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- /* SPDX-License-Identifier: GPL-2.0 */
- #ifndef _ASM_S390_ALTERNATIVE_H
- #define _ASM_S390_ALTERNATIVE_H
- #ifndef __ASSEMBLY__
- #include <linux/types.h>
- #include <linux/stddef.h>
- #include <linux/stringify.h>
- struct alt_instr {
- s32 instr_offset; /* original instruction */
- s32 repl_offset; /* offset to replacement instruction */
- u16 facility; /* facility bit set for replacement */
- u8 instrlen; /* length of original instruction */
- } __packed;
- void apply_alternative_instructions(void);
- void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
- /*
- * +---------------------------------+
- * |661: |662:
- * | oldinstr |
- * +---------------------------------+
- *
- * .altinstr_replacement section
- * +---------------------------------+
- * |6641: |6651:
- * | alternative instr 1 |
- * +---------------------------------+
- * |6642: |6652:
- * | alternative instr 2 |
- * +---------------------------------+
- *
- * .altinstructions section
- * +---------------------------------+
- * | alt_instr entries for each |
- * | alternative instr |
- * +---------------------------------+
- */
- #define b_altinstr(num) "664"#num
- #define e_altinstr(num) "665"#num
- #define oldinstr_len "662b-661b"
- #define altinstr_len(num) e_altinstr(num)"b-"b_altinstr(num)"b"
- #define OLDINSTR(oldinstr) \
- "661:\n\t" oldinstr "\n662:\n"
- #define ALTINSTR_ENTRY(facility, num) \
- "\t.long 661b - .\n" /* old instruction */ \
- "\t.long " b_altinstr(num)"b - .\n" /* alt instruction */ \
- "\t.word " __stringify(facility) "\n" /* facility bit */ \
- "\t.byte " oldinstr_len "\n" /* instruction len */ \
- "\t.org . - (" oldinstr_len ") + (" altinstr_len(num) ")\n" \
- "\t.org . - (" altinstr_len(num) ") + (" oldinstr_len ")\n"
- #define ALTINSTR_REPLACEMENT(altinstr, num) /* replacement */ \
- b_altinstr(num)":\n\t" altinstr "\n" e_altinstr(num) ":\n"
- /* alternative assembly primitive: */
- #define ALTERNATIVE(oldinstr, altinstr, facility) \
- ".pushsection .altinstr_replacement, \"ax\"\n" \
- ALTINSTR_REPLACEMENT(altinstr, 1) \
- ".popsection\n" \
- OLDINSTR(oldinstr) \
- ".pushsection .altinstructions,\"a\"\n" \
- ALTINSTR_ENTRY(facility, 1) \
- ".popsection\n"
- #define ALTERNATIVE_2(oldinstr, altinstr1, facility1, altinstr2, facility2)\
- ".pushsection .altinstr_replacement, \"ax\"\n" \
- ALTINSTR_REPLACEMENT(altinstr1, 1) \
- ALTINSTR_REPLACEMENT(altinstr2, 2) \
- ".popsection\n" \
- OLDINSTR(oldinstr) \
- ".pushsection .altinstructions,\"a\"\n" \
- ALTINSTR_ENTRY(facility1, 1) \
- ALTINSTR_ENTRY(facility2, 2) \
- ".popsection\n"
- /*
- * Alternative instructions for different CPU types or capabilities.
- *
- * This allows to use optimized instructions even on generic binary
- * kernels.
- *
- * oldinstr is padded with jump and nops at compile time if altinstr is
- * longer. altinstr is padded with jump and nops at run-time during patching.
- *
- * For non barrier like inlines please define new variants
- * without volatile and memory clobber.
- */
- #define alternative(oldinstr, altinstr, facility) \
- asm_inline volatile(ALTERNATIVE(oldinstr, altinstr, facility) : : : "memory")
- #define alternative_2(oldinstr, altinstr1, facility1, altinstr2, facility2) \
- asm_inline volatile(ALTERNATIVE_2(oldinstr, altinstr1, facility1, \
- altinstr2, facility2) ::: "memory")
- /* Alternative inline assembly with input. */
- #define alternative_input(oldinstr, newinstr, feature, input...) \
- asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
- : : input)
- /* Like alternative_input, but with a single output argument */
- #define alternative_io(oldinstr, altinstr, facility, output, input...) \
- asm_inline volatile(ALTERNATIVE(oldinstr, altinstr, facility) \
- : output : input)
- /* Use this macro if more than one output parameter is needed. */
- #define ASM_OUTPUT2(a...) a
- /* Use this macro if clobbers are needed without inputs. */
- #define ASM_NO_INPUT_CLOBBER(clobber...) : clobber
- #endif /* __ASSEMBLY__ */
- #endif /* _ASM_S390_ALTERNATIVE_H */
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