xref: /openbmc/linux/drivers/acpi/ioapic.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * IOAPIC/IOxAPIC/IOSAPIC driver
4  *
5  * Copyright (C) 2009 Fujitsu Limited.
6  * (c) Copyright 2009 Hewlett-Packard Development Company, L.P.
7  *
8  * Copyright (C) 2014 Intel Corporation
9  *
10  * Based on original drivers/pci/ioapic.c
11  *	Yinghai Lu <yinghai@kernel.org>
12  *	Jiang Liu <jiang.liu@intel.com>
13  */
14 
15 /*
16  * This driver manages I/O APICs added by hotplug after boot.
17  * We try to claim all I/O APIC devices, but those present at boot were
18  * registered when we parsed the ACPI MADT.
19  */
20 
21 #define pr_fmt(fmt) "ACPI: IOAPIC: " fmt
22 
23 #include <linux/slab.h>
24 #include <linux/acpi.h>
25 #include <linux/pci.h>
26 #include <acpi/acpi.h>
27 
28 struct acpi_pci_ioapic {
29 	acpi_handle	root_handle;
30 	acpi_handle	handle;
31 	u32		gsi_base;
32 	struct resource	res;
33 	struct pci_dev	*pdev;
34 	struct list_head list;
35 };
36 
37 static LIST_HEAD(ioapic_list);
38 static DEFINE_MUTEX(ioapic_list_lock);
39 
40 static acpi_status setup_res(struct acpi_resource *acpi_res, void *data)
41 {
42 	struct resource *res = data;
43 	struct resource_win win;
44 
45 	/*
46 	 * We might assign this to 'res' later, make sure all pointers are
47 	 * cleared before the resource is added to the global list
48 	 */
49 	memset(&win, 0, sizeof(win));
50 
51 	res->flags = 0;
52 	if (acpi_dev_filter_resource_type(acpi_res, IORESOURCE_MEM))
53 		return AE_OK;
54 
55 	if (!acpi_dev_resource_memory(acpi_res, res)) {
56 		if (acpi_dev_resource_address_space(acpi_res, &win) ||
57 		    acpi_dev_resource_ext_address_space(acpi_res, &win))
58 			*res = win.res;
59 	}
60 	if ((res->flags & IORESOURCE_PREFETCH) ||
61 	    (res->flags & IORESOURCE_DISABLED))
62 		res->flags = 0;
63 
64 	return AE_CTRL_TERMINATE;
65 }
66 
67 static bool acpi_is_ioapic(acpi_handle handle, char **type)
68 {
69 	acpi_status status;
70 	struct acpi_device_info *info;
71 	char *hid = NULL;
72 	bool match = false;
73 
74 	if (!acpi_has_method(handle, "_GSB"))
75 		return false;
76 
77 	status = acpi_get_object_info(handle, &info);
78 	if (ACPI_SUCCESS(status)) {
79 		if (info->valid & ACPI_VALID_HID)
80 			hid = info->hardware_id.string;
81 		if (hid) {
82 			if (strcmp(hid, "ACPI0009") == 0) {
83 				*type = "IOxAPIC";
84 				match = true;
85 			} else if (strcmp(hid, "ACPI000A") == 0) {
86 				*type = "IOAPIC";
87 				match = true;
88 			}
89 		}
90 		kfree(info);
91 	}
92 
93 	return match;
94 }
95 
96 static acpi_status handle_ioapic_add(acpi_handle handle, u32 lvl,
97 				     void *context, void **rv)
98 {
99 	acpi_status status;
100 	unsigned long long gsi_base;
101 	struct acpi_pci_ioapic *ioapic;
102 	struct pci_dev *dev = NULL;
103 	struct resource *res = NULL, *pci_res = NULL, *crs_res;
104 	char *type = NULL;
105 
106 	if (!acpi_is_ioapic(handle, &type))
107 		return AE_OK;
108 
109 	mutex_lock(&ioapic_list_lock);
110 	list_for_each_entry(ioapic, &ioapic_list, list)
111 		if (ioapic->handle == handle) {
112 			mutex_unlock(&ioapic_list_lock);
113 			return AE_OK;
114 		}
115 
116 	status = acpi_evaluate_integer(handle, "_GSB", NULL, &gsi_base);
117 	if (ACPI_FAILURE(status)) {
118 		acpi_handle_warn(handle, "failed to evaluate _GSB method\n");
119 		goto exit;
120 	}
121 
122 	ioapic = kzalloc(sizeof(*ioapic), GFP_KERNEL);
123 	if (!ioapic) {
124 		pr_err("cannot allocate memory for new IOAPIC\n");
125 		goto exit;
126 	} else {
127 		ioapic->root_handle = (acpi_handle)context;
128 		ioapic->handle = handle;
129 		ioapic->gsi_base = (u32)gsi_base;
130 		INIT_LIST_HEAD(&ioapic->list);
131 	}
132 
133 	if (acpi_ioapic_registered(handle, (u32)gsi_base))
134 		goto done;
135 
136 	dev = acpi_get_pci_dev(handle);
137 	if (dev && pci_resource_len(dev, 0)) {
138 		if (pci_enable_device(dev) < 0)
139 			goto exit_put;
140 		pci_set_master(dev);
141 		if (pci_request_region(dev, 0, type))
142 			goto exit_disable;
143 		pci_res = &dev->resource[0];
144 		ioapic->pdev = dev;
145 	} else {
146 		pci_dev_put(dev);
147 		dev = NULL;
148 	}
149 
150 	crs_res = &ioapic->res;
151 	acpi_walk_resources(handle, METHOD_NAME__CRS, setup_res, crs_res);
152 	crs_res->name = type;
153 	crs_res->flags |= IORESOURCE_BUSY;
154 	if (crs_res->flags == 0) {
155 		acpi_handle_warn(handle, "failed to get resource\n");
156 		goto exit_release;
157 	} else if (insert_resource(&iomem_resource, crs_res)) {
158 		acpi_handle_warn(handle, "failed to insert resource\n");
159 		goto exit_release;
160 	}
161 
162 	/* try pci resource first, then "_CRS" resource */
163 	res = pci_res;
164 	if (!res || !res->flags)
165 		res = crs_res;
166 
167 	if (acpi_register_ioapic(handle, res->start, (u32)gsi_base)) {
168 		acpi_handle_warn(handle, "failed to register IOAPIC\n");
169 		goto exit_release;
170 	}
171 done:
172 	list_add(&ioapic->list, &ioapic_list);
173 	mutex_unlock(&ioapic_list_lock);
174 
175 	if (dev)
176 		dev_info(&dev->dev, "%s at %pR, GSI %u\n",
177 			 type, res, (u32)gsi_base);
178 	else
179 		acpi_handle_info(handle, "%s at %pR, GSI %u\n",
180 				 type, res, (u32)gsi_base);
181 
182 	return AE_OK;
183 
184 exit_release:
185 	if (dev)
186 		pci_release_region(dev, 0);
187 	if (ioapic->res.flags && ioapic->res.parent)
188 		release_resource(&ioapic->res);
189 exit_disable:
190 	if (dev)
191 		pci_disable_device(dev);
192 exit_put:
193 	pci_dev_put(dev);
194 	kfree(ioapic);
195 exit:
196 	mutex_unlock(&ioapic_list_lock);
197 	*(acpi_status *)rv = AE_ERROR;
198 	return AE_OK;
199 }
200 
201 int acpi_ioapic_add(acpi_handle root_handle)
202 {
203 	acpi_status status, retval = AE_OK;
204 
205 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, root_handle,
206 				     UINT_MAX, handle_ioapic_add, NULL,
207 				     root_handle, (void **)&retval);
208 
209 	return ACPI_SUCCESS(status) && ACPI_SUCCESS(retval) ? 0 : -ENODEV;
210 }
211 
212 void pci_ioapic_remove(struct acpi_pci_root *root)
213 {
214 	struct acpi_pci_ioapic *ioapic, *tmp;
215 
216 	mutex_lock(&ioapic_list_lock);
217 	list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
218 		if (root->device->handle != ioapic->root_handle)
219 			continue;
220 		if (ioapic->pdev) {
221 			pci_release_region(ioapic->pdev, 0);
222 			pci_disable_device(ioapic->pdev);
223 			pci_dev_put(ioapic->pdev);
224 		}
225 	}
226 	mutex_unlock(&ioapic_list_lock);
227 }
228 
229 int acpi_ioapic_remove(struct acpi_pci_root *root)
230 {
231 	int retval = 0;
232 	struct acpi_pci_ioapic *ioapic, *tmp;
233 
234 	mutex_lock(&ioapic_list_lock);
235 	list_for_each_entry_safe(ioapic, tmp, &ioapic_list, list) {
236 		if (root->device->handle != ioapic->root_handle)
237 			continue;
238 		if (acpi_unregister_ioapic(ioapic->handle, ioapic->gsi_base))
239 			retval = -EBUSY;
240 		if (ioapic->res.flags && ioapic->res.parent)
241 			release_resource(&ioapic->res);
242 		list_del(&ioapic->list);
243 		kfree(ioapic);
244 	}
245 	mutex_unlock(&ioapic_list_lock);
246 
247 	return retval;
248 }
249