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 #define pr_fmt(fmt) "resctrl: " fmt
19
20 #include <linux/cpu.h>
21 #include <linux/module.h>
22 #include <linux/sizes.h>
23 #include <linux/slab.h>
24
25 #include <asm/cpu_device_id.h>
26 #include <asm/resctrl.h>
27
28 #include "internal.h"
29 #include "trace.h"
30
31 /**
32 * struct rmid_entry - dirty tracking for all RMID.
33 * @closid: The CLOSID for this entry.
34 * @rmid: The RMID for this entry.
35 * @busy: The number of domains with cached data using this RMID.
36 * @list: Member of the rmid_free_lru list when busy == 0.
37 *
38 * Depending on the architecture the correct monitor is accessed using
39 * both @closid and @rmid, or @rmid only.
40 *
41 * Take the rdtgroup_mutex when accessing.
42 */
43 struct rmid_entry {
44 u32 closid;
45 u32 rmid;
46 int busy;
47 struct list_head list;
48 };
49
50 /*
51 * @rmid_free_lru - A least recently used list of free RMIDs
52 * These RMIDs are guaranteed to have an occupancy less than the
53 * threshold occupancy
54 */
55 static LIST_HEAD(rmid_free_lru);
56
57 /*
58 * @closid_num_dirty_rmid The number of dirty RMID each CLOSID has.
59 * Only allocated when CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID is defined.
60 * Indexed by CLOSID. Protected by rdtgroup_mutex.
61 */
62 static u32 *closid_num_dirty_rmid;
63
64 /*
65 * @rmid_limbo_count - count of currently unused but (potentially)
66 * dirty RMIDs.
67 * This counts RMIDs that no one is currently using but that
68 * may have a occupancy value > resctrl_rmid_realloc_threshold. User can
69 * change the threshold occupancy value.
70 */
71 static unsigned int rmid_limbo_count;
72
73 /*
74 * @rmid_entry - The entry in the limbo and free lists.
75 */
76 static struct rmid_entry *rmid_ptrs;
77
78 /*
79 * Global boolean for rdt_monitor which is true if any
80 * resource monitoring is enabled.
81 */
82 bool rdt_mon_capable;
83
84 /*
85 * Global to indicate which monitoring events are enabled.
86 */
87 unsigned int rdt_mon_features;
88
89 /*
90 * This is the threshold cache occupancy in bytes at which we will consider an
91 * RMID available for re-allocation.
92 */
93 unsigned int resctrl_rmid_realloc_threshold;
94
95 /*
96 * This is the maximum value for the reallocation threshold, in bytes.
97 */
98 unsigned int resctrl_rmid_realloc_limit;
99
100 #define CF(cf) ((unsigned long)(1048576 * (cf) + 0.5))
101
102 static int snc_nodes_per_l3_cache = 1;
103
104 /*
105 * The correction factor table is documented in Documentation/arch/x86/resctrl.rst.
106 * If rmid > rmid threshold, MBM total and local values should be multiplied
107 * by the correction factor.
108 *
109 * The original table is modified for better code:
110 *
111 * 1. The threshold 0 is changed to rmid count - 1 so don't do correction
112 * for the case.
113 * 2. MBM total and local correction table indexed by core counter which is
114 * equal to (x86_cache_max_rmid + 1) / 8 - 1 and is from 0 up to 27.
115 * 3. The correction factor is normalized to 2^20 (1048576) so it's faster
116 * to calculate corrected value by shifting:
117 * corrected_value = (original_value * correction_factor) >> 20
118 */
119 static const struct mbm_correction_factor_table {
120 u32 rmidthreshold;
121 u64 cf;
122 } mbm_cf_table[] __initconst = {
123 {7, CF(1.000000)},
124 {15, CF(1.000000)},
125 {15, CF(0.969650)},
126 {31, CF(1.000000)},
127 {31, CF(1.066667)},
128 {31, CF(0.969650)},
129 {47, CF(1.142857)},
130 {63, CF(1.000000)},
131 {63, CF(1.185115)},
132 {63, CF(1.066553)},
133 {79, CF(1.454545)},
134 {95, CF(1.000000)},
135 {95, CF(1.230769)},
136 {95, CF(1.142857)},
137 {95, CF(1.066667)},
138 {127, CF(1.000000)},
139 {127, CF(1.254863)},
140 {127, CF(1.185255)},
141 {151, CF(1.000000)},
142 {127, CF(1.066667)},
143 {167, CF(1.000000)},
144 {159, CF(1.454334)},
145 {183, CF(1.000000)},
146 {127, CF(0.969744)},
147 {191, CF(1.280246)},
148 {191, CF(1.230921)},
149 {215, CF(1.000000)},
150 {191, CF(1.143118)},
151 };
152
153 static u32 mbm_cf_rmidthreshold __read_mostly = UINT_MAX;
154 static u64 mbm_cf __read_mostly;
155
156 static inline u64 get_corrected_mbm_count(u32 rmid, unsigned long val)
157 {
158 /* Correct MBM value. */
159 if (rmid > mbm_cf_rmidthreshold)
160 val = (val * mbm_cf) >> 20;
161
162 return val;
163 }
164
165 /*
166 * x86 and arm64 differ in their handling of monitoring.
167 * x86's RMID are independent numbers, there is only one source of traffic
168 * with an RMID value of '1'.
169 * arm64's PMG extends the PARTID/CLOSID space, there are multiple sources of
170 * traffic with a PMG value of '1', one for each CLOSID, meaning the RMID
171 * value is no longer unique.
172 * To account for this, resctrl uses an index. On x86 this is just the RMID,
173 * on arm64 it encodes the CLOSID and RMID. This gives a unique number.
174 *
175 * The domain's rmid_busy_llc and rmid_ptrs[] are sized by index. The arch code
176 * must accept an attempt to read every index.
