1/*
2 * IOAPIC/IOxAPIC/IOSAPIC driver
3 *
4 * Copyright (C) 2009 Fujitsu Limited.
5 * (c) Copyright 2009 Hewlett-Packard Development Company, L.P.
6 *
7 * Copyright (C) 2014 Intel Corporation
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * Based on original drivers/pci/ioapic.c
14 *	Yinghai Lu <yinghai@kernel.org>
15 *	Jiang Liu <jiang.liu@intel.com>
16 */
17
18/*
19 * This driver manages I/O APICs added by hotplug after boot.
20 * We try to claim all I/O APIC devices, but those present at boot were
21 * registered when we parsed the ACPI MADT.
22 */
23
24#define pr_fmt(fmt) "ACPI : IOAPIC: " fmt
25
26#include <linux/slab.h>
27#include <linux/acpi.h>
28#include <linux/pci.h>
29#include <acpi/acpi.h>
30
31struct acpi_pci_ioapic {
32	acpi_handle	root_handle;
33	acpi_handle	handle;
34	u32		gsi_base;
35	struct resource	res;
36	struct pci_dev	*pdev;
37	struct list_head list;
38};
39
40static LIST_HEAD(ioapic_list);
41static DEFINE_MUTEX(ioapic_list_lock);
42
43static acpi_status setup_res(struct acpi_resource *acpi_res, void *data)
44{
45	struct resource *res = data;
46	struct resource_win win;
47
48	res->flags = 0;
49	if (acpi_dev_filter_resource_type(acpi_res, IORESOURCE_MEM) == 0)
50		return AE_OK;
51
52	if (!acpi_dev_resource_memory(acpi_res, res)) {
53		if (acpi_dev_resource_address_space(acpi_res, &win) ||
54		    acpi_dev_resource_ext_address_space(acpi_res, &win))
55			*res = win.res;
56	}
57	if ((res->flags & IORESOURCE_PREFETCH) ||
58	    (res->flags & IORESOURCE_DISABLED))
59		res->flags = 0;
60
61	return AE_CTRL_TERMINATE;
62}
63
64static bool acpi_is_ioapic(acpi_handle handle, char **type)
65{
66	acpi_status status;
67	struct acpi_device_info *info;
68	char *hid = NULL;
69	bool match = false;
70
71	if (!acpi_has_method(handle, "_GSB"))
72		return false;
73
74	status = acpi_get_object_info(handle, &info);
75	if (ACPI_SUCCESS(status)) {
76		if (info->valid & ACPI_VALID_HID)
77			hid = info->hardware_id.string;
78		if (hid) {
79			if (strcmp(hid, "ACPI0009") == 0) {
80				*type = "IOxAPIC";
81				match = true;
82			} else if (strcmp(hid, "ACPI000A") == 0) {
83				*type = "IOAPIC";
84				match = true;
85			}
86		}
87		kfree(info);
88	}
89
90	return match;
91}
92
93static acpi_status handle_ioapic_add(acpi_handle handle, u32 lvl,
94				     void *context, void **rv)
95{
96	acpi_status status;
97	unsigned long long gsi_base;
98	struct acpi_pci_ioapic *ioapic;
99	struct pci_dev *dev = NULL;
100	struct resource *res = NULL;
101	char *type = NULL;
102
103	if (!acpi_is_ioapic(handle, &type))
104		return AE_OK;
105
106	mutex_lock(&ioapic_list_lock);
107	list_for_each_entry(ioapic, &ioapic_list, list)
108		if (ioapic->handle == handle) {
109			mutex_unlock(&ioapic_list_lock);
110			return AE_OK;
111		}
112
113	status = acpi_evaluate_integer(handle, "_GSB", NULL, &gsi_base);
114	if (ACPI_FAILURE(status)) {
115		acpi_handle_warn(handle, "failed to evaluate _GSB method\n");
116		goto exit;
117	}
118
119	ioapic = kzalloc(sizeof(*ioapic), GFP_KERNEL);
120	if (!ioapic) {
121		pr_err("cannot allocate memory for new IOAPIC\n");
122		goto exit;
123	} else {
124		ioapic->root_handle = (acpi_handle)context;
125		ioapic->handle = handle;
126		ioapic->gsi_base = (u32)gsi_base;
127		INIT_LIST_HEAD(&ioapic->list);
128	}
129
130	if (acpi_ioapic_registered(handle, (u32)gsi_base))
131		goto done;
132
133	dev = acpi_get_pci_dev(handle);
134	if (dev && pci_resource_len(dev, 0)) {
135		if (pci_enable_device(dev) < 0)
136			goto exit_put;
137		pci_set_master(dev);
138		if (pci_request_region(dev, 0, type))
139			goto exit_disable;
140		res = &dev->resource[0];
141		ioapic->pdev = dev;
142	} else {
143		pci_dev_put(dev);
144		dev = NULL;
145
146		res = &ioapic->res;
147		acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, res);
148		if (res->flags == 0) {
149			acpi_handle_warn(handle, "failed to get resource\n");
150			goto exit_free;
151		} else if (request_resource(&iomem_resource, res)) {
152			acpi_handle_warn(handle, "failed to insert resource\n");
153			goto exit_free;
154		}
155	}
156
157	if (acpi_register_ioapic(handle, res->start, (u32)gsi_base)) {
158		acpi_handle_warn(handle, "failed to register IOAPIC\n");
159		goto exit_release;
160	}
161done:
162	list_add(&ioapic->list, &ioapic_list);
163	mutex_unlock(&ioapic_list_lock);
164
165	if (dev)
166		dev_info(&dev->dev, "%s at %pR, GSI %u\n",
167			 type, res, (u32)gsi_base);
168	else
169		acpi_handle_info(handle, "%s at %pR, GSI %u\n",
170				 type, res, (u32)gsi_base);
171
172	return AE_OK;
173
174exit_release:
175	if (dev)
176		pci_release_region(dev, 0);
177	else
178		release_resource(res);
179exit_disable:
180	if (dev)
181		pci_disable_device(dev);
182exit_put:
183	pci_dev_put(dev);
184exit_free:
185	kfree(ioapic);
186exit:
187	mutex_unlock(&ioapic_list_lock);
188	*(acpi_status *)rv = AE_ERROR;
189	return AE_OK;
190}
191
192int acpi_ioapic_add(struct acpi_pci_root *root)
193{
194	acpi_status status, retval = AE_OK;
195
196	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root->device->handle,
197				     UINT_MAX, handle_ioapic_add, NULL,
198				     root->device->handle, (void **)&retval);
199
200	return ACPI_SUCCESS(status) && ACPI_SUCCESS(retval) ? 0 : -ENODEV;
201}
202
203int acpi_ioapic_remove(struct acpi_pci_root *root)
204{
205	int retval = 0;
206	struct acpi_pci_ioapic *ioapic, *tmp;
207
208	mutex_lock(&ioapic_list_lock);
209	list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
210		if (root->device->handle != ioapic->root_handle)
211			continue;
212
213		if (acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base))
214			retval = -EBUSY;
215
216		if (ioapic->pdev) {
217			pci_release_region(ioapic->pdev, 0);
218			pci_disable_device(ioapic->pdev);
219			pci_dev_put(ioapic->pdev);
220		} else if (ioapic->res.flags && ioapic->res.parent) {
221			release_resource(&ioapic->res);
222		}
223		list_del(&ioapic->list);
224		kfree(ioapic);
225	}
226	mutex_unlock(&ioapic_list_lock);
227
228	return retval;
229}
230