Fix preempt on PPC32 - have to set PREEMPT_ACTIVE when preempting kernel stuff.

arch/ppc/kernel/entry.S

@@ -531,12 +531,27 @@ restore_user:
 resume_kernel:
 	/* check current_thread_info->preempt_count */
 	rlwinm	r9,r1,0,0,18
-	lwz	r3,TI_PREEMPT(r9)
-	cmpwi	0,r3,0		/* if non-zero, just restore regs and return */
+	lwz	r0,TI_PREEMPT(r9)
+	cmpwi	0,r0,0		/* if non-zero, just restore regs and return */
 	bne	restore
-	lwz	r9,TI_FLAGS(r9)
-	andi.	r0,r9,_TIF_NEED_RESCHED
-	bne	do_resched
+	lwz	r0,TI_FLAGS(r9)
+	andi.	r0,r0,_TIF_NEED_RESCHED
+	beq+	restore
+	andi.	r0,r3,MSR_EE	/* interrupts off? */
+	beq	restore		/* don't schedule if so */
+1:	lis	r0,PREEMPT_ACTIVE@h
+	stw	r0,TI_PREEMPT(r9)
+	ori	r10,r10,MSR_EE
+	SYNC
+	MTMSRD(r10)		/* hard-enable interrupts */
+	bl	schedule
+	LOAD_MSR_KERNEL(r10,MSR_KERNEL)
+	SYNC
+	MTMSRD(r10)		/* disable interrupts */
+	rlwinm	r9,r1,0,0,18
+	lwz	r0,TI_FLAGS(r9)
+	andi.	r0,r0,_TIF_NEED_RESCHED
+	bne-	1b
 #else
 resume_kernel:
 #endif /* CONFIG_PREEMPT */
@@ -740,13 +755,6 @@ recheck:
 	lwz	r9,TI_FLAGS(r9)
 	andi.	r0,r9,_TIF_NEED_RESCHED
 	bne-	do_resched
-
-#ifdef CONFIG_PREEMPT
-	lwz	r0,_MSR(r1)
-	andi.	r0,r0,MSR_PR
-	beq	restore
-#endif
-
 	andi.	r0,r9,_TIF_SIGPENDING
 	beq	restore_user
 do_user_signal:			/* r10 contains MSR_KERNEL here */

arch/ppc/kernel/l2cr.S

@@ -272,10 +272,6 @@ BEGIN_FTR_SECTION
 	blr
 END_FTR_SECTION_IFCLR(CPU_FTR_L3CR)
 
-	/* Stop DST streams */
-	DSSALL
-	sync
-	
 	/* Turn off interrupts and data relocation. */
 	mfmsr	r7		/* Save MSR in r7 */
 	rlwinm	r4,r7,0,17,15
@@ -284,6 +280,10 @@ END_FTR_SECTION_IFCLR(CPU_FTR_L3CR)
 	mtmsr	r4
 	isync
 
+	/* Stop DST streams */
+	DSSALL
+	sync
+	
 	/* Get the current enable bit of the L3CR into r4 */
 	mfspr	r4,SPRN_L3CR