[linux-2.6-block.git] / arch / x86 / kernel / cpu / intel_rdt_monitor.c

/*
 * Resource Director Technology(RDT)
 * - Monitoring code
 *
 * Copyright (C) 2017 Intel Corporation
 *
 * Author:
 *    Vikas Shivappa <vikas.shivappa@intel.com>
 *
 * This replaces the cqm.c based on perf but we reuse a lot of
 * code and datastructures originally from Peter Zijlstra and Matt Fleming.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * More information about RDT be found in the Intel (R) x86 Architecture
 * Software Developer Manual June 2016, volume 3, section 17.17.
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <asm/cpu_device_id.h>
#include "intel_rdt.h"

#define MSR_IA32_QM_CTR		0x0c8e
#define MSR_IA32_QM_EVTSEL		0x0c8d

struct rmid_entry {
	u32				rmid;
	int				busy;
	struct list_head		list;
};

/**
 * @rmid_free_lru    A least recently used list of free RMIDs
 *     These RMIDs are guaranteed to have an occupancy less than the
 *     threshold occupancy
 */
static LIST_HEAD(rmid_free_lru);

/**
 * @rmid_limbo_count     count of currently unused but (potentially)
 *     dirty RMIDs.
 *     This counts RMIDs that no one is currently using but that
 *     may have a occupancy value > intel_cqm_threshold. User can change
 *     the threshold occupancy value.
 */
static unsigned int rmid_limbo_count;

/**
 * @rmid_entry - The entry in the limbo and free lists.
 */
static struct rmid_entry	*rmid_ptrs;

/*
 * Global boolean for rdt_monitor which is true if any
 * resource monitoring is enabled.
 */
bool rdt_mon_capable;

/*
 * Global to indicate which monitoring events are enabled.
 */
unsigned int rdt_mon_features;

/*
 * This is the threshold cache occupancy at which we will consider an
 * RMID available for re-allocation.
 */
unsigned int intel_cqm_threshold;

static inline struct rmid_entry *__rmid_entry(u32 rmid)
{
	struct rmid_entry *entry;

	entry = &rmid_ptrs[rmid];
	WARN_ON(entry->rmid != rmid);

	return entry;
}

static u64 __rmid_read(u32 rmid, u32 eventid)
{
	u64 val;

	/*
	 * As per the SDM, when IA32_QM_EVTSEL.EvtID (bits 7:0) is configured
	 * with a valid event code for supported resource type and the bits
	 * IA32_QM_EVTSEL.RMID (bits 41:32) are configured with valid RMID,
	 * IA32_QM_CTR.data (bits 61:0) reports the monitored data.
	 * IA32_QM_CTR.Error (bit 63) and IA32_QM_CTR.Unavailable (bit 62)
	 * are error bits.
	 */
	wrmsr(MSR_IA32_QM_EVTSEL, eventid, rmid);
	rdmsrl(MSR_IA32_QM_CTR, val);

	return val;
}

static bool rmid_dirty(struct rmid_entry *entry)
{
	u64 val = __rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID);

	return val >= intel_cqm_threshold;
}

/*
 * Check the RMIDs that are marked as busy for this domain. If the
 * reported LLC occupancy is below the threshold clear the busy bit and
 * decrement the count. If the busy count gets to zero on an RMID, we
 * free the RMID
 */
void __check_limbo(struct rdt_domain *d, bool force_free)
{
	struct rmid_entry *entry;
	struct rdt_resource *r;
	u32 crmid = 1, nrmid;

	r = &rdt_resources_all[RDT_RESOURCE_L3];

	/*
	 * Skip RMID 0 and start from RMID 1 and check all the RMIDs that
	 * are marked as busy for occupancy < threshold. If the occupancy
	 * is less than the threshold decrement the busy counter of the
	 * RMID and move it to the free list when the counter reaches 0.
	 */
	for (;;) {
		nrmid = find_next_bit(d->rmid_busy_llc, r->num_rmid, crmid);
		if (nrmid >= r->num_rmid)
			break;

		entry = __rmid_entry(nrmid);
		if (force_free || !rmid_dirty(entry)) {
			clear_bit(entry->rmid, d->rmid_busy_llc);
			if (!--entry->busy) {
				rmid_limbo_count--;
				list_add_tail(&entry->list, &rmid_free_lru);
			}
		}
		crmid = nrmid + 1;
	}
}

bool has_busy_rmid(struct rdt_resource *r, struct rdt_domain *d)
{
	return find_first_bit(d->rmid_busy_llc, r->num_rmid) != r->num_rmid;
}

