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authorSebastian Siewior <bigeasy@linutronix.de>2008-05-01 12:16:29 +1000
committerLinus Torvalds <torvalds@linux-foundation.org>2008-05-01 08:08:35 -0700
commita19325a77432338d2710b3ebbe7fd8e6627e81e3 (patch)
treeda28058ae14e32e2aeaebffd3c2eba2b31a7adda /arch/m68knommu
parent2d7f16d6d12682c41fb287ea8261df8e4679f638 (diff)
downloadlinux-a19325a77432338d2710b3ebbe7fd8e6627e81e3.tar.gz
m68knommu: ColdFire add support for kernel preemption
As the subject says this patch adds the support for kernel preemption
on m68knommu Coldfire. I thing the same changes could be applied to
68360 & 68328 but since I don't have the HW for testing, I don't touch it.

Signed-off-by: Sebastian Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/m68knommu')
-rw-r--r--arch/m68knommu/kernel/asm-offsets.c1
-rw-r--r--arch/m68knommu/platform/coldfire/entry.S16
2 files changed, 17 insertions, 0 deletions
diff --git a/arch/m68knommu/kernel/asm-offsets.c b/arch/m68knommu/kernel/asm-offsets.c
index fd0c685a7f11..c785d07c02cc 100644
--- a/arch/m68knommu/kernel/asm-offsets.c
+++ b/arch/m68knommu/kernel/asm-offsets.c
@@ -87,6 +87,7 @@ int main(void)
 	DEFINE(TI_TASK, offsetof(struct thread_info, task));
 	DEFINE(TI_EXECDOMAIN, offsetof(struct thread_info, exec_domain));
 	DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
+	DEFINE(TI_PREEMPTCOUNT, offsetof(struct thread_info, preempt_count));
 	DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
 
 	return 0;
diff --git a/arch/m68knommu/platform/coldfire/entry.S b/arch/m68knommu/platform/coldfire/entry.S
index 111b66dc737b..1af7c1d650f6 100644
--- a/arch/m68knommu/platform/coldfire/entry.S
+++ b/arch/m68knommu/platform/coldfire/entry.S
@@ -106,6 +106,22 @@ ret_from_exception:
 	btst	#5,%sp@(PT_SR)		/* check if returning to kernel */
 	jeq	Luser_return		/* if so, skip resched, signals */
 
+#ifdef CONFIG_PREEMPT
+	movel	%sp,%d1			/* get thread_info pointer */
+	andl	#-THREAD_SIZE,%d1	/* at base of kernel stack */
+	movel	%d1,%a0
+	movel	%a0@(TI_FLAGS),%d1	/* get thread_info->flags */
+	andl	#_TIF_NEED_RESCHED,%d1
+	jeq	Lkernel_return
+
+	movel	%a0@(TI_PREEMPTCOUNT),%d1
+	cmpl	#0,%d1
+	jne	Lkernel_return
+
+	pea	Lkernel_return
+	jmp	preempt_schedule_irq	/* preempt the kernel */
+#endif
+
 Lkernel_return:
 	moveml	%sp@,%d1-%d5/%a0-%a2
 	lea	%sp@(32),%sp		/* space for 8 regs */