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

From: Andy Lutomirski <luto@kernel.org>
To: X86 ML <x86@kernel.org>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
	Borislav Petkov <bp@alien8.de>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Brian Gerst <brgerst@gmail.com>,
	Matthew Whitehead <tedheadster@gmail.com>,
	Andy Lutomirski <luto@kernel.org>
Subject: [PATCH v2 4/6] x86/fpu: Fix "x86/fpu: Legacy x87 FPU detected" message
Date: Wed, 18 Jan 2017 11:15:40 -0800	[thread overview]
Message-ID: <bb839385e18e27bca23fe8666dfdad8170473045.1484705016.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1484705016.git.luto@kernel.org>
In-Reply-To: <cover.1484705016.git.luto@kernel.org>

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@kernel.org>
---
 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
