xref: /openbmc/linux/drivers/of/of_reserved_mem.c (revision bdeeed09)
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 
24 #define MAX_RESERVED_REGIONS	32
25 static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
26 static int reserved_mem_count;
27 
28 #if defined(CONFIG_HAVE_MEMBLOCK)
29 #include <linux/memblock.h>
30 int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
31 	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
32 	phys_addr_t *res_base)
33 {
34 	phys_addr_t base;
35 	/*
36 	 * We use __memblock_alloc_base() because memblock_alloc_base()
37 	 * panic()s on allocation failure.
38 	 */
39 	end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
40 	base = __memblock_alloc_base(size, align, end);
41 	if (!base)
42 		return -ENOMEM;
43 
44 	/*
45 	 * Check if the allocated region fits in to start..end window
46 	 */
47 	if (base < start) {
48 		memblock_free(base, size);
49 		return -ENOMEM;
50 	}
51 
52 	*res_base = base;
53 	if (nomap)
54 		return memblock_remove(base, size);
55 	return 0;
56 }
57 #else
58 int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
59 	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
60 	phys_addr_t *res_base)
61 {
62 	pr_err("Reserved memory not supported, ignoring region 0x%llx%s\n",
63 		  size, nomap ? " (nomap)" : "");
64 	return -ENOSYS;
65 }
66 #endif
67 
68 /**
69  * res_mem_save_node() - save fdt node for second pass initialization
70  */
71 void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
72 				      phys_addr_t base, phys_addr_t size)
73 {
74 	struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
75 
76 	if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
77 		pr_err("not enough space all defined regions.\n");
78 		return;
79 	}
80 
81 	rmem->fdt_node = node;
82 	rmem->name = uname;
83 	rmem->base = base;
84 	rmem->size = size;
85 
86 	reserved_mem_count++;
87 	return;
88 }
89 
90 /**
91  * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
92  *			  and 'alloc-ranges' properties
93  */
94 static int __init __reserved_mem_alloc_size(unsigned long node,
95 	const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
96 {
97 	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
98 	phys_addr_t start = 0, end = 0;
99 	phys_addr_t base = 0, align = 0, size;
100 	int len;
101 	const __be32 *prop;
102 	int nomap;
103 	int ret;
104 
105 	prop = of_get_flat_dt_prop(node, "size", &len);
106 	if (!prop)
107 		return -EINVAL;
108 
109 	if (len != dt_root_size_cells * sizeof(__be32)) {
110 		pr_err("invalid size property in '%s' node.\n", uname);
111 		return -EINVAL;
112 	}
113 	size = dt_mem_next_cell(dt_root_size_cells, &prop);
114 
115 	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
116 
117 	prop = of_get_flat_dt_prop(node, "alignment", &len);
118 	if (prop) {
119 		if (len != dt_root_addr_cells * sizeof(__be32)) {
120 			pr_err("invalid alignment property in '%s' node.\n",
121 				uname);
122 			return -EINVAL;
123 		}
124 		align = dt_mem_next_cell(dt_root_addr_cells, &prop);
125 	}
126 
127 	/* Need adjust the alignment to satisfy the CMA requirement */
128 	if (IS_ENABLED(CONFIG_CMA)
129 	    && of_flat_dt_is_compatible(node, "shared-dma-pool")
130 	    && of_get_flat_dt_prop(node, "reusable", NULL)
131 	    && !of_get_flat_dt_prop(node, "no-map", NULL)) {
132 		unsigned long order =
133 			max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
134 
135 		align = max(align, (phys_addr_t)PAGE_SIZE << order);
136 	}
137 
138 	prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
139 	if (prop) {
140 
141 		if (len % t_len != 0) {
142 			pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
143 			       uname);
144 			return -EINVAL;
145 		}
146 
147 		base = 0;
148 
149 		while (len > 0) {
150 			start = dt_mem_next_cell(dt_root_addr_cells, &prop);
151 			end = start + dt_mem_next_cell(dt_root_size_cells,
152 						       &prop);
153 
154 			ret = early_init_dt_alloc_reserved_memory_arch(size,
155 					align, start, end, nomap, &base);
156 			if (ret == 0) {
157 				pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
158 					uname, &base,
159 					(unsigned long)size / SZ_1M);
160 				break;
161 			}
162 			len -= t_len;
163 		}
164 
165 	} else {
166 		ret = early_init_dt_alloc_reserved_memory_arch(size, align,
