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