prom.c 51.8 KB
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/*
 * Procedures for creating, accessing and interpreting the device tree.
 *
 * Paul Mackerras	August 1996.
 * Copyright (C) 1996-2005 Paul Mackerras.
 * 
 *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
 *    {engebret|bergner}@us.ibm.com 
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#undef DEBUG

#include <stdarg.h>
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/threads.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/stringify.h>
#include <linux/delay.h>
#include <linux/initrd.h>
#include <linux/bitops.h>
#include <linux/module.h>

#include <asm/prom.h>
#include <asm/rtas.h>
#include <asm/lmb.h>
#include <asm/page.h>
#include <asm/processor.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/smp.h>
#include <asm/system.h>
#include <asm/mmu.h>
#include <asm/pgtable.h>
#include <asm/pci.h>
#include <asm/iommu.h>
#include <asm/btext.h>
#include <asm/sections.h>
#include <asm/machdep.h>
#include <asm/pSeries_reconfig.h>
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#include <asm/pci-bridge.h>
#ifdef CONFIG_PPC64
#include <asm/systemcfg.h>
#endif
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#ifdef DEBUG
#define DBG(fmt...) printk(KERN_ERR fmt)
#else
#define DBG(fmt...)
#endif

struct pci_reg_property {
	struct pci_address addr;
	u32 size_hi;
	u32 size_lo;
};

struct isa_reg_property {
	u32 space;
	u32 address;
	u32 size;
};


typedef int interpret_func(struct device_node *, unsigned long *,
			   int, int, int);

extern struct rtas_t rtas;
extern struct lmb lmb;
extern unsigned long klimit;

static int __initdata dt_root_addr_cells;
static int __initdata dt_root_size_cells;

#ifdef CONFIG_PPC64
static int __initdata iommu_is_off;
int __initdata iommu_force_on;
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unsigned long tce_alloc_start, tce_alloc_end;
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#endif

typedef u32 cell_t;

#if 0
static struct boot_param_header *initial_boot_params __initdata;
#else
struct boot_param_header *initial_boot_params;
#endif

static struct device_node *allnodes = NULL;

/* use when traversing tree through the allnext, child, sibling,
 * or parent members of struct device_node.
 */
static DEFINE_RWLOCK(devtree_lock);

/* export that to outside world */
struct device_node *of_chosen;

struct device_node *dflt_interrupt_controller;
int num_interrupt_controllers;

/*
 * Wrapper for allocating memory for various data that needs to be
 * attached to device nodes as they are processed at boot or when
 * added to the device tree later (e.g. DLPAR).  At boot there is
 * already a region reserved so we just increment *mem_start by size;
 * otherwise we call kmalloc.
 */
static void * prom_alloc(unsigned long size, unsigned long *mem_start)
{
	unsigned long tmp;

	if (!mem_start)
		return kmalloc(size, GFP_KERNEL);

	tmp = *mem_start;
	*mem_start += size;
	return (void *)tmp;
}

/*
 * Find the device_node with a given phandle.
 */
static struct device_node * find_phandle(phandle ph)
{
	struct device_node *np;

	for (np = allnodes; np != 0; np = np->allnext)
		if (np->linux_phandle == ph)
			return np;
	return NULL;
}

/*
 * Find the interrupt parent of a node.
 */
static struct device_node * __devinit intr_parent(struct device_node *p)
{
	phandle *parp;

	parp = (phandle *) get_property(p, "interrupt-parent", NULL);
	if (parp == NULL)
		return p->parent;
	p = find_phandle(*parp);
	if (p != NULL)
		return p;
	/*
	 * On a powermac booted with BootX, we don't get to know the
	 * phandles for any nodes, so find_phandle will return NULL.
	 * Fortunately these machines only have one interrupt controller
	 * so there isn't in fact any ambiguity.  -- paulus
	 */
	if (num_interrupt_controllers == 1)
		p = dflt_interrupt_controller;
	return p;
}

/*
 * Find out the size of each entry of the interrupts property
 * for a node.
 */
int __devinit prom_n_intr_cells(struct device_node *np)
{
	struct device_node *p;
	unsigned int *icp;

	for (p = np; (p = intr_parent(p)) != NULL; ) {
		icp = (unsigned int *)
			get_property(p, "#interrupt-cells", NULL);
		if (icp != NULL)
			return *icp;
		if (get_property(p, "interrupt-controller", NULL) != NULL
		    || get_property(p, "interrupt-map", NULL) != NULL) {
			printk("oops, node %s doesn't have #interrupt-cells\n",
			       p->full_name);
			return 1;
		}
	}
#ifdef DEBUG_IRQ
	printk("prom_n_intr_cells failed for %s\n", np->full_name);
#endif
	return 1;
}

