[PATCH V2 1/1] X86: Hyper-V: Get the local APIC timer frequency from the hypervisor

[Jan Beulich]

>>> On 03.09.13 at 20:30, "K. Y. Srinivasan" <kys at microsoft.com> wrote:
> @@ -76,6 +80,26 @@ static void __init ms_hyperv_init_platform(void)
>  	printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n",
>  	       ms_hyperv.features, ms_hyperv.hints);
>  
> +	if (ms_hyperv.features & HV_X64_MSR_APIC_FREQUENCY_AVAILABLE) {
> +		/*
> +		 * Get the APIC frequency.
> +		 */
> +		rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency);
> +		hv_lapic_frequency /= HZ;
> +		lapic_timer_frequency = hv_lapic_frequency;
> +		printk(KERN_INFO "HyperV: LAPIC Timer Frequency: %#x\n",
> +				lapic_timer_frequency);
> +
> +		/*
> +		 * On Hyper-V, when we are booting off an EFI firmware stack,
> +		 * we do not have many legacy devices including PIC, PIT etc.
> +		 */
> +		if (efi_enabled(EFI_BOOT)) {
> +			printk(KERN_INFO "HyperV: Using null_legacy_pic\n");
> +			legacy_pic = &null_legacy_pic;
> +		}

And this check is really connected to the feature check around the
whole block, rather than being independent? (I'd also think that
this latter message would suffice to be KERN_DEBUG).

Jan