linux/arch/powerpc/platforms/pseries/reconfig.c
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   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
  20#include <asm/prom.h>
  21#include <asm/machdep.h>
  22#include <asm/uaccess.h>
  23#include <asm/pSeries_reconfig.h>
  24#include <asm/mmu.h>
  25
  26
  27
  28/*
  29 * Routines for "runtime" addition and removal of device tree nodes.
  30 */
  31#ifdef CONFIG_PROC_DEVICETREE
  32/*
  33 * Add a node to /proc/device-tree.
  34 */
  35static void add_node_proc_entries(struct device_node *np)
  36{
  37        struct proc_dir_entry *ent;
  38
  39        ent = proc_mkdir(strrchr(np->full_name, '/') + 1, np->parent->pde);
  40        if (ent)
  41                proc_device_tree_add_node(np, ent);
  42}
  43
  44static void remove_node_proc_entries(struct device_node *np)
  45{
  46        struct property *pp = np->properties;
  47        struct device_node *parent = np->parent;
  48
  49        while (pp) {
  50                remove_proc_entry(pp->name, np->pde);
  51                pp = pp->next;
  52        }
  53        if (np->pde)
  54                remove_proc_entry(np->pde->name, parent->pde);
  55}
  56#else /* !CONFIG_PROC_DEVICETREE */
  57static void add_node_proc_entries(struct device_node *np)
  58{
  59        return;
  60}
  61
  62static void remove_node_proc_entries(struct device_node *np)
  63{
  64        return;
  65}
  66#endif /* CONFIG_PROC_DEVICETREE */
  67
  68/**
  69 *      derive_parent - basically like dirname(1)
  70 *      @path:  the full_name of a node to be added to the tree
  71 *
  72 *      Returns the node which should be the parent of the node
  73 *      described by path.  E.g., for path = "/foo/bar", returns
  74 *      the node with full_name = "/foo".
  75 */
  76static struct device_node *derive_parent(const char *path)
  77{
  78        struct device_node *parent = NULL;
  79        char *parent_path = "/";
  80        size_t parent_path_len = strrchr(path, '/') - path + 1;
  81
  82        /* reject if path is "/" */
  83        if (!strcmp(path, "/"))
  84                return ERR_PTR(-EINVAL);
  85
  86        if (strrchr(path, '/') != path) {
  87                parent_path = kmalloc(parent_path_len, GFP_KERNEL);
  88                if (!parent_path)
  89                        return ERR_PTR(-ENOMEM);
  90                strlcpy(parent_path, path, parent_path_len);
  91        }
  92        parent = of_find_node_by_path(parent_path);
  93        if (!parent)
  94                return ERR_PTR(-EINVAL);
  95        if (strcmp(parent_path, "/"))
  96                kfree(parent_path);
  97        return parent;
  98}
  99
 100static BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
 101
 102int pSeries_reconfig_notifier_register(struct notifier_block *nb)
 103{
 104        return blocking_notifier_chain_register(&pSeries_reconfig_chain, nb);
 105}
 106
 107void pSeries_reconfig_notifier_unregister(struct notifier_block *nb)
 108{
 109        blocking_notifier_chain_unregister(&pSeries_reconfig_chain, nb);
 110}
 111
 112int pSeries_reconfig_notify(unsigned long action, void *p)
 113{
 114        int err = blocking_notifier_call_chain(&pSeries_reconfig_chain,
 115                                                action, p);
 116
 117        return notifier_to_errno(err);
 118}
 119
 120static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
 121{
 122        struct device_node *np;
 123        int err = -ENOMEM;
 124
 125        np = kzalloc(sizeof(*np), GFP_KERNEL);
 126        if (!np)
 127                goto out_err;
 128
 129        np->full_name = kstrdup(path, GFP_KERNEL);
 130        if (!np->full_name)
 131                goto out_err;
 132
 133        np->properties = proplist;
 134        of_node_set_flag(np, OF_DYNAMIC);
 135        kref_init(&np->kref);
 136
 137        np->parent = derive_parent(path);
 138        if (IS_ERR(np->parent)) {
 139                err = PTR_ERR(np->parent);
 140                goto out_err;
 141        }
 142
 143        err = pSeries_reconfig_notify(PSERIES_RECONFIG_ADD, np);
 144        if (err) {
 145                printk(KERN_ERR "Failed to add device node %s\n", path);
 146                goto out_err;
 147        }
 148
 149        of_attach_node(np);
 150
 151        add_node_proc_entries(np);
 152
 153        of_node_put(np->parent);
 154
 155        return 0;
 156
 157out_err:
 158        if (np) {
 159                of_node_put(np->parent);
 160                kfree(np->full_name);
 161                kfree(np);
 162        }
 163        return err;
 164}
 165
 166static int pSeries_reconfig_remove_node(struct device_node *np)
 167{
 168        struct device_node *parent, *child;
