xref: /linux/drivers/crypto/nx/nx.c (revision 08ec212c0f92cbf30e3ecc7349f18151714041d6)
1 /**
2  * Routines supporting the Power 7+ Nest Accelerators driver
3  *
4  * Copyright (C) 2011-2012 International Business Machines Inc.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; version 2 only.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18  *
19  * Author: Kent Yoder <yoder1@us.ibm.com>
20  */
21 
22 #include <crypto/internal/hash.h>
23 #include <crypto/hash.h>
24 #include <crypto/aes.h>
25 #include <crypto/sha.h>
26 #include <crypto/algapi.h>
27 #include <crypto/scatterwalk.h>
28 #include <linux/module.h>
29 #include <linux/moduleparam.h>
30 #include <linux/types.h>
31 #include <linux/mm.h>
32 #include <linux/crypto.h>
33 #include <linux/scatterlist.h>
34 #include <linux/device.h>
35 #include <linux/of.h>
36 #include <asm/pSeries_reconfig.h>
37 #include <asm/hvcall.h>
38 #include <asm/vio.h>
39 
40 #include "nx_csbcpb.h"
41 #include "nx.h"
42 
43 
44 /**
45  * nx_hcall_sync - make an H_COP_OP hcall for the passed in op structure
46  *
47  * @nx_ctx: the crypto context handle
48  * @op: PFO operation struct to pass in
49  * @may_sleep: flag indicating the request can sleep
50  *
51  * Make the hcall, retrying while the hardware is busy. If we cannot yield
52  * the thread, limit the number of retries to 10 here.
53  */
54 int nx_hcall_sync(struct nx_crypto_ctx *nx_ctx,
55 		  struct vio_pfo_op    *op,
56 		  u32                   may_sleep)
57 {
58 	int rc, retries = 10;
59 	struct vio_dev *viodev = nx_driver.viodev;
60 
61 	atomic_inc(&(nx_ctx->stats->sync_ops));
62 
63 	do {
64 		rc = vio_h_cop_sync(viodev, op);
65 	} while ((rc == -EBUSY && !may_sleep && retries--) ||
66 	         (rc == -EBUSY && may_sleep && cond_resched()));
67 
68 	if (rc) {
69 		dev_dbg(&viodev->dev, "vio_h_cop_sync failed: rc: %d "
70 			"hcall rc: %ld\n", rc, op->hcall_err);
71 		atomic_inc(&(nx_ctx->stats->errors));
72 		atomic_set(&(nx_ctx->stats->last_error), op->hcall_err);
73 		atomic_set(&(nx_ctx->stats->last_error_pid), current->pid);
74 	}
75 
76 	return rc;
77 }
78 
79 /**
80  * nx_build_sg_list - build an NX scatter list describing a single  buffer
81  *
82  * @sg_head: pointer to the first scatter list element to build
83  * @start_addr: pointer to the linear buffer
84  * @len: length of the data at @start_addr
85  * @sgmax: the largest number of scatter list elements we're allowed to create
86  *
87  * This function will start writing nx_sg elements at @sg_head and keep
88  * writing them until all of the data from @start_addr is described or
89  * until sgmax elements have been written. Scatter list elements will be
90  * created such that none of the elements describes a buffer that crosses a 4K
91  * boundary.
92  */
93 struct nx_sg *nx_build_sg_list(struct nx_sg *sg_head,
94 			       u8           *start_addr,
95 			       unsigned int  len,
96 			       u32           sgmax)
97 {
98 	unsigned int sg_len = 0;
99 	struct nx_sg *sg;
100 	u64 sg_addr = (u64)start_addr;
101 	u64 end_addr;
102 
103 	/* determine the start and end for this address range - slightly
104 	 * different if this is in VMALLOC_REGION */
105 	if (is_vmalloc_addr(start_addr))
106 		sg_addr = page_to_phys(vmalloc_to_page(start_addr))
107 			  + offset_in_page(sg_addr);
108 	else
109 		sg_addr = __pa(sg_addr);
110 
111 	end_addr = sg_addr + len;
112 
113 	/* each iteration will write one struct nx_sg element and add the
114 	 * length of data described by that element to sg_len. Once @len bytes
115 	 * have been described (or @sgmax elements have been written), the
116 	 * loop ends. min_t is used to ensure @end_addr falls on the same page
117 	 * as sg_addr, if not, we need to create another nx_sg element for the
118 	 * data on the next page */
119 	for (sg = sg_head; sg_len < len; sg++) {
120 		sg->addr = sg_addr;
121 		sg_addr = min_t(u64, NX_PAGE_NUM(sg_addr + NX_PAGE_SIZE), end_addr);
122 		sg->len = sg_addr - sg->addr;
123 		sg_len += sg->len;
124 
125 		if ((sg - sg_head) == sgmax) {
126 			pr_err("nx: scatter/gather list overflow, pid: %d\n",
127 			       current->pid);
128 			return NULL;
129 		}
130 	}
131 
132 	/* return the moved sg_head pointer */
133 	return sg;
134 }
135 
136 /**
137  * nx_walk_and_build - walk a linux scatterlist and build an nx scatterlist
138  *
139  * @nx_dst: pointer to the first nx_sg element to write
140  * @sglen: max number of nx_sg entries we're allowed to write
141  * @sg_src: pointer to the source linux scatterlist to walk
142  * @start: number of bytes to fast-forward past at the beginning of @sg_src
143  * @src_len: number of bytes to walk in @sg_src
144  */
145 struct nx_sg *nx_walk_and_build(struct nx_sg       *nx_dst,
146 				unsigned int        sglen,
147 				struct scatterlist *sg_src,
148 				unsigned int        start,
149 				unsigned int        src_len)
150 {
151 	struct scatter_walk walk;
152 	struct nx_sg *nx_sg = nx_dst;
153 	unsigned int n, offset = 0, len = src_len;
154 	char *dst;
155 
156 	/* we need to fast forward through @start bytes first */
157 	for (;;) {
158 		scatterwalk_start(&walk, sg_src);
159 
160 		if (start < offset + sg_src->length)
161 			break;
162 
163 		offset += sg_src->length;
164 		sg_src = scatterwalk_sg_next(sg_src);
165 	}
166 
167 	/* start - offset is the number of bytes to advance in the scatterlist
168 	 * element we're currently looking at */
169 	scatterwalk_advance(&walk, start - offset);
170 
171 	while (len && nx_sg) {
172 		n = scatterwalk_clamp(&walk, len);
173 		if (!n) {
174 			scatterwalk_start(&walk, sg_next(walk.sg));
175 			n = scatterwalk_clamp(&walk, len);
176 		}
177 		dst = scatterwalk_map(&walk);
178 
179 		nx_sg = nx_build_sg_list(nx_sg, dst, n, sglen);
180 		len -= n;
181 
182 		scatterwalk_unmap(dst);
183 		scatterwalk_advance(&walk, n);
184 		scatterwalk_done(&walk, SCATTERWALK_FROM_SG, len);
185 	}
186 
187 	/* return the moved destination pointer */
188 	return nx_sg;
189 }
190 
191 /**
192  * nx_build_sg_lists - walk the input scatterlists and build arrays of NX
193  *                     scatterlists based on them.
194  *
195  * @nx_ctx: NX crypto context for the lists we're building
196  * @desc: the block cipher descriptor for the operation
197  * @dst: destination scatterlist
198  * @src: source scatterlist
199  * @nbytes: length of data described in the scatterlists
200  * @iv: destination for the iv data, if the algorithm requires it
201  *
202  * This is common code shared by all the AES algorithms. It uses the block
203  * cipher walk routines to traverse input and output scatterlists, building
204  * corresponding NX scatterlists
205  */
206 int nx_build_sg_lists(struct nx_crypto_ctx  *nx_ctx,
207 		      struct blkcipher_desc *desc,
208 		      struct scatterlist    *dst,
209 		      struct scatterlist    *src,
210 		      unsigned int           nbytes,
211 		      u8                    *iv)
212 {
213 	struct nx_sg *nx_insg = nx_ctx->in_sg;
214 	struct nx_sg *nx_outsg = nx_ctx->out_sg;
215 	struct blkcipher_walk walk;
216 	int rc;
217 
218 	blkcipher_walk_init(&walk, dst, src, nbytes);
219 	rc = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);
220 	if (rc)
221 		goto out;
222 
223 	if (iv)
224 		memcpy(iv, walk.iv, AES_BLOCK_SIZE);
225 
226 	while (walk.nbytes) {
227 		nx_insg = nx_build_sg_list(nx_insg, walk.src.virt.addr,
228 					   walk.nbytes, nx_ctx->ap->sglen);
229 		nx_outsg = nx_build_sg_list(nx_outsg, walk.dst.virt.addr,
230 					    walk.nbytes, nx_ctx->ap->sglen);
231 
232 		rc = blkcipher_walk_done(desc, &walk, 0);
233 		if (rc)
234 			break;
235 	}
236 
237 	if (walk.nbytes) {
238 		nx_insg = nx_build_sg_list(nx_insg, walk.src.virt.addr,
239 					   walk.nbytes, nx_ctx->ap->sglen);
240 		nx_outsg = nx_build_sg_list(nx_outsg, walk.dst.virt.addr,
241 					    walk.nbytes, nx_ctx->ap->sglen);
242 
243 		rc = 0;
244 	}
245 
246 	/* these lengths should be negative, which will indicate to phyp that
247 	 * the input and output parameters are scatterlists, not linear
248 	 * buffers */
249 	nx_ctx->op.inlen = (nx_ctx->in_sg - nx_insg) * sizeof(struct nx_sg);
250 	nx_ctx->op.outlen = (nx_ctx->out_sg - nx_outsg) * sizeof(struct nx_sg);
251 out:
252 	return rc;
253 }
254 
255 /**
256  * nx_ctx_init - initialize an nx_ctx's vio_pfo_op struct
257  *
258  * @nx_ctx: the nx context to initialize
259  * @function: the function code for the op
260  */
261 void nx_ctx_init(struct nx_crypto_ctx *nx_ctx, unsigned int function)
262 {
263 	memset(nx_ctx->kmem, 0, nx_ctx->kmem_len);
264 	nx_ctx->csbcpb->csb.valid |= NX_CSB_VALID_BIT;
265 
266 	nx_ctx->op.flags = function;
267 	nx_ctx->op.csbcpb = __pa(nx_ctx->csbcpb);
268 	nx_ctx->op.in = __pa(nx_ctx->in_sg);
269 	nx_ctx->op.out = __pa(nx_ctx->out_sg);
270 
271 	if (nx_ctx->csbcpb_aead) {
272 		nx_ctx->csbcpb_aead->csb.valid |= NX_CSB_VALID_BIT;
273 
274 		nx_ctx->op_aead.flags = function;
275 		nx_ctx->op_aead.csbcpb = __pa(nx_ctx->csbcpb_aead);
276 		nx_ctx->op_aead.in = __pa(nx_ctx->in_sg);
277 		nx_ctx->op_aead.out = __pa(nx_ctx->out_sg);
278 	}
279 }
280 
281 static void nx_of_update_status(struct device   *dev,
282 			       struct property *p,
283 			       struct nx_of    *props)
284 {
285 	if (!strncmp(p->value, "okay", p->length)) {
286 		props->status = NX_WAITING;
287 		props->flags |= NX_OF_FLAG_STATUS_SET;
288 	} else {
289 		dev_info(dev, "%s: status '%s' is not 'okay'\n", __func__,
290 			 (char *)p->value);
291 	}
292 }
293 
294 static void nx_of_update_sglen(struct device   *dev,
295 			       struct property *p,
296 			       struct nx_of    *props)
297 {
298 	if (p->length != sizeof(props->max_sg_len)) {
299 		dev_err(dev, "%s: unexpected format for "
300 			"ibm,max-sg-len property\n", __func__);
301 		dev_dbg(dev, "%s: ibm,max-sg-len is %d bytes "
302 			"long, expected %zd bytes\n", __func__,
303 			p->length, sizeof(props->max_sg_len));
304 		return;
305 	}
306 
307 	props->max_sg_len = *(u32 *)p->value;
308 	props->flags |= NX_OF_FLAG_MAXSGLEN_SET;
309 }
310 
311 static void nx_of_update_msc(struct device   *dev,
312 			     struct property *p,
313 			     struct nx_of    *props)
314 {
315 	struct msc_triplet *trip;
316 	struct max_sync_cop *msc;
317 	unsigned int bytes_so_far, i, lenp;
318 
319 	msc = (struct max_sync_cop *)p->value;
320 	lenp = p->length;
321 
322 	/* You can't tell if the data read in for this property is sane by its
323 	 * size alone. This is because there are sizes embedded in the data
324 	 * structure. The best we can do is check lengths as we parse and bail
325 	 * as soon as a length error is detected. */
326 	bytes_so_far = 0;
327 
328 	while ((bytes_so_far + sizeof(struct max_sync_cop)) <= lenp) {
329 		bytes_so_far += sizeof(struct max_sync_cop);
330 
331 		trip = msc->trip;
332 
333 		for (i = 0;
334 		     ((bytes_so_far + sizeof(struct msc_triplet)) <= lenp) &&
335 		     i < msc->triplets;
336 		     i++) {
337 			if (msc->fc > NX_MAX_FC || msc->mode > NX_MAX_MODE) {
338 				dev_err(dev, "unknown function code/mode "
339 					"combo: %d/%d (ignored)\n", msc->fc,
340 					msc->mode);
341 				goto next_loop;
342 			}
343 
344 			switch (trip->keybitlen) {
345 			case 128:
346 			case 160:
347 				props->ap[msc->fc][msc->mode][0].databytelen =
348 					trip->databytelen;
349 				props->ap[msc->fc][msc->mode][0].sglen =
350 					trip->sglen;
351 				break;
352 			case 192:
353 				props->ap[msc->fc][msc->mode][1].databytelen =
354 					trip->databytelen;
355 				props->ap[msc->fc][msc->mode][1].sglen =
356 					trip->sglen;
357 				break;
358 			case 256:
359 				if (msc->fc == NX_FC_AES) {
360 					props->ap[msc->fc][msc->mode][2].
361 						databytelen = trip->databytelen;
362 					props->ap[msc->fc][msc->mode][2].sglen =
363 						trip->sglen;
364 				} else if (msc->fc == NX_FC_AES_HMAC ||
365 					   msc->fc == NX_FC_SHA) {
366 					props->ap[msc->fc][msc->mode][1].
367 						databytelen = trip->databytelen;
368 					props->ap[msc->fc][msc->mode][1].sglen =
369 						trip->sglen;
370 				} else {
371 					dev_warn(dev, "unknown function "
372 						"code/key bit len combo"
373 						": (%u/256)\n", msc->fc);
374 				}
375 				break;
376 			case 512:
377 				props->ap[msc->fc][msc->mode][2].databytelen =
378 					trip->databytelen;
379 				props->ap[msc->fc][msc->mode][2].sglen =
380 					trip->sglen;
381 				break;
382 			default:
383 				dev_warn(dev, "unknown function code/key bit "
384 					 "len combo: (%u/%u)\n", msc->fc,
385 					 trip->keybitlen);
386 				break;
387 			}
388 next_loop:
389 			bytes_so_far += sizeof(struct msc_triplet);
390 			trip++;
391 		}
392 
393 		msc = (struct max_sync_cop *)trip;
394 	}
395 
396 	props->flags |= NX_OF_FLAG_MAXSYNCCOP_SET;
397 }
398 
399 /**
400  * nx_of_init - read openFirmware values from the device tree
401  *
402  * @dev: device handle
403  * @props: pointer to struct to hold the properties values
404  *
405  * Called once at driver probe time, this function will read out the
406  * openFirmware properties we use at runtime. If all the OF properties are
407  * acceptable, when we exit this function props->flags will indicate that
408  * we're ready to register our crypto algorithms.
409  */
410 static void nx_of_init(struct device *dev, struct nx_of *props)
411 {
412 	struct device_node *base_node = dev->of_node;
413 	struct property *p;
414 
415 	p = of_find_property(base_node, "status", NULL);
416 	if (!p)
417 		dev_info(dev, "%s: property 'status' not found\n", __func__);
418 	else
419 		nx_of_update_status(dev, p, props);
420 
421 	p = of_find_property(base_node, "ibm,max-sg-len", NULL);
422 	if (!p)
423 		dev_info(dev, "%s: property 'ibm,max-sg-len' not found\n",
424 			 __func__);
425 	else
426 		nx_of_update_sglen(dev, p, props);
427 
428 	p = of_find_property(base_node, "ibm,max-sync-cop", NULL);
429 	if (!p)
430 		dev_info(dev, "%s: property 'ibm,max-sync-cop' not found\n",
431 			 __func__);
432 	else
433 		nx_of_update_msc(dev, p, props);
434 }
435 
436 /**
437  * nx_register_algs - register algorithms with the crypto API
438  *
439  * Called from nx_probe()
440  *
441  * If all OF properties are in an acceptable state, the driver flags will
442  * indicate that we're ready and we'll create our debugfs files and register
443  * out crypto algorithms.
444  */
445 static int nx_register_algs(void)
446 {
447 	int rc = -1;
448 
449 	if (nx_driver.of.flags != NX_OF_FLAG_MASK_READY)
450 		goto out;
451 
452 	memset(&nx_driver.stats, 0, sizeof(struct nx_stats));
453 
454 	rc = NX_DEBUGFS_INIT(&nx_driver);
455 	if (rc)
456 		goto out;
457 
458 	rc = crypto_register_alg(&nx_ecb_aes_alg);
459 	if (rc)
460 		goto out;
461 
462 	rc = crypto_register_alg(&nx_cbc_aes_alg);
463 	if (rc)
464 		goto out_unreg_ecb;
465 
466 	rc = crypto_register_alg(&nx_ctr_aes_alg);
467 	if (rc)
468 		goto out_unreg_cbc;
469 
470 	rc = crypto_register_alg(&nx_ctr3686_aes_alg);
471 	if (rc)
472 		goto out_unreg_ctr;
473 
474 	rc = crypto_register_alg(&nx_gcm_aes_alg);
475 	if (rc)
476 		goto out_unreg_ctr3686;
477 
478 	rc = crypto_register_alg(&nx_gcm4106_aes_alg);
479 	if (rc)
480 		goto out_unreg_gcm;
481 
482 	rc = crypto_register_alg(&nx_ccm_aes_alg);
483 	if (rc)
484 		goto out_unreg_gcm4106;
485 
486 	rc = crypto_register_alg(&nx_ccm4309_aes_alg);
487 	if (rc)
488 		goto out_unreg_ccm;
489 
490 	rc = crypto_register_shash(&nx_shash_sha256_alg);
491 	if (rc)
492 		goto out_unreg_ccm4309;
493 
494 	rc = crypto_register_shash(&nx_shash_sha512_alg);
495 	if (rc)
496 		goto out_unreg_s256;
497 
498 	rc = crypto_register_shash(&nx_shash_aes_xcbc_alg);
499 	if (rc)
500 		goto out_unreg_s512;
501 
502 	nx_driver.of.status = NX_OKAY;
503 
504 	goto out;
505 
506 out_unreg_s512:
507 	crypto_unregister_shash(&nx_shash_sha512_alg);
508 out_unreg_s256:
509 	crypto_unregister_shash(&nx_shash_sha256_alg);
510 out_unreg_ccm4309:
511 	crypto_unregister_alg(&nx_ccm4309_aes_alg);
512 out_unreg_ccm:
513 	crypto_unregister_alg(&nx_ccm_aes_alg);
514 out_unreg_gcm4106:
515 	crypto_unregister_alg(&nx_gcm4106_aes_alg);
516 out_unreg_gcm:
517 	crypto_unregister_alg(&nx_gcm_aes_alg);
518 out_unreg_ctr3686:
519 	crypto_unregister_alg(&nx_ctr3686_aes_alg);
520 out_unreg_ctr:
521 	crypto_unregister_alg(&nx_ctr_aes_alg);
522 out_unreg_cbc:
523 	crypto_unregister_alg(&nx_cbc_aes_alg);
524 out_unreg_ecb:
525 	crypto_unregister_alg(&nx_ecb_aes_alg);
526 out:
527 	return rc;
528 }
529 
530 /**
531  * nx_crypto_ctx_init - create and initialize a crypto api context
532  *
533  * @nx_ctx: the crypto api context
534  * @fc: function code for the context
535  * @mode: the function code specific mode for this context
536  */
537 static int nx_crypto_ctx_init(struct nx_crypto_ctx *nx_ctx, u32 fc, u32 mode)
538 {
539 	if (nx_driver.of.status != NX_OKAY) {
540 		pr_err("Attempt to initialize NX crypto context while device "
541 		       "is not available!\n");
542 		return -ENODEV;
543 	}
544 
545 	/* we need an extra page for csbcpb_aead for these modes */
546 	if (mode == NX_MODE_AES_GCM || mode == NX_MODE_AES_CCM)
547 		nx_ctx->kmem_len = (4 * NX_PAGE_SIZE) +
548 				   sizeof(struct nx_csbcpb);
549 	else
550 		nx_ctx->kmem_len = (3 * NX_PAGE_SIZE) +
551 				   sizeof(struct nx_csbcpb);
552 
553 	nx_ctx->kmem = kmalloc(nx_ctx->kmem_len, GFP_KERNEL);
554 	if (!nx_ctx->kmem)
555 		return -ENOMEM;
556 
557 	/* the csbcpb and scatterlists must be 4K aligned pages */
558 	nx_ctx->csbcpb = (struct nx_csbcpb *)(round_up((u64)nx_ctx->kmem,
559 						       (u64)NX_PAGE_SIZE));
560 	nx_ctx->in_sg = (struct nx_sg *)((u8 *)nx_ctx->csbcpb + NX_PAGE_SIZE);
561 	nx_ctx->out_sg = (struct nx_sg *)((u8 *)nx_ctx->in_sg + NX_PAGE_SIZE);
562 
563 	if (mode == NX_MODE_AES_GCM || mode == NX_MODE_AES_CCM)
564 		nx_ctx->csbcpb_aead =
565 			(struct nx_csbcpb *)((u8 *)nx_ctx->out_sg +
566 					     NX_PAGE_SIZE);
567 
568 	/* give each context a pointer to global stats and their OF
569 	 * properties */
570 	nx_ctx->stats = &nx_driver.stats;
571 	memcpy(nx_ctx->props, nx_driver.of.ap[fc][mode],
572 	       sizeof(struct alg_props) * 3);
573 
574 	return 0;
575 }
576 
577 /* entry points from the crypto tfm initializers */
578 int nx_crypto_ctx_aes_ccm_init(struct crypto_tfm *tfm)
579 {
580 	return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
581 				  NX_MODE_AES_CCM);
582 }
583 
584 int nx_crypto_ctx_aes_gcm_init(struct crypto_tfm *tfm)
585 {
586 	return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
587 				  NX_MODE_AES_GCM);
588 }
589 
590 int nx_crypto_ctx_aes_ctr_init(struct crypto_tfm *tfm)
591 {
592 	return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
593 				  NX_MODE_AES_CTR);
594 }
595 
596 int nx_crypto_ctx_aes_cbc_init(struct crypto_tfm *tfm)
597 {
598 	return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
599 				  NX_MODE_AES_CBC);
600 }
601 
602 int nx_crypto_ctx_aes_ecb_init(struct crypto_tfm *tfm)
603 {
604 	return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
605 				  NX_MODE_AES_ECB);
606 }
607 
608 int nx_crypto_ctx_sha_init(struct crypto_tfm *tfm)
609 {
610 	return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_SHA, NX_MODE_SHA);
611 }
612 
613 int nx_crypto_ctx_aes_xcbc_init(struct crypto_tfm *tfm)
614 {
615 	return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
616 				  NX_MODE_AES_XCBC_MAC);
617 }
618 
619 /**
620  * nx_crypto_ctx_exit - destroy a crypto api context
621  *
622  * @tfm: the crypto transform pointer for the context
623  *
624  * As crypto API contexts are destroyed, this exit hook is called to free the
625  * memory associated with it.
626  */
627 void nx_crypto_ctx_exit(struct crypto_tfm *tfm)
628 {
629 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);
630 
631 	kzfree(nx_ctx->kmem);
632 	nx_ctx->csbcpb = NULL;
633 	nx_ctx->csbcpb_aead = NULL;
634 	nx_ctx->in_sg = NULL;
635 	nx_ctx->out_sg = NULL;
636 }
637 
638 static int __devinit nx_probe(struct vio_dev *viodev,
639 			      const struct vio_device_id *id)
640 {
641 	dev_dbg(&viodev->dev, "driver probed: %s resource id: 0x%x\n",
642 		viodev->name, viodev->resource_id);
643 
644 	if (nx_driver.viodev) {
645 		dev_err(&viodev->dev, "%s: Attempt to register more than one "
646 			"instance of the hardware\n", __func__);
647 		return -EINVAL;
648 	}
649 
650 	nx_driver.viodev = viodev;
651 
652 	nx_of_init(&viodev->dev, &nx_driver.of);
653 
654 	return nx_register_algs();
655 }
656 
657 static int __devexit nx_remove(struct vio_dev *viodev)
658 {
659 	dev_dbg(&viodev->dev, "entering nx_remove for UA 0x%x\n",
660 		viodev->unit_address);
661 
662 	if (nx_driver.of.status == NX_OKAY) {
663 		NX_DEBUGFS_FINI(&nx_driver);
664 
665 		crypto_unregister_alg(&nx_ccm_aes_alg);
666 		crypto_unregister_alg(&nx_ccm4309_aes_alg);
667 		crypto_unregister_alg(&nx_gcm_aes_alg);
668 		crypto_unregister_alg(&nx_gcm4106_aes_alg);
669 		crypto_unregister_alg(&nx_ctr_aes_alg);
670 		crypto_unregister_alg(&nx_ctr3686_aes_alg);
671 		crypto_unregister_alg(&nx_cbc_aes_alg);
672 		crypto_unregister_alg(&nx_ecb_aes_alg);
673 		crypto_unregister_shash(&nx_shash_sha256_alg);
674 		crypto_unregister_shash(&nx_shash_sha512_alg);
675 		crypto_unregister_shash(&nx_shash_aes_xcbc_alg);
676 	}
677 
678 	return 0;
679 }
680 
681 
682 /* module wide initialization/cleanup */
683 static int __init nx_init(void)
684 {
685 	return vio_register_driver(&nx_driver.viodriver);
686 }
687 
688 static void __exit nx_fini(void)
689 {
690 	vio_unregister_driver(&nx_driver.viodriver);
691 }
692 
693 static struct vio_device_id nx_crypto_driver_ids[] __devinitdata = {
694 	{ "ibm,sym-encryption-v1", "ibm,sym-encryption" },
695 	{ "", "" }
696 };
697 MODULE_DEVICE_TABLE(vio, nx_crypto_driver_ids);
698 
699 /* driver state structure */
700 struct nx_crypto_driver nx_driver = {
701 	.viodriver = {
702 		.id_table = nx_crypto_driver_ids,
703 		.probe = nx_probe,
704 		.remove = nx_remove,
705 		.name  = NX_NAME,
706 	},
707 };
708 
709 module_init(nx_init);
710 module_exit(nx_fini);
711 
712 MODULE_AUTHOR("Kent Yoder <yoder1@us.ibm.com>");
713 MODULE_DESCRIPTION(NX_STRING);
714 MODULE_LICENSE("GPL");
715 MODULE_VERSION(NX_VERSION);
716