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_MARK_DYNAMIC(np);
 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                 return -EBUSY;
 171         }
 172
 173         remove_node_proc_entries(np);
 174
 175         blocking_notifier_call_chain(&pSeries_reconfig_chain,
 176                             PSERIES_RECONFIG_REMOVE, np);
 177         of_detach_node(np);
 178
 179         of_node_put(parent);
 180         of_node_put(np); /* Must decrement the refcount */
 181         return 0;
 182 }
 183
 184 /*
 185  * /proc/ppc64/ofdt - yucky binary interface for adding and removing
 186  * OF device nodes.  Should be deprecated as soon as we get an
 187  * in-kernel wrapper for the RTAS ibm,configure-connector call.
 188  */
 189
 190 static void release_prop_list(const struct property *prop)
 191 {
 192         struct property *next;
 193         for (; prop; prop = next) {
 194                 next = prop->next;
 195                 kfree(prop->name);
 196                 kfree(prop->value);
 197                 kfree(prop);
 198         }
 199
 200 }
 201
 202 /**
 203  * parse_next_property - process the next property from raw input buffer
 204  * @buf: input buffer, must be nul-terminated
 205  * @end: end of the input buffer + 1, for validation
 206  * @name: return value; set to property name in buf
 207  * @length: return value; set to length of value
 208  * @value: return value; set to the property value in buf
 209  *
 210  * Note that the caller must make copies of the name and value returned,
 211  * this function does no allocation or copying of the data.  Return value
 212  * is set to the next name in buf, or NULL on error.
 213  */
 214 static char * parse_next_property(char *buf, char *end, char **name, int *length,
 215                                   unsigned char **value)
 216 {
 217         char *tmp;
 218
 219         *name = buf;
 220
 221         tmp = strchr(buf, ' ');
 222         if (!tmp) {
 223                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 224                        __FUNCTION__, __LINE__);
 225                 return NULL;
 226         }
 227         *tmp = '\0';
 228
 229         if (++tmp >= end) {
 230                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 231                        __FUNCTION__, __LINE__);
 232                 return NULL;
 233         }
 234
 235         /* now we're on the length */
 236         *length = -1;
 237         *length = simple_strtoul(tmp, &tmp, 10);
 238         if (*length == -1) {
 239                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 240                        __FUNCTION__, __LINE__);
 241                 return NULL;
 242         }
 243         if (*tmp != ' ' || ++tmp >= end) {
 244                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 245                        __FUNCTION__, __LINE__);
 246                 return NULL;
 247         }
 248
 249         /* now we're on the value */
 250         *value = tmp;
 251         tmp += *length;
 252         if (tmp > end) {
 253                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 254                        __FUNCTION__, __LINE__);
 255                 return NULL;
 256         }
 257         else if (tmp < end && *tmp != ' ' && *tmp != '\0') {
 258                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 259                        __FUNCTION__, __LINE__);
 260                 return NULL;
 261         }
 262         tmp++;
 263
 264         /* and now we should be on the next name, or the end */
 265         return tmp;
 266 }
 267
 268 static struct property *new_property(const char *name, const int length,
 269                                      const unsigned char *value, struct property *last)
 270 {
 271         struct property *new = kzalloc(sizeof(*new), GFP_KERNEL);
 272
 273         if (!new)
 274                 return NULL;
 275
 276         if (!(new->name = kmalloc(strlen(name) + 1, GFP_KERNEL)))
 277                 goto cleanup;
 278         if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
 279                 goto cleanup;
 280
 281         strcpy(new->name, name);
 282         memcpy(new->value, value, length);
 283         *(((char *)new->value) + length) = 0;
 284         new->length = length;
 285         new->next = last;
 286         return new;
 287
 288 cleanup:
 289         kfree(new->name);
 290         kfree(new->value);
 291         kfree(new);
 292         return NULL;
 293 }
 294
 295 static int do_add_node(char *buf, size_t bufsize)
 296 {
 297         char *path, *end, *name;
 298         struct device_node *np;
 299         struct property *prop = NULL;
 300         unsigned char* value;
 301         int length, rv = 0;
 302
 303         end = buf + bufsize;
 304         path = buf;
 305         buf = strchr(buf, ' ');
 306         if (!buf)
 307                 return -EINVAL;
 308         *buf = '\0';
 309         buf++;
 310
 311         if ((np = of_find_node_by_path(path))) {
 312                 of_node_put(np);
 313                 return -EINVAL;
 314         }
 315
 316         /* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
 317         while (buf < end &&
 318                (buf = parse_next_property(buf, end, &name, &length, &value))) {
 319                 struct property *last = prop;
 320
 321                 prop = new_property(name, length, value, last);
 322                 if (!prop) {
 323                         rv = -ENOMEM;
 324                         prop = last;
 325                         goto out;
 326                 }
 327         }
 328         if (!buf) {
 329                 rv = -EINVAL;
