Thomas Gleixner | 2025cf9 | 2019-05-29 07:18:02 -0700 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Liu, Jinsong | 92e3229 | 2012-11-08 05:41:13 +0000 | [diff] [blame] | 2 | /* |
| 3 | * xen-acpi-pad.c - Xen pad interface |
| 4 | * |
| 5 | * Copyright (c) 2012, Intel Corporation. |
| 6 | * Author: Liu, Jinsong <jinsong.liu@intel.com> |
Liu, Jinsong | 92e3229 | 2012-11-08 05:41:13 +0000 | [diff] [blame] | 7 | */ |
| 8 | |
Joe Perches | 283c097 | 2013-06-28 03:21:41 -0700 | [diff] [blame] | 9 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 10 | |
Liu, Jinsong | 92e3229 | 2012-11-08 05:41:13 +0000 | [diff] [blame] | 11 | #include <linux/kernel.h> |
| 12 | #include <linux/types.h> |
Lv Zheng | 8b48463 | 2013-12-03 08:49:16 +0800 | [diff] [blame] | 13 | #include <linux/acpi.h> |
Christoph Hellwig | 3cfa210 | 2018-09-25 13:30:09 -0700 | [diff] [blame] | 14 | #include <xen/xen.h> |
Liu, Jinsong | 92e3229 | 2012-11-08 05:41:13 +0000 | [diff] [blame] | 15 | #include <xen/interface/version.h> |
Konrad Rzeszutek Wilk | 394b40f | 2012-11-27 11:39:40 -0500 | [diff] [blame] | 16 | #include <xen/xen-ops.h> |
Lv Zheng | 8b48463 | 2013-12-03 08:49:16 +0800 | [diff] [blame] | 17 | #include <asm/xen/hypercall.h> |
Liu, Jinsong | 92e3229 | 2012-11-08 05:41:13 +0000 | [diff] [blame] | 18 | |
| 19 | #define ACPI_PROCESSOR_AGGREGATOR_CLASS "acpi_pad" |
| 20 | #define ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME "Processor Aggregator" |
| 21 | #define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80 |
| 22 | static DEFINE_MUTEX(xen_cpu_lock); |
| 23 | |
| 24 | static int xen_acpi_pad_idle_cpus(unsigned int idle_nums) |
| 25 | { |
| 26 | struct xen_platform_op op; |
| 27 | |
| 28 | op.cmd = XENPF_core_parking; |
| 29 | op.u.core_parking.type = XEN_CORE_PARKING_SET; |
| 30 | op.u.core_parking.idle_nums = idle_nums; |
| 31 | |
Stefano Stabellini | cfafae9 | 2015-11-23 10:36:12 +0000 | [diff] [blame] | 32 | return HYPERVISOR_platform_op(&op); |
Liu, Jinsong | 92e3229 | 2012-11-08 05:41:13 +0000 | [diff] [blame] | 33 | } |
| 34 | |
| 35 | static int xen_acpi_pad_idle_cpus_num(void) |
| 36 | { |
| 37 | struct xen_platform_op op; |
| 38 | |
| 39 | op.cmd = XENPF_core_parking; |
| 40 | op.u.core_parking.type = XEN_CORE_PARKING_GET; |
| 41 | |
Stefano Stabellini | cfafae9 | 2015-11-23 10:36:12 +0000 | [diff] [blame] | 42 | return HYPERVISOR_platform_op(&op) |
Liu, Jinsong | 92e3229 | 2012-11-08 05:41:13 +0000 | [diff] [blame] | 43 | ?: op.u.core_parking.idle_nums; |
| 44 | } |
| 45 | |
| 46 | /* |
| 47 | * Query firmware how many CPUs should be idle |
| 48 | * return -1 on failure |
| 49 | */ |
| 50 | static int acpi_pad_pur(acpi_handle handle) |
| 51 | { |
| 52 | struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; |
| 53 | union acpi_object *package; |
| 54 | int num = -1; |
| 55 | |
| 56 | if (ACPI_FAILURE(acpi_evaluate_object(handle, "_PUR", NULL, &buffer))) |
| 57 | return num; |
| 58 | |
| 59 | if (!buffer.length || !buffer.pointer) |
| 60 | return num; |
| 61 | |
| 62 | package = buffer.pointer; |
| 63 | |
| 64 | if (package->type == ACPI_TYPE_PACKAGE && |
| 65 | package->package.count == 2 && |
| 66 | package->package.elements[0].integer.value == 1) /* rev 1 */ |
| 67 | num = package->package.elements[1].integer.value; |
| 68 | |
| 69 | kfree(buffer.pointer); |
