Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Based on arch/arm/include/asm/assembler.h, arch/arm/mm/proc-macros.S
4 *
5 * Copyright (C) 1996-2000 Russell King
6 * Copyright (C) 2012 ARM Ltd.
7 */
8#ifndef __ASSEMBLY__
9#error "Only include this from assembly code"
10#endif
11
12#ifndef __ASM_ASSEMBLER_H
13#define __ASM_ASSEMBLER_H
14
15#include <asm-generic/export.h>
16
17#include <asm/alternative.h>
18#include <asm/asm-bug.h>
19#include <asm/asm-extable.h>
20#include <asm/asm-offsets.h>
21#include <asm/cpufeature.h>
22#include <asm/cputype.h>
23#include <asm/debug-monitors.h>
24#include <asm/page.h>
25#include <asm/pgtable-hwdef.h>
26#include <asm/ptrace.h>
27#include <asm/thread_info.h>
28
29 /*
30 * Provide a wxN alias for each wN register so what we can paste a xN
31 * reference after a 'w' to obtain the 32-bit version.
32 */
33 .irp n,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30
34 wx\n .req w\n
35 .endr
36
37 .macro save_and_disable_daif, flags
38 mrs \flags, daif
39 msr daifset, #0xf
40 .endm
41
42 .macro disable_daif
43 msr daifset, #0xf
44 .endm
45
46 .macro enable_daif
47 msr daifclr, #0xf
48 .endm
49
50 .macro restore_daif, flags:req
51 msr daif, \flags
52 .endm
53
54 /* IRQ/FIQ are the lowest priority flags, unconditionally unmask the rest. */
55 .macro enable_da
56 msr daifclr, #(8 | 4)
57 .endm
58
59/*
60 * Save/restore interrupts.
61 */
62 .macro save_and_disable_irq, flags
63 mrs \flags, daif
64 msr daifset, #3
65 .endm
66
67 .macro restore_irq, flags
68 msr daif, \flags
69 .endm
70
71 .macro enable_dbg
72 msr daifclr, #8
73 .endm
74
75 .macro disable_step_tsk, flgs, tmp
76 tbz \flgs, #TIF_SINGLESTEP, 9990f
77 mrs \tmp, mdscr_el1
78 bic \tmp, \tmp, #DBG_MDSCR_SS
79 msr mdscr_el1, \tmp
80 isb // Synchronise with enable_dbg
819990:
82 .endm
83
84 /* call with daif masked */
85 .macro enable_step_tsk, flgs, tmp
86 tbz \flgs, #TIF_SINGLESTEP, 9990f
87 mrs \tmp, mdscr_el1
88 orr \tmp, \tmp, #DBG_MDSCR_SS
89 msr mdscr_el1, \tmp
909990:
91 .endm
92
93/*
94 * RAS Error Synchronization barrier
95 */
96 .macro esb
97#ifdef CONFIG_ARM64_RAS_EXTN
98 hint #16
99#else
100 nop
101#endif
102 .endm
103
104/*
105 * Value prediction barrier
106 */
107 .macro csdb
108 hint #20
109 .endm
110
111/*
112 * Clear Branch History instruction
113 */
114 .macro clearbhb
115 hint #22
116 .endm
117
118/*
119 * Speculation barrier
120 */
121 .macro sb
122alternative_if_not ARM64_HAS_SB
123 dsb nsh
124 isb
125alternative_else
126 SB_BARRIER_INSN
127 nop
128alternative_endif
129 .endm
130
131/*
132 * NOP sequence
133 */
134 .macro nops, num
135 .rept \num
136 nop
137 .endr
138 .endm
139
140/*
141 * Register aliases.
142 */
143lr .req x30 // link register
144
145/*
146 * Vector entry
147 */
148 .macro ventry label
149 .align 7
150 b \label
151 .endm
152
153/*
154 * Select code when configured for BE.
155 */
156#ifdef CONFIG_CPU_BIG_ENDIAN
157#define CPU_BE(code...) code
158#else
159#define CPU_BE(code...)
160#endif
161
162/*
163 * Select code when configured for LE.
164 */
165#ifdef CONFIG_CPU_BIG_ENDIAN
166#define CPU_LE(code...)
