1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * pseries CPU Hotplug infrastructure. 4 * 5 * Split out from arch/powerpc/platforms/pseries/setup.c 6 * arch/powerpc/kernel/rtas.c, and arch/powerpc/platforms/pseries/smp.c 7 * 8 * Peter Bergner, IBM March 2001. 9 * Copyright (C) 2001 IBM. 10 * Dave Engebretsen, Peter Bergner, and 11 * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com 12 * Plus various changes from other IBM teams... 13 * 14 * Copyright (C) 2006 Michael Ellerman, IBM Corporation 15 */ 16 17#define pr_fmt(fmt) "pseries-hotplug-cpu: " fmt 18 19#include <linux/kernel.h> 20#include <linux/interrupt.h> 21#include <linux/delay.h> 22#include <linux/sched.h> /* for idle_task_exit */ 23#include <linux/sched/hotplug.h> 24#include <linux/cpu.h> 25#include <linux/of.h> 26#include <linux/slab.h> 27#include <asm/prom.h> 28#include <asm/rtas.h> 29#include <asm/firmware.h> 30#include <asm/machdep.h> 31#include <asm/vdso_datapage.h> 32#include <asm/xics.h> 33#include <asm/xive.h> 34#include <asm/plpar_wrappers.h> 35#include <asm/topology.h> 36 37#include "pseries.h" 38 39/* This version can't take the spinlock, because it never returns */ 40static int rtas_stop_self_token = RTAS_UNKNOWN_SERVICE; 41 42/* 43 * Record the CPU ids used on each nodes. 44 * Protected by cpu_add_remove_lock. 45 */ 46static cpumask_var_t node_recorded_ids_map[MAX_NUMNODES]; 47 48static void rtas_stop_self(void) 49{ 50 static struct rtas_args args; 51 52 local_irq_disable(); 53 54 BUG_ON(rtas_stop_self_token == RTAS_UNKNOWN_SERVICE); 55 56 rtas_call_unlocked(&args, rtas_stop_self_token, 0, 1, NULL); 57 58 panic("Alas, I survived.\n"); 59} 60 61static void pseries_cpu_offline_self(void) 62{ 63 unsigned int hwcpu = hard_smp_processor_id(); 64 65 local_irq_disable(); 66 idle_task_exit(); 67 if (xive_enabled()) 68 xive_teardown_cpu(); 69 else 70 xics_teardown_cpu(); 71 72 unregister_slb_shadow(hwcpu); 73 unregister_vpa(hwcpu); 74 rtas_stop_self(); 75 76 /* Should never get here... */ 77 BUG(); 78 for(;;); 79} 80 81static int pseries_cpu_disable(void) 82{ 83 int cpu = smp_processor_id(); 84 85 set_cpu_online(cpu, false); 86 vdso_data->processorCount--; 87 88 /*fix boot_cpuid here*/ 89 if (cpu == boot_cpuid) 90 boot_cpuid = cpumask_any(cpu_online_mask); 91 92 /* FIXME: abstract this to not be platform specific later on */ 93 if (xive_enabled()) 94 xive_smp_disable_cpu(); 95 else 96 xics_migrate_irqs_away(); 97 98 cleanup_cpu_mmu_context(); 99 100 return 0; 101} 102 103/* 104 * pseries_cpu_die: Wait for the cpu to die. 105 * @cpu: logical processor id of the CPU whose death we're awaiting. 106 * 107 * This function is called from the context of the thread which is performing 108 * the cpu-offline. Here we wait for long enough to allow the cpu in question 109 * to self-destroy so that the cpu-offline thread can send the CPU_DEAD 110 * notifications. 111 * 112 * OTOH, pseries_cpu_offline_self() is called by the @cpu when it wants to 113 * self-destruct. 