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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/opcodes-virt.h>
22#include <asm/asm-offsets.h>
23#include <asm/page.h>
24#include <asm/thread_info.h>
25#include <asm/uaccess-asm.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...) \
2449999: 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...) \
2549998: 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 - . ;\
2639997: 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
349THUMB( 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
3561: msr cpsr_c, \reg
3572:
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()
3739999:
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
4149999:
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 .irp c,,eq,ne,cs,cc,mi,pl,vs,vc,hi,ls,ge,lt,gt,le,hs,lo
449 .macro ret\c, reg
450#if __LINUX_ARM_ARCH__ < 6
451 mov\c pc, \reg
452#else
453 .ifeqs "\reg", "lr"
454 bx\c \reg
455 .else
456 mov\c pc, \reg
457 .endif
458#endif
459 .endm
460 .endr
461
462 .macro ret.w, reg
463 ret \reg
464#ifdef CONFIG_THUMB2_KERNEL
465 nop
466#endif
467 .endm
468
469 .macro bug, msg, line
470#ifdef CONFIG_THUMB2_KERNEL
4711: .inst 0xde02
472#else
4731: .inst 0xe7f001f2
474#endif
475#ifdef CONFIG_DEBUG_BUGVERBOSE
476 .pushsection .rodata.str, "aMS", %progbits, 1
4772: .asciz "\msg"
478 .popsection
479 .pushsection __bug_table, "aw"
480 .align 2
481 .word 1b, 2b
482 .hword \line
483 .popsection
484#endif
485 .endm
486
487#ifdef CONFIG_KPROBES
488#define _ASM_NOKPROBE(entry) \
489 .pushsection "_kprobe_blacklist", "aw" ; \
490 .balign 4 ; \
491 .long entry; \
492 .popsection
493#else
494#define _ASM_NOKPROBE(entry)
495#endif
496
497 .macro __adldst_l, op, reg, sym, tmp, c
498 .if __LINUX_ARM_ARCH__ < 7
499 ldr\c \tmp, .La\@
500 .subsection 1
501 .align 2
502.La\@: .long \sym - .Lpc\@
503 .previous
504 .else
505 .ifnb \c
506 THUMB( ittt \c )
507 .endif
508 movw\c \tmp, #:lower16:\sym - .Lpc\@
509 movt\c \tmp, #:upper16:\sym - .Lpc\@
510 .endif
511
512#ifndef CONFIG_THUMB2_KERNEL
513 .set .Lpc\@, . + 8 // PC bias
514 .ifc \op, add
515 add\c \reg, \tmp, pc
516 .else
517 \op\c \reg, [pc, \tmp]
518 .endif
519#else
520.Lb\@: add\c \tmp, \tmp, pc
521 /*
522 * In Thumb-2 builds, the PC bias depends on whether we are currently
523 * emitting into a .arm or a .thumb section. The size of the add opcode
524 * above will be 2 bytes when emitting in Thumb mode and 4 bytes when
525 * emitting in ARM mode, so let's use this to account for the bias.
526 */
527 .set .Lpc\@, . + (. - .Lb\@)
528
529 .ifnc \op, add
530 \op\c \reg, [\tmp]
531 .endif
532#endif
533 .endm
534
535 /*
536 * mov_l - move a constant value or [relocated] address into a register
537 */
538 .macro mov_l, dst:req, imm:req
539 .if __LINUX_ARM_ARCH__ < 7
540 ldr \dst, =\imm
541 .else
542 movw \dst, #:lower16:\imm
543 movt \dst, #:upper16:\imm
544 .endif
545 .endm
546
547 /*
548 * adr_l - adr pseudo-op with unlimited range
549 *
550 * @dst: destination register
551 * @sym: name of the symbol
552 * @cond: conditional opcode suffix
553 */
554 .macro adr_l, dst:req, sym:req, cond
555 __adldst_l add, \dst, \sym, \dst, \cond
556 .endm
557
558 /*
559 * ldr_l - ldr <literal> pseudo-op with unlimited range
560 *
561 * @dst: destination register
562 * @sym: name of the symbol
563 * @cond: conditional opcode suffix
564 */
565 .macro ldr_l, dst:req, sym:req, cond
566 __adldst_l ldr, \dst, \sym, \dst, \cond
567 .endm
568
569 /*
570 * str_l - str <literal> pseudo-op with unlimited range
571 *
572 * @src: source register
573 * @sym: name of the symbol
574 * @tmp: mandatory scratch register
575 * @cond: conditional opcode suffix
576 */
577 .macro str_l, src:req, sym:req, tmp:req, cond
578 __adldst_l str, \src, \sym, \tmp, \cond
579 .endm
580
581 /*
582 * rev_l - byte-swap a 32-bit value
583 *
584 * @val: source/destination register
585 * @tmp: scratch register
586 */
587 .macro rev_l, val:req, tmp:req
588 .if __LINUX_ARM_ARCH__ < 6
589 eor \tmp, \val, \val, ror #16
590 bic \tmp, \tmp, #0x00ff0000
591 mov \val, \val, ror #8
592 eor \val, \val, \tmp, lsr #8
593 .else
594 rev \val, \val
595 .endif
596 .endm
597
598#endif /* __ASM_ASSEMBLER_H__ */