linux_dsm_epyc7002/arch/arm/include/asm/smp_plat.h
Lorenzo Pieralisi 7f124aaf01 ARM: kernel: add logical mappings look-up
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>
2012-11-19 15:44:34 +00:00

70 lines
1.4 KiB
C

/*
* ARM specific SMP header, this contains our implementation
* details.
*/
#ifndef __ASMARM_SMP_PLAT_H
#define __ASMARM_SMP_PLAT_H
#include <linux/cpumask.h>
#include <linux/err.h>
#include <asm/cputype.h>
/*
* Return true if we are running on a SMP platform
*/
static inline bool is_smp(void)
{
#ifndef CONFIG_SMP
return false;
#elif defined(CONFIG_SMP_ON_UP)
extern unsigned int smp_on_up;
return !!smp_on_up;
#else
return true;
#endif
}
/* all SMP configurations have the extended CPUID registers */
static inline int tlb_ops_need_broadcast(void)
{
if (!is_smp())
return 0;
return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 2;
}
#if !defined(CONFIG_SMP) || __LINUX_ARM_ARCH__ >= 7
#define cache_ops_need_broadcast() 0
#else
static inline int cache_ops_need_broadcast(void)
{
if (!is_smp())
return 0;
return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 1;
}
#endif
/*
* Logical CPU mapping.
*/
extern int __cpu_logical_map[];
#define cpu_logical_map(cpu) __cpu_logical_map[cpu]
/*
* Retrieve logical cpu index corresponding to a given MPIDR[23:0]
* - mpidr: MPIDR[23:0] to be used for the look-up
*
* Returns the cpu logical index or -EINVAL on look-up error
*/
static inline int get_logical_index(u32 mpidr)
{
int cpu;
for (cpu = 0; cpu < nr_cpu_ids; cpu++)
if (cpu_logical_map(cpu) == mpidr)
return cpu;
return -EINVAL;
}
#endif