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 | |
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(sem: &bus_type_sem); |
38 | list_add_tail(new: &type->list, head: &bus_type_list); |
39 | up_write(sem: &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 | |
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(sem: &bus_type_sem); |
53 | list_del_init(entry: &type->list); |
54 | up_write(sem: &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 | |
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(sem: &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(sem: &bus_type_sem); |
74 | return ret; |
75 | } |
76 | |
77 | #define FIND_CHILD_MIN_SCORE 1 |
78 | #define FIND_CHILD_MID_SCORE 2 |
79 | #define FIND_CHILD_MAX_SCORE 3 |
80 | |
81 | static int match_any(struct acpi_device *adev, void *not_used) |
82 | { |
83 | return 1; |
84 | } |
85 | |
86 | static bool acpi_dev_has_children(struct acpi_device *adev) |
87 | { |
88 | return acpi_dev_for_each_child(adev, fn: match_any, NULL) > 0; |
89 | } |
90 | |
91 | static int find_child_checks(struct acpi_device *adev, bool check_children) |
92 | { |
93 | unsigned long long sta; |
94 | acpi_status status; |
95 | |
96 | if (check_children && !acpi_dev_has_children(adev)) |
97 | return -ENODEV; |
98 | |
99 | status = acpi_evaluate_integer(handle: adev->handle, pathname: "_STA" , NULL, data: &sta); |
100 | if (status == AE_NOT_FOUND) { |
101 | /* |
102 | * Special case: backlight device objects without _STA are |
103 | * preferred to other objects with the same _ADR value, because |
104 | * it is more likely that they are actually useful. |
105 | */ |
106 | if (adev->pnp.type.backlight) |
107 | return FIND_CHILD_MID_SCORE; |
108 | |
109 | return FIND_CHILD_MIN_SCORE; |
110 | } |
111 | |
112 | if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED)) |
113 | return -ENODEV; |
114 | |
115 | /* |
116 | * If the device has a _HID returning a valid ACPI/PNP device ID, it is |
117 | * better to make it look less attractive here, so that the other device |
118 | * with the same _ADR value (that may not have a valid device ID) can be |
119 | * matched going forward. [This means a second spec violation in a row, |
120 | * so whatever we do here is best effort anyway.] |
121 | */ |
122 | if (adev->pnp.type.platform_id) |
123 | return FIND_CHILD_MIN_SCORE; |
124 | |
125 | return FIND_CHILD_MAX_SCORE; |
126 | } |
127 | |
128 | struct find_child_walk_data { |
129 | struct acpi_device *adev; |
130 | u64 address; |
131 | int score; |
132 | bool check_sta; |
133 | bool check_children; |
134 | }; |
135 | |
136 | static int check_one_child(struct acpi_device *adev, void *data) |
137 | { |
138 | struct find_child_walk_data *wd = data; |
139 | int score; |
140 | |
141 | if (!adev->pnp.type.bus_address || acpi_device_adr(adev) != wd->address) |
142 | return 0; |
143 | |
144 | if (!wd->adev) { |
145 | /* |
146 | * This is the first matching object, so save it. If it is not |
147 | * necessary to look for any other matching objects, stop the |
148 | * search. |
149 | */ |
150 | wd->adev = adev; |
151 | return !(wd->check_sta || wd->check_children); |
152 | } |
153 | |
154 | /* |
155 | * There is more than one matching device object with the same _ADR |
156 | * value. That really is unexpected, so we are kind of beyond the scope |
157 | * of the spec here. We have to choose which one to return, though. |
158 | * |
159 | * First, get the score for the previously found object and terminate |
160 | * the walk if it is maximum. |
161 | */ |
162 | if (!wd->score) { |
163 | score = find_child_checks(adev: wd->adev, check_children: wd->check_children); |
164 | if (score == FIND_CHILD_MAX_SCORE) |
165 | return 1; |
166 | |
167 | wd->score = score; |
