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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Resource Director Technology(RDT)
4 * - Monitoring code
5 *
6 * Copyright (C) 2017 Intel Corporation
7 *
8 * Author:
9 * Vikas Shivappa <vikas.shivappa@intel.com>
10 *
11 * This replaces the cqm.c based on perf but we reuse a lot of
12 * code and datastructures originally from Peter Zijlstra and Matt Fleming.
13 *
14 * More information about RDT be found in the Intel (R) x86 Architecture
15 * Software Developer Manual June 2016, volume 3, section 17.17.
16 */
17
18#include <linux/module.h>
19#include <linux/slab.h>
20#include <asm/cpu_device_id.h>
21#include "internal.h"
22
23struct rmid_entry {
24 u32 rmid;
25 int busy;
26 struct list_head list;
27};
28
29/**
30 * @rmid_free_lru A least recently used list of free RMIDs
31 * These RMIDs are guaranteed to have an occupancy less than the
32 * threshold occupancy
33 */
34static LIST_HEAD(rmid_free_lru);
35
36/**
37 * @rmid_limbo_count count of currently unused but (potentially)
38 * dirty RMIDs.
39 * This counts RMIDs that no one is currently using but that
40 * may have a occupancy value > intel_cqm_threshold. User can change
41 * the threshold occupancy value.
42 */
43static unsigned int rmid_limbo_count;
44
45/**
46 * @rmid_entry - The entry in the limbo and free lists.
47 */
48static struct rmid_entry *rmid_ptrs;
49
50/*
51 * Global boolean for rdt_monitor which is true if any
52 * resource monitoring is enabled.
53 */
54bool rdt_mon_capable;
55
56/*
57 * Global to indicate which monitoring events are enabled.
58 */
59unsigned int rdt_mon_features;
60
61/*
62 * This is the threshold cache occupancy at which we will consider an
63 * RMID available for re-allocation.
64 */
65unsigned int resctrl_cqm_threshold;
66
67static inline struct rmid_entry *__rmid_entry(u32 rmid)
68{
69 struct rmid_entry *entry;
70
71 entry = &rmid_ptrs[rmid];
72 WARN_ON(entry->rmid != rmid);
73
74 return entry;
75}
76
77static u64 __rmid_read(u32 rmid, u32 eventid)
78{
79 u64 val;
80
81 /*
82 * As per the SDM, when IA32_QM_EVTSEL.EvtID (bits 7:0) is configured
83 * with a valid event code for supported resource type and the bits
84 * IA32_QM_EVTSEL.RMID (bits 41:32) are configured with valid RMID,
85 * IA32_QM_CTR.data (bits 61:0) reports the monitored data.
86 * IA32_QM_CTR.Error (bit 63) and IA32_QM_CTR.Unavailable (bit 62)
87 * are error bits.
88 */
89 wrmsr(MSR_IA32_QM_EVTSEL, eventid, rmid);
90 rdmsrl(MSR_IA32_QM_CTR, val);
91
92 return val;
93}
94
95static bool rmid_dirty(struct rmid_entry *entry)
96{
97 u64 val = __rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID);
98
99 return val >= resctrl_cqm_threshold;
100}
101
102/*
103 * Check the RMIDs that are marked as busy for this domain. If the
104 * reported LLC occupancy is below the threshold clear the busy bit and
105 * decrement the count. If the busy count gets to zero on an RMID, we
106 * free the RMID
107 */
108void __check_limbo(struct rdt_domain *d, bool force_free)
109{
110 struct rmid_entry *entry;
111 struct rdt_resource *r;
112 u32 crmid = 1, nrmid;
113
114 r = &rdt_resources_all[RDT_RESOURCE_L3];
115
116 /*
117 * Skip RMID 0 and start from RMID 1 and check all the RMIDs that
118 * are marked as busy for occupancy < threshold. If the occupancy
119 * is less than the threshold decrement the busy counter of the
120 * RMID and move it to the free list when the counter reaches 0.
121 */
122 for (;;) {
123 nrmid = find_next_bit(d->rmid_busy_llc, r->num_rmid, crmid);
124 if (nrmid >= r->num_rmid)
125 break;
126
127 entry = __rmid_entry(nrmid);
128 if (force_free || !rmid_dirty(entry)) {
129 clear_bit(entry->rmid, d->rmid_busy_llc);
130 if (!--entry->busy) {
131 rmid_limbo_count--;
132 list_add_tail(&entry->list, &rmid_free_lru);
133 }
134 }
135 crmid = nrmid + 1;
136 }
137}
138
139bool has_busy_rmid(struct rdt_resource *r, struct rdt_domain *d)
140{
141 return find_first_bit(d->rmid_busy_llc, r->num_rmid) != r->num_rmid;
142}
143
144/*
145 * As of now the RMIDs allocation is global.
146 * However we keep track of which packages the RMIDs
147 * are used to optimize the limbo list management.
148 */
149int alloc_rmid(void)
150{
151 struct rmid_entry *entry;
152
153 lockdep_assert_held(&rdtgroup_mutex);
154
155 if (list_empty(&rmid_free_lru))
156 return rmid_limbo_count ? -EBUSY : -ENOSPC;
157
158 entry = list_first_entry(&rmid_free_lru,
159 struct rmid_entry, list);
160 list_del(&entry->list);
161
162 return entry->rmid;
163}
164
165static void add_rmid_to_limbo(struct rmid_entry *entry)
166{
167 struct rdt_resource *r;
168 struct rdt_domain *d;
169 int cpu;
170 u64 val;
171
172 r = &rdt_resources_all[RDT_RESOURCE_L3];
173
174 entry->busy = 0;
175 cpu = get_cpu();
176 list_for_each_entry(d, &r->domains, list) {
177 if (cpumask_test_cpu(cpu, &d->cpu_mask)) {
178 val = __rmid_read(entry->rmid, QOS_L3_OCCUP_EVENT_ID);
179 if (val <= resctrl_cqm_threshold)
180 continue;
181 }
182
183 /*
184 * For the first limbo RMID in the domain,
185 * setup up the limbo worker.
