kernel/arch/powerpc/crypto/aes-spe-modes.S

   1 /*
   2  * AES modes (ECB/CBC/CTR/XTS) for PPC AES implementation
   3  *
   4  * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  */
  12
  13 #include <asm/ppc_asm.h>
  14 #include "aes-spe-regs.h"
  15
  16 #ifdef __BIG_ENDIAN__                   /* Macros for big endian builds */
  17
  18 #define LOAD_DATA(reg, off) \
  19         lwz             reg,off(rSP);   /* load with offset             */
  20 #define SAVE_DATA(reg, off) \
  21         stw             reg,off(rDP);   /* save with offset             */
  22 #define NEXT_BLOCK \
  23         addi            rSP,rSP,16;     /* increment pointers per bloc  */ \
  24         addi            rDP,rDP,16;
  25 #define LOAD_IV(reg, off) \
  26         lwz             reg,off(rIP);   /* IV loading with offset       */
  27 #define SAVE_IV(reg, off) \
  28         stw             reg,off(rIP);   /* IV saving with offset        */
  29 #define START_IV                        /* nothing to reset             */
  30 #define CBC_DEC 16                      /* CBC decrement per block      */
  31 #define CTR_DEC 1                       /* CTR decrement one byte       */
  32
  33 #else                                   /* Macros for little endian     */
  34
  35 #define LOAD_DATA(reg, off) \
  36         lwbrx           reg,0,rSP;      /* load reversed                */ \
  37         addi            rSP,rSP,4;      /* and increment pointer        */
  38 #define SAVE_DATA(reg, off) \
  39         stwbrx          reg,0,rDP;      /* save reversed                */ \
  40         addi            rDP,rDP,4;      /* and increment pointer        */
  41 #define NEXT_BLOCK                      /* nothing todo                 */
  42 #define LOAD_IV(reg, off) \
  43         lwbrx           reg,0,rIP;      /* load reversed                */ \
  44         addi            rIP,rIP,4;      /* and increment pointer        */
  45 #define SAVE_IV(reg, off) \
  46         stwbrx          reg,0,rIP;      /* load reversed                */ \
  47         addi            rIP,rIP,4;      /* and increment pointer        */
  48 #define START_IV \
  49         subi            rIP,rIP,16;     /* must reset pointer           */
  50 #define CBC_DEC 32                      /* 2 blocks because of incs     */
  51 #define CTR_DEC 17                      /* 1 block because of incs      */
  52
  53 #endif
  54
  55 #define SAVE_0_REGS
  56 #define LOAD_0_REGS
  57
  58 #define SAVE_4_REGS \
  59         stw             rI0,96(r1);     /* save 32 bit registers        */ \
  60         stw             rI1,100(r1);                                       \
  61         stw             rI2,104(r1);                                       \
  62         stw             rI3,108(r1);
  63
  64 #define LOAD_4_REGS \
  65         lwz             rI0,96(r1);     /* restore 32 bit registers     */ \
  66         lwz             rI1,100(r1);                                       \
  67         lwz             rI2,104(r1);                                       \
  68         lwz             rI3,108(r1);
  69
  70 #define SAVE_8_REGS \
  71         SAVE_4_REGS                                                        \
  72         stw             rG0,112(r1);    /* save 32 bit registers        */ \
  73         stw             rG1,116(r1);                                       \
  74         stw             rG2,120(r1);                                       \
  75         stw             rG3,124(r1);
  76
  77 #define LOAD_8_REGS \
  78         LOAD_4_REGS                                                        \
  79         lwz             rG0,112(r1);    /* restore 32 bit registers     */ \
  80         lwz             rG1,116(r1);                                       \
