1 files changed, 27 insertions, 4 deletions

diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index a59dcb5ab5fc..574269ed2232 100644
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -50,6 +50,7 @@ extern unsigned int processor_id;
                     : "cc");                                            \
                 __val;                                                  \
         })
+
 #define read_cpuid_ext(ext_reg)                                         \
         ({                                                              \
                 unsigned int __val;                                     \
@@ -59,12 +60,25 @@ extern unsigned int processor_id;
                     : "cc");                                            \
                 __val;                                                  \
         })
-#else
-#define read_cpuid(reg) (processor_id)
-#define read_cpuid_ext(reg) 0
-#endif
+
+#else /* ifdef CONFIG_CPU_CP15 */
 
 /*
+ * read_cpuid and read_cpuid_ext should only ever be called on machines that
+ * have cp15 so warn on other usages.
+ */
+#define read_cpuid(reg)                                                 \
+        ({                                                              \
+                WARN_ON_ONCE(1);                                        \
+                0;                                                      \
+        })
+
+#define read_cpuid_ext(reg) read_cpuid(reg)
+
+#endif /* ifdef CONFIG_CPU_CP15 / else */
+
+#ifdef CONFIG_CPU_CP15
+/*
  * The CPU ID never changes at run time, so we might as well tell the
  * compiler that it's constant.  Use this function to read the CPU ID
  * rather than directly reading processor_id or read_cpuid() directly.
@@ -74,6 +88,15 @@ static inline unsigned int __attribute_const__ read_cpuid_id(void)
         return read_cpuid(CPUID_ID);
 }
 
+#else /* ifdef CONFIG_CPU_CP15 */
+
+static inline unsigned int __attribute_const__ read_cpuid_id(void)
+{
+        return processor_id;
+}
+
+#endif /* ifdef CONFIG_CPU_CP15 / else */
+
 static inline unsigned int __attribute_const__ read_cpuid_cachetype(void)
 {
         return read_cpuid(CPUID_CACHETYPE);