drivers/s390/cio/blacklist.c

   1 /*
   2  *   S/390 common I/O routines -- blacklisting of specific devices
   3  *
   4  *    Copyright IBM Corp. 1999, 2013
   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 <linux/uaccess.h>
  21 #include <asm/cio.h>
  22 #include <asm/ipl.h>
  23
  24 #include "blacklist.h"
  25 #include "cio.h"
  26 #include "cio_debug.h"
  27 #include "css.h"
  28 #include "device.h"
  29
  30 /*
  31  * "Blacklisting" of certain devices:
  32  * Device numbers given in the commandline as cio_ignore=... won't be known
  33  * to Linux.
  34  *
  35  * These can be single devices or ranges of devices
  36  */
  37
  38 /* 65536 bits for each set to indicate if a devno is blacklisted or not */
  39 #define __BL_DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
  40                          (8*sizeof(long)))
  41 static unsigned long bl_dev[__MAX_SSID + 1][__BL_DEV_WORDS];
  42 typedef enum {add, free} range_action;
  43
  44 /*
  45  * Function: blacklist_range
  46  * (Un-)blacklist the devices from-to
  47  */
  48 static int blacklist_range(range_action action, unsigned int from_ssid,
  49                            unsigned int to_ssid, unsigned int from,
  50                            unsigned int to, int msgtrigger)
  51 {
  52         if ((from_ssid > to_ssid) || ((from_ssid == to_ssid) && (from > to))) {
  53                 if (msgtrigger)
  54                         pr_warn("0.%x.%04x to 0.%x.%04x is not a valid range for cio_ignore\n",
  55                                 from_ssid, from, 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_warn("%s is not a valid device for the cio_ignore kernel parameter\n",
 143                         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 if (strcmp(parm, "ipldev") == 0) {
 176                         if (ipl_info.type == IPL_TYPE_CCW) {
 177                                 from_cssid = 0;
 178                                 from_ssid = ipl_info.data.ccw.dev_id.ssid;
 179                                 from = ipl_info.data.ccw.dev_id.devno;
 180                         } else if (ipl_info.type == IPL_TYPE_FCP ||
 181                                    ipl_info.type == IPL_TYPE_FCP_DUMP) {
 182                                 from_cssid = 0;
 183                                 from_ssid = ipl_info.data.fcp.dev_id.ssid;
 184                                 from = ipl_info.data.fcp.dev_id.devno;
 185                         } else {
 186                                 continue;
 187                         }
 188                         to_cssid = from_cssid;
 189                         to_ssid = from_ssid;
 190                         to = from;
 191                 } else if (strcmp(parm, "condev") == 0) {
 192                         if (console_devno == -1)
 193                                 continue;
 194
 195                         from_cssid = to_cssid = 0;
 196                         from_ssid = to_ssid = 0;
 197                         from = to = console_devno;
 198                 } else {
 199                         rc = parse_busid(strsep(&parm, "-"), &from_cssid,
 200                                          &from_ssid, &from, msgtrigger);
 201                         if (!rc) {
 202                                 if (parm != NULL)
 203                                         rc = parse_busid(parm, &to_cssid,
 204                                                          &to_ssid, &to,
 205                                                          msgtrigger);
 206                                 else {
 207                                         to_cssid = from_cssid;
 208                                         to_ssid = from_ssid;
 209                                         to = from;
 210                                 }
 211                         }
 212                 }
 213                 if (!rc) {
 214                         rc = blacklist_range(ra, from_ssid, to_ssid, from, to,
 215                                              msgtrigger);
 216                         if (rc)
 217                                 totalrc = -EINVAL;
 218                 } else
 219                         totalrc = -EINVAL;
 220         }
 221
 222         return totalrc;
 223 }
 224
 225 static int __init
 226 blacklist_setup (char *str)
 227 {
 228         CIO_MSG_EVENT(6, "Reading blacklist parameters\n");
 229         if (blacklist_parse_parameters(str, add, 1))
 230                 return 0;
 231         return 1;
 232 }
 233
 234 __setup ("cio_ignore=", blacklist_setup);
 235
 236 /* Checking if devices are blacklisted */
 237
 238 /*
 239  * Function: is_blacklisted
 240  * Returns 1 if the given devicenumber can be found in the blacklist,
 241  * otherwise 0.
