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         .request_timeout = PCICA_CLEANUP_TIME,
  74 };
  75
  76 /**
  77  * Convert a ICAMEX message to a type4 MEX message.
  78  *
  79  * @zdev: crypto device pointer
  80  * @zreq: crypto request pointer
  81  * @mex: pointer to user input data
  82  *
  83  * Returns 0 on success or -EFAULT.
  84  */
  85 static int ICAMEX_msg_to_type4MEX_msg(struct zcrypt_device *zdev,
  86                                       struct ap_message *ap_msg,
  87                                       struct ica_rsa_modexpo *mex)
  88 {
  89         unsigned char *modulus, *exponent, *message;
  90         int mod_len;
  91
  92         mod_len = mex->inputdatalength;
  93
  94         if (mod_len <= 128) {
  95                 struct type4_sme *sme = ap_msg->message;
  96                 memset(sme, 0, sizeof(*sme));
  97                 ap_msg->length = sizeof(*sme);
  98                 sme->header.msg_fmt = TYPE4_SME_FMT;
  99                 sme->header.msg_len = sizeof(*sme);
 100                 sme->header.msg_type_code = TYPE4_TYPE_CODE;
 101                 sme->header.request_code = TYPE4_REQU_CODE;
 102                 modulus = sme->modulus + sizeof(sme->modulus) - mod_len;
 103                 exponent = sme->exponent + sizeof(sme->exponent) - mod_len;
 104                 message = sme->message + sizeof(sme->message) - mod_len;
 105         } else {
 106                 struct type4_lme *lme = ap_msg->message;
 107                 memset(lme, 0, sizeof(*lme));
 108                 ap_msg->length = sizeof(*lme);
 109                 lme->header.msg_fmt = TYPE4_LME_FMT;
 110                 lme->header.msg_len = sizeof(*lme);
 111                 lme->header.msg_type_code = TYPE4_TYPE_CODE;
 112                 lme->header.request_code = TYPE4_REQU_CODE;
 113                 modulus = lme->modulus + sizeof(lme->modulus) - mod_len;
 114                 exponent = lme->exponent + sizeof(lme->exponent) - mod_len;
 115                 message = lme->message + sizeof(lme->message) - mod_len;
 116         }
 117
 118         if (copy_from_user(modulus, mex->n_modulus, mod_len) ||
 119             copy_from_user(exponent, mex->b_key, mod_len) ||
 120             copy_from_user(message, mex->inputdata, mod_len))
 121                 return -EFAULT;
 122         return 0;
 123 }
 124
 125 /**
 126  * Convert a ICACRT message to a type4 CRT message.
 127  *
 128  * @zdev: crypto device pointer
 129  * @zreq: crypto request pointer
 130  * @crt: pointer to user input data
 131  *
 132  * Returns 0 on success or -EFAULT.
 133  */
 134 static int ICACRT_msg_to_type4CRT_msg(struct zcrypt_device *zdev,
 135                                       struct ap_message *ap_msg,
 136                                       struct ica_rsa_modexpo_crt *crt)
 137 {
 138         unsigned char *p, *q, *dp, *dq, *u, *inp;
 139         int mod_len, short_len, long_len;
 140
 141         mod_len = crt->inputdatalength;
 142         short_len = mod_len / 2;
 143         long_len = mod_len / 2 + 8;
 144
 145         if (mod_len <= 128) {
 146                 struct type4_scr *scr = ap_msg->message;
 147                 memset(scr, 0, sizeof(*scr));
 148                 ap_msg->length = sizeof(*scr);
 149                 scr->header.msg_type_code = TYPE4_TYPE_CODE;
 150                 scr->header.request_code = TYPE4_REQU_CODE;
 151                 scr->header.msg_fmt = TYPE4_SCR_FMT;
 152                 scr->header.msg_len = sizeof(*scr);
 153                 p = scr->p + sizeof(scr->p) - long_len;
 154                 q = scr->q + sizeof(scr->q) - short_len;
 155                 dp = scr->dp + sizeof(scr->dp) - long_len;
 156                 dq = scr->dq + sizeof(scr->dq) - short_len;
 157                 u = scr->u + sizeof(scr->u) - long_len;
 158                 inp = scr->message + sizeof(scr->message) - mod_len;
 159         } else {
 160                 struct type4_lcr *lcr = ap_msg->message;
 161                 memset(lcr, 0, sizeof(*lcr));
 162                 ap_msg->length = sizeof(*lcr);
 163                 lcr->header.msg_type_code = TYPE4_TYPE_CODE;
 164                 lcr->header.request_code = TYPE4_REQU_CODE;
 165                 lcr->header.msg_fmt = TYPE4_LCR_FMT;
 166                 lcr->header.msg_len = sizeof(*lcr);
 167                 p = lcr->p + sizeof(lcr->p) - long_len;
 168                 q = lcr->q + sizeof(lcr->q) - short_len;
 169                 dp = lcr->dp + sizeof(lcr->dp) - long_len;
 170                 dq = lcr->dq + sizeof(lcr->dq) - short_len;
 171                 u = lcr->u + sizeof(lcr->u) - long_len;
 172                 inp = lcr->message + sizeof(lcr->message) - mod_len;
 173         }
 174
 175         if (copy_from_user(p, crt->np_prime, long_len) ||
 176             copy_from_user(q, crt->nq_prime, short_len) ||
 177             copy_from_user(dp, crt->bp_key, long_len) ||
 178             copy_from_user(dq, crt->bq_key, short_len) ||
 179             copy_from_user(u, crt->u_mult_inv, long_len) ||
 180             copy_from_user(inp, crt->inputdata, mod_len))
 181                 return -EFAULT;
 182         return 0;
 183 }
 184
 185 /**
 186  * Copy results from a type 84 reply message back to user space.
