drivers/s390/cio/blacklist.c

   1 /*
   2  *  drivers/s390/cio/blacklist.c
   3  *   S/390 common I/O routines -- blacklisting of specific devices
   4  *   $Revision: 1.33 $
   5  *
   6  *    Copyright (C) 1999-2002 IBM Deutschland Entwicklung GmbH,
   7  *                            IBM Corporation
   8  *    Author(s): Ingo Adlung (adlung@de.ibm.com)
   9  *               Cornelia Huck (cohuck@de.ibm.com)
  10  *               Arnd Bergmann (arndb@de.ibm.com)
  11  */
  12
  13 #include <linux/config.h>
  14 #include <linux/init.h>
  15 #include <linux/vmalloc.h>
  16 #include <linux/slab.h>
  17 #include <linux/proc_fs.h>
  18 #include <linux/ctype.h>
  19 #include <linux/device.h>
  20
  21 #include <asm/cio.h>
  22 #include <asm/uaccess.h>
  23
  24 #include "blacklist.h"
  25 #include "cio.h"
  26 #include "cio_debug.h"
  27 #include "css.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 to indicate if a devno is blacklisted or not */
  38 #define __BL_DEV_WORDS (__MAX_SUBCHANNELS + (8*sizeof(long) - 1) / \
  39                          (8*sizeof(long)))
  40 static unsigned long bl_dev[__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 inline void
  48 blacklist_range (range_action action, unsigned int from, unsigned int to)
  49 {
  50         if (!to)
  51                 to = from;
  52
  53         if (from > to || to > __MAX_SUBCHANNELS) {
  54                 printk (KERN_WARNING "Invalid blacklist range "
  55                         "0x%04x to 0x%04x, skipping\n", from, to);
  56                 return;
  57         }
  58         for (; from <= to; from++) {
  59                 if (action == add)
  60                         set_bit (from, bl_dev);
  61                 else
  62                         clear_bit (from, bl_dev);
  63         }
  64 }
  65
  66 /*
  67  * Function: blacklist_busid
  68  * Get devno/busid from given string.
  69  * Shamelessly grabbed from dasd_devmap.c.
  70  */
  71 static inline int
  72 blacklist_busid(char **str, int *id0, int *id1, int *devno)
  73 {
  74         int val, old_style;
  75         char *sav;
  76
  77         sav = *str;
  78
  79         /* check for leading '0x' */
  80         old_style = 0;
  81         if ((*str)[0] == '0' && (*str)[1] == 'x') {
  82                 *str += 2;
  83                 old_style = 1;
  84         }
  85         if (!isxdigit((*str)[0]))       /* We require at least one hex digit */
  86                 goto confused;
  87         val = simple_strtoul(*str, str, 16);
  88         if (old_style || (*str)[0] != '.') {
  89                 *id0 = *id1 = 0;
  90                 if (val < 0 || val > 0xffff)
  91                         goto confused;
  92                 *devno = val;
  93                 if ((*str)[0] != ',' && (*str)[0] != '-' &&
  94                     (*str)[0] != '\n' && (*str)[0] != '\0')
  95                         goto confused;
  96                 return 0;
  97         }
  98         /* New style x.y.z busid */
  99         if (val < 0 || val > 0xff)
 100                 goto confused;
 101         *id0 = val;
 102         (*str)++;
 103         if (!isxdigit((*str)[0]))       /* We require at least one hex digit */
 104                 goto confused;
 105         val = simple_strtoul(*str, str, 16);
 106         if (val < 0 || val > 0xff || (*str)++[0] != '.')