177 */
178 static inline struct rmid_entry *__rmid_entry(u32 idx)
179 {
180 struct rmid_entry *entry;
181 u32 closid, rmid;
182
183 entry = &rmid_ptrs[idx];
184 resctrl_arch_rmid_idx_decode(idx, &closid, &rmid);
185
186 WARN_ON_ONCE(entry->closid != closid);
187 WARN_ON_ONCE(entry->rmid != rmid);
188
189 return entry;
190 }
191
192 /*
193 * When Sub-NUMA Cluster (SNC) mode is not enabled (as indicated by
194 * "snc_nodes_per_l3_cache == 1") no translation of the RMID value is
195 * needed. The physical RMID is the same as the logical RMID.
196 *
197 * On a platform with SNC mode enabled, Linux enables RMID sharing mode
198 * via MSR 0xCA0 (see the "RMID Sharing Mode" section in the "Intel
199 * Resource Director Technology Architecture Specification" for a full
200 * description of RMID sharing mode).
201 *
202 * In RMID sharing mode there are fewer "logical RMID" values available
203 * to accumulate data ("physical RMIDs" are divided evenly between SNC
204 * nodes that share an L3 cache). Linux creates an rdt_mon_domain for
205 * each SNC node.
206 *
207 * The value loaded into IA32_PQR_ASSOC is the "logical RMID".
208 *
209 * Data is collected independently on each SNC node and can be retrieved
210 * using the "physical RMID" value computed by this function and loaded
211 * into IA32_QM_EVTSEL. @cpu can be any CPU in the SNC node.
212 *
213 * The scope of the IA32_QM_EVTSEL and IA32_QM_CTR MSRs is at the L3
214 * cache. So a "physical RMID" may be read from any CPU that shares
215 * the L3 cache with the desired SNC node, not just from a CPU in
216 * the specific SNC node.
217 */
218 static int logical_rmid_to_physical_rmid(int cpu, int lrmid)
219 {
220 struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
221
222 if (snc_nodes_per_l3_cache == 1)
223 return lrmid;
224
225 return lrmid + (cpu_to_node(cpu) % snc_nodes_per_l3_cache) * r->num_rmid;
226 }
227
228 static int __rmid_read_phys(u32 prmid, enum resctrl_event_id eventid, u64 *val)
229 {
230 u64 msr_val;
231
232 /*
233 * As per the SDM, when IA32_QM_EVTSEL.EvtID (bits 7:0) is configured
234 * with a valid event code for supported resource type and the bits
235 * IA32_QM_EVTSEL.RMID (bits 41:32) are configured with valid RMID,
236 * IA32_QM_CTR.data (bits 61:0) reports the monitored data.
237 * IA32_QM_CTR.Error (bit 63) and IA32_QM_CTR.Unavailable (bit 62)
238 * are error bits.
239 */
240 wrmsr(MSR_IA32_QM_EVTSEL, eventid, prmid);
241 rdmsrl(MSR_IA32_QM_CTR, msr_val);
242
243 if (msr_val & RMID_VAL_ERROR)
244 return -EIO;
245 if (msr_val & RMID_VAL_UNAVAIL)
246 return -EINVAL;
247
248 *val = msr_val;
249 return 0;
250 }
251
252 static struct arch_mbm_state *get_arch_mbm_state(struct rdt_hw_mon_domain *hw_dom,
253 u32 rmid,
254 enum resctrl_event_id eventid)
255 {
256 switch (eventid) {
257 case QOS_L3_OCCUP_EVENT_ID:
258 return NULL;
259 case QOS_L3_MBM_TOTAL_EVENT_ID:
260 return &hw_dom->arch_mbm_total[rmid];
261 case QOS_L3_MBM_LOCAL_EVENT_ID:
262 return &hw_dom->arch_mbm_local[rmid];
263 }
264
265 /* Never expect to get here */
266 WARN_ON_ONCE(1);
267
268 return NULL;
269 }
270
271 void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_mon_domain *d,
272 u32 unused, u32 rmid,
273 enum resctrl_event_id eventid)
274 {
275 struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d);
276 int cpu = cpumask_any(&d->hdr.cpu_mask);
277 struct arch_mbm_state *am;
278 u32 prmid;
279
280 am = get_arch_mbm_state(hw_dom, rmid, eventid);
281 if (am) {
282 memset(am, 0, sizeof(*am));
283
284 prmid = logical_rmid_to_physical_rmid(cpu, rmid);
285 /* Record any initial, non-zero count value. */
286 __rmid_read_phys(prmid, eventid, &am->prev_msr);
287 }
288 }
289
290 /*
291 * Assumes that hardware counters are also reset and thus that there is
292 * no need to record initial non-zero counts.
