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 __ASSEMBLY__
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	s32 len;		/* end of original instructions */
26	u32 cond;		/* see ALT_COND_XXX */
27	u32 replacement;	/* replacement instruction or code */
28};
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, \"aw\"	!"	\
38	".word (0b-4-.), 1, " __stringify(cond) ","	\
39		__stringify(replacement) "	!"	\
40	".previous"
41
42#else
43
44/* to replace one single instructions by a new instruction */
45#define ALTERNATIVE(from, to, cond, replacement)\
46	.section .altinstructions, "aw"	!	\
47	.word (from - .), (to - from)/4	!	\
48	.word cond, replacement		!	\
49	.previous
50
51/* to replace multiple instructions by new code */
52#define ALTERNATIVE_CODE(from, num_instructions, cond, new_instr_ptr)\
53	.section .altinstructions, "aw"	!	\
54	.word (from - .), -num_instructions !	\
55	.word cond, (new_instr_ptr - .)	!	\
56	.previous
57
58#endif  /*  __ASSEMBLY__  */
59
60#endif /* __ASM_PARISC_ALTERNATIVE_H */
61