arch/powerpc/platforms/pseries/reconfig.c

   1 /*
   2  * pSeries_reconfig.c - support for dynamic reconfiguration (including PCI
   3  * Hotplug and Dynamic Logical Partitioning on RPA platforms).
   4  *
   5  * Copyright (C) 2005 Nathan Lynch
   6  * Copyright (C) 2005 IBM Corporation
   7  *
   8  *
   9  *      This program is free software; you can redistribute it and/or
  10  *      modify it under the terms of the GNU General Public License version
  11  *      2 as published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/kref.h>
  16 #include <linux/notifier.h>
  17 #include <linux/proc_fs.h>
  18
  19 #include <asm/prom.h>
  20 #include <asm/machdep.h>
  21 #include <asm/uaccess.h>
  22 #include <asm/pSeries_reconfig.h>
  23 #include <asm/mmu.h>
  24
  25
  26
  27 /*
  28  * Routines for "runtime" addition and removal of device tree nodes.
  29  */
  30 #ifdef CONFIG_PROC_DEVICETREE
  31 /*
  32  * Add a node to /proc/device-tree.
  33  */
  34 static void add_node_proc_entries(struct device_node *np)
  35 {
  36         struct proc_dir_entry *ent;
  37
  38         ent = proc_mkdir(strrchr(np->full_name, '/') + 1, np->parent->pde);
  39         if (ent)
  40                 proc_device_tree_add_node(np, ent);
  41 }
  42
  43 static void remove_node_proc_entries(struct device_node *np)
  44 {
  45         struct property *pp = np->properties;
  46         struct device_node *parent = np->parent;
  47
  48         while (pp) {
  49                 remove_proc_entry(pp->name, np->pde);
  50                 pp = pp->next;
  51         }
  52         if (np->pde)
  53                 remove_proc_entry(np->pde->name, parent->pde);
  54 }
  55 #else /* !CONFIG_PROC_DEVICETREE */
  56 static void add_node_proc_entries(struct device_node *np)
  57 {
  58         return;
  59 }
  60
  61 static void remove_node_proc_entries(struct device_node *np)
  62 {
  63         return;
  64 }
  65 #endif /* CONFIG_PROC_DEVICETREE */
  66
  67 /**
  68  *      derive_parent - basically like dirname(1)
  69  *      @path:  the full_name of a node to be added to the tree
  70  *
  71  *      Returns the node which should be the parent of the node
  72  *      described by path.  E.g., for path = "/foo/bar", returns
  73  *      the node with full_name = "/foo".
  74  */
  75 static struct device_node *derive_parent(const char *path)
  76 {
  77         struct device_node *parent = NULL;
  78         char *parent_path = "/";
  79         size_t parent_path_len = strrchr(path, '/') - path + 1;
  80
  81         /* reject if path is "/" */
  82         if (!strcmp(path, "/"))
  83                 return ERR_PTR(-EINVAL);
  84
  85         if (strrchr(path, '/') != path) {
  86                 parent_path = kmalloc(parent_path_len, GFP_KERNEL);
  87                 if (!parent_path)
  88                         return ERR_PTR(-ENOMEM);
  89                 strlcpy(parent_path, path, parent_path_len);
  90         }
  91         parent = of_find_node_by_path(parent_path);
  92         if (!parent)
  93                 return ERR_PTR(-EINVAL);
  94         if (strcmp(parent_path, "/"))
  95                 kfree(parent_path);
  96         return parent;
  97 }
  98
  99 static BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
 100
 101 int pSeries_reconfig_notifier_register(struct notifier_block *nb)
 102 {
 103         return blocking_notifier_chain_register(&pSeries_reconfig_chain, nb);
 104 }
 105
 106 void pSeries_reconfig_notifier_unregister(struct notifier_block *nb)
 107 {
 108         blocking_notifier_chain_unregister(&pSeries_reconfig_chain, nb);
 109 }
 110
 111 static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
 112 {
 113         struct device_node *np;
 114         int err = -ENOMEM;
 115
 116         np = kzalloc(sizeof(*np), GFP_KERNEL);
 117         if (!np)
 118                 goto out_err;
 119
 120         np->full_name = kmalloc(strlen(path) + 1, GFP_KERNEL);
 121         if (!np->full_name)
 122                 goto out_err;
 123
 124         strcpy(np->full_name, path);
 125
 126         np->properties = proplist;
 127         of_node_set_flag(np, OF_DYNAMIC);
 128         kref_init(&np->kref);
 129
 130         np->parent = derive_parent(path);
 131         if (IS_ERR(np->parent)) {
 132                 err = PTR_ERR(np->parent);
 133                 goto out_err;
 134         }
 135
 136         err = blocking_notifier_call_chain(&pSeries_reconfig_chain,
 137                                   PSERIES_RECONFIG_ADD, np);
 138         if (err == NOTIFY_BAD) {
 139                 printk(KERN_ERR "Failed to add device node %s\n", path);
 140                 err = -ENOMEM; /* For now, safe to assume kmalloc failure */
 141                 goto out_err;
 142         }
 143
 144         of_attach_node(np);
 145
 146         add_node_proc_entries(np);
 147
 148         of_node_put(np->parent);
 149
 150         return 0;
 151
 152 out_err:
 153         if (np) {
 154                 of_node_put(np->parent);
 155                 kfree(np->full_name);
 156                 kfree(np);
 157         }
 158         return err;
 159 }
 160
 161 static int pSeries_reconfig_remove_node(struct device_node *np)
 162 {
 163         struct device_node *parent, *child;
 164
 165         parent = of_get_parent(np);
 166         if (!parent)
 167                 return -EINVAL;
 168
 169         if ((child = of_get_next_child(np, NULL))) {
 170                 of_node_put(child);
 171                 of_node_put(parent);
 172                 return -EBUSY;
 173         }
 174
 175         remove_node_proc_entries(np);
 176
 177         blocking_notifier_call_chain(&pSeries_reconfig_chain,
 178                             PSERIES_RECONFIG_REMOVE, np);
 179         of_detach_node(np);
 180
 181         of_node_put(parent);
 182         of_node_put(np); /* Must decrement the refcount */
 183         return 0;
 184 }
 185
 186 /*
 187  * /proc/ppc64/ofdt - yucky binary interface for adding and removing
 188  * OF device nodes.  Should be deprecated as soon as we get an
 189  * in-kernel wrapper for the RTAS ibm,configure-connector call.
 190  */
 191
 192 static void release_prop_list(const struct property *prop)
 193 {
 194         struct property *next;
 195         for (; prop; prop = next) {
 196                 next = prop->next;
 197                 kfree(prop->name);
 198                 kfree(prop->value);
 199                 kfree(prop);
 200         }
 201
 202 }
 203
 204 /**
 205  * parse_next_property - process the next property from raw input buffer
 206  * @buf: input buffer, must be nul-terminated
 207  * @end: end of the input buffer + 1, for validation
 208  * @name: return value; set to property name in buf
 209  * @length: return value; set to length of value
 210  * @value: return value; set to the property value in buf
 211  *
 212  * Note that the caller must make copies of the name and value returned,
 213  * this function does no allocation or copying of the data.  Return value
 214  * is set to the next name in buf, or NULL on error.
 215  */
 216 static char * parse_next_property(char *buf, char *end, char **name, int *length,
 217                                   unsigned char **value)
 218 {
 219         char *tmp;
 220
 221         *name = buf;
 222
 223         tmp = strchr(buf, ' ');
 224         if (!tmp) {
 225                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 226                        __func__, __LINE__);
 227                 return NULL;
 228         }
 229         *tmp = '\0';
 230
 231         if (++tmp >= end) {
 232                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 233                        __func__, __LINE__);
 234                 return NULL;
 235         }
 236
 237         /* now we're on the length */
 238         *length = -1;
 239         *length = simple_strtoul(tmp, &tmp, 10);
 240         if (*length == -1) {
 241                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 242                        __func__, __LINE__);
 243                 return NULL;
 244         }
 245         if (*tmp != ' ' || ++tmp >= end) {
 246                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 247                        __func__, __LINE__);
 248                 return NULL;
 249         }
 250
 251         /* now we're on the value */
 252         *value = tmp;
 253         tmp += *length;
 254         if (tmp > end) {
 255                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 256                        __func__, __LINE__);
 257                 return NULL;
 258         }
 259         else if (tmp < end && *tmp != ' ' && *tmp != '\0') {
 260                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 261                        __func__, __LINE__);
 262                 return NULL;
 263         }
 264         tmp++;
 265
 266         /* and now we should be on the next name, or the end */
 267         return tmp;
 268 }
 269
 270 static struct property *new_property(const char *name, const int length,
 271                                      const unsigned char *value, struct property *last)
 272 {
 273         struct property *new = kzalloc(sizeof(*new), GFP_KERNEL);
 274
 275         if (!new)
 276                 return NULL;
 277
 278         if (!(new->name = kmalloc(strlen(name) + 1, GFP_KERNEL)))
 279                 goto cleanup;
 280         if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
 281                 goto cleanup;
 282
 283         strcpy(new->name, name);
 284         memcpy(new->value, value, length);
 285         *(((char *)new->value) + length) = 0;
 286         new->length = length;
 287         new->next = last;
 288         return new;
 289
 290 cleanup:
 291         kfree(new->name);
 292         kfree(new->value);
 293         kfree(new);
 294         return NULL;
 295 }
 296
 297 static int do_add_node(char *buf, size_t bufsize)
 298 {
 299         char *path, *end, *name;
