xref: /openbmc/linux/drivers/acpi/ioapic.c (revision 020c5260)
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 
31 struct 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 
40 static LIST_HEAD(ioapic_list);
41 static DEFINE_MUTEX(ioapic_list_lock);
42 
43 static acpi_status setup_res(struct acpi_resource *acpi_res, void *data)
44 {
45 	struct resource *res = data;
46 	struct resource_win win;
47 
48 	/*
49 	 * We might assign this to 'res' later, make sure all pointers are
50 	 * cleared before the resource is added to the global list
51 	 */
52 	memset(&win, 0, sizeof(win));
53 
54 	res->flags = 0;
55 	if (acpi_dev_filter_resource_type(acpi_res, IORESOURCE_MEM))
56 		return AE_OK;
57 
58 	if (!acpi_dev_resource_memory(acpi_res, res)) {
59 		if (acpi_dev_resource_address_space(acpi_res, &win) ||
60 		    acpi_dev_resource_ext_address_space(acpi_res, &win))
61 			*res = win.res;
62 	}
63 	if ((res->flags & IORESOURCE_PREFETCH) ||
64 	    (res->flags & IORESOURCE_DISABLED))
65 		res->flags = 0;
66 
67 	return AE_CTRL_TERMINATE;
68 }
69 
70 static bool acpi_is_ioapic(acpi_handle handle, char **type)
71 {
72 	acpi_status status;
73 	struct acpi_device_info *info;
74 	char *hid = NULL;
75 	bool match = false;
76 
77 	if (!acpi_has_method(handle, "_GSB"))
78 		return false;
79 
80 	status = acpi_get_object_info(handle, &info);
81 	if (ACPI_SUCCESS(status)) {
82 		if (info->valid & ACPI_VALID_HID)
83 			hid = info->hardware_id.string;
84 		if (hid) {
85 			if (strcmp(hid, "ACPI0009") == 0) {
86 				*type = "IOxAPIC";
87 				match = true;
88 			} else if (strcmp(hid, "ACPI000A") == 0) {
89 				*type = "IOAPIC";
90 				match = true;
91 			}
92 		}
93 		kfree(info);
94 	}
95 
96 	return match;
97 }
98 
99 static acpi_status handle_ioapic_add(acpi_handle handle, u32 lvl,
100 				     void *context, void **rv)
101 {
102 	acpi_status status;
103 	unsigned long long gsi_base;
104 	struct acpi_pci_ioapic *ioapic;
105 	struct pci_dev *dev = NULL;
106 	struct resource *res = NULL, *pci_res = NULL, *crs_res;
107 	char *type = NULL;
108 
109 	if (!acpi_is_ioapic(handle, &type))
110 		return AE_OK;
111 
112 	mutex_lock(&ioapic_list_lock);
113 	list_for_each_entry(ioapic, &ioapic_list, list)
114 		if (ioapic->handle == handle) {
115 			mutex_unlock(&ioapic_list_lock);
116 			return AE_OK;
117 		}
118 
119 	status = acpi_evaluate_integer(handle, "_GSB", NULL, &gsi_base);
120 	if (ACPI_FAILURE(status)) {
121 		acpi_handle_warn(handle, "failed to evaluate _GSB method\n");
122 		goto exit;
123 	}
124 
125 	ioapic = kzalloc(sizeof(*ioapic), GFP_KERNEL);
126 	if (!ioapic) {
127 		pr_err("cannot allocate memory for new IOAPIC\n");
128 		goto exit;
129 	} else {
130 		ioapic->root_handle = (acpi_handle)context;
131 		ioapic->handle = handle;
132 		ioapic->gsi_base = (u32)gsi_base;
133 		INIT_LIST_HEAD(&ioapic->list);
134 	}
135 
136 	if (acpi_ioapic_registered(handle, (u32)gsi_base))
137 		goto done;
138 
139 	dev = acpi_get_pci_dev(handle);
140 	if (dev && pci_resource_len(dev, 0)) {
141 		if (pci_enable_device(dev) < 0)
142 			goto exit_put;
143 		pci_set_master(dev);
