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1/*
2 * Device tree based initialization code for reserved memory.
3 *
4 * Copyright (c) 2013, 2015 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#include <linux/sort.h>
24
25#define MAX_RESERVED_REGIONS 16
26static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
27static int reserved_mem_count;
28
29#if defined(CONFIG_HAVE_MEMBLOCK)
30#include <linux/memblock.h>
31int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
32 phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
33 phys_addr_t *res_base)
34{
35 phys_addr_t base;
36 /*
37 * We use __memblock_alloc_base() because memblock_alloc_base()
38 * panic()s on allocation failure.
39 */
40 end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
41 base = __memblock_alloc_base(size, align, end);
42 if (!base)
43 return -ENOMEM;
44
45 /*
46 * Check if the allocated region fits in to start..end window
47 */
48 if (base < start) {
49 memblock_free(base, size);
50 return -ENOMEM;
51 }
52
53 *res_base = base;
54 if (nomap)
55 return memblock_remove(base, size);
56 return 0;
57}
58#else
59int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
60 phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
61 phys_addr_t *res_base)
62{
63 pr_err("Reserved memory not supported, ignoring region 0x%llx%s\n",
64 size, nomap ? " (nomap)" : "");
65 return -ENOSYS;
66}
67#endif
68
69/**
70 * res_mem_save_node() - save fdt node for second pass initialization
71 */
72void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
73 phys_addr_t base, phys_addr_t size)
74{
75 struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
76
77 if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
78 pr_err("Reserved memory: not enough space all defined regions.\n");
79 return;
80 }
81
82 rmem->fdt_node = node;
83 rmem->name = uname;
84 rmem->base = base;
85 rmem->size = size;
86
87 reserved_mem_count++;
88 return;
89}
90
91/**
92 * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
93 * and 'alloc-ranges' properties
94 */
95static int __init __reserved_mem_alloc_size(unsigned long node,
96 const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
97{
98 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
99 phys_addr_t start = 0, end = 0;
100 phys_addr_t base = 0, align = 0, size;
101 int len;
102 const __be32 *prop;
103 int nomap;
104 int ret;
105
106 prop = of_get_flat_dt_prop(node, "size", &len);
107 if (!prop)
108 return -EINVAL;
109
110 if (len != dt_root_size_cells * sizeof(__be32)) {
111 pr_err("Reserved memory: invalid size property in '%s' node.\n",
112 uname);
113 return -EINVAL;
114 }
115 size = dt_mem_next_cell(dt_root_size_cells, &prop);
116
117 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
118
119 prop = of_get_flat_dt_prop(node, "alignment", &len);
120 if (prop) {
121 if (len != dt_root_addr_cells * sizeof(__be32)) {
122 pr_err("Reserved memory: invalid alignment property in '%s' node.\n",
123 uname);
124 return -EINVAL;
125 }
126 align = dt_mem_next_cell(dt_root_addr_cells, &prop);
127 }
128
129 /* Need adjust the alignment to satisfy the CMA requirement */
130 if (IS_ENABLED(CONFIG_CMA) && of_flat_dt_is_compatible(node, "shared-dma-pool"))
131 align = max(align, (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order));
132
133 prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
134 if (prop) {
135
136 if (len % t_len != 0) {
137 pr_err("Reserved memory: invalid alloc-ranges property in '%s', skipping node.\n",
138 uname);
139 return -EINVAL;
140 }
141
142 base = 0;
143
144 while (len > 0) {
145 start = dt_mem_next_cell(dt_root_addr_cells, &prop);
146 end = start + dt_mem_next_cell(dt_root_size_cells,
147 &prop);
148
149 ret = early_init_dt_alloc_reserved_memory_arch(size,
150 align, start, end, nomap, &base);
151 if (ret == 0) {
152 pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
153 uname, &base,
154 (unsigned long)size / SZ_1M);
155 break;
156 }
157 len -= t_len;
158 }
159
160 } else {
161 ret = early_init_dt_alloc_reserved_memory_arch(size, align,
162 0, 0, nomap, &base);
163 if (ret == 0)
164 pr_debug("Reserved memory: allocated memory for '%s' node: base %pa, size %ld MiB\n",
