[haiku-commits] Re: BRANCH yongcong-github.master - in src: add-ons/kernel/bus_managers/acpi add-ons/kernel/bus_managers/acpi/acpica/components add-ons/kernel/bus_managers/acpi/acpica/include add-ons/kernel/bus_managers/acpi/include kits/tracker
- From: Jérôme Duval <korli@xxxxxxxxxxxxxxxx>
- To: haiku-commits@xxxxxxxxxxxxx
- Date: Tue, 21 Aug 2012 16:20:53 +0200
Hi Yongcong,
2012/8/21 yongcong-github.master <community@xxxxxxxxxxxx>:
> + cpuid_info cpuid;
> + get_current_cpuid(&cpuid, 5);
> + /* ecx[0] monitor/mwait extension supported
> + * ecx[1] support for treating interrupts as break-events for mwait
> + * edx number of sub-states
> + */
> + if (!((cpuid.regs.ecx & 0x1) && (cpuid.regs.ecx & 0x2) &&
> + cpuid.regs.edx)) {
> + return B_ERROR;
> + }
x86_check_feature() could have been used for these checks, provided
definitions are correctly added to
headers/private/kernel/arch/x86/arch_cpu.h and features loaded in
src/system/kernel/arch/x86/arch_cpu.cpp#detect_cpu()
As it's a private kernel API, that's probably not a good idea though.
BTW coding style recommands the use of != 0 for such checks ie:
((cpuid.regs.ecx & 0x2) != 0)
Bye,
Jérôme
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