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