  81         lwz             rG2,120(r1);                                       \
  82         lwz             rG3,124(r1);
  83
  84 #define INITIALIZE_CRYPT(tab,nr32bitregs) \
  85         mflr            r0;                                                \
  86         stwu            r1,-160(r1);    /* create stack frame           */ \
  87         lis             rT0,tab@h;      /* en-/decryption table pointer */ \
  88         stw             r0,8(r1);       /* save link register           */ \
  89         ori             rT0,rT0,tab@l;                                     \
  90         evstdw          r14,16(r1);                                        \
  91         mr              rKS,rKP;                                           \
  92         evstdw          r15,24(r1);     /* We must save non volatile    */ \
  93         evstdw          r16,32(r1);     /* registers. Take the chance   */ \
  94         evstdw          r17,40(r1);     /* and save the SPE part too    */ \
  95         evstdw          r18,48(r1);                                        \
  96         evstdw          r19,56(r1);                                        \
  97         evstdw          r20,64(r1);                                        \
  98         evstdw          r21,72(r1);                                        \
  99         evstdw          r22,80(r1);                                        \
 100         evstdw          r23,88(r1);                                        \
 101         SAVE_##nr32bitregs##_REGS
 102
 103 #define FINALIZE_CRYPT(nr32bitregs) \
 104         lwz             r0,8(r1);                                          \
 105         evldw           r14,16(r1);     /* restore SPE registers        */ \
 106         evldw           r15,24(r1);                                        \
 107         evldw           r16,32(r1);                                        \
 108         evldw           r17,40(r1);                                        \
 109         evldw           r18,48(r1);                                        \
 110         evldw           r19,56(r1);                                        \
 111         evldw           r20,64(r1);                                        \
 112         evldw           r21,72(r1);                                        \
 113         evldw           r22,80(r1);                                        \
 114         evldw           r23,88(r1);                                        \
 115         LOAD_##nr32bitregs##_REGS                                          \
 116         mtlr            r0;             /* restore link register        */ \
 117         xor             r0,r0,r0;                                          \
 118         stw             r0,16(r1);      /* delete sensitive data        */ \
 119         stw             r0,24(r1);      /* that we might have pushed    */ \
 120         stw             r0,32(r1);      /* from other context that runs */ \
 121         stw             r0,40(r1);      /* the same code                */ \
 122         stw             r0,48(r1);                                         \
 123         stw             r0,56(r1);                                         \
 124         stw             r0,64(r1);                                         \
 125         stw             r0,72(r1);                                         \
 126         stw             r0,80(r1);                                         \
 127         stw             r0,88(r1);                                         \
 128         addi            r1,r1,160;      /* cleanup stack frame          */
 129
 130 #define ENDIAN_SWAP(t0, t1, s0, s1) \
 131         rotrwi          t0,s0,8;        /* swap endianness for 2 GPRs   */ \
