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 DECLARE_BITMAP(core_power, NR_CPUS); 40static uint32_t core_entry_reg; 41static phys_addr_t cps_vec_pa; 42 43struct core_boot_config *mips_cps_core_bootcfg; 44 45static unsigned __init core_vpe_count(unsigned int cluster, unsigned core) 46{ 47 return min(smp_max_threads, mips_cps_numvps(cluster, core)); 48} 49 50static void __init *mips_cps_build_core_entry(void *addr) 51{ 52 extern void (*nmi_handler)(void); 53 u32 *p = addr; 54 u32 val; 55 struct uasm_label labels[2]; 56 struct uasm_reloc relocs[2]; 57 struct uasm_label *l = labels; 58 struct uasm_reloc *r = relocs; 59 60 memset(labels, 0, sizeof(labels)); 61 memset(relocs, 0, sizeof(relocs)); 62 63 uasm_i_mfc0(&p, GPR_K0, C0_STATUS); 64 UASM_i_LA(&p, GPR_T9, ST0_NMI); 65 uasm_i_and(&p, GPR_K0, GPR_K0, GPR_T9); 66 67 uasm_il_bnez(&p, &r, GPR_K0, label_not_nmi); 68 uasm_i_nop(&p); 69 UASM_i_LA(&p, GPR_K0, (long)&nmi_handler); 70 71 uasm_l_not_nmi(&l, p); 72 73 val = CAUSEF_IV; 74 uasm_i_lui(&p, GPR_K0, val >> 16); 75 uasm_i_ori(&p, GPR_K0, GPR_K0, val & 0xffff); 76 uasm_i_mtc0(&p, GPR_K0, C0_CAUSE); 77 val = ST0_CU1 | ST0_CU0 | ST0_BEV | ST0_KX_IF_64; 78 uasm_i_lui(&p, GPR_K0, val >> 16); 79 uasm_i_ori(&p, GPR_K0, GPR_K0, val & 0xffff); 80 uasm_i_mtc0(&p, GPR_K0, C0_STATUS); 81 uasm_i_ehb(&p); 82 uasm_i_ori(&p, GPR_A0, 0, read_c0_config() & CONF_CM_CMASK); 83 UASM_i_LA(&p, GPR_A1, (long)mips_gcr_base); 84#if defined(KBUILD_64BIT_SYM32) || defined(CONFIG_32BIT) 85 UASM_i_LA(&p, GPR_T9, CKSEG1ADDR(__pa_symbol(mips_cps_core_boot))); 86#else 87 UASM_i_LA(&p, GPR_T9, TO_UNCAC(__pa_symbol(mips_cps_core_boot))); 88#endif 89 uasm_i_jr(&p, GPR_T9); 90 uasm_i_nop(&p); 91 92 uasm_resolve_relocs(relocs, labels); 93 94 return p; 95} 96 97static int __init allocate_cps_vecs(void) 98{ 99 /* Try to allocate in KSEG1 first */ 100 cps_vec_pa = memblock_phys_alloc_range(BEV_VEC_SIZE, BEV_VEC_ALIGN, 101 0x0, CSEGX_SIZE - 1); 102 103 if (cps_vec_pa) 104 core_entry_reg = CKSEG1ADDR(cps_vec_pa) & 105 CM_GCR_Cx_RESET_BASE_BEVEXCBASE; 106 107 if (!cps_vec_pa && mips_cm_is64) { 108 cps_vec_pa = memblock_phys_alloc_range(BEV_VEC_SIZE, BEV_VEC_ALIGN, 109 0x0, SZ_4G - 1); 110 if (cps_vec_pa) 111 core_entry_reg = (cps_vec_pa & CM_GCR_Cx_RESET_BASE_BEVEXCBASE) | 112 CM_GCR_Cx_RESET_BASE_MODE; 113 } 114 115 if (!cps_vec_pa) 116 return -ENOMEM; 117 118 return 0; 119} 120 121static void __init setup_cps_vecs(void) 122{ 123 void *cps_vec; 124 125 cps_vec = (void *)CKSEG1ADDR_OR_64BIT(cps_vec_pa); 126 mips_cps_build_core_entry(cps_vec); 127 128 memcpy(cps_vec + 0x200, &excep_tlbfill, 0x80); 129 memcpy(cps_vec + 0x280, &excep_xtlbfill, 0x80); 130 memcpy(cps_vec + 0x300, &excep_cache, 0x80); 131 memcpy(cps_vec + 0x380, &excep_genex, 0x80); 132 