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linux
arm64: alternatives: Split up alternative.h
asm/alternative.h contains both the macros needed to use alternatives,
as well the type definitions and function prototypes for applying them.
Split the header in two, so that alternatives can be used from core
header files such as linux/compiler.h without the risk of circular
includes
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
+222
-209
+217
arch/arm64/include/asm/alternative-macros.h
+217
arch/arm64/include/asm/alternative-macros.h
···
1
+
/* SPDX-License-Identifier: GPL-2.0 */
2
+
#ifndef __ASM_ALTERNATIVE_MACROS_H
3
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#define __ASM_ALTERNATIVE_MACROS_H
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#include <asm/cpucaps.h>
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+
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#define ARM64_CB_PATCH ARM64_NCAPS
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/* A64 instructions are always 32 bits. */
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#define AARCH64_INSN_SIZE 4
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#ifndef __ASSEMBLY__
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+
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#include <linux/stringify.h>
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+
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#define ALTINSTR_ENTRY(feature) \
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" .word 661b - .\n" /* label */ \
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" .word 663f - .\n" /* new instruction */ \
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" .hword " __stringify(feature) "\n" /* feature bit */ \
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" .byte 662b-661b\n" /* source len */ \
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" .byte 664f-663f\n" /* replacement len */
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+
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#define ALTINSTR_ENTRY_CB(feature, cb) \
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" .word 661b - .\n" /* label */ \
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" .word " __stringify(cb) "- .\n" /* callback */ \
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" .hword " __stringify(feature) "\n" /* feature bit */ \
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" .byte 662b-661b\n" /* source len */ \
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" .byte 664f-663f\n" /* replacement len */
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+
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/*
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* alternative assembly primitive:
32
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*
33
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* If any of these .org directive fail, it means that insn1 and insn2
34
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* don't have the same length. This used to be written as
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*
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* .if ((664b-663b) != (662b-661b))
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* .error "Alternatives instruction length mismatch"
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* .endif
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*
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* but most assemblers die if insn1 or insn2 have a .inst. This should
41
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* be fixed in a binutils release posterior to 2.25.51.0.2 (anything
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* containing commit 4e4d08cf7399b606 or c1baaddf8861).
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*
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* Alternatives with callbacks do not generate replacement instructions.
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*/
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#define __ALTERNATIVE_CFG(oldinstr, newinstr, feature, cfg_enabled) \
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".if "__stringify(cfg_enabled)" == 1\n" \
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"661:\n\t" \
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oldinstr "\n" \
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"662:\n" \
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".pushsection .altinstructions,\"a\"\n" \
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ALTINSTR_ENTRY(feature) \
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".popsection\n" \
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".subsection 1\n" \
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"663:\n\t" \
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newinstr "\n" \
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"664:\n\t" \
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".org . - (664b-663b) + (662b-661b)\n\t" \
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".org . - (662b-661b) + (664b-663b)\n\t" \
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".previous\n" \
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".endif\n"
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#define __ALTERNATIVE_CFG_CB(oldinstr, feature, cfg_enabled, cb) \
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".if "__stringify(cfg_enabled)" == 1\n" \
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"661:\n\t" \
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oldinstr "\n" \
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"662:\n" \
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".pushsection .altinstructions,\"a\"\n" \
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ALTINSTR_ENTRY_CB(feature, cb) \
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".popsection\n" \
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"663:\n\t" \
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"664:\n\t" \
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".endif\n"
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#define _ALTERNATIVE_CFG(oldinstr, newinstr, feature, cfg, ...) \
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__ALTERNATIVE_CFG(oldinstr, newinstr, feature, IS_ENABLED(cfg))
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#define ALTERNATIVE_CB(oldinstr, cb) \
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__ALTERNATIVE_CFG_CB(oldinstr, ARM64_CB_PATCH, 1, cb)
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#else
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#include <asm/assembler.h>
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.macro altinstruction_entry orig_offset alt_offset feature orig_len alt_len
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.word \orig_offset - .
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.word \alt_offset - .
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.hword \feature
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.byte \orig_len
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.byte \alt_len
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.endm
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.macro alternative_insn insn1, insn2, cap, enable = 1
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.if \enable
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661: \insn1
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662: .pushsection .altinstructions, "a"
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altinstruction_entry 661b, 663f, \cap, 662b-661b, 664f-663f
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.popsection
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.subsection 1
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663: \insn2
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664: .previous
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.org . - (664b-663b) + (662b-661b)
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.org . - (662b-661b) + (664b-663b)
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.endif
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.endm
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/*
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* Alternative sequences
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*
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* The code for the case where the capability is not present will be
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* assembled and linked as normal. There are no restrictions on this
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* code.
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*
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* The code for the case where the capability is present will be
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* assembled into a special section to be used for dynamic patching.
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* Code for that case must:
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*
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* 1. Be exactly the same length (in bytes) as the default code
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* sequence.
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*
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* 2. Not contain a branch target that is used outside of the
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* alternative sequence it is defined in (branches into an
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* alternative sequence are not fixed up).
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*/
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/*
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* Begin an alternative code sequence.
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*/
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.macro alternative_if_not cap
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.set .Lasm_alt_mode, 0
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.pushsection .altinstructions, "a"
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altinstruction_entry 661f, 663f, \cap, 662f-661f, 664f-663f
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.popsection
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661:
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.endm
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+
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.macro alternative_if cap
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.set .Lasm_alt_mode, 1
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.pushsection .altinstructions, "a"
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altinstruction_entry 663f, 661f, \cap, 664f-663f, 662f-661f
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.popsection
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.subsection 1
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.align 2 /* So GAS knows label 661 is suitably aligned */
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661:
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.endm
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+
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.macro alternative_cb cb
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.set .Lasm_alt_mode, 0
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.pushsection .altinstructions, "a"
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altinstruction_entry 661f, \cb, ARM64_CB_PATCH, 662f-661f, 0
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.popsection
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661:
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.endm
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+
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/*
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* Provide the other half of the alternative code sequence.
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*/
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.macro alternative_else
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662:
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.if .Lasm_alt_mode==0
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.subsection 1
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.else
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.previous
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.endif
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663:
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.endm
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/*
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* Complete an alternative code sequence.
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*/
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.macro alternative_endif
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664:
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.if .Lasm_alt_mode==0
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.previous
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.endif
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.org . - (664b-663b) + (662b-661b)
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.org . - (662b-661b) + (664b-663b)
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.endm
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+
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/*
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* Callback-based alternative epilogue
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*/
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.macro alternative_cb_end
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662:
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.endm
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+
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/*
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* Provides a trivial alternative or default sequence consisting solely
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* of NOPs. The number of NOPs is chosen automatically to match the
189
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* previous case.
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*/
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.macro alternative_else_nop_endif
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alternative_else
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nops (662b-661b) / AARCH64_INSN_SIZE
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alternative_endif
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.endm
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#define _ALTERNATIVE_CFG(insn1, insn2, cap, cfg, ...) \
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alternative_insn insn1, insn2, cap, IS_ENABLED(cfg)
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.macro user_alt, label, oldinstr, newinstr, cond
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9999: alternative_insn "\oldinstr", "\newinstr", \cond
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_asm_extable 9999b, \label
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.endm
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#endif /* __ASSEMBLY__ */
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+
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/*
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* Usage: asm(ALTERNATIVE(oldinstr, newinstr, feature));
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*
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* Usage: asm(ALTERNATIVE(oldinstr, newinstr, feature, CONFIG_FOO));
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* N.B. If CONFIG_FOO is specified, but not selected, the whole block
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* will be omitted, including oldinstr.
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*/
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#define ALTERNATIVE(oldinstr, newinstr, ...) \
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_ALTERNATIVE_CFG(oldinstr, newinstr, __VA_ARGS__, 1)
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#endif /* __ASM_ALTERNATIVE_MACROS_H */
+2
-206
arch/arm64/include/asm/alternative.h
+2
-206
arch/arm64/include/asm/alternative.h
···
2
2
#ifndef __ASM_ALTERNATIVE_H
3
3
#define __ASM_ALTERNATIVE_H
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4
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#include <asm/cpucaps.h>
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#include <asm/insn.h>
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-
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#define ARM64_CB_PATCH ARM64_NCAPS
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#include <asm/alternative-macros.h>
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#ifndef __ASSEMBLY__
11
8
12
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#include <linux/init.h>
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#include <linux/types.h>
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11
#include <linux/stddef.h>
15
-
#include <linux/stringify.h>
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struct alt_instr {
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14
s32 orig_offset; /* offset to original instruction */
···
31
35
static inline void apply_alternatives_module(void *start, size_t length) { }
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#endif
33
37
34
-
#define ALTINSTR_ENTRY(feature) \
35
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" .word 661b - .\n" /* label */ \
36
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" .word 663f - .\n" /* new instruction */ \
37
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" .hword " __stringify(feature) "\n" /* feature bit */ \
38
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" .byte 662b-661b\n" /* source len */ \
39
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" .byte 664f-663f\n" /* replacement len */
40
-
41
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#define ALTINSTR_ENTRY_CB(feature, cb) \
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" .word 661b - .\n" /* label */ \
43
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" .word " __stringify(cb) "- .\n" /* callback */ \
44
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" .hword " __stringify(feature) "\n" /* feature bit */ \
45
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" .byte 662b-661b\n" /* source len */ \
46
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" .byte 664f-663f\n" /* replacement len */
47
-
48
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/*
49
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* alternative assembly primitive:
50
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*
51
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* If any of these .org directive fail, it means that insn1 and insn2
52
-
* don't have the same length. This used to be written as
53
-
*
54
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* .if ((664b-663b) != (662b-661b))
55
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* .error "Alternatives instruction length mismatch"
56
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* .endif
57
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*
58
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* but most assemblers die if insn1 or insn2 have a .inst. This should
59
-
* be fixed in a binutils release posterior to 2.25.51.0.2 (anything
60
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* containing commit 4e4d08cf7399b606 or c1baaddf8861).
61
-
*
62
-
* Alternatives with callbacks do not generate replacement instructions.
63
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*/
64
-
#define __ALTERNATIVE_CFG(oldinstr, newinstr, feature, cfg_enabled) \
65
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".if "__stringify(cfg_enabled)" == 1\n" \
66
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"661:\n\t" \
67
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oldinstr "\n" \
68
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"662:\n" \
69
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".pushsection .altinstructions,\"a\"\n" \
70
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ALTINSTR_ENTRY(feature) \
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".popsection\n" \
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".subsection 1\n" \
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"663:\n\t" \
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newinstr "\n" \
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"664:\n\t" \
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".org . - (664b-663b) + (662b-661b)\n\t" \
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".org . - (662b-661b) + (664b-663b)\n\t" \
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".previous\n" \
79
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".endif\n"
80
-
81
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#define __ALTERNATIVE_CFG_CB(oldinstr, feature, cfg_enabled, cb) \
82
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".if "__stringify(cfg_enabled)" == 1\n" \
83
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"661:\n\t" \
84
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oldinstr "\n" \
85
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"662:\n" \
86
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".pushsection .altinstructions,\"a\"\n" \
87
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ALTINSTR_ENTRY_CB(feature, cb) \
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".popsection\n" \
89
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"663:\n\t" \
90
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"664:\n\t" \
91
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".endif\n"
92
-
93
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#define _ALTERNATIVE_CFG(oldinstr, newinstr, feature, cfg, ...) \
94
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__ALTERNATIVE_CFG(oldinstr, newinstr, feature, IS_ENABLED(cfg))
95
-
96
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#define ALTERNATIVE_CB(oldinstr, cb) \
97
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__ALTERNATIVE_CFG_CB(oldinstr, ARM64_CB_PATCH, 1, cb)
98
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#else
99
-
100
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#include <asm/assembler.h>
101
-
102
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.macro altinstruction_entry orig_offset alt_offset feature orig_len alt_len
103
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.word \orig_offset - .
104
-
.word \alt_offset - .
105
-
.hword \feature
106
-
.byte \orig_len
107
-
.byte \alt_len
108
-
.endm
109
-
110
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.macro alternative_insn insn1, insn2, cap, enable = 1
111
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.if \enable
112
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661: \insn1
113
-
662: .pushsection .altinstructions, "a"
114
-
altinstruction_entry 661b, 663f, \cap, 662b-661b, 664f-663f
115
-
.popsection
116
-
.subsection 1
117
-
663: \insn2
118
-
664: .previous
119
-
.org . - (664b-663b) + (662b-661b)
120
-
.org . - (662b-661b) + (664b-663b)
121
-
.endif
122
-
.endm
123
-
124
-
/*
125
-
* Alternative sequences
126
-
*
127
-
* The code for the case where the capability is not present will be
128
-
* assembled and linked as normal. There are no restrictions on this
129
-
* code.
130
-
*
131
-
* The code for the case where the capability is present will be
132
-
* assembled into a special section to be used for dynamic patching.
133
-
* Code for that case must:
134
-
*
135
-
* 1. Be exactly the same length (in bytes) as the default code
136
-
* sequence.
137
-
*
138
-
* 2. Not contain a branch target that is used outside of the
139
-
* alternative sequence it is defined in (branches into an
140
-
* alternative sequence are not fixed up).
141
-
*/
142
-
143
-
/*
144
-
* Begin an alternative code sequence.
145
-
*/
146
-
.macro alternative_if_not cap
147
-
.set .Lasm_alt_mode, 0
148
-
.pushsection .altinstructions, "a"
149
-
altinstruction_entry 661f, 663f, \cap, 662f-661f, 664f-663f
150
-
.popsection
151
-
661:
152
-
.endm
153
-
154
-
.macro alternative_if cap
155
-
.set .Lasm_alt_mode, 1
156
-
.pushsection .altinstructions, "a"
157
-
altinstruction_entry 663f, 661f, \cap, 664f-663f, 662f-661f
158
-
.popsection
159
-
.subsection 1
160
-
.align 2 /* So GAS knows label 661 is suitably aligned */
161
-
661:
162
-
.endm
163
-
164
-
.macro alternative_cb cb
165
-
.set .Lasm_alt_mode, 0
166
-
.pushsection .altinstructions, "a"
167
-
altinstruction_entry 661f, \cb, ARM64_CB_PATCH, 662f-661f, 0
168
-
.popsection
169
-
661:
170
-
.endm
171
-
172
-
/*
173
-
* Provide the other half of the alternative code sequence.
174
-
*/
175
-
.macro alternative_else
176
-
662:
177
-
.if .Lasm_alt_mode==0
178
-
.subsection 1
179
-
.else
180
-
.previous
181
-
.endif
182
-
663:
183
-
.endm
184
-
185
-
/*
186
-
* Complete an alternative code sequence.
187
-
*/
188
-
.macro alternative_endif
189
-
664:
190
-
.if .Lasm_alt_mode==0
191
-
.previous
192
-
.endif
193
-
.org . - (664b-663b) + (662b-661b)
194
-
.org . - (662b-661b) + (664b-663b)
195
-
.endm
196
-
197
-
/*
198
-
* Callback-based alternative epilogue
199
-
*/
200
-
.macro alternative_cb_end
201
-
662:
202
-
.endm
203
-
204
-
/*
205
-
* Provides a trivial alternative or default sequence consisting solely
206
-
* of NOPs. The number of NOPs is chosen automatically to match the
207
-
* previous case.
208
-
*/
209
-
.macro alternative_else_nop_endif
210
-
alternative_else
211
-
nops (662b-661b) / AARCH64_INSN_SIZE
212
-
alternative_endif
213
-
.endm
214
-
215
-
#define _ALTERNATIVE_CFG(insn1, insn2, cap, cfg, ...) \
216
-
alternative_insn insn1, insn2, cap, IS_ENABLED(cfg)
217
-
218
-
.macro user_alt, label, oldinstr, newinstr, cond
219
-
9999: alternative_insn "\oldinstr", "\newinstr", \cond
220
-
_asm_extable 9999b, \label
221
-
.endm
222
-
223
-
#endif /* __ASSEMBLY__ */
224
-
225
-
/*
226
-
* Usage: asm(ALTERNATIVE(oldinstr, newinstr, feature));
227
-
*
228
-
* Usage: asm(ALTERNATIVE(oldinstr, newinstr, feature, CONFIG_FOO));
229
-
* N.B. If CONFIG_FOO is specified, but not selected, the whole block
230
-
* will be omitted, including oldinstr.
231
-
*/
232
-
#define ALTERNATIVE(oldinstr, newinstr, ...) \
233
-
_ALTERNATIVE_CFG(oldinstr, newinstr, __VA_ARGS__, 1)
234
-
38
+
#endif /* __ASSEMBLY__ */
235
39
#endif /* __ASM_ALTERNATIVE_H */
+1
-1
arch/arm64/include/asm/asm-uaccess.h
+1
-1
arch/arm64/include/asm/asm-uaccess.h
+1
-2
arch/arm64/include/asm/insn.h
+1
-2
arch/arm64/include/asm/insn.h