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  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);