdtgroup_kn_set_ugid(kn);
   2884	if (ret) {
   2885		rdt_last_cmd_puts("kernfs perm error\n");
   2886		goto out_destroy;
   2887	}
   2888
   2889	files = RFTYPE_BASE | BIT(RF_CTRLSHIFT + rtype);
   2890	ret = rdtgroup_add_files(kn, files);
   2891	if (ret) {
   2892		rdt_last_cmd_puts("kernfs fill error\n");
   2893		goto out_destroy;
   2894	}
   2895
   2896	if (rdt_mon_capable) {
   2897		ret = alloc_rmid();
   2898		if (ret < 0) {
   2899			rdt_last_cmd_puts("Out of RMIDs\n");
   2900			goto out_destroy;
   2901		}
   2902		rdtgrp->mon.rmid = ret;
   2903
   2904		ret = mkdir_mondata_all(kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
   2905		if (ret) {
   2906			rdt_last_cmd_puts("kernfs subdir error\n");
   2907			goto out_idfree;
   2908		}
   2909	}
   2910	kernfs_activate(kn);
   2911
   2912	/*
   2913	 * The caller unlocks the parent_kn upon success.
   2914	 */
   2915	return 0;
   2916
   2917out_idfree:
   2918	free_rmid(rdtgrp->mon.rmid);
   2919out_destroy:
   2920	kernfs_put(rdtgrp->kn);
   2921	kernfs_remove(rdtgrp->kn);
   2922out_free_rgrp:
   2923	kfree(rdtgrp);
   2924out_unlock:
   2925	rdtgroup_kn_unlock(parent_kn);
   2926	return ret;
   2927}
   2928
   2929static void mkdir_rdt_prepare_clean(struct rdtgroup *rgrp)
   2930{
   2931	kernfs_remove(rgrp->kn);
   2932	free_rmid(rgrp->mon.rmid);
   2933	rdtgroup_remove(rgrp);
   2934}
   2935
   2936/*
   2937 * Create a monitor group under "mon_groups" directory of a control
   2938 * and monitor group(ctrl_mon). This is a resource group
   2939 * to monitor a subset of tasks and cpus in its parent ctrl_mon group.
   2940 */
   2941static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn,
   2942			      const char *name, umode_t mode)
   2943{
   2944	struct rdtgroup *rdtgrp, *prgrp;
   2945	int ret;
   2946
   2947	ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTMON_GROUP, &rdtgrp);
   2948	if (ret)
   2949		return ret;
   2950
   2951	prgrp = rdtgrp->mon.parent;
   2952	rdtgrp->closid = prgrp->closid;
   2953
   2954	/*
   2955	 * Add the rdtgrp to the list of rdtgrps the parent
   2956	 * ctrl_mon group has to track.
   2957	 */
   2958	list_add_tail(&rdtgrp->mon.crdtgrp_list, &prgrp->mon.crdtgrp_list);
   2959
   2960	rdtgroup_kn_unlock(parent_kn);
   2961	return ret;
   2962}
   2963
   2964/*
   2965 * These are rdtgroups created under the root directory. Can be used
   2966 * to allocate and monitor resources.
   2967 */
   2968static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
   2969				   const char *name, umode_t mode)
   2970{
   2971	struct rdtgroup *rdtgrp;
   2972	struct kernfs_node *kn;
   2973	u32 closid;
   2974	int ret;
   2975
   2976	ret = mkdir_rdt_prepare(parent_kn, name, mode, RDTCTRL_GROUP, &rdtgrp);
   2977	if (ret)
   2978		return ret;
   2979
   2980	kn = rdtgrp->kn;
   2981	ret = closid_alloc();
   2982	if (ret < 0) {
   2983		rdt_last_cmd_puts("Out of CLOSIDs\n");
   2984		goto out_common_fail;
   2985	}
   2986	closid = ret;
   2987	ret = 0;
   2988
   2989	rdtgrp->closid = closid;
   2990	ret = rdtgroup_init_alloc(rdtgrp);
   2991	if (ret < 0)
   2992		goto out_id_free;
   2993
   2994	list_add(&rdtgrp->rdtgroup_list, &rdt_all_groups);
   2995
   2996	if (rdt_mon_capable) {
   2997		/*
   2998		 * Create an empty mon_groups directory to hold the subset
   2999		 * of tasks and cpus to monitor.
