1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2013 Imagination Technologies
4 * Author: Paul Burton <paul.burton@mips.com>
5 */
6
7#include <linux/cpu.h>
8#include <linux/delay.h>
9#include <linux/io.h>
10#include <linux/memblock.h>
11#include <linux/sched/task_stack.h>
12#include <linux/sched/hotplug.h>
13#include <linux/slab.h>
14#include <linux/smp.h>
15#include <linux/types.h>
16#include <linux/irq.h>
17
18#include <asm/bcache.h>
19#include <asm/mips-cps.h>
20#include <asm/mips_mt.h>
21#include <asm/mipsregs.h>
22#include <asm/pm-cps.h>
23#include <asm/r4kcache.h>
24#include <asm/regdef.h>
25#include <asm/smp.h>
26#include <asm/smp-cps.h>
27#include <asm/time.h>
28#include <asm/uasm.h>
29
30#define BEV_VEC_SIZE 0x500
31#define BEV_VEC_ALIGN 0x1000
32
33enum label_id {
34 label_not_nmi = 1,
35};
36
37UASM_L_LA(_not_nmi)
38
39static u64 core_entry_reg;
40static phys_addr_t cps_vec_pa;
41
42struct cluster_boot_config *mips_cps_cluster_bootcfg;
43
44static void power_up_other_cluster(unsigned int cluster)
45{
46 u32 stat, seq_state;
47 unsigned int timeout;
48
49 mips_cm_lock_other(cluster, CM_GCR_Cx_OTHER_CORE_CM, 0,
50 CM_GCR_Cx_OTHER_BLOCK_LOCAL);
51 stat = read_cpc_co_stat_conf();
52 mips_cm_unlock_other();
53
54 seq_state = stat & CPC_Cx_STAT_CONF_SEQSTATE;
55 seq_state >>= __ffs(CPC_Cx_STAT_CONF_SEQSTATE);
56 if (seq_state == CPC_Cx_STAT_CONF_SEQSTATE_U5)
57 return;
58
59 /* Set endianness & power up the CM */
60 mips_cm_lock_other(cluster, 0, 0, CM_GCR_Cx_OTHER_BLOCK_GLOBAL);
61 write_cpc_redir_sys_config(IS_ENABLED(CONFIG_CPU_BIG_ENDIAN));
62 write_cpc_redir_pwrup_ctl(1);
63 mips_cm_unlock_other();
64
65 /* Wait for the CM to start up */
66 timeout = 1000;
67 mips_cm_lock_other(cluster, CM_GCR_Cx_OTHER_CORE_CM, 0,
68 CM_GCR_Cx_OTHER_BLOCK_LOCAL);
69 while (1) {
70 stat = read_cpc_co_stat_conf();
71 seq_state = stat & CPC_Cx_STAT_CONF_SEQSTATE;
72 seq_state >>= __ffs(CPC_Cx_STAT_CONF_SEQSTATE);
73 if (seq_state == CPC_Cx_STAT_CONF_SEQSTATE_U5)
74 break;
75
76 if (timeout) {
77 mdelay(1);
78 timeout--;
79 } else {
80 pr_warn("Waiting for cluster %u CM to power up... STAT_CONF=0x%x\n",
81 cluster, stat);
82 mdelay(1000);
83 }
84 }
85
86 mips_cm_unlock_other();
87}
88
89static unsigned __init core_vpe_count(unsigned int cluster, unsigned core)
90{
91 return min(smp_max_threads, mips_cps_numvps(cluster, core));
92}
93
94static void __init *mips_cps_build_core_entry(void *addr)
95{
96 extern void (*nmi_handler)(void);
97 u32 *p = addr;
98 u32 val;
99 struct uasm_label labels[2];
100 struct uasm_reloc relocs[2];
101 struct uasm_label *l = labels;
102 struct uasm_reloc *r = relocs;
103
104 memset(labels, 0, sizeof(labels));
105 memset(relocs, 0, sizeof(relocs));
106
107 uasm_i_mfc0(&p, GPR_K0, C0_STATUS);
108 UASM_i_LA(&p, GPR_T9, ST0_NMI);
109 uasm_i_and(&p, GPR_K0, GPR_K0, GPR_T9);
110
111 uasm_il_bnez(&p, &r, GPR_K0, label_not_nmi);
112 uasm_i_nop(&p);
113 UASM_i_LA(&p, GPR_K0, (long)&nmi_handler);
114
115 uasm_l_not_nmi(&l, p);
116
117 val = CAUSEF_IV;
118 uasm_i_lui(&p, GPR_K0, val >> 16);
119 uasm_i_ori(&p, GPR_K0, GPR_K0, val & 0xffff);
120 uasm_i_mtc0(&p, GPR_K0, C0_CAUSE);
121 val = ST0_CU1 | ST0_CU0 | ST0_BEV | ST0_KX_IF_64;
122 uasm_i_lui(&p, GPR_K0, val >> 16);
123 uasm_i_ori(&p, GPR_K0, GPR_K0, val & 0xffff);
124 uasm_i_mtc0(&p, GPR_K0, C0_STATUS);
125 uasm_i_ehb(&p);
126 uasm_i_ori(&p, GPR_A0, 0, read_c0_config() & CONF_CM_CMASK);
127 UASM_i_LA(&p, GPR_A1, (long)mips_gcr_base);
