On Tue, Oct 10, 2017 at 07:38:33PM +0100, Dave P Martin wrote: > This patch uses the cpufeatures framework to determine common SVE > capabilities and vector lengths, and configures the runtime SVE > support code appropriately. > > ZCR_ELx is not really a feature register, but it is convenient to > use it as a template for recording the maximum vector length > supported by a CPU, using the LEN field. This field is similar to > a feature field in that it is a contiguous bitfield for which we > want to determine the minimum system-wide value. This patch adds > ZCR as a pseudo-register in cpuinfo/cpufeatures, with appropriate > custom code to populate it. Finding the minimum supported value of > the LEN field is left to the cpufeatures framework in the usual > way. > > The meaning of ID_AA64ZFR0_EL1 is not architecturally defined yet, > so for now we just require it to be zero. > > Note that much of this code is dormant and SVE still won't be used > yet, since system_supports_sve() remains hardwired to false. > > Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx> > Cc: Alex Bennée <alex.bennee@xxxxxxxxxx> > Cc: Suzuki K Poulose <Suzuki.Poulose@xxxxxxx> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