 187  *
 188  * @zdev: crypto device pointer
 189  * @reply: reply AP message.
 190  * @data: pointer to user output data
 191  * @length: size of user output data
 192  *
 193  * Returns 0 on success or -EFAULT.
 194  */
 195 static int convert_type84(struct zcrypt_device *zdev,
 196                           struct ap_message *reply,
 197                           char __user *outputdata,
 198                           unsigned int outputdatalength)
 199 {
 200         struct type84_hdr *t84h = reply->message;
 201         char *data;
 202
 203         if (t84h->len < sizeof(*t84h) + outputdatalength) {
 204                 /* The result is too short, the PCICA card may not do that.. */
 205                 zdev->online = 0;
 206                 return -EAGAIN; /* repeat the request on a different device. */
 207         }
 208         BUG_ON(t84h->len > PCICA_MAX_RESPONSE_SIZE);
 209         data = reply->message + t84h->len - outputdatalength;
 210         if (copy_to_user(outputdata, data, outputdatalength))
 211                 return -EFAULT;
 212         return 0;
 213 }
 214
 215 static int convert_response(struct zcrypt_device *zdev,
 216                             struct ap_message *reply,
 217                             char __user *outputdata,
 218                             unsigned int outputdatalength)
 219 {
 220         /* Response type byte is the second byte in the response. */
 221         switch (((unsigned char *) reply->message)[1]) {
 222         case TYPE82_RSP_CODE:
 223         case TYPE88_RSP_CODE:
 224                 return convert_error(zdev, reply);
 225         case TYPE84_RSP_CODE:
 226                 return convert_type84(zdev, reply,
 227                                       outputdata, outputdatalength);
 228         default: /* Unknown response type, this should NEVER EVER happen */
 229                 zdev->online = 0;
 230                 return -EAGAIN; /* repeat the request on a different device. */
 231         }
 232 }
 233
 234 /**
 235  * This function is called from the AP bus code after a crypto request
 236  * "msg" has finished with the reply message "reply".
 237  * It is called from tasklet context.
 238  * @ap_dev: pointer to the AP device
 239  * @msg: pointer to the AP message
 240  * @reply: pointer to the AP reply message
 241  */
 242 static void zcrypt_pcica_receive(struct ap_device *ap_dev,
 243                                  struct ap_message *msg,
 244                                  struct ap_message *reply)
 245 {
 246         static struct error_hdr error_reply = {
 247                 .type = TYPE82_RSP_CODE,
 248                 .reply_code = REP82_ERROR_MACHINE_FAILURE,
 249         };
 250         struct type84_hdr *t84h;
 251         int length;
 252
 253         /* Copy the reply message to the request message buffer. */
 254         if (IS_ERR(reply)) {
 255                 memcpy(msg->message, &error_reply, sizeof(error_reply));
 256                 goto out;
 257         }
 258         t84h = reply->message;
 259         if (t84h->code == TYPE84_RSP_CODE) {
 260                 length = min(PCICA_MAX_RESPONSE_SIZE, (int) t84h->len);
 261                 memcpy(msg->message, reply->message, length);
 262         } else
 263                 memcpy(msg->message, reply->message, sizeof error_reply);
 264 out:
 265         complete((struct completion *) msg->private);
 266 }
 267
 268 static atomic_t zcrypt_step = ATOMIC_INIT(0);
 269
 270 /**
 271  * The request distributor calls this function if it picked the PCICA
 272  * device to handle a modexpo request.
