diff options
Diffstat (limited to 'src/commonlib/device_tree.c')
| -rw-r--r-- | src/commonlib/device_tree.c | 2018 |
1 files changed, 2018 insertions, 0 deletions
diff --git a/src/commonlib/device_tree.c b/src/commonlib/device_tree.c new file mode 100644 index 0000000000..f70aaf7115 --- /dev/null +++ b/src/commonlib/device_tree.c @@ -0,0 +1,2018 @@ +/* Taken from depthcharge: src/base/device_tree.c */ +/* SPDX-License-Identifier: GPL-2.0-or-later */ + +#include <assert.h> +#include <commonlib/device_tree.h> +#include <ctype.h> +#include <endian.h> +#include <stdbool.h> +#include <stdint.h> +#ifdef __COREBOOT__ +#include <console/console.h> +#else +#include <stdio.h> +#define printk(level, ...) printf(__VA_ARGS__) +#endif +#include <stdio.h> +#include <string.h> +#include <stddef.h> +#include <stdlib.h> +#include <limits.h> + +#define FDT_PATH_MAX_DEPTH 10 // should be a good enough upper bound +#define FDT_PATH_MAX_LEN 128 // should be a good enough upper bound +#define FDT_MAX_MEMORY_NODES 4 // should be a good enough upper bound +#define FDT_MAX_MEMORY_REGIONS 16 // should be a good enough upper bound + +/* + * Functions for picking apart flattened trees. + */ + +static int fdt_skip_nops(const void *blob, uint32_t offset) +{ + uint32_t *ptr = (uint32_t *)(((uint8_t *)blob) + offset); + + int index = 0; + while (be32toh(ptr[index]) == FDT_TOKEN_NOP) + index++; + + return index * sizeof(uint32_t); +} + +int fdt_next_property(const void *blob, uint32_t offset, + struct fdt_property *prop) +{ + struct fdt_header *header = (struct fdt_header *)blob; + uint32_t *ptr = (uint32_t *)(((uint8_t *)blob) + offset); + + // skip NOP tokens + offset += fdt_skip_nops(blob, offset); + + int index = 0; + if (be32toh(ptr[index++]) != FDT_TOKEN_PROPERTY) + return 0; + + uint32_t size = be32toh(ptr[index++]); + uint32_t name_offset = be32toh(ptr[index++]); + name_offset += be32toh(header->strings_offset); + + if (prop) { + prop->name = (char *)((uint8_t *)blob + name_offset); + prop->data = &ptr[index]; + prop->size = size; + } + + index += DIV_ROUND_UP(size, sizeof(uint32_t)); + + return index * sizeof(uint32_t); +} + +/* + * fdt_next_node_name reads a node name + * + * @params blob address of FDT + * @params offset offset to the node to read the name from + * @params name parameter to hold the name that has been read or NULL + * + * @returns Either 0 on error or offset to the properties that come after the node name + */ +int fdt_next_node_name(const void *blob, uint32_t offset, const char **name) +{ + // skip NOP tokens + offset += fdt_skip_nops(blob, offset); + + char *ptr = ((char *)blob) + offset; + if (be32dec(ptr) != FDT_TOKEN_BEGIN_NODE) + return 0; + + ptr += 4; + if (name) + *name = ptr; + + return ALIGN_UP(strlen(ptr) + 1, 4) + 4; +} + +/* + * A utility function to skip past nodes in flattened trees. + */ +int fdt_skip_node(const void *blob, uint32_t start_offset) +{ + uint32_t offset = start_offset; + + const char *name; + int size = fdt_next_node_name(blob, offset, &name); + if (!size) + return 0; + offset += size; + + while ((size = fdt_next_property(blob, offset, NULL))) + offset += size; + + while ((size = fdt_skip_node(blob, offset))) + offset += size; + + // skip NOP tokens + offset += fdt_skip_nops(blob, offset); + + return offset - start_offset + sizeof(uint32_t); +} + +/* + * fdt_read_prop reads a property inside a node + * + * @params blob address of FDT + * @params node_offset offset to the node to read the property from + * @params prop_name name of the property to read + * @params fdt_prop property is saved inside this parameter + * + * @returns Either 0 if no property has been found or an offset that points to the location + * of the property + */ +u32 fdt_read_prop(const void *blob, u32 node_offset, const char *prop_name, + struct fdt_property *fdt_prop) +{ + u32 offset = node_offset; + + offset += fdt_next_node_name(blob, offset, NULL); // skip node name + + size_t size; + while ((size = fdt_next_property(blob, offset, fdt_prop))) { + if (strcmp(fdt_prop->name, prop_name) == 0) + return offset; + offset += size; + } + return 0; // property not found +} + +/* + * fdt_read_reg_prop reads the reg property inside a node + * + * @params blob address of FDT + * @params node_offset offset to the node to read the reg property from + * @params addr_cells number of cells used for one address + * @params size_cells number of cells used for one size + * @params regions all regions that are read inside the reg property are saved inside + * this array + * @params regions_count maximum number of entries that can be saved inside the regions array. + * + * Returns: Either 0 on error or returns the number of regions put into the regions array. + */ +u32 fdt_read_reg_prop(const void *blob, u32 node_offset, u32 addr_cells, u32 size_cells, + struct device_tree_region regions[], size_t regions_count) +{ + struct fdt_property prop; + u32 offset = fdt_read_prop(blob, node_offset, "reg", &prop); + + if (!offset) { + printk(BIOS_DEBUG, "no reg property found in node_offset: %x\n", node_offset); + return 0; + } + + // we found the reg property, now need to parse all regions in 'reg' + size_t count = prop.size / (4 * addr_cells + 4 * size_cells); + if (count > regions_count) { + printk(BIOS_ERR, "reg property at node_offset: %x has more entries (%zd) than regions array can hold (%zd)\n", node_offset, count, regions_count); + count = regions_count; + } + if (addr_cells > 2 || size_cells > 2) { + printk(BIOS_ERR, "addr_cells (%d) or size_cells (%d) bigger than 2\n", + addr_cells, size_cells); + return 0; + } + uint32_t *ptr = prop.data; + for (int i = 0; i < count; i++) { + if (addr_cells == 1) + regions[i].addr = be32dec(ptr); + else if (addr_cells == 2) + regions[i].addr = be64dec(ptr); + ptr += addr_cells; + if (size_cells == 1) + regions[i].size = be32dec(ptr); + else if (size_cells == 2) + regions[i].size = be64dec(ptr); + ptr += size_cells; + } + + return count; // return the number of regions found in the reg property +} + +static u32 fdt_read_cell_props(const void *blob, u32 node_offset, u32 *addrcp, u32 *sizecp) +{ + struct fdt_property prop; + u32 offset = node_offset; + size_t size; + while ((size = fdt_next_property(blob, offset, &prop))) { + if (addrcp && !strcmp(prop.name, "#address-cells")) + *addrcp = be32dec(prop.data); + if (sizecp && !strcmp(prop.name, "#size-cells")) + *sizecp = be32dec(prop.data); + offset += size; + } + return offset; +} + +/* + * fdt_find_node searches for a node relative to another node + * + * @params blob address of FDT + * + * @params parent_node_offset offset to node from which to traverse the tree + * + * @params path null terminated array of node names specifying a + * relative path (e.g: { "cpus", "cpu0", NULL }) + * + * @params addrcp/sizecp If any address-cells and size-cells properties are found that are + * part of the parent node of the node we are looking, addrcp and sizecp + * are set to these respectively. + * + * @returns: Either 0 if no node has been found or the offset to the node found + */ +static u32 fdt_find_node(const void *blob, u32 parent_node_offset, char **path, + u32 *addrcp, u32 *sizecp) +{ + if (*path == NULL) + return parent_node_offset; // node found + + size_t size = fdt_next_node_name(blob, parent_node_offset, NULL); // skip node name + + /* + * get address-cells and size-cells properties while skipping the others. + * According to spec address-cells and size-cells are not inherited, but we + * intentionally follow the Linux implementation here and treat them as inheritable. + */ + u32 node_offset = fdt_read_cell_props(blob, parent_node_offset + size, addrcp, sizecp); + + const char *node_name; + // walk all children nodes + while ((size = fdt_next_node_name(blob, node_offset, &node_name))) { + if (!strcmp(*path, node_name)) { + // traverse one level deeper into the path + return fdt_find_node(blob, node_offset, path + 1, addrcp, sizecp); + } + // node is not the correct one. skip current node + node_offset += fdt_skip_node(blob, node_offset); + } + + // we have searched everything and could not find a fitting node + return 0; +} + +/* + * fdt_find_node_by_path finds a node behind a given node path + * + * @params blob address of FDT + * @params path absolute path to the node that should be searched for + * + * @params addrcp/sizecp Pointer that will be updated with any #address-cells and #size-cells + * value found in the node of the node specified by node_offset. Either + * may be NULL to ignore. If no #address-cells and #size-cells is found + * default values of #address-cells=2 and #size-cells=1 are returned. + * + * @returns Either 0 on error or the offset to the node found behind the path + */ +u32 fdt_find_node_by_path(const void *blob, const char *path, u32 *addrcp, u32 *sizecp) +{ + // sanity check + if (path[0] != '/') { + printk(BIOS_ERR, "devicetree path must start with a /\n"); + return 0; + } + if (!blob) { + printk(BIOS_ERR, "devicetree blob is NULL\n"); + return 0; + } + + if (addrcp) + *addrcp = 2; + if (sizecp) + *sizecp = 1; + + struct fdt_header *fdt_hdr = (struct fdt_header *)blob; + + /* + * split path into separate nodes + * e.g: "/cpus/cpu0" -> { "cpus", "cpu0" } + */ + char *path_array[FDT_PATH_MAX_DEPTH]; + size_t path_size = strlen(path); + assert(path_size < FDT_PATH_MAX_LEN); + char path_copy[FDT_PATH_MAX_LEN]; + memcpy(path_copy, path, path_size + 1); + char *cur = path_copy; + int i; + for (i = 0; i < FDT_PATH_MAX_DEPTH; i++) { + path_array[i] = strtok_r(NULL, "/", &cur); + if (!path_array[i]) + break; + } + assert(i < FDT_PATH_MAX_DEPTH); + + return fdt_find_node(blob, be32toh(fdt_hdr->structure_offset), path_array, addrcp, sizecp); +} + +/* + * fdt_find_subnodes_by_prefix finds a node with a given prefix relative to a parent node + * + * @params blob The FDT to search. + * + * @params node_offset offset to the node of which the children should be searched + * + * @params prefix A string to search for a node with a given prefix. This can for example + * be 'cpu' to look for all nodes matching this prefix. Only children of + * node_offset are searched. Therefore in order to search all nodes matching + * the 'cpu' prefix, node_offset should probably point to the 'cpus' node. + * An empty prefix ("") searches for all children nodes of node_offset. + * + * @params addrcp/sizecp Pointer that will be updated with any #address-cells and #size-cells + * value found in the node of the node specified by node_offset. Either + * may be NULL to ignore. If no #address-cells and #size-cells is found + * addrcp and sizecp are left untouched. + * + * @params results Array of offsets pointing to each node matching the given prefix. + * @params results_len Number of entries allocated for the 'results' array + * + * @returns offset to last node found behind path or 0 if no node has been found + */ +size_t fdt_find_subnodes_by_prefix(const void *blob, u32 node_offset, const char *prefix, + u32 *addrcp, u32 *sizecp, u32 *results, size_t results_len) +{ + // sanity checks + if (!blob || !results || !prefix) { + printk(BIOS_ERR, "%s: input parameter cannot be null/\n", __func__); + return 0; + } + + u32 offset = node_offset; + + // we don't care about the name of the current node + u32 size = fdt_next_node_name(blob, offset, NULL); + if (!size) { + printk(BIOS_ERR, "%s: node_offset: %x does not point to a node\n", + __func__, node_offset); + return 0; + } + offset += size; + + /* + * update addrcp and sizecp if the node contains an address-cells and size-cells + * property. Otherwise use addrcp and sizecp provided by caller. + */ + offset = fdt_read_cell_props(blob, offset, addrcp, sizecp); + + size_t count_results = 0; + int prefix_len = strlen(prefix); + const char *node_name; + // walk all children nodes of offset + while ((size = fdt_next_node_name(blob, offset, &node_name))) { + + if (count_results >= results_len) { + printk(BIOS_WARNING, + "%s: results_len (%zd) smaller than count_results (%zd)\n", + __func__, results_len, count_results); + break; + } + + if (!strncmp(prefix, node_name, prefix_len)) { + // we found a node that matches the prefix + results[count_results++] = offset; + } + + // node does not match the prefix. skip current node + offset += fdt_skip_node(blob, offset); + } + + // return last occurrence + return count_results; +} + +static const char *fdt_read_alias_prop(const void *blob, const char *alias_name) +{ + u32 node_offset = fdt_find_node_by_path(blob, "/aliases", NULL, NULL); + if (!node_offset) { + printk(BIOS_DEBUG, "no /aliases node found\n"); + return NULL; + } + struct fdt_property alias_prop; + if (!fdt_read_prop(blob, node_offset, alias_name, &alias_prop)) { + printk(BIOS_DEBUG, "property %s in /aliases node not found\n", alias_name); + return NULL; + } + return (const char *)alias_prop.data; +} + +/* + * Find a node in the tree from a string device tree path. + * + * @params blob Address to the FDT + * @params alias_name node name alias that should be searched for. + * @params addrcp/sizecp Pointer that will be updated with any #address-cells and #size-cells + * value found in the node of the node specified by node_offset. Either + * may be NULL to ignore. If no #address-cells and #size-cells is found + * default values of #address-cells=2 and #size-cells=1 are returned. + * + * @returns offset to last node found behind path or 0 if no node has been found + */ +u32 fdt_find_node_by_alias(const void *blob, const char *alias_name, u32 *addrcp, u32 *sizecp) +{ + const char *node_name = fdt_read_alias_prop(blob, alias_name); + if (!node_name) { + printk(BIOS_DEBUG, "alias %s not found\n", alias_name); + return 0; + } + + u32 node_offset = fdt_find_node_by_path(blob, node_name, addrcp, sizecp); + if (!node_offset) { + // This should not happen (invalid devicetree) + printk(BIOS_WARNING, + "Could not find node '%s', which alias was referring to '%s'\n", + node_name, alias_name); + return 0; + } + return node_offset; +} + + +/* + * Functions for printing flattened trees. + */ + +static void print_indent(int depth) +{ + printk(BIOS_DEBUG, "%*s", depth * 8, ""); +} + +static void print_property(const struct fdt_property *prop, int depth) +{ + int is_string = prop->size > 0 && + ((char *)prop->data)[prop->size - 1] == '\0'; + + if (is_string) { + for (int i = 0; i < prop->size - 1; i++) { + if (!isprint(((char *)prop->data)[i])) { + is_string = 0; + break; + } + } + } + + print_indent(depth); + if (is_string) { + printk(BIOS_DEBUG, "%s = \"%s\";\n", + prop->name, (const char *)prop->data); + } else { + printk(BIOS_DEBUG, "%s = < ", prop->name); + for (int i = 0; i < MIN(128, prop->size); i += 4) { + uint32_t val = 0; + for (int j = 0; j < MIN(4, prop->size - i); j++) + val |= ((uint8_t *)prop->data)[i + j] << + (24 - j * 8); + printk(BIOS_DEBUG, "%#.2x ", val); + } + if (prop->size > 