293 */
294 void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_mon_domain *d)
295 {
296 struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d);
297
298 if (is_mbm_total_enabled())
299 memset(hw_dom->arch_mbm_total, 0,
300 sizeof(*hw_dom->arch_mbm_total) * r->num_rmid);
301
302 if (is_mbm_local_enabled())
303 memset(hw_dom->arch_mbm_local, 0,
304 sizeof(*hw_dom->arch_mbm_local) * r->num_rmid);
305 }
306
307 static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width)
308 {
309 u64 shift = 64 - width, chunks;
310
311 chunks = (cur_msr << shift) - (prev_msr << shift);
312 return chunks >> shift;
313 }
314
315 int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_mon_domain *d,
316 u32 unused, u32 rmid, enum resctrl_event_id eventid,
317 u64 *val, void *ignored)
318 {
319 struct rdt_hw_mon_domain *hw_dom = resctrl_to_arch_mon_dom(d);
320 struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
321 int cpu = cpumask_any(&d->hdr.cpu_mask);
322 struct arch_mbm_state *am;
323 u64 msr_val, chunks;
324 u32 prmid;
325 int ret;
326
327 resctrl_arch_rmid_read_context_check();
328
329 prmid = logical_rmid_to_physical_rmid(cpu, rmid);
330 ret = __rmid_read_phys(prmid, eventid, &msr_val);
331 if (ret)
332 return ret;
333
334 am = get_arch_mbm_state(hw_dom, rmid, eventid);
335 if (am) {
336 am->chunks += mbm_overflow_count(am->prev_msr, msr_val,
337 hw_res->mbm_width);
338 chunks = get_corrected_mbm_count(rmid, am->chunks);
339 am->prev_msr = msr_val;
340 } else {
341 chunks = msr_val;
342 }
343
344 *val = chunks * hw_res->mon_scale;
345
346 return 0;
347 }
348
349 static void limbo_release_entry(struct rmid_entry *entry)
350 {
351 lockdep_assert_held(&rdtgroup_mutex);
352
353 rmid_limbo_count--;
354 list_add_tail(&entry->list, &rmid_free_lru);
355
356 if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID))
357 closid_num_dirty_rmid[entry->closid]--;
358 }
359
360 /*
361 * Check the RMIDs that are marked as busy for this domain. If the
362 * reported LLC occupancy is below the threshold clear the busy bit and
363 * decrement the count. If the busy count gets to zero on an RMID, we
364 * free the RMID
365 */
366 void __check_limbo(struct rdt_mon_domain *d, bool force_free)
367 {
368 struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
369 u32 idx_limit = resctrl_arch_system_num_rmid_idx();
370 struct rmid_entry *entry;
371 u32 idx, cur_idx = 1;
372 void *arch_mon_ctx;
373 bool rmid_dirty;
374 u64 val = 0;
375
376 arch_mon_ctx = resctrl_arch_mon_ctx_alloc(r, QOS_L3_OCCUP_EVENT_ID);
377 if (IS_ERR(arch_mon_ctx)) {
378 pr_warn_ratelimited("Failed to allocate monitor context: %ld",
379 PTR_ERR(arch_mon_ctx));
380 return;
381 }
382
383 /*
384 * Skip RMID 0 and start from RMID 1 and check all the RMIDs that
385 * are marked as busy for occupancy < threshold. If the occupancy
386 * is less than the threshold decrement the busy counter of the
387 * RMID and move it to the free list when the counter reaches 0.
388 */
389 for (;;) {
390 idx = find_next_bit(d->rmid_busy_llc, idx_limit, cur_idx);
391 if (idx >= idx_limit)
392 break;
393
394 entry = __rmid_entry(idx);
395 if (resctrl_arch_rmid_read(r, d, entry->closid, entry->rmid,
396 QOS_L3_OCCUP_EVENT_ID, &val,
397 arch_mon_ctx)) {
398 rmid_dirty = true;
399 } else {
400 rmid_dirty = (val >= resctrl_rmid_realloc_threshold);
401
402 /*
403 * x86's CLOSID and RMID are independent numbers, so the entry's
404 * CLOSID is an empty CLOSID (X86_RESCTRL_EMPTY_CLOSID). On Arm the
405 * RMID (PMG) extends the CLOSID (PARTID) space with bits that aren't
406 * used to select the configuration. It is thus necessary to track both
407 * CLOSID and RMID because there may be dependencies between them
408 * on some architectures.
409 */
410 trace_mon_llc_occupancy_limbo(entry->closid, entry->rmid, d->hdr.id, val);
411 }
412
413 if (force_free || !rmid_dirty) {
414 clear_bit(idx, d->rmid_busy_llc);
415 if (!--entry->busy)
416 limbo_release_entry(entry);
417 }
418 cur_idx = idx + 1;
419 }
420
421 resctrl_arch_mon_ctx_free(r, QOS_L3_OCCUP_EVENT_ID, arch_mon_ctx);
422 }
423
424 bool has_busy_rmid(struct rdt_mon_domain *d)
425 {
426 u32 idx_limit = resctrl_arch_system_num_rmid_idx();
427
428 return find_first_bit(d->rmid_busy_llc, idx_limit) != idx_limit;
429 }
430
431 static struct rmid_entry *resctrl_find_free_rmid(u32 closid)
432 {
433 struct rmid_entry *itr;
434 u32 itr_idx, cmp_idx;
435
436 if (list_empty(&rmid_free_lru))
437 return rmid_limbo_count ? ERR_PTR(-EBUSY) : ERR_PTR(-ENOSPC);
438
439 list_for_each_entry(itr, &rmid_free_lru, list) {
440 /*
441 * Get the index of this free RMID, and the index it would need
442 * to be if it were used with this CLOSID.
443 * If the CLOSID is irrelevant on this architecture, the two
444 * index values are always the same on every entry and thus the
445 * very first entry will be returned.
446 */
447 itr_idx = resctrl_arch_rmid_idx_encode(itr->closid, itr->rmid);
448 cmp_idx = resctrl_arch_rmid_idx_encode(closid, itr->rmid);
449
450 if (itr_idx == cmp_idx)
451 return itr;
452 }
453
454 return ERR_PTR(-ENOSPC);
455 }
456
457 /**
458 * resctrl_find_cleanest_closid() - Find a CLOSID where all the associated
459 * RMID are clean, or the CLOSID that has
460 * the most clean RMID.
461 *
462 * MPAM's equivalent of RMID are per-CLOSID, meaning a freshly allocated CLOSID
463 * may not be able to allocate clean RMID. To avoid this the allocator will
464 * choose the CLOSID with the most clean RMID.
465 *
466 * When the CLOSID and RMID are independent numbers, the first free CLOSID will
467 * be returned.
468 */
469 int resctrl_find_cleanest_closid(void)
470 {
471 u32 cleanest_closid = ~0;
472 int i = 0;
473
474 lockdep_assert_held(&rdtgroup_mutex);
475
476 if (!IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID))
477 return -EIO;
478
479 for (i = 0; i < closids_supported(); i++) {
480 int num_dirty;
481
482 if (closid_allocated(i))
483 continue;
484
485 num_dirty = closid_num_dirty_rmid[i];
486 if (num_dirty == 0)
487 return i;
488
489 if (cleanest_closid == ~0)
490 cleanest_closid = i;
491
492 if (num_dirty < closid_num_dirty_rmid[cleanest_closid])
493 cleanest_closid = i;
494 }
495
496 if (cleanest_closid == ~0)
497 return -ENOSPC;
498
499 return cleanest_closid;
500 }
501
502 /*
503 * For MPAM the RMID value is not unique, and has to be considered with
504 * the CLOSID. The (CLOSID, RMID) pair is allocated on all domains, which
505 * allows all domains to be managed by a single free list.
