diff options
Diffstat (limited to 'arch/arm64/include/asm/alternative.h')
| -rw-r--r-- | arch/arm64/include/asm/alternative.h | 262 |
1 files changed, 6 insertions, 256 deletions
diff --git a/arch/arm64/include/asm/alternative.h b/arch/arm64/include/asm/alternative.h index b9f8d787eea9..00d97b8a757f 100644 --- a/arch/arm64/include/asm/alternative.h +++ b/arch/arm64/include/asm/alternative.h @@ -2,22 +2,18 @@ #ifndef __ASM_ALTERNATIVE_H #define __ASM_ALTERNATIVE_H -#include <asm/cpucaps.h> -#include <asm/insn.h> - -#define ARM64_CB_PATCH ARM64_NCAPS +#include <asm/alternative-macros.h> #ifndef __ASSEMBLY__ #include <linux/init.h> #include <linux/types.h> #include <linux/stddef.h> -#include <linux/stringify.h> struct alt_instr { s32 orig_offset; /* offset to original instruction */ s32 alt_offset; /* offset to replacement instruction */ - u16 cpufeature; /* cpufeature bit set for replacement */ + u16 cpucap; /* cpucap bit set for replacement */ u8 orig_len; /* size of original instruction(s) */ u8 alt_len; /* size of new instruction(s), <= orig_len */ }; @@ -27,7 +23,7 @@ typedef void (*alternative_cb_t)(struct alt_instr *alt, void __init apply_boot_alternatives(void); void __init apply_alternatives_all(void); -bool alternative_is_applied(u16 cpufeature); +bool alternative_is_applied(u16 cpucap); #ifdef CONFIG_MODULES void apply_alternatives_module(void *start, size_t length); @@ -35,254 +31,8 @@ void apply_alternatives_module(void *start, size_t length); static inline void apply_alternatives_module(void *start, size_t length) { } #endif -#define ALTINSTR_ENTRY(feature,cb) \ - " .word 661b - .\n" /* label */ \ - " .if " __stringify(cb) " == 0\n" \ - " .word 663f - .\n" /* new instruction */ \ - " .else\n" \ - " .word " __stringify(cb) "- .\n" /* callback */ \ - " .endif\n" \ - " .hword " __stringify(feature) "\n" /* feature bit */ \ - " .byte 662b-661b\n" /* source len */ \ - " .byte 664f-663f\n" /* replacement len */ - -/* - * alternative assembly primitive: - * - * If any of these .org directive fail, it means that insn1 and insn2 - * don't have the same length. This used to be written as - * - * .if ((664b-663b) != (662b-661b)) - * .error "Alternatives instruction length mismatch" - * .endif - * - * but most assemblers die if insn1 or insn2 have a .inst. This should - * be fixed in a binutils release posterior to 2.25.51.0.2 (anything - * containing commit 4e4d08cf7399b606 or c1baaddf8861). - * - * Alternatives with callbacks do not generate replacement instructions. - */ -#define __ALTERNATIVE_CFG(oldinstr, newinstr, feature, cfg_enabled, cb) \ - ".if "__stringify(cfg_enabled)" == 1\n" \ - "661:\n\t" \ - oldinstr "\n" \ - "662:\n" \ - ".pushsection .altinstructions,\"a\"\n" \ - ALTINSTR_ENTRY(feature,cb) \ - ".popsection\n" \ - " .if " __stringify(cb) " == 0\n" \ - ".pushsection .altinstr_replacement, \"a\"\n" \ - "663:\n\t" \ - newinstr "\n" \ - "664:\n\t" \ - ".popsection\n\t" \ - ".org . - (664b-663b) + (662b-661b)\n\t" \ - ".org . - (662b-661b) + (664b-663b)\n" \ - ".else\n\t" \ - "663:\n\t" \ - "664:\n\t" \ - ".endif\n" \ - ".endif\n" - -#define _ALTERNATIVE_CFG(oldinstr, newinstr, feature, cfg, ...) \ - __ALTERNATIVE_CFG(oldinstr, newinstr, feature, IS_ENABLED(cfg), 0) - -#define ALTERNATIVE_CB(oldinstr, cb) \ - __ALTERNATIVE_CFG(oldinstr, "NOT_AN_INSTRUCTION", ARM64_CB_PATCH, 1, cb) -#else - -#include <asm/assembler.h> - -.macro altinstruction_entry orig_offset alt_offset feature orig_len alt_len - .word \orig_offset - . - .word \alt_offset - . - .hword \feature - .byte \orig_len - .byte \alt_len -.endm - -.macro alternative_insn insn1, insn2, cap, enable = 1 - .if \enable -661: \insn1 -662: .pushsection .altinstructions, "a" - altinstruction_entry 661b, 663f, \cap, 662b-661b, 664f-663f - .popsection - .pushsection .altinstr_replacement, "ax" -663: \insn2 -664: .popsection - .org . - (664b-663b) + (662b-661b) - .org . - (662b-661b) + (664b-663b) - .endif -.endm - -/* - * Alternative sequences - * - * The code for the case where the capability is not present will be - * assembled and linked as normal. There are no restrictions on this - * code. - * - * The code for the case where the capability is present will be - * assembled into a special section to be used for dynamic patching. - * Code for that case must: - * - * 1. Be exactly the same length (in bytes) as the default code - * sequence. - * - * 2. Not contain a branch target that is used outside of the - * alternative sequence it is defined in (branches into an - * alternative sequence are not fixed up). - */ - -/* - * Begin an alternative code sequence. - */ -.macro alternative_if_not cap - .set .Lasm_alt_mode, 0 - .pushsection .altinstructions, "a" - altinstruction_entry 661f, 663f, \cap, 662f-661f, 664f-663f - .popsection -661: -.endm - -.macro alternative_if cap - .set .Lasm_alt_mode, 1 - .pushsection .altinstructions, "a" - altinstruction_entry 663f, 661f, \cap, 664f-663f, 662f-661f - .popsection - .pushsection .altinstr_replacement, "ax" - .align 2 /* So GAS knows label 661 is suitably aligned */ -661: -.endm - -.macro alternative_cb cb - .set .Lasm_alt_mode, 0 - .pushsection .altinstructions, "a" - altinstruction_entry 661f, \cb, ARM64_CB_PATCH, 662f-661f, 0 - .popsection -661: -.endm - -/* - * Provide the other half of the alternative code sequence. - */ -.macro alternative_else -662: - .if .Lasm_alt_mode==0 - .pushsection .altinstr_replacement, "ax" - .else - .popsection - .endif -663: -.endm - -/* - * Complete an alternative code sequence. - */ -.macro alternative_endif -664: - .if .Lasm_alt_mode==0 - .popsection - .endif - .org . - (664b-663b) + (662b-661b) - .org . - (662b-661b) + (664b-663b) -.endm - -/* - * Callback-based alternative epilogue - */ -.macro alternative_cb_end -662: -.endm - -/* - * Provides a trivial alternative or default sequence consisting solely - * of NOPs. The number of NOPs is chosen automatically to match the - * previous case. - */ -.macro alternative_else_nop_endif -alternative_else - nops (662b-661b) / AARCH64_INSN_SIZE -alternative_endif -.endm - -#define _ALTERNATIVE_CFG(insn1, insn2, cap, cfg, ...) \ - alternative_insn insn1, insn2, cap, IS_ENABLED(cfg) - -.macro user_alt, label, oldinstr, newinstr, cond -9999: alternative_insn "\oldinstr", "\newinstr", \cond - _ASM_EXTABLE 9999b, \label -.endm - -/* - * Generate the assembly for UAO alternatives with exception table entries. - * This is complicated as there is no post-increment or pair versions of the - * unprivileged instructions, and USER() only works for single instructions. - */ -#ifdef CONFIG_ARM64_UAO - .macro uao_ldp l, reg1, reg2, addr, post_inc - alternative_if_not ARM64_HAS_UAO -8888: ldp \reg1, \reg2, [\addr], \post_inc; -8889: nop; - nop; - alternative_else - ldtr \reg1, [\addr]; - ldtr \reg2, [\addr, #8]; - add \addr, \addr, \post_inc; - alternative_endif - - _asm_extable 8888b,\l; - _asm_extable 8889b,\l; - .endm - - .macro uao_stp l, reg1, reg2, addr, post_inc - alternative_if_not ARM64_HAS_UAO -8888: stp \reg1, \reg2, [\addr], \post_inc; -8889: nop; - nop; - alternative_else - sttr \reg1, [\addr]; - sttr \reg2, [\addr, #8]; - add \addr, \addr, \post_inc; - alternative_endif - - _asm_extable 8888b,\l; - _asm_extable 8889b,\l; - .endm - - .macro uao_user_alternative l, inst, alt_inst, reg, addr, post_inc - alternative_if_not ARM64_HAS_UAO -8888: \inst \reg, [\addr], \post_inc; - nop; - alternative_else - \alt_inst \reg, [\addr]; - add \addr, \addr, \post_inc; - alternative_endif - - _asm_extable 8888b,\l; - .endm -#else - .macro uao_ldp l, reg1, reg2, addr, post_inc - USER(\l, ldp \reg1, \reg2, [\addr], \post_inc) - .endm - .macro uao_stp l, reg1, reg2, addr, post_inc - USER(\l, stp \reg1, \reg2, [\addr], \post_inc) - .endm - .macro uao_user_alternative l, inst, alt_inst, reg, addr, post_inc - USER(\l, \inst \reg, [\addr], \post_inc) - .endm -#endif - -#endif /* __ASSEMBLY__ */ - -/* - * Usage: asm(ALTERNATIVE(oldinstr, newinstr, feature)); - * - * Usage: asm(ALTERNATIVE(oldinstr, newinstr, feature, CONFIG_FOO)); - * N.B. If CONFIG_FOO is specified, but not selected, the whole block - * will be omitted, including oldinstr. - */ -#define ALTERNATIVE(oldinstr, newinstr, ...) \ - _ALTERNATIVE_CFG(oldinstr, newinstr, __VA_ARGS__, 1) +void alt_cb_patch_nops(struct alt_instr *alt, __le32 *origptr, + __le32 *updptr, int nr_inst); +#endif /* __ASSEMBLY__ */ #endif /* __ASM_ALTERNATIVE_H */ |