commit a8e23a291852cd7c4fb5ca696dbb93912185ad10
author Peter Zijlstra <a.p.zijlstra@chello.nl> Wed Oct 27 15:32:57 2010 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> Wed Oct 27 18:03:05 2010 -0700
tree df0cf7cfe8d8600563a96cb5426de69759165e52
parent 12ba8d1e9262ce81a695795410bd9ee5c9407ba1

mm,x86: fix kmap_atomic_push vs ioremap_32.c

It appears i386 uses kmap_atomic infrastructure regardless of
CONFIG_HIGHMEM which results in a compile error when highmem is disabled.

Cure this by providing the needed few bits for both CONFIG_HIGHMEM and
CONFIG_X86_32.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/highmem.h

diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 8a85ec1..102f76b 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -37,27 +37,6 @@
 
 void kmap_flush_unused(void);
 
-DECLARE_PER_CPU(int, __kmap_atomic_idx);
-
-static inline int kmap_atomic_idx_push(void)
-{
-	int idx = __get_cpu_var(__kmap_atomic_idx)++;
-#ifdef CONFIG_DEBUG_HIGHMEM
-	WARN_ON_ONCE(in_irq() && !irqs_disabled());
-	BUG_ON(idx > KM_TYPE_NR);
-#endif
-	return idx;
-}
-
-static inline int kmap_atomic_idx_pop(void)
-{
-	int idx = --__get_cpu_var(__kmap_atomic_idx);
-#ifdef CONFIG_DEBUG_HIGHMEM
-	BUG_ON(idx < 0);
-#endif
-	return idx;
-}
-
 #else /* CONFIG_HIGHMEM */
 
 static inline unsigned int nr_free_highpages(void) { return 0; }
@@ -95,6 +74,31 @@
 
 #endif /* CONFIG_HIGHMEM */
 
+#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
+
+DECLARE_PER_CPU(int, __kmap_atomic_idx);
+
+static inline int kmap_atomic_idx_push(void)
+{
+	int idx = __get_cpu_var(__kmap_atomic_idx)++;
+#ifdef CONFIG_DEBUG_HIGHMEM
+	WARN_ON_ONCE(in_irq() && !irqs_disabled());
+	BUG_ON(idx > KM_TYPE_NR);
+#endif
+	return idx;
+}
+
+static inline int kmap_atomic_idx_pop(void)
+{
+	int idx = --__get_cpu_var(__kmap_atomic_idx);
+#ifdef CONFIG_DEBUG_HIGHMEM
+	BUG_ON(idx < 0);
+#endif
+	return idx;
+}
+
+#endif
+
 /*
  * Make both: kmap_atomic(page, idx) and kmap_atomic(page) work.
  */

mm/highmem.c

diff --git a/mm/highmem.c b/mm/highmem.c
index 781e754..693394d 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -29,6 +29,11 @@
 #include <linux/kgdb.h>
 #include <asm/tlbflush.h>
 
+
+#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
+DEFINE_PER_CPU(int, __kmap_atomic_idx);
+#endif
+
 /*
  * Virtual_count is not a pure "count".
  *  0 means that it is not mapped, and has not been mapped
@@ -43,7 +48,6 @@
 EXPORT_SYMBOL(totalhigh_pages);
 
 
-DEFINE_PER_CPU(int, __kmap_atomic_idx);
 EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx);
 
 unsigned int nr_free_highpages (void)