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
51static struct ap_device_id zcrypt_pcica_ids[] = {
52	{ AP_DEVICE(AP_DEVICE_TYPE_PCICA) },
53	{ /* end of list */ },
54};
55
56MODULE_DEVICE_TABLE(ap, zcrypt_pcica_ids);
57MODULE_AUTHOR("IBM Corporation");
58MODULE_DESCRIPTION("PCICA Cryptographic Coprocessor device driver, "
59		   "Copyright 2001, 2006 IBM Corporation");
60MODULE_LICENSE("GPL");
61
62static int zcrypt_pcica_probe(struct ap_device *ap_dev);
63static void zcrypt_pcica_remove(struct ap_device *ap_dev);
64static void zcrypt_pcica_receive(struct ap_device *, struct ap_message *,
65				 struct ap_message *);
66
67static struct ap_driver zcrypt_pcica_driver = {
68	.probe = zcrypt_pcica_probe,
69	.remove = zcrypt_pcica_remove,
70	.receive = zcrypt_pcica_receive,
71	.ids = zcrypt_pcica_ids,
72	.request_timeout = PCICA_CLEANUP_TIME,
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 */
84static 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 */
133static 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 */
194static 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
214static 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		zdev->online = 0;
229		return -EAGAIN;	/* repeat the request on a different device. */
230	}
231}
232
233/**
234 * This function is called from the AP bus code after a crypto request
235 * "msg" has finished with the reply message "reply".
236 * It is called from tasklet context.
237 * @ap_dev: pointer to the AP device
238 * @msg: pointer to the AP message
239 * @reply: pointer to the AP reply message
240 */
241static void zcrypt_pcica_receive(struct ap_device *ap_dev,
242				 struct ap_message *msg,
243				 struct ap_message *reply)
244{
245	static struct error_hdr error_reply = {
246		.type = TYPE82_RSP_CODE,
247		.reply_code = REP82_ERROR_MACHINE_FAILURE,
248	};
249	struct type84_hdr *t84h;
250	int length;
251
252	/* Copy the reply message to the request message buffer. */
253	if (IS_ERR(reply)) {
254		memcpy(msg->message, &error_reply, sizeof(error_reply));
255		goto out;
256	}
257	t84h = reply->message;
258	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);
263out:
264	complete((struct completion *) msg->private);
265}
266
267static atomic_t zcrypt_step = ATOMIC_INIT(0);
268
269/**
270 * The request distributor calls this function if it picked the PCICA
271 * device to handle a modexpo request.
272 * @zdev: pointer to zcrypt_device structure that identifies the
273 *	  PCICA device to the request distributor
274 * @mex: pointer to the modexpo request buffer
275 */
276static long zcrypt_pcica_modexpo(struct zcrypt_device *zdev,
277				 struct ica_rsa_modexpo *mex)
278{
279	struct ap_message ap_msg;
280	struct completion work;
281	int rc;
282
283	ap_init_message(&ap_msg);
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);
302out_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 */
314static 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_init_message(&ap_msg);
322	ap_msg.message = kmalloc(PCICA_MAX_MESSAGE_SIZE, GFP_KERNEL);
323	if (!ap_msg.message)
324		return -ENOMEM;
325	ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
326				atomic_inc_return(&zcrypt_step);
327	ap_msg.private = &work;
328	rc = ICACRT_msg_to_type4CRT_msg(zdev, &ap_msg, crt);
329	if (rc)
330		goto out_free;
331	init_completion(&work);
332	ap_queue_message(zdev->ap_dev, &ap_msg);
333	rc = wait_for_completion_interruptible(&work);
334	if (rc == 0)
335		rc = convert_response(zdev, &ap_msg, crt->outputdata,
336				      crt->outputdatalength);
337	else
338		/* Signal pending. */
339		ap_cancel_message(zdev->ap_dev, &ap_msg);
340out_free:
341	kfree(ap_msg.message);
342	return rc;
343}
344
345/**
346 * The crypto operations for a PCICA card.
347 */
348static struct zcrypt_ops zcrypt_pcica_ops = {
349	.rsa_modexpo = zcrypt_pcica_modexpo,
350	.rsa_modexpo_crt = zcrypt_pcica_modexpo_crt,
351};
352
353/**
354 * Probe function for PCICA cards. It always accepts the AP device
355 * since the bus_match already checked the hardware type.
356 * @ap_dev: pointer to the AP device.
357 */
358static int zcrypt_pcica_probe(struct ap_device *ap_dev)
359{
360	struct zcrypt_device *zdev;
361	int rc;
362
363	zdev = zcrypt_device_alloc(PCICA_MAX_RESPONSE_SIZE);
364	if (!zdev)
365		return -ENOMEM;
366	zdev->ap_dev = ap_dev;
367	zdev->ops = &zcrypt_pcica_ops;
368	zdev->online = 1;
369	zdev->user_space_type = ZCRYPT_PCICA;
370	zdev->type_string = "PCICA";
371	zdev->min_mod_size = PCICA_MIN_MOD_SIZE;
372	zdev->max_mod_size = PCICA_MAX_MOD_SIZE;
373	zdev->speed_rating = PCICA_SPEED_RATING;
374	zdev->max_exp_bit_length = PCICA_MAX_MOD_SIZE;
375	ap_dev->reply = &zdev->reply;
376	ap_dev->private = zdev;
377	rc = zcrypt_device_register(zdev);
378	if (rc)
379		goto out_free;
380	return 0;
381
382out_free:
383	ap_dev->private = NULL;
384	zcrypt_device_free(zdev);
385	return rc;
386}
387
388/**
389 * This is called to remove the extended PCICA driver information
390 * if an AP device is removed.
391 */
392static void zcrypt_pcica_remove(struct ap_device *ap_dev)
393{
394	struct zcrypt_device *zdev = ap_dev->private;
395
396	zcrypt_device_unregister(zdev);
397}
398
399int __init zcrypt_pcica_init(void)
400{
401	return ap_driver_register(&zcrypt_pcica_driver, THIS_MODULE, "pcica");
402}
403
404void zcrypt_pcica_exit(void)
405{
406	ap_driver_unregister(&zcrypt_pcica_driver);
407}
408
409module_init(zcrypt_pcica_init);
410module_exit(zcrypt_pcica_exit);
411