167 							0, 0, nomap, &base);
168 		if (ret == 0)
169 			pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
170 				uname, &base, (unsigned long)size / SZ_1M);
171 	}
172 
173 	if (base == 0) {
174 		pr_info("failed to allocate memory for node '%s'\n", uname);
175 		return -ENOMEM;
176 	}
177 
178 	*res_base = base;
179 	*res_size = size;
180 
181 	return 0;
182 }
183 
184 static const struct of_device_id __rmem_of_table_sentinel
185 	__used __section(__reservedmem_of_table_end);
186 
187 /**
188  * res_mem_init_node() - call region specific reserved memory init code
189  */
190 static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
191 {
192 	extern const struct of_device_id __reservedmem_of_table[];
193 	const struct of_device_id *i;
194 
195 	for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
196 		reservedmem_of_init_fn initfn = i->data;
197 		const char *compat = i->compatible;
198 
199 		if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
200 			continue;
201 
202 		if (initfn(rmem) == 0) {
203 			pr_info("initialized node %s, compatible id %s\n",
204 				rmem->name, compat);
205 			return 0;
206 		}
207 	}
208 	return -ENOENT;
209 }
210 
211 static int __init __rmem_cmp(const void *a, const void *b)
212 {
213 	const struct reserved_mem *ra = a, *rb = b;
214 
215 	if (ra->base < rb->base)
216 		return -1;
217 
218 	if (ra->base > rb->base)
219 		return 1;
220 
221 	return 0;
222 }
223 
224 static void __init __rmem_check_for_overlap(void)
225 {
226 	int i;
227 
228 	if (reserved_mem_count < 2)
229 		return;
230 
231 	sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
232 	     __rmem_cmp, NULL);
233 	for (i = 0; i < reserved_mem_count - 1; i++) {
234 		struct reserved_mem *this, *next;
235 
236 		this = &reserved_mem[i];
237 		next = &reserved_mem[i + 1];
238 		if (!(this->base && next->base))
239 			continue;
240 		if (this->base + this->size > next->base) {
241 			phys_addr_t this_end, next_end;
242 
243 			this_end = this->base + this->size;
244 			next_end = next->base + next->size;
245 			pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
246 			       this->name, &this->base, &this_end,
247 			       next->name, &next->base, &next_end);
248 		}
249 	}
250 }
251 
252 /**
253  * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
254  */
255 void __init fdt_init_reserved_mem(void)
256 {
257 	int i;
258 
259 	/* check for overlapping reserved regions */
260 	__rmem_check_for_overlap();
261 
262 	for (i = 0; i < reserved_mem_count; i++) {
263 		struct reserved_mem *rmem = &reserved_mem[i];
264 		unsigned long node = rmem->fdt_node;
265 		int len;
266 		const __be32 *prop;
267 		int err = 0;
268 
269 		prop = of_get_flat_dt_prop(node, "phandle", &len);
270 		if (!prop)
271 			prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
272 		if (prop)
273 			rmem->phandle = of_read_number(prop, len/4);
274 
275 		if (rmem->size == 0)
276 			err = __reserved_mem_alloc_size(node, rmem->name,
277 						 &rmem->base, &rmem->size);
278 		if (err == 0)
279 			__reserved_mem_init_node(rmem);
280 	}
281 }
282 
283 static inline struct reserved_mem *__find_rmem(struct device_node *node)
284 {
285 	unsigned int i;
286 
287 	if (!node->phandle)
288 		return NULL;
289 
290 	for (i = 0; i < reserved_mem_count; i++)
291 		if (reserved_mem[i].phandle == node->phandle)
292 			return &reserved_mem[i];
293 	return NULL;
294 }
295 
296 struct rmem_assigned_device {
297 	struct device *dev;
298 	struct reserved_mem *rmem;
299 	struct list_head list;
300 };
301 
302 static LIST_HEAD(of_rmem_assigned_device_list);
303 static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
304 
305 /**
306  * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
307  *					  given device
308  * @dev:	Pointer to the device to configure
309  * @np:		Pointer to the device_node with 'reserved-memory' property
310  * @idx:	Index of selected region
311  *
312  * This function assigns respective DMA-mapping operations based on reserved
313  * memory region specified by 'memory-region' property in @np node to the @dev
314  * device. When driver needs to use more than one reserved memory region, it
315  * should allocate child devices and initialize regions by name for each of
316  * child device.
