1 /* align.c - handle alignment exceptions for the Power PC. 2 * 3 * Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au> 4 * Copyright (c) 1998-1999 TiVo, Inc. 5 * PowerPC 403GCX modifications. 6 * Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu> 7 * PowerPC 403GCX/405GP modifications. 8 * Copyright (c) 2001-2002 PPC64 team, IBM Corp 9 * 64-bit and Power4 support 10 * Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp 11 * <benh@kernel.crashing.org> 12 * Merge ppc32 and ppc64 implementations 13 * 14 * This program is free software; you can redistribute it and/or 15 * modify it under the terms of the GNU General Public License 16 * as published by the Free Software Foundation; either version 17 * 2 of the License, or (at your option) any later version. 18 */ 19 20 #include <linux/kernel.h> 21 #include <linux/mm.h> 22 #include <asm/processor.h> 23 #include <linux/uaccess.h> 24 #include <asm/cache.h> 25 #include <asm/cputable.h> 26 #include <asm/emulated_ops.h> 27 #include <asm/switch_to.h> 28 #include <asm/disassemble.h> 29 #include <asm/cpu_has_feature.h> 30 31 struct aligninfo { 32 unsigned char len; 33 unsigned char flags; 34 }; 35 36 37 #define INVALID { 0, 0 } 38 39 /* Bits in the flags field */ 40 #define LD 0 /* load */ 41 #define ST 1 /* store */ 42 #define SE 2 /* sign-extend value, or FP ld/st as word */ 43 #define F 4 /* to/from fp regs */ 44 #define U 8 /* update index register */ 45 #define M 0x10 /* multiple load/store */ 46 #define SW 0x20 /* byte swap */ 47 #define S 0x40 /* single-precision fp or... */ 48 #define SX 0x40 /* ... byte count in XER */ 49 #define HARD 0x80 /* string, stwcx. */ 50 #define E4 0x40 /* SPE endianness is word */ 51 #define E8 0x80 /* SPE endianness is double word */ 52 #define SPLT 0x80 /* VSX SPLAT load */ 53 54 /* DSISR bits reported for a DCBZ instruction: */ 55 #define DCBZ 0x5f /* 8xx/82xx dcbz faults when cache not enabled */ 56 57 /* 58 * The PowerPC stores certain bits of the instruction that caused the 59 * alignment exception in the DSISR register. This array maps those 60 * bits to information about the operand length and what the 61 * instruction would do. 62 */ 63 static struct aligninfo aligninfo[128] = { 64 { 4, LD }, /* 00 0 0000: lwz / lwarx */ 65 INVALID, /* 00 0 0001 */ 66 { 4, ST }, /* 00 0 0010: stw */ 67 INVALID, /* 00 0 0011 */ 68 { 2, LD }, /* 00 0 0100: lhz */ 69 { 2, LD+SE }, /* 00 0 0101: lha */ 70 { 2, ST }, /* 00 0 0110: sth */ 71 { 4, LD+M }, /* 00 0 0111: lmw */ 72 { 4, LD+F+S }, /* 00 0 1000: lfs */ 73 { 8, LD+F }, /* 00 0 1001: lfd */ 74 { 4, ST+F+S }, /* 00 0 1010: stfs */ 75 { 8, ST+F }, /* 00 0 1011: stfd */ 76 { 16, LD }, /* 00 0 1100: lq */ 77 { 8, LD }, /* 00 0 1101: ld/ldu/lwa */ 78 INVALID, /* 00 0 1110 */ 79 { 8, ST }, /* 00 0 1111: std/stdu */ 80 { 4, LD+U }, /* 00 1 0000: lwzu */ 81 INVALID, /* 00 1 0001 */ 82 { 4, ST+U }, /* 00 1 0010: stwu */ 83 INVALID, /* 00 1 0011 */ 84 { 2, LD+U }, /* 00 1 0100: lhzu */ 85 { 2, LD+SE+U }, /* 00 1 0101: lhau */ 86 { 2, ST+U }, /* 00 1 0110: sthu */ 87 { 4, ST+M }, /* 00 1 0111: stmw */ 88 { 4, LD+F+S+U }, /* 00 1 1000: lfsu */ 89 { 8, LD+F+U }, /* 00 1 1001: lfdu */ 90 { 4, ST+F+S+U }, /* 00 1 1010: stfsu */ 91 { 8, ST+F+U }, /* 00 1 1011: stfdu */ 92 { 16, LD+F }, /* 00 1 1100: lfdp */ 93 INVALID, /* 00 1 1101 */ 94 { 16, ST+F }, /* 00 1 1110: stfdp */ 95 INVALID, /* 00 1 1111 */ 96 { 8, LD }, /* 01 0 0000: ldx */ 97 INVALID, /* 01 0 0001 */ 98 { 8, ST }, /* 01 0 0010: stdx */ 99 INVALID, /* 01 0 0011 */ 100 INVALID, /* 01 0 0100 */ 101 { 4, LD+SE }, /* 01 0 0101: lwax */ 102 INVALID, /* 01 0 0110 */ 