arch/powerpc/platforms/pseries/dlpar.c

   1 /*
   2  * Support for dynamic reconfiguration for PCI, Memory, and CPU
   3  * Hotplug and Dynamic Logical Partitioning on RPA platforms.
   4  *
   5  * Copyright (C) 2009 Nathan Fontenot
   6  * Copyright (C) 2009 IBM Corporation
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License version
  10  * 2 as published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/kref.h>
  15 #include <linux/notifier.h>
  16 #include <linux/proc_fs.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/cpu.h>
  19 #include <linux/slab.h>
  20 #include "offline_states.h"
  21
  22 #include <asm/prom.h>
  23 #include <asm/machdep.h>
  24 #include <asm/uaccess.h>
  25 #include <asm/rtas.h>
  26 #include <asm/pSeries_reconfig.h>
  27
  28 struct cc_workarea {
  29         u32     drc_index;
  30         u32     zero;
  31         u32     name_offset;
  32         u32     prop_length;
  33         u32     prop_offset;
  34 };
  35
  36 void dlpar_free_cc_property(struct property *prop)
  37 {
  38         kfree(prop->name);
  39         kfree(prop->value);
  40         kfree(prop);
  41 }
  42
  43 static struct property *dlpar_parse_cc_property(struct cc_workarea *ccwa)
  44 {
  45         struct property *prop;
  46         char *name;
  47         char *value;
  48
  49         prop = kzalloc(sizeof(*prop), GFP_KERNEL);
  50         if (!prop)
  51                 return NULL;
  52
  53         name = (char *)ccwa + ccwa->name_offset;
  54         prop->name = kstrdup(name, GFP_KERNEL);
  55
  56         prop->length = ccwa->prop_length;
  57         value = (char *)ccwa + ccwa->prop_offset;
  58         prop->value = kmemdup(value, prop->length, GFP_KERNEL);
  59         if (!prop->value) {
  60                 dlpar_free_cc_property(prop);
  61                 return NULL;
  62         }
  63
  64         return prop;
  65 }
  66
  67 static struct device_node *dlpar_parse_cc_node(struct cc_workarea *ccwa)
  68 {
  69         struct device_node *dn;
  70         char *name;
  71
  72         dn = kzalloc(sizeof(*dn), GFP_KERNEL);
  73         if (!dn)
  74                 return NULL;
  75
  76         /* The configure connector reported name does not contain a
  77          * preceding '/', so we allocate a buffer large enough to
  78          * prepend this to the full_name.
  79          */
  80         name = (char *)ccwa + ccwa->name_offset;
  81         dn->full_name = kasprintf(GFP_KERNEL, "/%s", name);
  82         if (!dn->full_name) {
  83                 kfree(dn);
  84                 return NULL;
  85         }
  86
  87         return dn;
  88 }
  89
  90 static void dlpar_free_one_cc_node(struct device_node *dn)
  91 {
  92         struct property *prop;
  93
  94         while (dn->properties) {
  95                 prop = dn->properties;
  96                 dn->properties = prop->next;
  97                 dlpar_free_cc_property(prop);
  98         }
  99
 100         kfree(dn->full_name);
 101         kfree(dn);
 102 }
 103
 104 void dlpar_free_cc_nodes(struct device_node *dn)
 105 {
 106         if (dn->child)
 107                 dlpar_free_cc_nodes(dn->child);
 108
 109         if (dn->sibling)
 110                 dlpar_free_cc_nodes(dn->sibling);
 111
 112         dlpar_free_one_cc_node(dn);
 113 }
 114
 115 #define COMPLETE        0
 116 #define NEXT_SIBLING    1
 117 #define NEXT_CHILD      2
 118 #define NEXT_PROPERTY   3
 119 #define PREV_PARENT     4
 120 #define MORE_MEMORY     5
 121 #define CALL_AGAIN      -2
 122 #define ERR_CFG_USE     -9003
 123
 124 struct device_node *dlpar_configure_connector(u32 drc_index)
 125 {
 126         struct device_node *dn;
 127         struct device_node *first_dn = NULL;
 128         struct device_node *last_dn = NULL;
 129         struct property *property;
 130         struct property *last_property = NULL;
 131         struct cc_workarea *ccwa;
 132         char *data_buf;
 133         int cc_token;
 134         int rc = -1;
 135
 136         cc_token = rtas_token("ibm,configure-connector");
 137         if (cc_token == RTAS_UNKNOWN_SERVICE)
 138                 return NULL;
 139
 140         data_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
 141         if (!data_buf)
 142                 return NULL;
 143
 144         ccwa = (struct cc_workarea *)&data_buf[0];
 145         ccwa->drc_index = drc_index;
 146         ccwa->zero = 0;
 147
 148         do {
 149                 /* Since we release the rtas_data_buf lock between configure
 150                  * connector calls we want to re-populate the rtas_data_buffer
 151                  * with the contents of the previous call.
