From 0336d8765856a96d3205c90b3ff9672e3304e756 Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: Mon, 26 Oct 2009 19:41:17 +0000
Subject: [PATCH] --- yaml --- r: 167873 b: refs/heads/master c:
 4f917ba3d5ee9c98d60fa357e799942df8412de3 h: refs/heads/master i:   167871:
 d0341705d5f2541d534b736be540f878e767c127 v: v3

---
 [refs]                               |  2 +-
 trunk/arch/powerpc/kernel/entry_64.S | 41 ++++++++++++++--------------
 2 files changed, 22 insertions(+), 21 deletions(-)

diff --git a/[refs] b/[refs]
index f1bfcff90842..2e37b4cd5c32 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 01deab98e3ad8ff27243a8d5f8dd746c7110ae4f
+refs/heads/master: 4f917ba3d5ee9c98d60fa357e799942df8412de3
diff --git a/trunk/arch/powerpc/kernel/entry_64.S b/trunk/arch/powerpc/kernel/entry_64.S
index f9fd54bfcc84..9763267e38b4 100644
--- a/trunk/arch/powerpc/kernel/entry_64.S
+++ b/trunk/arch/powerpc/kernel/entry_64.S
@@ -658,42 +658,43 @@ do_work:
 	cmpdi	r0,0
 	crandc	eq,cr1*4+eq,eq
 	bne	restore
-	/* here we are preempting the current task */
-1:
-#ifdef CONFIG_TRACE_IRQFLAGS
-	bl	.trace_hardirqs_on
-	/* Note: we just clobbered r10 which used to contain the previous
-	 * MSR before the hard-disabling done by the caller of do_work.
-	 * We don't have that value anymore, but it doesn't matter as
-	 * we will hard-enable unconditionally, we can just reload the
-	 * current MSR into r10
+
+	/* Here we are preempting the current task.
+	 *
+	 * Ensure interrupts are soft-disabled. We also properly mark
+	 * the PACA to reflect the fact that they are hard-disabled
+	 * and trace the change
 	 */
-	mfmsr	r10
-#endif /* CONFIG_TRACE_IRQFLAGS */
-	li	r0,1
+	li	r0,0
 	stb	r0,PACASOFTIRQEN(r13)
 	stb	r0,PACAHARDIRQEN(r13)
+	TRACE_DISABLE_INTS
+
+	/* Call the scheduler with soft IRQs off */
+1:	bl	.preempt_schedule_irq
+
+	/* Hard-disable interrupts again (and update PACA) */
 #ifdef CONFIG_PPC_BOOK3E
-	wrteei	1
-	bl	.preempt_schedule
 	wrteei	0
 #else
-	ori	r10,r10,MSR_EE
-	mtmsrd	r10,1		/* reenable interrupts */
-	bl	.preempt_schedule
 	mfmsr	r10
-	clrrdi	r9,r1,THREAD_SHIFT
-	rldicl	r10,r10,48,1	/* disable interrupts again */
+	rldicl	r10,r10,48,1
 	rotldi	r10,r10,16
 	mtmsrd	r10,1
 #endif /* CONFIG_PPC_BOOK3E */
+	li	r0,0
+	stb	r0,PACAHARDIRQEN(r13)
+
+	/* Re-test flags and eventually loop */
+	clrrdi	r9,r1,THREAD_SHIFT
 	ld	r4,TI_FLAGS(r9)
 	andi.	r0,r4,_TIF_NEED_RESCHED
 	bne	1b
 	b	restore
 
 user_work:
-#endif
+#endif /* CONFIG_PREEMPT */
+
 	/* Enable interrupts */
 #ifdef CONFIG_PPC_BOOK3E
 	wrteei	1