1. 30 1月, 2016 2 次提交
    • B
      x86/cpufeature: Replace the old static_cpu_has() with safe variant · bc696ca0
      Borislav Petkov 提交于
      So the old one didn't work properly before alternatives had run.
      And it was supposed to provide an optimized JMP because the
      assumption was that the offset it is jumping to is within a
      signed byte and thus a two-byte JMP.
      
      So I did an x86_64 allyesconfig build and dumped all possible
      sites where static_cpu_has() was used. The optimization amounted
      to all in all 12(!) places where static_cpu_has() had generated
      a 2-byte JMP. Which has saved us a whopping 36 bytes!
      
      This clearly is not worth the trouble so we can remove it. The
      only place where the optimization might count - in __switch_to()
      - we will handle differently. But that's not subject of this
      patch.
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1453842730-28463-6-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      bc696ca0
    • B
      x86/cpufeature: Carve out X86_FEATURE_* · cd4d09ec
      Borislav Petkov 提交于
      Move them to a separate header and have the following
      dependency:
      
        x86/cpufeatures.h <- x86/processor.h <- x86/cpufeature.h
      
      This makes it easier to use the header in asm code and not
      include the whole cpufeature.h and add guards for asm.
      Suggested-by: NH. Peter Anvin <hpa@zytor.com>
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1453842730-28463-5-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      cd4d09ec
  2. 29 1月, 2016 8 次提交
  3. 27 1月, 2016 1 次提交
  4. 24 1月, 2016 29 次提交