506 * Each domain also has a rmid_busy_llc to reduce the work of the limbo handler.
507 */
508 int alloc_rmid(u32 closid)
509 {
510 struct rmid_entry *entry;
511
512 lockdep_assert_held(&rdtgroup_mutex);
513
514 entry = resctrl_find_free_rmid(closid);
515 if (IS_ERR(entry))
516 return PTR_ERR(entry);
517
518 list_del(&entry->list);
519 return entry->rmid;
520 }
521
522 static void add_rmid_to_limbo(struct rmid_entry *entry)
523 {
524 struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
525 struct rdt_mon_domain *d;
526 u32 idx;
527
528 lockdep_assert_held(&rdtgroup_mutex);
529
530 /* Walking r->domains, ensure it can't race with cpuhp */
531 lockdep_assert_cpus_held();
532
533 idx = resctrl_arch_rmid_idx_encode(entry->closid, entry->rmid);
534
535 entry->busy = 0;
536 list_for_each_entry(d, &r->mon_domains, hdr.list) {
537 /*
538 * For the first limbo RMID in the domain,
539 * setup up the limbo worker.
540 */
541 if (!has_busy_rmid(d))
542 cqm_setup_limbo_handler(d, CQM_LIMBOCHECK_INTERVAL,
543 RESCTRL_PICK_ANY_CPU);
544 set_bit(idx, d->rmid_busy_llc);
545 entry->busy++;
546 }
547
548 rmid_limbo_count++;
549 if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID))
550 closid_num_dirty_rmid[entry->closid]++;
551 }
552
553 void free_rmid(u32 closid, u32 rmid)
554 {
555 u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid);
556 struct rmid_entry *entry;
557
558 lockdep_assert_held(&rdtgroup_mutex);
559
560 /*
561 * Do not allow the default rmid to be free'd. Comparing by index
562 * allows architectures that ignore the closid parameter to avoid an
563 * unnecessary check.
564 */
565 if (!resctrl_arch_mon_capable() ||
566 idx == resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID,
567 RESCTRL_RESERVED_RMID))
568 return;
569
570 entry = __rmid_entry(idx);
571
572 if (is_llc_occupancy_enabled())
573 add_rmid_to_limbo(entry);
574 else
575 list_add_tail(&entry->list, &rmid_free_lru);
576 }
577
578 static struct mbm_state *get_mbm_state(struct rdt_mon_domain *d, u32 closid,
579 u32 rmid, enum resctrl_event_id evtid)
580 {
581 u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid);
582
583 switch (evtid) {
584 case QOS_L3_MBM_TOTAL_EVENT_ID:
585 return &d->mbm_total[idx];
586 case QOS_L3_MBM_LOCAL_EVENT_ID:
587 return &d->mbm_local[idx];
588 default:
589 return NULL;
590 }
591 }
592
593 static int __mon_event_count(u32 closid, u32 rmid, struct rmid_read *rr)
594 {
595 int cpu = smp_processor_id();
596 struct rdt_mon_domain *d;
597 struct mbm_state *m;
598 int err, ret;
599 u64 tval = 0;
600
601 if (rr->first) {
602 resctrl_arch_reset_rmid(rr->r, rr->d, closid, rmid, rr->evtid);
603 m = get_mbm_state(rr->d, closid, rmid, rr->evtid);
604 if (m)
605 memset(m, 0, sizeof(struct mbm_state));
606 return 0;
607 }
608
609 if (rr->d) {
610 /* Reading a single domain, must be on a CPU in that domain. */
611 if (!cpumask_test_cpu(cpu, &rr->d->hdr.cpu_mask))
612 return -EINVAL;
613 rr->err = resctrl_arch_rmid_read(rr->r, rr->d, closid, rmid,
614 rr->evtid, &tval, rr->arch_mon_ctx);
615 if (rr->err)
616 return rr->err;
617
618 rr->val += tval;
619
620 return 0;
621 }
622
623 /* Summing domains that share a cache, must be on a CPU for that cache. */
624 if (!cpumask_test_cpu(cpu, &rr->ci->shared_cpu_map))
625 return -EINVAL;
626
627 /*
628 * Legacy files must report the sum of an event across all
629 * domains that share the same L3 cache instance.
630 * Report success if a read from any domain succeeds, -EINVAL
631 * (translated to "Unavailable" for user space) if reading from
632 * all domains fail for any reason.
633 */
634 ret = -EINVAL;
635 list_for_each_entry(d, &rr->r->mon_domains, hdr.list) {
636 if (d->ci->id != rr->ci->id)
637 continue;
638 err = resctrl_arch_rmid_read(rr->r, d, closid, rmid,
639 rr->evtid, &tval, rr->arch_mon_ctx);
640 if (!err) {
641 rr->val += tval;
642 ret = 0;
643 }
644 }
645
646 if (ret)
647 rr->err = ret;
648
649 return ret;
650 }
651
652 /*
653 * mbm_bw_count() - Update bw count from values previously read by
654 * __mon_event_count().
655 * @closid: The closid used to identify the cached mbm_state.
656 * @rmid: The rmid used to identify the cached mbm_state.
657 * @rr: The struct rmid_read populated by __mon_event_count().
658 *
659 * Supporting function to calculate the memory bandwidth
660 * and delta bandwidth in MBps. The chunks value previously read by
661 * __mon_event_count() is compared with the chunks value from the previous
662 * invocation. This must be called once per second to maintain values in MBps.