128) + printk(BIOS_DEBUG, "..."); + printk(BIOS_DEBUG, ">;\n"); + } +} + +static int print_flat_node(const void *blob, uint32_t start_offset, int depth) +{ + int offset = start_offset; + const char *name; + int size; + + size = fdt_next_node_name(blob, offset, &name); + if (!size) + return 0; + offset += size; + + print_indent(depth); + printk(BIOS_DEBUG, "%s {\n", name); + + struct fdt_property prop; + while ((size = fdt_next_property(blob, offset, &prop))) { + print_property(&prop, depth + 1); + + offset += size; + } + + printk(BIOS_DEBUG, "\n"); /* empty line between props and nodes */ + + while ((size = print_flat_node(blob, offset, depth + 1))) + offset += size; + + print_indent(depth); + printk(BIOS_DEBUG, "}\n"); + + return offset - start_offset + sizeof(uint32_t); +} + +void fdt_print_node(const void *blob, uint32_t offset) +{ + print_flat_node(blob, offset, 0); +} + +/* + * fdt_read_memory_regions finds memory ranges from a flat device-tree + * + * @params blob address of FDT + * @params regions all regions that are read inside the reg property of + * memory nodes are saved inside this array + * @params regions_count maximum number of entries that can be saved inside + * the regions array. + * + * Returns: Either 0 on error or returns the number of regions put into the regions array. + */ +size_t fdt_read_memory_regions(const void *blob, + struct device_tree_region regions[], + size_t regions_count) +{ + u32 node, root, addrcp, sizecp; + u32 nodes[FDT_MAX_MEMORY_NODES] = {0}; + size_t region_idx = 0; + size_t node_count = 0; + + if (!fdt_is_valid(blob)) + return 0; + + node = fdt_find_node_by_path(blob, "/memory", &addrcp, &sizecp); + if (node) { + region_idx += fdt_read_reg_prop(blob, node, addrcp, sizecp, + regions, regions_count); + if (region_idx >= regions_count) { + printk(BIOS_WARNING, "FDT: Too many memory regions\n"); + goto out; + } + } + + root = fdt_find_node_by_path(blob, "/", &addrcp, &sizecp); + node_count = fdt_find_subnodes_by_prefix(blob, root, "memory@", + &addrcp, &sizecp, nodes, + FDT_MAX_MEMORY_NODES); + if (node_count >= FDT_MAX_MEMORY_NODES) { + printk(BIOS_WARNING, "FDT: Too many memory nodes\n"); + /* Can still reading the regions for those we got */ + } + + for (size_t i = 0; i < MIN(node_count, FDT_MAX_MEMORY_NODES); i++) { + region_idx += fdt_read_reg_prop(blob, nodes[i], addrcp, sizecp, + ®ions[region_idx], + regions_count - region_idx); + if (region_idx >= regions_count) { + printk(BIOS_WARNING, "FDT: Too many memory regions\n"); + goto out; + } + } + +out: + for (size_t i = 0; i < MIN(region_idx, regions_count); i++) { + printk(BIOS_DEBUG, "FDT: Memory region [%#llx - %#llx]\n", + regions[i].addr, regions[i].addr + regions[i].size); + } + + return region_idx; +} + +/* + * fdt_get_memory_top finds top of memory from a flat device-tree + * + * @params blob address of FDT + * + * Returns: Either 0 on error or returns the maximum memory address + */ +uint64_t fdt_get_memory_top(const void *blob) +{ + struct device_tree_region regions[FDT_MAX_MEMORY_REGIONS] = {0}; + uint64_t top = 0; + uint64_t total = 0; + size_t count; + + if (!fdt_is_valid(blob)) + return 0; + + count = fdt_read_memory_regions(blob, regions, FDT_MAX_MEMORY_REGIONS); + for (size_t i = 0; i < MIN(count, FDT_MAX_MEMORY_REGIONS); i++) { + top = MAX(top, regions[i].addr + regions[i].size); + total += regions[i].size; + } + + printk(BIOS_DEBUG, "FDT: Found %u MiB of RAM\n", + (uint32_t)(total / MiB)); + + return top; +} + +/* + * Functions to turn a flattened tree into an unflattened one. + */ + +static int dt_prop_is_phandle(struct device_tree_property *prop) +{ + return !(strcmp("phandle", prop->prop.name) && + strcmp("linux,phandle", prop->prop.name)); +} + +static int fdt_unflatten_node(const void *blob, uint32_t start_offset, + struct device_tree *tree, + struct device_tree_node **new_node) +{ + struct list_node *last; + int offset = start_offset; + const char *name; + int size; + + size = fdt_next_node_name(blob, offset, &name); + if (!size) + return 0; + offset += size; + + struct device_tree_node *node = xzalloc(sizeof(*node)); + *new_node = node; + node->name = name; + + struct fdt_property fprop; + last = &node->properties; + while ((size = fdt_next_property(blob, offset, &fprop))) { + struct device_tree_property *prop = xzalloc(sizeof(*prop)); + prop->prop = fprop; + + if (dt_prop_is_phandle(prop)) { + node->phandle = be32dec(prop->prop.data); + if (node->phandle > tree->max_phandle) + tree->max_phandle = node->phandle; + } + + list_insert_after(&prop->list_node, last); + last = &prop->list_node; + + offset += size; + } + + struct device_tree_node *child; + last = &node->children; + while ((size = fdt_unflatten_node(blob, offset, tree, &child))) { + list_insert_after(&child->list_node, last); + last = &child->list_node; + + offset += size; + } + + return offset - start_offset + sizeof(uint32_t); +} + +static int fdt_unflatten_map_entry(const void *blob, uint32_t offset, + struct device_tree_reserve_map_entry **new) +{ + const uint64_t *ptr = (const uint64_t *)(((uint8_t *)blob) + offset); + const uint64_t start = be64toh(ptr[0]); + const uint64_t size = be64toh(ptr[1]); + + if (!size) + return 0; + + struct device_tree_reserve_map_entry *entry = xzalloc(sizeof(*entry)); + *new = entry; + entry->start = start; + entry->size = size; + + return sizeof(uint64_t) * 2; +} + +bool fdt_is_valid(const void *blob) +{ + const struct fdt_header *header = (const struct fdt_header *)blob; + + uint32_t magic = be32toh(header->magic); + uint32_t version = be32toh(header->version); + uint32_t last_comp_version = be32toh(header->last_comp_version); + + if (magic != FDT_HEADER_MAGIC) { + printk(BIOS_ERR, "Invalid device tree magic %#.8x!\n", magic); + return false; + } + if (last_comp_version > FDT_SUPPORTED_VERSION) { + printk(BIOS_ERR, "Unsupported device tree version %u(>=%u)\n", + version, last_comp_version); + return false; + } + if (version > FDT_SUPPORTED_VERSION) + printk(BIOS_NOTICE, "FDT version %u too new, should add support!\n", + version); + return true; +} + +struct device_tree *fdt_unflatten(const void *blob) +{ + struct device_tree *tree = xzalloc(sizeof(*tree)); + const struct fdt_header *header = (const struct fdt_header *)blob; + tree->header = header; + + if (!fdt_is_valid(blob)) + return NULL; + + uint32_t struct_offset = be32toh(header->structure_offset); + uint32_t strings_offset = be32toh(header->strings_offset); + uint32_t reserve_offset = be32toh(header->reserve_map_offset); + uint32_t min_offset = 0; + min_offset = MIN(struct_offset, strings_offset); + min_offset = MIN(min_offset, reserve_offset); + /* Assume everything up to the first non-header component is part of + the header and needs to be preserved. This will protect us against + new elements being added in the future. */ + tree->header_size = min_offset; + + struct device_tree_reserve_map_entry *entry; + uint32_t offset = reserve_offset; + int size; + struct list_node *last = &tree->reserve_map; + while ((size = fdt_unflatten_map_entry(blob, offset, &entry))) { + list_insert_after(&entry->list_node, last); + last = &entry->list_node; + + offset += size; + } + + fdt_unflatten_node(blob, struct_offset, tree, &tree->root); + + return tree; +} + + + +/* + * Functions to find the size of the device tree if it was flattened. + */ + +static void dt_flat_prop_size(struct device_tree_property *prop, + uint32_t *struct_size, uint32_t *strings_size) +{ + /* Starting