1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Link physical devices with ACPI devices support
4 *
5 * Copyright (c) 2005 David Shaohua Li <shaohua.li@intel.com>
6 * Copyright (c) 2005 Intel Corp.
7 */
8
9 #define pr_fmt(fmt) "ACPI: " fmt
10
11 #include <linux/acpi_iort.h>
12 #include <linux/export.h>
13 #include <linux/init.h>
14 #include <linux/list.h>
15 #include <linux/device.h>
16 #include <linux/slab.h>
17 #include <linux/rwsem.h>
18 #include <linux/acpi.h>
19 #include <linux/dma-mapping.h>
20 #include <linux/platform_device.h>
21
22 #include "internal.h"
23
24 static LIST_HEAD(bus_type_list);
25 static DECLARE_RWSEM(bus_type_sem);
26
27 #define PHYSICAL_NODE_STRING "physical_node"
28 #define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10)
29
register_acpi_bus_type(struct acpi_bus_type * type)30 int register_acpi_bus_type(struct acpi_bus_type *type)
31 {
32 if (acpi_disabled)
33 return -ENODEV;
34 if (type && type->match && type->find_companion) {
35 down_write(&bus_type_sem);
36 list_add_tail(&type->list, &bus_type_list);
37 up_write(&bus_type_sem);
38 pr_info("bus type %s registered\n", type->name);
39 return 0;
40 }
41 return -ENODEV;
42 }
43 EXPORT_SYMBOL_GPL(register_acpi_bus_type);
44
unregister_acpi_bus_type(struct acpi_bus_type * type)45 int unregister_acpi_bus_type(struct acpi_bus_type *type)
46 {
47 if (acpi_disabled)
48 return 0;
49 if (type) {
50 down_write(&bus_type_sem);
51 list_del_init(&type->list);
52 up_write(&bus_type_sem);
53 pr_info("bus type %s unregistered\n", type->name);
54 return 0;
55 }
56 return -ENODEV;
57 }
58 EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
59
acpi_get_bus_type(struct device * dev)60 static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
61 {
62 struct acpi_bus_type *tmp, *ret = NULL;
63
64 down_read(&bus_type_sem);
65 list_for_each_entry(tmp, &bus_type_list, list) {
66 if (tmp->match(dev)) {
67 ret = tmp;
68 break;
69 }
70 }
71 up_read(&bus_type_sem);
72 return ret;
73 }
74
75 #define FIND_CHILD_MIN_SCORE 1
76 #define FIND_CHILD_MAX_SCORE 2
77
find_child_checks(struct acpi_device * adev,bool check_children)78 static int find_child_checks(struct acpi_device *adev, bool check_children)
79 {
80 bool sta_present = true;
81 unsigned long long sta;
82 acpi_status status;
83
84 status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
85 if (status == AE_NOT_FOUND)
86 sta_present = false;
87 else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
88 return -ENODEV;
89
90 if (check_children && list_empty(&adev->children))
91 return -ENODEV;
92
93 /*
94 * If the device has a _HID returning a valid ACPI/PNP device ID, it is
95 * better to make it look less attractive here, so that the other device
96 * with the same _ADR value (that may not have a valid device ID) can be
97 * matched going forward. [This means a second spec violation in a row,
98 * so whatever we do here is best effort anyway.]
99 */
100 return sta_present && !adev->pnp.type.platform_id ?
101 FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
102 }
103
acpi_find_child_device(struct acpi_device * parent,u64 address,bool check_children)104 struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
105 u64 address, bool check_children)
106 {
107 struct acpi_device *adev, *ret = NULL;
108 int ret_score = 0;
109
110 if (!parent)
111 return NULL;
112
113 list_for_each_entry(adev, &parent->children, node) {
114 unsigned long long addr;
115 acpi_status status;
116 int score;
117
118 status = acpi_evaluate_integer(adev->handle, METHOD_NAME__ADR,
119 NULL, &addr);
120 if (ACPI_FAILURE(status) || addr != address)
121 continue;
122
123 if (!ret) {
124 /* This is the first matching object. Save it. */
125 ret = adev;
126 continue;
127 }
128 /*
129 * There is more than one matching device object with the same
130 * _ADR value. That really is unexpected, so we are kind of
131 * beyond the scope of the spec here. We have to choose which
132 * one to return, though.
133 *
134 * First, check if the previously found object is good enough
135 * and return it if so. Second, do the same for the object that
136 * we've just found.
137 */
138 if (!ret_score) {
139 ret_score = find_child_checks(ret, check_children);
140 if (ret_score == FIND_CHILD_MAX_SCORE)
141 return ret;
142 }
143 score = find_child_checks(adev, check_children);
144 if (score == FIND_CHILD_MAX_SCORE) {
145 return adev;
146 } else if (score > ret_score) {
147 ret = adev;
148 ret_score = score;
149 }
150 }
151 return ret;
152 }
153 EXPORT_SYMBOL_GPL(acpi_find_child_device);
154
acpi_physnode_link_name(char * buf,unsigned int node_id)155 static void acpi_physnode_link_name(char *buf, unsigned int node_id)
156 {
157 if (node_id > 0)
158 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
159 PHYSICAL_NODE_STRING "%u", node_id);
160 else
161 strcpy(buf, PHYSICAL_NODE_STRING);
162 }
163
acpi_bind_one(struct device * dev,struct acpi_device * acpi_dev)164 int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
165 {
166 struct acpi_device_physical_node *physical_node, *pn;
167 char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
168 struct list_head *physnode_list;
169 unsigned int node_id;
170 int retval = -EINVAL;
171
172 if (has_acpi_companion(dev)) {
173 if (acpi_dev) {
174 dev_warn(dev, "ACPI companion already set\n");
175 return -EINVAL;
176 } else {
177 acpi_dev = ACPI_COMPANION(dev);
178 }
179 }
180 if (!acpi_dev)
181 return -EINVAL;
182
183 acpi_dev_get(acpi_dev);
184 get_device(dev);
185 physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
186 if (!physical_node) {
187 retval = -ENOMEM;
188 goto err;
189 }
190
191 mutex_lock(&acpi_dev->physical_node_lock);
192
193 /*
194 * Keep the list sorted by node_id so that the IDs of removed nodes can
195 * be recycled easily.
