1/*
  2 * Device tree based initialization code for reserved memory.
  3 *
  4 * Copyright (c) 2013, 2015 The Linux Foundation. All Rights Reserved.
  5 * Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
  6 *		http://www.samsung.com
  7 * Author: Marek Szyprowski <m.szyprowski@samsung.com>
  8 * Author: Josh Cartwright <joshc@codeaurora.org>
  9 *
 10 * This program is free software; you can redistribute it and/or
 11 * modify it under the terms of the GNU General Public License as
 12 * published by the Free Software Foundation; either version 2 of the
 13 * License or (at your optional) any later version of the license.
 14 */
 15
 16#define pr_fmt(fmt)	"OF: reserved mem: " fmt
 17
 18#include <linux/err.h>
 19#include <linux/of.h>
 20#include <linux/of_fdt.h>
 21#include <linux/of_platform.h>
 22#include <linux/mm.h>
 23#include <linux/sizes.h>
 24#include <linux/of_reserved_mem.h>
 25#include <linux/sort.h>
 26#include <linux/slab.h>
 27
 28#define MAX_RESERVED_REGIONS	16
 29static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
 30static int reserved_mem_count;
 31
 32#if defined(CONFIG_HAVE_MEMBLOCK)
 33#include <linux/memblock.h>
 34int __init __weak 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	/*
 40	 * We use __memblock_alloc_base() because memblock_alloc_base()
 41	 * panic()s on allocation failure.
 42	 */
 43	end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
 44	base = __memblock_alloc_base(size, align, end);
 45	if (!base)
 46		return -ENOMEM;
 47
 48	/*
 49	 * Check if the allocated region fits in to start..end window
 50	 */
 51	if (base < start) {
 52		memblock_free(base, size);
 53		return -ENOMEM;
 54	}
 55
 56	*res_base = base;
 57	if (nomap)
 58		return memblock_remove(base, size);
 59	return 0;
 60}
 61#else
 62int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
 63	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
 64	phys_addr_t *res_base)
 65{
 66	pr_err("Reserved memory not supported, ignoring region 0x%llx%s\n",
 67		  size, nomap ? " (nomap)" : "");
 68	return -ENOSYS;
 69}
 70#endif
 71
 72/**
 73 * res_mem_save_node() - save fdt node for second pass initialization
 74 */
 75void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
 76				      phys_addr_t base, phys_addr_t size)
 77{
 78	struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
 79
 80	if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
 81		pr_err("not enough space all defined regions.\n");
 82		return;
 83	}
 84
 85	rmem->fdt_node = node;
 86	rmem->name = uname;
 87	rmem->base = base;
 88	rmem->size = size;
 89
 90	reserved_mem_count++;
 91	return;
 92}
 93
 94/**
 95 * res_mem_alloc_size() - allocate reserved memory described by 'size', 'align'
 96 *			  and 'alloc-ranges' properties
 97 */
 98static int __init __reserved_mem_alloc_size(unsigned long node,
 99	const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
100{
101	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
102	phys_addr_t start = 0, end = 0;
103	phys_addr_t base = 0, align = 0, size;
104	int len;
105	const __be32 *prop;
106	int nomap;
107	int ret;
108
109	prop = of_get_flat_dt_prop(node, "size", &len);
110	if (!prop)
111		return -EINVAL;
112
113	if (len != dt_root_size_cells * sizeof(__be32)) {
114		pr_err("invalid size property in '%s' node.\n", uname);
115		return -EINVAL;
116	}
117	size = dt_mem_next_cell(dt_root_size_cells, &prop);
118
119	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
120
121	prop = of_get_flat_dt_prop(node, "alignment", &len);
122	if (prop) {
123		if (len != dt_root_addr_cells * sizeof(__be32)) {
124			pr_err("invalid alignment property in '%s' node.\n",
125				uname);
126			return -EINVAL;
127		}
128		align = dt_mem_next_cell(dt_root_addr_cells, &prop);
129	}
130
131	/* Need adjust the alignment to satisfy the CMA requirement */
132	if (IS_ENABLED(CONFIG_CMA)
133	    && of_flat_dt_is_compatible(node, "shared-dma-pool")
134	    && of_get_flat_dt_prop(node, "reusable", NULL)
135	    && !of_get_flat_dt_prop(node, "no-map", NULL)) {
136		unsigned long order =
137			max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
138
139		align = max(align, (phys_addr_t)PAGE_SIZE << order);
140	}
141
142	prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
143	if (prop) {
144
145		if (len % t_len != 0) {
146			pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
147			       uname);
148			return -EINVAL;