 107                 goto confused;
 108         *id1 = val;
 109         if (!isxdigit((*str)[0]))       /* We require at least one hex digit */
 110                 goto confused;
 111         val = simple_strtoul(*str, str, 16);
 112         if (val < 0 || val > 0xffff)
 113                 goto confused;
 114         *devno = val;
 115         if ((*str)[0] != ',' && (*str)[0] != '-' &&
 116             (*str)[0] != '\n' && (*str)[0] != '\0')
 117                 goto confused;
 118         return 0;
 119 confused:
 120         strsep(str, ",\n");
 121         printk(KERN_WARNING "Invalid cio_ignore parameter '%s'\n", sav);
 122         return 1;
 123 }
 124
 125 static inline int
 126 blacklist_parse_parameters (char *str, range_action action)
 127 {
 128         unsigned int from, to, from_id0, to_id0, from_id1, to_id1;
 129
 130         while (*str != 0 && *str != '\n') {
 131                 range_action ra = action;
 132                 while(*str == ',')
 133                         str++;
 134                 if (*str == '!') {
 135                         ra = !action;
 136                         ++str;
 137                 }
 138
 139                 /*
 140                  * Since we have to parse the proc commands and the
 141                  * kernel arguments we have to check four cases
 142                  */
 143                 if (strncmp(str,"all,",4) == 0 || strcmp(str,"all") == 0 ||
 144                     strncmp(str,"all\n",4) == 0 || strncmp(str,"all ",4) == 0) {
 145                         from = 0;
 146                         to = __MAX_SUBCHANNELS;
 147                         str += 3;
 148                 } else {
 149                         int rc;
 150
 151                         rc = blacklist_busid(&str, &from_id0,
 152                                              &from_id1, &from);
 153                         if (rc)
 154                                 continue;
 155                         to = from;
 156                         to_id0 = from_id0;
 157                         to_id1 = from_id1;
 158                         if (*str == '-') {
 159                                 str++;
 160                                 rc = blacklist_busid(&str, &to_id0,
 161                                                      &to_id1, &to);
 162                                 if (rc)
 163                                         continue;
 164                         }
 165                         if (*str == '-') {
 166                                 printk(KERN_WARNING "invalid cio_ignore "
 167                                         "parameter '%s'\n",
 168                                         strsep(&str, ",\n"));
 169                                 continue;
 170                         }
 171                         if ((from_id0 != to_id0) || (from_id1 != to_id1)) {
 172                                 printk(KERN_WARNING "invalid cio_ignore range "
 173                                         "%x.%x.%04x-%x.%x.%04x\n",
 174                                         from_id0, from_id1, from,
 175                                         to_id0, to_id1, to);
 176                                 continue;
 177                         }
 178                 }
 179                 /* FIXME: ignoring id0 and id1 here. */
 180                 pr_debug("blacklist_setup: adding range "
 181                          "from 0.0.%04x to 0.0.%04x\n", from, to);
 182                 blacklist_range (ra, from, to);
 183         }
 184         return 1;
 185 }
 186
 187 /* Parsing the commandline for blacklist parameters, e.g. to blacklist
 188  * bus ids 0.0.1234, 0.0.1235 and 0.0.1236, you could use any of:
 189  * - cio_ignore=1234-1236
 190  * - cio_ignore=0x1234-0x1235,1236
 191  * - cio_ignore=0x1234,1235-1236
 192  * - cio_ignore=1236 cio_ignore=1234-0x1236
 193  * - cio_ignore=1234 cio_ignore=1236 cio_ignore=0x1235
 194  * - cio_ignore=0.0.1234-0.0.1236
 195  * - cio_ignore=0.0.1234,0x1235,1236
 196  * - ...
 197  */
 198 static int __init
 199 blacklist_setup (char *str)
 200 {
 201         CIO_MSG_EVENT(6, "Reading blacklist parameters\n");
 202         return blacklist_parse_parameters (str, add);
 203 }
 204
 205 __setup ("cio_ignore=", blacklist_setup);
 206
 207 /* Checking if devices are blacklisted */
 208
 209 /*
 210  * Function: is_blacklisted
 211  * Returns 1 if the given devicenumber can be found in the blacklist,
 212  * otherwise 0.
 213  * Used by validate_subchannel()
 214  */
 215 int
 216 is_blacklisted (int devno)
 217 {
 218         return test_bit (devno, bl_dev);
 219 }
 220
 221 #ifdef CONFIG_PROC_FS
 222 /*
 223  * Function: s390_redo_validation
 224  * Look for no longer blacklisted devices
 225  * FIXME: there must be a better way to do this */
 226 static inline void
 227 s390_redo_validation (void)
 228 {
 229         unsigned int irq;
 230
 231         CIO_TRACE_EVENT (0, "redoval");
 232         for (irq = 0; irq < __MAX_SUBCHANNELS; irq++) {
 233                 int ret;
 234                 struct subchannel *sch;
 235
 236                 sch = get_subchannel_by_schid(irq);
 237                 if (sch) {
 238                         /* Already known. */
 239                         put_device(&sch->dev);
 240                         continue;
 241                 }
 242                 ret = css_probe_device(irq);
 243                 if (ret == -ENXIO)
 244                         break; /* We're through. */
 245                 if (ret == -ENOMEM)
 246                         /*
 247                          * Stop validation for now. Bad, but no need for a
 248                          * panic.
