arch/riscv/include/asm/alternative-macros.h

   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