In preemptible kernel, only TIF_USEDFPU flag is reliable to distinguish
whether _init_fpu()/_restore_fp() is needed. Because the value of the
CP0_Status.CU1 isn't changed during preemption.
Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx>
---
arch/mips/loongson/loongson-3/cop2-ex.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/mips/loongson/loongson-3/cop2-ex.c b/arch/mips/loongson/loongson-3/cop2-ex.c
index 9182e8d..c1e9503 100644
--- a/arch/mips/loongson/loongson-3/cop2-ex.c
+++ b/arch/mips/loongson/loongson-3/cop2-ex.c
@@ -22,13 +22,13 @@
static int loongson_cu2_call(struct notifier_block *nfb, unsigned long action,
void *data)
{
- int fpu_enabled;
+ int fpu_owned;
int fr = !test_thread_flag(TIF_32BIT_FPREGS);
switch (action) {
case CU2_EXCEPTION:
preempt_disable();
- fpu_enabled = read_c0_status() & ST0_CU1;
+ fpu_owned = __is_fpu_owner();
if (!fr)
set_c0_status(ST0_CU1 | ST0_CU2);
else
@@ -39,8 +39,8 @@ static int loongson_cu2_call(struct notifier_block *nfb, unsigned long action,
KSTK_STATUS(current) |= ST0_FR;
else
KSTK_STATUS(current) &= ~ST0_FR;
- /* If FPU is enabled, we needn't init or restore fp */
- if(!fpu_enabled) {
+ /* If FPU is owned, we needn't init or restore fp */
+ if(!fpu_owned) {
set_thread_flag(TIF_USEDFPU);
if (!used_math()) {
_init_fpu();
--
1.7.7.3
