drivers/s390/cio/blacklist.c

   1 /*
   2  *  drivers/s390/cio/blacklist.c
   3  *   S/390 common I/O routines -- blacklisting of specific devices
   4  *
   5  *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
   6  *                            IBM Corporation
   7  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
   8  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   9  *               Arnd Bergmann (arndb@de.ibm.com)
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/vmalloc.h>
  14 #include <linux/slab.h>
  15 #include <linux/proc_fs.h>
  16 #include <linux/seq_file.h>
  17 #include <linux/ctype.h>
  18 #include <linux/device.h>
  19
  20 #include <asm/cio.h>
  21 #include <asm/uaccess.h>
  22
  23 #include "blacklist.h"
  24 #include "cio.h"
  25 #include "cio_debug.h"
  26 #include "css.h"
  27 #include "device.h"
  28
  29 /*
  30  * "Blacklisting" of certain devices:
  31  * Device numbers given in the commandline as cio_ignore=... won't be known
  32  * to Linux.
  33  *
  34  * These can be single devices or ranges of devices
  35  */
  36
  37 /* 65536 bits for each set to indicate if a devno is blacklisted or not */
  38 #define __BL_DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
  39                          (8*sizeof(long)))
  40 static unsigned long bl_dev[__MAX_SSID + 1][__BL_DEV_WORDS];
  41 typedef enum {add, free} range_action;
  42
  43 /*
  44  * Function: blacklist_range
  45  * (Un-)blacklist the devices from-to
  46  */
  47 static int blacklist_range(range_action action, unsigned int from_ssid,
  48                            unsigned int to_ssid, unsigned int from,
  49                            unsigned int to, int msgtrigger)
  50 {
  51         if ((from_ssid > to_ssid) || ((from_ssid == to_ssid) && (from > to))) {
  52                 if (msgtrigger)
  53                         printk(KERN_WARNING "cio: Invalid cio_ignore range "
  54                                "0.%x.%04x-0.%x.%04x\n", from_ssid, from,
  55                                to_ssid, to);
  56                 return 1;
  57         }
  58
  59         while ((from_ssid < to_ssid) || ((from_ssid == to_ssid) &&
  60                (from <= to))) {
  61                 if (action == add)
  62                         set_bit(from, bl_dev[from_ssid]);
  63                 else
  64                         clear_bit(from, bl_dev[from_ssid]);
  65                 from++;
  66                 if (from > __MAX_SUBCHANNEL) {
  67                         from_ssid++;
  68                         from = 0;
  69                 }
  70         }
  71
  72         return 0;
  73 }
  74
  75 static int pure_hex(char **cp, unsigned int *val, int min_digit,
  76                     int max_digit, int max_val)
  77 {
  78         int diff;
  79         unsigned int value;
  80
  81         diff = 0;
  82         *val = 0;
  83
  84         while (isxdigit(**cp) && (diff <= max_digit)) {
  85
  86                 if (isdigit(**cp))
  87                         value = **cp - '0';
  88                 else
  89                         value = tolower(**cp) - 'a' + 10;
  90                 *val = *val * 16 + value;
  91                 (*cp)++;
  92                 diff++;
  93         }
  94
  95         if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))
  96                 return 1;
  97
  98         return 0;
  99 }
 100
 101 static int parse_busid(char *str, unsigned int *cssid, unsigned int *ssid,
 102                        unsigned int *devno, int msgtrigger)
 103 {
 104         char *str_work;
 105         int val, rc, ret;
 106
 107         rc = 1;
 108
 109         if (*str == '\0')
 110                 goto out;
 111
 112         /* old style */
 113         str_work = str;
 114         val = simple_strtoul(str, &str_work, 16);
 115
 116         if (*str_work == '\0') {
 117                 if (val <= __MAX_SUBCHANNEL) {
 118                         *devno = val;
 119                         *ssid = 0;
 120                         *cssid = 0;
 121                         rc = 0;
 122                 }
 123                 goto out;
 124         }
 125
 126         /* new style */
 127         str_work = str;
 128         ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);
 129         if (ret || (str_work[0] != '.'))
 130                 goto out;
 131         str_work++;
 132         ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);
 133         if (ret || (str_work[0] != '.'))