103 INVALID, /* 01 0 0111 */ 104 { 4, LD+M+HARD+SX }, /* 01 0 1000: lswx */ 105 { 4, LD+M+HARD }, /* 01 0 1001: lswi */ 106 { 4, ST+M+HARD+SX }, /* 01 0 1010: stswx */ 107 { 4, ST+M+HARD }, /* 01 0 1011: stswi */ 108 INVALID, /* 01 0 1100 */ 109 { 8, LD+U }, /* 01 0 1101: ldu */ 110 INVALID, /* 01 0 1110 */ 111 { 8, ST+U }, /* 01 0 1111: stdu */ 112 { 8, LD+U }, /* 01 1 0000: ldux */ 113 INVALID, /* 01 1 0001 */ 114 { 8, ST+U }, /* 01 1 0010: stdux */ 115 INVALID, /* 01 1 0011 */ 116 INVALID, /* 01 1 0100 */ 117 { 4, LD+SE+U }, /* 01 1 0101: lwaux */ 118 INVALID, /* 01 1 0110 */ 119 INVALID, /* 01 1 0111 */ 120 INVALID, /* 01 1 1000 */ 121 INVALID, /* 01 1 1001 */ 122 INVALID, /* 01 1 1010 */ 123 INVALID, /* 01 1 1011 */ 124 INVALID, /* 01 1 1100 */ 125 INVALID, /* 01 1 1101 */ 126 INVALID, /* 01 1 1110 */ 127 INVALID, /* 01 1 1111 */ 128 INVALID, /* 10 0 0000 */ 129 INVALID, /* 10 0 0001 */ 130 INVALID, /* 10 0 0010: stwcx. */ 131 INVALID, /* 10 0 0011 */ 132 INVALID, /* 10 0 0100 */ 133 INVALID, /* 10 0 0101 */ 134 INVALID, /* 10 0 0110 */ 135 INVALID, /* 10 0 0111 */ 136 { 4, LD+SW }, /* 10 0 1000: lwbrx */ 137 INVALID, /* 10 0 1001 */ 138 { 4, ST+SW }, /* 10 0 1010: stwbrx */ 139 INVALID, /* 10 0 1011 */ 140 { 2, LD+SW }, /* 10 0 1100: lhbrx */ 141 { 4, LD+SE }, /* 10 0 1101 lwa */ 142 { 2, ST+SW }, /* 10 0 1110: sthbrx */ 143 { 16, ST }, /* 10 0 1111: stq */ 144 INVALID, /* 10 1 0000 */ 145 INVALID, /* 10 1 0001 */ 146 INVALID, /* 10 1 0010 */ 147 INVALID, /* 10 1 0011 */ 148 INVALID, /* 10 1 0100 */ 149 INVALID, /* 10 1 0101 */ 150 INVALID, /* 10 1 0110 */ 151 INVALID, /* 10 1 0111 */ 152 INVALID, /* 10 1 1000 */ 153 INVALID, /* 10 1 1001 */ 154 INVALID, /* 10 1 1010 */ 155 INVALID, /* 10 1 1011 */ 156 INVALID, /* 10 1 1100 */ 157 INVALID, /* 10 1 1101 */ 158 INVALID, /* 10 1 1110 */ 159 { 0, ST+HARD }, /* 10 1 1111: dcbz */ 160 { 4, LD }, /* 11 0 0000: lwzx */ 161 INVALID, /* 11 0 0001 */ 162 { 4, ST }, /* 11 0 0010: stwx */ 163 INVALID, /* 11 0 0011 */ 164 { 2, LD }, /* 11 0 0100: lhzx */ 165 { 2, LD+SE }, /* 11 0 0101: lhax */ 166 { 2, ST }, /* 11 0 0110: sthx */ 167 INVALID, /* 11 0 0111 */ 168 { 4, LD+F+S }, /* 11 0 1000: lfsx */ 169 { 8, LD+F }, /* 11 0 1001: lfdx */ 170 { 4, ST+F+S }, /* 11 0 1010: stfsx */ 171 { 8, ST+F }, /* 11 0 1011: stfdx */ 172 { 16, LD+F }, /* 11 0 1100: lfdpx */ 173 { 4, LD+F+SE }, /* 11 0 1101: lfiwax */ 174 { 16, ST+F }, /* 11 0 1110: stfdpx */ 175 { 4, ST+F }, /* 11 0 1111: stfiwx */ 176 { 4, LD+U }, /* 11 1 0000: lwzux */ 177 INVALID, /* 11 1 0001 */ 178 { 4, ST+U }, /* 11 1 0010: stwux */ 179 INVALID, /* 11 1 0011 */ 180 { 2, LD+U }, /* 11 1 0100: lhzux */ 181 { 2, LD+SE+U }, /* 11 1 0101: lhaux */ 182 { 2, ST+U }, /* 11 1 0110: sthux */ 183 INVALID, /* 11 1 0111 */ 184 { 4, LD+F+S+U }, /* 11 1 1000: lfsux */ 185 { 8, LD+F+U }, /* 11 1 1001: lfdux */ 186 { 4, ST+F+S+U }, /* 11 1 1010: stfsux */ 187 { 8, ST+F+U }, /* 11 1 1011: stfdux */ 188 INVALID, /* 11 1 1100 */ 189 { 4, LD+F }, /* 11 1 1101: lfiwzx */ 190 INVALID, /* 11 1 1110 */ 191 INVALID, /* 11 1 1111 */ 192 }; 193 194 /* 195 * The dcbz (data cache block zero) instruction 196 * gives an alignment fault if used on non-cacheable 197 * memory. We handle the fault mainly for the 198 * case when we are running with the cache disabled 199 * for debugging. 