Messages in this thread | | | Date | Thu, 16 Mar 2006 09:47:13 -0800 | From | Zachary Amsden <> | Subject | Re: [RFC, PATCH 12/24] i386 Vmi processor header |
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Chuck Ebbert wrote: > >> +/* Some CPUID calls want 'count' to be placed in ecx */ >> +static inline void cpuid_count(int op, int count, int *eax, int *ebx, int *ecx, >> + int *edx) >> +{ >> + asm volatile(""::"c"(count)); >> + vmi_cpuid(op, eax, ebx, ecx, edx); >> +} >> > > You can't assume those last two statements will stay together. > >From the gcc 4.0.2 info file: >
I know. I've abused this a bit. When we originally wrote the cpuid call, there were no ecx dependencies on cpuid. Never got around to fixing it properly. > >> <...> you can't expect a sequence of volatile `asm' instructions >> to remain perfectly consecutive. If you want consecutive output, use a >> single `asm'. >> > > Maybe you could make vmi_cpuid always take a 'count' param, then just make cpuid > do: > > vmi_cpuid(op, 0, eax, ebx, ecx, edx); > > and cpuid_count do: > > vmi_cpuid(op, count, eax, ebx, ecx, edx); >
That is the proper fix. I'll put that in the next round.
> > (And sorry about trimming the cc: but I'm reading from a digest and that list > is too long to enter manually.) >
N.P.
Thanks for looking at my code, Zach - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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