430 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * S/390 common I/O routines -- blacklisting of specific devices4 *5 * Copyright IBM Corp. 1999, 20136 * Author(s): Ingo Adlung (adlung@de.ibm.com)7 * Cornelia Huck (cornelia.huck@de.ibm.com)8 * Arnd Bergmann (arndb@de.ibm.com)9 */10 11#define KMSG_COMPONENT "cio"12#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt13 14#include <linux/init.h>15#include <linux/vmalloc.h>16#include <linux/proc_fs.h>17#include <linux/seq_file.h>18#include <linux/ctype.h>19#include <linux/device.h>20 21#include <linux/uaccess.h>22#include <asm/cio.h>23#include <asm/ipl.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 known34 * to Linux.35 *36 * These can be single devices or ranges of devices37 */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)))42static unsigned long bl_dev[__MAX_SSID + 1][__BL_DEV_WORDS];43typedef enum {add, free} range_action;44 45/*46 * Function: blacklist_range47 * (Un-)blacklist the devices from-to48 */49static 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_warn("0.%x.%04x to 0.%x.%04x is not a valid range for cio_ignore\n",56 from_ssid, from, to_ssid, to);57 58 return 1;59 }60 61 while ((from_ssid < to_ssid) || ((from_ssid == to_ssid) &&62 (from <= to))) {63 if (action == add)64 set_bit(from, bl_dev[from_ssid]);65 else66 clear_bit(from, bl_dev[from_ssid]);67 from++;68 if (from > __MAX_SUBCHANNEL) {69 from_ssid++;70 from = 0;71 }72 }73 74 return 0;75}76 77static int pure_hex(char **cp, unsigned int *val, int min_digit,78 int max_digit, int max_val)79{80 int diff;81 82 diff = 0;83 *val = 0;84 85 while (diff <= max_digit) {86 int value = hex_to_bin(**cp);87 88 if (value < 0)89 break;90 *val = *val * 16 + value;91 (*cp)++;92 diff++;93 }94 95 if ((diff < min_digit) || (diff > max_digit) || (*val > max_val))96 return 1;97 98 return 0;99}100 101static int parse_busid(char *str, unsigned int *cssid, unsigned int *ssid,102 unsigned int *devno, int msgtrigger)103{104 char *str_work;105 int val, rc, ret;106 107 rc = 1;108 109 if (*str == '\0')110 goto out;111 112 /* old style */113 str_work = str;114 val = simple_strtoul(str, &str_work, 16);115 116 if (*str_work == '\0') {117 if (val <= __MAX_SUBCHANNEL) {118 *devno = val;119 *ssid = 0;120 *cssid = 0;121 rc = 0;122 }123 goto out;124 }125 126 /* new style */127 str_work = str;128 ret = pure_hex(&str_work, cssid, 1, 2, __MAX_CSSID);129 if (ret || (str_work[0] != '.'))130 goto out;131 str_work++;132 ret = pure_hex(&str_work, ssid, 1, 1, __MAX_SSID);133 if (ret || (str_work[0] != '.'))134 goto out;135 str_work++;136 ret = pure_hex(&str_work, devno, 4, 4, __MAX_SUBCHANNEL);137 if (ret || (str_work[0] != '\0'))138 goto out;139 140 rc = 0;141out:142 if (rc && msgtrigger)143 pr_warn("%s is not a valid device for the cio_ignore kernel parameter\n",144 str);145 146 return rc;147}148 149static int blacklist_parse_parameters(char *str, range_action action,150 int msgtrigger)151{152 unsigned int from_cssid, to_cssid, from_ssid, to_ssid, from, to;153 int rc, totalrc;154 char *parm;155 range_action ra;156 157 totalrc = 0;158 159 while ((parm = strsep(&str, ","))) {160 