drivers/s390/crypto/zcrypt_pcica.c

   1 /*
   2  *  linux/drivers/s390/crypto/zcrypt_pcica.c
   3  *
   4  *  zcrypt 2.1.0
   5  *
   6  *  Copyright (C)  2001, 2006 IBM Corporation
   7  *  Author(s): Robert Burroughs
   8  *             Eric Rossman (edrossma@us.ibm.com)
   9  *
  10  *  Hotplug & misc device support: Jochen Roehrig (roehrig@de.ibm.com)
  11  *  Major cleanup & driver split: Martin Schwidefsky <schwidefsky@de.ibm.com>
  12  *                                Ralph Wuerthner <rwuerthn@de.ibm.com>
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2, or (at your option)
  17  * any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  27  */
  28
  29 #include <linux/module.h>
  30 #include <linux/init.h>
  31 #include <linux/err.h>
  32 #include <asm/atomic.h>
  33 #include <asm/uaccess.h>
  34
  35 #include "ap_bus.h"
  36 #include "zcrypt_api.h"
  37 #include "zcrypt_error.h"
  38 #include "zcrypt_pcica.h"
  39
  40 #define PCICA_MIN_MOD_SIZE        1     /*    8 bits    */
  41 #define PCICA_MAX_MOD_SIZE      256     /* 2048 bits    */
  42
  43 #define PCICA_SPEED_RATING      2800
  44
  45 #define PCICA_MAX_MESSAGE_SIZE  0x3a0   /* sizeof(struct type4_lcr)          */
  46 #define PCICA_MAX_RESPONSE_SIZE 0x110   /* max outputdatalength + type80_hdr */
  47
  48 #define PCICA_CLEANUP_TIME      (15*HZ)
  49
  50 static struct ap_device_id zcrypt_pcica_ids[] = {
  51         { AP_DEVICE(AP_DEVICE_TYPE_PCICA) },
  52         { /* end of list */ },
  53 };
  54
  55 #ifndef CONFIG_ZCRYPT_MONOLITHIC
  56 MODULE_DEVICE_TABLE(ap, zcrypt_pcica_ids);
  57 MODULE_AUTHOR("IBM Corporation");
  58 MODULE_DESCRIPTION("PCICA Cryptographic Coprocessor device driver, "
  59                    "Copyright 2001, 2006 IBM Corporation");
  60 MODULE_LICENSE("GPL");
  61 #endif
  62
  63 static int zcrypt_pcica_probe(struct ap_device *ap_dev);
  64 static void zcrypt_pcica_remove(struct ap_device *ap_dev);
  65 static void zcrypt_pcica_receive(struct ap_device *, struct ap_message *,
  66                                  struct ap_message *);
  67
  68 static struct ap_driver zcrypt_pcica_driver = {
  69         .probe = zcrypt_pcica_probe,
  70         .remove = zcrypt_pcica_remove,
  71         .receive = zcrypt_pcica_receive,
  72         .ids = zcrypt_pcica_ids,
  73 };
  74
  75 /**
  76  * Convert a ICAMEX message to a type4 MEX message.
  77  *
  78  * @zdev: crypto device pointer
  79  * @zreq: crypto request pointer
  80  * @mex: pointer to user input data
  81  *
  82  * Returns 0 on success or -EFAULT.
  83  */
  84 static int ICAMEX_msg_to_type4MEX_msg(struct zcrypt_device *zdev,
  85                                       struct ap_message *ap_msg,
  86                                       struct ica_rsa_modexpo *mex)
  87 {
  88         unsigned char *modulus, *exponent, *message;
  89         int mod_len;
  90
  91         mod_len = mex->inputdatalength;
  92
  93         if (mod_len <= 128) {
  94                 struct type4_sme *sme = ap_msg->message;
  95                 memset(sme, 0, sizeof(*sme));
  96                 ap_msg->length = sizeof(*sme);
  97                 sme->header.msg_fmt = TYPE4_SME_FMT;
  98                 sme->header.msg_len = sizeof(*sme);
  99                 sme->header.msg_type_code = TYPE4_TYPE_CODE;
 100                 sme->header.request_code = TYPE4_REQU_CODE;
 101                 modulus = sme->modulus + sizeof(sme->modulus) - mod_len;
 102                 exponent = sme->exponent + sizeof(sme->exponent) - mod_len;
 103                 message = sme->message + sizeof(sme->message) - mod_len;
 104         } else {
 105                 struct type4_lme *lme = ap_msg->message;
 106                 memset(lme, 0, sizeof(*lme));
 107                 ap_msg->length = sizeof(*lme);
 108                 lme->header.msg_fmt = TYPE4_LME_FMT;
 109                 lme->header.msg_len = sizeof(*lme);
 110                 lme->header.msg_type_code = TYPE4_TYPE_CODE;
 111                 lme->header.request_code = TYPE4_REQU_CODE;
 112                 modulus = lme->modulus + sizeof(lme->modulus) - mod_len;
 113                 exponent = lme->exponent + sizeof(lme->exponent) - mod_len;
 114                 message = lme->message + sizeof(lme->message) - mod_len;
 115         }
 116
 117         if (copy_from_user(modulus, mex->n_modulus, mod_len) ||
 118             copy_from_user(exponent, mex->b_key, mod_len) ||
 119             copy_from_user(message, mex->inputdata, mod_len))
 120                 return -EFAULT;
 121         return 0;
 122 }
 123
 124 /**
 125  * Convert a ICACRT message to a type4 CRT message.
