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6
7#include <linux/cpuhotplug.h>
8#include <linux/init.h>
9#include <linux/percpu.h>
10#include <linux/slab.h>
11#include <linux/suspend.h>
12
13#include <asm/asm-offsets.h>
14#include <asm/cacheflush.h>
15#include <asm/cacheops.h>
16#include <asm/idle.h>
17#include <asm/mips-cps.h>
18#include <asm/mipsmtregs.h>
19#include <asm/pm.h>
20#include <asm/pm-cps.h>
21#include <asm/smp-cps.h>
22#include <asm/uasm.h>
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38typedef unsigned (*cps_nc_entry_fn)(unsigned online, u32 *nc_ready_count);
39
40
41
42
43
44static DEFINE_PER_CPU_READ_MOSTLY(cps_nc_entry_fn[CPS_PM_STATE_COUNT],
45 nc_asm_enter);
46
47
48static DECLARE_BITMAP(state_support, CPS_PM_STATE_COUNT);
49
50
51
52
53
54static DEFINE_PER_CPU_ALIGNED(u32*, ready_count);
55
56
57static DEFINE_PER_CPU_ALIGNED(cpumask_t, online_coupled);
58
59
60
61
62
63static DEFINE_PER_CPU_ALIGNED(atomic_t, pm_barrier);
64
65
66DEFINE_PER_CPU_ALIGNED(struct mips_static_suspend_state, cps_cpu_state);
67
68
69static struct uasm_label labels[32];
70static struct uasm_reloc relocs[32];
71
72enum mips_reg {
73 zero, at, v0, v1, a0, a1, a2, a3,
74 t0, t1, t2, t3, t4, t5, t6, t7,
75 s0, s1, s2, s3, s4, s5, s6, s7,
76 t8, t9, k0, k1, gp, sp, fp, ra,
77};
78
79bool cps_pm_support_state(enum cps_pm_state state)
80{
81 return test_bit(state, state_support);
82}
83
84static void coupled_barrier(atomic_t *a, unsigned online)
85{
86
87
88
89
90
91
92 if (!coupled_coherence)
93 return;
94
95 smp_mb__before_atomic();
96 atomic_inc(a);
97
98 while (atomic_read(a) < online)
99 cpu_relax();
100
101 if (atomic_inc_return(a) == online * 2) {
102 atomic_set(a, 0);
103 return;
104 }
105
106 while (atomic_read(a) > online)
107 cpu_relax();
108}
109
110int cps_pm_enter_state(enum cps_pm_state state)
111{
112 unsigned cpu = smp_processor_id();
113 unsigned core = cpu_core(¤t_cpu_data);
114 unsigned online, left;
115 cpumask_t *coupled_mask = this_cpu_ptr(&online_coupled);
116 u32 *core_ready_count, *nc_core_ready_count;
117 void *nc_addr;
118 cps_nc_entry_fn entry;
119 struct core_boot_config *core_cfg;
120 struct vpe_boot_config *vpe_cfg;
121
122
123 entry = per_cpu(nc_asm_enter, core)[state];
124 if (!entry)
125 return -EINVAL;
126
127
128#if defined(CONFIG_MIPS_MT) || defined(CONFIG_CPU_MIPSR6)
129 if (cpu_online(cpu)) {
130 cpumask_and(coupled_mask, cpu_online_mask,
131 &cpu_sibling_map[cpu]);
132 online = cpumask_weight(coupled_mask);
133 cpumask_clear_cpu(cpu, coupled_mask);
134 } else
135#endif
136 {
137 cpumask_clear(coupled_mask);
138 online = 1;
139 }
140
141
142 if (IS_ENABLED(CONFIG_CPU_PM) && state == CPS_PM_POWER_GATED) {
143
144 if (!mips_cps_smp_in_use())
145 return -EINVAL;
146
147 core_cfg = &mips_cps_core_bootcfg[core];
148 vpe_cfg = &core_cfg->vpe_config[cpu_vpe_id(¤t_cpu_data)];
149 vpe_cfg->pc = (unsigned long)mips_cps_pm_restore;
150 vpe_cfg->gp = (unsigned long)current_thread_info();