token. */ + *struct_size += sizeof(uint32_t); + /* Size. */ + *struct_size += sizeof(uint32_t); + /* Name offset. */ + *struct_size += sizeof(uint32_t); + /* Property value. */ + *struct_size += ALIGN_UP(prop->prop.size, sizeof(uint32_t)); + + /* Property name. */ + *strings_size += strlen(prop->prop.name) + 1; +} + +static void dt_flat_node_size(struct device_tree_node *node, + uint32_t *struct_size, uint32_t *strings_size) +{ + /* Starting token. */ + *struct_size += sizeof(uint32_t); + /* Node name. */ + *struct_size += ALIGN_UP(strlen(node->name) + 1, sizeof(uint32_t)); + + struct device_tree_property *prop; + list_for_each(prop, node->properties, list_node) + dt_flat_prop_size(prop, struct_size, strings_size); + + struct device_tree_node *child; + list_for_each(child, node->children, list_node) + dt_flat_node_size(child, struct_size, strings_size); + + /* End token. */ + *struct_size += sizeof(uint32_t); +} + +uint32_t dt_flat_size(const struct device_tree *tree) +{ + uint32_t size = tree->header_size; + struct device_tree_reserve_map_entry *entry; + list_for_each(entry, tree->reserve_map, list_node) + size += sizeof(uint64_t) * 2; + size += sizeof(uint64_t) * 2; + + uint32_t struct_size = 0; + uint32_t strings_size = 0; + dt_flat_node_size(tree->root, &struct_size, &strings_size); + + size += struct_size; + /* End token. */ + size += sizeof(uint32_t); + + size += strings_size; + + return size; +} + + + +/* + * Functions to flatten a device tree. + */ + +static void dt_flatten_map_entry(struct device_tree_reserve_map_entry *entry, + void **map_start) +{ + ((uint64_t *)*map_start)[0] = htobe64(entry->start); + ((uint64_t *)*map_start)[1] = htobe64(entry->size); + *map_start = ((uint8_t *)*map_start) + sizeof(uint64_t) * 2; +} + +static void dt_flatten_prop(struct device_tree_property *prop, + void **struct_start, void *strings_base, + void **strings_start) +{ + uint8_t *dstruct = (uint8_t *)*struct_start; + uint8_t *dstrings = (uint8_t *)*strings_start; + + be32enc(dstruct, FDT_TOKEN_PROPERTY); + dstruct += sizeof(uint32_t); + + be32enc(dstruct, prop->prop.size); + dstruct += sizeof(uint32_t); + + uint32_t name_offset = (uintptr_t)dstrings - (uintptr_t)strings_base; + be32enc(dstruct, name_offset); + dstruct += sizeof(uint32_t); + + strcpy((char *)dstrings, prop->prop.name); + dstrings += strlen(prop->prop.name) + 1; + + memcpy(dstruct, prop->prop.data, prop->prop.size); + dstruct += ALIGN_UP(prop->prop.size, sizeof(uint32_t)); + + *struct_start = dstruct; + *strings_start = dstrings; +} + +static void dt_flatten_node(const struct device_tree_node *node, + void **struct_start, void *strings_base, + void **strings_start) +{ + uint8_t *dstruct = (uint8_t *)*struct_start; + uint8_t *dstrings = (uint8_t *)*strings_start; + + be32enc(dstruct, FDT_TOKEN_BEGIN_NODE); + dstruct += sizeof(uint32_t); + + strcpy((char *)dstruct, node->name); + dstruct += ALIGN_UP(strlen(node->name) + 1, sizeof(uint32_t)); + + struct device_tree_property *prop; + list_for_each(prop, node->properties, list_node) + dt_flatten_prop(prop, (void **)&dstruct, strings_base, + (void **)&dstrings); + + struct device_tree_node *child; + list_for_each(child, node->children, list_node) + dt_flatten_node(child, (void **)&dstruct, strings_base, + (void **)&dstrings); + + be32enc(dstruct, FDT_TOKEN_END_NODE); + dstruct += sizeof(uint32_t); + + *struct_start = dstruct; + *strings_start = dstrings; +} + +void dt_flatten(const struct device_tree *tree, void *start_dest) +{ + uint8_t *dest = (uint8_t *)start_dest; + + memcpy(dest, tree->header, tree->header_size); + struct fdt_header *header = (struct fdt_header *)dest; + dest += tree->header_size; + + struct device_tree_reserve_map_entry *entry; + list_for_each(entry, tree->reserve_map, list_node) + dt_flatten_map_entry(entry, (void **)&dest); + ((uint64_t *)dest)[0] = ((uint64_t *)dest)[1] = 0; + dest += sizeof(uint64_t) * 2; + + uint32_t struct_size = 0; + uint32_t strings_size = 0; + dt_flat_node_size(tree->root, &struct_size, &strings_size); + + uint8_t *struct_start = dest; + header->structure_offset = htobe32(dest - (uint8_t *)start_dest); + header->structure_size = htobe32(struct_size); + dest += struct_size; + + *((uint32_t *)dest) = htobe32(FDT_TOKEN_END); + dest += sizeof(uint32_t); + + uint8_t *strings_start = dest; + header->strings_offset = htobe32(dest - (uint8_t *)start_dest); + header->strings_size = htobe32(strings_size); + dest += strings_size; + + dt_flatten_node(tree->root, (void **)&struct_start, strings_start, + (void **)&strings_start); + + header->totalsize = htobe32(dest - (uint8_t *)start_dest); +} + + + +/* + * Functions for printing a non-flattened device tree. + */ + +static void print_node(const struct device_tree_node *node, int depth) +{ + print_indent(depth); + if (depth == 0) /* root node has no name, print a starting slash */ + printk(BIOS_DEBUG, "/"); + printk(BIOS_DEBUG, "%s {\n", node->name); + + struct device_tree_property *prop; + list_for_each(prop, node->properties, list_node) + print_property(&prop->prop, depth + 1); + + printk(BIOS_DEBUG, "\n"); /* empty line between props and nodes */ + + struct device_tree_node *child; + list_for_each(child, node->children, list_node) + print_node(child, depth + 1); + + print_indent(depth); + printk(BIOS_DEBUG, "};\n"); +} + +void dt_print_node(const struct device_tree_node *node) +{ + print_node(node, 0); +} + + + +/* + * Functions for reading and manipulating an unflattened device tree. + */ + +/* + * Read #address-cells and #size-cells properties from a node. + * + * @param node The device tree node to read from. + * @param addrcp Pointer to store #address-cells in, skipped if NULL. + * @param sizecp Pointer to store #size-cells in, skipped if NULL. + */ +void dt_read_cell_props(const struct device_tree_node *node, u32 *addrcp, + u32 *sizecp) +{ + struct device_tree_property *prop; + list_for_each(prop, node->properties, list_node) { + if (addrcp && !strcmp("#address-cells", prop->prop.name)) + *addrcp = be32dec(prop->prop.data); + if (sizecp && !strcmp("#size-cells", prop->prop.name)) + *sizecp = be32dec(prop->prop.data); + } +} + +/* + * Find a node from a device tree path, relative to a parent node. + * + * @param parent The node from which to start the relative path lookup. + * @param path An array of path component strings that will be looked + * up in order to find the node. Must be terminated with + * a NULL pointer. Example: {'firmware', 'coreboot', NULL} + * @param addrcp Pointer that will be updated with any #address-cells + * value found in the path. May be NULL to ignore. + * @param sizecp Pointer that will be updated with any #size-cells + * value found in the path. May be NULL to ignore. + * @param create 1: Create node(s) if not found. 0: Return NULL instead. + * @return The found/created node, or NULL. + */ +struct device_tree_node *dt_find_node(struct device_tree_node *parent, + const char **path, u32 *addrcp, + u32 *sizecp, int create) +{ + struct device_tree_node *node, *found = NULL; + + /* Update #address-cells and #size-cells for this level. */ + dt_read_cell_props(parent, addrcp, sizecp); + + if (!