arch/ppc64/kernel/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/pSeries_reconfig.h>
  21 #include <asm/uaccess.h>
  22
  23
  24
  25 /*
  26  * Routines for "runtime" addition and removal of device tree nodes.
  27  */
  28 #ifdef CONFIG_PROC_DEVICETREE
  29 /*
  30  * Add a node to /proc/device-tree.
  31  */
  32 static void add_node_proc_entries(struct device_node *np)
  33 {
  34         struct proc_dir_entry *ent;
  35
  36         ent = proc_mkdir(strrchr(np->full_name, '/') + 1, np->parent->pde);
  37         if (ent)
  38                 proc_device_tree_add_node(np, ent);
  39 }
  40
  41 static void remove_node_proc_entries(struct device_node *np)
  42 {
  43         struct property *pp = np->properties;
  44         struct device_node *parent = np->parent;
  45
  46         while (pp) {
  47                 remove_proc_entry(pp->name, np->pde);
  48                 pp = pp->next;
  49         }
  50
  51         /* Assuming that symlinks have the same parent directory as
  52          * np->pde.
  53          */
  54         if (np->name_link)
  55                 remove_proc_entry(np->name_link->name, parent->pde);
  56         if (np->addr_link)
  57                 remove_proc_entry(np->addr_link->name, parent->pde);
  58         if (np->pde)
  59                 remove_proc_entry(np->pde->name, parent->pde);
  60 }
  61 #else /* !CONFIG_PROC_DEVICETREE */
  62 static void add_node_proc_entries(struct device_node *np)
  63 {
  64         return;
  65 }
  66
  67 static void remove_node_proc_entries(struct device_node *np)
  68 {
  69         return;
  70 }
  71 #endif /* CONFIG_PROC_DEVICETREE */
  72
  73 /**
  74  *      derive_parent - basically like dirname(1)
  75  *      @path:  the full_name of a node to be added to the tree
  76  *
  77  *      Returns the node which should be the parent of the node
  78  *      described by path.  E.g., for path = "/foo/bar", returns
  79  *      the node with full_name = "/foo".
  80  */
  81 static struct device_node *derive_parent(const char *path)
  82 {
  83         struct device_node *parent = NULL;
  84         char *parent_path = "/";
  85         size_t parent_path_len = strrchr(path, '/') - path + 1;
  86
  87         /* reject if path is "/" */
  88         if (!strcmp(path, "/"))
  89                 return ERR_PTR(-EINVAL);
  90
  91         if (strrchr(path, '/') != path) {
  92                 parent_path = kmalloc(parent_path_len, GFP_KERNEL);
  93                 if (!parent_path)
  94                         return ERR_PTR(-ENOMEM);
  95                 strlcpy(parent_path, path, parent_path_len);
  96         }
  97         parent = of_find_node_by_path(parent_path);
  98         if (!parent)
  99                 return ERR_PTR(-EINVAL);
 100         if (strcmp(parent_path, "/"))
 101                 kfree(parent_path);
 102         return parent;
 103 }
 104
 105 static struct notifier_block *pSeries_reconfig_chain;
 106
 107 int pSeries_reconfig_notifier_register(struct notifier_block *nb)
 108 {
 109         return notifier_chain_register(&pSeries_reconfig_chain, nb);
 110 }
 111
 112 void pSeries_reconfig_notifier_unregister(struct notifier_block *nb)
 113 {
 114         notifier_chain_unregister(&pSeries_reconfig_chain, nb);
 115 }
 116
 117 static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
 118 {
 119         struct device_node *np;
 120         int err = -ENOMEM;
 121
 122         np = kcalloc(1, sizeof(*np), GFP_KERNEL);
 123         if (!np)
 124                 goto out_err;
 125
 126         np->full_name = kmalloc(strlen(path) + 1, GFP_KERNEL);
 127         if (!np->full_name)
 128                 goto out_err;
 129
 130         strcpy(np->full_name, path);
 131
 132         np->properties = proplist;
 133         OF_MARK_DYNAMIC(np);
 134         kref_init(&np->kref);
 135
 136         np->parent = derive_parent(path);
 137         if (IS_ERR(np->parent)) {
 138                 err = PTR_ERR(np->parent);
 139                 goto out_err;
 140         }
 141
 142         err = notifier_call_chain(&pSeries_reconfig_chain,
 143                                   PSERIES_RECONFIG_ADD, np);
 144         if (err == NOTIFY_BAD) {
 145                 printk(KERN_ERR "Failed to add device node %s\n", path);
 146                 err = -ENOMEM; /* For now, safe to assume kmalloc failure */
 147                 goto out_err;
 148         }
 149
 150         of_attach_node(np);
 151
 152         add_node_proc_entries(np);
 153
