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 #include <linux/slab.h>
  19
  20 #include <asm/prom.h>
  21 #include <asm/machdep.h>
  22 #include <asm/uaccess.h>
  23 #include <asm/pSeries_reconfig.h>
  24 #include <asm/mmu.h>
  25
  26
  27
  28 /*
  29  * Routines for "runtime" addition and removal of device tree nodes.
  30  */
  31 #ifdef CONFIG_PROC_DEVICETREE
  32 /*
  33  * Add a node to /proc/device-tree.
  34  */
  35 static void add_node_proc_entries(struct device_node *np)
  36 {
  37         struct proc_dir_entry *ent;
  38
  39         ent = proc_mkdir(strrchr(np->full_name, '/') + 1, np->parent->pde);
  40         if (ent)
  41                 proc_device_tree_add_node(np, ent);
  42 }
  43
  44 static void remove_node_proc_entries(struct device_node *np)
  45 {
  46         struct property *pp = np->properties;
  47         struct device_node *parent = np->parent;
  48
  49         while (pp) {
  50                 remove_proc_entry(pp->name, np->pde);
  51                 pp = pp->next;
  52         }
  53         if (np->pde)
  54                 remove_proc_entry(np->pde->name, parent->pde);
  55 }
  56 #else /* !CONFIG_PROC_DEVICETREE */
  57 static void add_node_proc_entries(struct device_node *np)
  58 {
  59         return;
  60 }
  61
  62 static void remove_node_proc_entries(struct device_node *np)
  63 {
  64         return;
  65 }
  66 #endif /* CONFIG_PROC_DEVICETREE */
  67
  68 /**
  69  *      derive_parent - basically like dirname(1)
  70  *      @path:  the full_name of a node to be added to the tree
  71  *
  72  *      Returns the node which should be the parent of the node
  73  *      described by path.  E.g., for path = "/foo/bar", returns
  74  *      the node with full_name = "/foo".
  75  */
  76 static struct device_node *derive_parent(const char *path)
  77 {
  78         struct device_node *parent = NULL;
  79         char *parent_path = "/";
  80         size_t parent_path_len = strrchr(path, '/') - path + 1;
  81
  82         /* reject if path is "/" */
  83         if (!strcmp(path, "/"))
  84                 return ERR_PTR(-EINVAL);
  85
  86         if (strrchr(path, '/') != path) {
  87                 parent_path = kmalloc(parent_path_len, GFP_KERNEL);
  88                 if (!parent_path)
  89                         return ERR_PTR(-ENOMEM);
  90                 strlcpy(parent_path, path, parent_path_len);
  91         }
  92         parent = of_find_node_by_path(parent_path);
  93         if (!parent)
  94                 return ERR_PTR(-EINVAL);
  95         if (strcmp(parent_path, "/"))
  96                 kfree(parent_path);
  97         return parent;
  98 }
  99
 100 static BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
 101
 102 int pSeries_reconfig_notifier_register(struct notifier_block *nb)
 103 {
 104         return blocking_notifier_chain_register(&pSeries_reconfig_chain, nb);
 105 }
 106
 107 void pSeries_reconfig_notifier_unregister(struct notifier_block *nb)
 108 {
 109         blocking_notifier_chain_unregister(&pSeries_reconfig_chain, nb);
 110 }
 111
 112 int pSeries_reconfig_notify(unsigned long action, void *p)
 113 {
 114         int err = blocking_notifier_call_chain(&pSeries_reconfig_chain,
 115                                                 action, p);
 116
 117         return notifier_to_errno(err);
 118 }
 119
 120 static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
 121 {
 122         struct device_node *np;
 123         int err = -ENOMEM;
 124
 125         np = kzalloc(sizeof(*np), GFP_KERNEL);
 126         if (!np)
 127                 goto out_err;
 128
 129         np->full_name = kstrdup(path, GFP_KERNEL);
 130         if (!np->full_name)
 131                 goto out_err;
 132
 133         np->properties = proplist;
 134         of_node_set_flag(np, OF_DYNAMIC);
 135         kref_init(&np->kref);
 136
 137         np->parent = derive_parent(path);
 138         if (IS_ERR(np->parent)) {
 139                 err = PTR_ERR(np->parent);
 140                 goto out_err;
 141         }
 142
 143         err = pSeries_reconfig_notify(PSERIES_RECONFIG_ADD, np);
 144         if (err) {
 145                 printk(KERN_ERR "Failed to add device node %s\n", path);
 146                 goto out_err;
 147         }
 148
 149         of_attach_node(np);
 150
 151         add_node_proc_entries(np);
 152
 153         of_node_put(np->parent);
 154
 155         return 0;
 156
 157 out_err:
 158         if (np) {
 159                 of_node_put(np->parent);
 160                 kfree(np->full_name);
 161                 kfree(np);
 162         }
 163         return err;
 164 }
 165
 166 static int pSeries_reconfig_remove_node(struct device_node *np)
 167 {
 168         struct device_node *parent, *child;
 169
 170         parent = of_get_parent(np);
