12025cf9eSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
292e3229dSLiu, Jinsong /*
392e3229dSLiu, Jinsong * xen-acpi-pad.c - Xen pad interface
492e3229dSLiu, Jinsong *
592e3229dSLiu, Jinsong * Copyright (c) 2012, Intel Corporation.
692e3229dSLiu, Jinsong * Author: Liu, Jinsong <jinsong.liu@intel.com>
792e3229dSLiu, Jinsong */
892e3229dSLiu, Jinsong
9283c0972SJoe Perches #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10283c0972SJoe Perches
1192e3229dSLiu, Jinsong #include <linux/kernel.h>
1292e3229dSLiu, Jinsong #include <linux/types.h>
138b48463fSLv Zheng #include <linux/acpi.h>
143cfa210bSChristoph Hellwig #include <xen/xen.h>
1592e3229dSLiu, Jinsong #include <xen/interface/version.h>
16394b40f6SKonrad Rzeszutek Wilk #include <xen/xen-ops.h>
178b48463fSLv Zheng #include <asm/xen/hypercall.h>
1892e3229dSLiu, Jinsong
1992e3229dSLiu, Jinsong #define ACPI_PROCESSOR_AGGREGATOR_CLASS "acpi_pad"
2092e3229dSLiu, Jinsong #define ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME "Processor Aggregator"
2192e3229dSLiu, Jinsong #define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80
2292e3229dSLiu, Jinsong static DEFINE_MUTEX(xen_cpu_lock);
2392e3229dSLiu, Jinsong
xen_acpi_pad_idle_cpus(unsigned int idle_nums)2492e3229dSLiu, Jinsong static int xen_acpi_pad_idle_cpus(unsigned int idle_nums)
2592e3229dSLiu, Jinsong {
2692e3229dSLiu, Jinsong struct xen_platform_op op;
2792e3229dSLiu, Jinsong
2892e3229dSLiu, Jinsong op.cmd = XENPF_core_parking;
2992e3229dSLiu, Jinsong op.u.core_parking.type = XEN_CORE_PARKING_SET;
3092e3229dSLiu, Jinsong op.u.core_parking.idle_nums = idle_nums;
3192e3229dSLiu, Jinsong
32cfafae94SStefano Stabellini return HYPERVISOR_platform_op(&op);
3392e3229dSLiu, Jinsong }
3492e3229dSLiu, Jinsong
xen_acpi_pad_idle_cpus_num(void)3592e3229dSLiu, Jinsong static int xen_acpi_pad_idle_cpus_num(void)
3692e3229dSLiu, Jinsong {
3792e3229dSLiu, Jinsong struct xen_platform_op op;
3892e3229dSLiu, Jinsong
3992e3229dSLiu, Jinsong op.cmd = XENPF_core_parking;
4092e3229dSLiu, Jinsong op.u.core_parking.type = XEN_CORE_PARKING_GET;
4192e3229dSLiu, Jinsong
42cfafae94SStefano Stabellini return HYPERVISOR_platform_op(&op)
4392e3229dSLiu, Jinsong ?: op.u.core_parking.idle_nums;
4492e3229dSLiu, Jinsong }
4592e3229dSLiu, Jinsong
4692e3229dSLiu, Jinsong /*
4792e3229dSLiu, Jinsong * Query firmware how many CPUs should be idle
4892e3229dSLiu, Jinsong * return -1 on failure
4992e3229dSLiu, Jinsong */
acpi_pad_pur(acpi_handle handle)5092e3229dSLiu, Jinsong static int acpi_pad_pur(acpi_handle handle)
5192e3229dSLiu, Jinsong {
5292e3229dSLiu, Jinsong struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
5392e3229dSLiu, Jinsong union acpi_object *package;
5492e3229dSLiu, Jinsong int num = -1;
5592e3229dSLiu, Jinsong
5692e3229dSLiu, Jinsong if (ACPI_FAILURE(acpi_evaluate_object(handle, "_PUR", NULL, &buffer)))
5792e3229dSLiu, Jinsong return num;
5892e3229dSLiu, Jinsong
5992e3229dSLiu, Jinsong if (!buffer.length || !buffer.pointer)
6092e3229dSLiu, Jinsong return num;
6192e3229dSLiu, Jinsong
6292e3229dSLiu, Jinsong package = buffer.pointer;
6392e3229dSLiu, Jinsong
6492e3229dSLiu, Jinsong if (package->type == ACPI_TYPE_PACKAGE &&
6592e3229dSLiu, Jinsong package->package.count == 2 &&
6692e3229dSLiu, Jinsong package->package.elements[0].integer.value == 1) /* rev 1 */
6792e3229dSLiu, Jinsong num = package->package.elements[1].integer.value;
6892e3229dSLiu, Jinsong
6992e3229dSLiu, Jinsong kfree(buffer.pointer);
7092e3229dSLiu, Jinsong return num;
7192e3229dSLiu, Jinsong }
7292e3229dSLiu, Jinsong
acpi_pad_handle_notify(acpi_handle handle)7392e3229dSLiu, Jinsong static void acpi_pad_handle_notify(acpi_handle handle)
7492e3229dSLiu, Jinsong {
7592e3229dSLiu, Jinsong int idle_nums;
76772c5399SJiang Liu struct acpi_buffer param = {
77772c5399SJiang Liu .length = 4,
78772c5399SJiang Liu .pointer = (void *)&idle_nums,
79772c5399SJiang Liu };
80772c5399SJiang Liu
8192e3229dSLiu, Jinsong
8292e3229dSLiu, Jinsong mutex_lock(&xen_cpu_lock);