 300         struct device_node *np;
 301         struct property *prop = NULL;
 302         unsigned char* value;
 303         int length, rv = 0;
 304
 305         end = buf + bufsize;
 306         path = buf;
 307         buf = strchr(buf, ' ');
 308         if (!buf)
 309                 return -EINVAL;
 310         *buf = '\0';
 311         buf++;
 312
 313         if ((np = of_find_node_by_path(path))) {
 314                 of_node_put(np);
 315                 return -EINVAL;
 316         }
 317
 318         /* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
 319         while (buf < end &&
 320                (buf = parse_next_property(buf, end, &name, &length, &value))) {
 321                 struct property *last = prop;
 322
 323                 prop = new_property(name, length, value, last);
 324                 if (!prop) {
 325                         rv = -ENOMEM;
 326                         prop = last;
 327                         goto out;
 328                 }
 329         }
 330         if (!buf) {
 331                 rv = -EINVAL;
 332                 goto out;
 333         }
 334
 335         rv = pSeries_reconfig_add_node(path, prop);
 336
 337 out:
 338         if (rv)
 339                 release_prop_list(prop);
 340         return rv;
 341 }
 342
 343 static int do_remove_node(char *buf)
 344 {
 345         struct device_node *node;
 346         int rv = -ENODEV;
 347
 348         if ((node = of_find_node_by_path(buf)))
 349                 rv = pSeries_reconfig_remove_node(node);
 350
 351         of_node_put(node);
 352         return rv;
 353 }
 354
 355 static char *parse_node(char *buf, size_t bufsize, struct device_node **npp)
 356 {
 357         char *handle_str;
 358         phandle handle;
 359         *npp = NULL;
 360
 361         handle_str = buf;
 362
 363         buf = strchr(buf, ' ');
 364         if (!buf)
 365                 return NULL;
 366         *buf = '\0';
 367         buf++;
 368
 369         handle = simple_strtoul(handle_str, NULL, 0);
 370
 371         *npp = of_find_node_by_phandle(handle);
 372         return buf;
 373 }
 374
 375 static int do_add_property(char *buf, size_t bufsize)
 376 {
 377         struct property *prop = NULL;
 378         struct device_node *np;
 379         unsigned char *value;
 380         char *name, *end;
 381         int length;
 382         end = buf + bufsize;
 383         buf = parse_node(buf, bufsize, &np);
 384
 385         if (!np)
 386                 return -ENODEV;
 387
 388         if (parse_next_property(buf, end, &name, &length, &value) == NULL)
 389                 return -EINVAL;
 390
 391         prop = new_property(name, length, value, NULL);
 392         if (!prop)
 393                 return -ENOMEM;
 394
 395         prom_add_property(np, prop);
 396
 397         return 0;
 398 }
 399
 400 static int do_remove_property(char *buf, size_t bufsize)
 401 {
 402         struct device_node *np;
 403         char *tmp;
 404         struct property *prop;
 405         buf = parse_node(buf, bufsize, &np);
 406
 407         if (!np)
 408                 return -ENODEV;
 409
 410         tmp = strchr(buf,' ');
 411         if (tmp)
 412                 *tmp = '\0';
 413
 414         if (strlen(buf) == 0)
 415                 return -EINVAL;
 416
 417         prop = of_find_property(np, buf, NULL);
 418
 419         return prom_remove_property(np, prop);
 420 }
 421
 422 static int do_update_property(char *buf, size_t bufsize)
 423 {
 424         struct device_node *np;
 425         unsigned char *value;
 426         char *name, *end, *next_prop;
 427         int rc, length;
 428         struct property *newprop, *oldprop;
 429         buf = parse_node(buf, bufsize, &np);
 430         end = buf + bufsize;
 431
 432         if (!np)
 433                 return -ENODEV;
 434
 435         next_prop = parse_next_property(buf, end, &name, &length, &value);
 436         if (!next_prop)
 437                 return -EINVAL;
 438
 439         newprop = new_property(name, length, value, NULL);
 440         if (!newprop)
 441                 return -ENOMEM;
 442
 443         if (!strcmp(name, "slb-size") || !strcmp(name, "ibm,slb-size"))
 444                 slb_set_size(*(int *)value);
 445
 446         oldprop = of_find_property(np, name,NULL);
 447         if (!oldprop) {
 448                 if (strlen(name))
 449                         return prom_add_property(np, newprop);
 450                 return -ENODEV;
 451         }
 452
 453         rc = prom_update_property(np, newprop, oldprop);
 454         if (rc)
 455                 return rc;
 456
 457         /* For memory under the ibm,dynamic-reconfiguration-memory node
 458          * of the device tree, adding and removing memory is just an update
 459          * to the ibm,dynamic-memory property instead of adding/removing a
 460          * memory node in the device tree.  For these cases we still need to
 461          * involve the notifier chain.