200 */ 201 static int emulate_dcbz(struct pt_regs *regs, unsigned char __user *addr) 202 { 203 long __user *p; 204 int i, size; 205 206 #ifdef __powerpc64__ 207 size = ppc64_caches.l1d.block_size; 208 #else 209 size = L1_CACHE_BYTES; 210 #endif 211 p = (long __user *) (regs->dar & -size); 212 if (user_mode(regs) && !access_ok(VERIFY_WRITE, p, size)) 213 return -EFAULT; 214 for (i = 0; i < size / sizeof(long); ++i) 215 if (__put_user_inatomic(0, p+i)) 216 return -EFAULT; 217 return 1; 218 } 219 220 /* 221 * Emulate load & store multiple instructions 222 * On 64-bit machines, these instructions only affect/use the 223 * bottom 4 bytes of each register, and the loads clear the 224 * top 4 bytes of the affected register. 225 */ 226 #ifdef __BIG_ENDIAN__ 227 #ifdef CONFIG_PPC64 228 #define REG_BYTE(rp, i) *((u8 *)((rp) + ((i) >> 2)) + ((i) & 3) + 4) 229 #else 230 #define REG_BYTE(rp, i) *((u8 *)(rp) + (i)) 231 #endif 232 #else 233 #define REG_BYTE(rp, i) (*(((u8 *)((rp) + ((i)>>2)) + ((i)&3)))) 234 #endif 235 236 #define SWIZ_PTR(p) ((unsigned char __user *)((p) ^ swiz)) 237 238 static int emulate_multiple(struct pt_regs *regs, unsigned char __user *addr, 239 unsigned int reg, unsigned int nb, 240 unsigned int flags, unsigned int instr, 241 unsigned long swiz) 242 { 243 unsigned long *rptr; 244 unsigned int nb0, i, bswiz; 245 unsigned long p; 246 247 /* 248 * We do not try to emulate 8 bytes multiple as they aren't really 249 * available in our operating environments and we don't try to 250 * emulate multiples operations in kernel land as they should never 251 * be used/generated there at least not on unaligned boundaries 252 */ 253 if (unlikely((nb > 4) || !user_mode(regs))) 254 return 0; 255 256 /* lmw, stmw, lswi/x, stswi/x */ 257 nb0 = 0; 258 if (flags & HARD) { 259 if (flags & SX) { 260 nb = regs->xer & 127; 261 if (nb == 0) 262 return 1; 263 } else { 264 unsigned long pc = regs->nip ^ (swiz & 4); 265 266 if (__get_user_inatomic(instr, 267 (unsigned int __user *)pc)) 268 return -EFAULT; 269 if (swiz == 0 && (flags & SW)) 270 instr = cpu_to_le32(instr); 271 nb = (instr >> 11) & 0x1f; 272 if (nb == 0) 273 nb = 32; 274 } 275 if (nb + reg * 4 > 128) { 276 nb0 = nb + reg * 4 - 128; 277 nb = 128 - reg * 4; 278 } 279 #ifdef __LITTLE_ENDIAN__ 280 /* 281 * String instructions are endian neutral but the code 282 * below is not. Force byte swapping on so that the 283 * effects of swizzling are undone in the load/store 284 * loops below. 285 */ 286 flags ^= SW; 287 #endif 288 } else { 289 /* lwm, stmw */ 290 nb = (32 - reg) * 4; 291 } 292 293 if (!access_ok((flags & ST ? VERIFY_WRITE: VERIFY_READ), addr, nb+nb0)) 294 return -EFAULT; /* bad address */ 295 296 rptr = ®s->gpr[reg]; 297 p = (unsigned long) addr; 298 bswiz = (flags & SW)? 3: 0; 299 300 if (!(flags & ST)) { 301 /* 302 * This zeroes the top 4 bytes of the affected registers 303 * in 64-bit mode, and also zeroes out any remaining 304 * bytes of the last register for lsw*. 305 */ 306 memset(rptr, 0, ((nb + 3) / 4) * sizeof(unsigned long)); 307 if (nb0 > 0) 308 memset(®s->gpr[0], 0, 309 ((nb0 + 3) / 4) * sizeof(unsigned long)); 310 311 for (i = 0; i < nb; ++i, ++p) 312 if (__get_user_inatomic(REG_BYTE(rptr, i ^ bswiz), 313 SWIZ_PTR(p))) 314 return -EFAULT; 315 if (nb0 > 0) { 316 rptr = ®s->gpr[0]; 317 addr += nb; 318 for (i = 0; i < nb0; ++i, ++p) 319 if (__get_user_inatomic(REG_BYTE(rptr, 320 i ^ bswiz), 321 SWIZ_PTR(p))) 322 return -EFAULT; 323 } 324 325 } else { 326 for (i = 0; i < nb; ++i, ++p) 327 if (__put_user_inatomic(REG_BYTE(rptr, i ^ bswiz), 328 SWIZ_PTR(p))) 329 return -EFAULT; 330 if (nb0 > 0) { 331 rptr = ®s->gpr[0]; 332 addr += nb; 333 for (i = 0; i < nb0; ++i, ++p) 334 if (__put_user_inatomic(REG_BYTE(rptr, 335 i ^ bswiz), 336 SWIZ_PTR(p))) 337 return -EFAULT; 338 } 339 } 340 return 1; 341 } 342 343 /* 344 * Emulate floating-point pair loads and stores. 