149		}
150
151		base = 0;
152
153		while (len > 0) {
154			start = dt_mem_next_cell(dt_root_addr_cells, &prop);
155			end = start + dt_mem_next_cell(dt_root_size_cells,
156						       &prop);
157
158			ret = early_init_dt_alloc_reserved_memory_arch(size,
159					align, start, end, nomap, &base);
160			if (ret == 0) {
161				pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
162					uname, &base,
163					(unsigned long)size / SZ_1M);
164				break;
165			}
166			len -= t_len;
167		}
168
169	} else {
170		ret = early_init_dt_alloc_reserved_memory_arch(size, align,
171							0, 0, nomap, &base);
172		if (ret == 0)
173			pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
174				uname, &base, (unsigned long)size / SZ_1M);
175	}
176
177	if (base == 0) {
178		pr_info("failed to allocate memory for node '%s'\n", uname);
179		return -ENOMEM;
180	}
181
182	*res_base = base;
183	*res_size = size;
184
185	return 0;
186}
187
188static const struct of_device_id __rmem_of_table_sentinel
189	__used __section(__reservedmem_of_table_end);
190
191/**
192 * res_mem_init_node() - call region specific reserved memory init code
193 */
194static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
195{
196	extern const struct of_device_id __reservedmem_of_table[];
197	const struct of_device_id *i;
198
199	for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
200		reservedmem_of_init_fn initfn = i->data;
201		const char *compat = i->compatible;
202
203		if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
204			continue;
205
206		if (initfn(rmem) == 0) {
207			pr_info("initialized node %s, compatible id %s\n",
208				rmem->name, compat);
209			return 0;
210		}
211	}
212	return -ENOENT;
213}
214
215static int __init __rmem_cmp(const void *a, const void *b)
216{
217	const struct reserved_mem *ra = a, *rb = b;
218
219	if (ra->base < rb->base)
220		return -1;
221
222	if (ra->base > rb->base)
223		return 1;
224
225	return 0;
226}
227
228static void __init __rmem_check_for_overlap(void)
229{
230	int i;
231
232	if (reserved_mem_count < 2)
233		return;
234
235	sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
236	     __rmem_cmp, NULL);
237	for (i = 0; i < reserved_mem_count - 1; i++) {
238		struct reserved_mem *this, *next;
239
240		this = &reserved_mem[i];
241		next = &reserved_mem[i + 1];
242		if (!(this->base && next->base))
243			continue;
244		if (this->base + this->size > next->base) {
245			phys_addr_t this_end, next_end;
246
247			this_end = this->base + this->size;
248			next_end = next->base + next->size;
249			pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
250			       this->name, &this->base, &this_end,
251			       next->name, &next->base, &next_end);
252		}
253	}
254}
255
256/**
257 * fdt_init_reserved_mem - allocate and init all saved reserved memory regions
258 */
259void __init fdt_init_reserved_mem(void)
260{
261	int i;
262
263	/* check for overlapping reserved regions */
264	__rmem_check_for_overlap();
265
266	for (i = 0; i < reserved_mem_count; i++) {
267		struct reserved_mem *rmem = &reserved_mem[i];
268		unsigned long node = rmem->fdt_node;
269		int len;
270		const __be32 *prop;
271		int err = 0;
272
273		prop = of_get_flat_dt_prop(node, "phandle", &len);
274		if (!prop)
275			prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
276		if (prop)
277			rmem->phandle = of_read_number(prop, len/4);
278
279		if (rmem->size == 0)
280			err = __reserved_mem_alloc_size(node, rmem->name,
281						 &rmem->base, &rmem->size);
282		if (err == 0)
283			__reserved_mem_init_node(rmem);
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	rmem = __find_rmem(target);
340	of_node_put(target);
341
342	if (!rmem || !rmem->ops || !rmem->ops->device_init)
343		return -EINVAL;
344
345	rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
346	if (!rd)
347		return -ENOMEM;
348
349	ret = rmem->ops->device_init(rmem, dev);
350	if (ret == 0) {
351		rd->dev = dev;
352		rd->rmem = rmem;
353
354		mutex_lock(&of_rmem_assigned_device_mutex);
355		list_add(&rd->list, &of_rmem_assigned_device_list);
356		mutex_unlock(&of_rmem_assigned_device_mutex);
357
358		dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
359	} else {
360		kfree(rd);
361	}
362
363	return ret;
364}
365EXPORT_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 */
374void 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}
395EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);