arch/powerpc/platforms/pseries/reconfig.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * pSeries_reconfig.c - support for dynamic reconfiguration (including PCI
   4  * Hotplug and Dynamic Logical Partitioning on RPA platforms).
   5  *
   6  * Copyright (C) 2005 Nathan Lynch
   7  * Copyright (C) 2005 IBM Corporation
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/notifier.h>
  12 #include <linux/proc_fs.h>
  13 #include <linux/slab.h>
  14 #include <linux/of.h>
  15
  16 #include <asm/prom.h>
  17 #include <asm/machdep.h>
  18 #include <linux/uaccess.h>
  19 #include <asm/mmu.h>
  20
  21 #include "of_helpers.h"
  22
  23 static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
  24 {
  25         struct device_node *np;
  26         int err = -ENOMEM;
  27
  28         np = kzalloc(sizeof(*np), GFP_KERNEL);
  29         if (!np)
  30                 goto out_err;
  31
  32         np->full_name = kstrdup(kbasename(path), GFP_KERNEL);
  33         if (!np->full_name)
  34                 goto out_err;
  35
  36         np->properties = proplist;
  37         of_node_set_flag(np, OF_DYNAMIC);
  38         of_node_init(np);
  39
  40         np->parent = pseries_of_derive_parent(path);
  41         if (IS_ERR(np->parent)) {
  42                 err = PTR_ERR(np->parent);
  43                 goto out_err;
  44         }
  45
  46         err = of_attach_node(np);
  47         if (err) {
  48                 printk(KERN_ERR "Failed to add device node %s\n", path);
  49                 goto out_err;
  50         }
  51
  52         of_node_put(np->parent);
  53
  54         return 0;
  55
  56 out_err:
  57         if (np) {
  58                 of_node_put(np->parent);
  59                 kfree(np->full_name);
  60                 kfree(np);
  61         }
  62         return err;
  63 }
  64
  65 static int pSeries_reconfig_remove_node(struct device_node *np)
  66 {
  67         struct device_node *parent, *child;
  68
  69         parent = of_get_parent(np);
  70         if (!parent)
  71                 return -EINVAL;
  72
  73         if ((child = of_get_next_child(np, NULL))) {
  74                 of_node_put(child);
  75                 of_node_put(parent);
  76                 return -EBUSY;
  77         }
  78
  79         of_detach_node(np);
  80         of_node_put(parent);
  81         return 0;
  82 }
  83
  84 /*
  85  * /proc/powerpc/ofdt - yucky binary interface for adding and removing
  86  * OF device nodes.  Should be deprecated as soon as we get an
  87  * in-kernel wrapper for the RTAS ibm,configure-connector call.
  88  */
  89
  90 static void release_prop_list(const struct property *prop)
  91 {
  92         struct property *next;
  93         for (; prop; prop = next) {
  94                 next = prop->next;
  95                 kfree(prop->name);
  96                 kfree(prop->value);
  97                 kfree(prop);
  98         }
  99
 100 }
 101
 102 /**
 103  * parse_next_property - process the next property from raw input buffer
 104  * @buf: input buffer, must be nul-terminated
 105  * @end: end of the input buffer + 1, for validation
 106  * @name: return value; set to property name in buf
 107  * @length: return value; set to length of value
 108  * @value: return value; set to the property value in buf
 109  *
 110  * Note that the caller must make copies of the name and value returned,
 111  * this function does no allocation or copying of the data.  Return value
 112  * is set to the next name in buf, or NULL on error.