186 */
187 if (!has_busy_rmid(r, d))
188 cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL);
189 set_bit(entry->rmid, d->rmid_busy_llc);
190 entry->busy++;
191 }
192 put_cpu();
193
194 if (entry->busy)
195 rmid_limbo_count++;
196 else
197 list_add_tail(&entry->list, &rmid_free_lru);
198}
199
200void free_rmid(u32 rmid)
201{
202 struct rmid_entry *entry;
203
204 if (!rmid)
205 return;
206
207 lockdep_assert_held(&rdtgroup_mutex);
208
209 entry = __rmid_entry(rmid);
210
211 if (is_llc_occupancy_enabled())
212 add_rmid_to_limbo(entry);
213 else
214 list_add_tail(&entry->list, &rmid_free_lru);
215}
216
217static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr)
218{
219 u64 shift = 64 - MBM_CNTR_WIDTH, chunks;
220
221 chunks = (cur_msr << shift) - (prev_msr << shift);
222 return chunks >>= shift;
223}
224
225static int __mon_event_count(u32 rmid, struct rmid_read *rr)
226{
227 struct mbm_state *m;
228 u64 chunks, tval;
229
230 tval = __rmid_read(rmid, rr->evtid);
231 if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL)) {
232 rr->val = tval;
233 return -EINVAL;
234 }
235 switch (rr->evtid) {
236 case QOS_L3_OCCUP_EVENT_ID:
237 rr->val += tval;
238 return 0;
239 case QOS_L3_MBM_TOTAL_EVENT_ID:
240 m = &rr->d->mbm_total[rmid];
241 break;
242 case QOS_L3_MBM_LOCAL_EVENT_ID:
243 m = &rr->d->mbm_local[rmid];
244 break;
245 default:
246 /*
247 * Code would never reach here because
248 * an invalid event id would fail the __rmid_read.
249 */
250 return -EINVAL;
251 }
252
253 if (rr->first) {
254 memset(m, 0, sizeof(struct mbm_state));
255 m->prev_bw_msr = m->prev_msr = tval;
256 return 0;
257 }
258
259 chunks = mbm_overflow_count(m->prev_msr, tval);
260 m->chunks += chunks;
261 m->prev_msr = tval;
262
263 rr->val += m->chunks;
264 return 0;
265}
266
267/*
268 * Supporting function to calculate the memory bandwidth
269 * and delta bandwidth in MBps.
270 */
271static void mbm_bw_count(u32 rmid, struct rmid_read *rr)
272{
273 struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3];
274 struct mbm_state *m = &rr->d->mbm_local[rmid];
275 u64 tval, cur_bw, chunks;
276
277 tval = __rmid_read(rmid, rr->evtid);
278 if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL))
279 return;
280
281 chunks = mbm_overflow_count(m->prev_bw_msr, tval);
282 m->chunks_bw += chunks;
283 m->chunks = m->chunks_bw;
284 cur_bw = (chunks * r->mon_scale) >> 20;
285
286 if (m->delta_comp)
287 m->delta_bw = abs(cur_bw - m->prev_bw);
288 m->delta_comp = false;
289 m->prev_bw = cur_bw;
290 m->prev_bw_msr = tval;
291}
292
293/*
294 * This is called via IPI to read the CQM/MBM counters
295 * on a domain.
296 */
297void mon_event_count(void *info)
298{
299 struct rdtgroup *rdtgrp, *entry;
300 struct rmid_read *rr = info;
301 struct list_head *head;
302
303 rdtgrp = rr->rgrp;
304
305 if (__mon_event_count(rdtgrp->mon.rmid, rr))
306 return;
307
308 /*
309 * For Ctrl groups read data from child monitor groups.
310 */
311 head = &rdtgrp->mon.crdtgrp_list;
312
313 if (rdtgrp->type == RDTCTRL_GROUP) {
314 list_for_each_entry(entry, head, mon.crdtgrp_list) {
315 if (__mon_event_count(entry->mon.rmid, rr))
316 return;
317 }
318 }
319}
320
321/*
322 * Feedback loop for MBA software controller (mba_sc)
323 *
324 * mba_sc is a feedback loop where we periodically read MBM counters and
325 * adjust the bandwidth percentage values via the IA32_MBA_THRTL_MSRs so
326 * that:
327 *
328 * current bandwdith(cur_bw) < user specified bandwidth(user_bw)
329 *
330 * This uses the MBM counters to measure the bandwidth and MBA throttle
331 * MSRs to control the bandwidth for a particular rdtgrp. It builds on the
332 * fact that resctrl rdtgroups have both monitoring and control.
333 *
334 * The frequency of the checks is 1s and we just tag along the MBM overflow
335 * timer. Having 1s interval makes the calculation of bandwidth simpler.
336 *
337 * Although MBA's goal is to restrict the bandwidth to a maximum, there may
338 * be a need to increase the bandwidth to avoid uncecessarily restricting
339 * the L2 <-> L3 traffic.
340 *
341 * Since MBA controls the L2 external bandwidth where as MBM measures the
342 * L3 external bandwidth the following sequence could lead to such a
343 * situation.
344 *
345 * Consider an rdtgroup which had high L3 <-> memory traffic in initial
346 * phases -> mba_sc kicks in and reduced bandwidth percentage values -> but
347 * after some time rdtgroup has mostly L2 <-> L3 traffic.
348 *
349 * In this case we may restrict the rdtgroup's L2 <-> L3 traffic as its
350 * throttle MSRs already have low percentage values. To avoid
351 * unnecessarily restricting such rdtgroups, we also increase the bandwidth.
352 */
353static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm)
354{
355 u32 closid, rmid, cur_msr, cur_msr_val, new_msr_val;
356 struct mbm_state *pmbm_data, *cmbm_data;
357 u32 cur_bw, delta_bw, user_bw;
358 struct rdt_resource *r_mba;
359 struct rdt_domain *dom_mba;
360 struct list_head *head;
361 struct rdtgroup *entry;
362
363 if (!is_mbm_local_enabled())
364 return;
365
366 r_mba = &rdt_resources_all[RDT_RESOURCE_MBA];
367 closid = rgrp->closid;
368 rmid = rgrp->mon.rmid;
369 pmbm_data = &dom_mbm->mbm_local[rmid];
370
371 dom_mba = get_domain_from_cpu(smp_processor_id(), r_mba);
372 if (!dom_mba) {
373 pr_warn_once("Failure to get domain for MBA update\n");
374 return;
375 }
376
377 cur_bw = pmbm_data->prev_bw;
378 user_bw = dom_mba->mbps_val[closid];
379 delta_bw = pmbm_data->delta_bw;
380 cur_msr_val = dom_mba->ctrl_val[closid];
381
382 /*
383 * For Ctrl groups read data from child monitor groups.
