[U-Boot] [PATCH 15/69] x86: cpu: Add functions to return the family and stepping

[Simon Glass]

Hi Bin,

On 10 March 2016 at 21:52, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi Simon,
>
> On Mon, Mar 7, 2016 at 10:27 AM, Simon Glass <sjg at chromium.org> wrote:
>> These two identifiers can be useful for drivers which need to adjust their
>> behaviour depending on the CPU family or stepping (revision).
>>
>> Signed-off-by: Simon Glass <sjg at chromium.org>
>> ---
>>
>>  arch/x86/cpu/cpu.c         | 10 ++++++++++
>>  arch/x86/include/asm/cpu.h | 14 ++++++++++++++
>>  2 files changed, 24 insertions(+)
>>
>> diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
>> index 8800e09..e2aad19 100644
>> --- a/arch/x86/cpu/cpu.c
>> +++ b/arch/x86/cpu/cpu.c
>> @@ -333,6 +333,16 @@ static inline void get_fms(struct cpuinfo_x86 *c, uint32_t tfms)
>>                 c->x86_model += ((tfms >> 16) & 0xF) << 4;
>>  }
>>
>> +u32 cpu_get_family_model(void)
>> +{
>> +       return gd->arch.x86_device & 0x0fff0ff0;
>
> The decrypted family and model are stored in gd->arch.x86 and
> gd->arch.x86_model. Returning raw data would still need the caller to
> parse it. Why not just return these directly?

I want to compare them in one shot to BROADWELL_FAMILY_ULT, etc.

What exactly are you suggesting?

>
>> +}
>> +
>> +u32 cpu_get_stepping(void)
>> +{
>> +       return gd->arch.x86_device & 0xf;
>
> This is gd->arch.x86_mask.

OK. That's a funny name for stepping.

>
>> +}
>> +
>>  int x86_cpu_init_f(void)
>>  {
>>         const u32 em_rst = ~X86_CR0_EM;
>> diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
>> index 18b0345..987dc65 100644
>> --- a/arch/x86/include/asm/cpu.h
>> +++ b/arch/x86/include/asm/cpu.h
>> @@ -260,4 +260,18 @@ void cpu_call32(ulong code_seg32, ulong target, ulong table);
>>   */
>>  int cpu_jump_to_64bit(ulong setup_base, ulong target);
>>
>> +/**
>> + * cpu_get_family_model() - Get the family and model for the CPU
>> + *
>> + * @return the CPU ID masked with 0x0fff0ff0
>> + */
>> +u32 cpu_get_family_model(void);
>> +
>> +/**
>> + * cpu_get_stepping() - Get the stepping value for the CPU
>> + *
>> + * @return the CPU ID masked with 0xf
>> + */
>> +u32 cpu_get_stepping(void);
>> +
>>  #endif
>> --
>
> Regards,
> Bin