From db9c70e8f3291490fec0da56dce2bfa7837e99f2 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 11 Apr 2014 20:37:37 +0200 Subject: [PATCH] crypto: ghash-clmulni-intel - use C implementation for setkey() commit 8ceee72808d1ae3fb191284afc2257a2be964725 upstream. 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 Acked-by: H. Peter Anvin Fixes: 0e1227d356e9b (crypto: ghash - Add PCLMULQDQ accelerated implementation) Signed-off-by: Herbert Xu --- arch/x86/crypto/ghash-clmulni-intel_asm.S | 28 ---------------------------- arch/x86/crypto/ghash-clmulni-intel_glue.c | 14 +++++++++++--- 2 files changed, 11 insertions(+), 31 deletions(-) diff --git a/arch/x86/crypto/ghash-clmulni-intel_asm.S b/arch/x86/crypto/ghash-clmulni-intel_asm.S index 1eb7f90cb7b9..eb4d2a254b35 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 @@ -131,27 +127,3 @@ ENTRY(clmul_ghash_update) movups DATA, (%rdi) .Lupdate_just_ret: ret - -/* - * 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 diff --git a/arch/x86/crypto/ghash-clmulni-intel_glue.c b/arch/x86/crypto/ghash-clmulni-intel_glue.c index b4bf0a63b520..c07446d17463 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; } -- 1.8.3.2