/*
 * As of now the RMIDs allocation is global.
 * However we keep track of which packages the RMIDs
 * are used to optimize the limbo list management.
 */
int alloc_rmid(void)
{
	struct rmid_entry *entry;

	lockdep_assert_held(&rdtgroup_mutex);

	if (list_empty(&rmid_free_lru))
		return rmid_limbo_count ? -EBUSY : -ENOSPC;

	entry = list_first_entry(&rmid_free_lru,
				 struct rmid_entry, list);
	list_del(&entry->list);

	return entry->rmid;
}

static void add_rmid_to_limbo(struct rmid_entry *entry)
{
	struct rdt_resource *r;
	struct rdt_domain *d;
	int cpu;
	u64 val;

	r = &rdt_resources_all[RDT_RESOURCE_L3];

	entry->busy = 0;
	cpu = get_cpu();
	list_for_each_entry(d, &r->domains, list) {
		if (cpumask_test_cpu(cpu, &d->cpu_mask)) {
			val = __rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID);
			if (val <= intel_cqm_threshold)
				continue;
		}

		/*
		 * For the first limbo RMID in the domain,
		 * setup up the limbo worker.
		 */
		if (!has_busy_rmid(r, d))
			cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL);
		set_bit(entry->rmid, d->rmid_busy_llc);
		entry->busy++;
	}
	put_cpu();

	if (entry->busy)
		rmid_limbo_count++;
	else
		list_add_tail(&entry->list, &rmid_free_lru);
}

void free_rmid(u32 rmid)
{
	struct rmid_entry *entry;

	if (!rmid)
		return;

	lockdep_assert_held(&rdtgroup_mutex);

	entry = __rmid_entry(rmid);

	if (is_llc_occupancy_enabled())
		add_rmid_to_limbo(entry);
	else
		list_add_tail(&entry->list, &rmid_free_lru);
}

static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr)
{
	u64 shift = 64 - MBM_CNTR_WIDTH, chunks;

	chunks = (cur_msr << shift) - (prev_msr << shift);
	return chunks >>= shift;
}

static int __mon_event_count(u32 rmid, struct rmid_read *rr)
{
	struct mbm_state *m;
	u64 chunks, tval;

	tval = __rmid_read(rmid, rr->evtid);
	if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL)) {
		rr->val = tval;
		return -EINVAL;
	}
	switch (rr->evtid) {
	case QOS_L3_OCCUP_EVENT_ID:
		rr->val += tval;
		return 0;
	case QOS_L3_MBM_TOTAL_EVENT_ID:
		m = &rr->d->mbm_total[rmid];
		break;
	case QOS_L3_MBM_LOCAL_EVENT_ID:
		m = &rr->d->mbm_local[rmid];
		break;
	default:
		/*
		 * Code would never reach here because
		 * an invalid event id would fail the __rmid_read.
		 */
		return -EINVAL;
	}

	if (rr->first) {
		memset(m, 0, sizeof(struct mbm_state));
		m->prev_bw_msr = m->prev_msr = tval;
		return 0;
	}

	chunks = mbm_overflow_count(m->prev_msr, tval);
	m->chunks += chunks;
	m->prev_msr = tval;

	rr->val += m->chunks;
	return 0;
}

/*
 * Supporting function to calculate the memory bandwidth
 * and delta bandwidth in MBps.
 */
static void mbm_bw_count(u32 rmid, struct rmid_read *rr)
{
	struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3];
	struct mbm_state *m = &rr->d->mbm_local[rmid];
	u64 tval, cur_bw, chunks;

	tval = __rmid_read(rmid, rr->evtid);
	if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL))
		return;

	chunks = mbm_overflow_count(m->prev_bw_msr, tval);
	m->chunks_bw += chunks;
	m->chunks = m->chunks_bw;
	cur_bw = (chunks * r->mon_scale) >> 20;

	if (m->delta_comp)
		m->delta_bw = abs(cur_bw - m->prev_bw);
	m->delta_comp = false;
	m->prev_bw = cur_bw;
	m->prev_bw_msr = tval;
}

/*
 * This is called via IPI to read the CQM/MBM counters
 * on a domain.
 */
void mon_event_count(void *info)
{
	struct rdtgroup *rdtgrp, *entry;
	struct rmid_read *rr = info;
	struct list_head *head;

	rdtgrp = rr->rgrp;

	if (__mon_event_count(rdtgrp->mon.rmid, rr))
		return;