 126  *
 127  * @zdev: crypto device pointer
 128  * @zreq: crypto request pointer
 129  * @crt: pointer to user input data
 130  *
 131  * Returns 0 on success or -EFAULT.
 132  */
 133 static int ICACRT_msg_to_type4CRT_msg(struct zcrypt_device *zdev,
 134                                       struct ap_message *ap_msg,
 135                                       struct ica_rsa_modexpo_crt *crt)
 136 {
 137         unsigned char *p, *q, *dp, *dq, *u, *inp;
 138         int mod_len, short_len, long_len;
 139
 140         mod_len = crt->inputdatalength;
 141         short_len = mod_len / 2;
 142         long_len = mod_len / 2 + 8;
 143
 144         if (mod_len <= 128) {
 145                 struct type4_scr *scr = ap_msg->message;
 146                 memset(scr, 0, sizeof(*scr));
 147                 ap_msg->length = sizeof(*scr);
 148                 scr->header.msg_type_code = TYPE4_TYPE_CODE;
 149                 scr->header.request_code = TYPE4_REQU_CODE;
 150                 scr->header.msg_fmt = TYPE4_SCR_FMT;
 151                 scr->header.msg_len = sizeof(*scr);
 152                 p = scr->p + sizeof(scr->p) - long_len;
 153                 q = scr->q + sizeof(scr->q) - short_len;
 154                 dp = scr->dp + sizeof(scr->dp) - long_len;
 155                 dq = scr->dq + sizeof(scr->dq) - short_len;
 156                 u = scr->u + sizeof(scr->u) - long_len;
 157                 inp = scr->message + sizeof(scr->message) - mod_len;
 158         } else {
 159                 struct type4_lcr *lcr = ap_msg->message;
 160                 memset(lcr, 0, sizeof(*lcr));
 161                 ap_msg->length = sizeof(*lcr);
 162                 lcr->header.msg_type_code = TYPE4_TYPE_CODE;
 163                 lcr->header.request_code = TYPE4_REQU_CODE;
 164                 lcr->header.msg_fmt = TYPE4_LCR_FMT;
 165                 lcr->header.msg_len = sizeof(*lcr);
 166                 p = lcr->p + sizeof(lcr->p) - long_len;
 167                 q = lcr->q + sizeof(lcr->q) - short_len;
 168                 dp = lcr->dp + sizeof(lcr->dp) - long_len;
 169                 dq = lcr->dq + sizeof(lcr->dq) - short_len;
 170                 u = lcr->u + sizeof(lcr->u) - long_len;
 171                 inp = lcr->message + sizeof(lcr->message) - mod_len;
 172         }
 173
 174         if (copy_from_user(p, crt->np_prime, long_len) ||
 175             copy_from_user(q, crt->nq_prime, short_len) ||
 176             copy_from_user(dp, crt->bp_key, long_len) ||
 177             copy_from_user(dq, crt->bq_key, short_len) ||
 178             copy_from_user(u, crt->u_mult_inv, long_len) ||
 179             copy_from_user(inp, crt->inputdata, mod_len))
 180                 return -EFAULT;
 181         return 0;
 182 }
 183
 184 /**
 185  * Copy results from a type 84 reply message back to user space.
 186  *
 187  * @zdev: crypto device pointer
 188  * @reply: reply AP message.
 189  * @data: pointer to user output data
 190  * @length: size of user output data
 191  *
 192  * Returns 0 on success or -EFAULT.
