xref: /OK3568_Linux_fs/kernel/arch/parisc/include/asm/alternative.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun #ifndef __ASM_PARISC_ALTERNATIVE_H
3*4882a593Smuzhiyun #define __ASM_PARISC_ALTERNATIVE_H
4*4882a593Smuzhiyun 
5*4882a593Smuzhiyun #define ALT_COND_ALWAYS		0x80	/* always replace instruction */
6*4882a593Smuzhiyun #define ALT_COND_NO_SMP		0x01	/* when running UP instead of SMP */
7*4882a593Smuzhiyun #define ALT_COND_NO_DCACHE	0x02	/* if system has no d-cache  */
8*4882a593Smuzhiyun #define ALT_COND_NO_ICACHE	0x04	/* if system has no i-cache  */
9*4882a593Smuzhiyun #define ALT_COND_NO_SPLIT_TLB	0x08	/* if split_tlb == 0  */
10*4882a593Smuzhiyun #define ALT_COND_NO_IOC_FDC	0x10	/* if I/O cache does not need flushes */
11*4882a593Smuzhiyun #define ALT_COND_RUN_ON_QEMU	0x20	/* if running on QEMU */
12*4882a593Smuzhiyun 
13*4882a593Smuzhiyun #define INSN_PxTLB	0x02		/* modify pdtlb, pitlb */
14*4882a593Smuzhiyun #define INSN_NOP	0x08000240	/* nop */
15*4882a593Smuzhiyun 
16*4882a593Smuzhiyun #ifndef __ASSEMBLY__
17*4882a593Smuzhiyun 
18*4882a593Smuzhiyun #include <linux/init.h>
19*4882a593Smuzhiyun #include <linux/types.h>
20*4882a593Smuzhiyun #include <linux/stddef.h>
21*4882a593Smuzhiyun #include <linux/stringify.h>
22*4882a593Smuzhiyun 
23*4882a593Smuzhiyun struct alt_instr {
24*4882a593Smuzhiyun 	s32 orig_offset;	/* offset to original instructions */
25*4882a593Smuzhiyun 	s32 len;		/* end of original instructions */
26*4882a593Smuzhiyun 	u32 cond;		/* see ALT_COND_XXX */
27*4882a593Smuzhiyun 	u32 replacement;	/* replacement instruction or code */
28*4882a593Smuzhiyun };
29*4882a593Smuzhiyun 
30*4882a593Smuzhiyun void set_kernel_text_rw(int enable_read_write);
31*4882a593Smuzhiyun void apply_alternatives_all(void);
32*4882a593Smuzhiyun void apply_alternatives(struct alt_instr *start, struct alt_instr *end,
33*4882a593Smuzhiyun 	const char *module_name);
34*4882a593Smuzhiyun 
35*4882a593Smuzhiyun /* Alternative SMP implementation. */
36*4882a593Smuzhiyun #define ALTERNATIVE(cond, replacement)		"!0:"	\
37*4882a593Smuzhiyun 	".section .altinstructions, \"aw\"	!"	\
38*4882a593Smuzhiyun 	".word (0b-4-.), 1, " __stringify(cond) ","	\
39*4882a593Smuzhiyun 		__stringify(replacement) "	!"	\
40*4882a593Smuzhiyun 	".previous"
41*4882a593Smuzhiyun 
42*4882a593Smuzhiyun #else
43*4882a593Smuzhiyun 
44*4882a593Smuzhiyun /* to replace one single instructions by a new instruction */
45*4882a593Smuzhiyun #define ALTERNATIVE(from, to, cond, replacement)\
46*4882a593Smuzhiyun 	.section .altinstructions, "aw"	!	\
47*4882a593Smuzhiyun 	.word (from - .), (to - from)/4	!	\
48*4882a593Smuzhiyun 	.word cond, replacement		!	\
49*4882a593Smuzhiyun 	.previous
50*4882a593Smuzhiyun 
51*4882a593Smuzhiyun /* to replace multiple instructions by new code */
52*4882a593Smuzhiyun #define ALTERNATIVE_CODE(from, num_instructions, cond, new_instr_ptr)\
53*4882a593Smuzhiyun 	.section .altinstructions, "aw"	!	\
54*4882a593Smuzhiyun 	.word (from - .), -num_instructions !	\
55*4882a593Smuzhiyun 	.word cond, (new_instr_ptr - .)	!	\
56*4882a593Smuzhiyun 	.previous
57*4882a593Smuzhiyun 
58*4882a593Smuzhiyun #endif  /*  __ASSEMBLY__  */
59*4882a593Smuzhiyun 
60*4882a593Smuzhiyun #endif /* __ASM_PARISC_ALTERNATIVE_H */
61