// SPDX-License-Identifier: GPL-2.0 /* * Functions for working with the Flattened Device Tree data format * * Copyright 2009 Benjamin Herrenschmidt, IBM Corp * benh@kernel.crashing.org */ #define pr_fmt(fmt) "OF: fdt: " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* for COMMAND_LINE_SIZE */ #include #include "of_private.h" /* * __dtb_empty_root_begin[] and __dtb_empty_root_end[] magically created by * cmd_wrap_S_dtb in scripts/Makefile.dtbs */ extern uint8_t __dtb_empty_root_begin[]; extern uint8_t __dtb_empty_root_end[]; /* * of_fdt_limit_memory - limit the number of regions in the /memory node * @limit: maximum entries * * Adjust the flattened device tree to have at most 'limit' number of * memory entries in the /memory node. This function may be called * any time after initial_boot_param is set. */ void __init of_fdt_limit_memory(int limit) { int memory; int len; const void *val; int cell_size = sizeof(uint32_t)*(dt_root_addr_cells + dt_root_size_cells); memory = fdt_path_offset(initial_boot_params, "/memory"); if (memory > 0) { val = fdt_getprop(initial_boot_params, memory, "reg", &len); if (len > limit*cell_size) { len = limit*cell_size; pr_debug("Limiting number of entries to %d\n", limit); fdt_setprop(initial_boot_params, memory, "reg", val, len); } } } bool of_fdt_device_is_available(const void *blob, unsigned long node) { const char *status = fdt_getprop(blob, node, "status", NULL); if (!status) return true; if (!strcmp(status, "ok") || !strcmp(status, "okay")) return true; return false; } static void *unflatten_dt_alloc(void **mem, unsigned long size, unsigned long align) { void *res; *mem = PTR_ALIGN(*mem, align); res = *mem; *mem += size; return res; } static void populate_properties(const void *blob, int offset, void **mem, struct device_node *np, const char *nodename, bool dryrun) { struct property *pp, **pprev = NULL; int cur; bool has_name = false; pprev = &np->properties; for (cur = fdt_first_property_offset(blob, offset); cur >= 0; cur = fdt_next_property_offset(blob, cur)) { const __be32 *val; const char *pname; u32 sz; val = fdt_getprop_by_offset(blob, cur, &pname, &sz); if (!val) { pr_warn("Cannot locate property at 0x%x\n", cur); continue; } if (!pname) { pr_warn("Cannot find property name at 0x%x\n", cur); continue; } if (!strcmp(pname, "name")) has_name = true; pp = unflatten_dt_alloc(mem, sizeof(struct property), __alignof__(struct property)); if (dryrun) continue; /* We accept flattened tree phandles either in * ePAPR-style "phandle" properties, or the * legacy "linux,phandle" properties. If both * appear and have different values, things * will get weird. Don't do that. */ if (!strcmp(pname, "phandle") || !strcmp(pname, "linux,phandle")) { if (!np->phandle) np->phandle = be32_to_cpup(val); } /* And we process the "ibm,phandle" property * used in pSeries dynamic device tree * stuff */ if (!strcmp(pname, "ibm,phandle")) np->phandle = be32_to_cpup(val); pp->name = (char *)pname; pp->length = sz; pp->value = (__be32 *)val; *pprev = pp; pprev = &pp->next; } /* With version 0x10 we may not have the name property, * recreate it here from the unit name if absent */ if (!has_name) { const char *p = nodename, *ps = p, *pa = NULL; int len; while (*p) { if ((*p) == '@') pa = p; else if ((*p) == '/') ps = p + 1; p++; } if (pa < ps) pa = p; len = (pa - ps) + 1; pp = unflatten_dt_alloc(mem, sizeof(struct property) + len, __alignof__(struct property)); if (!dryrun) { pp->name = "name"; pp->length = len; pp->value = pp + 1; *pprev = pp; memcpy(pp->value, ps, len - 1); ((char *)pp->value)[len - 1] = 0; pr_debug("fixed up name for %s -> %s\n", nodename, (char *)pp->value); } } } static int populate_node(const void *blob, int offset, void **mem, struct device_node *dad, struct device_node **pnp, bool dryrun) { struct device_node *np; const char *pathp; int len; pathp = fdt_get_name(blob, offset, &len); if (!pathp) { *pnp = NULL; return len; } len++; np = unflatten_dt_alloc(mem, sizeof(struct device_node) + len, __alignof__(struct device_node)); if (!dryrun) { char *fn; of_node_init(np); np->full_name = fn = ((char *)np) + sizeof(*np); memcpy(fn, pathp, len); if (dad != NULL) { np->parent = dad; np->sibling = dad->child; dad->child = np; } } populate_properties(blob, offset, mem, np, pathp, dryrun); if (!dryrun) { np->name = of_get_property(np, "name", NULL); if (!np->name) np->name = ""; } *pnp = np; return 0; } static void reverse_nodes(struct device_node *parent) { struct device_node *child, *next; /* In-depth first */ child = parent->child; while (child) { reverse_nodes(child); child = child->sibling; } /* Reverse the nodes in the child list */ child = parent->child; parent->child = NULL; while (child) { next = child->sibling; child->sibling = parent->child; parent->child = child; child = next; } } /** * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree * @blob: The parent device tree blob * @mem: Memory chunk to use for allocating device nodes and properties * @dad: Parent struct device_node * @nodepp: The device_node tree created by the call * * Return: The size of unflattened device tree or error code */ static int unflatten_dt_nodes(const void *blob, void *mem, struct device_node *dad, struct device_node **nodepp) { struct device_node *root; int offset = 0, depth = 0, initial_depth = 0; #define FDT_MAX_DEPTH 64 struct device_node *nps[FDT_MAX_DEPTH]; void *base = mem; bool dryrun = !base; int ret; if (nodepp) *nodepp = NULL; /* * We're unflattening device sub-tree if @dad is valid. There are * possibly multiple nodes in the first level of depth. We need * set @depth to 1 to make fdt_next_node() happy as it bails * immediately when negative @depth is found. Otherwise, the device * nodes except the first one won't be unflattened successfully. */ if (dad) depth = initial_depth = 1; root = dad; nps[depth] = dad; for (offset = 0; offset >= 0 && depth >= initial_depth; offset = fdt_next_node(blob, offset, &depth)) { if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH - 1)) continue; if (!IS_ENABLED(CONFIG_OF_KOBJ) && !of_fdt_device_is_available(blob, offset)) continue; ret = populate_node(blob, offset, &mem, nps[depth], &nps[depth+1], dryrun); if (ret < 0) return ret; if (!dryrun && nodepp && !*nodepp) *nodepp = nps[depth+1]; if (!dryrun && !root) root = nps[depth+1]; } if (offset < 0 && offset != -FDT_ERR_NOTFOUND) { pr_err("Error %d processing FDT\n", offset); return -EINVAL; } /* * Reverse the child list. Some drivers assumes node order matches .dts * node order */ if (!dryrun) reverse_nodes(root); return mem - base; } /** * __unflatten_device_tree - create tree of device_nodes from flat blob * @blob: The blob to expand * @dad: Parent device node * @mynodes: The device_node tree created by the call * @dt_alloc: An allocator that provides a virtual address to memory * for the resulting tree * @detached: if true set OF_DETACHED on @mynodes * * unflattens a device-tree, creating the tree of struct device_node. It also * fills the "name" and "type" pointers of the nodes so the normal device-tree * walking functions can be used. * * Return: NULL on failure or the memory chunk containing the unflattened * device tree on success. */ void *__unflatten_device_tree(const void *blob, struct device_node *dad, struct device_node **mynodes, void *(*dt_alloc)(u64 size, u64 align), bool detached) { int size; void *mem; int ret; if (mynodes) *mynodes = NULL; pr_debug(" -> unflatten_device_tree()\n"); if (!blob) { pr_debug("No device tree pointer\n"); return NULL; } pr_debug("Unflattening device tree:\n"); pr_debug("magic: %08x\n", fdt_magic(blob)); pr_debug("size: %08x\n", fdt_totalsize(blob)); pr_debug("version: %08x\n", fdt_version(blob)); if (fdt_check_header(blob)) { pr_err("Invalid device tree blob header\n"); return NULL; } /* First pass, scan for size */ size = unflatten_dt_nodes(blob, NULL, dad, NULL); if (size <= 0) return NULL; size = ALIGN(size, 4); pr_debug(" size is %d, allocating...\n", size); /* Allocate memory for the expanded device tree */ mem = dt_alloc(size + 4, __alignof__(struct device_node)); if (!mem) return NULL; memset(mem, 0, size); *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef); pr_debug(" unflattening %p...\n", mem); /* Second pass, do actual unflattening */ ret = unflatten_dt_nodes(blob, mem, dad, mynodes); if (be32_to_cpup(mem + size) != 0xdeadbeef) pr_warn("End of tree marker overwritten: %08x\n", be32_to_cpup(mem + size)); if (ret <= 0) return NULL; if (detached && mynodes && *mynodes) { of_node_set_flag(*mynodes, OF_DETACHED); pr_debug("unflattened tree is detached\n"); } pr_debug(" <- unflatten_device_tree()\n"); return mem; } static void *kernel_tree_alloc(u64 size, u64 align) { return kzalloc(size, GFP_KERNEL); } static DEFINE_MUTEX(of_fdt_unflatten_mutex); /** * of_fdt_unflatten_tree - create tree of device_nodes from flat blob * @blob: Flat device tree blob * @dad: Parent device node * @mynodes: The device tree created by the call * * unflattens the device-tree passed by the firmware, creating the * tree of struct device_node. It also fills the "name" and "type" * pointers of the nodes so the normal device-tree walking functions * can be used. * * Return: NULL on failure or the memory chunk containing the unflattened * device tree on success. */ void *of_fdt_unflatten_tree(const unsigned long *blob, struct device_node *dad, struct device_node **mynodes) { void *mem; mutex_lock(&of_fdt_unflatten_mutex); mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc, true); mutex_unlock(&of_fdt_unflatten_mutex); return mem; } EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree); /* Everything below here references initial_boot_params directly. */ int __initdata dt_root_addr_cells; int __initdata dt_root_size_cells; void *initial_boot_params __ro_after_init; #ifdef CONFIG_OF_EARLY_FLATTREE static u32 of_fdt_crc32; /* * fdt_reserve_elfcorehdr() - reserves memory for elf core header * * This function reserves the memory occupied by an elf core header * described in the device tree. This region contains all the * information about primary kernel's core image and is used by a dump * capture kernel to access the system memory on primary kernel. */ static void __init fdt_reserve_elfcorehdr(void) { if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size) return; if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) { pr_warn("elfcorehdr is overlapped\n"); return; } memblock_reserve(elfcorehdr_addr, elfcorehdr_size); pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n", elfcorehdr_size >> 10, elfcorehdr_addr); } /** * early_init_fdt_scan_reserved_mem() - create reserved memory regions * * This function grabs memory from early allocator for device exclusive use * defined in device tree structures. It should be called by arch specific code * once the early allocator (i.e. memblock) has been fully activated. */ void __init early_init_fdt_scan_reserved_mem(void) { int n; u64 base, size; if (!initial_boot_params) return; fdt_scan_reserved_mem(); fdt_reserve_elfcorehdr(); /* Process header /memreserve/ fields */ for (n = 0; ; n++) { fdt_get_mem_rsv(initial_boot_params, n, &base, &size); if (!size) break; memblock_reserve(base, size); } fdt_init_reserved_mem(); } /** * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob */ void __init early_init_fdt_reserve_self(void) { if (!initial_boot_params) return; /* Reserve the dtb region */ memblock_reserve(__pa(initial_boot_params), fdt_totalsize(initial_boot_params)); } /** * of_scan_flat_dt - scan flattened tree blob and call callback on each. * @it: callback function * @data: context data pointer * * This function is used to scan the flattened device-tree, it is * used to extract the memory information at boot before we can * unflatten the tree */ int __init of_scan_flat_dt(int (*it)(unsigned long node, const char *uname, int depth, void *data), void *data) { const void *blob = initial_boot_params; const char *pathp; int offset, rc = 0, depth = -1; if (!blob) return 0; for (offset = fdt_next_node(blob, -1, &depth); offset >= 0 && depth >= 0 && !rc; offset = fdt_next_node(blob, offset, &depth)) { pathp = fdt_get_name(blob, offset, NULL); rc = it(offset, pathp, depth, data); } return rc; } /** * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each. * @parent: parent node * @it: callback function * @data: context data pointer * * This function is used to scan sub-nodes of a node. */ int __init of_scan_flat_dt_subnodes(unsigned long parent, int (*it)(unsigned long node, const char *uname, void *data), void *data) { const void *blob = initial_boot_params; int node; fdt_for_each_subnode(node, blob, parent) { const char *pathp; int rc; pathp = fdt_get_name(blob, node, NULL); rc = it(node, pathp, data); if (rc) return rc; } return 0; } /** * of_get_flat_dt_subnode_by_name - get the subnode by given name * * @node: the parent node * @uname: the name of subnode * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none */ int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname) { return fdt_subnode_offset(initial_boot_params, node, uname); } /* * of_get_flat_dt_root - find the root node in the flat blob */ unsigned long __init of_get_flat_dt_root(void) { return 0; } /* * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr * * This function can be used within scan_flattened_dt callback to get * access to properties */ const void *__init of_get_flat_dt_prop(unsigned long node, const char *name, int *size) { return fdt_getprop(initial_boot_params, node, name, size); } /** * of_fdt_is_compatible - Return true if given node from the given blob has * compat in its compatible list * @blob: A device tree blob * @node: node to test * @compat: compatible string to compare with compatible list. * * Return: a non-zero value on match with smaller values returned for more * specific compatible values. */ static int of_fdt_is_compatible(const void *blob, unsigned long node, const char *compat) { const char *cp; int cplen; unsigned long l, score = 0; cp = fdt_getprop(blob, node, "compatible", &cplen); if (cp == NULL) return 0; while (cplen > 0) { score++; if (of_compat_cmp(cp, compat, strlen(compat)) == 0) return score; l = strlen(cp) + 1; cp += l; cplen -= l; } return 0; } /** * of_flat_dt_is_compatible - Return true if given node has compat in compatible list * @node: node to test * @compat: compatible string to compare with compatible list. */ int __init of_flat_dt_is_compatible(unsigned long node, const char *compat) { return of_fdt_is_compatible(initial_boot_params, node, compat); } /* * of_flat_dt_match - Return true if node matches a list of compatible values */ static int __init of_flat_dt_match(unsigned long node, const char *const *compat) { unsigned int tmp, score = 0; if (!compat) return 0; while (*compat) { tmp = of_fdt_is_compatible(initial_boot_params, node, *compat); if (tmp && (score == 0 || (tmp < score))) score = tmp; compat++; } return score; } /* * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle */ uint32_t __init of_get_flat_dt_phandle(unsigned long node) { return fdt_get_phandle(initial_boot_params, node); } const char * __init of_flat_dt_get_machine_name(void) { const char *name; unsigned long dt_root = of_get_flat_dt_root(); name = of_get_flat_dt_prop(dt_root, "model", NULL); if (!name) name = of_get_flat_dt_prop(dt_root, "compatible", NULL); return name; } /** * of_flat_dt_match_machine - Iterate match tables to find matching machine. * * @default_match: A machine specific ptr to return in case of no match. * @get_next_compat: callback function to return next compatible match table. * * Iterate through machine match tables to find the best match for the machine * compatible string in the FDT. */ const void * __init of_flat_dt_match_machine(const void *default_match, const void * (*get_next_compat)(const char * const**)) { const void *data = NULL; const void *best_data = default_match; const char *const *compat; unsigned long dt_root; unsigned int best_score = ~1, score = 0; dt_root = of_get_flat_dt_root(); while ((data = get_next_compat(&compat))) { score = of_flat_dt_match(dt_root, compat); if (score > 0 && score < best_score) { best_data = data; best_score = score; } } if (!best_data) { const char *prop; int size; pr_err("\n unrecognized device tree list:\n[ "); prop = of_get_flat_dt_prop(dt_root, "compatible", &size); if (prop) { while (size > 0) { printk("'%s' ", prop); size -= strlen(prop) + 1; prop += strlen(prop) + 1; } } printk("]\n\n"); return NULL; } pr_info("Machine model: %s\n", of_flat_dt_get_machine_name()); return best_data; } static void __early_init_dt_declare_initrd(unsigned long start, unsigned long end) { /* * __va() is not yet available this early on some platforms. In that * case, the platform uses phys_initrd_start/phys_initrd_size instead * and does the VA conversion itself. */ if (!IS_ENABLED(CONFIG_ARM64) && !