Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-13 07:31:45 +00:00
Code Issues Packages Projects Releases Wiki Activity

ARM: stub out read_cpuid and read_cpuid_ext for CPU_CP15=n

Browse Source 
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: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Message-Id: 1359646587-1788-2-git-send-email-u.kleine-koenig@pengutronix.de
This commit is contained in:
Uwe Kleine-König 2013-01-31 11:08:03 +01:00
parent ac52e83f4c
commit 6ebd4d038d
1 changed files with 27 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
arch/arm/include/asm/cputype.h
View File

@ -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);