/*
 * Map an interrupt from a device up to the platform interrupt
 * descriptor.
 */
static int __devinit map_interrupt(unsigned int **irq, struct device_node **ictrler,
				   struct device_node *np, unsigned int *ints,
				   int nintrc)
{
	struct device_node *p, *ipar;
	unsigned int *imap, *imask, *ip;
	int i, imaplen, match;
	int newintrc = 0, newaddrc = 0;
	unsigned int *reg;
	int naddrc;

	reg = (unsigned int *) get_property(np, "reg", NULL);
	naddrc = prom_n_addr_cells(np);
	p = intr_parent(np);
	while (p != NULL) {
		if (get_property(p, "interrupt-controller", NULL) != NULL)
			/* this node is an interrupt controller, stop here */
			break;
		imap = (unsigned int *)
			get_property(p, "interrupt-map", &imaplen);
		if (imap == NULL) {
			p = intr_parent(p);
			continue;
		}
		imask = (unsigned int *)
			get_property(p, "interrupt-map-mask", NULL);
		if (imask == NULL) {
			printk("oops, %s has interrupt-map but no mask\n",
			       p->full_name);
			return 0;
		}
		imaplen /= sizeof(unsigned int);
		match = 0;
		ipar = NULL;
		while (imaplen > 0 && !match) {
			/* check the child-interrupt field */
			match = 1;
			for (i = 0; i < naddrc && match; ++i)
				match = ((reg[i] ^ imap[i]) & imask[i]) == 0;
			for (; i < naddrc + nintrc && match; ++i)
				match = ((ints[i-naddrc] ^ imap[i]) & imask[i]) == 0;
			imap += naddrc + nintrc;
			imaplen -= naddrc + nintrc;
			/* grab the interrupt parent */
			ipar = find_phandle((phandle) *imap++);
			--imaplen;
			if (ipar == NULL && num_interrupt_controllers == 1)
				/* cope with BootX not giving us phandles */
				ipar = dflt_interrupt_controller;
			if (ipar == NULL) {
				printk("oops, no int parent %x in map of %s\n",
				       imap[-1], p->full_name);
				return 0;
			}
			/* find the parent's # addr and intr cells */
			ip = (unsigned int *)
				get_property(ipar, "#interrupt-cells", NULL);
			if (ip == NULL) {
				printk("oops, no #interrupt-cells on %s\n",
				       ipar->full_name);
				return 0;
			}
			newintrc = *ip;
			ip = (unsigned int *)
				get_property(ipar, "#address-cells", NULL);
			newaddrc = (ip == NULL)? 0: *ip;
			imap += newaddrc + newintrc;
			imaplen -= newaddrc + newintrc;
		}
		if (imaplen < 0) {
			printk("oops, error decoding int-map on %s, len=%d\n",
			       p->full_name, imaplen);
			return 0;
		}
		if (!match) {
#ifdef DEBUG_IRQ
			printk("oops, no match in %s int-map for %s\n",
			       p->full_name, np->full_name);
#endif
			return 0;
		}
		p = ipar;
		naddrc = newaddrc;
		nintrc = newintrc;
		ints = imap - nintrc;
		reg = ints - naddrc;
	}
	if (p == NULL) {
#ifdef DEBUG_IRQ
		printk("hmmm, int tree for %s doesn't have ctrler\n",
		       np->full_name);
#endif
		return 0;
	}
	*irq = ints;
	*ictrler = p;
	return nintrc;
}

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static unsigned char map_isa_senses[4] = {
	IRQ_SENSE_LEVEL | IRQ_POLARITY_NEGATIVE,
	IRQ_SENSE_LEVEL | IRQ_POLARITY_POSITIVE,
	IRQ_SENSE_EDGE  | IRQ_POLARITY_NEGATIVE,
	IRQ_SENSE_EDGE  | IRQ_POLARITY_POSITIVE
};

static unsigned char map_mpic_senses[4] = {
	IRQ_SENSE_EDGE  | IRQ_POLARITY_POSITIVE,
	IRQ_SENSE_LEVEL | IRQ_POLARITY_NEGATIVE,
	/* 2 seems to be used for the 8259 cascade... */
	IRQ_SENSE_LEVEL | IRQ_POLARITY_POSITIVE,
	IRQ_SENSE_EDGE  | IRQ_POLARITY_NEGATIVE,
};