 152                  */
 153                 spin_lock(&rtas_data_buf_lock);
 154
 155                 memcpy(rtas_data_buf, data_buf, RTAS_DATA_BUF_SIZE);
 156                 rc = rtas_call(cc_token, 2, 1, NULL, rtas_data_buf, NULL);
 157                 memcpy(data_buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);
 158
 159                 spin_unlock(&rtas_data_buf_lock);
 160
 161                 switch (rc) {
 162                 case COMPLETE:
 163                         break;
 164
 165                 case NEXT_SIBLING:
 166                         dn = dlpar_parse_cc_node(ccwa);
 167                         if (!dn)
 168                                 goto cc_error;
 169
 170                         dn->parent = last_dn->parent;
 171                         last_dn->sibling = dn;
 172                         last_dn = dn;
 173                         break;
 174
 175                 case NEXT_CHILD:
 176                         dn = dlpar_parse_cc_node(ccwa);
 177                         if (!dn)
 178                                 goto cc_error;
 179
 180                         if (!first_dn)
 181                                 first_dn = dn;
 182                         else {
 183                                 dn->parent = last_dn;
 184                                 if (last_dn)
 185                                         last_dn->child = dn;
 186                         }
 187
 188                         last_dn = dn;
 189                         break;
 190
 191                 case NEXT_PROPERTY:
 192                         property = dlpar_parse_cc_property(ccwa);
 193                         if (!property)
 194                                 goto cc_error;
 195
 196                         if (!last_dn->properties)
 197                                 last_dn->properties = property;
 198                         else
 199                                 last_property->next = property;
 200
 201                         last_property = property;
 202                         break;
 203
 204                 case PREV_PARENT:
 205                         last_dn = last_dn->parent;
 206                         break;
 207
 208                 case CALL_AGAIN:
 209                         break;
 210
 211                 case MORE_MEMORY:
 212                 case ERR_CFG_USE:
 213                 default:
 214                         printk(KERN_ERR "Unexpected Error (%d) "
 215                                "returned from configure-connector\n", rc);
 216                         goto cc_error;
 217                 }
 218         } while (rc);
 219
 220 cc_error:
 221         kfree(data_buf);
 222
 223         if (rc) {
 224                 if (first_dn)
 225                         dlpar_free_cc_nodes(first_dn);
 226
 227                 return NULL;
 228         }
 229
 230         return first_dn;
 231 }
 232
 233 static struct device_node *derive_parent(const char *path)
 234 {
 235         struct device_node *parent;
 236         char *last_slash;
 237
 238         last_slash = strrchr(path, '/');
 239         if (last_slash == path) {
 240                 parent = of_find_node_by_path("/");
 241         } else {
 242                 char *parent_path;
 243                 int parent_path_len = last_slash - path + 1;
 244                 parent_path = kmalloc(parent_path_len, GFP_KERNEL);
 245                 if (!parent_path)
 246                         return NULL;
 247
 248                 strlcpy(parent_path, path, parent_path_len);
 249                 parent = of_find_node_by_path(parent_path);
 250                 kfree(parent_path);
 251         }
 252
 253         return parent;
 254 }
 255
 256 int dlpar_attach_node(struct device_node *dn)
 257 {
 258 #ifdef CONFIG_PROC_DEVICETREE
 259         struct proc_dir_entry *ent;
 260 #endif
 261         int rc;
 262
 263         of_node_set_flag(dn, OF_DYNAMIC);
 264         kref_init(&dn->kref);
 265         dn->parent = derive_parent(dn->full_name);
 266         if (!dn->parent)
 267                 return -ENOMEM;
 268
 269         rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
 270                                           PSERIES_RECONFIG_ADD, dn);
 271         if (rc == NOTIFY_BAD) {
 272                 printk(KERN_ERR "Failed to add device node %s\n",
 273                        dn->full_name);
 274                 return -ENOMEM; /* For now, safe to assume kmalloc failure */
 275         }
 276
 277         of_attach_node(dn);
 278
 279 #ifdef CONFIG_PROC_DEVICETREE
 280         ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
 281         if (ent)
 282                 proc_device_tree_add_node(dn, ent);
 283 #endif
 284
 285         of_node_put(dn->parent);
