xref: /linux/arch/parisc/include/asm/alternative.h (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
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 
23 struct 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 
30 void set_kernel_text_rw(int enable_read_write);
31 void apply_alternatives_all(void);
32 void 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  /*  __ASSEMBLY__  */
65 
66 #endif /* __ASM_PARISC_ALTERNATIVE_H */
67