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of_reserved_mem.c (10173B)


      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);