• Linus Torvalds's avatar
    i387: don't ever touch TS_USEDFPU directly, use helper functions · 6d59d7a9
    Linus Torvalds authored
    This creates three helper functions that do the TS_USEDFPU accesses, and
    makes everybody that used to do it by hand use those helpers instead.
    
    In addition, there's a couple of helper functions for the "change both
    CR0.TS and TS_USEDFPU at the same time" case, and the places that do
    that together have been changed to use those.  That means that we have
    fewer random places that open-code this situation.
    
    The intent is partly to clarify the code without actually changing any
    semantics yet (since we clearly still have some hard to reproduce bug in
    this area), but also to make it much easier to use another approach
    entirely to caching the CR0.TS bit for software accesses.
    
    Right now we use a bit in the thread-info 'status' variable (this patch
    does not change that), but we might want to make it a full field of its
    own or even make it a per-cpu variable.
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    6d59d7a9
traps.c 19 KB