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()
 350 {
 351         mutex_lock(&pseries_cpu_hotplug_mutex);
 352 }
 353
 354 void cpu_hotplug_driver_unlock()
 355 {
 356         mutex_unlock(&pseries_cpu_hotplug_mutex);
 357 }
 358
 359 static int dlpar_online_cpu(struct device_node *dn)
 360 {
 361         int rc = 0;
 362         unsigned int cpu;
 363         int len, nthreads, i;
 364         const u32 *intserv;
 365
 366         intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
 367         if (!intserv)
 368                 return -EINVAL;
 369
 370         nthreads = len / sizeof(u32);
 371
 372         cpu_maps_update_begin();
 373         for (i = 0; i < nthreads; i++) {
 374                 for_each_present_cpu(cpu) {
 375                         if (get_hard_smp_processor_id(cpu) != intserv[i])
 376                                 continue;
 377                         BUG_ON(get_cpu_current_state(cpu)
 378                                         != CPU_STATE_OFFLINE);
 379                         cpu_maps_update_done();
 380                         rc = cpu_up(cpu);
 381                         if (rc)
 382                                 goto out;
 383                         cpu_maps_update_begin();
 384
 385                         break;
 386                 }
 387                 if (cpu == num_possible_cpus())
 388                         printk(KERN_WARNING "Could not find cpu to online "
 389                                "with physical id 0x%x\n", intserv[i]);
 390         }
 391         cpu_maps_update_done();
 392
 393 out:
 394         return rc;
 395
 396 }
 397
 398 static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
 399 {
 400         struct device_node *dn;
 401         unsigned long drc_index;
 402         char *cpu_name;
 403         int rc;
 404
 405         cpu_hotplug_driver_lock();
 406         rc = strict_strtoul(buf, 0, &drc_index);
 407         if (rc) {
 408                 rc = -EINVAL;
 409                 goto out;
 410         }
 411
 412         dn = dlpar_configure_connector(drc_index);
 413         if (!dn) {
 414                 rc = -EINVAL;
 415                 goto out;
 416         }
 417
 418         /* configure-connector reports cpus as living in the base
 419          * directory of the device tree.  CPUs actually live in the
 420          * cpus directory so we need to fixup the full_name.
 421          */
 422         cpu_name = kzalloc(strlen(dn->full_name) + strlen("/cpus") + 1,
 423                            GFP_KERNEL);
 424         if (!cpu_name) {
 425                 dlpar_free_cc_nodes(dn);
 426                 rc = -ENOMEM;
 427                 goto out;
 428         }
 429
 430         sprintf(cpu_name, "/cpus%s", dn->full_name);
 431         kfree(dn->full_name);
 432         dn->full_name = cpu_name;
 433
 434         rc = dlpar_acquire_drc(drc_index);
 435         if (rc) {
 436                 dlpar_free_cc_nodes(dn);
 437                 rc = -EINVAL;
 438                 goto out;
 439         }
 440
 441         rc = dlpar_attach_node(dn);
 442         if (rc) {
 443                 dlpar_release_drc(drc_index);
 444                 dlpar_free_cc_nodes(dn);
 445         }
 446
 447         rc = dlpar_online_cpu(dn);
 448 out:
 449         cpu_hotplug_driver_unlock();
 450
 451         return rc ? rc : count;
 452 }
 453
 454 static int dlpar_offline_cpu(struct device_node *dn)
 455 {
 456         int rc = 0;
 457         unsigned int cpu;
 458         int len, nthreads, i;
 459         const u32 *intserv;
 460
 461         intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
 462         if (!intserv)
 463                 return -EINVAL;
 464
 465         nthreads = len / sizeof(u32);
 466
 467         cpu_maps_update_begin();
 468         for (i = 0; i < nthreads; i++) {
 469                 for_each_present_cpu(cpu) {
 470                         if (get_hard_smp_processor_id(cpu) != intserv[i])
 471                                 continue;
 472
 473                         if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)
 474                                 break;
 475
 476                         if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {
 477                                 cpu_maps_update_done();
 478                                 rc = cpu_down(cpu);
 479                                 if (rc)
 480                                         goto out;
 481                                 cpu_maps_update_begin();
 482                                 break;
 483
 484                         }
 485
 486                         /*
 487                          * The cpu is in CPU_STATE_INACTIVE.
 488                          * Upgrade it's state to CPU_STATE_OFFLINE.
 489                          */
 490                         set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
 491                         BUG_ON(plpar_hcall_norets(H_PROD, intserv[i])
 492                                                                 != H_SUCCESS);
 493                         __cpu_die(cpu);
 494                         break;
 495                 }
 496                 if (cpu == num_possible_cpus())
 497                         printk(KERN_WARNING "Could not find cpu to offline "
 498                                "with physical id 0x%x\n", intserv[i]);
 499         }
 500         cpu_maps_update_done();
 501
 502 out:
 503         return rc;
 504
 505 }
 506
 507 static ssize_t dlpar_cpu_release(const char *buf, size_t count)
 508 {
 509         struct device_node *dn;
 510         const u32 *drc_index;
 511         int rc;
 512
 513         dn = of_find_node_by_path(buf);
 514         if (!dn)
 515                 return -EINVAL;
 516
 517         drc_index = of_get_property(dn, "ibm,my-drc-index", NULL);
 518         if (!drc_index) {
 519                 of_node_put(dn);
 520                 return -EINVAL;
 521         }
 522
 523         cpu_hotplug_driver_lock();
 524         rc = dlpar_offline_cpu(dn);
 525         if (rc) {
 526                 of_node_put(dn);
 527                 rc = -EINVAL;
 528                 goto out;
 529         }
 530
 531         rc = dlpar_release_drc(*drc_index);
 532         if (rc) {
 533                 of_node_put(dn);
 534                 goto out;
 535         }
 536
 537         rc = dlpar_detach_node(dn);
 538         if (rc) {
 539                 dlpar_acquire_drc(*drc_index);
 540                 goto out;
 541         }
 542
 543         of_node_put(dn);
 544 out:
 545         cpu_hotplug_driver_unlock();
 546         return rc ? rc : count;
 547 }
 548
 549 static int __init pseries_dlpar_init(void)
 550 {
 551         ppc_md.cpu_probe = dlpar_cpu_probe;
 552         ppc_md.cpu_release = dlpar_cpu_release;
 553
 554         return 0;
 555 }
 556 machine_device_initcall(pseries, pseries_dlpar_init);
 557
 558 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */