1 files changed, 14 insertions, 105 deletions

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 916ddc4aac44..8a936723c791 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -618,9 +618,8 @@ static inline void check_stack_overflow(void)
 	sp = current_stack_pointer() & (THREAD_SIZE-1);
 
 	/* check for stack overflow: is there less than 2KB free? */
-	if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
-		pr_err("do_IRQ: stack overflow: %ld\n",
-			sp - sizeof(struct thread_info));
+	if (unlikely(sp < 2048)) {
+		pr_err("do_IRQ: stack overflow: %ld\n", sp);
 		dump_stack();
 	}
 #endif
@@ -660,36 +659,21 @@ void __do_irq(struct pt_regs *regs)
 void do_IRQ(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
-	struct thread_info *curtp, *irqtp, *sirqtp;
+	void *cursp, *irqsp, *sirqsp;
 
 	/* Switch to the irq stack to handle this */
-	curtp = current_thread_info();
-	irqtp = hardirq_ctx[raw_smp_processor_id()];
-	sirqtp = softirq_ctx[raw_smp_processor_id()];
+	cursp = (void *)(current_stack_pointer() & ~(THREAD_SIZE - 1));
+	irqsp = hardirq_ctx[raw_smp_processor_id()];
+	sirqsp = softirq_ctx[raw_smp_processor_id()];
 
 	/* Already there ? */
-	if (unlikely(curtp == irqtp || curtp == sirqtp)) {
+	if (unlikely(cursp == irqsp || cursp == sirqsp)) {
 		__do_irq(regs);
 		set_irq_regs(old_regs);
 		return;
 	}
-
-	/* Prepare the thread_info in the irq stack */
-	irqtp->task = curtp->task;
-	irqtp->flags = 0;
-
-	/* Copy the preempt_count so that the [soft]irq checks work. */
-	irqtp->preempt_count = curtp->preempt_count;
-
 	/* Switch stack and call */
-	call_do_irq(regs, irqtp);
-
-	/* Restore stack limit */
-	irqtp->task = NULL;
-
-	/* Copy back updates to the thread_info */
-	if (irqtp->flags)
-		set_bits(irqtp->flags, &curtp->flags);
+	call_do_irq(regs, irqsp);
 
 	set_irq_regs(old_regs);
 }
@@ -698,90 +682,20 @@ void __init init_IRQ(void)
 {
 	if (ppc_md.init_IRQ)
 		ppc_md.init_IRQ();
-
-	exc_lvl_ctx_init();
-
-	irq_ctx_init();
 }
 
 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
-struct thread_info   *critirq_ctx[NR_CPUS] __read_mostly;
-struct thread_info    *dbgirq_ctx[NR_CPUS] __read_mostly;
-struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly;
-
-void exc_lvl_ctx_init(void)
-{
-	struct thread_info *tp;
-	int i, cpu_nr;
-
-	for_each_possible_cpu(i) {
-#ifdef CONFIG_PPC64
-		cpu_nr = i;
-#else
-#ifdef CONFIG_SMP
-		cpu_nr = get_hard_smp_processor_id(i);
-#else
-		cpu_nr = 0;
-#endif
+void   *critirq_ctx[NR_CPUS] __read_mostly;
+void    *dbgirq_ctx[NR_CPUS] __read_mostly;
+void *mcheckirq_ctx[NR_CPUS] __read_mostly;
 #endif
 
-		memset((void *)critirq_ctx[cpu_nr], 0, THREAD_SIZE);
-		tp = critirq_ctx[cpu_nr];
-		tp->cpu = cpu_nr;
-		tp->preempt_count = 0;
-
-#ifdef CONFIG_BOOKE
-		memset((void *)dbgirq_ctx[cpu_nr], 0, THREAD_SIZE);
-		tp = dbgirq_ctx[cpu_nr];
-		tp->cpu = cpu_nr;
-		tp->preempt_count = 0;
-
-		memset((void *)mcheckirq_ctx[cpu_nr], 0, THREAD_SIZE);
-		tp = mcheckirq_ctx[cpu_nr];
-		tp->cpu = cpu_nr;
-		tp->preempt_count = HARDIRQ_OFFSET;
-#endif
-	}
-}
-#endif
-
-struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
-struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
-
-void irq_ctx_init(void)
-{
-	struct thread_info *tp;
-	int i;
-
-	for_each_possible_cpu(i) {
-		memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
-		tp = softirq_ctx[i];
-		tp->cpu = i;
-		klp_init_thread_info(tp);
-
-		memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
-		tp = hardirq_ctx[i];
-		tp->cpu = i;
-		klp_init_thread_info(tp);
-	}
-}
+void *softirq_ctx[NR_CPUS] __read_mostly;
+void *hardirq_ctx[NR_CPUS] __read_mostly;
 
 void do_softirq_own_stack(void)
 {
-	struct thread_info *curtp, *irqtp;
-
-	curtp = current_thread_info();
-	irqtp = softirq_ctx[smp_processor_id()];
-	irqtp->task = curtp->task;
-	irqtp->flags = 0;
-	call_do_softirq(irqtp);
-	irqtp->task = NULL;
-
-	/* Set any flag that may have been set on the
-	 * alternate stack
-	 */
-	if (irqtp->flags)
-		set_bits(irqtp->flags, &curtp->flags);
+	call_do_softirq(softirq_ctx[smp_processor_id()]);
 }
 
 irq_hw_number_t virq_to_hw(unsigned int virq)
@@ -827,11 +741,6 @@ int irq_choose_cpu(const struct cpumask *mask)
 }
 #endif
 
-int arch_early_irq_init(void)
-{
-	return 0;
-}
-
 #ifdef CONFIG_PPC64
 static int __init setup_noirqdistrib(char *str)
 {