RE: [Xen-devel] [PATCH 1/2] Xen acpi pad implement

[Liu, Jinsong]

Stefano Stabellini wrote:
>>> diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
>>> index 0e86370..a2af622 100644
>>> --- a/drivers/xen/Makefile
>>> +++ b/drivers/xen/Makefile
>>> @@ -29,6 +29,7 @@ obj-$(CONFIG_XEN_MCE_LOG)           += mcelog.o
>>>  obj-$(CONFIG_XEN_PCIDEV_BACKEND)     += xen-pciback/
>>>  obj-$(CONFIG_XEN_PRIVCMD)            += xen-privcmd.o
>>>  obj-$(CONFIG_XEN_ACPI_PROCESSOR)     += xen-acpi-processor.o
>>> +obj-$(CONFIG_XEN_DOM0)                       += xen_acpi_pad.o
>>>  xen-evtchn-y                         := evtchn.o
>>>  xen-gntdev-y                         := gntdev.o
>>>  xen-gntalloc-y                               := gntalloc.o
> 
> it should really depend on ACPI and maybe also X86, otherwise it is
> going to break the ARM build
> 
> 

Hmm, XEN_DOM0 has already depended on ACPI and X86_LOCAL_APIC (which depends on X86_64).

Thanks,
Jinsong

>>> diff --git a/drivers/xen/xen_acpi_pad.c b/drivers/xen/xen_acpi_pad.c
>>> new file mode 100644
>>> index 0000000..e8c26a4
>>> --- /dev/null
>>> +++ b/drivers/xen/xen_acpi_pad.c
>>> @@ -0,0 +1,206 @@
>>> +/*
>>> + * xen_acpi_pad.c - Xen pad interface
>>> + *
>>> + * Copyright (c) 2012, Intel Corporation.
>>> + *    Author: Liu, Jinsong <jinsong.liu@xxxxxxxxx> + *
>>> + * This program is free software; you can redistribute it and/or
>>> modify it + * under the terms and conditions of the GNU General
>>> Public License, + * version 2, as published by the Free Software
>>> Foundation. + * + * This program is distributed in the hope it will
>>> be useful, but WITHOUT + * ANY WARRANTY; without even the implied
>>> warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR
>>> PURPOSE.  See the GNU General Public License for + * more details.
>>> + */ +
>>> +#include <linux/kernel.h>
>>> +#include <linux/types.h>
>>> +#include <acpi/acpi_bus.h>
>>> +#include <acpi/acpi_drivers.h>
>>> +#include <asm/xen/hypercall.h>
>>> +#include <xen/interface/version.h>
>>> +
>>> +#define ACPI_PROCESSOR_AGGREGATOR_CLASS      "acpi_pad"
>>> +#define ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME "Processor
>>> Aggregator" +#define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80
>>> +
>>> +static DEFINE_MUTEX(xen_pad_lock);
>>> +
>>> +static int xen_pad_set_idle_cpus(int num_cpus)
>>> +{
>>> +     struct xen_platform_op op;
>>> +
>>> +     if (num_cpus < 0)
>>> +             return -EINVAL;
>>> +
>>> +     /* set cpu nums expected to be idled */
>>> +     op.cmd = XENPF_core_parking;
>>> +     op.u.core_parking.type = XEN_CORE_PARKING_SET;
>>> +     op.u.core_parking.idle_nums = num_cpus;
>>> +
>>> +     return HYPERVISOR_dom0_op(&op);
>>> +}
>>> +
>>> +/*
>>> + * Cannot get idle cpus by using hypercall once (shared with _SET)
>>> + * because of the characteristic of Xen continue_hypercall_on_cpu
>>> + */ +static int xen_pad_get_idle_cpus(void)
>>> +{
>>> +     int ret;
>>> +     struct xen_platform_op op;
>>> +
>>> +     /* get cpu nums actually be idled */
>>> +     op.cmd = XENPF_core_parking;
>>> +     op.u.core_parking.type = XEN_CORE_PARKING_GET;
>>> +     ret = HYPERVISOR_dom0_op(&op);
