Re: [Xen-devel] [PATCH] pm: don't truncate processors' ACPI IDs to 8 bits

["Jan Beulich" <JBeulich@xxxxxxxxxx>]

>>> On 24.08.11 at 22:00, Steven <wangwangkang@xxxxxxxxx> wrote:
> Why do you use "u32"? Is it because u32 can support more CPU id than u8?

Yes, of course. ACPI specifies them to be 32 bits wide.

Jan

> On Fri, Aug 19, 2011 at 11:04 AM, Jan Beulich <JBeulich@xxxxxxxxxx> wrote:
>> This is just another adjustment to allow systems with very many CPUs
>> (or unusual ACPI IDs) to be properly power-managed.
>>
>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
>>
>> --- a/xen/arch/ia64/linux-xen/acpi.c
>> +++ b/xen/arch/ia64/linux-xen/acpi.c
>> @@ -221,11 +221,14 @@ static u16 ia64_acpiid_to_sapicid[ MAX_L
>>                {[0 ... MAX_LOCAL_SAPIC - 1] = 0xffff };
>>
>>  /* acpi id to cpu id */
>> -int get_cpu_id(u8 acpi_id)
>> +int get_cpu_id(u32 acpi_id)
>>  {
>>        int i;
>>        u16 apic_id;
>>
>> +       if ( acpi_id >= MAX_LOCAL_SAPIC )
>> +               return -EINVAL;
>> +
>>        apic_id = ia64_acpiid_to_sapicid[acpi_id];
>>        if ( apic_id == 0xffff )
>>                return -EINVAL;
>> --- a/xen/arch/x86/acpi/cpu_idle.c
>> +++ b/xen/arch/x86/acpi/cpu_idle.c
>> @@ -895,11 +895,14 @@ static void set_cx(
>>         acpi_power->safe_state = cx;
>>  }
>>
>> -int get_cpu_id(u8 acpi_id)
>> +int get_cpu_id(u32 acpi_id)
>>  {
>>     int i;
>>     u32 apic_id;
>>
>> +    if ( acpi_id >= MAX_MADT_ENTRIES )
>> +        return -1;
>> +
>>     apic_id = x86_acpiid_to_apicid[acpi_id];
>>     if ( apic_id == BAD_APICID )
>>         return -1;
>> @@ -976,7 +979,7 @@ long set_cx_pminfo(uint32_t cpu, struct
>>     print_cx_pminfo(cpu, power);
>>
>>     /* map from acpi_id to cpu_id */
>> -    cpu_id = get_cpu_id((u8)cpu);
>> +    cpu_id = get_cpu_id(cpu);
>>     if ( cpu_id == -1 )
>>     {
>>         printk(XENLOG_ERR "no cpu_id for acpi_id %d\n", cpu);
>> --- a/xen/include/acpi/cpufreq/processor_perf.h
>> +++ b/xen/include/acpi/cpufreq/processor_perf.h
>> @@ -6,7 +6,7 @@
>>
>>  #define XEN_PX_INIT 0x80000000
>>
>> -int get_cpu_id(u8);
>> +int get_cpu_id(u32);
>>  int powernow_cpufreq_init(void);
>>  unsigned int powernow_register_driver(void);
>>  unsigned int get_measured_perf(unsigned int cpu, unsigned int flag);
>>
>>
>>
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxxxxxxxx 
>> http://lists.xensource.com/xen-devel 
>>
>>




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