Skip to content

Commit

Permalink
crypto: s390 - add System z hardware support for CTR mode
Browse files Browse the repository at this point in the history 
This patch adds System z hardware acceleration support for AES, DES
and 3DES in CTR mode. The hardware support is available starting with
System z196.

Signed-off-by: Gerald Schaefer <[email protected]>
Signed-off-by: Jan Glauber <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
  • Loading branch information
@gerald-schaefer @herbertx
gerald-schaefer authored and herbertx committed May 4, 2011
1 parent 9996e34 commit 0200f3e
Show file tree
Hide file tree
Showing 4 changed files with 383 additions and 6 deletions.
146 changes: 144 additions & 2 deletions arch/s390/crypto/aes_s390.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,8 @@
#define AES_KEYLEN_192 2
#define AES_KEYLEN_256 4

static char keylen_flag = 0;
static u8 *ctrblk;
static char keylen_flag;

struct s390_aes_ctx {
u8 iv[AES_BLOCK_SIZE];
Expand Down Expand Up @@ -724,9 +725,128 @@ static struct crypto_alg xts_aes_alg = {
}
};

static int ctr_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len)
{
struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);

switch (key_len) {
case 16:
sctx->enc = KMCTR_AES_128_ENCRYPT;
sctx->dec = KMCTR_AES_128_DECRYPT;
break;
case 24:
sctx->enc = KMCTR_AES_192_ENCRYPT;
sctx->dec = KMCTR_AES_192_DECRYPT;
break;
case 32:
sctx->enc = KMCTR_AES_256_ENCRYPT;
sctx->dec = KMCTR_AES_256_DECRYPT;
break;
}

return aes_set_key(tfm, in_key, key_len);
}

static int ctr_aes_crypt(struct blkcipher_desc *desc, long func,
struct s390_aes_ctx *sctx, struct blkcipher_walk *walk)
{
int ret = blkcipher_walk_virt_block(desc, walk, AES_BLOCK_SIZE);
unsigned int i, n, nbytes;
u8 buf[AES_BLOCK_SIZE];
u8 *out, *in;

if (!walk->nbytes)
return ret;

memcpy(ctrblk, walk->iv, AES_BLOCK_SIZE);
while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) {
out = walk->dst.virt.addr;
in = walk->src.virt.addr;
while (nbytes >= AES_BLOCK_SIZE) {
/* only use complete blocks, max. PAGE_SIZE */
n = (nbytes > PAGE_SIZE) ? PAGE_SIZE :
nbytes & ~(AES_BLOCK_SIZE - 1);
for (i = AES_BLOCK_SIZE; i < n; i += AES_BLOCK_SIZE) {
memcpy(ctrblk + i, ctrblk + i - AES_BLOCK_SIZE,
AES_BLOCK_SIZE);
crypto_inc(ctrblk + i, AES_BLOCK_SIZE);
}
ret = crypt_s390_kmctr(func, sctx->key, out, in, n, ctrblk);
BUG_ON(ret < 0 || ret != n);
if (n > AES_BLOCK_SIZE)
memcpy(ctrblk, ctrblk + n - AES_BLOCK_SIZE,
AES_BLOCK_SIZE);
crypto_inc(ctrblk, AES_BLOCK_SIZE);
out += n;
in += n;
nbytes -= n;
}
ret = blkcipher_walk_done(desc, walk, nbytes);
}
/*
* final block may be < AES_BLOCK_SIZE, copy only nbytes
*/
if (nbytes) {
out = walk->dst.virt.addr;
in = walk->src.virt.addr;
ret = crypt_s390_kmctr(func, sctx->key, buf, in,
AES_BLOCK_SIZE, ctrblk);
BUG_ON(ret < 0 || ret != AES_BLOCK_SIZE);
memcpy(out, buf, nbytes);
crypto_inc(ctrblk, AES_BLOCK_SIZE);
ret = blkcipher_walk_done(desc, walk, 0);
}
memcpy(walk->iv, ctrblk, AES_BLOCK_SIZE);
return ret;
}

static int ctr_aes_encrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;

blkcipher_walk_init(&walk, dst, src, nbytes);
return ctr_aes_crypt(desc, sctx->enc, sctx, &walk);
}

static int ctr_aes_decrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;

blkcipher_walk_init(&walk, dst, src, nbytes);
return ctr_aes_crypt(desc, sctx->dec, sctx, &walk);
}

static struct crypto_alg ctr_aes_alg = {
.cra_name = "ctr(aes)",
.cra_driver_name = "ctr-aes-s390",
.cra_priority = CRYPT_S390_COMPOSITE_PRIORITY,
.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
.cra_blocksize = 1,
.cra_ctxsize = sizeof(struct s390_aes_ctx),
.cra_type = &crypto_blkcipher_type,
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(ctr_aes_alg.cra_list),
.cra_u = {
.blkcipher = {
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.setkey = ctr_aes_set_key,
.encrypt = ctr_aes_encrypt,
.decrypt = ctr_aes_decrypt,
}
}
};

static int __init aes_s390_init(void)
{
unsigned long long facility_bits[2];
int ret;

if (crypt_s390_func_available(KM_AES_128_ENCRYPT, CRYPT_S390_MSA))
Expand Down Expand Up @@ -765,9 +885,29 @@ static int __init aes_s390_init(void)
goto xts_aes_err;
}

if (crypt_s390_func_available(KMCTR_AES_128_ENCRYPT,
CRYPT_S390_MSA | CRYPT_S390_MSA4) &&
crypt_s390_func_available(KMCTR_AES_192_ENCRYPT,
CRYPT_S390_MSA | CRYPT_S390_MSA4) &&
crypt_s390_func_available(KMCTR_AES_256_ENCRYPT,
CRYPT_S390_MSA | CRYPT_S390_MSA4)) {
ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
if (!ctrblk) {
ret = -ENOMEM;
goto ctr_aes_err;
}
ret = crypto_register_alg(&ctr_aes_alg);
if (ret) {
free_page((unsigned long) ctrblk);
goto ctr_aes_err;
}
}

