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/libfdt.h>
16#include <linux/of.h>
17#include <linux/of_fdt.h>
18#include <linux/of_platform.h>
19#include <linux/mm.h>
20#include <linux/sizes.h>
21#include <linux/of_reserved_mem.h>
22#include <linux/sort.h>
23#include <linux/slab.h>
24#include <linux/memblock.h>
25#include <linux/kmemleak.h>
26#include <linux/cma.h>
27
28#include "of_private.h"
29
30#define MAX_RESERVED_REGIONS 64
31static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
32static int reserved_mem_count;
33
34static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
35 phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
36 phys_addr_t *res_base)
37{
38 phys_addr_t base;
39 int err = 0;
40
41 end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
42 align = !align ? SMP_CACHE_BYTES : align;
43 base = memblock_phys_alloc_range(size, align, start, end);
44 if (!base)
45 return -ENOMEM;
46
47 *res_base = base;
48 if (nomap) {
49 err = memblock_mark_nomap(base, size);
50 if (err)
51 memblock_phys_free(base, size);
52 }
53
54 kmemleak_ignore_phys(phys: base);
55
56 return err;
57}
58
59/*
60 * fdt_reserved_mem_save_node() - save fdt node for second pass initialization
61 */
62static void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
63 phys_addr_t base, phys_addr_t size)
64{
65 struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
66
67 if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
68 pr_err("not enough space for all defined regions.\n");
69 return;
70 }
71
72 rmem->fdt_node = node;
73 rmem->name = uname;
74 rmem->base = base;
75 rmem->size = size;
76
77 reserved_mem_count++;
78 return;
79}
80
81static int __init early_init_dt_reserve_memory(phys_addr_t base,
82 phys_addr_t size, bool nomap)
83{
84 if (nomap) {
85 /*
86 * If the memory is already reserved (by another region), we
87 * should not allow it to be marked nomap, but don't worry
88 * if the region isn't memory as it won't be mapped.
89 */
90 if (memblock_overlaps_region(type: &memblock.memory, base, size) &&
91 memblock_is_region_reserved(base, size))
92 return -EBUSY;
93
94 return memblock_mark_nomap(base, size);
95 }
96 return memblock_reserve(base, size);
97}
98
99/*
100 * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
101 */
102static int __init __reserved_mem_reserve_reg(unsigned long node,
103 const char *uname)
104{
105 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
106 phys_addr_t base, size;
107 int len;
108 const __be32 *prop;
109 int first = 1;
110 bool nomap;
111
112 prop = of_get_flat_dt_prop(node, name: "reg", size: &len);
113 if (!prop)
114 return -ENOENT;
115
116 if (len && len % t_len != 0) {
117 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
118 uname);
119 return -EINVAL;
120 }
121
122 nomap = of_get_flat_dt_prop(node, name: "no-map", NULL) != NULL;
123
124 while (len >= t_len) {
125 base = dt_mem_next_cell(s: dt_root_addr_cells, cellp: &prop);
126 size = dt_mem_next_cell(s: dt_root_size_cells, cellp: &prop);
127
128 if (size &&
129 early_init_dt_reserve_memory(base, size, nomap) == 0)
130 pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n",
131 uname, &base, (unsigned long)(size / SZ_1M));
132 else
133 pr_err("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
134 uname, &base, (unsigned long)(size / SZ_1M));
135
136 len -= t_len;
137 if (first) {
138 fdt_reserved_mem_save_node(node, uname, base, size);
139 first = 0;
