LXR linux/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_ERRATA_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
  23888 :
  24        \new_c
  25889 :
  26        .previous
  27        .org    . - (889b - 888b) + (887b - 886b)
  28        .org    . - (887b - 886b) + (889b - 888b)
  29        .endif
  30.endm
  31
  32.macro __ALTERNATIVE_CFG old_c, new_c, vendor_id, errata_id, enable
  33886 :
  34        \old_c
  35887 :
  36        ALT_NEW_CONTENT \vendor_id, \errata_id, \enable, \new_c
  37.endm
  38
  39#define _ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, CONFIG_k) \
  40        __ALTERNATIVE_CFG old_c, new_c, vendor_id, errata_id, IS_ENABLED(CONFIG_k)
  41
  42#else /* !__ASSEMBLY__ */
  43
  44#include <asm/asm.h>
  45#include <linux/stringify.h>
  46
  47#define ALT_ENTRY(oldptr, newptr, vendor_id, errata_id, newlen) \
  48        RISCV_PTR " " oldptr "\n" \
  49        RISCV_PTR " " newptr "\n" \
  50        REG_ASM " " vendor_id "\n" \
  51        REG_ASM " " newlen "\n" \
  52        ".word " errata_id "\n"
  53
  54#define ALT_NEW_CONTENT(vendor_id, errata_id, enable, new_c) \
  55        ".if " __stringify(enable) " == 1\n"                            \
  56        ".pushsection .alternative, \"a\"\n"                            \
  57        ALT_ENTRY("886b", "888f", __stringify(vendor_id), __stringify(errata_id), "889f - 888f") \
  58        ".popsection\n"                                                 \
  59        ".subsection 1\n"                                               \
  60        "888 :\n"                                                       \
  61        new_c "\n"                                                      \
  62        "889 :\n"                                                       \
  63        ".previous\n"                                                   \
  64        ".org   . - (887b - 886b) + (889b - 888b)\n"                    \
  65        ".org   . - (889b - 888b) + (887b - 886b)\n"                    \
  66        ".endif\n"
  67
  68#define __ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, enable) \
  69        "886 :\n"       \
  70        old_c "\n"      \
  71        "887 :\n"       \
  72        ALT_NEW_CONTENT(vendor_id, errata_id, enable, new_c)
  73
  74#define _ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, CONFIG_k)  \
  75        __ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, IS_ENABLED(CONFIG_k))
  76
  77#endif /* __ASSEMBLY__ */
  78
  79#else /* !CONFIG_RISCV_ERRATA_ALTERNATIVE*/
  80#ifdef __ASSEMBLY__
  81
  82.macro __ALTERNATIVE_CFG old_c
  83        \old_c
  84.endm
  85
  86#define _ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, CONFIG_k) \
  87        __ALTERNATIVE_CFG old_c
  88
  89#else /* !__ASSEMBLY__ */
  90
  91#define __ALTERNATIVE_CFG(old_c)  \
  92        old_c "\n"
  93
  94#define _ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, CONFIG_k) \
  95        __ALTERNATIVE_CFG(old_c)
  96
  97#endif /* __ASSEMBLY__ */
  98#endif /* CONFIG_RISCV_ERRATA_ALTERNATIVE */
  99/*
 100 * Usage:
 101 *   ALTERNATIVE(old_content, new_content, vendor_id, errata_id, CONFIG_k)
 102 * in the assembly code. Otherwise,
 103 *   asm(ALTERNATIVE(old_content, new_content, vendor_id, errata_id, CONFIG_k));
 104 *
 105 * old_content: The old content which is probably replaced with new content.
 106 * new_content: The new content.
 107 * vendor_id: The CPU vendor ID.
 108 * errata_id: The errata ID.
 109 * CONFIG_k: The Kconfig of this errata. When Kconfig is disabled, the old
 110 *           content will alwyas be executed.
 111 */
 112#define ALTERNATIVE(old_content, new_content, vendor_id, errata_id, CONFIG_k) \
 113        _ALTERNATIVE_CFG(old_content, new_content, vendor_id, errata_id, CONFIG_k)
 114
 115/*
 116 * A vendor wants to replace an old_content, but another vendor has used
 117 * ALTERNATIVE() to patch its customized content at the same location. In
 118 * this case, this vendor can create a new macro ALTERNATIVE_2() based
 119 * on the following sample code and then replace ALTERNATIVE() with
 120 * ALTERNATIVE_2() to append its customized content.
 121 *
 122 * .macro __ALTERNATIVE_CFG_2 old_c, new_c_1, vendor_id_1, errata_id_1, enable_1, \
 123 *                                   new_c_2, vendor_id_2, errata_id_2, enable_2
 124 * 886 :
 125 *      \old_c
 126 * 887 :
 127 *      ALT_NEW_CONTENT \vendor_id_1, \errata_id_1, \enable_1, \new_c_1
 128 *      ALT_NEW_CONTENT \vendor_id_2, \errata_id_2, \enable_2, \new_c_2
 129 * .endm
 130 *
 131 * #define _ALTERNATIVE_CFG_2(old_c, new_c_1, vendor_id_1, errata_id_1, CONFIG_k_1, \
 132 *                                   new_c_2, vendor_id_2, errata_id_2, CONFIG_k_2) \
 133 *        __ALTERNATIVE_CFG_2 old_c, new_c_1, vendor_id_1, errata_id_1, IS_ENABLED(CONFIG_k_1), \
 134 *                                   new_c_2, vendor_id_2, errata_id_2, IS_ENABLED(CONFIG_k_2) \
 135 *
 136 * #define ALTERNATIVE_2(old_content, new_content_1, vendor_id_1, errata_id_1, CONFIG_k_1, \
 137 *                                    new_content_2, vendor_id_2, errata_id_2, CONFIG_k_2) \
 138 *         _ALTERNATIVE_CFG_2(old_content, new_content_1, vendor_id_1, errata_id_1, CONFIG_k_1, \
 139 *                                         new_content_2, vendor_id_2, errata_id_2, CONFIG_k_2)
 140 *
 141 */
 142#endif
 143