1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * arch/arm/include/asm/assembler.h 4 * 5 * Copyright (C) 1996-2000 Russell King 6 * 7 * This file contains arm architecture specific defines 8 * for the different processors. 9 * 10 * Do not include any C declarations in this file - it is included by 11 * assembler source. 12 */ 13 #ifndef __ASM_ASSEMBLER_H__ 14 #define __ASM_ASSEMBLER_H__ 15 16 #ifndef __ASSEMBLY__ 17 #error "Only include this from assembly code" 18 #endif 19 20 #include <asm/ptrace.h> 21 #include <asm/domain.h> 22 #include <asm/opcodes-virt.h> 23 #include <asm/asm-offsets.h> 24 #include <asm/page.h> 25 #include <asm/thread_info.h> 26 27 #define IOMEM(x) (x) 28 29 /* 30 * Endian independent macros for shifting bytes within registers. 31 */ 32 #ifndef __ARMEB__ 33 #define lspull lsr 34 #define lspush lsl 35 #define get_byte_0 lsl #0 36 #define get_byte_1 lsr #8 37 #define get_byte_2 lsr #16 38 #define get_byte_3 lsr #24 39 #define put_byte_0 lsl #0 40 #define put_byte_1 lsl #8 41 #define put_byte_2 lsl #16 42 #define put_byte_3 lsl #24 43 #else 44 #define lspull lsl 45 #define lspush lsr 46 #define get_byte_0 lsr #24 47 #define get_byte_1 lsr #16 48 #define get_byte_2 lsr #8 49 #define get_byte_3 lsl #0 50 #define put_byte_0 lsl #24 51 #define put_byte_1 lsl #16 52 #define put_byte_2 lsl #8 53 #define put_byte_3 lsl #0 54 #endif 55 56 /* Select code for any configuration running in BE8 mode */ 57 #ifdef CONFIG_CPU_ENDIAN_BE8 58 #define ARM_BE8(code...) code 59 #else 60 #define ARM_BE8(code...) 61 #endif 62 63 /* 64 * Data preload for architectures that support it 65 */ 66 #if __LINUX_ARM_ARCH__ >= 5 67 #define PLD(code...) code 68 #else 69 #define PLD(code...) 70 #endif 71 72 /* 73 * This can be used to enable code to cacheline align the destination 74 * pointer when bulk writing to memory. Experiments on StrongARM and 75 * XScale didn't show this a worthwhile thing to do when the cache is not 76 * set to write-allocate (this would need further testing on XScale when WA 77 * is used). 78 * 79 * On Feroceon there is much to gain however, regardless of cache mode. 80 */ 81 #ifdef CONFIG_CPU_FEROCEON 82 #define CALGN(code...) code 83 #else 84 #define CALGN(code...) 85 #endif 86 87 #define IMM12_MASK 0xfff 88 89 /* 90 * Enable and disable interrupts 91 */ 92 #if __LINUX_ARM_ARCH__ >= 6 93 .macro disable_irq_notrace 94 cpsid i 95 .endm 96 97 .macro enable_irq_notrace 98 cpsie i 99 .endm 100 #else 101 .macro disable_irq_notrace 102 msr cpsr_c, #PSR_I_BIT | SVC_MODE 103 .endm 104 105 .macro enable_irq_notrace 106 msr cpsr_c, #SVC_MODE 107 .endm 108 #endif 109 110 .macro asm_trace_hardirqs_off, save=1 111 #if defined(CONFIG_TRACE_IRQFLAGS) 112 .if \save 113 stmdb sp!, {r0-r3, ip, lr} 114 .endif 115 bl trace_hardirqs_off 116 .if \save 117 ldmia sp!, {r0-r3, ip, lr} 118 .endif 119 #endif 120 .endm 121 122 .macro asm_trace_hardirqs_on, cond=al, save=1 123 #if defined(CONFIG_TRACE_IRQFLAGS) 124 /* 125 * actually the registers should be pushed and pop'd conditionally, but 126 * after bl the flags are certainly clobbered 127 */ 128 .if \save 129 stmdb sp!, {r0-r3, ip, lr} 130 .endif 131 bl\cond trace_hardirqs_on 132 .if \save 133 ldmia sp!, {r0-r3, ip, lr} 134 .endif 135 #endif 136 .endm 137 138 .macro disable_irq, save=1 139 disable_irq_notrace 140 asm_trace_hardirqs_off \save 141 .endm 142 143 .macro enable_irq 144 asm_trace_hardirqs_on 145 enable_irq_notrace 146 .endm 147 /* 148 * Save the current IRQ state and disable IRQs. Note that this macro 149 * assumes FIQs are enabled, and that the processor is in SVC mode. 150 */ 151 .macro save_and_disable_irqs, oldcpsr 152 #ifdef CONFIG_CPU_V7M 153 mrs \oldcpsr, primask 154 #else 155 mrs \oldcpsr, cpsr 156 #endif 157 disable_irq 158 .endm 159 160 .macro save_and_disable_irqs_notrace, oldcpsr 161 #ifdef CONFIG_CPU_V7M 162 mrs \oldcpsr, primask 163 #else 164 mrs \oldcpsr, cpsr 165 #endif 166 disable_irq_notrace 167 .endm 168 169 /* 170 * Restore interrupt state previously stored in a register. We don't 171 * guarantee that this will preserve the flags. 172 */ 173 .macro restore_irqs_notrace, oldcpsr 174 #ifdef CONFIG_CPU_V7M 175 msr primask, \oldcpsr 176 #else 177 msr cpsr_c, \oldcpsr 178 #endif 179 .endm 180 181 .macro restore_irqs, oldcpsr 182 tst \oldcpsr, #PSR_I_BIT 183 asm_trace_hardirqs_on cond=eq 184 restore_irqs_notrace \oldcpsr 185 .endm 186 187 /* 188 * Assembly version of "adr rd, BSYM(sym)". This should only be used to 189 * reference local symbols in the same assembly file which are to be 190 * resolved by the assembler. Other usage is undefined. 191 */ 192 .irp c,,eq,ne,cs,cc,mi,pl,vs,vc,hi,ls,ge,lt,gt,le,hs,lo 193 .macro badr\c, rd, sym 194 #ifdef CONFIG_THUMB2_KERNEL 195 adr\c \rd, \sym + 1 196 #else 197 adr\c \rd, \sym 198 #endif 199 .endm 200 .endr 201 202 /* 203 * Get current thread_info. 204 */ 205 .macro get_thread_info, rd 206 ARM( mov \rd, sp, lsr #THREAD_SIZE_ORDER + PAGE_SHIFT ) 207 THUMB( mov \rd, sp ) 208 THUMB( lsr \rd, \rd, #THREAD_SIZE_ORDER + PAGE_SHIFT ) 209 mov \rd, \rd, lsl #THREAD_SIZE_ORDER + PAGE_SHIFT 210 .endm 211 212 /* 213 * Increment/decrement the preempt count. 214 */ 215 #ifdef CONFIG_PREEMPT_COUNT 216 .macro inc_preempt_count, ti, tmp 217 ldr \tmp, [\ti, #TI_PREEMPT] @ get preempt count 218 add \tmp, \tmp, #1 @ increment it 219 str \tmp, [\ti, #TI_PREEMPT] 220 .endm 221 222 .macro dec_preempt_count, ti, tmp 223 ldr \tmp, [\ti, #TI_PREEMPT] @ get preempt count 224 sub \tmp, \tmp, #1 @ decrement it 225 str \tmp, [\ti, #TI_PREEMPT] 226 .endm 227 228 .macro dec_preempt_count_ti, ti, tmp 229 get_thread_info \ti 230 dec_preempt_count \ti, \tmp 231 .endm 232 #else 233 .macro inc_preempt_count, ti, tmp 234 .endm 235 236 .macro dec_preempt_count, ti, tmp 237 .endm 238 239 .macro dec_preempt_count_ti, ti, tmp 240 .endm 241 #endif 242 243 #define USERL(l, x...) \ 244 9999: x; \ 245 .pushsection __ex_table,"a"; \ 246 .align 3; \ 247 .long 9999b,l; \ 248 .popsection 249 250 #define USER(x...) USERL(9001f, x) 251 252 #ifdef CONFIG_SMP 253 #define ALT_SMP(instr...) \ 254 9998: instr 255 /* 256 * Note: if you get assembler errors from ALT_UP() when building with 257 * CONFIG_THUMB2_KERNEL, you almost certainly need to use 258 * ALT_SMP( W(instr) ... ) 259 */ 260 #define ALT_UP(instr...) \ 261 .pushsection ".alt.smp.init", "a" ;\ 262 .long 9998b ;\ 263 9997: instr ;\ 264 .if . - 9997b == 2 ;\ 265 nop ;\ 266 .endif ;\ 267 .if . - 9997b != 4 ;\ 268 .error "ALT_UP() content must assemble to exactly 4 bytes";\ 269 .endif ;\ 270 .popsection 271 #define ALT_UP_B(label) \ 272 .pushsection ".alt.smp.init", "a" ;\ 273 .long 9998b ;\ 274 W(b) . + (label - 9998b) ;\ 275 .popsection 276 #else 277 #define ALT_SMP(instr...) 278 #define ALT_UP(instr...) instr 279 #define ALT_UP_B(label) b label 280 #endif 281 282 /* 283 * Instruction barrier 284 */ 285 .macro instr_sync 286 #if __LINUX_ARM_ARCH__ >= 7 287 isb 288 #elif __LINUX_ARM_ARCH__ == 6 289 mcr p15, 0, r0, c7, c5, 4 290 #endif 291 .endm 292 293 /* 294 * SMP data memory barrier 295 */ 296 .macro smp_dmb mode 297 #ifdef CONFIG_SMP 298 #if __LINUX_ARM_ARCH__ >= 7 299 .ifeqs "\mode","arm" 300 ALT_SMP(dmb ish) 301 .else 302 ALT_SMP(W(dmb) ish) 303 .endif 304 #elif __LINUX_ARM_ARCH__ == 6 305 ALT_SMP(mcr p15, 0, r0, c7, c10, 5) @ dmb 306 #else 307 #error Incompatible SMP platform 308 #endif 309 .ifeqs "\mode","arm" 310 ALT_UP(nop) 311 .else 312 ALT_UP(W(nop)) 313 .endif 314 #endif 315 .endm 316 317 #if defined(CONFIG_CPU_V7M) 318 /* 319 * setmode is used to assert to be in svc mode during boot. For v7-M 320 * this is done in __v7m_setup, so setmode can be empty here. 321 */ 322 .macro setmode, mode, reg 323 .endm 324 #elif defined(CONFIG_THUMB2_KERNEL) 325 .macro setmode, mode, reg 326 mov \reg, #\mode 327 msr cpsr_c, \reg 328 .endm 329 #else 330 .macro setmode, mode, reg 331 msr cpsr_c, #\mode 332 .endm 333 #endif 334 335 /* 336 * Helper macro to enter SVC mode cleanly and mask interrupts. reg is 337 * a scratch register for the macro to overwrite. 338 * 339 * This macro is intended for forcing the CPU into SVC mode at boot time. 340 * you cannot return to the original mode. 341 */ 342 .macro safe_svcmode_maskall reg:req 343 #if __LINUX_ARM_ARCH__ >= 6 && !defined(CONFIG_CPU_V7M) 344 mrs \reg , cpsr 345 eor \reg, \reg, #HYP_MODE 346 tst \reg, #MODE_MASK 347 bic \reg , \reg , #MODE_MASK 348 orr \reg , \reg , #PSR_I_BIT | PSR_F_BIT | SVC_MODE 349 THUMB( orr \reg , \reg , #PSR_T_BIT ) 350 bne 1f 351 orr \reg, \reg, #PSR_A_BIT 352 badr lr, 2f 353 msr spsr_cxsf, \reg 354 __MSR_ELR_HYP(14) 355 __ERET 356 1: msr cpsr_c, \reg 357 2: 358 #else 359 /* 360 * workaround for possibly broken pre-v6 hardware 361 * (akita, Sharp Zaurus C-1000, PXA270-based) 362 */ 363 setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, \reg 364 #endif 365 .endm 366 367 /* 368 * STRT/LDRT access macros with ARM and Thumb-2 variants 369 */ 370 #ifdef CONFIG_THUMB2_KERNEL 371 372 .macro usraccoff, instr, reg, ptr, inc, off, cond, abort, t=TUSER() 373 9999: 374 .if \inc == 1 375 \instr\()b\t\cond\().w \reg, [\ptr, #\off] 376 .elseif \inc == 4 377 \instr\t\cond\().w \reg, [\ptr, #\off] 378 .else 379 .error "Unsupported inc macro argument" 380 .endif 381 382 .pushsection __ex_table,"a" 383 .align 3 384 .long 9999b, \abort 385 .popsection 386 .endm 387 388 .macro usracc, instr, reg, ptr, inc, cond, rept, abort 389 @ explicit IT instruction needed because of the label 390 @ introduced by the USER macro 391 .ifnc \cond,al 392 .if \rept == 1 393 itt \cond 394 .elseif \rept == 2 395 ittt \cond 396 .else 397 .error "Unsupported rept macro argument" 398 .endif 399 .endif 400 401 @ Slightly optimised to avoid incrementing the pointer twice 402 usraccoff \instr, \reg, \ptr, \inc, 0, \cond, \abort 403 .if \rept == 2 404 usraccoff \instr, \reg, \ptr, \inc, \inc, \cond, \abort 405 .endif 406 407 add\cond \ptr, #\rept * \inc 408 .endm 409 410 #else /* !CONFIG_THUMB2_KERNEL */ 411 412 .macro usracc, instr, reg, ptr, inc, cond, rept, abort, t=TUSER() 413 .rept \rept 414 9999: 415 .if \inc == 1 416 \instr\()b\t\cond \reg, [\ptr], #\inc 417 .elseif \inc == 4 418 \instr\t\cond \reg, [\ptr], #\inc 419 .else 420 .error "Unsupported inc macro argument" 421 .endif 422 423 .pushsection __ex_table,"a" 424 .align 3 425 .long 9999b, \abort 426 .popsection 427 .endr 428 .endm 429 430 #endif /* CONFIG_THUMB2_KERNEL */ 431 432 .macro strusr, reg, ptr, inc, cond=al, rept=1, abort=9001f 433 usracc str, \reg, \ptr, \inc, \cond, \rept, \abort 434 .endm 435 436 .macro ldrusr, reg, ptr, inc, cond=al, rept=1, abort=9001f 437 usracc ldr, \reg, \ptr, \inc, \cond, \rept, \abort 438 .endm 439 440 /* Utility macro for declaring string literals */ 441 .macro string name:req, string 442 .type \name , #object 443 \name: 444 .asciz "\string" 445 .size \name , . - \name 446 .endm 447 448 .macro csdb 449 #ifdef CONFIG_THUMB2_KERNEL 450 .inst.w 0xf3af8014 451 #else 452 .inst 0xe320f014 453 #endif 454 .endm 455 456 .macro check_uaccess, addr:req, size:req, limit:req, tmp:req, bad:req 457 #ifndef CONFIG_CPU_USE_DOMAINS 458 adds \tmp, \addr, #\size - 1 459 sbcscc \tmp, \tmp, \limit 460 bcs \bad 461 #ifdef CONFIG_CPU_SPECTRE 462 movcs \addr, #0 463 csdb 464 #endif 465 #endif 466 .endm 467 468 .macro uaccess_mask_range_ptr, addr:req, size:req, limit:req, tmp:req 469 #ifdef CONFIG_CPU_SPECTRE 470 sub \tmp, \limit, #1 471 subs \tmp, \tmp, \addr @ tmp = limit - 1 - addr 472 addhs \tmp, \tmp, #1 @ if (tmp >= 0) { 473 subshs \tmp, \tmp, \size @ tmp = limit - (addr + size) } 474 movlo \addr, #0 @ if (tmp < 0) addr = NULL 475 csdb 476 #endif 477 .endm 478 479 .macro uaccess_disable, tmp, isb=1 480 #ifdef CONFIG_CPU_SW_DOMAIN_PAN 481 /* 482 * Whenever we re-enter userspace, the domains should always be 483 * set appropriately. 484 */ 485 mov \tmp, #DACR_UACCESS_DISABLE 486 mcr p15, 0, \tmp, c3, c0, 0 @ Set domain register 487 .if \isb 488 instr_sync 489 .endif 490 #endif 491 .endm 492 493 .macro uaccess_enable, tmp, isb=1 494 #ifdef CONFIG_CPU_SW_DOMAIN_PAN 495 /* 496 * Whenever we re-enter userspace, the domains should always be 497 * set appropriately. 498 */ 499 mov \tmp, #DACR_UACCESS_ENABLE 500 mcr p15, 0, \tmp, c3, c0, 0 501 .if \isb 502 instr_sync 503 .endif 504 #endif 505 .endm 506 507 .macro uaccess_save, tmp 508 #ifdef CONFIG_CPU_SW_DOMAIN_PAN 509 mrc p15, 0, \tmp, c3, c0, 0 510 str \tmp, [sp, #SVC_DACR] 511 #endif 512 .endm 513 514 .macro uaccess_restore 515 #ifdef CONFIG_CPU_SW_DOMAIN_PAN 516 ldr r0, [sp, #SVC_DACR] 517 mcr p15, 0, r0, c3, c0, 0 518 #endif 519 .endm 520 521 .irp c,,eq,ne,cs,cc,mi,pl,vs,vc,hi,ls,ge,lt,gt,le,hs,lo 522 .macro ret\c, reg 523 #if __LINUX_ARM_ARCH__ < 6 524 mov\c pc, \reg 525 #else 526 .ifeqs "\reg", "lr" 527 bx\c \reg 528 .else 529 mov\c pc, \reg 530 .endif 531 #endif 532 .endm 533 .endr 534 535 .macro ret.w, reg 536 ret \reg 537 #ifdef CONFIG_THUMB2_KERNEL 538 nop 539 #endif 540 .endm 541 542 .macro bug, msg, line 543 #ifdef CONFIG_THUMB2_KERNEL 544 1: .inst 0xde02 545 #else 546 1: .inst 0xe7f001f2 547 #endif 548 #ifdef CONFIG_DEBUG_BUGVERBOSE 549 .pushsection .rodata.str, "aMS", %progbits, 1 550 2: .asciz "\msg" 551 .popsection 552 .pushsection __bug_table, "aw" 553 .align 2 554 .word 1b, 2b 555 .hword \line 556 .popsection 557 #endif 558 .endm 559 560 #ifdef CONFIG_KPROBES 561 #define _ASM_NOKPROBE(entry) \ 562 .pushsection "_kprobe_blacklist", "aw" ; \ 563 .balign 4 ; \ 564 .long entry; \ 565 .popsection 566 #else 567 #define _ASM_NOKPROBE(entry) 568 #endif 569 570 #endif /* __ASM_ASSEMBLER_H__ */ 571