/*
* linux/drivers/s390/crypto/zcrypt_cex2a.c
*
* zcrypt 2.1.0
*
* Copyright (C) 2001, 2006 IBM Corporation
* Author(s): Robert Burroughs
* Eric Rossman (edrossma@us.ibm.com)
*
* Hotplug & misc device support: Jochen Roehrig (roehrig@de.ibm.com)
* Major cleanup & driver split: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Ralph Wuerthner <rwuerthn@de.ibm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <asm/atomic.h>
#include <asm/uaccess.h>
#include "ap_bus.h"
#include "zcrypt_api.h"
#include "zcrypt_error.h"
#include "zcrypt_cex2a.h"
#define CEX2A_MIN_MOD_SIZE 1 /* 8 bits */
#define CEX2A_MAX_MOD_SIZE 256 /* 2048 bits */
#define CEX2A_SPEED_RATING 970
#define CEX2A_MAX_MESSAGE_SIZE 0x390 /* sizeof(struct type50_crb2_msg) */
#define CEX2A_MAX_RESPONSE_SIZE 0x110 /* max outputdatalength + type80_hdr */
#define CEX2A_CLEANUP_TIME (15*HZ)
static struct ap_device_id zcrypt_cex2a_ids[] = {
{ AP_DEVICE(AP_DEVICE_TYPE_CEX2A) },
{ /* end of list */ },
};
#ifndef CONFIG_ZCRYPT_MONOLITHIC
MODULE_DEVICE_TABLE(ap, zcrypt_cex2a_ids);
MODULE_AUTHOR("IBM Corporation");
MODULE_DESCRIPTION("CEX2A Cryptographic Coprocessor device driver, "
"Copyright 2001, 2006 IBM Corporation");
MODULE_LICENSE("GPL");
#endif
static int zcrypt_cex2a_probe(struct ap_device *ap_dev);
static void zcrypt_cex2a_remove(struct ap_device *ap_dev);
static void zcrypt_cex2a_receive(struct ap_device *, struct ap_message *,
struct ap_message *);
static struct ap_driver zcrypt_cex2a_driver = {
.probe = zcrypt_cex2a_probe,
.remove = zcrypt_cex2a_remove,
.receive = zcrypt_cex2a_receive,
.ids = zcrypt_cex2a_ids,
};
/**
* Convert a ICAMEX message to a type50 MEX message.
*
* @zdev: crypto device pointer
* @zreq: crypto request pointer
* @mex: pointer to user input data
*
* Returns 0 on success or -EFAULT.
*/
static int ICAMEX_msg_to_type50MEX_msg(struct zcrypt_device *zdev,
struct ap_message *ap_msg,
struct ica_rsa_modexpo *mex)
{
unsigned char *mod, *exp, *inp;
int mod_len;
mod_len = mex->inputdatalength;
if (mod_len <= 128) {
struct type50_meb1_msg *meb1 = ap_msg->message;
memset(meb1, 0, sizeof(*meb1));
ap_msg->length = sizeof(*meb1);
meb1->header.msg_type_code = TYPE50_TYPE_CODE;
meb1->header.msg_len = sizeof(*meb1);
meb1->keyblock_type = TYPE50_MEB1_FMT;
mod = meb1->modulus + sizeof(meb1->modulus) - mod_len;
exp = meb1->exponent + sizeof(meb1->exponent) - mod_len;
inp = meb1->message + sizeof(meb1->message) - mod_len;
} else {
struct type50_meb2_msg *meb2 = ap_msg->message;
memset(meb2, 0, sizeof(*meb2));
ap_msg->length = sizeof(*meb2);
meb2->header.msg_type_code = TYPE50_TYPE_CODE;
meb2->header.msg_len = sizeof(*meb2);
meb2->keyblock_type = TYPE50_MEB2_FMT;
mod = meb2->modulus + sizeof(meb2->modulus) - mod_len;
exp = meb2->exponent + sizeof(meb2->exponent) - mod_len;
inp = meb2->message + sizeof(meb2->message) - mod_len;
}
if (copy_from_user(mod, mex->n_modulus, mod_len) ||
copy_from_user(exp, mex->b_key, mod_len) ||
copy_from_user(inp, mex->inputdata, mod_len))
return -EFAULT;
return 0;
}
/**
* Convert a ICACRT message to a type50 CRT message.
*
* @zdev: crypto device pointer
* @zreq: crypto request pointer
* @crt: pointer to user input data
*
* Returns 0 on success or -EFAULT.
*/
static int ICACRT_msg_to_type50CRT_msg(struct zcrypt_device *zdev,
struct ap_message *ap_msg,
struct ica_rsa_modexpo_crt *crt)
{
int mod_len, short_len, long_len, long_offset;
unsigned char *p, *q, *dp, *dq, *u, *inp;
mod_len = crt->inputdatalength;
short_len = mod_len / 2;
long_len = mod_len / 2 + 8;
/*
* CEX2A cannot handle p, dp, or U > 128 bytes.
* If we have one of these, we need to do extra checking.