663 */
664 static void mbm_bw_count(u32 closid, u32 rmid, struct rmid_read *rr)
665 {
666 u32 idx = resctrl_arch_rmid_idx_encode(closid, rmid);
667 struct mbm_state *m = &rr->d->mbm_local[idx];
668 u64 cur_bw, bytes, cur_bytes;
669
670 cur_bytes = rr->val;
671 bytes = cur_bytes - m->prev_bw_bytes;
672 m->prev_bw_bytes = cur_bytes;
673
674 cur_bw = bytes / SZ_1M;
675
676 m->prev_bw = cur_bw;
677 }
678
679 /*
680 * This is scheduled by mon_event_read() to read the CQM/MBM counters
681 * on a domain.
682 */
683 void mon_event_count(void *info)
684 {
685 struct rdtgroup *rdtgrp, *entry;
686 struct rmid_read *rr = info;
687 struct list_head *head;
688 int ret;
689
690 rdtgrp = rr->rgrp;
691
692 ret = __mon_event_count(rdtgrp->closid, rdtgrp->mon.rmid, rr);
693
694 /*
695 * For Ctrl groups read data from child monitor groups and
696 * add them together. Count events which are read successfully.
697 * Discard the rmid_read's reporting errors.
698 */
699 head = &rdtgrp->mon.crdtgrp_list;
700
701 if (rdtgrp->type == RDTCTRL_GROUP) {
702 list_for_each_entry(entry, head, mon.crdtgrp_list) {
703 if (__mon_event_count(entry->closid, entry->mon.rmid,
704 rr) == 0)
705 ret = 0;
706 }
707 }
708
709 /*
710 * __mon_event_count() calls for newly created monitor groups may
711 * report -EINVAL/Unavailable if the monitor hasn't seen any traffic.
712 * Discard error if any of the monitor event reads succeeded.
713 */
714 if (ret == 0)
715 rr->err = 0;
716 }
717
718 /*
719 * Feedback loop for MBA software controller (mba_sc)
720 *
721 * mba_sc is a feedback loop where we periodically read MBM counters and
722 * adjust the bandwidth percentage values via the IA32_MBA_THRTL_MSRs so
723 * that:
724 *
725 * current bandwidth(cur_bw) < user specified bandwidth(user_bw)
726 *
727 * This uses the MBM counters to measure the bandwidth and MBA throttle
728 * MSRs to control the bandwidth for a particular rdtgrp. It builds on the
729 * fact that resctrl rdtgroups have both monitoring and control.
730 *
731 * The frequency of the checks is 1s and we just tag along the MBM overflow
732 * timer. Having 1s interval makes the calculation of bandwidth simpler.
733 *
734 * Although MBA's goal is to restrict the bandwidth to a maximum, there may
735 * be a need to increase the bandwidth to avoid unnecessarily restricting
736 * the L2 <-> L3 traffic.
737 *
738 * Since MBA controls the L2 external bandwidth where as MBM measures the
739 * L3 external bandwidth the following sequence could lead to such a
740 * situation.
741 *
742 * Consider an rdtgroup which had high L3 <-> memory traffic in initial
743 * phases -> mba_sc kicks in and reduced bandwidth percentage values -> but
744 * after some time rdtgroup has mostly L2 <-> L3 traffic.
745 *
746 * In this case we may restrict the rdtgroup's L2 <-> L3 traffic as its
747 * throttle MSRs already have low percentage values. To avoid
748 * unnecessarily restricting such rdtgroups, we also increase the bandwidth.
749 */
750 static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_mon_domain *dom_mbm)
751 {
752 u32 closid, rmid, cur_msr_val, new_msr_val;
753 struct mbm_state *pmbm_data, *cmbm_data;
754 struct rdt_ctrl_domain *dom_mba;
755 struct rdt_resource *r_mba;
756 u32 cur_bw, user_bw, idx;
757 struct list_head *head;
758 struct rdtgroup *entry;
759
760 if (!is_mbm_local_enabled())
761 return;
762
763 r_mba = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl;
764
765 closid = rgrp->closid;
766 rmid = rgrp->mon.rmid;
767 idx = resctrl_arch_rmid_idx_encode(closid, rmid);
768 pmbm_data = &dom_mbm->mbm_local[idx];
769
770 dom_mba = get_ctrl_domain_from_cpu(smp_processor_id(), r_mba);
771 if (!dom_mba) {
772 pr_warn_once("Failure to get domain for MBA update\n");
773 return;
774 }
775
776 cur_bw = pmbm_data->prev_bw;
777 user_bw = dom_mba->mbps_val[closid];
778
779 /* MBA resource doesn't support CDP */
780 cur_msr_val = resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE);
781
782 /*
783 * For Ctrl groups read data from child monitor groups.
784 */
785 head = &rgrp->mon.crdtgrp_list;
786 list_for_each_entry(entry, head, mon.crdtgrp_list) {
787 cmbm_data = &dom_mbm->mbm_local[entry->mon.rmid];
788 cur_bw += cmbm_data->prev_bw;
789 }
790
791 /*
792 * Scale up/down the bandwidth linearly for the ctrl group. The
793 * bandwidth step is the bandwidth granularity specified by the
794 * hardware.
795 * Always increase throttling if current bandwidth is above the
796 * target set by user.
797 * But avoid thrashing up and down on every poll by checking
798 * whether a decrease in throttling is likely to push the group
799 * back over target. E.g. if currently throttling to 30% of bandwidth
800 * on a system with 10% granularity steps, check whether moving to
801 * 40% would go past the limit by multiplying current bandwidth by
802 * "(30 + 10) / 30".
803 */
804 if (cur_msr_val > r_mba->membw.min_bw && user_bw < cur_bw) {
805 new_msr_val = cur_msr_val - r_mba->membw.bw_gran;
806 } else if (cur_msr_val < MAX_MBA_BW &&
807 (user_bw > (cur_bw * (cur_msr_val + r_mba->membw.min_bw) / cur_msr_val))) {
808 new_msr_val = cur_msr_val + r_mba->membw.bw_gran;
809 } else {
810 return;
811 }
812
813 resctrl_arch_update_one(r_mba, dom_mba, closid, CDP_NONE, new_msr_val);
814 }
815
816 static void mbm_update(struct rdt_resource *r, struct rdt_mon_domain *d,
817 u32 closid, u32 rmid)
818 {
819 struct rmid_read rr = {0};
820
821 rr.r = r;
822 rr.d = d;
823
824 /*
825 * This is protected from concurrent reads from user
826 * as both the user and we hold the global mutex.