151 vpe_cfg->sp = 0;
152 }
153
154
155 cpumask_clear_cpu(cpu, &cpu_coherent_mask);
156 smp_mb__after_atomic();
157
158
159 core_ready_count = per_cpu(ready_count, core);
160 nc_addr = kmap_noncoherent(virt_to_page(core_ready_count),
161 (unsigned long)core_ready_count);
162 nc_addr += ((unsigned long)core_ready_count & ~PAGE_MASK);
163 nc_core_ready_count = nc_addr;
164
165
166 WRITE_ONCE(*nc_core_ready_count, 0);
167 coupled_barrier(&per_cpu(pm_barrier, core), online);
168
169
170 left = entry(online, nc_core_ready_count);
171
172
173 kunmap_noncoherent();
174
175
176 cpumask_set_cpu(cpu, &cpu_coherent_mask);
177
178
179
180
181
182
183
184
185
186 if (coupled_coherence && (state == CPS_PM_NC_WAIT) && (left == online))
187 arch_send_call_function_ipi_mask(coupled_mask);
188
189 return 0;
190}
191
192static void cps_gen_cache_routine(u32 **pp, struct uasm_label **pl,
193 struct uasm_reloc **pr,
194 const struct cache_desc *cache,
195 unsigned op, int lbl)
196{
197 unsigned cache_size = cache->ways << cache->waybit;
198 unsigned i;
199 const unsigned unroll_lines = 32;
200
201
202 if (cache->flags & MIPS_CACHE_NOT_PRESENT)
203 return;
204
205
206 UASM_i_LA(pp, t0, (long)CKSEG0);
207
208
209 if (cache_size < 0x8000)
210 uasm_i_addiu(pp, t1, t0, cache_size);
211 else
212 UASM_i_LA(pp, t1, (long)(CKSEG0 + cache_size));
213
214
215 uasm_build_label(pl, *pp, lbl);
216
217
218 for (i = 0; i < unroll_lines; i++) {
219 if (cpu_has_mips_r6) {
220 uasm_i_cache(pp, op, 0, t0);
221 uasm_i_addiu(pp, t0, t0, cache->linesz);
222 } else {
223 uasm_i_cache(pp, op, i * cache->linesz, t0);
224 }
225 }
226
227 if (!cpu_has_mips_r6)
228
229 uasm_i_addiu(pp, t0, t0, unroll_lines * cache->linesz);
230
231
232 uasm_il_bne(pp, pr, t0, t1, lbl);
233 uasm_i_nop(pp);
234}
235
236static int cps_gen_flush_fsb(u32 **pp, struct uasm_label **pl,
237 struct uasm_reloc **pr,
238 const struct cpuinfo_mips *cpu_info,
239 int lbl)
240{
241 unsigned i, fsb_size = 8;
242 unsigned num_loads = (fsb_size * 3) / 2;
243 unsigned line_stride = 2;
244 unsigned line_size = cpu_info->dcache.linesz;
245 unsigned perf_counter, perf_event;
246 unsigned revision = cpu_info->processor_id & PRID_REV_MASK;
247
248
249
250
251
252 switch (__get_cpu_type(cpu_info->cputype)) {
253 case CPU_INTERAPTIV:
254 perf_counter = 1;
255 perf_event = 51;
256 break;
257
258 case CPU_PROAPTIV:
259
260 if (revision >= PRID_REV_ENCODE_332(1, 1, 0))
261 return 0;
262
263
264 return -1;
265
266 default:
267
268 return 0;
269 }
270
271
272
273
274
275
276
277
278 uasm_i_mfc0(pp, t2, 25, (perf_counter * 2) + 0);
279 uasm_i_mfc0(pp, t3, 25, (perf_counter * 2) + 1);
280
281
282 uasm_i_addiu(pp, t0, zero, (perf_event << 5) | 0xf);
283 uasm_i_mtc0(pp, t0, 25, (perf_counter * 2) + 0);
284 uasm_i_ehb(pp);
285 uasm_i_mtc0(pp, zero, 25, (perf_counter * 2) + 1);
286 uasm_i_ehb(pp);
287
288
289 UASM_i_LA(pp, t0, (long)CKSEG0);
290
291
292 uasm_build_label(pl, *pp, lbl);
293
294
295 for (i = 0; i < num_loads; i++)
