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