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