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static int __devinit finish_node_interrupts(struct device_node *np,
					    unsigned long *mem_start,
					    int measure_only)
{
	unsigned int *ints;
	int intlen, intrcells, intrcount;
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	int i, j, n, sense;
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	unsigned int *irq, virq;
	struct device_node *ic;

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	if (num_interrupt_controllers == 0) {
		/*
		 * Old machines just have a list of interrupt numbers
		 * and no interrupt-controller nodes.
		 */
		ints = (unsigned int *) get_property(np, "AAPL,interrupts",
						     &intlen);
		/* XXX old interpret_pci_props looked in parent too */
		/* XXX old interpret_macio_props looked for interrupts
		   before AAPL,interrupts */
		if (ints == NULL)
			ints = (unsigned int *) get_property(np, "interrupts",
							     &intlen);
		if (ints == NULL)
			return 0;

		np->n_intrs = intlen / sizeof(unsigned int);
		np->intrs = prom_alloc(np->n_intrs * sizeof(np->intrs[0]),
				       mem_start);
		if (!np->intrs)
			return -ENOMEM;
		if (measure_only)
			return 0;

		for (i = 0; i < np->n_intrs; ++i) {
			np->intrs[i].line = *ints++;
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			np->intrs[i].sense = IRQ_SENSE_LEVEL
				| IRQ_POLARITY_NEGATIVE;
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		}
		return 0;
	}

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	ints = (unsigned int *) get_property(np, "interrupts", &intlen);
	if (ints == NULL)
		return 0;
	intrcells = prom_n_intr_cells(np);
	intlen /= intrcells * sizeof(unsigned int);

	np->intrs = prom_alloc(intlen * sizeof(*(np->intrs)), mem_start);
	if (!np->intrs)
		return -ENOMEM;

	if (measure_only)
		return 0;

	intrcount = 0;
	for (i = 0; i < intlen; ++i, ints += intrcells) {
		n = map_interrupt(&irq, &ic, np, ints, intrcells);
		if (n <= 0)
			continue;

		/* don't map IRQ numbers under a cascaded 8259 controller */
		if (ic && device_is_compatible(ic, "chrp,iic")) {
			np->intrs[intrcount].line = irq[0];
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			sense = (n > 1)? (irq[1] & 3): 3;
			np->intrs[intrcount].sense = map_isa_senses[sense];
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		} else {
			virq = virt_irq_create_mapping(irq[0]);
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#ifdef CONFIG_PPC64
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			if (virq == NO_IRQ) {
				printk(KERN_CRIT "Could not allocate interrupt"
				       " number for %s\n", np->full_name);
				continue;
			}
#endif
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			np->intrs[intrcount].line = irq_offset_up(virq);
			sense = (n > 1)? (irq[1] & 3): 1;
			np->intrs[intrcount].sense = map_mpic_senses[sense];
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		}

#ifdef CONFIG_PPC64
		/* We offset irq numbers for the u3 MPIC by 128 in PowerMac */
		if (systemcfg->platform == PLATFORM_POWERMAC && ic && ic->parent) {
			char *name = get_property(ic->parent, "name", NULL);
			if (name && !strcmp(name, "u3"))
				np->intrs[intrcount].line += 128;
			else if (!(name && !strcmp(name, "mac-io")))
				/* ignore other cascaded controllers, such as
				   the k2-sata-root */
				break;
		}
#endif
		if (n > 2) {
			printk("hmmm, got %d intr cells for %s:", n,
			       np->full_name);
			for (j = 0; j < n; ++j)
				printk(" %d", irq[j]);
			printk("\n");
		}
		++intrcount;
	}
	np->n_intrs = intrcount;

	return 0;
}

static int __devinit interpret_pci_props(struct device_node *np,
					 unsigned long *mem_start,
					 int naddrc, int nsizec,
					 int measure_only)
{
	struct address_range *adr;
	struct pci_reg_property *pci_addrs;
	int i, l, n_addrs;