345 * Only POWER6 has these instructions, and it does true little-endian, 346 * so we don't need the address swizzling. 347 */ 348 static int emulate_fp_pair(unsigned char __user *addr, unsigned int reg, 349 unsigned int flags) 350 { 351 char *ptr0 = (char *) ¤t->thread.TS_FPR(reg); 352 char *ptr1 = (char *) ¤t->thread.TS_FPR(reg+1); 353 int i, ret, sw = 0; 354 355 if (reg & 1) 356 return 0; /* invalid form: FRS/FRT must be even */ 357 if (flags & SW) 358 sw = 7; 359 ret = 0; 360 for (i = 0; i < 8; ++i) { 361 if (!(flags & ST)) { 362 ret |= __get_user(ptr0[i^sw], addr + i); 363 ret |= __get_user(ptr1[i^sw], addr + i + 8); 364 } else { 365 ret |= __put_user(ptr0[i^sw], addr + i); 366 ret |= __put_user(ptr1[i^sw], addr + i + 8); 367 } 368 } 369 if (ret) 370 return -EFAULT; 371 return 1; /* exception handled and fixed up */ 372 } 373 374 #ifdef CONFIG_PPC64 375 static int emulate_lq_stq(struct pt_regs *regs, unsigned char __user *addr, 376 unsigned int reg, unsigned int flags) 377 { 378 char *ptr0 = (char *)®s->gpr[reg]; 379 char *ptr1 = (char *)®s->gpr[reg+1]; 380 int i, ret, sw = 0; 381 382 if (reg & 1) 383 return 0; /* invalid form: GPR must be even */ 384 if (flags & SW) 385 sw = 7; 386 ret = 0; 387 for (i = 0; i < 8; ++i) { 388 if (!(flags & ST)) { 389 ret |= __get_user(ptr0[i^sw], addr + i); 390 ret |= __get_user(ptr1[i^sw], addr + i + 8); 391 } else { 392 ret |= __put_user(ptr0[i^sw], addr + i); 393 ret |= __put_user(ptr1[i^sw], addr + i + 8); 394 } 395 } 396 if (ret) 397 return -EFAULT; 398 return 1; /* exception handled and fixed up */ 399 } 400 #endif /* CONFIG_PPC64 */ 401 402 #ifdef CONFIG_SPE 403 404 static struct aligninfo spe_aligninfo[32] = { 405 { 8, LD+E8 }, /* 0 00 00: evldd[x] */ 406 { 8, LD+E4 }, /* 0 00 01: evldw[x] */ 407 { 8, LD }, /* 0 00 10: evldh[x] */ 408 INVALID, /* 0 00 11 */ 409 { 2, LD }, /* 0 01 00: evlhhesplat[x] */ 410 INVALID, /* 0 01 01 */ 411 { 2, LD }, /* 0 01 10: evlhhousplat[x] */ 412 { 2, LD+SE }, /* 0 01 11: evlhhossplat[x] */ 413 { 4, LD }, /* 0 10 00: evlwhe[x] */ 414 INVALID, /* 0 10 01 */ 415 { 4, LD }, /* 0 10 10: evlwhou[x] */ 416 { 4, LD+SE }, /* 0 10 11: evlwhos[x] */ 417 { 4, LD+E4 }, /* 0 11 00: evlwwsplat[x] */ 418 INVALID, /* 0 11 01 */ 419 { 4, LD }, /* 0 11 10: evlwhsplat[x] */ 420 INVALID, /* 0 11 11 */ 421 422 { 8, ST+E8 }, /* 1 00 00: evstdd[x] */ 423 { 8, ST+E4 }, /* 1 00 01: evstdw[x] */ 424 { 8, ST }, /* 1 00 10: evstdh[x] */ 425 INVALID, /* 1 00 11 */ 426 INVALID, /* 1 01 00 */ 427 INVALID, /* 1 01 01 */ 428 INVALID, /* 1 01 10 */ 429 INVALID, /* 1 01 11 */ 430 { 4, ST }, /* 1 10 00: evstwhe[x] */ 431 INVALID, /* 1 10 01 */ 432 { 4, ST }, /* 1 10 10: evstwho[x] */ 433 INVALID, /* 1 10 11 */ 434 { 4, ST+E4 }, /* 1 11 00: evstwwe[x] */ 435 INVALID, /* 1 11 01 */ 436 { 4, ST+E4 }, /* 1 11 10: evstwwo[x] */ 437 INVALID, /* 1 11 11 */ 438 }; 439 440 #define EVLDD 0x00 441 #define EVLDW 0x01 442 #define EVLDH 0x02 443 #define EVLHHESPLAT 0x04 444 #define EVLHHOUSPLAT 0x06 445 #define EVLHHOSSPLAT 0x07 446 #define EVLWHE 0x08 447 #define EVLWHOU 0x0A 448 #define EVLWHOS 0x0B 449 #define EVLWWSPLAT 0x0C 450 #define EVLWHSPLAT 0x0E 451 #define EVSTDD 0x10 452 #define EVSTDW 0x11 453 #define EVSTDH 0x12 454 #define EVSTWHE 0x18 455 #define EVSTWHO 0x1A 456 #define EVSTWWE 0x1C 457 #define EVSTWWO 0x1E 458 459 /* 460 * Emulate SPE loads and stores. 461 * Only Book-E has these instructions, and it does true little-endian, 462 * so we don't need the address swizzling. 