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         of_node_init(dn);
  90
  91         return dn;
  92 }
  93
  94 static void dlpar_free_one_cc_node(struct device_node *dn)
  95 {
  96         struct property *prop;
  97
  98         while (dn->properties) {
  99                 prop = dn->properties;
 100                 dn->properties = prop->next;
 101                 dlpar_free_cc_property(prop);
 102         }
 103
 104         kfree(dn->full_name);
 105         kfree(dn);
 106 }
 107
 108 void dlpar_free_cc_nodes(struct device_node *dn)
 109 {
 110         if (dn->child)
 111                 dlpar_free_cc_nodes(dn->child);
 112
 113         if (dn->sibling)
 114                 dlpar_free_cc_nodes(dn->sibling);
 115
 116         dlpar_free_one_cc_node(dn);
 117 }
 118
 119 #define COMPLETE        0
 120 #define NEXT_SIBLING    1
 121 #define NEXT_CHILD      2
 122 #define NEXT_PROPERTY   3
 123 #define PREV_PARENT     4
 124 #define MORE_MEMORY     5
 125 #define CALL_AGAIN      -2
 126 #define ERR_CFG_USE     -9003
 127
 128 struct device_node *dlpar_configure_connector(u32 drc_index,
 129                                               struct device_node *parent)
 130 {
 131         struct device_node *dn;
 132         struct device_node *first_dn = NULL;
 133         struct device_node *last_dn = NULL;
 134         struct property *property;
 135         struct property *last_property = NULL;
 136         struct cc_workarea *ccwa;
 137         char *data_buf;
 138         const char *parent_path = parent->full_name;
 139         int cc_token;
 140         int rc = -1;
 141
 142         cc_token = rtas_token("ibm,configure-connector");
 143         if (cc_token == RTAS_UNKNOWN_SERVICE)
 144                 return NULL;
 145
 146         data_buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
 147         if (!data_buf)
 148                 return NULL;
 149
 150         ccwa = (struct cc_workarea *)&data_buf[0];
 151         ccwa->drc_index = drc_index;
 152         ccwa->zero = 0;
 153
 154         do {
 155                 /* Since we release the rtas_data_buf lock between configure
 156                  * connector calls we want to re-populate the rtas_data_buffer
 157                  * with the contents of the previous call.
 158                  */
 159                 spin_lock(&rtas_data_buf_lock);
 160
 161                 memcpy(rtas_data_buf, data_buf, RTAS_DATA_BUF_SIZE);
 162                 rc = rtas_call(cc_token, 2, 1, NULL, rtas_data_buf, NULL);
 163                 memcpy(data_buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);
 164
 165                 spin_unlock(&rtas_data_buf_lock);
 166
 167                 switch (rc) {
 168                 case COMPLETE:
 169                         break;
 170
 171                 case NEXT_SIBLING:
 172                         dn = dlpar_parse_cc_node(ccwa, parent_path);
 173                         if (!dn)
 174                                 goto cc_error;
 175
 176                         dn->parent = last_dn->parent;
 177                         last_dn->sibling = dn;
 178                         last_dn = dn;
 179                         break;
 180
 181                 case NEXT_CHILD:
 182                         if (first_dn)
 183                                 parent_path = last_dn->full_name;
 184
 185                         dn = dlpar_parse_cc_node(ccwa, parent_path);
 186                         if (!dn)
 187                                 goto cc_error;
 188
 189                         if (!first_dn) {
 190                                 dn->parent = parent;
 191                                 first_dn = dn;
 192                         } else {
 193                                 dn->parent = last_dn;
 194                                 if (last_dn)
 195                                         last_dn->child = dn;
 196                         }
 197
 198                         last_dn = dn;
 199                         break;
 200
 201                 case NEXT_PROPERTY:
 202                         property = dlpar_parse_cc_property(ccwa);
 203                         if (!property)
 204                                 goto cc_error;
 205
 206                         if (!last_dn->properties)
 207                                 last_dn->properties = property;
 208                         else
 209                                 last_property->next = property;
 210
 211                         last_property = property;
 212                         break;
 213
 214                 case PREV_PARENT:
 215                         last_dn = last_dn->parent;
 216                         parent_path = last_dn->parent->full_name;
 217                         break;
 218
 219                 case CALL_AGAIN:
 220                         break;
 221
 222                 case MORE_MEMORY:
 223                 case ERR_CFG_USE:
 224                 default:
 225                         printk(KERN_ERR "Unexpected Error (%d) "
 226                                "returned from configure-connector\n", rc);
 227                         goto cc_error;
 228                 }
 229         } while (rc);
 230
 231 cc_error:
 232         kfree(data_buf);
 233
 234         if (rc) {
 235                 if (first_dn)
 236                         dlpar_free_cc_nodes(first_dn);
 237
 238                 return NULL;
 239         }
 240
 241         return first_dn;
 242 }
 243
 244 static struct device_node *derive_parent(const char *path)
 245 {
 246         struct device_node *parent;
 247         char *last_slash;
 248
 249         last_slash = strrchr(path, '/');
 250         if (last_slash == path) {
 251                 parent = of_find_node_by_path("/");
 252         } else {
 253                 char *parent_path;
 254                 int parent_path_len = last_slash - path + 1;
 255                 parent_path = kmalloc(parent_path_len, GFP_KERNEL);
 256                 if (!parent_path)
 257                         return NULL;
 258
 259                 strlcpy(parent_path, path, parent_path_len);
 260                 parent = of_find_node_by_path(parent_path);
 261                 kfree(parent_path);
 262         }
 263
 264         return parent;
 265 }
 266
 267 int dlpar_attach_node(struct device_node *dn)
 268 {
 269         int rc;
 270
 271         dn->parent = derive_parent(dn->full_name);
 272         if (!dn->parent)
 273                 return -ENOMEM;
 274
 275         rc = of_attach_node(dn);
 276         if (rc) {
 277                 printk(KERN_ERR "Failed to add device node %s\n",
 278                        dn->full_name);
 279                 return rc;
 280         }
 281
 282         of_node_put(dn->parent);
 283         return 0;
 284 }
 285
 286 int dlpar_detach_node(struct device_node *dn)
 287 {
 288         struct device_node *child;
 289         int rc;
 290
 291         child = of_get_next_child(dn, NULL);
 292         while (child) {
 293                 dlpar_detach_node(child);
 294                 child = of_get_next_child(dn, child);
 295         }
 296
 297         rc = of_detach_node(dn);
 298         if (rc)
 299                 return rc;
 300
 301         of_node_put(dn); /* Must decrement the refcount */
 302         return 0;
 303 }
 304
 305 #define DR_ENTITY_SENSE         9003
 306 #define DR_ENTITY_PRESENT       1
 307 #define DR_ENTITY_UNUSABLE      2
 308 #define ALLOCATION_STATE        9003
 309 #define ALLOC_UNUSABLE          0
 310 #define ALLOC_USABLE            1
 311 #define ISOLATION_STATE         9001
 312 #define ISOLATE                 0
 313 #define UNISOLATE               1
 314
 315 int dlpar_acquire_drc(u32 drc_index)
 316 {
 317         int dr_status, rc;
 318
 319         rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
 320                        DR_ENTITY_SENSE, drc_index);
 321         if (rc || dr_status != DR_ENTITY_UNUSABLE)
 322                 return -1;
 323
 324         rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_USABLE);
 325         if (rc)
 326                 return rc;
 327
 328         rc = rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
 329         if (rc) {
 330                 rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
 331                 return rc;
 332         }
 333
 334         return 0;
 335 }
 336
 337 int dlpar_release_drc(u32 drc_index)
 338 {
 339         int dr_status, rc;
 340
 341         rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
 342                        DR_ENTITY_SENSE, drc_index);
 343         if (rc || dr_status != DR_ENTITY_PRESENT)
 344                 return -1;
 345
 346         rc = rtas_set_indicator(ISOLATION_STATE, drc_index, ISOLATE);
 347         if (rc)
 348                 return rc;
 349
 350         rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
 351         if (rc) {
 352                 rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
 353                 return rc;
 354         }
 355
 356         return 0;
 357 }
 358
 359 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 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, *parent;
