From: Greentime Hu <greentime.hu@xxxxxxxxxx> clear vector registers on boot if kernel supports V. Signed-off-by: Greentime Hu <greentime.hu@xxxxxxxxxx> Signed-off-by: Vineet Gupta <vineetg@xxxxxxxxxxxx> Signed-off-by: Andy Chiu <andy.chiu@xxxxxxxxxx> Acked-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> Reviewed-by: Heiko Stuebner <heiko.stuebner@xxxxxxxx> Tested-by: Heiko Stuebner <heiko.stuebner@xxxxxxxx> --- arch/riscv/kernel/head.S | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 4bf6c449d78b..3fd6a4bd9c3e 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -392,7 +392,7 @@ ENTRY(reset_regs) #ifdef CONFIG_FPU csrr t0, CSR_MISA andi t0, t0, (COMPAT_HWCAP_ISA_F | COMPAT_HWCAP_ISA_D) - beqz t0, .Lreset_regs_done + beqz t0, .Lreset_regs_done_fpu li t1, SR_FS csrs CSR_STATUS, t1 @@ -430,8 +430,31 @@ ENTRY(reset_regs) fmv.s.x f31, zero csrw fcsr, 0 /* note that the caller must clear SR_FS */ +.Lreset_regs_done_fpu: #endif /* CONFIG_FPU */ -.Lreset_regs_done: + +#ifdef CONFIG_RISCV_ISA_V + csrr t0, CSR_MISA + li t1, COMPAT_HWCAP_ISA_V + and t0, t0, t1 + beqz t0, .Lreset_regs_done_vector + + /* + * Clear vector registers and reset vcsr + * VLMAX has a defined value, VLEN is a constant, + * and this form of vsetvli is defined to set vl to VLMAX. + */ + li t1, SR_VS + csrs CSR_STATUS, t1 + csrs CSR_VCSR, x0 + vsetvli t1, x0, e8, m8, ta, ma + vmv.v.i v0, 0 + vmv.v.i v8, 0 + vmv.v.i v16, 0 + vmv.v.i v24, 0 + /* note that the caller must clear SR_VS */ +.Lreset_regs_done_vector: +#endif /* CONFIG_RISCV_ISA_V */ ret END(reset_regs) #endif /* CONFIG_RISCV_M_MODE */ -- 2.17.1