 462          */
 463         if (!strcmp(name, "ibm,dynamic-memory")) {
 464                 int action;
 465
 466                 next_prop = parse_next_property(next_prop, end, &name,
 467                                                 &length, &value);
 468                 if (!next_prop)
 469                         return -EINVAL;
 470
 471                 if (!strcmp(name, "add"))
 472                         action = PSERIES_DRCONF_MEM_ADD;
 473                 else
 474                         action = PSERIES_DRCONF_MEM_REMOVE;
 475
 476                 rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
 477                                                   action, value);
 478                 if (rc == NOTIFY_BAD) {
 479                         rc = prom_update_property(np, oldprop, newprop);
 480                         return -ENOMEM;
 481                 }
 482         }
 483
 484         return 0;
 485 }
 486
 487 /**
 488  * ofdt_write - perform operations on the Open Firmware device tree
 489  *
 490  * @file: not used
 491  * @buf: command and arguments
 492  * @count: size of the command buffer
 493  * @off: not used
 494  *
 495  * Operations supported at this time are addition and removal of
 496  * whole nodes along with their properties.  Operations on individual
 497  * properties are not implemented (yet).
 498  */
 499 static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t count,
 500                           loff_t *off)
 501 {
 502         int rv = 0;
 503         char *kbuf;
 504         char *tmp;
 505
 506         if (!(kbuf = kmalloc(count + 1, GFP_KERNEL))) {
 507                 rv = -ENOMEM;
 508                 goto out;
 509         }
 510         if (copy_from_user(kbuf, buf, count)) {
 511                 rv = -EFAULT;
 512                 goto out;
 513         }
 514
 515         kbuf[count] = '\0';
 516
 517         tmp = strchr(kbuf, ' ');
 518         if (!tmp) {
 519                 rv = -EINVAL;
 520                 goto out;
 521         }
 522         *tmp = '\0';
 523         tmp++;
 524
 525         if (!strcmp(kbuf, "add_node"))
 526                 rv = do_add_node(tmp, count - (tmp - kbuf));
 527         else if (!strcmp(kbuf, "remove_node"))
 528                 rv = do_remove_node(tmp);
 529         else if (!strcmp(kbuf, "add_property"))
 530                 rv = do_add_property(tmp, count - (tmp - kbuf));
 531         else if (!strcmp(kbuf, "remove_property"))
 532                 rv = do_remove_property(tmp, count - (tmp - kbuf));
 533         else if (!strcmp(kbuf, "update_property"))
 534                 rv = do_update_property(tmp, count - (tmp - kbuf));
 535         else
 536                 rv = -EINVAL;
 537 out:
 538         kfree(kbuf);
 539         return rv ? rv : count;
 540 }
 541
 542 static const struct file_operations ofdt_fops = {
 543         .write = ofdt_write
 544 };
 545
 546 /* create /proc/ppc64/ofdt write-only by root */
 547 static int proc_ppc64_create_ofdt(void)
 548 {
 549         struct proc_dir_entry *ent;
 550
 551         if (!machine_is(pseries))
 552                 return 0;
 553
 554         ent = proc_create("ppc64/ofdt", S_IWUSR, NULL, &ofdt_fops);
 555         if (ent)
 556                 ent->size = 0;
 557
 558         return 0;
 559 }
 560 __initcall(proc_ppc64_create_ofdt);