	/*
	 * For Ctrl groups read data from child monitor groups.
	 */
	head = &rdtgrp->mon.crdtgrp_list;

	if (rdtgrp->type == RDTCTRL_GROUP) {
		list_for_each_entry(entry, head, mon.crdtgrp_list) {
			if (__mon_event_count(entry->mon.rmid, rr))
				return;
		}
	}
}

static void mbm_update(struct rdt_domain *d, int rmid)
{
	struct rmid_read rr;

	rr.first = false;
	rr.d = d;

	/*
	 * This is protected from concurrent reads from user
	 * as both the user and we hold the global mutex.
	 */
	if (is_mbm_total_enabled()) {
		rr.evtid = QOS_L3_MBM_TOTAL_EVENT_ID;
		__mon_event_count(rmid, &rr);
	}
	if (is_mbm_local_enabled()) {
		rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID;
		__mon_event_count(rmid, &rr);
	}
}

/*
 * Handler to scan the limbo list and move the RMIDs
 * to free list whose occupancy < threshold_occupancy.
 */
void cqm_handle_limbo(struct work_struct *work)
{
	unsigned long delay = msecs_to_jiffies(CQM_LIMBOCHECK_INTERVAL);
	int cpu = smp_processor_id();
	struct rdt_resource *r;
	struct rdt_domain *d;

	mutex_lock(&rdtgroup_mutex);

	r = &rdt_resources_all[RDT_RESOURCE_L3];
	d = get_domain_from_cpu(cpu, r);

	if (!d) {
		pr_warn_once("Failure to get domain for limbo worker\n");
		goto out_unlock;
	}

	__check_limbo(d, false);

	if (has_busy_rmid(r, d))
		schedule_delayed_work_on(cpu, &d->cqm_limbo, delay);

out_unlock:
	mutex_unlock(&rdtgroup_mutex);
}

void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms)
{
	unsigned long delay = msecs_to_jiffies(delay_ms);
	struct rdt_resource *r;
	int cpu;

	r = &rdt_resources_all[RDT_RESOURCE_L3];

	cpu = cpumask_any(&dom->cpu_mask);
	dom->cqm_work_cpu = cpu;

	schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay);
}

void mbm_handle_overflow(struct work_struct *work)
{
	unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL);
	struct rdtgroup *prgrp, *crgrp;
	int cpu = smp_processor_id();
	struct list_head *head;
	struct rdt_domain *d;

	mutex_lock(&rdtgroup_mutex);

	if (!static_branch_likely(&rdt_enable_key))
		goto out_unlock;

	d = get_domain_from_cpu(cpu, &rdt_resources_all[RDT_RESOURCE_L3]);
	if (!d)
		goto out_unlock;

	list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
		mbm_update(d, prgrp->mon.rmid);

		head = &prgrp->mon.crdtgrp_list;
		list_for_each_entry(crgrp, head, mon.crdtgrp_list)
			mbm_update(d, crgrp->mon.rmid);
	}

	schedule_delayed_work_on(cpu, &d->mbm_over, delay);

out_unlock:
	mutex_unlock(&rdtgroup_mutex);
}

void mbm_setup_overflow_handler(struct rdt_domain *dom, unsigned long delay_ms)
{
	unsigned long delay = msecs_to_jiffies(delay_ms);
	int cpu;

	if (!static_branch_likely(&rdt_enable_key))
		return;
	cpu = cpumask_any(&dom->cpu_mask);
	dom->mbm_work_cpu = cpu;
	schedule_delayed_work_on(cpu, &dom->mbm_over, delay);
}

static int dom_data_init(struct rdt_resource *r)
{
	struct rmid_entry *entry = NULL;
	int i, nr_rmids;

	nr_rmids = r->num_rmid;
	rmid_ptrs = kcalloc(nr_rmids, sizeof(struct rmid_entry), GFP_KERNEL);
	if (!rmid_ptrs)
		return -ENOMEM;

	for (i = 0; i < nr_rmids; i++) {
		entry = &rmid_ptrs[i];
		INIT_LIST_HEAD(&entry->list);

		entry->rmid = i;
		list_add_tail(&entry->list, &rmid_free_lru);
	}

	/*
	 * RMID 0 is special and is always allocated. It's used for all
	 * tasks that are not monitored.
	 */
	entry = __rmid_entry(0);
	list_del(&entry->list);

	return 0;
}

static struct mon_evt llc_occupancy_event = {
	.name		= "llc_occupancy",
	.evtid		= QOS_L3_OCCUP_EVENT_ID,
};

static struct mon_evt mbm_total_event = {
	.name		= "mbm_total_bytes",
	.evtid		= QOS_L3_MBM_TOTAL_EVENT_ID,
};

static struct mon_evt mbm_local_event = {
	.name		= "mbm_local_bytes",
	.evtid		= QOS_L3_MBM_LOCAL_EVENT_ID,
};

