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