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 
27 struct 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  */
38 static 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  */
47 static unsigned int rmid_limbo_count;
48 
49 /*
50  * @rmid_entry - The entry in the limbo and free lists.
51  */
52 static struct rmid_entry	*rmid_ptrs;
53 
54 /*
55  * Global boolean for rdt_monitor which is true if any
56  * resource monitoring is enabled.
57  */
58 bool rdt_mon_capable;
59 
60 /*
61  * Global to indicate which monitoring events are enabled.
62  */
63 unsigned 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  */
69 unsigned int resctrl_rmid_realloc_threshold;
70 
71 /*
72  * This is the maximum value for the reallocation threshold, in bytes.
73  */
74 unsigned 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  */
93 static 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 
127 static u32 mbm_cf_rmidthreshold __read_mostly = UINT_MAX;
128 static u64 mbm_cf __read_mostly;
129 
get_corrected_mbm_count(u32 rmid,unsigned long val)130 static 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 
__rmid_entry(u32 rmid)139 static 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 
__rmid_read(u32 rmid,enum resctrl_event_id eventid,u64 * val)149 static 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 
get_arch_mbm_state(struct rdt_hw_domain * hw_dom,u32 rmid,enum resctrl_event_id eventid)173 static 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 
resctrl_arch_reset_rmid(struct rdt_resource * r,struct rdt_domain * d,u32 rmid,enum resctrl_event_id eventid)192 void 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  */
resctrl_arch_reset_rmid_all(struct rdt_resource * r,struct rdt_domain * d)211 void 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 
mbm_overflow_count(u64 prev_msr,u64 cur_msr,unsigned int width)224 static 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 
resctrl_arch_rmid_read(struct rdt_resource * r,struct rdt_domain * d,u32 rmid,enum resctrl_event_id eventid,u64 * val)232 int 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  */
__check_limbo(struct rdt_domain * d,bool force_free)269 void __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 
has_busy_rmid(struct rdt_resource * r,struct rdt_domain * d)308 bool 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  */
alloc_rmid(void)318 int 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 
add_rmid_to_limbo(struct rmid_entry * entry)334 static 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 
free_rmid(u32 rmid)369 void 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 
get_mbm_state(struct rdt_domain * d,u32 rmid,enum resctrl_event_id evtid)386 static 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 
__mon_event_count(u32 rmid,struct rmid_read * rr)399 static 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  */
mbm_bw_count(u32 rmid,struct rmid_read * rr)432 static 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  */
mon_event_count(void * info)453 void 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  */
update_mba_bw(struct rdtgroup * rgrp,struct rdt_domain * dom_mbm)519 static 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 
mbm_update(struct rdt_resource * r,struct rdt_domain * d,int rmid)603 static 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  */
cqm_handle_limbo(struct work_struct * work)639 void 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 
cqm_setup_limbo_handler(struct rdt_domain * dom,unsigned long delay_ms)659 void 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 
mbm_handle_overflow(struct work_struct * work)670 void 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 
700 out_unlock:
701 	mutex_unlock(&rdtgroup_mutex);
702 }
703 
mbm_setup_overflow_handler(struct rdt_domain * dom,unsigned long delay_ms)704 void 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 
dom_data_init(struct rdt_resource * r)716 static 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 
744 static struct mon_evt llc_occupancy_event = {
745 	.name		= "llc_occupancy",
746 	.evtid		= QOS_L3_OCCUP_EVENT_ID,
747 };
748 
749 static struct mon_evt mbm_total_event = {
750 	.name		= "mbm_total_bytes",
751 	.evtid		= QOS_L3_MBM_TOTAL_EVENT_ID,
752 };
753 
754 static 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  */
l3_mon_evt_init(struct rdt_resource * r)766 static 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 
rdt_get_mon_l3_config(struct rdt_resource * r)778 int __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 
intel_rdt_mbm_apply_quirk(void)833 void __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 }
846