xref: /openbmc/u-boot/drivers/core/devres.c (revision dd1033e4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
4  *
5  * Based on the original work in Linux by
6  * Copyright (c) 2006  SUSE Linux Products GmbH
7  * Copyright (c) 2006  Tejun Heo <teheo@suse.de>
8  */
9 
10 #include <common.h>
11 #include <linux/compat.h>
12 #include <linux/kernel.h>
13 #include <linux/list.h>
14 #include <dm/device.h>
15 #include <dm/root.h>
16 #include <dm/util.h>
17 
18 /**
19  * struct devres - Bookkeeping info for managed device resource
20  * @entry: List to associate this structure with a device
21  * @release: Callback invoked when this resource is released
22  * @probe: Flag to show when this resource was allocated
23 	   (true = probe, false = bind)
24  * @name: Name of release function
25  * @size: Size of resource data
26  * @data: Resource data
27  */
28 struct devres {
29 	struct list_head		entry;
30 	dr_release_t			release;
31 	bool				probe;
32 #ifdef CONFIG_DEBUG_DEVRES
33 	const char			*name;
34 	size_t				size;
35 #endif
36 	unsigned long long		data[];
37 };
38 
39 #ifdef CONFIG_DEBUG_DEVRES
40 static void set_node_dbginfo(struct devres *dr, const char *name, size_t size)
41 {
42 	dr->name = name;
43 	dr->size = size;
44 }
45 
46 static void devres_log(struct udevice *dev, struct devres *dr,
47 		       const char *op)
48 {
49 	printf("%s: DEVRES %3s %p %s (%lu bytes)\n",
50 	       dev->name, op, dr, dr->name, (unsigned long)dr->size);
51 }
52 #else /* CONFIG_DEBUG_DEVRES */
53 #define set_node_dbginfo(dr, n, s)	do {} while (0)
54 #define devres_log(dev, dr, op)		do {} while (0)
55 #endif
56 
57 #if CONFIG_DEBUG_DEVRES
58 void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
59 		     const char *name)
60 #else
61 void *_devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
62 #endif
63 {
64 	size_t tot_size = sizeof(struct devres) + size;
65 	struct devres *dr;
66 
67 	dr = kmalloc(tot_size, gfp);
68 	if (unlikely(!dr))
69 		return NULL;
70 
71 	INIT_LIST_HEAD(&dr->entry);
72 	dr->release = release;
73 	set_node_dbginfo(dr, name, size);
74 
75 	return dr->data;
76 }
77 
78 void devres_free(void *res)
79 {
80 	if (res) {
81 		struct devres *dr = container_of(res, struct devres, data);
82 
83 		BUG_ON(!list_empty(&dr->entry));
84 		kfree(dr);
85 	}
86 }
87 
88 void devres_add(struct udevice *dev, void *res)
89 {
90 	struct devres *dr = container_of(res, struct devres, data);
91 
92 	devres_log(dev, dr, "ADD");
93 	BUG_ON(!list_empty(&dr->entry));
94 	dr->probe = dev->flags & DM_FLAG_BOUND ? true : false;
95 	list_add_tail(&dr->entry, &dev->devres_head);
96 }
97 
98 void *devres_find(struct udevice *dev, dr_release_t release,
99 		  dr_match_t match, void *match_data)
100 {
101 	struct devres *dr;
102 
103 	list_for_each_entry_reverse(dr, &dev->devres_head, entry) {
104 		if (dr->release != release)
105 			continue;
106 		if (match && !match(dev, dr->data, match_data))
107 			continue;
108 		return dr->data;
109 	}
110 
111 	return NULL;
112 }
113 
114 void *devres_get(struct udevice *dev, void *new_res,
115 		 dr_match_t match, void *match_data)
116 {
117 	struct devres *new_dr = container_of(new_res, struct devres, data);
118 	void *res;
119 
120 	res = devres_find(dev, new_dr->release, match, match_data);
121 	if (!res) {
122 		devres_add(dev, new_res);
123 		res = new_res;
124 		new_res = NULL;
125 	}
126 	devres_free(new_res);
127 
128 	return res;
129 }
130 
131 void *devres_remove(struct udevice *dev, dr_release_t release,
132 		    dr_match_t match, void *match_data)
133 {
134 	void *res;
135 
136 	res = devres_find(dev, release, match, match_data);
137 	if (res) {
138 		struct devres *dr = container_of(res, struct devres, data);
139 
140 		list_del_init(&dr->entry);
141 		devres_log(dev, dr, "REM");
142 	}
143 
144 	return res;
145 }
146 
147 int devres_destroy(struct udevice *dev, dr_release_t release,
148 		   dr_match_t match, void *match_data)
149 {
150 	void *res;
151 
152 	res = devres_remove(dev, release, match, match_data);
153 	if (unlikely(!res))
154 		return -ENOENT;
155 
156 	devres_free(res);
157 	return 0;
158 }
159 
160 int devres_release(struct udevice *dev, dr_release_t release,
161 		   dr_match_t match, void *match_data)
162 {
163 	void *res;
164 
165 	res = devres_remove(dev, release, match, match_data);
166 	if (unlikely(!res))
167 		return -ENOENT;
168 
169 	(*release)(dev, res);
170 	devres_free(res);
171 	return 0;
172 }
173 
174 static void release_nodes(struct udevice *dev, struct list_head *head,
175 			  bool probe_only)
176 {
177 	struct devres *dr, *tmp;
178 
179 	list_for_each_entry_safe_reverse(dr, tmp, head, entry)  {
180 		if (probe_only && !dr->probe)
181 			break;
182 		devres_log(dev, dr, "REL");
183 		dr->release(dev, dr->data);
184 		list_del(&dr->entry);
185 		kfree(dr);
186 	}
187 }
188 
189 void devres_release_probe(struct udevice *dev)
190 {
191 	release_nodes(dev, &dev->devres_head, true);
192 }
193 
194 void devres_release_all(struct udevice *dev)
195 {
196 	release_nodes(dev, &dev->devres_head, false);
197 }
198 
199 #ifdef CONFIG_DEBUG_DEVRES
200 static void dump_resources(struct udevice *dev, int depth)
201 {
202 	struct devres *dr;
203 	struct udevice *child;
204 
205 	printf("- %s\n", dev->name);
206 
207 	list_for_each_entry(dr, &dev->devres_head, entry)
208 		printf("    %p (%lu byte) %s  %s\n", dr,
209 		       (unsigned long)dr->size, dr->name,
210 		       dr->probe ? "PROBE" : "BIND");
211 
212 	list_for_each_entry(child, &dev->child_head, sibling_node)
213 		dump_resources(child, depth + 1);
214 }
215 
216 void dm_dump_devres(void)
217 {
218 	struct udevice *root;
219 
220 	root = dm_root();
221 	if (root)
222 		dump_resources(root, 0);
223 }
224 #endif
225 
226 /*
227  * Managed kmalloc/kfree
228  */
229 static void devm_kmalloc_release(struct udevice *dev, void *res)
230 {
231 	/* noop */
232 }
233 
234 static int devm_kmalloc_match(struct udevice *dev, void *res, void *data)
235 {
236 	return res == data;
237 }
238 
239 void *devm_kmalloc(struct udevice *dev, size_t size, gfp_t gfp)
240 {
241 	void *data;
242 
243 	data = _devres_alloc(devm_kmalloc_release, size, gfp);
244 	if (unlikely(!data))
245 		return NULL;
246 
247 	devres_add(dev, data);
248 
249 	return data;
250 }
251 
252 void devm_kfree(struct udevice *dev, void *p)
253 {
254 	int rc;
255 
256 	rc = devres_destroy(dev, devm_kmalloc_release, devm_kmalloc_match, p);
257 	WARN_ON(rc);
258 }
259