1 // SPDX-License-Identifier: GPL-2.0
3 * Alternative live-patching for parisc.
4 * Copyright (C) 2018 Helge Deller <deller@gmx.de>
8 #include <asm/processor.h>
9 #include <asm/sections.h>
10 #include <asm/alternative.h>
12 #include <linux/module.h>
14 static int no_alternatives;
15 static int __init setup_no_alternatives(char *str)
20 __setup("no-alternatives", setup_no_alternatives);
22 void __init_or_module apply_alternatives(struct alt_instr *start,
23 struct alt_instr *end, const char *module_name)
25 struct alt_instr *entry;
26 int index = 0, applied = 0;
27 int num_cpus = num_online_cpus();
29 for (entry = start; entry < end; entry++, index++) {
31 u32 *from, len, cond, replacement;
33 from = (u32 *)((ulong)&entry->orig_offset + entry->orig_offset);
36 replacement = entry->replacement;
40 if (cond != ALT_COND_ALWAYS && no_alternatives)
43 pr_debug("Check %d: Cond 0x%x, Replace %02d instructions @ 0x%px with 0x%08x\n",
44 index, cond, len, from, replacement);
46 if ((cond & ALT_COND_NO_SMP) && (num_cpus != 1))
48 if ((cond & ALT_COND_NO_DCACHE) && (cache_info.dc_size != 0))
50 if ((cond & ALT_COND_NO_ICACHE) && (cache_info.ic_size != 0))
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.
58 if ((cond & ALT_COND_NO_IOC_FDC) &&
59 ((boot_cpu_data.cpu_type <= pcxw_) ||
60 (boot_cpu_data.pdc.capabilities & PDC_MODEL_IOPDIR_FDC)))
63 /* Want to replace pdtlb by a pdtlb,l instruction? */
64 if (replacement == INSN_PxTLB) {
66 if (boot_cpu_data.cpu_type >= pcxu) /* >= pa2.0 ? */
67 replacement |= (1 << 10); /* set el bit */
71 * Replace instruction with NOPs?
72 * For long distance insert a branch instruction instead.
74 if (replacement == INSN_NOP && len > 1)
75 replacement = 0xe8000002 + (len-2)*8; /* "b,n .+8" */
77 pr_debug("Do %d: Cond 0x%x, Replace %02d instructions @ 0x%px with 0x%08x\n",
78 index, cond, len, from, replacement);
80 /* Replace instruction */
85 pr_info("%s%salternatives: applied %d out of %d patches\n",
86 module_name ? : "", module_name ? " " : "",
91 void __init apply_alternatives_all(void)
93 set_kernel_text_rw(1);
95 apply_alternatives((struct alt_instr *) &__alt_instructions,
96 (struct alt_instr *) &__alt_instructions_end, NULL);
98 set_kernel_text_rw(0);