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, &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");
+}