--- zzzz-none-000/linux-3.10.107/arch/mips/kernel/r2300_switch.S	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/mips/kernel/r2300_switch.S	2021-02-04 17:41:59.000000000 +0000
@@ -31,18 +31,8 @@
 #define ST_OFF (_THREAD_SIZE - 32 - PT_SIZE + PT_STATUS)
 
 /*
- * FPU context is saved iff the process has used it's FPU in the current
- * time slice as indicated by TIF_USEDFPU.  In any case, the CU1 bit for user
- * space STATUS register should be 0, so that a process *always* starts its
- * userland with FPU disabled after each context switch.
- *
- * FPU will be enabled as soon as the process accesses FPU again, through
- * do_cpu() trap.
- */
-
-/*
  * task_struct *resume(task_struct *prev, task_struct *next,
- *		       struct thread_info *next_ti, int usedfpu)
+ *		       struct thread_info *next_ti)
  */
 LEAF(resume)
 	mfc0	t1, CP0_STATUS
@@ -50,22 +40,13 @@
 	cpu_save_nonscratch a0
 	sw	ra, THREAD_REG31(a0)
 
-	beqz	a3, 1f
-
-	PTR_L	t3, TASK_THREAD_INFO(a0)
+#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
+	PTR_LA	t8, __stack_chk_guard
+	LONG_L	t9, TASK_STACK_CANARY(a1)
+	LONG_S	t9, 0(t8)
+#endif
 
 	/*
-	 * clear saved user stack CU1 bit
-	 */
-	lw	t0, ST_OFF(t3)
-	li	t1, ~ST0_CU1
-	and	t0, t0, t1
-	sw	t0, ST_OFF(t3)
-
-	fpu_save_single a0, t0			# clobbers t0
-
-1:
-	/*
 	 * The order of restoring the registers takes care of the race
 	 * updating $28, $29 and kernelsp without disabling ints.
 	 */
@@ -108,10 +89,11 @@
  * the property that no matter whether considered as single or as double
  * precision represents signaling NANS.
  *
- * We initialize fcr31 to rounding to nearest, no exceptions.
+ * The value to initialize fcr31 to comes in $a0.
  */
 
-#define FPU_DEFAULT  0x00000000
+	.set push
+	SET_HARDFLOAT
 
 LEAF(_init_fpu)
 	mfc0	t0, CP0_STATUS
@@ -119,8 +101,7 @@
 	or	t0, t1
 	mtc0	t0, CP0_STATUS
 
-	li	t1, FPU_DEFAULT
-	ctc1	t1, fcr31
+	ctc1	a0, fcr31
 
 	li	t0, -1
 
@@ -158,3 +139,5 @@
 	mtc1	t0, $f31
 	jr	ra
 	END(_init_fpu)
+
+	.set pop