arm64/ipipe: Modifications of 3.18 arm64 support

__this_cpu_ptr equivilant is raw_cpu_ptr, not this_cpu_ptr.
Restore need_resched check in arch_cpu_idle.
Remove unused __ipipe_stall_root function.

arch/arm64/kernel/ipipe.c

@@ -315,12 +315,6 @@ asmlinkage int __ipipe_check_root_interruptible(void)
 	return __ipipe_root_p && !irqs_disabled();
 }
 
-
-asmlinkage void __ipipe_stall_root(void)
-{
-	ipipe_stall_root();
-}
-
 __kprobes int
 __ipipe_switch_to_notifier_call_chain(struct atomic_notifier_head *nh,
 				      unsigned long val, void *v)
@@ -467,7 +461,7 @@ asmlinkage void __exception __ipipe_grab_irq(int irq, struct pt_regs *regs)
 
 static void __ipipe_do_IRQ(unsigned irq, void *cookie)
 {
-	struct pt_regs *regs = this_cpu_ptr(&ipipe_percpu.tick_regs);
+	struct pt_regs *regs = raw_cpu_ptr(&ipipe_percpu.tick_regs);
 	__handle_domain_irq(NULL, irq, false, regs);
 }
 
@@ -477,7 +471,7 @@ void __switch_mm_inner(struct mm_struct *prev, struct mm_struct *next,
 {
 #ifdef CONFIG_IPIPE_WANT_ACTIVE_MM
 	struct mm_struct ** const active_mm =
-		this_cpu_ptr(&ipipe_percpu.active_mm);
+		raw_cpu_ptr(&ipipe_percpu.active_mm);
 #endif /* CONFIG_IPIPE_WANT_ACTIVE_MM */
 #ifdef CONFIG_IPIPE_WANT_PREEMPTIBLE_SWITCH
 	struct thread_info *const tip = current_thread_info();
@@ -534,7 +528,7 @@ void deferred_switch_mm(struct mm_struct *next)
 {
 #ifdef CONFIG_IPIPE_WANT_ACTIVE_MM
 	struct mm_struct ** const active_mm =
-		this_cpu_ptr(&ipipe_percpu.active_mm);
+		raw_cpu_ptr(&ipipe_percpu.active_mm);
 	struct mm_struct *prev = *active_mm;
 #endif /* CONFIG_IPIPE_WANT_ACTIVE_MM */
 #ifdef CONFIG_IPIPE_WANT_PREEMPTIBLE_SWITCH

arch/arm64/kernel/process.c

@@ -110,7 +110,8 @@ void arch_cpu_idle(void)
 	 * This should do all the clock switching and wait for interrupt
 	 * tricks
 	 */
-	__ipipe_halt_root();
+	if (!need_resched())
+		__ipipe_halt_root();
 	local_irq_enable();
 }
 

arch/arm64/kernel/smp.c

@@ -560,8 +560,7 @@ EXPORT_SYMBOL_GPL(__ipipe_first_ipi);
 static void  __ipipe_do_IPI(unsigned virq, void *cookie)
 {
 	enum ipi_msg_type msg = virq - IPIPE_IPI_BASE;
-	struct pt_regs *p = this_cpu_ptr(&ipipe_percpu.tick_regs);
-	handle_IPI(msg, p);
+	handle_IPI(msg, raw_cpu_ptr(&ipipe_percpu.tick_regs));
 }
 
 void __ipipe_ipis_alloc(void)