128#if defined(KBUILD_64BIT_SYM32) || defined(CONFIG_32BIT)
129 UASM_i_LA(&p, GPR_T9, CKSEG1ADDR(__pa_symbol(mips_cps_core_boot)));
130#else
131 UASM_i_LA(&p, GPR_T9, TO_UNCAC(__pa_symbol(mips_cps_core_boot)));
132#endif
133 uasm_i_jr(&p, GPR_T9);
134 uasm_i_nop(&p);
135
136 uasm_resolve_relocs(relocs, labels);
137
138 return p;
139}
140
141static bool __init check_64bit_reset(void)
142{
143 bool cx_64bit_reset = false;
144
145 mips_cm_lock_other(0, 0, 0, CM_GCR_Cx_OTHER_BLOCK_LOCAL);
146 write_gcr_co_reset64_base(CM_GCR_Cx_RESET64_BASE_BEVEXCBASE);
147 if ((read_gcr_co_reset64_base() & CM_GCR_Cx_RESET64_BASE_BEVEXCBASE) ==
148 CM_GCR_Cx_RESET64_BASE_BEVEXCBASE)
149 cx_64bit_reset = true;
150 mips_cm_unlock_other();
151
152 return cx_64bit_reset;
153}
154
155static int __init allocate_cps_vecs(void)
156{
157 /* Try to allocate in KSEG1 first */
158 cps_vec_pa = memblock_phys_alloc_range(BEV_VEC_SIZE, BEV_VEC_ALIGN,
159 0x0, CSEGX_SIZE - 1);
160
161 if (cps_vec_pa)
162 core_entry_reg = CKSEG1ADDR(cps_vec_pa) &
163 CM_GCR_Cx_RESET_BASE_BEVEXCBASE;
164
165 if (!cps_vec_pa && mips_cm_is64) {
166 phys_addr_t end;
167
168 if (check_64bit_reset()) {
169 pr_info("VP Local Reset Exception Base support 47 bits address\n");
170 end = MEMBLOCK_ALLOC_ANYWHERE;
171 } else {
172 end = SZ_4G - 1;
173 }
174 cps_vec_pa = memblock_phys_alloc_range(BEV_VEC_SIZE, BEV_VEC_ALIGN, 0, end);
175 if (cps_vec_pa) {
176 if (check_64bit_reset())
177 core_entry_reg = (cps_vec_pa & CM_GCR_Cx_RESET64_BASE_BEVEXCBASE) |
178 CM_GCR_Cx_RESET_BASE_MODE;
179 else
180 core_entry_reg = (cps_vec_pa & CM_GCR_Cx_RESET_BASE_BEVEXCBASE) |
181 CM_GCR_Cx_RESET_BASE_MODE;
182 }
183 }
184
185 if (!cps_vec_pa)
186 return -ENOMEM;
187
188 return 0;
189}
190
191static void __init setup_cps_vecs(void)
192{
193 void *cps_vec;
194
195 cps_vec = (void *)CKSEG1ADDR_OR_64BIT(cps_vec_pa);
196 mips_cps_build_core_entry(addr: cps_vec);
197
198 memcpy(cps_vec + 0x200, &excep_tlbfill, 0x80);
199 memcpy(cps_vec + 0x280, &excep_xtlbfill, 0x80);
200 memcpy(cps_vec + 0x300, &excep_cache, 0x80);
201 memcpy(cps_vec + 0x380, &excep_genex, 0x80);
202 memcpy(cps_vec + 0x400, &excep_intex, 0x80);
203 memcpy(cps_vec + 0x480, &excep_ejtag, 0x80);
204
205 /* Make sure no prefetched data in cache */
206 blast_inv_dcache_range(CKSEG0ADDR_OR_64BIT(cps_vec_pa), CKSEG0ADDR_OR_64BIT(cps_vec_pa) + BEV_VEC_SIZE);
207 bc_inv(CKSEG0ADDR_OR_64BIT(cps_vec_pa), BEV_VEC_SIZE);
208 __sync();
209}
210
211static void __init cps_smp_setup(void)
212{
213 unsigned int nclusters, ncores, nvpes, core_vpes;
214 int cl, c, v;
215
216 /* Detect & record VPE topology */
217 nvpes = 0;
218 nclusters = mips_cps_numclusters();
219 pr_info("%s topology ", cpu_has_mips_r6 ? "VP" : "VPE");
220 for (cl = 0; cl < nclusters; cl++) {
221 if (cl > 0)
222 pr_cont(",");
223 pr_cont("{");
224
225 if (mips_cm_revision() >= CM_REV_CM3_5)
226 power_up_other_cluster(cl);
227
228 ncores = mips_cps_numcores(cl);
229 for (c = 0; c < ncores; c++) {
230 core_vpes = core_vpe_count(cluster: cl, core: c);
231
232 if (c > 0)
233 pr_cont(",");
234 pr_cont("%u", core_vpes);
235
236 /* Use the number of VPEs in cluster 0 core 0 for smp_num_siblings */
237 if (!cl && !c)
238 smp_num_siblings = core_vpes;
239 cpumask_set_cpu(cpu: nvpes, dstp: &__cpu_primary_thread_mask);
240
241 for (v = 0; v < min_t(int, core_vpes, NR_CPUS - nvpes); v++) {
242 cpu_set_cluster(&cpu_data[nvpes + v], cl);
243 cpu_set_core(&cpu_data[nvpes + v], c);
244 cpu_set_vpe_id(&cpu_data[nvpes + v], v);
245 }
246
247 nvpes += core_vpes;
248 }
249
250 pr_cont("}");
251 }
252 pr_cont(" total %u\n", nvpes);
253
254 /* Indicate present CPUs (CPU being synonymous with VPE) */
255 for (v = 0; v < min_t(unsigned, nvpes, NR_CPUS); v++) {
256 set_cpu_possible(cpu: v, possible: true);
257 set_cpu_present(v, true);
258 __cpu_number_map[v] = v;
259 __cpu_logical_map[v] = v;
260 }
261
262 /* Set a coherent default CCA (CWB) */
263 change_c0_config(CONF_CM_CMASK, 0x5);
264
265 /* Initialise core 0 */
266 mips_cps_core_init();
267
268 /* Make core 0 coherent with everything */
269 write_gcr_cl_coherence(0xff);
270
271 if (allocate_cps_vecs())
272 pr_err("Failed to allocate CPS vectors\n");
273
274 if (core_entry_reg && mips_cm_revision() >= CM_REV_CM3)
275 write_gcr_bev_base(core_entry_reg);
276
277#ifdef CONFIG_MIPS_MT_FPAFF
278 /* If we have an FPU, enroll ourselves in the FPU-full mask */
279 if (cpu_has_fpu)
280 cpumask_set_cpu(0, &mt_fpu_cpumask);
281#endif /* CONFIG_MIPS_MT_FPAFF */
282}
283
284unsigned long calibrate_delay_is_known(void)
285{
286 int first_cpu_cluster = 0;
287
288 /* The calibration has to be done on the primary CPU of the cluster */
289 if (mips_cps_first_online_in_cluster(&first_cpu_cluster))
290 return 0;
291
292 return cpu_data[first_cpu_cluster].udelay_val;
293}
294
295static void __init cps_prepare_cpus(unsigned int max_cpus)
296{
297 unsigned int nclusters, ncores, core_vpes, nvpe = 0, c, cl, cca;
298 bool cca_unsuitable, cores_limited;
299 struct cluster_boot_config *cluster_bootcfg;
300 struct core_boot_config *core_bootcfg;
301
302 mips_mt_set_cpuoptions();
303
304 if (!core_entry_reg) {
305 pr_err("core_entry address unsuitable, disabling smp-cps\n");
306 goto err_out;
307 }
308
309 /* Detect whether the CCA is unsuited to multi-core SMP */
310 cca = read_c0_config() & CONF_CM_CMASK;
311 switch (cca) {
312 case 0x4: /* CWBE */
313 case 0x5: /* CWB */
314 /* The CCA is coherent, multi-core is fine */
315 cca_unsuitable = false;
316 break;
317
318 default:
319 /* CCA is not coherent, multi-core is not usable */
320 cca_unsuitable = true;
321 }
322
323 /* Warn the user if the CCA prevents multi-core */
324 cores_limited = false;
325 if (cca_unsuitable || cpu_has_dc_aliases) {
326 for_each_present_cpu(c) {
327 if (cpus_are_siblings(smp_processor_id(), c))
328 continue;
329
330 set_cpu_present(c, false);
331 cores_limited = true;
332 }
333 }
334 if (cores_limited)
335 pr_warn("Using only one core due to %s%s%s\n",
336 cca_unsuitable ? "unsuitable CCA" : "",
337 (cca_unsuitable && cpu_has_dc_aliases) ? " & " : "",
338 cpu_has_dc_aliases ? "dcache aliasing" : "");
339
340 setup_cps_vecs();
341
342 /* Allocate cluster boot configuration structs */
343 nclusters = mips_cps_numclusters();
344 mips_cps_cluster_bootcfg = kcalloc(nclusters,
345 sizeof(*mips_cps_cluster_bootcfg),
346 GFP_KERNEL);
347 if (!mips_cps_cluster_bootcfg)
348 goto err_out;
349
350 if (nclusters > 1)
351 mips_cm_update_property();
352
353 for (cl = 0; cl < nclusters; cl++) {
354 /* Allocate core boot configuration structs */
355 ncores = mips_cps_numcores(cl);
356 core_bootcfg = kcalloc(ncores, sizeof(*core_bootcfg),
357 GFP_KERNEL);
358 if (!core_bootcfg)
359 goto err_out;
360 mips_cps_cluster_bootcfg[cl].core_config = core_bootcfg;
361
362 mips_cps_cluster_bootcfg[cl].core_power =
363 kcalloc(BITS_TO_LONGS(ncores), sizeof(unsigned long),
364 GFP_KERNEL);
365 if (!mips_cps_cluster_bootcfg[cl].core_power)
