xref: /openbmc/linux/drivers/of/of_reserved_mem.c (revision 62e59c4e)
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 #define MAX_RESERVED_REGIONS	32
26 static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
27 static int reserved_mem_count;
28 
29 static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
30 	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
31 	phys_addr_t *res_base)
32 {
33 	phys_addr_t base;
34 
35 	end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
36 	align = !align ? SMP_CACHE_BYTES : align;
37 	base = memblock_find_in_range(start, end, size, align);
38 	if (!base)
39 		return -ENOMEM;
40 
41 	*res_base = base;
42 	if (nomap)
43 		return memblock_remove(base, size);
44 
45 	return memblock_reserve(base, size);
46 }
47 
48 /**
49  * res_mem_save_node() - save fdt node for second pass initialization
50  */
51 void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
52 				      phys_addr_t base, phys_addr_t size)
53 {
54 	struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
55 
56 	if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
57 		pr_err("not enough space all defined regions.\n");
58 		return;
59 	}
60 
61 	rmem->fdt_node = node;
62 	rmem->name = uname;
63 	rmem->base = base;
64 	rmem->size = size;
65 
66 	reserved_mem_count++;
67 	return;
68 }
69 
70 /**
71  * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
72  *			  and 'alloc-ranges' properties
73  */
74 static int __init __reserved_mem_alloc_size(unsigned long node,
75 	const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
76 {
77 	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
78 	phys_addr_t start = 0, end = 0;
79 	phys_addr_t base = 0, align = 0, size;
80 	int len;
81 	const __be32 *prop;
82 	int nomap;
83 	int ret;
84 
85 	prop = of_get_flat_dt_prop(node, "size", &len);
86 	if (!prop)
87 		return -EINVAL;
88 
89 	if (len != dt_root_size_cells * sizeof(__be32)) {
90 		pr_err("invalid size property in '%s' node.\n", uname);
91 		return -EINVAL;
92 	}
93 	size = dt_mem_next_cell(dt_root_size_cells, &prop);
94 
95 	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
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 	/* Need adjust the alignment to satisfy the CMA requirement */
108 	if (IS_ENABLED(CONFIG_CMA)
109 	    && of_flat_dt_is_compatible(node, "shared-dma-pool")
110 	    && of_get_flat_dt_prop(node, "reusable", NULL)
111 	    && !of_get_flat_dt_prop(node, "no-map", NULL)) {
112 		unsigned long order =
113 			max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
114 
115 		align = max(align, (phys_addr_t)PAGE_SIZE << order);
116 	}
117 
118 	prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
119 	if (prop) {
120 
121 		if (len % t_len != 0) {
122 			pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
123 			       uname);
124 			return -EINVAL;
125 		}
126 
127 		base = 0;
128 
129 		while (len > 0) {
130 			start = dt_mem_next_cell(dt_root_addr_cells, &prop);
131 			end = start + dt_mem_next_cell(dt_root_size_cells,
132 						       &prop);
133 
134 			ret = early_init_dt_alloc_reserved_memory_arch(size,
135 					align, start, end, nomap, &base);
136 			if (ret == 0) {
137 				pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
138 					uname, &base,
139 					(unsigned long)size / SZ_1M);
140 				break;
141 			}
142 			len -= t_len;
143 		}
144 
145 	} else {
146 		ret = early_init_dt_alloc_reserved_memory_arch(size, align,
147 							0, 0, nomap, &base);
148 		if (ret == 0)
149 			pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
150 				uname, &base, (unsigned long)size / SZ_1M);
151 	}
152 
153 	if (base == 0) {
154 		pr_info("failed to allocate memory for node '%s'\n", uname);
155 		return -ENOMEM;
156 	}
157 
158 	*res_base = base;
159 	*res_size = size;
160 
161 	return 0;
162 }
163 
164 static const struct of_device_id __rmem_of_table_sentinel
165 	__used __section(__reservedmem_of_table_end);
166 
167 /**
168  * res_mem_init_node() - call region specific reserved memory init code
169  */
170 static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
171 {
172 	extern const struct of_device_id __reservedmem_of_table[];
173 	const struct of_device_id *i;
174 
175 	for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
176 		reservedmem_of_init_fn initfn = i->data;
177 		const char *compat = i->compatible;
178 
179 		if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
180 			continue;
181 
182 		if (initfn(rmem) == 0) {
183 			pr_info("initialized node %s, compatible id %s\n",
184 				rmem->name, compat);
185 			return 0;
186 		}
187 	}
188 	return -ENOENT;
189 }
190 
191 static int __init __rmem_cmp(const void *a, const void *b)
192 {
193 	const struct reserved_mem *ra = a, *rb = b;
194 
195 	if (ra->base < rb->base)
196 		return -1;
197 
198 	if (ra->base > rb->base)
199 		return 1;
200 
201 	return 0;
202 }
203 
204 static void __init __rmem_check_for_overlap(void)
205 {
206 	int i;
207 
208 	if (reserved_mem_count < 2)
209 		return;
210 
211 	sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
212 	     __rmem_cmp, NULL);
213 	for (i = 0; i < reserved_mem_count - 1; i++) {
214 		struct reserved_mem *this, *next;
215 
216 		this = &reserved_mem[i];
217 		next = &reserved_mem[i + 1];