memcpy(cps_vec + 0x400, &excep_intex, 0x80); 133 memcpy(cps_vec + 0x480, &excep_ejtag, 0x80); 134 135 /* Make sure no prefetched data in cache */ 136 blast_inv_dcache_range(CKSEG0ADDR_OR_64BIT(cps_vec_pa), CKSEG0ADDR_OR_64BIT(cps_vec_pa) + BEV_VEC_SIZE); 137 bc_inv(CKSEG0ADDR_OR_64BIT(cps_vec_pa), BEV_VEC_SIZE); 138 __sync(); 139} 140 141static void __init cps_smp_setup(void) 142{ 143 unsigned int nclusters, ncores, nvpes, core_vpes; 144 int cl, c, v; 145 146 /* Detect & record VPE topology */ 147 nvpes = 0; 148 nclusters = mips_cps_numclusters(); 149 pr_info("%s topology ", cpu_has_mips_r6 ? "VP" : "VPE"); 150 for (cl = 0; cl < nclusters; cl++) { 151 if (cl > 0) 152 pr_cont(","); 153 pr_cont("{"); 154 155 ncores = mips_cps_numcores(cl); 156 for (c = 0; c < ncores; c++) { 157 core_vpes = core_vpe_count(cl, c); 158 159 if (c > 0) 160 pr_cont(","); 161 pr_cont("%u", core_vpes); 162 163 /* Use the number of VPEs in cluster 0 core 0 for smp_num_siblings */ 164 if (!cl && !c) 165 smp_num_siblings = core_vpes; 166 167 for (v = 0; v < min_t(int, core_vpes, NR_CPUS - nvpes); v++) { 168 cpu_set_cluster(&cpu_data[nvpes + v], cl); 169 cpu_set_core(&cpu_data[nvpes + v], c); 170 cpu_set_vpe_id(&cpu_data[nvpes + v], v); 171 } 172 173 nvpes += core_vpes; 174 } 175 176 pr_cont("}"); 177 } 178 pr_cont(" total %u\n", nvpes); 179 180 /* Indicate present CPUs (CPU being synonymous with VPE) */ 181 for (v = 0; v < min_t(unsigned, nvpes, NR_CPUS); v++) { 182 set_cpu_possible(v, cpu_cluster(&cpu_data[v]) == 0); 183 set_cpu_present(v, cpu_cluster(&cpu_data[v]) == 0); 184 __cpu_number_map[v] = v; 185 __cpu_logical_map[v] = v; 186 } 187 188 /* Set a coherent default CCA (CWB) */ 189 change_c0_config(CONF_CM_CMASK, 0x5); 190 191 /* Core 0 is powered up (we're running on it) */ 192 bitmap_set(core_power, 0, 1); 193 194 /* Initialise core 0 */ 195 mips_cps_core_init(); 196 197 /* Make core 0 coherent with everything */ 198 write_gcr_cl_coherence(0xff); 199 200 if (allocate_cps_vecs()) 201 pr_err("Failed to allocate CPS vectors\n"); 202 203 if (core_entry_reg && mips_cm_revision() >= CM_REV_CM3) 204 write_gcr_bev_base(core_entry_reg); 205 206#ifdef CONFIG_MIPS_MT_FPAFF 207 /* If we have an FPU, enroll ourselves in the FPU-full mask */ 208 if (cpu_has_fpu) 209 cpumask_set_cpu(0, &mt_fpu_cpumask); 210#endif /* CONFIG_MIPS_MT_FPAFF */ 211} 212 213static void __init cps_prepare_cpus(unsigned int max_cpus) 214{ 215 unsigned ncores, core_vpes, c, cca; 216 bool cca_unsuitable, cores_limited; 217 218 mips_mt_set_cpuoptions(); 219 220 if (!core_entry_reg) { 221 pr_err("core_entry address unsuitable, disabling smp-cps\n"); 222 goto err_out; 223 } 224 225 /* Detect whether the CCA is unsuited to multi-core SMP */ 226 cca = read_c0_config() & CONF_CM_CMASK; 227 switch (cca) { 228 case 0x4: /* CWBE */ 229 case 0x5: /* CWB */ 230 /* The CCA is coherent, multi-core is fine */ 231 cca_unsuitable = false; 232 break; 233 234 default: 235 /* CCA is not coherent, multi-core is not usable */ 236 cca_unsuitable = true; 237 } 238 239 /* Warn the user if the CCA prevents multi-core */ 240 cores_limited = false; 241 if (cca_unsuitable || cpu_has_dc_aliases) { 242 for_each_present_cpu(c) { 243 if (cpus_are_siblings(smp_processor_id(), c)) 244 continue; 245 246 set_cpu_present(c, false); 247 cores_limited = true; 248 } 249 } 250 if (cores_limited) 251 pr_warn("Using only one core due to %s%s%s\n", 252 cca_unsuitable ? "unsuitable CCA" : "", 253 (cca_unsuitable && cpu_has_dc_aliases) ? " & " : "", 254 cpu_has_dc_aliases ? "dcache aliasing" : ""); 255 256 setup_cps_vecs(); 257 258 /* Allocate core boot configuration structs */ 259 ncores = mips_cps_numcores(0); 260 mips_cps_core_bootcfg = kcalloc(ncores, sizeof(*mips_cps_core_bootcfg), 261 GFP_KERNEL); 262 if (!mips_cps_core_bootcfg) { 263 pr_err("Failed to allocate boot config for %u cores\n", ncores); 264 goto err_out; 265 } 266 267 /* Allocate VPE boot configuration structs */ 268 for (c = 0; c < ncores; c++) { 269 core_vpes = core_vpe_count(0, c); 270 mips_cps_core_bootcfg[c].vpe_config = kcalloc(core_vpes, 271 sizeof(*mips_cps_core_bootcfg[c].vpe_config), 272 GFP_KERNEL); 273 if (!mips_cps_core_bootcfg[c].vpe_config) { 274 pr_err("Failed to allocate %u VPE boot configs\n", 275 core_vpes); 276 goto err_out; 277 } 278 } 279 280 /* Mark this CPU as booted */ 281 atomic_set(&mips_cps_core_bootcfg[cpu_core(¤t_cpu_data)].vpe_mask, 282 1 << cpu_vpe_id(¤t_cpu_data)); 283 284 return; 285err_out: 286 /* Clean up allocations */ 287 if (mips_cps_core_bootcfg) { 288 for (c = 0; c < ncores; c++) 289 kfree(mips_cps_core_bootcfg[c].vpe_config); 290 kfree(mips_cps_core_bootcfg); 291 mips_cps_core_bootcfg = NULL; 292 } 293 294 /* Effectively disable SMP by declaring CPUs not present */ 295 for_each_possible_cpu(c) { 296 if (c == 0) 297 continue; 298 set_cpu_present(c, false); 299 } 300} 301 302static void boot_core(unsigned int core, unsigned int vpe_id) 303{ 304 u32 stat, seq_state; 305 unsigned timeout; 306 307 /* Select the appropriate core */ 308 mips_cm_lock_other(0, core, 0, CM_GCR_Cx_OTHER_BLOCK_LOCAL); 309 310 /* Set its reset vector */ 311 write_gcr_co_reset_base(core_entry_reg); 312 313 /* Ensure its coherency is disabled */ 314 write_gcr_co_coherence(0); 315 316 /* Start it with the legacy memory map and exception base */ 317 write_gcr_co_reset_ext_base(CM_GCR_Cx_RESET_EXT_BASE_UEB); 318 319 /* Ensure the core can access the GCRs */ 320 set_gcr_access(1 << core); 321 322 if (mips_cpc_present()) { 323 /* Reset the core */ 324 mips_cpc_lock_other(core); 325 326 if (mips_cm_revision() >= CM_REV_CM3) { 327 /* Run only the requested VP following the reset */ 328 write_cpc_co_vp_stop(0xf); 329 write_cpc_co_vp_run(1 << vpe_id); 330 331 /* 332 * Ensure that the VP_RUN register is written before the 333 * core leaves reset. 