384 */
385 head = &rgrp->mon.crdtgrp_list;
386 list_for_each_entry(entry, head, mon.crdtgrp_list) {
387 cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid];
388 cur_bw += cmbm_data->prev_bw;
389 delta_bw += cmbm_data->delta_bw;
390 }
391
392 /*
393 * Scale up/down the bandwidth linearly for the ctrl group. The
394 * bandwidth step is the bandwidth granularity specified by the
395 * hardware.
396 *
397 * The delta_bw is used when increasing the bandwidth so that we
398 * dont alternately increase and decrease the control values
399 * continuously.
400 *
401 * For ex: consider cur_bw = 90MBps, user_bw = 100MBps and if
402 * bandwidth step is 20MBps(> user_bw - cur_bw), we would keep
403 * switching between 90 and 110 continuously if we only check
404 * cur_bw < user_bw.
405 */
406 if (cur_msr_val > r_mba->membw.min_bw && user_bw < cur_bw) {
407 new_msr_val = cur_msr_val - r_mba->membw.bw_gran;
408 } else if (cur_msr_val < MAX_MBA_BW &&
409 (user_bw > (cur_bw + delta_bw))) {
410 new_msr_val = cur_msr_val + r_mba->membw.bw_gran;
411 } else {
412 return;
413 }
414
415 cur_msr = r_mba->msr_base + closid;
416 wrmsrl(cur_msr, delay_bw_map(new_msr_val, r_mba));
417 dom_mba->ctrl_val[closid] = new_msr_val;
418
419 /*
420 * Delta values are updated dynamically package wise for each
421 * rdtgrp everytime the throttle MSR changes value.
422 *
423 * This is because (1)the increase in bandwidth is not perfectly
424 * linear and only "approximately" linear even when the hardware
425 * says it is linear.(2)Also since MBA is a core specific
426 * mechanism, the delta values vary based on number of cores used
427 * by the rdtgrp.
428 */
429 pmbm_data->delta_comp = true;
430 list_for_each_entry(entry, head, mon.crdtgrp_list) {
431 cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid];
432 cmbm_data->delta_comp = true;
433 }
434}
435
436static void mbm_update(struct rdt_domain *d, int rmid)
437{
438 struct rmid_read rr;
439
440 rr.first = false;
441 rr.d = d;
442
443 /*
444 * This is protected from concurrent reads from user
445 * as both the user and we hold the global mutex.
446 */
447 if (is_mbm_total_enabled()) {
448 rr.evtid = QOS_L3_MBM_TOTAL_EVENT_ID;
449 __mon_event_count(rmid, &rr);
450 }
451 if (is_mbm_local_enabled()) {
452 rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID;
453
454 /*
455 * Call the MBA software controller only for the
456 * control groups and when user has enabled
457 * the software controller explicitly.
458 */
459 if (!is_mba_sc(NULL))
460 __mon_event_count(rmid, &rr);
461 else
462 mbm_bw_count(rmid, &rr);
463 }
464}
465
466/*
467 * Handler to scan the limbo list and move the RMIDs
468 * to free list whose occupancy < threshold_occupancy.
469 */
470void cqm_handle_limbo(struct work_struct *work)
471{
472 unsigned long delay = msecs_to_jiffies(CQM_LIMBOCHECK_INTERVAL);
473 int cpu = smp_processor_id();
474 struct rdt_resource *r;
475 struct rdt_domain *d;
476
477 mutex_lock(&rdtgroup_mutex);
478
479 r = &rdt_resources_all[RDT_RESOURCE_L3];
480 d = get_domain_from_cpu(cpu, r);
481
482 if (!d) {
483 pr_warn_once("Failure to get domain for limbo worker\n");
484 goto out_unlock;
485 }
486
487 __check_limbo(d, false);
488
489 if (has_busy_rmid(r, d))
490 schedule_delayed_work_on(cpu, &d->cqm_limbo, delay);
491
492out_unlock:
493 mutex_unlock(&rdtgroup_mutex);
494}
495
496void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms)
497{
498 unsigned long delay = msecs_to_jiffies(delay_ms);
499 int cpu;
500
501 cpu = cpumask_any(&dom->cpu_mask);
502 dom->cqm_work_cpu = cpu;
503
504 schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay);
505}
506
507void mbm_handle_overflow(struct work_struct *work)
508{
509 unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL);
510 struct rdtgroup *prgrp, *crgrp;
511 int cpu = smp_processor_id();
512 struct list_head *head;
513 struct rdt_domain *d;
514
515 mutex_lock(&rdtgroup_mutex);
516
517 if (!static_branch_likely(&rdt_enable_key))
518 goto out_unlock;
519
520 d = get_domain_from_cpu(cpu, &rdt_resources_all[RDT_RESOURCE_L3]);
521 if (!d)
522 goto out_unlock;
523
524 list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
525 mbm_update(d, prgrp->mon.rmid);
526
527 head = &prgrp->mon.crdtgrp_list;
528 list_for_each_entry(crgrp, head, mon.crdtgrp_list)
529 mbm_update(d, crgrp->mon.rmid);
530
531 if (is_mba_sc(NULL))
532 update_mba_bw(prgrp, d);
533 }
534
535 schedule_delayed_work_on(cpu, &d->mbm_over, delay);
536
537out_unlock:
538 mutex_unlock(&rdtgroup_mutex);
539}
540
541void mbm_setup_overflow_handler(struct rdt_domain *dom, unsigned long delay_ms)
542{
543 unsigned long delay = msecs_to_jiffies(delay_ms);
544 int cpu;
545
546 if (!static_branch_likely(&rdt_enable_key))
547 return;
548 cpu = cpumask_any(&dom->cpu_mask);
549 dom->mbm_work_cpu = cpu;
550 schedule_delayed_work_on(cpu, &dom->mbm_over, delay);
551}
552
553static int dom_data_init(struct rdt_resource *r)
554{
555 struct rmid_entry *entry = NULL;
556 int i, nr_rmids;
557
558 nr_rmids = r->num_rmid;
559 rmid_ptrs = kcalloc(nr_rmids, sizeof(struct rmid_entry), GFP_KERNEL);
560 if (!rmid_ptrs)
561 return -ENOMEM;
562
563 for (i = 0; i < nr_rmids; i++) {
564 entry = &rmid_ptrs[i];
565 INIT_LIST_HEAD(&entry->list);
566
567 entry->rmid = i;
568 list_add_tail(&entry->list, &rmid_free_lru);
569 }
570
571 /*
572 * RMID 0 is special and is always allocated. It's used for all
573 * tasks that are not monitored.
574 */
575 entry = __rmid_entry(0);
576 list_del(&entry->list);
577
578 return 0;
579}
580
581static struct mon_evt llc_occupancy_event = {
582 .name = "llc_occupancy",
583 .evtid = QOS_L3_OCCUP_EVENT_ID,
584};
585
586static struct mon_evt mbm_total_event = {
587 .name = "mbm_total_bytes",
588 .evtid = QOS_L3_MBM_TOTAL_EVENT_ID,
589};
590
591static struct mon_evt mbm_local_event = {
592 .name = "mbm_local_bytes",
593 .evtid = QOS_L3_MBM_LOCAL_EVENT_ID,
594};
595
596/*
597 * Initialize the event list for the resource.
598 *
599 * Note that MBM events are also part of RDT_RESOURCE_L3 resource
600 * because as per the SDM the total and local memory bandwidth
601 * are enumerated as part of L3 monitoring.
602 */
603static void l3_mon_evt_init(struct rdt_resource *r)
604{
605 INIT_LIST_HEAD(&r->evt_list);
606
607 if (is_llc_occupancy_enabled())
608 list_add_tail(&llc_occupancy_event.list, &r->evt_list);
609 if (is_mbm_total_enabled())
610 list_add_tail(&mbm_total_event.list, &r->evt_list);
611 if (is_mbm_local_enabled())
612 list_add_tail(&mbm_local_event.list, &r->evt_list);
613}
614
615int rdt_get_mon_l3_config(struct rdt_resource *r)
616{
617 unsigned int cl_size = boot_cpu_data.x86_cache_size;
618 int ret;
619
620 r->mon_scale = boot_cpu_data.x86_cache_occ_scale;
621 r->num_rmid = boot_cpu_data.x86_cache_max_rmid + 1;
622
623 /*
624 * A reasonable upper limit on the max threshold is the number
625 * of lines tagged per RMID if all RMIDs have the same number of
626 * lines tagged in the LLC.
627 *
628 * For a 35MB LLC and 56 RMIDs, this is ~1.8% of the LLC.
629 */
630 resctrl_cqm_threshold = cl_size * 1024 / r->num_rmid;
631
632 /* h/w works in units of "boot_cpu_data.x86_cache_occ_scale" */
633 resctrl_cqm_threshold /= r->mon_scale;
634
635 ret = dom_data_init(r);
636 if (ret)
637 return ret;
638
639 l3_mon_evt_init(r);
640
641 r->mon_capable = true;
642 r->mon_enabled = true;
643
644 return 0;
645}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Resource Director Technology(RDT)
4 * - Monitoring code
5 *
6 * Copyright (C) 2017 Intel Corporation
7 *
8 * Author:
9 * Vikas Shivappa <vikas.shivappa@intel.com>
10 *
11 * This replaces the cqm.c based on perf but we reuse a lot of
12 * code and datastructures originally from Peter Zijlstra and Matt Fleming.
13 *
14 * More information about RDT be found in the Intel (R) x86 Architecture
15 * Software Developer Manual June 2016, volume 3, section 17.17.
16 */
17
18#include <linux/module.h>
19#include <linux/sizes.h>
20#include <linux/slab.h>
21
22#include <asm/cpu_device_id.h>
23#include <asm/resctrl.h>
24
25#include "internal.h"
26
27struct rmid_entry {
28 u32 rmid;
29 int busy;
30 struct list_head list;
31};
32
33/*
34 * @rmid_free_lru - A least recently used list of free RMIDs
35 * These RMIDs are guaranteed to have an occupancy less than the
36 * threshold occupancy
37 */
38static LIST_HEAD(rmid_free_lru);
39
40/*
41 * @rmid_limbo_count - count of currently unused but (potentially)
42 * dirty RMIDs.
43 * This counts RMIDs that no one is currently using but that
44 * may have a occupancy value > resctrl_rmid_realloc_threshold. User can
45 * change the threshold occupancy value.
46 */
47static unsigned int rmid_limbo_count;
48
49/*
50 * @rmid_entry - The entry in the limbo and free lists.
51 */
52static struct rmid_entry *rmid_ptrs;
53
54/*
55 * Global boolean for rdt_monitor which is true if any
56 * resource monitoring is enabled.
57 */
58bool rdt_mon_capable;
59
60/*
61 * Global to indicate which monitoring events are enabled.
62 */
63unsigned int rdt_mon_features;
64
65/*
66 * This is the threshold cache occupancy in bytes at which we will consider an
67 * RMID available for re-allocation.
68 */
69unsigned int resctrl_rmid_realloc_threshold;
70
71/*
72 * This is the maximum value for the reallocation threshold, in bytes.
73 */
74unsigned int resctrl_rmid_realloc_limit;
75
76#define CF(cf) ((unsigned long)(1048576 * (cf) + 0.5))
77
78/*
79 * The correction factor table is documented in Documentation/arch/x86/resctrl.rst.
80 * If rmid > rmid threshold, MBM total and local values should be multiplied
81 * by the correction factor.
82 *
83 * The original table is modified for better code:
84 *
85 * 1. The threshold 0 is changed to rmid count - 1 so don't do correction
86 * for the case.
87 * 2. MBM total and local correction table indexed by core counter which is
88 * equal to (x86_cache_max_rmid + 1) / 8 - 1 and is from 0 up to 27.
89 * 3. The correction factor is normalized to 2^20 (1048576) so it's faster
90 * to calculate corrected value by shifting:
91 * corrected_value = (original_value * correction_factor) >> 20
92 */
93static const struct mbm_correction_factor_table {
94 u32 rmidthreshold;
95 u64 cf;
96} mbm_cf_table[] __initconst = {
97 {7, CF(1.000000)},
98 {15, CF(1.000000)},
99 {15, CF(0.969650)},
100 {31, CF(1.000000)},
101 {31, CF(1.066667)},
102 {31, CF(0.969650)},
103 {47, CF(1.142857)},
104 {63, CF(1.000000)},
105 {63, CF(1.185115)},
106 {63, CF(1.066553)},
107 {79, CF(1.454545)},
108 {95, CF(1.000000)},
109 {95, CF(1.230769)},
110 {95, CF(1.142857)},
111 {95, CF(1.066667)},
112 {127, CF(1.000000)},
113 {127, CF(1.254863)},
114 {127, CF(1.185255)},
115 {151, CF(1.000000)},
116 {127, CF(1.066667)},
117 {167, CF(1.000000)},
118 {159, CF(1.454334)},
119 {183, CF(1.000000)},
120 {127, CF(0.969744)},
121 {191, CF(1.280246)},
122 {191, CF(1.230921)},
123 {215, CF(1.000000)},
124 {191, CF(1.143118)},
125};
126
127static u32 mbm_cf_rmidthreshold __read_mostly = UINT_MAX;
128static u64 mbm_cf __read_mostly;
129
130static inline u64 get_corrected_mbm_count(u32 rmid, unsigned long val)
131{
132 /* Correct MBM value. */
133 if (rmid > mbm_cf_rmidthreshold)
134 val = (val * mbm_cf) >> 20;
135
136 return val;
137}
138
139static inline struct rmid_entry *__rmid_entry(u32 rmid)
140{
141 struct rmid_entry *entry;
142
143 entry = &rmid_ptrs[rmid];
144 WARN_ON(entry->rmid != rmid);
145
146 return entry;
147}
148
149static int __rmid_read(u32 rmid, enum resctrl_event_id eventid, u64 *val)
150{
151 u64 msr_val;
152
153 /*
154 * As per the SDM, when IA32_QM_EVTSEL.EvtID (bits 7:0) is configured
155 * with a valid event code for supported resource type and the bits
156 * IA32_QM_EVTSEL.RMID (bits 41:32) are configured with valid RMID,
157 * IA32_QM_CTR.data (bits 61:0) reports the monitored data.
158 * IA32_QM_CTR.Error (bit 63) and IA32_QM_CTR.Unavailable (bit 62)
159 * are error bits.
160 */
161 wrmsr(MSR_IA32_QM_EVTSEL, eventid, rmid);
162 rdmsrl(MSR_IA32_QM_CTR, msr_val);
163
164 if (msr_val & RMID_VAL_ERROR)
165 return -EIO;
166 if (msr_val & RMID_VAL_UNAVAIL)
167 return -EINVAL;
168
169 *val = msr_val;
170 return 0;
171}
172
173static struct arch_mbm_state *get_arch_mbm_state(struct rdt_hw_domain *hw_dom,
174 u32 rmid,
175 enum resctrl_event_id eventid)
176{
177 switch (eventid) {
178 case QOS_L3_OCCUP_EVENT_ID:
179 return NULL;
180 case QOS_L3_MBM_TOTAL_EVENT_ID:
181 return &hw_dom->arch_mbm_total[rmid];
182 case QOS_L3_MBM_LOCAL_EVENT_ID:
183 return &hw_dom->arch_mbm_local[rmid];
184 }
185
186 /* Never expect to get here */
187 WARN_ON_ONCE(1);
188
189 return NULL;
190}
191
192void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d,
193 u32 rmid, enum resctrl_event_id eventid)
194{
195 struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
196 struct arch_mbm_state *am;
197
198 am = get_arch_mbm_state(hw_dom, rmid, eventid);
199 if (am) {
200 memset(am, 0, sizeof(*am));
201
202 /* Record any initial, non-zero count value. */
203 __rmid_read(rmid, eventid, &am->prev_msr);
204 }
205}
206
207/*
208 * Assumes that hardware counters are also reset and thus that there is
209 * no need to record initial non-zero counts.
210 */
211void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_domain *d)
212{
213 struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
214
215 if (is_mbm_total_enabled())
216 memset(hw_dom->arch_mbm_total, 0,
217 sizeof(*hw_dom->arch_mbm_total) * r->num_rmid);
218
219 if (is_mbm_local_enabled())
220 memset(hw_dom->arch_mbm_local, 0,
221 sizeof(*hw_dom->arch_mbm_local) * r->num_rmid);
222}
223
224static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width)
225{
226 u64 shift = 64 - width, chunks;
227
228 chunks = (cur_msr << shift) - (prev_msr << shift);
229 return chunks >> shift;
230}
231
232int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d,
233 u32 rmid, enum resctrl_event_id eventid, u64 *val)
234{
235 struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
236 struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
237 struct arch_mbm_state *am;
238 u64 msr_val, chunks;
239 int ret;
240
241 if (!cpumask_test_cpu(smp_processor_id(), &d->cpu_mask))
242 return -EINVAL;
243
244 ret = __rmid_read(rmid, eventid, &msr_val);
245 if (ret)
246 return ret;
247
248 am = get_arch_mbm_state(hw_dom, rmid, eventid);
249 if (am) {
250 am->chunks += mbm_overflow_count(am->prev_msr, msr_val,
251 hw_res->mbm_width);
252 chunks = get_corrected_mbm_count(rmid, am->chunks);
253 am->prev_msr = msr_val;
254 } else {
255 chunks = msr_val;
256 }
257
258 *val = chunks * hw_res->mon_scale;
259
260 return 0;
261}
262
263/*
264 * Check the RMIDs that are marked as busy for this domain. If the
265 * reported LLC occupancy is below the threshold clear the busy bit and
266 * decrement the count. If the busy count gets to zero on an RMID, we
267 * free the RMID
268 */
269void __check_limbo(struct rdt_domain *d, bool force_free)
270{
271 struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
272 struct rmid_entry *entry;
273 u32 crmid = 1, nrmid;
274 bool rmid_dirty;
275 u64 val = 0;
276
277 /*
278 * Skip RMID 0 and start from RMID 1 and check all the RMIDs that
279 * are marked as busy for occupancy < threshold. If the occupancy
280 * is less than the threshold decrement the busy counter of the
281 * RMID and move it to the free list when the counter reaches 0.
282 */
283 for (;;) {
284 nrmid = find_next_bit(d->rmid_busy_llc, r->num_rmid, crmid);
285 if (nrmid >= r->num_rmid)
286 break;
287
288 entry = __rmid_entry(nrmid);
289
290 if (resctrl_arch_rmid_read(r, d, entry->rmid,
291 QOS_L3_OCCUP_EVENT_ID, &val)) {
292 rmid_dirty = true;
293 } else {
294 rmid_dirty = (val >= resctrl_rmid_realloc_threshold);
295 }
296
297 if (force_free || !rmid_dirty) {
298 clear_bit(entry->rmid, d->rmid_busy_llc);
299 if (!--entry->busy) {
300 rmid_limbo_count--;
301 list_add_tail(&entry->list, &rmid_free_lru);
302 }
303 }
304 crmid = nrmid + 1;
305 }
306}
307
308bool has_busy_rmid(struct rdt_resource *r, struct rdt_domain *d)
309{
310 return find_first_bit(d->rmid_busy_llc, r->num_rmid) != r->num_rmid;
311}
312
313/*
314 * As of now the RMIDs allocation is global.
315 * However we keep track of which packages the RMIDs
316 * are used to optimize the limbo list management.
317 */
318int alloc_rmid(void)
319{
320 struct rmid_entry *entry;
321
322 lockdep_assert_held(&rdtgroup_mutex);
323
324 if (list_empty(&rmid_free_lru))
325 return rmid_limbo_count ? -EBUSY : -ENOSPC;
326
327 entry = list_first_entry(&rmid_free_lru,
328 struct rmid_entry, list);
329 list_del(&entry->list);
330
331 return entry->rmid;
332}
333
334static void add_rmid_to_limbo(struct rmid_entry *entry)
335{
336 struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
337 struct rdt_domain *d;
338 int cpu, err;
339 u64 val = 0;
340
341 entry->busy = 0;
342 cpu = get_cpu();
343 list_for_each_entry(d, &r->domains, list) {
344 if (cpumask_test_cpu(cpu, &d->cpu_mask)) {
345 err = resctrl_arch_rmid_read(r, d, entry->rmid,
346 QOS_L3_OCCUP_EVENT_ID,
347 &val);
348 if (err || val <= resctrl_rmid_realloc_threshold)
349 continue;
350 }
351
352 /*
353 * For the first limbo RMID in the domain,
354 * setup up the limbo worker.
355 */
356 if (!has_busy_rmid(r, d))
357 cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL);
358 set_bit(entry->rmid, d->rmid_busy_llc);
359 entry->busy++;
360 }
361 put_cpu();
362
363 if (entry->busy)
364 rmid_limbo_count++;
365 else
366 list_add_tail(&entry->list, &rmid_free_lru);
367}
368
369void free_rmid(u32 rmid)
370{
371 struct rmid_entry *entry;
372
373 if (!rmid)
374 return;
375
376 lockdep_assert_held(&rdtgroup_mutex);
377
378 entry = __rmid_entry(rmid);
379
380 if (is_llc_occupancy_enabled())
381 add_rmid_to_limbo(entry);
382 else
383 list_add_tail(&entry->list, &rmid_free_lru);
384}
385
386static struct mbm_state *get_mbm_state(struct rdt_domain *d, u32 rmid,
387 enum resctrl_event_id evtid)
388{
389 switch (evtid) {
390 case QOS_L3_MBM_TOTAL_EVENT_ID:
391 return &d->mbm_total[rmid];
392 case QOS_L3_MBM_LOCAL_EVENT_ID:
393 return &d->mbm_local[rmid];
394 default:
395 return NULL;
396 }
397}
398
399static int __mon_event_count(u32 rmid, struct rmid_read *rr)
400{
401 struct mbm_state *m;
402 u64 tval = 0;
403
404 if (rr->first) {
405 resctrl_arch_reset_rmid(rr->r, rr->d, rmid, rr->evtid);
406 m = get_mbm_state(rr->d, rmid, rr->evtid);
407 if (m)
408 memset(m, 0, sizeof(struct mbm_state));
409 return 0;
410 }
411
412 rr->err = resctrl_arch_rmid_read(rr->r, rr->d, rmid, rr->evtid, &tval);
413 if (rr->err)
414 return rr->err;
415
416 rr->val += tval;
417
418 return 0;
419}
420
421/*
422 * mbm_bw_count() - Update bw count from values previously read by
423 * __mon_event_count().
424 * @rmid: The rmid used to identify the cached mbm_state.
425 * @rr: The struct rmid_read populated by __mon_event_count().
426 *
427 * Supporting function to calculate the memory bandwidth
428 * and delta bandwidth in MBps. The chunks value previously read by
429 * __mon_event_count() is compared with the chunks value from the previous
430 * invocation. This must be called once per second to maintain values in MBps.
431 */
432static void mbm_bw_count(u32 rmid, struct rmid_read *rr)
433{
434 struct mbm_state *m = &rr->d->mbm_local[rmid];
435 u64 cur_bw, bytes, cur_bytes;
436
437 cur_bytes = rr->val;
438 bytes = cur_bytes - m->prev_bw_bytes;
439 m->prev_bw_bytes = cur_bytes;
440
441 cur_bw = bytes / SZ_1M;
442
443 if (m->delta_comp)
444 m->delta_bw = abs(cur_bw - m->prev_bw);
445 m->delta_comp = false;
446 m->prev_bw = cur_bw;
447}
448
449/*
450 * This is called via IPI to read the CQM/MBM counters
451 * on a domain.
452 */
453void mon_event_count(void *info)
454{
455 struct rdtgroup *rdtgrp, *entry;
456 struct rmid_read *rr = info;
457 struct list_head *head;
458 int ret;
459
460 rdtgrp = rr->rgrp;
461
462 ret = __mon_event_count(rdtgrp->mon.rmid, rr);
463
464 /*
465 * For Ctrl groups read data from child monitor groups and
466 * add them together. Count events which are read successfully.
467 * Discard the rmid_read's reporting errors.
468 */
469 head = &rdtgrp->mon.crdtgrp_list;
470
471 if (rdtgrp->type == RDTCTRL_GROUP) {
472 list_for_each_entry(entry, head, mon.crdtgrp_list) {
473 if (__mon_event_count(entry->mon.rmid, rr) == 0)
474 ret = 0;
475 }
476 }
477
478 /*
479 * __mon_event_count() calls for newly created monitor groups may
480 * report -EINVAL/Unavailable if the monitor hasn't seen any traffic.
481 * Discard error if any of the monitor event reads succeeded.
482 */
483 if (ret == 0)
484 rr->err = 0;
485}
486
487/*
488 * Feedback loop for MBA software controller (mba_sc)
489 *
490 * mba_sc is a feedback loop where we periodically read MBM counters and
491 * adjust the bandwidth percentage values via the IA32_MBA_THRTL_MSRs so
492 * that:
493 *
494 * current bandwidth(cur_bw) < user specified bandwidth(user_bw)
495 *
496 * This uses the MBM counters to measure the bandwidth and MBA throttle
497 * MSRs to control the bandwidth for a particular rdtgrp. It builds on the
498 * fact that resctrl rdtgroups have both monitoring and control.
