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 static 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 = kzalloc(prop->length, GFP_KERNEL);
  59         if (!prop->value) {
  60                 dlpar_free_cc_property(prop);
  61                 return NULL;
  62         }
  63
  64         memcpy(prop->value, value, prop->length);
  65         return prop;
  66 }
  67
  68 static struct device_node *dlpar_parse_cc_node(struct cc_workarea *ccwa)
  69 {
  70         struct device_node *dn;
  71         char *name;
  72
  73         dn = kzalloc(sizeof(*dn), GFP_KERNEL);
  74         if (!dn)
  75                 return NULL;
  76
  77         /* The configure connector reported name does not contain a
  78          * preceeding '/', so we allocate a buffer large enough to
  79          * prepend this to the full_name.
  80          */
  81         name = (char *)ccwa + ccwa->name_offset;
  82         dn->full_name = kasprintf(GFP_KERNEL, "/%s", name);
  83         if (!dn->full_name) {
  84                 kfree(dn);
  85                 return NULL;
  86         }
  87
  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 #ifdef CONFIG_PROC_DEVICETREE
 240         struct proc_dir_entry *ent;
 241 #endif
 242         int rc;
 243
 244         of_node_set_flag(dn, OF_DYNAMIC);
 245         kref_init(&dn->kref);
 246         dn->parent = derive_parent(dn->full_name);
 247         if (!dn->parent)
 248                 return -ENOMEM;
 249
 250         rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
 251                                           PSERIES_RECONFIG_ADD, dn);
 252         if (rc == NOTIFY_BAD) {
 253                 printk(KERN_ERR "Failed to add device node %s\n",
 254                        dn->full_name);
 255                 return -ENOMEM; /* For now, safe to assume kmalloc failure */
 256         }
 257
 258         of_attach_node(dn);
 259
 260 #ifdef CONFIG_PROC_DEVICETREE
 261         ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
 262         if (ent)
 263                 proc_device_tree_add_node(dn, ent);
 264 #endif
 265
 266         of_node_put(dn->parent);
 267         return 0;
 268 }
 269
 270 int dlpar_detach_node(struct device_node *dn)
 271 {
 272 #ifdef CONFIG_PROC_DEVICETREE
 273         struct device_node *parent = dn->parent;
 274         struct property *prop = dn->properties;
 275
 276         while (prop) {
 277                 remove_proc_entry(prop->name, dn->pde);
 278                 prop = prop->next;
 279         }
 280
 281         if (dn->pde)
 282                 remove_proc_entry(dn->pde->name, parent->pde);
 283 #endif
 284
 285         blocking_notifier_call_chain(&pSeries_reconfig_chain,
 286                             PSERIES_RECONFIG_REMOVE, dn);
 287         of_detach_node(dn);
 288         of_node_put(dn); /* Must decrement the refcount */
 289
 290         return 0;
 291 }
 292
 293 #define DR_ENTITY_SENSE         9003
 294 #define DR_ENTITY_PRESENT       1
 295 #define DR_ENTITY_UNUSABLE      2
 296 #define ALLOCATION_STATE        9003
 297 #define ALLOC_UNUSABLE          0
 298 #define ALLOC_USABLE            1
 299 #define ISOLATION_STATE         9001
 300 #define ISOLATE                 0
 301 #define UNISOLATE               1
 302
 303 int dlpar_acquire_drc(u32 drc_index)
 304 {
 305         int dr_status, rc;
 306
 307         rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
 308                        DR_ENTITY_SENSE, drc_index);
 309         if (rc || dr_status != DR_ENTITY_UNUSABLE)
 310                 return -1;
 311
 312         rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_USABLE);
 313         if (rc)
 314                 return rc;
 315
 316         rc = rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
 317         if (rc) {
 318                 rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
 319                 return rc;
 320         }
 321
 322         return 0;
 323 }
 324
 325 int dlpar_release_drc(u32 drc_index)
 326 {
 327         int dr_status, rc;
 328
 329         rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
 330                        DR_ENTITY_SENSE, drc_index);
 331         if (rc || dr_status != DR_ENTITY_PRESENT)
 332                 return -1;
 333
 334         rc = rtas_set_indicator(ISOLATION_STATE, drc_index, ISOLATE);
 335         if (rc)
 336                 return rc;
 337
 338         rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
 339         if (rc) {
 340                 rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
 341                 return rc;
 342         }
 343
 344         return 0;
 345 }
 346
 347 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 348
 349 static int dlpar_online_cpu(struct device_node *dn)
 350 {
 351         int rc = 0;
 352         unsigned int cpu;
 353         int len, nthreads, i;
 354         const u32 *intserv;
 355
 356         intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
 357         if (!intserv)
 358                 return -EINVAL;
 359
 360         nthreads = len / sizeof(u32);
 361
 362         cpu_maps_update_begin();
 363         for (i = 0; i < nthreads; i++) {
 364                 for_each_present_cpu(cpu) {
 365                         if (get_hard_smp_processor_id(cpu) != intserv[i])
 366                                 continue;
 367                         BUG_ON(get_cpu_current_state(cpu)
 368                                         != CPU_STATE_OFFLINE);
 369                         cpu_maps_update_done();
 370                         rc = cpu_up(cpu);
 371                         if (rc)
 372                                 goto out;
 373                         cpu_maps_update_begin();
 374
 375                         break;
 376                 }
 377                 if (cpu == num_possible_cpus())
 378                         printk(KERN_WARNING "Could not find cpu to online "
 379                                "with physical id 0x%x\n", intserv[i]);
 380         }
 381         cpu_maps_update_done();
 382
 383 out:
 384         return rc;
 385
 386 }
 387
 388 static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
 389 {
 390         struct device_node *dn;
 391         unsigned long drc_index;
 392         char *cpu_name;
 393         int rc;
 394
 395         cpu_hotplug_driver_lock();
 396         rc = strict_strtoul(buf, 0, &drc_index);
 397         if (rc) {
 398                 rc = -EINVAL;
 399                 goto out;
 400         }
 401
 402         dn = dlpar_configure_connector(drc_index);
 403         if (!dn) {
 404                 rc = -EINVAL;
 405                 goto out;
 406         }
 407
 408         /* configure-connector reports cpus as living in the base
 409          * directory of the device tree.  CPUs actually live in the
 410          * cpus directory so we need to fixup the full_name.