 273  * @zdev: pointer to zcrypt_device structure that identifies the
 274  *        PCICA device to the request distributor
 275  * @mex: pointer to the modexpo request buffer
 276  */
 277 static long zcrypt_pcica_modexpo(struct zcrypt_device *zdev,
 278                                  struct ica_rsa_modexpo *mex)
 279 {
 280         struct ap_message ap_msg;
 281         struct completion work;
 282         int rc;
 283
 284         ap_msg.message = kmalloc(PCICA_MAX_MESSAGE_SIZE, GFP_KERNEL);
 285         if (!ap_msg.message)
 286                 return -ENOMEM;
 287         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 288                                 atomic_inc_return(&zcrypt_step);
 289         ap_msg.private = &work;
 290         rc = ICAMEX_msg_to_type4MEX_msg(zdev, &ap_msg, mex);
 291         if (rc)
 292                 goto out_free;
 293         init_completion(&work);
 294         ap_queue_message(zdev->ap_dev, &ap_msg);
 295         rc = wait_for_completion_interruptible(&work);
 296         if (rc == 0)
 297                 rc = convert_response(zdev, &ap_msg, mex->outputdata,
 298                                       mex->outputdatalength);
 299         else
 300                 /* Signal pending. */
 301                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 302 out_free:
 303         kfree(ap_msg.message);
 304         return rc;
 305 }
 306
 307 /**
 308  * The request distributor calls this function if it picked the PCICA
 309  * device to handle a modexpo_crt request.
 310  * @zdev: pointer to zcrypt_device structure that identifies the
 311  *        PCICA device to the request distributor
 312  * @crt: pointer to the modexpoc_crt request buffer
 313  */
 314 static long zcrypt_pcica_modexpo_crt(struct zcrypt_device *zdev,
 315                                      struct ica_rsa_modexpo_crt *crt)
 316 {
 317         struct ap_message ap_msg;
 318         struct completion work;
 319         int rc;
 320
 321         ap_msg.message = kmalloc(PCICA_MAX_MESSAGE_SIZE, GFP_KERNEL);
 322         if (!ap_msg.message)
 323                 return -ENOMEM;
 324         ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
 325                                 atomic_inc_return(&zcrypt_step);
 326         ap_msg.private = &work;
 327         rc = ICACRT_msg_to_type4CRT_msg(zdev, &ap_msg, crt);
 328         if (rc)
 329                 goto out_free;
 330         init_completion(&work);
 331         ap_queue_message(zdev->ap_dev, &ap_msg);
 332         rc = wait_for_completion_interruptible(&work);
 333         if (rc == 0)
 334                 rc = convert_response(zdev, &ap_msg, crt->outputdata,
 335                                       crt->outputdatalength);
 336         else
 337                 /* Signal pending. */
 338                 ap_cancel_message(zdev->ap_dev, &ap_msg);
 339 out_free:
 340         kfree(ap_msg.message);
 341         return rc;
 342 }
 343
 344 /**
 345  * The crypto operations for a PCICA card.
 346  */
 347 static struct zcrypt_ops zcrypt_pcica_ops = {
 348         .rsa_modexpo = zcrypt_pcica_modexpo,
 349         .rsa_modexpo_crt = zcrypt_pcica_modexpo_crt,
 350 };
 351
 352 /**
 353  * Probe function for PCICA cards. It always accepts the AP device
 354  * since the bus_match already checked the hardware type.
 355  * @ap_dev: pointer to the AP device.
 356  */
 357 static int zcrypt_pcica_probe(struct ap_device *ap_dev)
 358 {
 359         struct zcrypt_device *zdev;
 360         int rc;
 361
 362         zdev = zcrypt_device_alloc(PCICA_MAX_RESPONSE_SIZE);
 363         if (!zdev)
 364                 return -ENOMEM;
 365         zdev->ap_dev = ap_dev;
 366         zdev->ops = &zcrypt_pcica_ops;
 367         zdev->online = 1;
 368         zdev->user_space_type = ZCRYPT_PCICA;
 369         zdev->type_string = "PCICA";
 370         zdev->min_mod_size = PCICA_MIN_MOD_SIZE;
 371         zdev->max_mod_size = PCICA_MAX_MOD_SIZE;
 372         zdev->speed_rating = PCICA_SPEED_RATING;
 373         ap_dev->reply = &zdev->reply;
 374         ap_dev->private = zdev;
 375         rc = zcrypt_device_register(zdev);
 376         if (rc)
 377                 goto out_free;
 378         return 0;
 379
 380 out_free:
 381         ap_dev->private = NULL;
 382         zcrypt_device_free(zdev);
 383         return rc;
 384 }
 385
 386 /**
 387  * This is called to remove the extended PCICA driver information
 388  * if an AP device is removed.
 389  */
 390 static void zcrypt_pcica_remove(struct ap_device *ap_dev)
 391 {
 392         struct zcrypt_device *zdev = ap_dev->private;
 393
 394         zcrypt_device_unregister(zdev);
 395 }
 396
 397 int __init zcrypt_pcica_init(void)
 398 {
 399         return ap_driver_register(&zcrypt_pcica_driver, THIS_MODULE, "pcica");
 400 }
 401
 402 void zcrypt_pcica_exit(void)
 403 {
 404         ap_driver_unregister(&zcrypt_pcica_driver);
 405 }
 406
 407 #ifndef CONFIG_ZCRYPT_MONOLITHIC
 408 module_init(zcrypt_pcica_init);
 409 module_exit(zcrypt_pcica_exit);
 410 #endif