Re: [PATCH 3/7] arm64: Use arch_timer_read_counter instead of arch_counter_get_cntvct

From: Mark Rutland
Date: Mon Apr 08 2019 - 11:59:58 EST


On Mon, Apr 08, 2019 at 04:49:03PM +0100, Marc Zyngier wrote:
> Only arch_timer_read_counter will guarantee that workarounds are
> applied. So let's use this one instead of arch_counter_get_cntvct.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>

Acked-by: Mark Rutland <mark.rutland@xxxxxxx>

Mark.

> ---
> arch/arm64/kernel/traps.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
> index 8ad119c3f665..6190a60388cf 100644
> --- a/arch/arm64/kernel/traps.c
> +++ b/arch/arm64/kernel/traps.c
> @@ -493,7 +493,7 @@ static void cntvct_read_handler(unsigned int esr, struct pt_regs *regs)
> {
> int rt = ESR_ELx_SYS64_ISS_RT(esr);
>
> - pt_regs_write_reg(regs, rt, arch_counter_get_cntvct());
> + pt_regs_write_reg(regs, rt, arch_timer_read_counter());
> arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);
> }
>
> @@ -665,7 +665,7 @@ static void compat_cntvct_read_handler(unsigned int esr, struct pt_regs *regs)
> {
> int rt = (esr & ESR_ELx_CP15_64_ISS_RT_MASK) >> ESR_ELx_CP15_64_ISS_RT_SHIFT;
> int rt2 = (esr & ESR_ELx_CP15_64_ISS_RT2_MASK) >> ESR_ELx_CP15_64_ISS_RT2_SHIFT;
> - u64 val = arch_counter_get_cntvct();
> + u64 val = arch_timer_read_counter();
>
> pt_regs_write_reg(regs, rt, lower_32_bits(val));
> pt_regs_write_reg(regs, rt2, upper_32_bits(val));
> --
> 2.20.1
>