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