   3000		 */
   3001		ret = mongroup_create_dir(kn, rdtgrp, "mon_groups", NULL);
   3002		if (ret) {
   3003			rdt_last_cmd_puts("kernfs subdir error\n");
   3004			goto out_del_list;
   3005		}
   3006	}
   3007
   3008	goto out_unlock;
   3009
   3010out_del_list:
   3011	list_del(&rdtgrp->rdtgroup_list);
   3012out_id_free:
   3013	closid_free(closid);
   3014out_common_fail:
   3015	mkdir_rdt_prepare_clean(rdtgrp);
   3016out_unlock:
   3017	rdtgroup_kn_unlock(parent_kn);
   3018	return ret;
   3019}
   3020
   3021/*
   3022 * We allow creating mon groups only with in a directory called "mon_groups"
   3023 * which is present in every ctrl_mon group. Check if this is a valid
   3024 * "mon_groups" directory.
   3025 *
   3026 * 1. The directory should be named "mon_groups".
   3027 * 2. The mon group itself should "not" be named "mon_groups".
   3028 *   This makes sure "mon_groups" directory always has a ctrl_mon group
   3029 *   as parent.
   3030 */
   3031static bool is_mon_groups(struct kernfs_node *kn, const char *name)
   3032{
   3033	return (!strcmp(kn->name, "mon_groups") &&
   3034		strcmp(name, "mon_groups"));
   3035}
   3036
   3037static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name,
   3038			  umode_t mode)
   3039{
   3040	/* Do not accept '\n' to avoid unparsable situation. */
   3041	if (strchr(name, '\n'))
   3042		return -EINVAL;
   3043
   3044	/*
   3045	 * If the parent directory is the root directory and RDT
   3046	 * allocation is supported, add a control and monitoring
   3047	 * subdirectory
   3048	 */
   3049	if (rdt_alloc_capable && parent_kn == rdtgroup_default.kn)
   3050		return rdtgroup_mkdir_ctrl_mon(parent_kn, name, mode);
   3051
   3052	/*
   3053	 * If RDT monitoring is supported and the parent directory is a valid
   3054	 * "mon_groups" directory, add a monitoring subdirectory.
   3055	 */
   3056	if (rdt_mon_capable && is_mon_groups(parent_kn, name))
   3057		return rdtgroup_mkdir_mon(parent_kn, name, mode);
   3058
   3059	return -EPERM;
   3060}
   3061
   3062static int rdtgroup_rmdir_mon(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask)
   3063{
   3064	struct rdtgroup *prdtgrp = rdtgrp->mon.parent;
   3065	int cpu;
   3066
   3067	/* Give any tasks back to the parent group */
   3068	rdt_move_group_tasks(rdtgrp, prdtgrp, tmpmask);
   3069
   3070	/* Update per cpu rmid of the moved CPUs first */
   3071	for_each_cpu(cpu, &rdtgrp->cpu_mask)
   3072		per_cpu(pqr_state.default_rmid, cpu) = prdtgrp->mon.rmid;
   3073	/*
   3074	 * Update the MSR on moved CPUs and CPUs which have moved
   3075	 * task running on them.