*path) + return parent; + + /* Find the next node in the path, if it exists. */ + list_for_each(node, parent->children, list_node) { + if (!strcmp(node->name, *path)) { + found = node; + break; + } + } + + /* Otherwise create it or return NULL. */ + if (!found) { + if (!create) + return NULL; + + found = calloc(1, sizeof(*found)); + if (!found) + return NULL; + found->name = strdup(*path); + if (!found->name) + return NULL; + + list_insert_after(&found->list_node, &parent->children); + } + + return dt_find_node(found, path + 1, addrcp, sizecp, create); +} + +/* + * Find a node in the tree from a string device tree path. + * + * @param tree The device tree to search. + * @param path A string representing a path in the device tree, with + * nodes separated by '/'. Example: "/firmware/coreboot" + * @param addrcp Pointer that will be updated with any #address-cells + * value found in the path. May be NULL to ignore. + * @param sizecp Pointer that will be updated with any #size-cells + * value found in the path. May be NULL to ignore. + * @param create 1: Create node(s) if not found. 0: Return NULL instead. + * @return The found/created node, or NULL. + * + * It is the caller responsibility to provide a path string that doesn't end + * with a '/' and doesn't contain any "//". If the path does not start with a + * '/', the first segment is interpreted as an alias. */ +struct device_tree_node *dt_find_node_by_path(struct device_tree *tree, + const char *path, u32 *addrcp, + u32 *sizecp, int create) +{ + char *sub_path; + char *duped_str; + struct device_tree_node *parent; + char *next_slash; + /* Hopefully enough depth for any node. */ + const char *path_array[15]; + int i; + struct device_tree_node *node = NULL; + + if (path[0] == '/') { /* regular path */ + if (path[1] == '\0') { /* special case: "/" is root node */ + dt_read_cell_props(tree->root, addrcp, sizecp); + return tree->root; + } + + sub_path = duped_str = strdup(&path[1]); + if (!sub_path) + return NULL; + + parent = tree->root; + } else { /* alias */ + char *alias; + + alias = duped_str = strdup(path); + if (!alias) + return NULL; + + sub_path = strchr(alias, '/'); + if (sub_path) + *sub_path = '\0'; + + parent = dt_find_node_by_alias(tree, alias); + if (!parent) { + printk(BIOS_DEBUG, + "Could not find node '%s', alias '%s' does not exist\n", + path, alias); + free(duped_str); + return NULL; + } + + if (!sub_path) { + /* it's just the alias, no sub-path */ + free(duped_str); + return parent; + } + + sub_path++; + } + + next_slash = sub_path; + path_array[0] = sub_path; + for (i = 1; i < (ARRAY_SIZE(path_array) - 1); i++) { + next_slash = strchr(next_slash, '/'); + if (!next_slash) + break; + + *next_slash++ = '\0'; + path_array[i] = next_slash; + } + + if (!next_slash) { + path_array[i] = NULL; + node = dt_find_node(parent, path_array, + addrcp, sizecp, create); + } + + free(duped_str); + return node; +} + +/* + * Find a node from an alias + * + * @param tree The device tree. + * @param alias The alias name. + * @return The found node, or NULL. + */ +struct device_tree_node *dt_find_node_by_alias(struct device_tree *tree, + const char *alias) +{ + struct device_tree_node *node; + const char *alias_path; + + node = dt_find_node_by_path(tree, "/aliases", NULL, NULL, 0); + if (!node) + return NULL; + + alias_path = dt_find_string_prop(node, alias); + if (!alias_path) + return NULL; + + return dt_find_node_by_path(tree, alias_path, NULL, NULL, 0); +} + +struct device_tree_node *dt_find_node_by_phandle(struct device_tree_node *root, + uint32_t phandle) +{ + if (!root) + return NULL; + + if (root->phandle == phandle) + return root; + + struct device_tree_node *node; + struct device_tree_node *result; + list_for_each(node, root->children, list_node) { + result = dt_find_node_by_phandle(node, phandle); + if (result) + return result; + } + + return NULL; +} + +/* + * Check if given node is compatible. + * + * @param node The node which is to be checked for compatible property. + * @param compat The compatible string to match. + * @return 1 = compatible, 0 = not compatible. + */ +static int dt_check_compat_match(struct device_tree_node *node, + const char *compat) +{ + struct device_tree_property *prop; + + list_for_each(prop, node->properties, list_node) { + if (!strcmp("compatible", prop->prop.name)) { + size_t bytes = prop->prop.size; + const char *str = prop->prop.data; + while (bytes > 0) { + if (!strncmp(compat, str, bytes)) + return 1; + size_t len = strnlen(str, bytes) + 1; + if (bytes <= len) + break; + str += len; + bytes -= len; + } + break; + } + } + + return 0; +} + +/* + * Find a node from a compatible string, in the subtree of a parent node. + * + * @param parent The parent node under which to look. + * @param compat The compatible string to find. + * @return The found node, or NULL. + */ +struct device_tree_node *dt_find_compat(struct device_tree_node *parent, + const char *compat) +{ + /* Check if the parent node itself is compatible. */ + if (dt_check_compat_match(parent, compat)) + return parent; + + struct device_tree_node *child; + list_for_each(child, parent->children, list_node) { + struct device_tree_node *found = dt_find_compat(child, compat); + if (found) + return found; + } + + return NULL; +} + +/* + * Find the next compatible child of a given parent. All children up to the + * child passed in by caller are ignored. If child is NULL, it considers all the + * children to find the first child which is compatible. + * + * @param parent The parent node under which to look. + * @param child The child node to start search from (exclusive). If NULL + * consider all children. + * @param compat The compatible string to find. + * @return The found node, or NULL. + */ +struct device_tree_node * +dt_find_next_compat_child(struct device_tree_node *parent, + struct device_tree_node *child, + const char *compat) +{ + struct device_tree_node *next; + int ignore = 0; + + if (child) + ignore = 1; + + list_for_each(next, parent->children, list_node) { + if (ignore) { + if (child == next) + ignore = 0; + continue; + } + + if (dt_check_compat_match(next, compat)) + return next; + } + + return NULL; +} + +/* + * Find a node with matching property value, in the subtree of a parent node. + * + * @param parent The parent node under which to look. + * @param name The property name to look for. + * @param data The property value to look for. + * @param size The property size. + */ +struct device_tree_node *dt_find_prop_value(struct device_tree_node *parent, + const char *name, void *data, + size_t size) +{ + struct device_tree_property *prop; + + /* Check if parent itself has the required property value. */ + list_for_each(prop, parent->properties, list_node) { + if (!strcmp(name, prop->prop.name)) { + size_t bytes = prop->prop.size; + const void *prop_data = prop->prop.data; + if (size != bytes) + break; + if (!memcmp(data, prop_data, size)) + return parent; + break; + } + } + + struct device_tree_node *child; + list_for_each(child, parent->children, list_node) { + struct device_tree_node *found = dt_find_prop_value(child, name, + data, size); + if (found) + return found; + } + return NULL; +} + +/* + * Write an arbitrary sized big-endian integer into a pointer. + * + * @param dest Pointer to the DT property data buffer to write. + * @param src The integer to write (in CPU endianness). + * @param length the length of the destination integer in bytes. + */ +void dt_write_int(u8 *dest, u64 src, size_t length) +{ + while (length--) { + dest[length] = (u8)src; + src >>= 8; + } +} + +/* + * Delete a property by name in a given node if it exists. + * + * @param node The device tree node to operate on. + * @param name The name of the property to