218 		if (!(this->base && next->base))
219 			continue;
220 		if (this->base + this->size > next->base) {
221 			phys_addr_t this_end, next_end;
222 
223 			this_end = this->base + this->size;
224 			next_end = next->base + next->size;
225 			pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
226 			       this->name, &this->base, &this_end,
227 			       next->name, &next->base, &next_end);
228 		}
229 	}
230 }
231 
232 /**
233  * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
234  */
235 void __init fdt_init_reserved_mem(void)
236 {
237 	int i;
238 
239 	/* check for overlapping reserved regions */
240 	__rmem_check_for_overlap();
241 
242 	for (i = 0; i < reserved_mem_count; i++) {
243 		struct reserved_mem *rmem = &reserved_mem[i];
244 		unsigned long node = rmem->fdt_node;
245 		int len;
246 		const __be32 *prop;
247 		int err = 0;
248 
249 		prop = of_get_flat_dt_prop(node, "phandle", &len);
250 		if (!prop)
251 			prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
252 		if (prop)
253 			rmem->phandle = of_read_number(prop, len/4);
254 
255 		if (rmem->size == 0)
256 			err = __reserved_mem_alloc_size(node, rmem->name,
257 						 &rmem->base, &rmem->size);
258 		if (err == 0)
259 			__reserved_mem_init_node(rmem);
260 	}
261 }
262 
263 static inline struct reserved_mem *__find_rmem(struct device_node *node)
264 {
265 	unsigned int i;
266 
267 	if (!node->phandle)
268 		return NULL;
269 
270 	for (i = 0; i < reserved_mem_count; i++)
271 		if (reserved_mem[i].phandle == node->phandle)
272 			return &reserved_mem[i];
273 	return NULL;
274 }
275 
276 struct rmem_assigned_device {
277 	struct device *dev;
278 	struct reserved_mem *rmem;
279 	struct list_head list;
280 };
281 
282 static LIST_HEAD(of_rmem_assigned_device_list);
283 static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
284 
285 /**
286  * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
287  *					  given device
288  * @dev:	Pointer to the device to configure
289  * @np:		Pointer to the device_node with 'reserved-memory' property
290  * @idx:	Index of selected region
291  *
292  * This function assigns respective DMA-mapping operations based on reserved
293  * memory region specified by 'memory-region' property in @np node to the @dev
294  * device. When driver needs to use more than one reserved memory region, it
295  * should allocate child devices and initialize regions by name for each of
296  * child device.
297  *
298  * Returns error code or zero on success.
299  */
300 int of_reserved_mem_device_init_by_idx(struct device *dev,
301 				       struct device_node *np, int idx)
302 {
303 	struct rmem_assigned_device *rd;
304 	struct device_node *target;
305 	struct reserved_mem *rmem;
306 	int ret;
307 
308 	if (!np || !dev)
309 		return -EINVAL;
310 
311 	target = of_parse_phandle(np, "memory-region", idx);
312 	if (!target)
313 		return -ENODEV;
314 
315 	rmem = __find_rmem(target);
316 	of_node_put(target);
317 
318 	if (!rmem || !rmem->ops || !rmem->ops->device_init)
319 		return -EINVAL;
320 
321 	rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
322 	if (!rd)
323 		return -ENOMEM;
324 
325 	ret = rmem->ops->device_init(rmem, dev);
326 	if (ret == 0) {
327 		rd->dev = dev;
328 		rd->rmem = rmem;
329 
330 		mutex_lock(&of_rmem_assigned_device_mutex);
331 		list_add(&rd->list, &of_rmem_assigned_device_list);
332 		mutex_unlock(&of_rmem_assigned_device_mutex);
333 
334 		dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
335 	} else {
336 		kfree(rd);
337 	}
338 
339 	return ret;
340 }
341 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
342 
343 /**
344  * of_reserved_mem_device_release() - release reserved memory device structures
345  * @dev:	Pointer to the device to deconfigure
346  *
347  * This function releases structures allocated for memory region handling for
348  * the given device.
349  */
350 void of_reserved_mem_device_release(struct device *dev)
351 {
352 	struct rmem_assigned_device *rd;
353 	struct reserved_mem *rmem = NULL;
354 
355 	mutex_lock(&of_rmem_assigned_device_mutex);
356 	list_for_each_entry(rd, &of_rmem_assigned_device_list, list) {
357 		if (rd->dev == dev) {
358 			rmem = rd->rmem;
359 			list_del(&rd->list);
360 			kfree(rd);
361 			break;
362 		}
363 	}
364 	mutex_unlock(&of_rmem_assigned_device_mutex);
365 
366 	if (!rmem || !rmem->ops || !rmem->ops->device_release)
367 		return;
368 
369 	rmem->ops->device_release(rmem, dev);
370 }
371 EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
372 
373 /**
374  * of_reserved_mem_lookup() - acquire reserved_mem from a device node
375  * @np:		node pointer of the desired reserved-memory region
376  *
377  * This function allows drivers to acquire a reference to the reserved_mem
378  * struct based on a device node handle.
379  *
380  * Returns a reserved_mem reference, or NULL on error.
381  */
382 struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
383 {
384 	const char *name;
385 	int i;
386 
387 	if (!np->full_name)
388 		return NULL;
389 
390 	name = kbasename(np->full_name);
391 	for (i = 0; i < reserved_mem_count; i++)
392 		if (!strcmp(reserved_mem[i].name, name))
393 			return &reserved_mem[i];
394 
395 	return NULL;
396 }
397 EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);
398