463 */ 464 static int emulate_spe(struct pt_regs *regs, unsigned int reg, 465 unsigned int instr) 466 { 467 int ret; 468 union { 469 u64 ll; 470 u32 w[2]; 471 u16 h[4]; 472 u8 v[8]; 473 } data, temp; 474 unsigned char __user *p, *addr; 475 unsigned long *evr = ¤t->thread.evr[reg]; 476 unsigned int nb, flags; 477 478 instr = (instr >> 1) & 0x1f; 479 480 /* DAR has the operand effective address */ 481 addr = (unsigned char __user *)regs->dar; 482 483 nb = spe_aligninfo[instr].len; 484 flags = spe_aligninfo[instr].flags; 485 486 /* Verify the address of the operand */ 487 if (unlikely(user_mode(regs) && 488 !access_ok((flags & ST ? VERIFY_WRITE : VERIFY_READ), 489 addr, nb))) 490 return -EFAULT; 491 492 /* userland only */ 493 if (unlikely(!user_mode(regs))) 494 return 0; 495 496 flush_spe_to_thread(current); 497 498 /* If we are loading, get the data from user space, else 499 * get it from register values 500 */ 501 if (flags & ST) { 502 data.ll = 0; 503 switch (instr) { 504 case EVSTDD: 505 case EVSTDW: 506 case EVSTDH: 507 data.w[0] = *evr; 508 data.w[1] = regs->gpr[reg]; 509 break; 510 case EVSTWHE: 511 data.h[2] = *evr >> 16; 512 data.h[3] = regs->gpr[reg] >> 16; 513 break; 514 case EVSTWHO: 515 data.h[2] = *evr & 0xffff; 516 data.h[3] = regs->gpr[reg] & 0xffff; 517 break; 518 case EVSTWWE: 519 data.w[1] = *evr; 520 break; 521 case EVSTWWO: 522 data.w[1] = regs->gpr[reg]; 523 break; 524 default: 525 return -EINVAL; 526 } 527 } else { 528 temp.ll = data.ll = 0; 529 ret = 0; 530 p = addr; 531 532 switch (nb) { 533 case 8: 534 ret |= __get_user_inatomic(temp.v[0], p++); 535 ret |= __get_user_inatomic(temp.v[1], p++); 536 ret |= __get_user_inatomic(temp.v[2], p++); 537 ret |= __get_user_inatomic(temp.v[3], p++); 538 case 4: 539 ret |= __get_user_inatomic(temp.v[4], p++); 540 ret |= __get_user_inatomic(temp.v[5], p++); 541 case 2: 542 ret |= __get_user_inatomic(temp.v[6], p++); 543 ret |= __get_user_inatomic(temp.v[7], p++); 544 if (unlikely(ret)) 545 return -EFAULT; 546 } 547 548 switch (instr) { 549 case EVLDD: 550 case EVLDW: 551 case EVLDH: 552 data.ll = temp.ll; 553 break; 554 case EVLHHESPLAT: 555 data.h[0] = temp.h[3]; 556 data.h[2] = temp.h[3]; 557 break; 558 case EVLHHOUSPLAT: 559 case EVLHHOSSPLAT: 560 data.h[1] = temp.h[3]; 561 data.h[3] = temp.h[3]; 562 break; 563 case EVLWHE: 564 data.h[0] = temp.h[2]; 565 data.h[2] = temp.h[3]; 566 break; 567 case EVLWHOU: 568 case EVLWHOS: 569 data.h[1] = temp.h[2]; 570 data.h[3] = temp.h[3]; 571 break; 572 case EVLWWSPLAT: 573 data.w[0] = temp.w[1]; 574 data.w[1] = temp.w[1]; 575 break; 576 case EVLWHSPLAT: 577 data.h[0] = temp.h[2]; 578 data.h[1] = temp.h[2]; 579 data.h[2] = temp.h[3]; 580 data.h[3] = temp.h[3]; 581 break; 582 default: 583 return -EINVAL; 584 } 585 } 586 587 if (flags & SW) { 588 switch (flags & 0xf0) { 589 case E8: 590 data.ll = swab64(data.ll); 591 break; 592 case E4: 593 data.w[0] = swab32(data.w[0]); 594 data.w[1] = swab32(data.w[1]); 595 break; 596 /* Its half word endian */ 597 default: 598 data.h[0] = swab16(data.h[0]); 599 data.h[1] = swab16(data.h[1]); 600 data.h[2] = swab16(data.h[2]); 601 data.h[3] = swab16(data.h[3]); 602 break; 603 } 604 } 605 606 if (flags & SE) { 607 data.w[0] = (s16)data.h[1]; 608 data.w[1] = (s16)data.h[3]; 609 } 610 611 /* Store result to memory or update registers */ 612 if (flags & ST) { 613 ret = 0; 614 p = addr; 615 switch (nb) { 616 case 8: 617 ret |= __put_user_inatomic(data.v[0], p++); 618 ret |= __put_user_inatomic(data.v[1], p++); 619 ret |= __put_user_inatomic(data.v[2], p++); 620 ret |= __put_user_inatomic(data.v[3], p++); 621 case 4: 622 ret |= __put_user_inatomic(data.v[4], p++); 623 ret |= __put_user_inatomic(data.v[5], p++); 624 case 2: 625 ret |= __put_user_inatomic(data.v[6], p++); 626 ret |= __put_user_inatomic(data.v[7], p++); 627 } 628 if (unlikely(ret)) 629 return -EFAULT; 630 } else { 631 *evr = data.w[0]; 632 regs->gpr[reg] = data.w[1]; 633 } 634 635 return 1; 636 } 637 #endif /* CONFIG_SPE */ 638 639 #ifdef CONFIG_VSX 640 /* 641 * Emulate VSX instructions... 