/*
 * Initialize the event list for the resource.
 *
 * Note that MBM events are also part of RDT_RESOURCE_L3 resource
 * because as per the SDM the total and local memory bandwidth
 * are enumerated as part of L3 monitoring.
 */
static void l3_mon_evt_init(struct rdt_resource *r)
{
	INIT_LIST_HEAD(&r->evt_list);

	if (is_llc_occupancy_enabled())
		list_add_tail(&llc_occupancy_event.list, &r->evt_list);
	if (is_mbm_total_enabled())
		list_add_tail(&mbm_total_event.list, &r->evt_list);
	if (is_mbm_local_enabled())
		list_add_tail(&mbm_local_event.list, &r->evt_list);
}

int rdt_get_mon_l3_config(struct rdt_resource *r)
{
	int ret;

	r->mon_scale = boot_cpu_data.x86_cache_occ_scale;
	r->num_rmid = boot_cpu_data.x86_cache_max_rmid + 1;

	/*
	 * A reasonable upper limit on the max threshold is the number
	 * of lines tagged per RMID if all RMIDs have the same number of
	 * lines tagged in the LLC.
	 *
	 * For a 35MB LLC and 56 RMIDs, this is ~1.8% of the LLC.
	 */
	intel_cqm_threshold = boot_cpu_data.x86_cache_size * 1024 / r->num_rmid;

	/* h/w works in units of "boot_cpu_data.x86_cache_occ_scale" */
	intel_cqm_threshold /= r->mon_scale;

	ret = dom_data_init(r);
	if (ret)
		return ret;

	l3_mon_evt_init(r);

	r->mon_capable = true;
	r->mon_enabled = true;