 134                 goto out;
 135         str_work++;
 136         ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);
 137         if (ret || (str_work[0] != '\0'))
 138                 goto out;
 139
 140         rc = 0;
 141 out:
 142         if (rc && msgtrigger)
 143                 printk(KERN_WARNING "cio: Invalid cio_ignore device '%s'\n",
 144                        str);
 145
 146         return rc;
 147 }
 148
 149 static int blacklist_parse_parameters(char *str, range_action action,
 150                                       int msgtrigger)
 151 {
 152         unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;
 153         int rc, totalrc;
 154         char *parm;
 155         range_action ra;
 156
 157         totalrc = 0;
 158
 159         while ((parm = strsep(&str, ","))) {
 160                 rc = 0;
 161                 ra = action;
 162                 if (*parm == '!') {
 163                         if (ra == add)
 164                                 ra = free;
 165                         else
 166                                 ra = add;
 167                         parm++;
 168                 }
 169                 if (strcmp(parm, "all") == 0) {
 170                         from_cssid = 0;
 171                         from_ssid = 0;
 172                         from = 0;
 173                         to_cssid = __MAX_CSSID;
 174                         to_ssid = __MAX_SSID;
 175                         to = __MAX_SUBCHANNEL;
 176                 } else {
 177                         rc = parse_busid(strsep(&parm, "-"), &from_cssid,
 178                                          &from_ssid, &from, msgtrigger);
 179                         if (!rc) {
 180                                 if (parm != NULL)
 181                                         rc = parse_busid(parm, &to_cssid,
 182                                                          &to_ssid, &to,
 183                                                          msgtrigger);
 184                                 else {
 185                                         to_cssid = from_cssid;
 186                                         to_ssid = from_ssid;
 187                                         to = from;
 188                                 }
 189                         }
 190                 }
 191                 if (!rc) {
 192                         rc = blacklist_range(ra, from_ssid, to_ssid, from, to,
 193                                              msgtrigger);
 194                         if (rc)
 195                                 totalrc = -EINVAL;
 196                 } else
 197                         totalrc = -EINVAL;
 198         }
 199
 200         return totalrc;
 201 }
 202
 203 static int __init
 204 blacklist_setup (char *str)
 205 {
 206         CIO_MSG_EVENT(6, "Reading blacklist parameters\n");
 207         if (blacklist_parse_parameters(str, add, 1))
 208                 return 0;
 209         return 1;
 210 }
 211
 212 __setup ("cio_ignore=", blacklist_setup);
 213
 214 /* Checking if devices are blacklisted */
 215
 216 /*
 217  * Function: is_blacklisted
 218  * Returns 1 if the given devicenumber can be found in the blacklist,
 219  * otherwise 0.
 220  * Used by validate_subchannel()
 221  */
 222 int
 223 is_blacklisted (int ssid, int devno)
 224 {
 225         return test_bit (devno, bl_dev[ssid]);
 226 }
 227
 228 #ifdef CONFIG_PROC_FS
 229 /*
 230  * Function: blacklist_parse_proc_parameters
 231  * parse the stuff which is piped to /proc/cio_ignore
 232  */
 233 static int blacklist_parse_proc_parameters(char *buf)
 234 {
 235         int rc;
 236         char *parm;
 237
 238         parm = strsep(&buf, " ");
 239
 240         if (strcmp("free", parm) == 0)
 241                 rc = blacklist_parse_parameters(buf, free, 0);
 242         else if (strcmp("add", parm) == 0)
 243                 rc = blacklist_parse_parameters(buf, add, 0);
 244         else if (strcmp("purge", parm) == 0)
 245                 return ccw_purge_blacklisted();
 246         else
 247                 return -EINVAL;
 248
 249         css_schedule_reprobe();
 250
 251         return rc;
 252 }
 253
 254 /* Iterator struct for all devices. */
 255 struct ccwdev_iter {
 256         int devno;
 257         int ssid;
 258         int in_range;
 259 };
 260
 261 static void *
 262 cio_ignore_proc_seq_start(struct seq_file *s, loff_t *offset)
 263 {
 264         struct ccwdev_iter *iter;
 265
 266         if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
