[PATCH v2 4/6] x86/fpu: Fix "x86/fpu: Legacy x87 FPU detected" message

From: Andy Lutomirski
Date: Wed Jan 18 2017 - 14:16:02 EST


That message isn't at all clear -- what does "Legacy x87" even
mean?

Clarify it. If there's no FPU, say "x86/fpu: No FPU detected". If
there's an FPU that doesn't have XSAVE, say "x86/fpu: x87 FPU will use
FSAVE|FXSAVE".

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/kernel/fpu/xstate.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 1d7770447b3e..1691311e5b23 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -705,8 +705,14 @@ void __init fpu__init_system_xstate(void)
WARN_ON_FPU(!on_boot_cpu);
on_boot_cpu = 0;

+ if (!boot_cpu_has(X86_FEATURE_FPU)) {
+ pr_info("x86/fpu: No FPU detected.\n");
+ return;
+ }
+
if (!boot_cpu_has(X86_FEATURE_XSAVE)) {
- pr_info("x86/fpu: Legacy x87 FPU detected.\n");
+ pr_info("x86/fpu: x87 FPU will use %s.\n",
+ boot_cpu_has(X86_FEATURE_FXSR) ? "FXSAVE" : "FSAVE");
return;
}

--
2.9.3