642 */ 643 static int emulate_vsx(unsigned char __user *addr, unsigned int reg, 644 unsigned int areg, struct pt_regs *regs, 645 unsigned int flags, unsigned int length, 646 unsigned int elsize) 647 { 648 char *ptr; 649 unsigned long *lptr; 650 int ret = 0; 651 int sw = 0; 652 int i, j; 653 654 /* userland only */ 655 if (unlikely(!user_mode(regs))) 656 return 0; 657 658 flush_vsx_to_thread(current); 659 660 if (reg < 32) 661 ptr = (char *) ¤t->thread.fp_state.fpr[reg][0]; 662 else 663 ptr = (char *) ¤t->thread.vr_state.vr[reg - 32]; 664 665 lptr = (unsigned long *) ptr; 666 667 #ifdef __LITTLE_ENDIAN__ 668 if (flags & SW) { 669 elsize = length; 670 sw = length-1; 671 } else { 672 /* 673 * The elements are BE ordered, even in LE mode, so process 674 * them in reverse order. 675 */ 676 addr += length - elsize; 677 678 /* 8 byte memory accesses go in the top 8 bytes of the VR */ 679 if (length == 8) 680 ptr += 8; 681 } 682 #else 683 if (flags & SW) 684 sw = elsize-1; 685 #endif 686 687 for (j = 0; j < length; j += elsize) { 688 for (i = 0; i < elsize; ++i) { 689 if (flags & ST) 690 ret |= __put_user(ptr[i^sw], addr + i); 691 else 692 ret |= __get_user(ptr[i^sw], addr + i); 693 } 694 ptr += elsize; 695 #ifdef __LITTLE_ENDIAN__ 696 addr -= elsize; 697 #else 698 addr += elsize; 699 #endif 700 } 701 702 #ifdef __BIG_ENDIAN__ 703 #define VSX_HI 0 704 #define VSX_LO 1 705 #else 706 #define VSX_HI 1 707 #define VSX_LO 0 708 #endif 709 710 if (!ret) { 711 if (flags & U) 712 regs->gpr[areg] = regs->dar; 713 714 /* Splat load copies the same data to top and bottom 8 bytes */ 715 if (flags & SPLT) 716 lptr[VSX_LO] = lptr[VSX_HI]; 717 /* For 8 byte loads, zero the low 8 bytes */ 718 else if (!(flags & ST) && (8 == length)) 719 lptr[VSX_LO] = 0; 720 } else 721 return -EFAULT; 722 723 return 1; 724 } 725 #endif 726 727 /* 728 * Called on alignment exception. Attempts to fixup 729 * 730 * Return 1 on success 731 * Return 0 if unable to handle the interrupt 732 * Return -EFAULT if data address is bad 733 */ 734 735 int fix_alignment(struct pt_regs *regs) 736 { 737 unsigned int instr, nb, flags, instruction = 0; 738 unsigned int reg, areg; 739 unsigned int dsisr; 740 unsigned char __user *addr; 741 unsigned long p, swiz; 742 int ret, i; 743 union data { 744 u64 ll; 745 double dd; 746 unsigned char v[8]; 747 struct { 748 #ifdef __LITTLE_ENDIAN__ 749 int low32; 750 unsigned hi32; 751 #else 752 unsigned hi32; 753 int low32; 754 #endif 755 } x32; 756 struct { 757 #ifdef __LITTLE_ENDIAN__ 758 short low16; 759 unsigned char hi48[6]; 760 #else 761 unsigned char hi48[6]; 762 short low16; 763 #endif 764 } x16; 765 } data; 766 767 /* 768 * We require a complete register set, if not, then our assembly 769 * is broken 770 */ 771 CHECK_FULL_REGS(regs); 772 773 dsisr = regs->dsisr; 774 775 /* Some processors don't provide us with a DSISR we can use here, 776 * let's make one up from the instruction 777 */ 778 if (cpu_has_feature(CPU_FTR_NODSISRALIGN)) { 779 unsigned long pc = regs->nip; 780 781 if (cpu_has_feature(CPU_FTR_PPC_LE) && (regs->msr & MSR_LE)) 782 pc ^= 4; 783 if (unlikely(__get_user_inatomic(instr, 784 (unsigned int __user *)pc))) 785 return -EFAULT; 786 if (cpu_has_feature(CPU_FTR_REAL_LE) && (regs->msr & MSR_LE)) 787 instr = cpu_to_le32(instr); 