499 *
500 * The frequency of the checks is 1s and we just tag along the MBM overflow
501 * timer. Having 1s interval makes the calculation of bandwidth simpler.
502 *
503 * Although MBA's goal is to restrict the bandwidth to a maximum, there may
504 * be a need to increase the bandwidth to avoid unnecessarily restricting
505 * the L2 <-> L3 traffic.
506 *
507 * Since MBA controls the L2 external bandwidth where as MBM measures the
508 * L3 external bandwidth the following sequence could lead to such a
509 * situation.
510 *
511 * Consider an rdtgroup which had high L3 <-> memory traffic in initial
512 * phases -> mba_sc kicks in and reduced bandwidth percentage values -> but
513 * after some time rdtgroup has mostly L2 <-> L3 traffic.
514 *
515 * In this case we may restrict the rdtgroup's L2 <-> L3 traffic as its
516 * throttle MSRs already have low percentage values. To avoid
517 * unnecessarily restricting such rdtgroups, we also increase the bandwidth.
518 */
519static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm)
520{
521 u32 closid, rmid, cur_msr_val, new_msr_val;
522 struct mbm_state *pmbm_data, *cmbm_data;
523 u32 cur_bw, delta_bw, user_bw;
524 struct rdt_resource *r_mba;
525 struct rdt_domain *dom_mba;
526 struct list_head *head;
527 struct rdtgroup *entry;
528
529 if (!is_mbm_local_enabled())
530 return;
531
532 r_mba = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl;
533
534 closid = rgrp->closid;
535 rmid = rgrp->mon.rmid;
536 pmbm_data = &dom_mbm->mbm_local[rmid];
537
538 dom_mba = get_domain_from_cpu(smp_processor_id(), r_mba);
539 if (!dom_mba) {
540 pr_warn_once("Failure to get domain for MBA update\n");
541 return;
542 }
543
544 cur_bw = pmbm_data->prev_bw;
545 user_bw = dom_mba->mbps_val[closid];
546 delta_bw = pmbm_data->delta_bw;
547
548 /* MBA resource doesn't support CDP */
549 cur_msr_val = resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE);
550
551 /*
552 * For Ctrl groups read data from child monitor groups.
553 */
554 head = &rgrp->mon.crdtgrp_list;
555 list_for_each_entry(entry, head, mon.crdtgrp_list) {
556 cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid];
557 cur_bw += cmbm_data->prev_bw;
558 delta_bw += cmbm_data->delta_bw;
559 }
560
561 /*
562 * Scale up/down the bandwidth linearly for the ctrl group. The
563 * bandwidth step is the bandwidth granularity specified by the
564 * hardware.
565 *
566 * The delta_bw is used when increasing the bandwidth so that we
567 * dont alternately increase and decrease the control values
568 * continuously.
569 *
570 * For ex: consider cur_bw = 90MBps, user_bw = 100MBps and if
571 * bandwidth step is 20MBps(> user_bw - cur_bw), we would keep
572 * switching between 90 and 110 continuously if we only check
573 * cur_bw < user_bw.
574 */
575 if (cur_msr_val > r_mba->membw.min_bw && user_bw < cur_bw) {
576 new_msr_val = cur_msr_val - r_mba->membw.bw_gran;
577 } else if (cur_msr_val < MAX_MBA_BW &&
578 (user_bw > (cur_bw + delta_bw))) {
579 new_msr_val = cur_msr_val + r_mba->membw.bw_gran;
580 } else {
581 return;
582 }
583
584 resctrl_arch_update_one(r_mba, dom_mba, closid, CDP_NONE, new_msr_val);
585
586 /*
587 * Delta values are updated dynamically package wise for each
588 * rdtgrp every time the throttle MSR changes value.
589 *
590 * This is because (1)the increase in bandwidth is not perfectly
591 * linear and only "approximately" linear even when the hardware
592 * says it is linear.(2)Also since MBA is a core specific
593 * mechanism, the delta values vary based on number of cores used
594 * by the rdtgrp.
595 */
596 pmbm_data->delta_comp = true;
597 list_for_each_entry(entry, head, mon.crdtgrp_list) {
598 cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid];
599 cmbm_data->delta_comp = true;
600 }
601}
602
603static void mbm_update(struct rdt_resource *r, struct rdt_domain *d, int rmid)
604{
605 struct rmid_read rr;
606
607 rr.first = false;
608 rr.r = r;
609 rr.d = d;
610
611 /*
612 * This is protected from concurrent reads from user
613 * as both the user and we hold the global mutex.
614 */
615 if (is_mbm_total_enabled()) {
616 rr.evtid = QOS_L3_MBM_TOTAL_EVENT_ID;
617 rr.val = 0;
618 __mon_event_count(rmid, &rr);
619 }
620 if (is_mbm_local_enabled()) {
621 rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID;
622 rr.val = 0;
623 __mon_event_count(rmid, &rr);
624
625 /*
626 * Call the MBA software controller only for the
627 * control groups and when user has enabled
628 * the software controller explicitly.
629 */
630 if (is_mba_sc(NULL))
631 mbm_bw_count(rmid, &rr);
632 }
633}
634
635/*
636 * Handler to scan the limbo list and move the RMIDs
637 * to free list whose occupancy < threshold_occupancy.