 286         return 0;
 287 }
 288
 289 int dlpar_detach_node(struct device_node *dn)
 290 {
 291 #ifdef CONFIG_PROC_DEVICETREE
 292         struct device_node *parent = dn->parent;
 293         struct property *prop = dn->properties;
 294
 295         while (prop) {
 296                 remove_proc_entry(prop->name, dn->pde);
 297                 prop = prop->next;
 298         }
 299
 300         if (dn->pde)
 301                 remove_proc_entry(dn->pde->name, parent->pde);
 302 #endif
 303
 304         blocking_notifier_call_chain(&pSeries_reconfig_chain,
 305                             PSERIES_RECONFIG_REMOVE, dn);
 306         of_detach_node(dn);
 307         of_node_put(dn); /* Must decrement the refcount */
 308
 309         return 0;
 310 }
 311
 312 #define DR_ENTITY_SENSE         9003
 313 #define DR_ENTITY_PRESENT       1
 314 #define DR_ENTITY_UNUSABLE      2
 315 #define ALLOCATION_STATE        9003
 316 #define ALLOC_UNUSABLE          0
 317 #define ALLOC_USABLE            1
 318 #define ISOLATION_STATE         9001
 319 #define ISOLATE                 0
 320 #define UNISOLATE               1
 321
 322 int dlpar_acquire_drc(u32 drc_index)
 323 {
 324         int dr_status, rc;
 325
 326         rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
 327                        DR_ENTITY_SENSE, drc_index);
 328         if (rc || dr_status != DR_ENTITY_UNUSABLE)
 329                 return -1;
 330
 331         rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_USABLE);
 332         if (rc)
 333                 return rc;
 334
 335         rc = rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
 336         if (rc) {
 337                 rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
 338                 return rc;
 339         }
 340
 341         return 0;
 342 }
 343
 344 int dlpar_release_drc(u32 drc_index)
 345 {
 346         int dr_status, rc;
 347
 348         rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
 349                        DR_ENTITY_SENSE, drc_index);
 350         if (rc || dr_status != DR_ENTITY_PRESENT)
 351                 return -1;
 352
 353         rc = rtas_set_indicator(ISOLATION_STATE, drc_index, ISOLATE);
 354         if (rc)
 355                 return rc;
 356
 357         rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
 358         if (rc) {
 359                 rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
 360                 return rc;
 361         }
 362
 363         return 0;
 364 }
 365
 366 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 367
 368 static int dlpar_online_cpu(struct device_node *dn)
 369 {
 370         int rc = 0;
 371         unsigned int cpu;
 372         int len, nthreads, i;
 373         const u32 *intserv;
 374
 375         intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
 376         if (!intserv)
 377                 return -EINVAL;
 378
 379         nthreads = len / sizeof(u32);
 380
 381         cpu_maps_update_begin();
 382         for (i = 0; i < nthreads; i++) {
 383                 for_each_present_cpu(cpu) {
 384                         if (get_hard_smp_processor_id(cpu) != intserv[i])
 385                                 continue;
 386                         BUG_ON(get_cpu_current_state(cpu)
 387                                         != CPU_STATE_OFFLINE);
 388                         cpu_maps_update_done();
 389                         rc = cpu_up(cpu);
 390                         if (rc)
 391                                 goto out;
 392                         cpu_maps_update_begin();
 393
 394                         break;
 395                 }
 396                 if (cpu == num_possible_cpus())
 397                         printk(KERN_WARNING "Could not find cpu to online "
 398                                "with physical id 0x%x\n", intserv[i]);
 399         }
 400         cpu_maps_update_done();
 401
 402 out:
 403         return rc;
 404
 405 }
 406
 407 static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
 408 {
 409         struct device_node *dn;
 410         unsigned long drc_index;
 411         char *cpu_name;
 412         int rc;
 413
 414         cpu_hotplug_driver_lock();
 415         rc = strict_strtoul(buf, 0, &drc_index);
 416         if (rc) {
 417                 rc = -EINVAL;
 418                 goto out;
 419         }
 420
 421         dn = dlpar_configure_connector(drc_index);
 422         if (!dn) {
 423                 rc = -EINVAL;
 424                 goto out;
 425         }
 426
 427         /* configure-connector reports cpus as living in the base
 428          * directory of the device tree.  CPUs actually live in the
 429          * cpus directory so we need to fixup the full_name.