	return 0;
}
Commit	Line	Data
6a445edc VS	1	/*
	2	* Resource Director Technology(RDT)
	3	* - Monitoring code
	4	*
	5	* Copyright (C) 2017 Intel Corporation
	6	*
	7	* Author:
	8	* Vikas Shivappa <vikas.shivappa@intel.com>
	9	*
	10	* This replaces the cqm.c based on perf but we reuse a lot of
	11	* code and datastructures originally from Peter Zijlstra and Matt Fleming.
	12	*
	13	* This program is free software; you can redistribute it and/or modify it
	14	* under the terms and conditions of the GNU General Public License,
	15	* version 2, as published by the Free Software Foundation.
	16	*
	17	* This program is distributed in the hope it will be useful, but WITHOUT
	18	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	19	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	20	* more details.
	21	*
	22	* More information about RDT be found in the Intel (R) x86 Architecture
	23	* Software Developer Manual June 2016, volume 3, section 17.17.
	24	*/
	25
	26	#include <linux/module.h>
	27	#include <linux/slab.h>
	28	#include <asm/cpu_device_id.h>
	29	#include "intel_rdt.h"
	30
edf6fa1c VS	31	#define MSR_IA32_QM_CTR 0x0c8e
	32	#define MSR_IA32_QM_EVTSEL 0x0c8d
	33
6a445edc VS	34	struct rmid_entry {
6a445edc VS	35	u32 rmid;
24247aee	36	int busy;
6a445edc VS	37	struct list_head list;
	38	};
	39
	40	/**
	41	* @rmid_free_lru A least recently used list of free RMIDs
	42	* These RMIDs are guaranteed to have an occupancy less than the
	43	* threshold occupancy
	44	*/
	45	static LIST_HEAD(rmid_free_lru);
	46
	47	/**
24247aee	48	* @rmid_limbo_count count of currently unused but (potentially)
6a445edc	49	* dirty RMIDs.
24247aee	50	* This counts RMIDs that no one is currently using but that
6a445edc VS	51	* may have a occupancy value > intel_cqm_threshold. User can change
	52	* the threshold occupancy value.
	53	*/
5fd88b60	54	static unsigned int rmid_limbo_count;
6a445edc VS	55
	56	/**
	57	* @rmid_entry - The entry in the limbo and free lists.
	58	*/
	59	static struct rmid_entry *rmid_ptrs;
	60
	61	/*
	62	* Global boolean for rdt_monitor which is true if any
	63	* resource monitoring is enabled.
	64	*/
	65	bool rdt_mon_capable;
	66
	67	/*
	68	* Global to indicate which monitoring events are enabled.
	69	*/
	70	unsigned int rdt_mon_features;
	71
	72	/*
	73	* This is the threshold cache occupancy at which we will consider an
	74	* RMID available for re-allocation.
	75	*/
	76	unsigned int intel_cqm_threshold;
	77
	78	static inline struct rmid_entry *__rmid_entry(u32 rmid)
	79	{
	80	struct rmid_entry *entry;
	81
	82	entry = &rmid_ptrs[rmid];
	83	WARN_ON(entry->rmid != rmid);
	84
	85	return entry;
	86	}
	87
edf6fa1c VS	88	static u64 __rmid_read(u32 rmid, u32 eventid)
	89	{
	90	u64 val;
	91
	92	/*
	93	* As per the SDM, when IA32_QM_EVTSEL.EvtID (bits 7:0) is configured
	94	* with a valid event code for supported resource type and the bits
	95	* IA32_QM_EVTSEL.RMID (bits 41:32) are configured with valid RMID,
	96	* IA32_QM_CTR.data (bits 61:0) reports the monitored data.
	97	* IA32_QM_CTR.Error (bit 63) and IA32_QM_CTR.Unavailable (bit 62)
	98	* are error bits.
	99	*/
	100	wrmsr(MSR_IA32_QM_EVTSEL, eventid, rmid);
	101	rdmsrl(MSR_IA32_QM_CTR, val);
	102
	103	return val;
	104	}
	105
24247aee	106	static bool rmid_dirty(struct rmid_entry *entry)
edf6fa1c	107	{
24247aee	108	u64 val = __rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID);
edf6fa1c	109
24247aee	110	return val >= intel_cqm_threshold;
edf6fa1c VS	111	}
	112
	113	/*
24247aee VS	114	* Check the RMIDs that are marked as busy for this domain. If the
	115	* reported LLC occupancy is below the threshold clear the busy bit and
	116	* decrement the count. If the busy count gets to zero on an RMID, we
	117	* free the RMID
edf6fa1c	118	*/
24247aee	119	void __check_limbo(struct rdt_domain *d, bool force_free)
edf6fa1c	120	{
24247aee	121	struct rmid_entry *entry;
