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linux-next/drivers/crypto/vmx/aes_cbc.c
Anton Blanchard dc4fbba11e powerpc: Create disable_kernel_{fp,altivec,vsx,spe}()
The enable_kernel_*() functions leave the relevant MSR bits enabled
until we exit the kernel sometime later. Create disable versions
that wrap the kernel use of FP, Altivec VSX or SPE.

While we don't want to disable it normally for performance reasons
(MSR writes are slow), it will be used for a debug boot option that
does this and catches bad uses in other areas of the kernel.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-01 13:52:25 +11:00

202 lines
5.2 KiB
C

/**
* AES CBC routines supporting VMX instructions on the Power 8
*
* Copyright (C) 2015 International Business Machines Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 only.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
*/
#include <linux/types.h>
#include <linux/err.h>
#include <linux/crypto.h>
#include <linux/delay.h>
#include <linux/hardirq.h>
#include <asm/switch_to.h>
#include <crypto/aes.h>
#include <crypto/scatterwalk.h>
#include "aesp8-ppc.h"
struct p8_aes_cbc_ctx {
struct crypto_blkcipher *fallback;
struct aes_key enc_key;
struct aes_key dec_key;
};
static int p8_aes_cbc_init(struct crypto_tfm *tfm)
{
const char *alg;
struct crypto_blkcipher *fallback;
struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
if (!(alg = crypto_tfm_alg_name(tfm))) {
printk(KERN_ERR "Failed to get algorithm name.\n");
return -ENOENT;
}
fallback =
crypto_alloc_blkcipher(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(fallback)) {
printk(KERN_ERR
"Failed to allocate transformation for '%s': %ld\n",
alg, PTR_ERR(fallback));
return PTR_ERR(fallback);
}
printk(KERN_INFO "Using '%s' as fallback implementation.\n",
crypto_tfm_alg_driver_name((struct crypto_tfm *) fallback));
crypto_blkcipher_set_flags(
fallback,
crypto_blkcipher_get_flags((struct crypto_blkcipher *)tfm));
ctx->fallback = fallback;
return 0;
}
static void p8_aes_cbc_exit(struct crypto_tfm *tfm)
{
struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
if (ctx->fallback) {
crypto_free_blkcipher(ctx->fallback);
ctx->fallback = NULL;
}
}
static int p8_aes_cbc_setkey(struct crypto_tfm *tfm, const u8 *key,
unsigned int keylen)
{
int ret;
struct p8_aes_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
ret = aes_p8_set_encrypt_key(key, keylen * 8, &ctx->enc_key);
ret += aes_p8_set_decrypt_key(key, keylen * 8, &ctx->dec_key);
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
ret += crypto_blkcipher_setkey(ctx->fallback, key, keylen);
return ret;
}
static int p8_aes_cbc_encrypt(struct blkcipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
int ret;
struct blkcipher_walk walk;
struct p8_aes_cbc_ctx *ctx =
crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
struct blkcipher_desc fallback_desc = {
.tfm = ctx->fallback,
.info = desc->info,
.flags = desc->flags
};
if (in_interrupt()) {
ret = crypto_blkcipher_encrypt(&fallback_desc, dst, src,
nbytes);
} else {
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
blkcipher_walk_init(&walk, dst, src, nbytes);
ret = blkcipher_walk_virt(desc, &walk);
while ((nbytes = walk.nbytes)) {
aes_p8_cbc_encrypt(walk.src.virt.addr,
walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK,
&ctx->enc_key, walk.iv, 1);
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
}
return ret;
}
static int p8_aes_cbc_decrypt(struct blkcipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
int ret;
struct blkcipher_walk walk;
struct p8_aes_cbc_ctx *ctx =
crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
struct blkcipher_desc fallback_desc = {
.tfm = ctx->fallback,
.info = desc->info,
.flags = desc->flags
};
if (in_interrupt()) {
ret = crypto_blkcipher_decrypt(&fallback_desc, dst, src,
nbytes);
} else {
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
blkcipher_walk_init(&walk, dst, src, nbytes);
ret = blkcipher_walk_virt(desc, &walk);
while ((nbytes = walk.nbytes)) {
aes_p8_cbc_encrypt(walk.src.virt.addr,
walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK,
&ctx->dec_key, walk.iv, 0);
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
}
return ret;
}
struct crypto_alg p8_aes_cbc_alg = {
.cra_name = "cbc(aes)",
.cra_driver_name = "p8_aes_cbc",
.cra_module = THIS_MODULE,
.cra_priority = 1000,
.cra_type = &crypto_blkcipher_type,
.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_NEED_FALLBACK,
.cra_alignmask = 0,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct p8_aes_cbc_ctx),
.cra_init = p8_aes_cbc_init,
.cra_exit = p8_aes_cbc_exit,
.cra_blkcipher = {
.ivsize = 0,
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.setkey = p8_aes_cbc_setkey,
.encrypt = p8_aes_cbc_encrypt,
.decrypt = p8_aes_cbc_decrypt,
},
};