1/*
2 *  zcrypt 2.1.0
3 *
4 *  Copyright IBM Corp. 2001, 2006
5 *  Author(s): Robert Burroughs
6 *	       Eric Rossman (edrossma@us.ibm.com)
7 *
8 *  Hotplug & misc device support: Jochen Roehrig (roehrig@de.ibm.com)
9 *  Major cleanup & driver split: Martin Schwidefsky <schwidefsky@de.ibm.com>
10 *				  Ralph Wuerthner <rwuerthn@de.ibm.com>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2, or (at your option)
15 * any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 */
26
27#define KMSG_COMPONENT "zcrypt"
28#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
29
30#include <linux/module.h>
31#include <linux/slab.h>
32#include <linux/init.h>
33#include <linux/err.h>
34#include <linux/atomic.h>
35#include <asm/uaccess.h>
36
37#include "ap_bus.h"
38#include "zcrypt_api.h"
39#include "zcrypt_error.h"
40#include "zcrypt_pcica.h"
41
42#define PCICA_MIN_MOD_SIZE	  1	/*    8 bits	*/
43#define PCICA_MAX_MOD_SIZE	256	/* 2048 bits	*/
44
45#define PCICA_SPEED_RATING	2800
46
47#define PCICA_MAX_MESSAGE_SIZE	0x3a0	/* sizeof(struct type4_lcr)	     */
48#define PCICA_MAX_RESPONSE_SIZE 0x110	/* max outputdatalength + type80_hdr */
49
50#define PCICA_CLEANUP_TIME	(15*HZ)
51
52static struct ap_device_id zcrypt_pcica_ids[] = {
53	{ AP_DEVICE(AP_DEVICE_TYPE_PCICA) },
54	{ /* end of list */ },
55};
56
57MODULE_DEVICE_TABLE(ap, zcrypt_pcica_ids);
58MODULE_AUTHOR("IBM Corporation");
59MODULE_DESCRIPTION("PCICA Cryptographic Coprocessor device driver, "
60		   "Copyright IBM Corp. 2001, 2006");
61MODULE_LICENSE("GPL");
62
63static int zcrypt_pcica_probe(struct ap_device *ap_dev);
64static void zcrypt_pcica_remove(struct ap_device *ap_dev);
65static void zcrypt_pcica_receive(struct ap_device *, struct ap_message *,
66				 struct ap_message *);
67
68static struct ap_driver zcrypt_pcica_driver = {
69	.probe = zcrypt_pcica_probe,
70	.remove = zcrypt_pcica_remove,
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		pr_err("Cryptographic device %x failed and was set offline\n",
206		       zdev->ap_dev->qid);
207		ZCRYPT_DBF_DEV(DBF_ERR, zdev, "dev%04xo%drc%d",
208			       zdev->ap_dev->qid, zdev->online, t84h->code);
209		return -EAGAIN;	/* repeat the request on a different device. */
210	}
211	BUG_ON(t84h->len > PCICA_MAX_RESPONSE_SIZE);
212	data = reply->message + t84h->len - outputdatalength;
213	if (copy_to_user(outputdata, data, outputdatalength))
214		return -EFAULT;
215	return 0;
216}
217
218static int convert_response(struct zcrypt_device *zdev,
219			    struct ap_message *reply,
220			    char __user *outputdata,
221			    unsigned int outputdatalength)
222{
223	/* Response type byte is the second byte in the response. */
224	switch (((unsigned char *) reply->message)[1]) {
225	case TYPE82_RSP_CODE:
226	case TYPE88_RSP_CODE:
227		return convert_error(zdev, reply);
228	case TYPE84_RSP_CODE:
229		return convert_type84(zdev, reply,
230				      outputdata, outputdatalength);
231	default: /* Unknown response type, this should NEVER EVER happen */
232		zdev->online = 0;
233		pr_err("Cryptographic device %x failed and was set offline\n",
234		       zdev->ap_dev->qid);
235		ZCRYPT_DBF_DEV(DBF_ERR, zdev, "dev%04xo%dfail",
236			       zdev->ap_dev->qid, zdev->online);
237		return -EAGAIN;	/* repeat the request on a different device. */
238	}
239}
240
241/**
242 * This function is called from the AP bus code after a crypto request
243 * "msg" has finished with the reply message "reply".
244 * It is called from tasklet context.
245 * @ap_dev: pointer to the AP device
246 * @msg: pointer to the AP message
247 * @reply: pointer to the AP reply message
248 */
249static void zcrypt_pcica_receive(struct ap_device *ap_dev,
250				 struct ap_message *msg,
251				 struct ap_message *reply)
252{
253	static struct error_hdr error_reply = {
254		.type = TYPE82_RSP_CODE,
255		.reply_code = REP82_ERROR_MACHINE_FAILURE,
256	};
257	struct type84_hdr *t84h;
258	int length;
259
260	/* Copy the reply message to the request message buffer. */
261	if (IS_ERR(reply)) {
262		memcpy(msg->message, &error_reply, sizeof(error_reply));
263		goto out;
264	}
265	t84h = reply->message;
266	if (t84h->code == TYPE84_RSP_CODE) {
267		length = min(PCICA_MAX_RESPONSE_SIZE, (int) t84h->len);
268		memcpy(msg->message, reply->message, length);
269	} else
270		memcpy(msg->message, reply->message, sizeof error_reply);
271out:
272	complete((struct completion *) msg->private);
273}
274
275static atomic_t zcrypt_step = ATOMIC_INIT(0);
276
277/**
278 * The request distributor calls this function if it picked the PCICA
279 * device to handle a modexpo request.