 193  */
 194 static int convert_type84(struct zcrypt_device *zdev,
 195                           struct ap_message *reply,
 196                           char __user *outputdata,
 197                           unsigned int outputdatalength)
 198 {
 199         struct type84_hdr *t84h = reply->message;
 200         char *data;
 201
 202         if (t84h->len < sizeof(*t84h) + outputdatalength) {
 203                 /* The result is too short, the PCICA card may not do that.. */
 204                 zdev->online = 0;
 205                 return -EAGAIN; /* repeat the request on a different device. */
 206         }
 207         BUG_ON(t84h->len > PCICA_MAX_RESPONSE_SIZE);
 208         data = reply->message + t84h->len - outputdatalength;
 209         if (copy_to_user(outputdata, data, outputdatalength))
 210                 return -EFAULT;
 211         return 0;
 212 }
 213
 214 static int convert_response(struct zcrypt_device *zdev,
 215                             struct ap_message *reply,
 216                             char __user *outputdata,
 217                             unsigned int outputdatalength)
 218 {
 219         /* Response type byte is the second byte in the response. */
 220         switch (((unsigned char *) reply->message)[1]) {
 221         case TYPE82_RSP_CODE:
 222         case TYPE88_RSP_CODE:
 223                 return convert_error(zdev, reply);
 224         case TYPE84_RSP_CODE:
 225                 return convert_type84(zdev, reply,
 226                                       outputdata, outputdatalength);
 227         default: /* Unknown response type, this should NEVER EVER happen */
 228                 PRINTK("Unrecognized Message Header: %08x%08x\n",
 229                        *(unsigned int *) reply->message,
 230                        *(unsigned int *) (reply->message+4));
 231                 zdev->online = 0;
 232                 return -EAGAIN; /* repeat the request on a different device. */
 233         }
 234 }
 235
 236 /**
 237  * This function is called from the AP bus code after a crypto request
 238  * "msg" has finished with the reply message "reply".
 239  * It is called from tasklet context.
 240  * @ap_dev: pointer to the AP device
 241  * @msg: pointer to the AP message
 242  * @reply: pointer to the AP reply message
 243  */
 244 static void zcrypt_pcica_receive(struct ap_device *ap_dev,
 245                                  struct ap_message *msg,
 246                                  struct ap_message *reply)
 247 {
 248         static struct error_hdr error_reply = {
 249                 .type = TYPE82_RSP_CODE,
 250                 .reply_code = REP82_ERROR_MACHINE_FAILURE,
 251         };
 252         struct type84_hdr *t84h = reply->message;
 253         int length;
 254
 255         /* Copy the reply message to the request message buffer. */
 256         if (IS_ERR(reply))
 257                 memcpy(msg->message, &error_reply, sizeof(error_reply));
 258         else if (t84h->code == TYPE84_RSP_CODE) {
 259                 length = min(PCICA_MAX_RESPONSE_SIZE, (int) t84h->len);
 260                 memcpy(msg->message, reply->message, length);
 261         } else
 262                 memcpy(msg->message, reply->message, sizeof error_reply);
 263         complete((struct completion *) msg->private);
 264 }
 265
 266 static atomic_t zcrypt_step = ATOMIC_INIT(0);
 267
 268 /**
 269  * The request distributor calls this function if it picked the PCICA
 270  * device to handle a modexpo request.
 271  * @zdev: pointer to zcrypt_device structure that identifies the
 272  *        PCICA device to the request distributor
 273  * @mex: pointer to the modexpo request buffer
 274  */
 275 static long zcrypt_pcica_modexpo(struct zcrypt_device *zdev,
 276                                  struct ica_rsa_modexpo *mex)
 277 {
 278         struct ap_message ap_msg;
 279         struct completion work;
 280         int rc;
 281
 282         ap_msg.message = kmalloc(PCICA_MAX_MESSAGE_SIZE, GFP_KERNEL);
 283         if (!ap_msg.message)
 284                 return -ENOMEM;
 285         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 286                                 atomic_inc_return(&zcrypt_step);
 287         ap_msg.private = &work;
 288         rc = ICAMEX_msg_to_type4MEX_msg(zdev, &ap_msg, mex);
 289         if (rc)
 290                 goto out_free;
 291         init_completion(&work);
 292         ap_queue_message(zdev->ap_dev, &ap_msg);
 293         rc = wait_for_completion_interruptible_timeout(
 294                                 &work, PCICA_CLEANUP_TIME);
 295         if (rc > 0)
 296                 rc = convert_response(zdev, &ap_msg, mex->outputdata,
 297                                       mex->outputdatalength);
 298         else {
 299                 /* Signal pending or message timed out. */
 300                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 301                 if (rc == 0)
 302                         /* Message timed out. */
 303                         rc = -ETIME;
 304         }
 305 out_free:
 306         kfree(ap_msg.message);
 307         return rc;
 308 }
 309
 310 /**
 311  * The request distributor calls this function if it picked the PCICA
 312  * device to handle a modexpo_crt request.
