Messages in this thread | | | Date | Wed, 18 Sep 2019 07:20:17 -0700 | From | Matthew Wilcox <> | Subject | Re: [PATCH v4 1/3] arm64: cpufeature: introduce helper cpu_has_hw_af() |
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On Wed, Sep 18, 2019 at 09:19:12PM +0800, Jia He wrote: > +/* Decouple AF from AFDBM. */ > +bool cpu_has_hw_af(void) > +{ > + return (read_cpuid(ID_AA64MMFR1_EL1) & 0xf); > +} > +
Do you really want to call read_cpuid() every time? I would have thought you'd want to use the static branch mechanism to do the right thing at boot time. See Documentation/static-keys.txt.
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