>>> +     if (ret < 0)
>>> +             return ret;
>>> +
>>> +     return op.u.core_parking.idle_nums;
>>> +}
>>> +
>>> +/*
>>> + * Query firmware how many CPUs should be idle
>>> + * return -1 on failure
>>> + */
>>> +static int xen_acpi_pad_pur(acpi_handle handle)
>>> +{
>>> +     struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
>>> +     union acpi_object *package;
>>> +     int num = -1;
>>> +
>>> +     if (ACPI_FAILURE(acpi_evaluate_object(handle, "_PUR", NULL,
>>> &buffer))) +             return num; +
>>> +     if (!buffer.length || !buffer.pointer)
>>> +             return num;
>>> +
>>> +     package = buffer.pointer;
>>> +
>>> +     if (package->type == ACPI_TYPE_PACKAGE &&
>>> +             package->package.count == 2 &&
>>> +             package->package.elements[0].integer.value == 1) /*
>>> rev 1 */ + +             num =
>>> package->package.elements[1].integer.value; + +    
>>> kfree(buffer.pointer); +     return num;
>>> +}
>>> +
>>> +/* Notify firmware how many CPUs are idle */
>>> +static void xen_acpi_pad_ost(acpi_handle handle, int stat, +    
>>> uint32_t idle_cpus) +{
>>> +     union acpi_object params[3] = {
>>> +             {.type = ACPI_TYPE_INTEGER,},
>>> +             {.type = ACPI_TYPE_INTEGER,},
>>> +             {.type = ACPI_TYPE_BUFFER,},
>>> +     };
>>> +     struct acpi_object_list arg_list = {3, params}; +
>>> +     params[0].integer.value = ACPI_PROCESSOR_AGGREGATOR_NOTIFY;
>>> +     params[1].integer.value =  stat;
>>> +     params[2].buffer.length = 4;
>>> +     params[2].buffer.pointer = (void *)&idle_cpus;
>>> +     acpi_evaluate_object(handle, "_OST", &arg_list, NULL); +}
>>> +
>>> +static void xen_acpi_pad_handle_notify(acpi_handle handle) +{
>>> +     int num_cpus;
>>> +
>>> +     num_cpus = xen_acpi_pad_pur(handle);
>>> +     if (num_cpus < 0)
>>> +             return;
>>> +
>>> +     mutex_lock(&xen_pad_lock);
>>> +     if (xen_pad_set_idle_cpus(num_cpus)) {
>>> +             mutex_unlock(&xen_pad_lock);
>>> +             return;
>>> +     }
>>> +
>>> +     num_cpus = xen_pad_get_idle_cpus();
>>> +     if (num_cpus < 0) {
>>> +             mutex_unlock(&xen_pad_lock);
>>> +             return;
>>> +     }
>>> +     mutex_unlock(&xen_pad_lock);
>>> +
>>> +     xen_acpi_pad_ost(handle, 0, num_cpus);
>>> +}
>>> +
>>> +static void xen_acpi_pad_notify(acpi_handle handle, u32 event, +  
>>> void *data) +{
>>> +     switch (event) {
>>> +     case ACPI_PROCESSOR_AGGREGATOR_NOTIFY:
>>> +             xen_acpi_pad_handle_notify(handle);
>>> +             break;
>>> +     default:
>>> +             pr_warn("Unsupported event [0x%x]\n", event); +      
>>> break; +     }
>>> +}
>>> +
>>> +static int xen_acpi_pad_add(struct acpi_device *device) +{
>>> +     acpi_status status;
>>> +
>>> +     strcpy(acpi_device_name(device),
>>> ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME); +    
>>> strcpy(acpi_device_class(device), ACPI_PROCESSOR_AGGREGATOR_CLASS);
>>> + +     status = acpi_install_notify_handler(device->handle, +     
>>> ACPI_DEVICE_NOTIFY, xen_acpi_pad_notify, device); +     if
>>> (ACPI_FAILURE(status)) +             return -ENODEV;
>>> +
>>> +     return 0;