 313  * @zdev: pointer to zcrypt_device structure that identifies the
 314  *        PCICA device to the request distributor
 315  * @crt: pointer to the modexpoc_crt request buffer
 316  */
 317 static long zcrypt_pcica_modexpo_crt(struct zcrypt_device *zdev,
 318                                      struct ica_rsa_modexpo_crt *crt)
 319 {
 320         struct ap_message ap_msg;
 321         struct completion work;
 322         int rc;
 323
 324         ap_msg.message = kmalloc(PCICA_MAX_MESSAGE_SIZE, GFP_KERNEL);
 325         if (!ap_msg.message)
 326                 return -ENOMEM;
 327         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 328                                 atomic_inc_return(&zcrypt_step);
 329         ap_msg.private = &work;
 330         rc = ICACRT_msg_to_type4CRT_msg(zdev, &ap_msg, crt);
 331         if (rc)
 332                 goto out_free;
 333         init_completion(&work);
 334         ap_queue_message(zdev->ap_dev, &ap_msg);
 335         rc = wait_for_completion_interruptible_timeout(
 336                                 &work, PCICA_CLEANUP_TIME);
 337         if (rc > 0)
 338                 rc = convert_response(zdev, &ap_msg, crt->outputdata,
 339                                       crt->outputdatalength);
 340         else {
 341                 /* Signal pending or message timed out. */
 342                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 343                 if (rc == 0)
 344                         /* Message timed out. */
 345                         rc = -ETIME;
 346         }
 347 out_free:
 348         kfree(ap_msg.message);
 349         return rc;
 350 }
 351
 352 /**
 353  * The crypto operations for a PCICA card.
 354  */
 355 static struct zcrypt_ops zcrypt_pcica_ops = {
 356         .rsa_modexpo = zcrypt_pcica_modexpo,
 357         .rsa_modexpo_crt = zcrypt_pcica_modexpo_crt,
 358 };
 359
 360 /**
 361  * Probe function for PCICA cards. It always accepts the AP device
 362  * since the bus_match already checked the hardware type.
 363  * @ap_dev: pointer to the AP device.
 364  */
 365 static int zcrypt_pcica_probe(struct ap_device *ap_dev)
 366 {
 367         struct zcrypt_device *zdev;
 368         int rc;
 369
 370         zdev = zcrypt_device_alloc(PCICA_MAX_RESPONSE_SIZE);
 371         if (!zdev)
 372                 return -ENOMEM;
 373         zdev->ap_dev = ap_dev;
 374         zdev->ops = &zcrypt_pcica_ops;
 375         zdev->online = 1;
 376         zdev->user_space_type = ZCRYPT_PCICA;
 377         zdev->type_string = "PCICA";
 378         zdev->min_mod_size = PCICA_MIN_MOD_SIZE;
 379         zdev->max_mod_size = PCICA_MAX_MOD_SIZE;
 380         zdev->speed_rating = PCICA_SPEED_RATING;
 381         ap_dev->reply = &zdev->reply;
 382         ap_dev->private = zdev;
 383         rc = zcrypt_device_register(zdev);
 384         if (rc)
 385                 goto out_free;
 386         return 0;
 387
 388 out_free:
 389         ap_dev->private = NULL;
 390         zcrypt_device_free(zdev);
 391         return rc;
 392 }
 393
 394 /**
 395  * This is called to remove the extended PCICA driver information
 396  * if an AP device is removed.
 397  */
 398 static void zcrypt_pcica_remove(struct ap_device *ap_dev)
 399 {
 400         struct zcrypt_device *zdev = ap_dev->private;
 401
 402         zcrypt_device_unregister(zdev);
 403 }
 404
 405 int __init zcrypt_pcica_init(void)
 406 {
 407         return ap_driver_register(&zcrypt_pcica_driver, THIS_MODULE, "pcica");
 408 }
 409
 410 void zcrypt_pcica_exit(void)
 411 {
 412         ap_driver_unregister(&zcrypt_pcica_driver);
 413 }
 414
 415 #ifndef CONFIG_ZCRYPT_MONOLITHIC
 416 module_init(zcrypt_pcica_init);
 417 module_exit(zcrypt_pcica_exit);
 418 #endif