 154         of_node_put(np->parent);
 155
 156         return 0;
 157
 158 out_err:
 159         if (np) {
 160                 of_node_put(np->parent);
 161                 kfree(np->full_name);
 162                 kfree(np);
 163         }
 164         return err;
 165 }
 166
 167 static int pSeries_reconfig_remove_node(struct device_node *np)
 168 {
 169         struct device_node *parent, *child;
 170
 171         parent = of_get_parent(np);
 172         if (!parent)
 173                 return -EINVAL;
 174
 175         if ((child = of_get_next_child(np, NULL))) {
 176                 of_node_put(child);
 177                 return -EBUSY;
 178         }
 179
 180         remove_node_proc_entries(np);
 181
 182         notifier_call_chain(&pSeries_reconfig_chain,
 183                             PSERIES_RECONFIG_REMOVE, np);
 184         of_detach_node(np);
 185
 186         of_node_put(parent);
 187         of_node_put(np); /* Must decrement the refcount */
 188         return 0;
 189 }
 190
 191 /*
 192  * /proc/ppc64/ofdt - yucky binary interface for adding and removing
 193  * OF device nodes.  Should be deprecated as soon as we get an
 194  * in-kernel wrapper for the RTAS ibm,configure-connector call.
 195  */
 196
 197 static void release_prop_list(const struct property *prop)
 198 {
 199         struct property *next;
 200         for (; prop; prop = next) {
 201                 next = prop->next;
 202                 kfree(prop->name);
 203                 kfree(prop->value);
 204                 kfree(prop);
 205         }
 206
 207 }
 208
 209 /**
 210  * parse_next_property - process the next property from raw input buffer
 211  * @buf: input buffer, must be nul-terminated
 212  * @end: end of the input buffer + 1, for validation
 213  * @name: return value; set to property name in buf
 214  * @length: return value; set to length of value
 215  * @value: return value; set to the property value in buf
 216  *
 217  * Note that the caller must make copies of the name and value returned,
 218  * this function does no allocation or copying of the data.  Return value
 219  * is set to the next name in buf, or NULL on error.
 220  */
 221 static char * parse_next_property(char *buf, char *end, char **name, int *length,
 222                                   unsigned char **value)
 223 {
 224         char *tmp;
 225
 226         *name = buf;
 227
 228         tmp = strchr(buf, ' ');
 229         if (!tmp) {
 230                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 231                        __FUNCTION__, __LINE__);
 232                 return NULL;
 233         }
 234         *tmp = '\0';
 235
 236         if (++tmp >= end) {
 237                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 238                        __FUNCTION__, __LINE__);
 239                 return NULL;
 240         }
 241
 242         /* now we're on the length */
 243         *length = -1;
 244         *length = simple_strtoul(tmp, &tmp, 10);
 245         if (*length == -1) {
 246                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 247                        __FUNCTION__, __LINE__);
 248                 return NULL;
 249         }
 250         if (*tmp != ' ' || ++tmp >= end) {
 251                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 252                        __FUNCTION__, __LINE__);
 253                 return NULL;
 254         }
 255
 256         /* now we're on the value */
 257         *value = tmp;
 258         tmp += *length;
 259         if (tmp > end) {
 260                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 261                        __FUNCTION__, __LINE__);
 262                 return NULL;
 263         }
 264         else if (tmp < end && *tmp != ' ' && *tmp != '\0') {
 265                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 266                        __FUNCTION__, __LINE__);
 267                 return NULL;
 268         }
 269         tmp++;
 270
 271         /* and now we should be on the next name, or the end */
 272         return tmp;
 273 }
 274
 275 static struct property *new_property(const char *name, const int length,
 276                                      const unsigned char *value, struct property *last)
 277 {
 278         struct property *new = kmalloc(sizeof(*new), GFP_KERNEL);
 279
 280         if (!new)
 281                 return NULL;
 282         memset(new, 0, sizeof(*new));
 283
 284         if (!(new->name = kmalloc(strlen(name) + 1, GFP_KERNEL)))
