1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 1994, 95, 96, 99, 2001 Ralf Baechle 7 * Copyright (C) 1994, 1995, 1996 Paul M. Antoine. 8 * Copyright (C) 1999 Silicon Graphics, Inc. 9 * Copyright (C) 2007 Maciej W. Rozycki 10 */ 11 #ifndef _ASM_STACKFRAME_H 12 #define _ASM_STACKFRAME_H 13 14 #include <linux/threads.h> 15 16 #include <asm/asm.h> 17 #include <asm/asmmacro.h> 18 #include <asm/mipsregs.h> 19 #include <asm/asm-offsets.h> 20 #include <asm/thread_info.h> 21 22 /* Make the addition of cfi info a little easier. */ 23 .macro cfi_rel_offset reg offset=0 docfi=0 24 .if \docfi 25 .cfi_rel_offset \reg, \offset 26 .endif 27 .endm 28 29 .macro cfi_st reg offset=0 docfi=0 30 LONG_S \reg, \offset(sp) 31 cfi_rel_offset \reg, \offset, \docfi 32 .endm 33 34 .macro cfi_restore reg offset=0 docfi=0 35 .if \docfi 36 .cfi_restore \reg 37 .endif 38 .endm 39 40 .macro cfi_ld reg offset=0 docfi=0 41 LONG_L \reg, \offset(sp) 42 cfi_restore \reg \offset \docfi 43 .endm 44 45 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) 46 #define STATMASK 0x3f 47 #else 48 #define STATMASK 0x1f 49 #endif 50 51 .macro SAVE_AT docfi=0 52 .set push 53 .set noat 54 cfi_st $1, PT_R1, \docfi 55 .set pop 56 .endm 57 58 .macro SAVE_TEMP docfi=0 59 #ifdef CONFIG_CPU_HAS_SMARTMIPS 60 mflhxu v1 61 LONG_S v1, PT_LO(sp) 62 mflhxu v1 63 LONG_S v1, PT_HI(sp) 64 mflhxu v1 65 LONG_S v1, PT_ACX(sp) 66 #elif !defined(CONFIG_CPU_MIPSR6) 67 mfhi v1 68 #endif 69 #ifdef CONFIG_32BIT 70 cfi_st $8, PT_R8, \docfi 71 cfi_st $9, PT_R9, \docfi 72 #endif 73 cfi_st $10, PT_R10, \docfi 74 cfi_st $11, PT_R11, \docfi 75 cfi_st $12, PT_R12, \docfi 76 #if !defined(CONFIG_CPU_HAS_SMARTMIPS) && !defined(CONFIG_CPU_MIPSR6) 77 LONG_S v1, PT_HI(sp) 78 mflo v1 79 #endif 80 cfi_st $13, PT_R13, \docfi 81 cfi_st $14, PT_R14, \docfi 82 cfi_st $15, PT_R15, \docfi 83 cfi_st $24, PT_R24, \docfi 84 #if !defined(CONFIG_CPU_HAS_SMARTMIPS) && !defined(CONFIG_CPU_MIPSR6) 85 LONG_S v1, PT_LO(sp) 86 #endif 87 #ifdef CONFIG_CPU_CAVIUM_OCTEON 88 /* 89 * The Octeon multiplier state is affected by general 90 * multiply instructions. It must be saved before and 91 * kernel code might corrupt it 92 */ 93 jal octeon_mult_save 94 #endif 95 .endm 96 97 .macro SAVE_STATIC docfi=0 98 cfi_st $16, PT_R16, \docfi 99 cfi_st $17, PT_R17, \docfi 100 cfi_st $18, PT_R18, \docfi 101 cfi_st $19, PT_R19, \docfi 102 cfi_st $20, PT_R20, \docfi 103 cfi_st $21, PT_R21, \docfi 104 cfi_st $22, PT_R22, \docfi 105 cfi_st $23, PT_R23, \docfi 106 cfi_st $30, PT_R30, \docfi 107 .endm 108 109 /* 110 * get_saved_sp returns the SP for the current CPU by looking in the 111 * kernelsp array for it. If tosp is set, it stores the current sp in 112 * k0 and loads the new value in sp. If not, it clobbers k0 and 113 * stores the new value in k1, leaving sp unaffected. 114 */ 115 #ifdef CONFIG_SMP 116 117 /* SMP variation */ 118 .macro get_saved_sp docfi=0 tosp=0 119 ASM_CPUID_MFC0 k0, ASM_SMP_CPUID_REG 120 #if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32) 121 lui k1, %hi(kernelsp) 122 #else 123 lui k1, %highest(kernelsp) 124 daddiu k1, %higher(kernelsp) 125 dsll k1, 16 126 daddiu k1, %hi(kernelsp) 127 dsll k1, 16 128 #endif 129 LONG_SRL k0, SMP_CPUID_PTRSHIFT 130 LONG_ADDU k1, k0 131 .if \tosp 132 move k0, sp 133 .if \docfi 134 .cfi_register sp, k0 135 .endif 136 LONG_L sp, %lo(kernelsp)(k1) 137 .else 138 LONG_L k1, %lo(kernelsp)(k1) 139 .endif 140 .endm 141 142 .macro set_saved_sp stackp temp temp2 143 ASM_CPUID_MFC0 \temp, ASM_SMP_CPUID_REG 144 LONG_SRL \temp, SMP_CPUID_PTRSHIFT 145 LONG_S \stackp, kernelsp(\temp) 146 .endm 147 #else /* !CONFIG_SMP */ 148 /* Uniprocessor variation */ 149 .macro get_saved_sp docfi=0 tosp=0 150 #ifdef CONFIG_CPU_JUMP_WORKAROUNDS 151 /* 152 * Clear BTB (branch target buffer), forbid RAS (return address 153 * stack) to workaround the Out-of-order Issue in Loongson2F 154 * via its diagnostic register. 155 */ 156 move k0, ra 157 jal 1f 158 nop 159 1: jal 1f 160 nop 161 1: jal 1f 162 nop 163 1: jal 1f 164 nop 165 1: move ra, k0 166 li k0, 3 167 mtc0 k0, $22 168 #endif /* CONFIG_CPU_JUMP_WORKAROUNDS */ 169 #if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32) 170 lui k1, %hi(kernelsp) 171 #else 172 lui k1, %highest(kernelsp) 173 daddiu k1, %higher(kernelsp) 174 dsll k1, k1, 16 175 daddiu k1, %hi(kernelsp) 176 dsll k1, k1, 16 177 #endif 178 .if \tosp 179 move k0, sp 180 .if \docfi 181 .cfi_register sp, k0 182 .endif 183 LONG_L sp, %lo(kernelsp)(k1) 184 .else 185 LONG_L k1, %lo(kernelsp)(k1) 186 .endif 187 .endm 188 189 .macro set_saved_sp stackp temp temp2 190 LONG_S \stackp, kernelsp 191 .endm 192 #endif 193 194 .macro SAVE_SOME docfi=0 195 .set push 196 .set noat 197 .set reorder 198 mfc0 k0, CP0_STATUS 199 sll k0, 3 /* extract cu0 bit */ 200 .set noreorder 201 bltz k0, 8f 202 move k0, sp 203 .if \docfi 204 .cfi_register sp, k0 205 .endif 206 #ifdef CONFIG_EVA 207 /* 208 * Flush interAptiv's Return Prediction Stack (RPS) by writing 209 * EntryHi. Toggling Config7.RPS is slower and less portable. 210 * 211 * The RPS isn't automatically flushed when exceptions are 212 * taken, which can result in kernel mode speculative accesses 213 * to user addresses if the RPS mispredicts. That's harmless 214 * when user and kernel share the same address space, but with 215 * EVA the same user segments may be unmapped to kernel mode, 216 * even containing sensitive MMIO regions or invalid memory. 217 * 218 * This can happen when the kernel sets the return address to 219 * ret_from_* and jr's to the exception handler, which looks 220 * more like a tail call than a function call. If nested calls 221 * don't evict the last user address in the RPS, it will 222 * mispredict the return and fetch from a user controlled 223 * address into the icache. 224 * 225 * More recent EVA-capable cores with MAAR to restrict 226 * speculative accesses aren't affected. 