 171         if (!parent)
 172                 return -EINVAL;
 173
 174         if ((child = of_get_next_child(np, NULL))) {
 175                 of_node_put(child);
 176                 of_node_put(parent);
 177                 return -EBUSY;
 178         }
 179
 180         remove_node_proc_entries(np);
 181
 182         pSeries_reconfig_notify(PSERIES_RECONFIG_REMOVE, np);
 183         of_detach_node(np);
 184
 185         of_node_put(parent);
 186         of_node_put(np); /* Must decrement the refcount */
 187         return 0;
 188 }
 189
 190 /*
 191  * /proc/powerpc/ofdt - yucky binary interface for adding and removing
 192  * OF device nodes.  Should be deprecated as soon as we get an
 193  * in-kernel wrapper for the RTAS ibm,configure-connector call.
 194  */
 195
 196 static void release_prop_list(const struct property *prop)
 197 {
 198         struct property *next;
 199         for (; prop; prop = next) {
 200                 next = prop->next;
 201                 kfree(prop->name);
 202                 kfree(prop->value);
 203                 kfree(prop);
 204         }
 205
 206 }
 207
 208 /**
 209  * parse_next_property - process the next property from raw input buffer
 210  * @buf: input buffer, must be nul-terminated
 211  * @end: end of the input buffer + 1, for validation
 212  * @name: return value; set to property name in buf
 213  * @length: return value; set to length of value
 214  * @value: return value; set to the property value in buf
 215  *
 216  * Note that the caller must make copies of the name and value returned,
 217  * this function does no allocation or copying of the data.  Return value
 218  * is set to the next name in buf, or NULL on error.
 219  */
 220 static char * parse_next_property(char *buf, char *end, char **name, int *length,
 221                                   unsigned char **value)
 222 {
 223         char *tmp;
 224
 225         *name = buf;
 226
 227         tmp = strchr(buf, ' ');
 228         if (!tmp) {
 229                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 230                        __func__, __LINE__);
 231                 return NULL;
 232         }
 233         *tmp = '\0';
 234
 235         if (++tmp >= end) {
 236                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 237                        __func__, __LINE__);
 238                 return NULL;
 239         }
 240
 241         /* now we're on the length */
 242         *length = -1;
 243         *length = simple_strtoul(tmp, &tmp, 10);
 244         if (*length == -1) {
 245                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 246                        __func__, __LINE__);
 247                 return NULL;
 248         }
 249         if (*tmp != ' ' || ++tmp >= end) {
 250                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 251                        __func__, __LINE__);
 252                 return NULL;
 253         }
 254
 255         /* now we're on the value */
 256         *value = tmp;
 257         tmp += *length;
 258         if (tmp > end) {
 259                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 260                        __func__, __LINE__);
 261                 return NULL;
 262         }
 263         else if (tmp < end && *tmp != ' ' && *tmp != '\0') {
 264                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 265                        __func__, __LINE__);
 266                 return NULL;
 267         }
 268         tmp++;
 269
 270         /* and now we should be on the next name, or the end */
 271         return tmp;
 272 }
 273
 274 static struct property *new_property(const char *name, const int length,
 275                                      const unsigned char *value, struct property *last)
 276 {
 277         struct property *new = kzalloc(sizeof(*new), GFP_KERNEL);
 278
 279         if (!new)
 280                 return NULL;
 281
 282         if (!(new->name = kmalloc(strlen(name) + 1, GFP_KERNEL)))
 283                 goto cleanup;
 284         if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
 285                 goto cleanup;
 286
 287         strcpy(new->name, name);
 288         memcpy(new->value, value, length);
 289         *(((char *)new->value) + length) = 0;
 290         new->length = length;
 291         new->next = last;
 292         return new;
 293
 294 cleanup:
 295         kfree(new->name);
 296         kfree(new->value);
 297         kfree(new);
 298         return NULL;
 299 }
 300
 301 static int do_add_node(char *buf, size_t bufsize)
 302 {
 303         char *path, *end, *name;
 304         struct device_node *np;
 305         struct property *prop = NULL;
 306         unsigned char* value;
 307         int length, rv = 0;
 308
 309         end = buf + bufsize;