 169
 170        parent = of_get_parent(np);
 171        if (!parent)
 172                return -EINVAL;
 173
 174        if ((child = of_get_next_child(np, NULL))) {
 175                of_node_put(child);
 176                of_node_put(parent);
 177                return -EBUSY;
 178        }
 179
 180        remove_node_proc_entries(np);
 181
 182        pSeries_reconfig_notify(PSERIES_RECONFIG_REMOVE, np);
 183        of_detach_node(np);
 184
 185        of_node_put(parent);
 186        of_node_put(np); /* Must decrement the refcount */
 187        return 0;
 188}
 189
 190/*
 191 * /proc/powerpc/ofdt - yucky binary interface for adding and removing
 192 * OF device nodes.  Should be deprecated as soon as we get an
 193 * in-kernel wrapper for the RTAS ibm,configure-connector call.
 194 */
 195
 196static void release_prop_list(const struct property *prop)
 197{
 198        struct property *next;
 199        for (; prop; prop = next) {
 200                next = prop->next;
 201                kfree(prop->name);
 202                kfree(prop->value);
 203                kfree(prop);
 204        }
 205
 206}
 207
 208/**
 209 * parse_next_property - process the next property from raw input buffer
 210 * @buf: input buffer, must be nul-terminated
 211 * @end: end of the input buffer + 1, for validation
 212 * @name: return value; set to property name in buf
 213 * @length: return value; set to length of value
 214 * @value: return value; set to the property value in buf
 215 *
 216 * Note that the caller must make copies of the name and value returned,
 217 * this function does no allocation or copying of the data.  Return value
 218 * is set to the next name in buf, or NULL on error.
 219 */
 220static char * parse_next_property(char *buf, char *end, char **name, int *length,
 221                                  unsigned char **value)
 222{
 223        char *tmp;
 224
 225        *name = buf;
 226
 227        tmp = strchr(buf, ' ');
 228        if (!tmp) {
 229                printk(KERN_ERR "property parse failed in %s at line %d\n",
 230                       __func__, __LINE__);
 231                return NULL;
 232        }
 233        *tmp = '\0';
 234
 235        if (++tmp >= end) {
 236                printk(KERN_ERR "property parse failed in %s at line %d\n",
 237                       __func__, __LINE__);
 238                return NULL;
 239        }
 240
 241        /* now we're on the length */
 242        *length = -1;
 243        *length = simple_strtoul(tmp, &tmp, 10);
 244        if (*length == -1) {
 245                printk(KERN_ERR "property parse failed in %s at line %d\n",
 246                       __func__, __LINE__);
 247                return NULL;
 248        }
 249        if (*tmp != ' ' || ++tmp >= end) {
 250                printk(KERN_ERR "property parse failed in %s at line %d\n",
 251                       __func__, __LINE__);
 252                return NULL;
 253        }
 254
 255        /* now we're on the value */
 256        *value = tmp;
 257        tmp += *length;
 258        if (tmp > end) {
 259                printk(KERN_ERR "property parse failed in %s at line %d\n",
 260                       __func__, __LINE__);
 261                return NULL;
 262        }
 263        else if (tmp < end && *tmp != ' ' && *tmp != '\0') {
 264                printk(KERN_ERR "property parse failed in %s at line %d\n",
 265                       __func__, __LINE__);
 266                return NULL;
 267        }
 268        tmp++;
 269
 270        /* and now we should be on the next name, or the end */
 271        return tmp;
 272}
 273
 274static struct property *new_property(const char *name, const int length,
 275                                     const unsigned char *value, struct property *last)
 276{
 277        struct property *new = kzalloc(sizeof(*new), GFP_KERNEL);
 278
 279        if (!new)
 280                return NULL;
 281
 282        if (!(new->name = kmalloc(strlen(name) + 1, GFP_KERNEL)))
 283                goto cleanup;
 284        if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
 285                goto cleanup;
 286
 287        strcpy(new->name, name);
 288        memcpy(new->value, value, length);
 289        *(((char *)new->value) + length) = 0;
 290        new->length = length;
 291        new->next = last;
 292        return new;
 293
 294cleanup:
 295        kfree(new->name);
 296        kfree(new->value);
 297        kfree(new);
 298        return NULL;
 299}
 300
 301static int do_add_node(char *buf, size_t bufsize)
 302{
 303        char *path, *end, *name;
 304        struct device_node *np;
 305        struct property *prop = NULL;
 306        unsigned char* value;