114 */ 115static void pseries_cpu_die(unsigned int cpu) 116{ 117 int cpu_status = 1; 118 unsigned int pcpu = get_hard_smp_processor_id(cpu); 119 unsigned long timeout = jiffies + msecs_to_jiffies(120000); 120 121 while (true) { 122 cpu_status = smp_query_cpu_stopped(pcpu); 123 if (cpu_status == QCSS_STOPPED || 124 cpu_status == QCSS_HARDWARE_ERROR) 125 break; 126 127 if (time_after(jiffies, timeout)) { 128 pr_warn("CPU %i (hwid %i) didn't die after 120 seconds\n", 129 cpu, pcpu); 130 timeout = jiffies + msecs_to_jiffies(120000); 131 } 132 133 cond_resched(); 134 } 135 136 if (cpu_status == QCSS_HARDWARE_ERROR) { 137 pr_warn("CPU %i (hwid %i) reported error while dying\n", 138 cpu, pcpu); 139 } 140 141 paca_ptrs[cpu]->cpu_start = 0; 142} 143 144/** 145 * find_cpu_id_range - found a linear ranger of @nthreads free CPU ids. 146 * @nthreads : the number of threads (cpu ids) 147 * @assigned_node : the node it belongs to or NUMA_NO_NODE if free ids from any 148 * node can be peek. 149 * @cpu_mask: the returned CPU mask. 150 * 151 * Returns 0 on success. 152 */ 153static int find_cpu_id_range(unsigned int nthreads, int assigned_node, 154 cpumask_var_t *cpu_mask) 155{ 156 cpumask_var_t candidate_mask; 157 unsigned int cpu, node; 158 int rc = -ENOSPC; 159 160 if (!zalloc_cpumask_var(&candidate_mask, GFP_KERNEL)) 161 return -ENOMEM; 162 163 cpumask_clear(*cpu_mask); 164 for (cpu = 0; cpu < nthreads; cpu++) 165 cpumask_set_cpu(cpu, *cpu_mask); 166 167 BUG_ON(!cpumask_subset(cpu_present_mask, cpu_possible_mask)); 168 169 /* Get a bitmap of unoccupied slots. */ 170 cpumask_xor(candidate_mask, cpu_possible_mask, cpu_present_mask); 171 172 if (assigned_node != NUMA_NO_NODE) { 173 /* 174 * Remove free ids previously assigned on the other nodes. We 175 * can walk only online nodes because once a node became online 176 * it is not turned offlined back. 177 */ 178 for_each_online_node(node) { 179 if (node == assigned_node) 180 continue; 181 cpumask_andnot(candidate_mask, candidate_mask, 182 node_recorded_ids_map[node]); 183 } 184 } 185 186 if (cpumask_empty(candidate_mask)) 187 goto out; 188 189 while (!cpumask_empty(*cpu_mask)) { 190 if (cpumask_subset(*cpu_mask, candidate_mask)) 191 /* Found a range where we can insert the new cpu(s) */ 192 break; 193 cpumask_shift_left(*cpu_mask, *cpu_mask, nthreads); 194 } 195 196 if (!cpumask_empty(*cpu_mask)) 197 rc = 0; 198 199out: 200 free_cpumask_var(candidate_mask); 201 return rc; 202} 203 204/* 205 * Update cpu_present_mask and paca(s) for a new cpu node. The wrinkle 206 * here is that a cpu device node may represent multiple logical cpus 207 * in the SMT case. We must honor the assumption in other code that 208 * the logical ids for sibling SMT threads x and y are adjacent, such 209 * that x^1 == y and y^1 == x. 210 */ 211static int pseries_add_processor(struct device_node *np) 212{ 213 int len, nthreads, node, cpu, assigned_node; 214 int rc = 0; 215 cpumask_var_t cpu_mask; 216 const __be32 *intserv; 217 218 intserv = of_get_property(np, "ibm,ppc-interrupt-server#s", &len); 219 if (!intserv) 220 return 0; 221 222 nthreads = len / sizeof(u32); 223 224 if (!alloc_cpumask_var(&cpu_mask, GFP_KERNEL)) 225 return -ENOMEM; 226 227 /* 228 * Fetch from the DT nodes read by dlpar_configure_connector() the NUMA 229 * node id the added CPU belongs to. 230 */ 231 node = of_node_to_nid(np); 232 if (node < 0 || !node_possible(node)) 233 node = first_online_node; 234 235 BUG_ON(node == NUMA_NO_NODE); 236 assigned_node = node; 237 238 cpu_maps_update_begin(); 239 240 rc = find_cpu_id_range(nthreads, node, &cpu_mask); 241 if (rc && nr_node_ids > 1) { 242 /* 243 * Try again, considering the free CPU ids from the other node. 244 */ 245 node = NUMA_NO_NODE; 246 rc = find_cpu_id_range(nthreads, NUMA_NO_NODE, &cpu_mask); 247 } 248 249 if (rc) { 250 pr_err("Cannot add cpu %pOF; this system configuration" 251 " supports %d logical cpus.\n", np, num_possible_cpus()); 252 goto out; 253 } 254 255 for_each_cpu(cpu, cpu_mask) { 256 BUG_ON(cpu_present(cpu)); 257 set_cpu_present(cpu, true); 258 set_hard_smp_processor_id(cpu, be32_to_cpu(*intserv++)); 259 } 260 261 /* Record the newly used CPU ids for the associate node. */ 262 cpumask_or(node_recorded_ids_map[assigned_node], 263 node_recorded_ids_map[assigned_node], cpu_mask); 264 265 /* 266 * If node is set to NUMA_NO_NODE, CPU ids have be reused from 267 * another node, remove them from its mask. 268 */ 269 if (node == NUMA_NO_NODE) { 270 cpu = cpumask_first(cpu_mask); 271 pr_warn("Reusing free CPU ids %d-%d from another node\n", 272 cpu, cpu + nthreads - 1); 273 for_each_online_node(node) { 274 if (node == assigned_node) 275 continue; 276 cpumask_andnot(node_recorded_ids_map[node], 277 node_recorded_ids_map[node], 278 cpu_mask); 279 } 280 } 281 282out: 283 cpu_maps_update_done(); 284 free_cpumask_var(cpu_mask); 285 return rc; 286} 287 288/* 289 * Update the present map for a cpu node which is going away, and set 290 * the hard id in the paca(s) to -1 to be consistent with boot time 291 * convention for non-present cpus. 292 */ 293static void pseries_remove_processor(struct device_node *np) 294{ 295 unsigned int cpu; 296 int len, nthreads, i; 297 const __be32 *intserv; 298 u32 thread; 299 300 intserv = of_get_property(np, "ibm,ppc-interrupt-server#s", &len); 301 if (!intserv) 302 return; 303 304 nthreads = len / sizeof(u32); 305 306 cpu_maps_update_begin(); 307 for (i = 0; i < nthreads; i++) { 308 thread = be32_to_cpu(intserv[i]); 309 for_each_present_cpu(cpu) { 310 if (get_hard_smp_processor_id(cpu) != thread) 311 continue; 312 BUG_ON(cpu_online(cpu)); 313 set_cpu_present(cpu, false); 314 set_hard_smp_processor_id(cpu, -1); 315 update_numa_cpu_lookup_table(cpu, -1); 316 break; 317 } 318 if (cpu >= nr_cpu_ids) 319 printk(KERN_WARNING "Could not find cpu to remove " 320 "with physical id 0x%x\n", thread); 321 } 322 cpu_maps_update_done(); 323} 324 325static int dlpar_offline_cpu(struct device_node *dn) 326{ 327 int rc = 0; 328 unsigned int cpu; 329 int len, nthreads, i; 330 const __be32 *intserv; 331 u32 thread; 332 333 intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len); 334 if (!intserv) 335 return -EINVAL; 336 337 nthreads = len / sizeof(u32); 338 339 cpu_maps_update_begin(); 340 for (i = 0; i < nthreads; i++) { 341 thread = be32_to_cpu(intserv[i]); 342 for_each_present_cpu(cpu) { 343 if (get_hard_smp_processor_id(cpu) != thread) 344 continue; 345 346 if (!cpu_online(cpu)) 347 break; 348 349 /* 350 * device_offline() will return -EBUSY (via cpu_down()) if there 351 * is only one CPU left. Check it here to fail earlier and with a 352 * more informative error message, while also retaining the 353 * cpu_add_remove_lock to be sure that no CPUs are being 354 * online/offlined during this check. 