xref: /linux/drivers/crypto/nx/nx.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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/hvcall.h>
37 #include <asm/vio.h>
38 
39 #include "nx_csbcpb.h"
40 #include "nx.h"
41 
42 
43 /**
44  * nx_hcall_sync - make an H_COP_OP hcall for the passed in op structure
45  *
46  * @nx_ctx: the crypto context handle
47  * @op: PFO operation struct to pass in
48  * @may_sleep: flag indicating the request can sleep
49  *
50  * Make the hcall, retrying while the hardware is busy. If we cannot yield
51  * the thread, limit the number of retries to 10 here.
52  */
53 int nx_hcall_sync(struct nx_crypto_ctx *nx_ctx,
54 		  struct vio_pfo_op    *op,
55 		  u32                   may_sleep)
56 {
57 	int rc, retries = 10;
58 	struct vio_dev *viodev = nx_driver.viodev;
59 
60 	atomic_inc(&(nx_ctx->stats->sync_ops));
61 
62 	do {
63 		rc = vio_h_cop_sync(viodev, op);
64 	} while (rc == -EBUSY && !may_sleep && retries--);
65 
66 	if (rc) {
67 		dev_dbg(&viodev->dev, "vio_h_cop_sync failed: rc: %d "
68 			"hcall rc: %ld\n", rc, op->hcall_err);
69 		atomic_inc(&(nx_ctx->stats->errors));
70 		atomic_set(&(nx_ctx->stats->last_error), op->hcall_err);
71 		atomic_set(&(nx_ctx->stats->last_error_pid), current->pid);
72 	}
73 
74 	return rc;
75 }
76 
77 /**
78  * nx_build_sg_list - build an NX scatter list describing a single  buffer
79  *
80  * @sg_head: pointer to the first scatter list element to build
81  * @start_addr: pointer to the linear buffer
82  * @len: length of the data at @start_addr
83  * @sgmax: the largest number of scatter list elements we're allowed to create
84  *
85  * This function will start writing nx_sg elements at @sg_head and keep
86  * writing them until all of the data from @start_addr is described or
87  * until sgmax elements have been written. Scatter list elements will be
88  * created such that none of the elements describes a buffer that crosses a 4K
89  * boundary.
90  */
91 struct nx_sg *nx_build_sg_list(struct nx_sg *sg_head,
92 			       u8           *start_addr,
93 			       unsigned int  len,
94 			       u32           sgmax)
95 {
96 	unsigned int sg_len = 0;
97 	struct nx_sg *sg;
98 	u64 sg_addr = (u64)start_addr;
99 	u64 end_addr;
100 
101 	/* determine the start and end for this address range - slightly
102 	 * different if this is in VMALLOC_REGION */
103 	if (is_vmalloc_addr(start_addr))
104 		sg_addr = page_to_phys(vmalloc_to_page(start_addr))
105 			  + offset_in_page(sg_addr);
106 	else
107 		sg_addr = __pa(sg_addr);
108 
109 	end_addr = sg_addr + len;
110 
111 	/* each iteration will write one struct nx_sg element and add the
112 	 * length of data described by that element to sg_len. Once @len bytes
113 	 * have been described (or @sgmax elements have been written), the
114 	 * loop ends. min_t is used to ensure @end_addr falls on the same page
115 	 * as sg_addr, if not, we need to create another nx_sg element for the
116 	 * data on the next page.
117 	 *
118 	 * Also when using vmalloc'ed data, every time that a system page
119 	 * boundary is crossed the physical address needs to be re-calculated.
120 	 */
121 	for (sg = sg_head; sg_len < len; sg++) {
122 		u64 next_page;
123 
124 		sg->addr = sg_addr;
125 		sg_addr = min_t(u64, NX_PAGE_NUM(sg_addr + NX_PAGE_SIZE),
126 				end_addr);
127 
128 		next_page = (sg->addr & PAGE_MASK) + PAGE_SIZE;
129 		sg->len = min_t(u64, sg_addr, next_page) - sg->addr;
130 		sg_len += sg->len;
131 
132 		if (sg_addr >= next_page &&
133 				is_vmalloc_addr(start_addr + sg_len)) {
134 			sg_addr = page_to_phys(vmalloc_to_page(
135 						start_addr + sg_len));
136 			end_addr = sg_addr + len - sg_len;
137 		}
138 
139 		if ((sg - sg_head) == sgmax) {
140 			pr_err("nx: scatter/gather list overflow, pid: %d\n",
141 			       current->pid);
142 			return NULL;
143 		}
144 	}
145 
146 	/* return the moved sg_head pointer */
147 	return sg;
148 }
149 
150 /**
151  * nx_walk_and_build - walk a linux scatterlist and build an nx scatterlist
152  *
153  * @nx_dst: pointer to the first nx_sg element to write
154  * @sglen: max number of nx_sg entries we're allowed to write
155  * @sg_src: pointer to the source linux scatterlist to walk
156  * @start: number of bytes to fast-forward past at the beginning of @sg_src
157  * @src_len: number of bytes to walk in @sg_src
158  */
159 struct nx_sg *nx_walk_and_build(struct nx_sg       *nx_dst,
160 				unsigned int        sglen,
161 				struct scatterlist *sg_src,
162 				unsigned int        start,
163 				unsigned int        src_len)
164 {
165 	struct scatter_walk walk;
166 	struct nx_sg *nx_sg = nx_dst;
167 	unsigned int n, offset = 0, len = src_len;
168 	char *dst;
169 
170 	/* we need to fast forward through @start bytes first */
171 	for (;;) {
172 		scatterwalk_start(&walk, sg_src);
173 
174 		if (start < offset + sg_src->length)
175 			break;
176 
177 		offset += sg_src->length;
178 		sg_src = scatterwalk_sg_next(sg_src);
179 	}
180 
181 	/* start - offset is the number of bytes to advance in the scatterlist
182 	 * element we're currently looking at */
183 	scatterwalk_advance(&walk, start - offset);
184 
185 	while (len && nx_sg) {
186 		n = scatterwalk_clamp(&walk, len);
187 		if (!n) {
188 			scatterwalk_start(&walk, sg_next(walk.sg));
189 			n = scatterwalk_clamp(&walk, len);
190 		}
191 		dst = scatterwalk_map(&walk);
192 
193 		nx_sg = nx_build_sg_list(nx_sg, dst, n, sglen);
194 		len -= n;
195 
196 		scatterwalk_unmap(dst);
197 		scatterwalk_advance(&walk, n);
198 		scatterwalk_done(&walk, SCATTERWALK_FROM_SG, len);
199 	}
200 
201 	/* return the moved destination pointer */
202 	return nx_sg;
203 }
204 
205 /**
206  * nx_build_sg_lists - walk the input scatterlists and build arrays of NX
207  *                     scatterlists based on them.
208  *
209  * @nx_ctx: NX crypto context for the lists we're building
210  * @desc: the block cipher descriptor for the operation
211  * @dst: destination scatterlist
212  * @src: source scatterlist
213  * @nbytes: length of data described in the scatterlists
214  * @offset: number of bytes to fast-forward past at the beginning of
215  *          scatterlists.
216  * @iv: destination for the iv data, if the algorithm requires it
217  *
218  * This is common code shared by all the AES algorithms. It uses the block
219  * cipher walk routines to traverse input and output scatterlists, building
220  * corresponding NX scatterlists
221  */
222 int nx_build_sg_lists(struct nx_crypto_ctx  *nx_ctx,
223 		      struct blkcipher_desc *desc,
224 		      struct scatterlist    *dst,
225 		      struct scatterlist    *src,
226 		      unsigned int           nbytes,
227 		      unsigned int           offset,
228 		      u8                    *iv)
229 {
230 	struct nx_sg *nx_insg = nx_ctx->in_sg;
231 	struct nx_sg *nx_outsg = nx_ctx->out_sg;
232 
233 	if (iv)
234 		memcpy(iv, desc->info, AES_BLOCK_SIZE);
235 
236 	nx_insg = nx_walk_and_build(nx_insg, nx_ctx->ap->sglen, src,
237 				    offset, nbytes);
238 	nx_outsg = nx_walk_and_build(nx_outsg, nx_ctx->ap->sglen, dst,
239 				    offset, nbytes);
240 
241 	/* these lengths should be negative, which will indicate to phyp that
242 	 * the input and output parameters are scatterlists, not linear
243 	 * buffers */
244 	nx_ctx->op.inlen = (nx_ctx->in_sg - nx_insg) * sizeof(struct nx_sg);
245 	nx_ctx->op.outlen = (nx_ctx->out_sg - nx_outsg) * sizeof(struct nx_sg);
246 
247 	return 0;
248 }
249 
250 /**
251  * nx_ctx_init - initialize an nx_ctx's vio_pfo_op struct
252  *
253  * @nx_ctx: the nx context to initialize
254  * @function: the function code for the op
255  */
256 void nx_ctx_init(struct nx_crypto_ctx *nx_ctx, unsigned int function)
257 {
258 	spin_lock_init(&nx_ctx->lock);
259 	memset(nx_ctx->kmem, 0, nx_ctx->kmem_len);
260 	nx_ctx->csbcpb->csb.valid |= NX_CSB_VALID_BIT;
261 
262 	nx_ctx->op.flags = function;
263 	nx_ctx->op.csbcpb = __pa(nx_ctx->csbcpb);
264 	nx_ctx->op.in = __pa(nx_ctx->in_sg);
265 	nx_ctx->op.out = __pa(nx_ctx->out_sg);
266 
267 	if (nx_ctx->csbcpb_aead) {
268 		nx_ctx->csbcpb_aead->csb.valid |= NX_CSB_VALID_BIT;
269 
270 		nx_ctx->op_aead.flags = function;
271 		nx_ctx->op_aead.csbcpb = __pa(nx_ctx->csbcpb_aead);
272 		nx_ctx->op_aead.in = __pa(nx_ctx->in_sg);
273 		nx_ctx->op_aead.out = __pa(nx_ctx->out_sg);
274 	}
275 }
276 
277 static void nx_of_update_status(struct device   *dev,
278 			       struct property *p,
279 			       struct nx_of    *props)
280 {
281 	if (!strncmp(p->value, "okay", p->length)) {
282 		props->status = NX_WAITING;
283 		props->flags |= NX_OF_FLAG_STATUS_SET;
284 	} else {
285 		dev_info(dev, "%s: status '%s' is not 'okay'\n", __func__,
286 			 (char *)p->value);
287 	}
288 }
289 
290 static void nx_of_update_sglen(struct device   *dev,
291 			       struct property *p,
292 			       struct nx_of    *props)
293 {
294 	if (p->length != sizeof(props->max_sg_len)) {
295 		dev_err(dev, "%s: unexpected format for "
296 			"ibm,max-sg-len property\n", __func__);
297 		dev_dbg(dev, "%s: ibm,max-sg-len is %d bytes "
298 			"long, expected %zd bytes\n", __func__,
299 			p->length, sizeof(props->max_sg_len));
300 		return;
301 	}
302 
303 	props->max_sg_len = *(u32 *)p->value;
304 	props->flags |= NX_OF_FLAG_MAXSGLEN_SET;
305 }
306 
307 static void nx_of_update_msc(struct device   *dev,
308 			     struct property *p,
309 			     struct nx_of    *props)
310 {
311 	struct msc_triplet *trip;
312 	struct max_sync_cop *msc;
313 	unsigned int bytes_so_far, i, lenp;
314 
315 	msc = (struct max_sync_cop *)p->value;
316 	lenp = p->length;
317 
318 	/* You can't tell if the data read in for this property is sane by its
319 	 * size alone. This is because there are sizes embedded in the data
320 	 * structure. The best we can do is check lengths as we parse and bail
321 	 * as soon as a length error is detected. */
322 	bytes_so_far = 0;
323 
324 	while ((bytes_so_far + sizeof(struct max_sync_cop)) <= lenp) {
325 		bytes_so_far += sizeof(struct max_sync_cop);
326 
327 		trip = msc->trip;
328 
329 		for (i = 0;
330 		     ((bytes_so_far + sizeof(struct msc_triplet)) <= lenp) &&
331 		     i < msc->triplets;
332 		     i++) {
333 			if (msc->fc > NX_MAX_FC || msc->mode > NX_MAX_MODE) {
334 				dev_err(dev, "unknown function code/mode "
335 					"combo: %d/%d (ignored)\n", msc->fc,
336 					msc->mode);
337 				goto next_loop;
338 			}
339 
340 			switch (trip->keybitlen) {
341 			case 128:
342 			case 160:
343 				props->ap[msc->fc][msc->mode][0].databytelen =
344 					trip->databytelen;
345 				props->ap[msc->fc][msc->mode][0].sglen =
346 					trip->sglen;
347 				break;
348 			case 192:
349 				props->ap[msc->fc][msc->mode][1].databytelen =
350 					trip->databytelen;
351 				props->ap[msc->fc][msc->mode][1].sglen =
352 					trip->sglen;
353 				break;
354 			case 256:
355 				if (msc->fc == NX_FC_AES) {
356 					props->ap[msc->fc][msc->mode][2].
357 						databytelen = trip->databytelen;
358 					props->ap[msc->fc][msc->mode][2].sglen =
359 						trip->sglen;
360 				} else if (msc->fc == NX_FC_AES_HMAC ||
361 					   msc->fc == NX_FC_SHA) {
362 					props->ap[msc->fc][msc->mode][1].
363 						databytelen = trip->databytelen;
364 					props->ap[msc->fc][msc->mode][1].sglen =
365 						trip->sglen;
366 				} else {
367 					dev_warn(dev, "unknown function "
368 						"code/key bit len combo"
369 						": (%u/256)\n", msc->fc);
370 				}
371 				break;
372 			case 512:
373 				props->ap[msc->fc][msc->mode][2].databytelen =
374 					trip->databytelen;
375 				props->ap[msc->fc][msc->mode][2].sglen =
376 					trip->sglen;
377 				break;
378 			default:
379 				dev_warn(dev, "unknown function code/key bit "
380 					 "len combo: (%u/%u)\n", msc->fc,
381 					 trip->keybitlen);
382 				break;
383 			}
384 next_loop:
385 			bytes_so_far += sizeof(struct msc_triplet);
386 			trip++;
387 		}
388 
389 		msc = (struct max_sync_cop *)trip;
390 	}
391 
392 	props->flags |= NX_OF_FLAG_MAXSYNCCOP_SET;
393 }
394 
395 /**
396  * nx_of_init - read openFirmware values from the device tree
397  *
398  * @dev: device handle
399  * @props: pointer to struct to hold the properties values
400  *
401  * Called once at driver probe time, this function will read out the
402  * openFirmware properties we use at runtime. If all the OF properties are
403  * acceptable, when we exit this function props->flags will indicate that
404  * we're ready to register our crypto algorithms.
405  */
406 static void nx_of_init(struct device *dev, struct nx_of *props)
407 {
408 	struct device_node *base_node = dev->of_node;
409 	struct property *p;
410 
411 	p = of_find_property(base_node, "status", NULL);
412 	if (!p)
413 		dev_info(dev, "%s: property 'status' not found\n", __func__);
414 	else
415 		nx_of_update_status(dev, p, props);
416 
417 	p = of_find_property(base_node, "ibm,max-sg-len", NULL);
418 	if (!p)
419 		dev_info(dev, "%s: property 'ibm,max-sg-len' not found\n",
420 			 __func__);
421 	else
422 		nx_of_update_sglen(dev, p, props);
423 
424 	p = of_find_property(base_node, "ibm,max-sync-cop", NULL);
425 	if (!p)
426 		dev_info(dev, "%s: property 'ibm,max-sync-cop' not found\n",
427 			 __func__);
428 	else
429 		nx_of_update_msc(dev, p, props);
430 }
431 
432 /**
433  * nx_register_algs - register algorithms with the crypto API
434  *
435  * Called from nx_probe()
436  *
437  * If all OF properties are in an acceptable state, the driver flags will
438  * indicate that we're ready and we'll create our debugfs files and register
439  * out crypto algorithms.
440  */
441 static int nx_register_algs(void)
442 {
443 	int rc = -1;
444 
445 	if (nx_driver.of.flags != NX_OF_FLAG_MASK_READY)
446 		goto out;
447 
448 	memset(&nx_driver.stats, 0, sizeof(struct nx_stats));
449 
450 	rc = NX_DEBUGFS_INIT(&nx_driver);
451 	if (rc)
452 		goto out;
453 
454 	nx_driver.of.status = NX_OKAY;
455 
456 	rc = crypto_register_alg(&nx_ecb_aes_alg);
457 	if (rc)
458 		goto out;
459 
460 	rc = crypto_register_alg(&nx_cbc_aes_alg);
461 	if (rc)
462 		goto out_unreg_ecb;
463 
464 	rc = crypto_register_alg(&nx_ctr_aes_alg);
465 	if (rc)
466 		goto out_unreg_cbc;
467 
468 	rc = crypto_register_alg(&nx_ctr3686_aes_alg);
469 	if (rc)
470 		goto out_unreg_ctr;
471 
472 	rc = crypto_register_alg(&nx_gcm_aes_alg);
473 	if (rc)
474 		goto out_unreg_ctr3686;
475 
476 	rc = crypto_register_alg(&nx_gcm4106_aes_alg);
477 	if (rc)
478 		goto out_unreg_gcm;
479 
480 	rc = crypto_register_alg(&nx_ccm_aes_alg);
481 	if (rc)
482 		goto out_unreg_gcm4106;
483 
484 	rc = crypto_register_alg(&nx_ccm4309_aes_alg);
485 	if (rc)
486 		goto out_unreg_ccm;
487 
488 	rc = crypto_register_shash(&nx_shash_sha256_alg);
489 	if (rc)
490 		goto out_unreg_ccm4309;
491 
492 	rc = crypto_register_shash(&nx_shash_sha512_alg);
493 	if (rc)
494 		goto out_unreg_s256;
495 
496 	rc = crypto_register_shash(&nx_shash_aes_xcbc_alg);
497 	if (rc)
498 		goto out_unreg_s512;
499 
500 	goto out;
501 
502 out_unreg_s512:
503 	crypto_unregister_shash(&nx_shash_sha512_alg);
504 out_unreg_s256:
505 	crypto_unregister_shash(&nx_shash_sha256_alg);
506 out_unreg_ccm4309:
507 	crypto_unregister_alg(&nx_ccm4309_aes_alg);
508 out_unreg_ccm:
509 	crypto_unregister_alg(&nx_ccm_aes_alg);
510 out_unreg_gcm4106:
511 	crypto_unregister_alg(&nx_gcm4106_aes_alg);
512 out_unreg_gcm:
513 	crypto_unregister_alg(&nx_gcm_aes_alg);
514 out_unreg_ctr3686:
515 	crypto_unregister_alg(&nx_ctr3686_aes_alg);
516 out_unreg_ctr:
517 	crypto_unregister_alg(&nx_ctr_aes_alg);
518 out_unreg_cbc:
519 	crypto_unregister_alg(&nx_cbc_aes_alg);
520 out_unreg_ecb:
521 	crypto_unregister_alg(&nx_ecb_aes_alg);
522 out:
523 	return rc;
524 }
525 
526 /**
527  * nx_crypto_ctx_init - create and initialize a crypto api context
528  *
529  * @nx_ctx: the crypto api context
530  * @fc: function code for the context
531  * @mode: the function code specific mode for this context
532  */
533 static int nx_crypto_ctx_init(struct nx_crypto_ctx *nx_ctx, u32 fc, u32 mode)
534 {
535 	if (nx_driver.of.status != NX_OKAY) {
536 		pr_err("Attempt to initialize NX crypto context while device "
537 		       "is not available!\n");
538 		return -ENODEV;
539 	}
540 
541 	/* we need an extra page for csbcpb_aead for these modes */
542 	if (mode == NX_MODE_AES_GCM || mode == NX_MODE_AES_CCM)
543 		nx_ctx->kmem_len = (4 * NX_PAGE_SIZE) +
544 				   sizeof(struct nx_csbcpb);
545 	else
546 		nx_ctx->kmem_len = (3 * NX_PAGE_SIZE) +
547 				   sizeof(struct nx_csbcpb);
548 
549 	nx_ctx->kmem = kmalloc(nx_ctx->kmem_len, GFP_KERNEL);
550 	if (!nx_ctx->kmem)
551 		return -ENOMEM;
552 
553 	/* the csbcpb and scatterlists must be 4K aligned pages */
554 	nx_ctx->csbcpb = (struct nx_csbcpb *)(round_up((u64)nx_ctx->kmem,
555 						       (u64)NX_PAGE_SIZE));
556 	nx_ctx->in_sg = (struct nx_sg *)((u8 *)nx_ctx->csbcpb + NX_PAGE_SIZE);
557 	nx_ctx->out_sg = (struct nx_sg *)((u8 *)nx_ctx->in_sg + NX_PAGE_SIZE);
558 
559 	if (mode == NX_MODE_AES_GCM || mode == NX_MODE_AES_CCM)
560 		nx_ctx->csbcpb_aead =
561 			(struct nx_csbcpb *)((u8 *)nx_ctx->out_sg +
562 					     NX_PAGE_SIZE);
563 
564 	/* give each context a pointer to global stats and their OF
565 	 * properties */
566 	nx_ctx->stats = &nx_driver.stats;
567 	memcpy(nx_ctx->props, nx_driver.of.ap[fc][mode],
568 	       sizeof(struct alg_props) * 3);
569 
570 	return 0;
571 }
572 
573 /* entry points from the crypto tfm initializers */
574 int nx_crypto_ctx_aes_ccm_init(struct crypto_tfm *tfm)
575 {
576 	return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
577 				  NX_MODE_AES_CCM);
578 }
579 
580 int nx_crypto_ctx_aes_gcm_init(struct crypto_tfm *tfm)
581 {
582 	return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
583 				  NX_MODE_AES_GCM);
584 }
585 
586 int nx_crypto_ctx_aes_ctr_init(struct crypto_tfm *tfm)
587 {
588 	return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
589 				  NX_MODE_AES_CTR);
590 }
591 
592 int nx_crypto_ctx_aes_cbc_init(struct crypto_tfm *tfm)
593 {
594 	return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
595 				  NX_MODE_AES_CBC);
596 }
597 
598 int nx_crypto_ctx_aes_ecb_init(struct crypto_tfm *tfm)
599 {
600 	return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
601 				  NX_MODE_AES_ECB);
602 }
603 
604 int nx_crypto_ctx_sha_init(struct crypto_tfm *tfm)
605 {
606 	return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_SHA, NX_MODE_SHA);
607 }
608 
609 int nx_crypto_ctx_aes_xcbc_init(struct crypto_tfm *tfm)
610 {
611 	return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
612 				  NX_MODE_AES_XCBC_MAC);
613 }
614 
615 /**
616  * nx_crypto_ctx_exit - destroy a crypto api context
617  *
618  * @tfm: the crypto transform pointer for the context
619  *
620  * As crypto API contexts are destroyed, this exit hook is called to free the
621  * memory associated with it.
622  */
623 void nx_crypto_ctx_exit(struct crypto_tfm *tfm)
624 {
625 	struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);
626 
627 	kzfree(nx_ctx->kmem);
628 	nx_ctx->csbcpb = NULL;
629 	nx_ctx->csbcpb_aead = NULL;
630 	nx_ctx->in_sg = NULL;
631 	nx_ctx->out_sg = NULL;
632 }
633 
634 static int nx_probe(struct vio_dev *viodev, const struct vio_device_id *id)
635 {
636 	dev_dbg(&viodev->dev, "driver probed: %s resource id: 0x%x\n",
637 		viodev->name, viodev->resource_id);
638 
639 	if (nx_driver.viodev) {
640 		dev_err(&viodev->dev, "%s: Attempt to register more than one "
641 			"instance of the hardware\n", __func__);
642 		return -EINVAL;
643 	}
644 
645 	nx_driver.viodev = viodev;
646 
647 	nx_of_init(&viodev->dev, &nx_driver.of);
648 
649 	return nx_register_algs();
650 }
651 
652 static int nx_remove(struct vio_dev *viodev)
653 {
654 	dev_dbg(&viodev->dev, "entering nx_remove for UA 0x%x\n",
655 		viodev->unit_address);
656 
657 	if (nx_driver.of.status == NX_OKAY) {
658 		NX_DEBUGFS_FINI(&nx_driver);
659 
660 		crypto_unregister_alg(&nx_ccm_aes_alg);
661 		crypto_unregister_alg(&nx_ccm4309_aes_alg);
662 		crypto_unregister_alg(&nx_gcm_aes_alg);
663 		crypto_unregister_alg(&nx_gcm4106_aes_alg);
664 		crypto_unregister_alg(&nx_ctr_aes_alg);
665 		crypto_unregister_alg(&nx_ctr3686_aes_alg);
666 		crypto_unregister_alg(&nx_cbc_aes_alg);
667 		crypto_unregister_alg(&nx_ecb_aes_alg);
668 		crypto_unregister_shash(&nx_shash_sha256_alg);
669 		crypto_unregister_shash(&nx_shash_sha512_alg);
670 		crypto_unregister_shash(&nx_shash_aes_xcbc_alg);
671 	}
672 
673 	return 0;
674 }
675 
676 
677 /* module wide initialization/cleanup */
678 static int __init nx_init(void)
679 {
680 	return vio_register_driver(&nx_driver.viodriver);
681 }
682 
683 static void __exit nx_fini(void)
684 {
685 	vio_unregister_driver(&nx_driver.viodriver);
686 }
687 
688 static struct vio_device_id nx_crypto_driver_ids[] = {
689 	{ "ibm,sym-encryption-v1", "ibm,sym-encryption" },
690 	{ "", "" }
691 };
692 MODULE_DEVICE_TABLE(vio, nx_crypto_driver_ids);
693 
694 /* driver state structure */
695 struct nx_crypto_driver nx_driver = {
696 	.viodriver = {
697 		.id_table = nx_crypto_driver_ids,
698 		.probe = nx_probe,
699 		.remove = nx_remove,
700 		.name  = NX_NAME,
701 	},
702 };
703 
704 module_init(nx_init);
705 module_exit(nx_fini);
706 
707 MODULE_AUTHOR("Kent Yoder <yoder1@us.ibm.com>");
708 MODULE_DESCRIPTION(NX_STRING);
709 MODULE_LICENSE("GPL");
710 MODULE_VERSION(NX_VERSION);
711