144 		if (pci_request_region(dev, 0, type))
145 			goto exit_disable;
146 		pci_res = &dev->resource[0];
147 		ioapic->pdev = dev;
148 	} else {
149 		pci_dev_put(dev);
150 		dev = NULL;
151 	}
152 
153 	crs_res = &ioapic->res;
154 	acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, crs_res);
155 	crs_res->name = type;
156 	crs_res->flags |= IORESOURCE_BUSY;
157 	if (crs_res->flags == 0) {
158 		acpi_handle_warn(handle, "failed to get resource\n");
159 		goto exit_release;
160 	} else if (insert_resource(&iomem_resource, crs_res)) {
161 		acpi_handle_warn(handle, "failed to insert resource\n");
162 		goto exit_release;
163 	}
164 
165 	/* try pci resource first, then "_CRS" resource */
166 	res = pci_res;
167 	if (!res || !res->flags)
168 		res = crs_res;
169 
170 	if (acpi_register_ioapic(handle, res->start, (u32)gsi_base)) {
171 		acpi_handle_warn(handle, "failed to register IOAPIC\n");
172 		goto exit_release;
173 	}
174 done:
175 	list_add(&ioapic->list, &ioapic_list);
176 	mutex_unlock(&ioapic_list_lock);
177 
178 	if (dev)
179 		dev_info(&dev->dev, "%s at %pR, GSI %u\n",
180 			 type, res, (u32)gsi_base);
181 	else
182 		acpi_handle_info(handle, "%s at %pR, GSI %u\n",
183 				 type, res, (u32)gsi_base);
184 
185 	return AE_OK;
186 
187 exit_release:
188 	if (dev)
189 		pci_release_region(dev, 0);
190 	if (ioapic->res.flags && ioapic->res.parent)
191 		release_resource(&ioapic->res);
192 exit_disable:
193 	if (dev)
194 		pci_disable_device(dev);
195 exit_put:
196 	pci_dev_put(dev);
197 	kfree(ioapic);
198 exit:
199 	mutex_unlock(&ioapic_list_lock);
200 	*(acpi_status *)rv = AE_ERROR;
201 	return AE_OK;
202 }
203 
204 int acpi_ioapic_add(acpi_handle root_handle)
205 {
206 	acpi_status status, retval = AE_OK;
207 
208 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root_handle,
209 				     UINT_MAX, handle_ioapic_add, NULL,
210 				     root_handle, (void **)&retval);
211 
212 	return ACPI_SUCCESS(status) && ACPI_SUCCESS(retval) ? 0 : -ENODEV;
213 }
214 
215 void pci_ioapic_remove(struct acpi_pci_root *root)
216 {
217 	struct acpi_pci_ioapic *ioapic, *tmp;
218 
219 	mutex_lock(&ioapic_list_lock);
220 	list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
221 		if (root->device->handle != ioapic->root_handle)
222 			continue;
223 		if (ioapic->pdev) {
224 			pci_release_region(ioapic->pdev, 0);
225 			pci_disable_device(ioapic->pdev);
226 			pci_dev_put(ioapic->pdev);
227 		}
228 	}
229 	mutex_unlock(&ioapic_list_lock);
230 }
231 
232 int acpi_ioapic_remove(struct acpi_pci_root *root)
233 {
234 	int retval = 0;
235 	struct acpi_pci_ioapic *ioapic, *tmp;
236 
237 	mutex_lock(&ioapic_list_lock);
238 	list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
239 		if (root->device->handle != ioapic->root_handle)
240 			continue;
241 		if (acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base))
242 			retval = -EBUSY;
243 		if (ioapic->res.flags && ioapic->res.parent)
244 			release_resource(&ioapic->res);
245 		list_del(&ioapic->list);
246 		kfree(ioapic);
247 	}
248 	mutex_unlock(&ioapic_list_lock);
249 
250 	return retval;
251 }
252