355 */ 356 if (num_online_cpus() == 1) { 357 pr_warn("Unable to remove last online CPU %pOFn\n", dn); 358 rc = -EBUSY; 359 goto out_unlock; 360 } 361 362 cpu_maps_update_done(); 363 rc = device_offline(get_cpu_device(cpu)); 364 if (rc) 365 goto out; 366 cpu_maps_update_begin(); 367 break; 368 } 369 if (cpu == num_possible_cpus()) { 370 pr_warn("Could not find cpu to offline with physical id 0x%x\n", 371 thread); 372 } 373 } 374out_unlock: 375 cpu_maps_update_done(); 376 377out: 378 return rc; 379} 380 381static int dlpar_online_cpu(struct device_node *dn) 382{ 383 int rc = 0; 384 unsigned int cpu; 385 int len, nthreads, i; 386 const __be32 *intserv; 387 u32 thread; 388 389 intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len); 390 if (!intserv) 391 return -EINVAL; 392 393 nthreads = len / sizeof(u32); 394 395 cpu_maps_update_begin(); 396 for (i = 0; i < nthreads; i++) { 397 thread = be32_to_cpu(intserv[i]); 398 for_each_present_cpu(cpu) { 399 if (get_hard_smp_processor_id(cpu) != thread) 400 continue; 401 402 if (!topology_is_primary_thread(cpu)) { 403 if (cpu_smt_control != CPU_SMT_ENABLED) 404 break; 405 if (!topology_smt_thread_allowed(cpu)) 406 break; 407 } 408 409 cpu_maps_update_done(); 410 find_and_update_cpu_nid(cpu); 411 rc = device_online(get_cpu_device(cpu)); 412 if (rc) { 413 dlpar_offline_cpu(dn); 414 goto out; 415 } 416 cpu_maps_update_begin(); 417 418 break; 419 } 420 if (cpu == num_possible_cpus()) 421 printk(KERN_WARNING "Could not find cpu to online " 422 "with physical id 0x%x\n", thread); 423 } 424 cpu_maps_update_done(); 425 426out: 427 return rc; 428 429} 430 431static bool dlpar_cpu_exists(struct device_node *parent, u32 drc_index) 432{ 433 struct device_node *child = NULL; 434 u32 my_drc_index; 435 bool found; 436 int rc; 437 438 /* Assume cpu doesn't exist */ 439 found = false; 440 441 for_each_child_of_node(parent, child) { 442 rc = of_property_read_u32(child, "ibm,my-drc-index", 443 &my_drc_index); 444 if (rc) 445 continue; 446 447 if (my_drc_index == drc_index) { 448 of_node_put(child); 449 found = true; 450 break; 451 } 452 } 453 454 return found; 455} 456 457static bool drc_info_valid_index(struct device_node *parent, u32 drc_index) 458{ 459 struct property *info; 460 struct of_drc_info drc; 461 const __be32 *value; 462 u32 index; 463 int count, i, j; 464 465 info = of_find_property(parent, "ibm,drc-info", NULL); 466 if (!info) 467 return false; 468 469 value = of_prop_next_u32(info, NULL, &count); 470 471 /* First value of ibm,drc-info is number of drc-info records */ 472 if (value) 473 value++; 474 else 475 return false; 476 477 for (i = 0; i < count; i++) { 478 if (of_read_drc_info_cell(&info, &value, &drc)) 479 return false; 480 481 if (strncmp(drc.drc_type, "CPU", 3)) 482 break; 483 484 if (drc_index > drc.last_drc_index) 485 continue; 486 487 index = drc.drc_index_start; 488 for (j = 0; j < drc.num_sequential_elems; j++) { 489 if (drc_index == index) 490 return true; 491 492 index += drc.sequential_inc; 493 } 494 } 495 496 return false; 497} 498 499static bool valid_cpu_drc_index(struct device_node *parent, u32 drc_index) 500{ 501 bool found = false; 502 int rc, index; 503 504 if (of_property_present(parent, "ibm,drc-info")) 505 return drc_info_valid_index(parent, drc_index); 506 507 /* Note that the format of the ibm,drc-indexes array is 508 * the number of entries in the array followed by the array 509 * of drc values so we start looking at index = 1. 510 */ 511 index = 1; 512 while (!found) { 513 u32 drc; 514 515 rc = of_property_read_u32_index(parent, "ibm,drc-indexes", 516 index++, &drc); 517 518 if (rc) 519 break; 520 521 if (drc == drc_index) 522 found = true; 523 } 524 525 return found; 526} 527 528static int pseries_cpuhp_attach_nodes(struct device_node *dn) 529{ 530 struct of_changeset cs; 531 int ret; 532 533 /* 534 * This device node is unattached but may have siblings; open-code the 535 * traversal. 536 */ 537 for (of_changeset_init(&cs); dn != NULL; dn = dn->sibling) { 538 ret = of_changeset_attach_node(&cs, dn); 539 if (ret) 540 goto out; 541 } 542 543 ret = of_changeset_apply(&cs); 544out: 545 of_changeset_destroy(&cs); 546 return ret; 547} 548 549static ssize_t dlpar_cpu_add(u32 drc_index) 550{ 551 struct device_node *dn, *parent; 552 int rc, saved_rc; 553 554 pr_debug("Attempting to add CPU, drc index: %x\n", drc_index); 555 556 parent = of_find_node_by_path("/cpus"); 557 if (!parent) { 558 pr_warn("Failed to find CPU root node \"/cpus\"\n"); 559 return -ENODEV; 560 } 561 562 if (dlpar_cpu_exists(parent, drc_index)) { 563 of_node_put(parent); 564 pr_warn("CPU with drc index %x already exists\n", drc_index); 565 return -EINVAL; 566 } 567 568 if (!valid_cpu_drc_index(parent, drc_index)) { 569 of_node_put(parent); 570 pr_warn("Cannot find CPU (drc index %x) to add.\n", drc_index); 571 return -EINVAL; 572 } 573 574 rc = dlpar_acquire_drc(drc_index); 575 if (rc) { 576 pr_warn("Failed to acquire DRC, rc: %d, drc index: %x\n", 577 rc, drc_index); 578 of_node_put(parent); 579 return -EINVAL; 580 } 581 582 dn = dlpar_configure_connector(cpu_to_be32(drc_index), parent); 583 if (!dn) { 584 pr_warn("Failed call to configure-connector, drc index: %x\n", 585 drc_index); 586 dlpar_release_drc(drc_index); 587 of_node_put(parent); 588 return -EINVAL; 589 } 590 591 rc = pseries_cpuhp_attach_nodes(dn); 592 593 /* Regardless we are done with parent now */ 594 of_node_put(parent); 595 596 if (rc) { 597 saved_rc = rc; 598 pr_warn("Failed to attach node %pOFn, rc: %d, drc index: %x\n", 599 dn, rc, drc_index); 600 601 rc = dlpar_release_drc(drc_index); 602 if (!rc) 603 dlpar_free_cc_nodes(dn); 604 605 return saved_rc; 606 } 607 608 update_numa_distance(dn); 609 610 rc = dlpar_online_cpu(dn); 611 if (rc) { 612 saved_rc = rc; 613 pr_warn("Failed to online cpu %pOFn, rc: %d, drc index: %x\n", 614 dn, rc, drc_index); 615 616 rc = dlpar_detach_node(dn); 617 if (!rc) 618 dlpar_release_drc(drc_index); 619 620 return saved_rc; 621 } 622 623 pr_debug("Successfully added CPU %pOFn, drc index: %x\n", dn, 624 drc_index); 625 return rc; 626} 627 628static unsigned int