 132         rotrwi          t1,s1,8;                                           \
 133         rlwimi          t0,s0,8,8,15;                                      \
 134         rlwimi          t1,s1,8,8,15;                                      \
 135         rlwimi          t0,s0,8,24,31;                                     \
 136         rlwimi          t1,s1,8,24,31;
 137
 138 #define GF128_MUL(d0, d1, d2, d3, t0) \
 139         li              t0,0x87;        /* multiplication in GF128      */ \
 140         cmpwi           d3,-1;                                             \
 141         iselgt          t0,0,t0;                                           \
 142         rlwimi          d3,d2,0,0,0;    /* propagate "carry" bits       */ \
 143         rotlwi          d3,d3,1;                                           \
 144         rlwimi          d2,d1,0,0,0;                                       \
 145         rotlwi          d2,d2,1;                                           \
 146         rlwimi          d1,d0,0,0,0;                                       \
 147         slwi            d0,d0,1;        /* shift left 128 bit           */ \
 148         rotlwi          d1,d1,1;                                           \
 149         xor             d0,d0,t0;
 150
 151 #define START_KEY(d0, d1, d2, d3) \
 152         lwz             rW0,0(rKP);                                        \
 153         mtctr           rRR;                                               \
 154         lwz             rW1,4(rKP);                                        \
 155         lwz             rW2,8(rKP);                                        \
 156         lwz             rW3,12(rKP);                                       \
 157         xor             rD0,d0,rW0;                                        \
 158         xor             rD1,d1,rW1;                                        \
 159         xor             rD2,d2,rW2;                                        \
 160         xor             rD3,d3,rW3;
 161
 162 /*
 163  * ppc_encrypt_aes(u8 *out, const u8 *in, u32 *key_enc,
 164  *                 u32 rounds)
 165  *
 166  * called from glue layer to encrypt a single 16 byte block
 167  * round values are AES128 = 4, AES192 = 5, AES256 = 6
 168  *
 169  */
 170 _GLOBAL(ppc_encrypt_aes)
 171         INITIALIZE_CRYPT(PPC_AES_4K_ENCTAB, 0)
 172         LOAD_DATA(rD0, 0)
 173         LOAD_DATA(rD1, 4)
 174         LOAD_DATA(rD2, 8)
 175         LOAD_DATA(rD3, 12)
 176         START_KEY(rD0, rD1, rD2, rD3)
 177         bl              ppc_encrypt_block
 178         xor             rD0,rD0,rW0
 179         SAVE_DATA(rD0, 0)
 180         xor             rD1,rD1,rW1
 181         SAVE_DATA(rD1, 4)
 182         xor             rD2,rD2,rW2
 183         SAVE_DATA(rD2, 8)
 184         xor             rD3,rD3,rW3
 185         SAVE_DATA(rD3, 12)
 186         FINALIZE_CRYPT(0)
 187         blr
 188
 189 /*
 190  * ppc_decrypt_aes(u8 *out, const u8 *in, u32 *key_dec,
 191  *                 u32 rounds)
 192  *
 193  * called from glue layer to decrypt a single 16 byte block
 194  * round values are AES128 = 4, AES192 = 5, AES256 = 6
 195  *
 196  */
 197 _GLOBAL(ppc_decrypt_aes)
 198         INITIALIZE_CRYPT(PPC_AES_4K_DECTAB,0)
 199         LOAD_DATA(rD0, 0)
 200         addi            rT1,rT0,4096
 201         LOAD_DATA(rD1, 4)
 202         LOAD_DATA(rD2, 8)
 203         LOAD_DATA(rD3, 12)
 204         START_KEY(rD0, rD1, rD2, rD3)
 205         bl              ppc_decrypt_block
 206         xor             rD0,rD0,rW0
 207         SAVE_DATA(rD0, 0)
 208         xor             rD1,rD1,rW1
 209         SAVE_DATA(rD1, 4)
 210         xor             rD2,rD2,rW2
 211         SAVE_DATA(rD2, 8)
 212         xor             rD3,rD3,rW3
