• C
    x86: A fast way to check capabilities of the current cpu · 349c004e
    Christoph Lameter 提交于
    Add this_cpu_has() which determines if the current cpu has a certain
    ability using a segment prefix and a bit test operation.
    
    For that we need to add bit operations to x86s percpu.h.
    
    Many uses of cpu_has use a pointer passed to a function to determine
    the current flags. That is no longer necessary after this patch.
    
    However, this patch only converts the straightforward cases where
    cpu_has is used with this_cpu_ptr. The rest is work for later.
    
    -tj: Rolled up patch to add x86_ prefix and use percpu_read() instead
         of percpu_read_stable().
    Signed-off-by: NChristoph Lameter <cl@linux.com>
    Acked-by: NTejun Heo <tj@kernel.org>
    Signed-off-by: NTejun Heo <tj@kernel.org>
    349c004e
cpufeature.h 17.7 KB