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

[Steven <wangwangkang@xxxxxxxxx>]

Why do you use "u32"? Is it because u32 can support more CPU id than u8?


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);
>
>
>
>
> _______________________________________________
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> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel
>
>

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