 249                          */
 250                         break;
 251         }
 252 }
 253
 254 /*
 255  * Function: blacklist_parse_proc_parameters
 256  * parse the stuff which is piped to /proc/cio_ignore
 257  */
 258 static inline void
 259 blacklist_parse_proc_parameters (char *buf)
 260 {
 261         if (strncmp (buf, "free ", 5) == 0) {
 262                 blacklist_parse_parameters (buf + 5, free);
 263         } else if (strncmp (buf, "add ", 4) == 0) {
 264                 /*
 265                  * We don't need to check for known devices since
 266                  * css_probe_device will handle this correctly.
 267                  */
 268                 blacklist_parse_parameters (buf + 4, add);
 269         } else {
 270                 printk (KERN_WARNING "cio_ignore: Parse error; \n"
 271                         KERN_WARNING "try using 'free all|<devno-range>,"
 272                                      "<devno-range>,...'\n"
 273                         KERN_WARNING "or 'add <devno-range>,"
 274                                      "<devno-range>,...'\n");
 275                 return;
 276         }
 277
 278         s390_redo_validation ();
 279 }
 280
 281 /* FIXME: These should be real bus ids and not home-grown ones! */
 282 static int cio_ignore_read (char *page, char **start, off_t off,
 283                             int count, int *eof, void *data)
 284 {
 285         const unsigned int entry_size = 18; /* "0.0.ABCD-0.0.EFGH\n" */
 286         long devno;
 287         int len;
 288
 289         len = 0;
 290         for (devno = off; /* abuse the page variable
 291                            * as counter, see fs/proc/generic.c */
 292              devno <= __MAX_SUBCHANNELS && len + entry_size < count; devno++) {
 293                 if (!test_bit(devno, bl_dev))
 294                         continue;
 295                 len += sprintf(page + len, "0.0.%04lx", devno);
 296                 if (test_bit(devno + 1, bl_dev)) { /* print range */
 297                         while (++devno < __MAX_SUBCHANNELS)
 298                                 if (!test_bit(devno, bl_dev))
 299                                         break;
 300                         len += sprintf(page + len, "-0.0.%04lx", --devno);
 301                 }
 302                 len += sprintf(page + len, "\n");
 303         }
 304
 305         if (devno <= __MAX_SUBCHANNELS)
 306                 *eof = 1;
 307         *start = (char *) (devno - off); /* number of checked entries */
 308         return len;
 309 }
 310
 311 static int cio_ignore_write(struct file *file, const char __user *user_buf,
 312                              unsigned long user_len, void *data)
 313 {
 314         char *buf;
 315
 316         if (user_len > 65536)
 317                 user_len = 65536;
 318         buf = vmalloc (user_len + 1); /* maybe better use the stack? */
 319         if (buf == NULL)
 320                 return -ENOMEM;
 321         if (strncpy_from_user (buf, user_buf, user_len) < 0) {
 322                 vfree (buf);
 323                 return -EFAULT;
 324         }
 325         buf[user_len] = '\0';
 326
 327         blacklist_parse_proc_parameters (buf);
 328
 329         vfree (buf);
 330         return user_len;
 331 }
 332
 333 static int
 334 cio_ignore_proc_init (void)
 335 {
 336         struct proc_dir_entry *entry;
 337
 338         entry = create_proc_entry ("cio_ignore", S_IFREG | S_IRUGO | S_IWUSR,
 339                                    &proc_root);
 340         if (!entry)
 341                 return 0;
 342
 343         entry->read_proc  = cio_ignore_read;
 344         entry->write_proc = cio_ignore_write;
 345
 346         return 1;
 347 }
 348
 349 __initcall (cio_ignore_proc_init);
 350
 351 #endif /* CONFIG_PROC_FS */