366 goto err_out;
367
368 /* Allocate VPE boot configuration structs */
369 for (c = 0; c < ncores; c++) {
370 int v;
371 core_vpes = core_vpe_count(cluster: cl, core: c);
372 core_bootcfg[c].vpe_config = kcalloc(core_vpes,
373 sizeof(*core_bootcfg[c].vpe_config),
374 GFP_KERNEL);
375 for (v = 0; v < core_vpes; v++)
376 cpumask_set_cpu(nvpe++, &mips_cps_cluster_bootcfg[cl].cpumask);
377 if (!core_bootcfg[c].vpe_config)
378 goto err_out;
379 }
380 }
381
382 /* Mark this CPU as powered up & booted */
383 cl = cpu_cluster(&current_cpu_data);
384 c = cpu_core(&current_cpu_data);
385 cluster_bootcfg = &mips_cps_cluster_bootcfg[cl];
386 cpu_smt_set_num_threads(num_threads: core_vpes, max_threads: core_vpes);
387 core_bootcfg = &cluster_bootcfg->core_config[c];
388 bitmap_set(cluster_bootcfg->core_power, cpu_core(&current_cpu_data), 1);
389 atomic_set(&core_bootcfg->vpe_mask, 1 << cpu_vpe_id(&current_cpu_data));
390
391 return;
392err_out:
393 /* Clean up allocations */
394 if (mips_cps_cluster_bootcfg) {
395 for (cl = 0; cl < nclusters; cl++) {
396 cluster_bootcfg = &mips_cps_cluster_bootcfg[cl];
397 ncores = mips_cps_numcores(cl);
398 for (c = 0; c < ncores; c++) {
399 core_bootcfg = &cluster_bootcfg->core_config[c];
400 kfree(objp: core_bootcfg->vpe_config);
401 }
402 kfree(mips_cps_cluster_bootcfg[c].core_config);
403 }
404 kfree(mips_cps_cluster_bootcfg);
405 mips_cps_cluster_bootcfg = NULL;
406 }
407
408 /* Effectively disable SMP by declaring CPUs not present */
409 for_each_possible_cpu(c) {
410 if (c == 0)
411 continue;
412 set_cpu_present(c, false);
413 }
414}
415
416static void init_cluster_l2(void)
417{
418 u32 l2_cfg, l2sm_cop, result;
419
420 while (!mips_cm_is_l2_hci_broken) {
421 l2_cfg = read_gcr_redir_l2_ram_config();
422
423 /* If HCI is not supported, use the state machine below */
424 if (!(l2_cfg & CM_GCR_L2_RAM_CONFIG_PRESENT))
425 break;
426 if (!(l2_cfg & CM_GCR_L2_RAM_CONFIG_HCI_SUPPORTED))
427 break;
428
429 /* If the HCI_DONE bit is set, we're finished */
430 if (l2_cfg & CM_GCR_L2_RAM_CONFIG_HCI_DONE)
431 return;
432 }
433
434 l2sm_cop = read_gcr_redir_l2sm_cop();
435 if (WARN(!(l2sm_cop & CM_GCR_L2SM_COP_PRESENT),
436 "L2 init not supported on this system yet"))
437 return;
438
439 /* Clear L2 tag registers */
440 write_gcr_redir_l2_tag_state(0);
441 write_gcr_redir_l2_ecc(0);
442
443 /* Ensure the L2 tag writes complete before the state machine starts */
444 mb();
445
446 /* Wait for the L2 state machine to be idle */
447 do {
448 l2sm_cop = read_gcr_redir_l2sm_cop();
449 } while (l2sm_cop & CM_GCR_L2SM_COP_RUNNING);
450
451 /* Start a store tag operation */
452 l2sm_cop = CM_GCR_L2SM_COP_TYPE_IDX_STORETAG;
453 l2sm_cop <<= __ffs(CM_GCR_L2SM_COP_TYPE);
454 l2sm_cop |= CM_GCR_L2SM_COP_CMD_START;
455 write_gcr_redir_l2sm_cop(l2sm_cop);
456
457 /* Ensure the state machine starts before we poll for completion */
458 mb();
459
460 /* Wait for the operation to be complete */
461 do {
462 l2sm_cop = read_gcr_redir_l2sm_cop();
463 result = l2sm_cop & CM_GCR_L2SM_COP_RESULT;
464 result >>= __ffs(CM_GCR_L2SM_COP_RESULT);
465 } while (!result);
466
467 WARN(result != CM_GCR_L2SM_COP_RESULT_DONE_OK,
468 "L2 state machine failed cache init with error %u\n", result);
469}
470
471static void boot_core(unsigned int cluster, unsigned int core,
472 unsigned int vpe_id)
473{
474 struct cluster_boot_config *cluster_cfg;
475 u32 access, stat, seq_state;
476 unsigned int timeout, ncores;
477
