Re: [PATCH v4] x86/vmware: use BIT() macro for shifting

From: Srivatsa S. Bhat
Date: Thu Jun 02 2022 - 09:02:10 EST


On 6/1/22 3:18 AM, Shreenidhi Shedi wrote:
> From: Shreenidhi Shedi <sshedi@xxxxxxxxxx>
>
> Using BIT() macro improves readability & it uses unsigned long for
> shifting which is an added advantage.
>
> Kernel builds with -fno-strict-overflow CFLAG hence shifting a signed
> integer by 31 bits is not an issue in this case.
>
> Signed-off-by: Shreenidhi Shedi <sshedi@xxxxxxxxxx>
> ---

Looks good to me.

Reviewed-by: Srivatsa S. Bhat (VMware) <srivatsa@xxxxxxxxxxxxx>

> arch/x86/kernel/cpu/vmware.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
> index c04b933f4..02039ec35 100644
> --- a/arch/x86/kernel/cpu/vmware.c
> +++ b/arch/x86/kernel/cpu/vmware.c
> @@ -476,8 +476,8 @@ static bool __init vmware_legacy_x2apic_available(void)
> {
> uint32_t eax, ebx, ecx, edx;
> VMWARE_CMD(GETVCPU_INFO, eax, ebx, ecx, edx);
> - return (eax & (1 << VMWARE_CMD_VCPU_RESERVED)) == 0 &&
> - (eax & (1 << VMWARE_CMD_LEGACY_X2APIC)) != 0;
> + return !(eax & BIT(VMWARE_CMD_VCPU_RESERVED)) &&
> + (eax & BIT(VMWARE_CMD_LEGACY_X2APIC));
> }
>
> #ifdef CONFIG_AMD_MEM_ENCRYPT
> --
> 2.36.1
>
Regards,
Srivatsa
VMware Photon OS