 310         path = buf;
 311         buf = strchr(buf, ' ');
 312         if (!buf)
 313                 return -EINVAL;
 314         *buf = '\0';
 315         buf++;
 316
 317         if ((np = of_find_node_by_path(path))) {
 318                 of_node_put(np);
 319                 return -EINVAL;
 320         }
 321
 322         /* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
 323         while (buf < end &&
 324                (buf = parse_next_property(buf, end, &name, &length, &value))) {
 325                 struct property *last = prop;
 326
 327                 prop = new_property(name, length, value, last);
 328                 if (!prop) {
 329                         rv = -ENOMEM;
 330                         prop = last;
 331                         goto out;
 332                 }
 333         }
 334         if (!buf) {
 335                 rv = -EINVAL;
 336                 goto out;
 337         }
 338
 339         rv = pSeries_reconfig_add_node(path, prop);
 340
 341 out:
 342         if (rv)
 343                 release_prop_list(prop);
 344         return rv;
 345 }
 346
 347 static int do_remove_node(char *buf)
 348 {
 349         struct device_node *node;
 350         int rv = -ENODEV;
 351
 352         if ((node = of_find_node_by_path(buf)))
 353                 rv = pSeries_reconfig_remove_node(node);
 354
 355         of_node_put(node);
 356         return rv;
 357 }
 358
 359 static char *parse_node(char *buf, size_t bufsize, struct device_node **npp)
 360 {
 361         char *handle_str;
 362         phandle handle;
 363         *npp = NULL;
 364
 365         handle_str = buf;
 366
 367         buf = strchr(buf, ' ');
 368         if (!buf)
 369                 return NULL;
 370         *buf = '\0';
 371         buf++;
 372
 373         handle = simple_strtoul(handle_str, NULL, 0);
 374
 375         *npp = of_find_node_by_phandle(handle);
 376         return buf;
 377 }
 378
 379 static int do_add_property(char *buf, size_t bufsize)
 380 {
 381         struct property *prop = NULL;
 382         struct device_node *np;
 383         unsigned char *value;
 384         char *name, *end;
 385         int length;
 386         end = buf + bufsize;
 387         buf = parse_node(buf, bufsize, &np);
 388
 389         if (!np)
 390                 return -ENODEV;
 391
 392         if (parse_next_property(buf, end, &name, &length, &value) == NULL)
 393                 return -EINVAL;
 394
 395         prop = new_property(name, length, value, NULL);
 396         if (!prop)
 397                 return -ENOMEM;
 398
 399         prom_add_property(np, prop);
 400
 401         return 0;
 402 }
 403
 404 static int do_remove_property(char *buf, size_t bufsize)
 405 {
 406         struct device_node *np;
 407         char *tmp;
 408         struct property *prop;
 409         buf = parse_node(buf, bufsize, &np);
 410
 411         if (!np)
 412                 return -ENODEV;
 413
 414         tmp = strchr(buf,' ');
 415         if (tmp)
 416                 *tmp = '\0';
 417
 418         if (strlen(buf) == 0)
 419                 return -EINVAL;
 420
 421         prop = of_find_property(np, buf, NULL);
 422
 423         return prom_remove_property(np, prop);
 424 }
 425
 426 static int do_update_property(char *buf, size_t bufsize)
 427 {
 428         struct device_node *np;
 429         unsigned char *value;
 430         char *name, *end, *next_prop;
 431         int rc, length;
 432         struct property *newprop, *oldprop;
 433         buf = parse_node(buf, bufsize, &np);
 434         end = buf + bufsize;
 435
 436         if (!np)
 437                 return -ENODEV;
 438
 439         next_prop = parse_next_property(buf, end, &name, &length, &value);
 440         if (!next_prop)
 441                 return -EINVAL;
 442
 443         newprop = new_property(name, length, value, NULL);
 444         if (!newprop)
 445                 return -ENOMEM;
 446
 447         if (!strcmp(name, "slb-size") || !strcmp(name, "ibm,slb-size"))
 448                 slb_set_size(*(int *)value);
 449
 450         oldprop = of_find_property(np, name,NULL);
 451         if (!oldprop) {
 452                 if (strlen(name))
 453                         return prom_add_property(np, newprop);
 454                 return -ENODEV;
 455         }
 456
 457         rc = prom_update_property(np, newprop, oldprop);
 458         if (rc)
 459                 return rc;
 460
 461         /* For memory under the ibm,dynamic-reconfiguration-memory node
 462          * of the device tree, adding and removing memory is just an update
 463          * to the ibm,dynamic-memory property instead of adding/removing a
 464          * memory node in the device tree.  For these cases we still need to
 465          * involve the notifier chain.
