[ARM] pxa: silence warnings from cpu_is_xxx() macros

If only a single CPU type is selected, __cpu_is_xxx() doesn't
use its argument.  This causes the compiler to issue a warning
about an unused variable in the parent function.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

include/asm-arm/arch-pxa/hardware.h

@@ -121,38 +121,32 @@
 
 #define cpu_is_pxa21x()					\
 	({						\
-		unsigned int id = read_cpuid(CPUID_ID);	\
-		__cpu_is_pxa21x(id);			\
+		__cpu_is_pxa21x(read_cpuid_id());	\
 	})
 
 #define cpu_is_pxa25x()					\
 	({						\
-		unsigned int id = read_cpuid(CPUID_ID);	\
-		__cpu_is_pxa25x(id);			\
+		__cpu_is_pxa25x(read_cpuid_id());	\
 	})
 
 #define cpu_is_pxa27x()					\
 	({						\
-		unsigned int id = read_cpuid(CPUID_ID);	\
-		__cpu_is_pxa27x(id);			\
+		__cpu_is_pxa27x(read_cpuid_id());	\
 	})
 
 #define cpu_is_pxa300()					\
 	({						\
-		unsigned int id = read_cpuid(CPUID_ID);	\
-		__cpu_is_pxa300(id);			\
+		__cpu_is_pxa300(read_cpuid_id());	\
 	 })
 
 #define cpu_is_pxa310()					\
 	({						\
-		unsigned int id = read_cpuid(CPUID_ID);	\
-		__cpu_is_pxa310(id);			\
+		__cpu_is_pxa310(read_cpuid_id());	\
 	 })
 
 #define cpu_is_pxa320()					\
 	({						\
-		unsigned int id = read_cpuid(CPUID_ID);	\
-		__cpu_is_pxa320(id);			\
+		__cpu_is_pxa320(read_cpuid_id());	\
 	 })
 
 /*
@@ -174,14 +168,12 @@
 
 #define cpu_is_pxa2xx()					\
 	({						\
-		unsigned int id = read_cpuid(CPUID_ID);	\
-		__cpu_is_pxa2xx(id);			\
+		__cpu_is_pxa2xx(read_cpuid_id());	\
 	 })
 
 #define cpu_is_pxa3xx()					\
 	({						\
-		unsigned int id = read_cpuid(CPUID_ID);	\
-		__cpu_is_pxa3xx(id);			\
+		__cpu_is_pxa3xx(read_cpuid_id());	\
 	 })
 
 /*

include/asm-arm/system.h

@@ -75,8 +75,21 @@
 #ifndef __ASSEMBLY__
 
 #include <linux/linkage.h>
+#include <linux/stringify.h>
 #include <linux/irqflags.h>
 
+/*
+ * 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.
+ */
+static inline unsigned int read_cpuid_id(void) __attribute_const__;
+
+static inline unsigned int read_cpuid_id(void)
+{
+	return read_cpuid(CPUID_ID);
+}
+
 #define __exception	__attribute__((section(".exception.text")))
 
 struct thread_info;