rc = 0;161 ra = action;162 if (*parm == '!') {163 if (ra == add)164 ra = free;165 else166 ra = add;167 parm++;168 }169 if (strcmp(parm, "all") == 0) {170 from_cssid = 0;171 from_ssid = 0;172 from = 0;173 to_cssid = __MAX_CSSID;174 to_ssid = __MAX_SSID;175 to = __MAX_SUBCHANNEL;176 } else if (strcmp(parm, "ipldev") == 0) {177 if (ipl_info.type == IPL_TYPE_CCW) {178 from_cssid = 0;179 from_ssid = ipl_info.data.ccw.dev_id.ssid;180 from = ipl_info.data.ccw.dev_id.devno;181 } else if (ipl_info.type == IPL_TYPE_FCP ||182 ipl_info.type == IPL_TYPE_FCP_DUMP) {183 from_cssid = 0;184 from_ssid = ipl_info.data.fcp.dev_id.ssid;185 from = ipl_info.data.fcp.dev_id.devno;186 } else {187 continue;188 }189 to_cssid = from_cssid;190 to_ssid = from_ssid;191 to = from;192 } else if (strcmp(parm, "condev") == 0) {193 if (console_devno == -1)194 continue;195 196 from_cssid = to_cssid = 0;197 from_ssid = to_ssid = 0;198 from = to = console_devno;199 } else {200 rc = parse_busid(strsep(&parm, "-"), &from_cssid,201 &from_ssid, &from, msgtrigger);202 if (!rc) {203 if (parm != NULL)204 rc = parse_busid(parm, &to_cssid,205 &to_ssid, &to,206 msgtrigger);207 else {208 to_cssid = from_cssid;209 to_ssid = from_ssid;210 to = from;211 }212 }213 }214 if (!rc) {215 rc = blacklist_range(ra, from_ssid, to_ssid, from, to,216 msgtrigger);217 if (rc)218 totalrc = -EINVAL;219 } else220 totalrc = -EINVAL;221 }222 223 return totalrc;224}225 226static int __init227blacklist_setup (char *str)228{229 CIO_MSG_EVENT(6, "Reading blacklist parameters\n");230 if (blacklist_parse_parameters(str, add, 1))231 return 0;232 return 1;233}234 235__setup ("cio_ignore=", blacklist_setup);236 237/* Checking if devices are blacklisted */238 239/*240 * Function: is_blacklisted241 * Returns 1 if the given devicenumber can be found in the blacklist,242 * otherwise 0.243 * Used by validate_subchannel()244 */245int246is_blacklisted (int ssid, int devno)247{248 return test_bit (devno, bl_dev[ssid]);249}250 251#ifdef CONFIG_PROC_FS252/*253 * Function: blacklist_parse_proc_parameters254 * parse the stuff which is piped to /proc/cio_ignore255 */256static int blacklist_parse_proc_parameters(char *buf)257{258 int rc;259 char *parm;260 261 parm = strsep(&buf, " ");262 263 if (strcmp("free", parm) == 0) {264 rc = blacklist_parse_parameters(buf, free, 0);265 /*266 * Evaluate the subchannels without an online device. This way,267 * no path-verification will be triggered on those subchannels268 * and it avoids unnecessary delays.269 */270 css_schedule_eval_cond(CSS_EVAL_NOT_ONLINE, 0);271 } else if (strcmp("add", parm) == 0)272 rc = blacklist_parse_parameters(buf, add, 0);273 else if (strcmp("purge", parm) == 0)274 return ccw_purge_blacklisted();275 else276 return -EINVAL;277 278 279 return rc;280}281 282/* Iterator struct for all devices. */283struct ccwdev_iter {284 int devno;285 int ssid;286 int in_range;287};288 289static void *290cio_ignore_proc_seq_start(struct seq_file *s, loff_t *offset)291{292 struct ccwdev_iter *iter = s->private;293 294 if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))295 return NULL;296 memset(iter, 0, sizeof(*iter));297 