xref: /openbmc/linux/drivers/of/of_reserved_mem.c (revision afb46f79)
1 /*
2  * Device tree based initialization code for reserved memory.
3  *
4  * Copyright (c) 2013, The Linux Foundation. All Rights Reserved.
5  * Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
6  *		http://www.samsung.com
7  * Author: Marek Szyprowski <m.szyprowski@samsung.com>
8  * Author: Josh Cartwright <joshc@codeaurora.org>
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License as
12  * published by the Free Software Foundation; either version 2 of the
13  * License or (at your optional) any later version of the license.
14  */
15 
16 #include <linux/err.h>
17 #include <linux/of.h>
18 #include <linux/of_fdt.h>
19 #include <linux/of_platform.h>
20 #include <linux/mm.h>
21 #include <linux/sizes.h>
22 #include <linux/of_reserved_mem.h>
23 
24 #define MAX_RESERVED_REGIONS	16
25 static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
26 static int reserved_mem_count;
27 
28 #if defined(CONFIG_HAVE_MEMBLOCK)
29 #include <linux/memblock.h>
30 int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
31 	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
32 	phys_addr_t *res_base)
33 {
34 	/*
35 	 * We use __memblock_alloc_base() because memblock_alloc_base()
36 	 * panic()s on allocation failure.
37 	 */
38 	phys_addr_t base = __memblock_alloc_base(size, align, end);
39 	if (!base)
40 		return -ENOMEM;
41 
42 	/*
43 	 * Check if the allocated region fits in to start..end window
44 	 */
45 	if (base < start) {
46 		memblock_free(base, size);
47 		return -ENOMEM;
48 	}
49 
50 	*res_base = base;
51 	if (nomap)
52 		return memblock_remove(base, size);
53 	return 0;
54 }
55 #else
56 int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
57 	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
58 	phys_addr_t *res_base)
59 {
60 	pr_err("Reserved memory not supported, ignoring region 0x%llx%s\n",
61 		  size, nomap ? " (nomap)" : "");
62 	return -ENOSYS;
63 }
64 #endif
65 
66 /**
67  * res_mem_save_node() - save fdt node for second pass initialization
68  */
69 void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
70 				      phys_addr_t base, phys_addr_t size)
71 {
72 	struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
73 
74 	if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
75 		pr_err("Reserved memory: not enough space all defined regions.\n");
76 		return;
77 	}
78 
79 	rmem->fdt_node = node;
80 	rmem->name = uname;
81 	rmem->base = base;
82 	rmem->size = size;
83 
84 	reserved_mem_count++;
85 	return;
86 }
87 
88 /**
89  * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
90  *			  and 'alloc-ranges' properties
91  */
92 static int __init __reserved_mem_alloc_size(unsigned long node,
93 	const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
94 {
95 	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
96 	phys_addr_t start = 0, end = 0;
97 	phys_addr_t base = 0, align = 0, size;
98 	unsigned long len;
99 	__be32 *prop;
100 	int nomap;
101 	int ret;
102 
103 	prop = of_get_flat_dt_prop(node, "size", &len);
104 	if (!prop)
105 		return -EINVAL;
106 
107 	if (len != dt_root_size_cells * sizeof(__be32)) {
108 		pr_err("Reserved memory: invalid size property in '%s' node.\n",
109 				uname);
110 		return -EINVAL;
111 	}
112 	size = dt_mem_next_cell(dt_root_size_cells, &prop);
113 
114 	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
115 
116 	prop = of_get_flat_dt_prop(node, "alignment", &len);
117 	if (prop) {
118 		if (len != dt_root_addr_cells * sizeof(__be32)) {
119 			pr_err("Reserved memory: invalid alignment property in '%s' node.\n",
120 				uname);
121 			return -EINVAL;
122 		}
123 		align = dt_mem_next_cell(dt_root_addr_cells, &prop);
124 	}
125 
126 	prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
127 	if (prop) {
128 
129 		if (len % t_len != 0) {
130 			pr_err("Reserved memory: invalid alloc-ranges property in '%s', skipping node.\n",
131 			       uname);
132 			return -EINVAL;
133 		}
134 
135 		base = 0;
136 
137 		while (len > 0) {
138 			start = dt_mem_next_cell(dt_root_addr_cells, &prop);
139 			end = start + dt_mem_next_cell(dt_root_size_cells,
140 						       &prop);
141 
142 			ret = early_init_dt_alloc_reserved_memory_arch(size,
143 					align, start, end, nomap, &base);
144 			if (ret == 0) {
145 				pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
146 					uname, &base,
147 					(unsigned long)size / SZ_1M);
148 				break;
149 			}
150 			len -= t_len;
151 		}
152 
153 	} else {
154 		ret = early_init_dt_alloc_reserved_memory_arch(size, align,
155 							0, 0, nomap, &base);
156 		if (ret == 0)
157 			pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
158 				uname, &base, (unsigned long)size / SZ_1M);
159 	}
160 
161 	if (base == 0) {
162 		pr_info("Reserved memory: failed to allocate memory for node '%s'\n",
163 			uname);
164 		return -ENOMEM;
165 	}
166 
167 	*res_base = base;
168 	*res_size = size;
169 
170 	return 0;
171 }
172 
173 static const struct of_device_id __rmem_of_table_sentinel
174 	__used __section(__reservedmem_of_table_end);
175 
176 /**
177  * res_mem_init_node() - call region specific reserved memory init code
178  */
179 static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
180 {
181 	extern const struct of_device_id __reservedmem_of_table[];
182 	const struct of_device_id *i;
183 
184 	for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
185 		reservedmem_of_init_fn initfn = i->data;
186 		const char *compat = i->compatible;
187 
188 		if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
189 			continue;
190 
191 		if (initfn(rmem, rmem->fdt_node, rmem->name) == 0) {
192 			pr_info("Reserved memory: initialized node %s, compatible id %s\n",
193 				rmem->name, compat);
194 			return 0;
195 		}
196 	}
197 	return -ENOENT;
198 }
199 
200 /**
201  * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
202  */
203 void __init fdt_init_reserved_mem(void)
204 {
205 	int i;
206 	for (i = 0; i < reserved_mem_count; i++) {
207 		struct reserved_mem *rmem = &reserved_mem[i];
208 		unsigned long node = rmem->fdt_node;
209 		int err = 0;
210 
211 		if (rmem->size == 0)
212 			err = __reserved_mem_alloc_size(node, rmem->name,
213 						 &rmem->base, &rmem->size);
214 		if (err == 0)
215 			__reserved_mem_init_node(rmem);
216 	}
217 }
218