 113  */
 114 static char * parse_next_property(char *buf, char *end, char **name, int *length,
 115                                   unsigned char **value)
 116 {
 117         char *tmp;
 118
 119         *name = buf;
 120
 121         tmp = strchr(buf, ' ');
 122         if (!tmp) {
 123                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 124                        __func__, __LINE__);
 125                 return NULL;
 126         }
 127         *tmp = '\0';
 128
 129         if (++tmp >= end) {
 130                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 131                        __func__, __LINE__);
 132                 return NULL;
 133         }
 134
 135         /* now we're on the length */
 136         *length = -1;
 137         *length = simple_strtoul(tmp, &tmp, 10);
 138         if (*length == -1) {
 139                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 140                        __func__, __LINE__);
 141                 return NULL;
 142         }
 143         if (*tmp != ' ' || ++tmp >= end) {
 144                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 145                        __func__, __LINE__);
 146                 return NULL;
 147         }
 148
 149         /* now we're on the value */
 150         *value = tmp;
 151         tmp += *length;
 152         if (tmp > end) {
 153                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 154                        __func__, __LINE__);
 155                 return NULL;
 156         }
 157         else if (tmp < end && *tmp != ' ' && *tmp != '\0') {
 158                 printk(KERN_ERR "property parse failed in %s at line %d\n",
 159                        __func__, __LINE__);
 160                 return NULL;
 161         }
 162         tmp++;
 163
 164         /* and now we should be on the next name, or the end */
 165         return tmp;
 166 }
 167
 168 static struct property *new_property(const char *name, const int length,
 169                                      const unsigned char *value, struct property *last)
 170 {
 171         struct property *new = kzalloc(sizeof(*new), GFP_KERNEL);
 172
 173         if (!new)
 174                 return NULL;
 175
 176         if (!(new->name = kstrdup(name, GFP_KERNEL)))
 177                 goto cleanup;
 178         if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
 179                 goto cleanup;
 180
 181         memcpy(new->value, value, length);
 182         *(((char *)new->value) + length) = 0;
 183         new->length = length;
 184         new->next = last;
 185         return new;
 186
 187 cleanup:
 188         kfree(new->name);
 189         kfree(new->value);
 190         kfree(new);
 191         return NULL;
 192 }
 193
 194 static int do_add_node(char *buf, size_t bufsize)
 195 {
 196         char *path, *end, *name;
 197         struct device_node *np;
 198         struct property *prop = NULL;
 199         unsigned char* value;
 200         int length, rv = 0;
 201
 202         end = buf + bufsize;
 203         path = buf;
 204         buf = strchr(buf, ' ');
 205         if (!buf)
 206                 return -EINVAL;
 207         *buf = '\0';
 208         buf++;
 209
 210         if ((np = of_find_node_by_path(path))) {
 211                 of_node_put(np);
 212                 return -EINVAL;
 213         }
 214
 215         /* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
 216         while (buf < end &&
 217                (buf = parse_next_property(buf, end, &name, &length, &value))) {
 218                 struct property *last = prop;
 219
 220                 prop = new_property(name, length, value, last);
 221                 if (!prop) {
 222                         rv = -ENOMEM;
 223                         prop = last;
 224                         goto out;
 225                 }
 226         }
 227         if (!buf) {
 228                 rv = -EINVAL;
 229                 goto out;
 230         }
 231
 232         rv = pSeries_reconfig_add_node(path, prop);
 233
 234 out:
 235         if (rv)
 236                 release_prop_list(prop);
 237         return rv;
 238 }
 239
 240 static int do_remove_node(char *buf)
 241 {
 242         struct device_node *node;
 243         int rv = -ENODEV;
 244
 245         if ((node = of_find_node_by_path(buf)))
 246                 rv = pSeries_reconfig_remove_node(node);
 247
 248         of_node_put(node);
 249         return rv;
 250 }
 251
 252 static char *parse_node(char *buf, size_t bufsize, struct device_node **npp)
 253 {
 254         char *handle_str;
 255         phandle handle;
 256         *npp = NULL;
 257
 258         handle_str = buf;