*/
if (long_len > 128) {
/*
* zcrypt_rsa_crt already checked for the leading
* zeroes of np_prime, bp_key and u_mult_inc.
*/
long_offset = long_len - 128;
long_len = 128;
} else
long_offset = 0;
/*
* Instead of doing extra work for p, dp, U > 64 bytes, we'll just use
* the larger message structure.
*/
if (long_len <= 64) {
struct type50_crb1_msg *crb1 = ap_msg->message;
memset(crb1, 0, sizeof(*crb1));
ap_msg->length = sizeof(*crb1);
crb1->header.msg_type_code = TYPE50_TYPE_CODE;
crb1->header.msg_len = sizeof(*crb1);
crb1->keyblock_type = TYPE50_CRB1_FMT;
p = crb1->p + sizeof(crb1->p) - long_len;
q = crb1->q + sizeof(crb1->q) - short_len;
dp = crb1->dp + sizeof(crb1->dp) - long_len;
dq = crb1->dq + sizeof(crb1->dq) - short_len;
u = crb1->u + sizeof(crb1->u) - long_len;
inp = crb1->message + sizeof(crb1->message) - mod_len;
} else {
struct type50_crb2_msg *crb2 = ap_msg->message;
memset(crb2, 0, sizeof(*crb2));
ap_msg->length = sizeof(*crb2);
crb2->header.msg_type_code = TYPE50_TYPE_CODE;
crb2->header.msg_len = sizeof(*crb2);
crb2->keyblock_type = TYPE50_CRB2_FMT;
p = crb2->p + sizeof(crb2->p) - long_len;
q = crb2->q + sizeof(crb2->q) - short_len;
dp = crb2->dp + sizeof(crb2->dp) - long_len;
dq = crb2->dq + sizeof(crb2->dq) - short_len;
u = crb2->u + sizeof(crb2->u) - long_len;
inp = crb2->message + sizeof(crb2->message) - mod_len;
}
if (copy_from_user(p, crt->np_prime + long_offset, long_len) ||
copy_from_user(q, crt->nq_prime, short_len) ||
copy_from_user(dp, crt->bp_key + long_offset, long_len) ||
copy_from_user(dq, crt->bq_key, short_len) ||
copy_from_user(u, crt->u_mult_inv + long_offset, long_len) ||
copy_from_user(inp, crt->inputdata, mod_len))
return -EFAULT;
return 0;
}
/**
* Copy results from a type 80 reply message back to user space.
*
* @zdev: crypto device pointer
* @reply: reply AP message.
* @data: pointer to user output data
* @length: size of user output data
*
* Returns 0 on success or -EFAULT.
*/
static int convert_type80(struct zcrypt_device *zdev,
struct ap_message *reply,
char __user *outputdata,
unsigned int outputdatalength)
{
struct type80_hdr *t80h = reply->message;
unsigned char *data;
if (t80h->len < sizeof(*t80h) + outputdatalength) {
/* The result is too short, the CEX2A card may not do that.. */
zdev->online = 0;
return -EAGAIN; /* repeat the request on a different device. */
}
BUG_ON(t80h->len > CEX2A_MAX_RESPONSE_SIZE);
data = reply->message + t80h->len - outputdatalength;
if (copy_to_user(outputdata, data, outputdatalength))
return -EFAULT;
return 0;
}
static int convert_response(struct zcrypt_device *zdev,
struct ap_message *reply,
char __user *outputdata,
unsigned int outputdatalength)
{
/* Response type byte is the second byte in the response. */
switch (((unsigned char *) reply->message)[1]) {
case TYPE82_RSP_CODE:
case TYPE88_RSP_CODE:
return convert_error(zdev, reply);
case TYPE80_RSP_CODE:
return convert_type80(zdev, reply,
outputdata, outputdatalength);
default: /* Unknown response type, this should NEVER EVER happen */
PRINTK("Unrecognized Message Header: %08x%08x\n",
*(unsigned int *) reply->message,
*(unsigned int *) (reply->message+4));
zdev->online = 0;
return -EAGAIN; /* repeat the request on a different device. */
}
}
/**
* This function is called from the AP bus code after a crypto request
* "msg" has finished with the reply message "reply".
* It is called from tasklet context.
* @ap_dev: pointer to the AP device
* @msg: pointer to the AP message
* @reply: pointer to the AP reply message
*/
static void zcrypt_cex2a_receive(struct ap_device *ap_dev,
struct ap_message *msg,
struct ap_message *reply)
{
static struct error_hdr error_reply = {
.type = TYPE82_RSP_CODE,
.reply_code = REP82_ERROR_MACHINE_FAILURE,
};
struct type80_hdr *t80h = reply->message;
int length;
/* Copy the reply message to the request message buffer. */
if (IS_ERR(reply))
memcpy(msg->message, &error_reply, sizeof(error_reply));
else if (t80h->type == TYPE80_RSP_CODE) {
length = min(CEX2A_MAX_RESPONSE_SIZE, (int) t80h->len);
memcpy(msg->message, reply->message, length);
} else
memcpy(msg->message, reply->message, sizeof error_reply);
complete((struct completion *) msg->private);
}
static atomic_t zcrypt_step = ATOMIC_INIT(0);
/**
* The request distributor calls this function if it picked the CEX2A
* device to handle a modexpo request.
