3 files changed, 24 insertions, 1 deletions

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index e62a4ccea54d..69ee5b7517ec 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -97,7 +97,7 @@ static ssize_t show_crash_notes(struct sys_device *dev, struct sysdev_attribute
          * boot up and this data does not change there after. Hence this
          * operation should be safe. No locking required.
          */
-        addr = __pa(per_cpu_ptr(crash_notes, cpunum));
+        addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum));
         rc = sprintf(buf, "%Lx\n", addr);
         return rc;
 }
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 878836ca999c..6ac984fa34f8 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -154,6 +154,7 @@ struct percpu_data {
 
 extern void *__alloc_percpu(size_t size, size_t align);
 extern void free_percpu(void *__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);
diff --git a/mm/percpu.c b/mm/percpu.c
index 5adfc268b408..008fbd9e6fa4 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -74,6 +74,7 @@
 #include <asm/cacheflush.h>
 #include <asm/sections.h>
 #include <asm/tlbflush.h>
+#include <asm/io.h>
 
 #define PCPU_SLOT_BASE_SHIFT            5       /* 1-31 shares the same slot */
 #define PCPU_DFL_MAP_ALLOC              16      /* start a map with 16 ents */
@@ -1302,6 +1303,27 @@ void free_percpu(void *ptr)
 }
 EXPORT_SYMBOL_GPL(free_percpu);
 
+/**
+ * per_cpu_ptr_to_phys - convert translated percpu address to physical address
+ * @addr: the address to be converted to physical address
+ *
+ * Given @addr which is dereferenceable address obtained via one of
+ * percpu access macros, this function translates it into its physical
+ * address.  The caller is responsible for ensuring @addr stays valid
+ * until this function finishes.
+ *
+ * RETURNS:
+ * The physical address for @addr.
+ */
+phys_addr_t per_cpu_ptr_to_phys(void *addr)
+{
+        if ((unsigned long)addr < VMALLOC_START ||
+                        (unsigned long)addr >= VMALLOC_END)
+                return __pa(addr);
+        else
+                return page_to_phys(vmalloc_to_page(addr));
+}
+
 static inline size_t pcpu_calc_fc_sizes(size_t static_size,
                                         size_t reserved_size,
                                         ssize_t *dyn_sizep)