pseries_cpuhp_cache_use_count(const struct device_node *cachedn) 629{ 630 unsigned int use_count = 0; 631 struct device_node *dn, *tn; 632 633 WARN_ON(!of_node_is_type(cachedn, "cache")); 634 635 for_each_of_cpu_node(dn) { 636 tn = of_find_next_cache_node(dn); 637 of_node_put(tn); 638 if (tn == cachedn) 639 use_count++; 640 } 641 642 for_each_node_by_type(dn, "cache") { 643 tn = of_find_next_cache_node(dn); 644 of_node_put(tn); 645 if (tn == cachedn) 646 use_count++; 647 } 648 649 return use_count; 650} 651 652static int pseries_cpuhp_detach_nodes(struct device_node *cpudn) 653{ 654 struct device_node *dn; 655 struct of_changeset cs; 656 int ret = 0; 657 658 of_changeset_init(&cs); 659 ret = of_changeset_detach_node(&cs, cpudn); 660 if (ret) 661 goto out; 662 663 dn = cpudn; 664 while ((dn = of_find_next_cache_node(dn))) { 665 if (pseries_cpuhp_cache_use_count(dn) > 1) { 666 of_node_put(dn); 667 break; 668 } 669 670 ret = of_changeset_detach_node(&cs, dn); 671 of_node_put(dn); 672 if (ret) 673 goto out; 674 } 675 676 ret = of_changeset_apply(&cs); 677out: 678 of_changeset_destroy(&cs); 679 return ret; 680} 681 682static ssize_t dlpar_cpu_remove(struct device_node *dn, u32 drc_index) 683{ 684 int rc; 685 686 pr_debug("Attempting to remove CPU %pOFn, drc index: %x\n", 687 dn, drc_index); 688 689 rc = dlpar_offline_cpu(dn); 690 if (rc) { 691 pr_warn("Failed to offline CPU %pOFn, rc: %d\n", dn, rc); 692 return -EINVAL; 693 } 694 695 rc = dlpar_release_drc(drc_index); 696 if (rc) { 697 pr_warn("Failed to release drc (%x) for CPU %pOFn, rc: %d\n", 698 drc_index, dn, rc); 699 dlpar_online_cpu(dn); 700 return rc; 701 } 702 703 rc = pseries_cpuhp_detach_nodes(dn); 704 if (rc) { 705 int saved_rc = rc; 706 707 pr_warn("Failed to detach CPU %pOFn, rc: %d", dn, rc); 708 709 rc = dlpar_acquire_drc(drc_index); 710 if (!rc) 711 dlpar_online_cpu(dn); 712 713 return saved_rc; 714 } 715 716 pr_debug("Successfully removed CPU, drc index: %x\n", drc_index); 717 return 0; 718} 719 720static struct device_node *cpu_drc_index_to_dn(u32 drc_index) 721{ 722 struct device_node *dn; 723 u32 my_index; 724 int rc; 725 726 for_each_node_by_type(dn, "cpu") { 727 rc = of_property_read_u32(dn, "ibm,my-drc-index", &my_index); 728 if (rc) 729 continue; 730 731 if (my_index == drc_index) 732 break; 733 } 734 735 return dn; 736} 737 738static int dlpar_cpu_remove_by_index(u32 drc_index) 739{ 740 struct device_node *dn; 741 int rc; 742 743 dn = cpu_drc_index_to_dn(drc_index); 744 if (!dn) { 745 pr_warn("Cannot find CPU (drc index %x) to remove\n", 746 drc_index); 747 return -ENODEV; 748 } 749 750 rc = dlpar_cpu_remove(dn, drc_index); 751 of_node_put(dn); 752 return rc; 753} 754 755int dlpar_cpu(struct pseries_hp_errorlog *hp_elog) 756{ 757 u32 drc_index; 758 int rc; 759 760 drc_index = hp_elog->_drc_u.drc_index; 761 762 lock_device_hotplug(); 763 764 switch (hp_elog->action) { 765 case PSERIES_HP_ELOG_ACTION_REMOVE: 766 if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX) { 767 rc = dlpar_cpu_remove_by_index(drc_index); 768 /* 769 * Setting the isolation state of an UNISOLATED/CONFIGURED 770 * device to UNISOLATE is a no-op, but the hypervisor can 771 * use it as a hint that the CPU removal failed. 