delete. + */ +void dt_delete_prop(struct device_tree_node *node, const char *name) +{ + struct device_tree_property *prop; + + list_for_each(prop, node->properties, list_node) { + if (!strcmp(prop->prop.name, name)) { + list_remove(&prop->list_node); + return; + } + } +} + +/* + * Add an arbitrary property to a node, or update it if it already exists. + * + * @param node The device tree node to add to. + * @param name The name of the new property. + * @param data The raw data blob to be stored in the property. + * @param size The size of data in bytes. + */ +void dt_add_bin_prop(struct device_tree_node *node, const char *name, + void *data, size_t size) +{ + struct device_tree_property *prop; + + list_for_each(prop, node->properties, list_node) { + if (!strcmp(prop->prop.name, name)) { + prop->prop.data = data; + prop->prop.size = size; + return; + } + } + + prop = xzalloc(sizeof(*prop)); + list_insert_after(&prop->list_node, &node->properties); + prop->prop.name = name; + prop->prop.data = data; + prop->prop.size = size; +} + +/* + * Find given string property in a node and return its content. + * + * @param node The device tree node to search. + * @param name The name of the property. + * @return The found string, or NULL. + */ +const char *dt_find_string_prop(const struct device_tree_node *node, + const char *name) +{ + const void *content; + size_t size; + + dt_find_bin_prop(node, name, &content, &size); + + return content; +} + +/* + * Find given property in a node. + * + * @param node The device tree node to search. + * @param name The name of the property. + * @param data Pointer to return raw data blob in the property. + * @param size Pointer to return the size of data in bytes. + */ +void dt_find_bin_prop(const struct device_tree_node *node, const char *name, + const void **data, size_t *size) +{ + struct device_tree_property *prop; + + *data = NULL; + *size = 0; + + list_for_each(prop, node->properties, list_node) { + if (!strcmp(prop->prop.name, name)) { + *data = prop->prop.data; + *size = prop->prop.size; + return; + } + } +} + +/* + * Add a string property to a node, or update it if it already exists. + * + * @param node The device tree node to add to. + * @param name The name of the new property. + * @param str The zero-terminated string to be stored in the property. + */ +void dt_add_string_prop(struct device_tree_node *node, const char *name, + const char *str) +{ + dt_add_bin_prop(node, name, (char *)str, strlen(str) + 1); +} + +/* + * Add a 32-bit integer property to a node, or update it if it already exists. + * + * @param node The device tree node to add to. + * @param name The name of the new property. + * @param val The integer to be stored in the property. + */ +void dt_add_u32_prop(struct device_tree_node *node, const char *name, u32 val) +{ + u32 *val_ptr = xmalloc(sizeof(val)); + *val_ptr = htobe32(val); + dt_add_bin_prop(node, name, val_ptr, sizeof(*val_ptr)); +} + +/* + * Add a 64-bit integer property to a node, or update it if it already exists. + * + * @param node The device tree node to add to. + * @param name The name of the new property. + * @param val The integer to be stored in the property. + */ +void dt_add_u64_prop(struct device_tree_node *node, const char *name, u64 val) +{ + u64 *val_ptr = xmalloc(sizeof(val)); + *val_ptr = htobe64(val); + dt_add_bin_prop(node, name, val_ptr, sizeof(*val_ptr)); +} + +/* + * Add a 'reg' address list property to a node, or update it if it exists. + * + * @param node The device tree node to add to. + * @param regions Array of address values to be stored in the property. + * @param sizes Array of corresponding size values to 'addrs'. + * @param count Number of values in 'addrs' and 'sizes' (must be equal). + * @param addr_cells Value of #address-cells property valid for this node. + * @param size_cells Value of #size-cells property valid for this node. + */ +void dt_add_reg_prop(struct device_tree_node *node, u64 *addrs, u64 *sizes, + int count, u32 addr_cells, u32 size_cells) +{ + int i; + size_t length = (addr_cells + size_cells) * sizeof(u32) * count; + u8 *data = xmalloc(length); + u8 *cur = data; + + for (i = 0; i < count; i++) { + dt_write_int(cur, addrs[i], addr_cells * sizeof(u32)); + cur += addr_cells * sizeof(u32); + dt_write_int(cur, sizes[i], size_cells * sizeof(u32)); + cur += size_cells * sizeof(u32); + } + + dt_add_bin_prop(node, "reg", data, length); +} + +/* + * Fixups to apply to a kernel's device tree before booting it. + */ + +struct list_node device_tree_fixups; + +int dt_apply_fixups(struct device_tree *tree) +{ + struct device_tree_fixup *fixup; + list_for_each(fixup, device_tree_fixups, list_node) { + assert(fixup->fixup); + if (fixup->fixup(fixup, tree)) + return 1; + } + return 0; +} + +int dt_set_bin_prop_by_path(struct device_tree *tree, const char *path, + void *data, size_t data_size, int create) +{ + char *path_copy, *prop_name; + struct device_tree_node *dt_node; + + path_copy = strdup(path); + + if (!path_copy) { + printk(BIOS_ERR, "Failed to allocate a copy of path %s\n", + path); + return 1; + } + + prop_name = strrchr(path_copy, '/'); + if (!prop_name) { + free(path_copy); + printk(BIOS_ERR, "Path %s does not include '/'\n", path); + return 1; + } + + *prop_name++ = '\0'; /* Separate path from the property name. */ + + dt_node = dt_find_node_by_path(tree, path_copy, NULL, + NULL, create); + + if (!dt_node) { + printk(BIOS_ERR, "Failed to %s %s in the device tree\n", + create ? "create" : "find", path_copy); + free(path_copy); + return 1; + } + + dt_add_bin_prop(dt_node, prop_name, data, data_size); + free(path_copy); + + return 0; +} + +/* + * Prepare the /reserved-memory/ node. + * + * Technically, this can be called more than one time, to init and/or retrieve + * the node. But dt_add_u32_prop() may leak a bit of memory if you do. + * + * @tree: Device tree to add/retrieve from. + * @return: The /reserved-memory/ node (or NULL, if error). + */ +struct device_tree_node *dt_init_reserved_memory_node(struct device_tree *tree) +{ + struct device_tree_node *reserved; + u32 addr = 0, size = 0; + + reserved = dt_find_node_by_path(tree, "/reserved-memory", &addr, + &size, 1); + if (!reserved) + return NULL; + + /* Binding doc says this should have the same #{address,size}-cells as + the root. */ + dt_add_u32_prop(reserved, "#address-cells", addr); + dt_add_u32_prop(reserved, "#size-cells", size); + /* Binding doc says this should be empty (1:1 mapping from root). */ + dt_add_bin_prop(reserved, "ranges", NULL, 0); + + return reserved; +} + +/* + * Increment a single phandle in prop at a given offset by a given adjustment. + * + * @param prop Property whose phandle should be adjusted. + * @param adjustment Value that should be added to the existing phandle. + * @param offset Byte offset of the phandle in the property data. + * + * @return New phandle value, or 0 on error. + */ +static uint32_t dt_adjust_phandle(struct device_tree_property *prop, + uint32_t adjustment, uint32_t offset) +{ + if (offset + 4 > prop->prop.size) + return 0; + + uint32_t phandle = be32dec(prop->prop.data + offset); + if (phandle == 0 || + phandle == FDT_PHANDLE_ILLEGAL || + phandle == 0xffffffff) + return 0; + + phandle += adjustment; + if (phandle >= FDT_PHANDLE_ILLEGAL) + return 0; + + be32enc(prop->prop.data + offset, phandle); + return phandle; +} + +/* + * Adjust all phandles in subtree by adding a new base offset. + * + * @param