638 */
639void cqm_handle_limbo(struct work_struct *work)
640{
641 unsigned long delay = msecs_to_jiffies(CQM_LIMBOCHECK_INTERVAL);
642 int cpu = smp_processor_id();
643 struct rdt_resource *r;
644 struct rdt_domain *d;
645
646 mutex_lock(&rdtgroup_mutex);
647
648 r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
649 d = container_of(work, struct rdt_domain, cqm_limbo.work);
650
651 __check_limbo(d, false);
652
653 if (has_busy_rmid(r, d))
654 schedule_delayed_work_on(cpu, &d->cqm_limbo, delay);
655
656 mutex_unlock(&rdtgroup_mutex);
657}
658
659void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms)
660{
661 unsigned long delay = msecs_to_jiffies(delay_ms);
662 int cpu;
663
664 cpu = cpumask_any(&dom->cpu_mask);
665 dom->cqm_work_cpu = cpu;
666
667 schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay);
668}
669
670void mbm_handle_overflow(struct work_struct *work)
671{
672 unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL);
673 struct rdtgroup *prgrp, *crgrp;
674 int cpu = smp_processor_id();
675 struct list_head *head;
676 struct rdt_resource *r;
677 struct rdt_domain *d;
678
679 mutex_lock(&rdtgroup_mutex);
680
681 if (!static_branch_likely(&rdt_mon_enable_key))
682 goto out_unlock;
683
684 r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
685 d = container_of(work, struct rdt_domain, mbm_over.work);
686
687 list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
688 mbm_update(r, d, prgrp->mon.rmid);
689
690 head = &prgrp->mon.crdtgrp_list;
691 list_for_each_entry(crgrp, head, mon.crdtgrp_list)
692 mbm_update(r, d, crgrp->mon.rmid);
693
694 if (is_mba_sc(NULL))
695 update_mba_bw(prgrp, d);
696 }
697
698 schedule_delayed_work_on(cpu, &d->mbm_over, delay);
699
700out_unlock:
701 mutex_unlock(&rdtgroup_mutex);
702}
703
704void mbm_setup_overflow_handler(struct rdt_domain *dom, unsigned long delay_ms)
705{
706 unsigned long delay = msecs_to_jiffies(delay_ms);
707 int cpu;
708
709 if (!static_branch_likely(&rdt_mon_enable_key))
710 return;
711 cpu = cpumask_any(&dom->cpu_mask);
712 dom->mbm_work_cpu = cpu;
713 schedule_delayed_work_on(cpu, &dom->mbm_over, delay);
714}
715
716static int dom_data_init(struct rdt_resource *r)
717{
718 struct rmid_entry *entry = NULL;
719 int i, nr_rmids;
720
721 nr_rmids = r->num_rmid;
722 rmid_ptrs = kcalloc(nr_rmids, sizeof(struct rmid_entry), GFP_KERNEL);
723 if (!rmid_ptrs)
724 return -ENOMEM;
725
726 for (i = 0; i < nr_rmids; i++) {
727 entry = &rmid_ptrs[i];
728 INIT_LIST_HEAD(&entry->list);
729
730 entry->rmid = i;
731 list_add_tail(&entry->list, &rmid_free_lru);
732 }
733
734 /*
735 * RMID 0 is special and is always allocated. It's used for all
736 * tasks that are not monitored.
737 */
738 entry = __rmid_entry(0);
739 list_del(&entry->list);
740
741 return 0;
742}
743
744static struct mon_evt llc_occupancy_event = {
745 .name = "llc_occupancy",
746 .evtid = QOS_L3_OCCUP_EVENT_ID,
747};
748
749static struct mon_evt mbm_total_event = {
750 .name = "mbm_total_bytes",
751 .evtid = QOS_L3_MBM_TOTAL_EVENT_ID,
752};
753
754static struct mon_evt mbm_local_event = {
755 .name = "mbm_local_bytes",
756 .evtid = QOS_L3_MBM_LOCAL_EVENT_ID,
757};
758
759/*
760 * Initialize the event list for the resource.
761 *
762 * Note that MBM events are also part of RDT_RESOURCE_L3 resource
763 * because as per the SDM the total and local memory bandwidth
764 * are enumerated as part of L3 monitoring.
765 */
766static void l3_mon_evt_init(struct rdt_resource *r)
767{
768 INIT_LIST_HEAD(&r->evt_list);
769
770 if (is_llc_occupancy_enabled())
771 list_add_tail(&llc_occupancy_event.list, &r->evt_list);
772 if (is_mbm_total_enabled())
773 list_add_tail(&mbm_total_event.list, &r->evt_list);
774 if (is_mbm_local_enabled())
775 list_add_tail(&mbm_local_event.list, &r->evt_list);
776}
777
778int __init rdt_get_mon_l3_config(struct rdt_resource *r)
779{
780 unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset;
781 struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
782 unsigned int threshold;
783 int ret;
784
785 resctrl_rmid_realloc_limit = boot_cpu_data.x86_cache_size * 1024;
786 hw_res->mon_scale = boot_cpu_data.x86_cache_occ_scale;
787 r->num_rmid = boot_cpu_data.x86_cache_max_rmid + 1;
788 hw_res->mbm_width = MBM_CNTR_WIDTH_BASE;
789
790 if (mbm_offset > 0 && mbm_offset <= MBM_CNTR_WIDTH_OFFSET_MAX)
791 hw_res->mbm_width += mbm_offset;
792 else if (mbm_offset > MBM_CNTR_WIDTH_OFFSET_MAX)
793 pr_warn("Ignoring impossible MBM counter offset\n");
794
795 /*
796 * A reasonable upper limit on the max threshold is the number
797 * of lines tagged per RMID if all RMIDs have the same number of
798 * lines tagged in the LLC.
799 *
800 * For a 35MB LLC and 56 RMIDs, this is ~1.8% of the LLC.
801 */
802 threshold = resctrl_rmid_realloc_limit / r->num_rmid;
803
804 /*
805 * Because num_rmid may not be a power of two, round the value
806 * to the nearest multiple of hw_res->mon_scale so it matches a
807 * value the hardware will measure. mon_scale may not be a power of 2.
808 */
809 resctrl_rmid_realloc_threshold = resctrl_arch_round_mon_val(threshold);
810
811 ret = dom_data_init(r);
812 if (ret)
813 return ret;
814
815 if (rdt_cpu_has(X86_FEATURE_BMEC)) {
816 if (rdt_cpu_has(X86_FEATURE_CQM_MBM_TOTAL)) {
817 mbm_total_event.configurable = true;
818 mbm_config_rftype_init("mbm_total_bytes_config");
819 }
820 if (rdt_cpu_has(X86_FEATURE_CQM_MBM_LOCAL)) {
821 mbm_local_event.configurable = true;
822 mbm_config_rftype_init("mbm_local_bytes_config");
823 }
824 }
825
826 l3_mon_evt_init(r);
827
828 r->mon_capable = true;
829
830 return 0;
831}
832
833void __init intel_rdt_mbm_apply_quirk(void)
834{
835 int cf_index;
836
837 cf_index = (boot_cpu_data.x86_cache_max_rmid + 1) / 8 - 1;
838 if (cf_index >= ARRAY_SIZE(mbm_cf_table)) {
839 pr_info("No MBM correction factor available\n");
840 return;
841 }
842
843 mbm_cf_rmidthreshold = mbm_cf_table[cf_index].rmidthreshold;
844 mbm_cf = mbm_cf_table[cf_index].cf;
845}