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Diffstat (limited to '')
| -rw-r--r-- | drivers/of/fdt.c | 590 |
1 files changed, 590 insertions, 0 deletions
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c new file mode 100644 index 000000000000..406757a9d7ea --- /dev/null +++ b/drivers/of/fdt.c @@ -0,0 +1,590 @@ +/* + * Functions for working with the Flattened Device Tree data format + * + * Copyright 2009 Benjamin Herrenschmidt, IBM Corp + * benh@kernel.crashing.org + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/initrd.h> +#include <linux/of.h> +#include <linux/of_fdt.h> +#include <linux/string.h> +#include <linux/errno.h> + +#ifdef CONFIG_PPC +#include <asm/machdep.h> +#endif /* CONFIG_PPC */ + +#include <asm/page.h> + +int __initdata dt_root_addr_cells; +int __initdata dt_root_size_cells; + +struct boot_param_header *initial_boot_params; + +char *find_flat_dt_string(u32 offset) +{ + return ((char *)initial_boot_params) + + be32_to_cpu(initial_boot_params->off_dt_strings) + offset; +} + +/** + * 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) +{ + unsigned long p = ((unsigned long)initial_boot_params) + + be32_to_cpu(initial_boot_params->off_dt_struct); + int rc = 0; + int depth = -1; + + do { + u32 tag = be32_to_cpup((__be32 *)p); + char *pathp; + + p += 4; + if (tag == OF_DT_END_NODE) { + depth--; + continue; + } + if (tag == OF_DT_NOP) + continue; + if (tag == OF_DT_END) + break; + if (tag == OF_DT_PROP) { + u32 sz = be32_to_cpup((__be32 *)p); + p += 8; + if (be32_to_cpu(initial_boot_params->version) < 0x10) + p = _ALIGN(p, sz >= 8 ? 8 : 4); + p += sz; + p = _ALIGN(p, 4); + continue; + } + if (tag != OF_DT_BEGIN_NODE) { + pr_err("Invalid tag %x in flat device tree!\n", tag); + return -EINVAL; + } + depth++; + pathp = (char *)p; + p = _ALIGN(p + strlen(pathp) + 1, 4); + if ((*pathp) == '/') { + char *lp, *np; + for (lp = NULL, np = pathp; *np; np++) + if ((*np) == '/') + lp = np+1; + if (lp != NULL) + pathp = lp; + } + rc = it(p, pathp, depth, data); + if (rc != 0) + break; + } while (1); + + return rc; +} + +/** + * of_get_flat_dt_root - find the root node in the flat blob + */ +unsigned long __init of_get_flat_dt_root(void) +{ + unsigned long p = ((unsigned long)initial_boot_params) + + be32_to_cpu(initial_boot_params->off_dt_struct); + + while (be32_to_cpup((__be32 *)p) == OF_DT_NOP) + p += 4; + BUG_ON(be32_to_cpup((__be32 *)p) != OF_DT_BEGIN_NODE); + p += 4; + return _ALIGN(p + strlen((char *)p) + 1, 4); +} + +/** + * 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 + */ +void *__init of_get_flat_dt_prop(unsigned long node, const char *name, + unsigned long *size) +{ + unsigned long p = node; + + do { + u32 tag = be32_to_cpup((__be32 *)p); + u32 sz, noff; + const char *nstr; + + p += 4; + if (tag == OF_DT_NOP) + continue; + if (tag != OF_DT_PROP) + return NULL; + + sz = be32_to_cpup((__be32 *)p); + noff = be32_to_cpup((__be32 *)(p + 4)); + p += 8; + if (be32_to_cpu(initial_boot_params->version) < 0x10) + p = _ALIGN(p, sz >= 8 ? 8 : 4); + + nstr = find_flat_dt_string(noff); + if (nstr == NULL) { + pr_warning("Can't find property index name !\n"); + return NULL; + } + if (strcmp(name, nstr) == 0) { + if (size) + *size = sz; + return (void *)p; + } + p += sz; + p = _ALIGN(p, 4); + } while (1); +} + +/** + * 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) +{ + const char *cp; + unsigned long cplen, l; + + cp = of_get_flat_dt_prop(node, "compatible", &cplen); + if (cp == NULL) + return 0; + while (cplen > 0) { + if (strncasecmp(cp, compat, strlen(compat)) == 0) + return 1; + l = strlen(cp) + 1; + cp += l; + cplen -= l; + } + + return 0; +} + +static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size, + unsigned long align) +{ + void *res; + + *mem = _ALIGN(*mem, align); + res = (void *)*mem; + *mem += size; + + return res; +} + +/** + * unflatten_dt_node - Alloc and populate a device_node from the flat tree + * @p: pointer to node in flat tree + * @dad: Parent struct device_node + * @allnextpp: pointer to ->allnext from last allocated device_node + * @fpsize: Size of the node path up at the current depth. + */ +unsigned long __init unflatten_dt_node(unsigned long mem, + unsigned long *p, + struct device_node *dad, + struct device_node ***allnextpp, + unsigned long fpsize) +{ + struct device_node *np; + struct property *pp, **prev_pp = NULL; + char *pathp; + u32 tag; + unsigned int l, allocl; + int has_name = 0; + int new_format = 0; + + tag = be32_to_cpup((__be32 *)(*p)); + if (tag != OF_DT_BEGIN_NODE) { + pr_err("Weird tag at start of node: %x\n", tag); + return mem; + } + *p += 4; + pathp = (char *)*p; + l = allocl = strlen(pathp) + 1; + *p = _ALIGN(*p + l, 4); + + /* version 0x10 has a more compact unit name here instead of the full + * path. we accumulate the full path size using "fpsize", we'll rebuild + * it later. We detect this because the first character of the name is + * not '/'. + */ + if ((*pathp) != '/') { + new_format = 1; + if (fpsize == 0) { + /* root node: special case. fpsize accounts for path + * plus terminating zero. root node only has '/', so + * fpsize should be 2, but we want to avoid the first + * level nodes to have two '/' so we use fpsize 1 here + */ + fpsize = 1; + allocl = 2; + } else { + /* account for '/' and path size minus terminal 0 + * already in 'l' + */ + fpsize += l; + allocl = fpsize; + } + } + + np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl, + __alignof__(struct device_node)); + if (allnextpp) { + memset(np, 0, sizeof(*np)); + np->full_name = ((char *)np) + sizeof(struct device_node); + if (new_format) { + char *fn = np->full_name; + /* rebuild full path for new format */ + if (dad && dad->parent) { + strcpy(fn, dad->full_name); +#ifdef DEBUG + if ((strlen(fn) + l + 1) != allocl) { + pr_debug("%s: p: %d, l: %d, a: %d\n", + pathp, (int)strlen(fn), + l, allocl); + } +#endif + fn += strlen(fn); + } + *(fn++) = '/'; + memcpy(fn, pathp, l); + } else + memcpy(np->full_name, pathp, l); + prev_pp = &np->properties; + **allnextpp = np; + *allnextpp = &np->allnext; + if (dad != NULL) { + np->parent = dad; + /* we temporarily use the next field as `last_child'*/ + if (dad->next == NULL) + dad->child = np; + else + dad->next->sibling = np; + dad->next = np; + } + kref_init(&np->kref); + } + while (1) { + u32 sz, noff; + char *pname; + + tag = be32_to_cpup((__be32 *)(*p)); + if (tag == OF_DT_NOP) { + *p += 4; + continue; + } + if (tag != OF_DT_PROP) + break; + *p += 4; + sz = be32_to_cpup((__be32 *)(*p)); + noff = be32_to_cpup((__be32 *)((*p) + 4)); + *p += 8; + if (be32_to_cpu(initial_boot_params->version) < 0x10) + *p = _ALIGN(*p, sz >= 8 ? 8 : 4); + + pname = find_flat_dt_string(noff); + if (pname == NULL) { + pr_info("Can't find property name in list !\n"); + break; + } + if (strcmp(pname, "name") == 0) + has_name = 1; + l = strlen(pname) + 1; + pp = unflatten_dt_alloc(&mem, sizeof(struct property), + __alignof__(struct property)); + if (allnextpp) { + /* 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") == 0) || + (strcmp(pname, "linux,phandle") == 0)) { + if (np->phandle == 0) + np->phandle = *((u32 *)*p); + } + /* And we process the "ibm,phandle" property + * used in pSeries dynamic device tree + * stuff */ + if (strcmp(pname, "ibm,phandle") == 0) + np->phandle = *((u32 *)*p); + pp->name = pname; + pp->length = sz; + pp->value = (void *)*p; + *prev_pp = pp; + prev_pp = &pp->next; + } + *p = _ALIGN((*p) + sz, 4); + } + /* with version 0x10 we may not have the name property, recreate + * it here from the unit name if absent + */ + if (!has_name) { + char *p1 = pathp, *ps = pathp, *pa = NULL; + int sz; + + while (*p1) { + if ((*p1) == '@') + pa = p1; + if ((*p1) == '/') + ps = p1 + 1; + p1++; + } + if (pa < ps) + pa = p1; + sz = (pa - ps) + 1; + pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz, + __alignof__(struct property)); + if (allnextpp) { + pp->name = "name"; + pp->length = sz; + pp->value = pp + 1; + *prev_pp = pp; + prev_pp = &pp->next; + memcpy(pp->value, ps, sz - 1); + ((char *)pp->value)[sz - 1] = 0; + pr_debug("fixed up name for %s -> %s\n", pathp, + (char *)pp->value); + } + } + if (allnextpp) { + *prev_pp = NULL; + np->name = of_get_property(np, "name", NULL); + np->type = of_get_property(np, "device_type", NULL); + + if (!np->name) + np->name = "<NULL>"; + if (!np->type) + np->type = "<NULL>"; + } + while (tag == OF_DT_BEGIN_NODE) { + mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize); + tag = be32_to_cpup((__be32 *)(*p)); + } + if (tag != OF_DT_END_NODE) { + pr_err("Weird tag at end of node: %x\n", tag); + return mem; + } + *p += 4; + return mem; +} + +#ifdef CONFIG_BLK_DEV_INITRD +/** + * early_init_dt_check_for_initrd - Decode initrd location from flat tree + * @node: reference to node containing initrd location ('chosen') + */ +void __init early_init_dt_check_for_initrd(unsigned long node) +{ + unsigned long start, end, len; + __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_ulong(prop, len/4); + + prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len); + if (!prop) + return; + end = of_read_ulong(prop, len/4); + + early_init_dt_setup_initrd_arch(start, end); + pr_debug("initrd_start=0x%lx initrd_end=0x%lx\n", start, end); +} +#else +inline void early_init_dt_check_for_initrd(unsigned long node) +{ +} +#endif /* CONFIG_BLK_DEV_INITRD */ + +/** + * 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) +{ + __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, __be32 **cellp) +{ + __be32 *p = *cellp; + + *cellp = p + s; + return of_read_number(p, s); +} + +/** + * early_init_dt_scan_memory - Look for an parse memory nodes + */ +int __init early_init_dt_scan_memory(unsigned long node, const char *uname, + int depth, void *data) +{ + char *type = of_get_flat_dt_prop(node, "device_type", NULL); + __be32 *reg, *endp; + unsigned long l; + + /* We are scanning "memory" nodes only */ + if (type == NULL) { + /* + * The longtrail doesn't have a device_type on the + * /memory node, so look for the node called /memory@0. + */ + if (depth != 1 || strcmp(uname, "memory@0") != 0) + return 0; + } else if (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)); + + pr_debug("memory scan node %s, reg size %ld, data: %x %x %x %x,\n", + uname, l, reg[0], reg[1], reg[2], reg[3]); + + 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); + } + + return 0; +} + +int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, + int depth, void *data) +{ + unsigned long l; + char *p; + + pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname); + + if (depth != 1 || + (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0)) + return 0; + + early_init_dt_check_for_initrd(node); + + /* Retreive command line */ + p = of_get_flat_dt_prop(node, "bootargs", &l); + if (p != NULL && l > 0) + strlcpy(cmd_line, p, min((int)l, COMMAND_LINE_SIZE)); + +#ifdef CONFIG_CMDLINE +#ifndef CONFIG_CMDLINE_FORCE + if (p == NULL || l == 0 || (l == 1 && (*p) == 0)) +#endif + strlcpy(cmd_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE); +#endif /* CONFIG_CMDLINE */ + + early_init_dt_scan_chosen_arch(node); + + pr_debug("Command line is: %s\n", cmd_line); + + /* break now */ + return 1; +} + +/** + * 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) +{ + unsigned long start, mem, size; + struct device_node **allnextp = &allnodes; + + pr_debug(" -> unflatten_device_tree()\n"); + + /* First pass, scan for size */ + start = ((unsigned long)initial_boot_params) + + be32_to_cpu(initial_boot_params->off_dt_struct); + size = unflatten_dt_node(0, &start, NULL, NULL, 0); + size = (size | 3) + 1; + + pr_debug(" size is %lx, allocating...\n", size); + + /* Allocate memory for the expanded device tree */ + mem = early_init_dt_alloc_memory_arch(size + 4, + __alignof__(struct device_node)); + mem = (unsigned long) __va(mem); + + ((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef); + + pr_debug(" unflattening %lx...\n", mem); + + /* Second pass, do actual unflattening */ + start = ((unsigned long)initial_boot_params) + + be32_to_cpu(initial_boot_params->off_dt_struct); + unflatten_dt_node(mem, &start, NULL, &allnextp, 0); + if (be32_to_cpup((__be32 *)start) != OF_DT_END) + pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start)); + if (be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef) + pr_warning("End of tree marker overwritten: %08x\n", + be32_to_cpu(((__be32 *)mem)[size / 4])); + *allnextp = NULL; + + /* Get pointer to OF "/chosen" node for use everywhere */ + of_chosen = of_find_node_by_path("/chosen"); + if (of_chosen == NULL) + of_chosen = of_find_node_by_path("/chosen@0"); + + pr_debug(" <- unflatten_device_tree()\n"); +} |