478 cluster_cfg = &mips_cps_cluster_bootcfg[cluster];
479 ncores = mips_cps_numcores(cluster);
480
481 if ((cluster != cpu_cluster(&current_cpu_data)) &&
482 bitmap_empty(cluster_cfg->core_power, ncores)) {
483 power_up_other_cluster(cluster);
484
485 mips_cm_lock_other(cluster, core, 0,
486 CM_GCR_Cx_OTHER_BLOCK_GLOBAL);
487
488 /* Ensure cluster GCRs are where we expect */
489 write_gcr_redir_base(read_gcr_base());
490 write_gcr_redir_cpc_base(read_gcr_cpc_base());
491 write_gcr_redir_gic_base(read_gcr_gic_base());
492
493 init_cluster_l2();
494
495 /* Mirror L2 configuration */
496 write_gcr_redir_l2_only_sync_base(read_gcr_l2_only_sync_base());
497 write_gcr_redir_l2_pft_control(read_gcr_l2_pft_control());
498 write_gcr_redir_l2_pft_control_b(read_gcr_l2_pft_control_b());
499
500 /* Mirror ECC/parity setup */
501 write_gcr_redir_err_control(read_gcr_err_control());
502
503 /* Set BEV base */
504 write_gcr_redir_bev_base(core_entry_reg);
505
506 mips_cm_unlock_other();
507 }
508
509 if (cluster != cpu_cluster(&current_cpu_data)) {
510 mips_cm_lock_other(cluster, core, 0,
511 CM_GCR_Cx_OTHER_BLOCK_GLOBAL);
512
513 /* Ensure the core can access the GCRs */
514 access = read_gcr_redir_access();
515 access |= BIT(core);
516 write_gcr_redir_access(access);
517
518 mips_cm_unlock_other();
519 } else {
520 /* Ensure the core can access the GCRs */
521 access = read_gcr_access();
522 access |= BIT(core);
523 write_gcr_access(access);
524 }
525
526 /* Select the appropriate core */
527 mips_cm_lock_other(cluster, core, 0, CM_GCR_Cx_OTHER_BLOCK_LOCAL);
528
529 /* Set its reset vector */
530 if (mips_cm_is64)
531 write_gcr_co_reset64_base(core_entry_reg);
532 else
533 write_gcr_co_reset_base(core_entry_reg);
534
535 /* Ensure its coherency is disabled */
536 write_gcr_co_coherence(0);
537
538 /* Start it with the legacy memory map and exception base */
539 write_gcr_co_reset_ext_base(CM_GCR_Cx_RESET_EXT_BASE_UEB);
540
541 /* Ensure the core can access the GCRs */
542 if (mips_cm_revision() < CM_REV_CM3)
543 set_gcr_access(1 << core);
544 else
545 set_gcr_access_cm3(1 << core);
546
547 if (mips_cpc_present()) {
548 /* Reset the core */
549 mips_cpc_lock_other(core);
550
551 if (mips_cm_revision() >= CM_REV_CM3) {
552 /* Run only the requested VP following the reset */
553 write_cpc_co_vp_stop(0xf);
554 write_cpc_co_vp_run(1 << vpe_id);
555
556 /*
557 * Ensure that the VP_RUN register is written before the
558 * core leaves reset.
559 */
560 wmb();
561 }
562
563 write_cpc_co_cmd(CPC_Cx_CMD_RESET);
564
565 timeout = 100;
566 while (true) {
567 stat = read_cpc_co_stat_conf();
568 seq_state = stat & CPC_Cx_STAT_CONF_SEQSTATE;
569 seq_state >>= __ffs(CPC_Cx_STAT_CONF_SEQSTATE);
570
571 /* U6 == coherent execution, ie. the core is up */
572 if (seq_state == CPC_Cx_STAT_CONF_SEQSTATE_U6)
573 break;
574
575 /* Delay a little while before we start warning */
576 if (timeout) {
577 timeout--;
578 mdelay(10);
579 continue;
580 }
581
582 pr_warn("Waiting for core %u to start... STAT_CONF=0x%x\n",
583 core, stat);
584 mdelay(1000);
585 }
586
587 mips_cpc_unlock_other();
588 } else {
589 /* Take the core out of reset */
590 write_gcr_co_reset_release(0);
591 }
592
593 mips_cm_unlock_other();
594
595 /* The core is now powered up */
596 bitmap_set(map: cluster_cfg->core_power, start: core, nbits: 1);
597
598 /*
599 * Restore CM_PWRUP=0 so that the CM can power down if all the cores in
600 * the cluster do (eg. if they're all removed via hotplug.
