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
  28 /*
  29  * "Blacklisting" of certain devices:
  30  * Device numbers given in the commandline as cio_ignore=... won't be known
  31  * to Linux.
  32  *
  33  * These can be single devices or ranges of devices
  34  */
  35
  36 /* 65536 bits for each set to indicate if a devno is blacklisted or not */
  37 #define __BL_DEV_WORDS ((__MAX_SUBCHANNEL + (8*sizeof(long) - 1)) / \
  38                          (8*sizeof(long)))
  39 static unsigned long bl_dev[__MAX_SSID + 1][__BL_DEV_WORDS];
  40 typedef enum {add, free} range_action;
  41
  42 /*
  43  * Function: blacklist_range
  44  * (Un-)blacklist the devices from-to
  45  */
  46 static int blacklist_range(range_action action, unsigned int from_ssid,
  47                            unsigned int to_ssid, unsigned int from,
  48                            unsigned int to, int msgtrigger)
  49 {
  50         if ((from_ssid > to_ssid) || ((from_ssid == to_ssid) && (from > to))) {
  51                 if (msgtrigger)
  52                         printk(KERN_WARNING "cio: Invalid cio_ignore range "
  53                                "0.%x.%04x-0.%x.%04x\n", from_ssid, from,
  54                                to_ssid, to);
  55                 return 1;
  56         }
  57
  58         while ((from_ssid < to_ssid) || ((from_ssid == to_ssid) &&
  59                (from <= to))) {
  60                 if (action == add)
  61                         set_bit(from, bl_dev[from_ssid]);
  62                 else
  63                         clear_bit(from, bl_dev[from_ssid]);
  64                 from++;
  65                 if (from > __MAX_SUBCHANNEL) {
  66                         from_ssid++;
  67                         from = 0;
  68                 }
  69         }
  70
  71         return 0;
  72 }
  73
  74 static int pure_hex(char **cp, unsigned int *val, int min_digit,
  75                     int max_digit, int max_val)
  76 {
  77         int diff;
  78         unsigned int value;
  79
  80         diff = 0;
  81         *val = 0;
  82
  83         while (isxdigit(**cp) && (diff <= max_digit)) {
  84
  85                 if (isdigit(**cp))
  86                         value = **cp - '0';
  87                 else
  88                         value = tolower(**cp) - 'a' + 10;
  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                 printk(KERN_WARNING "cio: Invalid cio_ignore device '%s'\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 {
 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 = 1;
 195                 } else
 196                         totalrc = 1;
 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
 244                 return 1;
 245
 246         css_schedule_reprobe();
 247
 248         return rc;
 249 }
 250
 251 /* Iterator struct for all devices. */
 252 struct ccwdev_iter {
 253         int devno;
 254         int ssid;
 255         int in_range;
 256 };
 257
 258 static void *
 259 cio_ignore_proc_seq_start(struct seq_file *s, loff_t *offset)
 260 {
 261         struct ccwdev_iter *iter;
 262
 263         if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))
 264                 return NULL;
 265         iter = kzalloc(sizeof(struct ccwdev_iter), GFP_KERNEL);
 266         if (!iter)
 267                 return ERR_PTR(-ENOMEM);
 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         if (!IS_ERR(it))
 277                 kfree(it);
 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         size_t i;
 333         ssize_t rc, ret;
 334
 335         if (*offset)
 336                 return -EINVAL;
 337         if (user_len > 65536)
 338                 user_len = 65536;
 339         buf = vmalloc (user_len + 1); /* maybe better use the stack? */
 340         if (buf == NULL)
 341                 return -ENOMEM;
 342         memset(buf, 0, user_len + 1);
 343
 344         if (strncpy_from_user (buf, user_buf, user_len) < 0) {
 345                 rc = -EFAULT;
 346                 goto out_free;
 347         }
 348
 349         i = user_len - 1;
 350         while ((i >= 0) && (isspace(buf[i]) || (buf[i] == 0))) {
 351                 buf[i] = '\0';
 352                 i--;
 353         }
 354         ret = blacklist_parse_proc_parameters(buf);
 355         if (ret)
 356                 rc = -EINVAL;
 357         else
 358                 rc = user_len;
 359
 360 out_free:
 361         vfree (buf);
 362         return rc;
 363 }
 364
 365 static const struct seq_operations cio_ignore_proc_seq_ops = {
 366         .start = cio_ignore_proc_seq_start,
 367         .stop  = cio_ignore_proc_seq_stop,
 368         .next  = cio_ignore_proc_seq_next,
 369         .show  = cio_ignore_proc_seq_show,
 370 };
 371
 372 static int
 373 cio_ignore_proc_open(struct inode *inode, struct file *file)
 374 {
 375         return seq_open(file, &cio_ignore_proc_seq_ops);
 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,
 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 */