From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- arch/parisc/kernel/alternative.c | 122 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 122 insertions(+) create mode 100644 arch/parisc/kernel/alternative.c (limited to 'arch/parisc/kernel/alternative.c') diff --git a/arch/parisc/kernel/alternative.c b/arch/parisc/kernel/alternative.c new file mode 100644 index 000000000..25c4d6c33 --- /dev/null +++ b/arch/parisc/kernel/alternative.c @@ -0,0 +1,122 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Alternative live-patching for parisc. + * Copyright (C) 2018 Helge Deller + * + */ + +#include +#include +#include +#include + +#include + +static int no_alternatives; +static int __init setup_no_alternatives(char *str) +{ + no_alternatives = 1; + return 1; +} +__setup("no-alternatives", setup_no_alternatives); + +void __init_or_module apply_alternatives(struct alt_instr *start, + struct alt_instr *end, const char *module_name) +{ + struct alt_instr *entry; + int index = 0, applied = 0; + int num_cpus = num_present_cpus(); + u16 cond_check; + + cond_check = ALT_COND_ALWAYS | + ((num_cpus == 1) ? ALT_COND_NO_SMP : 0) | + ((cache_info.dc_size == 0) ? ALT_COND_NO_DCACHE : 0) | + ((cache_info.ic_size == 0) ? ALT_COND_NO_ICACHE : 0) | + (running_on_qemu ? ALT_COND_RUN_ON_QEMU : 0) | + ((split_tlb == 0) ? ALT_COND_NO_SPLIT_TLB : 0) | + /* + * If the PDC_MODEL capabilities has Non-coherent IO-PDIR bit + * set (bit #61, big endian), we have to flush and sync every + * time IO-PDIR is changed in Ike/Astro. + */ + (((boot_cpu_data.cpu_type > pcxw_) && + ((boot_cpu_data.pdc.capabilities & PDC_MODEL_IOPDIR_FDC) == 0)) + ? ALT_COND_NO_IOC_FDC : 0); + + for (entry = start; entry < end; entry++, index++) { + + u32 *from, replacement; + u16 cond; + s16 len; + + from = (u32 *)((ulong)&entry->orig_offset + entry->orig_offset); + len = entry->len; + cond = entry->cond; + replacement = entry->replacement; + + WARN_ON(!cond); + + if ((cond & ALT_COND_ALWAYS) == 0 && no_alternatives) + continue; + + pr_debug("Check %d: Cond 0x%x, Replace %02d instructions @ 0x%px with 0x%08x\n", + index, cond, len, from, replacement); + + /* Bounce out if none of the conditions are true. */ + if ((cond & cond_check) == 0) + continue; + + /* Want to replace pdtlb by a pdtlb,l instruction? */ + if (replacement == INSN_PxTLB) { + replacement = *from; + if (boot_cpu_data.cpu_type >= pcxu) /* >= pa2.0 ? */ + replacement |= (1 << 10); /* set el bit */ + } + + /* + * Replace instruction with NOPs? + * For long distance insert a branch instruction instead. + */ + if (replacement == INSN_NOP && len > 1) + replacement = 0xe8000002 + (len-2)*8; /* "b,n .+8" */ + + pr_debug("ALTERNATIVE %3d: Cond %2x, Replace %2d instructions to 0x%08x @ 0x%px (%pS)\n", + index, cond, len, replacement, from, from); + + if (len < 0) { + /* Replace multiple instruction by new code */ + u32 *source; + len = -len; + source = (u32 *)((ulong)&entry->replacement + entry->replacement); + memcpy(from, source, 4 * len); + } else { + /* Replace by one instruction */ + *from = replacement; + } + applied++; + } + + pr_info("%s%salternatives: applied %d out of %d patches\n", + module_name ? : "", module_name ? " " : "", + applied, index); +} + + +void __init apply_alternatives_all(void) +{ + set_kernel_text_rw(1); + + apply_alternatives((struct alt_instr *) &__alt_instructions, + (struct alt_instr *) &__alt_instructions_end, NULL); + + if (cache_info.dc_size == 0 && cache_info.ic_size == 0) { + pr_info("alternatives: optimizing cache-flushes.\n"); + static_branch_disable(&parisc_has_cache); + } + if (cache_info.dc_size == 0) + static_branch_disable(&parisc_has_dcache); + if (cache_info.ic_size == 0) + static_branch_disable(&parisc_has_icache); + + set_kernel_text_rw(0); +} -- cgit v1.2.3