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