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/ioport.h>
16#include <linux/libfdt.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#include <linux/slab.h>
25#include <linux/memblock.h>
26#include <linux/kmemleak.h>
27#include <linux/cma.h>
28#include <linux/dma-map-ops.h>
29
30#include "of_private.h"
31
32static struct reserved_mem reserved_mem_array[MAX_RESERVED_REGIONS] __initdata;
33static struct reserved_mem *reserved_mem __refdata = reserved_mem_array;
34static int total_reserved_mem_cnt = MAX_RESERVED_REGIONS;
35static int reserved_mem_count;
36
37static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
38 phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
39 phys_addr_t *res_base)
40{
41 phys_addr_t base;
42 int err = 0;
43
44 end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
45 align = !align ? SMP_CACHE_BYTES : align;
46 base = memblock_phys_alloc_range(size, align, start, end);
47 if (!base)
48 return -ENOMEM;
49
50 *res_base = base;
51 if (nomap) {
52 err = memblock_mark_nomap(base, size);
53 if (err)
54 memblock_phys_free(base, size);
55 }
56
57 if (!err)
58 kmemleak_ignore_phys(phys: base);
59
60 return err;
61}
62
63/*
64 * alloc_reserved_mem_array() - allocate memory for the reserved_mem
65 * array using memblock
66 *
67 * This function is used to allocate memory for the reserved_mem
68 * array according to the total number of reserved memory regions
69 * defined in the DT.
70 * After the new array is allocated, the information stored in
71 * the initial static array is copied over to this new array and
72 * the new array is used from this point on.
73 */
74static void __init alloc_reserved_mem_array(void)
75{
76 struct reserved_mem *new_array;
77 size_t alloc_size, copy_size, memset_size;
78
79 alloc_size = array_size(total_reserved_mem_cnt, sizeof(*new_array));
80 if (alloc_size == SIZE_MAX) {
81 pr_err("Failed to allocate memory for reserved_mem array with err: %d", -EOVERFLOW);
82 return;
83 }
84
85 new_array = memblock_alloc(size: alloc_size, SMP_CACHE_BYTES);
86 if (!new_array) {
87 pr_err("Failed to allocate memory for reserved_mem array with err: %d", -ENOMEM);
88 return;
89 }
90
91 copy_size = array_size(reserved_mem_count, sizeof(*new_array));
92 if (copy_size == SIZE_MAX) {
93 memblock_free(ptr: new_array, size: alloc_size);
94 total_reserved_mem_cnt = MAX_RESERVED_REGIONS;
95 pr_err("Failed to allocate memory for reserved_mem array with err: %d", -EOVERFLOW);
96 return;
97 }
98
99 memset_size = alloc_size - copy_size;
100
101 memcpy(new_array, reserved_mem, copy_size);
102 memset(new_array + reserved_mem_count, 0, memset_size);
103
104 reserved_mem = new_array;
105}
106
107static void __init fdt_init_reserved_mem_node(struct reserved_mem *rmem);
108/*
109 * fdt_reserved_mem_save_node() - save fdt node for second pass initialization
110 */
111static void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
112 phys_addr_t base, phys_addr_t size)
113{
114 struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
115
116 if (reserved_mem_count == total_reserved_mem_cnt) {
117 pr_err("not enough space for all defined regions.\n");
118 return;
119 }
120
121 rmem->fdt_node = node;
122 rmem->name = uname;
123 rmem->base = base;
124 rmem->size = size;
125
126 /* Call the region specific initialization function */
127 fdt_init_reserved_mem_node(rmem);
128
129 reserved_mem_count++;
130 return;
131}
132
133static int __init early_init_dt_reserve_memory(phys_addr_t base,
134 phys_addr_t size, bool nomap)
135{
136 if (nomap) {
137 /*
138 * If the memory is already reserved (by another region), we
139 * should not allow it to be marked nomap, but don't worry
140 * if the region isn't memory as it won't be mapped.
141 */
142 if (memblock_overlaps_region(type: &memblock.memory, base, size) &&
143 memblock_is_region_reserved(base, size))
144 return -EBUSY;
145
146 return memblock_mark_nomap(base, size);
147 }
148 return memblock_reserve(base, size);
149}
150
151/*
152 * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
153 */
154static int __init __reserved_mem_reserve_reg(unsigned long node,
155 const char *uname)
156{
157 phys_addr_t base, size;
158 int i, len;
159 const __be32 *prop;
160 bool nomap, default_cma;
161
162 prop = of_flat_dt_get_addr_size_prop(node, name: "reg", entries: &len);
163 if (!prop)
164 return -ENOENT;
165
166 nomap = of_get_flat_dt_prop(node, name: "no-map", NULL) != NULL;
167 default_cma = of_get_flat_dt_prop(node, name: "linux,cma-default", NULL);
168
169 if (default_cma && cma_skip_dt_default_reserved_mem()) {
170 pr_err("Skipping dt linux,cma-default for \"cma=\" kernel param.\n");
171 return -EINVAL;
172 }
173
174 for (i = 0; i < len; i++) {
175 u64 b, s;
176
177 of_flat_dt_read_addr_size(prop, entry_index: i, addr: &b, size: &s);
178
179 base = b;
180 size = s;
181
182 if (size && early_init_dt_reserve_memory(base, size, nomap) == 0) {
183 /* Architecture specific contiguous memory fixup. */
184 if (of_flat_dt_is_compatible(node, name: "shared-dma-pool") &&
185 of_get_flat_dt_prop(node, name: "reusable", NULL))
186 dma_contiguous_early_fixup(base, size);
187 pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n",
188 uname, &base, (unsigned long)(size / SZ_1M));
189 } else {
190 pr_err("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
191 uname, &base, (unsigned long)(size / SZ_1M));
192 }
193 }
194 return 0;
195}
196
197/*
198 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
199 * in /reserved-memory matches the values supported by the current implementation,
200 * also check if ranges property has been provided
201 */
202static int __init __reserved_mem_check_root(unsigned long node)
203{
204 const __be32 *prop;
205
206 prop = of_get_flat_dt_prop(node, name: "#size-cells", NULL);
207 if (!prop || be32_to_cpup(p: prop) != dt_root_size_cells)
208 return -EINVAL;
209
210 prop = of_get_flat_dt_prop(node, name: "#address-cells", NULL);
211 if (!prop || be32_to_cpup(p: prop) != dt_root_addr_cells)
212 return -EINVAL;
213
214 prop = of_get_flat_dt_prop(node, name: "ranges", NULL);
215 if (!prop)
216 return -EINVAL;
217 return 0;
218}
219
220static void __init __rmem_check_for_overlap(void);
221
222/**
223 * fdt_scan_reserved_mem_reg_nodes() - Store info for the "reg" defined
224 * reserved memory regions.
225 *
226 * This function is used to scan through the DT and store the
227 * information for the reserved memory regions that are defined using
228 * the "reg" property. The region node number, name, base address, and
229 * size are all stored in the reserved_mem array by calling the
230 * fdt_reserved_mem_save_node() function.
231 */
232void __init fdt_scan_reserved_mem_reg_nodes(void)
233{
234 const void *fdt = initial_boot_params;
235 phys_addr_t base, size;
236 int node, child;
237
238 if (!fdt)
239 return;
240
241 node = fdt_path_offset(fdt, path: "/reserved-memory");
242 if (node < 0) {
243 pr_info("Reserved memory: No reserved-memory node in the DT\n");
244 return;
245 }
246
247 /* Attempt dynamic allocation of a new reserved_mem array */
248 alloc_reserved_mem_array();
249
250 if (__reserved_mem_check_root(node)) {
251 pr_err("Reserved memory: unsupported node format, ignoring\n");
252 return;
253 }
254
255 fdt_for_each_subnode(child, fdt, node) {
256 const char *uname;
257 bool default_cma = of_get_flat_dt_prop(node: child, name: "linux,cma-default", NULL);
258 u64 b, s;
259
260 if (!of_fdt_device_is_available(blob: fdt, node: child))
261 continue;
262 if (default_cma && cma_skip_dt_default_reserved_mem())
263 continue;
264
265 if (!of_flat_dt_get_addr_size(node: child, name: "reg", addr: &b, size: &s))
266 continue;
267
268 base = b;
269 size = s;
270
271 if (size) {
272 uname = fdt_get_name(fdt, nodeoffset: child, NULL);
273 fdt_reserved_mem_save_node(node: child, uname, base, size);
274 }
275 }
276
277 /* check for overlapping reserved regions */
278 __rmem_check_for_overlap();
279}
280
281static int __init __reserved_mem_alloc_size(unsigned long node, const char *uname);
282
283/*
284 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
285 */
286int __init fdt_scan_reserved_mem(void)
287{
288 int node, child;
289 int dynamic_nodes_cnt = 0, count = 0;
290 int dynamic_nodes[MAX_RESERVED_REGIONS];
291 const void *fdt = initial_boot_params;
292
293 node = fdt_path_offset(fdt, path: "/reserved-memory");
294 if (node < 0)
295 return -ENODEV;
296
297 if (__reserved_mem_check_root(node) != 0) {
298 pr_err("Reserved memory: unsupported node format, ignoring\n");
299 return -EINVAL;
300 }
301
302 fdt_for_each_subnode(child, fdt, node) {
303 const char *uname;
304 int err;
305
306 if (!of_fdt_device_is_available(blob: fdt, node: child))
307 continue;
308
309 uname = fdt_get_name(fdt, nodeoffset: child, NULL);
310
311 err = __reserved_mem_reserve_reg(node: child, uname);
312 if (!err)
313 count++;
314 /*
315 * Save the nodes for the dynamically-placed regions
316 * into an array which will be used for allocation right
317 * after all the statically-placed regions are reserved
318 * or marked as no-map. This is done to avoid dynamically
319 * allocating from one of the statically-placed regions.
320 */
321 if (err == -ENOENT && of_get_flat_dt_prop(node: child, name: "size", NULL)) {
322 dynamic_nodes[dynamic_nodes_cnt] = child;
323 dynamic_nodes_cnt++;
324 }
325 }
326 for (int i = 0; i < dynamic_nodes_cnt; i++) {
327 const char *uname;
328 int err;
329
330 child = dynamic_nodes[i];
331 uname = fdt_get_name(fdt, nodeoffset: child, NULL);
332 err = __reserved_mem_alloc_size(node: child, uname);
333 if (!err)
334 count++;
335 }
336 total_reserved_mem_cnt = count;
337 return 0;
338}
339
340/*
341 * __reserved_mem_alloc_in_range() - allocate reserved memory described with
342 * 'alloc-ranges'. Choose bottom-up/top-down depending on nearby existing
343 * reserved regions to keep the reserved memory contiguous if possible.
344 */
345static int __init __reserved_mem_alloc_in_range(phys_addr_t size,
346 phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
347 phys_addr_t *res_base)
348{
349 bool prev_bottom_up = memblock_bottom_up();
350 bool bottom_up = false, top_down = false;
351 int ret, i;
352
353 for (i = 0; i < reserved_mem_count; i++) {
354 struct reserved_mem *rmem = &reserved_mem[i];
355
356 /* Skip regions that were not reserved yet */
357 if (rmem->size == 0)
358 continue;
359
360 /*
361 * If range starts next to an existing reservation, use bottom-up:
362 * |....RRRR................RRRRRRRR..............|
363 * --RRRR------
364 */
365 if (start >= rmem->base && start <= (rmem->base + rmem->size))
366 bottom_up = true;
367
368 /*
369 * If range ends next to an existing reservation, use top-down:
370 * |....RRRR................RRRRRRRR..............|
371 * -------RRRR-----
372 */
373 if (end >= rmem->base && end <= (rmem->base + rmem->size))
374 top_down = true;
375 }
376
377 /* Change setting only if either bottom-up or top-down was selected */
378 if (bottom_up != top_down)
379 memblock_set_bottom_up(enable: bottom_up);
380
381 ret = early_init_dt_alloc_reserved_memory_arch(size, align,
382 start, end, nomap, res_base);
383
384 /* Restore old setting if needed */
385 if (bottom_up != top_down)
386 memblock_set_bottom_up(enable: prev_bottom_up);
387
388 return ret;
389}
390
391/*
392 * __reserved_mem_alloc_size() - allocate reserved memory described by
393 * 'size', 'alignment' and 'alloc-ranges' properties.
394 */
395static int __init __reserved_mem_alloc_size(unsigned long node, const char *uname)
396{
397 phys_addr_t start = 0, end = 0;
398 phys_addr_t base = 0, align = 0, size;
399 int i, len;
400 const __be32 *prop;
401 bool nomap, default_cma;
402 int ret;
403
404 prop = of_get_flat_dt_prop(node, name: "size", size: &len);
405 if (!prop)
406 return -EINVAL;
407
408 if (len != dt_root_size_cells * sizeof(__be32)) {
409 pr_err("invalid size property in '%s' node.\n", uname);
410 return -EINVAL;
411 }
412 size = dt_mem_next_cell(s: dt_root_size_cells, cellp: &prop);
413
414 prop = of_get_flat_dt_prop(node, name: "alignment", size: &len);
415 if (prop) {
416 if (len != dt_root_addr_cells * sizeof(__be32)) {
417 pr_err("invalid alignment property in '%s' node.\n",
418 uname);
419 return -EINVAL;
420 }
421 align = dt_mem_next_cell(s: dt_root_addr_cells, cellp: &prop);
422 }
423
424 nomap = of_get_flat_dt_prop(node, name: "no-map", NULL) != NULL;
425 default_cma = of_get_flat_dt_prop(node, name: "linux,cma-default", NULL);
426
427 if (default_cma && cma_skip_dt_default_reserved_mem()) {
428 pr_err("Skipping dt linux,cma-default for \"cma=\" kernel param.\n");
429 return -EINVAL;
430 }
431
432 /* Need adjust the alignment to satisfy the CMA requirement */
433 if (IS_ENABLED(CONFIG_CMA)
434 && of_flat_dt_is_compatible(node, name: "shared-dma-pool")
435 && of_get_flat_dt_prop(node, name: "reusable", NULL)
436 && !nomap)
437 align = max_t(phys_addr_t, align, CMA_MIN_ALIGNMENT_BYTES);
438
439 prop = of_flat_dt_get_addr_size_prop(node, name: "alloc-ranges", entries: &len);
440 if (prop) {
441 for (i = 0; i < len; i++) {
442 u64 b, s;
443
444 of_flat_dt_read_addr_size(prop, entry_index: i, addr: &b, size: &s);
445
446 start = b;
447 end = b + s;
448
449 base = 0;
450 ret = __reserved_mem_alloc_in_range(size, align,
451 start, end, nomap, res_base: &base);
452 if (ret == 0) {
453 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
454 uname, &base,
455 (unsigned long)(size / SZ_1M));
456 break;
457 }
458 }
459 } else {
460 ret = early_init_dt_alloc_reserved_memory_arch(size, align,
461 start: 0, end: 0, nomap, res_base: &base);
462 if (ret == 0)
463 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
464 uname, &base, (unsigned long)(size / SZ_1M));
465 }
466
467 if (base == 0) {
468 pr_err("failed to allocate memory for node '%s': size %lu MiB\n",
469 uname, (unsigned long)(size / SZ_1M));
470 return -ENOMEM;
471 }
472 /* Architecture specific contiguous memory fixup. */
473 if (of_flat_dt_is_compatible(node, name: "shared-dma-pool") &&
474 of_get_flat_dt_prop(node, name: "reusable", NULL))
475 dma_contiguous_early_fixup(base, size);
476 /* Save region in the reserved_mem array */
477 fdt_reserved_mem_save_node(node, uname, base, size);
478 return 0;
479}
480
481static const struct of_device_id __rmem_of_table_sentinel
482 __used __section("__reservedmem_of_table_end");
483
484/*
485 * __reserved_mem_init_node() - call region specific reserved memory init code
486 */
487static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
488{
489 extern const struct of_device_id __reservedmem_of_table[];
490 const struct of_device_id *i;
491 int ret = -ENOENT;
492
493 for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
494 reservedmem_of_init_fn initfn = i->data;
495 const char *compat = i->compatible;
496
497 if (!of_flat_dt_is_compatible(node: rmem->fdt_node, name: compat))
498 continue;
499
500 ret = initfn(rmem);
501 if (ret == 0) {
502 pr_info("initialized node %s, compatible id %s\n",
503 rmem->name, compat);
504 break;
505 }
506 }
507 return ret;
508}
509
510static int __init __rmem_cmp(const void *a, const void *b)
511{
512 const struct reserved_mem *ra = a, *rb = b;
513
514 if (ra->base < rb->base)
515 return -1;
516
517 if (ra->base > rb->base)
518 return 1;
519
520 /*
521 * Put the dynamic allocations (address == 0, size == 0) before static
522 * allocations at address 0x0 so that overlap detection works
523 * correctly.
524 */
525 if (ra->size < rb->size)
526 return -1;
527 if (ra->size > rb->size)
528 return 1;
529
530 if (ra->fdt_node < rb->fdt_node)
531 return -1;
532 if (ra->fdt_node > rb->fdt_node)
533 return 1;
534
535 return 0;
536}
537
538static void __init __rmem_check_for_overlap(void)
539{
540 int i;
541
542 if (reserved_mem_count < 2)
543 return;
544
545 sort(base: reserved_mem, num: reserved_mem_count, size: sizeof(reserved_mem[0]),
546 cmp_func: __rmem_cmp, NULL);
547 for (i = 0; i < reserved_mem_count - 1; i++) {
548 struct reserved_mem *this, *next;
549
550 this = &reserved_mem[i];
551 next = &reserved_mem[i + 1];
552
553 if (this->base + this->size > next->base) {
554 phys_addr_t this_end, next_end;
555
556 this_end = this->base + this->size;
557 next_end = next->base + next->size;
558 pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
559 this->name, &this->base, &this_end,
560 next->name, &next->base, &next_end);
561 }
562 }
563}
564
565/**
566 * fdt_init_reserved_mem_node() - Initialize a reserved memory region
567 * @rmem: reserved_mem struct of the memory region to be initialized.
568 *
569 * This function is used to call the region specific initialization
570 * function for a reserved memory region.
571 */
572static void __init fdt_init_reserved_mem_node(struct reserved_mem *rmem)
573{
574 unsigned long node = rmem->fdt_node;
575 int err = 0;
576 bool nomap;
577
578 nomap = of_get_flat_dt_prop(node, name: "no-map", NULL) != NULL;
579
580 err = __reserved_mem_init_node(rmem);
581 if (err != 0 && err != -ENOENT) {
582 pr_info("node %s compatible matching fail\n", rmem->name);
583 if (nomap)
584 memblock_clear_nomap(base: rmem->base, size: rmem->size);
585 else
586 memblock_phys_free(base: rmem->base, size: rmem->size);
587 } else {
588 phys_addr_t end = rmem->base + rmem->size - 1;
589 bool reusable =
590 (of_get_flat_dt_prop(node, name: "reusable", NULL)) != NULL;
591
592 pr_info("%pa..%pa (%lu KiB) %s %s %s\n",
593 &rmem->base, &end, (unsigned long)(rmem->size / SZ_1K),
594 nomap ? "nomap" : "map",
595 reusable ? "reusable" : "non-reusable",
596 rmem->name ? rmem->name : "unknown");
597 }
598}
599
600struct rmem_assigned_device {
601 struct device *dev;
602 struct reserved_mem *rmem;
603 struct list_head list;
604};
605
606static LIST_HEAD(of_rmem_assigned_device_list);
607static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
608
609/**
610 * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
611 * given device
612 * @dev: Pointer to the device to configure
613 * @np: Pointer to the device_node with 'reserved-memory' property
614 * @idx: Index of selected region
615 *
616 * This function assigns respective DMA-mapping operations based on reserved
617 * memory region specified by 'memory-region' property in @np node to the @dev
618 * device. When driver needs to use more than one reserved memory region, it
619 * should allocate child devices and initialize regions by name for each of
620 * child device.
621 *
622 * Returns error code or zero on success.
623 */
624int of_reserved_mem_device_init_by_idx(struct device *dev,
625 struct device_node *np, int idx)
626{
627 struct rmem_assigned_device *rd;
628 struct device_node *target;
629 struct reserved_mem *rmem;
630 int ret;
631
632 if (!np || !dev)
633 return -EINVAL;
634
635 target = of_parse_phandle(np, phandle_name: "memory-region", index: idx);
636 if (!target)
637 return -ENODEV;
638
639 if (!of_device_is_available(device: target)) {
640 of_node_put(node: target);
641 return 0;
642 }
643
644 rmem = of_reserved_mem_lookup(np: target);
645 of_node_put(node: target);
646
647 if (!rmem || !rmem->ops || !rmem->ops->device_init)
648 return -EINVAL;
649
650 rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
651 if (!rd)
652 return -ENOMEM;
653
654 ret = rmem->ops->device_init(rmem, dev);
655 if (ret == 0) {
656 rd->dev = dev;
657 rd->rmem = rmem;
658
659 mutex_lock(&of_rmem_assigned_device_mutex);
660 list_add(new: &rd->list, head: &of_rmem_assigned_device_list);
661 mutex_unlock(lock: &of_rmem_assigned_device_mutex);
662
663 dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
664 } else {
665 kfree(objp: rd);
666 }
667
668 return ret;
669}
670EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
671
672/**
673 * of_reserved_mem_device_init_by_name() - assign named reserved memory region
674 * to given device
675 * @dev: pointer to the device to configure
676 * @np: pointer to the device node with 'memory-region' property
677 * @name: name of the selected memory region
678 *
679 * Returns: 0 on success or a negative error-code on failure.
680 */
681int of_reserved_mem_device_init_by_name(struct device *dev,
682 struct device_node *np,
683 const char *name)
684{
685 int idx = of_property_match_string(np, propname: "memory-region-names", string: name);
686
687 return of_reserved_mem_device_init_by_idx(dev, np, idx);
688}
689EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name);
690
691/**
692 * of_reserved_mem_device_release() - release reserved memory device structures
693 * @dev: Pointer to the device to deconfigure
694 *
695 * This function releases structures allocated for memory region handling for
696 * the given device.
697 */
698void of_reserved_mem_device_release(struct device *dev)
699{
700 struct rmem_assigned_device *rd, *tmp;
701 LIST_HEAD(release_list);
702
703 mutex_lock(&of_rmem_assigned_device_mutex);
704 list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) {
705 if (rd->dev == dev)
706 list_move_tail(list: &rd->list, head: &release_list);
707 }
708 mutex_unlock(lock: &of_rmem_assigned_device_mutex);
709
710 list_for_each_entry_safe(rd, tmp, &release_list, list) {
711 if (rd->rmem && rd->rmem->ops && rd->rmem->ops->device_release)
712 rd->rmem->ops->device_release(rd->rmem, dev);
713
714 kfree(objp: rd);
715 }
716}
717EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
718
719/**
720 * of_reserved_mem_lookup() - acquire reserved_mem from a device node
721 * @np: node pointer of the desired reserved-memory region
722 *
723 * This function allows drivers to acquire a reference to the reserved_mem
724 * struct based on a device node handle.
725 *
726 * Returns a reserved_mem reference, or NULL on error.
727 */
728struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
729{
730 const char *name;
731 int i;
732
733 if (!np->full_name)
734 return NULL;
735
736 name = kbasename(path: np->full_name);
737 for (i = 0; i < reserved_mem_count; i++)
738 if (!strcmp(reserved_mem[i].name, name))
739 return &reserved_mem[i];
740
741 return NULL;
742}
743EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);
744
745/**
746 * of_reserved_mem_region_to_resource() - Get a reserved memory region as a resource
747 * @np: node containing 'memory-region' property
748 * @idx: index of 'memory-region' property to lookup
749 * @res: Pointer to a struct resource to fill in with reserved region
750 *
751 * This function allows drivers to lookup a node's 'memory-region' property
752 * entries by index and return a struct resource for the entry.
753 *
754 * Returns 0 on success with @res filled in. Returns -ENODEV if 'memory-region'
755 * is missing or unavailable, -EINVAL for any other error.
756 */
757int of_reserved_mem_region_to_resource(const struct device_node *np,
758 unsigned int idx, struct resource *res)
759{
760 struct reserved_mem *rmem;
761
762 if (!np)
763 return -EINVAL;
764
765 struct device_node __free(device_node) *target = of_parse_phandle(np, phandle_name: "memory-region", index: idx);
766 if (!target || !of_device_is_available(device: target))
767 return -ENODEV;
768
769 rmem = of_reserved_mem_lookup(target);
770 if (!rmem)
771 return -EINVAL;
772
773 resource_set_range(res, start: rmem->base, size: rmem->size);
774 res->flags = IORESOURCE_MEM;
775 res->name = rmem->name;
776 return 0;
777}
778EXPORT_SYMBOL_GPL(of_reserved_mem_region_to_resource);
779
780/**
781 * of_reserved_mem_region_to_resource_byname() - Get a reserved memory region as a resource
782 * @np: node containing 'memory-region' property
783 * @name: name of 'memory-region' property entry to lookup
784 * @res: Pointer to a struct resource to fill in with reserved region
785 *
786 * This function allows drivers to lookup a node's 'memory-region' property
787 * entries by name and return a struct resource for the entry.
788 *
789 * Returns 0 on success with @res filled in, or a negative error-code on
790 * failure.
791 */
792int of_reserved_mem_region_to_resource_byname(const struct device_node *np,
793 const char *name,
794 struct resource *res)
795{
796 int idx;
797
798 if (!name)
799 return -EINVAL;
800
801 idx = of_property_match_string(np, propname: "memory-region-names", string: name);
802 if (idx < 0)
803 return idx;
804
805 return of_reserved_mem_region_to_resource(np, idx, res);
806}
807EXPORT_SYMBOL_GPL(of_reserved_mem_region_to_resource_byname);
808
809/**
810 * of_reserved_mem_region_count() - Return the number of 'memory-region' entries
811 * @np: node containing 'memory-region' property
812 *
813 * This function allows drivers to retrieve the number of entries for a node's
814 * 'memory-region' property.
815 *
816 * Returns the number of entries on success, or negative error code on a
817 * malformed property.
818 */
819int of_reserved_mem_region_count(const struct device_node *np)
820{
821 return of_count_phandle_with_args(np, list_name: "memory-region", NULL);
822}
823EXPORT_SYMBOL_GPL(of_reserved_mem_region_count);
824

source code of linux/drivers/of/of_reserved_mem.c