1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* prom_common.c: OF device tree support common code.
3  *
4  * Paul Mackerras	August 1996.
5  * Copyright (C) 1996-2005 Paul Mackerras.
6  *
7  *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8  *    {engebret|bergner}@us.ibm.com
9  *
10  *  Adapted for sparc by David S. Miller davem@davemloft.net
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/export.h>
15 #include <linux/errno.h>
16 #include <linux/mutex.h>
17 #include <linux/slab.h>
18 #include <linux/of.h>
19 #include <linux/of_pdt.h>
20 #include <asm/prom.h>
21 #include <asm/oplib.h>
22 
23 #include "prom.h"
24 
25 struct device_node *of_console_device;
26 EXPORT_SYMBOL(of_console_device);
27 
28 char *of_console_path;
29 EXPORT_SYMBOL(of_console_path);
30 
31 char *of_console_options;
32 EXPORT_SYMBOL(of_console_options);
33 
of_getintprop_default(struct device_node * np,const char * name,int def)34 int of_getintprop_default(struct device_node *np, const char *name, int def)
35 {
36 	struct property *prop;
37 	int len;
38 
39 	prop = of_find_property(np, name, &len);
40 	if (!prop || len != 4)
41 		return def;
42 
43 	return *(int *) prop->value;
44 }
45 EXPORT_SYMBOL(of_getintprop_default);
46 
47 DEFINE_MUTEX(of_set_property_mutex);
48 EXPORT_SYMBOL(of_set_property_mutex);
49 
of_set_property(struct device_node * dp,const char * name,void * val,int len)50 int of_set_property(struct device_node *dp, const char *name, void *val, int len)
51 {
52 	struct property **prevp;
53 	unsigned long flags;
54 	void *new_val;
55 	int err;
56 
57 	new_val = kmemdup(val, len, GFP_KERNEL);
58 	if (!new_val)
59 		return -ENOMEM;
60 
61 	err = -ENODEV;
62 
63 	mutex_lock(&of_set_property_mutex);
64 	raw_spin_lock_irqsave(&devtree_lock, flags);
65 	prevp = &dp->properties;
66 	while (*prevp) {
67 		struct property *prop = *prevp;
68 
69 		if (!strcasecmp(prop->name, name)) {
70 			void *old_val = prop->value;
71 			int ret;
72 
73 			ret = prom_setprop(dp->phandle, name, val, len);
74 
75 			err = -EINVAL;
76 			if (ret >= 0) {
77 				prop->value = new_val;
78 				prop->length = len;
79 
80 				if (OF_IS_DYNAMIC(prop))
81 					kfree(old_val);
82 
83 				OF_MARK_DYNAMIC(prop);
84 
85 				err = 0;
86 			}
87 			break;
88 		}
89 		prevp = &(*prevp)->next;
90 	}
91 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
92 	mutex_unlock(&of_set_property_mutex);
93 
94 	/* XXX Upate procfs if necessary... */
95 
96 	return err;
97 }
98 EXPORT_SYMBOL(of_set_property);
99 
of_find_in_proplist(const char * list,const char * match,int len)100 int of_find_in_proplist(const char *list, const char *match, int len)
101 {
102 	while (len > 0) {
103 		int l;
104 
105 		if (!strcmp(list, match))
106 			return 1;
107 		l = strlen(list) + 1;
108 		list += l;
109 		len -= l;
110 	}
111 	return 0;
112 }
113 EXPORT_SYMBOL(of_find_in_proplist);
114 
115 /*
116  * SPARC32 and SPARC64's prom_nextprop() do things differently
117  * here, despite sharing the same interface.  SPARC32 doesn't fill in 'buf',
118  * returning NULL on an error.  SPARC64 fills in 'buf', but sets it to an
119  * empty string upon error.
120  */
handle_nextprop_quirks(char * buf,const char * name)121 static int __init handle_nextprop_quirks(char *buf, const char *name)
122 {
123 	if (!name || strlen(name) == 0)
124 		return -1;
125 
126 #ifdef CONFIG_SPARC32
127 	strcpy(buf, name);
128 #endif
129 	return 0;
130 }
131 
prom_common_nextprop(phandle node,char * prev,char * buf)132 static int __init prom_common_nextprop(phandle node, char *prev, char *buf)
133 {
134 	const char *name;
135 
136 	buf[0] = '\0';
137 	name = prom_nextprop(node, prev, buf);
138 	return handle_nextprop_quirks(buf, name);
139 }
140 
141 unsigned int prom_early_allocated __initdata;
142 
143 static struct of_pdt_ops prom_sparc_ops __initdata = {
144 	.nextprop = prom_common_nextprop,
145 	.getproplen = prom_getproplen,
146 	.getproperty = prom_getproperty,
147 	.getchild = prom_getchild,
148 	.getsibling = prom_getsibling,
149 };
150 
prom_build_devicetree(void)151 void __init prom_build_devicetree(void)
152 {
153 	of_pdt_build_devicetree(prom_root_node, &prom_sparc_ops);
154 	of_console_init();
155 
156 	pr_info("PROM: Built device tree with %u bytes of memory.\n",
157 			prom_early_allocated);
158 }
159