 430          */
 431         cpu_name = kasprintf(GFP_KERNEL, "/cpus%s", dn->full_name);
 432         if (!cpu_name) {
 433                 dlpar_free_cc_nodes(dn);
 434                 rc = -ENOMEM;
 435                 goto out;
 436         }
 437
 438         kfree(dn->full_name);
 439         dn->full_name = cpu_name;
 440
 441         rc = dlpar_acquire_drc(drc_index);
 442         if (rc) {
 443                 dlpar_free_cc_nodes(dn);
 444                 rc = -EINVAL;
 445                 goto out;
 446         }
 447
 448         rc = dlpar_attach_node(dn);
 449         if (rc) {
 450                 dlpar_release_drc(drc_index);
 451                 dlpar_free_cc_nodes(dn);
 452                 goto out;
 453         }
 454
 455         rc = dlpar_online_cpu(dn);
 456 out:
 457         cpu_hotplug_driver_unlock();
 458
 459         return rc ? rc : count;
 460 }
 461
 462 static int dlpar_offline_cpu(struct device_node *dn)
 463 {
 464         int rc = 0;
 465         unsigned int cpu;
 466         int len, nthreads, i;
 467         const u32 *intserv;
 468
 469         intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
 470         if (!intserv)
 471                 return -EINVAL;
 472
 473         nthreads = len / sizeof(u32);
 474
 475         cpu_maps_update_begin();
 476         for (i = 0; i < nthreads; i++) {
 477                 for_each_present_cpu(cpu) {
 478                         if (get_hard_smp_processor_id(cpu) != intserv[i])
 479                                 continue;
 480
 481                         if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)
 482                                 break;
 483
 484                         if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {
 485                                 set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
 486                                 cpu_maps_update_done();
 487                                 rc = cpu_down(cpu);
 488                                 if (rc)
 489                                         goto out;
 490                                 cpu_maps_update_begin();
 491                                 break;
 492
 493                         }
 494
 495                         /*
 496                          * The cpu is in CPU_STATE_INACTIVE.
 497                          * Upgrade it's state to CPU_STATE_OFFLINE.
 498                          */
 499                         set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
 500                         BUG_ON(plpar_hcall_norets(H_PROD, intserv[i])
 501                                                                 != H_SUCCESS);
 502                         __cpu_die(cpu);
 503                         break;
 504                 }
 505                 if (cpu == num_possible_cpus())
 506                         printk(KERN_WARNING "Could not find cpu to offline "
 507                                "with physical id 0x%x\n", intserv[i]);
 508         }
 509         cpu_maps_update_done();
 510
 511 out:
 512         return rc;
 513
 514 }
 515
 516 static ssize_t dlpar_cpu_release(const char *buf, size_t count)
 517 {
 518         struct device_node *dn;
 519         const u32 *drc_index;
 520         int rc;
 521
 522         dn = of_find_node_by_path(buf);
 523         if (!dn)
 524                 return -EINVAL;
 525
 526         drc_index = of_get_property(dn, "ibm,my-drc-index", NULL);
 527         if (!drc_index) {
 528                 of_node_put(dn);
 529                 return -EINVAL;
 530         }
 531
 532         cpu_hotplug_driver_lock();
 533         rc = dlpar_offline_cpu(dn);
 534         if (rc) {
 535                 of_node_put(dn);
 536                 rc = -EINVAL;
 537                 goto out;
 538         }
 539
 540         rc = dlpar_release_drc(*drc_index);
 541         if (rc) {
 542                 of_node_put(dn);
 543                 goto out;
 544         }
 545
 546         rc = dlpar_detach_node(dn);
 547         if (rc) {
 548                 dlpar_acquire_drc(*drc_index);
 549                 goto out;
 550         }
 551
 552         of_node_put(dn);
 553 out:
 554         cpu_hotplug_driver_unlock();
 555         return rc ? rc : count;
 556 }
 557
 558 static int __init pseries_dlpar_init(void)
 559 {
 560         ppc_md.cpu_probe = dlpar_cpu_probe;
 561         ppc_md.cpu_release = dlpar_cpu_release;
 562
 563         return 0;
 564 }
 565 machine_device_initcall(pseries, pseries_dlpar_init);
 566
 567 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */