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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/powerpc/crypto/aes-spe-modes.S
Initial import
Diffstat (limited to 'arch/powerpc/crypto/aes-spe-modes.S')
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1 files changed, 630 insertions, 0 deletions
diff --git a/arch/powerpc/crypto/aes-spe-modes.S b/arch/powerpc/crypto/aes-spe-modes.S
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+++ b/arch/powerpc/crypto/aes-spe-modes.S
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+/*
+ * AES modes (ECB/CBC/CTR/XTS) for PPC AES implementation
+ *
+ * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#include <asm/ppc_asm.h>
+#include "aes-spe-regs.h"
+
+#ifdef __BIG_ENDIAN__ /* Macros for big endian builds */
+
+#define LOAD_DATA(reg, off) \
+ lwz reg,off(rSP); /* load with offset */
+#define SAVE_DATA(reg, off) \
+ stw reg,off(rDP); /* save with offset */
+#define NEXT_BLOCK \
+ addi rSP,rSP,16; /* increment pointers per bloc */ \
+ addi rDP,rDP,16;
+#define LOAD_IV(reg, off) \
+ lwz reg,off(rIP); /* IV loading with offset */
+#define SAVE_IV(reg, off) \
+ stw reg,off(rIP); /* IV saving with offset */
+#define START_IV /* nothing to reset */
+#define CBC_DEC 16 /* CBC decrement per block */
+#define CTR_DEC 1 /* CTR decrement one byte */
+
+#else /* Macros for little endian */
+
+#define LOAD_DATA(reg, off) \
+ lwbrx reg,0,rSP; /* load reversed */ \
+ addi rSP,rSP,4; /* and increment pointer */
+#define SAVE_DATA(reg, off) \
+ stwbrx reg,0,rDP; /* save reversed */ \
+ addi rDP,rDP,4; /* and increment pointer */
+#define NEXT_BLOCK /* nothing todo */
+#define LOAD_IV(reg, off) \
+ lwbrx reg,0,rIP; /* load reversed */ \
+ addi rIP,rIP,4; /* and increment pointer */
+#define SAVE_IV(reg, off) \
+ stwbrx reg,0,rIP; /* load reversed */ \
+ addi rIP,rIP,4; /* and increment pointer */
+#define START_IV \
+ subi rIP,rIP,16; /* must reset pointer */
+#define CBC_DEC 32 /* 2 blocks because of incs */
+#define CTR_DEC 17 /* 1 block because of incs */
+
+#endif
+
+#define SAVE_0_REGS
+#define LOAD_0_REGS
+
+#define SAVE_4_REGS \
+ stw rI0,96(r1); /* save 32 bit registers */ \
+ stw rI1,100(r1); \
+ stw rI2,104(r1); \
+ stw rI3,108(r1);
+
+#define LOAD_4_REGS \
+ lwz rI0,96(r1); /* restore 32 bit registers */ \
+ lwz rI1,100(r1); \
+ lwz rI2,104(r1); \
+ lwz rI3,108(r1);
+
+#define SAVE_8_REGS \
+ SAVE_4_REGS \
+ stw rG0,112(r1); /* save 32 bit registers */ \
+ stw rG1,116(r1); \
+ stw rG2,120(r1); \
+ stw rG3,124(r1);
+
+#define LOAD_8_REGS \
+ LOAD_4_REGS \
+ lwz rG0,112(r1); /* restore 32 bit registers */ \
+ lwz rG1,116(r1); \
+ lwz rG2,120(r1); \
+ lwz rG3,124(r1);
+
+#define INITIALIZE_CRYPT(tab,nr32bitregs) \
+ mflr r0; \
+ stwu r1,-160(r1); /* create stack frame */ \
+ lis rT0,tab@h; /* en-/decryption table pointer */ \
+ stw r0,8(r1); /* save link register */ \
+ ori rT0,rT0,tab@l; \
+ evstdw r14,16(r1); \
+ mr rKS,rKP; \
+ evstdw r15,24(r1); /* We must save non volatile */ \
+ evstdw r16,32(r1); /* registers. Take the chance */ \
+ evstdw r17,40(r1); /* and save the SPE part too */ \
+ evstdw r18,48(r1); \
+ evstdw r19,56(r1); \
+ evstdw r20,64(r1); \
+ evstdw r21,72(r1); \
+ evstdw r22,80(r1); \
+ evstdw r23,88(r1); \
+ SAVE_##nr32bitregs##_REGS
+
+#define FINALIZE_CRYPT(nr32bitregs) \
+ lwz r0,8(r1); \
+ evldw r14,16(r1); /* restore SPE registers */ \
+ evldw r15,24(r1); \
+ evldw r16,32(r1); \
+ evldw r17,40(r1); \
+ evldw r18,48(r1); \
+ evldw r19,56(r1); \
+ evldw r20,64(r1); \
+ evldw r21,72(r1); \
+ evldw r22,80(r1); \
+ evldw r23,88(r1); \
+ LOAD_##nr32bitregs##_REGS \
+ mtlr r0; /* restore link register */ \
+ xor r0,r0,r0; \
+ stw r0,16(r1); /* delete sensitive data */ \
+ stw r0,24(r1); /* that we might have pushed */ \
+ stw r0,32(r1); /* from other context that runs */ \
+ stw r0,40(r1); /* the same code */ \
+ stw r0,48(r1); \
+ stw r0,56(r1); \
+ stw r0,64(r1); \
+ stw r0,72(r1); \
+ stw r0,80(r1); \
+ stw r0,88(r1); \
+ addi r1,r1,160; /* cleanup stack frame */
+
+#define ENDIAN_SWAP(t0, t1, s0, s1) \
+ rotrwi t0,s0,8; /* swap endianness for 2 GPRs */ \
+ rotrwi t1,s1,8; \
+ rlwimi t0,s0,8,8,15; \
+ rlwimi t1,s1,8,8,15; \
+ rlwimi t0,s0,8,24,31; \
+ rlwimi t1,s1,8,24,31;
+
+#define GF128_MUL(d0, d1, d2, d3, t0) \
+ li t0,0x87; /* multiplication in GF128 */ \
+ cmpwi d3,-1; \
+ iselgt t0,0,t0; \
+ rlwimi d3,d2,0,0,0; /* propagate "carry" bits */ \
+ rotlwi d3,d3,1; \
+ rlwimi d2,d1,0,0,0; \
+ rotlwi d2,d2,1; \
+ rlwimi d1,d0,0,0,0; \
+ slwi d0,d0,1; /* shift left 128 bit */ \
+ rotlwi d1,d1,1; \
+ xor d0,d0,t0;
+
+#define START_KEY(d0, d1, d2, d3) \
+ lwz rW0,0(rKP); \
+ mtctr rRR; \
+ lwz rW1,4(rKP); \
+ lwz rW2,8(rKP); \
+ lwz rW3,12(rKP); \
+ xor rD0,d0,rW0; \
+ xor rD1,d1,rW1; \
+ xor rD2,d2,rW2; \
+ xor rD3,d3,rW3;
+
+/*
+ * ppc_encrypt_aes(u8 *out, const u8 *in, u32 *key_enc,
+ * u32 rounds)
+ *
+ * called from glue layer to encrypt a single 16 byte block
+ * round values are AES128 = 4, AES192 = 5, AES256 = 6
+ *
+ */
+_GLOBAL(ppc_encrypt_aes)
+ INITIALIZE_CRYPT(PPC_AES_4K_ENCTAB, 0)
+ LOAD_DATA(rD0, 0)
+ LOAD_DATA(rD1, 4)
+ LOAD_DATA(rD2, 8)
+ LOAD_DATA(rD3, 12)
+ START_KEY(rD0, rD1, rD2, rD3)
+ bl ppc_encrypt_block
+ xor rD0,rD0,rW0
+ SAVE_DATA(rD0, 0)
+ xor rD1,rD1,rW1
+ SAVE_DATA(rD1, 4)
+ xor rD2,rD2,rW2
+ SAVE_DATA(rD2, 8)
+ xor rD3,rD3,rW3
+ SAVE_DATA(rD3, 12)
+ FINALIZE_CRYPT(0)
+ blr
+
+/*
+ * ppc_decrypt_aes(u8 *out, const u8 *in, u32 *key_dec,
+ * u32 rounds)
+ *
+ * called from glue layer to decrypt a single 16 byte block
+ * round values are AES128 = 4, AES192 = 5, AES256 = 6
+ *
+ */
+_GLOBAL(ppc_decrypt_aes)
+ INITIALIZE_CRYPT(PPC_AES_4K_DECTAB,0)
+ LOAD_DATA(rD0, 0)
+ addi rT1,rT0,4096
+ LOAD_DATA(rD1, 4)
+ LOAD_DATA(rD2, 8)
+ LOAD_DATA(rD3, 12)
+ START_KEY(rD0, rD1, rD2, rD3)
+ bl ppc_decrypt_block
+ xor rD0,rD0,rW0
+ SAVE_DATA(rD0, 0)
+ xor rD1,rD1,rW1
+ SAVE_DATA(rD1, 4)
+ xor rD2,rD2,rW2
+ SAVE_DATA(rD2, 8)
+ xor rD3,rD3,rW3
+ SAVE_DATA(rD3, 12)
+ FINALIZE_CRYPT(0)
+ blr
+
+/*
+ * ppc_encrypt_ecb(u8 *out, const u8 *in, u32 *key_enc,
+ * u32 rounds, u32 bytes);
+ *
+ * called from glue layer to encrypt multiple blocks via ECB
+ * Bytes must be larger or equal 16 and only whole blocks are
+ * processed. round values are AES128 = 4, AES192 = 5 and
+ * AES256 = 6
+ *
+ */
+_GLOBAL(ppc_encrypt_ecb)
+ INITIALIZE_CRYPT(PPC_AES_4K_ENCTAB, 0)
+ppc_encrypt_ecb_loop:
+ LOAD_DATA(rD0, 0)
+ mr rKP,rKS
+ LOAD_DATA(rD1, 4)
+ subi rLN,rLN,16
+ LOAD_DATA(rD2, 8)
+ cmpwi rLN,15
+ LOAD_DATA(rD3, 12)
+ START_KEY(rD0, rD1, rD2, rD3)
+ bl ppc_encrypt_block
+ xor rD0,rD0,rW0
+ SAVE_DATA(rD0, 0)
+ xor rD1,rD1,rW1
+ SAVE_DATA(rD1, 4)
+ xor rD2,rD2,rW2
+ SAVE_DATA(rD2, 8)
+ xor rD3,rD3,rW3
+ SAVE_DATA(rD3, 12)
+ NEXT_BLOCK
+ bt gt,ppc_encrypt_ecb_loop
+ FINALIZE_CRYPT(0)
+ blr
+
+/*
+ * ppc_decrypt_ecb(u8 *out, const u8 *in, u32 *key_dec,
+ * u32 rounds, u32 bytes);
+ *
+ * called from glue layer to decrypt multiple blocks via ECB
+ * Bytes must be larger or equal 16 and only whole blocks are
+ * processed. round values are AES128 = 4, AES192 = 5 and
+ * AES256 = 6
+ *
+ */
+_GLOBAL(ppc_decrypt_ecb)
+ INITIALIZE_CRYPT(PPC_AES_4K_DECTAB, 0)
+ addi rT1,rT0,4096
+ppc_decrypt_ecb_loop:
+ LOAD_DATA(rD0, 0)
+ mr rKP,rKS
+ LOAD_DATA(rD1, 4)
+ subi rLN,rLN,16
+ LOAD_DATA(rD2, 8)
+ cmpwi rLN,15
+ LOAD_DATA(rD3, 12)
+ START_KEY(rD0, rD1, rD2, rD3)
+ bl ppc_decrypt_block
+ xor rD0,rD0,rW0
+ SAVE_DATA(rD0, 0)
+ xor rD1,rD1,rW1
+ SAVE_DATA(rD1, 4)
+ xor rD2,rD2,rW2
+ SAVE_DATA(rD2, 8)
+ xor rD3,rD3,rW3
+ SAVE_DATA(rD3, 12)
+ NEXT_BLOCK
+ bt gt,ppc_decrypt_ecb_loop
+ FINALIZE_CRYPT(0)
+ blr
+
+/*
+ * ppc_encrypt_cbc(u8 *out, const u8 *in, u32 *key_enc,
+ * 32 rounds, u32 bytes, u8 *iv);
+ *
+ * called from glue layer to encrypt multiple blocks via CBC
+ * Bytes must be larger or equal 16 and only whole blocks are
+ * processed. round values are AES128 = 4, AES192 = 5 and
+ * AES256 = 6
+ *
+ */
+_GLOBAL(ppc_encrypt_cbc)
+ INITIALIZE_CRYPT(PPC_AES_4K_ENCTAB, 4)
+ LOAD_IV(rI0, 0)
+ LOAD_IV(rI1, 4)
+ LOAD_IV(rI2, 8)
+ LOAD_IV(rI3, 12)
+ppc_encrypt_cbc_loop:
+ LOAD_DATA(rD0, 0)
+ mr rKP,rKS
+ LOAD_DATA(rD1, 4)
+ subi rLN,rLN,16
+ LOAD_DATA(rD2, 8)
+ cmpwi rLN,15
+ LOAD_DATA(rD3, 12)
+ xor rD0,rD0,rI0
+ xor rD1,rD1,rI1
+ xor rD2,rD2,rI2
+ xor rD3,rD3,rI3
+ START_KEY(rD0, rD1, rD2, rD3)
+ bl ppc_encrypt_block
+ xor rI0,rD0,rW0
+ SAVE_DATA(rI0, 0)
+ xor rI1,rD1,rW1
+ SAVE_DATA(rI1, 4)
+ xor rI2,rD2,rW2
+ SAVE_DATA(rI2, 8)
+ xor rI3,rD3,rW3
+ SAVE_DATA(rI3, 12)
+ NEXT_BLOCK
+ bt gt,ppc_encrypt_cbc_loop
+ START_IV
+ SAVE_IV(rI0, 0)
+ SAVE_IV(rI1, 4)
+ SAVE_IV(rI2, 8)
+ SAVE_IV(rI3, 12)
+ FINALIZE_CRYPT(4)
+ blr
+
+/*
+ * ppc_decrypt_cbc(u8 *out, const u8 *in, u32 *key_dec,
+ * u32 rounds, u32 bytes, u8 *iv);
+ *
+ * called from glue layer to decrypt multiple blocks via CBC
+ * round values are AES128 = 4, AES192 = 5, AES256 = 6
+ *
+ */
+_GLOBAL(ppc_decrypt_cbc)
+ INITIALIZE_CRYPT(PPC_AES_4K_DECTAB, 4)
+ li rT1,15
+ LOAD_IV(rI0, 0)
+ andc rLN,rLN,rT1
+ LOAD_IV(rI1, 4)
+ subi rLN,rLN,16
+ LOAD_IV(rI2, 8)
+ add rSP,rSP,rLN /* reverse processing */
+ LOAD_IV(rI3, 12)
+ add rDP,rDP,rLN
+ LOAD_DATA(rD0, 0)
+ addi rT1,rT0,4096
+ LOAD_DATA(rD1, 4)
+ LOAD_DATA(rD2, 8)
+ LOAD_DATA(rD3, 12)
+ START_IV
+ SAVE_IV(rD0, 0)
+ SAVE_IV(rD1, 4)
+ SAVE_IV(rD2, 8)
+ cmpwi rLN,16
+ SAVE_IV(rD3, 12)
+ bt lt,ppc_decrypt_cbc_end
+ppc_decrypt_cbc_loop:
+ mr rKP,rKS
+ START_KEY(rD0, rD1, rD2, rD3)
+ bl ppc_decrypt_block
+ subi rLN,rLN,16
+ subi rSP,rSP,CBC_DEC
+ xor rW0,rD0,rW0
+ LOAD_DATA(rD0, 0)
+ xor rW1,rD1,rW1
+ LOAD_DATA(rD1, 4)
+ xor rW2,rD2,rW2
+ LOAD_DATA(rD2, 8)
+ xor rW3,rD3,rW3
+ LOAD_DATA(rD3, 12)
+ xor rW0,rW0,rD0
+ SAVE_DATA(rW0, 0)
+ xor rW1,rW1,rD1
+ SAVE_DATA(rW1, 4)
+ xor rW2,rW2,rD2
+ SAVE_DATA(rW2, 8)
+ xor rW3,rW3,rD3
+ SAVE_DATA(rW3, 12)
+ cmpwi rLN,15
+ subi rDP,rDP,CBC_DEC
+ bt gt,ppc_decrypt_cbc_loop
+ppc_decrypt_cbc_end:
+ mr rKP,rKS
+ START_KEY(rD0, rD1, rD2, rD3)
+ bl ppc_decrypt_block
+ xor rW0,rW0,rD0
+ xor rW1,rW1,rD1
+ xor rW2,rW2,rD2
+ xor rW3,rW3,rD3
+ xor rW0,rW0,rI0 /* decrypt with initial IV */
+ SAVE_DATA(rW0, 0)
+ xor rW1,rW1,rI1
+ SAVE_DATA(rW1, 4)
+ xor rW2,rW2,rI2
+ SAVE_DATA(rW2, 8)
+ xor rW3,rW3,rI3
+ SAVE_DATA(rW3, 12)
+ FINALIZE_CRYPT(4)
+ blr
+
+/*
+ * ppc_crypt_ctr(u8 *out, const u8 *in, u32 *key_enc,
+ * u32 rounds, u32 bytes, u8 *iv);
+ *
+ * called from glue layer to encrypt/decrypt multiple blocks
+ * via CTR. Number of bytes does not need to be a multiple of
+ * 16. Round values are AES128 = 4, AES192 = 5, AES256 = 6
+ *
+ */
+_GLOBAL(ppc_crypt_ctr)
+ INITIALIZE_CRYPT(PPC_AES_4K_ENCTAB, 4)
+ LOAD_IV(rI0, 0)
+ LOAD_IV(rI1, 4)
+ LOAD_IV(rI2, 8)
+ cmpwi rLN,16
+ LOAD_IV(rI3, 12)
+ START_IV
+ bt lt,ppc_crypt_ctr_partial
+ppc_crypt_ctr_loop:
+ mr rKP,rKS
+ START_KEY(rI0, rI1, rI2, rI3)
+ bl ppc_encrypt_block
+ xor rW0,rD0,rW0
+ xor rW1,rD1,rW1
+ xor rW2,rD2,rW2
+ xor rW3,rD3,rW3
+ LOAD_DATA(rD0, 0)
+ subi rLN,rLN,16
+ LOAD_DATA(rD1, 4)
+ LOAD_DATA(rD2, 8)
+ LOAD_DATA(rD3, 12)
+ xor rD0,rD0,rW0
+ SAVE_DATA(rD0, 0)
+ xor rD1,rD1,rW1
+ SAVE_DATA(rD1, 4)
+ xor rD2,rD2,rW2
+ SAVE_DATA(rD2, 8)
+ xor rD3,rD3,rW3
+ SAVE_DATA(rD3, 12)
+ addic rI3,rI3,1 /* increase counter */
+ addze rI2,rI2
+ addze rI1,rI1
+ addze rI0,rI0
+ NEXT_BLOCK
+ cmpwi rLN,15
+ bt gt,ppc_crypt_ctr_loop
+ppc_crypt_ctr_partial:
+ cmpwi rLN,0
+ bt eq,ppc_crypt_ctr_end
+ mr rKP,rKS
+ START_KEY(rI0, rI1, rI2, rI3)
+ bl ppc_encrypt_block
+ xor rW0,rD0,rW0
+ SAVE_IV(rW0, 0)
+ xor rW1,rD1,rW1
+ SAVE_IV(rW1, 4)
+ xor rW2,rD2,rW2
+ SAVE_IV(rW2, 8)
+ xor rW3,rD3,rW3
+ SAVE_IV(rW3, 12)
+ mtctr rLN
+ subi rIP,rIP,CTR_DEC
+ subi rSP,rSP,1
+ subi rDP,rDP,1
+ppc_crypt_ctr_xorbyte:
+ lbzu rW4,1(rIP) /* bytewise xor for partial block */
+ lbzu rW5,1(rSP)
+ xor rW4,rW4,rW5
+ stbu rW4,1(rDP)
+ bdnz ppc_crypt_ctr_xorbyte
+ subf rIP,rLN,rIP
+ addi rIP,rIP,1
+ addic rI3,rI3,1
+ addze rI2,rI2
+ addze rI1,rI1
+ addze rI0,rI0
+ppc_crypt_ctr_end:
+ SAVE_IV(rI0, 0)
+ SAVE_IV(rI1, 4)
+ SAVE_IV(rI2, 8)
+ SAVE_IV(rI3, 12)
+ FINALIZE_CRYPT(4)
+ blr
+
+/*
+ * ppc_encrypt_xts(u8 *out, const u8 *in, u32 *key_enc,
+ * u32 rounds, u32 bytes, u8 *iv, u32 *key_twk);
+ *
+ * called from glue layer to encrypt multiple blocks via XTS
+ * If key_twk is given, the initial IV encryption will be
+ * processed too. Round values are AES128 = 4, AES192 = 5,
+ * AES256 = 6
+ *
+ */
+_GLOBAL(ppc_encrypt_xts)
+ INITIALIZE_CRYPT(PPC_AES_4K_ENCTAB, 8)
+ LOAD_IV(rI0, 0)
+ LOAD_IV(rI1, 4)
+ LOAD_IV(rI2, 8)
+ cmpwi rKT,0
+ LOAD_IV(rI3, 12)
+ bt eq,ppc_encrypt_xts_notweak
+ mr rKP,rKT
+ START_KEY(rI0, rI1, rI2, rI3)
+ bl ppc_encrypt_block
+ xor rI0,rD0,rW0
+ xor rI1,rD1,rW1
+ xor rI2,rD2,rW2
+ xor rI3,rD3,rW3
+ppc_encrypt_xts_notweak:
+ ENDIAN_SWAP(rG0, rG1, rI0, rI1)
+ ENDIAN_SWAP(rG2, rG3, rI2, rI3)
+ppc_encrypt_xts_loop:
+ LOAD_DATA(rD0, 0)
+ mr rKP,rKS
+ LOAD_DATA(rD1, 4)
+ subi rLN,rLN,16
+ LOAD_DATA(rD2, 8)
+ LOAD_DATA(rD3, 12)
+ xor rD0,rD0,rI0
+ xor rD1,rD1,rI1