827 */
828 if (is_mbm_total_enabled()) {
829 rr.evtid = QOS_L3_MBM_TOTAL_EVENT_ID;
830 rr.val = 0;
831 rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
832 if (IS_ERR(rr.arch_mon_ctx)) {
833 pr_warn_ratelimited("Failed to allocate monitor context: %ld",
834 PTR_ERR(rr.arch_mon_ctx));
835 return;
836 }
837
838 __mon_event_count(closid, rmid, &rr);
839
840 resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
841 }
842 if (is_mbm_local_enabled()) {
843 rr.evtid = QOS_L3_MBM_LOCAL_EVENT_ID;
844 rr.val = 0;
845 rr.arch_mon_ctx = resctrl_arch_mon_ctx_alloc(rr.r, rr.evtid);
846 if (IS_ERR(rr.arch_mon_ctx)) {
847 pr_warn_ratelimited("Failed to allocate monitor context: %ld",
848 PTR_ERR(rr.arch_mon_ctx));
849 return;
850 }
851
852 __mon_event_count(closid, rmid, &rr);
853
854 /*
855 * Call the MBA software controller only for the
856 * control groups and when user has enabled
857 * the software controller explicitly.
858 */
859 if (is_mba_sc(NULL))
860 mbm_bw_count(closid, rmid, &rr);
861
862 resctrl_arch_mon_ctx_free(rr.r, rr.evtid, rr.arch_mon_ctx);
863 }
864 }
865
866 /*
867 * Handler to scan the limbo list and move the RMIDs
868 * to free list whose occupancy < threshold_occupancy.
869 */
870 void cqm_handle_limbo(struct work_struct *work)
871 {
872 unsigned long delay = msecs_to_jiffies(CQM_LIMBOCHECK_INTERVAL);
873 struct rdt_mon_domain *d;
874
875 cpus_read_lock();
876 mutex_lock(&rdtgroup_mutex);
877
878 d = container_of(work, struct rdt_mon_domain, cqm_limbo.work);
879
880 __check_limbo(d, false);
881
882 if (has_busy_rmid(d)) {
883 d->cqm_work_cpu = cpumask_any_housekeeping(&d->hdr.cpu_mask,
884 RESCTRL_PICK_ANY_CPU);
885 schedule_delayed_work_on(d->cqm_work_cpu, &d->cqm_limbo,
886 delay);
887 }
888
889 mutex_unlock(&rdtgroup_mutex);
890 cpus_read_unlock();
891 }
892
893 /**
894 * cqm_setup_limbo_handler() - Schedule the limbo handler to run for this
895 * domain.
896 * @dom: The domain the limbo handler should run for.
897 * @delay_ms: How far in the future the handler should run.
898 * @exclude_cpu: Which CPU the handler should not run on,
899 * RESCTRL_PICK_ANY_CPU to pick any CPU.
900 */
901 void cqm_setup_limbo_handler(struct rdt_mon_domain *dom, unsigned long delay_ms,
902 int exclude_cpu)
903 {
904 unsigned long delay = msecs_to_jiffies(delay_ms);
905 int cpu;
906
907 cpu = cpumask_any_housekeeping(&dom->hdr.cpu_mask, exclude_cpu);
908 dom->cqm_work_cpu = cpu;
909
910 if (cpu < nr_cpu_ids)
911 schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay);
912 }
913
914 void mbm_handle_overflow(struct work_struct *work)
915 {
916 unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL);
917 struct rdtgroup *prgrp, *crgrp;
918 struct rdt_mon_domain *d;
919 struct list_head *head;
920 struct rdt_resource *r;
921
922 cpus_read_lock();
923 mutex_lock(&rdtgroup_mutex);
924
925 /*
926 * If the filesystem has been unmounted this work no longer needs to
927 * run.
928 */
929 if (!resctrl_mounted || !resctrl_arch_mon_capable())
930 goto out_unlock;
931
932 r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
933 d = container_of(work, struct rdt_mon_domain, mbm_over.work);
934
935 list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
936 mbm_update(r, d, prgrp->closid, prgrp->mon.rmid);
937
938 head = &prgrp->mon.crdtgrp_list;
939 list_for_each_entry(crgrp, head, mon.crdtgrp_list)
940 mbm_update(r, d, crgrp->closid, crgrp->mon.rmid);
941
942 if (is_mba_sc(NULL))
943 update_mba_bw(prgrp, d);
944 }
945
946 /*
947 * Re-check for housekeeping CPUs. This allows the overflow handler to
948 * move off a nohz_full CPU quickly.
949 */
950 d->mbm_work_cpu = cpumask_any_housekeeping(&d->hdr.cpu_mask,
951 RESCTRL_PICK_ANY_CPU);
952 schedule_delayed_work_on(d->mbm_work_cpu, &d->mbm_over, delay);
953
954 out_unlock:
955 mutex_unlock(&rdtgroup_mutex);
956 cpus_read_unlock();
957 }
958
959 /**
960 * mbm_setup_overflow_handler() - Schedule the overflow handler to run for this
961 * domain.
962 * @dom: The domain the overflow handler should run for.
963 * @delay_ms: How far in the future the handler should run.
964 * @exclude_cpu: Which CPU the handler should not run on,
965 * RESCTRL_PICK_ANY_CPU to pick any CPU.
966 */
967 void mbm_setup_overflow_handler(struct rdt_mon_domain *dom, unsigned long delay_ms,
968 int exclude_cpu)
969 {
970 unsigned long delay = msecs_to_jiffies(delay_ms);
971 int cpu;
972
973 /*
974 * When a domain comes online there is no guarantee the filesystem is
975 * mounted. If not, there is no need to catch counter overflow.