317  *
318  * Returns error code or zero on success.
319  */
320 int of_reserved_mem_device_init_by_idx(struct device *dev,
321 				       struct device_node *np, int idx)
322 {
323 	struct rmem_assigned_device *rd;
324 	struct device_node *target;
325 	struct reserved_mem *rmem;
326 	int ret;
327 
328 	if (!np || !dev)
329 		return -EINVAL;
330 
331 	target = of_parse_phandle(np, "memory-region", idx);
332 	if (!target)
333 		return -ENODEV;
334 
335 	rmem = __find_rmem(target);
336 	of_node_put(target);
337 
338 	if (!rmem || !rmem->ops || !rmem->ops->device_init)
339 		return -EINVAL;
340 
341 	rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
342 	if (!rd)
343 		return -ENOMEM;
344 
345 	ret = rmem->ops->device_init(rmem, dev);
346 	if (ret == 0) {
347 		rd->dev = dev;
348 		rd->rmem = rmem;
349 
350 		mutex_lock(&of_rmem_assigned_device_mutex);
351 		list_add(&rd->list, &of_rmem_assigned_device_list);
352 		mutex_unlock(&of_rmem_assigned_device_mutex);
353 		/* ensure that dma_ops is set for virtual devices
354 		 * using reserved memory
355 		 */
356 		of_dma_configure(dev, np);
357 
358 		dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
359 	} else {
360 		kfree(rd);
361 	}
362 
363 	return ret;
364 }
365 EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
366 
367 /**
368  * of_reserved_mem_device_release() - release reserved memory device structures
369  * @dev:	Pointer to the device to deconfigure
370  *
371  * This function releases structures allocated for memory region handling for
372  * the given device.
373  */
374 void of_reserved_mem_device_release(struct device *dev)
375 {
376 	struct rmem_assigned_device *rd;
377 	struct reserved_mem *rmem = NULL;
378 
379 	mutex_lock(&of_rmem_assigned_device_mutex);
380 	list_for_each_entry(rd, &of_rmem_assigned_device_list, list) {
381 		if (rd->dev == dev) {
382 			rmem = rd->rmem;
383 			list_del(&rd->list);
384 			kfree(rd);
385 			break;
386 		}
387 	}
388 	mutex_unlock(&of_rmem_assigned_device_mutex);
389 
390 	if (!rmem || !rmem->ops || !rmem->ops->device_release)
391 		return;
392 
393 	rmem->ops->device_release(rmem, dev);
394 }
395 EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
396 
397 /**
398  * of_reserved_mem_lookup() - acquire reserved_mem from a device node
399  * @np:		node pointer of the desired reserved-memory region
400  *
401  * This function allows drivers to acquire a reference to the reserved_mem
402  * struct based on a device node handle.
403  *
404  * Returns a reserved_mem reference, or NULL on error.
405  */
406 struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
407 {
408 	const char *name;
409 	int i;
410 
411 	if (!np->full_name)
412 		return NULL;
413 
414 	name = kbasename(np->full_name);
415 	for (i = 0; i < reserved_mem_count; i++)
416 		if (!strcmp(reserved_mem[i].name, name))
417 			return &reserved_mem[i];
418 
419 	return NULL;
420 }
421 EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);
422