 213         SAVE_DATA(rD3, 12)
 214         FINALIZE_CRYPT(0)
 215         blr
 216
 217 /*
 218  * ppc_encrypt_ecb(u8 *out, const u8 *in, u32 *key_enc,
 219  *                 u32 rounds, u32 bytes);
 220  *
 221  * called from glue layer to encrypt multiple blocks via ECB
 222  * Bytes must be larger or equal 16 and only whole blocks are
 223  * processed. round values are AES128 = 4, AES192 = 5 and
 224  * AES256 = 6
 225  *
 226  */
 227 _GLOBAL(ppc_encrypt_ecb)
 228         INITIALIZE_CRYPT(PPC_AES_4K_ENCTAB, 0)
 229 ppc_encrypt_ecb_loop:
 230         LOAD_DATA(rD0, 0)
 231         mr              rKP,rKS
 232         LOAD_DATA(rD1, 4)
 233         subi            rLN,rLN,16
 234         LOAD_DATA(rD2, 8)
 235         cmpwi           rLN,15
 236         LOAD_DATA(rD3, 12)
 237         START_KEY(rD0, rD1, rD2, rD3)
 238         bl              ppc_encrypt_block
 239         xor             rD0,rD0,rW0
 240         SAVE_DATA(rD0, 0)
 241         xor             rD1,rD1,rW1
 242         SAVE_DATA(rD1, 4)
 243         xor             rD2,rD2,rW2
 244         SAVE_DATA(rD2, 8)
 245         xor             rD3,rD3,rW3
 246         SAVE_DATA(rD3, 12)
 247         NEXT_BLOCK
 248         bt              gt,ppc_encrypt_ecb_loop
 249         FINALIZE_CRYPT(0)
 250         blr
 251
 252 /*
 253  * ppc_decrypt_ecb(u8 *out, const u8 *in, u32 *key_dec,
 254  *                 u32 rounds, u32 bytes);
 255  *
 256  * called from glue layer to decrypt multiple blocks via ECB
 257  * Bytes must be larger or equal 16 and only whole blocks are
 258  * processed. round values are AES128 = 4, AES192 = 5 and
 259  * AES256 = 6
 260  *
 261  */
 262 _GLOBAL(ppc_decrypt_ecb)
 263         INITIALIZE_CRYPT(PPC_AES_4K_DECTAB, 0)
 264         addi            rT1,rT0,4096
 265 ppc_decrypt_ecb_loop:
 266         LOAD_DATA(rD0, 0)
 267         mr              rKP,rKS
 268         LOAD_DATA(rD1, 4)
 269         subi            rLN,rLN,16
 270         LOAD_DATA(rD2, 8)
 271         cmpwi           rLN,15
 272         LOAD_DATA(rD3, 12)
 273         START_KEY(rD0, rD1, rD2, rD3)
 274         bl              ppc_decrypt_block
 275         xor             rD0,rD0,rW0
 276         SAVE_DATA(rD0, 0)
 277         xor             rD1,rD1,rW1
 278         SAVE_DATA(rD1, 4)
 279         xor             rD2,rD2,rW2
 280         SAVE_DATA(rD2, 8)
 281         xor             rD3,rD3,rW3
 282         SAVE_DATA(rD3, 12)
 283         NEXT_BLOCK
 284         bt              gt,ppc_decrypt_ecb_loop
 285         FINALIZE_CRYPT(0)
 286         blr
 287
 288 /*
 289  * ppc_encrypt_cbc(u8 *out, const u8 *in, u32 *key_enc,
 290  *                 32 rounds, u32 bytes, u8 *iv);
 291  *
 292  * called from glue layer to encrypt multiple blocks via CBC
 293  * Bytes must be larger or equal 16 and only whole blocks are
 294  * processed. round values are AES128 = 4, AES192 = 5 and
 295  * AES256 = 6
 296  *
 297  */
 298 _GLOBAL(ppc_encrypt_cbc)
 299         INITIALIZE_CRYPT(PPC_AES_4K_ENCTAB, 4)
 300         LOAD_IV(rI0, 0)
 301         LOAD_IV(rI1, 4)
 302         LOAD_IV(rI2, 8)
 303         LOAD_IV(rI3, 12)
 304 ppc_encrypt_cbc_loop:
 305         LOAD_DATA(rD0, 0)
 306         mr              rKP,rKS
 307         LOAD_DATA(rD1, 4)
 308         subi            rLN,rLN,16
 309         LOAD_DATA(rD2, 8)
 310         cmpwi           rLN,15
 311         LOAD_DATA(rD3, 12)
 312         xor             rD0,rD0,rI0
 313         xor             rD1,rD1,rI1
 314         xor             rD2,rD2,rI2
 315         xor             rD3,rD3,rI3
 316         START_KEY(rD0, rD1, rD2, rD3)
 317         bl              ppc_encrypt_block
 318         xor             rI0,rD0,rW0
 319         SAVE_DATA(rI0, 0)
 320         xor             rI1,rD1,rW1
 321         SAVE_DATA(rI1, 4)
