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