196 */
197 physnode_list = &acpi_dev->physical_node_list;
198 node_id = 0;
199 list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
200 /* Sanity check. */
201 if (pn->dev == dev) {
202 mutex_unlock(&acpi_dev->physical_node_lock);
203
204 dev_warn(dev, "Already associated with ACPI node\n");
205 kfree(physical_node);
206 if (ACPI_COMPANION(dev) != acpi_dev)
207 goto err;
208
209 put_device(dev);
210 acpi_dev_put(acpi_dev);
211 return 0;
212 }
213 if (pn->node_id == node_id) {
214 physnode_list = &pn->node;
215 node_id++;
216 }
217 }
218
219 physical_node->node_id = node_id;
220 physical_node->dev = dev;
221 list_add(&physical_node->node, physnode_list);
222 acpi_dev->physical_node_count++;
223
224 if (!has_acpi_companion(dev))
225 ACPI_COMPANION_SET(dev, acpi_dev);
226
227 acpi_physnode_link_name(physical_node_name, node_id);
228 retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
229 physical_node_name);
230 if (retval)
231 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
232 physical_node_name, retval);
233
234 retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
235 "firmware_node");
236 if (retval)
237 dev_err(dev, "Failed to create link firmware_node (%d)\n",
238 retval);
239
240 mutex_unlock(&acpi_dev->physical_node_lock);
241
242 if (acpi_dev->wakeup.flags.valid)
243 device_set_wakeup_capable(dev, true);
244
245 return 0;
246
247 err:
248 ACPI_COMPANION_SET(dev, NULL);
249 put_device(dev);
250 acpi_dev_put(acpi_dev);
251 return retval;
252 }
253 EXPORT_SYMBOL_GPL(acpi_bind_one);
254
acpi_unbind_one(struct device * dev)255 int acpi_unbind_one(struct device *dev)
256 {
257 struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
258 struct acpi_device_physical_node *entry;
259
260 if (!acpi_dev)
261 return 0;
262
263 mutex_lock(&acpi_dev->physical_node_lock);
264
265 list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
266 if (entry->dev == dev) {
267 char physnode_name[PHYSICAL_NODE_NAME_SIZE];
268
269 list_del(&entry->node);
270 acpi_dev->physical_node_count--;
271
272 acpi_physnode_link_name(physnode_name, entry->node_id);
273 sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
274 sysfs_remove_link(&dev->kobj, "firmware_node");
275 ACPI_COMPANION_SET(dev, NULL);
276 /* Drop references taken by acpi_bind_one(). */
277 put_device(dev);
278 acpi_dev_put(acpi_dev);
279 kfree(entry);
280 break;
281 }
282
283 mutex_unlock(&acpi_dev->physical_node_lock);
284 return 0;
285 }
286 EXPORT_SYMBOL_GPL(acpi_unbind_one);
287
acpi_device_notify(struct device * dev)288 void acpi_device_notify(struct device *dev)
289 {
290 struct acpi_bus_type *type = acpi_get_bus_type(dev);
291 struct acpi_device *adev;
292 int ret;
293
294 ret = acpi_bind_one(dev, NULL);
295 if (ret) {
296 if (!type)
297 goto err;
298
299 adev = type->find_companion(dev);
300 if (!adev) {
301 dev_dbg(dev, "ACPI companion not found\n");
302 goto err;
303 }
304 ret = acpi_bind_one(dev, adev);
305 if (ret)
306 goto err;
307 }
308 adev = ACPI_COMPANION(dev);
309
310 if (dev_is_platform(dev))
311 acpi_configure_pmsi_domain(dev);
312
313 if (type && type->setup)
314 type->setup(dev);
315 else if (adev->handler && adev->handler->bind)
316 adev->handler->bind(dev);
317
318 acpi_handle_debug(ACPI_HANDLE(dev), "Bound to device %s\n",
319 dev_name(dev));
320
321 return;
322
323 err:
324 dev_dbg(dev, "No ACPI support\n");
325 }
326
acpi_device_notify_remove(struct device * dev)327 void acpi_device_notify_remove(struct device *dev)
328 {
329 struct acpi_device *adev = ACPI_COMPANION(dev);
330 struct acpi_bus_type *type;
331
332 if (!adev)
333 return;
334
335 type = acpi_get_bus_type(dev);
336 if (type && type->cleanup)
337 type->cleanup(dev);
338 else if (adev->handler && adev->handler->unbind)
339 adev->handler->unbind(dev);
340
341 acpi_unbind_one(dev);
342 }
343