296 uasm_i_lw(pp, zero, i * line_size * line_stride, t0);
297
298
299
300
301
302 for (i = 0; i < num_loads; i++) {
303 uasm_i_cache(pp, Hit_Invalidate_D,
304 i * line_size * line_stride, t0);
305 uasm_i_cache(pp, Hit_Writeback_Inv_SD,
306 i * line_size * line_stride, t0);
307 }
308
309
310 uasm_i_sync(pp, STYPE_SYNC);
311 uasm_i_ehb(pp);
312
313
314 uasm_i_mfc0(pp, t1, 25, (perf_counter * 2) + 1);
315
316
317 uasm_il_beqz(pp, pr, t1, lbl);
318 uasm_i_nop(pp);
319
320
321 uasm_i_mtc0(pp, t2, 25, (perf_counter * 2) + 0);
322 uasm_i_ehb(pp);
323 uasm_i_mtc0(pp, t3, 25, (perf_counter * 2) + 1);
324 uasm_i_ehb(pp);
325
326 return 0;
327}
328
329static void cps_gen_set_top_bit(u32 **pp, struct uasm_label **pl,
330 struct uasm_reloc **pr,
331 unsigned r_addr, int lbl)
332{
333 uasm_i_lui(pp, t0, uasm_rel_hi(0x80000000));
334 uasm_build_label(pl, *pp, lbl);
335 uasm_i_ll(pp, t1, 0, r_addr);
336 uasm_i_or(pp, t1, t1, t0);
337 uasm_i_sc(pp, t1, 0, r_addr);
338 uasm_il_beqz(pp, pr, t1, lbl);
339 uasm_i_nop(pp);
340}
341
342static void *cps_gen_entry_code(unsigned cpu, enum cps_pm_state state)
343{
344 struct uasm_label *l = labels;
345 struct uasm_reloc *r = relocs;
346 u32 *buf, *p;
347 const unsigned r_online = a0;
348 const unsigned r_nc_count = a1;
349 const unsigned r_pcohctl = t7;
350 const unsigned max_instrs = 256;
351 unsigned cpc_cmd;
352 int err;
353 enum {
354 lbl_incready = 1,
355 lbl_poll_cont,
356 lbl_secondary_hang,
357 lbl_disable_coherence,
358 lbl_flush_fsb,
359 lbl_invicache,
360 lbl_flushdcache,
361 lbl_hang,
362 lbl_set_cont,
363 lbl_secondary_cont,
364 lbl_decready,
365 };
366
367
368 p = buf = kcalloc(max_instrs, sizeof(u32), GFP_KERNEL);
369 if (!buf)
370 return NULL;
371
372
373 memset(labels, 0, sizeof(labels));
374 memset(relocs, 0, sizeof(relocs));
375
376 if (IS_ENABLED(CONFIG_CPU_PM) && state == CPS_PM_POWER_GATED) {
377
378 if (!mips_cps_smp_in_use())
379 goto out_err;
380
381
382
383
384
385
386 UASM_i_LA(&p, t0, (long)mips_cps_pm_save);
387 uasm_i_jalr(&p, v0, t0);
388 uasm_i_nop(&p);
389 }
390
391
392
393
394
395
396 UASM_i_LA(&p, r_pcohctl, (long)addr_gcr_cl_coherence());
397
398 if (coupled_coherence) {
399
400 uasm_i_sync(&p, STYPE_SYNC_MB);
401 uasm_build_label(&l, p, lbl_incready);
402 uasm_i_ll(&p, t1, 0, r_nc_count);
403 uasm_i_addiu(&p, t2, t1, 1);
404 uasm_i_sc(&p, t2, 0, r_nc_count);
405 uasm_il_beqz(&p, &r, t2, lbl_incready);
406 uasm_i_addiu(&p, t1, t1, 1);
407
408
409 uasm_i_sync(&p, STYPE_SYNC_MB);
410
411
412
413
414
415 uasm_il_beq(&p, &r, t1, r_online, lbl_disable_coherence);
416 uasm_i_nop(&p);
417
418 if (state < CPS_PM_POWER_GATED) {
419
420
421
422
423
424
425 uasm_i_addiu(&p, t1, zero, -1);
426 uasm_build_label(&l, p, lbl_poll_cont);
427 uasm_i_lw(&p, t0, 0, r_nc_count);
428 uasm_il_bltz(&p, &r, t0, lbl_secondary_cont);
429 uasm_i_ehb(&p);
430 if (cpu_has_mipsmt)
431 uasm_i_yield(&p, zero, t1);
432 uasm_il_b(&p, &r, lbl_poll_cont);
433 uasm_i_nop(&p);
434 } else {
435
436
437
438
439 if (cpu_has_mipsmt) {
