RE: [Xen-devel] [PATCH] Add cpu hotplug support for 2.6.32 branch

["Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx>]

Jeremy, I think all this patch is purely for acpi changes, so not sure if it is 
ok to apply it on origin/xen/dom0/acpi-next?
I have a talk with Ke, the xen/dom0/acpi-next has already covere all work for 
PM and CPU/Mem hotplug in a cleaner way and is based on 2.6.32 kernel, so maybe 
we can use that for the base tree.

Thanks
--jyh

>-----Original Message-----
>From: Jeremy Fitzhardinge [mailto:jeremy@xxxxxxxx]
>Sent: Thursday, August 19, 2010 3:41 AM
>To: Jiang, Yunhong
>Cc: Xen-devel
>Subject: Re: [Xen-devel] [PATCH] Add cpu hotplug support for 2.6.32 branch
>
> On 08/17/2010 08:04 PM, Jiang, Yunhong wrote:
>> Hi, Jeremy, followed patch port pcpu hotplug support to 2.6.32 pvops dom0. I 
>> don't
>know if xen/next-2.6.32 branch is the right base. If it is not, can you please 
>advice me
>which branch should I base on?
>
>No, that's not really a good base.  Ideally you should base on plain
>v2.6.32, but if that doesn't work, base it on whatever topic branch has
>your pre-requisite changes.  If that's too complex (too many changes
>from multiple branches), then base on xen/next.
>
>The existing xen/dom0/pcpu-hotplug branch should a useful guide.
>
>Alternatively, if you can provide me with a merge of
>xen/dom0/pcpu-hotplug into xen/next (ie, with conflict resolution done),
>then I could just use that. (Though it looks like certain parts may have
>already been merged - I didn't look closely.)
>
>Thanks,
>    J
>
>> Thanks
>> --jyh
>>
>> Add cpu hotplug support for 2.6.32 branch
>>
>> Add physical CPU hotplug support to origin/xen/next-2.6.32 branch.
>> Please notice that, even with this change, the acpi_processor->id is
>> still always -1. This is because several workaround in PM side depends
>> on acpi_processor->id == -1. As the CPU hotplug logic does not depends
>> on acpi_processor->id, I'd still keep it no changes.
>>
>> But we need change the acpi_processor->id in the future.
>>
>> Signed-off-by: Jiang, Yunhong <yunhong.jiang@xxxxxxxxx>
>>
>>
>> diff --git a/drivers/acpi/processor_xen.c b/drivers/acpi/processor_xen.c
>> index 2f37c9c..305398d 100644
>> --- a/drivers/acpi/processor_xen.c
>> +++ b/drivers/acpi/processor_xen.c
>> @@ -39,6 +39,7 @@
>>  #include <acpi/acpi_drivers.h>
>>  #include <acpi/processor.h>
>>  #include <xen/acpi.h>
>> +#include <xen/pcpu.h>
>>
>>  #define PREFIX "ACPI: "
>>
>> @@ -82,6 +83,42 @@ struct acpi_driver xen_acpi_processor_driver = {
>>              },
>>  };
>>
>> +static int is_processor_present(acpi_handle handle)
>> +{
>> +    acpi_status status;
>> +    unsigned long long sta = 0;
>> +
>> +
>> +    status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
>> +
>> +    if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT))
>> +            return 1;
>> +
>> +    /*
>> +     * _STA is mandatory for a processor that supports hot plug
>> +     */
>> +    if (status == AE_NOT_FOUND)
>> +            ACPI_DEBUG_PRINT((ACPI_DB_INFO,
>> +                            "Processor does not support hot plug\n"));
>> +    else
>> +            ACPI_EXCEPTION((AE_INFO, status,
>> +                            "Processor Device is not present"));
>> +    return 0;
>> +}