+ xor rD2,rD2,rI2
+ xor rD3,rD3,rI3
+ START_KEY(rD0, rD1, rD2, rD3)
+ bl ppc_encrypt_block
+ xor rD0,rD0,rW0
+ xor rD1,rD1,rW1
+ xor rD2,rD2,rW2
+ xor rD3,rD3,rW3
+ xor rD0,rD0,rI0
+ SAVE_DATA(rD0, 0)
+ xor rD1,rD1,rI1
+ SAVE_DATA(rD1, 4)
+ xor rD2,rD2,rI2
+ SAVE_DATA(rD2, 8)
+ xor rD3,rD3,rI3
+ SAVE_DATA(rD3, 12)
+ GF128_MUL(rG0, rG1, rG2, rG3, rW0)
+ ENDIAN_SWAP(rI0, rI1, rG0, rG1)
+ ENDIAN_SWAP(rI2, rI3, rG2, rG3)
+ cmpwi rLN,0
+ NEXT_BLOCK
+ bt gt,ppc_encrypt_xts_loop
+ START_IV
+ SAVE_IV(rI0, 0)
+ SAVE_IV(rI1, 4)
+ SAVE_IV(rI2, 8)
+ SAVE_IV(rI3, 12)
+ FINALIZE_CRYPT(8)
+ blr
+
+/*
+ * ppc_decrypt_xts(u8 *out, const u8 *in, u32 *key_dec,
+ * u32 rounds, u32 blocks, u8 *iv, u32 *key_twk);
+ *
+ * called from glue layer to decrypt multiple blocks via XTS
+ * If key_twk is given, the initial IV encryption will be
+ * processed too. Round values are AES128 = 4, AES192 = 5,
+ * AES256 = 6
+ *
+ */
+_GLOBAL(ppc_decrypt_xts)
+ INITIALIZE_CRYPT(PPC_AES_4K_DECTAB, 8)
+ LOAD_IV(rI0, 0)
+ addi rT1,rT0,4096
+ LOAD_IV(rI1, 4)
+ LOAD_IV(rI2, 8)
+ cmpwi rKT,0
+ LOAD_IV(rI3, 12)
+ bt eq,ppc_decrypt_xts_notweak
+ subi rT0,rT0,4096
+ mr rKP,rKT
+ START_KEY(rI0, rI1, rI2, rI3)
+ bl ppc_encrypt_block
+ xor rI0,rD0,rW0
+ xor rI1,rD1,rW1
+ xor rI2,rD2,rW2
+ xor rI3,rD3,rW3
+ addi rT0,rT0,4096
+ppc_decrypt_xts_notweak:
+ ENDIAN_SWAP(rG0, rG1, rI0, rI1)
+ ENDIAN_SWAP(rG2, rG3, rI2, rI3)
+ppc_decrypt_xts_loop:
+ LOAD_DATA(rD0, 0)
+ mr rKP,rKS
+ LOAD_DATA(rD1, 4)
+ subi rLN,rLN,16
+ LOAD_DATA(rD2, 8)
+ LOAD_DATA(rD3, 12)
+ xor rD0,rD0,rI0
+ xor rD1,rD1,rI1
+ xor rD2,rD2,rI2
+ xor rD3,rD3,rI3
+ START_KEY(rD0, rD1, rD2, rD3)
+ bl ppc_decrypt_block
+ xor rD0,rD0,rW0
+ xor rD1,rD1,rW1
+ xor rD2,rD2,rW2
+ xor rD3,rD3,rW3
+ xor rD0,rD0,rI0
+ SAVE_DATA(rD0, 0)
+ xor rD1,rD1,rI1
+ SAVE_DATA(rD1, 4)
+ xor rD2,rD2,rI2
+ SAVE_DATA(rD2, 8)
+ xor rD3,rD3,rI3
+ SAVE_DATA(rD3, 12)
+ GF128_MUL(rG0, rG1, rG2, rG3, rW0)
+ ENDIAN_SWAP(rI0, rI1, rG0, rG1)
+ ENDIAN_SWAP(rI2, rI3, rG2, rG3)
+ cmpwi rLN,0
+ NEXT_BLOCK
+ bt gt,ppc_decrypt_xts_loop
+ START_IV
+ SAVE_IV(rI0, 0)
+ SAVE_IV(rI1, 4)
+ SAVE_IV(rI2, 8)
+ SAVE_IV(rI3, 12)
+ FINALIZE_CRYPT(8)
+ blr