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Diffstat (limited to 'arch/arm64/crypto/polyval-ce-core.S')
| -rw-r--r-- | arch/arm64/crypto/polyval-ce-core.S | 361 |
1 files changed, 0 insertions, 361 deletions
diff --git a/arch/arm64/crypto/polyval-ce-core.S b/arch/arm64/crypto/polyval-ce-core.S deleted file mode 100644 index b5326540d2e3..000000000000 --- a/arch/arm64/crypto/polyval-ce-core.S +++ /dev/null @@ -1,361 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * Implementation of POLYVAL using ARMv8 Crypto Extensions. - * - * Copyright 2021 Google LLC - */ -/* - * This is an efficient implementation of POLYVAL using ARMv8 Crypto Extensions - * It works on 8 blocks at a time, by precomputing the first 8 keys powers h^8, - * ..., h^1 in the POLYVAL finite field. This precomputation allows us to split - * finite field multiplication into two steps. - * - * In the first step, we consider h^i, m_i as normal polynomials of degree less - * than 128. We then compute p(x) = h^8m_0 + ... + h^1m_7 where multiplication - * is simply polynomial multiplication. - * - * In the second step, we compute the reduction of p(x) modulo the finite field - * modulus g(x) = x^128 + x^127 + x^126 + x^121 + 1. - * - * This two step process is equivalent to computing h^8m_0 + ... + h^1m_7 where - * multiplication is finite field multiplication. The advantage is that the - * two-step process only requires 1 finite field reduction for every 8 - * polynomial multiplications. Further parallelism is gained by interleaving the - * multiplications and polynomial reductions. - */ - -#include <linux/linkage.h> -#define STRIDE_BLOCKS 8 - -KEY_POWERS .req x0 -MSG .req x1 -BLOCKS_LEFT .req x2 -ACCUMULATOR .req x3 -KEY_START .req x10 -EXTRA_BYTES .req x11 -TMP .req x13 - -M0 .req v0 -M1 .req v1 -M2 .req v2 -M3 .req v3 -M4 .req v4 -M5 .req v5 -M6 .req v6 -M7 .req v7 -KEY8 .req v8 -KEY7 .req v9 -KEY6 .req v10 -KEY5 .req v11 -KEY4 .req v12 -KEY3 .req v13 -KEY2 .req v14 -KEY1 .req v15 -PL .req v16 -PH .req v17 -TMP_V .req v18 -LO .req v20 -MI .req v21 -HI .req v22 -SUM .req v23 -GSTAR .req v24 - - .text - - .arch armv8-a+crypto - .align 4 - -.Lgstar: - .quad 0xc200000000000000, 0xc200000000000000 - -/* - * Computes the product of two 128-bit polynomials in X and Y and XORs the - * components of the 256-bit product into LO, MI, HI. - * - * Given: - * X = [X_1 : X_0] - * Y = [Y_1 : Y_0] - * - * We compute: - * LO += X_0 * Y_0 - * MI += (X_0 + X_1) * (Y_0 + Y_1) - * HI += X_1 * Y_1 - * - * Later, the 256-bit result can be extracted as: - * [HI_1 : HI_0 + HI_1 + MI_1 + LO_1 : LO_1 + HI_0 + MI_0 + LO_0 : LO_0] - * This step is done when computing the polynomial reduction for efficiency - * reasons. - * - * Karatsuba multiplication is used instead of Schoolbook multiplication because - * it was found to be slightly faster on ARM64 CPUs. - * - */ -.macro karatsuba1 X Y - X .req \X - Y .req \Y - ext v25.16b, X.16b, X.16b, #8 - ext v26.16b, Y.16b, Y.16b, #8 - eor v25.16b, v25.16b, X.16b - eor v26.16b, v26.16b, Y.16b - pmull2 v28.1q, X.2d, Y.2d - pmull v29.1q, X.1d, Y.1d - pmull v27.1q, v25.1d, v26.1d - eor HI.16b, HI.16b, v28.16b - eor LO.16b, LO.16b, v29.16b - eor MI.16b, MI.16b, v27.16b - .unreq X - .unreq Y -.endm - -/* - * Same as karatsuba1, except overwrites HI, LO, MI rather than XORing into - * them. - */ -.macro karatsuba1_store X Y - X .req \X - Y .req \Y - ext v25.16b, X.16b, X.16b, #8 - ext v26.16b, Y.16b, Y.16b, #8 - eor v25.16b, v25.16b, X.16b - eor v26.16b, v26.16b, Y.16b - pmull2 HI.1q, X.2d, Y.2d - pmull LO.1q, X.1d, Y.1d - pmull MI.1q, v25.1d, v26.1d - .unreq X - .unreq Y -.endm - -/* - * Computes the 256-bit polynomial represented by LO, HI, MI. Stores - * the result in PL, PH. - * [PH : PL] = - * [HI_1 : HI_1 + HI_0 + MI_1 + LO_1 : HI_0 + MI_0 + LO_1 + LO_0 : LO_0] - */ -.macro karatsuba2 - // v4 = [HI_1 + MI_1 : HI_0 + MI_0] - eor v4.16b, HI.16b, MI.16b - // v4 = [HI_1 + MI_1 + LO_1 : HI_0 + MI_0 + LO_0] - eor v4.16b, v4.16b, LO.16b - // v5 = [HI_0 : LO_1] - ext v5.16b, LO.16b, HI.16b, #8 - // v4 = [HI_1 + HI_0 + MI_1 + LO_1 : HI_0 + MI_0 + LO_1 + LO_0] - eor v4.16b, v4.16b, v5.16b - // HI = [HI_0 : HI_1] - ext HI.16b, HI.16b, HI.16b, #8 - // LO = [LO_0 : LO_1] - ext LO.16b, LO.16b, LO.16b, #8 - // PH = [HI_1 : HI_1 + HI_0 + MI_1 + LO_1] - ext PH.16b, v4.16b, HI.16b, #8 - // PL = [HI_0 + MI_0 + LO_1 + LO_0 : LO_0] - ext PL.16b, LO.16b, v4.16b, #8 -.endm - -/* - * Computes the 128-bit reduction of PH : PL. Stores the result in dest. - * - * This macro computes p(x) mod g(x) where p(x) is in montgomery form and g(x) = - * x^128 + x^127 + x^126 + x^121 + 1. - * - * We have a 256-bit polynomial PH : PL = P_3 : P_2 : P_1 : P_0 that is the - * product of two 128-bit polynomials in Montgomery form. We need to reduce it - * mod g(x). Also, since polynomials in Montgomery form have an "extra" factor - * of x^128, this product has two extra factors of x^128. To get it back into - * Montgomery form, we need to remove one of these factors by dividing by x^128. - * - * To accomplish both of these goals, we add multiples of g(x) that cancel out - * the low 128 bits P_1 : P_0, leaving just the high 128 bits. Since the low - * bits are zero, the polynomial division by x^128 can be done by right - * shifting. - * - * Since the only nonzero term in the low 64 bits of g(x) is the constant term, - * the multiple of g(x) needed to cancel out P_0 is P_0 * g(x). The CPU can - * only do 64x64 bit multiplications, so split P_0 * g(x) into x^128 * P_0 + - * x^64 * g*(x) * P_0 + P_0, where g*(x) is bits 64-127 of g(x). Adding this to - * the original polynomial gives P_3 : P_2 + P_0 + T_1 : P_1 + T_0 : 0, where T - * = T_1 : T_0 = g*(x) * P_0. Thus, bits 0-63 got "folded" into bits 64-191. - * - * Repeating this same process on the next 64 bits "folds" bits 64-127 into bits - * 128-255, giving the answer in bits 128-255. This time, we need to cancel P_1 - * + T_0 in bits 64-127. The multiple of g(x) required is (P_1 + T_0) * g(x) * - * x^64. Adding this to our previous computation gives P_3 + P_1 + T_0 + V_1 : - * P_2 + P_0 + T_1 + V_0 : 0 : 0, where V = V_1 : V_0 = g*(x) * (P_1 + T_0). - * - * So our final computation is: - * T = T_1 : T_0 = g*(x) * P_0 - * V = V_1 : V_0 = g*(x) * (P_1 + T_0) - * p(x) / x^{128} mod g(x) = P_3 + P_1 + T_0 + V_1 : P_2 + P_0 + T_1 + V_0 - * - * The implementation below saves a XOR instruction by computing P_1 + T_0 : P_0 - * + T_1 and XORing into dest, rather than separately XORing P_1 : P_0 and T_0 : - * T_1 into dest. This allows us to reuse P_1 + T_0 when computing V. - */ -.macro montgomery_reduction dest - DEST .req \dest - // TMP_V = T_1 : T_0 = P_0 * g*(x) - pmull TMP_V.1q, PL.1d, GSTAR.1d - // TMP_V = T_0 : T_1 - ext TMP_V.16b, TMP_V.16b, TMP_V.16b, #8 - // TMP_V = P_1 + T_0 : P_0 + T_1 - eor TMP_V.16b, PL.16b, TMP_V.16b - // PH = P_3 + P_1 + T_0 : P_2 + P_0 + T_1 - eor PH.16b, PH.16b, TMP_V.16b - // TMP_V = V_1 : V_0 = (P_1 + T_0) * g*(x) - pmull2 TMP_V.1q, TMP_V.2d, GSTAR.2d - eor DEST.16b, PH.16b, TMP_V.16b - .unreq DEST -.endm - -/* - * Compute Polyval on 8 blocks. - * - * If reduce is set, also computes the montgomery reduction of the - * previous full_stride call and XORs with the first message block. - * (m_0 + REDUCE(PL, PH))h^8 + ... + m_7h^1. - * I.e., the first multiplication uses m_0 + REDUCE(PL, PH) instead of m_0. - * - * Sets PL, PH. - */ -.macro full_stride reduce - eor LO.16b, LO.16b, LO.16b - eor MI.16b, MI.16b, MI.16b - eor HI.16b, HI.16b, HI.16b - - ld1 {M0.16b, M1.16b, M2.16b, M3.16b}, [MSG], #64 - ld1 {M4.16b, M5.16b, M6.16b, M7.16b}, [MSG], #64 - - karatsuba1 M7 KEY1 - .if \reduce - pmull TMP_V.1q, PL.1d, GSTAR.1d - .endif - - karatsuba1 M6 KEY2 - .if \reduce - ext TMP_V.16b, TMP_V.16b, TMP_V.16b, #8 - .endif - - karatsuba1 M5 KEY3 - .if \reduce - eor TMP_V.16b, PL.16b, TMP_V.16b - .endif - - karatsuba1 M4 KEY4 - .if \reduce - eor PH.16b, PH.16b, TMP_V.16b - .endif - - karatsuba1 M3 KEY5 - .if \reduce - pmull2 TMP_V.1q, TMP_V.2d, GSTAR.2d - .endif - - karatsuba1 M2 KEY6 - .if \reduce - eor SUM.16b, PH.16b, TMP_V.16b - .endif - - karatsuba1 M1 KEY7 - eor M0.16b, M0.16b, SUM.16b - - karatsuba1 M0 KEY8 - karatsuba2 -.endm - -/* - * Handle any extra blocks after full_stride loop. - */ -.macro