165 uname, &base, (unsigned long)size / SZ_1M);
166 }
167
168 if (base == 0) {
169 pr_info("Reserved memory: failed to allocate memory for node '%s'\n",
170 uname);
171 return -ENOMEM;
172 }
173
174 *res_base = base;
175 *res_size = size;
176
177 return 0;
178}
179
180static const struct of_device_id __rmem_of_table_sentinel
181 __used __section(__reservedmem_of_table_end);
182
183/**
184 * res_mem_init_node() - call region specific reserved memory init code
185 */
186static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
187{
188 extern const struct of_device_id __reservedmem_of_table[];
189 const struct of_device_id *i;
190
191 for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
192 reservedmem_of_init_fn initfn = i->data;
193 const char *compat = i->compatible;
194
195 if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
196 continue;
197
198 if (initfn(rmem) == 0) {
199 pr_info("Reserved memory: initialized node %s, compatible id %s\n",
200 rmem->name, compat);
201 return 0;
202 }
203 }
204 return -ENOENT;
205}
206
207static int __init __rmem_cmp(const void *a, const void *b)
208{
209 const struct reserved_mem *ra = a, *rb = b;
210
211 if (ra->base < rb->base)
212 return -1;
213
214 if (ra->base > rb->base)
215 return 1;
216
217 return 0;
218}
219
220static void __init __rmem_check_for_overlap(void)
221{
222 int i;
223
224 if (reserved_mem_count < 2)
225 return;
226
227 sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
228 __rmem_cmp, NULL);
229 for (i = 0; i < reserved_mem_count - 1; i++) {
230 struct reserved_mem *this, *next;
231
232 this = &reserved_mem[i];
233 next = &reserved_mem[i + 1];
234 if (!(this->base && next->base))
235 continue;
236 if (this->base + this->size > next->base) {
237 phys_addr_t this_end, next_end;
238
239 this_end = this->base + this->size;
240 next_end = next->base + next->size;
241 pr_err("Reserved memory: OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
242 this->name, &this->base, &this_end,
243 next->name, &next->base, &next_end);
244 }
245 }
246}
247
248/**
249 * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
250 */
251void __init fdt_init_reserved_mem(void)
252{
253 int i;
254
255 /* check for overlapping reserved regions */
256 __rmem_check_for_overlap();
257
258 for (i = 0; i < reserved_mem_count; i++) {
259 struct reserved_mem *rmem = &reserved_mem[i];
260 unsigned long node = rmem->fdt_node;
261 int len;
262 const __be32 *prop;
263 int err = 0;
264
265 prop = of_get_flat_dt_prop(node, "phandle", &len);
266 if (!prop)
267 prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
268 if (prop)
269 rmem->phandle = of_read_number(prop, len/4);
270
271 if (rmem->size == 0)
272 err = __reserved_mem_alloc_size(node, rmem->name,
273 &rmem->base, &rmem->size);
274 if (err == 0)
275 __reserved_mem_init_node(rmem);
276 }
277}
278
279static inline struct reserved_mem *__find_rmem(struct device_node *node)
280{
281 unsigned int i;
282
283 if (!node->phandle)
284 return NULL;
285
286 for (i = 0; i < reserved_mem_count; i++)
287 if (reserved_mem[i].phandle == node->phandle)
288 return &reserved_mem[i];
289 return NULL;
290}
291
292/**
293 * of_reserved_mem_device_init() - assign reserved memory region to given device
294 *
295 * This function assign memory region pointed by "memory-region" device tree
296 * property to the given device.
297 */
298int of_reserved_mem_device_init(struct device *dev)
299{
300 struct reserved_mem *rmem;
301 struct device_node *np;
302 int ret;
303
304 np = of_parse_phandle(dev->of_node, "memory-region", 0);
305 if (!np)
306 return -ENODEV;
307
308 rmem = __find_rmem(np);
309 of_node_put(np);
310
311 if (!rmem || !rmem->ops || !rmem->ops->device_init)
312 return -EINVAL;
313
314 ret = rmem->ops->device_init(rmem, dev);
315 if (ret == 0)
316 dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
317
318 return ret;
319}
320EXPORT_SYMBOL_GPL(of_reserved_mem_device_init);
321
322/**
323 * of_reserved_mem_device_release() - release reserved memory device structures
324 *
325 * This function releases structures allocated for memory region handling for
326 * the given device.
327 */
328void of_reserved_mem_device_release(struct device *dev)
329{
330 struct reserved_mem *rmem;
331 struct device_node *np;
332
333 np = of_parse_phandle(dev->of_node, "memory-region", 0);
334 if (!np)
335 return;
336
337 rmem = __find_rmem(np);
338 of_node_put(np);
339
340 if (!rmem || !rmem->ops || !rmem->ops->device_release)
341 return;
342
343 rmem->ops->device_release(rmem, dev);
344}
345EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Device tree based initialization code for reserved memory.
4 *
5 * Copyright (c) 2013, 2015 The Linux Foundation. All Rights Reserved.
6 * Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
7 * http://www.samsung.com
8 * Author: Marek Szyprowski <m.szyprowski@samsung.com>
9 * Author: Josh Cartwright <joshc@codeaurora.org>
10 */
11
12#define pr_fmt(fmt) "OF: reserved mem: " fmt
13
14#include <linux/err.h>
15#include <linux/of.h>
16#include <linux/of_fdt.h>
17#include <linux/of_platform.h>
18#include <linux/mm.h>
19#include <linux/sizes.h>
20#include <linux/of_reserved_mem.h>
21#include <linux/sort.h>
22#include <linux/slab.h>
23#include <linux/memblock.h>
24
25#include "of_private.h"
26
27#define MAX_RESERVED_REGIONS 64
28static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
29static int reserved_mem_count;
30
31static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
32 phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
33 phys_addr_t *res_base)
34{
35 phys_addr_t base;
36
37 end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
38 align = !align ? SMP_CACHE_BYTES : align;
39 base = memblock_find_in_range(start, end, size, align);
40 if (!base)
41 return -ENOMEM;
42
43 *res_base = base;
44 if (nomap)
45 return memblock_mark_nomap(base, size);
46
47 return memblock_reserve(base, size);
48}
49
50/*
51 * fdt_reserved_mem_save_node() - save fdt node for second pass initialization
52 */
53void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
54 phys_addr_t base, phys_addr_t size)
55{
56 struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
57
58 if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
59 pr_err("not enough space for all defined regions.\n");
60 return;
61 }
62
63 rmem->fdt_node = node;
64 rmem->name = uname;
65 rmem->base = base;
66 rmem->size = size;
67
68 reserved_mem_count++;
69 return;
70}
71
72/*
73 * __reserved_mem_alloc_size() - allocate reserved memory described by
74 * 'size', 'alignment' and 'alloc-ranges' properties.
75 */
76static int __init __reserved_mem_alloc_size(unsigned long node,
77 const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
78{
79 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
80 phys_addr_t start = 0, end = 0;
81 phys_addr_t base = 0, align = 0, size;
82 int len;
83 const __be32 *prop;
84 bool nomap;
85 int ret;
86
87 prop = of_get_flat_dt_prop(node, "size", &len);
88 if (!prop)
89 return -EINVAL;
90
91 if (len != dt_root_size_cells * sizeof(__be32)) {
92 pr_err("invalid size property in '%s' node.\n", uname);
93 return -EINVAL;
94 }
95 size = dt_mem_next_cell(dt_root_size_cells, &prop);
96
97 prop = of_get_flat_dt_prop(node, "alignment", &len);
98 if (prop) {
99 if (len != dt_root_addr_cells * sizeof(__be32)) {
100 pr_err("invalid alignment property in '%s' node.\n",
101 uname);
102 return -EINVAL;
103 }
104 align = dt_mem_next_cell(dt_root_addr_cells, &prop);
105 }
106
107 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
108
109 /* Need adjust the alignment to satisfy the CMA requirement */
110 if (IS_ENABLED(CONFIG_CMA)
111 && of_flat_dt_is_compatible(node, "shared-dma-pool")
112 && of_get_flat_dt_prop(node, "reusable", NULL)
113 && !nomap) {
114 unsigned long order =
115 max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
116
117 align = max(align, (phys_addr_t)PAGE_SIZE << order);
118 }
119
120 prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
121 if (prop) {
122
123 if (len % t_len != 0) {
124 pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
125 uname);
126 return -EINVAL;
127 }
128
129 base = 0;
130
131 while (len > 0) {
132 start = dt_mem_next_cell(dt_root_addr_cells, &prop);
133 end = start + dt_mem_next_cell(dt_root_size_cells,
134 &prop);
135
136 ret = early_init_dt_alloc_reserved_memory_arch(size,
137 align, start, end, nomap, &base);
138 if (ret == 0) {
139 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
140 uname, &base,
141 (unsigned long)(size / SZ_1M));
142 break;
143 }
144 len -= t_len;
145 }
146
147 } else {
148 ret = early_init_dt_alloc_reserved_memory_arch(size, align,
149 0, 0, nomap, &base);
150 if (ret == 0)
