1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_ALTERNATIVE_MACROS_H
3 #define __ASM_ALTERNATIVE_MACROS_H
4 
5 #ifdef CONFIG_RISCV_ALTERNATIVE
6 
7 #ifdef __ASSEMBLY__
8 
9 .macro ALT_ENTRY oldptr newptr vendor_id errata_id new_len
10 	RISCV_PTR \oldptr
11 	RISCV_PTR \newptr
12 	REG_ASM \vendor_id
13 	REG_ASM \new_len
14 	.word	\errata_id
15 .endm
16 
17 .macro ALT_NEW_CONTENT vendor_id, errata_id, enable = 1, new_c : vararg
18 	.if \enable
19 	.pushsection .alternative, "a"
20 	ALT_ENTRY 886b, 888f, \vendor_id, \errata_id, 889f - 888f
21 	.popsection
22 	.subsection 1
23 888 :
24 	.option push
25 	.option norvc
26 	.option norelax
27 	\new_c
28 	.option pop
29 889 :
30 	.org    . - (889b - 888b) + (887b - 886b)
31 	.org    . - (887b - 886b) + (889b - 888b)
32 	.previous
33 	.endif
34 .endm
35 
36 .macro __ALTERNATIVE_CFG old_c, new_c, vendor_id, errata_id, enable
37 886 :
38 	.option push
39 	.option norvc
40 	.option norelax
41 	\old_c
42 	.option pop
43 887 :
44 	ALT_NEW_CONTENT \vendor_id, \errata_id, \enable, \new_c
45 .endm
46 
47 #define _ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, CONFIG_k) \
48 	__ALTERNATIVE_CFG old_c, new_c, vendor_id, errata_id, IS_ENABLED(CONFIG_k)
49 
50 .macro __ALTERNATIVE_CFG_2 old_c, new_c_1, vendor_id_1, errata_id_1, enable_1, \
51 				  new_c_2, vendor_id_2, errata_id_2, enable_2
52 886 :
53 	.option push
54 	.option norvc
55 	.option norelax
56 	\old_c
57 	.option pop
58 887 :
59 	ALT_NEW_CONTENT \vendor_id_1, \errata_id_1, \enable_1, \new_c_1
60 	ALT_NEW_CONTENT \vendor_id_2, \errata_id_2, \enable_2, \new_c_2
61 .endm
62 
63 #define _ALTERNATIVE_CFG_2(old_c, new_c_1, vendor_id_1, errata_id_1,	\
64 					CONFIG_k_1,			\
65 				  new_c_2, vendor_id_2, errata_id_2,	\
66 					CONFIG_k_2)			\
67 	__ALTERNATIVE_CFG_2 old_c, new_c_1, vendor_id_1, errata_id_1,	\
68 					IS_ENABLED(CONFIG_k_1),		\
69 				   new_c_2, vendor_id_2, errata_id_2,	\
70 					IS_ENABLED(CONFIG_k_2)
71 
72 #else /* !__ASSEMBLY__ */
73 
74 #include <asm/asm.h>
75 #include <linux/stringify.h>
76 
77 #define ALT_ENTRY(oldptr, newptr, vendor_id, errata_id, newlen)		\
78 	RISCV_PTR " " oldptr "\n"					\
79 	RISCV_PTR " " newptr "\n"					\
80 	REG_ASM " " vendor_id "\n"					\
81 	REG_ASM " " newlen "\n"						\
82 	".word " errata_id "\n"
83 
84 #define ALT_NEW_CONTENT(vendor_id, errata_id, enable, new_c)		\
85 	".if " __stringify(enable) " == 1\n"				\
86 	".pushsection .alternative, \"a\"\n"				\
87 	ALT_ENTRY("886b", "888f", __stringify(vendor_id), __stringify(errata_id), "889f - 888f") \
88 	".popsection\n"							\
89 	".subsection 1\n"						\
90 	"888 :\n"							\
91 	".option push\n"						\
92 	".option norvc\n"						\
93 	".option norelax\n"						\
94 	new_c "\n"							\
95 	".option pop\n"							\
96 	"889 :\n"							\
97 	".org	. - (887b - 886b) + (889b - 888b)\n"			\
98 	".org	. - (889b - 888b) + (887b - 886b)\n"			\
99 	".previous\n"							\
100 	".endif\n"
101 
102 #define __ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, enable)	\
103 	"886 :\n"							\
104 	".option push\n"						\
105 	".option norvc\n"						\
106 	".option norelax\n"						\
107 	old_c "\n"							\
108 	".option pop\n"							\
109 	"887 :\n"							\
110 	ALT_NEW_CONTENT(vendor_id, errata_id, enable, new_c)
111 
112 #define _ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, CONFIG_k)	\