 267                 return NULL;
 268         iter = kzalloc(sizeof(struct ccwdev_iter), GFP_KERNEL);
 269         if (!iter)
 270                 return ERR_PTR(-ENOMEM);
 271         iter->ssid = *offset / (__MAX_SUBCHANNEL + 1);
 272         iter->devno = *offset % (__MAX_SUBCHANNEL + 1);
 273         return iter;
 274 }
 275
 276 static void
 277 cio_ignore_proc_seq_stop(struct seq_file *s, void *it)
 278 {
 279         if (!IS_ERR(it))
 280                 kfree(it);
 281 }
 282
 283 static void *
 284 cio_ignore_proc_seq_next(struct seq_file *s, void *it, loff_t *offset)
 285 {
 286         struct ccwdev_iter *iter;
 287
 288         if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
 289                 return NULL;
 290         iter = it;
 291         if (iter->devno == __MAX_SUBCHANNEL) {
 292                 iter->devno = 0;
 293                 iter->ssid++;
 294                 if (iter->ssid > __MAX_SSID)
 295                         return NULL;
 296         } else
 297                 iter->devno++;
 298         (*offset)++;
 299         return iter;
 300 }
 301
 302 static int
 303 cio_ignore_proc_seq_show(struct seq_file *s, void *it)
 304 {
 305         struct ccwdev_iter *iter;
 306
 307         iter = it;
 308         if (!is_blacklisted(iter->ssid, iter->devno))
 309                 /* Not blacklisted, nothing to output. */
 310                 return 0;
 311         if (!iter->in_range) {
 312                 /* First device in range. */
 313                 if ((iter->devno == __MAX_SUBCHANNEL) ||
 314                     !is_blacklisted(iter->ssid, iter->devno + 1))
 315                         /* Singular device. */
 316                         return seq_printf(s, "0.%x.%04x\n",
 317                                           iter->ssid, iter->devno);
 318                 iter->in_range = 1;
 319                 return seq_printf(s, "0.%x.%04x-", iter->ssid, iter->devno);
 320         }
 321         if ((iter->devno == __MAX_SUBCHANNEL) ||
 322             !is_blacklisted(iter->ssid, iter->devno + 1)) {
 323                 /* Last device in range. */
 324                 iter->in_range = 0;
 325                 return seq_printf(s, "0.%x.%04x\n", iter->ssid, iter->devno);
 326         }
 327         return 0;
 328 }
 329
 330 static ssize_t
 331 cio_ignore_write(struct file *file, const char __user *user_buf,
 332                  size_t user_len, loff_t *offset)
 333 {
 334         char *buf;
 335         size_t i;
 336         ssize_t rc, ret;
 337
 338         if (*offset)
 339                 return -EINVAL;
 340         if (user_len > 65536)
 341                 user_len = 65536;
 342         buf = vmalloc (user_len + 1); /* maybe better use the stack? */
 343         if (buf == NULL)
 344                 return -ENOMEM;
 345         memset(buf, 0, user_len + 1);
 346
 347         if (strncpy_from_user (buf, user_buf, user_len) < 0) {
 348                 rc = -EFAULT;
 349                 goto out_free;
 350         }
 351
 352         i = user_len - 1;
 353         while ((i >= 0) && (isspace(buf[i]) || (buf[i] == 0))) {
 354                 buf[i] = '\0';
 355                 i--;
 356         }
 357         ret = blacklist_parse_proc_parameters(buf);
 358         if (ret)
 359                 rc = ret;
 360         else
 361                 rc = user_len;
 362
 363 out_free:
 364         vfree (buf);
 365         return rc;
 366 }
 367
 368 static const struct seq_operations cio_ignore_proc_seq_ops = {
 369         .start = cio_ignore_proc_seq_start,
 370         .stop  = cio_ignore_proc_seq_stop,
 371         .next  = cio_ignore_proc_seq_next,
 372         .show  = cio_ignore_proc_seq_show,
 373 };
 374
 375 static int
 376 cio_ignore_proc_open(struct inode *inode, struct file *file)
 377 {
 378         return seq_open(file, &cio_ignore_proc_seq_ops);
 379 }
 380
 381 static const struct file_operations cio_ignore_proc_fops = {
 382         .open    = cio_ignore_proc_open,
 383         .read    = seq_read,
 384         .llseek  = seq_lseek,
 385         .release = seq_release,
 386         .write   = cio_ignore_write,
 387 };
 388
 389 static int
 390 cio_ignore_proc_init (void)
 391 {
 392         struct proc_dir_entry *entry;
 393
 394         entry = proc_create("cio_ignore", S_IFREG | S_IRUGO | S_IWUSR, NULL,
 395                             &cio_ignore_proc_fops);
 396         if (!entry)
 397                 return -ENOENT;
 398         return 0;
 399 }
 400
 401 __initcall (cio_ignore_proc_init);
 402
 403 #endif /* CONFIG_PROC_FS */