From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> Reset vector registers at boot-time and disable vector instructions execution for kernel mode. Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> Co-developed-by: Vincent Chen <vincent.chen@xxxxxxxxxx> Signed-off-by: Vincent Chen <vincent.chen@xxxxxxxxxx> Co-developed-by: Han-Kuan Chen <hankuan.chen@xxxxxxxxxx> Signed-off-by: Han-Kuan Chen <hankuan.chen@xxxxxxxxxx> Co-developed-by: Greentime Hu <greentime.hu@xxxxxxxxxx> Signed-off-by: Greentime Hu <greentime.hu@xxxxxxxxxx> Reviewed-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx> --- arch/riscv/kernel/entry.S | 6 +++--- arch/riscv/kernel/head.S | 35 +++++++++++++++++++++++++++++------ 2 files changed, 32 insertions(+), 9 deletions(-) diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index b9eda3fcbd6d..1e9987376591 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -77,10 +77,10 @@ _save_context: * Disable user-mode memory access as it should only be set in the * actual user copy routines. * - * Disable the FPU to detect illegal usage of floating point in kernel - * space. + * Disable the FPU/Vector to detect illegal usage of floating point + * or vector in kernel space. */ - li t0, SR_SUM | SR_FS + li t0, SR_SUM | SR_FS | SR_VS REG_L s0, TASK_TI_USER_SP(tp) csrrc s1, CSR_STATUS, t0 diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index b865046e4dbb..2c81ca42ec4e 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -140,10 +140,10 @@ secondary_start_sbi: .option pop /* - * Disable FPU to detect illegal usage of - * floating point in kernel space + * Disable FPU & VECTOR to detect illegal usage of + * floating point or vector in kernel space */ - li t0, SR_FS + li t0, SR_FS | SR_VS csrc CSR_STATUS, t0 /* Set trap vector to spin forever to help debug */ @@ -234,10 +234,10 @@ pmp_done: .option pop /* - * Disable FPU to detect illegal usage of - * floating point in kernel space + * Disable FPU & VECTOR to detect illegal usage of + * floating point or vector in kernel space */ - li t0, SR_FS + li t0, SR_FS | SR_VS csrc CSR_STATUS, t0 #ifdef CONFIG_RISCV_BOOT_SPINWAIT @@ -431,6 +431,29 @@ ENTRY(reset_regs) csrw fcsr, 0 /* note that the caller must clear SR_FS */ #endif /* CONFIG_FPU */ + +#ifdef CONFIG_VECTOR + csrr t0, CSR_MISA + li t1, COMPAT_HWCAP_ISA_V + and t0, t0, t1 + beqz t0, .Lreset_regs_done + + /* + * 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 */ +#endif /* CONFIG_VECTOR */ + .Lreset_regs_done: ret END(reset_regs) -- 2.25.1