167#else
168#define CPU_LE(code...) code
169#endif
170
171/*
172 * Define a macro that constructs a 64-bit value by concatenating two
173 * 32-bit registers. Note that on big endian systems the order of the
174 * registers is swapped.
175 */
176#ifndef CONFIG_CPU_BIG_ENDIAN
177 .macro regs_to_64, rd, lbits, hbits
178#else
179 .macro regs_to_64, rd, hbits, lbits
180#endif
181 orr \rd, \lbits, \hbits, lsl #32
182 .endm
183
184/*
185 * Pseudo-ops for PC-relative adr/ldr/str <reg>, <symbol> where
186 * <symbol> is within the range +/- 4 GB of the PC.
187 */
188 /*
189 * @dst: destination register (64 bit wide)
190 * @sym: name of the symbol
191 */
192 .macro adr_l, dst, sym
193 adrp \dst, \sym
194 add \dst, \dst, :lo12:\sym
195 .endm
196
197 /*
198 * @dst: destination register (32 or 64 bit wide)
199 * @sym: name of the symbol
200 * @tmp: optional 64-bit scratch register to be used if <dst> is a
201 * 32-bit wide register, in which case it cannot be used to hold
202 * the address
203 */
204 .macro ldr_l, dst, sym, tmp=
205 .ifb \tmp
206 adrp \dst, \sym
207 ldr \dst, [\dst, :lo12:\sym]
208 .else
209 adrp \tmp, \sym
210 ldr \dst, [\tmp, :lo12:\sym]
211 .endif
212 .endm
213
214 /*
215 * @src: source register (32 or 64 bit wide)
216 * @sym: name of the symbol
217 * @tmp: mandatory 64-bit scratch register to calculate the address
218 * while <src> needs to be preserved.
219 */
220 .macro str_l, src, sym, tmp
221 adrp \tmp, \sym
222 str \src, [\tmp, :lo12:\sym]
223 .endm
224
225 /*
226 * @dst: destination register
227 */
228#if defined(__KVM_NVHE_HYPERVISOR__) || defined(__KVM_VHE_HYPERVISOR__)
229 .macro get_this_cpu_offset, dst
230 mrs \dst, tpidr_el2
231 .endm
232#else
233 .macro get_this_cpu_offset, dst
234alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
235 mrs \dst, tpidr_el1
236alternative_else
237 mrs \dst, tpidr_el2
238alternative_endif
239 .endm
240
241 .macro set_this_cpu_offset, src
242alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
243 msr tpidr_el1, \src
244alternative_else
245 msr tpidr_el2, \src
246alternative_endif
247 .endm
248#endif
249
250 /*
251 * @dst: Result of per_cpu(sym, smp_processor_id()) (can be SP)
252 * @sym: The name of the per-cpu variable
253 * @tmp: scratch register
254 */
255 .macro adr_this_cpu, dst, sym, tmp
256 adrp \tmp, \sym
257 add \dst, \tmp, #:lo12:\sym
258 get_this_cpu_offset \tmp
259 add \dst, \dst, \tmp
260 .endm
261
262 /*
263 * @dst: Result of READ_ONCE(per_cpu(sym, smp_processor_id()))
264 * @sym: The name of the per-cpu variable
265 * @tmp: scratch register
266 */
267 .macro ldr_this_cpu dst, sym, tmp
268 adr_l \dst, \sym
269 get_this_cpu_offset \tmp
270 ldr \dst, [\dst, \tmp]
271 .endm
272
273/*
274 * vma_vm_mm - get mm pointer from vma pointer (vma->vm_mm)
275 */
276 .macro vma_vm_mm, rd, rn
277 ldr \rd, [\rn, #VMA_VM_MM]
278 .endm
279
280/*
281 * read_ctr - read CTR_EL0. If the system has mismatched register fields,
282 * provide the system wide safe value from arm64_ftr_reg_ctrel0.sys_val
283 */
284 .macro read_ctr, reg
285#ifndef __KVM_NVHE_HYPERVISOR__
286alternative_if_not ARM64_MISMATCHED_CACHE_TYPE
287 mrs \reg, ctr_el0 // read CTR
288 nop
289alternative_else
290 ldr_l \reg, arm64_ftr_reg_ctrel0 + ARM64_FTR_SYSVAL
291alternative_endif
292#else
293alternative_if_not ARM64_KVM_PROTECTED_MODE
294 ASM_BUG()
295alternative_else_nop_endif
296alternative_cb ARM64_ALWAYS_SYSTEM, kvm_compute_final_ctr_el0
297 movz \reg, #0
298 movk \reg, #0, lsl #16
299 movk \reg, #0, lsl #32
300 movk \reg, #0, lsl #48
301alternative_cb_end
302#endif
303 .endm
304
305
306/*
307 * raw_dcache_line_size - get the minimum D-cache line size on this CPU
308 * from the CTR register.
