3 files changed, 40 insertions, 26 deletions

diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index a93e5bfdccb8..c7845130bfdf 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -2,10 +2,10 @@
 #define __LINUX_PERCPU_H
 
 #include <linux/preempt.h>
-#include <linux/slab.h> /* For kmalloc() */
 #include <linux/smp.h>
 #include <linux/cpumask.h>
 #include <linux/pfn.h>
+#include <linux/init.h>
 
 #include <asm/percpu.h>
 
@@ -135,9 +135,6 @@ extern int __init pcpu_page_first_chunk(size_t reserved_size,
 #define per_cpu_ptr(ptr, cpu)   SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
 
 extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
-extern void __percpu *__alloc_percpu(size_t size, size_t align);
-extern void free_percpu(void __percpu *__pdata);
-extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
 
 #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
 extern void __init setup_per_cpu_areas(void);
@@ -147,27 +144,6 @@ extern void __init setup_per_cpu_areas(void);
 
 #define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
 
-static inline void __percpu *__alloc_percpu(size_t size, size_t align)
-{
-        /*
-         * Can't easily make larger alignment work with kmalloc.  WARN
-         * on it.  Larger alignment should only be used for module
-         * percpu sections on SMP for which this path isn't used.
-         */
-        WARN_ON_ONCE(align > SMP_CACHE_BYTES);
-        return kzalloc(size, GFP_KERNEL);
-}
-
-static inline void free_percpu(void __percpu *p)
-{
-        kfree(p);
-}
-
-static inline phys_addr_t per_cpu_ptr_to_phys(void *addr)
-{
-        return __pa(addr);
-}
-
 static inline void __init setup_per_cpu_areas(void) { }
 
 static inline void *pcpu_lpage_remapped(void *kaddr)
@@ -177,6 +153,10 @@ static inline void *pcpu_lpage_remapped(void *kaddr)
 
 #endif /* CONFIG_SMP */
 
+extern void __percpu *__alloc_percpu(size_t size, size_t align);
+extern void free_percpu(void __percpu *__pdata);
+extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
+
 #define alloc_percpu(type)      \
         (typeof(type) __percpu *)__alloc_percpu(sizeof(type), __alignof__(type))
 
diff --git a/mm/Makefile b/mm/Makefile
index 7a68d2ab5560..6c2a73a54a43 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -33,7 +33,11 @@ obj-$(CONFIG_FAILSLAB) += failslab.o
 obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o
 obj-$(CONFIG_FS_XIP) += filemap_xip.o
 obj-$(CONFIG_MIGRATION) += migrate.o
-obj-$(CONFIG_SMP) += percpu.o
+ifdef CONFIG_SMP
+obj-y += percpu.o
+else
+obj-y += percpu_up.o
+endif
 obj-$(CONFIG_QUICKLIST) += quicklist.o
 obj-$(CONFIG_CGROUP_MEM_RES_CTLR) += memcontrol.o page_cgroup.o
 obj-$(CONFIG_MEMORY_FAILURE) += memory-failure.o
diff --git a/mm/percpu_up.c b/mm/percpu_up.c
new file mode 100644
index 000000000000..c4351c7f57d2
--- /dev/null
+++ b/mm/percpu_up.c
@@ -0,0 +1,30 @@
+/*
+ * mm/percpu_up.c - dummy percpu memory allocator implementation for UP
+ */
+
+#include <linux/module.h>
+#include <linux/percpu.h>
+#include <linux/slab.h>
+
+void __percpu *__alloc_percpu(size_t size, size_t align)
+{
+        /*
+         * Can't easily make larger alignment work with kmalloc.  WARN
+         * on it.  Larger alignment should only be used for module
+         * percpu sections on SMP for which this path isn't used.
+         */
+        WARN_ON_ONCE(align > SMP_CACHE_BYTES);
+        return kzalloc(size, GFP_KERNEL);
+}
+EXPORT_SYMBOL_GPL(__alloc_percpu);
+
+void free_percpu(void __percpu *p)
+{
+        kfree(p);
+}
+EXPORT_SYMBOL_GPL(free_percpu);
+
+phys_addr_t per_cpu_ptr_to_phys(void *addr)
+{
+        return __pa(addr);
+}