diff options
Diffstat (limited to 'drivers/of/fdt.c')
| -rw-r--r-- | drivers/of/fdt.c | 1299 |
1 files changed, 1299 insertions, 0 deletions
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c new file mode 100644 index 000000000..384510d02 --- /dev/null +++ b/drivers/of/fdt.c @@ -0,0 +1,1299 @@ +// 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 <linux/crc32.h> +#include <linux/kernel.h> +#include <linux/initrd.h> +#include <linux/memblock.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/of_fdt.h> +#include <linux/of_reserved_mem.h> +#include <linux/sizes.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/libfdt.h> +#include <linux/debugfs.h> +#include <linux/serial_core.h> +#include <linux/sysfs.h> +#include <linux/random.h> + +#include <asm/setup.h> /* for COMMAND_LINE_SIZE */ +#include <asm/page.h> + +#include "of_private.h" + +/* + * 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 nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT; + int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT; + const __be32 *addr_prop; + const __be32 *size_prop; + int root_offset; + int cell_size; + + root_offset = fdt_path_offset(initial_boot_params, "/"); + if (root_offset < 0) + return; + + addr_prop = fdt_getprop(initial_boot_params, root_offset, + "#address-cells", NULL); + if (addr_prop) + nr_address_cells = fdt32_to_cpu(*addr_prop); + + size_prop = fdt_getprop(initial_boot_params, root_offset, + "#size-cells", NULL); + if (size_prop) + nr_size_cells = fdt32_to_cpu(*size_prop); + + cell_size = sizeof(uint32_t)*(nr_address_cells + nr_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); + } + } +} + +static 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; + pprev = &pp->next; + 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); + } + } + + if (!dryrun) + *pprev = NULL; +} + +static bool 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; + unsigned int l, allocl; + + pathp = fdt_get_name(blob, offset, &l); + if (!pathp) { + *pnp = NULL; + return false; + } + + allocl = ++l; + + np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl, + __alignof__(struct device_node)); + if (!dryrun) { + char *fn; + of_node_init(np); + np->full_name = fn = ((char *)np) + sizeof(*np); + + memcpy(fn, pathp, l); + + 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 = "<NULL>"; + } + + *pnp = np; + return true; +} + +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; + + 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; + + if (!populate_node(blob, offset, &mem, nps[depth], + &nps[depth+1], dryrun)) + return mem - base; + + 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; + + 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 */ + 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 (detached && 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; + +/** + * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property + */ +static int __init __reserved_mem_reserve_reg(unsigned long node, + const char *uname) +{ + int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32); + phys_addr_t base, size; + int len; + const __be32 *prop; + int first = 1; + bool nomap; + + prop = of_get_flat_dt_prop(node, "reg", &len); + if (!prop) + return -ENOENT; + + if (len && len % t_len != 0) { + pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n", + uname); + return -EINVAL; + } + + nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL; + + while (len >= t_len) { + base = dt_mem_next_cell(dt_root_addr_cells, &prop); + size = dt_mem_next_cell(dt_root_size_cells, &prop); + + if (size && + early_init_dt_reserve_memory_arch(base, size, nomap) == 0) + pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n", + uname, &base, (unsigned long)(size / SZ_1M)); + else + pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n", + uname, &base, (unsigned long)(size / SZ_1M)); + + len -= t_len; + if (first) { + fdt_reserved_mem_save_node(node, uname, base, size); + first = 0; + } + } + return 0; +} + +/** + * __reserved_mem_check_root() - check if #size-cells, #address-cells provided + * in /reserved-memory matches the values supported by the current implementation, + * also check if ranges property has been provided + */ +static int __init __reserved_mem_check_root(unsigned long node) +{ + const __be32 *prop; + + prop = of_get_flat_dt_prop(node, "#size-cells", NULL); + if (!prop || be32_to_cpup(prop) != dt_root_size_cells) + return -EINVAL; + + prop = of_get_flat_dt_prop(node, "#address-cells", NULL); + if (!prop || be32_to_cpup(prop) != dt_root_addr_cells) + return -EINVAL; + + prop = of_get_flat_dt_prop(node, "ranges", NULL); + if (!prop) + return -EINVAL; + return 0; +} + +/** + * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory + */ +static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname, + int depth, void *data) +{ + static int found; + int err; + + if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) { + if (__reserved_mem_check_root(node) != 0) { + pr_err("Reserved memory: unsupported node format, ignoring\n"); + /* break scan */ + return 1; + } + found = 1; + /* scan next node */ + return 0; + } else if (!found) { + /* scan next node */ + return 0; + } else if (found && depth < 2) { + /* scanning of /reserved-memory has been finished */ + return 1; + } + + if (!of_fdt_device_is_available(initial_boot_params, node)) + return 0; + + err = __reserved_mem_reserve_reg(node, uname); + if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL)) + fdt_reserved_mem_save_node(node, uname, 0, 0); + + /* scan next node */ + return 0; +} + +/** + * 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; + + /* Process header /memreserve/ fields */ + for (n = 0; ; n++) { + fdt_get_mem_rsv(initial_boot_params, n, &base, &size); + if (!size) + break; + early_init_dt_reserve_memory_arch(base, size, false); + } + + of_scan_flat_dt(__fdt_scan_reserved_mem, NULL); + 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 */ + early_init_dt_reserve_memory_arch(__pa(initial_boot_params), + fdt_totalsize(initial_boot_params), + false); +} + +/** + * 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. + * @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_prop - 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); +} + +struct fdt_scan_status { + const char *name; + int namelen; + int depth; + int found; + int (*iterator)(unsigned long node, const char *uname, int depth, void *data); + void *data; +}; + +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; +} + +#ifdef CONFIG_BLK_DEV_INITRD +static void __early_init_dt_declare_initrd(unsigned long start, + unsigned long end) +{ + /* ARM64 would cause a BUG to occur here when CONFIG_DEBUG_VM is + * enabled since __va() is called too early. ARM64 does make use + * of phys_initrd_start/phys_initrd_size so we can skip this + * conversion. + */ + if (!IS_ENABLED(CONFIG_ARM64)) { + 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; + + 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); + + __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", + (unsigned long long)start, (unsigned long long)end); +} +#else +static inline void early_init_dt_check_for_initrd(unsigned long node) +{ +} +#endif /* CONFIG_BLK_DEV_INITRD */ + +#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 **p_match; + const void *fdt = initial_boot_params; + + 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 (p_match = __earlycon_table; p_match < __earlycon_table_end; + p_match++) { + const struct earlycon_id *match = *p_match; + + if (!match->compatible[0]) + continue; + + if (fdt_node_check_compatible(fdt, offset, match->compatible)) + continue; + + if (of_setup_earlycon(match, offset, options) == 0) + 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(unsigned long node, const char *uname, + int depth, void *data) +{ + const __be32 *prop; + + if (depth != 0) + return 0; + + 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); + + /* break now */ + return 1; +} + +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(unsigned long node, const char *uname, + int depth, void *data) +{ + 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) + return 0; + + 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) + return 0; + + endp = reg + (l / sizeof(__be32)); + hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL); + + pr_debug("memory scan node %s, reg size %d,\n", uname, 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", (unsigned long long)base, + (unsigned long long)size); + + early_init_dt_add_memory_arch(base, size); + + if (!hotpluggable) + continue; + + if (early_init_dt_mark_hotplug_memory_arch(base, size)) + pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n", + base, base + size); + } + + return 0; +} + +int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, + int depth, void *data) +{ + int l; + const char *p; + const void *rng_seed; + + pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname); + + if (depth != 1 || !data || + (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0)) + return 0; + + early_init_dt_check_for_initrd(node); + + /* Retrieve command line */ + p = of_get_flat_dt_prop(node, "bootargs", &l); + if (p != NULL && l > 0) + strlcpy(data, p, min(l, COMMAND_LINE_SIZE)); + + /* + * 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(data, " ", COMMAND_LINE_SIZE); + strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); +#elif defined(CONFIG_CMDLINE_FORCE) + strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); +#else + /* No arguments from boot loader, use kernel's cmdl*/ + if (!((char *)data)[0]) + strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE); +#endif +#endif /* CONFIG_CMDLINE */ + + pr_debug("Command line is: %s\n", (char *)data); + + 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)); + } + + /* break now */ + return 1; +} + +#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); +} + +int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size) +{ + return memblock_mark_hotplug(base, size); +} + +int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base, + phys_addr_t size, bool nomap) +{ + if (nomap) { + /* + * If the memory is already reserved (by another region), we + * should not allow it to be marked nomap. + */ + if (memblock_is_region_reserved(base, size)) + return -EBUSY; + + return memblock_mark_nomap(base, size); + } + return memblock_reserve(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)); + return true; +} + + +void __init early_init_dt_scan_nodes(void) +{ + int rc = 0; + + /* Retrieve various information from the /chosen node */ + rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); + if (!rc) + pr_warn("No chosen node found, continuing without\n"); + + /* Initialize {size,address}-cells info */ + of_scan_flat_dt(early_init_dt_scan_root, NULL); + + /* Setup memory, calling early_init_dt_add_memory_arch */ + of_scan_flat_dt(early_init_dt_scan_memory, NULL); +} + +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; +} + +/** + * 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) +{ + __unflatten_device_tree(initial_boot_params, 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) +{ + int size; + void *dt; + + if (!initial_boot_params) { + pr_warn("No valid device tree found, continuing without\n"); + return; + } + + size = fdt_totalsize(initial_boot_params); + dt = early_init_dt_alloc_memory_arch(size, + roundup_pow_of_two(FDT_V17_SIZE)); + + if (dt) { + memcpy(dt, initial_boot_params, size); + initial_boot_params = dt; + } + 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 */ |