From 678c668a7732f3a11c25ae86d5737a019667e3c5 Mon Sep 17 00:00:00 2001
From: Christophe Leroy <christophe.leroy@c-s.fr>
Date: Thu, 17 Jan 2019 23:26:56 +1100
Subject: [PATCH] powerpc/64: Use task_stack_page() to initialise paca->kstack

Rather than using the thread info use task_stack_page() to initialise
paca->kstack, that way it will work with THREAD_INFO_IN_TASK.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Split out of larger patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/kernel/smp.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 5366d9e7bed40..829ef5411b50b 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -20,6 +20,7 @@
 #include <linux/kernel.h>
 #include <linux/export.h>
 #include <linux/sched/mm.h>
+#include <linux/sched/task_stack.h>
 #include <linux/sched/topology.h>
 #include <linux/smp.h>
 #include <linux/interrupt.h>
@@ -984,7 +985,8 @@ static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
 
 #ifdef CONFIG_PPC64
 	paca_ptrs[cpu]->__current = idle;
-	paca_ptrs[cpu]->kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
+	paca_ptrs[cpu]->kstack = (unsigned long)task_stack_page(idle) +
+				 THREAD_SIZE - STACK_FRAME_OVERHEAD;
 #endif
 	ti->cpu = cpu;
 	secondary_ti = current_set[cpu] = ti;