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 #include <linux/acpi_iort.h>
10 #include <linux/export.h>
11 #include <linux/init.h>
12 #include <linux/list.h>
13 #include <linux/device.h>
14 #include <linux/slab.h>
15 #include <linux/rwsem.h>
16 #include <linux/acpi.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/platform_device.h>
19
20 #include "internal.h"
21
22 #define ACPI_GLUE_DEBUG 0
23 #if ACPI_GLUE_DEBUG
24 #define DBG(fmt, ...) \
25 printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__)
26 #else
27 #define DBG(fmt, ...) \
28 do { \
29 if (0) \
30 printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__); \
31 } while (0)
32 #endif
33 static LIST_HEAD(bus_type_list);
34 static DECLARE_RWSEM(bus_type_sem);
35
36 #define PHYSICAL_NODE_STRING "physical_node"
37 #define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10)
38
register_acpi_bus_type(struct acpi_bus_type * type)39 int register_acpi_bus_type(struct acpi_bus_type *type)
40 {
41 if (acpi_disabled)
42 return -ENODEV;
43 if (type && type->match && type->find_companion) {
44 down_write(&bus_type_sem);
45 list_add_tail(&type->list, &bus_type_list);
46 up_write(&bus_type_sem);
47 printk(KERN_INFO PREFIX "bus type %s registered\n", type->name);
48 return 0;
49 }
50 return -ENODEV;
51 }
52 EXPORT_SYMBOL_GPL(register_acpi_bus_type);
53
unregister_acpi_bus_type(struct acpi_bus_type * type)54 int unregister_acpi_bus_type(struct acpi_bus_type *type)
55 {
56 if (acpi_disabled)
57 return 0;
58 if (type) {
59 down_write(&bus_type_sem);
60 list_del_init(&type->list);
61 up_write(&bus_type_sem);
62 printk(KERN_INFO PREFIX "bus type %s unregistered\n",
63 type->name);
64 return 0;
65 }
66 return -ENODEV;
67 }
68 EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
69
acpi_get_bus_type(struct device * dev)70 static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
71 {
72 struct acpi_bus_type *tmp, *ret = NULL;
73
74 down_read(&bus_type_sem);
75 list_for_each_entry(tmp, &bus_type_list, list) {
76 if (tmp->match(dev)) {
77 ret = tmp;
78 break;
79 }
80 }
81 up_read(&bus_type_sem);
82 return ret;
83 }
84
85 #define FIND_CHILD_MIN_SCORE 1
86 #define FIND_CHILD_MAX_SCORE 2
87
find_child_checks(struct acpi_device * adev,bool check_children)88 static int find_child_checks(struct acpi_device *adev, bool check_children)
89 {
90 bool sta_present = true;
91 unsigned long long sta;
92 acpi_status status;
93
94 status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
95 if (status == AE_NOT_FOUND)
96 sta_present = false;
97 else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
98 return -ENODEV;
99
100 if (check_children && list_empty(&adev->children))
101 return -ENODEV;
102
103 /*
104 * If the device has a _HID returning a valid ACPI/PNP device ID, it is
105 * better to make it look less attractive here, so that the other device
106 * with the same _ADR value (that may not have a valid device ID) can be
107 * matched going forward. [This means a second spec violation in a row,
108 * so whatever we do here is best effort anyway.]
109 */
110 return sta_present && !adev->pnp.type.platform_id ?
111 FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
112 }
113
acpi_find_child_device(struct acpi_device * parent,u64 address,bool check_children)114 struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
115 u64 address, bool check_children)
116 {
117 struct acpi_device *adev, *ret = NULL;
118 int ret_score = 0;
119
120 if (!parent)
121 return NULL;
122
123 list_for_each_entry(adev, &parent->children, node) {
124 unsigned long long addr;
125 acpi_status status;
126 int score;
127
128 status = acpi_evaluate_integer(adev->handle, METHOD_NAME__ADR,
129 NULL, &addr);
130 if (ACPI_FAILURE(status) || addr != address)
131 continue;
132
133 if (!ret) {
134 /* This is the first matching object. Save it. */
135 ret = adev;
136 continue;
137 }
138 /*
139 * There is more than one matching device object with the same
140 * _ADR value. That really is unexpected, so we are kind of
141 * beyond the scope of the spec here. We have to choose which
142 * one to return, though.
143 *
144 * First, check if the previously found object is good enough
145 * and return it if so. Second, do the same for the object that
146 * we've just found.
147 */
148 if (!ret_score) {
149 ret_score = find_child_checks(ret, check_children);
150 if (ret_score == FIND_CHILD_MAX_SCORE)
151 return ret;
152 }
153 score = find_child_checks(adev, check_children);
154 if (score == FIND_CHILD_MAX_SCORE) {
155 return adev;
156 } else if (score > ret_score) {
157 ret = adev;
158 ret_score = score;
159 }
160 }
161 return ret;
162 }
163 EXPORT_SYMBOL_GPL(acpi_find_child_device);
164
acpi_physnode_link_name(char * buf,unsigned int node_id)165 static void acpi_physnode_link_name(char *buf, unsigned int node_id)
166 {
167 if (node_id > 0)
168 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
169 PHYSICAL_NODE_STRING "%u", node_id);
170 else
171 strcpy(buf, PHYSICAL_NODE_STRING);
172 }
173
acpi_bind_one(struct device * dev,struct acpi_device * acpi_dev)174 int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
175 {
176 struct acpi_device_physical_node *physical_node, *pn;
177 char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
178 struct list_head *physnode_list;
179 unsigned int node_id;
180 int retval = -EINVAL;
181
182 if (has_acpi_companion(dev)) {
183 if (acpi_dev) {
184 dev_warn(dev, "ACPI companion already set\n");
185 return -EINVAL;
186 } else {
187 acpi_dev = ACPI_COMPANION(dev);
188 }
189 }
190 if (!acpi_dev)
191 return -EINVAL;
192
193 get_device(&acpi_dev->dev);
194 get_device(dev);
195 physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
196 if (!physical_node) {
197 retval = -ENOMEM;
198 goto err;
199 }
200
201 mutex_lock(&acpi_dev->physical_node_lock);
202
203 /*
204 * Keep the list sorted by node_id so that the IDs of removed nodes can
205 * be recycled easily.