788 dsisr = make_dsisr(instr); 789 instruction = instr; 790 } 791 792 /* extract the operation and registers from the dsisr */ 793 reg = (dsisr >> 5) & 0x1f; /* source/dest register */ 794 areg = dsisr & 0x1f; /* register to update */ 795 796 #ifdef CONFIG_SPE 797 if ((instr >> 26) == 0x4) { 798 PPC_WARN_ALIGNMENT(spe, regs); 799 return emulate_spe(regs, reg, instr); 800 } 801 #endif 802 803 instr = (dsisr >> 10) & 0x7f; 804 instr |= (dsisr >> 13) & 0x60; 805 806 /* Lookup the operation in our table */ 807 nb = aligninfo[instr].len; 808 flags = aligninfo[instr].flags; 809 810 /* 811 * Handle some cases which give overlaps in the DSISR values. 812 */ 813 if (IS_XFORM(instruction)) { 814 switch (get_xop(instruction)) { 815 case 532: /* ldbrx */ 816 nb = 8; 817 flags = LD+SW; 818 break; 819 case 660: /* stdbrx */ 820 nb = 8; 821 flags = ST+SW; 822 break; 823 case 20: /* lwarx */ 824 case 84: /* ldarx */ 825 case 116: /* lharx */ 826 case 276: /* lqarx */ 827 return 0; /* not emulated ever */ 828 } 829 } 830 831 /* Byteswap little endian loads and stores */ 832 swiz = 0; 833 if ((regs->msr & MSR_LE) != (MSR_KERNEL & MSR_LE)) { 834 flags ^= SW; 835 #ifdef __BIG_ENDIAN__ 836 /* 837 * So-called "PowerPC little endian" mode works by 838 * swizzling addresses rather than by actually doing 839 * any byte-swapping. To emulate this, we XOR each 840 * byte address with 7. We also byte-swap, because 841 * the processor's address swizzling depends on the 842 * operand size (it xors the address with 7 for bytes, 843 * 6 for halfwords, 4 for words, 0 for doublewords) but 844 * we will xor with 7 and load/store each byte separately. 845 */ 846 if (cpu_has_feature(CPU_FTR_PPC_LE)) 847 swiz = 7; 848 #endif 849 } 850 851 /* DAR has the operand effective address */ 852 addr = (unsigned char __user *)regs->dar; 853 854 #ifdef CONFIG_VSX 855 if ((instruction & 0xfc00003e) == 0x7c000018) { 856 unsigned int elsize; 857 858 /* Additional register addressing bit (64 VSX vs 32 FPR/GPR) */ 859 reg |= (instruction & 0x1) << 5; 860 /* Simple inline decoder instead of a table */ 861 /* VSX has only 8 and 16 byte memory accesses */ 862 nb = 8; 863 if (instruction & 0x200) 864 nb = 16; 865 866 /* Vector stores in little-endian mode swap individual 867 elements, so process them separately */ 868 elsize = 4; 869 if (instruction & 0x80) 870 elsize = 8; 871 872 flags = 0; 873 if ((regs->msr & MSR_LE) != (MSR_KERNEL & MSR_LE)) 874 flags |= SW; 875 if (instruction & 0x100) 876 flags |= ST; 877 if (instruction & 0x040) 878 flags |= U; 879 /* splat load needs a special decoder */ 880 if ((instruction & 0x400) == 0){ 881 flags |= SPLT; 882 nb = 8; 883 } 884 PPC_WARN_ALIGNMENT(vsx, regs); 885 return emulate_vsx(addr, reg, areg, regs, flags, nb, elsize); 886 } 887 #endif 888 889 /* 890 * ISA 3.0 (such as P9) copy, copy_first, paste and paste_last alignment 891 * check. 892 * 893 * Send a SIGBUS to the process that caused the fault. 894 * 895 * We do not emulate these because paste may contain additional metadata 896 * when pasting to a co-processor. Furthermore, paste_last is the 897 * synchronisation point for preceding copy/paste sequences. 898 */ 899 if ((instruction & 0xfc0006fe) == PPC_INST_COPY) 900 return -EIO; 901 902 /* A size of 0 indicates an instruction we don't support, with 903 * the exception of DCBZ which is handled as a special case here 904 */ 905 if (instr == DCBZ) { 906 PPC_WARN_ALIGNMENT(dcbz, regs); 907 return emulate_dcbz(regs, addr); 908 } 909 if (unlikely(nb == 0)) 910 return 0; 911 912 /* Load/Store Multiple instructions are handled in their own 913 * function 914 */ 915 if (flags & M) { 916 PPC_WARN_ALIGNMENT(multiple, regs); 917 return emulate_multiple(regs, addr, reg, nb, 918 flags, instr, swiz); 919 } 920 921 /* Verify the address of the operand */ 922 if (unlikely(user_mode(regs) && 923 !access_ok((flags & ST ? VERIFY_WRITE : VERIFY_READ), 924 addr, nb))) 925 return -EFAULT; 926 927 /* Force the fprs into the save area so we can reference them */ 928 if (flags & F) { 929 /* userland only */ 930 if (unlikely(!user_mode(regs))) 931 return 0; 932 flush_fp_to_thread(current); 933 } 934 935 if (nb == 16) { 936 if (flags & F) { 937 /* Special case for 16-byte FP loads and stores */ 938 PPC_WARN_ALIGNMENT(fp_pair, regs); 939 return emulate_fp_pair(addr, reg, flags); 940 } else { 941 #ifdef CONFIG_PPC64 942 /* Special case for 16-byte loads and stores */ 943 PPC_WARN_ALIGNMENT(lq_stq, regs); 944 return emulate_lq_stq(regs, addr, reg, flags); 945 #else 946 return 0; 947 #endif 948 } 949 } 950 951 PPC_WARN_ALIGNMENT(unaligned, regs); 952 953 /* If we are loading, get the data from user space, else 954 * get it from register values 955 */ 956 if (!(flags & ST)) { 957 unsigned int start = 0; 958 959 switch (nb) { 960 case 4: 961 start = offsetof(union data, x32.low32); 962 break; 963 case 2: 964 start = offsetof(union data, x16.low16); 965 break; 966 } 967 968 data.ll = 0; 969 ret = 0; 970 p = (unsigned long)addr; 971 972 for (i = 0; i < nb; i++) 973 ret |= __get_user_inatomic(data.v[start + i], 974 SWIZ_PTR(p++)); 975 976 if (unlikely(ret)) 977 return -EFAULT; 978 979 } else if (flags & F) { 980 data.ll = current->thread.TS_FPR(reg); 981 if (flags & S) { 982 /* Single-precision FP store requires conversion... */ 983 #ifdef CONFIG_PPC_FPU 984 preempt_disable(); 985 enable_kernel_fp(); 986 cvt_df(&data.dd, (float *)&data.x32.low32); 987 disable_kernel_fp(); 988 preempt_enable(); 989 #else 990 return 0; 991 #endif 992 } 993 } else 994 data.ll = regs->gpr[reg]; 995 996 if (flags & SW) { 997 switch (nb) { 998 case 8: 999 data.ll = swab64(data.ll); 1000 break; 1001 case 4: 1002 data.x32.low32 = swab32(data.x32.low32); 1003 break; 1004 case 2: 1005 data.x16.low16 = swab16(data.x16.low16); 1006 break; 1007 } 1008 } 1009 1010 /* Perform other misc operations like sign extension 1011 * or floating point single precision conversion 1012 */ 1013 switch (flags & ~(U|SW)) { 1014 case LD+SE: /* sign extending integer loads */ 1015 case LD+F+SE: /* sign extend for lfiwax */ 1016 if ( nb == 2 ) 1017 data.ll = data.x16.low16; 1018 else /* nb must be 4 */ 1019 data.ll = data.x32.low32; 1020 break; 1021 1022 /* Single-precision FP load requires conversion... */ 1023 case LD+F+S: 1024 #ifdef CONFIG_PPC_FPU 1025 preempt_disable(); 1026 enable_kernel_fp(); 1027 cvt_fd((float *)&data.x32.low32, &data.dd); 1028 disable_kernel_fp(); 1029 preempt_enable(); 1030 #else 1031 return 0; 1032 #endif 1033 break; 1034 } 1035 1036 /* Store result to memory or update registers */ 1037 if (flags & ST) { 1038 unsigned int start = 0; 1039 1040 switch (nb) { 1041 case 4: 1042 start = offsetof(union data, x32.low32); 1043 break; 1044 case 2: 1045 start = offsetof(union data, x16.low16); 1046 break; 1047 } 1048 1049 ret = 0; 1050 p = (unsigned long)addr; 1051 1052 for (i = 0; i < nb; i++) 1053 ret |= __put_user_inatomic(data.v[start + i], 1054 SWIZ_PTR(p++)); 1055 1056 if (unlikely(ret)) 1057 return -EFAULT; 1058 } else if (flags & F) 1059 current->thread.TS_FPR(reg) = data.ll; 1060 else 1061 regs->gpr[reg] = data.ll; 1062 1063 /* Update RA as needed */ 1064 if (flags & U) 1065 regs->gpr[areg] = regs->dar; 1066 1067 return 1; 1068 } 1069