140 }
141 }
142 return 0;
143}
144
145/*
146 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
147 * in /reserved-memory matches the values supported by the current implementation,
148 * also check if ranges property has been provided
149 */
150static int __init __reserved_mem_check_root(unsigned long node)
151{
152 const __be32 *prop;
153
154 prop = of_get_flat_dt_prop(node, name: "#size-cells", NULL);
155 if (!prop || be32_to_cpup(p: prop) != dt_root_size_cells)
156 return -EINVAL;
157
158 prop = of_get_flat_dt_prop(node, name: "#address-cells", NULL);
159 if (!prop || be32_to_cpup(p: prop) != dt_root_addr_cells)
160 return -EINVAL;
161
162 prop = of_get_flat_dt_prop(node, name: "ranges", NULL);
163 if (!prop)
164 return -EINVAL;
165 return 0;
166}
167
168/*
169 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
170 */
171int __init fdt_scan_reserved_mem(void)
172{
173 int node, child;
174 const void *fdt = initial_boot_params;
175
176 node = fdt_path_offset(fdt, path: "/reserved-memory");
177 if (node < 0)
178 return -ENODEV;
179
180 if (__reserved_mem_check_root(node) != 0) {
181 pr_err("Reserved memory: unsupported node format, ignoring\n");
182 return -EINVAL;
183 }
184
185 fdt_for_each_subnode(child, fdt, node) {
186 const char *uname;
187 int err;
188
189 if (!of_fdt_device_is_available(blob: fdt, node: child))
190 continue;
191
192 uname = fdt_get_name(fdt, nodeoffset: child, NULL);
193
194 err = __reserved_mem_reserve_reg(node: child, uname);
195 if (err == -ENOENT && of_get_flat_dt_prop(node: child, name: "size", NULL))
196 fdt_reserved_mem_save_node(node: child, uname, base: 0, size: 0);
197 }
198 return 0;
199}
200
201/*
202 * __reserved_mem_alloc_in_range() - allocate reserved memory described with
203 * 'alloc-ranges'. Choose bottom-up/top-down depending on nearby existing
204 * reserved regions to keep the reserved memory contiguous if possible.
205 */
206static int __init __reserved_mem_alloc_in_range(phys_addr_t size,
207 phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
208 phys_addr_t *res_base)
209{
210 bool prev_bottom_up = memblock_bottom_up();
211 bool bottom_up = false, top_down = false;
212 int ret, i;
213
214 for (i = 0; i < reserved_mem_count; i++) {
215 struct reserved_mem *rmem = &reserved_mem[i];
216
217 /* Skip regions that were not reserved yet */
218 if (rmem->size == 0)
219 continue;
220
221 /*
222 * If range starts next to an existing reservation, use bottom-up:
223 * |....RRRR................RRRRRRRR..............|
224 * --RRRR------
225 */
226 if (start >= rmem->base && start <= (rmem->base + rmem->size))
227 bottom_up = true;
228
229 /*
230 * If range ends next to an existing reservation, use top-down:
231 * |....RRRR................RRRRRRRR..............|
232 * -------RRRR-----
233 */
234 if (end >= rmem->base && end <= (rmem->base + rmem->size))
235 top_down = true;
236 }
237
238 /* Change setting only if either bottom-up or top-down was selected */
239 if (bottom_up != top_down)
240 memblock_set_bottom_up(enable: bottom_up);
241
242 ret = early_init_dt_alloc_reserved_memory_arch(size, align,
243 start, end, nomap, res_base);
244
245 /* Restore old setting if needed */
246 if (bottom_up != top_down)
247 memblock_set_bottom_up(enable: prev_bottom_up);
248
249 return ret;
250}
251
252/*
253 * __reserved_mem_alloc_size() - allocate reserved memory described by
254 * 'size', 'alignment' and 'alloc-ranges' properties.
