On Thu, Jan 15, 2015 at 09:22:24PM -0000, Thomas Gleixner wrote:
> There is no point in postponing the hardware disablement of x2apic. It
> can be disabled right away in the nox2apic setup function.
>
> Disable it right away and set the state to DISABLED . This allows to
> remove all the nox2apic conditionals all over the place.
>
> Signed-off-by: Thomas Gleixner <[email protected]>
> ---
...
> @@ -1488,6 +1484,19 @@ enum {
> };
> static int x2apic_state;
>
> +static inline void disable_x2apic(void)
> +{
> + u64 msr;
> +
> + rdmsrl(MSR_IA32_APICBASE, msr);
> + if (!(msr & X2APIC_ENABLE))
> + return;
> + /* Disable xapic and x2apic first and then reenable xapic mode */
> + wrmsrl(MSR_IA32_APICBASE, msr & ~(X2APIC_ENABLE | XAPIC_ENABLE));
> + wrmsrl(MSR_IA32_APICBASE, msr & ~X2APIC_ENABLE);
> + printk_once(KERN_INFO "x2apic disabled\n");
> +}
> +
> static int __init setup_nox2apic(char *str)
> {
> if (x2apic_enabled()) {
> @@ -1498,28 +1507,17 @@ static int __init setup_nox2apic(char *s
> apicid);
> return 0;
> }
> -
> - pr_warning("x2apic already enabled. will disable it\n");
> - } else
> - setup_clear_cpu_cap(X86_FEATURE_X2APIC);
> -
> - nox2apic = true;
> + pr_warning("x2apic already enabled.\n");
> + disable_x2apic();
> + }
> + setup_clear_cpu_cap(X86_FEATURE_X2APIC);
> x2apic_state = X2APIC_DISABLED;
> + x2apic_mode = 0;
> return 0;
> }
> early_param("nox2apic", setup_nox2apic);
>
> -/*
> - * Need to disable xapic and x2apic at the same time and then enable xapic
> mode
> - */
> -static inline void __disable_x2apic(u64 msr)
> -{
> - wrmsrl(MSR_IA32_APICBASE,
> - msr & ~(X2APIC_ENABLE | XAPIC_ENABLE));
> - wrmsrl(MSR_IA32_APICBASE, msr & ~X2APIC_ENABLE);
> -}
> -
> -static __init void disable_x2apic(void)
> +static __init void x2apic_disable(void)
This is still misleading: we have x2apic_disable() and disable_x2apic().
What is what? Can we clarify them more and maybe prepend one of them
with "__" to show which is the lower level helper...
Or is the logic that all functions beginning with the "x2apic_" prefix
are called from outside and the "enable_/disable_x2apic" ones are the
internal helpers?
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
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