772 */ 773 if (rc) 774 dlpar_unisolate_drc(drc_index); 775 } 776 else 777 rc = -EINVAL; 778 break; 779 case PSERIES_HP_ELOG_ACTION_ADD: 780 if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX) 781 rc = dlpar_cpu_add(drc_index); 782 else 783 rc = -EINVAL; 784 break; 785 default: 786 pr_err("Invalid action (%d) specified\n", hp_elog->action); 787 rc = -EINVAL; 788 break; 789 } 790 791 unlock_device_hotplug(); 792 return rc; 793} 794 795#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE 796 797static ssize_t dlpar_cpu_probe(const char *buf, size_t count) 798{ 799 u32 drc_index; 800 int rc; 801 802 rc = kstrtou32(buf, 0, &drc_index); 803 if (rc) 804 return -EINVAL; 805 806 rc = dlpar_cpu_add(drc_index); 807 808 return rc ? rc : count; 809} 810 811static ssize_t dlpar_cpu_release(const char *buf, size_t count) 812{ 813 struct device_node *dn; 814 u32 drc_index; 815 int rc; 816 817 dn = of_find_node_by_path(buf); 818 if (!dn) 819 return -EINVAL; 820 821 rc = of_property_read_u32(dn, "ibm,my-drc-index", &drc_index); 822 if (rc) { 823 of_node_put(dn); 824 return -EINVAL; 825 } 826 827 rc = dlpar_cpu_remove(dn, drc_index); 828 of_node_put(dn); 829 830 return rc ? rc : count; 831} 832 833#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */ 834 835static int pseries_smp_notifier(struct notifier_block *nb, 836 unsigned long action, void *data) 837{ 838 struct of_reconfig_data *rd = data; 839 int err = 0; 840 841 switch (action) { 842 case OF_RECONFIG_ATTACH_NODE: 843 err = pseries_add_processor(rd->dn); 844 break; 845 case OF_RECONFIG_DETACH_NODE: 846 pseries_remove_processor(rd->dn); 847 break; 848 } 849 return notifier_from_errno(err); 850} 851 852static struct notifier_block pseries_smp_nb = { 853 .notifier_call = pseries_smp_notifier, 854}; 855 856void __init pseries_cpu_hotplug_init(void) 857{ 858 int qcss_tok; 859 860 rtas_stop_self_token = rtas_function_token(RTAS_FN_STOP_SELF); 861 qcss_tok = rtas_function_token(RTAS_FN_QUERY_CPU_STOPPED_STATE); 862 863 if (rtas_stop_self_token == RTAS_UNKNOWN_SERVICE || 864 qcss_tok == RTAS_UNKNOWN_SERVICE) { 865 printk(KERN_INFO "CPU Hotplug not supported by firmware " 866 "- disabling.\n"); 867 return; 868 } 869 870 smp_ops->cpu_offline_self = pseries_cpu_offline_self; 871 smp_ops->cpu_disable = pseries_cpu_disable; 872 smp_ops->cpu_die = pseries_cpu_die; 873} 874 875static int __init pseries_dlpar_init(void) 876{ 877 unsigned int node; 878 879#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE 880 ppc_md.cpu_probe = dlpar_cpu_probe; 881 ppc_md.cpu_release = dlpar_cpu_release; 882#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */ 883 884 /* Processors can be added/removed only on LPAR */ 885 if (firmware_has_feature(FW_FEATURE_LPAR)) { 886 for_each_node(node) { 887 if (!alloc_cpumask_var_node(&node_recorded_ids_map[node], 888 GFP_KERNEL, node)) 889 return -ENOMEM; 890 891 /* Record ids of CPU added at boot time */ 892 cpumask_copy(node_recorded_ids_map[node], 893 cpumask_of_node(node)); 894 } 895 896 of_reconfig_notifier_register(&pseries_smp_nb); 897 } 898 899 return 0; 900} 901machine_arch_initcall(pseries, pseries_dlpar_init); 902