linux/drivers/xen/xen-acpi-pad.c
Rafael J. Wysocki 51fac8388a ACPI: Remove useless type argument of driver .remove() operation
The second argument of ACPI driver .remove() operation is only used
by the ACPI processor driver and the value passed to that driver
through it is always available from the given struct acpi_device
object's removal_type field.  For this reason, the second ACPI driver
.remove() argument is in fact useless, so drop it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
2013-01-26 00:37:24 +01:00

182 lines
4.4 KiB
C

/*
* xen-acpi-pad.c - Xen pad interface
*
* Copyright (c) 2012, Intel Corporation.
* Author: Liu, Jinsong <jinsong.liu@intel.com>
*
* 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>
#include <xen/xen-ops.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_cpu_lock);
static int xen_acpi_pad_idle_cpus(unsigned int idle_nums)
{
struct xen_platform_op op;
op.cmd = XENPF_core_parking;
op.u.core_parking.type = XEN_CORE_PARKING_SET;
op.u.core_parking.idle_nums = idle_nums;
return HYPERVISOR_dom0_op(&op);
}
static int xen_acpi_pad_idle_cpus_num(void)
{
struct xen_platform_op op;
op.cmd = XENPF_core_parking;
op.u.core_parking.type = XEN_CORE_PARKING_GET;
return HYPERVISOR_dom0_op(&op)
?: op.u.core_parking.idle_nums;
}
/*
* Query firmware how many CPUs should be idle
* return -1 on failure
*/
static int 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 acpi_pad_ost(acpi_handle handle, int stat,
uint32_t idle_nums)
{
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_nums;
acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
}
static void acpi_pad_handle_notify(acpi_handle handle)
{
int idle_nums;
mutex_lock(&xen_cpu_lock);
idle_nums = acpi_pad_pur(handle);
if (idle_nums < 0) {
mutex_unlock(&xen_cpu_lock);
return;
}
idle_nums = xen_acpi_pad_idle_cpus(idle_nums)
?: xen_acpi_pad_idle_cpus_num();
if (idle_nums >= 0)
acpi_pad_ost(handle, 0, idle_nums);
mutex_unlock(&xen_cpu_lock);
}
static void acpi_pad_notify(acpi_handle handle, u32 event,
void *data)
{
switch (event) {
case ACPI_PROCESSOR_AGGREGATOR_NOTIFY:
acpi_pad_handle_notify(handle);
break;
default:
pr_warn("Unsupported event [0x%x]\n", event);
break;
}
}
static int 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, acpi_pad_notify, device);
if (ACPI_FAILURE(status))
return -ENODEV;
return 0;
}
static int acpi_pad_remove(struct acpi_device *device)
{
mutex_lock(&xen_cpu_lock);
xen_acpi_pad_idle_cpus(0);
mutex_unlock(&xen_cpu_lock);
acpi_remove_notify_handler(device->handle,
ACPI_DEVICE_NOTIFY, acpi_pad_notify);
return 0;
}
static const struct acpi_device_id pad_device_ids[] = {
{"ACPI000C", 0},
{"", 0},
};
static struct acpi_driver acpi_pad_driver = {
.name = "processor_aggregator",
.class = ACPI_PROCESSOR_AGGREGATOR_CLASS,
.ids = pad_device_ids,
.ops = {
.add = acpi_pad_add,
.remove = acpi_pad_remove,
},
};
static int __init xen_acpi_pad_init(void)
{
/* Only DOM0 is responsible for Xen acpi pad */
if (!xen_initial_domain())
return -ENODEV;
/* Only Xen4.2 or later support Xen acpi pad */
if (!xen_running_on_version_or_later(4, 2))
return -ENODEV;
return acpi_bus_register_driver(&acpi_pad_driver);
}
subsys_initcall(xen_acpi_pad_init);