334 */ 335 wmb(); 336 } 337 338 write_cpc_co_cmd(CPC_Cx_CMD_RESET); 339 340 timeout = 100; 341 while (true) { 342 stat = read_cpc_co_stat_conf(); 343 seq_state = stat & CPC_Cx_STAT_CONF_SEQSTATE; 344 seq_state >>= __ffs(CPC_Cx_STAT_CONF_SEQSTATE); 345 346 /* U6 == coherent execution, ie. the core is up */ 347 if (seq_state == CPC_Cx_STAT_CONF_SEQSTATE_U6) 348 break; 349 350 /* Delay a little while before we start warning */ 351 if (timeout) { 352 timeout--; 353 mdelay(10); 354 continue; 355 } 356 357 pr_warn("Waiting for core %u to start... STAT_CONF=0x%x\n", 358 core, stat); 359 mdelay(1000); 360 } 361 362 mips_cpc_unlock_other(); 363 } else { 364 /* Take the core out of reset */ 365 write_gcr_co_reset_release(0); 366 } 367 368 mips_cm_unlock_other(); 369 370 /* The core is now powered up */ 371 bitmap_set(core_power, core, 1); 372} 373 374static void remote_vpe_boot(void *dummy) 375{ 376 unsigned core = cpu_core(¤t_cpu_data); 377 struct core_boot_config *core_cfg = &mips_cps_core_bootcfg[core]; 378 379 mips_cps_boot_vpes(core_cfg, cpu_vpe_id(¤t_cpu_data)); 380} 381 382static int cps_boot_secondary(int cpu, struct task_struct *idle) 383{ 384 unsigned core = cpu_core(&cpu_data[cpu]); 385 unsigned vpe_id = cpu_vpe_id(&cpu_data[cpu]); 386 struct core_boot_config *core_cfg = &mips_cps_core_bootcfg[core]; 387 struct vpe_boot_config *vpe_cfg = &core_cfg->vpe_config[vpe_id]; 388 unsigned int remote; 389 int err; 390 391 /* We don't yet support booting CPUs in other clusters */ 392 if (cpu_cluster(&cpu_data[cpu]) != cpu_cluster(&raw_current_cpu_data)) 393 return -ENOSYS; 394 395 vpe_cfg->pc = (unsigned long)&smp_bootstrap; 396 vpe_cfg->sp = __KSTK_TOS(idle); 397 vpe_cfg->gp = (unsigned long)task_thread_info(idle); 398 399 atomic_or(1 << cpu_vpe_id(&cpu_data[cpu]), &core_cfg->vpe_mask); 400 401 preempt_disable(); 402 403 if (!test_bit(core, core_power)) { 404 /* Boot a VPE on a powered down core */ 405 boot_core(core, vpe_id); 406 goto out; 407 } 408 409 if (cpu_has_vp) { 410 mips_cm_lock_other(0, core, vpe_id, CM_GCR_Cx_OTHER_BLOCK_LOCAL); 411 write_gcr_co_reset_base(core_entry_reg); 412 mips_cm_unlock_other(); 413 } 414 415 if (!cpus_are_siblings(cpu, smp_processor_id())) { 416 /* Boot a VPE on another powered up core */ 417 for (remote = 0; remote < NR_CPUS; remote++) { 418 if (!cpus_are_siblings(cpu, remote)) 419 continue; 420 if (cpu_online(remote)) 421 break; 422 } 423 if (remote >= NR_CPUS) { 424 pr_crit("No online CPU in core %u