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
25static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
26static int reserved_mem_count;
27
28#if defined(CONFIG_HAVE_MEMBLOCK)
29#include <linux/memblock.h>
30int __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	phys_addr_t base;
35	/*
36	 * We use __memblock_alloc_base() because memblock_alloc_base()
37	 * panic()s on allocation failure.
38	 */
39	end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
40	base = __memblock_alloc_base(size, align, end);
41	if (!base)
42		return -ENOMEM;
43
44	/*
45	 * Check if the allocated region fits in to start..end window
46	 */
47	if (base < start) {
48		memblock_free(base, size);
49		return -ENOMEM;
50	}
51
52	*res_base = base;
53	if (nomap)
54		return memblock_remove(base, size);
55	return 0;
56}
57#else
58int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
59	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
60	phys_addr_t *res_base)
61{
62	pr_err("Reserved memory not supported, ignoring region 0x%llx%s\n",
63		  size, nomap ? " (nomap)" : "");
64	return -ENOSYS;
65}
66#endif
67
68/**
69 * res_mem_save_node() - save fdt node for second pass initialization
70 */
71void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
72				      phys_addr_t base, phys_addr_t size)
73{
74	struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
75
76	if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
77		pr_err("Reserved memory: not enough space all defined regions.\n");
78		return;
79	}
80
81	rmem->fdt_node = node;
82	rmem->name = uname;
83	rmem->base = base;
84	rmem->size = size;
85
86	reserved_mem_count++;
87	return;
88}
89
90/**
91 * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
92 *			  and 'alloc-ranges' properties
93 */
94static int __init __reserved_mem_alloc_size(unsigned long node,
95	const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
96{
97	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
98	phys_addr_t start = 0, end = 0;
99	phys_addr_t base = 0, align = 0, size;
100	int len;
101	const __be32 *prop;
102	int nomap;
103	int ret;
104
105	prop = of_get_flat_dt_prop(node, "size", &len);
106	if (!prop)
107		return -EINVAL;
108
109	if (len != dt_root_size_cells * sizeof(__be32)) {
110		pr_err("Reserved memory: invalid size property in '%s' node.\n",
111				uname);
112		return -EINVAL;
113	}
114	size = dt_mem_next_cell(dt_root_size_cells, &prop);
115
116	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
117
118	prop = of_get_flat_dt_prop(node, "alignment", &len);
119	if (prop) {
120		if (len != dt_root_addr_cells * sizeof(__be32)) {
121			pr_err("Reserved memory: invalid alignment property in '%s' node.\n",
122				uname);
123			return -EINVAL;
124		}
125		align = dt_mem_next_cell(dt_root_addr_cells, &prop);
126	}
127
128	prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
129	if (prop) {
130
131		if (len % t_len != 0) {
132			pr_err("Reserved memory: invalid alloc-ranges property in '%s', skipping node.\n",
133			       uname);
134			return -EINVAL;
135		}
136
137		base = 0;
138
139		while (len > 0) {
140			start = dt_mem_next_cell(dt_root_addr_cells, &prop);
141			end = start + dt_mem_next_cell(dt_root_size_cells,
142						       &prop);
143
144			ret = early_init_dt_alloc_reserved_memory_arch(size,
145					align, start, end, nomap, &base);
146			if (ret == 0) {
147				pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
148					uname, &base,
149					(unsigned long)size / SZ_1M);
150				break;
151			}
152			len -= t_len;
153		}
154
155	} else {
156		ret = early_init_dt_alloc_reserved_memory_arch(size, align,
157							0, 0, nomap, &base);
158		if (ret == 0)
159			pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
160				uname, &base, (unsigned long)size / SZ_1M);
161	}
162
163	if (base == 0) {
164		pr_info("Reserved memory: failed to allocate memory for node '%s'\n",
165			uname);
166		return -ENOMEM;
167	}
168
169	*res_base = base;
170	*res_size = size;
171
172	return 0;
173}
174
175static const struct of_device_id __rmem_of_table_sentinel
176	__used __section(__reservedmem_of_table_end);
177
178/**
179 * res_mem_init_node() - call region specific reserved memory init code
180 */
181static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
182{
183	extern const struct of_device_id __reservedmem_of_table[];
184	const struct of_device_id *i;
185
186	for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
187		reservedmem_of_init_fn initfn = i->data;
188		const char *compat = i->compatible;
189
190		if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
191			continue;
192
193		if (initfn(rmem) == 0) {
194			pr_info("Reserved memory: initialized node %s, compatible id %s\n",
195				rmem->name, compat);
196			return 0;
197		}
198	}
199	return -ENOENT;
200}
201
202/**
203 * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
204 */
205void __init fdt_init_reserved_mem(void)
206{
207	int i;
208	for (i = 0; i < reserved_mem_count; i++) {
209		struct reserved_mem *rmem = &reserved_mem[i];
210		unsigned long node = rmem->fdt_node;
211		int len;
212		const __be32 *prop;
213		int err = 0;
214
215		prop = of_get_flat_dt_prop(node, "phandle", &len);
216		if (!prop)
217			prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
218		if (prop)
219			rmem->phandle = of_read_number(prop, len/4);
220
221		if (rmem->size == 0)
222			err = __reserved_mem_alloc_size(node, rmem->name,
223						 &rmem->base, &rmem->size);
224		if (err == 0)
225			__reserved_mem_init_node(rmem);
226	}
227}
228
229static inline struct reserved_mem *__find_rmem(struct device_node *node)
230{
231	unsigned int i;
232
233	if (!node->phandle)
234		return NULL;
235
236	for (i = 0; i < reserved_mem_count; i++)
237		if (reserved_mem[i].phandle == node->phandle)
238			return &reserved_mem[i];
239	return NULL;
240}
241
242/**
243 * of_reserved_mem_device_init() - assign reserved memory region to given device
244 *
245 * This function assign memory region pointed by "memory-region" device tree
246 * property to the given device.
247 */
248int of_reserved_mem_device_init(struct device *dev)
249{
250	struct reserved_mem *rmem;
251	struct device_node *np;
252	int ret;
253
254	np = of_parse_phandle(dev->of_node, "memory-region", 0);
255	if (!np)
256		return -ENODEV;
257
258	rmem = __find_rmem(np);
259	of_node_put(np);
260
261	if (!rmem || !rmem->ops || !rmem->ops->device_init)
262		return -EINVAL;
263
264	ret = rmem->ops->device_init(rmem, dev);
265	if (ret == 0)
266		dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
267
268	return ret;
269}
270EXPORT_SYMBOL_GPL(of_reserved_mem_device_init);
271
272/**
273 * of_reserved_mem_device_release() - release reserved memory device structures
274 *
275 * This function releases structures allocated for memory region handling for
276 * the given device.
277 */
278void of_reserved_mem_device_release(struct device *dev)
279{
280	struct reserved_mem *rmem;
281	struct device_node *np;
282
283	np = of_parse_phandle(dev->of_node, "memory-region", 0);
284	if (!np)
285		return;
286
287	rmem = __find_rmem(np);
288	of_node_put(np);
289
290	if (!rmem || !rmem->ops || !rmem->ops->device_release)
291		return;
292
293	rmem->ops->device_release(rmem, dev);
294}
295EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
296