edf6fa1c	122	struct rdt_resource *r;
24247aee	123	u32 crmid = 1, nrmid;
edf6fa1c VS	124
	125	r = &rdt_resources_all[RDT_RESOURCE_L3];
	126
edf6fa1c	127	/*
24247aee VS	128	* Skip RMID 0 and start from RMID 1 and check all the RMIDs that
	129	* are marked as busy for occupancy < threshold. If the occupancy
	130	* is less than the threshold decrement the busy counter of the
	131	* RMID and move it to the free list when the counter reaches 0.
edf6fa1c	132	*/
24247aee VS	133	for (;;) {
	134	nrmid = find_next_bit(d->rmid_busy_llc, r->num_rmid, crmid);
	135	if (nrmid >= r->num_rmid)
	136	break;
	137
	138	entry = __rmid_entry(nrmid);
	139	if (force_free \|\| !rmid_dirty(entry)) {
	140	clear_bit(entry->rmid, d->rmid_busy_llc);
	141	if (!--entry->busy) {
	142	rmid_limbo_count--;
edf6fa1c	143	list_add_tail(&entry->list, &rmid_free_lru);
edf6fa1c VS	144	}
edf6fa1c VS	145	}
24247aee	146	crmid = nrmid + 1;
edf6fa1c	147	}
24247aee	148	}
edf6fa1c	149
24247aee VS	150	bool has_busy_rmid(struct rdt_resource r, struct rdt_domain d)
	151	{
	152	return find_first_bit(d->rmid_busy_llc, r->num_rmid) != r->num_rmid;
edf6fa1c VS	153	}
	154
	155	/*
	156	* As of now the RMIDs allocation is global.
	157	* However we keep track of which packages the RMIDs
	158	* are used to optimize the limbo list management.
	159	*/
	160	int alloc_rmid(void)
	161	{
	162	struct rmid_entry *entry;
edf6fa1c VS	163
	164	lockdep_assert_held(&rdtgroup_mutex);
	165
24247aee VS	166	if (list_empty(&rmid_free_lru))
24247aee VS	167	return rmid_limbo_count ? -EBUSY : -ENOSPC;
edf6fa1c VS	168
	169	entry = list_first_entry(&rmid_free_lru,
	170	struct rmid_entry, list);
	171	list_del(&entry->list);
	172
	173	return entry->rmid;
	174	}
	175
	176	static void add_rmid_to_limbo(struct rmid_entry *entry)
	177	{
	178	struct rdt_resource *r;
	179	struct rdt_domain *d;
24247aee	180	int cpu;
edf6fa1c VS	181	u64 val;
	182
	183	r = &rdt_resources_all[RDT_RESOURCE_L3];
	184
24247aee	185	entry->busy = 0;
edf6fa1c VS	186	cpu = get_cpu();
	187	list_for_each_entry(d, &r->domains, list) {
	188	if (cpumask_test_cpu(cpu, &d->cpu_mask)) {
	189	val = __rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID);
	190	if (val <= intel_cqm_threshold)
	191	continue;
	192	}
24247aee VS	193
	194	/*
	195	* For the first limbo RMID in the domain,
	196	* setup up the limbo worker.
	197	*/
	198	if (!has_busy_rmid(r, d))
	199	cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL);
edf6fa1c	200	set_bit(entry->rmid, d->rmid_busy_llc);
24247aee	201	entry->busy++;
edf6fa1c VS	202	}
	203	put_cpu();
	204
24247aee VS	205	if (entry->busy)
	206	rmid_limbo_count++;
	207	else
edf6fa1c	208	list_add_tail(&entry->list, &rmid_free_lru);
edf6fa1c VS	209	}
	210
	211	void free_rmid(u32 rmid)
	212	{
	213	struct rmid_entry *entry;
	214
	215	if (!rmid)
	216	return;
	217
	218	lockdep_assert_held(&rdtgroup_mutex);
	219
	220	entry = __rmid_entry(rmid);
	221
	222	if (is_llc_occupancy_enabled())
	223	add_rmid_to_limbo(entry);
	224	else
	225	list_add_tail(&entry->list, &rmid_free_lru);
	226	}
	227
ba0f26d8 VS	228	static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr)
	229	{
	230	u64 shift = 64 - MBM_CNTR_WIDTH, chunks;
	231
	232	chunks = (cur_msr << shift) - (prev_msr << shift);
	233	return chunks >>= shift;
	234	}
	235
d89b7379 VS	236	static int __mon_event_count(u32 rmid, struct rmid_read *rr)
d89b7379 VS	237	{
9f52425b	238	struct mbm_state *m;
ba0f26d8	239	u64 chunks, tval;
d89b7379 VS	240
	241	tval = __rmid_read(rmid, rr->evtid);
	242	if (tval & (RMID_VAL_ERROR \| RMID_VAL_UNAVAIL)) {
	243	rr->val = tval;
	244	return -EINVAL;
	245	}
	246	switch (rr->evtid) {
	247	case QOS_L3_OCCUP_EVENT_ID:
	248	rr->val += tval;
	249	return 0;
9f52425b TL	250	case QOS_L3_MBM_TOTAL_EVENT_ID:
	251	m = &rr->d->mbm_total[rmid];
	252	break;
	253	case QOS_L3_MBM_LOCAL_EVENT_ID:
	254	m = &rr->d->mbm_local[rmid];
	255	break;
d89b7379 VS	256	default:
	257	/*
	258	* Code would never reach here because
	259	* an invalid event id would fail the __rmid_read.
	260	*/
	261	return -EINVAL;
	262	}
a4de1dfd VS	263
a4de1dfd VS	264	if (rr->first) {
ba0f26d8 VS	265	memset(m, 0, sizeof(struct mbm_state));
ba0f26d8 VS	266	m->prev_bw_msr = m->prev_msr = tval;
a4de1dfd VS	267	return 0;
	268	}
	269
ba0f26d8	270	chunks = mbm_overflow_count(m->prev_msr, tval);
9f52425b TL	271	m->chunks += chunks;
	272	m->prev_msr = tval;
	273
	274	rr->val += m->chunks;
	275	return 0;
d89b7379 VS	276	}
d89b7379 VS	277
ba0f26d8 VS	278	/*
	279	* Supporting function to calculate the memory bandwidth
	280	* and delta bandwidth in MBps.
	281	*/
	282	static void mbm_bw_count(u32 rmid, struct rmid_read *rr)
	283	{
	284	struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3];
	285	struct mbm_state *m = &rr->d->mbm_local[rmid];
	286	u64 tval, cur_bw, chunks;
	287
	288	tval = __rmid_read(rmid, rr->evtid);
	289	if (tval & (RMID_VAL_ERROR \| RMID_VAL_UNAVAIL))
	290	return;
	291
	292	chunks = mbm_overflow_count(m->prev_bw_msr, tval);
	293	m->chunks_bw += chunks;
	294	m->chunks = m->chunks_bw;
	295	cur_bw = (chunks * r->mon_scale) >> 20;
	296
	297	if (m->delta_comp)
	298	m->delta_bw = abs(cur_bw - m->prev_bw);
	299	m->delta_comp = false;
	300	m->prev_bw = cur_bw;
	301	m->prev_bw_msr = tval;
	302	}
	303
d89b7379 VS	304	/*
	305	* This is called via IPI to read the CQM/MBM counters
	306	* on a domain.
	307	*/
	308	void mon_event_count(void *info)
	309	{
	310	struct rdtgroup rdtgrp, entry;
	311	struct rmid_read *rr = info;
	312	struct list_head *head;
	313
	314	rdtgrp = rr->rgrp;
	315
	316	if (__mon_event_count(rdtgrp->mon.rmid, rr))
	317	return;
	318
	319	/*
	320	* For Ctrl groups read data from child monitor groups.
	321	*/
	322	head = &rdtgrp->mon.crdtgrp_list;
	323
	324	if (rdtgrp->type == RDTCTRL_GROUP) {
	325	list_for_each_entry(entry, head, mon.crdtgrp_list) {
	326	if (__mon_event_count(entry->mon.rmid, rr))
	327	return;
	328	}
	329	}
	330	}
4af4a88e	331
e3302683 VS	332	static void mbm_update(struct rdt_domain *d, int rmid)
	333	{
	334	struct rmid_read rr;
	335
	336	rr.first = false;
	337	rr.d = d;
	338
	339	/*
	340	* This is protected from concurrent reads from user
	341	* as both the user and we hold the global mutex.
	342	*/
	343	if (is_mbm_total_enabled()) {
	344	rr.evtid = QOS_L3_MBM_TOTAL_EVENT_ID;
	345	__mon_event_count(rmid, &rr);
	346	}
	347	if (is_mbm_local_enabled()) {
	348	rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID;
	349	__mon_event_count(rmid, &rr);
	350	}
	351	}
	352
24247aee VS	353	/*
	354	* Handler to scan the limbo list and move the RMIDs
	355	* to free list whose occupancy < threshold_occupancy.
	356	*/
	357	void cqm_handle_limbo(struct work_struct *work)
	358	{
	359	unsigned long delay = msecs_to_jiffies(CQM_LIMBOCHECK_INTERVAL);
	360	int cpu = smp_processor_id();
	361	struct rdt_resource *r;
	362	struct rdt_domain *d;
	363
	364	mutex_lock(&rdtgroup_mutex);
	365
	366	r = &rdt_resources_all[RDT_RESOURCE_L3];
	367	d = get_domain_from_cpu(cpu, r);
	368
	369	if (!d) {
	370	pr_warn_once("Failure to get domain for limbo worker\n");
	371	goto out_unlock;
	372	}
	373
	374	__check_limbo(d, false);
	375
	376	if (has_busy_rmid(r, d))
	377	schedule_delayed_work_on(cpu, &d->cqm_limbo, delay);
	378
	379	out_unlock:
	380	mutex_unlock(&rdtgroup_mutex);
	381	}
	382
	383	void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms)
	384	{
	385	unsigned long delay = msecs_to_jiffies(delay_ms);
	386	struct rdt_resource *r;
	387	int cpu;
	388
	389	r = &rdt_resources_all[RDT_RESOURCE_L3];
	390
	391	cpu = cpumask_any(&dom->cpu_mask);
	392	dom->cqm_work_cpu = cpu;
	393
	394	schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay);
	395	}
	396
e3302683 VS	397	void mbm_handle_overflow(struct work_struct *work)
