c0e9587841
Rather than trying to (inaccurately) decode the cache type from the registers each time we need to decide what type of cache we have, use a bitmask initialized early during boot. Since the setup is a one-off initialization, we can be a little more clever and take account of the CPU architecture as well. Note that we continue to achieve the compactness on optimised kernels by forcing tests to always-false or always-true as appropriate, thereby allowing the compiler to do build-time code elimination. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
53 lines
1.6 KiB
C
53 lines
1.6 KiB
C
#ifndef __ASM_ARM_CACHETYPE_H
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#define __ASM_ARM_CACHETYPE_H
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#define CACHEID_VIVT (1 << 0)
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#define CACHEID_VIPT_NONALIASING (1 << 1)
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#define CACHEID_VIPT_ALIASING (1 << 2)
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#define CACHEID_VIPT (CACHEID_VIPT_ALIASING|CACHEID_VIPT_NONALIASING)
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#define CACHEID_ASID_TAGGED (1 << 3)
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extern unsigned int cacheid;
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#define cache_is_vivt() cacheid_is(CACHEID_VIVT)
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#define cache_is_vipt() cacheid_is(CACHEID_VIPT)
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#define cache_is_vipt_nonaliasing() cacheid_is(CACHEID_VIPT_NONALIASING)
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#define cache_is_vipt_aliasing() cacheid_is(CACHEID_VIPT_ALIASING)
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#define icache_is_vivt_asid_tagged() cacheid_is(CACHEID_ASID_TAGGED)
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/*
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* __LINUX_ARM_ARCH__ is the minimum supported CPU architecture
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* Mask out support which will never be present on newer CPUs.
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* - v6+ is never VIVT
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* - v7+ VIPT never aliases
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*/
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#if __LINUX_ARM_ARCH__ >= 7
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#define __CACHEID_ARCH_MIN (CACHEID_VIPT_NONALIASING | CACHEID_ASID_TAGGED)
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#elif __LINUX_ARM_ARCH__ >= 6
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#define __CACHEID_ARCH_MIN (~CACHEID_VIVT)
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#else
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#define __CACHEID_ARCH_MIN (~0)
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#endif
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/*
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* Mask out support which isn't configured
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*/
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#if defined(CONFIG_CPU_CACHE_VIVT) && !defined(CONFIG_CPU_CACHE_VIPT)
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#define __CACHEID_ALWAYS (CACHEID_VIVT)
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#define __CACHEID_NEVER (~CACHEID_VIVT)
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#elif !defined(CONFIG_CPU_CACHE_VIVT) && defined(CONFIG_CPU_CACHE_VIPT)
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#define __CACHEID_ALWAYS (0)
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#define __CACHEID_NEVER (CACHEID_VIVT)
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#else
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#define __CACHEID_ALWAYS (0)
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#define __CACHEID_NEVER (0)
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#endif
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static inline unsigned int __attribute__((pure)) cacheid_is(unsigned int mask)
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{
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return (__CACHEID_ALWAYS & mask) |
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(~__CACHEID_NEVER & __CACHEID_ARCH_MIN & mask & cacheid);
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}
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#endif
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