255 */
256static int __init __reserved_mem_alloc_size(unsigned long node,
257 const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
258{
259 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
260 phys_addr_t start = 0, end = 0;
261 phys_addr_t base = 0, align = 0, size;
262 int len;
263 const __be32 *prop;
264 bool nomap;
265 int ret;
266
267 prop = of_get_flat_dt_prop(node, name: "size", size: &len);
268 if (!prop)
269 return -EINVAL;
270
271 if (len != dt_root_size_cells * sizeof(__be32)) {
272 pr_err("invalid size property in '%s' node.\n", uname);
273 return -EINVAL;
274 }
275 size = dt_mem_next_cell(s: dt_root_size_cells, cellp: &prop);
276
277 prop = of_get_flat_dt_prop(node, name: "alignment", size: &len);
278 if (prop) {
279 if (len != dt_root_addr_cells * sizeof(__be32)) {
280 pr_err("invalid alignment property in '%s' node.\n",
281 uname);
282 return -EINVAL;
283 }
284 align = dt_mem_next_cell(s: dt_root_addr_cells, cellp: &prop);
285 }
286
287 nomap = of_get_flat_dt_prop(node, name: "no-map", NULL) != NULL;
288
289 /* Need adjust the alignment to satisfy the CMA requirement */
290 if (IS_ENABLED(CONFIG_CMA)
291 && of_flat_dt_is_compatible(node, name: "shared-dma-pool")
292 && of_get_flat_dt_prop(node, name: "reusable", NULL)
293 && !nomap)
294 align = max_t(phys_addr_t, align, CMA_MIN_ALIGNMENT_BYTES);
295
296 prop = of_get_flat_dt_prop(node, name: "alloc-ranges", size: &len);
297 if (prop) {
298
299 if (len % t_len != 0) {
300 pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
301 uname);
302 return -EINVAL;
303 }
304
305 base = 0;
306
307 while (len > 0) {
308 start = dt_mem_next_cell(s: dt_root_addr_cells, cellp: &prop);
309 end = start + dt_mem_next_cell(s: dt_root_size_cells,
310 cellp: &prop);
311
312 ret = __reserved_mem_alloc_in_range(size, align,
313 start, end, nomap, res_base: &base);
314 if (ret == 0) {
315 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
316 uname, &base,
317 (unsigned long)(size / SZ_1M));
318 break;
319 }
320 len -= t_len;
321 }
322
323 } else {
324 ret = early_init_dt_alloc_reserved_memory_arch(size, align,
325 start: 0, end: 0, nomap, res_base: &base);
326 if (ret == 0)
327 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
328 uname, &base, (unsigned long)(size / SZ_1M));
329 }
330
331 if (base == 0) {
332 pr_err("failed to allocate memory for node '%s': size %lu MiB\n",
333 uname, (unsigned long)(size / SZ_1M));
334 return -ENOMEM;
335 }
336
337 *res_base = base;
338 *res_size = size;
339
340 return 0;
341}
342
343static const struct of_device_id __rmem_of_table_sentinel
344 __used __section("__reservedmem_of_table_end");
345
346/*
347 * __reserved_mem_init_node() - call region specific reserved memory init code
348 */
349static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
350{
351 extern const struct of_device_id __reservedmem_of_table[];
352 const struct of_device_id *i;
353 int ret = -ENOENT;
354
355 for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
356 reservedmem_of_init_fn initfn = i->data;
357 const char *compat = i->compatible;
358
359 if (!of_flat_dt_is_compatible(node: rmem->fdt_node, name: compat))
360 continue;
361
362 ret = initfn(rmem);
363 if (ret == 0) {
364 pr_info("initialized node %s, compatible id %s\n",
365 rmem->name, compat);
366 break;
367 }
368 }
369 return ret;
370}
371
372static int __init __rmem_cmp(const void *a, const void *b)
373{
374 const struct reserved_mem *ra = a, *rb = b;
375
376 if (ra->base < rb->base)
377 return -1;
378
379 if (ra->base > rb->base)
380 return 1;
381
382 /*
383 * Put the dynamic allocations (address == 0, size == 0) before static
384 * allocations at address 0x0 so that overlap detection works
385 * correctly.
