x86/cpufeature: Speed up cpu_feature_enabled()
When GCC cannot do constant folding for this macro, it falls back to
cpu_has(). But static_cpu_has() is optimal and it works at all times
now. So use it and speedup the fallback case.
Before we had this:
mov 0x99d674(%rip),%rdx # ffffffff81b0d9f4 <boot_cpu_data+0x34>
shr $0x2e,%rdx
and $0x1,%edx
jne ffffffff811704e9 <do_munmap+0x3f9>
After alternatives patching, it turns into:
jmp 0xffffffff81170390
nopl (%rax)
...
callq ffffffff81056e00 <mpx_notify_unmap>
ffffffff81170390: mov 0x170(%r12),%rdi
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Joerg Roedel <joro@8bytes.org>
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/1455578358-28347-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1 file changed