	pci_addrs = (struct pci_reg_property *)
		get_property(np, "assigned-addresses", &l);
	if (!pci_addrs)
		return 0;

	n_addrs = l / sizeof(*pci_addrs);

	adr = prom_alloc(n_addrs * sizeof(*adr), mem_start);
	if (!adr)
		return -ENOMEM;

 	if (measure_only)
 		return 0;

 	np->addrs = adr;
 	np->n_addrs = n_addrs;

 	for (i = 0; i < n_addrs; i++) {
 		adr[i].space = pci_addrs[i].addr.a_hi;
 		adr[i].address = pci_addrs[i].addr.a_lo |
			((u64)pci_addrs[i].addr.a_mid << 32);
 		adr[i].size = pci_addrs[i].size_lo;
	}

	return 0;
}

static int __init interpret_dbdma_props(struct device_node *np,
					unsigned long *mem_start,
					int naddrc, int nsizec,
					int measure_only)
{
	struct reg_property32 *rp;
	struct address_range *adr;
	unsigned long base_address;
	int i, l;
	struct device_node *db;

	base_address = 0;
	if (!measure_only) {
		for (db = np->parent; db != NULL; db = db->parent) {
			if (!strcmp(db->type, "dbdma") && db->n_addrs != 0) {
				base_address = db->addrs[0].address;
				break;
			}
		}
	}

	rp = (struct reg_property32 *) get_property(np, "reg", &l);
	if (rp != 0 && l >= sizeof(struct reg_property32)) {
		i = 0;
		adr = (struct address_range *) (*mem_start);
		while ((l -= sizeof(struct reg_property32)) >= 0) {
			if (!measure_only) {
				adr[i].space = 2;
				adr[i].address = rp[i].address + base_address;
				adr[i].size = rp[i].size;
			}
			++i;
		}
		np->addrs = adr;
		np->n_addrs = i;
		(*mem_start) += i * sizeof(struct address_range);
	}

	return 0;
}

static int __init interpret_macio_props(struct device_node *np,
					unsigned long *mem_start,
					int naddrc, int nsizec,
					int measure_only)
{
	struct reg_property32 *rp;
	struct address_range *adr;
	unsigned long base_address;
	int i, l;
	struct device_node *db;

	base_address = 0;
	if (!measure_only) {
		for (db = np->parent; db != NULL; db = db->parent) {
			if (!strcmp(db->type, "mac-io") && db->n_addrs != 0) {
				base_address = db->addrs[0].address;
				break;
			}
		}
	}

	rp = (struct reg_property32 *) get_property(np, "reg", &l);
	if (rp != 0 && l >= sizeof(struct reg_property32)) {
		i = 0;
		adr = (struct address_range *) (*mem_start);
		while ((l -= sizeof(struct reg_property32)) >= 0) {
			if (!measure_only) {
				adr[i].space = 2;
				adr[i].address = rp[i].address + base_address;
				adr[i].size = rp[i].size;
			}
			++i;
		}
		np->addrs = adr;
		np->n_addrs = i;
		(*mem_start) += i * sizeof(struct address_range);
	}

	return 0;
}

static int __init interpret_isa_props(struct device_node *np,
				      unsigned long *mem_start,
				      int naddrc, int nsizec,
				      int measure_only)
{
	struct isa_reg_property *rp;
	struct address_range *adr;
	int i, l;

	rp = (struct isa_reg_property *) get_property(np, "reg", &l);
	if (rp != 0 && l >= sizeof(struct isa_reg_property)) {
		i = 0;
		adr = (struct address_range *) (*mem_start);
		while ((l -= sizeof(struct isa_reg_property)) >= 0) {
			if (!measure_only) {
				adr[i].space = rp[i].space;
				adr[i].address = rp[i].address;
				adr[i].size = rp[i].size;
			}
			++i;
		}
		np->addrs = adr;
		np->n_addrs = i;
		(*mem_start) += i * sizeof(struct address_range);
	}

	return 0;
}

static int __init interpret_root_props(struct device_node *np,
				       unsigned long *mem_start,
				       int naddrc, int nsizec,
				       int measure_only)
{
	struct address_range *adr;
	int i, l;
	unsigned int *rp;
	int rpsize = (naddrc + nsizec) * sizeof(unsigned int);

