diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index 831bebacb7fb..8f3994a7f0ca 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -24,29 +24,27 @@ #define RISCV_ISA_EXT_u ('u' - 'a') /* - * Increse this to higher value as kernel support more ISA extensions. + * These macros represent the logical IDs of each multi-letter RISC-V ISA + * extension and are used in the ISA bitmap. The logical IDs start from + * RISCV_ISA_EXT_BASE, which allows the 0-25 range to be reserved for single + * letter extensions. The maximum, RISCV_ISA_EXT_MAX, is defined in order + * to allocate the bitmap and may be increased when necessary. + * + * New extensions should just be added to the bottom, rather than added + * alphabetically, in order to avoid unnecessary shuffling. */ -#define RISCV_ISA_EXT_MAX 64 -#define RISCV_ISA_EXT_NAME_LEN_MAX 32 +#define RISCV_ISA_EXT_BASE 26 -/* The base ID for multi-letter ISA extensions */ -#define RISCV_ISA_EXT_BASE 26 +#define RISCV_ISA_EXT_SSCOFPMF 26 +#define RISCV_ISA_EXT_SSTC 27 +#define RISCV_ISA_EXT_SVINVAL 28 +#define RISCV_ISA_EXT_SVPBMT 29 +#define RISCV_ISA_EXT_ZBB 30 +#define RISCV_ISA_EXT_ZICBOM 31 +#define RISCV_ISA_EXT_ZIHINTPAUSE 32 -/* - * These macros represent the logical ID for each multi-letter RISC-V ISA extension. - * The logical ID should start from RISCV_ISA_EXT_BASE and must not exceed - * RISCV_ISA_EXT_MAX. 0-25 range is reserved for single letter - * extensions while all the multi-letter extensions should define the next - * available logical extension id. - * Entries are sorted alphabetically. - */ -#define RISCV_ISA_EXT_SSCOFPMF 26 -#define RISCV_ISA_EXT_SSTC 27 -#define RISCV_ISA_EXT_SVINVAL 28 -#define RISCV_ISA_EXT_SVPBMT 29 -#define RISCV_ISA_EXT_ZBB 30 -#define RISCV_ISA_EXT_ZICBOM 31 -#define RISCV_ISA_EXT_ZIHINTPAUSE 32 +#define RISCV_ISA_EXT_MAX 64 +#define RISCV_ISA_EXT_NAME_LEN_MAX 32 #ifndef __ASSEMBLY__