to start CPU%d\n", 425 core, cpu); 426 goto out; 427 } 428 429 err = smp_call_function_single(remote, remote_vpe_boot, 430 NULL, 1); 431 if (err) 432 panic("Failed to call remote CPU\n"); 433 goto out; 434 } 435 436 BUG_ON(!cpu_has_mipsmt && !cpu_has_vp); 437 438 /* Boot a VPE on this core */ 439 mips_cps_boot_vpes(core_cfg, vpe_id); 440out: 441 preempt_enable(); 442 return 0; 443} 444 445static void cps_init_secondary(void) 446{ 447 int core = cpu_core(¤t_cpu_data); 448 449 /* Disable MT - we only want to run 1 TC per VPE */ 450 if (cpu_has_mipsmt) 451 dmt(); 452 453 if (mips_cm_revision() >= CM_REV_CM3) { 454 unsigned int ident = read_gic_vl_ident(); 455 456 /* 457 * Ensure that our calculation of the VP ID matches up with 458 * what the GIC reports, otherwise we'll have configured 459 * interrupts incorrectly. 460 */ 461 BUG_ON(ident != mips_cm_vp_id(smp_processor_id())); 462 } 463 464 if (core > 0 && !read_gcr_cl_coherence()) 465 pr_warn("Core %u is not in coherent domain\n", core); 466 467 if (cpu_has_veic) 468 clear_c0_status(ST0_IM); 469 else 470 change_c0_status(ST0_IM, STATUSF_IP2 | STATUSF_IP3 | 471 STATUSF_IP4 | STATUSF_IP5 | 472 STATUSF_IP6 | STATUSF_IP7); 473} 474 475static void cps_smp_finish(void) 476{ 477 write_c0_compare(read_c0_count() + (8 * mips_hpt_frequency / HZ)); 478 479#ifdef CONFIG_MIPS_MT_FPAFF 480 /* If we have an FPU, enroll ourselves in the FPU-full mask */ 481 if (cpu_has_fpu) 482 cpumask_set_cpu(smp_processor_id(), &mt_fpu_cpumask); 483#endif /* CONFIG_MIPS_MT_FPAFF */ 484 485 local_irq_enable(); 486} 487 488#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_KEXEC_CORE) 489 490enum cpu_death { 491 CPU_DEATH_HALT, 492 CPU_DEATH_POWER, 493}; 494 495static void cps_shutdown_this_cpu(enum cpu_death death) 496{ 497 unsigned int cpu, core, vpe_id; 498 499 cpu = smp_processor_id(); 500 core = cpu_core(&cpu_data[cpu]); 501 502 if (death == CPU_DEATH_HALT) { 503 vpe_id = cpu_vpe_id(&cpu_data[cpu]); 504 505 pr_debug("Halting core %d VP%d\n", core, vpe_id); 506 if (cpu_has_mipsmt) { 507 /* Halt this TC */ 508 write_c0_tchalt(TCHALT_H); 509 instruction_hazard(); 510 } else if (cpu_has_vp) { 511 write_cpc_cl_vp_stop(1 << vpe_id); 512 513 /* Ensure that the VP_STOP register is written */ 514 wmb(); 515 } 516 } else { 517 if (IS_ENABLED(CONFIG_HOTPLUG_CPU)) { 518 pr_debug("Gating power to core %d\n", core); 519 /* Power down the core */ 520 cps_pm_enter_state(CPS_PM_POWER_GATED); 521 } 522 } 523} 524 525#ifdef CONFIG_KEXEC_CORE 526 527static void cps_kexec_nonboot_cpu(void) 528{ 529 if (cpu_has_mipsmt || cpu_has_vp) 530 cps_shutdown_this_cpu(CPU_DEATH_HALT); 531 else 532 cps_shutdown_this_cpu(CPU_DEATH_POWER); 533} 534 535#endif /* CONFIG_KEXEC_CORE */ 536 537#endif /* CONFIG_HOTPLUG_CPU || CONFIG_KEXEC_CORE */ 538 539#ifdef CONFIG_HOTPLUG_CPU 540 541static int cps_cpu_disable(void) 542{ 543 unsigned cpu = smp_processor_id(); 544 struct core_boot_config *core_cfg; 545 546 if (!cps_pm_support_state(CPS_PM_POWER_GATED)) 547 return -EINVAL; 548 549 core_cfg = &mips_cps_core_bootcfg[cpu_core(¤t_cpu_data)]; 550 atomic_sub(1 << cpu_vpe_id(¤t_cpu_data), &core_cfg->vpe_mask); 551 smp_mb__after_atomic(); 552 set_cpu_online(cpu, false); 553 calculate_cpu_foreign_map(); 554 irq_migrate_all_off_this_cpu(); 555 556 return 0; 557} 558 559static unsigned cpu_death_sibling; 560static enum cpu_death cpu_death; 561 562void play_dead(void) 563{ 564 unsigned int cpu; 565 566 local_irq_disable(); 567 idle_task_exit(); 568 cpu = smp_processor_id(); 569 cpu_death = CPU_DEATH_POWER; 570 571 pr_debug("CPU%d going offline\n", cpu); 572 573 if (cpu_has_mipsmt || cpu_has_vp) { 574 /* Look for another online VPE within the core */ 575 for_each_online_cpu(cpu_death_sibling) { 576 if (!cpus_are_siblings(cpu, cpu_death_sibling)) 577 continue; 578 579 /* 580 * There is an online VPE within the core. Just halt 581 * this TC and leave the core alone. 582 */ 583 cpu_death = CPU_DEATH_HALT; 584 break; 585 } 586 } 587 588 cpuhp_ap_report_dead(); 589 590 cps_shutdown_this_cpu(cpu_death); 591 592 /* This should never be reached */ 593 panic("Failed to offline CPU %u", cpu); 594} 595 596static void wait_for_sibling_halt(void *ptr_cpu) 597{ 598 unsigned cpu = (unsigned long)ptr_cpu; 599 unsigned vpe_id = cpu_vpe_id(&cpu_data[cpu]); 600 unsigned halted; 601 unsigned long flags; 602 603 do { 604 local_irq_save(flags); 605 settc(vpe_id); 606 halted = read_tc_c0_tchalt(); 607 local_irq_restore(flags); 608 } while (!(halted & TCHALT_H)); 609} 610 611static void cps_cpu_die(unsigned int cpu) { } 612 613static void cps_cleanup_dead_cpu(unsigned cpu) 614{ 615 unsigned core = cpu_core(&cpu_data[cpu]); 616 unsigned int vpe_id = cpu_vpe_id(&cpu_data[cpu]); 617 ktime_t fail_time; 618 unsigned stat; 619 int err; 620 621 /* 622 * Now wait for the CPU to actually offline. Without doing this that 623 * offlining may race with one or more of: 624 * 625 * - Onlining the CPU again. 626 * - Powering down the core if another VPE within it is offlined. 627 * - A sibling VPE entering a non-coherent state. 628 * 629 * In the non-MT halt case (ie. infinite loop) the CPU is doing nothing 630 * with which we could race, so do nothing. 