diff options
Diffstat (limited to 'arch/riscv/include/asm/alternative-macros.h')
| -rw-r--r-- | arch/riscv/include/asm/alternative-macros.h | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/alternative-macros.h b/arch/riscv/include/asm/alternative-macros.h new file mode 100644 index 000000000000..88c08705f64a --- /dev/null +++ b/arch/riscv/include/asm/alternative-macros.h @@ -0,0 +1,142 @@ +/* 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 : + .previous + .org . - (889b - 888b) + (887b - 886b) + .org . - (887b - 886b) + (889b - 888b) + .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_CONSTENT(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" \ + ".previous\n" \ + ".org . - (887b - 886b) + (889b - 888b)\n" \ + ".org . - (889b - 888b) + (887b - 886b)\n" \ + ".endif\n" + +#define __ALTERNATIVE_CFG(old_c, new_c, vendor_id, errata_id, enable) \ + "886 :\n" \ + old_c "\n" \ + "887 :\n" \ + ALT_NEW_CONSTENT(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 |