386 */
387 if (ra->size < rb->size)
388 return -1;
389 if (ra->size > rb->size)
390 return 1;
391
392 if (ra->fdt_node < rb->fdt_node)
393 return -1;
394 if (ra->fdt_node > rb->fdt_node)
395 return 1;
396
397 return 0;
398}
399
400static void __init __rmem_check_for_overlap(void)
401{
402 int i;
403
404 if (reserved_mem_count < 2)
405 return;
406
407 sort(base: reserved_mem, num: reserved_mem_count, size: sizeof(reserved_mem[0]),
408 cmp_func: __rmem_cmp, NULL);
409 for (i = 0; i < reserved_mem_count - 1; i++) {
410 struct reserved_mem *this, *next;
411
412 this = &reserved_mem[i];
413 next = &reserved_mem[i + 1];
414
415 if (this->base + this->size > next->base) {
416 phys_addr_t this_end, next_end;
417
418 this_end = this->base + this->size;
419 next_end = next->base + next->size;
420 pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
421 this->name, &this->base, &this_end,
422 next->name, &next->base, &next_end);
423 }
424 }
425}
426
427/**
428 * fdt_init_reserved_mem() - allocate and init all saved reserved memory regions
429 */
430void __init fdt_init_reserved_mem(void)
431{
432 int i;
433
434 /* check for overlapping reserved regions */
435 __rmem_check_for_overlap();
436
437 for (i = 0; i < reserved_mem_count; i++) {
438 struct reserved_mem *rmem = &reserved_mem[i];
439 unsigned long node = rmem->fdt_node;
440 int len;
441 const __be32 *prop;
442 int err = 0;
443 bool nomap;
444
445 nomap = of_get_flat_dt_prop(node, name: "no-map", NULL) != NULL;
446 prop = of_get_flat_dt_prop(node, name: "phandle", size: &len);
447 if (!prop)
448 prop = of_get_flat_dt_prop(node, name: "linux,phandle", size: &len);
449 if (prop)
450 rmem->phandle = of_read_number(cell: prop, size: len/4);
451
452 if (rmem->size == 0)
453 err = __reserved_mem_alloc_size(node, uname: rmem->name,
454 res_base: &rmem->base, res_size: &rmem->size);
455 if (err == 0) {
456 err = __reserved_mem_init_node(rmem);
457 if (err != 0 && err != -ENOENT) {
458 pr_info("node %s compatible matching fail\n",
459 rmem->name);
460 if (nomap)
461 memblock_clear_nomap(base: rmem->base, size: rmem->size);
462 else
463 memblock_phys_free(base: rmem->base,
464 size: rmem->size);
465 } else {
466 phys_addr_t end = rmem->base + rmem->size - 1;
467 bool reusable =
468 (of_get_flat_dt_prop(node, name: "reusable", NULL)) != NULL;
469
470 pr_info("%pa..%pa (%lu KiB) %s %s %s\n",
471 &rmem->base, &end, (unsigned long)(rmem->size / SZ_1K),
472 nomap ? "nomap" : "map",
473 reusable ? "reusable" : "non-reusable",
474 rmem->name ? rmem->name : "unknown");
475 }
476 }
477 }
478}
479
480static inline struct reserved_mem *__find_rmem(struct device_node *node)
481{
482 unsigned int i;
483
484 if (!node->phandle)
485 return NULL;
486
487 for (i = 0; i < reserved_mem_count; i++)
488 if (reserved_mem[i].phandle == node->phandle)
489 return &reserved_mem[i];
490 return NULL;
491}
492
493struct rmem_assigned_device {
494 struct device *dev;
495 struct reserved_mem *rmem;
496 struct list_head list;
497};
498
499static LIST_HEAD(of_rmem_assigned_device_list);
500static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
501
502/**
503 * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
504 * given device
505 * @dev: Pointer to the device to configure
506 * @np: Pointer to the device_node with 'reserved-memory' property
507 * @idx: Index of selected region
508 *
509 * This function assigns respective DMA-mapping operations based on reserved
510 * memory region specified by 'memory-region' property in @np node to the @dev
511 * device. When driver needs to use more than one reserved memory region, it
512 * should allocate child devices and initialize regions by name for each of
513 * child device.
514 *
515 * Returns error code or zero on success.
516 */
517int of_reserved_mem_device_init_by_idx(struct device *dev,
518 struct device_node *np, int idx)
519{
520 struct rmem_assigned_device *rd;
521 struct device_node *target;
522 struct reserved_mem *rmem;
523 int ret;
524
525 if (!np || !dev)
526 return -EINVAL;
527
528 target = of_parse_phandle(np, phandle_name: "memory-region", index: idx);
529 if (!target)
530 return -ENODEV;
531
532 if (!of_device_is_available(device: target)) {
533 of_node_put(node: target);
534 return 0;
535 }
536
537 rmem = __find_rmem(node: target);
538 of_node_put(node: target);
539
540 if (!rmem || !rmem->ops || !rmem->ops->device_init)
541 return -EINVAL;
542
543 rd = kmalloc(size: sizeof(struct rmem_assigned_device), GFP_KERNEL);
544 if (!rd)
545 return -ENOMEM;
546
547 ret = rmem->ops->device_init(rmem, dev);
548 if (ret == 0) {
549 rd->dev = dev;
550 rd->rmem = rmem;
551
552 mutex_lock(&of_rmem_assigned_device_mutex);
553 list_add(new: &rd->list, head: &of_rmem_assigned_device_list);
554 mutex_unlock(lock: &of_rmem_assigned_device_mutex);
555
556 dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
557 } else {
558 kfree(objp: rd);
559 }
560
561 return ret;
562}
563EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
564
565/**
566 * of_reserved_mem_device_init_by_name() - assign named reserved memory region
567 * to given device
568 * @dev: pointer to the device to configure
569 * @np: pointer to the device node with 'memory-region' property
570 * @name: name of the selected memory region
571 *
572 * Returns: 0 on success or a negative error-code on failure.
573 */
574int of_reserved_mem_device_init_by_name(struct device *dev,
575 struct device_node *np,
576 const char *name)
577{
578 int idx = of_property_match_string(np, propname: "memory-region-names", string: name);
579
580 return of_reserved_mem_device_init_by_idx(dev, np, idx);
581}
582EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name);
583
584/**
585 * of_reserved_mem_device_release() - release reserved memory device structures
586 * @dev: Pointer to the device to deconfigure
587 *
588 * This function releases structures allocated for memory region handling for
589 * the given device.
590 */
591void of_reserved_mem_device_release(struct device *dev)
592{
593 struct rmem_assigned_device *rd, *tmp;
594 LIST_HEAD(release_list);
595
596 mutex_lock(&of_rmem_assigned_device_mutex);
597 list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) {
598 if (rd->dev == dev)
599 list_move_tail(list: &rd->list, head: &release_list);
600 }
601 mutex_unlock(lock: &of_rmem_assigned_device_mutex);
602
603 list_for_each_entry_safe(rd, tmp, &release_list, list) {
604 if (rd->rmem && rd->rmem->ops && rd->rmem->ops->device_release)
605 rd->rmem->ops->device_release(rd->rmem, dev);
606
607 kfree(objp: rd);
608 }
609}
610EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
611
612/**
613 * of_reserved_mem_lookup() - acquire reserved_mem from a device node
614 * @np: node pointer of the desired reserved-memory region
615 *
616 * This function allows drivers to acquire a reference to the reserved_mem
617 * struct based on a device node handle.
618 *
619 * Returns a reserved_mem reference, or NULL on error.
620 */
621struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
622{
623 const char *name;
624 int i;
625
626 if (!np->full_name)
627 return NULL;
628
629 name = kbasename(path: np->full_name);
630 for (i = 0; i < reserved_mem_count; i++)
631 if (!strcmp(reserved_mem[i].name, name))
632 return &reserved_mem[i];
633
634 return NULL;
635}
636EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);
637

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