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crypto: ghash-clmulni-intel - use C implementation for setkey()

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The GHASH setkey() function uses SSE registers but fails to call
kernel_fpu_begin()/kernel_fpu_end(). Instead of adding these calls, and
then having to deal with the restriction that they cannot be called from
interrupt context, move the setkey() implementation to the C domain.

Note that setkey() does not use any particular SSE features and is not
expected to become a performance bottleneck.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Fixes: 0e1227d356 (crypto: ghash - Add PCLMULQDQ accelerated implementation)
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Ard Biesheuvel
2014-03-27 18:14:40 +01:00
committed by Herbert Xu
parent 37b2894717
commit 8ceee72808
2 changed files with 11 additions and 32 deletions
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29
arch/x86/crypto/ghash-clmulni-intel_asm.S
View File

@@ -24,10 +24,6 @@
.align 16 .align 16
.Lbswap_mask: .Lbswap_mask:
.octa 0x000102030405060708090a0b0c0d0e0f .octa 0x000102030405060708090a0b0c0d0e0f
.Lpoly:
.octa 0xc2000000000000000000000000000001
.Ltwo_one:
.octa 0x00000001000000000000000000000001
#define DATA %xmm0 #define DATA %xmm0
#define SHASH %xmm1 #define SHASH %xmm1
@@ -134,28 +130,3 @@ ENTRY(clmul_ghash_update)
.Lupdate_just_ret: .Lupdate_just_ret:
ret ret
ENDPROC(clmul_ghash_update) ENDPROC(clmul_ghash_update)
/*
* void clmul_ghash_setkey(be128 *shash, const u8 *key);
*
* Calculate hash_key << 1 mod poly
*/
ENTRY(clmul_ghash_setkey)
movaps .Lbswap_mask, BSWAP
movups (%rsi), %xmm0
PSHUFB_XMM BSWAP %xmm0
movaps %xmm0, %xmm1
psllq $1, %xmm0
psrlq $63, %xmm1
movaps %xmm1, %xmm2
pslldq $8, %xmm1
psrldq $8, %xmm2
por %xmm1, %xmm0
# reduction
pshufd $0b00100100, %xmm2, %xmm1
pcmpeqd .Ltwo_one, %xmm1
pand .Lpoly, %xmm1
pxor %xmm1, %xmm0
movups %xmm0, (%rdi)
ret
ENDPROC(clmul_ghash_setkey)

14
arch/x86/crypto/ghash-clmulni-intel_glue.c
View File

@@ -30,8 +30,6 @@ void clmul_ghash_mul(char *dst, const be128 *shash);
void clmul_ghash_update(char *dst, const char *src, unsigned int srclen, void clmul_ghash_update(char *dst, const char *src, unsigned int srclen,
const be128 *shash); const be128 *shash);
void clmul_ghash_setkey(be128 *shash, const u8 *key);
struct ghash_async_ctx { struct ghash_async_ctx {
struct cryptd_ahash *cryptd_tfm; struct cryptd_ahash *cryptd_tfm;
}; };
@@ -58,13 +56,23 @@ static int ghash_setkey(struct crypto_shash *tfm,
const u8 *key, unsigned int keylen) const u8 *key, unsigned int keylen)
{ {
struct ghash_ctx *ctx = crypto_shash_ctx(tfm); struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
be128 *x = (be128 *)key;
u64 a, b;
if (keylen != GHASH_BLOCK_SIZE) { if (keylen != GHASH_BLOCK_SIZE) {
crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
return -EINVAL; return -EINVAL;
} }
clmul_ghash_setkey(&ctx->shash, key); /* perform multiplication by 'x' in GF(2^128) */
a = be64_to_cpu(x->a);
b = be64_to_cpu(x->b);
ctx->shash.a = (__be64)((b << 1) | (a >> 63));
ctx->shash.b = (__be64)((a << 1) | (b >> 63));
if (a >> 63)
ctx->shash.b ^= cpu_to_be64(0xc2);
return 0; return 0;
} }