partial_stride - add KEY_POWERS, KEY_START, #(STRIDE_BLOCKS << 4) - sub KEY_POWERS, KEY_POWERS, BLOCKS_LEFT, lsl #4 - ld1 {KEY1.16b}, [KEY_POWERS], #16 - - ld1 {TMP_V.16b}, [MSG], #16 - eor SUM.16b, SUM.16b, TMP_V.16b - karatsuba1_store KEY1 SUM - sub BLOCKS_LEFT, BLOCKS_LEFT, #1 - - tst BLOCKS_LEFT, #4 - beq .Lpartial4BlocksDone - ld1 {M0.16b, M1.16b, M2.16b, M3.16b}, [MSG], #64 - ld1 {KEY8.16b, KEY7.16b, KEY6.16b, KEY5.16b}, [KEY_POWERS], #64 - karatsuba1 M0 KEY8 - karatsuba1 M1 KEY7 - karatsuba1 M2 KEY6 - karatsuba1 M3 KEY5 -.Lpartial4BlocksDone: - tst BLOCKS_LEFT, #2 - beq .Lpartial2BlocksDone - ld1 {M0.16b, M1.16b}, [MSG], #32 - ld1 {KEY8.16b, KEY7.16b}, [KEY_POWERS], #32 - karatsuba1 M0 KEY8 - karatsuba1 M1 KEY7 -.Lpartial2BlocksDone: - tst BLOCKS_LEFT, #1 - beq .LpartialDone - ld1 {M0.16b}, [MSG], #16 - ld1 {KEY8.16b}, [KEY_POWERS], #16 - karatsuba1 M0 KEY8 -.LpartialDone: - karatsuba2 - montgomery_reduction SUM -.endm - -/* - * Perform montgomery multiplication in GF(2^128) and store result in op1. - * - * Computes op1*op2*x^{-128} mod x^128 + x^127 + x^126 + x^121 + 1 - * If op1, op2 are in montgomery form, this computes the montgomery - * form of op1*op2. - * - * void pmull_polyval_mul(u8 *op1, const u8 *op2); - */ -SYM_FUNC_START(pmull_polyval_mul) - adr TMP, .Lgstar - ld1 {GSTAR.2d}, [TMP] - ld1 {v0.16b}, [x0] - ld1 {v1.16b}, [x1] - karatsuba1_store v0 v1 - karatsuba2 - montgomery_reduction SUM - st1 {SUM.16b}, [x0] - ret -SYM_FUNC_END(pmull_polyval_mul) - -/* - * Perform polynomial evaluation as specified by POLYVAL. This computes: - * h^n * accumulator + h^n * m_0 + ... + h^1 * m_{n-1} - * where n=nblocks, h is the hash key, and m_i are the message blocks. - * - * x0 - pointer to precomputed key powers h^8 ... h^1 - * x1 - pointer to message blocks - * x2 - number of blocks to hash - * x3 - pointer to accumulator - * - * void pmull_polyval_update(const struct polyval_ctx *ctx, const u8 *in, - * size_t nblocks, u8 *accumulator); - */ -SYM_FUNC_START(pmull_polyval_update) - adr TMP, .Lgstar - mov KEY_START, KEY_POWERS - ld1 {GSTAR.2d}, [TMP] - ld1 {SUM.16b}, [ACCUMULATOR] - subs BLOCKS_LEFT, BLOCKS_LEFT, #STRIDE_BLOCKS - blt .LstrideLoopExit - ld1 {KEY8.16b, KEY7.16b, KEY6.16b, KEY5.16b}, [KEY_POWERS], #64 - ld1 {KEY4.16b, KEY3.16b, KEY2.16b, KEY1.16b}, [KEY_POWERS], #64 - full_stride 0 - subs BLOCKS_LEFT, BLOCKS_LEFT, #STRIDE_BLOCKS - blt .LstrideLoopExitReduce -.LstrideLoop: - full_stride 1 - subs BLOCKS_LEFT, BLOCKS_LEFT, #STRIDE_BLOCKS - bge .LstrideLoop -.LstrideLoopExitReduce: - montgomery_reduction SUM -.LstrideLoopExit: - adds BLOCKS_LEFT, BLOCKS_LEFT, #STRIDE_BLOCKS - beq .LskipPartial - partial_stride -.LskipPartial: - st1 {SUM.16b}, [ACCUMULATOR] - ret -SYM_FUNC_END(pmull_polyval_update) |
