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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2014-03-27 18:14:40 +0100
committerHerbert Xu <herbert@gondor.apana.org.au>2014-04-01 17:22:47 +0800
commit8ceee72808d1ae3fb191284afc2257a2be964725 (patch)
tree30112eda2dac48ea04c9bd035dd918b82a47c2af /arch/x86/crypto
parent37b28947170ebe55cb4f689ded5857d943c6578e (diff)
downloadlinux-8ceee72808d1ae3fb191284afc2257a2be964725.tar.bz2
crypto: ghash-clmulni-intel - use C implementation for setkey()
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: 0e1227d356e9b (crypto: ghash - Add PCLMULQDQ accelerated implementation) Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch/x86/crypto')
-rw-r--r--arch/x86/crypto/ghash-clmulni-intel_asm.S29
-rw-r--r--arch/x86/crypto/ghash-clmulni-intel_glue.c14
2 files changed, 11 insertions, 32 deletions
diff --git a/arch/x86/crypto/ghash-clmulni-intel_asm.S b/arch/x86/crypto/ghash-clmulni-intel_asm.S
index 586f41aac361..185fad49d86f 100644
--- a/arch/x86/crypto/ghash-clmulni-intel_asm.S
+++ b/arch/x86/crypto/ghash-clmulni-intel_asm.S
@@ -24,10 +24,6 @@
.align 16
.Lbswap_mask:
.octa 0x000102030405060708090a0b0c0d0e0f
-.Lpoly:
- .octa 0xc2000000000000000000000000000001
-.Ltwo_one:
- .octa 0x00000001000000000000000000000001
#define DATA %xmm0
#define SHASH %xmm1
@@ -134,28 +130,3 @@ ENTRY(clmul_ghash_update)
.Lupdate_just_ret:
ret
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)
diff --git a/arch/x86/crypto/ghash-clmulni-intel_glue.c b/arch/x86/crypto/ghash-clmulni-intel_glue.c
index 6759dd1135be..d785cf2c529c 100644
--- a/arch/x86/crypto/ghash-clmulni-intel_glue.c
+++ b/arch/x86/crypto/ghash-clmulni-intel_glue.c
@@ -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,
const be128 *shash);
-void clmul_ghash_setkey(be128 *shash, const u8 *key);
-
struct ghash_async_ctx {
struct cryptd_ahash *cryptd_tfm;
};
@@ -58,13 +56,23 @@ static int ghash_setkey(struct crypto_shash *tfm,
const u8 *key, unsigned int keylen)
{
struct ghash_ctx *ctx = crypto_shash_ctx(tfm);
+ be128 *x = (be128 *)key;
+ u64 a, b;
if (keylen != GHASH_BLOCK_SIZE) {
crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
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;
}