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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#include <linux/kmemleak.h>
25#include <linux/cma.h>
26
27#include "of_private.h"
28
29#define MAX_RESERVED_REGIONS 64
30static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
31static int reserved_mem_count;
32
33static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
34 phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
35 phys_addr_t *res_base)
36{
37 phys_addr_t base;
38 int err = 0;
39
40 end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
41 align = !align ? SMP_CACHE_BYTES : align;
42 base = memblock_phys_alloc_range(size, align, start, end);
43 if (!base)
44 return -ENOMEM;
45
46 *res_base = base;
47 if (nomap) {
48 err = memblock_mark_nomap(base, size);
49 if (err)
50 memblock_phys_free(base, size);
51 }
52
53 kmemleak_ignore_phys(base);
54
55 return err;
56}
57
58/*
59 * fdt_reserved_mem_save_node() - save fdt node for second pass initialization
60 */
61void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
62 phys_addr_t base, phys_addr_t size)
63{
64 struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
65
66 if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
67 pr_err("not enough space for all defined regions.\n");
68 return;
69 }
70
71 rmem->fdt_node = node;
72 rmem->name = uname;
73 rmem->base = base;
74 rmem->size = size;
75
76 reserved_mem_count++;
77 return;
78}
79
80/*
81 * __reserved_mem_alloc_size() - allocate reserved memory described by
82 * 'size', 'alignment' and 'alloc-ranges' properties.
83 */
84static int __init __reserved_mem_alloc_size(unsigned long node,
85 const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
86{
87 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
88 phys_addr_t start = 0, end = 0;
89 phys_addr_t base = 0, align = 0, size;
90 int len;
91 const __be32 *prop;
92 bool nomap;
93 int ret;
94
95 prop = of_get_flat_dt_prop(node, "size", &len);
96 if (!prop)
97 return -EINVAL;
98
99 if (len != dt_root_size_cells * sizeof(__be32)) {
100 pr_err("invalid size property in '%s' node.\n", uname);
101 return -EINVAL;
102 }
103 size = dt_mem_next_cell(dt_root_size_cells, &prop);
104
105 prop = of_get_flat_dt_prop(node, "alignment", &len);
106 if (prop) {
107 if (len != dt_root_addr_cells * sizeof(__be32)) {
108 pr_err("invalid alignment property in '%s' node.\n",
109 uname);
110 return -EINVAL;
111 }
112 align = dt_mem_next_cell(dt_root_addr_cells, &prop);
113 }
114
115 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
116
117 /* Need adjust the alignment to satisfy the CMA requirement */
118 if (IS_ENABLED(CONFIG_CMA)
119 && of_flat_dt_is_compatible(node, "shared-dma-pool")
120 && of_get_flat_dt_prop(node, "reusable", NULL)
121 && !nomap)
122 align = max_t(phys_addr_t, align, CMA_MIN_ALIGNMENT_BYTES);
123
124 prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
125 if (prop) {
126
127 if (len % t_len != 0) {
128 pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
129 uname);
130 return -EINVAL;
131 }
132
133 base = 0;
134
135 while (len > 0) {
136 start = dt_mem_next_cell(dt_root_addr_cells, &prop);
137 end = start + dt_mem_next_cell(dt_root_size_cells,
138 &prop);
139
140 ret = early_init_dt_alloc_reserved_memory_arch(size,
141 align, start, end, nomap, &base);
142 if (ret == 0) {
143 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
144 uname, &base,
145 (unsigned long)(size / SZ_1M));
146 break;
147 }
148 len -= t_len;
149 }
150
151 } else {
152 ret = early_init_dt_alloc_reserved_memory_arch(size, align,
153 0, 0, nomap, &base);
154 if (ret == 0)
155 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
156 uname, &base, (unsigned long)(size / SZ_1M));
157 }
158
159 if (base == 0) {
160 pr_err("failed to allocate memory for node '%s': size %lu MiB\n",
161 uname, (unsigned long)(size / SZ_1M));
162 return -ENOMEM;
163 }
164
165 *res_base = base;
166 *res_size = size;
167
168 return 0;
169}
170
171static const struct of_device_id __rmem_of_table_sentinel
172 __used __section("__reservedmem_of_table_end");
173
174/*
175 * __reserved_mem_init_node() - call region specific reserved memory init code
176 */
177static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
178{
179 extern const struct of_device_id __reservedmem_of_table[];
180 const struct of_device_id *i;
181 int ret = -ENOENT;
182
183 for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
184 reservedmem_of_init_fn initfn = i->data;
185 const char *compat = i->compatible;
186
187 if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
188 continue;
189
190 ret = initfn(rmem);
191 if (ret == 0) {
192 pr_info("initialized node %s, compatible id %s\n",
193 rmem->name, compat);
194 break;
195 }
196 }
197 return ret;
198}
199
200static int __init __rmem_cmp(const void *a, const void *b)
201{
202 const struct reserved_mem *ra = a, *rb = b;
203
204 if (ra->base < rb->base)
205 return -1;
206
207 if (ra->base > rb->base)
208 return 1;
209
210 /*
211 * Put the dynamic allocations (address == 0, size == 0) before static
212 * allocations at address 0x0 so that overlap detection works
213 * correctly.
214 */
215 if (ra->size < rb->size)
216 return -1;
217 if (ra->size > rb->size)
218 return 1;
219
220 return 0;
221}
222
223static void __init __rmem_check_for_overlap(void)
224{
225 int i;
226
227 if (reserved_mem_count < 2)
228 return;
229
230 sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
231 __rmem_cmp, NULL);
232 for (i = 0; i < reserved_mem_count - 1; i++) {
233 struct reserved_mem *this, *next;
234
235 this = &reserved_mem[i];
236 next = &reserved_mem[i + 1];
237
238 if (this->base + this->size > next->base) {
239 phys_addr_t this_end, next_end;
240
241 this_end = this->base + this->size;
242 next_end = next->base + next->size;
243 pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
244 this->name, &this->base, &this_end,
245 next->name, &next->base, &next_end);
246 }
247 }
248}
249
250/**
251 * fdt_init_reserved_mem() - allocate and init all saved reserved memory regions
252 */
253void __init fdt_init_reserved_mem(void)
254{
255 int i;
256
257 /* check for overlapping reserved regions */
258 __rmem_check_for_overlap();
259
260 for (i = 0; i < reserved_mem_count; i++) {
261 struct reserved_mem *rmem = &reserved_mem[i];
262 unsigned long node = rmem->fdt_node;
263 int len;
264 const __be32 *prop;
265 int err = 0;
266 bool nomap;
267
268 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
269 prop = of_get_flat_dt_prop(node, "phandle", &len);
270 if (!prop)
271 prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
272 if (prop)
273 rmem->phandle = of_read_number(prop, len/4);
274
275 if (rmem->size == 0)
276 err = __reserved_mem_alloc_size(node, rmem->name,
277 &rmem->base, &rmem->size);
278 if (err == 0) {
279 err = __reserved_mem_init_node(rmem);
280 if (err != 0 && err != -ENOENT) {
281 pr_info("node %s compatible matching fail\n",
282 rmem->name);
283 if (nomap)
284 memblock_clear_nomap(rmem->base, rmem->size);
285 else
286 memblock_phys_free(rmem->base,
287 rmem->size);
288 }
289 }
290 }
291}
292
293static inline struct reserved_mem *__find_rmem(struct device_node *node)
294{
295 unsigned int i;
296
297 if (!node->phandle)
298 return NULL;
299
300 for (i = 0; i < reserved_mem_count; i++)
301 if (reserved_mem[i].phandle == node->phandle)
302 return &reserved_mem[i];
303 return NULL;
304}
305
306struct rmem_assigned_device {
307 struct device *dev;
308 struct reserved_mem *rmem;
309 struct list_head list;
310};
311
312static LIST_HEAD(of_rmem_assigned_device_list);
313static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
314
315/**
316 * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
317 * given device
318 * @dev: Pointer to the device to configure
319 * @np: Pointer to the device_node with 'reserved-memory' property
320 * @idx: Index of selected region
321 *
322 * This function assigns respective DMA-mapping operations based on reserved
323 * memory region specified by 'memory-region' property in @np node to the @dev
324 * device. When driver needs to use more than one reserved memory region, it
325 * should allocate child devices and initialize regions by name for each of
326 * child device.
327 *
328 * Returns error code or zero on success.
329 */
330int of_reserved_mem_device_init_by_idx(struct device *dev,
331 struct device_node *np, int idx)
332{
333 struct rmem_assigned_device *rd;
334 struct device_node *target;
335 struct reserved_mem *rmem;
336 int ret;
337
338 if (!np || !dev)
339 return -EINVAL;
340
341 target = of_parse_phandle(np, "memory-region", idx);
342 if (!target)
343 return -ENODEV;
344
345 if (!of_device_is_available(target)) {
346 of_node_put(target);
347 return 0;
348 }
349
350 rmem = __find_rmem(target);
351 of_node_put(target);
352
353 if (!rmem || !rmem->ops || !rmem->ops->device_init)
354 return -EINVAL;
355
356 rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
357 if (!rd)
358 return -ENOMEM;
359
360 ret = rmem->ops->device_init(rmem, dev);
361 if (ret == 0) {
362 rd->dev = dev;
363 rd->rmem = rmem;
364
365 mutex_lock(&of_rmem_assigned_device_mutex);
366 list_add(&rd->list, &of_rmem_assigned_device_list);
367 mutex_unlock(&of_rmem_assigned_device_mutex);
368
369 dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
370 } else {
371 kfree(rd);
372 }
373
374 return ret;
375}
376EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
377
378/**
379 * of_reserved_mem_device_init_by_name() - assign named reserved memory region
380 * to given device
381 * @dev: pointer to the device to configure
382 * @np: pointer to the device node with 'memory-region' property
383 * @name: name of the selected memory region
384 *
385 * Returns: 0 on success or a negative error-code on failure.
386 */
387int of_reserved_mem_device_init_by_name(struct device *dev,
388 struct device_node *np,
389 const char *name)
390{
391 int idx = of_property_match_string(np, "memory-region-names", name);
392
393 return of_reserved_mem_device_init_by_idx(dev, np, idx);
394}
395EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name);
396
397/**
398 * of_reserved_mem_device_release() - release reserved memory device structures
399 * @dev: Pointer to the device to deconfigure
400 *
401 * This function releases structures allocated for memory region handling for
402 * the given device.
403 */
404void of_reserved_mem_device_release(struct device *dev)
405{
406 struct rmem_assigned_device *rd, *tmp;
407 LIST_HEAD(release_list);
408
409 mutex_lock(&of_rmem_assigned_device_mutex);
410 list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) {
411 if (rd->dev == dev)
412 list_move_tail(&rd->list, &release_list);
413 }
414 mutex_unlock(&of_rmem_assigned_device_mutex);
415
416 list_for_each_entry_safe(rd, tmp, &release_list, list) {
417 if (rd->rmem && rd->rmem->ops && rd->rmem->ops->device_release)
418 rd->rmem->ops->device_release(rd->rmem, dev);
419
420 kfree(rd);
421 }
422}
423EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
424
425/**
426 * of_reserved_mem_lookup() - acquire reserved_mem from a device node
427 * @np: node pointer of the desired reserved-memory region
428 *
429 * This function allows drivers to acquire a reference to the reserved_mem
430 * struct based on a device node handle.
431 *
432 * Returns a reserved_mem reference, or NULL on error.
433 */
434struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
435{
436 const char *name;
437 int i;
438
439 if (!np->full_name)
440 return NULL;
441
442 name = kbasename(np->full_name);
443 for (i = 0; i < reserved_mem_count; i++)
444 if (!strcmp(reserved_mem[i].name, name))
445 return &reserved_mem[i];
446
447 return NULL;
448}
449EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);