 411          */
 412         cpu_name = kasprintf(GFP_KERNEL, "/cpus%s", dn->full_name);
 413         if (!cpu_name) {
 414                 dlpar_free_cc_nodes(dn);
 415                 rc = -ENOMEM;
 416                 goto out;
 417         }
 418
 419         kfree(dn->full_name);
 420         dn->full_name = cpu_name;
 421
 422         rc = dlpar_acquire_drc(drc_index);
 423         if (rc) {
 424                 dlpar_free_cc_nodes(dn);
 425                 rc = -EINVAL;
 426                 goto out;
 427         }
 428
 429         rc = dlpar_attach_node(dn);
 430         if (rc) {
 431                 dlpar_release_drc(drc_index);
 432                 dlpar_free_cc_nodes(dn);
 433                 goto out;
 434         }
 435
 436         rc = dlpar_online_cpu(dn);
 437 out:
 438         cpu_hotplug_driver_unlock();
 439
 440         return rc ? rc : count;
 441 }
 442
 443 static int dlpar_offline_cpu(struct device_node *dn)
 444 {
 445         int rc = 0;
 446         unsigned int cpu;
 447         int len, nthreads, i;
 448         const u32 *intserv;
 449
 450         intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
 451         if (!intserv)
 452                 return -EINVAL;
 453
 454         nthreads = len / sizeof(u32);
 455
 456         cpu_maps_update_begin();
 457         for (i = 0; i < nthreads; i++) {
 458                 for_each_present_cpu(cpu) {
 459                         if (get_hard_smp_processor_id(cpu) != intserv[i])
 460                                 continue;
 461
 462                         if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)
 463                                 break;
 464
 465                         if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {
 466                                 cpu_maps_update_done();
 467                                 rc = cpu_down(cpu);
 468                                 if (rc)
 469                                         goto out;
 470                                 cpu_maps_update_begin();
 471                                 break;
 472
 473                         }
 474
 475                         /*
 476                          * The cpu is in CPU_STATE_INACTIVE.
 477                          * Upgrade it's state to CPU_STATE_OFFLINE.
 478                          */
 479                         set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
 480                         BUG_ON(plpar_hcall_norets(H_PROD, intserv[i])
 481                                                                 != H_SUCCESS);
 482                         __cpu_die(cpu);
 483                         break;
 484                 }
 485                 if (cpu == num_possible_cpus())
 486                         printk(KERN_WARNING "Could not find cpu to offline "
 487                                "with physical id 0x%x\n", intserv[i]);
 488         }
 489         cpu_maps_update_done();
 490
 491 out:
 492         return rc;
 493
 494 }
 495
 496 static ssize_t dlpar_cpu_release(const char *buf, size_t count)
 497 {
 498         struct device_node *dn;
 499         const u32 *drc_index;
 500         int rc;
 501
 502         dn = of_find_node_by_path(buf);
 503         if (!dn)
 504                 return -EINVAL;
 505
 506         drc_index = of_get_property(dn, "ibm,my-drc-index", NULL);
 507         if (!drc_index) {
 508                 of_node_put(dn);
 509                 return -EINVAL;
 510         }
 511
 512         cpu_hotplug_driver_lock();
 513         rc = dlpar_offline_cpu(dn);
 514         if (rc) {
 515                 of_node_put(dn);
 516                 rc = -EINVAL;
 517                 goto out;
 518         }
 519
 520         rc = dlpar_release_drc(*drc_index);
 521         if (rc) {
 522                 of_node_put(dn);
 523                 goto out;
 524         }
 525
 526         rc = dlpar_detach_node(dn);
 527         if (rc) {
 528                 dlpar_acquire_drc(*drc_index);
 529                 goto out;
 530         }
 531
 532         of_node_put(dn);
 533 out:
 534         cpu_hotplug_driver_unlock();
 535         return rc ? rc : count;
 536 }
 537
 538 static int __init pseries_dlpar_init(void)
 539 {
 540         ppc_md.cpu_probe = dlpar_cpu_probe;
 541         ppc_md.cpu_release = dlpar_cpu_release;
 542
 543         return 0;
 544 }
 545 machine_device_initcall(pseries, pseries_dlpar_init);
 546
 547 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */