[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / xen / xen-acpi-pad.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);
Commit	Line	Data
92e3229d LJ	1	/*
	2	* xen-acpi-pad.c - Xen pad interface
	3	*
	4	* Copyright (c) 2012, Intel Corporation.
	5	* Author: Liu, Jinsong <jinsong.liu@intel.com>
	6	*
	7	* This program is free software; you can redistribute it and/or modify it
	8	* under the terms and conditions of the GNU General Public License,
	9	* version 2, as published by the Free Software Foundation.
	10	*
	11	* This program is distributed in the hope it will be useful, but WITHOUT
	12	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	13	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	14	* more details.
	15	*/
	16
	17	#include <linux/kernel.h>
	18	#include <linux/types.h>
	19	#include <acpi/acpi_bus.h>
	20	#include <acpi/acpi_drivers.h>
	21	#include <asm/xen/hypercall.h>
	22	#include <xen/interface/version.h>
394b40f6	23	#include <xen/xen-ops.h>
92e3229d LJ	24
	25	#define ACPI_PROCESSOR_AGGREGATOR_CLASS "acpi_pad"
	26	#define ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME "Processor Aggregator"
	27	#define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80
	28	static DEFINE_MUTEX(xen_cpu_lock);
	29
	30	static int xen_acpi_pad_idle_cpus(unsigned int idle_nums)
	31	{
	32	struct xen_platform_op op;
	33
	34	op.cmd = XENPF_core_parking;
	35	op.u.core_parking.type = XEN_CORE_PARKING_SET;
	36	op.u.core_parking.idle_nums = idle_nums;
	37
	38	return HYPERVISOR_dom0_op(&op);
	39	}
	40
	41	static int xen_acpi_pad_idle_cpus_num(void)
	42	{
	43	struct xen_platform_op op;
	44
	45	op.cmd = XENPF_core_parking;
	46	op.u.core_parking.type = XEN_CORE_PARKING_GET;
	47
	48	return HYPERVISOR_dom0_op(&op)
	49	?: op.u.core_parking.idle_nums;
	50	}
	51
	52	/*
	53	* Query firmware how many CPUs should be idle
	54	* return -1 on failure
	55	*/
	56	static int acpi_pad_pur(acpi_handle handle)
	57	{
	58	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	59	union acpi_object *package;
	60	int num = -1;
	61
	62	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_PUR", NULL, &buffer)))
	63	return num;
	64
	65	if (!buffer.length \|\| !buffer.pointer)
	66	return num;
	67
	68	package = buffer.pointer;
	69
	70	if (package->type == ACPI_TYPE_PACKAGE &&
	71	package->package.count == 2 &&
	72	package->package.elements[0].integer.value == 1) /* rev 1 */
	73	num = package->package.elements[1].integer.value;
	74
	75	kfree(buffer.pointer);
	76	return num;
	77	}
	78
	79	/* Notify firmware how many CPUs are idle */
	80	static void acpi_pad_ost(acpi_handle handle, int stat,
	81	uint32_t idle_nums)
	82	{
	83	union acpi_object params[3] = {
	84	{.type = ACPI_TYPE_INTEGER,},
	85	{.type = ACPI_TYPE_INTEGER,},
	86	{.type = ACPI_TYPE_BUFFER,},
	87	};
88	struct acpi_object_list arg_list = {3, params};
89
90	params[0].integer.value = ACPI_PROCESSOR_AGGREGATOR_NOTIFY;
91	params[1].integer.value = stat;
92	params[2].buffer.length = 4;
93	params[2].buffer.pointer = (void *)&idle_nums;
94	acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
95	}
96
97	static void acpi_pad_handle_notify(acpi_handle handle)
98	{
99	int idle_nums;
100
101	mutex_lock(&xen_cpu_lock);
102	idle_nums = acpi_pad_pur(handle);
103	if (idle_nums < 0) {
104	mutex_unlock(&xen_cpu_lock);
105	return;
106	}
107
108	idle_nums = xen_acpi_pad_idle_cpus(idle_nums)
109	?: xen_acpi_pad_idle_cpus_num();
110	if (idle_nums >= 0)
111	acpi_pad_ost(handle, 0, idle_nums);
112	mutex_unlock(&xen_cpu_lock);
113	}
114
115	static void acpi_pad_notify(acpi_handle handle, u32 event,
116	void *data)
117	{
118	switch (event) {
119	case ACPI_PROCESSOR_AGGREGATOR_NOTIFY:
120	acpi_pad_handle_notify(handle);
121	break;
122	default:
123	pr_warn("Unsupported event [0x%x]\n", event);
124	break;
125	}
126	}
127
128	static int acpi_pad_add(struct acpi_device *device)
129	{
130	acpi_status status;
131
132	strcpy(acpi_device_name(device), ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME);
133	strcpy(acpi_device_class(device), ACPI_PROCESSOR_AGGREGATOR_CLASS);
134
135	status = acpi_install_notify_handler(device->handle,
136	ACPI_DEVICE_NOTIFY, acpi_pad_notify, device);
137	if (ACPI_FAILURE(status))
138	return -ENODEV;
139
140	return 0;
141	}
142
51fac838	143	static int acpi_pad_remove(struct acpi_device *device)
92e3229d LJ	144	{
	145	mutex_lock(&xen_cpu_lock);
	146	xen_acpi_pad_idle_cpus(0);
	147	mutex_unlock(&xen_cpu_lock);
	148
	149	acpi_remove_notify_handler(device->handle,
	150	ACPI_DEVICE_NOTIFY, acpi_pad_notify);
	151	return 0;
	152	}
	153
	154	static const struct acpi_device_id pad_device_ids[] = {
	155	{"ACPI000C", 0},
	156	{"", 0},
	157	};
	158
	159	static struct acpi_driver acpi_pad_driver = {
	160	.name = "processor_aggregator",
	161	.class = ACPI_PROCESSOR_AGGREGATOR_CLASS,
	162	.ids = pad_device_ids,
	163	.ops = {
	164	.add = acpi_pad_add,
	165	.remove = acpi_pad_remove,
	166	},
	167	};
	168
	169	static int __init xen_acpi_pad_init(void)
	170	{
	171	/* Only DOM0 is responsible for Xen acpi pad */
	172	if (!xen_initial_domain())
	173	return -ENODEV;
	174
	175	/* Only Xen4.2 or later support Xen acpi pad */
	176	if (!xen_running_on_version_or_later(4, 2))
	177	return -ENODEV;
	178
	179	return acpi_bus_register_driver(&acpi_pad_driver);
	180	}
	181	subsys_initcall(xen_acpi_pad_init);