x86_32-use-kmap-switch-for-non-highmem-as-well.patch

Subject: x86/32: Use kmap switch for non highmem as well
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 13 Feb 2013 10:59:53 +0100

Even with CONFIG_HIGHMEM=n we need to take care of the "atomic"
mappings which are installed via iomap_atomic.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable-rt@vger.kernel.org
---
 arch/x86/kernel/process_32.c |    2 +-
 include/linux/sched.h        |    4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

Index: linux-stable/arch/x86/kernel/process_32.c
===================================================================
--- linux-stable.orig/arch/x86/kernel/process_32.c
+++ linux-stable/arch/x86/kernel/process_32.c
@@ -277,7 +277,7 @@ __switch_to(struct task_struct *prev_p, 
 		     task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT))
 		__switch_to_xtra(prev_p, next_p, tss);
 
-#if defined CONFIG_PREEMPT_RT_FULL && defined CONFIG_HIGHMEM
+#ifdef CONFIG_PREEMPT_RT_FULL
 	/*
 	 * Save @prev's kmap_atomic stack
 	 */
Index: linux-stable/include/linux/sched.h
===================================================================
--- linux-stable.orig/include/linux/sched.h
+++ linux-stable/include/linux/sched.h
@@ -1621,9 +1621,11 @@ struct task_struct {
 	int softirq_nestcnt;
 	unsigned int softirqs_raised;
 #endif
-#if defined CONFIG_PREEMPT_RT_FULL && defined CONFIG_HIGHMEM
+#ifdef CONFIG_PREEMPT_RT_FULL
+# if defined CONFIG_HIGHMEM || defined CONFIG_X86_32
 	int kmap_idx;
 	pte_t kmap_pte[KM_TYPE_NR];
+# endif
 #endif
 
 #ifdef CONFIG_DEBUG_PREEMPT