• Ingo Molnar's avatar
    x86/fpu: Introduce cpu_has_xfeatures(xfeatures_mask, feature_name) · 5b073430
    Ingo Molnar authored
    A lot of FPU using driver code is querying complex CPU features to be
    able to figure out whether a given set of xstate features is supported
    by the CPU or not.
    
    Introduce a simplified API function that can be used on any CPU type
    to get this information. Also add an error string return pointer,
    so that the driver can print a meaningful error message with a
    standardized feature name.
    
    Also mark xfeatures_mask as __read_only.
    
    Cc: Andy Lutomirski <luto@amacapital.net>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Dave Hansen <dave.hansen@linux.intel.com>
    Cc: Fenghua Yu <fenghua.yu@intel.com>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Oleg Nesterov <oleg@redhat.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
    5b073430
xstate.c 19.7 KB