-
Ingo Molnar authored
Mike Galbraith reported: " My i7-4790 box is having one hell of a time with this merge window, dead in the water. BIOS setting "Limit CPUID Maximum" upsets new fpu code mightily. " It turns out that Linux does a double workaround here, as per: 066941bd ("x86: unmask CPUID levels on Intel CPUs") it undoes the BIOS workaround - but as a side effect the CPUID state is not completely constant during early init anymore, and the new FPU init code did not take this into account. So what happened is that the xstate init code did not have full CPUID available, which broke subsequent attempts to use xstate features. Fix this by ordering the early FPU init code to after we've stabilized the CPUID state. Reported-bisected-and-tested-by: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150627082514.GA10894@gmail.comSigned-off-by: Ingo Molnar <mingo@kernel.org>
db52ef74