151 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
152 uname, &base, (unsigned long)(size / SZ_1M));
153 }
154
155 if (base == 0) {
156 pr_info("failed to allocate memory for node '%s'\n", uname);
157 return -ENOMEM;
158 }
159
160 *res_base = base;
161 *res_size = size;
162
163 return 0;
164}
165
166static const struct of_device_id __rmem_of_table_sentinel
167 __used __section("__reservedmem_of_table_end");
168
169/*
170 * __reserved_mem_init_node() - call region specific reserved memory init code
171 */
172static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
173{
174 extern const struct of_device_id __reservedmem_of_table[];
175 const struct of_device_id *i;
176 int ret = -ENOENT;
177
178 for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
179 reservedmem_of_init_fn initfn = i->data;
180 const char *compat = i->compatible;
181
182 if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
183 continue;
184
185 ret = initfn(rmem);
186 if (ret == 0) {
187 pr_info("initialized node %s, compatible id %s\n",
188 rmem->name, compat);
189 break;
190 }
191 }
192 return ret;
193}
194
195static int __init __rmem_cmp(const void *a, const void *b)
196{
197 const struct reserved_mem *ra = a, *rb = b;
198
199 if (ra->base < rb->base)
200 return -1;
201
202 if (ra->base > rb->base)
203 return 1;
204
205 /*
206 * Put the dynamic allocations (address == 0, size == 0) before static
207 * allocations at address 0x0 so that overlap detection works
208 * correctly.
209 */
210 if (ra->size < rb->size)
211 return -1;
212 if (ra->size > rb->size)
213 return 1;
214
215 return 0;
216}
217
218static void __init __rmem_check_for_overlap(void)
219{
220 int i;
221
222 if (reserved_mem_count < 2)
223 return;
224
225 sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
226 __rmem_cmp, NULL);
227 for (i = 0; i < reserved_mem_count - 1; i++) {
228 struct reserved_mem *this, *next;
229
230 this = &reserved_mem[i];
231 next = &reserved_mem[i + 1];
232
233 if (this->base + this->size > next->base) {
234 phys_addr_t this_end, next_end;
235
236 this_end = this->base + this->size;
237 next_end = next->base + next->size;
238 pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
239 this->name, &this->base, &this_end,
240 next->name, &next->base, &next_end);
241 }
242 }
243}
244
245/**
246 * fdt_init_reserved_mem() - allocate and init all saved reserved memory regions
247 */
248void __init fdt_init_reserved_mem(void)
249{
250 int i;
251
252 /* check for overlapping reserved regions */
253 __rmem_check_for_overlap();
254
255 for (i = 0; i < reserved_mem_count; i++) {
256 struct reserved_mem *rmem = &reserved_mem[i];
257 unsigned long node = rmem->fdt_node;
258 int len;
259 const __be32 *prop;
260 int err = 0;
261 bool nomap;
262
263 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
264 prop = of_get_flat_dt_prop(node, "phandle", &len);
265 if (!prop)
266 prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
267 if (prop)
268 rmem->phandle = of_read_number(prop, len/4);
269
270 if (rmem->size == 0)
271 err = __reserved_mem_alloc_size(node, rmem->name,
272 &rmem->base, &rmem->size);
273 if (err == 0) {
274 err = __reserved_mem_init_node(rmem);
275 if (err != 0 && err != -ENOENT) {
276 pr_info("node %s compatible matching fail\n",
277 rmem->name);
278 if (nomap)
279 memblock_clear_nomap(rmem->base, rmem->size);
280 else
281 memblock_free(rmem->base, rmem->size);
282 }
283 }
284 }
285}
286
287static inline struct reserved_mem *__find_rmem(struct device_node *node)
288{
289 unsigned int i;
290
291 if (!node->phandle)
292 return NULL;
293
294 for (i = 0; i < reserved_mem_count; i++)
295 if (reserved_mem[i].phandle == node->phandle)
296 return &reserved_mem[i];
297 return NULL;
298}
299
300struct rmem_assigned_device {
301 struct device *dev;
302 struct reserved_mem *rmem;
303 struct list_head list;
304};
305
306static LIST_HEAD(of_rmem_assigned_device_list);
307static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
308
309/**
310 * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
311 * given device
312 * @dev: Pointer to the device to configure
313 * @np: Pointer to the device_node with 'reserved-memory' property
314 * @idx: Index of selected region
315 *
316 * This function assigns respective DMA-mapping operations based on reserved
317 * memory region specified by 'memory-region' property in @np node to the @dev
318 * device. When driver needs to use more than one reserved memory region, it
319 * should allocate child devices and initialize regions by name for each of
320 * child device.
