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, cond, replacement;
34 from = (u32 *)((ulong)&entry->orig_offset + entry->orig_offset);
37 replacement = entry->replacement;
41 if (cond != ALT_COND_ALWAYS && no_alternatives)
44 pr_debug("Check %d: Cond 0x%x, Replace %02d instructions @ 0x%px with 0x%08x\n",
45 index, cond, len, from, replacement);
47 if ((cond & ALT_COND_NO_SMP) && (num_cpus != 1))
49 if ((cond & ALT_COND_NO_DCACHE) && (cache_info.dc_size != 0))
51 if ((cond & ALT_COND_NO_ICACHE) && (cache_info.ic_size != 0))
53 if ((cond & ALT_COND_RUN_ON_QEMU) && !running_on_qemu)
57 * If the PDC_MODEL capabilities has Non-coherent IO-PDIR bit
58 * set (bit #61, big endian), we have to flush and sync every
59 * time IO-PDIR is changed in Ike/Astro.
61 if ((cond & ALT_COND_NO_IOC_FDC) &&
62 ((boot_cpu_data.cpu_type <= pcxw_) ||
63 (boot_cpu_data.pdc.capabilities & PDC_MODEL_IOPDIR_FDC)))
66 /* Want to replace pdtlb by a pdtlb,l instruction? */
67 if (replacement == INSN_PxTLB) {
69 if (boot_cpu_data.cpu_type >= pcxu) /* >= pa2.0 ? */
70 replacement |= (1 << 10); /* set el bit */
74 * Replace instruction with NOPs?
75 * For long distance insert a branch instruction instead.
77 if (replacement == INSN_NOP && len > 1)
78 replacement = 0xe8000002 + (len-2)*8; /* "b,n .+8" */
80 pr_debug("ALTERNATIVE %3d: Cond %2x, Replace %2d instructions to 0x%08x @ 0x%px (%pS)\n",
81 index, cond, len, replacement, from, from);
84 /* Replace multiple instruction by new code */
87 source = (u32 *)((ulong)&entry->replacement + entry->replacement);
88 memcpy(from, source, 4 * len);
90 /* Replace by one instruction */
96 pr_info("%s%salternatives: applied %d out of %d patches\n",
97 module_name ? : "", module_name ? " " : "",
102 void __init apply_alternatives_all(void)
104 set_kernel_text_rw(1);
106 apply_alternatives((struct alt_instr *) &__alt_instructions,
107 (struct alt_instr *) &__alt_instructions_end, NULL);
109 set_kernel_text_rw(0);