976 */
977 if (!resctrl_mounted || !resctrl_arch_mon_capable())
978 return;
979 cpu = cpumask_any_housekeeping(&dom->hdr.cpu_mask, exclude_cpu);
980 dom->mbm_work_cpu = cpu;
981
982 if (cpu < nr_cpu_ids)
983 schedule_delayed_work_on(cpu, &dom->mbm_over, delay);
984 }
985
986 static int dom_data_init(struct rdt_resource *r)
987 {
988 u32 idx_limit = resctrl_arch_system_num_rmid_idx();
989 u32 num_closid = resctrl_arch_get_num_closid(r);
990 struct rmid_entry *entry = NULL;
991 int err = 0, i;
992 u32 idx;
993
994 mutex_lock(&rdtgroup_mutex);
995 if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
996 u32 *tmp;
997
998 /*
999 * If the architecture hasn't provided a sanitised value here,
1000 * this may result in larger arrays than necessary. Resctrl will
1001 * use a smaller system wide value based on the resources in
1002 * use.
1003 */
1004 tmp = kcalloc(num_closid, sizeof(*tmp), GFP_KERNEL);
1005 if (!tmp) {
1006 err = -ENOMEM;
1007 goto out_unlock;
1008 }
1009
1010 closid_num_dirty_rmid = tmp;
1011 }
1012
1013 rmid_ptrs = kcalloc(idx_limit, sizeof(struct rmid_entry), GFP_KERNEL);
1014 if (!rmid_ptrs) {
1015 if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
1016 kfree(closid_num_dirty_rmid);
1017 closid_num_dirty_rmid = NULL;
1018 }
1019 err = -ENOMEM;
1020 goto out_unlock;
1021 }
1022
1023 for (i = 0; i < idx_limit; i++) {
1024 entry = &rmid_ptrs[i];
1025 INIT_LIST_HEAD(&entry->list);
1026
1027 resctrl_arch_rmid_idx_decode(i, &entry->closid, &entry->rmid);
1028 list_add_tail(&entry->list, &rmid_free_lru);
1029 }
1030
1031 /*
1032 * RESCTRL_RESERVED_CLOSID and RESCTRL_RESERVED_RMID are special and
1033 * are always allocated. These are used for the rdtgroup_default
1034 * control group, which will be setup later in rdtgroup_init().
1035 */
1036 idx = resctrl_arch_rmid_idx_encode(RESCTRL_RESERVED_CLOSID,
1037 RESCTRL_RESERVED_RMID);
1038 entry = __rmid_entry(idx);
1039 list_del(&entry->list);
1040
1041 out_unlock:
1042 mutex_unlock(&rdtgroup_mutex);
1043
1044 return err;
1045 }
1046
1047 static void __exit dom_data_exit(void)
1048 {
1049 mutex_lock(&rdtgroup_mutex);
1050
1051 if (IS_ENABLED(CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID)) {
1052 kfree(closid_num_dirty_rmid);
1053 closid_num_dirty_rmid = NULL;
1054 }
1055
1056 kfree(rmid_ptrs);
1057 rmid_ptrs = NULL;
1058
1059 mutex_unlock(&rdtgroup_mutex);
1060 }
1061
1062 static struct mon_evt llc_occupancy_event = {
1063 .name = "llc_occupancy",
1064 .evtid = QOS_L3_OCCUP_EVENT_ID,
1065 };
1066
1067 static struct mon_evt mbm_total_event = {
1068 .name = "mbm_total_bytes",
1069 .evtid = QOS_L3_MBM_TOTAL_EVENT_ID,
1070 };
1071
1072 static struct mon_evt mbm_local_event = {
1073 .name = "mbm_local_bytes",
1074 .evtid = QOS_L3_MBM_LOCAL_EVENT_ID,
1075 };
1076
1077 /*
1078 * Initialize the event list for the resource.
1079 *
1080 * Note that MBM events are also part of RDT_RESOURCE_L3 resource
1081 * because as per the SDM the total and local memory bandwidth
1082 * are enumerated as part of L3 monitoring.
1083 */
1084 static void l3_mon_evt_init(struct rdt_resource *r)
1085 {
1086 INIT_LIST_HEAD(&r->evt_list);
1087
1088 if (is_llc_occupancy_enabled())
1089 list_add_tail(&llc_occupancy_event.list, &r->evt_list);
1090 if (is_mbm_total_enabled())
1091 list_add_tail(&mbm_total_event.list, &r->evt_list);
1092 if (is_mbm_local_enabled())
1093 list_add_tail(&mbm_local_event.list, &r->evt_list);
1094 }
1095
1096 /*
1097 * The power-on reset value of MSR_RMID_SNC_CONFIG is 0x1
1098 * which indicates that RMIDs are configured in legacy mode.
1099 * This mode is incompatible with Linux resctrl semantics
1100 * as RMIDs are partitioned between SNC nodes, which requires
1101 * a user to know which RMID is allocated to a task.
1102 * Clearing bit 0 reconfigures the RMID counters for use
1103 * in RMID sharing mode. This mode is better for Linux.
1104 * The RMID space is divided between all SNC nodes with the
1105 * RMIDs renumbered to start from zero in each node when
1106 * counting operations from tasks. Code to read the counters
1107 * must adjust RMID counter numbers based on SNC node. See
1108 * logical_rmid_to_physical_rmid() for code that does this.
1109 */
1110 void arch_mon_domain_online(struct rdt_resource *r, struct rdt_mon_domain *d)
1111 {
1112 if (snc_nodes_per_l3_cache > 1)
1113 msr_clear_bit(MSR_RMID_SNC_CONFIG, 0);
1114 }
1115
1116 /* CPU models that support MSR_RMID_SNC_CONFIG */
1117 static const struct x86_cpu_id snc_cpu_ids[] __initconst = {
1118 X86_MATCH_VFM(INTEL_ICELAKE_X, 0),
1119 X86_MATCH_VFM(INTEL_SAPPHIRERAPIDS_X, 0),
1120 X86_MATCH_VFM(INTEL_EMERALDRAPIDS_X, 0),
1121 X86_MATCH_VFM(INTEL_GRANITERAPIDS_X, 0),
1122 X86_MATCH_VFM(INTEL_ATOM_CRESTMONT_X, 0),
1123 {}
1124 };
1125
1126 /*
1127 * There isn't a simple hardware bit that indicates whether a CPU is running
1128 * in Sub-NUMA Cluster (SNC) mode. Infer the state by comparing the
1129 * number of CPUs sharing the L3 cache with CPU0 to the number of CPUs in
1130 * the same NUMA node as CPU0.
