On Tue, Jul 11, 2017 at 01:07:46AM -0400, Brian Gerst wrote:
> > If I make the scattered feature support conditional on CONFIG_X86_64
> > (based on comment below) then cpu_has() will always be false unless
> > CONFIG_X86_64 is enabled. So this won't need to be wrapped by the
> > #ifdef.
>
> If you change it to use cpu_feature_enabled(), gcc will see that it is
> disabled and eliminate the dead code at compile time.
Just do this:
if (cpu_has(c, X86_FEATURE_SME)) {
if (IS_ENABLED(CONFIG_X86_32)) {
clear_cpu_cap(c, X86_FEATURE_SME);
} else {
u64 msr;
/* Check if SME is enabled */
rdmsrl(MSR_K8_SYSCFG, msr);
if (!(msr & MSR_K8_SYSCFG_MEM_ENCRYPT))
clear_cpu_cap(c, X86_FEATURE_SME);
}
}
so that it is explicit that we disable it on 32-bit and we can save us
the ifdeffery elsewhere.
Thanks.
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
--
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
