1 // SPDX-License-Identifier: GPL-2.0+
3 * Device tree based initialization code for reserved memory.
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>
12 #define pr_fmt(fmt) "OF: reserved mem: " fmt
14 #include <linux/err.h>
15 #include <linux/libfdt.h>
17 #include <linux/of_fdt.h>
18 #include <linux/of_platform.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>
28 #include "of_private.h"
30 #define MAX_RESERVED_REGIONS 64
31 static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
32 static int reserved_mem_count;
34 static 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)
41 end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
42 align = !align ? SMP_CACHE_BYTES : align;
43 base = memblock_phys_alloc_range(size, align, start, end);
49 err = memblock_mark_nomap(base, size);
51 memblock_phys_free(base, size);
54 kmemleak_ignore_phys(base);
60 * fdt_reserved_mem_save_node() - save fdt node for second pass initialization
62 static void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
63 phys_addr_t base, phys_addr_t size)
65 struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
67 if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
68 pr_err("not enough space for all defined regions.\n");
72 rmem->fdt_node = node;
81 static int __init early_init_dt_reserve_memory(phys_addr_t base,
82 phys_addr_t size, bool nomap)
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.
90 if (memblock_overlaps_region(&memblock.memory, base, size) &&
91 memblock_is_region_reserved(base, size))
94 return memblock_mark_nomap(base, size);
96 return memblock_reserve(base, size);
100 * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
102 static int __init __reserved_mem_reserve_reg(unsigned long node,
105 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
106 phys_addr_t base, size;
112 prop = of_get_flat_dt_prop(node, "reg", &len);
116 if (len && len % t_len != 0) {
117 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
122 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
124 while (len >= t_len) {
125 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
126 size = dt_mem_next_cell(dt_root_size_cells, &prop);
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));
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));
138 fdt_reserved_mem_save_node(node, uname, base, size);
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
150 static int __init __reserved_mem_check_root(unsigned long node)
154 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
155 if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
158 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
159 if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
162 prop = of_get_flat_dt_prop(node, "ranges", NULL);
169 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
171 int __init fdt_scan_reserved_mem(void)
174 const void *fdt = initial_boot_params;
176 node = fdt_path_offset(fdt, "/reserved-memory");
180 if (__reserved_mem_check_root(node) != 0) {
181 pr_err("Reserved memory: unsupported node format, ignoring\n");
185 fdt_for_each_subnode(child, fdt, node) {
189 if (!of_fdt_device_is_available(fdt, child))
192 uname = fdt_get_name(fdt, child, NULL);
194 err = __reserved_mem_reserve_reg(child, uname);
195 if (err == -ENOENT && of_get_flat_dt_prop(child, "size", NULL))
196 fdt_reserved_mem_save_node(child, uname, 0, 0);
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.
206 static 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)
210 bool prev_bottom_up = memblock_bottom_up();
211 bool bottom_up = false, top_down = false;
214 for (i = 0; i < reserved_mem_count; i++) {
215 struct reserved_mem *rmem = &reserved_mem[i];
217 /* Skip regions that were not reserved yet */
222 * If range starts next to an existing reservation, use bottom-up:
223 * |....RRRR................RRRRRRRR..............|
226 if (start >= rmem->base && start <= (rmem->base + rmem->size))
230 * If range ends next to an existing reservation, use top-down:
231 * |....RRRR................RRRRRRRR..............|
234 if (end >= rmem->base && end <= (rmem->base + rmem->size))
238 /* Change setting only if either bottom-up or top-down was selected */
239 if (bottom_up != top_down)
240 memblock_set_bottom_up(bottom_up);
242 ret = early_init_dt_alloc_reserved_memory_arch(size, align,
243 start, end, nomap, res_base);
245 /* Restore old setting if needed */
246 if (bottom_up != top_down)
247 memblock_set_bottom_up(prev_bottom_up);
253 * __reserved_mem_alloc_size() - allocate reserved memory described by
254 * 'size', 'alignment' and 'alloc-ranges' properties.