168 | } |
169 | /* |
170 | * Second, if the object that has just been found has a better score, |
171 | * replace the previously found one with it and terminate the walk if |
172 | * the new score is maximum. |
173 | */ |
174 | score = find_child_checks(adev, check_children: wd->check_children); |
175 | if (score > wd->score) { |
176 | wd->adev = adev; |
177 | if (score == FIND_CHILD_MAX_SCORE) |
178 | return 1; |
179 | |
180 | wd->score = score; |
181 | } |
182 | |
183 | /* Continue, because there may be better matches. */ |
184 | return 0; |
185 | } |
186 | |
187 | static struct acpi_device *acpi_find_child(struct acpi_device *parent, |
188 | u64 address, bool check_children, |
189 | bool check_sta) |
190 | { |
191 | struct find_child_walk_data wd = { |
192 | .address = address, |
193 | .check_children = check_children, |
194 | .check_sta = check_sta, |
195 | .adev = NULL, |
196 | .score = 0, |
197 | }; |
198 | |
199 | if (parent) |
200 | acpi_dev_for_each_child(adev: parent, fn: check_one_child, data: &wd); |
201 | |
202 | return wd.adev; |
203 | } |
204 | |
205 | struct acpi_device *acpi_find_child_device(struct acpi_device *parent, |
206 | u64 address, bool check_children) |
207 | { |
208 | return acpi_find_child(parent, address, check_children, check_sta: true); |
209 | } |
210 | EXPORT_SYMBOL_GPL(acpi_find_child_device); |
211 | |
212 | struct acpi_device *acpi_find_child_by_adr(struct acpi_device *adev, |
213 | acpi_bus_address adr) |
214 | { |
215 | return acpi_find_child(parent: adev, address: adr, check_children: false, check_sta: false); |
216 | } |
217 | EXPORT_SYMBOL_GPL(acpi_find_child_by_adr); |
218 | |
219 | static void acpi_physnode_link_name(char *buf, unsigned int node_id) |
220 | { |
221 | if (node_id > 0) |
222 | snprintf(buf, PHYSICAL_NODE_NAME_SIZE, |
223 | PHYSICAL_NODE_STRING "%u" , node_id); |
224 | else |
225 | strcpy(p: buf, PHYSICAL_NODE_STRING); |
226 | } |
227 | |
228 | int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev) |
229 | { |
230 | struct acpi_device_physical_node *physical_node, *pn; |
231 | char physical_node_name[PHYSICAL_NODE_NAME_SIZE]; |
232 | struct list_head *physnode_list; |
233 | unsigned int node_id; |
234 | int retval = -EINVAL; |
235 | |
236 | if (has_acpi_companion(dev)) { |
237 | if (acpi_dev) { |
238 | dev_warn(dev, "ACPI companion already set\n" ); |
239 | return -EINVAL; |
240 | } else { |
241 | acpi_dev = ACPI_COMPANION(dev); |
242 | } |
243 | } |
244 | if (!acpi_dev) |
245 | return -EINVAL; |
246 | |
247 | acpi_dev_get(adev: acpi_dev); |
248 | get_device(dev); |
249 | physical_node = kzalloc(size: sizeof(*physical_node), GFP_KERNEL); |
250 | if (!physical_node) { |
251 | retval = -ENOMEM; |
252 | goto err; |
253 | } |
254 | |
255 | mutex_lock(&acpi_dev->physical_node_lock); |
256 | |
257 | /* |
258 | * Keep the list sorted by node_id so that the IDs of removed nodes can |
259 | * be recycled easily. |
260 | */ |
261 | physnode_list = &acpi_dev->physical_node_list; |
262 | node_id = 0; |
263 | list_for_each_entry(pn, &acpi_dev->physical_node_list, node) { |
264 | /* Sanity check. */ |
265 | if (pn->dev == dev) { |
266 | mutex_unlock(lock: &acpi_dev->physical_node_lock); |
267 | |
268 | dev_warn(dev, "Already associated with ACPI node\n" ); |
269 | kfree(objp: physical_node); |
270 | if (ACPI_COMPANION(dev) != acpi_dev) |
271 | goto err; |
272 | |
273 | put_device(dev); |
274 | acpi_dev_put(adev: acpi_dev); |
275 | return 0; |
276 | } |
277 | if (pn->node_id == node_id) { |
278 | physnode_list = &pn->node; |
279 | node_id++; |
280 | } |
281 | } |
282 | |
283 | physical_node->node_id = node_id; |
284 | physical_node->dev = dev; |
285 | list_add(new: &physical_node->node, head: physnode_list); |