out:
return ret;

ctr_aes_err:
crypto_unregister_alg(&xts_aes_alg);
xts_aes_err:
crypto_unregister_alg(&cbc_aes_alg);
cbc_aes_err:
Expand All @@ -780,6 +920,8 @@ static int __init aes_s390_init(void)

static void __exit aes_s390_fini(void)
{
crypto_unregister_alg(&ctr_aes_alg);
free_page((unsigned long) ctrblk);
crypto_unregister_alg(&xts_aes_alg);
crypto_unregister_alg(&cbc_aes_alg);
crypto_unregister_alg(&ecb_aes_alg);
Expand Down
66 changes: 65 additions & 1 deletion arch/s390/crypto/crypt_s390.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -34,7 +34,8 @@ enum crypt_s390_operations {
CRYPT_S390_KMC = 0x0200,
CRYPT_S390_KIMD = 0x0300,
CRYPT_S390_KLMD = 0x0400,
CRYPT_S390_KMAC = 0x0500
CRYPT_S390_KMAC = 0x0500,
CRYPT_S390_KMCTR = 0x0600
};

/*
Expand Down Expand Up @@ -82,6 +83,26 @@ enum crypt_s390_kmc_func {
KMC_PRNG = CRYPT_S390_KMC | 0x43,
};

/*
* function codes for KMCTR (CIPHER MESSAGE WITH COUNTER)
* instruction
*/
enum crypt_s390_kmctr_func {
KMCTR_QUERY = CRYPT_S390_KMCTR | 0x0,
KMCTR_DEA_ENCRYPT = CRYPT_S390_KMCTR | 0x1,
KMCTR_DEA_DECRYPT = CRYPT_S390_KMCTR | 0x1 | 0x80,
KMCTR_TDEA_128_ENCRYPT = CRYPT_S390_KMCTR | 0x2,
KMCTR_TDEA_128_DECRYPT = CRYPT_S390_KMCTR | 0x2 | 0x80,
KMCTR_TDEA_192_ENCRYPT = CRYPT_S390_KMCTR | 0x3,
KMCTR_TDEA_192_DECRYPT = CRYPT_S390_KMCTR | 0x3 | 0x80,
KMCTR_AES_128_ENCRYPT = CRYPT_S390_KMCTR | 0x12,
KMCTR_AES_128_DECRYPT = CRYPT_S390_KMCTR | 0x12 | 0x80,
KMCTR_AES_192_ENCRYPT = CRYPT_S390_KMCTR | 0x13,
KMCTR_AES_192_DECRYPT = CRYPT_S390_KMCTR | 0x13 | 0x80,
KMCTR_AES_256_ENCRYPT = CRYPT_S390_KMCTR | 0x14,
KMCTR_AES_256_DECRYPT = CRYPT_S390_KMCTR | 0x14 | 0x80,
};

/*
* function codes for KIMD (COMPUTE INTERMEDIATE MESSAGE DIGEST)
* instruction
Expand Down Expand Up @@ -292,6 +313,45 @@ static inline int crypt_s390_kmac(long func, void *param,
return (func & CRYPT_S390_FUNC_MASK) ? src_len - __src_len : __src_len;
}

/**
* crypt_s390_kmctr:
* @func: the function code passed to KMCTR; see crypt_s390_kmctr_func
* @param: address of parameter block; see POP for details on each func
* @dest: address of destination memory area
* @src: address of source memory area
* @src_len: length of src operand in bytes
* @counter: address of counter value
*
* Executes the KMCTR (CIPHER MESSAGE WITH COUNTER) operation of the CPU.
*
* Returns -1 for failure, 0 for the query func, number of processed
* bytes for encryption/decryption funcs
*/
static inline int crypt_s390_kmctr(long func, void *param, u8 *dest,
const u8 *src, long src_len, u8 *counter)
{
register long __func asm("0") = func & CRYPT_S390_FUNC_MASK;
register void *__param asm("1") = param;
register const u8 *__src asm("2") = src;
register long __src_len asm("3") = src_len;
register u8 *__dest asm("4") = dest;
register u8 *__ctr asm("6") = counter;
int ret = -1;

asm volatile(
"0: .insn rrf,0xb92d0000,%3,%1,%4,0 \n" /* KMCTR opcode */
"1: brc 1,0b \n" /* handle partial completion */
" la %0,0\n"
"2:\n"
EX_TABLE(0b,2b) EX_TABLE(1b,2b)
: "+d" (ret), "+a" (__src), "+d" (__src_len), "+a" (__dest),
"+a" (__ctr)
: "d" (__func), "a" (__param) : "cc", "memory");
if (ret < 0)
return ret;
return (func & CRYPT_S390_FUNC_MASK) ? src_len - __src_len : __src_len;
}

/**
* crypt_s390_func_available:
* @func: the function code of the specific function; 0 if op in general
Expand Down Expand Up @@ -329,6 +389,10 @@ static inline int crypt_s390_func_available(int func,
case CRYPT_S390_KMAC:
ret = crypt_s390_kmac(KMAC_QUERY, &status, NULL, 0);
break;
case CRYPT_S390_KMCTR:
ret = crypt_s390_kmctr(KMCTR_QUERY, &status, NULL, NULL, 0,
NULL);
break;
default:
return 0;
}
Expand Down
Loading

0 comments on commit 0200f3e

Please sign in to comment.