projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 8cc28269 HD |
1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* | |
| 3 | * Alternative live-patching for parisc. | |
| 4 | * Copyright (C) 2018 Helge Deller <deller@gmx.de> | |
| 5 | * | |
| 6 | */ | |
| 7 | ||
| 8 | #include <asm/processor.h> | |
| 9 | #include <asm/sections.h> | |
| 10 | #include <asm/alternative.h> | |
| 11 | ||
| 12 | #include <linux/module.h> | |
| 13 | ||
| 14 | static int no_alternatives; | |
| 15 | static int __init setup_no_alternatives(char *str) | |
| 16 | { | |
| 17 | no_alternatives = 1; | |
| 18 | return 1; | |
| 19 | } | |
| 20 | __setup("no-alternatives", setup_no_alternatives); | |
| 21 | ||
| 22 | void __init_or_module apply_alternatives(struct alt_instr *start, | |
| 23 | struct alt_instr *end, const char *module_name) | |
| 24 | { | |
| 25 | struct alt_instr *entry; | |
| 26 | int index = 0, applied = 0; | |
| 27 | int num_cpus = num_online_cpus(); | |
| 28 | ||
| 29 | for (entry = start; entry < end; entry++, index++) { | |
| 30 | ||
| 31 | u32 *from, len, cond, replacement; | |
| 32 | ||
| 33 | from = (u32 *)((ulong)&entry->orig_offset + entry->orig_offset); | |
| 34 | len = entry->len; | |
| 35 | cond = entry->cond; | |
| 36 | replacement = entry->replacement; | |
| 37 | ||
| 38 | WARN_ON(!cond); | |
| 39 | ||
| 40 | if (cond != ALT_COND_ALWAYS && no_alternatives) | |
| 41 | continue; | |
| 42 | ||
| 43 | pr_debug("Check %d: Cond 0x%x, Replace %02d instructions @ 0x%px with 0x%08x\n", | |
| 44 | index, cond, len, from, replacement); | |
| 45 | ||
| 46 | if ((cond & ALT_COND_NO_SMP) && (num_cpus != 1)) | |
| 47 | continue; | |
| 48 | if ((cond & ALT_COND_NO_DCACHE) && (cache_info.dc_size != 0)) | |
| 49 | continue; | |
| 50 | if ((cond & ALT_COND_NO_ICACHE) && (cache_info.ic_size != 0)) | |
| 51 | continue; | |
| 52 | ||
| 53 | /* | |
| 54 | * If the PDC_MODEL capabilities has Non-coherent IO-PDIR bit | |
| 55 | * set (bit #61, big endian), we have to flush and sync every | |
| 56 | * time IO-PDIR is changed in Ike/Astro. | |
| 57 | */ | |
| 58 | if ((cond & ALT_COND_NO_IOC_FDC) && | |
| 59 | (boot_cpu_data.pdc.capabilities & PDC_MODEL_IOPDIR_FDC)) | |
| 60 | continue; | |
| 61 | ||
| 62 | /* Want to replace pdtlb by a pdtlb,l instruction? */ | |
| 63 | if (replacement == INSN_PxTLB) { | |
| 64 | replacement = *from; | |
| 65 | if (boot_cpu_data.cpu_type >= pcxu) /* >= pa2.0 ? */ | |
| 66 | replacement |= (1 << 10); /* set el bit */ | |
| 67 | } | |
| 68 | ||
| 69 | /* | |
| 70 | * Replace instruction with NOPs? | |
| 71 | * For long distance insert a branch instruction instead. | |
| 72 | */ | |
| 73 | if (replacement == INSN_NOP && len > 1) | |
| 74 | replacement = 0xe8000002 + (len-2)*8; /* "b,n .+8" */ | |
| 75 | ||
| 76 | pr_debug("Do %d: Cond 0x%x, Replace %02d instructions @ 0x%px with 0x%08x\n", | |
| 77 | index, cond, len, from, replacement); | |
| 78 | ||
| 79 | /* Replace instruction */ | |
| 80 | *from = replacement; | |
| 81 | applied++; | |
| 82 | } | |
| 83 | ||
| 84 | pr_info("%s%salternatives: applied %d out of %d patches\n", | |
| 85 | module_name ? : "", module_name ? " " : "", | |
| 86 | applied, index); | |
| 87 | } | |
| 88 | ||
| 89 | ||
| 90 | void __init apply_alternatives_all(void) | |
| 91 | { | |
| 92 | set_kernel_text_rw(1); | |
| 93 | ||
| 94 | apply_alternatives((struct alt_instr *) &__alt_instructions, | |
| 95 | (struct alt_instr *) &__alt_instructions_end, NULL); | |
| 96 | ||
| 97 | set_kernel_text_rw(0); | |
| 98 | } |