x86, fpu: enable eagerfpu by default for xsaveopt
xsaveopt/xrstor support optimized state save/restore by tracking the
INIT state and MODIFIED state during context-switch.
Enable eagerfpu by default for processors supporting xsaveopt.
Can be disabled by passing "eagerfpu=off" boot parameter.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1347300665-6209-3-git-send-email-suresh.b.siddha@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index c0afd2c..e99f754 100644
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -557,6 +557,9 @@
prepare_fx_sw_frame();
setup_init_fpu_buf();
+ if (cpu_has_xsaveopt && !disable_eagerfpu)
+ setup_force_cpu_cap(X86_FEATURE_EAGER_FPU);
+
pr_info("enabled xstate_bv 0x%llx, cntxt size 0x%x\n",
pcntxt_mask, xstate_size);
}