iter->ssid = *offset / (__MAX_SUBCHANNEL + 1);298 iter->devno = *offset % (__MAX_SUBCHANNEL + 1);299 return iter;300}301 302static void303cio_ignore_proc_seq_stop(struct seq_file *s, void *it)304{305}306 307static void *308cio_ignore_proc_seq_next(struct seq_file *s, void *it, loff_t *offset)309{310 struct ccwdev_iter *iter;311 loff_t p = *offset;312 313 (*offset)++;314 if (p >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1))315 return NULL;316 iter = it;317 if (iter->devno == __MAX_SUBCHANNEL) {318 iter->devno = 0;319 iter->ssid++;320 if (iter->ssid > __MAX_SSID)321 return NULL;322 } else323 iter->devno++;324 return iter;325}326 327static int328cio_ignore_proc_seq_show(struct seq_file *s, void *it)329{330 struct ccwdev_iter *iter;331 332 iter = it;333 if (!is_blacklisted(iter->ssid, iter->devno))334 /* Not blacklisted, nothing to output. */335 return 0;336 if (!iter->in_range) {337 /* First device in range. */338 if ((iter->devno == __MAX_SUBCHANNEL) ||339 !is_blacklisted(iter->ssid, iter->devno + 1)) {340 /* Singular device. */341 seq_printf(s, "0.%x.%04x\n", iter->ssid, iter->devno);342 return 0;343 }344 iter->in_range = 1;345 seq_printf(s, "0.%x.%04x-", iter->ssid, iter->devno);346 return 0;347 }348 if ((iter->devno == __MAX_SUBCHANNEL) ||349 !is_blacklisted(iter->ssid, iter->devno + 1)) {350 /* Last device in range. */351 iter->in_range = 0;352 seq_printf(s, "0.%x.%04x\n", iter->ssid, iter->devno);353 }354 return 0;355}356 357static ssize_t358cio_ignore_write(struct file *file, const char __user *user_buf,359 size_t user_len, loff_t *offset)360{361 char *buf;362 ssize_t rc, ret, i;363 364 if (*offset)365 return -EINVAL;366 if (user_len > 65536)367 user_len = 65536;368 buf = vzalloc(user_len + 1); /* maybe better use the stack? */369 if (buf == NULL)370 return -ENOMEM;371 372 if (strncpy_from_user (buf, user_buf, user_len) < 0) {373 rc = -EFAULT;374 goto out_free;375 }376 377 i = user_len - 1;378 while ((i >= 0) && (isspace(buf[i]) || (buf[i] == 0))) {379 buf[i] = '\0';380 i--;381 }382 ret = blacklist_parse_proc_parameters(buf);383 if (ret)384 rc = ret;385 else386 rc = user_len;387 388out_free:389 vfree (buf);390 return rc;391}392 393static const struct seq_operations cio_ignore_proc_seq_ops = {394 .start = cio_ignore_proc_seq_start,395 .stop = cio_ignore_proc_seq_stop,396 .next = cio_ignore_proc_seq_next,397 .show = cio_ignore_proc_seq_show,398};399 400static int401cio_ignore_proc_open(struct inode *inode, struct file *file)402{403 return seq_open_private(file, &cio_ignore_proc_seq_ops,404 sizeof(struct ccwdev_iter));405}406 407static const struct proc_ops cio_ignore_proc_ops = {408 .proc_open = cio_ignore_proc_open,409 .proc_read = seq_read,410 .proc_lseek = seq_lseek,411 .proc_release = seq_release_private,412 .proc_write = cio_ignore_write,413};414 415static int416cio_ignore_proc_init (void)417{418 struct proc_dir_entry *entry;419 420 entry = proc_create("cio_ignore", S_IFREG | S_IRUGO | S_IWUSR, NULL,421 &cio_ignore_proc_ops);422 if (!entry)423 return -ENOENT;424 return 0;425}426 427__initcall (cio_ignore_proc_init);428 429#endif /* CONFIG_PROC_FS */430