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/pci.h>
21 #include <linux/pci-acpi.h>
22 #include <linux/platform_device.h>
23
24 #include "internal.h"
25
26 static LIST_HEAD(bus_type_list);
27 static DECLARE_RWSEM(bus_type_sem);
28
29 #define PHYSICAL_NODE_STRING "physical_node"
30 #define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10)
31
register_acpi_bus_type(struct acpi_bus_type * type)32 int register_acpi_bus_type(struct acpi_bus_type *type)
33 {
34 if (acpi_disabled)
35 return -ENODEV;
36 if (type && type->match && type->find_companion) {
37 down_write(&bus_type_sem);
38 list_add_tail(&type->list, &bus_type_list);
39 up_write(&bus_type_sem);
40 pr_info("bus type %s registered\n", type->name);
41 return 0;
42 }
43 return -ENODEV;
44 }
45 EXPORT_SYMBOL_GPL(register_acpi_bus_type);
46
unregister_acpi_bus_type(struct acpi_bus_type * type)47 int unregister_acpi_bus_type(struct acpi_bus_type *type)
48 {
49 if (acpi_disabled)
50 return 0;
51 if (type) {
52 down_write(&bus_type_sem);
53 list_del_init(&type->list);
54 up_write(&bus_type_sem);
55 pr_info("bus type %s unregistered\n", type->name);
56 return 0;
57 }
58 return -ENODEV;
59 }
60 EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
61
acpi_get_bus_type(struct device * dev)62 static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
63 {
64 struct acpi_bus_type *tmp, *ret = NULL;
65
66 down_read(&bus_type_sem);
67 list_for_each_entry(tmp, &bus_type_list, list) {
68 if (tmp->match(dev)) {
69 ret = tmp;
70 break;
71 }
72 }
73 up_read(&bus_type_sem);
74 return ret;
75 }
76
77 #define FIND_CHILD_MIN_SCORE 1
78 #define FIND_CHILD_MAX_SCORE 2
79
find_child_checks(struct acpi_device * adev,bool check_children)80 static int find_child_checks(struct acpi_device *adev, bool check_children)
81 {
82 bool sta_present = true;
83 unsigned long long sta;
84 acpi_status status;
85
86 status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
87 if (status == AE_NOT_FOUND)
88 sta_present = false;
89 else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
90 return -ENODEV;
91
92 if (check_children && list_empty(&adev->children))
93 return -ENODEV;
94
95 /*
96 * If the device has a _HID returning a valid ACPI/PNP device ID, it is
97 * better to make it look less attractive here, so that the other device
98 * with the same _ADR value (that may not have a valid device ID) can be
99 * matched going forward. [This means a second spec violation in a row,
100 * so whatever we do here is best effort anyway.]
101 */
102 return sta_present && !adev->pnp.type.platform_id ?
103 FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
104 }
105
acpi_find_child_device(struct acpi_device * parent,u64 address,bool check_children)106 struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
107 u64 address, bool check_children)
108 {
109 struct acpi_device *adev, *ret = NULL;
110 int ret_score = 0;
111
112 if (!parent)
113 return NULL;
114
115 list_for_each_entry(adev, &parent->children, node) {
116 acpi_bus_address addr = acpi_device_adr(adev);
117 int score;
118
119 if (!adev->pnp.type.bus_address || addr != address)
120 continue;
121
122 if (!ret) {
123 /* This is the first matching object. Save it. */
124 ret = adev;
125 continue;
126 }
127 /*
128 * There is more than one matching device object with the same
129 * _ADR value. That really is unexpected, so we are kind of
130 * beyond the scope of the spec here. We have to choose which
131 * one to return, though.
132 *
133 * First, check if the previously found object is good enough
134 * and return it if so. Second, do the same for the object that
135 * we've just found.
136 */
137 if (!ret_score) {
138 ret_score = find_child_checks(ret, check_children);
139 if (ret_score == FIND_CHILD_MAX_SCORE)
140 return ret;
141 }
142 score = find_child_checks(adev, check_children);
143 if (score == FIND_CHILD_MAX_SCORE) {
144 return adev;
145 } else if (score > ret_score) {
146 ret = adev;
147 ret_score = score;
148 }
149 }
150 return ret;
151 }
152 EXPORT_SYMBOL_GPL(acpi_find_child_device);
153
acpi_physnode_link_name(char * buf,unsigned int node_id)154 static void acpi_physnode_link_name(char *buf, unsigned int node_id)
155 {
156 if (node_id > 0)
157 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
158 PHYSICAL_NODE_STRING "%u", node_id);
159 else
160 strcpy(buf, PHYSICAL_NODE_STRING);
161 }
162
acpi_bind_one(struct device * dev,struct acpi_device * acpi_dev)163 int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
164 {
165 struct acpi_device_physical_node *physical_node, *pn;
166 char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
167 struct list_head *physnode_list;
168 unsigned int node_id;
169 int retval = -EINVAL;
170
171 if (has_acpi_companion(dev)) {
172 if (acpi_dev) {
173 dev_warn(dev, "ACPI companion already set\n");
174 return -EINVAL;
175 } else {
176 acpi_dev = ACPI_COMPANION(dev);
177 }
178 }
179 if (!acpi_dev)
180 return -EINVAL;
181
182 acpi_dev_get(acpi_dev);
183 get_device(dev);
184 physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
185 if (!physical_node) {
186 retval = -ENOMEM;
187 goto err;
188 }
189
190 mutex_lock(&acpi_dev->physical_node_lock);
191
192 /*
193 * Keep the list sorted by node_id so that the IDs of removed nodes can
194 * be recycled easily.
195 */
196 physnode_list = &acpi_dev->physical_node_list;
197 node_id = 0;
198 list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
199 /* Sanity check. */
200 if (pn->dev == dev) {
201 mutex_unlock(&acpi_dev->physical_node_lock);
202
203 dev_warn(dev, "Already associated with ACPI node\n");
204 kfree(physical_node);
205 if (ACPI_COMPANION(dev) != acpi_dev)
206 goto err;
207
208 put_device(dev);
209 acpi_dev_put(acpi_dev);
210 return 0;
211 }
212 if (pn->node_id == node_id) {
213 physnode_list = &pn->node;
214 node_id++;
215 }
216 }
217
218 physical_node->node_id = node_id;
219 physical_node->dev = dev;
220 list_add(&physical_node->node, physnode_list);
221 acpi_dev->physical_node_count++;
222
223 if (!has_acpi_companion(dev))
224 ACPI_COMPANION_SET(dev, acpi_dev);
225
226 acpi_physnode_link_name(physical_node_name, node_id);
227 retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
228 physical_node_name);
229 if (retval)
230 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
231 physical_node_name, retval);
232
233 retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
234 "firmware_node");
235 if (retval)
236 dev_err(dev, "Failed to create link firmware_node (%d)\n",
237 retval);
238
239 mutex_unlock(&acpi_dev->physical_node_lock);
240
241 if (acpi_dev->wakeup.flags.valid)
242 device_set_wakeup_capable(dev, true);
243
244 return 0;
245
246 err:
247 ACPI_COMPANION_SET(dev, NULL);
248 put_device(dev);
249 acpi_dev_put(acpi_dev);
250 return retval;
251 }
252 EXPORT_SYMBOL_GPL(acpi_bind_one);
253
acpi_unbind_one(struct device * dev)254 int acpi_unbind_one(struct device *dev)
255 {
256 struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
257 struct acpi_device_physical_node *entry;
258
259 if (!acpi_dev)
260 return 0;
261
262 mutex_lock(&acpi_dev->physical_node_lock);
263
264 list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
265 if (entry->dev == dev) {
266 char physnode_name[PHYSICAL_NODE_NAME_SIZE];
267
268 list_del(&entry->node);
269 acpi_dev->physical_node_count--;
270
271 acpi_physnode_link_name(physnode_name, entry->node_id);
272 sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
273 sysfs_remove_link(&dev->kobj, "firmware_node");
274 ACPI_COMPANION_SET(dev, NULL);
275 /* Drop references taken by acpi_bind_one(). */
276 put_device(dev);
277 acpi_dev_put(acpi_dev);
278 kfree(entry);
279 break;
280 }
281
282 mutex_unlock(&acpi_dev->physical_node_lock);
283 return 0;
284 }
285 EXPORT_SYMBOL_GPL(acpi_unbind_one);
286
acpi_device_notify(struct device * dev)287 void acpi_device_notify(struct device *dev)
288 {
289 struct acpi_device *adev;
290 int ret;
291
292 ret = acpi_bind_one(dev, NULL);
293 if (ret) {
294 struct acpi_bus_type *type = acpi_get_bus_type(dev);
295
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 if (type->setup) {
309 type->setup(dev);
310 goto done;
311 }
312 } else {
313 adev = ACPI_COMPANION(dev);
314
315 if (dev_is_pci(dev)) {
316 pci_acpi_setup(dev, adev);
317 goto done;
318 } else if (dev_is_platform(dev)) {
319 acpi_configure_pmsi_domain(dev);
320 }
321 }
322
323 if (adev->handler && adev->handler->bind)
324 adev->handler->bind(dev);
325
326 done:
327 acpi_handle_debug(ACPI_HANDLE(dev), "Bound to device %s\n",
328 dev_name(dev));
329
330 return;
331
332 err:
333 dev_dbg(dev, "No ACPI support\n");
334 }
335
acpi_device_notify_remove(struct device * dev)336 void acpi_device_notify_remove(struct device *dev)
337 {
338 struct acpi_device *adev = ACPI_COMPANION(dev);
339
340 if (!adev)
341 return;
342
343 if (dev_is_pci(dev))
344 pci_acpi_cleanup(dev, adev);
345 else if (adev->handler && adev->handler->unbind)
346 adev->handler->unbind(dev);
347
348 acpi_unbind_one(dev);
349 }
350