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Commit 6ebd4d03 authored by Uwe Kleine-König's avatar Uwe Kleine-König
Browse files

ARM: stub out read_cpuid and read_cpuid_ext for CPU_CP15=n 



Traditionally for !CPU_CP15 read_cpuid and read_cpuid_ext returned the
processor id independent of the parameter passed in. This is wrong of
course but theoretically this doesn't harm because it's only called on
machines having a cp15.

Instead return 0 unconditionally which might make unused code paths be
better optimizable and so smaller and warn about unexpected usage.

Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Message-Id: 1359646587-1788-2-git-send-email-u.kleine-koenig@pengutronix.de
parent ac52e83f

arch/arm/include/asm/cputype.h

+27 −4
Original line number Diff line number Diff line
@@ -50,6 +50,7 @@ extern unsigned int processor_id; 
		    : "cc");						\

		__val;							\

	})



#define read_cpuid_ext(ext_reg)						\

	({								\

		unsigned int __val;					\
@@ -59,11 +60,24 @@ 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
@@ -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);