   3076	 */
   3077	cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
   3078	update_closid_rmid(tmpmask, NULL);
   3079
   3080	rdtgrp->flags = RDT_DELETED;
   3081	free_rmid(rdtgrp->mon.rmid);
   3082
   3083	/*
   3084	 * Remove the rdtgrp from the parent ctrl_mon group's list
   3085	 */
   3086	WARN_ON(list_empty(&prdtgrp->mon.crdtgrp_list));
   3087	list_del(&rdtgrp->mon.crdtgrp_list);
   3088
   3089	kernfs_remove(rdtgrp->kn);
   3090
   3091	return 0;
   3092}
   3093
   3094static int rdtgroup_ctrl_remove(struct rdtgroup *rdtgrp)
   3095{
   3096	rdtgrp->flags = RDT_DELETED;
   3097	list_del(&rdtgrp->rdtgroup_list);
   3098
   3099	kernfs_remove(rdtgrp->kn);
   3100	return 0;
   3101}
   3102
   3103static int rdtgroup_rmdir_ctrl(struct rdtgroup *rdtgrp, cpumask_var_t tmpmask)
   3104{
   3105	int cpu;
   3106
   3107	/* Give any tasks back to the default group */
   3108	rdt_move_group_tasks(rdtgrp, &rdtgroup_default, tmpmask);
   3109
   3110	/* Give any CPUs back to the default group */
   3111	cpumask_or(&rdtgroup_default.cpu_mask,
   3112		   &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask);
   3113
   3114	/* Update per cpu closid and rmid of the moved CPUs first */
   3115	for_each_cpu(cpu, &rdtgrp->cpu_mask) {
   3116		per_cpu(pqr_state.default_closid, cpu) = rdtgroup_default.closid;
   3117		per_cpu(pqr_state.default_rmid, cpu) = rdtgroup_default.mon.rmid;
   3118	}
   3119
   3120	/*
   3121	 * Update the MSR on moved CPUs and CPUs which have moved
   3122	 * task running on them.
   3123	 */
   3124	cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
   3125	update_closid_rmid(tmpmask, NULL);
   3126
   3127	closid_free(rdtgrp->closid);
   3128	free_rmid(rdtgrp->mon.rmid);
   3129
   3130	rdtgroup_ctrl_remove(rdtgrp);
   3131
   3132	/*
   3133	 * Free all the child monitor group rmids.
   3134	 */
   3135	free_all_child_rdtgrp(rdtgrp);
   3136
   3137	return 0;
   3138}
   3139
   3140static int rdtgroup_rmdir(struct kernfs_node *kn)
   3141{
   3142	struct kernfs_node *parent_kn = kn->parent;
   3143	struct rdtgroup *rdtgrp;
   3144	cpumask_var_t tmpmask;
   3145	int ret = 0;
   3146
   3147	if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL))
   3148		return -ENOMEM;
   3149
   3150	rdtgrp = rdtgroup_kn_lock_live(kn);
   3151	if (!rdtgrp) {
   3152		ret = -EPERM;
   3153		goto out;
   3154	}
   3155
   3156	/*
   3157	 * If the rdtgroup is a ctrl_mon group and parent directory
   3158	 * is the root directory, remove the ctrl_mon group.
   3159	 *
   3160	 * If the rdtgroup is a mon group and parent directory
   3161	 * is a valid "mon_groups" directory, remove the mon group.
   3162	 */
   3163	if (rdtgrp->type == RDTCTRL_GROUP && parent_kn == rdtgroup_default.kn &&
   3164	    rdtgrp != &rdtgroup_default) {
   3165		if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP ||
   3166		    rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
   3167			ret = rdtgroup_ctrl_remove(rdtgrp);
   3168		} else {
   3169			ret = rdtgroup_rmdir_ctrl(rdtgrp, tmpmask);
   3170		}
   3171	} else if (rdtgrp->type == RDTMON_GROUP &&
   3172		 is_mon_groups(parent_kn, kn->name)) {
   3173		ret = rdtgroup_rmdir_mon(rdtgrp, tmpmask);
   3174	} else {
   3175		ret = -EPERM;
   3176	}
   3177
   3178out:
   3179	rdtgroup_kn_unlock(kn);
   3180	free_cpumask_var(tmpmask);
   3181	return ret;
   3182}
   3183
   3184static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf)
   3185{
   3186	if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3))
   3187		seq_puts(seq, ",cdp");
   3188
   3189	if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2))
   3190		seq_puts(seq, ",cdpl2");
   3191
   3192	if (is_mba_sc(&rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl))
   3193		seq_puts(seq, ",mba_MBps");
   3194
   3195	return 0;
   3196}
   3197