440
441 uasm_i_addiu(&p, t0, zero, TCHALT_H);
442 uasm_i_mtc0(&p, t0, 2, 4);
443 } else if (cpu_has_vp) {
444
445 unsigned int vpe_id;
446
447 vpe_id = cpu_vpe_id(&cpu_data[cpu]);
448 uasm_i_addiu(&p, t0, zero, 1 << vpe_id);
449 UASM_i_LA(&p, t1, (long)addr_cpc_cl_vp_stop());
450 uasm_i_sw(&p, t0, 0, t1);
451 } else {
452 BUG();
453 }
454 uasm_build_label(&l, p, lbl_secondary_hang);
455 uasm_il_b(&p, &r, lbl_secondary_hang);
456 uasm_i_nop(&p);
457 }
458 }
459
460
461
462
463
464
465 uasm_build_label(&l, p, lbl_disable_coherence);
466
467
468 cps_gen_cache_routine(&p, &l, &r, &cpu_data[cpu].icache,
469 Index_Invalidate_I, lbl_invicache);
470
471
472 cps_gen_cache_routine(&p, &l, &r, &cpu_data[cpu].dcache,
473 Index_Writeback_Inv_D, lbl_flushdcache);
474
475
476 uasm_i_sync(&p, STYPE_SYNC);
477 uasm_i_ehb(&p);
478
479 if (mips_cm_revision() < CM_REV_CM3) {
480
481
482
483
484
485 uasm_i_addiu(&p, t0, zero, 1 << cpu_core(&cpu_data[cpu]));
486 uasm_i_sw(&p, t0, 0, r_pcohctl);
487 uasm_i_lw(&p, t0, 0, r_pcohctl);
488
489
490 uasm_i_sync(&p, STYPE_SYNC);
491 uasm_i_ehb(&p);
492 }
493
494
495 uasm_i_sw(&p, zero, 0, r_pcohctl);
496 uasm_i_lw(&p, t0, 0, r_pcohctl);
497
498 if (state >= CPS_PM_CLOCK_GATED) {
499 err = cps_gen_flush_fsb(&p, &l, &r, &cpu_data[cpu],
500 lbl_flush_fsb);
501 if (err)
502 goto out_err;
503
504
505 switch (state) {
506 case CPS_PM_CLOCK_GATED:
507 cpc_cmd = CPC_Cx_CMD_CLOCKOFF;
508 break;
509 case CPS_PM_POWER_GATED:
510 cpc_cmd = CPC_Cx_CMD_PWRDOWN;
511 break;
512 default:
513 BUG();
514 goto out_err;
515 }
516
517
518 UASM_i_LA(&p, t0, (long)addr_cpc_cl_cmd());
519 uasm_i_addiu(&p, t1, zero, cpc_cmd);
520 uasm_i_sw(&p, t1, 0, t0);
521
522 if (state == CPS_PM_POWER_GATED) {
523
524 uasm_build_label(&l, p, lbl_hang);
525 uasm_il_b(&p, &r, lbl_hang);
526 uasm_i_nop(&p);
527
528
529
530
531
532
533 goto gen_done;
534 }
535
536
537 uasm_i_sync(&p, STYPE_SYNC);
538 uasm_i_ehb(&p);
539 }
540
541 if (state == CPS_PM_NC_WAIT) {
542
543
544
545
546
547 if (coupled_coherence)
548 cps_gen_set_top_bit(&p, &l, &r, r_nc_count,
549 lbl_set_cont);
550
551
552
553
554
555
556 uasm_build_label(&l, p, lbl_secondary_cont);
557
558
559 uasm_i_wait(&p, 0);
560 }
561
562
563
564
565
566
567 uasm_i_addiu(&p, t0, zero, mips_cm_revision() < CM_REV_CM3
568 ? CM_GCR_Cx_COHERENCE_COHDOMAINEN
569 : CM3_GCR_Cx_COHERENCE_COHEN);
570
571 uasm_i_sw(&p, t0, 0, r_pcohctl);
572 uasm_i_lw(&p, t0, 0, r_pcohctl);
573
574
575 uasm_i_sync(&p, STYPE_SYNC);
576 uasm_i_ehb(&p);
577
578 if (coupled_coherence && (state == CPS_PM_NC_WAIT)) {
579
580 uasm_build_label(&l, p, lbl_decready);
581 uasm_i_sync(&p, STYPE_SYNC_MB);
582 uasm_i_ll(&p, t1, 0, r_nc_count);
583 uasm_i_addiu(&p, t2, t1, -1);
584 uasm_i_sc(&p, t2, 0, r_nc_count);
585 uasm_il_beqz(&p, &r, t2, lbl_decready);
586 uasm_i_andi(&p, v0, t1, (1 << fls(smp_num_siblings)) - 1);
587
588
589 uasm_i_sync(&p, STYPE_SYNC_MB);
590 }
591
592 if (coupled_coherence && (state == CPS_PM_CLOCK_GATED)) {