8392e3229dSLiu, Jinsong idle_nums = acpi_pad_pur(handle);
8492e3229dSLiu, Jinsong if (idle_nums < 0) {
8592e3229dSLiu, Jinsong mutex_unlock(&xen_cpu_lock);
8692e3229dSLiu, Jinsong return;
8792e3229dSLiu, Jinsong }
8892e3229dSLiu, Jinsong
8992e3229dSLiu, Jinsong idle_nums = xen_acpi_pad_idle_cpus(idle_nums)
9092e3229dSLiu, Jinsong ?: xen_acpi_pad_idle_cpus_num();
9192e3229dSLiu, Jinsong if (idle_nums >= 0)
92772c5399SJiang Liu acpi_evaluate_ost(handle, ACPI_PROCESSOR_AGGREGATOR_NOTIFY,
93772c5399SJiang Liu 0, ¶m);
9492e3229dSLiu, Jinsong mutex_unlock(&xen_cpu_lock);
9592e3229dSLiu, Jinsong }
9692e3229dSLiu, Jinsong
acpi_pad_notify(acpi_handle handle,u32 event,void * data)9792e3229dSLiu, Jinsong static void acpi_pad_notify(acpi_handle handle, u32 event,
9892e3229dSLiu, Jinsong void *data)
9992e3229dSLiu, Jinsong {
10092e3229dSLiu, Jinsong switch (event) {
10192e3229dSLiu, Jinsong case ACPI_PROCESSOR_AGGREGATOR_NOTIFY:
10292e3229dSLiu, Jinsong acpi_pad_handle_notify(handle);
10392e3229dSLiu, Jinsong break;
10492e3229dSLiu, Jinsong default:
10592e3229dSLiu, Jinsong pr_warn("Unsupported event [0x%x]\n", event);
10692e3229dSLiu, Jinsong break;
10792e3229dSLiu, Jinsong }
10892e3229dSLiu, Jinsong }
10992e3229dSLiu, Jinsong
acpi_pad_add(struct acpi_device * device)11092e3229dSLiu, Jinsong static int acpi_pad_add(struct acpi_device *device)
11192e3229dSLiu, Jinsong {
11292e3229dSLiu, Jinsong acpi_status status;
11392e3229dSLiu, Jinsong
11492e3229dSLiu, Jinsong strcpy(acpi_device_name(device), ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME);
11592e3229dSLiu, Jinsong strcpy(acpi_device_class(device), ACPI_PROCESSOR_AGGREGATOR_CLASS);
11692e3229dSLiu, Jinsong
11792e3229dSLiu, Jinsong status = acpi_install_notify_handler(device->handle,
11892e3229dSLiu, Jinsong ACPI_DEVICE_NOTIFY, acpi_pad_notify, device);
11992e3229dSLiu, Jinsong if (ACPI_FAILURE(status))
12092e3229dSLiu, Jinsong return -ENODEV;
12192e3229dSLiu, Jinsong
12292e3229dSLiu, Jinsong return 0;
12392e3229dSLiu, Jinsong }
12492e3229dSLiu, Jinsong
acpi_pad_remove(struct acpi_device * device)125*6c0eb5baSDawei Li static void acpi_pad_remove(struct acpi_device *device)
12692e3229dSLiu, Jinsong {
12792e3229dSLiu, Jinsong mutex_lock(&xen_cpu_lock);
12892e3229dSLiu, Jinsong xen_acpi_pad_idle_cpus(0);
12992e3229dSLiu, Jinsong mutex_unlock(&xen_cpu_lock);
13092e3229dSLiu, Jinsong
13192e3229dSLiu, Jinsong acpi_remove_notify_handler(device->handle,
13292e3229dSLiu, Jinsong ACPI_DEVICE_NOTIFY, acpi_pad_notify);
13392e3229dSLiu, Jinsong }
13492e3229dSLiu, Jinsong
13592e3229dSLiu, Jinsong static const struct acpi_device_id pad_device_ids[] = {
13692e3229dSLiu, Jinsong {"ACPI000C", 0},
13792e3229dSLiu, Jinsong {"", 0},
13892e3229dSLiu, Jinsong };
13992e3229dSLiu, Jinsong
14092e3229dSLiu, Jinsong static struct acpi_driver acpi_pad_driver = {
14192e3229dSLiu, Jinsong .name = "processor_aggregator",
14292e3229dSLiu, Jinsong .class = ACPI_PROCESSOR_AGGREGATOR_CLASS,
14392e3229dSLiu, Jinsong .ids = pad_device_ids,
14492e3229dSLiu, Jinsong .ops = {
14592e3229dSLiu, Jinsong .add = acpi_pad_add,
14692e3229dSLiu, Jinsong .remove = acpi_pad_remove,
14792e3229dSLiu, Jinsong },
14892e3229dSLiu, Jinsong };
14992e3229dSLiu, Jinsong
xen_acpi_pad_init(void)15092e3229dSLiu, Jinsong static int __init xen_acpi_pad_init(void)
15192e3229dSLiu, Jinsong {
15292e3229dSLiu, Jinsong /* Only DOM0 is responsible for Xen acpi pad */
15392e3229dSLiu, Jinsong if (!xen_initial_domain())
15492e3229dSLiu, Jinsong return -ENODEV;
15592e3229dSLiu, Jinsong
15692e3229dSLiu, Jinsong /* Only Xen4.2 or later support Xen acpi pad */
15792e3229dSLiu, Jinsong if (!xen_running_on_version_or_later(4, 2))
15892e3229dSLiu, Jinsong return -ENODEV;
15992e3229dSLiu, Jinsong
16092e3229dSLiu, Jinsong return acpi_bus_register_driver(&acpi_pad_driver);
16192e3229dSLiu, Jinsong }
16292e3229dSLiu, Jinsong subsys_initcall(xen_acpi_pad_init);
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