projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 9fa1db4c | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 686140a1 VG |
2 | #ifndef _ASM_S390_ALTERNATIVE_H |
| 3 | #define _ASM_S390_ALTERNATIVE_H | |
| 4 | ||
| 5 | #ifndef __ASSEMBLY__ | |
| 6 | ||
| 7 | #include <linux/types.h> | |
| 8 | #include <linux/stddef.h> | |
| 9 | #include <linux/stringify.h> | |
| 10 | ||
| 11 | struct alt_instr { | |
| 12 | s32 instr_offset; /* original instruction */ | |
| 13 | s32 repl_offset; /* offset to replacement instruction */ | |
| 14 | u16 facility; /* facility bit set for replacement */ | |
| 15 | u8 instrlen; /* length of original instruction */ | |
| 686140a1 VG |
16 | } __packed; |
| 17 | ||
| 049a2c2d HC |
18 | void apply_alternative_instructions(void); |
| 19 | void apply_alternatives(struct alt_instr *start, struct alt_instr *end); | |
| 20 | ||
| 686140a1 | 21 | /* |
| e6ed91fd HC |
22 | * +---------------------------------+ |
| 23 | * |661: |662: | |
| 24 | * | oldinstr | | |
| 25 | * +---------------------------------+ | |
| 686140a1 VG |
26 | * |
| 27 | * .altinstr_replacement section | |
| e6ed91fd | 28 | * +---------------------------------+ |
| 686140a1 VG |
29 | * |6641: |6651: |
| 30 | * | alternative instr 1 | | |
| e6ed91fd HC |
31 | * +---------------------------------+ |
| 32 | * |6642: |6652: | |
| 33 | * | alternative instr 2 | | |
| 34 | * +---------------------------------+ | |
| 686140a1 VG |
35 | * |
| 36 | * .altinstructions section | |
| 37 | * +---------------------------------+ | |
| 38 | * | alt_instr entries for each | | |
| 39 | * | alternative instr | | |
| 40 | * +---------------------------------+ | |
| 41 | */ | |
| 42 | ||
| e6ed91fd HC |
43 | #define b_altinstr(num) "664"#num |
| 44 | #define e_altinstr(num) "665"#num | |
| 686140a1 | 45 | #define oldinstr_len "662b-661b" |
| 686140a1 | 46 | #define altinstr_len(num) e_altinstr(num)"b-"b_altinstr(num)"b" |
| 686140a1 | 47 | |
| e6ed91fd HC |
48 | #define OLDINSTR(oldinstr) \ |
| 49 | "661:\n\t" oldinstr "\n662:\n" | |
| 686140a1 VG |
50 | |
| 51 | #define ALTINSTR_ENTRY(facility, num) \ | |
| 52 | "\t.long 661b - .\n" /* old instruction */ \ | |
| 53 | "\t.long " b_altinstr(num)"b - .\n" /* alt instruction */ \ | |
| 54 | "\t.word " __stringify(facility) "\n" /* facility bit */ \ | |
| e6ed91fd | 55 | "\t.byte " oldinstr_len "\n" /* instruction len */ \ |
| 207ddb91 | 56 | "\t.org . - (" oldinstr_len ") & 1\n" \ |
| e6ed91fd HC |
57 | "\t.org . - (" oldinstr_len ") + (" altinstr_len(num) ")\n" \ |
| 58 | "\t.org . - (" altinstr_len(num) ") + (" oldinstr_len ")\n" | |
| 686140a1 VG |
59 | |
| 60 | #define ALTINSTR_REPLACEMENT(altinstr, num) /* replacement */ \ | |
| e6ed91fd | 61 | b_altinstr(num)":\n\t" altinstr "\n" e_altinstr(num) ":\n" |
| 686140a1 | 62 | |
| 686140a1 VG |
63 | /* alternative assembly primitive: */ |
| 64 | #define ALTERNATIVE(oldinstr, altinstr, facility) \ | |
| 65 | ".pushsection .altinstr_replacement, \"ax\"\n" \ | |
| 66 | ALTINSTR_REPLACEMENT(altinstr, 1) \ | |
| 67 | ".popsection\n" \ | |
| e6ed91fd | 68 | OLDINSTR(oldinstr) \ |
| 686140a1 VG |
69 | ".pushsection .altinstructions,\"a\"\n" \ |
| 70 | ALTINSTR_ENTRY(facility, 1) \ | |
| 71 | ".popsection\n" | |
| 72 | ||
| 73 | #define ALTERNATIVE_2(oldinstr, altinstr1, facility1, altinstr2, facility2)\ | |
| 74 | ".pushsection .altinstr_replacement, \"ax\"\n" \ | |
| 75 | ALTINSTR_REPLACEMENT(altinstr1, 1) \ | |
| 76 | ALTINSTR_REPLACEMENT(altinstr2, 2) \ | |
| 77 | ".popsection\n" \ | |
| e6ed91fd | 78 | OLDINSTR(oldinstr) \ |
| 686140a1 VG |
79 | ".pushsection .altinstructions,\"a\"\n" \ |
| 80 | ALTINSTR_ENTRY(facility1, 1) \ | |
| 81 | ALTINSTR_ENTRY(facility2, 2) \ | |
| 82 | ".popsection\n" | |
| 686140a1 VG |
83 | |
| 84 | /* | |
| 85 | * Alternative instructions for different CPU types or capabilities. | |
| 86 | * | |
| 87 | * This allows to use optimized instructions even on generic binary | |
| 88 | * kernels. | |
| 89 | * | |
| 90 | * oldinstr is padded with jump and nops at compile time if altinstr is | |
| 91 | * longer. altinstr is padded with jump and nops at run-time during patching. | |
| 92 | * | |
| 93 | * For non barrier like inlines please define new variants | |
| 94 | * without volatile and memory clobber. | |
| 95 | */ | |
| 96 | #define alternative(oldinstr, altinstr, facility) \ | |
| cceb0183 | 97 | asm_inline volatile(ALTERNATIVE(oldinstr, altinstr, facility) : : : "memory") |
| 686140a1 VG |
98 | |
| 99 | #define alternative_2(oldinstr, altinstr1, facility1, altinstr2, facility2) \ | |
| cceb0183 | 100 | asm_inline volatile(ALTERNATIVE_2(oldinstr, altinstr1, facility1, \ |
| 686140a1 VG |
101 | altinstr2, facility2) ::: "memory") |
| 102 | ||
| 80841ad8 HC |
103 | /* Alternative inline assembly with input. */ |
| 104 | #define alternative_input(oldinstr, newinstr, feature, input...) \ | |
| 105 | asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \ | |
| 106 | : : input) | |
| 107 | ||
| 108 | /* Like alternative_input, but with a single output argument */ | |
| 109 | #define alternative_io(oldinstr, altinstr, facility, output, input...) \ | |
| 110 | asm_inline volatile(ALTERNATIVE(oldinstr, altinstr, facility) \ | |
| 111 | : output : input) | |
| 112 | ||
| 113 | /* Use this macro if more than one output parameter is needed. */ | |
| 114 | #define ASM_OUTPUT2(a...) a | |
| 115 | ||
| 116 | /* Use this macro if clobbers are needed without inputs. */ | |
| 117 | #define ASM_NO_INPUT_CLOBBER(clobber...) : clobber | |
| 118 | ||
| 686140a1 VG |
119 | #endif /* __ASSEMBLY__ */ |
| 120 | ||
| 121 | #endif /* _ASM_S390_ALTERNATIVE_H */ |