321 *
322 * Returns error code or zero on success.
323 */
324int of_reserved_mem_device_init_by_idx(struct device *dev,
325 struct device_node *np, int idx)
326{
327 struct rmem_assigned_device *rd;
328 struct device_node *target;
329 struct reserved_mem *rmem;
330 int ret;
331
332 if (!np || !dev)
333 return -EINVAL;
334
335 target = of_parse_phandle(np, "memory-region", idx);
336 if (!target)
337 return -ENODEV;
338
339 if (!of_device_is_available(target)) {
340 of_node_put(target);
341 return 0;
342 }
343
344 rmem = __find_rmem(target);
345 of_node_put(target);
346
347 if (!rmem || !rmem->ops || !rmem->ops->device_init)
348 return -EINVAL;
349
350 rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
351 if (!rd)
352 return -ENOMEM;
353
354 ret = rmem->ops->device_init(rmem, dev);
355 if (ret == 0) {
356 rd->dev = dev;
357 rd->rmem = rmem;
358
359 mutex_lock(&of_rmem_assigned_device_mutex);
360 list_add(&rd->list, &of_rmem_assigned_device_list);
361 mutex_unlock(&of_rmem_assigned_device_mutex);
362
363 dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
364 } else {
365 kfree(rd);
366 }
367
368 return ret;
369}
370EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
371
372/**
373 * of_reserved_mem_device_init_by_name() - assign named reserved memory region
374 * to given device
375 * @dev: pointer to the device to configure
376 * @np: pointer to the device node with 'memory-region' property
377 * @name: name of the selected memory region
378 *
379 * Returns: 0 on success or a negative error-code on failure.
380 */
381int of_reserved_mem_device_init_by_name(struct device *dev,
382 struct device_node *np,
383 const char *name)
384{
385 int idx = of_property_match_string(np, "memory-region-names", name);
386
387 return of_reserved_mem_device_init_by_idx(dev, np, idx);
388}
389EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name);
390
391/**
392 * of_reserved_mem_device_release() - release reserved memory device structures
393 * @dev: Pointer to the device to deconfigure
394 *
395 * This function releases structures allocated for memory region handling for
396 * the given device.
397 */
398void of_reserved_mem_device_release(struct device *dev)
399{
400 struct rmem_assigned_device *rd, *tmp;
401 LIST_HEAD(release_list);
402
403 mutex_lock(&of_rmem_assigned_device_mutex);
404 list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) {
405 if (rd->dev == dev)
406 list_move_tail(&rd->list, &release_list);
407 }
408 mutex_unlock(&of_rmem_assigned_device_mutex);
409
410 list_for_each_entry_safe(rd, tmp, &release_list, list) {
411 if (rd->rmem && rd->rmem->ops && rd->rmem->ops->device_release)
412 rd->rmem->ops->device_release(rd->rmem, dev);
413
414 kfree(rd);
415 }
416}
417EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
418
419/**
420 * of_reserved_mem_lookup() - acquire reserved_mem from a device node
421 * @np: node pointer of the desired reserved-memory region
422 *
423 * This function allows drivers to acquire a reference to the reserved_mem
424 * struct based on a device node handle.
425 *
426 * Returns a reserved_mem reference, or NULL on error.
427 */
428struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
429{
430 const char *name;
431 int i;
432
433 if (!np->full_name)
434 return NULL;
435
436 name = kbasename(np->full_name);
437 for (i = 0; i < reserved_mem_count; i++)
438 if (!strcmp(reserved_mem[i].name, name))
439 return &reserved_mem[i];
440
441 return NULL;
442}
443EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);