280 * @zdev: pointer to zcrypt_device structure that identifies the
281 *	  PCICA device to the request distributor
282 * @mex: pointer to the modexpo request buffer
283 */
284static long zcrypt_pcica_modexpo(struct zcrypt_device *zdev,
285				 struct ica_rsa_modexpo *mex)
286{
287	struct ap_message ap_msg;
288	struct completion work;
289	int rc;
290
291	ap_init_message(&ap_msg);
292	ap_msg.message = kmalloc(PCICA_MAX_MESSAGE_SIZE, GFP_KERNEL);
293	if (!ap_msg.message)
294		return -ENOMEM;
295	ap_msg.receive = zcrypt_pcica_receive;
296	ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
297				atomic_inc_return(&zcrypt_step);
298	ap_msg.private = &work;
299	rc = ICAMEX_msg_to_type4MEX_msg(zdev, &ap_msg, mex);
300	if (rc)
301		goto out_free;
302	init_completion(&work);
303	ap_queue_message(zdev->ap_dev, &ap_msg);
304	rc = wait_for_completion_interruptible(&work);
305	if (rc == 0)
306		rc = convert_response(zdev, &ap_msg, mex->outputdata,
307				      mex->outputdatalength);
308	else
309		/* Signal pending. */
310		ap_cancel_message(zdev->ap_dev, &ap_msg);
311out_free:
312	kfree(ap_msg.message);
313	return rc;
314}
315
316/**
317 * The request distributor calls this function if it picked the PCICA
318 * device to handle a modexpo_crt request.
319 * @zdev: pointer to zcrypt_device structure that identifies the
320 *	  PCICA device to the request distributor
321 * @crt: pointer to the modexpoc_crt request buffer
322 */
323static long zcrypt_pcica_modexpo_crt(struct zcrypt_device *zdev,
324				     struct ica_rsa_modexpo_crt *crt)
325{
326	struct ap_message ap_msg;
327	struct completion work;
328	int rc;
329
330	ap_init_message(&ap_msg);
331	ap_msg.message = kmalloc(PCICA_MAX_MESSAGE_SIZE, GFP_KERNEL);
332	if (!ap_msg.message)
333		return -ENOMEM;
334	ap_msg.receive = zcrypt_pcica_receive;
335	ap_msg.psmid = (((unsigned long long) current->pid) << 32) +
336				atomic_inc_return(&zcrypt_step);
337	ap_msg.private = &work;
338	rc = ICACRT_msg_to_type4CRT_msg(zdev, &ap_msg, crt);
339	if (rc)
340		goto out_free;
341	init_completion(&work);
342	ap_queue_message(zdev->ap_dev, &ap_msg);
343	rc = wait_for_completion_interruptible(&work);
344	if (rc == 0)
345		rc = convert_response(zdev, &ap_msg, crt->outputdata,
346				      crt->outputdatalength);
347	else
348		/* Signal pending. */
349		ap_cancel_message(zdev->ap_dev, &ap_msg);
350out_free:
351	kfree(ap_msg.message);
352	return rc;
353}
354
355/**
356 * The crypto operations for a PCICA card.
357 */
358static struct zcrypt_ops zcrypt_pcica_ops = {
359	.rsa_modexpo = zcrypt_pcica_modexpo,
360	.rsa_modexpo_crt = zcrypt_pcica_modexpo_crt,
361};
362
363/**
364 * Probe function for PCICA cards. It always accepts the AP device
365 * since the bus_match already checked the hardware type.
366 * @ap_dev: pointer to the AP device.
367 */
368static int zcrypt_pcica_probe(struct ap_device *ap_dev)
369{
370	struct zcrypt_device *zdev;
371	int rc;
372
373	zdev = zcrypt_device_alloc(PCICA_MAX_RESPONSE_SIZE);
374	if (!zdev)
375		return -ENOMEM;
376	zdev->ap_dev = ap_dev;
377	zdev->ops = &zcrypt_pcica_ops;
378	zdev->online = 1;
379	zdev->user_space_type = ZCRYPT_PCICA;
380	zdev->type_string = "PCICA";
381	zdev->min_mod_size = PCICA_MIN_MOD_SIZE;
382	zdev->max_mod_size = PCICA_MAX_MOD_SIZE;
383	zdev->speed_rating = PCICA_SPEED_RATING;
384	zdev->max_exp_bit_length = PCICA_MAX_MOD_SIZE;
385	ap_dev->reply = &zdev->reply;
386	ap_dev->private = zdev;
387	rc = zcrypt_device_register(zdev);
388	if (rc)
389		goto out_free;
390	return 0;
391
392out_free:
393	ap_dev->private = NULL;
394	zcrypt_device_free(zdev);
395	return rc;
396}
397
398/**
399 * This is called to remove the extended PCICA driver information
400 * if an AP device is removed.
401 */
402static void zcrypt_pcica_remove(struct ap_device *ap_dev)
403{
404	struct zcrypt_device *zdev = ap_dev->private;
405
406	zcrypt_device_unregister(zdev);
407}
408
409int __init zcrypt_pcica_init(void)
410{
411	return ap_driver_register(&zcrypt_pcica_driver, THIS_MODULE, "pcica");
412}
413
414void zcrypt_pcica_exit(void)
415{
416	ap_driver_unregister(&zcrypt_pcica_driver);
417}
418
419module_init(zcrypt_pcica_init);
420module_exit(zcrypt_pcica_exit);
421