206 */
207 physnode_list = &acpi_dev->physical_node_list;
208 node_id = 0;
209 list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
210 /* Sanity check. */
211 if (pn->dev == dev) {
212 mutex_unlock(&acpi_dev->physical_node_lock);
213
214 dev_warn(dev, "Already associated with ACPI node\n");
215 kfree(physical_node);
216 if (ACPI_COMPANION(dev) != acpi_dev)
217 goto err;
218
219 put_device(dev);
220 put_device(&acpi_dev->dev);
221 return 0;
222 }
223 if (pn->node_id == node_id) {
224 physnode_list = &pn->node;
225 node_id++;
226 }
227 }
228
229 physical_node->node_id = node_id;
230 physical_node->dev = dev;
231 list_add(&physical_node->node, physnode_list);
232 acpi_dev->physical_node_count++;
233
234 if (!has_acpi_companion(dev))
235 ACPI_COMPANION_SET(dev, acpi_dev);
236
237 acpi_physnode_link_name(physical_node_name, node_id);
238 retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
239 physical_node_name);
240 if (retval)
241 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
242 physical_node_name, retval);
243
244 retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
245 "firmware_node");
246 if (retval)
247 dev_err(dev, "Failed to create link firmware_node (%d)\n",
248 retval);
249
250 mutex_unlock(&acpi_dev->physical_node_lock);
251
252 if (acpi_dev->wakeup.flags.valid)
253 device_set_wakeup_capable(dev, true);
254
255 return 0;
256
257 err:
258 ACPI_COMPANION_SET(dev, NULL);
259 put_device(dev);
260 put_device(&acpi_dev->dev);
261 return retval;
262 }
263 EXPORT_SYMBOL_GPL(acpi_bind_one);
264
acpi_unbind_one(struct device * dev)265 int acpi_unbind_one(struct device *dev)
266 {
267 struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
268 struct acpi_device_physical_node *entry;
269
270 if (!acpi_dev)
271 return 0;
272
273 mutex_lock(&acpi_dev->physical_node_lock);
274
275 list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
276 if (entry->dev == dev) {
277 char physnode_name[PHYSICAL_NODE_NAME_SIZE];
278
279 list_del(&entry->node);
280 acpi_dev->physical_node_count--;
281
282 acpi_physnode_link_name(physnode_name, entry->node_id);
283 sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
284 sysfs_remove_link(&dev->kobj, "firmware_node");
285 ACPI_COMPANION_SET(dev, NULL);
286 /* Drop references taken by acpi_bind_one(). */
287 put_device(dev);
288 put_device(&acpi_dev->dev);
289 kfree(entry);
290 break;
291 }
292
293 mutex_unlock(&acpi_dev->physical_node_lock);
294 return 0;
295 }
296 EXPORT_SYMBOL_GPL(acpi_unbind_one);
297
acpi_device_notify(struct device * dev)298 static int acpi_device_notify(struct device *dev)
299 {
300 struct acpi_bus_type *type = acpi_get_bus_type(dev);
301 struct acpi_device *adev;
302 int ret;
303
304 ret = acpi_bind_one(dev, NULL);
305 if (ret && type) {
306 struct acpi_device *adev;
307
308 adev = type->find_companion(dev);
309 if (!adev) {
310 DBG("Unable to get handle for %s\n", dev_name(dev));
311 ret = -ENODEV;
312 goto out;
313 }
314 ret = acpi_bind_one(dev, adev);
315 if (ret)
316 goto out;
317 }
318 adev = ACPI_COMPANION(dev);
319 if (!adev)
320 goto out;
321
322 if (dev_is_platform(dev))
323 acpi_configure_pmsi_domain(dev);
324
325 if (type && type->setup)
326 type->setup(dev);
327 else if (adev->handler && adev->handler->bind)
328 adev->handler->bind(dev);
329
330 out:
331 #if ACPI_GLUE_DEBUG
332 if (!ret) {
333 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
334
335 acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
336 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
337 kfree(buffer.pointer);
338 } else
339 DBG("Device %s -> No ACPI support\n", dev_name(dev));
340 #endif
341
342 return ret;
343 }
344
acpi_device_notify_remove(struct device * dev)345 static int acpi_device_notify_remove(struct device *dev)
346 {
347 struct acpi_device *adev = ACPI_COMPANION(dev);
348 struct acpi_bus_type *type;
349
350 if (!adev)
351 return 0;
352
353 type = acpi_get_bus_type(dev);
354 if (type && type->cleanup)
355 type->cleanup(dev);
356 else if (adev->handler && adev->handler->unbind)
357 adev->handler->unbind(dev);
358
359 acpi_unbind_one(dev);
360 return 0;
361 }
362
acpi_platform_notify(struct device * dev,enum kobject_action action)363 int acpi_platform_notify(struct device *dev, enum kobject_action action)
364 {
365 switch (action) {
366 case KOBJ_ADD:
367 acpi_device_notify(dev);
368 break;
369 case KOBJ_REMOVE:
370 acpi_device_notify_remove(dev);
371 break;
372 default:
373 break;
374 }
375 return 0;
376 }
377