xref: /openbmc/linux/drivers/acpi/glue.c (revision f64e4275)
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_MID_SCORE	2
79 #define FIND_CHILD_MAX_SCORE	3
80 
match_any(struct acpi_device * adev,void * not_used)81 static int match_any(struct acpi_device *adev, void *not_used)
82 {
83 	return 1;
84 }
85 
acpi_dev_has_children(struct acpi_device * adev)86 static bool acpi_dev_has_children(struct acpi_device *adev)
87 {
88 	return acpi_dev_for_each_child(adev, match_any, NULL) > 0;
89 }
90 
find_child_checks(struct acpi_device * adev,bool check_children)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(adev->handle, "_STA", NULL, &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 
check_one_child(struct acpi_device * adev,void * data)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(wd->adev, 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, 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 
acpi_find_child(struct acpi_device * parent,u64 address,bool check_children,bool check_sta)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(parent, check_one_child, &wd);
201 
202 	return wd.adev;
203 }
204 
acpi_find_child_device(struct acpi_device * parent,u64 address,bool check_children)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, true);
209 }
210 EXPORT_SYMBOL_GPL(acpi_find_child_device);
211 
acpi_find_child_by_adr(struct acpi_device * adev,acpi_bus_address adr)212 struct acpi_device *acpi_find_child_by_adr(struct acpi_device *adev,
213 					   acpi_bus_address adr)
214 {
215 	return acpi_find_child(adev, adr, false, false);
216 }
217 EXPORT_SYMBOL_GPL(acpi_find_child_by_adr);
218 
acpi_physnode_link_name(char * buf,unsigned int node_id)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(buf, PHYSICAL_NODE_STRING);
226 }
227 
acpi_bind_one(struct device * dev,struct acpi_device * acpi_dev)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(acpi_dev);
248 	get_device(dev);
249 	physical_node = kzalloc(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(&acpi_dev->physical_node_lock);
267 
268 			dev_warn(dev, "Already associated with ACPI node\n");
269 			kfree(physical_node);
270 			if (ACPI_COMPANION(dev) != acpi_dev)
271 				goto err;
272 
273 			put_device(dev);
274 			acpi_dev_put(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(&physical_node->node, 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(physical_node_name, node_id);
292 	retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
293 				   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(&dev->kobj, &acpi_dev->dev.kobj,
299 				   "firmware_node");
300 	if (retval)
301 		dev_err(dev, "Failed to create link firmware_node (%d)\n",
302 			retval);
303 
304 	mutex_unlock(&acpi_dev->physical_node_lock);
305 
306 	if (acpi_dev->wakeup.flags.valid)
307 		device_set_wakeup_capable(dev, true);
308 
309 	return 0;
310 
311  err:
312 	ACPI_COMPANION_SET(dev, NULL);
313 	put_device(dev);
314 	acpi_dev_put(acpi_dev);
315 	return retval;
316 }
317 EXPORT_SYMBOL_GPL(acpi_bind_one);
318 
acpi_unbind_one(struct device * dev)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->node);
334 			acpi_dev->physical_node_count--;
335 
336 			acpi_physnode_link_name(physnode_name, entry->node_id);
337 			sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
338 			sysfs_remove_link(&dev->kobj, "firmware_node");
339 			ACPI_COMPANION_SET(dev, NULL);
340 			/* Drop references taken by acpi_bind_one(). */
341 			put_device(dev);
342 			acpi_dev_put(acpi_dev);
343 			kfree(entry);
344 			break;
345 		}
346 
347 	mutex_unlock(&acpi_dev->physical_node_lock);
348 	return 0;
349 }
350 EXPORT_SYMBOL_GPL(acpi_unbind_one);
351 
acpi_device_notify(struct device * dev)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 
acpi_device_notify_remove(struct device * dev)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