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It turns out that the logical CPU mapping is useful even when !CONFIG_SMP for manipulation of devices like interrupt and power controllers when running a UP kernel on a CPU other than 0. This can happen when kexecing a UP image from an SMP kernel. In the future, multi-cluster systems running AMP configurations will require something similar for mapping cluster IDs, so it makes sense to decouple this logic in preparation for this support. Acked-by: Yang Bai <hamo.by@gmail.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reported-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
53 lines
978 B
C
53 lines
978 B
C
/*
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* ARM specific SMP header, this contains our implementation
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* details.
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*/
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#ifndef __ASMARM_SMP_PLAT_H
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#define __ASMARM_SMP_PLAT_H
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#include <asm/cputype.h>
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/*
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* Return true if we are running on a SMP platform
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*/
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static inline bool is_smp(void)
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{
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#ifndef CONFIG_SMP
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return false;
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#elif defined(CONFIG_SMP_ON_UP)
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extern unsigned int smp_on_up;
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return !!smp_on_up;
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#else
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return true;
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#endif
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}
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/* all SMP configurations have the extended CPUID registers */
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static inline int tlb_ops_need_broadcast(void)
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{
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if (!is_smp())
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return 0;
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return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 2;
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}
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#if !defined(CONFIG_SMP) || __LINUX_ARM_ARCH__ >= 7
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#define cache_ops_need_broadcast() 0
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#else
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static inline int cache_ops_need_broadcast(void)
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{
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if (!is_smp())
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return 0;
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return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 1;
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}
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#endif
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/*
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* Logical CPU mapping.
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*/
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extern int __cpu_logical_map[];
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#define cpu_logical_map(cpu) __cpu_logical_map[cpu]
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#endif
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