| 70 | return num; |
| 71 | } |
| 72 | |
Liu, Jinsong | 92e3229 | 2012-11-08 05:41:13 +0000 | [diff] [blame] | 73 | static void acpi_pad_handle_notify(acpi_handle handle) |
| 74 | { |
| 75 | int idle_nums; |
Jiang Liu | 772c539 | 2014-02-19 14:02:17 +0800 | [diff] [blame] | 76 | struct acpi_buffer param = { |
| 77 | .length = 4, |
| 78 | .pointer = (void *)&idle_nums, |
| 79 | }; |
| 80 | |
Liu, Jinsong | 92e3229 | 2012-11-08 05:41:13 +0000 | [diff] [blame] | 81 | |
| 82 | mutex_lock(&xen_cpu_lock); |
| 83 | idle_nums = acpi_pad_pur(handle); |
| 84 | if (idle_nums < 0) { |
| 85 | mutex_unlock(&xen_cpu_lock); |
| 86 | return; |
| 87 | } |
| 88 | |
| 89 | idle_nums = xen_acpi_pad_idle_cpus(idle_nums) |
| 90 | ?: xen_acpi_pad_idle_cpus_num(); |
| 91 | if (idle_nums >= 0) |
Jiang Liu | 772c539 | 2014-02-19 14:02:17 +0800 | [diff] [blame] | 92 | acpi_evaluate_ost(handle, ACPI_PROCESSOR_AGGREGATOR_NOTIFY, |
| 93 | 0, ¶m); |
Liu, Jinsong | 92e3229 | 2012-11-08 05:41:13 +0000 | [diff] [blame] | 94 | mutex_unlock(&xen_cpu_lock); |
| 95 | } |
| 96 | |
| 97 | static void acpi_pad_notify(acpi_handle handle, u32 event, |
| 98 | void *data) |
| 99 | { |
| 100 | switch (event) { |
| 101 | case ACPI_PROCESSOR_AGGREGATOR_NOTIFY: |
| 102 | acpi_pad_handle_notify(handle); |
| 103 | break; |
| 104 | default: |
| 105 | pr_warn("Unsupported event [0x%x]\n", event); |
| 106 | break; |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | static int acpi_pad_add(struct acpi_device *device) |
| 111 | { |
| 112 | acpi_status status; |
| 113 | |
| 114 | strcpy(acpi_device_name(device), ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME); |
| 115 | strcpy(acpi_device_class(device), ACPI_PROCESSOR_AGGREGATOR_CLASS); |
| 116 | |
| 117 | status = acpi_install_notify_handler(device->handle, |
| 118 | ACPI_DEVICE_NOTIFY, acpi_pad_notify, device); |
| 119 | if (ACPI_FAILURE(status)) |
| 120 | return -ENODEV; |
| 121 | |
| 122 | return 0; |
| 123 | } |
| 124 | |
Rafael J. Wysocki | 51fac83 | 2013-01-24 00:24:48 +0100 | [diff] [blame] | 125 | static int acpi_pad_remove(struct acpi_device *device) |
Liu, Jinsong | 92e3229 | 2012-11-08 05:41:13 +0000 | [diff] [blame] | 126 | { |
| 127 | mutex_lock(&xen_cpu_lock); |
| 128 | xen_acpi_pad_idle_cpus(0); |
| 129 | mutex_unlock(&xen_cpu_lock); |
| 130 | |
| 131 | acpi_remove_notify_handler(device->handle, |
| 132 | ACPI_DEVICE_NOTIFY, acpi_pad_notify); |
| 133 | return 0; |
| 134 | } |
| 135 | |
| 136 | static const struct acpi_device_id pad_device_ids[] = { |
| 137 | {"ACPI000C", 0}, |
| 138 | {"", 0}, |
| 139 | }; |
| 140 | |
| 141 | static struct acpi_driver acpi_pad_driver = { |
| 142 | .name = "processor_aggregator", |
| 143 | .class = ACPI_PROCESSOR_AGGREGATOR_CLASS, |
| 144 | .ids = pad_device_ids, |
| 145 | .ops = { |
| 146 | .add = acpi_pad_add, |
| 147 | .remove = acpi_pad_remove, |
| 148 | }, |
| 149 | }; |
| 150 | |
| 151 | static int __init xen_acpi_pad_init(void) |
| 152 | { |
| 153 | /* Only DOM0 is responsible for Xen acpi pad */ |
| 154 | if (!xen_initial_domain()) |
| 155 | return -ENODEV; |
| 156 | |
| 157 | /* Only Xen4.2 or later support Xen acpi pad */ |
| 158 | if (!xen_running_on_version_or_later(4, 2)) |
| 159 | return -ENODEV; |
| 160 | |
| 161 | return acpi_bus_register_driver(&acpi_pad_driver); |
| 162 | } |
| 163 | subsys_initcall(xen_acpi_pad_init); |