309 */
310 .macro raw_dcache_line_size, reg, tmp
311 mrs \tmp, ctr_el0 // read CTR
312 ubfm \tmp, \tmp, #16, #19 // cache line size encoding
313 mov \reg, #4 // bytes per word
314 lsl \reg, \reg, \tmp // actual cache line size
315 .endm
316
317/*
318 * dcache_line_size - get the safe D-cache line size across all CPUs
319 */
320 .macro dcache_line_size, reg, tmp
321 read_ctr \tmp
322 ubfm \tmp, \tmp, #16, #19 // cache line size encoding
323 mov \reg, #4 // bytes per word
324 lsl \reg, \reg, \tmp // actual cache line size
325 .endm
326
327/*
328 * raw_icache_line_size - get the minimum I-cache line size on this CPU
329 * from the CTR register.
330 */
331 .macro raw_icache_line_size, reg, tmp
332 mrs \tmp, ctr_el0 // read CTR
333 and \tmp, \tmp, #0xf // cache line size encoding
334 mov \reg, #4 // bytes per word
335 lsl \reg, \reg, \tmp // actual cache line size
336 .endm
337
338/*
339 * icache_line_size - get the safe I-cache line size across all CPUs
340 */
341 .macro icache_line_size, reg, tmp
342 read_ctr \tmp
343 and \tmp, \tmp, #0xf // cache line size encoding
344 mov \reg, #4 // bytes per word
345 lsl \reg, \reg, \tmp // actual cache line size
346 .endm
347
348/*
349 * tcr_set_t0sz - update TCR.T0SZ so that we can load the ID map
350 */
351 .macro tcr_set_t0sz, valreg, t0sz
352 bfi \valreg, \t0sz, #TCR_T0SZ_OFFSET, #TCR_TxSZ_WIDTH
353 .endm
354
355/*
356 * tcr_set_t1sz - update TCR.T1SZ
357 */
358 .macro tcr_set_t1sz, valreg, t1sz
359 bfi \valreg, \t1sz, #TCR_T1SZ_OFFSET, #TCR_TxSZ_WIDTH
360 .endm
361
362/*
363 * idmap_get_t0sz - get the T0SZ value needed to cover the ID map
364 *
365 * Calculate the maximum allowed value for TCR_EL1.T0SZ so that the
366 * entire ID map region can be mapped. As T0SZ == (64 - #bits used),
367 * this number conveniently equals the number of leading zeroes in
368 * the physical address of _end.
369 */
370 .macro idmap_get_t0sz, reg
371 adrp \reg, _end
372 orr \reg, \reg, #(1 << VA_BITS_MIN) - 1
373 clz \reg, \reg
374 .endm
375
376/*
377 * tcr_compute_pa_size - set TCR.(I)PS to the highest supported
378 * ID_AA64MMFR0_EL1.PARange value
379 *
380 * tcr: register with the TCR_ELx value to be updated
381 * pos: IPS or PS bitfield position
382 * tmp{0,1}: temporary registers
383 */
384 .macro tcr_compute_pa_size, tcr, pos, tmp0, tmp1
385 mrs \tmp0, ID_AA64MMFR0_EL1
386 // Narrow PARange to fit the PS field in TCR_ELx
387 ubfx \tmp0, \tmp0, #ID_AA64MMFR0_EL1_PARANGE_SHIFT, #3
388 mov \tmp1, #ID_AA64MMFR0_EL1_PARANGE_MAX
389 cmp \tmp0, \tmp1
390 csel \tmp0, \tmp1, \tmp0, hi
391 bfi \tcr, \tmp0, \pos, #3
392 .endm
393
394 .macro __dcache_op_workaround_clean_cache, op, addr
395alternative_if_not ARM64_WORKAROUND_CLEAN_CACHE
396 dc \op, \addr
397alternative_else
398 dc civac, \addr
399alternative_endif
400 .endm
401
402/*
403 * Macro to perform a data cache maintenance for the interval
404 * [start, end) with dcache line size explicitly provided.
405 *
406 * op: operation passed to dc instruction
407 * domain: domain used in dsb instruciton
408 * start: starting virtual address of the region
409 * end: end virtual address of the region
410 * linesz: dcache line size
411 * fixup: optional label to branch to on user fault
412 * Corrupts: start, end, tmp
413 */
414 .macro dcache_by_myline_op op, domain, start, end, linesz, tmp, fixup
415 sub \tmp, \linesz, #1
416 bic \start, \start, \tmp
417.Ldcache_op\@:
418 .ifc \op, cvau
419 __dcache_op_workaround_clean_cache \op, \start
420 .else
421 .ifc \op, cvac
422 __dcache_op_workaround_clean_cache \op, \start
423 .else
424 .ifc \op, cvap
425 sys 3, c7, c12, 1, \start // dc cvap
426 .else
427 .ifc \op, cvadp
428 sys 3, c7, c13, 1, \start // dc cvadp
429 .else
430 dc \op, \start
431 .endif
432 .endif
433 .endif
434 .endif
435 add \start, \start, \linesz
436 cmp \start, \end
437 b.lo .Ldcache_op\@
438 dsb \domain
439
440 _cond_uaccess_extable .Ldcache_op\@, \fixup
441 .endm
442
443/*
444 * Macro to perform a data cache maintenance for the interval
445 * [start, end)
446 *
447 * op: operation passed to dc instruction
448 * domain: domain used in dsb instruciton
449 * start: starting virtual address of the region
450 * end: end virtual address of the region
451 * fixup: optional label to branch to on user fault
452 * Corrupts: start, end, tmp1, tmp2
453 */
454 .macro dcache_by_line_op op, domain, start, end, tmp1, tmp2, fixup
455 dcache_line_size \tmp1, \tmp2
456 dcache_by_myline_op \op, \domain, \start, \end, \tmp1, \tmp2, \fixup
457 .endm
458
459/*
460 * Macro to perform an instruction cache maintenance for the interval
461 * [start, end)
462 *
463 * start, end: virtual addresses describing the region
464 * fixup: optional label to branch to on user fault
465 * Corrupts: tmp1, tmp2
466 */
467 .macro invalidate_icache_by_line start, end, tmp1, tmp2, fixup
468 icache_line_size \tmp1, \tmp2
469 sub \tmp2, \tmp1, #1
470 bic \tmp2, \start, \tmp2
471.Licache_op\@:
472 ic ivau, \tmp2 // invalidate I line PoU
473 add \tmp2, \tmp2, \tmp1
474 cmp \tmp2, \end
475 b.lo .Licache_op\@
476 dsb ish
477 isb
478
479 _cond_uaccess_extable .Licache_op\@, \fixup
480 .endm
481
482/*
483 * load_ttbr1 - install @pgtbl as a TTBR1 page table
484 * pgtbl preserved
485 * tmp1/tmp2 clobbered, either may overlap with pgtbl
486 */
487 .macro load_ttbr1, pgtbl, tmp1, tmp2
488 phys_to_ttbr \tmp1, \pgtbl
489 offset_ttbr1 \tmp1, \tmp2
490 msr ttbr1_el1, \tmp1
491 isb
492 .endm
493
494/*
495 * To prevent the possibility of old and new partial table walks being visible
496 * in the tlb, switch the ttbr to a zero page when we invalidate the old
497 * records. D4.7.1 'General TLB maintenance requirements' in ARM DDI 0487A.i
498 * Even switching to our copied tables will cause a changed output address at
499 * each stage of the walk.
500 */
501 .macro break_before_make_ttbr_switch zero_page, page_table, tmp, tmp2
502 phys_to_ttbr \tmp, \zero_page
503 msr ttbr1_el1, \tmp
504 isb
505 tlbi vmalle1
506 dsb nsh
507 load_ttbr1 \page_table, \tmp, \tmp2
508 .endm
509
510/*
511 * reset_pmuserenr_el0 - reset PMUSERENR_EL0 if PMUv3 present
512 */
513 .macro reset_pmuserenr_el0, tmpreg
514 mrs \tmpreg, id_aa64dfr0_el1
515 sbfx \tmpreg, \tmpreg, #ID_AA64DFR0_EL1_PMUVer_SHIFT, #4
516 cmp \tmpreg, #1 // Skip if no PMU present
517 b.lt 9000f
518 msr pmuserenr_el0, xzr // Disable PMU access from EL0
5199000:
520 .endm
521
522/*
523 * reset_amuserenr_el0 - reset AMUSERENR_EL0 if AMUv1 present
524 */
525 .macro reset_amuserenr_el0, tmpreg
526 mrs \tmpreg, id_aa64pfr0_el1 // Check ID_AA64PFR0_EL1
527 ubfx \tmpreg, \tmpreg, #ID_AA64PFR0_EL1_AMU_SHIFT, #4
528 cbz \tmpreg, .Lskip_\@ // Skip if no AMU present
529 msr_s SYS_AMUSERENR_EL0, xzr // Disable AMU access from EL0
530.Lskip_\@:
531 .endm
532/*
533 * copy_page - copy src to dest using temp registers t1-t8
534 */
535 .macro copy_page dest:req src:req t1:req t2:req t3:req t4:req t5:req t6:req t7:req t8:req
5369998: ldp \t1, \t2, [\src]
537 ldp \t3, \t4, [\src, #16]
538 ldp \t5, \t6, [\src, #32]
539 ldp \t7, \t8, [\src, #48]
540 add \src, \src, #64
541 stnp \t1, \t2, [\dest]
542 stnp \t3, \t4, [\dest, #16]
543 stnp \t5, \t6, [\dest, #32]
544 stnp \t7, \t8, [\dest, #48]
545 add \dest, \dest, #64
546 tst \src, #(PAGE_SIZE - 1)
547 b.ne 9998b
548 .endm
549
550/*
551 * Annotate a function as being unsuitable for kprobes.
552 */
553#ifdef CONFIG_KPROBES
554#define NOKPROBE(x) \
555 .pushsection "_kprobe_blacklist", "aw"; \
556 .quad x; \
557 .popsection;
558#else
559#define NOKPROBE(x)
560#endif
561
562#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
563#define EXPORT_SYMBOL_NOKASAN(name)
564#else
565#define EXPORT_SYMBOL_NOKASAN(name) EXPORT_SYMBOL(name)
566#endif
567
568 /*
569 * Emit a 64-bit absolute little endian symbol reference in a way that
570 * ensures that it will be resolved at build time, even when building a
571 * PIE binary. This requires cooperation from the linker script, which
572 * must emit the lo32/hi32 halves individually.
573 */
574 .macro le64sym, sym
575 .long \sym\()_lo32
576 .long \sym\()_hi32
577 .endm
578
579 /*
580 * mov_q - move an immediate constant into a 64-bit register using
581 * between 2 and 4 movz/movk instructions (depending on the
582 * magnitude and sign of the operand)
583 */
584 .macro mov_q, reg, val
585 .if (((\val) >> 31) == 0 || ((\val) >> 31) == 0x1ffffffff)
586 movz \reg, :abs_g1_s:\val
587 .else
588 .if (((\val) >> 47) == 0 || ((\val) >> 47) == 0x1ffff)
589 movz \reg, :abs_g2_s:\val
590 .else
591 movz \reg, :abs_g3:\val
592 movk \reg, :abs_g2_nc:\val
593 .endif
594 movk \reg, :abs_g1_nc:\val
595 .endif
596 movk \reg, :abs_g0_nc:\val
597 .endm
598
599/*
600 * Return the current task_struct.
601 */
602 .macro get_current_task, rd
603 mrs \rd, sp_el0
604 .endm
605
606/*
607 * Offset ttbr1 to allow for 48-bit kernel VAs set with 52-bit PTRS_PER_PGD.
608 * orr is used as it can cover the immediate value (and is idempotent).
609 * In future this may be nop'ed out when dealing with 52-bit kernel VAs.
610 * ttbr: Value of ttbr to set, modified.
611 */
612 .macro offset_ttbr1, ttbr, tmp
613#ifdef CONFIG_ARM64_VA_BITS_52
614 mrs_s \tmp, SYS_ID_AA64MMFR2_EL1
615 and \tmp, \tmp, #(0xf << ID_AA64MMFR2_EL1_VARange_SHIFT)
616 cbnz \tmp, .Lskipoffs_\@
617 orr \ttbr, \ttbr, #TTBR1_BADDR_4852_OFFSET
618.Lskipoffs_\@ :
619#endif
620 .endm
621
622/*
623 * Perform the reverse of offset_ttbr1.
624 * bic is used as it can cover the immediate value and, in future, won't need
625 * to be nop'ed out when dealing with 52-bit kernel VAs.
626 */
627 .macro restore_ttbr1, ttbr
628#ifdef CONFIG_ARM64_VA_BITS_52
629 bic \ttbr, \ttbr, #TTBR1_BADDR_4852_OFFSET
630#endif
631 .endm
632
633/*
634 * Arrange a physical address in a TTBR register, taking care of 52-bit
635 * addresses.
636 *
637 * phys: physical address, preserved
638 * ttbr: returns the TTBR value
639 */
640 .macro phys_to_ttbr, ttbr, phys
641#ifdef CONFIG_ARM64_PA_BITS_52
642 orr \ttbr, \phys, \phys, lsr #46
643 and \ttbr, \ttbr, #TTBR_BADDR_MASK_52
644#else
645 mov \ttbr, \phys
646#endif
647 .endm
648
649 .macro phys_to_pte, pte, phys
650#ifdef CONFIG_ARM64_PA_BITS_52
651 /*
652 * We assume \phys is 64K aligned and this is guaranteed by only
653 * supporting this configuration with 64K pages.
654 */
655 orr \pte, \phys, \phys, lsr #36
656 and \pte, \pte, #PTE_ADDR_MASK
657#else
658 mov \pte, \phys
659#endif
660 .endm
661
662 .macro pte_to_phys, phys, pte
663#ifdef CONFIG_ARM64_PA_BITS_52
664 ubfiz \phys, \pte, #(48 - 16 - 12), #16
665 bfxil \phys, \pte, #16, #32
666 lsl \phys, \phys, #16
667#else
668 and \phys, \pte, #PTE_ADDR_MASK
669#endif
670 .endm
671
672/*
673 * tcr_clear_errata_bits - Clear TCR bits that trigger an errata on this CPU.
674 */
675 .macro tcr_clear_errata_bits, tcr, tmp1, tmp2
676#ifdef CONFIG_FUJITSU_ERRATUM_010001
677 mrs \tmp1, midr_el1
678
679 mov_q \tmp2, MIDR_FUJITSU_ERRATUM_010001_MASK
680 and \tmp1, \tmp1, \tmp2
681 mov_q \tmp2, MIDR_FUJITSU_ERRATUM_010001
682 cmp \tmp1, \tmp2
683 b.ne 10f
684
685 mov_q \tmp2, TCR_CLEAR_FUJITSU_ERRATUM_010001
686 bic \tcr, \tcr, \tmp2
68710:
688#endif /* CONFIG_FUJITSU_ERRATUM_010001 */
689 .endm
690
691/**
692 * Errata workaround prior to disable MMU. Insert an ISB immediately prior
693 * to executing the MSR that will change SCTLR_ELn[M] from a value of 1 to 0.
694 */
695 .macro pre_disable_mmu_workaround
696#ifdef CONFIG_QCOM_FALKOR_ERRATUM_E1041
697 isb
698#endif
699 .endm
700
701 /*
702 * frame_push - Push @regcount callee saved registers to the stack,
703 * starting at x19, as well as x29/x30, and set x29 to
704 * the new value of sp. Add @extra bytes of stack space
705 * for locals.
706 */
707 .macro frame_push, regcount:req, extra
708 __frame st, \regcount, \extra
709 .endm
710
711 /*
712 * frame_pop - Pop the callee saved registers from the stack that were
713 * pushed in the most recent call to frame_push, as well
714 * as x29/x30 and any extra stack space that may have been
715 * allocated.
716 */
717 .macro frame_pop
718 __frame ld
719 .endm
720
721 .macro __frame_regs, reg1, reg2, op, num
722 .if .Lframe_regcount == \num
723 \op\()r \reg1, [sp, #(\num + 1) * 8]
724 .elseif .Lframe_regcount > \num
725 \op\()p \reg1, \reg2, [sp, #(\num + 1) * 8]
726 .endif
727 .endm
728
729 .macro __frame, op, regcount, extra=0
730 .ifc \op, st
731 .if (\regcount) < 0 || (\regcount) > 10
732 .error "regcount should be in the range [0 ... 10]"
733 .endif
734 .if ((\extra) % 16) != 0
735 .error "extra should be a multiple of 16 bytes"
736 .endif
737 .ifdef .Lframe_regcount
738 .if .Lframe_regcount != -1
739 .error "frame_push/frame_pop may not be nested"
740 .endif
741 .endif
742 .set .Lframe_regcount, \regcount
743 .set .Lframe_extra, \extra
744 .set .Lframe_local_offset, ((\regcount + 3) / 2) * 16
745 stp x29, x30, [sp, #-.Lframe_local_offset - .Lframe_extra]!
746 mov x29, sp
747 .endif
748
749 __frame_regs x19, x20, \op, 1
750 __frame_regs x21, x22, \op, 3
751 __frame_regs x23, x24, \op, 5
752 __frame_regs x25, x26, \op, 7
753 __frame_regs x27, x28, \op, 9
754
755 .ifc \op, ld
756 .if .Lframe_regcount == -1
757 .error "frame_push/frame_pop may not be nested"
758 .endif
759 ldp x29, x30, [sp], #.Lframe_local_offset + .Lframe_extra
760 .set .Lframe_regcount, -1
761 .endif
762 .endm
763
764/*
765 * Set SCTLR_ELx to the @reg value, and invalidate the local icache
766 * in the process. This is called when setting the MMU on.
767 */
768.macro set_sctlr, sreg, reg
769 msr \sreg, \reg
770 isb
771 /*
772 * Invalidate the local I-cache so that any instructions fetched
773 * speculatively from the PoC are discarded, since they may have
774 * been dynamically patched at the PoU.
775 */
776 ic iallu
777 dsb nsh
778 isb
779.endm
780
781.macro set_sctlr_el1, reg
782 set_sctlr sctlr_el1, \reg
783.endm
784
785.macro set_sctlr_el2, reg
786 set_sctlr sctlr_el2, \reg
787.endm
788
789 /*
790 * Check whether preempt/bh-disabled asm code should yield as soon as
791 * it is able. This is the case if we are currently running in task
792 * context, and either a softirq is pending, or the TIF_NEED_RESCHED
793 * flag is set and re-enabling preemption a single time would result in
794 * a preempt count of zero. (Note that the TIF_NEED_RESCHED flag is
795 * stored negated in the top word of the thread_info::preempt_count
796 * field)
797 */
798 .macro cond_yield, lbl:req, tmp:req, tmp2:req
799 get_current_task \tmp
800 ldr \tmp, [\tmp, #TSK_TI_PREEMPT]
801 /*
802 * If we are serving a softirq, there is no point in yielding: the
803 * softirq will not be preempted no matter what we do, so we should
804 * run to completion as quickly as we can.
805 */
806 tbnz \tmp, #SOFTIRQ_SHIFT, .Lnoyield_\@
807#ifdef CONFIG_PREEMPTION
808 sub \tmp, \tmp, #PREEMPT_DISABLE_OFFSET
809 cbz \tmp, \lbl
810#endif
811 adr_l \tmp, irq_stat + IRQ_CPUSTAT_SOFTIRQ_PENDING
812 get_this_cpu_offset \tmp2
813 ldr w\tmp, [\tmp, \tmp2]
814 cbnz w\tmp, \lbl // yield on pending softirq in task context
815.Lnoyield_\@:
816 .endm
817
818/*
819 * Branch Target Identifier (BTI)
820 */
821 .macro bti, targets
822 .equ .L__bti_targets_c, 34
823 .equ .L__bti_targets_j, 36
824 .equ .L__bti_targets_jc,38
825 hint #.L__bti_targets_\targets
826 .endm
827
828/*
829 * This macro emits a program property note section identifying
830 * architecture features which require special handling, mainly for
831 * use in assembly files included in the VDSO.
832 */
833
834#define NT_GNU_PROPERTY_TYPE_0 5
835#define GNU_PROPERTY_AARCH64_FEATURE_1_AND 0xc0000000
836
837#define GNU_PROPERTY_AARCH64_FEATURE_1_BTI (1U << 0)
838#define GNU_PROPERTY_AARCH64_FEATURE_1_PAC (1U << 1)
839
840#ifdef CONFIG_ARM64_BTI_KERNEL
841#define GNU_PROPERTY_AARCH64_FEATURE_1_DEFAULT \
842 ((GNU_PROPERTY_AARCH64_FEATURE_1_BTI | \
843 GNU_PROPERTY_AARCH64_FEATURE_1_PAC))
844#endif
845
846#ifdef GNU_PROPERTY_AARCH64_FEATURE_1_DEFAULT
847.macro emit_aarch64_feature_1_and, feat=GNU_PROPERTY_AARCH64_FEATURE_1_DEFAULT
848 .pushsection .note.gnu.property, "a"
849 .align 3
850 .long 2f - 1f
851 .long 6f - 3f
852 .long NT_GNU_PROPERTY_TYPE_0
8531: .string "GNU"
8542:
855 .align 3
8563: .long GNU_PROPERTY_AARCH64_FEATURE_1_AND
857 .long 5f - 4f
8584:
859 /*
860 * This is described with an array of char in the Linux API
861 * spec but the text and all other usage (including binutils,
862 * clang and GCC) treat this as a 32 bit value so no swizzling
863 * is required for big endian.
864 */
865 .long \feat
8665:
867 .align 3
8686:
869 .popsection
870.endm
871
872#else
873.macro emit_aarch64_feature_1_and, feat=0
874.endm
875
876#endif /* GNU_PROPERTY_AARCH64_FEATURE_1_DEFAULT */
877
878 .macro __mitigate_spectre_bhb_loop tmp
879#ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
880alternative_cb ARM64_ALWAYS_SYSTEM, spectre_bhb_patch_loop_iter
881 mov \tmp, #32 // Patched to correct the immediate
882alternative_cb_end
883.Lspectre_bhb_loop\@:
884 b . + 4
885 subs \tmp, \tmp, #1
886 b.ne .Lspectre_bhb_loop\@
887 sb
888#endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */
889 .endm
890
891 .macro mitigate_spectre_bhb_loop tmp
892#ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
893alternative_cb ARM64_ALWAYS_SYSTEM, spectre_bhb_patch_loop_mitigation_enable
894 b .L_spectre_bhb_loop_done\@ // Patched to NOP
895alternative_cb_end
896 __mitigate_spectre_bhb_loop \tmp
897.L_spectre_bhb_loop_done\@:
898#endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */
899 .endm
900
901 /* Save/restores x0-x3 to the stack */
902 .macro __mitigate_spectre_bhb_fw
903#ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
904 stp x0, x1, [sp, #-16]!
905 stp x2, x3, [sp, #-16]!
906 mov w0, #ARM_SMCCC_ARCH_WORKAROUND_3
907alternative_cb ARM64_ALWAYS_SYSTEM, smccc_patch_fw_mitigation_conduit
908 nop // Patched to SMC/HVC #0
909alternative_cb_end
910 ldp x2, x3, [sp], #16
911 ldp x0, x1, [sp], #16
912#endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */
913 .endm
914
915 .macro mitigate_spectre_bhb_clear_insn
916#ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
917alternative_cb ARM64_ALWAYS_SYSTEM, spectre_bhb_patch_clearbhb
918 /* Patched to NOP when not supported */
919 clearbhb
920 isb
921alternative_cb_end
922#endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */
923 .endm
924#endif /* __ASM_ASSEMBLER_H */