 259
 260         buf = strchr(buf, ' ');
 261         if (!buf)
 262                 return NULL;
 263         *buf = '\0';
 264         buf++;
 265
 266         handle = simple_strtoul(handle_str, NULL, 0);
 267
 268         *npp = of_find_node_by_phandle(handle);
 269         return buf;
 270 }
 271
 272 static int do_add_property(char *buf, size_t bufsize)
 273 {
 274         struct property *prop = NULL;
 275         struct device_node *np;
 276         unsigned char *value;
 277         char *name, *end;
 278         int length;
 279         end = buf + bufsize;
 280         buf = parse_node(buf, bufsize, &np);
 281
 282         if (!np)
 283                 return -ENODEV;
 284
 285         if (parse_next_property(buf, end, &name, &length, &value) == NULL)
 286                 return -EINVAL;
 287
 288         prop = new_property(name, length, value, NULL);
 289         if (!prop)
 290                 return -ENOMEM;
 291
 292         of_add_property(np, prop);
 293
 294         return 0;
 295 }
 296
 297 static int do_remove_property(char *buf, size_t bufsize)
 298 {
 299         struct device_node *np;
 300         char *tmp;
 301         buf = parse_node(buf, bufsize, &np);
 302
 303         if (!np)
 304                 return -ENODEV;
 305
 306         tmp = strchr(buf,' ');
 307         if (tmp)
 308                 *tmp = '\0';
 309
 310         if (strlen(buf) == 0)
 311                 return -EINVAL;
 312
 313         return of_remove_property(np, of_find_property(np, buf, NULL));
 314 }
 315
 316 static int do_update_property(char *buf, size_t bufsize)
 317 {
 318         struct device_node *np;
 319         unsigned char *value;
 320         char *name, *end, *next_prop;
 321         int length;
 322         struct property *newprop;
 323         buf = parse_node(buf, bufsize, &np);
 324         end = buf + bufsize;
 325
 326         if (!np)
 327                 return -ENODEV;
 328
 329         next_prop = parse_next_property(buf, end, &name, &length, &value);
 330         if (!next_prop)
 331                 return -EINVAL;
 332
 333         if (!strlen(name))
 334                 return -ENODEV;
 335
 336         newprop = new_property(name, length, value, NULL);
 337         if (!newprop)
 338                 return -ENOMEM;
 339
 340         if (!strcmp(name, "slb-size") || !strcmp(name, "ibm,slb-size"))
 341                 slb_set_size(*(int *)value);
 342
 343         return of_update_property(np, newprop);
 344 }
 345
 346 /**
 347  * ofdt_write - perform operations on the Open Firmware device tree
 348  *
 349  * @file: not used
 350  * @buf: command and arguments
 351  * @count: size of the command buffer
 352  * @off: not used
 353  *
 354  * Operations supported at this time are addition and removal of
 355  * whole nodes along with their properties.  Operations on individual
 356  * properties are not implemented (yet).
 357  */
 358 static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t count,
 359                           loff_t *off)
 360 {
 361         int rv;
 362         char *kbuf;
 363         char *tmp;
 364
 365         kbuf = memdup_user_nul(buf, count);
 366         if (IS_ERR(kbuf))
 367                 return PTR_ERR(kbuf);
 368
 369         tmp = strchr(kbuf, ' ');
 370         if (!tmp) {
 371                 rv = -EINVAL;
 372                 goto out;
 373         }
 374         *tmp = '\0';
 375         tmp++;
 376
 377         if (!strcmp(kbuf, "add_node"))
 378                 rv = do_add_node(tmp, count - (tmp - kbuf));
 379         else if (!strcmp(kbuf, "remove_node"))
 380                 rv = do_remove_node(tmp);
 381         else if (!strcmp(kbuf, "add_property"))
 382                 rv = do_add_property(tmp, count - (tmp - kbuf));
 383         else if (!strcmp(kbuf, "remove_property"))
 384                 rv = do_remove_property(tmp, count - (tmp - kbuf));
 385         else if (!strcmp(kbuf, "update_property"))
 386                 rv = do_update_property(tmp, count - (tmp - kbuf));
 387         else
 388                 rv = -EINVAL;
 389 out:
 390         kfree(kbuf);
 391         return rv ? rv : count;
 392 }
 393
 394 static const struct proc_ops ofdt_proc_ops = {
 395         .proc_write     = ofdt_write,
 396         .proc_lseek     = noop_llseek,
 397 };
 398
 399 /* create /proc/powerpc/ofdt write-only by root */
 400 static int proc_ppc64_create_ofdt(void)
 401 {
 402         struct proc_dir_entry *ent;
 403
 404         ent = proc_create("powerpc/ofdt", 0200, NULL, &ofdt_proc_ops);
 405         if (ent)
 406                 proc_set_size(ent, 0);
 407
 408         return 0;
 409 }
 410 machine_device_initcall(pseries, proc_ppc64_create_ofdt);