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 patch_id new_len
10 .4byte \oldptr - .
11 .4byte \newptr - .
12 .2byte \vendor_id
13 .2byte \new_len
14 .4byte \patch_id
15 .endm
16
17 .macro ALT_NEW_CONTENT vendor_id, patch_id, enable = 1, new_c
18 .if \enable
19 .pushsection .alternative, "a"
20 ALT_ENTRY 886b, 888f, \vendor_id, \patch_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, patch_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, \patch_id, \enable, "\new_c"
45 .endm
46
47 .macro ALTERNATIVE_CFG_2 old_c, new_c_1, vendor_id_1, patch_id_1, enable_1, \
48 new_c_2, vendor_id_2, patch_id_2, enable_2
49 ALTERNATIVE_CFG "\old_c", "\new_c_1", \vendor_id_1, \patch_id_1, \enable_1
50 ALT_NEW_CONTENT \vendor_id_2, \patch_id_2, \enable_2, "\new_c_2"
51 .endm
52
53 #define __ALTERNATIVE_CFG(...) ALTERNATIVE_CFG __VA_ARGS__
54 #define __ALTERNATIVE_CFG_2(...) ALTERNATIVE_CFG_2 __VA_ARGS__
55
56 #else /* !__ASSEMBLY__ */
57
58 #include <asm/asm.h>
59 #include <linux/stringify.h>
60
61 #define ALT_ENTRY(oldptr, newptr, vendor_id, patch_id, newlen) \
62 ".4byte ((" oldptr ") - .) \n" \
63 ".4byte ((" newptr ") - .) \n" \
64 ".2byte " vendor_id "\n" \
65 ".2byte " newlen "\n" \
66 ".4byte " patch_id "\n"
67
68 #define ALT_NEW_CONTENT(vendor_id, patch_id, enable, new_c) \
69 ".if " __stringify(enable) " == 1\n" \
70 ".pushsection .alternative, \"a\"\n" \
71 ALT_ENTRY("886b", "888f", __stringify(vendor_id), __stringify(patch_id), "889f - 888f") \
72 ".popsection\n" \
73 ".subsection 1\n" \
74 "888 :\n" \
75 ".option push\n" \
76 ".option norvc\n" \
77 ".option norelax\n" \
78 new_c "\n" \
79 ".option pop\n" \
80 "889 :\n" \
81 ".org . - (887b - 886b) + (889b - 888b)\n" \
82 ".org . - (889b - 888b) + (887b - 886b)\n" \
83 ".previous\n" \
84 ".endif\n"
85
86 #define __ALTERNATIVE_CFG(old_c, new_c, vendor_id, patch_id, enable) \
87 "886 :\n" \
88 ".option push\n" \
89 ".option norvc\n" \
90 ".option norelax\n" \
91 old_c "\n" \
92 ".option pop\n" \
93 "887 :\n" \
94 ALT_NEW_CONTENT(vendor_id, patch_id, enable, new_c)
95
96 #define __ALTERNATIVE_CFG_2(old_c, new_c_1, vendor_id_1, patch_id_1, enable_1, \
97 new_c_2, vendor_id_2, patch_id_2, enable_2) \
98 __ALTERNATIVE_CFG(old_c, new_c_1, vendor_id_1, patch_id_1, enable_1) \
99 ALT_NEW_CONTENT(vendor_id_2, patch_id_2, enable_2, new_c_2)
100
101 #endif /* __ASSEMBLY__ */
102
103 #define _ALTERNATIVE_CFG(old_c, new_c, vendor_id, patch_id, CONFIG_k) \
104 __ALTERNATIVE_CFG(old_c, new_c, vendor_id, patch_id, IS_ENABLED(CONFIG_k))
105
106 #define _ALTERNATIVE_CFG_2(old_c, new_c_1, vendor_id_1, patch_id_1, CONFIG_k_1, \
107 new_c_2, vendor_id_2, patch_id_2, CONFIG_k_2) \
108 __ALTERNATIVE_CFG_2(old_c, new_c_1, vendor_id_1, patch_id_1, IS_ENABLED(CONFIG_k_1), \
109 new_c_2, vendor_id_2, patch_id_2, IS_ENABLED(CONFIG_k_2))
110
111 #else /* CONFIG_RISCV_ALTERNATIVE */
112 #ifdef __ASSEMBLY__
113
114 .macro ALTERNATIVE_CFG old_c
115 \old_c
116 .endm
117
118 #define _ALTERNATIVE_CFG(old_c, ...) \
119 ALTERNATIVE_CFG old_c
120
121 #define _ALTERNATIVE_CFG_2(old_c, ...) \
122 ALTERNATIVE_CFG old_c
123
124 #else /* !__ASSEMBLY__ */
125
126 #define __ALTERNATIVE_CFG(old_c) \
127 old_c "\n"
128
129 #define _ALTERNATIVE_CFG(old_c, ...) \
130 __ALTERNATIVE_CFG(old_c)
131
132 #define _ALTERNATIVE_CFG_2(old_c, ...) \
133 __ALTERNATIVE_CFG(old_c)
134
135 #endif /* __ASSEMBLY__ */
136 #endif /* CONFIG_RISCV_ALTERNATIVE */
137
138 /*
139 * Usage:
140 * ALTERNATIVE(old_content, new_content, vendor_id, patch_id, CONFIG_k)
141 * in the assembly code. Otherwise,
142 * asm(ALTERNATIVE(old_content, new_content, vendor_id, patch_id, CONFIG_k));
143 *
144 * old_content: The old content which is probably replaced with new content.
145 * new_content: The new content.
146 * vendor_id: The CPU vendor ID.
147 * patch_id: The patch ID (erratum ID or cpufeature ID).
148 * CONFIG_k: The Kconfig of this patch ID. When Kconfig is disabled, the old
149 * content will always be executed.
150 */
151 #define ALTERNATIVE(old_content, new_content, vendor_id, patch_id, CONFIG_k) \
152 _ALTERNATIVE_CFG(old_content, new_content, vendor_id, patch_id, CONFIG_k)
153
154 /*
155 * A vendor wants to replace an old_content, but another vendor has used
156 * ALTERNATIVE() to patch its customized content at the same location. In
157 * this case, this vendor can create a new macro ALTERNATIVE_2() based
158 * on the following sample code and then replace ALTERNATIVE() with
159 * ALTERNATIVE_2() to append its customized content.
160 */
161 #define ALTERNATIVE_2(old_content, new_content_1, vendor_id_1, patch_id_1, CONFIG_k_1, \
162 new_content_2, vendor_id_2, patch_id_2, CONFIG_k_2) \
163 _ALTERNATIVE_CFG_2(old_content, new_content_1, vendor_id_1, patch_id_1, CONFIG_k_1, \
164 new_content_2, vendor_id_2, patch_id_2, CONFIG_k_2)
165
166 #endif
167
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