sh: Fix occasional FPU register corruption under preempt.

Presently with preempt enabled there's the possibility to be preempted
after the TIF_USEDFPU test and the register save, leading to bogus
state post-__switch_to(). Use an explicit preempt_disable()/enable()
pair around unlazy_fpu()/clear_fpu() to avoid this. Follows the x86
change.

Reported-by: Takuo Koguchi <takuo.koguchi.sw@hitachi.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/asm-sh/processor_32.h b/include/asm-sh/processor_32.h
index df2d5b039ef4..c09305d6a9d9 100644
--- a/include/asm-sh/processor_32.h
+++ b/include/asm-sh/processor_32.h
@@ -70,6 +70,7 @@ extern struct sh_cpuinfo cpu_data[];
  */
 #define SR_DSP          0x00001000
 #define SR_IMASK        0x000000f0
+#define SR_FD           0x00008000
 
 /*
  * FPU structure and data