593
594
595
596
597
598 cps_gen_set_top_bit(&p, &l, &r, r_nc_count, lbl_set_cont);
599
600
601
602
603
604
605
606
607
608 uasm_build_label(&l, p, lbl_secondary_cont);
609
610
611 uasm_i_sync(&p, STYPE_SYNC_MB);
612 }
613
614
615 uasm_i_jr(&p, ra);
616 uasm_i_nop(&p);
617
618gen_done:
619
620 BUG_ON((p - buf) > max_instrs);
621 BUG_ON((l - labels) > ARRAY_SIZE(labels));
622 BUG_ON((r - relocs) > ARRAY_SIZE(relocs));
623
624
625 uasm_resolve_relocs(relocs, labels);
626
627
628 local_flush_icache_range((unsigned long)buf, (unsigned long)p);
629
630 return buf;
631out_err:
632 kfree(buf);
633 return NULL;
634}
635
636static int cps_pm_online_cpu(unsigned int cpu)
637{
638 enum cps_pm_state state;
639 unsigned core = cpu_core(&cpu_data[cpu]);
640 void *entry_fn, *core_rc;
641
642 for (state = CPS_PM_NC_WAIT; state < CPS_PM_STATE_COUNT; state++) {
643 if (per_cpu(nc_asm_enter, core)[state])
644 continue;
645 if (!test_bit(state, state_support))
646 continue;
647
648 entry_fn = cps_gen_entry_code(cpu, state);
649 if (!entry_fn) {
650 pr_err("Failed to generate core %u state %u entry\n",
651 core, state);
652 clear_bit(state, state_support);
653 }
654
655 per_cpu(nc_asm_enter, core)[state] = entry_fn;
656 }
657
658 if (!per_cpu(ready_count, core)) {
659 core_rc = kmalloc(sizeof(u32), GFP_KERNEL);
660 if (!core_rc) {
661 pr_err("Failed allocate core %u ready_count\n", core);
662 return -ENOMEM;
663 }
664 per_cpu(ready_count, core) = core_rc;
665 }
666
667 return 0;
668}
669
670static int cps_pm_power_notifier(struct notifier_block *this,
671 unsigned long event, void *ptr)
672{
673 unsigned int stat;
674
675 switch (event) {
676 case PM_SUSPEND_PREPARE:
677 stat = read_cpc_cl_stat_conf();
678
679
680
681
682
683
684
685
686
687
688 if (stat & CPC_Cx_STAT_CONF_EJTAG_PROBE) {
689 pr_warn("JTAG probe is connected - abort suspend\n");
690 return NOTIFY_BAD;
691 }
692 return NOTIFY_DONE;
693 default:
694 return NOTIFY_DONE;
695 }
696}
697
698static int __init cps_pm_init(void)
699{
700
701 if (!mips_cm_present()) {
702 pr_warn("pm-cps: no CM, non-coherent states unavailable\n");
703 return 0;
704 }
705
706
707
708
709
710
711 if (cpu_wait == r4k_wait_irqoff)
712 set_bit(CPS_PM_NC_WAIT, state_support);
713 else
714 pr_warn("pm-cps: non-coherent wait unavailable\n");
715
716
717 if (mips_cpc_present()) {
718
719 if (read_cpc_cl_stat_conf() & CPC_Cx_STAT_CONF_CLKGAT_IMPL)
720 set_bit(CPS_PM_CLOCK_GATED, state_support);
721 else
722 pr_warn("pm-cps: CPC does not support clock gating\n");
723
724
725 if (mips_cps_smp_in_use())
726 set_bit(CPS_PM_POWER_GATED, state_support);
727 else
728 pr_warn("pm-cps: CPS SMP not in use, power gating unavailable\n");
729 } else {
730 pr_warn("pm-cps: no CPC, clock & power gating unavailable\n");
731 }
732
733 pm_notifier(cps_pm_power_notifier, 0);
734
735 return cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "mips/cps_pm:online",
736 cps_pm_online_cpu, NULL);
737}
738arch_initcall(cps_pm_init);
739