 322         xor             rI2,rD2,rW2
 323         SAVE_DATA(rI2, 8)
 324         xor             rI3,rD3,rW3
 325         SAVE_DATA(rI3, 12)
 326         NEXT_BLOCK
 327         bt              gt,ppc_encrypt_cbc_loop
 328         START_IV
 329         SAVE_IV(rI0, 0)
 330         SAVE_IV(rI1, 4)
 331         SAVE_IV(rI2, 8)
 332         SAVE_IV(rI3, 12)
 333         FINALIZE_CRYPT(4)
 334         blr
 335
 336 /*
 337  * ppc_decrypt_cbc(u8 *out, const u8 *in, u32 *key_dec,
 338  *                 u32 rounds, u32 bytes, u8 *iv);
 339  *
 340  * called from glue layer to decrypt multiple blocks via CBC
 341  * round values are AES128 = 4, AES192 = 5, AES256 = 6
 342  *
 343  */
 344 _GLOBAL(ppc_decrypt_cbc)
 345         INITIALIZE_CRYPT(PPC_AES_4K_DECTAB, 4)
 346         li              rT1,15
 347         LOAD_IV(rI0, 0)
 348         andc            rLN,rLN,rT1
 349         LOAD_IV(rI1, 4)
 350         subi            rLN,rLN,16
 351         LOAD_IV(rI2, 8)
 352         add             rSP,rSP,rLN     /* reverse processing           */
 353         LOAD_IV(rI3, 12)
 354         add             rDP,rDP,rLN
 355         LOAD_DATA(rD0, 0)
 356         addi            rT1,rT0,4096
 357         LOAD_DATA(rD1, 4)
 358         LOAD_DATA(rD2, 8)
 359         LOAD_DATA(rD3, 12)
 360         START_IV
 361         SAVE_IV(rD0, 0)
 362         SAVE_IV(rD1, 4)
 363         SAVE_IV(rD2, 8)
 364         cmpwi           rLN,16
 365         SAVE_IV(rD3, 12)
 366         bt              lt,ppc_decrypt_cbc_end
 367 ppc_decrypt_cbc_loop:
 368         mr              rKP,rKS
 369         START_KEY(rD0, rD1, rD2, rD3)
 370         bl              ppc_decrypt_block
 371         subi            rLN,rLN,16
 372         subi            rSP,rSP,CBC_DEC
 373         xor             rW0,rD0,rW0
 374         LOAD_DATA(rD0, 0)
 375         xor             rW1,rD1,rW1
 376         LOAD_DATA(rD1, 4)
 377         xor             rW2,rD2,rW2
 378         LOAD_DATA(rD2, 8)
 379         xor             rW3,rD3,rW3
 380         LOAD_DATA(rD3, 12)
 381         xor             rW0,rW0,rD0
 382         SAVE_DATA(rW0, 0)
 383         xor             rW1,rW1,rD1
 384         SAVE_DATA(rW1, 4)
 385         xor             rW2,rW2,rD2
 386         SAVE_DATA(rW2, 8)
 387         xor             rW3,rW3,rD3
 388         SAVE_DATA(rW3, 12)
 389         cmpwi           rLN,15
 390         subi            rDP,rDP,CBC_DEC
 391         bt              gt,ppc_decrypt_cbc_loop
 392 ppc_decrypt_cbc_end:
 393         mr              rKP,rKS
 394         START_KEY(rD0, rD1, rD2, rD3)
 395         bl              ppc_decrypt_block
 396         xor             rW0,rW0,rD0
 397         xor             rW1,rW1,rD1
 398         xor             rW2,rW2,rD2
 399         xor             rW3,rW3,rD3
 400         xor             rW0,rW0,rI0     /* decrypt with initial IV      */
 401         SAVE_DATA(rW0, 0)
 402         xor             rW1,rW1,rI1
 403         SAVE_DATA(rW1, 4)
 404         xor             rW2,rW2,rI2
 405         SAVE_DATA(rW2, 8)
 406         xor             rW3,rW3,rI3
 407         SAVE_DATA(rW3, 12)
 408         FINALIZE_CRYPT(4)
 409         blr
 410
 411 /*
 412  * ppc_crypt_ctr(u8 *out, const u8 *in, u32 *key_enc,
 413  *               u32 rounds, u32 bytes, u8 *iv);
 414  *
 415  * called from glue layer to encrypt/decrypt multiple blocks
 416  * via CTR. Number of bytes does not need to be a multiple of
 417  * 16. Round values are AES128 = 4, AES192 = 5, AES256 = 6
 418  *
 419  */
 420 _GLOBAL(ppc_crypt_ctr)
 421         INITIALIZE_CRYPT(PPC_AES_4K_ENCTAB, 4)
 422         LOAD_IV(rI0, 0)
 423         LOAD_IV(rI1, 4)
 424         LOAD_IV(rI2, 8)
 425         cmpwi           rLN,16
 426         LOAD_IV(rI3, 12)
 427         START_IV