 403         u32 drc_index;
 404         int rc;
 405
 406         rc = kstrtou32(buf, 0, &drc_index);
 407         if (rc)
 408                 return -EINVAL;
 409
 410         parent = of_find_node_by_path("/cpus");
 411         if (!parent)
 412                 return -ENODEV;
 413
 414         dn = dlpar_configure_connector(drc_index, parent);
 415         if (!dn)
 416                 return -EINVAL;
 417
 418         of_node_put(parent);
 419
 420         rc = dlpar_acquire_drc(drc_index);
 421         if (rc) {
 422                 dlpar_free_cc_nodes(dn);
 423                 return -EINVAL;
 424         }
 425
 426         rc = dlpar_attach_node(dn);
 427         if (rc) {
 428                 dlpar_release_drc(drc_index);
 429                 dlpar_free_cc_nodes(dn);
 430                 return rc;
 431         }
 432
 433         rc = dlpar_online_cpu(dn);
 434         if (rc)
 435                 return rc;
 436
 437         return count;
 438 }
 439
 440 static int dlpar_offline_cpu(struct device_node *dn)
 441 {
 442         int rc = 0;
 443         unsigned int cpu;
 444         int len, nthreads, i;
 445         const u32 *intserv;
 446
 447         intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len);
 448         if (!intserv)
 449                 return -EINVAL;
 450
 451         nthreads = len / sizeof(u32);
 452
 453         cpu_maps_update_begin();
 454         for (i = 0; i < nthreads; i++) {
 455                 for_each_present_cpu(cpu) {
 456                         if (get_hard_smp_processor_id(cpu) != intserv[i])
 457                                 continue;
 458
 459                         if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE)
 460                                 break;
 461
 462                         if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {
 463                                 set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
 464                                 cpu_maps_update_done();
 465                                 rc = cpu_down(cpu);
 466                                 if (rc)
 467                                         goto out;
 468                                 cpu_maps_update_begin();
 469                                 break;
 470
 471                         }
 472
 473                         /*
 474                          * The cpu is in CPU_STATE_INACTIVE.
 475                          * Upgrade it's state to CPU_STATE_OFFLINE.
 476                          */
 477                         set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
 478                         BUG_ON(plpar_hcall_norets(H_PROD, intserv[i])
 479                                                                 != H_SUCCESS);
 480                         __cpu_die(cpu);
 481                         break;
 482                 }
 483                 if (cpu == num_possible_cpus())
 484                         printk(KERN_WARNING "Could not find cpu to offline "
 485                                "with physical id 0x%x\n", intserv[i]);
 486         }
 487         cpu_maps_update_done();
 488
 489 out:
 490         return rc;
 491
 492 }
 493
 494 static ssize_t dlpar_cpu_release(const char *buf, size_t count)
 495 {
 496         struct device_node *dn;
 497         const u32 *drc_index;
 498         int rc;
 499
 500         dn = of_find_node_by_path(buf);
 501         if (!dn)
 502                 return -EINVAL;
 503
 504         drc_index = of_get_property(dn, "ibm,my-drc-index", NULL);
 505         if (!drc_index) {
 506                 of_node_put(dn);
 507                 return -EINVAL;
 508         }
 509
 510         rc = dlpar_offline_cpu(dn);
 511         if (rc) {
 512                 of_node_put(dn);
 513                 return -EINVAL;
 514         }
 515
 516         rc = dlpar_release_drc(*drc_index);
 517         if (rc) {
 518                 of_node_put(dn);
 519                 return rc;
 520         }
 521
 522         rc = dlpar_detach_node(dn);
 523         if (rc) {
 524                 dlpar_acquire_drc(*drc_index);
 525                 return rc;
 526         }
 527
 528         of_node_put(dn);
 529
 530         return count;
 531 }
 532
 533 static int __init pseries_dlpar_init(void)
 534 {
 535         ppc_md.cpu_probe = dlpar_cpu_probe;
 536         ppc_md.cpu_release = dlpar_cpu_release;
 537
 538         return 0;
 539 }
 540 machine_device_initcall(pseries, pseries_dlpar_init);
 541
 542 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */