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