linux/arch/riscv/include/asm/alternative-macros.h
Yuan Tan 174e8ac027
riscv: alternatives: fix a typo in comment
In the usage of ALTERNATIVE, "always" is misspelled as "alwyas".

Signed-off-by: Yuan Tan <tanyuan@tinylab.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230723165155.4896-1-tanyuan@tinylab.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-02 13:49:07 -07:00

167 lines
4.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_ALTERNATIVE_MACROS_H
#define __ASM_ALTERNATIVE_MACROS_H
#ifdef CONFIG_RISCV_ALTERNATIVE
#ifdef __ASSEMBLY__
.macro ALT_ENTRY oldptr newptr vendor_id patch_id new_len
.4byte \oldptr - .
.4byte \newptr - .
.2byte \vendor_id
.2byte \new_len
.4byte \patch_id
.endm
.macro ALT_NEW_CONTENT vendor_id, patch_id, enable = 1, new_c
.if \enable
.pushsection .alternative, "a"
ALT_ENTRY 886b, 888f, \vendor_id, \patch_id, 889f - 888f
.popsection
.subsection 1
888 :
.option push
.option norvc
.option norelax
\new_c
.option pop
889 :
.org . - (889b - 888b) + (887b - 886b)
.org . - (887b - 886b) + (889b - 888b)
.previous
.endif
.endm
.macro ALTERNATIVE_CFG old_c, new_c, vendor_id, patch_id, enable
886 :
.option push
.option norvc
.option norelax
\old_c
.option pop
887 :
ALT_NEW_CONTENT \vendor_id, \patch_id, \enable, "\new_c"
.endm
.macro ALTERNATIVE_CFG_2 old_c, new_c_1, vendor_id_1, patch_id_1, enable_1, \
new_c_2, vendor_id_2, patch_id_2, enable_2
ALTERNATIVE_CFG "\old_c", "\new_c_1", \vendor_id_1, \patch_id_1, \enable_1
ALT_NEW_CONTENT \vendor_id_2, \patch_id_2, \enable_2, "\new_c_2"
.endm
#define __ALTERNATIVE_CFG(...) ALTERNATIVE_CFG __VA_ARGS__
#define __ALTERNATIVE_CFG_2(...) ALTERNATIVE_CFG_2 __VA_ARGS__
#else /* !__ASSEMBLY__ */
#include <asm/asm.h>
#include <linux/stringify.h>
#define ALT_ENTRY(oldptr, newptr, vendor_id, patch_id, newlen) \
".4byte ((" oldptr ") - .) \n" \
".4byte ((" newptr ") - .) \n" \
".2byte " vendor_id "\n" \
".2byte " newlen "\n" \
".4byte " patch_id "\n"
#define ALT_NEW_CONTENT(vendor_id, patch_id, enable, new_c) \
".if " __stringify(enable) " == 1\n" \
".pushsection .alternative, \"a\"\n" \
ALT_ENTRY("886b", "888f", __stringify(vendor_id), __stringify(patch_id), "889f - 888f") \
".popsection\n" \
".subsection 1\n" \
"888 :\n" \
".option push\n" \
".option norvc\n" \
".option norelax\n" \
new_c "\n" \
".option pop\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, patch_id, enable) \
"886 :\n" \
".option push\n" \
".option norvc\n" \
".option norelax\n" \
old_c "\n" \
".option pop\n" \
"887 :\n" \
ALT_NEW_CONTENT(vendor_id, patch_id, enable, new_c)
#define __ALTERNATIVE_CFG_2(old_c, new_c_1, vendor_id_1, patch_id_1, enable_1, \
new_c_2, vendor_id_2, patch_id_2, enable_2) \
__ALTERNATIVE_CFG(old_c, new_c_1, vendor_id_1, patch_id_1, enable_1) \
ALT_NEW_CONTENT(vendor_id_2, patch_id_2, enable_2, new_c_2)
#endif /* __ASSEMBLY__ */
#define _ALTERNATIVE_CFG(old_c, new_c, vendor_id, patch_id, CONFIG_k) \
__ALTERNATIVE_CFG(old_c, new_c, vendor_id, patch_id, IS_ENABLED(CONFIG_k))
#define _ALTERNATIVE_CFG_2(old_c, new_c_1, vendor_id_1, patch_id_1, CONFIG_k_1, \
new_c_2, vendor_id_2, patch_id_2, CONFIG_k_2) \
__ALTERNATIVE_CFG_2(old_c, new_c_1, vendor_id_1, patch_id_1, IS_ENABLED(CONFIG_k_1), \
new_c_2, vendor_id_2, patch_id_2, IS_ENABLED(CONFIG_k_2))
#else /* CONFIG_RISCV_ALTERNATIVE */
#ifdef __ASSEMBLY__
.macro ALTERNATIVE_CFG old_c
\old_c
.endm
#define _ALTERNATIVE_CFG(old_c, ...) \
ALTERNATIVE_CFG old_c
#define _ALTERNATIVE_CFG_2(old_c, ...) \
ALTERNATIVE_CFG old_c
#else /* !__ASSEMBLY__ */
#define __ALTERNATIVE_CFG(old_c) \
old_c "\n"
#define _ALTERNATIVE_CFG(old_c, ...) \
__ALTERNATIVE_CFG(old_c)
#define _ALTERNATIVE_CFG_2(old_c, ...) \
__ALTERNATIVE_CFG(old_c)
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_RISCV_ALTERNATIVE */
/*
* Usage:
* ALTERNATIVE(old_content, new_content, vendor_id, patch_id, CONFIG_k)
* in the assembly code. Otherwise,
* asm(ALTERNATIVE(old_content, new_content, vendor_id, patch_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.
* patch_id: The patch ID (erratum ID or cpufeature ID).
* CONFIG_k: The Kconfig of this patch ID. When Kconfig is disabled, the old
* content will always be executed.
*/
#define ALTERNATIVE(old_content, new_content, vendor_id, patch_id, CONFIG_k) \
_ALTERNATIVE_CFG(old_content, new_content, vendor_id, patch_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.
*/
#define ALTERNATIVE_2(old_content, new_content_1, vendor_id_1, patch_id_1, CONFIG_k_1, \
new_content_2, vendor_id_2, patch_id_2, CONFIG_k_2) \
_ALTERNATIVE_CFG_2(old_content, new_content_1, vendor_id_1, patch_id_1, CONFIG_k_1, \
new_content_2, vendor_id_2, patch_id_2, CONFIG_k_2)
#endif