1131 * It is not possible to accurately determine SNC state if the system is
1132 * booted with a maxcpus=N parameter. That distorts the ratio of SNC nodes
1133 * to L3 caches. It will be OK if system is booted with hyperthreading
1134 * disabled (since this doesn't affect the ratio).
1135 */
1136 static __init int snc_get_config(void)
1137 {
1138 struct cacheinfo *ci = get_cpu_cacheinfo_level(0, RESCTRL_L3_CACHE);
1139 const cpumask_t *node0_cpumask;
1140 int cpus_per_node, cpus_per_l3;
1141 int ret;
1142
1143 if (!x86_match_cpu(snc_cpu_ids) || !ci)
1144 return 1;
1145
1146 cpus_read_lock();
1147 if (num_online_cpus() != num_present_cpus())
1148 pr_warn("Some CPUs offline, SNC detection may be incorrect\n");
1149 cpus_read_unlock();
1150
1151 node0_cpumask = cpumask_of_node(cpu_to_node(0));
1152
1153 cpus_per_node = cpumask_weight(node0_cpumask);
1154 cpus_per_l3 = cpumask_weight(&ci->shared_cpu_map);
1155
1156 if (!cpus_per_node || !cpus_per_l3)
1157 return 1;
1158
1159 ret = cpus_per_l3 / cpus_per_node;
1160
1161 /* sanity check: Only valid results are 1, 2, 3, 4 */
1162 switch (ret) {
1163 case 1:
1164 break;
1165 case 2 ... 4:
1166 pr_info("Sub-NUMA Cluster mode detected with %d nodes per L3 cache\n", ret);
1167 rdt_resources_all[RDT_RESOURCE_L3].r_resctrl.mon_scope = RESCTRL_L3_NODE;
1168 break;
1169 default:
1170 pr_warn("Ignore improbable SNC node count %d\n", ret);
1171 ret = 1;
1172 break;
1173 }
1174
1175 return ret;
1176 }
1177
1178 int __init rdt_get_mon_l3_config(struct rdt_resource *r)
1179 {
1180 unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset;
1181 struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
1182 unsigned int threshold;
1183 int ret;
1184
1185 snc_nodes_per_l3_cache = snc_get_config();
1186
1187 resctrl_rmid_realloc_limit = boot_cpu_data.x86_cache_size * 1024;
1188 hw_res->mon_scale = boot_cpu_data.x86_cache_occ_scale / snc_nodes_per_l3_cache;
1189 r->num_rmid = (boot_cpu_data.x86_cache_max_rmid + 1) / snc_nodes_per_l3_cache;
1190 hw_res->mbm_width = MBM_CNTR_WIDTH_BASE;
1191
1192 if (mbm_offset > 0 && mbm_offset <= MBM_CNTR_WIDTH_OFFSET_MAX)
1193 hw_res->mbm_width += mbm_offset;
1194 else if (mbm_offset > MBM_CNTR_WIDTH_OFFSET_MAX)
1195 pr_warn("Ignoring impossible MBM counter offset\n");
1196
1197 /*
1198 * A reasonable upper limit on the max threshold is the number
1199 * of lines tagged per RMID if all RMIDs have the same number of
1200 * lines tagged in the LLC.
1201 *
1202 * For a 35MB LLC and 56 RMIDs, this is ~1.8% of the LLC.
1203 */
1204 threshold = resctrl_rmid_realloc_limit / r->num_rmid;
1205
1206 /*
1207 * Because num_rmid may not be a power of two, round the value
1208 * to the nearest multiple of hw_res->mon_scale so it matches a
1209 * value the hardware will measure. mon_scale may not be a power of 2.
1210 */
1211 resctrl_rmid_realloc_threshold = resctrl_arch_round_mon_val(threshold);
1212
1213 ret = dom_data_init(r);
1214 if (ret)
1215 return ret;
1216
1217 if (rdt_cpu_has(X86_FEATURE_BMEC)) {
1218 u32 eax, ebx, ecx, edx;
1219
1220 /* Detect list of bandwidth sources that can be tracked */
1221 cpuid_count(0x80000020, 3, &eax, &ebx, &ecx, &edx);
1222 hw_res->mbm_cfg_mask = ecx & MAX_EVT_CONFIG_BITS;
1223
1224 if (rdt_cpu_has(X86_FEATURE_CQM_MBM_TOTAL)) {
1225 mbm_total_event.configurable = true;
1226 mbm_config_rftype_init("mbm_total_bytes_config");
1227 }
1228 if (rdt_cpu_has(X86_FEATURE_CQM_MBM_LOCAL)) {
1229 mbm_local_event.configurable = true;
1230 mbm_config_rftype_init("mbm_local_bytes_config");
1231 }
1232 }
1233
1234 l3_mon_evt_init(r);
1235
1236 r->mon_capable = true;
1237
1238 return 0;
1239 }
1240
1241 void __exit rdt_put_mon_l3_config(void)
1242 {
1243 dom_data_exit();
1244 }
1245
1246 void __init intel_rdt_mbm_apply_quirk(void)
1247 {
1248 int cf_index;
1249
1250 cf_index = (boot_cpu_data.x86_cache_max_rmid + 1) / 8 - 1;
1251 if (cf_index >= ARRAY_SIZE(mbm_cf_table)) {
1252 pr_info("No MBM correction factor available\n");
1253 return;
1254 }
1255
1256 mbm_cf_rmidthreshold = mbm_cf_table[cf_index].rmidthreshold;
1257 mbm_cf = mbm_cf_table[cf_index].cf;
1258 }
1259
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.