631 */ 632 if (cpu_death == CPU_DEATH_POWER) { 633 /* 634 * Wait for the core to enter a powered down or clock gated 635 * state, the latter happening when a JTAG probe is connected 636 * in which case the CPC will refuse to power down the core. 637 */ 638 fail_time = ktime_add_ms(ktime_get(), 2000); 639 do { 640 mips_cm_lock_other(0, core, 0, CM_GCR_Cx_OTHER_BLOCK_LOCAL); 641 mips_cpc_lock_other(core); 642 stat = read_cpc_co_stat_conf(); 643 stat &= CPC_Cx_STAT_CONF_SEQSTATE; 644 stat >>= __ffs(CPC_Cx_STAT_CONF_SEQSTATE); 645 mips_cpc_unlock_other(); 646 mips_cm_unlock_other(); 647 648 if (stat == CPC_Cx_STAT_CONF_SEQSTATE_D0 || 649 stat == CPC_Cx_STAT_CONF_SEQSTATE_D2 || 650 stat == CPC_Cx_STAT_CONF_SEQSTATE_U2) 651 break; 652 653 /* 654 * The core ought to have powered down, but didn't & 655 * now we don't really know what state it's in. It's 656 * likely that its _pwr_up pin has been wired to logic 657 * 1 & it powered back up as soon as we powered it 658 * down... 659 * 660 * The best we can do is warn the user & continue in 661 * the hope that the core is doing nothing harmful & 662 * might behave properly if we online it later. 663 */ 664 if (WARN(ktime_after(ktime_get(), fail_time), 665 "CPU%u hasn't powered down, seq. state %u\n", 666 cpu, stat)) 667 break; 668 } while (1); 669 670 /* Indicate the core is powered off */ 671 bitmap_clear(core_power, core, 1); 672 } else if (cpu_has_mipsmt) { 673 /* 674 * Have a CPU with access to the offlined CPUs registers wait 675 * for its TC to halt. 676 */ 677 err = smp_call_function_single(cpu_death_sibling, 678 wait_for_sibling_halt, 679 (void *)(unsigned long)cpu, 1); 680 if (err) 681 panic("Failed to call remote sibling CPU\n"); 682 } else if (cpu_has_vp) { 683 do { 684 mips_cm_lock_other(0, core, vpe_id, CM_GCR_Cx_OTHER_BLOCK_LOCAL); 685 stat = read_cpc_co_vp_running(); 686 mips_cm_unlock_other(); 687 } while (stat & (1 << vpe_id)); 688 } 689} 690 691#endif /* CONFIG_HOTPLUG_CPU */ 692 693static const struct plat_smp_ops cps_smp_ops = { 694 .smp_setup = cps_smp_setup, 695 .prepare_cpus = cps_prepare_cpus, 696 .boot_secondary = cps_boot_secondary, 697 .init_secondary = cps_init_secondary, 698 .smp_finish = cps_smp_finish, 699 .send_ipi_single = mips_smp_send_ipi_single, 700 .send_ipi_mask = mips_smp_send_ipi_mask, 701#ifdef CONFIG_HOTPLUG_CPU 702 .cpu_disable = cps_cpu_disable, 703 .cpu_die = cps_cpu_die, 704 .cleanup_dead_cpu = cps_cleanup_dead_cpu, 705#endif 706#ifdef CONFIG_KEXEC_CORE 707 .kexec_nonboot_cpu = cps_kexec_nonboot_cpu, 708#endif 709}; 710 711bool mips_cps_smp_in_use(void) 712{ 713 extern const struct plat_smp_ops *mp_ops; 714 return mp_ops == &cps_smp_ops; 715} 716 717int register_cps_smp_ops(void) 718{ 719 if (!mips_cm_present()) { 720 pr_warn("MIPS CPS SMP unable to proceed without a CM\n"); 721 return -ENODEV; 722 } 723 724 /* check we have a GIC - we need one for IPIs */ 725 if (!(read_gcr_gic_status() & CM_GCR_GIC_STATUS_EX)) { 726 pr_warn("MIPS CPS SMP unable to proceed without a GIC\n"); 727 return -ENODEV; 728 } 729 730 register_smp_ops(&cps_smp_ops); 731 return 0; 732} 733