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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __ASM_PARISC_ALTERNATIVE_H
3#define __ASM_PARISC_ALTERNATIVE_H
4
5#define ALT_COND_ALWAYS 0x80 /* always replace instruction */
6#define ALT_COND_NO_SMP 0x01 /* when running UP instead of SMP */
7#define ALT_COND_NO_DCACHE 0x02 /* if system has no d-cache */
8#define ALT_COND_NO_ICACHE 0x04 /* if system has no i-cache */
9#define ALT_COND_NO_SPLIT_TLB 0x08 /* if split_tlb == 0 */
10#define ALT_COND_NO_IOC_FDC 0x10 /* if I/O cache does not need flushes */
11#define ALT_COND_RUN_ON_QEMU 0x20 /* if running on QEMU */
12
13#define INSN_PxTLB 0x02 /* modify pdtlb, pitlb */
14#define INSN_NOP 0x08000240 /* nop */
15
16#ifndef __ASSEMBLER__
17
18#include <linux/init.h>
19#include <linux/types.h>
20#include <linux/stddef.h>
21#include <linux/stringify.h>
22
23struct alt_instr {
24 s32 orig_offset; /* offset to original instructions */
25 s16 len; /* end of original instructions */
26 u16 cond; /* see ALT_COND_XXX */
27 u32 replacement; /* replacement instruction or code */
28} __packed;
29
30void set_kernel_text_rw(int enable_read_write);
31void apply_alternatives_all(void);
32void apply_alternatives(struct alt_instr *start, struct alt_instr *end,
33 const char *module_name);
34
35/* Alternative SMP implementation. */
36#define ALTERNATIVE(cond, replacement) "!0:" \
37 ".section .altinstructions, \"a\" !" \
38 ".align 4 !" \
39 ".word (0b-4-.) !" \
40 ".hword 1, " __stringify(cond) " !" \
41 ".word " __stringify(replacement) " !" \
42 ".previous"
43
44#else
45
46/* to replace one single instructions by a new instruction */
47#define ALTERNATIVE(from, to, cond, replacement)\
48 .section .altinstructions, "a" ! \
49 .align 4 ! \
50 .word (from - .) ! \
51 .hword (to - from)/4, cond ! \
52 .word replacement ! \
53 .previous
54
55/* to replace multiple instructions by new code */
56#define ALTERNATIVE_CODE(from, num_instructions, cond, new_instr_ptr)\
57 .section .altinstructions, "a" ! \
58 .align 4 ! \
59 .word (from - .) ! \
60 .hword -num_instructions, cond ! \
61 .word (new_instr_ptr - .) ! \
62 .previous
63
64#endif /* __ASSEMBLER__ */
65
66#endif /* __ASM_PARISC_ALTERNATIVE_H */