>> +
>> +static acpi_status
>> +xen_acpi_processor_hotadd_init(struct acpi_processor *pr, int *p_cpu)
>> +{
>> +    if (!is_processor_present(pr->handle))
>> +            return AE_ERROR;
>> +
>> +    if (processor_cntl_xen_notify(pr,
>> +                            PROCESSOR_HOTPLUG, HOTPLUG_TYPE_ADD))
>> +            return AE_ERROR;
>> +
>> +    return AE_OK;
>> +}
>> +
>>  static int xen_acpi_processor_get_info(struct acpi_device *device)
>>  {
>>      acpi_status status = 0;
>> @@ -164,14 +201,12 @@ static int xen_acpi_processor_get_info(struct
>acpi_device *device)
>>       *  They should be ignored _iff they are physically not present.
>>       *
>>       */
>> -#if 0
>> -    if (pr->id == -1) {
>> +    if (xen_pcpu_index(pr->acpi_id, 1) == -1) {
>>              if (ACPI_FAILURE
>> -                (acpi_processor_hotadd_init(pr->handle, &pr->id))) {
>> +                (xen_acpi_processor_hotadd_init(pr, &pr->id))) {
>>                      return -ENODEV;
>>              }
>>      }
>> -#endif
>>
>>      /*
>>       * On some boxes several processors use the same processor bus id.
>> diff --git a/drivers/xen/pcpu.c b/drivers/xen/pcpu.c
>> index 6450c17..6d1a770 100644
>> --- a/drivers/xen/pcpu.c
>> +++ b/drivers/xen/pcpu.c
>> @@ -313,6 +313,38 @@ static struct pcpu *_sync_pcpu(int cpu_num, int *max_id,
>int *result)
>>      return pcpu;
>>  }
>>
>> +int xen_pcpu_index(uint32_t id, int is_acpiid)
>> +{
>> +    int cpu_num = 0, max_id = 0, ret;
>> +    xen_platform_op_t op = {
>> +            .cmd            = XENPF_get_cpuinfo,
>> +            .interface_version  = XENPF_INTERFACE_VERSION,
>> +    };
>> +    struct xenpf_pcpuinfo *info = &op.u.pcpu_info;
>> +
>> +    info->xen_cpuid = 0;
>> +    ret = HYPERVISOR_dom0_op(&op);
>> +    if (ret)
>> +            return -1;
>> +    max_id = op.u.pcpu_info.max_present;
>> +
>> +    while ((cpu_num <= max_id)) {
>> +            info->xen_cpuid = cpu_num;
>> +            ret = HYPERVISOR_dom0_op(&op);
>> +            if (ret)
>> +                    continue;
>> +
>> +            if (op.u.pcpu_info.max_present > max_id)
>> +                    max_id = op.u.pcpu_info.max_present;
>> +            if (id == (is_acpiid ? info->acpi_id : info->apic_id))
>> +                    return cpu_num;
>> +            cpu_num++;
>> +    }
>> +
>> +    return -1;
>> +}
>> +EXPORT_SYMBOL(xen_pcpu_index);
>> +
>>  /*
>>   * Sync dom0's pcpu information with xen hypervisor's
>>   */
>> @@ -417,4 +449,4 @@ static int __init xen_pcpu_init(void)
>>      return err;
>>  }
>>
>> -subsys_initcall(xen_pcpu_init);
>> +arch_initcall(xen_pcpu_init);
>> diff --git a/include/xen/pcpu.h b/include/xen/pcpu.h
>> index fb2bf6b..7e8f9d1 100644
>> --- a/include/xen/pcpu.h
>> +++ b/include/xen/pcpu.h
>> @@ -27,4 +27,6 @@ static inline int xen_pcpu_online(uint32_t flags)
>>  extern int register_xen_pcpu_notifier(struct notifier_block *nb);
>>
>>  extern void unregister_xen_pcpu_notifier(struct notifier_block *nb);
>> +
>> +extern int xen_pcpu_index(uint32_t acpi_id, int is_acpiid);
>>  #endif
>>
>>
>>
>>
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>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>> http://lists.xensource.com/xen-devel


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