summaryrefslogtreecommitdiff
path: root/target/linux/generic-2.6/files/crypto/ocf/c7108/aes-7108.c
blob: a5ac0549572c0c4781b9eb013d1e001c1019e478 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
/*
 * Copyright (C) 2006 Micronas USA
 *
 * 1. Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Effort sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F30602-01-2-0537.
 *
 */

//#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/crypto.h>
#include <linux/mm.h>
#include <linux/skbuff.h>
#include <linux/random.h>
#include <asm/io.h>
#include <asm/delay.h>
//#include <asm/scatterlist.h>
#include <linux/scatterlist.h>
#include <linux/dma-mapping.h>
#include <linux/highmem.h>
#include <cryptodev.h>
#include <uio.h>
#include <aes-7108.h>

/* Runtime mode */
static int c7108_crypto_mode = C7108_AES_CTRL_MODE_CTR;
//static int c7108_crypto_mode = C7108_AES_CTRL_MODE_CBC;

static int32_t c7108_id = -1;
static struct cipher_7108 **c7108_sessions = NULL;
static u_int32_t c7108_sesnum = 0;
static unsigned long iobar;

/* Crypto entry points */
static	int c7108_process(void *, struct cryptop *, int);
static	int c7108_newsession(void *, u_int32_t *, struct cryptoini *);
static	int c7108_freesession(void *, u_int64_t);

/* Globals */
static int debug = 0;
static spinlock_t csr_mutex;

/* Generic controller-based lock */
#define AES_LOCK()\
          spin_lock(&csr_mutex)
#define AES_UNLOCK()\
          spin_unlock(&csr_mutex)

/* 7108 AES register access */
#define c7108_reg_wr8(a,d)   iowrite8(d, (void*)(iobar+(a)))
#define c7108_reg_wr16(a,d)  iowrite16(d, (void*)(iobar+(a)))
#define c7108_reg_wr32(a,d)  iowrite32(d, (void*)(iobar+(a)))
#define c7108_reg_rd8(a)     ioread8((void*)(iobar+(a)))
#define c7108_reg_rd16(a)    ioread16((void*)(iobar+(a)))
#define c7108_reg_rd32(a)    ioread32((void*)(iobar+(a)))

static int 
c7108_xlate_key(int klen, u8* k8ptr, u32* k32ptr)
{
        int i, nw=0;
	nw = ((klen >= 256) ? 8 : (klen >= 192) ? 6 : 4);
	for ( i = 0; i < nw; i++) { 
	    k32ptr[i] =    (k8ptr[i+3] << 24) | (k8ptr[i+2] << 16) | 
		           (k8ptr[i+1] << 8)  | k8ptr[i];
	    
	}
	return 0;
}

static int 
c7108_cache_key(int klen, u32* k32ptr, u8* k8ptr)
{
        int i, nb=0;
	u8* ptr = (u8*)k32ptr;
	nb = ((klen >= 256) ? 32 : (klen >= 192) ? 24 : 16);
	for ( i = 0; i < nb; i++)
	    k8ptr[i] = ptr[i];
	return 0;
}

static int
c7108_aes_setup_dma(u32 src, u32 dst, u32 len)
{
        if (len < 16) {
	    printk("len < 16\n");
	    return -10;
	}
	if (len % 16) {
	    printk("len not multiple of 16\n");
	    return -11;
	}	
	c7108_reg_wr16(C7108_AES_DMA_SRC0_LO, (u16) src);
	c7108_reg_wr16(C7108_AES_DMA_SRC0_HI, (u16)((src & 0xffff0000) >> 16));
	c7108_reg_wr16(C7108_AES_DMA_DST0_LO, (u16) dst);
	c7108_reg_wr16(C7108_AES_DMA_DST0_HI, (u16)((dst & 0xffff0000) >> 16));
	c7108_reg_wr16(C7108_AES_DMA_LEN, (u16) ((len / 16) - 1));

	return 0;
}

static int
c7108_aes_set_hw_iv(u8 iv[16])
{
        c7108_reg_wr16(C7108_AES_IV0_LO, (u16) ((iv[1] << 8) | iv[0]));
	c7108_reg_wr16(C7108_AES_IV0_HI, (u16) ((iv[3] << 8) | iv[2]));
	c7108_reg_wr16(C7108_AES_IV1_LO, (u16) ((iv[5] << 8) | iv[4]));
	c7108_reg_wr16(C7108_AES_IV1_HI, (u16) ((iv[7] << 8) | iv[6]));
	c7108_reg_wr16(C7108_AES_IV2_LO, (u16) ((iv[9] << 8) | iv[8]));
	c7108_reg_wr16(C7108_AES_IV2_HI, (u16) ((iv[11] << 8) | iv[10]));
	c7108_reg_wr16(C7108_AES_IV3_LO, (u16) ((iv[13] << 8) | iv[12]));
	c7108_reg_wr16(C7108_AES_IV3_HI, (u16) ((iv[15] << 8) | iv[14]));

    return 0;
}

static void
c7108_aes_read_dkey(u32 * dkey)
{
        dkey[0] = (c7108_reg_rd16(C7108_AES_EKEY0_HI) << 16) | 
	           c7108_reg_rd16(C7108_AES_EKEY0_LO);
	dkey[1] = (c7108_reg_rd16(C7108_AES_EKEY1_HI) << 16) | 
	           c7108_reg_rd16(C7108_AES_EKEY1_LO);
	dkey[2] = (c7108_reg_rd16(C7108_AES_EKEY2_HI) << 16) | 
	           c7108_reg_rd16(C7108_AES_EKEY2_LO);
	dkey[3] = (c7108_reg_rd16(C7108_AES_EKEY3_HI) << 16) | 
	           c7108_reg_rd16(C7108_AES_EKEY3_LO);
	dkey[4] = (c7108_reg_rd16(C7108_AES_EKEY4_HI) << 16) | 
                   c7108_reg_rd16(C7108_AES_EKEY4_LO);
	dkey[5] = (c7108_reg_rd16(C7108_AES_EKEY5_HI) << 16) | 
                   c7108_reg_rd16(C7108_AES_EKEY5_LO);
	dkey[6] = (c7108_reg_rd16(C7108_AES_EKEY6_HI) << 16) | 
                   c7108_reg_rd16(C7108_AES_EKEY6_LO);
	dkey[7] = (c7108_reg_rd16(C7108_AES_EKEY7_HI) << 16) | 
                   c7108_reg_rd16(C7108_AES_EKEY7_LO);
}

static int
c7108_aes_cipher(int op,
		 u32 dst,
		 u32 src,
		 u32 len,
		 int klen,
		 u16 mode,
		 u32 key[8],
		 u8 iv[16])
{
        int rv = 0, cnt=0;
	u16 ctrl = 0, stat = 0;

	AES_LOCK();

	/* Setup key length */
	if (klen == 128) {
	    ctrl |= C7108_AES_KEY_LEN_128;
	} else if (klen == 192) {
	    ctrl |= C7108_AES_KEY_LEN_192;
	} else if (klen == 256) {
	    ctrl |= C7108_AES_KEY_LEN_256;
	} else {
	    AES_UNLOCK();
	    return -3;
	}
	
	/* Check opcode */
	if (C7108_AES_ENCRYPT == op) {
	    ctrl |= C7108_AES_ENCRYPT;
	} else if (C7108_AES_DECRYPT == op) {
	    ctrl |= C7108_AES_DECRYPT;
	} else {
	    AES_UNLOCK();
	    return -4;
	}
	
	/* check mode */
	if ( (mode != C7108_AES_CTRL_MODE_CBC) &&
	     (mode != C7108_AES_CTRL_MODE_CFB) &&
	     (mode != C7108_AES_CTRL_MODE_OFB) &&
	     (mode != C7108_AES_CTRL_MODE_CTR) && 
	     (mode != C7108_AES_CTRL_MODE_ECB) ) { 
	    AES_UNLOCK();	    
	    return -5;
	}
	
	/* Now set mode */
	ctrl |= mode;
	
	/* For CFB, OFB, and CTR, neither backward key
	 * expansion nor key inversion is required.
	 */
	if ( (C7108_AES_DECRYPT == op) &&  
	     (C7108_AES_CTRL_MODE_CBC == mode ||
	      C7108_AES_CTRL_MODE_ECB == mode ) ){ 

	    /* Program Key */
	    c7108_reg_wr16(C7108_AES_KEY0_LO, (u16) key[4]);
	    c7108_reg_wr16(C7108_AES_KEY0_HI, (u16) (key[4] >> 16));
	    c7108_reg_wr16(C7108_AES_KEY1_LO, (u16) key[5]);
	    c7108_reg_wr16(C7108_AES_KEY1_HI, (u16) (key[5] >> 16));
	    c7108_reg_wr16(C7108_AES_KEY2_LO, (u16) key[6]);
	    c7108_reg_wr16(C7108_AES_KEY2_HI, (u16) (key[6] >> 16));
	    c7108_reg_wr16(C7108_AES_KEY3_LO, (u16) key[7]);
	    c7108_reg_wr16(C7108_AES_KEY3_HI, (u16) (key[7] >> 16));
	    c7108_reg_wr16(C7108_AES_KEY6_LO, (u16) key[2]);
	    c7108_reg_wr16(C7108_AES_KEY6_HI, (u16) (key[2] >> 16));
	    c7108_reg_wr16(C7108_AES_KEY7_LO, (u16) key[3]);
	    c7108_reg_wr16(C7108_AES_KEY7_HI, (u16) (key[3] >> 16));
	    
	    
	    if (192 == klen) { 
		c7108_reg_wr16(C7108_AES_KEY4_LO, (u16) key[7]);
		c7108_reg_wr16(C7108_AES_KEY4_HI, (u16) (key[7] >> 16));
		c7108_reg_wr16(C7108_AES_KEY5_LO, (u16) key[7]);
		c7108_reg_wr16(C7108_AES_KEY5_HI, (u16) (key[7] >> 16));
		
	    } else if (256 == klen) {
		/* 256 */
		c7108_reg_wr16(C7108_AES_KEY4_LO, (u16) key[0]);
		c7108_reg_wr16(C7108_AES_KEY4_HI, (u16) (key[0] >> 16));
		c7108_reg_wr16(C7108_AES_KEY5_LO, (u16) key[1]);
		c7108_reg_wr16(C7108_AES_KEY5_HI, (u16) (key[1] >> 16));
		
	    }
	    
	} else { 
	    /* Program Key */
	    c7108_reg_wr16(C7108_AES_KEY0_LO, (u16) key[0]);
	    c7108_reg_wr16(C7108_AES_KEY0_HI, (u16) (key[0] >> 16));
	    c7108_reg_wr16(C7108_AES_KEY1_LO, (u16) key[1]);
	    c7108_reg_wr16(C7108_AES_KEY1_HI, (u16) (key[1] >> 16));
	    c7108_reg_wr16(C7108_AES_KEY2_LO, (u16) key[2]);
	    c7108_reg_wr16(C7108_AES_KEY2_HI, (u16) (key[2] >> 16));
	    c7108_reg_wr16(C7108_AES_KEY3_LO, (u16) key[3]);
	    c7108_reg_wr16(C7108_AES_KEY3_HI, (u16) (key[3] >> 16));
	    c7108_reg_wr16(C7108_AES_KEY4_LO, (u16) key[4]);
	    c7108_reg_wr16(C7108_AES_KEY4_HI, (u16) (key[4] >> 16));
	    c7108_reg_wr16(C7108_AES_KEY5_LO, (u16) key[5]);
	    c7108_reg_wr16(C7108_AES_KEY5_HI, (u16) (key[5] >> 16));
	    c7108_reg_wr16(C7108_AES_KEY6_LO, (u16) key[6]);
	    c7108_reg_wr16(C7108_AES_KEY6_HI, (u16) (key[6] >> 16));
	    c7108_reg_wr16(C7108_AES_KEY7_LO, (u16) key[7]);
	    c7108_reg_wr16(C7108_AES_KEY7_HI, (u16) (key[7] >> 16));
	    
	}
	
	/* Set IV always */
	c7108_aes_set_hw_iv(iv);
	
	/* Program DMA addresses */
	if ((rv = c7108_aes_setup_dma(src, dst, len)) < 0) { 
	    AES_UNLOCK();
	    return rv;
	}

	
	/* Start AES cipher */
	c7108_reg_wr16(C7108_AES_CTRL, ctrl | C7108_AES_GO);
	
	//printk("Ctrl: 0x%x\n", ctrl | C7108_AES_GO);
	do {
	    /* TODO: interrupt mode */
	    //        printk("aes_stat=0x%x\n", stat);
	    //udelay(100);
	} while ((cnt++ < 1000000) && 
		 !((stat=c7108_reg_rd16(C7108_AES_CTRL))&C7108_AES_OP_DONE));


	if ((mode == C7108_AES_CTRL_MODE_ECB)||
	    (mode == C7108_AES_CTRL_MODE_CBC)) { 
	    /* Save out key when the lock is held ... */
	    c7108_aes_read_dkey(key);
	}
	
	AES_UNLOCK();
	return 0;
	
}

/*
 * Generate a new crypto device session.
 */
static int
c7108_newsession(void *arg, u_int32_t *sid, struct cryptoini *cri)
{
	struct cipher_7108 **swd;
	u_int32_t i;
	char *algo;
	int mode, xfm_type;

	dprintk("%s()\n", __FUNCTION__);
	if (sid == NULL || cri == NULL) {
		dprintk("%s,%d - EINVAL\n", __FILE__, __LINE__);
		return EINVAL;
	}

	if (c7108_sessions) {
		for (i = 1; i < c7108_sesnum; i++)
			if (c7108_sessions[i] == NULL)
				break;
	} else
		i = 1;		/* NB: to silence compiler warning */

	if (c7108_sessions == NULL || i == c7108_sesnum) {
	    if (c7108_sessions == NULL) {
		i = 1; /* We leave c7108_sessions[0] empty */
		c7108_sesnum = CRYPTO_SW_SESSIONS;
	    } else
		c7108_sesnum *= 2;
	    
	    swd = kmalloc(c7108_sesnum * sizeof(struct cipher_7108 *), 
			  GFP_ATOMIC);
	    if (swd == NULL) {
		/* Reset session number */
		if (c7108_sesnum == CRYPTO_SW_SESSIONS)
		    c7108_sesnum = 0;
		else
		    c7108_sesnum /= 2;
		dprintk("%s,%d: ENOBUFS\n", __FILE__, __LINE__);
		return ENOBUFS;
	    }
	    memset(swd, 0, c7108_sesnum * sizeof(struct cipher_7108 *));
	    
	    /* Copy existing sessions */
	    if (c7108_sessions) {
		memcpy(swd, c7108_sessions,
		       (c7108_sesnum / 2) * sizeof(struct cipher_7108 *));
		kfree(c7108_sessions);
	    }
	    
	    c7108_sessions = swd;

	}
	
	swd = &c7108_sessions[i];
	*sid = i;

	while (cri) {
		*swd = (struct cipher_7108 *) 
		    kmalloc(sizeof(struct cipher_7108), GFP_ATOMIC);
		if (*swd == NULL) {
		    c7108_freesession(NULL, i);
		    dprintk("%s,%d: EINVAL\n", __FILE__, __LINE__);
		    return ENOBUFS;
		}
		memset(*swd, 0, sizeof(struct cipher_7108));

		algo = NULL;
		mode = 0;
		xfm_type = HW_TYPE_CIPHER;

		switch (cri->cri_alg) {

		case CRYPTO_AES_CBC:
			algo = "aes";
			mode = CRYPTO_TFM_MODE_CBC;
			c7108_crypto_mode = C7108_AES_CTRL_MODE_CBC;
			break;
#if 0
		case CRYPTO_AES_CTR:
			algo = "aes_ctr";
			mode = CRYPTO_TFM_MODE_CBC;
			c7108_crypto_mode = C7108_AES_CTRL_MODE_CTR;
			break;
		case CRYPTO_AES_ECB:
			algo = "aes_ecb";
			mode = CRYPTO_TFM_MODE_CBC;
			c7108_crypto_mode = C7108_AES_CTRL_MODE_ECB;
			break;
		case CRYPTO_AES_OFB:
			algo = "aes_ofb";
			mode = CRYPTO_TFM_MODE_CBC;
			c7108_crypto_mode = C7108_AES_CTRL_MODE_OFB;
			break;
		case CRYPTO_AES_CFB:
			algo = "aes_cfb";
			mode = CRYPTO_TFM_MODE_CBC;
			c7108_crypto_mode = C7108_AES_CTRL_MODE_CFB;
			break;
#endif
		default:
		        printk("unsupported crypto algorithm: %d\n", 
			       cri->cri_alg);
			return -EINVAL;
			break;
		}


		if (!algo || !*algo) {
		    printk("cypher_7108_crypto: Unknown algo 0x%x\n", 
			   cri->cri_alg);
		    c7108_freesession(NULL, i);
		    return EINVAL;
		}
		
		if (xfm_type == HW_TYPE_CIPHER) {
		    if (debug) {
			dprintk("%s key:", __FUNCTION__);
			for (i = 0; i < (cri->cri_klen + 7) / 8; i++)
			    dprintk("%s0x%02x", (i % 8) ? " " : "\n    ",
				    cri->cri_key[i]);
			dprintk("\n");
		    }

		} else if (xfm_type == SW_TYPE_HMAC || 
			   xfm_type == SW_TYPE_HASH) {
		    printk("cypher_7108_crypto: HMAC unsupported!\n");
		    return -EINVAL;
		    c7108_freesession(NULL, i);
		} else {
		    printk("cypher_7108_crypto: "
			   "Unhandled xfm_type %d\n", xfm_type);
		    c7108_freesession(NULL, i);
		    return EINVAL;
		}
		
		(*swd)->cri_alg = cri->cri_alg;
		(*swd)->xfm_type = xfm_type;
		
		cri = cri->cri_next;
		swd = &((*swd)->next);
	}
	return 0;
}

/*
 * Free a session.
 */
static int
c7108_freesession(void *arg, u_int64_t tid)
{
	struct cipher_7108 *swd;
	u_int32_t sid = CRYPTO_SESID2LID(tid);

	dprintk("%s()\n", __FUNCTION__);
	if (sid > c7108_sesnum || c7108_sessions == NULL ||
			c7108_sessions[sid] == NULL) {
		dprintk("%s,%d: EINVAL\n", __FILE__, __LINE__);
		return(EINVAL);
	}

	/* Silently accept and return */
	if (sid == 0)
		return(0);

	while ((swd = c7108_sessions[sid]) != NULL) {
		c7108_sessions[sid] = swd->next;
		kfree(swd);
	}
	return 0;
}

/*
 * Process a hardware request.
 */
static int
c7108_process(void *arg, struct cryptop *crp, int hint)
{
	struct cryptodesc *crd;
	struct cipher_7108 *sw;
	u_int32_t lid;
	int type;
	u32 hwkey[8];

#define SCATTERLIST_MAX 16
	struct scatterlist sg[SCATTERLIST_MAX];
	int sg_num, sg_len, skip;
	struct sk_buff *skb = NULL;
	struct uio *uiop = NULL;

	dprintk("%s()\n", __FUNCTION__);
	/* Sanity check */
	if (crp == NULL) {
		dprintk("%s,%d: EINVAL\n", __FILE__, __LINE__);
		return EINVAL;
	}

	crp->crp_etype = 0;

	if (crp->crp_desc == NULL || crp->crp_buf == NULL) {
		dprintk("%s,%d: EINVAL\n", __FILE__, __LINE__);
		crp->crp_etype = EINVAL;
		goto done;
	}

	lid = crp->crp_sid & 0xffffffff;
	if (lid >= c7108_sesnum || lid == 0 || c7108_sessions == NULL ||
			c7108_sessions[lid] == NULL) {
		crp->crp_etype = ENOENT;
		dprintk("%s,%d: ENOENT\n", __FILE__, __LINE__);
		goto done;
	}

	/*
	 * do some error checking outside of the loop for SKB and IOV
	 * processing this leaves us with valid skb or uiop pointers
	 * for later
	 */
	if (crp->crp_flags & CRYPTO_F_SKBUF) {
		skb = (struct sk_buff *) crp->crp_buf;
		if (skb_shinfo(skb)->nr_frags >= SCATTERLIST_MAX) {
			printk("%s,%d: %d nr_frags > SCATTERLIST_MAX", 
			       __FILE__, __LINE__,
			       skb_shinfo(skb)->nr_frags);
			goto done;
		}
	} else if (crp->crp_flags & CRYPTO_F_IOV) {
		uiop = (struct uio *) crp->crp_buf;
		if (uiop->uio_iovcnt > SCATTERLIST_MAX) {
			printk("%s,%d: %d uio_iovcnt > SCATTERLIST_MAX", 
			       __FILE__, __LINE__,
			       uiop->uio_iovcnt);
			goto done;
		}
	}

	/* Go through crypto descriptors, processing as we go */
	for (crd = crp->crp_desc; crd; crd = crd->crd_next) {
	    /*
	     * Find the crypto context.
	     *
	     * XXX Note that the logic here prevents us from having
	     * XXX the same algorithm multiple times in a session
	     * XXX (or rather, we can but it won't give us the right
	     * XXX results). To do that, we'd need some way of differentiating
	     * XXX between the various instances of an algorithm (so we can
	     * XXX locate the correct crypto context).
	     */
	    for (sw = c7108_sessions[lid]; 
		 sw && sw->cri_alg != crd->crd_alg;
		 sw = sw->next)
		;
	    
	    /* No such context ? */
	    if (sw == NULL) {
		crp->crp_etype = EINVAL;
		dprintk("%s,%d: EINVAL\n", __FILE__, __LINE__);
		goto done;
	    }
	    
	    skip = crd->crd_skip;
	    
	    /*
	     * setup the SG list skip from the start of the buffer
	     */
	    memset(sg, 0, sizeof(sg));
	    if (crp->crp_flags & CRYPTO_F_SKBUF) {
		int i, len;
		type = CRYPTO_BUF_SKBUF;
		
		sg_num = 0;
		sg_len = 0;

		if (skip < skb_headlen(skb)) {
		    //sg[sg_num].page   = virt_to_page(skb->data + skip);
			//sg[sg_num].offset = offset_in_page(skb->data + skip);
		    len = skb_headlen(skb) - skip;
		    if (len + sg_len > crd->crd_len)
			len = crd->crd_len - sg_len;
		    //sg[sg_num].length = len;
		    sg_set_page(&sg[sg_num], virt_to_page(skb->data + skip), len, offset_in_page(skb->data + skip));
			sg_len += sg[sg_num].length;
		    sg_num++;
		    skip = 0;
		} else
		    skip -= skb_headlen(skb);
		
		for (i = 0; sg_len < crd->crd_len &&
			 i < skb_shinfo(skb)->nr_frags &&
			 sg_num < SCATTERLIST_MAX; i++) {
		    if (skip < skb_shinfo(skb)->frags[i].size) {
			//sg[sg_num].page   = skb_shinfo(skb)->frags[i].page;
			//sg[sg_num].offset = skb_shinfo(skb)->frags[i].page_offset + skip;
			len = skb_shinfo(skb)->frags[i].size - skip;
			if (len + sg_len > crd->crd_len)
			    len = crd->crd_len - sg_len;
			//sg[sg_num].length = len;
			sg_set_page(&sg[sg_num], skb_shinfo(skb)->frags[i].page, len, skb_shinfo(skb)->frags[i].page_offset + skip);
			sg_len += sg[sg_num].length;
			sg_num++;
			skip = 0;
		    } else
			skip -= skb_shinfo(skb)->frags[i].size;
		}
	    } else if (crp->crp_flags & CRYPTO_F_IOV) {
		int len;
		type = CRYPTO_BUF_IOV;
		sg_len = 0;
		for (sg_num = 0; sg_len < crd->crd_len &&
			 sg_num < uiop->uio_iovcnt &&
			 sg_num < SCATTERLIST_MAX; sg_num++) {
		    if (skip < uiop->uio_iov[sg_num].iov_len) {
			//sg[sg_num].page   =			    virt_to_page(uiop->uio_iov[sg_num].iov_base+skip);
			//sg[sg_num].offset =			   offset_in_page(uiop->uio_iov[sg_num].iov_base+skip);
			len = uiop->uio_iov[sg_num].iov_len - skip;
			if (len + sg_len > crd->crd_len)
			    len = crd->crd_len - sg_len;
			//sg[sg_num].length = len;
			sg_set_page(&sg[sg_num], virt_to_page(uiop->uio_iov[sg_num].iov_base+skip), len, offset_in_page(uiop->uio_iov[sg_num].iov_base+skip));
			sg_len += sg[sg_num].length;
			skip = 0;
		    } else 
			skip -= uiop->uio_iov[sg_num].iov_len;
		}
	    } else {
		type = CRYPTO_BUF_CONTIG;
		//sg[0].page   = virt_to_page(crp->crp_buf + skip);
		//sg[0].offset = offset_in_page(crp->crp_buf + skip);
		sg_len = (crp->crp_ilen - skip);
		if (sg_len > crd->crd_len)
		    sg_len = crd->crd_len;
		//sg[0].length = sg_len;
		sg_set_page(&sg[0], virt_to_page(crp->crp_buf + skip), sg_len, offset_in_page(crp->crp_buf + skip));
		sg_num = 1;
	    }
	    
	    
	    switch (sw->xfm_type) {

	    case HW_TYPE_CIPHER: {

		unsigned char iv[64];
		unsigned char *ivp = iv;
		int i;
		int ivsize = 16;    /* fixed for AES */
		int blocksize = 16; /* fixed for AES */

		if (sg_len < blocksize) {
		    crp->crp_etype = EINVAL;
		    dprintk("%s,%d: EINVAL len %d < %d\n", 
			    __FILE__, __LINE__,
			    sg_len, 
			    blocksize);
		    goto done;
		}
		
		if (ivsize > sizeof(iv)) {
		    crp->crp_etype = EINVAL;
		    dprintk("%s,%d: EINVAL\n", __FILE__, __LINE__);
		    goto done;
		}
		
		if (crd->crd_flags & CRD_F_ENCRYPT) { /* encrypt */
		    
		    if (crd->crd_flags & CRD_F_IV_EXPLICIT) {
			ivp = crd->crd_iv;
		    } else {
			get_random_bytes(ivp, ivsize);
		    }
		    /*
		     * do we have to copy the IV back to the buffer ?
		     */
		    if ((crd->crd_flags & CRD_F_IV_PRESENT) == 0) {
			    crypto_copyback(crp->crp_buf,
					  crd->crd_inject,
					  ivsize,
					  (caddr_t)ivp);
		    }

		    c7108_xlate_key(crd->crd_klen,
				    (u8*)crd->crd_key, (u32*)hwkey);

		    /* Encrypt SG list */
		    for (i = 0; i < sg_num; i++) { 
			sg[i].dma_address = 
			    dma_map_single(NULL, 
					   kmap(sg_page(&sg[i])) + sg[i].offset, sg_len, DMA_BIDIRECTIONAL);
#if 0							   
			printk("sg[%d]:0x%08x, off 0x%08x "
			       "kmap 0x%08x phys 0x%08x\n", 
			       i, sg[i].page, sg[i].offset,
			       kmap(sg[i].page) + sg[i].offset,
			       sg[i].dma_address);
#endif
			c7108_aes_cipher(C7108_AES_ENCRYPT,
					 sg[i].dma_address,
					 sg[i].dma_address,
					 sg_len,
					 crd->crd_klen,
					 c7108_crypto_mode,
					 hwkey,
					 ivp);

			if ((c7108_crypto_mode == C7108_AES_CTRL_MODE_CBC)||
			    (c7108_crypto_mode == C7108_AES_CTRL_MODE_ECB)) { 
			    /* Read back expanded key and cache it in key
			     * context.
			     * NOTE: for ECB/CBC modes only (not CTR, CFB, OFB)
			     *       where you set the key once.
			     */
			    c7108_cache_key(crd->crd_klen, 
					    (u32*)hwkey, (u8*)crd->crd_key);
#if 0
			    printk("%s expanded key:", __FUNCTION__);
			    for (i = 0; i < (crd->crd_klen + 7) / 8; i++)
				printk("%s0x%02x", (i % 8) ? " " : "\n    ",
				       crd->crd_key[i]);
			    printk("\n");
#endif
			}
		    }
		}
		else { /*decrypt */

		    if (crd->crd_flags & CRD_F_IV_EXPLICIT) {
			ivp = crd->crd_iv;
		    } else {
			crypto_copydata(crp->crp_buf, crd->crd_inject,
				  ivsize, (caddr_t)ivp);
		    }

		    c7108_xlate_key(crd->crd_klen,
				    (u8*)crd->crd_key, (u32*)hwkey);

		    /* Decrypt SG list */
		    for (i = 0; i < sg_num; i++) { 
			sg[i].dma_address = 
			    dma_map_single(NULL, 
					   kmap(sg_page(&sg[i])) + sg[i].offset,
					   sg_len, DMA_BIDIRECTIONAL);

#if 0
			printk("sg[%d]:0x%08x, off 0x%08x "
			       "kmap 0x%08x phys 0x%08x\n", 
			       i, sg[i].page, sg[i].offset,
			       kmap(sg[i].page) + sg[i].offset,
			       sg[i].dma_address);
#endif
			c7108_aes_cipher(C7108_AES_DECRYPT,
					 sg[i].dma_address,
					 sg[i].dma_address,
					 sg_len,
					 crd->crd_klen,
					 c7108_crypto_mode,
					 hwkey,
					 ivp);
		    }
		}
	    } break;
	    case SW_TYPE_HMAC:
	    case SW_TYPE_HASH:
		crp->crp_etype = EINVAL;
		goto done;
		break;
		
	    case SW_TYPE_COMP:
		crp->crp_etype = EINVAL;
		goto done;
		break;
		
	    default:
		/* Unknown/unsupported algorithm */
		dprintk("%s,%d: EINVAL\n", __FILE__, __LINE__);
		crp->crp_etype = EINVAL;
		goto done;
	    }
	}
	
done:
	crypto_done(crp);
	return 0;
}

static struct {                                                                                                                 
	softc_device_decl sc_dev;                                                                                               
} a7108dev;

static device_method_t a7108_methods = {                                                                                          
/* crypto device methods */                                                                                             
	DEVMETHOD(cryptodev_newsession, c7108_newsession),                                                                  
	DEVMETHOD(cryptodev_freesession, c7108_freesession),                                                             
	DEVMETHOD(cryptodev_process, c7108_process),                                                                     
	DEVMETHOD(cryptodev_kprocess, NULL) 
};   

static int
cypher_7108_crypto_init(void)
{
	dprintk("%s(%p)\n", __FUNCTION__, cypher_7108_crypto_init);
	
	iobar = (unsigned long)ioremap(CCU_AES_REG_BASE, 0x4000);
	printk("7108: AES @ 0x%08x (0x%08x phys) %s mode\n", 
	       iobar, CCU_AES_REG_BASE, 
	       c7108_crypto_mode & C7108_AES_CTRL_MODE_CBC ? "CBC" :
	       c7108_crypto_mode & C7108_AES_CTRL_MODE_ECB ? "ECB" : 
	       c7108_crypto_mode & C7108_AES_CTRL_MODE_CTR ? "CTR" : 
	       c7108_crypto_mode & C7108_AES_CTRL_MODE_CFB ? "CFB" : 
	       c7108_crypto_mode & C7108_AES_CTRL_MODE_OFB ? "OFB" : "???");
	csr_mutex  = SPIN_LOCK_UNLOCKED;

	memset(&a7108dev, 0, sizeof(a7108dev));                                                                                     
	softc_device_init(&a7108dev, "aes7108", 0, a7108_methods);

       	c7108_id = crypto_get_driverid(softc_get_device(&a7108dev), CRYPTOCAP_F_HARDWARE);
	if (c7108_id < 0)
		panic("7108: crypto device cannot initialize!");

//	crypto_register(c7108_id, CRYPTO_AES_CBC, 0, 0, c7108_newsession, c7108_freesession, c7108_process, NULL);
	crypto_register(c7108_id, CRYPTO_AES_CBC, 0, 0);

	return(0);
}

static void
cypher_7108_crypto_exit(void)
{
	dprintk("%s()\n", __FUNCTION__);
	crypto_unregister_all(c7108_id);
	c7108_id = -1;
}

module_init(cypher_7108_crypto_init);
module_exit(cypher_7108_crypto_exit);

MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("Cypher 7108 Crypto (OCF module for kernel crypto)");