	rp = (unsigned int *) get_property(np, "reg", &l);
	if (rp != 0 && l >= rpsize) {
		i = 0;
		adr = (struct address_range *) (*mem_start);
		while ((l -= rpsize) >= 0) {
			if (!measure_only) {
				adr[i].space = 0;
				adr[i].address = rp[naddrc - 1];
				adr[i].size = rp[naddrc + nsizec - 1];
			}
			++i;
			rp += naddrc + nsizec;
		}
		np->addrs = adr;
		np->n_addrs = i;
		(*mem_start) += i * sizeof(struct address_range);
	}

	return 0;
}

static int __devinit finish_node(struct device_node *np,
				 unsigned long *mem_start,
				 interpret_func *ifunc,
				 int naddrc, int nsizec,
				 int measure_only)
{
	struct device_node *child;
	int *ip, rc = 0;

	/* get the device addresses and interrupts */
	if (ifunc != NULL)
		rc = ifunc(np, mem_start, naddrc, nsizec, measure_only);
	if (rc)
		goto out;

	rc = finish_node_interrupts(np, mem_start, measure_only);
	if (rc)
		goto out;

	/* Look for #address-cells and #size-cells properties. */
	ip = (int *) get_property(np, "#address-cells", NULL);
	if (ip != NULL)
		naddrc = *ip;
	ip = (int *) get_property(np, "#size-cells", NULL);
	if (ip != NULL)
		nsizec = *ip;

	if (!strcmp(np->name, "device-tree") || np->parent == NULL)
		ifunc = interpret_root_props;
	else if (np->type == 0)
		ifunc = NULL;
	else if (!strcmp(np->type, "pci") || !strcmp(np->type, "vci"))
		ifunc = interpret_pci_props;
	else if (!strcmp(np->type, "dbdma"))
		ifunc = interpret_dbdma_props;
	else if (!strcmp(np->type, "mac-io") || ifunc == interpret_macio_props)
		ifunc = interpret_macio_props;
	else if (!strcmp(np->type, "isa"))
		ifunc = interpret_isa_props;
	else if (!strcmp(np->name, "uni-n") || !strcmp(np->name, "u3"))
		ifunc = interpret_root_props;
	else if (!((ifunc == interpret_dbdma_props
		    || ifunc == interpret_macio_props)
		   && (!strcmp(np->type, "escc")
		       || !strcmp(np->type, "media-bay"))))
		ifunc = NULL;

	for (child = np->child; child != NULL; child = child->sibling) {
		rc = finish_node(child, mem_start, ifunc,
				 naddrc, nsizec, measure_only);
		if (rc)
			goto out;
	}
out:
	return rc;
}

static void __init scan_interrupt_controllers(void)
{
	struct device_node *np;
	int n = 0;
	char *name, *ic;
	int iclen;

	for (np = allnodes; np != NULL; np = np->allnext) {
		ic = get_property(np, "interrupt-controller", &iclen);
		name = get_property(np, "name", NULL);
		/* checking iclen makes sure we don't get a false
		   match on /chosen.interrupt_controller */
		if ((name != NULL
		     && strcmp(name, "interrupt-controller") == 0)
		    || (ic != NULL && iclen == 0
			&& strcmp(name, "AppleKiwi"))) {
			if (n == 0)
				dflt_interrupt_controller = np;
			++n;
		}
	}
	num_interrupt_controllers = n;
}

/**
 * finish_device_tree is called once things are running normally
 * (i.e. with text and data mapped to the address they were linked at).
 * It traverses the device tree and fills in some of the additional,
 * fields in each node like {n_}addrs and {n_}intrs, the virt interrupt
 * mapping is also initialized at this point.
 */
void __init finish_device_tree(void)
{
	unsigned long start, end, size = 0;

	DBG(" -> finish_device_tree\n");

#ifdef CONFIG_PPC64
	/* Initialize virtual IRQ map */
	virt_irq_init();
#endif
	scan_interrupt_controllers();

	/*
	 * Finish device-tree (pre-parsing some properties etc...)
	 * We do this in 2 passes. One with "measure_only" set, which
	 * will only measure the amount of memory needed, then we can
	 * allocate that memory, and call finish_node again. However,
	 * we must be careful as most routines will fail nowadays when
	 * prom_alloc() returns 0, so we must make sure our first pass
	 * doesn't start at 0. We pre-initialize size to 16 for that
	 * reason and then remove those additional 16 bytes
	 */
	size = 16;
	finish_node(allnodes, &size, NULL, 0, 0, 1);
	size -= 16;
	end = start = (unsigned long) __va(lmb_alloc(size, 128));
	finish_node(allnodes, &end, NULL, 0, 0, 0);
	BUG_ON(end != start + size);