>>> +}
>>> +
>>> +static int xen_acpi_pad_remove(struct acpi_device *device, +    
>>> int type) +{
>>> +     mutex_lock(&xen_pad_lock);
>>> +     xen_pad_set_idle_cpus(0);
>>> +     mutex_unlock(&xen_pad_lock);
>>> +
>>> +     acpi_remove_notify_handler(device->handle,
>>> +             ACPI_DEVICE_NOTIFY, xen_acpi_pad_notify); +    
>>> return 0; +}
>>> +
>>> +static const struct acpi_device_id pad_device_ids[] = { +    
>>> {"ACPI000C", 0}, +     {"", 0},
>>> +};
>>> +
>>> +static struct acpi_driver xen_acpi_pad_driver = {
>>> +     .name = "processor_aggregator",
>>> +     .class = ACPI_PROCESSOR_AGGREGATOR_CLASS,
>>> +     .ids = pad_device_ids,
>>> +     .ops = {
>>> +             .add = xen_acpi_pad_add,
>>> +             .remove = xen_acpi_pad_remove,
>>> +     },
>>> +};
>>> +
>>> +static int __init xen_acpi_pad_init(void)
>>> +{
>>> +     int ret = -ENOSYS;
>>> +     unsigned int version = HYPERVISOR_xen_version(XENVER_version,
>>> NULL); 
>> 
>> Heh. so if you run this on baremetal I wonder what will happen.
>> 
>>> +     unsigned int major = version >> 16;
>>> +     unsigned int minor = version & 0xffff;
>>> +
>>> +     /* Only DOM0 is responsible for Xen acpi pad */
>>> +     if (!xen_initial_domain())
>>> +             return -ENODEV;
>>> +
>> 
>> I think the check for version should happen here.
>> 
>>> +     /* Only Xen4.2 or later support Xen acpi pad */
>>> +     if (((major == 4) && (minor >= 2)) || (major > 4))
>>> +             ret = acpi_bus_register_driver(&xen_acpi_pad_driver);
>>> + +     return ret;
>>> +}
>>> +subsys_initcall(xen_acpi_pad_init);
>>> diff --git a/include/xen/interface/platform.h
>>> b/include/xen/interface/platform.h index 4755b5f..a3be54c 100644
>>> --- a/include/xen/interface/platform.h +++
>>> b/include/xen/interface/platform.h @@ -324,6 +324,22 @@ struct
>>>  xenpf_cpu_ol { };
>>>  DEFINE_GUEST_HANDLE_STRUCT(xenpf_cpu_ol);
>>> 
>>> +/*
>>> + * CMD 58 and 59 are reserved for cpu hotadd and memory hotadd,
>>> + * which are already occupied at Xen hypervisor side. + */
>>> +#define XENPF_core_parking   60
>>> +struct xenpf_core_parking {
>>> +     /* IN variables */
>>> +#define XEN_CORE_PARKING_SET 1
>>> +#define XEN_CORE_PARKING_GET 2
>>> +     uint32_t type;
>>> +     /* IN variables:  set cpu nums expected to be idled */
>>> +     /* OUT variables: get cpu nums actually be idled */ +    
>>> uint32_t idle_nums; +};
>>> +DEFINE_GUEST_HANDLE_STRUCT(xenpf_core_parking);
>>> +
>>>  struct xen_platform_op {
>>>       uint32_t cmd;
>>>       uint32_t interface_version; /* XENPF_INTERFACE_VERSION */
>>> @@ -341,6 +357,7 @@ struct xen_platform_op {
>>>               struct xenpf_set_processor_pminfo set_pminfo;
>>>               struct xenpf_pcpuinfo          pcpu_info;
>>>               struct xenpf_cpu_ol            cpu_ol;
>>> +             struct xenpf_core_parking      core_parking;
>>>               uint8_t                        pad[128];       } u;
>>>  };
>>> --
>>> 1.7.1
>> 
>> 
>>> _______________________________________________
>>> Xen-devel mailing list
>>> Xen-devel@xxxxxxxxxxxxx
>>> http://lists.xen.org/xen-devel
>> 
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