drivers/s390/cio/blacklist.c

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