* @zdev: pointer to zcrypt_device structure that identifies the
* CEX2A device to the request distributor
* @mex: pointer to the modexpo request buffer
*/
static long zcrypt_cex2a_modexpo(struct zcrypt_device *zdev,
struct ica_rsa_modexpo *mex)
{
struct ap_message ap_msg;
struct completion work;
int rc;
ap_msg.message = kmalloc(CEX2A_MAX_MESSAGE_SIZE, GFP_KERNEL);
if (!ap_msg.message)
return -ENOMEM;
ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
atomic_inc_return(&zcrypt_step);
ap_msg.private = &work;
rc = ICAMEX_msg_to_type50MEX_msg(zdev, &ap_msg, mex);
if (rc)
goto out_free;
init_completion(&work);
ap_queue_message(zdev->ap_dev, &ap_msg);
rc = wait_for_completion_interruptible_timeout(
&work, CEX2A_CLEANUP_TIME);
if (rc > 0)
rc = convert_response(zdev, &ap_msg, mex->outputdata,
mex->outputdatalength);
else {
/* Signal pending or message timed out. */
ap_cancel_message(zdev->ap_dev, &ap_msg);
if (rc == 0)
/* Message timed out. */
rc = -ETIME;
}
out_free:
kfree(ap_msg.message);
return rc;
}
/**
* The request distributor calls this function if it picked the CEX2A
* device to handle a modexpo_crt request.
* @zdev: pointer to zcrypt_device structure that identifies the
* CEX2A device to the request distributor
* @crt: pointer to the modexpoc_crt request buffer
*/
static long zcrypt_cex2a_modexpo_crt(struct zcrypt_device *zdev,
struct ica_rsa_modexpo_crt *crt)
{
struct ap_message ap_msg;
struct completion work;
int rc;
ap_msg.message = kmalloc(CEX2A_MAX_MESSAGE_SIZE, GFP_KERNEL);
if (!ap_msg.message)
return -ENOMEM;
ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
atomic_inc_return(&zcrypt_step);
ap_msg.private = &work;
rc = ICACRT_msg_to_type50CRT_msg(zdev, &ap_msg, crt);
if (rc)
goto out_free;
init_completion(&work);
ap_queue_message(zdev->ap_dev, &ap_msg);
rc = wait_for_completion_interruptible_timeout(
&work, CEX2A_CLEANUP_TIME);
if (rc > 0)
rc = convert_response(zdev, &ap_msg, crt->outputdata,
crt->outputdatalength);
else {
/* Signal pending or message timed out. */
ap_cancel_message(zdev->ap_dev, &ap_msg);
if (rc == 0)
/* Message timed out. */
rc = -ETIME;
}
out_free:
kfree(ap_msg.message);
return rc;
}
/**
* The crypto operations for a CEX2A card.
*/
static struct zcrypt_ops zcrypt_cex2a_ops = {
.rsa_modexpo = zcrypt_cex2a_modexpo,
.rsa_modexpo_crt = zcrypt_cex2a_modexpo_crt,
};
/**
* Probe function for CEX2A cards. It always accepts the AP device
* since the bus_match already checked the hardware type.
* @ap_dev: pointer to the AP device.
*/
static int zcrypt_cex2a_probe(struct ap_device *ap_dev)
{
struct zcrypt_device *zdev;
int rc;
zdev = zcrypt_device_alloc(CEX2A_MAX_RESPONSE_SIZE);
if (!zdev)
return -ENOMEM;
zdev->ap_dev = ap_dev;
zdev->ops = &zcrypt_cex2a_ops;
zdev->online = 1;
zdev->user_space_type = ZCRYPT_CEX2A;
zdev->type_string = "CEX2A";
zdev->min_mod_size = CEX2A_MIN_MOD_SIZE;
zdev->max_mod_size = CEX2A_MAX_MOD_SIZE;
zdev->short_crt = 1;
zdev->speed_rating = CEX2A_SPEED_RATING;
ap_dev->reply = &zdev->reply;
ap_dev->private = zdev;
rc = zcrypt_device_register(zdev);
if (rc)
goto out_free;
return 0;
out_free:
ap_dev->private = NULL;
zcrypt_device_free(zdev);
return rc;
}
/**
* This is called to remove the extended CEX2A driver information
* if an AP device is removed.
*/
static void zcrypt_cex2a_remove(struct ap_device *ap_dev)
{
struct zcrypt_device *zdev = ap_dev->private;
zcrypt_device_unregister(zdev);
}
int __init zcrypt_cex2a_init(void)
{
return ap_driver_register(&zcrypt_cex2a_driver, THIS_MODULE, "cex2a");
}
void __exit zcrypt_cex2a_exit(void)
{
ap_driver_unregister(&zcrypt_cex2a_driver);
}
#ifndef CONFIG_ZCRYPT_MONOLITHIC
module_init(zcrypt_cex2a_init);
module_exit(zcrypt_cex2a_exit);
#endif