 307        int length, rv = 0;
 308
 309        end = buf + bufsize;
 310        path = buf;
 311        buf = strchr(buf, ' ');
 312        if (!buf)
 313                return -EINVAL;
 314        *buf = '\0';
 315        buf++;
 316
 317        if ((np = of_find_node_by_path(path))) {
 318                of_node_put(np);
 319                return -EINVAL;
 320        }
 321
 322        /* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
 323        while (buf < end &&
 324               (buf = parse_next_property(buf, end, &name, &length, &value))) {
 325                struct property *last = prop;
 326
 327                prop = new_property(name, length, value, last);
 328                if (!prop) {
 329                        rv = -ENOMEM;
 330                        prop = last;
 331                        goto out;
 332                }
 333        }
 334        if (!buf) {
 335                rv = -EINVAL;
 336                goto out;
 337        }
 338
 339        rv = pSeries_reconfig_add_node(path, prop);
 340
 341out:
 342        if (rv)
 343                release_prop_list(prop);
 344        return rv;
 345}
 346
 347static int do_remove_node(char *buf)
 348{
 349        struct device_node *node;
 350        int rv = -ENODEV;
 351
 352        if ((node = of_find_node_by_path(buf)))
 353                rv = pSeries_reconfig_remove_node(node);
 354
 355        of_node_put(node);
 356        return rv;
 357}
 358
 359static char *parse_node(char *buf, size_t bufsize, struct device_node **npp)
 360{
 361        char *handle_str;
 362        phandle handle;
 363        *npp = NULL;
 364
 365        handle_str = buf;
 366
 367        buf = strchr(buf, ' ');
 368        if (!buf)
 369                return NULL;
 370        *buf = '\0';
 371        buf++;
 372
 373        handle = simple_strtoul(handle_str, NULL, 0);
 374
 375        *npp = of_find_node_by_phandle(handle);
 376        return buf;
 377}
 378
 379static int do_add_property(char *buf, size_t bufsize)
 380{
 381        struct property *prop = NULL;
 382        struct device_node *np;
 383        unsigned char *value;
 384        char *name, *end;
 385        int length;
 386        end = buf + bufsize;
 387        buf = parse_node(buf, bufsize, &np);
 388
 389        if (!np)
 390                return -ENODEV;
 391
 392        if (parse_next_property(buf, end, &name, &length, &value) == NULL)
 393                return -EINVAL;
 394
 395        prop = new_property(name, length, value, NULL);
 396        if (!prop)
 397                return -ENOMEM;
 398
 399        prom_add_property(np, prop);
 400
 401        return 0;
 402}
 403
 404static int do_remove_property(char *buf, size_t bufsize)
 405{
 406        struct device_node *np;
 407        char *tmp;
 408        struct property *prop;
 409        buf = parse_node(buf, bufsize, &np);
 410
 411        if (!np)
 412                return -ENODEV;
 413
 414        tmp = strchr(buf,' ');
 415        if (tmp)
 416                *tmp = '\0';
 417
 418        if (strlen(buf) == 0)
 419                return -EINVAL;
 420
 421        prop = of_find_property(np, buf, NULL);
 422
 423        return prom_remove_property(np, prop);
 424}
 425
 426static int do_update_property(char *buf, size_t bufsize)
 427{
 428        struct device_node *np;
 429        unsigned char *value;
 430        char *name, *end, *next_prop;
 431        int rc, length;
 432        struct property *newprop, *oldprop;
 433        buf = parse_node(buf, bufsize, &np);
 434        end = buf + bufsize;
 435
 436        if (!np)
 437                return -ENODEV;
 438
 439        next_prop = parse_next_property(buf, end, &name, &length, &value);
 440        if (!next_prop)
 441                return -EINVAL;
 442
 443        newprop = new_property(name, length, value, NULL);
 444        if (!newprop)
 445                return -ENOMEM;
 446
 447        if (!strcmp(name, "slb-size") || !strcmp(name, "ibm,slb-size"))
 448                slb_set_size(*(int *)value);
 449
 450        oldprop = of_find_property(np, name,NULL);
 451        if (!oldprop) {
 452                if (strlen(name))
 453                        return prom_add_property(np, newprop);
 454                return -ENODEV;
 455        }
 456
 457        rc = prom_update_property(np, newprop, oldprop);
 458        if (rc)
 459                return rc;
 460
 461        /* For memory under the ibm,dynamic-reconfiguration-memory node
 462         * of the device tree, adding and removing memory is just an update
 463         * to the ibm,dynamic-memory property instead of adding/removing a
 464         * memory node in the device tree.  For these cases we still need to
 465         * involve the notifier chain.