227 */ 228 MFC0 k0, CP0_ENTRYHI 229 MTC0 k0, CP0_ENTRYHI 230 #endif 231 .set reorder 232 /* Called from user mode, new stack. */ 233 get_saved_sp docfi=\docfi tosp=1 234 8: 235 #ifdef CONFIG_CPU_DADDI_WORKAROUNDS 236 .set at=k1 237 #endif 238 PTR_SUBU sp, PT_SIZE 239 #ifdef CONFIG_CPU_DADDI_WORKAROUNDS 240 .set noat 241 #endif 242 .if \docfi 243 .cfi_def_cfa sp,0 244 .endif 245 cfi_st k0, PT_R29, \docfi 246 cfi_rel_offset sp, PT_R29, \docfi 247 cfi_st v1, PT_R3, \docfi 248 /* 249 * You might think that you don't need to save $0, 250 * but the FPU emulator and gdb remote debug stub 251 * need it to operate correctly 252 */ 253 LONG_S $0, PT_R0(sp) 254 mfc0 v1, CP0_STATUS 255 cfi_st v0, PT_R2, \docfi 256 LONG_S v1, PT_STATUS(sp) 257 cfi_st $4, PT_R4, \docfi 258 mfc0 v1, CP0_CAUSE 259 cfi_st $5, PT_R5, \docfi 260 LONG_S v1, PT_CAUSE(sp) 261 cfi_st $6, PT_R6, \docfi 262 cfi_st ra, PT_R31, \docfi 263 MFC0 ra, CP0_EPC 264 cfi_st $7, PT_R7, \docfi 265 #ifdef CONFIG_64BIT 266 cfi_st $8, PT_R8, \docfi 267 cfi_st $9, PT_R9, \docfi 268 #endif 269 LONG_S ra, PT_EPC(sp) 270 .if \docfi 271 .cfi_rel_offset ra, PT_EPC 272 .endif 273 cfi_st $25, PT_R25, \docfi 274 cfi_st $28, PT_R28, \docfi 275 276 /* Set thread_info if we're coming from user mode */ 277 mfc0 k0, CP0_STATUS 278 sll k0, 3 /* extract cu0 bit */ 279 bltz k0, 9f 280 281 ori $28, sp, _THREAD_MASK 282 xori $28, _THREAD_MASK 283 #ifdef CONFIG_CPU_CAVIUM_OCTEON 284 .set mips64 285 pref 0, 0($28) /* Prefetch the current pointer */ 286 #endif 287 9: 288 .set pop 289 .endm 290 291 .macro SAVE_ALL docfi=0 292 SAVE_SOME \docfi 293 SAVE_AT \docfi 294 SAVE_TEMP \docfi 295 SAVE_STATIC \docfi 296 .endm 297 298 .macro RESTORE_AT docfi=0 299 .set push 300 .set noat 301 cfi_ld $1, PT_R1, \docfi 302 .set pop 303 .endm 304 305 .macro RESTORE_TEMP docfi=0 306 #ifdef CONFIG_CPU_CAVIUM_OCTEON 307 /* Restore the Octeon multiplier state */ 308 jal octeon_mult_restore 309 #endif 310 #ifdef CONFIG_CPU_HAS_SMARTMIPS 311 LONG_L $24, PT_ACX(sp) 312 mtlhx $24 313 LONG_L $24, PT_HI(sp) 314 mtlhx $24 315 LONG_L $24, PT_LO(sp) 316 mtlhx $24 317 #elif !defined(CONFIG_CPU_MIPSR6) 318 LONG_L $24, PT_LO(sp) 319 mtlo $24 320 LONG_L $24, PT_HI(sp) 321 mthi $24 322 #endif 323 #ifdef CONFIG_32BIT 324 cfi_ld $8, PT_R8, \docfi 325 cfi_ld $9, PT_R9, \docfi 326 #endif 327 cfi_ld $10, PT_R10, \docfi 328 cfi_ld $11, PT_R11, \docfi 329 cfi_ld $12, PT_R12, \docfi 330 cfi_ld $13, PT_R13, \docfi 331 cfi_ld $14, PT_R14, \docfi 332 cfi_ld $15, PT_R15, \docfi 333 cfi_ld $24, PT_R24, \docfi 334 .endm 335 336 .macro RESTORE_STATIC docfi=0 337 cfi_ld $16, PT_R16, \docfi 338 cfi_ld $17, PT_R17, \docfi 339 cfi_ld $18, PT_R18, \docfi 340 cfi_ld $19, PT_R19, \docfi 341 cfi_ld $20, PT_R20, \docfi 342 cfi_ld $21, PT_R21, \docfi 343 cfi_ld $22, PT_R22, \docfi 344 cfi_ld $23, PT_R23, \docfi 345 cfi_ld $30, PT_R30, \docfi 346 .endm 347 348 .macro RESTORE_SP docfi=0 349 cfi_ld sp, PT_R29, \docfi 350 .endm 351 352 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) 353 354 .macro RESTORE_SOME docfi=0 355 .set push 356 .set reorder 357 .set noat 358 mfc0 a0, CP0_STATUS 359 li v1, ST0_CU1 | ST0_IM 360 ori a0, STATMASK 361 xori a0, STATMASK 362 mtc0 a0, CP0_STATUS 363 and a0, v1 364 LONG_L v0, PT_STATUS(sp) 365 nor v1, $0, v1 366 and v0, v1 367 or v0, a0 368 mtc0 v0, CP0_STATUS 369 cfi_ld $31, PT_R31, \docfi 370 cfi_ld $28, PT_R28, \docfi 371 cfi_ld $25, PT_R25, \docfi 372 cfi_ld $7, PT_R7, \docfi 373 cfi_ld $6, PT_R6, \docfi 374 cfi_ld $5, PT_R5, \docfi 375 cfi_ld $4, PT_R4, \docfi 376 cfi_ld $3, PT_R3, \docfi 377 cfi_ld $2, PT_R2, \docfi 378 .set pop 379 .endm 380 381 .macro RESTORE_SP_AND_RET docfi=0 382 .set push 383 .set noreorder 384 LONG_L k0, PT_EPC(sp) 385 RESTORE_SP \docfi 386 jr k0 387 rfe 388 .set pop 389 .endm 390 391 #else 392 .macro RESTORE_SOME docfi=0 393 .set push 394 .set reorder 395 .set noat 396 mfc0 a0, CP0_STATUS 397 ori a0, STATMASK 398 xori a0, STATMASK 399 mtc0 a0, CP0_STATUS 400 li v1, ST0_CU1 | ST0_FR | ST0_IM 401 and a0, v1 402 LONG_L v0, PT_STATUS(sp) 403 nor v1, $0, v1 404 and v0, v1 405 or v0, a0 406 mtc0 v0, CP0_STATUS 407 LONG_L v1, PT_EPC(sp) 408 MTC0 v1, CP0_EPC 409 cfi_ld $31, PT_R31, \docfi 410 cfi_ld $28, PT_R28, \docfi 411 cfi_ld $25, PT_R25, \docfi 412 #ifdef CONFIG_64BIT 413 cfi_ld $8, PT_R8, \docfi 414 cfi_ld $9, PT_R9, \docfi 415 #endif 416 cfi_ld $7, PT_R7, \docfi 417 cfi_ld $6, PT_R6, \docfi 418 cfi_ld $5, PT_R5, \docfi 419 cfi_ld $4, PT_R4, \docfi 420 cfi_ld $3, PT_R3, \docfi 421 cfi_ld $2, PT_R2, \docfi 422 .set pop 423 .endm 424 425 .macro RESTORE_SP_AND_RET docfi=0 426 RESTORE_SP \docfi 427 #if defined(CONFIG_CPU_MIPSR5) || defined(CONFIG_CPU_MIPSR6) 428 eretnc 429 #else 430 .set push 431 .set arch=r4000 432 eret 433 .set pop 434 #endif 435 .endm 436 437 #endif 438 439 .macro RESTORE_ALL docfi=0 440 RESTORE_TEMP \docfi 441 RESTORE_STATIC \docfi 442 RESTORE_AT \docfi 443 RESTORE_SOME \docfi 444 RESTORE_SP \docfi 445 .endm 446 447 /* 448 * Move to kernel mode and disable interrupts. 449 * Set cp0 enable bit as sign that we're running on the kernel stack 450 */ 451 .macro CLI 452 mfc0 t0, CP0_STATUS 453 li t1, ST0_KERNEL_CUMASK | STATMASK 454 or t0, t1 455 xori t0, STATMASK 456 mtc0 t0, CP0_STATUS 457 irq_disable_hazard 458 .endm 459 460 /* 461 * Move to kernel mode and enable interrupts. 462 * Set cp0 enable bit as sign that we're running on the kernel stack 463 */ 464 .macro STI 465 mfc0 t0, CP0_STATUS 466 li t1, ST0_KERNEL_CUMASK | STATMASK 467 or t0, t1 468 xori t0, STATMASK & ~1 469 mtc0 t0, CP0_STATUS 470 irq_enable_hazard 471 .endm 472 473 /* 474 * Just move to kernel mode and leave interrupts as they are. Note 475 * for the R3000 this means copying the previous enable from IEp. 476 * Set cp0 enable bit as sign that we're running on the kernel stack 477 */ 478 .macro KMODE 479 mfc0 t0, CP0_STATUS 480 li t1, ST0_KERNEL_CUMASK | (STATMASK & ~1) 481 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) 482 andi t2, t0, ST0_IEP 483 srl t2, 2 484 or t0, t2 485 #endif 486 or t0, t1 487 xori t0, STATMASK & ~1 488 mtc0 t0, CP0_STATUS 489 irq_disable_hazard 490 .endm 491 492 #endif /* _ASM_STACKFRAME_H */ 493