diff options
| -rw-r--r-- | arch/riscv/include/asm/insn.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/insn.h b/arch/riscv/include/asm/insn.h index 2a23890b4577..98453535324a 100644 --- a/arch/riscv/include/asm/insn.h +++ b/arch/riscv/include/asm/insn.h @@ -290,3 +290,51 @@ static __always_inline bool riscv_insn_is_branch(u32 code) (RVC_X(x_, RVC_B_IMM_5_OPOFF, RVC_B_IMM_5_MASK) << RVC_B_IMM_5_OFF) | \ (RVC_X(x_, RVC_B_IMM_7_6_OPOFF, RVC_B_IMM_7_6_MASK) << RVC_B_IMM_7_6_OFF) | \ (RVC_IMM_SIGN(x_) << RVC_B_IMM_SIGN_OFF); }) + +/* + * Put together one immediate from a U-type and I-type instruction pair. + * + * The U-type contains an upper immediate, meaning bits[31:12] with [11:0] + * being zero, while the I-type contains a 12bit immediate. + * Combined these can encode larger 32bit values and are used for example + * in auipc + jalr pairs to allow larger jumps. + * + * @utype_insn: instruction containing the upper immediate + * @itype_insn: instruction + * Return: combined immediate + */ +static inline s32 riscv_insn_extract_utype_itype_imm(u32 utype_insn, u32 itype_insn) +{ + s32 imm; + + imm = RV_EXTRACT_UTYPE_IMM(utype_insn); + imm += RV_EXTRACT_ITYPE_IMM(itype_insn); + + return imm; +} + +/* + * Update a set of two instructions (U-type + I-type) with an immediate value. + * + * Used for example in auipc+jalrs pairs the U-type instructions contains + * a 20bit upper immediate representing bits[31:12], while the I-type + * instruction contains a 12bit immediate representing bits[11:0]. + * + * This also takes into account that both separate immediates are + * considered as signed values, so if the I-type immediate becomes + * negative (BIT(11) set) the U-type part gets adjusted. + * + * @utype_insn: pointer to the utype instruction of the pair + * @itype_insn: pointer to the itype instruction of the pair + * @imm: the immediate to insert into the two instructions + */ +static inline void riscv_insn_insert_utype_itype_imm(u32 *utype_insn, u32 *itype_insn, s32 imm) +{ + /* drop possible old IMM values */ + *utype_insn &= ~(RV_U_IMM_31_12_MASK); + *itype_insn &= ~(RV_I_IMM_11_0_MASK << RV_I_IMM_11_0_OPOFF); + + /* add the adapted IMMs */ + *utype_insn |= (imm & RV_U_IMM_31_12_MASK) + ((imm & BIT(11)) << 1); + *itype_insn |= ((imm & RV_I_IMM_11_0_MASK) << RV_I_IMM_11_0_OPOFF); +} |