 242  * Used by validate_subchannel()
 243  */
 244 int
 245 is_blacklisted (int ssid, int devno)
 246 {
 247         return test_bit (devno, bl_dev[ssid]);
 248 }
 249
 250 #ifdef CONFIG_PROC_FS
 251 /*
 252  * Function: blacklist_parse_proc_parameters
 253  * parse the stuff which is piped to /proc/cio_ignore
 254  */
 255 static int blacklist_parse_proc_parameters(char *buf)
 256 {
 257         int rc;
 258         char *parm;
 259
 260         parm = strsep(&buf, " ");
 261
 262         if (strcmp("free", parm) == 0) {
 263                 rc = blacklist_parse_parameters(buf, free, 0);
 264                 css_schedule_eval_all_unreg(0);
 265         } else if (strcmp("add", parm) == 0)
 266                 rc = blacklist_parse_parameters(buf, add, 0);
 267         else if (strcmp("purge", parm) == 0)
 268                 return ccw_purge_blacklisted();
 269         else
 270                 return -EINVAL;
 271
 272
 273         return rc;
 274 }
 275
 276 /* Iterator struct for all devices. */
 277 struct ccwdev_iter {
 278         int devno;
 279         int ssid;
 280         int in_range;
 281 };
 282
 283 static void *
 284 cio_ignore_proc_seq_start(struct seq_file *s, loff_t *offset)
 285 {
 286         struct ccwdev_iter *iter = s->private;
 287
 288         if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
 289                 return NULL;
 290         memset(iter, 0, sizeof(*iter));
 291         iter->ssid = *offset / (__MAX_SUBCHANNEL + 1);
 292         iter->devno = *offset % (__MAX_SUBCHANNEL + 1);
 293         return iter;
 294 }
 295
 296 static void
 297 cio_ignore_proc_seq_stop(struct seq_file *s, void *it)
 298 {
 299 }
 300
 301 static void *
 302 cio_ignore_proc_seq_next(struct seq_file *s, void *it, loff_t *offset)
 303 {
 304         struct ccwdev_iter *iter;
 305
 306         if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
 307                 return NULL;
 308         iter = it;
 309         if (iter->devno == __MAX_SUBCHANNEL) {
 310                 iter->devno = 0;
 311                 iter->ssid++;
 312                 if (iter->ssid > __MAX_SSID)
 313                         return NULL;
 314         } else
 315                 iter->devno++;
 316         (*offset)++;
 317         return iter;
 318 }
 319
 320 static int
 321 cio_ignore_proc_seq_show(struct seq_file *s, void *it)
 322 {
 323         struct ccwdev_iter *iter;
 324
 325         iter = it;
 326         if (!is_blacklisted(iter->ssid, iter->devno))
 327                 /* Not blacklisted, nothing to output. */
 328                 return 0;
 329         if (!iter->in_range) {
 330                 /* First device in range. */
 331                 if ((iter->devno == __MAX_SUBCHANNEL) ||
 332                     !is_blacklisted(iter->ssid, iter->devno + 1)) {
 333                         /* Singular device. */
 334                         seq_printf(s, "0.%x.%04x\n", iter->ssid, iter->devno);
 335                         return 0;
 336                 }
 337                 iter->in_range = 1;
 338                 seq_printf(s, "0.%x.%04x-", iter->ssid, iter->devno);
 339                 return 0;
 340         }
 341         if ((iter->devno == __MAX_SUBCHANNEL) ||
 342             !is_blacklisted(iter->ssid, iter->devno + 1)) {
 343                 /* Last device in range. */
 344                 iter->in_range = 0;
 345                 seq_printf(s, "0.%x.%04x\n", iter->ssid, iter->devno);
 346         }
 347         return 0;
 348 }
 349
 350 static ssize_t
 351 cio_ignore_write(struct file *file, const char __user *user_buf,
 352                  size_t user_len, loff_t *offset)
 353 {
 354         char *buf;
 355         ssize_t rc, ret, i;
 356
 357         if (*offset)
 358                 return -EINVAL;
 359         if (user_len > 65536)
 360                 user_len = 65536;
 361         buf = vzalloc(user_len + 1); /* maybe better use the stack? */
 362         if (buf == NULL)
 363                 return -ENOMEM;
 364
 365         if (strncpy_from_user (buf, user_buf, user_len) < 0) {
 366                 rc = -EFAULT;
 367                 goto out_free;
 368         }
 369
 370         i = user_len - 1;
 371         while ((i >= 0) && (isspace(buf[i]) || (buf[i] == 0))) {
 372                 buf[i] = '\0';
 373                 i--;
 374         }
 375         ret = blacklist_parse_proc_parameters(buf);
 376         if (ret)
 377                 rc = ret;
 378         else
 379                 rc = user_len;
 380
 381 out_free:
 382         vfree (buf);
 383         return rc;
 384 }
 385
 386 static const struct seq_operations cio_ignore_proc_seq_ops = {
 387         .start = cio_ignore_proc_seq_start,
 388         .stop  = cio_ignore_proc_seq_stop,
 389         .next  = cio_ignore_proc_seq_next,
 390         .show  = cio_ignore_proc_seq_show,
 391 };
 392
 393 static int
 394 cio_ignore_proc_open(struct inode *inode, struct file *file)
 395 {
 396         return seq_open_private(file, &cio_ignore_proc_seq_ops,
 397                                 sizeof(struct ccwdev_iter));
 398 }
 399
 400 static const struct file_operations cio_ignore_proc_fops = {
 401         .open    = cio_ignore_proc_open,
 402         .read    = seq_read,
 403         .llseek  = seq_lseek,
 404         .release = seq_release_private,
 405         .write   = cio_ignore_write,
 406 };
 407
 408 static int
 409 cio_ignore_proc_init (void)
 410 {
 411         struct proc_dir_entry *entry;
 412
 413         entry = proc_create("cio_ignore", S_IFREG | S_IRUGO | S_IWUSR, NULL,
 414                             &cio_ignore_proc_fops);
 415         if (!entry)
 416                 return -ENOENT;
 417         return 0;
 418 }
 419
 420 __initcall (cio_ignore_proc_init);
 421
 422 #endif /* CONFIG_PROC_FS */