aboutsummaryrefslogtreecommitdiff
path: root/drivers/of/fdt.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/of/fdt.c')
-rw-r--r--drivers/of/fdt.c590
1 files changed, 590 insertions, 0 deletions
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
new file mode 100644
index 00000000000..406757a9d7e
--- /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, &reg);
+ size = dt_mem_next_cell(dt_root_size_cells, &reg);
+
+ 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");
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-17 18:03:51 +0000