	398	{
	399	unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL);
	400	struct rdtgroup prgrp, crgrp;
	401	int cpu = smp_processor_id();
	402	struct list_head *head;
	403	struct rdt_domain *d;
	404
	405	mutex_lock(&rdtgroup_mutex);
	406
	407	if (!static_branch_likely(&rdt_enable_key))
	408	goto out_unlock;
	409
	410	d = get_domain_from_cpu(cpu, &rdt_resources_all[RDT_RESOURCE_L3]);
	411	if (!d)
	412	goto out_unlock;
	413
	414	list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
	415	mbm_update(d, prgrp->mon.rmid);
	416
	417	head = &prgrp->mon.crdtgrp_list;
	418	list_for_each_entry(crgrp, head, mon.crdtgrp_list)
	419	mbm_update(d, crgrp->mon.rmid);
	420	}
	421
	422	schedule_delayed_work_on(cpu, &d->mbm_over, delay);
24247aee	423
e3302683 VS	424	out_unlock:
	425	mutex_unlock(&rdtgroup_mutex);
	426	}
	427
bbc4615e	428	void mbm_setup_overflow_handler(struct rdt_domain *dom, unsigned long delay_ms)
e3302683	429	{
bbc4615e	430	unsigned long delay = msecs_to_jiffies(delay_ms);
e3302683 VS	431	int cpu;
	432
	433	if (!static_branch_likely(&rdt_enable_key))
	434	return;
	435	cpu = cpumask_any(&dom->cpu_mask);
	436	dom->mbm_work_cpu = cpu;
	437	schedule_delayed_work_on(cpu, &dom->mbm_over, delay);
	438	}
	439
6a445edc VS	440	static int dom_data_init(struct rdt_resource *r)
	441	{
	442	struct rmid_entry *entry = NULL;
	443	int i, nr_rmids;
	444
	445	nr_rmids = r->num_rmid;
	446	rmid_ptrs = kcalloc(nr_rmids, sizeof(struct rmid_entry), GFP_KERNEL);
	447	if (!rmid_ptrs)
	448	return -ENOMEM;
	449
	450	for (i = 0; i < nr_rmids; i++) {
	451	entry = &rmid_ptrs[i];
	452	INIT_LIST_HEAD(&entry->list);
	453
	454	entry->rmid = i;
	455	list_add_tail(&entry->list, &rmid_free_lru);
	456	}
	457
	458	/*
	459	* RMID 0 is special and is always allocated. It's used for all
	460	* tasks that are not monitored.
	461	*/
	462	entry = __rmid_entry(0);
	463	list_del(&entry->list);
	464
	465	return 0;
	466	}
	467
	468	static struct mon_evt llc_occupancy_event = {
	469	.name = "llc_occupancy",
	470	.evtid = QOS_L3_OCCUP_EVENT_ID,
	471	};
	472
9f52425b TL	473	static struct mon_evt mbm_total_event = {
	474	.name = "mbm_total_bytes",
	475	.evtid = QOS_L3_MBM_TOTAL_EVENT_ID,
	476	};
	477
	478	static struct mon_evt mbm_local_event = {
	479	.name = "mbm_local_bytes",
	480	.evtid = QOS_L3_MBM_LOCAL_EVENT_ID,
	481	};
	482
6a445edc VS	483	/*
	484	* Initialize the event list for the resource.
	485	*
	486	* Note that MBM events are also part of RDT_RESOURCE_L3 resource
	487	* because as per the SDM the total and local memory bandwidth
	488	* are enumerated as part of L3 monitoring.
	489	*/
	490	static void l3_mon_evt_init(struct rdt_resource *r)
	491	{
	492	INIT_LIST_HEAD(&r->evt_list);
	493
	494	if (is_llc_occupancy_enabled())
	495	list_add_tail(&llc_occupancy_event.list, &r->evt_list);
9f52425b TL	496	if (is_mbm_total_enabled())
	497	list_add_tail(&mbm_total_event.list, &r->evt_list);
	498	if (is_mbm_local_enabled())
	499	list_add_tail(&mbm_local_event.list, &r->evt_list);
6a445edc VS	500	}
	501
	502	int rdt_get_mon_l3_config(struct rdt_resource *r)
	503	{
	504	int ret;
	505
	506	r->mon_scale = boot_cpu_data.x86_cache_occ_scale;
	507	r->num_rmid = boot_cpu_data.x86_cache_max_rmid + 1;
	508
	509	/*
	510	* A reasonable upper limit on the max threshold is the number
	511	* of lines tagged per RMID if all RMIDs have the same number of
	512	* lines tagged in the LLC.
	513	*
	514	* For a 35MB LLC and 56 RMIDs, this is ~1.8% of the LLC.
	515	*/
	516	intel_cqm_threshold = boot_cpu_data.x86_cache_size * 1024 / r->num_rmid;
	517
	518	/* h/w works in units of "boot_cpu_data.x86_cache_occ_scale" */
	519	intel_cqm_threshold /= r->mon_scale;
	520
	521	ret = dom_data_init(r);
	522	if (ret)
	523	return ret;
	524
	525	l3_mon_evt_init(r);
	526
	527	r->mon_capable = true;
	528	r->mon_enabled = true;
	529
	530	return 0;
	531	}