	DBG(" <- finish_device_tree\n");
}

static inline char *find_flat_dt_string(u32 offset)
{
	return ((char *)initial_boot_params) +
		initial_boot_params->off_dt_strings + offset;
}

/**
 * This function is used to scan the flattened device-tree, it is
 * used to extract the memory informations at boot before we can
 * unflatten the tree
 */
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int __init of_scan_flat_dt(int (*it)(unsigned long node,
				     const char *uname, int depth,
				     void *data),
			   void *data)
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{
	unsigned long p = ((unsigned long)initial_boot_params) +
		initial_boot_params->off_dt_struct;
	int rc = 0;
	int depth = -1;

	do {
		u32 tag = *((u32 *)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 = *((u32 *)p);
			p += 8;
			if (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) {
			printk(KERN_WARNING "Invalid tag %x scanning flattened"
			       " 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;
}

/**
 * This  function can be used within scan_flattened_dt callback to get
 * access to properties
 */
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void* __init of_get_flat_dt_prop(unsigned long node, const char *name,
				 unsigned long *size)
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{
	unsigned long p = node;

	do {
		u32 tag = *((u32 *)p);
		u32 sz, noff;
		const char *nstr;

		p += 4;
		if (tag == OF_DT_NOP)
			continue;
		if (tag != OF_DT_PROP)
			return NULL;

		sz = *((u32 *)p);
		noff = *((u32 *)(p + 4));
		p += 8;
		if (initial_boot_params->version < 0x10)
			p = _ALIGN(p, sz >= 8 ? 8 : 4);

		nstr = find_flat_dt_string(noff);
		if (nstr == NULL) {
			printk(KERN_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);
}

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;
}

static 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 = *((u32 *)(*p));
	if (tag != OF_DT_BEGIN_NODE) {
		printk("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 *p = np->full_name;
			/* rebuild full path for new format */
			if (dad && dad->parent) {
				strcpy(p, dad->full_name);
#ifdef DEBUG
				if ((strlen(p) + l + 1) != allocl) {
					DBG("%s: p: %d, l: %d, a: %d\n",
					    pathp, strlen(p), l, allocl);
				}
#endif
				p += strlen(p);
			}
			*(p++) = '/';
			memcpy(p, 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 == 0)
				dad->child = np;
			else
				dad->next->sibling = np;
			dad->next = np;
		}
		kref_init(&np->kref);
	}
	while(1) {
		u32 sz, noff;
		char *pname;

		tag = *((u32 *)(*p));
		if (tag == OF_DT_NOP) {
			*p += 4;
			continue;
		}
		if (tag != OF_DT_PROP)
			break;
		*p += 4;
		sz = *((u32 *)(*p));
		noff = *((u32 *)((*p) + 4));
		*p += 8;
		if (initial_boot_params->version < 0x10)
			*p = _ALIGN(*p, sz >= 8 ? 8 : 4);

		pname = find_flat_dt_string(noff);
		if (pname == NULL) {
			printk("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) {
			if (strcmp(pname, "linux,phandle") == 0) {
				np->node = *((u32 *)*p);
				if (np->linux_phandle == 0)
					np->linux_phandle = np->node;
			}
			if (strcmp(pname, "ibm,phandle") == 0)
				np->linux_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 *p = pathp, *ps = pathp, *pa = NULL;
		int sz;

		while (*p) {
			if ((*p) == '@')
				pa = p;
			if ((*p) == '/')
				ps = p + 1;
			p++;
		}
		if (pa < ps)
			pa = p;
		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 = (unsigned char *)(pp + 1);
			*prev_pp = pp;
			prev_pp = &pp->next;
			memcpy(pp->value, ps, sz - 1);
			((char *)pp->value)[sz - 1] = 0;
			DBG("fixed up name for %s -> %s\n", pathp, pp->value);
		}
	}
	if (allnextpp) {
		*prev_pp = NULL;
		np->name = get_property(np, "name", NULL);
		np->type = get_property(np, "device_type", NULL);