 428         bt              lt,ppc_crypt_ctr_partial
 429 ppc_crypt_ctr_loop:
 430         mr              rKP,rKS
 431         START_KEY(rI0, rI1, rI2, rI3)
 432         bl              ppc_encrypt_block
 433         xor             rW0,rD0,rW0
 434         xor             rW1,rD1,rW1
 435         xor             rW2,rD2,rW2
 436         xor             rW3,rD3,rW3
 437         LOAD_DATA(rD0, 0)
 438         subi            rLN,rLN,16
 439         LOAD_DATA(rD1, 4)
 440         LOAD_DATA(rD2, 8)
 441         LOAD_DATA(rD3, 12)
 442         xor             rD0,rD0,rW0
 443         SAVE_DATA(rD0, 0)
 444         xor             rD1,rD1,rW1
 445         SAVE_DATA(rD1, 4)
 446         xor             rD2,rD2,rW2
 447         SAVE_DATA(rD2, 8)
 448         xor             rD3,rD3,rW3
 449         SAVE_DATA(rD3, 12)
 450         addic           rI3,rI3,1       /* increase counter                     */
 451         addze           rI2,rI2
 452         addze           rI1,rI1
 453         addze           rI0,rI0
 454         NEXT_BLOCK
 455         cmpwi           rLN,15
 456         bt              gt,ppc_crypt_ctr_loop
 457 ppc_crypt_ctr_partial:
 458         cmpwi           rLN,0
 459         bt              eq,ppc_crypt_ctr_end
 460         mr              rKP,rKS
 461         START_KEY(rI0, rI1, rI2, rI3)
 462         bl              ppc_encrypt_block
 463         xor             rW0,rD0,rW0
 464         SAVE_IV(rW0, 0)
 465         xor             rW1,rD1,rW1
 466         SAVE_IV(rW1, 4)
 467         xor             rW2,rD2,rW2
 468         SAVE_IV(rW2, 8)
 469         xor             rW3,rD3,rW3
 470         SAVE_IV(rW3, 12)
 471         mtctr           rLN
 472         subi            rIP,rIP,CTR_DEC
 473         subi            rSP,rSP,1
 474         subi            rDP,rDP,1
 475 ppc_crypt_ctr_xorbyte:
 476         lbzu            rW4,1(rIP)      /* bytewise xor for partial block       */
 477         lbzu            rW5,1(rSP)
 478         xor             rW4,rW4,rW5
 479         stbu            rW4,1(rDP)
 480         bdnz            ppc_crypt_ctr_xorbyte
 481         subf            rIP,rLN,rIP
 482         addi            rIP,rIP,1
 483         addic           rI3,rI3,1
 484         addze           rI2,rI2
 485         addze           rI1,rI1
 486         addze           rI0,rI0
 487 ppc_crypt_ctr_end:
 488         SAVE_IV(rI0, 0)
 489         SAVE_IV(rI1, 4)
 490         SAVE_IV(rI2, 8)
 491         SAVE_IV(rI3, 12)
 492         FINALIZE_CRYPT(4)
 493         blr
 494
 495 /*
 496  * ppc_encrypt_xts(u8 *out, const u8 *in, u32 *key_enc,
 497  *                 u32 rounds, u32 bytes, u8 *iv, u32 *key_twk);
 498  *
 499  * called from glue layer to encrypt multiple blocks via XTS
 500  * If key_twk is given, the initial IV encryption will be
 501  * processed too. Round values are AES128 = 4, AES192 = 5,
 502  * AES256 = 6
 503  *
 504  */
 505 _GLOBAL(ppc_encrypt_xts)
 506         INITIALIZE_CRYPT(PPC_AES_4K_ENCTAB, 8)
 507         LOAD_IV(rI0, 0)
 508         LOAD_IV(rI1, 4)
 509         LOAD_IV(rI2, 8)
 510         cmpwi           rKT,0
 511         LOAD_IV(rI3, 12)
 512         bt              eq,ppc_encrypt_xts_notweak
 513         mr              rKP,rKT
 514         START_KEY(rI0, rI1, rI2, rI3)
 515         bl              ppc_encrypt_block
 516         xor             rI0,rD0,rW0
 517         xor             rI1,rD1,rW1
 518         xor             rI2,rD2,rW2
 519         xor             rI3,rD3,rW3
 520 ppc_encrypt_xts_notweak:
 521         ENDIAN_SWAP(rG0, rG1, rI0, rI1)
 522         ENDIAN_SWAP(rG2, rG3, rI2, rI3)
 523 ppc_encrypt_xts_loop:
 524         LOAD_DATA(rD0, 0)
 525         mr              rKP,rKS
 526         LOAD_DATA(rD1, 4)
 527         subi            rLN,rLN,16