(IS_ENABLED(CONFIG_RISCV) && IS_ENABLED(CONFIG_64BIT))) { initrd_start = (unsigned long)__va(start); initrd_end = (unsigned long)__va(end); initrd_below_start_ok = 1; } } /** * early_init_dt_check_for_initrd - Decode initrd location from flat tree * @node: reference to node containing initrd location ('chosen') */ static void __init early_init_dt_check_for_initrd(unsigned long node) { u64 start, end; int len; const __be32 *prop; if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD)) return; pr_debug("Looking for initrd properties... "); prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len); if (!prop) return; start = of_read_number(prop, len/4); prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len); if (!prop) return; end = of_read_number(prop, len/4); if (start > end) return; __early_init_dt_declare_initrd(start, end); phys_initrd_start = start; phys_initrd_size = end - start; pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end); } /** * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat * tree * @node: reference to node containing elfcorehdr location ('chosen') */ static void __init early_init_dt_check_for_elfcorehdr(unsigned long node) { const __be32 *prop; int len; if (!IS_ENABLED(CONFIG_CRASH_DUMP)) return; pr_debug("Looking for elfcorehdr property... "); prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len); if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells))) return; elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop); elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop); pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n", elfcorehdr_addr, elfcorehdr_size); } static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND; /* * The main usage of linux,usable-memory-range is for crash dump kernel. * Originally, the number of usable-memory regions is one. Now there may * be two regions, low region and high region. * To make compatibility with existing user-space and older kdump, the low * region is always the last range of linux,usable-memory-range if exist. */ #define MAX_USABLE_RANGES 2 /** * early_init_dt_check_for_usable_mem_range - Decode usable memory range * location from flat tree */ void __init early_init_dt_check_for_usable_mem_range(void) { struct memblock_region rgn[MAX_USABLE_RANGES] = {0}; const __be32 *prop, *endp; int len, i; unsigned long node = chosen_node_offset; if ((long)node < 0) return; pr_debug("Looking for usable-memory-range property... "); prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells))) return; endp = prop + (len / sizeof(__be32)); for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) { rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop); rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop); pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n", i, &rgn[i].base, &rgn[i].size); } memblock_cap_memory_range(rgn[0].base, rgn[0].size); for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++) memblock_add(rgn[i].base, rgn[i].size); } #ifdef CONFIG_SERIAL_EARLYCON int __init early_init_dt_scan_chosen_stdout(void) { int offset; const char *p, *q, *options = NULL; int l; const struct earlycon_id *match; const void *fdt = initial_boot_params; int ret; offset = fdt_path_offset(fdt, "/chosen"); if (offset < 0) offset = fdt_path_offset(fdt, "/chosen@0"); if (offset < 0) return -ENOENT; p = fdt_getprop(fdt, offset, "stdout-path", &l); if (!p) p = fdt_getprop(fdt, offset, "linux,stdout-path", &l); if (!p || !l) return -ENOENT; q = strchrnul(p, ':'); if (*q != '\0') options = q + 1; l = q - p; /* Get the node specified by stdout-path */ offset = fdt_path_offset_namelen(fdt, p, l); if (offset < 0) { pr_warn("earlycon: stdout-path %.*s not found\n", l, p); return 0; } for (match = __earlycon_table; match < __earlycon_table_end; match++) { if (!match->compatible[0]) continue; if (fdt_node_check_compatible(fdt, offset, match->compatible)) continue; ret = of_setup_earlycon(match, offset, options); if (!ret || ret == -EALREADY) return 0; } return -ENODEV; } #endif /* * early_init_dt_scan_root - fetch the top level address and size cells */ int __init early_init_dt_scan_root(void) { const __be32 *prop; const void *fdt = initial_boot_params; int node = fdt_path_offset(fdt, "/"); if (node < 0) return -ENODEV; dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT; dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT; prop = of_get_flat_dt_prop(node, "#size-cells", NULL); if (prop) dt_root_size_cells = be32_to_cpup(prop); pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells); prop = of_get_flat_dt_prop(node, "#address-cells", NULL); if (prop) dt_root_addr_cells = be32_to_cpup(prop); pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells); return 0; } u64 __init dt_mem_next_cell(int s, const __be32 **cellp) { const __be32 *p = *cellp; *cellp = p + s; return of_read_number(p, s); } /* * early_init_dt_scan_memory - Look for and parse memory nodes */ int __init early_init_dt_scan_memory(void) { int node, found_memory = 0; const void *fdt = initial_boot_params; fdt_for_each_subnode(node, fdt, 0) { const char *type = of_get_flat_dt_prop(node, "device_type", NULL); const __be32 *reg, *endp; int l; bool hotpluggable; /* We are scanning "memory" nodes only */ if (type == NULL || strcmp(type, "memory") != 0) continue; if (!of_fdt_device_is_available(fdt, node)) continue; reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l); if (reg == NULL) reg = of_get_flat_dt_prop(node, "reg", &l); if (reg == NULL) continue; endp = reg + (l / sizeof(__be32)); hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL); pr_debug("memory scan node %s, reg size %d,\n", fdt_get_name(fdt, node, NULL), l); while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) { u64 base, size; base = dt_mem_next_cell(dt_root_addr_cells, ®); size = dt_mem_next_cell(dt_root_size_cells, ®); if (size == 0) continue; pr_debug(" - %llx, %llx\n", base, size); early_init_dt_add_memory_arch(base, size); found_memory = 1; if (!hotpluggable) continue; if (memblock_mark_hotplug(base, size)) pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n", base, base + size); } } return found_memory; } int __init early_init_dt_scan_chosen(char *cmdline) { int l, node; const char *p; const void *rng_seed; const void *fdt = initial_boot_params; node = fdt_path_offset(fdt, "/chosen"); if (node < 0) node = fdt_path_offset(fdt, "/chosen@0"); if (node < 0) /* Handle the cmdline config options even if no /chosen node */ goto handle_cmdline; chosen_node_offset = node; early_init_dt_check_for_initrd(node); early_init_dt_check_for_elfcorehdr(node); rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l); if (rng_seed && l > 0) { add_bootloader_randomness(rng_seed, l); /* try to clear seed so it won't be found. */ fdt_nop_property(initial_boot_params, node, "rng-seed"); /* update CRC check value */ of_fdt_crc32 = crc32_be(~0, initial_boot_params, fdt_totalsize(initial_boot_params)); } /* Retrieve command line */ p = of_get_flat_dt_prop(node, "bootargs", &l); if (p != NULL && l > 0) strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE)); handle_cmdline: /* * CONFIG_CMDLINE is meant to be a default in case nothing else * managed to set the command line, unless CONFIG_CMDLINE_FORCE * is set in which case we override whatever was found earlier. */ #ifdef CONFIG_CMDLINE #if defined(CONFIG_CMDLINE_EXTEND) strlcat(cmdline, " ", COMMAND_LINE_SIZE); strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); #elif defined(CONFIG_CMDLINE_FORCE) strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); #else /* No arguments from boot loader, use kernel's cmdl*/ if (!((char *)cmdline)[0]) strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE); #endif #endif /* CONFIG_CMDLINE */ pr_debug("Command line is: %s\n", (char *)cmdline); return 0; } #ifndef MIN_MEMBLOCK_ADDR #define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET) #endif #ifndef MAX_MEMBLOCK_ADDR #define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0) #endif void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) { const u64 phys_offset = MIN_MEMBLOCK_ADDR; if (size < PAGE_SIZE - (base & ~PAGE_MASK)) { pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", base, base + size); return; } if (!PAGE_ALIGNED(base)) { size -= PAGE_SIZE - (base & ~PAGE_MASK); base = PAGE_ALIGN(base); } size &= PAGE_MASK; if (base > MAX_MEMBLOCK_ADDR) { pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", base, base + size); return; } if (base + size - 1 > MAX_MEMBLOCK_ADDR) { pr_warn("Ignoring memory range 0x%llx - 0x%llx\n", ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size); size = MAX_MEMBLOCK_ADDR - base + 1; } if (base + size < phys_offset) { pr_warn("Ignoring memory block 0x%llx - 0x%llx\n", base, base + size); return; } if (base < phys_offset) { pr_warn("Ignoring memory range 0x%llx - 0x%llx\n", base, phys_offset); size -= phys_offset - base; base = phys_offset; } memblock_add(base, size); } static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align) { void *ptr = memblock_alloc(size, align); if (!ptr) panic("%s: Failed to allocate %llu bytes align=0x%llx\n", __func__, size, align); return ptr; } bool __init early_init_dt_verify(void *params) { if (!params) return false; /* check device tree validity */ if (fdt_check_header(params)) return false; /* Setup flat device-tree pointer */ initial_boot_params = params; of_fdt_crc32 = crc32_be(~0, initial_boot_params, fdt_totalsize(initial_boot_params)); /* Initialize {size,address}-cells info */ early_init_dt_scan_root(); return true; } void __init early_init_dt_scan_nodes(void) { int rc; /* Retrieve various information from the /chosen node */ rc = early_init_dt_scan_chosen(boot_command_line); if (rc) pr_warn("No chosen node found, continuing without\n"); /* Setup memory, calling early_init_dt_add_memory_arch */ early_init_dt_scan_memory(); /* Handle linux,usable-memory-range property */ early_init_dt_check_for_usable_mem_range(); } bool __init early_init_dt_scan(void *params) { bool status; status = early_init_dt_verify(params); if (!status) return false; early_init_dt_scan_nodes(); return true; } static void *__init copy_device_tree(void *fdt) { int size; void *dt; size = fdt_totalsize(fdt); dt = early_init_dt_alloc_memory_arch(size, roundup_pow_of_two(FDT_V17_SIZE)); if (dt) memcpy(dt, fdt, size); return dt; } /** * unflatten_device_tree - create tree of device_nodes from flat blob * * unflattens the device-tree passed by the firmware, creating the * tree of struct device_node. It also fills the "name" and "type" * pointers of the nodes so the normal device-tree walking functions * can be used. */ void __init unflatten_device_tree(void) { void *fdt = initial_boot_params; /* Don't use the bootloader provided DTB if ACPI is enabled */ if (!acpi_disabled) fdt = NULL; /* * Populate an empty root node when ACPI is enabled or bootloader * doesn't provide one. */ if (!fdt) { fdt = (void *) __dtb_empty_root_begin; /* fdt_totalsize() will be used for copy size */ if (fdt_totalsize(fdt) > __dtb_empty_root_end - __dtb_empty_root_begin) { pr_err("invalid size in dtb_empty_root\n"); return; } of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt)); fdt = copy_device_tree(fdt); } __unflatten_device_tree(fdt, NULL, &of_root, early_init_dt_alloc_memory_arch, false); /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */ of_alias_scan(early_init_dt_alloc_memory_arch); unittest_unflatten_overlay_base(); } /** * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob * * Copies and unflattens the device-tree passed by the firmware, creating the * tree of struct device_node. It also fills the "name" and "type" * pointers of the nodes so the normal device-tree walking functions * can be used. This should only be used when the FDT memory has not been * reserved such is the case when the FDT is built-in to the kernel init * section. If the FDT memory is reserved already then unflatten_device_tree * should be used instead. */ void __init unflatten_and_copy_device_tree(void) { if (initial_boot_params) initial_boot_params = copy_device_tree(initial_boot_params); unflatten_device_tree(); } #ifdef CONFIG_SYSFS static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) { memcpy(buf, initial_boot_params + off, count); return count; } static int __init of_fdt_raw_init(void) { static struct bin_attribute of_fdt_raw_attr = __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0); if (!initial_boot_params) return 0; if (of_fdt_crc32 != crc32_be(~0, initial_boot_params, fdt_totalsize(initial_boot_params))) { pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n"); return 0; } of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params); return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr); } late_initcall(of_fdt_raw_init); #endif #endif /* CONFIG_OF_EARLY_FLATTREE */