 466         */
 467        if (!strcmp(name, "ibm,dynamic-memory")) {
 468                int action;
 469
 470                next_prop = parse_next_property(next_prop, end, &name,
 471                                                &length, &value);
 472                if (!next_prop)
 473                        return -EINVAL;
 474
 475                if (!strcmp(name, "add"))
 476                        action = PSERIES_DRCONF_MEM_ADD;
 477                else
 478                        action = PSERIES_DRCONF_MEM_REMOVE;
 479
 480                rc = pSeries_reconfig_notify(action, value);
 481                if (rc) {
 482                        prom_update_property(np, oldprop, newprop);
 483                        return rc;
 484                }
 485        }
 486
 487        return 0;
 488}
 489
 490/**
 491 * ofdt_write - perform operations on the Open Firmware device tree
 492 *
 493 * @file: not used
 494 * @buf: command and arguments
 495 * @count: size of the command buffer
 496 * @off: not used
 497 *
 498 * Operations supported at this time are addition and removal of
 499 * whole nodes along with their properties.  Operations on individual
 500 * properties are not implemented (yet).
 501 */
 502static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t count,
 503                          loff_t *off)
 504{
 505        int rv = 0;
 506        char *kbuf;
 507        char *tmp;
 508
 509        if (!(kbuf = kmalloc(count + 1, GFP_KERNEL))) {
 510                rv = -ENOMEM;
 511                goto out;
 512        }
 513        if (copy_from_user(kbuf, buf, count)) {
 514                rv = -EFAULT;
 515                goto out;
 516        }
 517
 518        kbuf[count] = '\0';
 519
 520        tmp = strchr(kbuf, ' ');
 521        if (!tmp) {
 522                rv = -EINVAL;
 523                goto out;
 524        }
 525        *tmp = '\0';
 526        tmp++;
 527
 528        if (!strcmp(kbuf, "add_node"))
 529                rv = do_add_node(tmp, count - (tmp - kbuf));
 530        else if (!strcmp(kbuf, "remove_node"))
 531                rv = do_remove_node(tmp);
 532        else if (!strcmp(kbuf, "add_property"))
 533                rv = do_add_property(tmp, count - (tmp - kbuf));
 534        else if (!strcmp(kbuf, "remove_property"))
 535                rv = do_remove_property(tmp, count - (tmp - kbuf));
 536        else if (!strcmp(kbuf, "update_property"))
 537                rv = do_update_property(tmp, count - (tmp - kbuf));
 538        else
 539                rv = -EINVAL;
 540out:
 541        kfree(kbuf);
 542        return rv ? rv : count;
 543}
 544
 545static const struct file_operations ofdt_fops = {
 546        .write = ofdt_write,
 547        .llseek = noop_llseek,
 548};
 549
 550/* create /proc/powerpc/ofdt write-only by root */
 551static int proc_ppc64_create_ofdt(void)
 552{
 553        struct proc_dir_entry *ent;
 554
 555        if (!machine_is(pseries))
 556                return 0;
 557
 558        ent = proc_create("powerpc/ofdt", S_IWUSR, NULL, &ofdt_fops);
 559        if (ent)
 560                ent->size = 0;
 561
 562        return 0;
 563}
 564__initcall(proc_ppc64_create_ofdt);
 565