 528         LOAD_DATA(rD2, 8)
 529         LOAD_DATA(rD3, 12)
 530         xor             rD0,rD0,rI0
 531         xor             rD1,rD1,rI1
 532         xor             rD2,rD2,rI2
 533         xor             rD3,rD3,rI3
 534         START_KEY(rD0, rD1, rD2, rD3)
 535         bl              ppc_encrypt_block
 536         xor             rD0,rD0,rW0
 537         xor             rD1,rD1,rW1
 538         xor             rD2,rD2,rW2
 539         xor             rD3,rD3,rW3
 540         xor             rD0,rD0,rI0
 541         SAVE_DATA(rD0, 0)
 542         xor             rD1,rD1,rI1
 543         SAVE_DATA(rD1, 4)
 544         xor             rD2,rD2,rI2
 545         SAVE_DATA(rD2, 8)
 546         xor             rD3,rD3,rI3
 547         SAVE_DATA(rD3, 12)
 548         GF128_MUL(rG0, rG1, rG2, rG3, rW0)
 549         ENDIAN_SWAP(rI0, rI1, rG0, rG1)
 550         ENDIAN_SWAP(rI2, rI3, rG2, rG3)
 551         cmpwi           rLN,0
 552         NEXT_BLOCK
 553         bt              gt,ppc_encrypt_xts_loop
 554         START_IV
 555         SAVE_IV(rI0, 0)
 556         SAVE_IV(rI1, 4)
 557         SAVE_IV(rI2, 8)
 558         SAVE_IV(rI3, 12)
 559         FINALIZE_CRYPT(8)
 560         blr
 561
 562 /*
 563  * ppc_decrypt_xts(u8 *out, const u8 *in, u32 *key_dec,
 564  *                 u32 rounds, u32 blocks, u8 *iv, u32 *key_twk);
 565  *
 566  * called from glue layer to decrypt multiple blocks via XTS
 567  * If key_twk is given, the initial IV encryption will be
 568  * processed too. Round values are AES128 = 4, AES192 = 5,
 569  * AES256 = 6
 570  *
 571  */
 572 _GLOBAL(ppc_decrypt_xts)
 573         INITIALIZE_CRYPT(PPC_AES_4K_DECTAB, 8)
 574         LOAD_IV(rI0, 0)
 575         addi            rT1,rT0,4096
 576         LOAD_IV(rI1, 4)
 577         LOAD_IV(rI2, 8)
 578         cmpwi           rKT,0
 579         LOAD_IV(rI3, 12)
 580         bt              eq,ppc_decrypt_xts_notweak
 581         subi            rT0,rT0,4096
 582         mr              rKP,rKT
 583         START_KEY(rI0, rI1, rI2, rI3)
 584         bl              ppc_encrypt_block
 585         xor             rI0,rD0,rW0
 586         xor             rI1,rD1,rW1
 587         xor             rI2,rD2,rW2
 588         xor             rI3,rD3,rW3
 589         addi            rT0,rT0,4096
 590 ppc_decrypt_xts_notweak:
 591         ENDIAN_SWAP(rG0, rG1, rI0, rI1)
 592         ENDIAN_SWAP(rG2, rG3, rI2, rI3)
 593 ppc_decrypt_xts_loop:
 594         LOAD_DATA(rD0, 0)
 595         mr              rKP,rKS
 596         LOAD_DATA(rD1, 4)
 597         subi            rLN,rLN,16
 598         LOAD_DATA(rD2, 8)
 599         LOAD_DATA(rD3, 12)
 600         xor             rD0,rD0,rI0
 601         xor             rD1,rD1,rI1
 602         xor             rD2,rD2,rI2
 603         xor             rD3,rD3,rI3
 604         START_KEY(rD0, rD1, rD2, rD3)
 605         bl              ppc_decrypt_block
 606         xor             rD0,rD0,rW0
 607         xor             rD1,rD1,rW1
 608         xor             rD2,rD2,rW2
 609         xor             rD3,rD3,rW3
 610         xor             rD0,rD0,rI0
 611         SAVE_DATA(rD0, 0)
 612         xor             rD1,rD1,rI1
 613         SAVE_DATA(rD1, 4)
 614         xor             rD2,rD2,rI2
 615         SAVE_DATA(rD2, 8)
 616         xor             rD3,rD3,rI3
 617         SAVE_DATA(rD3, 12)
 618         GF128_MUL(rG0, rG1, rG2, rG3, rW0)
 619         ENDIAN_SWAP(rI0, rI1, rG0, rG1)
 620         ENDIAN_SWAP(rI2, rI3, rG2, rG3)
 621         cmpwi           rLN,0
 622         NEXT_BLOCK
 623         bt              gt,ppc_decrypt_xts_loop
 624         START_IV
 625         SAVE_IV(rI0, 0)
 626         SAVE_IV(rI1, 4)
 627         SAVE_IV(rI2, 8)
 628         SAVE_IV(rI3, 12)
 629         FINALIZE_CRYPT(8)
 630         blr