[PATCH 1/2] arm64: adding cpu lookup functionality

Mathieu Poirier mathieu.poirier at linaro.org
Mon Feb 2 13:20:09 PST 2015


On 2 February 2015 at 06:50, Will Deacon <will.deacon at arm.com> wrote:
> On Fri, Jan 30, 2015 at 10:54:25PM +0000, mathieu.poirier at linaro.org wrote:
>> From: Mathieu Poirier <mathieu.poirier at linaro.org>
>>
>> Adding a lookup function allowing for quick and easy mapping
>> between processor HWID (as found, for example) in DT specifications
>> and the CPU index known to the kernel.
>>
>> Signed-off-by: Mathieu Poirier <mathieu.poirier at linaro.org>
>> ---
>>  arch/arm64/include/asm/smp_plat.h | 12 ++++++++++++
>>  1 file changed, 12 insertions(+)
>>
>> diff --git a/arch/arm64/include/asm/smp_plat.h b/arch/arm64/include/asm/smp_plat.h
>> index 59e282311b58..8e4b011303b1 100644
>> --- a/arch/arm64/include/asm/smp_plat.h
>> +++ b/arch/arm64/include/asm/smp_plat.h
>> @@ -19,6 +19,7 @@
>>  #ifndef __ASM_SMP_PLAT_H
>>  #define __ASM_SMP_PLAT_H
>>
>> +#include <linux/cpumask.h>
>>  #include <asm/types.h>
>>
>>  struct mpidr_hash {
>> @@ -40,4 +41,15 @@ static inline u32 mpidr_hash_size(void)
>>  extern u64 __cpu_logical_map[NR_CPUS];
>>  #define cpu_logical_map(cpu)    __cpu_logical_map[cpu]
>>
>> +static inline int get_logical_index(u64 mpidr)
>> +{
>> +     int cpu;
>> +
>> +     for (cpu = 0; cpu < nr_cpu_ids; cpu++)
>> +             if (cpu_logical_map(cpu) == mpidr)
>> +                     return cpu;
>> +     return -EINVAL;
>> +}
>
> Can you not achieve the same thing using arch_find_n_match_cpu_physical_id
> in the coresight code?
>
> Will

I ended up using "of_get_cpu_node()", which uses
"arch_find_n_match_cpu_physical_id()".  Thanks for pointing this out.

Mathieu



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