Implement a faster version of the GHASH transform which amortizes the reduction modulo the characteristic polynomial across two input blocks at a time. On a Cortex-A53, the gcm(aes) performance increases 24%, from 3.0 cycles per byte to 2.4 cpb for large input sizes. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> --- Raw numbers after the patch. arch/arm64/crypto/ghash-ce-core.S | 86 +++++++------------- arch/arm64/crypto/ghash-ce-glue.c | 34 +++++--- 2 files changed, 52 insertions(+), 68 deletions(-) diff --git a/arch/arm64/crypto/ghash-ce-core.S b/arch/arm64/crypto/ghash-ce-core.S index dac0df29d194..f7281e7a592f 100644 --- a/arch/arm64/crypto/ghash-ce-core.S +++ b/arch/arm64/crypto/ghash-ce-core.S @@ -290,6 +290,10 @@ ENDPROC(pmull_ghash_update_p8) KS1 .req v9 INP0 .req v10 INP1 .req v11 + HH .req v12 + XL2 .req v13 + XM2 .req v14 + XH2 .req v15 .macro load_round_keys, rounds, rk cmp \rounds, #12 @@ -323,6 +327,7 @@ ENDPROC(pmull_ghash_update_p8) .endm .macro pmull_gcm_do_crypt, enc + ld1 {HH.2d}, [x4], #16 ld1 {SHASH.2d}, [x4] ld1 {XL.2d}, [x1] ldr x8, [x5, #8] // load lower counter @@ -330,10 +335,11 @@ ENDPROC(pmull_ghash_update_p8) load_round_keys w7, x6 movi MASK.16b, #0xe1 - ext SHASH2.16b, SHASH.16b, SHASH.16b, #8 + trn1 SHASH2.2d, SHASH.2d, HH.2d + trn2 T1.2d, SHASH.2d, HH.2d CPU_LE( rev x8, x8 ) shl MASK.2d, MASK.2d, #57 - eor SHASH2.16b, SHASH2.16b, SHASH.16b + eor SHASH2.16b, SHASH2.16b, T1.16b .if \enc == 1 ldr x10, [sp] @@ -358,116 +364,82 @@ CPU_LE( rev x8, x8 ) ins KS0.d[1], x9 // set lower counter ins KS1.d[1], x11 - rev64 T1.16b, INP0.16b + rev64 T1.16b, INP1.16b cmp w7, #12 b.ge 2f // AES-192/256? 1: enc_round KS0, v21 - - ext T2.16b, XL.16b, XL.16b, #8 ext IN1.16b, T1.16b, T1.16b, #8 enc_round KS1, v21 - - eor T1.16b, T1.16b, T2.16b - eor XL.16b, XL.16b, IN1.16b + pmull2 XH2.1q, SHASH.2d, IN1.2d // a1 * b1 enc_round KS0, v22 - - pmull2 XH.1q, SHASH.2d, XL.2d // a1 * b1 - eor T1.16b, T1.16b, XL.16b + eor T1.16b, T1.16b, IN1.16b enc_round KS1, v22 - - pmull XL.1q, SHASH.1d, XL.1d // a0 * b0 - pmull XM.1q, SHASH2.1d, T1.1d // (a1 + a0)(b1 + b0) + pmull XL2.1q, SHASH.1d, IN1.1d // a0 * b0 enc_round KS0, v23 - - ext T1.16b, XL.16b, XH.16b, #8 - eor T2.16b, XL.16b, XH.16b - eor XM.16b, XM.16b, T1.16b + pmull XM2.1q, SHASH2.1d, T1.1d // (a1 + a0)(b1 + b0) enc_round KS1, v23 - - eor XM.16b, XM.16b, T2.16b - pmull T2.1q, XL.1d, MASK.1d + rev64 T1.16b, INP0.16b + ext T2.16b, XL.16b, XL.16b, #8 enc_round KS0, v24 - - mov XH.d[0], XM.d[1] - mov XM.d[1], XL.d[0] + ext IN1.16b, T1.16b, T1.16b, #8 + eor T1.16b, T1.16b, T2.16b enc_round KS1, v24 - - eor XL.16b, XM.16b, T2.16b + eor XL.16b, XL.16b, IN1.16b enc_round KS0, v25 - - ext T2.16b, XL.16b, XL.16b, #8 + eor T1.16b, T1.16b, XL.16b enc_round KS1, v25 - - pmull XL.1q, XL.1d, MASK.1d - eor T2.16b, T2.16b, XH.16b + pmull2 XH.1q, HH.2d, XL.2d // a1 * b1 enc_round KS0, v26 - - eor XL.16b, XL.16b, T2.16b - rev64 T1.16b, INP1.16b + pmull XL.1q, HH.1d, XL.1d // a0 * b0 enc_round KS1, v26 - - ext T2.16b, XL.16b, XL.16b, #8 - ext IN1.16b, T1.16b, T1.16b, #8 + pmull2 XM.1q, SHASH2.2d, T1.2d // (a1 + a0)(b1 + b0) enc_round KS0, v27 - - eor T1.16b, T1.16b, T2.16b - eor XL.16b, XL.16b, IN1.16b + eor XL.16b, XL.16b, XL2.16b + eor XH.16b, XH.16b, XH2.16b enc_round KS1, v27 - - pmull2 XH.1q, SHASH.2d, XL.2d // a1 * b1 - eor T1.16b, T1.16b, XL.16b + eor XM.16b, XM.16b, XM2.16b + ext T1.16b, XL.16b, XH.16b, #8 enc_round KS0, v28 - - pmull XL.1q, SHASH.1d, XL.1d // a0 * b0 - pmull XM.1q, SHASH2.1d, T1.1d // (a1 + a0)(b1 + b0) - - enc_round KS1, v28 - - ext T1.16b, XL.16b, XH.16b, #8 eor T2.16b, XL.16b, XH.16b eor XM.16b, XM.16b, T1.16b - enc_round KS0, v29 - + enc_round KS1, v28 eor XM.16b, XM.16b, T2.16b + + enc_round KS0, v29 pmull T2.1q, XL.1d, MASK.1d enc_round KS1, v29 - mov XH.d[0], XM.d[1] mov XM.d[1], XL.d[0] aese KS0.16b, v30.16b - eor XL.16b, XM.16b, T2.16b aese KS1.16b, v30.16b - ext T2.16b, XL.16b, XL.16b, #8 eor KS0.16b, KS0.16b, v31.16b - pmull XL.1q, XL.1d, MASK.1d eor T2.16b, T2.16b, XH.16b eor KS1.16b, KS1.16b, v31.16b - eor XL.16b, XL.16b, T2.16b .if \enc == 0 diff --git a/arch/arm64/crypto/ghash-ce-glue.c b/arch/arm64/crypto/ghash-ce-glue.c index e649f9f6e689..c41ac62c90e9 100644 --- a/arch/arm64/crypto/ghash-ce-glue.c +++ b/arch/arm64/crypto/ghash-ce-glue.c @@ -46,6 +46,7 @@ struct ghash_desc_ctx { struct gcm_aes_ctx { struct crypto_aes_ctx aes_key; + u64 h2[2]; struct ghash_key ghash_key; }; @@ -62,12 +63,11 @@ static void (*pmull_ghash_update)(int blocks, u64 dg[], const char *src, const char *head); asmlinkage void pmull_gcm_encrypt(int blocks, u64 dg[], u8 dst[], - const u8 src[], struct ghash_key const *k, - u8 ctr[], u32 const rk[], int rounds, - u8 ks[]); + const u8 src[], u64 const *k, u8 ctr[], + u32 const rk[], int rounds, u8 ks[]); asmlinkage void pmull_gcm_decrypt(int blocks, u64 dg[], u8 dst[], - const u8 src[], struct ghash_key const *k, + const u8 src[], u64 const *k, u8 ctr[], u32 const rk[], int rounds); asmlinkage void pmull_gcm_encrypt_block(u8 dst[], u8 const src[], @@ -233,7 +233,8 @@ static int gcm_setkey(struct crypto_aead *tfm, const u8 *inkey, unsigned int keylen) { struct gcm_aes_ctx *ctx = crypto_aead_ctx(tfm); - u8 key[GHASH_BLOCK_SIZE]; + be128 h1, h2; + u8 *key = (u8 *)&h1; int ret; ret = crypto_aes_expand_key(&ctx->aes_key, inkey, keylen); @@ -245,7 +246,19 @@ static int gcm_setkey(struct crypto_aead *tfm, const u8 *inkey, __aes_arm64_encrypt(ctx->aes_key.key_enc, key, (u8[AES_BLOCK_SIZE]){}, num_rounds(&ctx->aes_key)); - return __ghash_setkey(&ctx->ghash_key, key, sizeof(key)); + __ghash_setkey(&ctx->ghash_key, key, sizeof(be128)); + + /* calculate H^2 (used for 2-way aggregation) */ + h2 = h1; + gf128mul_lle(&h2, &h1); + + ctx->h2[0] = (be64_to_cpu(h2.b) << 1) | (be64_to_cpu(h2.a) >> 63); + ctx->h2[1] = (be64_to_cpu(h2.a) << 1) | (be64_to_cpu(h2.b) >> 63); + + if (be64_to_cpu(h2.a) >> 63) + ctx->h2[1] ^= 0xc200000000000000UL; + + return 0; } static int gcm_setauthsize(struct crypto_aead *tfm, unsigned int authsize) @@ -379,9 +392,8 @@ static int gcm_encrypt(struct aead_request *req) kernel_neon_begin(); pmull_gcm_encrypt(blocks, dg, walk.dst.virt.addr, - walk.src.virt.addr, &ctx->ghash_key, - iv, ctx->aes_key.key_enc, nrounds, - ks); + walk.src.virt.addr, ctx->h2, iv, + ctx->aes_key.key_enc, nrounds, ks); kernel_neon_end(); err = skcipher_walk_done(&walk, @@ -487,8 +499,8 @@ static int gcm_decrypt(struct aead_request *req) kernel_neon_begin(); pmull_gcm_decrypt(blocks, dg, walk.dst.virt.addr, - walk.src.virt.addr, &ctx->ghash_key, - iv, ctx->aes_key.key_enc, nrounds); + walk.src.virt.addr, ctx->h2, iv, + ctx->aes_key.key_enc, nrounds); kernel_neon_end(); err = skcipher_walk_done(&walk, -- 2.18.0 BASELINE: ========= test 0 (128 bit key, 16 byte blocks): 445165 operations in 1 seconds ( 7122640 bytes) test 1 (128 bit key, 64 byte blocks): 437076 operations in 1 seconds ( 27972864 bytes) test 2 (128 bit key, 256 byte blocks): 354203 operations in 1 seconds ( 90675968 bytes) test 3 (128 bit key, 512 byte blocks): 284031 operations in 1 seconds (145423872 bytes) test 4 (128 bit key, 1024 byte blocks): 203473 operations in 1 seconds (208356352 bytes) test 5 (128 bit key, 2048 byte blocks): 129855 operations in 1 seconds (265943040 bytes) test 6 (128 bit key, 4096 byte blocks): 75686 operations in 1 seconds (310009856 bytes) test 7 (128 bit key, 8192 byte blocks): 40167 operations in 1 seconds (329048064 bytes) test 8 (192 bit key, 16 byte blocks): 441610 operations in 1 seconds ( 7065760 bytes) test 9 (192 bit key, 64 byte blocks): 429364 operations in 1 seconds ( 27479296 bytes) test 10 (192 bit key, 256 byte blocks): 343303 operations in 1 seconds ( 87885568 bytes) test 11 (192 bit key, 512 byte blocks): 272029 operations in 1 seconds (139278848 bytes) test 12 (192 bit key, 1024 byte blocks): 192399 operations in 1 seconds (197016576 bytes) test 13 (192 bit key, 2048 byte blocks): 121298 operations in 1 seconds (248418304 bytes) test 14 (192 bit key, 4096 byte blocks): 69994 operations in 1 seconds (286695424 bytes) test 15 (192 bit key, 8192 byte blocks): 37045 operations in 1 seconds (303472640 bytes) test 16 (256 bit key, 16 byte blocks): 438244 operations in 1 seconds ( 7011904 bytes) test 17 (256 bit key, 64 byte blocks): 423345 operations in 1 seconds ( 27094080 bytes) test 18 (256 bit key, 256 byte blocks): 336844 operations in 1 seconds ( 86232064 bytes) test 19 (256 bit key, 512 byte blocks): 265711 operations in 1 seconds (136044032 bytes) test 20 (256 bit key, 1024 byte blocks): 186853 operations in 1 seconds (191337472 bytes) test 21 (256 bit key, 2048 byte blocks): 117301 operations in 1 seconds (240232448 bytes) test 22 (256 bit key, 4096 byte blocks): 67513 operations in 1 seconds (276533248 bytes) test 23 (256 bit key, 8192 byte blocks): 35629 operations in 1 seconds (291872768 bytes) THIS PATCH: =========== test 0 (128 bit key, 16 byte blocks): 441257 operations in 1 seconds ( 7060112 bytes) test 1 (128 bit key, 64 byte blocks): 436595 operations in 1 seconds ( 27942080 bytes) test 2 (128 bit key, 256 byte blocks): 369839 operations in 1 seconds ( 94678784 bytes) test 3 (128 bit key, 512 byte blocks): 308239 operations in 1 seconds (157818368 bytes) test 4 (128 bit key, 1024 byte blocks): 231004 operations in 1 seconds (236548096 bytes) test 5 (128 bit key, 2048 byte blocks): 153930 operations in 1 seconds (315248640 bytes) test 6 (128 bit key, 4096 byte blocks): 92739 operations in 1 seconds (379858944 bytes) test 7 (128 bit key, 8192 byte blocks): 49934 operations in 1 seconds (409059328 bytes) test 8 (192 bit key, 16 byte blocks): 437427 operations in 1 seconds ( 6998832 bytes) test 9 (192 bit key, 64 byte blocks): 429462 operations in 1 seconds ( 27485568 bytes) test 10 (192 bit key, 256 byte blocks): 358183 operations in 1 seconds ( 91694848 bytes) test 11 (192 bit key, 512 byte blocks): 294539 operations in 1 seconds (150803968 bytes) test 12 (192 bit key, 1024 byte blocks): 217082 operations in 1 seconds (222291968 bytes) test 13 (192 bit key, 2048 byte blocks): 140672 operations in 1 seconds (288096256 bytes) test 14 (192 bit key, 4096 byte blocks): 84369 operations in 1 seconds (345575424 bytes) test 15 (192 bit key, 8192 byte blocks): 45280 operations in 1 seconds (370933760 bytes) test 16 (256 bit key, 16 byte blocks): 434127 operations in 1 seconds ( 6946032 bytes) test 17 (256 bit key, 64 byte blocks): 423837 operations in 1 seconds ( 27125568 bytes) test 18 (256 bit key, 256 byte blocks): 351244 operations in 1 seconds ( 89918464 bytes) test 19 (256 bit key, 512 byte blocks): 286884 operations in 1 seconds (146884608 bytes) test 20 (256 bit key, 1024 byte blocks): 209954 operations in 1 seconds (214992896 bytes) test 21 (256 bit key, 2048 byte blocks): 136553 operations in 1 seconds (279660544 bytes) test 22 (256 bit key, 4096 byte blocks): 80749 operations in 1 seconds (330747904 bytes) test 23 (256 bit key, 8192 byte blocks): 43118 operations in 1 seconds (353222656 bytes)