node Root node of the subtree to work on. + * @param base New phandle base to be added to all phandles. + * + * @return New highest phandle in the subtree, or 0 on error. + */ +static uint32_t dt_adjust_all_phandles(struct device_tree_node *node, + uint32_t base) +{ + uint32_t new_max = MAX(base, 1); /* make sure we don't return 0 */ + struct device_tree_property *prop; + struct device_tree_node *child; + + if (!node) + return new_max; + + list_for_each(prop, node->properties, list_node) + if (dt_prop_is_phandle(prop)) { + node->phandle = dt_adjust_phandle(prop, base, 0); + if (!node->phandle) + return 0; + new_max = MAX(new_max, node->phandle); + } /* no break -- can have more than one phandle prop */ + + list_for_each(child, node->children, list_node) + new_max = MAX(new_max, dt_adjust_all_phandles(child, base)); + + return new_max; +} + +/* + * Apply a /__local_fixup__ subtree to the corresponding overlay subtree. + * + * @param node Root node of the overlay subtree to fix up. + * @param node Root node of the /__local_fixup__ subtree. + * @param base Adjustment that was added to phandles in the overlay. + * + * @return 0 on success, -1 on error. + */ +static int dt_fixup_locals(struct device_tree_node *node, + struct device_tree_node *fixup, uint32_t base) +{ + struct device_tree_property *prop; + struct device_tree_property *fixup_prop; + struct device_tree_node *child; + struct device_tree_node *fixup_child; + int i; + + /* + * For local fixups the /__local_fixup__ subtree contains the same node + * hierarchy as the main tree we're fixing up. Each property contains + * the fixup offsets for the respective property in the main tree. For + * each property in the fixup node, find the corresponding property in + * the base node and apply fixups to all offsets it specifies. + */ + list_for_each(fixup_prop, fixup->properties, list_node) { + struct device_tree_property *base_prop = NULL; + list_for_each(prop, node->properties, list_node) + if (!strcmp(prop->prop.name, fixup_prop->prop.name)) { + base_prop = prop; + break; + } + + /* We should always find a corresponding base prop for a fixup, + and fixup props contain a list of 32-bit fixup offsets. */ + if (!base_prop || fixup_prop->prop.size % sizeof(uint32_t)) + return -1; + + for (i = 0; i < fixup_prop->prop.size; i += sizeof(uint32_t)) + if (!dt_adjust_phandle(base_prop, base, be32dec( + fixup_prop->prop.data + i))) + return -1; + } + + /* Now recursively descend both the base tree and the /__local_fixups__ + subtree in sync to apply all fixups. */ + list_for_each(fixup_child, fixup->children, list_node) { + struct device_tree_node *base_child = NULL; + list_for_each(child, node->children, list_node) + if (!strcmp(child->name, fixup_child->name)) { + base_child = child; + break; + } + + /* All fixup nodes should have a corresponding base node. */ + if (!base_child) + return -1; + + if (dt_fixup_locals(base_child, fixup_child, base) < 0) + return -1; + } + + return 0; +} + +/* + * Update all /__symbols__ properties in an overlay that start with + * "/fragment@X/__overlay__" with corresponding path prefix in the base tree. + * + * @param symbols /__symbols__ done to update. + * @param fragment /fragment@X node that references to should be updated. + * @param base_path Path of base tree node that the fragment overlaid. + */ +static void dt_fix_symbols(struct device_tree_node *symbols, + struct device_tree_node *fragment, + const char *base_path) +{ + struct device_tree_property *prop; + char buf[512]; /* Should be enough for maximum DT path length? */ + char node_path[64]; /* easily enough for /fragment@XXXX/__overlay__ */ + + if (!symbols) /* If the overlay has no /__symbols__ node, we're done! */ + return; + + int len = snprintf(node_path, sizeof(node_path), "/%s/__overlay__", + fragment->name); + + list_for_each(prop, symbols->properties, list_node) + if (!strncmp(prop->prop.data, node_path, len)) { + prop->prop.size = snprintf(buf, sizeof(buf), "%s%s", + base_path, (char *)prop->prop.data + len) + 1; + free(prop->prop.data); + prop->prop.data = strdup(buf); + } +} + +/* + * Fix up overlay according to a property in /__fixup__. If the fixed property + * is a /fragment@X:target, also update /__symbols__ references to fragment. + * + * @params overlay Overlay to fix up. + * @params fixup /__fixup__ property. + * @params phandle phandle value to insert where the fixup points to. + * @params base_path Path to the base DT node that the fixup points to. + * @params overlay_symbols /__symbols__ node of the overlay. + * + * @return 0 on success, -1 on error. + */ +static int dt_fixup_external(struct device_tree *overlay, + struct device_tree_property *fixup, + uint32_t phandle, const char *base_path, + struct device_tree_node *overlay_symbols) +{ + struct device_tree_property *prop; + + /* External fixup properties are encoded as "<path>:<prop>:<offset>". */ + char *entry = fixup->prop.data; + while ((void *)entry < fixup->prop.data + fixup->prop.size) { + /* okay to destroy fixup property value, won't need it again */ + char *node_path = entry; + entry = strchr(node_path, ':'); + if (!entry) + return -1; + *entry++ = '\0'; + + char *prop_name = entry; + entry = strchr(prop_name, ':'); + if (!entry) + return -1; + *entry++ = '\0'; + + struct device_tree_node *ovl_node = dt_find_node_by_path( + overlay, node_path, NULL, NULL, 0); + if (!ovl_node || !isdigit(*entry)) + return -1; + + struct device_tree_property *ovl_prop = NULL; + list_for_each(prop, ovl_node->properties, list_node) + if (!strcmp(prop->prop.name, prop_name)) { + ovl_prop = prop; + break; + } + + /* Move entry to first char after number, must be a '\0'. */ + uint32_t offset = skip_atoi(&entry); + if (!ovl_prop || offset + 4 > ovl_prop->prop.size || entry[0]) + return -1; + entry++; /* jump over '\0' to potential next fixup */ + + be32enc(ovl_prop->prop.data + offset, phandle); + + /* If this is a /fragment@X:target property, update references + to this fragment in the overlay __symbols__ now. */ + if (offset == 0 && !strcmp(prop_name, "target") && + !strchr(node_path + 1, '/')) /* only toplevel nodes */ + dt_fix_symbols(overlay_symbols, ovl_node, base_path); + } + + return 0; +} + +/* + * Apply all /__fixup__ properties in the overlay. This will destroy the + * property data in /__fixup__ and it should not be accessed again. + * + * @params tree Base device tree that the overlay updates. + * @params symbols /__symbols__ node of the base device tree. + * @params overlay Overlay to fix up. + * @params fixups /__fixup__ node in the overlay. + * @params overlay_symbols /__symbols__ node of the overlay. + * + * @return 0 on success, -1 on error. + */ +static int dt_fixup_all_externals(struct device_tree *tree, + struct device_tree_node *symbols, + struct device_tree *overlay, + struct device_tree_node *fixups, + struct device_tree_node *overlay_symbols) +{ + struct device_tree_property *fix; + + /* If we have any external fixups, base tree must have /__symbols__. */ + if (!symbols) + return -1; + + /* + * Unlike /__local_fixups__, /__fixups__ is not a whole subtree that + * mirrors the node hierarchy. It's just a directory of fixup properties + * that each directly contain all information necessary to apply them. + */ + list_for_each(fix, fixups->properties, list_node) { + /* The name of a fixup property is the label of the node we want + a property to phandle-reference. Look up in /__symbols__. */ + const char *path = dt_find_string_prop(symbols, fix->prop.name); + if (!path) + return -1; + + /* Find node the label pointed to figure out its phandle. */ + struct device_tree_node *node = dt_find_node_by_path(tree, path, + NULL, NULL, 0); + if (!node) + return -1; + + /* Write into the overlay property(s) pointing to that node. */ + if (dt_fixup_external(overlay, fix, node->phandle, + path, overlay_symbols) < 0) + return -1; + } + + return 0; +} + +/* + * Copy all nodes and properties from one DT subtree into another. This is a + * shallow copy so both trees will point to the same property data afterwards. + * + * @params dst Destination subtree to copy into. + * @params src Source subtree to copy from. + * @params upd 1 to overwrite same-name properties, 0 to discard them. + */ +static void dt_copy_subtree(struct device_tree_node *dst, + struct device_tree_node *src, int upd) +{ + struct device_tree_property *prop; + struct device_tree_property *src_prop; + list_for_each(src_prop, src->properties, list_node) { + if (dt_prop_is_phandle(src_prop) || + !strcmp(src_prop->prop.name, "name")) { + printk(BIOS_DEBUG, + "WARNING: ignoring illegal overlay prop '%s'\n", + src_prop->prop.name); + continue; + } + + struct device_tree_property *dst_prop = NULL; + list_for_each(prop, dst->properties, list_node) + if (!strcmp(prop->prop.name, src_prop->prop.name)) { + dst_prop = prop; + break; + } + + if (dst_prop) { + if (!upd) { + printk(BIOS_DEBUG, + "WARNING: ignoring prop update '%s'\n", + src_prop->prop.name); + continue; + } + } else { + dst_prop = xzalloc(sizeof(*dst_prop)); + list_insert_after(&dst_prop->list_node, + &dst->properties); + } + + dst_prop->prop = src_prop->prop; + } + + struct device_tree_node *node; + struct device_tree_node *src_node; + list_for_each(src_node, src->children, list_node) { + struct device_tree_node *dst_node = NULL; + list_for_each(node, dst->children, list_node) + if (!strcmp(node->name, src_node->name)) { + dst_node = node; + break; + } + + if (!dst_node) { + dst_node = xzalloc(sizeof(*dst_node)); + *dst_node = *src_node; + list_insert_after(&dst_node->list_node, &dst->children); + } else { + dt_copy_subtree(dst_node, src_node, upd); + } + } +} + +/* + * Apply an overlay /fragment@X node to a base device tree. + * + * @param tree Base device tree. + * @param fragment /fragment@X node. + * @params overlay_symbols /__symbols__ node of the overlay. + * + * @return 0 on success, -1 on error. + */ +static int dt_import_fragment(struct device_tree *tree, + struct device_tree_node *fragment, + struct device_tree_node *overlay_symbols) +{ + /* The actual overlaid nodes/props are in an __overlay__ child node. */ + static const char *overlay_path[] = { "__overlay__", NULL }; + struct device_tree_node *overlay = dt_find_node(fragment, overlay_path, + NULL, NULL, 0); + + /* If it doesn't have an __overlay__ child, it's not a fragment. */ + if (!overlay) + return 0; + + /* Target node of the fragment can be given by path or by phandle. */ + struct device_tree_property *prop; + struct device_tree_property *phandle = NULL; + struct device_tree_property *path = NULL; + list_for_each(prop, fragment->properties, list_node) { + if (!strcmp(prop->prop.name, "target")) { + phandle = prop; + break; /* phandle target has priority, stop looking */ + } + if (!strcmp(prop->prop.name, "target-path")) + path = prop; + } + + struct device_tree_node *target = NULL; + if (phandle) { + if (phandle->prop.size != sizeof(uint32_t)) + return -1; + target = dt_find_node_by_phandle(tree->root, + be32dec(phandle->prop.data)); + /* Symbols already updated as part of dt_fixup_external(). */ + } else if (path) { + target = dt_find_node_by_path(tree, path->prop.data, + NULL, NULL, 0); + dt_fix_symbols(overlay_symbols, fragment, path->prop.data); + } + if (!target) + return -1; + + dt_copy_subtree(target, overlay, 1); + return 0; +} + +/* + * Apply a device tree overlay to a base device tree. This will + * destroy/incorporate the overlay data, so it should not be freed or reused. + * See dtc.git/Documentation/dt-object-internal.txt for overlay format details. + * + * @param tree Unflattened base device tree to add the overlay into. + * @param overlay Unflattened overlay device tree to apply to the base. + * + * @return 0 on success, -1 on error. + */ +int dt_apply_overlay(struct device_tree *tree, struct device_tree *overlay) +{ + /* + * First, we need to make sure phandles inside the overlay don't clash + * with those in the base tree. We just define the highest phandle value + * in the base tree as the "phandle offset" for this overlay and + * increment all phandles in it by that value. + */ + uint32_t phandle_base = tree->max_phandle; + uint32_t new_max = dt_adjust_all_phandles(overlay->root, phandle_base); + if (!new_max) { + printk(BIOS_ERR, "invalid phandles in overlay\n"); + return -1; + } + tree->max_phandle = new_max; + + /* Now that we changed phandles in the overlay, we need to update any + nodes referring to them. Those are listed in /__local_fixups__. */ + struct device_tree_node *local_fixups = dt_find_node_by_path(overlay, + "/__local_fixups__", NULL, NULL, 0); + if (local_fixups && dt_fixup_locals(overlay->root, local_fixups, + phandle_base) < 0) { + printk(BIOS_ERR, "invalid local fixups in overlay\n"); + return -1; + } + + /* + * Besides local phandle references (from nodes within the overlay to + * other nodes within the overlay), the overlay may also contain phandle + * references to the base tree. These are stored with invalid values and + * must be updated now. /__symbols__ contains a list of all labels in + * the base tree, and /__fixups__ describes all nodes in the overlay + * that contain external phandle references. + * We also take this opportunity to update all /fragment@X/__overlay__/ + * prefixes in the overlay's /__symbols__ node to the correct path that + * the fragment will be placed in later, since this is the only step + * where we have all necessary information for that easily available. + */ + struct device_tree_node *symbols = dt_find_node_by_path(tree, + "/__symbols__", NULL, NULL, 0); + struct device_tree_node *fixups = dt_find_node_by_path(overlay, + "/__fixups__", NULL, NULL, 0); + struct device_tree_node *overlay_symbols = dt_find_node_by_path(overlay, + "/__symbols__", NULL, NULL, 0); + if (fixups && dt_fixup_all_externals(tree, symbols, overlay, + fixups, overlay_symbols) < 0) { + printk(BIOS_ERR, "cannot match external fixups from overlay\n"); + return -1; + } + + /* After all this fixing up, we can finally merge overlay into the tree + (one fragment at a time, because for some reason it's split up). */ + struct device_tree_node *fragment; + list_for_each(fragment, overlay->root->children, list_node) + if (dt_import_fragment(tree, fragment, overlay_symbols) < 0) { + printk(BIOS_ERR, "bad DT fragment '%s'\n", + fragment->name); + return -1; + } + + /* + * We need to also update /__symbols__ to include labels from this + * overlay, in case we want to load further overlays with external + * phandle references to it. If the base tree already has a /__symbols__ + * we merge them together, otherwise we just insert the overlay's + * /__symbols__ node into the base tree root. + */ + if (overlay_symbols) { + if (symbols) + dt_copy_subtree(symbols, overlay_symbols, 0); + else + list_insert_after(&overlay_symbols->list_node, + &tree->root->children); + } + + return 0; +} |