 466          */
 467         if (!strcmp(name, "ibm,dynamic-memory")) {
 468                 int action;
 469
 470                 next_prop = parse_next_property(next_prop, end, &name,
 471                                                 &length, &value);
 472                 if (!next_prop)
 473                         return -EINVAL;
 474
 475                 if (!strcmp(name, "add"))
 476                         action = PSERIES_DRCONF_MEM_ADD;
 477                 else
 478                         action = PSERIES_DRCONF_MEM_REMOVE;
 479
 480                 rc = pSeries_reconfig_notify(action, value);
 481                 if (rc) {
 482                         prom_update_property(np, oldprop, newprop);
 483                         return rc;
 484                 }
 485         }
 486
 487         return 0;
 488 }
 489
 490 /**
 491  * ofdt_write - perform operations on the Open Firmware device tree
 492  *
 493  * @file: not used
 494  * @buf: command and arguments
 495  * @count: size of the command buffer
 496  * @off: not used
 497  *
 498  * Operations supported at this time are addition and removal of
 499  * whole nodes along with their properties.  Operations on individual
 500  * properties are not implemented (yet).
 501  */
 502 static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t count,
 503                           loff_t *off)
 504 {
 505         int rv = 0;
 506         char *kbuf;
 507         char *tmp;
 508
 509         if (!(kbuf = kmalloc(count + 1, GFP_KERNEL))) {
 510                 rv = -ENOMEM;
 511                 goto out;
 512         }
 513         if (copy_from_user(kbuf, buf, count)) {
 514                 rv = -EFAULT;
 515                 goto out;
 516         }
 517
 518         kbuf[count] = '\0';
 519
 520         tmp = strchr(kbuf, ' ');
 521         if (!tmp) {
 522                 rv = -EINVAL;
 523                 goto out;
 524         }
 525         *tmp = '\0';
 526         tmp++;
 527
 528         if (!strcmp(kbuf, "add_node"))
 529                 rv = do_add_node(tmp, count - (tmp - kbuf));
 530         else if (!strcmp(kbuf, "remove_node"))
 531                 rv = do_remove_node(tmp);
 532         else if (!strcmp(kbuf, "add_property"))
 533                 rv = do_add_property(tmp, count - (tmp - kbuf));
 534         else if (!strcmp(kbuf, "remove_property"))
 535                 rv = do_remove_property(tmp, count - (tmp - kbuf));
 536         else if (!strcmp(kbuf, "update_property"))
 537                 rv = do_update_property(tmp, count - (tmp - kbuf));
 538         else
 539                 rv = -EINVAL;
 540 out:
 541         kfree(kbuf);
 542         return rv ? rv : count;
 543 }
 544
 545 static const struct file_operations ofdt_fops = {
 546         .write = ofdt_write,
 547         .llseek = noop_llseek,
 548 };
 549
 550 /* create /proc/powerpc/ofdt write-only by root */
 551 static int proc_ppc64_create_ofdt(void)
 552 {
 553         struct proc_dir_entry *ent;
 554
 555         if (!machine_is(pseries))
 556                 return 0;
 557
 558         ent = proc_create("powerpc/ofdt", S_IWUSR, NULL, &ofdt_fops);
 559         if (ent)
 560                 ent->size = 0;
 561
 562         return 0;
 563 }
 564 __initcall(proc_ppc64_create_ofdt);