[PATCH 1/2] arm64: Change the cpuinfo_arm64 member type for some sysregs to u64

[Shaokun Zhang]

Hi Catalin,

On 2021/5/12 2:23, Catalin Marinas wrote:
> The architecture has been updated and the CTR_EL0, CNTFRQ_EL1,

s/CNTFRQ_EL1/CNTFRQ_EL0?

> DCZID_EL0, MIDR_EL1, REVIDR_EL1 registers are all 64-bit, even if most
> of them have a RES0 top 32-bit.
> 
> Change their type to u64 in struct cpuinfo_arm64.
> 
> Signed-off-by: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Will Deacon <will at kernel.org>
> Cc: Mark Rutland <mark.rutland at arm.com>
> Cc: Suzuki K Poulose <Suzuki.Poulose at arm.com>
> ---
> 
> CTR_EL0 gained a new field with MTE in the top 32-bit, TminLine. I have
> no idea what software is supposed to do with this field. I even have a
> Jira ticket from 2019 asking for it to be removed. So I don't think we
> should bother adding the mask/checks for it to the kernel.
> 
>  arch/arm64/include/asm/cpu.h | 10 +++++-----
>  arch/arm64/kernel/cpuinfo.c  |  2 +-
>  2 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/cpu.h b/arch/arm64/include/asm/cpu.h
> index 7faae6ff3ab4..fe5a8499ddc2 100644
> --- a/arch/arm64/include/asm/cpu.h
> +++ b/arch/arm64/include/asm/cpu.h
> @@ -15,11 +15,11 @@
>  struct cpuinfo_arm64 {
>  	struct cpu	cpu;
>  	struct kobject	kobj;
> -	u32		reg_ctr;
> -	u32		reg_cntfrq;
> -	u32		reg_dczid;
> -	u32		reg_midr;
> -	u32		reg_revidr;
> +	u64		reg_ctr;
> +	u64		reg_cntfrq;

One more question: is it ok to change the function prototype to u64 also?
For CNTFRQ_EL0, if the Arm ARM expand the clock to more than 4GHz and it
will also work this change (arch_timer and watchdog shall change at the
the same time).

Thanks,
Shaokun

> +	u64		reg_dczid;
> +	u64		reg_midr;
> +	u64		reg_revidr;
>  
>  	u64		reg_id_aa64dfr0;
>  	u64		reg_id_aa64dfr1;
> diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
> index 77605aec25fe..4bea701117d4 100644
> --- a/arch/arm64/kernel/cpuinfo.c
> +++ b/arch/arm64/kernel/cpuinfo.c
> @@ -246,7 +246,7 @@ static struct kobj_type cpuregs_kobj_type = {
>  		struct cpuinfo_arm64 *info = kobj_to_cpuinfo(kobj);		\
>  										\
>  		if (info->reg_midr)						\
> -			return sprintf(buf, "0x%016x\n", info->reg_##_field);	\
> +			return sprintf(buf, "0x%016llx\n", info->reg_##_field);	\
>  		else								\
>  			return 0;						\
>  	}									\
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> .
>