kernel/arch/riscv/include/asm/alternative-macros.h
2024-07-22 17:22:30 +08:00

143 lines
4.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_ALTERNATIVE_MACROS_H
#define __ASM_ALTERNATIVE_MACROS_H
#ifdef CONFIG_RISCV_ERRATA_ALTERNATIVE
#ifdef __ASSEMBLY__
.macro ALT_ENTRY oldptr newptr vendor_id errata_id new_len
RISCV_PTR \oldptr
RISCV_PTR \newptr
REG_ASM \vendor_id
REG_ASM \new_len
.word \errata_id
.endm
.macro ALT_NEW_CONTENT vendor_id, errata_id, enable = 1, new_c : vararg
.if \enable
.pushsection .alternative, "a"
ALT_ENTRY 886b, 888f, \vendor_id, \errata_id, 889f - 888f
.popsection
.subsection 1
888 :
\new_c
889 :
.org . - (889b - 888b) + (887b - 886b)
.org . - (887b - 886b) + (889b - 888b)
.previous
.endif
.endm
.macro __ALTERNATIVE_CFG old_c, new_c, vendor_id, errata_id, enable
886 :
\old_c
887 :
ALT_NEW_CONTENT \vendor_id, \errata_id, \enable, \new_c
.endm
#define _ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, CONFIG_k) \
__ALTERNATIVE_CFG old_c, new_c, vendor_id, errata_id, IS_ENABLED(CONFIG_k)
#else /* !__ASSEMBLY__ */
#include <asm/asm.h>
#include <linux/stringify.h>
#define ALT_ENTRY(oldptr, newptr, vendor_id, errata_id, newlen) \
RISCV_PTR " " oldptr "\n" \
RISCV_PTR " " newptr "\n" \
REG_ASM " " vendor_id "\n" \
REG_ASM " " newlen "\n" \
".word " errata_id "\n"
#define ALT_NEW_CONTENT(vendor_id, errata_id, enable, new_c) \
".if " __stringify(enable) " == 1\n" \
".pushsection .alternative, \"a\"\n" \
ALT_ENTRY("886b", "888f", __stringify(vendor_id), __stringify(errata_id), "889f - 888f") \
".popsection\n" \
".subsection 1\n" \
"888 :\n" \
new_c "\n" \
"889 :\n" \
".org . - (887b - 886b) + (889b - 888b)\n" \
".org . - (889b - 888b) + (887b - 886b)\n" \
".previous\n" \
".endif\n"
#define __ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, enable) \
"886 :\n" \
old_c "\n" \
"887 :\n" \
ALT_NEW_CONTENT(vendor_id, errata_id, enable, new_c)
#define _ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, CONFIG_k) \
__ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, IS_ENABLED(CONFIG_k))
#endif /* __ASSEMBLY__ */
#else /* !CONFIG_RISCV_ERRATA_ALTERNATIVE*/
#ifdef __ASSEMBLY__
.macro __ALTERNATIVE_CFG old_c
\old_c
.endm
#define _ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, CONFIG_k) \
__ALTERNATIVE_CFG old_c
#else /* !__ASSEMBLY__ */
#define __ALTERNATIVE_CFG(old_c) \
old_c "\n"
#define _ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, CONFIG_k) \
__ALTERNATIVE_CFG(old_c)
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_RISCV_ERRATA_ALTERNATIVE */
/*
* Usage:
* ALTERNATIVE(old_content, new_content, vendor_id, errata_id, CONFIG_k)
* in the assembly code. Otherwise,
* asm(ALTERNATIVE(old_content, new_content, vendor_id, errata_id, CONFIG_k));
*
* old_content: The old content which is probably replaced with new content.
* new_content: The new content.
* vendor_id: The CPU vendor ID.
* errata_id: The errata ID.
* CONFIG_k: The Kconfig of this errata. When Kconfig is disabled, the old
* content will alwyas be executed.
*/
#define ALTERNATIVE(old_content, new_content, vendor_id, errata_id, CONFIG_k) \
_ALTERNATIVE_CFG(old_content, new_content, vendor_id, errata_id, CONFIG_k)
/*
* A vendor wants to replace an old_content, but another vendor has used
* ALTERNATIVE() to patch its customized content at the same location. In
* this case, this vendor can create a new macro ALTERNATIVE_2() based
* on the following sample code and then replace ALTERNATIVE() with
* ALTERNATIVE_2() to append its customized content.
*
* .macro __ALTERNATIVE_CFG_2 old_c, new_c_1, vendor_id_1, errata_id_1, enable_1, \
* new_c_2, vendor_id_2, errata_id_2, enable_2
* 886 :
* \old_c
* 887 :
* ALT_NEW_CONTENT \vendor_id_1, \errata_id_1, \enable_1, \new_c_1
* ALT_NEW_CONTENT \vendor_id_2, \errata_id_2, \enable_2, \new_c_2
* .endm
*
* #define _ALTERNATIVE_CFG_2(old_c, new_c_1, vendor_id_1, errata_id_1, CONFIG_k_1, \
* new_c_2, vendor_id_2, errata_id_2, CONFIG_k_2) \
* __ALTERNATIVE_CFG_2 old_c, new_c_1, vendor_id_1, errata_id_1, IS_ENABLED(CONFIG_k_1), \
* new_c_2, vendor_id_2, errata_id_2, IS_ENABLED(CONFIG_k_2) \
*
* #define ALTERNATIVE_2(old_content, new_content_1, vendor_id_1, errata_id_1, CONFIG_k_1, \
* new_content_2, vendor_id_2, errata_id_2, CONFIG_k_2) \
* _ALTERNATIVE_CFG_2(old_content, new_content_1, vendor_id_1, errata_id_1, CONFIG_k_1, \
* new_content_2, vendor_id_2, errata_id_2, CONFIG_k_2)
*
*/
#endif