 285                 goto cleanup;
 286         if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
 287                 goto cleanup;
 288
 289         strcpy(new->name, name);
 290         memcpy(new->value, value, length);
 291         *(((char *)new->value) + length) = 0;
 292         new->length = length;
 293         new->next = last;
 294         return new;
 295
 296 cleanup:
 297         if (new->name)
 298                 kfree(new->name);
 299         if (new->value)
 300                 kfree(new->value);
 301         kfree(new);
 302         return NULL;
 303 }
 304
 305 static int do_add_node(char *buf, size_t bufsize)
 306 {
 307         char *path, *end, *name;
 308         struct device_node *np;
 309         struct property *prop = NULL;
 310         unsigned char* value;
 311         int length, rv = 0;
 312
 313         end = buf + bufsize;
 314         path = buf;
 315         buf = strchr(buf, ' ');
 316         if (!buf)
 317                 return -EINVAL;
 318         *buf = '\0';
 319         buf++;
 320
 321         if ((np = of_find_node_by_path(path))) {
 322                 of_node_put(np);
 323                 return -EINVAL;
 324         }
 325
 326         /* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
 327         while (buf < end &&
 328                (buf = parse_next_property(buf, end, &name, &length, &value))) {
 329                 struct property *last = prop;
 330
 331                 prop = new_property(name, length, value, last);
 332                 if (!prop) {
 333                         rv = -ENOMEM;
 334                         prop = last;
 335                         goto out;
 336                 }
 337         }
 338         if (!buf) {
 339                 rv = -EINVAL;
 340                 goto out;
 341         }
 342
 343         rv = pSeries_reconfig_add_node(path, prop);
 344
 345 out:
 346         if (rv)
 347                 release_prop_list(prop);
 348         return rv;
 349 }
 350
 351 static int do_remove_node(char *buf)
 352 {
 353         struct device_node *node;
 354         int rv = -ENODEV;
 355
 356         if ((node = of_find_node_by_path(buf)))
 357                 rv = pSeries_reconfig_remove_node(node);
 358
 359         of_node_put(node);
 360         return rv;
 361 }
 362
 363 /**
 364  * ofdt_write - perform operations on the Open Firmware device tree
 365  *
 366  * @file: not used
 367  * @buf: command and arguments
 368  * @count: size of the command buffer
 369  * @off: not used
 370  *
 371  * Operations supported at this time are addition and removal of
 372  * whole nodes along with their properties.  Operations on individual
 373  * properties are not implemented (yet).
 374  */
 375 static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t count,
 376                           loff_t *off)
 377 {
 378         int rv = 0;
 379         char *kbuf;
 380         char *tmp;
 381
 382         if (!(kbuf = kmalloc(count + 1, GFP_KERNEL))) {
 383                 rv = -ENOMEM;
 384                 goto out;
 385         }
 386         if (copy_from_user(kbuf, buf, count)) {
 387                 rv = -EFAULT;
 388                 goto out;
 389         }
 390
 391         kbuf[count] = '\0';
 392
 393         tmp = strchr(kbuf, ' ');
 394         if (!tmp) {
 395                 rv = -EINVAL;
 396                 goto out;
 397         }
 398         *tmp = '\0';
 399         tmp++;
 400
 401         if (!strcmp(kbuf, "add_node"))
 402                 rv = do_add_node(tmp, count - (tmp - kbuf));
 403         else if (!strcmp(kbuf, "remove_node"))
 404                 rv = do_remove_node(tmp);
 405         else
 406                 rv = -EINVAL;
 407 out:
 408         kfree(kbuf);
 409         return rv ? rv : count;
 410 }
 411
 412 static struct file_operations ofdt_fops = {
 413         .write = ofdt_write
 414 };
 415
 416 /* create /proc/ppc64/ofdt write-only by root */
 417 static int proc_ppc64_create_ofdt(void)
 418 {
 419         struct proc_dir_entry *ent;
 420
 421         if (!(systemcfg->platform & PLATFORM_PSERIES))
 422                 return 0;
 423
 424         ent = create_proc_entry("ppc64/ofdt", S_IWUSR, NULL);
 425         if (ent) {
 426                 ent->nlink = 1;
 427                 ent->data = NULL;
 428                 ent->size = 0;
 429                 ent->proc_fops = &ofdt_fops;
 430         }
 431
 432         return 0;
 433 }
 434 __initcall(proc_ppc64_create_ofdt);