601 */
602 if (mips_cm_revision() >= CM_REV_CM3_5) {
603 mips_cm_lock_other(cluster, 0, 0, CM_GCR_Cx_OTHER_BLOCK_GLOBAL);
604 write_cpc_redir_pwrup_ctl(0);
605 mips_cm_unlock_other();
606 }
607}
608
609static void remote_vpe_boot(void *dummy)
610{
611 unsigned int cluster = cpu_cluster(&current_cpu_data);
612 unsigned core = cpu_core(&current_cpu_data);
613 struct cluster_boot_config *cluster_cfg =
614 &mips_cps_cluster_bootcfg[cluster];
615 struct core_boot_config *core_cfg = &cluster_cfg->core_config[core];
616
617 mips_cps_boot_vpes(core_cfg, cpu_vpe_id(&current_cpu_data));
618}
619
620static int cps_boot_secondary(int cpu, struct task_struct *idle)
621{
622 unsigned int cluster = cpu_cluster(&cpu_data[cpu]);
623 unsigned core = cpu_core(&cpu_data[cpu]);
624 unsigned vpe_id = cpu_vpe_id(&cpu_data[cpu]);
625 struct cluster_boot_config *cluster_cfg =
626 &mips_cps_cluster_bootcfg[cluster];
627 struct core_boot_config *core_cfg = &cluster_cfg->core_config[core];
628 struct vpe_boot_config *vpe_cfg = &core_cfg->vpe_config[vpe_id];
629 unsigned int remote;
630 int err;
631
632 vpe_cfg->pc = (unsigned long)&smp_bootstrap;
633 vpe_cfg->sp = __KSTK_TOS(idle);
634 vpe_cfg->gp = (unsigned long)task_thread_info(idle);
635
636 atomic_or(1 << cpu_vpe_id(&cpu_data[cpu]), &core_cfg->vpe_mask);
637
638 preempt_disable();
639
640 if (!test_bit(core, cluster_cfg->core_power)) {
641 /* Boot a VPE on a powered down core */
642 boot_core(cluster, core, vpe_id);
643 goto out;
644 }
645
646 if (cpu_has_vp) {
647 mips_cm_lock_other(cluster, core, vpe_id,
648 CM_GCR_Cx_OTHER_BLOCK_LOCAL);
649 if (mips_cm_is64)
650 write_gcr_co_reset64_base(core_entry_reg);
651 else
652 write_gcr_co_reset_base(core_entry_reg);
653 mips_cm_unlock_other();
654 }
655
656 if (!cpus_are_siblings(cpu, smp_processor_id())) {
657 /* Boot a VPE on another powered up core */
658 for (remote = 0; remote < NR_CPUS; remote++) {
659 if (!cpus_are_siblings(cpu, remote))
660 continue;
661 if (cpu_online(cpu: remote))
662 break;
663 }
664 if (remote >= NR_CPUS) {
665 pr_crit("No online CPU in core %u to start CPU%d\n",
666 core, cpu);
667 goto out;
668 }
669
670 err = smp_call_function_single(cpuid: remote, func: remote_vpe_boot,
671 NULL, wait: 1);
672 if (err)
673 panic(fmt: "Failed to call remote CPU\n");
674 goto out;
675 }
676
677 BUG_ON(!cpu_has_mipsmt && !cpu_has_vp);
678
679 /* Boot a VPE on this core */
680 mips_cps_boot_vpes(core_cfg, vpe_id);
681out:
682 preempt_enable();
683 return 0;
684}
685
686static void cps_init_secondary(void)
687{
688 int core = cpu_core(&current_cpu_data);
689
690 /* Disable MT - we only want to run 1 TC per VPE */
691 if (cpu_has_mipsmt)
692 dmt();
693
694 if (mips_cm_revision() >= CM_REV_CM3) {
695 unsigned int ident = read_gic_vl_ident();
696
697 /*
698 * Ensure that our calculation of the VP ID matches up with
699 * what the GIC reports, otherwise we'll have configured
700 * interrupts incorrectly.