256 static int __init __reserved_mem_alloc_size(unsigned long node,
257 const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
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;
267 prop = of_get_flat_dt_prop(node, "size", &len);
271 if (len != dt_root_size_cells * sizeof(__be32)) {
272 pr_err("invalid size property in '%s' node.\n", uname);
275 size = dt_mem_next_cell(dt_root_size_cells, &prop);
277 prop = of_get_flat_dt_prop(node, "alignment", &len);
279 if (len != dt_root_addr_cells * sizeof(__be32)) {
280 pr_err("invalid alignment property in '%s' node.\n",
284 align = dt_mem_next_cell(dt_root_addr_cells, &prop);
287 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
289 /* Need adjust the alignment to satisfy the CMA requirement */
290 if (IS_ENABLED(CONFIG_CMA)
291 && of_flat_dt_is_compatible(node, "shared-dma-pool")
292 && of_get_flat_dt_prop(node, "reusable", NULL)
294 align = max_t(phys_addr_t, align, CMA_MIN_ALIGNMENT_BYTES);
296 prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
299 if (len % t_len != 0) {
300 pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
308 start = dt_mem_next_cell(dt_root_addr_cells, &prop);
309 end = start + dt_mem_next_cell(dt_root_size_cells,
312 ret = __reserved_mem_alloc_in_range(size, align,
313 start, end, nomap, &base);
315 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
317 (unsigned long)(size / SZ_1M));
324 ret = early_init_dt_alloc_reserved_memory_arch(size, align,
327 pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
328 uname, &base, (unsigned long)(size / SZ_1M));
332 pr_err("failed to allocate memory for node '%s': size %lu MiB\n",
333 uname, (unsigned long)(size / SZ_1M));
343 static const struct of_device_id __rmem_of_table_sentinel
344 __used __section("__reservedmem_of_table_end");
347 * __reserved_mem_init_node() - call region specific reserved memory init code
349 static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
351 extern const struct of_device_id __reservedmem_of_table[];
352 const struct of_device_id *i;
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;
359 if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
364 pr_info("initialized node %s, compatible id %s\n",
372 static int __init __rmem_cmp(const void *a, const void *b)
374 const struct reserved_mem *ra = a, *rb = b;
376 if (ra->base < rb->base)
379 if (ra->base > rb->base)
383 * Put the dynamic allocations (address == 0, size == 0) before static
384 * allocations at address 0x0 so that overlap detection works
387 if (ra->size < rb->size)
389 if (ra->size > rb->size)
392 if (ra->fdt_node < rb->fdt_node)
394 if (ra->fdt_node > rb->fdt_node)
400 static void __init __rmem_check_for_overlap(void)
404 if (reserved_mem_count < 2)
407 sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
409 for (i = 0; i < reserved_mem_count - 1; i++) {
410 struct reserved_mem *this, *next;
412 this = &reserved_mem[i];
413 next = &reserved_mem[i + 1];
415 if (this->base + this->size > next->base) {
416 phys_addr_t this_end, next_end;
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);
428 * fdt_init_reserved_mem() - allocate and init all saved reserved memory regions
430 void __init fdt_init_reserved_mem(void)
434 /* check for overlapping reserved regions */
435 __rmem_check_for_overlap();
437 for (i = 0; i < reserved_mem_count; i++) {
438 struct reserved_mem *rmem = &reserved_mem[i];
439 unsigned long node = rmem->fdt_node;
445 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
446 prop = of_get_flat_dt_prop(node, "phandle", &len);
448 prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
450 rmem->phandle = of_read_number(prop, len/4);
453 err = __reserved_mem_alloc_size(node, rmem->name,
454 &rmem->base, &rmem->size);
456 err = __reserved_mem_init_node(rmem);
457 if (err != 0 && err != -ENOENT) {
458 pr_info("node %s compatible matching fail\n",
461 memblock_clear_nomap(rmem->base, rmem->size);
463 memblock_phys_free(rmem->base,
466 phys_addr_t end = rmem->base + rmem->size - 1;
468 (of_get_flat_dt_prop(node, "reusable", NULL)) != NULL;
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");
480 static inline struct reserved_mem *__find_rmem(struct device_node *node)
487 for (i = 0; i < reserved_mem_count; i++)
488 if (reserved_mem[i].phandle == node->phandle)
489 return &reserved_mem[i];
493 struct rmem_assigned_device {
495 struct reserved_mem *rmem;
496 struct list_head list;
499 static LIST_HEAD(of_rmem_assigned_device_list);
500 static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
503 * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
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
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
515 * Returns error code or zero on success.
517 int of_reserved_mem_device_init_by_idx(struct device *dev,
518 struct device_node *np, int idx)
520 struct rmem_assigned_device *rd;
521 struct device_node *target;
522 struct reserved_mem *rmem;
528 target = of_parse_phandle(np, "memory-region", idx);
532 if (!of_device_is_available(target)) {
537 rmem = __find_rmem(target);
540 if (!rmem || !rmem->ops || !rmem->ops->device_init)
543 rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
547 ret = rmem->ops->device_init(rmem, dev);
552 mutex_lock(&of_rmem_assigned_device_mutex);
553 list_add(&rd->list, &of_rmem_assigned_device_list);
554 mutex_unlock(&of_rmem_assigned_device_mutex);
556 dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
563 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
566 * of_reserved_mem_device_init_by_name() - assign named reserved memory region
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
572 * Returns: 0 on success or a negative error-code on failure.
574 int of_reserved_mem_device_init_by_name(struct device *dev,
575 struct device_node *np,
578 int idx = of_property_match_string(np, "memory-region-names", name);
580 return of_reserved_mem_device_init_by_idx(dev, np, idx);
582 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name);
585 * of_reserved_mem_device_release() - release reserved memory device structures
586 * @dev: Pointer to the device to deconfigure
588 * This function releases structures allocated for memory region handling for
591 void of_reserved_mem_device_release(struct device *dev)
593 struct rmem_assigned_device *rd, *tmp;
594 LIST_HEAD(release_list);
596 mutex_lock(&of_rmem_assigned_device_mutex);
597 list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) {
599 list_move_tail(&rd->list, &release_list);
601 mutex_unlock(&of_rmem_assigned_device_mutex);
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);
610 EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
613 * of_reserved_mem_lookup() - acquire reserved_mem from a device node
614 * @np: node pointer of the desired reserved-memory region
616 * This function allows drivers to acquire a reference to the reserved_mem
617 * struct based on a device node handle.
619 * Returns a reserved_mem reference, or NULL on error.
621 struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
629 name = kbasename(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];
636 EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);