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In ARM SMP systems the MPIDR register ([23:0] bits) is used to uniquely identify CPUs. In order to retrieve the logical CPU index corresponding to a given MPIDR value and guarantee a consistent translation throughout the kernel, this patch adds a look-up based on the MPIDR[23:0] so that kernel subsystems can use it whenever the logical cpu index corresponding to a given MPIDR value is needed. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org>
70 lines
1.4 KiB
C
70 lines
1.4 KiB
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 <linux/cpumask.h>
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#include <linux/err.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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/*
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* Retrieve logical cpu index corresponding to a given MPIDR[23:0]
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* - mpidr: MPIDR[23:0] to be used for the look-up
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*
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* Returns the cpu logical index or -EINVAL on look-up error
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*/
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static inline int get_logical_index(u32 mpidr)
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{
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int cpu;
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for (cpu = 0; cpu < nr_cpu_ids; cpu++)
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if (cpu_logical_map(cpu) == mpidr)
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return cpu;
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return -EINVAL;
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}
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#endif
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