[PATCH 1/8] fpu/init: Get rid of two redundant clts() calls

From: Andy Lutomirski
Date: Mon Oct 31 2016 - 18:19:04 EST


CR0.TS is cleared by a direct CR0 write in fpu__init_cpu_generic().
We don't need to call clts() two more times right after that.

Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/kernel/fpu/init.c | 18 ------------------
1 file changed, 18 deletions(-)

diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
index 1a09d133c801..60dece392b3a 100644
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -10,15 +10,6 @@
#include <linux/init.h>

/*
- * Initialize the TS bit in CR0 according to the style of context-switches
- * we are using:
- */
-static void fpu__init_cpu_ctx_switch(void)
-{
- clts();
-}
-
-/*
* Initialize the registers found in all CPUs, CR0 and CR4:
*/
static void fpu__init_cpu_generic(void)
@@ -55,7 +46,6 @@ void fpu__init_cpu(void)
{
fpu__init_cpu_generic();
fpu__init_cpu_xstate();
- fpu__init_cpu_ctx_switch();
}

/*
@@ -290,14 +280,6 @@ void __init fpu__init_system(struct cpuinfo_x86 *c)
*/
fpu__init_cpu();

- /*
- * But don't leave CR0::TS set yet, as some of the FPU setup
- * methods depend on being able to execute FPU instructions
- * that will fault on a set TS, such as the FXSAVE in
- * fpu__init_system_mxcsr().
- */
- clts();
-
fpu__init_system_generic();
fpu__init_system_xstate_size_legacy();
fpu__init_system_xstate();
--
2.7.4