   3198static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = {
   3199	.mkdir		= rdtgroup_mkdir,
   3200	.rmdir		= rdtgroup_rmdir,
   3201	.show_options	= rdtgroup_show_options,
   3202};
   3203
   3204static int __init rdtgroup_setup_root(void)
   3205{
   3206	int ret;
   3207
   3208	rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops,
   3209				      KERNFS_ROOT_CREATE_DEACTIVATED |
   3210				      KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK,
   3211				      &rdtgroup_default);
   3212	if (IS_ERR(rdt_root))
   3213		return PTR_ERR(rdt_root);
   3214
   3215	mutex_lock(&rdtgroup_mutex);
   3216
   3217	rdtgroup_default.closid = 0;
   3218	rdtgroup_default.mon.rmid = 0;
   3219	rdtgroup_default.type = RDTCTRL_GROUP;
   3220	INIT_LIST_HEAD(&rdtgroup_default.mon.crdtgrp_list);
   3221
   3222	list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups);
   3223
   3224	ret = rdtgroup_add_files(kernfs_root_to_node(rdt_root), RF_CTRL_BASE);
   3225	if (ret) {
   3226		kernfs_destroy_root(rdt_root);
   3227		goto out;
   3228	}
   3229
   3230	rdtgroup_default.kn = kernfs_root_to_node(rdt_root);
   3231	kernfs_activate(rdtgroup_default.kn);
   3232
   3233out:
   3234	mutex_unlock(&rdtgroup_mutex);
   3235
   3236	return ret;
   3237}
   3238
   3239/*
   3240 * rdtgroup_init - rdtgroup initialization
   3241 *
   3242 * Setup resctrl file system including set up root, create mount point,
   3243 * register rdtgroup filesystem, and initialize files under root directory.
   3244 *
   3245 * Return: 0 on success or -errno
   3246 */
   3247int __init rdtgroup_init(void)
   3248{
   3249	int ret = 0;
   3250
   3251	seq_buf_init(&last_cmd_status, last_cmd_status_buf,
   3252		     sizeof(last_cmd_status_buf));
   3253
   3254	ret = rdtgroup_setup_root();
   3255	if (ret)
   3256		return ret;
   3257
   3258	ret = sysfs_create_mount_point(fs_kobj, "resctrl");
   3259	if (ret)
   3260		goto cleanup_root;
   3261
   3262	ret = register_filesystem(&rdt_fs_type);
   3263	if (ret)
   3264		goto cleanup_mountpoint;
   3265
   3266	/*
   3267	 * Adding the resctrl debugfs directory here may not be ideal since
   3268	 * it would let the resctrl debugfs directory appear on the debugfs
   3269	 * filesystem before the resctrl filesystem is mounted.
   3270	 * It may also be ok since that would enable debugging of RDT before
   3271	 * resctrl is mounted.
   3272	 * The reason why the debugfs directory is created here and not in
   3273	 * rdt_get_tree() is because rdt_get_tree() takes rdtgroup_mutex and
   3274	 * during the debugfs directory creation also &sb->s_type->i_mutex_key
   3275	 * (the lockdep class of inode->i_rwsem). Other filesystem
   3276	 * interactions (eg. SyS_getdents) have the lock ordering:
   3277	 * &sb->s_type->i_mutex_key --> &mm->mmap_lock
   3278	 * During mmap(), called with &mm->mmap_lock, the rdtgroup_mutex
   3279	 * is taken, thus creating dependency:
   3280	 * &mm->mmap_lock --> rdtgroup_mutex for the latter that can cause
   3281	 * issues considering the other two lock dependencies.
   3282	 * By creating the debugfs directory here we avoid a dependency
   3283	 * that may cause deadlock (even though file operations cannot
   3284	 * occur until the filesystem is mounted, but I do not know how to
   3285	 * tell lockdep that).
   3286	 */
   3287	debugfs_resctrl = debugfs_create_dir("resctrl", NULL);
   3288
   3289	return 0;
   3290
   3291cleanup_mountpoint:
   3292	sysfs_remove_mount_point(fs_kobj, "resctrl");
   3293cleanup_root:
   3294	kernfs_destroy_root(rdt_root);
   3295
   3296	return ret;
   3297}
   3298
   3299void __exit rdtgroup_exit(void)
   3300{
   3301	debugfs_remove_recursive(debugfs_resctrl);
   3302	unregister_filesystem(&rdt_fs_type);
   3303	sysfs_remove_mount_point(fs_kobj, "resctrl");
   3304	kernfs_destroy_root(rdt_root);
   3305}