xref: /openbmc/u-boot/drivers/core/devres.c (revision 2d2811c2)
1 /*
2  * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
3  *
4  * Based on the original work in Linux by
5  * Copyright (c) 2006  SUSE Linux Products GmbH
6  * Copyright (c) 2006  Tejun Heo <teheo@suse.de>
7  *
8  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 #include <common.h>
12 #include <linux/compat.h>
13 #include <linux/kernel.h>
14 #include <linux/list.h>
15 #include <dm/device.h>
16 #include <dm/root.h>
17 #include <dm/util.h>
18 
19 /**
20  * struct devres - Bookkeeping info for managed device resource
21  * @entry: List to associate this structure with a device
22  * @release: Callback invoked when this resource is released
23  * @probe: Flag to show when this resource was allocated
24 	   (true = probe, false = bind)
25  * @name: Name of release function
26  * @size: Size of resource data
27  * @data: Resource data
28  */
29 struct devres {
30 	struct list_head		entry;
31 	dr_release_t			release;
32 	bool				probe;
33 #ifdef CONFIG_DEBUG_DEVRES
34 	const char			*name;
35 	size_t				size;
36 #endif
37 	unsigned long long		data[];
38 };
39 
40 #ifdef CONFIG_DEBUG_DEVRES
41 static void set_node_dbginfo(struct devres *dr, const char *name, size_t size)
42 {
43 	dr->name = name;
44 	dr->size = size;
45 }
46 
47 static void devres_log(struct udevice *dev, struct devres *dr,
48 		       const char *op)
49 {
50 	printf("%s: DEVRES %3s %p %s (%lu bytes)\n",
51 	       dev->name, op, dr, dr->name, (unsigned long)dr->size);
52 }
53 #else /* CONFIG_DEBUG_DEVRES */
54 #define set_node_dbginfo(dr, n, s)	do {} while (0)
55 #define devres_log(dev, dr, op)		do {} while (0)
56 #endif
57 
58 #if CONFIG_DEBUG_DEVRES
59 void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
60 		     const char *name)
61 #else
62 void *_devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
63 #endif
64 {
65 	size_t tot_size = sizeof(struct devres) + size;
66 	struct devres *dr;
67 
68 	dr = kmalloc(tot_size, gfp);
69 	if (unlikely(!dr))
70 		return NULL;
71 
72 	INIT_LIST_HEAD(&dr->entry);
73 	dr->release = release;
74 	set_node_dbginfo(dr, name, size);
75 
76 	return dr->data;
77 }
78 
79 void devres_free(void *res)
80 {
81 	if (res) {
82 		struct devres *dr = container_of(res, struct devres, data);
83 
84 		BUG_ON(!list_empty(&dr->entry));
85 		kfree(dr);
86 	}
87 }
88 
89 void devres_add(struct udevice *dev, void *res)
90 {
91 	struct devres *dr = container_of(res, struct devres, data);
92 
93 	devres_log(dev, dr, "ADD");
94 	BUG_ON(!list_empty(&dr->entry));
95 	dr->probe = dev->flags & DM_FLAG_BOUND ? true : false;
96 	list_add_tail(&dr->entry, &dev->devres_head);
97 }
98 
99 void *devres_find(struct udevice *dev, dr_release_t release,
100 		  dr_match_t match, void *match_data)
101 {
102 	struct devres *dr;
103 
104 	list_for_each_entry_reverse(dr, &dev->devres_head, entry) {
105 		if (dr->release != release)
106 			continue;
107 		if (match && !match(dev, dr->data, match_data))
108 			continue;
109 		return dr->data;
110 	}
111 
112 	return NULL;
113 }
114 
115 void *devres_get(struct udevice *dev, void *new_res,
116 		 dr_match_t match, void *match_data)
117 {
118 	struct devres *new_dr = container_of(new_res, struct devres, data);
119 	void *res;
120 
121 	res = devres_find(dev, new_dr->release, match, match_data);
122 	if (!res) {
123 		devres_add(dev, new_res);
124 		res = new_res;
125 		new_res = NULL;
126 	}
127 	devres_free(new_res);
128 
129 	return res;
130 }
131 
132 void *devres_remove(struct udevice *dev, dr_release_t release,
133 		    dr_match_t match, void *match_data)
134 {
135 	void *res;
136 
137 	res = devres_find(dev, release, match, match_data);
138 	if (res) {
139 		struct devres *dr = container_of(res, struct devres, data);
140 
141 		list_del_init(&dr->entry);
142 		devres_log(dev, dr, "REM");
143 	}
144 
145 	return res;
146 }
147 
148 int devres_destroy(struct udevice *dev, dr_release_t release,
149 		   dr_match_t match, void *match_data)
150 {
151 	void *res;
152 
153 	res = devres_remove(dev, release, match, match_data);
154 	if (unlikely(!res))
155 		return -ENOENT;
156 
157 	devres_free(res);
158 	return 0;
159 }
160 
161 int devres_release(struct udevice *dev, dr_release_t release,
162 		   dr_match_t match, void *match_data)
163 {
164 	void *res;
165 
166 	res = devres_remove(dev, release, match, match_data);
167 	if (unlikely(!res))
168 		return -ENOENT;
169 
170 	(*release)(dev, res);
171 	devres_free(res);
172 	return 0;
173 }
174 
175 static void release_nodes(struct udevice *dev, struct list_head *head,
176 			  bool probe_only)
177 {
178 	struct devres *dr, *tmp;
179 
180 	list_for_each_entry_safe_reverse(dr, tmp, head, entry)  {
181 		if (probe_only && !dr->probe)
182 			break;
183 		devres_log(dev, dr, "REL");
184 		dr->release(dev, dr->data);
185 		list_del(&dr->entry);
186 		kfree(dr);
187 	}
188 }
189 
190 void devres_release_probe(struct udevice *dev)
191 {
192 	release_nodes(dev, &dev->devres_head, true);
193 }
194 
195 void devres_release_all(struct udevice *dev)
196 {
197 	release_nodes(dev, &dev->devres_head, false);
198 }
199 
200 #ifdef CONFIG_DEBUG_DEVRES
201 static void dump_resources(struct udevice *dev, int depth)
202 {
203 	struct devres *dr;
204 	struct udevice *child;
205 
206 	printf("- %s\n", dev->name);
207 
208 	list_for_each_entry(dr, &dev->devres_head, entry)
209 		printf("    %p (%lu byte) %s  %s\n", dr,
210 		       (unsigned long)dr->size, dr->name,
211 		       dr->probe ? "PROBE" : "BIND");
212 
213 	list_for_each_entry(child, &dev->child_head, sibling_node)
214 		dump_resources(child, depth + 1);
215 }
216 
217 void dm_dump_devres(void)
218 {
219 	struct udevice *root;
220 
221 	root = dm_root();
222 	if (root)
223 		dump_resources(root, 0);
224 }
225 #endif
226 
227 /*
228  * Managed kmalloc/kfree
229  */
230 static void devm_kmalloc_release(struct udevice *dev, void *res)
231 {
232 	/* noop */
233 }
234 
235 static int devm_kmalloc_match(struct udevice *dev, void *res, void *data)
236 {
237 	return res == data;
238 }
239 
240 void *devm_kmalloc(struct udevice *dev, size_t size, gfp_t gfp)
241 {
242 	void *data;
243 
244 	data = _devres_alloc(devm_kmalloc_release, size, gfp);
245 	if (unlikely(!data))
246 		return NULL;
247 
248 	devres_add(dev, data);
249 
250 	return data;
251 }
252 
253 void devm_kfree(struct udevice *dev, void *p)
254 {
255 	int rc;
256 
257 	rc = devres_destroy(dev, devm_kmalloc_release, devm_kmalloc_match, p);
258 	WARN_ON(rc);
259 }
260