286 | acpi_dev->physical_node_count++; |
287 | |
288 | if (!has_acpi_companion(dev)) |
289 | ACPI_COMPANION_SET(dev, acpi_dev); |
290 | |
291 | acpi_physnode_link_name(buf: physical_node_name, node_id); |
292 | retval = sysfs_create_link(kobj: &acpi_dev->dev.kobj, target: &dev->kobj, |
293 | name: physical_node_name); |
294 | if (retval) |
295 | dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n" , |
296 | physical_node_name, retval); |
297 | |
298 | retval = sysfs_create_link(kobj: &dev->kobj, target: &acpi_dev->dev.kobj, |
299 | name: "firmware_node" ); |
300 | if (retval) |
301 | dev_err(dev, "Failed to create link firmware_node (%d)\n" , |
302 | retval); |
303 | |
304 | mutex_unlock(lock: &acpi_dev->physical_node_lock); |
305 | |
306 | if (acpi_dev->wakeup.flags.valid) |
307 | device_set_wakeup_capable(dev, capable: true); |
308 | |
309 | return 0; |
310 | |
311 | err: |
312 | ACPI_COMPANION_SET(dev, NULL); |
313 | put_device(dev); |
314 | acpi_dev_put(adev: acpi_dev); |
315 | return retval; |
316 | } |
317 | EXPORT_SYMBOL_GPL(acpi_bind_one); |
318 | |
319 | int acpi_unbind_one(struct device *dev) |
320 | { |
321 | struct acpi_device *acpi_dev = ACPI_COMPANION(dev); |
322 | struct acpi_device_physical_node *entry; |
323 | |
324 | if (!acpi_dev) |
325 | return 0; |
326 | |
327 | mutex_lock(&acpi_dev->physical_node_lock); |
328 | |
329 | list_for_each_entry(entry, &acpi_dev->physical_node_list, node) |
330 | if (entry->dev == dev) { |
331 | char physnode_name[PHYSICAL_NODE_NAME_SIZE]; |
332 | |
333 | list_del(entry: &entry->node); |
334 | acpi_dev->physical_node_count--; |
335 | |
336 | acpi_physnode_link_name(buf: physnode_name, node_id: entry->node_id); |
337 | sysfs_remove_link(kobj: &acpi_dev->dev.kobj, name: physnode_name); |
338 | sysfs_remove_link(kobj: &dev->kobj, name: "firmware_node" ); |
339 | ACPI_COMPANION_SET(dev, NULL); |
340 | /* Drop references taken by acpi_bind_one(). */ |
341 | put_device(dev); |
342 | acpi_dev_put(adev: acpi_dev); |
343 | kfree(objp: entry); |
344 | break; |
345 | } |
346 | |
347 | mutex_unlock(lock: &acpi_dev->physical_node_lock); |
348 | return 0; |
349 | } |
350 | EXPORT_SYMBOL_GPL(acpi_unbind_one); |
351 | |
352 | void acpi_device_notify(struct device *dev) |
353 | { |
354 | struct acpi_device *adev; |
355 | int ret; |
356 | |
357 | ret = acpi_bind_one(dev, NULL); |
358 | if (ret) { |
359 | struct acpi_bus_type *type = acpi_get_bus_type(dev); |
360 | |
361 | if (!type) |
362 | goto err; |
363 | |
364 | adev = type->find_companion(dev); |
365 | if (!adev) { |
366 | dev_dbg(dev, "ACPI companion not found\n" ); |
367 | goto err; |
368 | } |
369 | ret = acpi_bind_one(dev, adev); |
370 | if (ret) |
371 | goto err; |
372 | |
373 | if (type->setup) { |
374 | type->setup(dev); |
375 | goto done; |
376 | } |
377 | } else { |
378 | adev = ACPI_COMPANION(dev); |
379 | |
380 | if (dev_is_pci(dev)) { |
381 | pci_acpi_setup(dev, adev); |
382 | goto done; |
383 | } else if (dev_is_platform(dev)) { |
384 | acpi_configure_pmsi_domain(dev); |
385 | } |
386 | } |
387 | |
388 | if (adev->handler && adev->handler->bind) |
389 | adev->handler->bind(dev); |
390 | |
391 | done: |
392 | acpi_handle_debug(ACPI_HANDLE(dev), "Bound to device %s\n" , |
393 | dev_name(dev)); |
394 | |
395 | return; |
396 | |
397 | err: |
398 | dev_dbg(dev, "No ACPI support\n" ); |
399 | } |
400 | |
401 | void acpi_device_notify_remove(struct device *dev) |
402 | { |
403 | struct acpi_device *adev = ACPI_COMPANION(dev); |
404 | |
405 | if (!adev) |
406 | return; |
407 | |
408 | if (dev_is_pci(dev)) |
409 | pci_acpi_cleanup(dev, adev); |
410 | else if (adev->handler && adev->handler->unbind) |
411 | adev->handler->unbind(dev); |
412 | |
413 | acpi_unbind_one(dev); |
414 | } |
415 | |