701 */
702 BUG_ON(ident != mips_cm_vp_id(smp_processor_id()));
703 }
704
705 if (core > 0 && !read_gcr_cl_coherence())
706 pr_warn("Core %u is not in coherent domain\n", core);
707
708 if (cpu_has_veic)
709 clear_c0_status(ST0_IM);
710 else
711 change_c0_status(ST0_IM, STATUSF_IP2 | STATUSF_IP3 |
712 STATUSF_IP4 | STATUSF_IP5 |
713 STATUSF_IP6 | STATUSF_IP7);
714}
715
716static void cps_smp_finish(void)
717{
718 write_c0_compare(read_c0_count() + (8 * mips_hpt_frequency / HZ));
719
720#ifdef CONFIG_MIPS_MT_FPAFF
721 /* If we have an FPU, enroll ourselves in the FPU-full mask */
722 if (cpu_has_fpu)
723 cpumask_set_cpu(smp_processor_id(), &mt_fpu_cpumask);
724#endif /* CONFIG_MIPS_MT_FPAFF */
725
726 local_irq_enable();
727}
728
729#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_KEXEC_CORE)
730
731enum cpu_death {
732 CPU_DEATH_HALT,
733 CPU_DEATH_POWER,
734};
735
736static void cps_shutdown_this_cpu(enum cpu_death death)
737{
738 unsigned int cpu, core, vpe_id;
739
740 cpu = smp_processor_id();
741 core = cpu_core(&cpu_data[cpu]);
742
743 if (death == CPU_DEATH_HALT) {
744 vpe_id = cpu_vpe_id(&cpu_data[cpu]);
745
746 pr_debug("Halting core %d VP%d\n", core, vpe_id);
747 if (cpu_has_mipsmt) {
748 /* Halt this TC */
749 write_c0_tchalt(TCHALT_H);
750 instruction_hazard();
751 } else if (cpu_has_vp) {
752 write_cpc_cl_vp_stop(1 << vpe_id);
753
754 /* Ensure that the VP_STOP register is written */
755 wmb();
756 }
757 } else {
758 if (IS_ENABLED(CONFIG_HOTPLUG_CPU)) {
759 pr_debug("Gating power to core %d\n", core);
760 /* Power down the core */
761 cps_pm_enter_state(CPS_PM_POWER_GATED);
762 }
763 }
764}
765
766#ifdef CONFIG_KEXEC_CORE
767
768static void cps_kexec_nonboot_cpu(void)
769{
770 if (cpu_has_mipsmt || cpu_has_vp)
771 cps_shutdown_this_cpu(death: CPU_DEATH_HALT);
772 else
773 cps_shutdown_this_cpu(death: CPU_DEATH_POWER);
774}
775
776#endif /* CONFIG_KEXEC_CORE */
777
778#endif /* CONFIG_HOTPLUG_CPU || CONFIG_KEXEC_CORE */
779
780#ifdef CONFIG_HOTPLUG_CPU
781
782static int cps_cpu_disable(void)
783{
784 unsigned cpu = smp_processor_id();
785 struct cluster_boot_config *cluster_cfg;
786 struct core_boot_config *core_cfg;
787
788 if (!cps_pm_support_state(CPS_PM_POWER_GATED))
789 return -EINVAL;
790
791 cluster_cfg = &mips_cps_cluster_bootcfg[cpu_cluster(&current_cpu_data)];
792 core_cfg = &cluster_cfg->core_config[cpu_core(&current_cpu_data)];
793 atomic_sub(1 << cpu_vpe_id(&current_cpu_data), &core_cfg->vpe_mask);
794 smp_mb__after_atomic();
795 set_cpu_online(cpu, online: false);
796 calculate_cpu_foreign_map();
797 irq_migrate_all_off_this_cpu();
798
799 return 0;
800}
801
802static unsigned cpu_death_sibling;
803static enum cpu_death cpu_death;
804
805void play_dead(void)
806{
807 unsigned int cpu;
808
809 local_irq_disable();
810 idle_task_exit();
811 cpu = smp_processor_id();
812 cpu_death = CPU_DEATH_POWER;
813
814 pr_debug("CPU%d going offline\n", cpu);
815
816 if (cpu_has_mipsmt || cpu_has_vp) {
817 /* Look for another online VPE within the core */
818 for_each_online_cpu(cpu_death_sibling) {
819 if (!cpus_are_siblings(cpu, cpu_death_sibling))
820 continue;
821
822 /*
823 * There is an online VPE within the core. Just halt
824 * this TC and leave the core alone.
825 */
826 cpu_death = CPU_DEATH_HALT;
827 break;
828 }
829 }
830
831 cpuhp_ap_report_dead();
832
833 cps_shutdown_this_cpu(death: cpu_death);
834
835 /* This should never be reached */
836 panic(fmt: "Failed to offline CPU %u", cpu);
837}
838
839static void wait_for_sibling_halt(void *ptr_cpu)
840{
841 unsigned cpu = (unsigned long)ptr_cpu;
842 unsigned vpe_id = cpu_vpe_id(&cpu_data[cpu]);
843 unsigned halted;
844 unsigned long flags;
845
846 do {
847 local_irq_save(flags);
848 settc(vpe_id);
849 halted = read_tc_c0_tchalt();
850 local_irq_restore(flags);
851 } while (!(halted & TCHALT_H));
852}
853
854static void cps_cpu_die(unsigned int cpu) { }
855
856static void cps_cleanup_dead_cpu(unsigned cpu)
857{
858 unsigned int cluster = cpu_cluster(&cpu_data[cpu]);
859 unsigned core = cpu_core(&cpu_data[cpu]);
860 unsigned int vpe_id = cpu_vpe_id(&cpu_data[cpu]);
861 ktime_t fail_time;
862 unsigned stat;
863 int err;
864 struct cluster_boot_config *cluster_cfg;
865
866 cluster_cfg = &mips_cps_cluster_bootcfg[cluster];
867
868 /*
869 * Now wait for the CPU to actually offline. Without doing this that
870 * offlining may race with one or more of:
871 *
872 * - Onlining the CPU again.