 330                 goto out;
 331         }
 332
 333         rv = pSeries_reconfig_add_node(path, prop);
 334
 335 out:
 336         if (rv)
 337                 release_prop_list(prop);
 338         return rv;
 339 }
 340
 341 static int do_remove_node(char *buf)
 342 {
 343         struct device_node *node;
 344         int rv = -ENODEV;
 345
 346         if ((node = of_find_node_by_path(buf)))
 347                 rv = pSeries_reconfig_remove_node(node);
 348
 349         of_node_put(node);
 350         return rv;
 351 }
 352
 353 static char *parse_node(char *buf, size_t bufsize, struct device_node **npp)
 354 {
 355         char *handle_str;
 356         phandle handle;
 357         *npp = NULL;
 358
 359         handle_str = buf;
 360
 361         buf = strchr(buf, ' ');
 362         if (!buf)
 363                 return NULL;
 364         *buf = '\0';
 365         buf++;
 366
 367         handle = simple_strtoul(handle_str, NULL, 10);
 368
 369         *npp = of_find_node_by_phandle(handle);
 370         return buf;
 371 }
 372
 373 static int do_add_property(char *buf, size_t bufsize)
 374 {
 375         struct property *prop = NULL;
 376         struct device_node *np;
 377         unsigned char *value;
 378         char *name, *end;
 379         int length;
 380         end = buf + bufsize;
 381         buf = parse_node(buf, bufsize, &np);
 382
 383         if (!np)
 384                 return -ENODEV;
 385
 386         if (parse_next_property(buf, end, &name, &length, &value) == NULL)
 387                 return -EINVAL;
 388
 389         prop = new_property(name, length, value, NULL);
 390         if (!prop)
 391                 return -ENOMEM;
 392
 393         prom_add_property(np, prop);
 394
 395         return 0;
 396 }
 397
 398 static int do_remove_property(char *buf, size_t bufsize)
 399 {
 400         struct device_node *np;
 401         char *tmp;
 402         struct property *prop;
 403         buf = parse_node(buf, bufsize, &np);
 404
 405         if (!np)
 406                 return -ENODEV;
 407
 408         tmp = strchr(buf,' ');
 409         if (tmp)
 410                 *tmp = '\0';
 411
 412         if (strlen(buf) == 0)
 413                 return -EINVAL;
 414
 415         prop = of_find_property(np, buf, NULL);
 416
 417         return prom_remove_property(np, prop);
 418 }
 419
 420 static int do_update_property(char *buf, size_t bufsize)
 421 {
 422         struct device_node *np;
 423         unsigned char *value;
 424         char *name, *end;
 425         int length;
 426         struct property *newprop, *oldprop;
 427         buf = parse_node(buf, bufsize, &np);
 428         end = buf + bufsize;
 429
 430         if (!np)
 431                 return -ENODEV;
 432
 433         if (parse_next_property(buf, end, &name, &length, &value) == NULL)
 434                 return -EINVAL;
 435
 436         newprop = new_property(name, length, value, NULL);
 437         if (!newprop)
 438                 return -ENOMEM;
 439
 440         oldprop = of_find_property(np, name,NULL);
 441         if (!oldprop)
 442                 return -ENODEV;
 443
 444         return prom_update_property(np, newprop, oldprop);
 445 }
 446
 447 /**
 448  * ofdt_write - perform operations on the Open Firmware device tree
 449  *
 450  * @file: not used
 451  * @buf: command and arguments
 452  * @count: size of the command buffer
 453  * @off: not used
 454  *
 455  * Operations supported at this time are addition and removal of
 456  * whole nodes along with their properties.  Operations on individual
 457  * properties are not implemented (yet).
 458  */
 459 static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t count,
 460                           loff_t *off)
 461 {
 462         int rv = 0;
 463         char *kbuf;
 464         char *tmp;
 465
 466         if (!(kbuf = kmalloc(count + 1, GFP_KERNEL))) {
 467                 rv = -ENOMEM;
 468                 goto out;
 469         }
 470         if (copy_from_user(kbuf, buf, count)) {
 471                 rv = -EFAULT;
 472                 goto out;
 473         }
 474
 475         kbuf[count] = '\0';
 476
 477         tmp = strchr(kbuf, ' ');
 478         if (!tmp) {
 479                 rv = -EINVAL;
 480                 goto out;
 481         }
 482         *tmp = '\0';
 483         tmp++;
 484
 485         if (!strcmp(kbuf, "add_node"))
 486                 rv = do_add_node(tmp, count - (tmp - kbuf));
 487         else if (!strcmp(kbuf, "remove_node"))
 488                 rv = do_remove_node(tmp);
 489         else if (!strcmp(kbuf, "add_property"))
 490                 rv = do_add_property(tmp, count - (tmp - kbuf));
 491         else if (!strcmp(kbuf, "remove_property"))
 492                 rv = do_remove_property(tmp, count - (tmp - kbuf));
 493         else if (!strcmp(kbuf, "update_property"))
 494                 rv = do_update_property(tmp, count - (tmp - kbuf));
 495         else
 496                 rv = -EINVAL;
 497 out:
 498         kfree(kbuf);
 499         return rv ? rv : count;
 500 }
 501
 502 static const struct file_operations ofdt_fops = {
 503         .write = ofdt_write
 504 };
 505
 506 /* create /proc/ppc64/ofdt write-only by root */
 507 static int proc_ppc64_create_ofdt(void)
 508 {
 509         struct proc_dir_entry *ent;
 510
 511         if (!machine_is(pseries))
 512                 return 0;
 513
 514         ent = create_proc_entry("ppc64/ofdt", S_IWUSR, NULL);
 515         if (ent) {
 516                 ent->data = NULL;
 517                 ent->size = 0;
 518                 ent->proc_fops = &ofdt_fops;
 519         }
 520
 521         return 0;
 522 }
 523 __initcall(proc_ppc64_create_ofdt);