113 	__ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, IS_ENABLED(CONFIG_k))
114 
115 #define __ALTERNATIVE_CFG_2(old_c, new_c_1, vendor_id_1, errata_id_1,	\
116 					enable_1,			\
117 				   new_c_2, vendor_id_2, errata_id_2,	\
118 					enable_2)			\
119 	"886 :\n"							\
120 	".option push\n"						\
121 	".option norvc\n"						\
122 	".option norelax\n"						\
123 	old_c "\n"							\
124 	".option pop\n"							\
125 	"887 :\n"							\
126 	ALT_NEW_CONTENT(vendor_id_1, errata_id_1, enable_1, new_c_1)	\
127 	ALT_NEW_CONTENT(vendor_id_2, errata_id_2, enable_2, new_c_2)
128 
129 #define _ALTERNATIVE_CFG_2(old_c, new_c_1, vendor_id_1, errata_id_1,	\
130 					CONFIG_k_1,			\
131 				  new_c_2, vendor_id_2, errata_id_2,	\
132 					CONFIG_k_2)			\
133 	__ALTERNATIVE_CFG_2(old_c, new_c_1, vendor_id_1, errata_id_1,	\
134 					IS_ENABLED(CONFIG_k_1),		\
135 				   new_c_2, vendor_id_2, errata_id_2,	\
136 					IS_ENABLED(CONFIG_k_2))
137 
138 #endif /* __ASSEMBLY__ */
139 
140 #else /* CONFIG_RISCV_ALTERNATIVE */
141 #ifdef __ASSEMBLY__
142 
143 .macro __ALTERNATIVE_CFG old_c
144 	\old_c
145 .endm
146 
147 #define _ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, CONFIG_k) \
148 	__ALTERNATIVE_CFG old_c
149 
150 #define _ALTERNATIVE_CFG_2(old_c, new_c_1, vendor_id_1, errata_id_1,	\
151 					CONFIG_k_1,			\
152 				  new_c_2, vendor_id_2, errata_id_2,	\
153 					CONFIG_k_2)			\
154        __ALTERNATIVE_CFG old_c
155 
156 #else /* !__ASSEMBLY__ */
157 
158 #define __ALTERNATIVE_CFG(old_c)  \
159 	old_c "\n"
160 
161 #define _ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, CONFIG_k) \
162 	__ALTERNATIVE_CFG(old_c)
163 
164 #define _ALTERNATIVE_CFG_2(old_c, new_c_1, vendor_id_1, errata_id_1,	\
165 					CONFIG_k_1,			\
166 				  new_c_2, vendor_id_2, errata_id_2,	\
167 					CONFIG_k_2) \
168        __ALTERNATIVE_CFG(old_c)
169 
170 #endif /* __ASSEMBLY__ */
171 #endif /* CONFIG_RISCV_ALTERNATIVE */
172 
173 /*
174  * Usage:
175  *   ALTERNATIVE(old_content, new_content, vendor_id, errata_id, CONFIG_k)
176  * in the assembly code. Otherwise,
177  *   asm(ALTERNATIVE(old_content, new_content, vendor_id, errata_id, CONFIG_k));
178  *
179  * old_content: The old content which is probably replaced with new content.
180  * new_content: The new content.
181  * vendor_id: The CPU vendor ID.
182  * errata_id: The errata ID.
183  * CONFIG_k: The Kconfig of this errata. When Kconfig is disabled, the old
184  *	     content will alwyas be executed.
185  */
186 #define ALTERNATIVE(old_content, new_content, vendor_id, errata_id, CONFIG_k) \
187 	_ALTERNATIVE_CFG(old_content, new_content, vendor_id, errata_id, CONFIG_k)
188 
189 /*
190  * A vendor wants to replace an old_content, but another vendor has used
191  * ALTERNATIVE() to patch its customized content at the same location. In
192  * this case, this vendor can create a new macro ALTERNATIVE_2() based
193  * on the following sample code and then replace ALTERNATIVE() with
194  * ALTERNATIVE_2() to append its customized content.
195  */
196 #define ALTERNATIVE_2(old_content, new_content_1, vendor_id_1,		\
197 					errata_id_1, CONFIG_k_1,	\
198 				   new_content_2, vendor_id_2,		\
199 					errata_id_2, CONFIG_k_2)	\
200 	_ALTERNATIVE_CFG_2(old_content, new_content_1, vendor_id_1,	\
201 					    errata_id_1, CONFIG_k_1,	\
202 					new_content_2, vendor_id_2,	\
203 					    errata_id_2, CONFIG_k_2)
204 
205 #endif
206