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