xref: /linux/arch/parisc/include/asm/alternative.h (revision dc3e0896003ee9b3bcc34c53965dc4bbc8671c44)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_PARISC_ALTERNATIVE_H
3 #define __ASM_PARISC_ALTERNATIVE_H
4 
5 #define ALT_COND_NO_SMP		0x01	/* when running UP instead of SMP */
6 #define ALT_COND_NO_DCACHE	0x02	/* if system has no d-cache  */
7 #define ALT_COND_NO_ICACHE	0x04	/* if system has no i-cache  */
8 #define ALT_COND_NO_SPLIT_TLB	0x08	/* if split_tlb == 0  */
9 #define ALT_COND_NO_IOC_FDC	0x10	/* if I/O cache does not need flushes */
10 
11 #define INSN_PxTLB	0x02		/* modify pdtlb, pitlb */
12 #define INSN_NOP	0x08000240	/* nop */
13 
14 #ifndef __ASSEMBLY__
15 
16 #include <linux/init.h>
17 #include <linux/types.h>
18 #include <linux/stddef.h>
19 #include <linux/stringify.h>
20 
21 struct alt_instr {
22 	s32 orig_offset;	/* offset to original instructions */
23 	u32 len;		/* end of original instructions */
24 	u32 cond;		/* see ALT_COND_XXX */
25 	u32 replacement;	/* replacement instruction or code */
26 };
27 
28 void set_kernel_text_rw(int enable_read_write);
29 
30 /* Alternative SMP implementation. */
31 #define ALTERNATIVE(cond, replacement)		"!0:"	\
32 	".section .altinstructions, \"aw\"	!"	\
33 	".word (0b-4-.), 1, " __stringify(cond) ","	\
34 		__stringify(replacement) "	!"	\
35 	".previous"
36 
37 #else
38 
39 #define ALTERNATIVE(from, to, cond, replacement)\
40 	.section .altinstructions, "aw"	!	\
41 	.word (from - .), (to - from)/4	!	\
42 	.word cond, replacement		!	\
43 	.previous
44 
45 #endif  /*  __ASSEMBLY__  */
46 
47 #endif /* __ASM_PARISC_ALTERNATIVE_H */
48