| 1 | /* $OpenBSD: codepatch.h,v 1.1 2026/06/23 11:45:54 kettenis Exp $ */ |
| 2 | /* |
| 3 | * Copyright (c) 2014-2015 Stefan Fritsch <sf@sfritsch.de> |
| 4 | * |
| 5 | * Permission to use, copy, modify, and distribute this software for any |
| 6 | * purpose with or without fee is hereby granted, provided that the above |
| 7 | * copyright notice and this permission notice appear in all copies. |
| 8 | * |
| 9 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| 10 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| 11 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
| 12 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 13 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| 14 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
| 15 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 16 | */ |
| 17 | |
| 18 | #ifndef _MACHINE_CODEPATCH_H_ |
| 19 | #define _MACHINE_CODEPATCH_H_ |
| 20 | |
| 21 | #include <machine/param.h> |
| 22 | |
| 23 | #ifndef _LOCORE |
| 24 | |
| 25 | /* code in this section will be unmapped after boot */ |
| 26 | #define __cptext __attribute__((section(".cptext"))) |
| 27 | |
| 28 | __cptext void *codepatch_maprw(vaddr_t *nva, vaddr_t dest); |
| 29 | __cptext void codepatch_unmaprw(vaddr_t nva); |
| 30 | __cptext void codepatch_fill_nop(void *caddr, uint16_t len); |
| 31 | __cptext void codepatch_nop(uint16_t tag); |
| 32 | void codepatch_disable(void); |
| 33 | |
| 34 | #endif /* !_LOCORE */ |
| 35 | |
| 36 | /* |
| 37 | * Mark the start of some code snippet to be patched. |
| 38 | */ |
| 39 | #define CODEPATCH_START 998: |
| 40 | /* |
| 41 | * Mark the end of some code to be patched, and assign the given tag. |
| 42 | */ |
| 43 | #define CODEPATCH_END2(startnum,tag) \ |
| 44 | 999: \ |
| 45 | .section .codepatch, "a" ;\ |
| 46 | .quad startnum##b ;\ |
| 47 | .short (999b - startnum##b) ;\ |
| 48 | .short tag ;\ |
| 49 | .int 0 ;\ |
| 50 | .previous |
| 51 | #define CODEPATCH_END(tag) CODEPATCH_END2(998,tag) |
| 52 | |
| 53 | #define CPTAG_REPEAT_TLBI 1 |
| 54 | |
| 55 | |
| 56 | /* Would be neat if these could be in something like .cptext */ |
| 57 | #define CODEPATCH_CODE(symbol, instructions...) \ |
| 58 | .section .rodata; \ |
| 59 | .globl symbol; \ |
| 60 | symbol: instructions; \ |
| 61 | .size symbol, . - symbol |
| 62 | |
| 63 | /* provide a (short) variable with the length of the patch */ |
| 64 | #define CODEPATCH_CODE_LEN(symbol, instructions...) \ |
| 65 | CODEPATCH_CODE(symbol, instructions); \ |
| 66 | 996: .globl symbol##_len; \ |
| 67 | .align 2; \ |
| 68 | symbol##_len: \ |
| 69 | .short 996b - symbol; \ |
| 70 | .size symbol##_len, 2 |
| 71 | |
| 72 | #endif /* _MACHINE_CODEPATCH_H_ */ |