873 * - Powering down the core if another VPE within it is offlined.
874 * - A sibling VPE entering a non-coherent state.
875 *
876 * In the non-MT halt case (ie. infinite loop) the CPU is doing nothing
877 * with which we could race, so do nothing.
878 */
879 if (cpu_death == CPU_DEATH_POWER) {
880 /*
881 * Wait for the core to enter a powered down or clock gated
882 * state, the latter happening when a JTAG probe is connected
883 * in which case the CPC will refuse to power down the core.
884 */
885 fail_time = ktime_add_ms(kt: ktime_get(), msec: 2000);
886 do {
887 mips_cm_lock_other(0, core, 0, CM_GCR_Cx_OTHER_BLOCK_LOCAL);
888 mips_cpc_lock_other(core);
889 stat = read_cpc_co_stat_conf();
890 stat &= CPC_Cx_STAT_CONF_SEQSTATE;
891 stat >>= __ffs(CPC_Cx_STAT_CONF_SEQSTATE);
892 mips_cpc_unlock_other();
893 mips_cm_unlock_other();
894
895 if (stat == CPC_Cx_STAT_CONF_SEQSTATE_D0 ||
896 stat == CPC_Cx_STAT_CONF_SEQSTATE_D2 ||
897 stat == CPC_Cx_STAT_CONF_SEQSTATE_U2)
898 break;
899
900 /*
901 * The core ought to have powered down, but didn't &
902 * now we don't really know what state it's in. It's
903 * likely that its _pwr_up pin has been wired to logic
904 * 1 & it powered back up as soon as we powered it
905 * down...
906 *
907 * The best we can do is warn the user & continue in
908 * the hope that the core is doing nothing harmful &
909 * might behave properly if we online it later.
910 */
911 if (WARN(ktime_after(ktime_get(), fail_time),
912 "CPU%u hasn't powered down, seq. state %u\n",
913 cpu, stat))
914 break;
915 } while (1);
916
917 /* Indicate the core is powered off */
918 bitmap_clear(map: cluster_cfg->core_power, start: core, nbits: 1);
919 } else if (cpu_has_mipsmt) {
920 /*
921 * Have a CPU with access to the offlined CPUs registers wait
922 * for its TC to halt.
923 */
924 err = smp_call_function_single(cpuid: cpu_death_sibling,
925 func: wait_for_sibling_halt,
926 info: (void *)(unsigned long)cpu, wait: 1);
927 if (err)
928 panic(fmt: "Failed to call remote sibling CPU\n");
929 } else if (cpu_has_vp) {
930 do {
931 mips_cm_lock_other(0, core, vpe_id, CM_GCR_Cx_OTHER_BLOCK_LOCAL);
932 stat = read_cpc_co_vp_running();
933 mips_cm_unlock_other();
934 } while (stat & (1 << vpe_id));
935 }
936}
937
938#endif /* CONFIG_HOTPLUG_CPU */
939
940static const struct plat_smp_ops cps_smp_ops = {
941 .smp_setup = cps_smp_setup,
942 .prepare_cpus = cps_prepare_cpus,
943 .boot_secondary = cps_boot_secondary,
944 .init_secondary = cps_init_secondary,
945 .smp_finish = cps_smp_finish,
946 .send_ipi_single = mips_smp_send_ipi_single,
947 .send_ipi_mask = mips_smp_send_ipi_mask,
948#ifdef CONFIG_HOTPLUG_CPU
949 .cpu_disable = cps_cpu_disable,
950 .cpu_die = cps_cpu_die,
951 .cleanup_dead_cpu = cps_cleanup_dead_cpu,
952#endif
953#ifdef CONFIG_KEXEC_CORE
954 .kexec_nonboot_cpu = cps_kexec_nonboot_cpu,
955#endif
956};
957
958bool mips_cps_smp_in_use(void)
959{
960 extern const struct plat_smp_ops *mp_ops;
961 return mp_ops == &cps_smp_ops;
962}
963
964int register_cps_smp_ops(void)
965{
966 if (!mips_cm_present()) {
967 pr_warn("MIPS CPS SMP unable to proceed without a CM\n");
968 return -ENODEV;
969 }
970
971 /* check we have a GIC - we need one for IPIs */
972 if (!(read_gcr_gic_status() & CM_GCR_GIC_STATUS_EX)) {
973 pr_warn("MIPS CPS SMP unable to proceed without a GIC\n");
974 return -ENODEV;
975 }
976
977 register_smp_ops(&cps_smp_ops);
978 return 0;
979}
980

source code of linux/arch/mips/kernel/smp-cps.c