Patchwork [5/5] x86: OLPC: add OLPC device-tree support

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Submitter Andres Salomon
Date Oct. 10, 2010, 9:06 a.m.
Message ID <20101010020626.102437f5@debxo>
Download mbox | patch
Permalink /patch/67343/
State Not Applicable
Delegated to: David Miller
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Comments

Andres Salomon - Oct. 10, 2010, 9:06 a.m.
Make use of PROC_DEVICETREE to export the tree, and sparc's PROMTREE code to
call into OLPC's Open Firmware to build the tree.

Signed-off-by: Andres Salomon <dilinger@queued.net>
---
 arch/x86/Kconfig                |    2 +
 arch/x86/include/asm/olpc_ofw.h |    4 +
 arch/x86/include/asm/prom.h     |    1 +
 arch/x86/kernel/Makefile        |    1 +
 arch/x86/kernel/olpc_ofw.c      |    8 ++
 arch/x86/kernel/olpc_prom.c     |  152 +++++++++++++++++++++++++++++++++++++++
 drivers/of/pdt.c                |    2 +
 fs/proc/proc_devtree.c          |    4 +
 include/linux/of_pdt.h          |    1 +
 9 files changed, 175 insertions(+), 0 deletions(-)
 create mode 100644 arch/x86/include/asm/prom.h
 create mode 100644 arch/x86/kernel/olpc_prom.c
Grant Likely - Oct. 11, 2010, 4:13 a.m.
On Sun, Oct 10, 2010 at 02:06:26AM -0700, Andres Salomon wrote:
> 
> Make use of PROC_DEVICETREE to export the tree, and sparc's PROMTREE code to
> call into OLPC's Open Firmware to build the tree.
> 
> Signed-off-by: Andres Salomon <dilinger@queued.net>

Holding off on this one until I hear from the x86 maintainers [cc'd].

g.

> ---
>  arch/x86/Kconfig                |    2 +
>  arch/x86/include/asm/olpc_ofw.h |    4 +
>  arch/x86/include/asm/prom.h     |    1 +
>  arch/x86/kernel/Makefile        |    1 +
>  arch/x86/kernel/olpc_ofw.c      |    8 ++
>  arch/x86/kernel/olpc_prom.c     |  152 +++++++++++++++++++++++++++++++++++++++
>  drivers/of/pdt.c                |    2 +
>  fs/proc/proc_devtree.c          |    4 +
>  include/linux/of_pdt.h          |    1 +
>  9 files changed, 175 insertions(+), 0 deletions(-)
>  create mode 100644 arch/x86/include/asm/prom.h
>  create mode 100644 arch/x86/kernel/olpc_prom.c
> 
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index cea0cd9..7d4ef72 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -2069,6 +2069,8 @@ config OLPC_OPENFIRMWARE
>  	bool "Support for OLPC's Open Firmware"
>  	depends on !X86_64 && !X86_PAE
>  	default y if OLPC
> +	select OF
> +	select OF_PROMTREE
>  	help
>  	  This option adds support for the implementation of Open Firmware
>  	  that is used on the OLPC XO-1 Children's Machine.
> diff --git a/arch/x86/include/asm/olpc_ofw.h b/arch/x86/include/asm/olpc_ofw.h
> index 08fde47..13075df 100644
> --- a/arch/x86/include/asm/olpc_ofw.h
> +++ b/arch/x86/include/asm/olpc_ofw.h
> @@ -28,4 +28,8 @@ static inline void setup_olpc_ofw_pgd(void) { }
>  
>  #endif /* !CONFIG_OLPC_OPENFIRMWARE */
>  
> +#ifdef CONFIG_PROC_DEVICETREE
> +extern void olpc_prom_build_devicetree(void);
> +#endif /* CONFIG_PROC_DEVICETREE */
> +
>  #endif /* _ASM_X86_OLPC_OFW_H */
> diff --git a/arch/x86/include/asm/prom.h b/arch/x86/include/asm/prom.h
> new file mode 100644
> index 0000000..b4ec95f
> --- /dev/null
> +++ b/arch/x86/include/asm/prom.h
> @@ -0,0 +1 @@
> +/* dummy prom.h; here to make linux/of.h's #includes happy */
> diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
> index fedf32a..ced0c9a 100644
> --- a/arch/x86/kernel/Makefile
> +++ b/arch/x86/kernel/Makefile
> @@ -107,6 +107,7 @@ scx200-y			+= scx200_32.o
>  
>  obj-$(CONFIG_OLPC)		+= olpc.o
>  obj-$(CONFIG_OLPC_OPENFIRMWARE)	+= olpc_ofw.o
> +obj-$(CONFIG_PROC_DEVICETREE)	+= olpc_prom.o
>  obj-$(CONFIG_X86_MRST)		+= mrst.o
>  
>  microcode-y				:= microcode_core.o
> diff --git a/arch/x86/kernel/olpc_ofw.c b/arch/x86/kernel/olpc_ofw.c
> index 3218aa7..6c4d243 100644
> --- a/arch/x86/kernel/olpc_ofw.c
> +++ b/arch/x86/kernel/olpc_ofw.c
> @@ -1,5 +1,7 @@
>  #include <linux/kernel.h>
>  #include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_pdt.h>
>  #include <linux/init.h>
>  #include <asm/page.h>
>  #include <asm/setup.h>
> @@ -38,6 +40,12 @@ void __init setup_olpc_ofw_pgd(void)
>  	/* implicit optimization barrier here due to uninline function return */
>  
>  	early_iounmap(base, sizeof(olpc_ofw_pgd) * PTRS_PER_PGD);
> +
> +#ifdef CONFIG_PROC_DEVICETREE
> +	/* OFW set up succesfully; use it for the device tree */
> +	of_pdt_init_devicetree = olpc_prom_build_devicetree;
> +#endif
> +
>  }
>  
>  int __olpc_ofw(const char *name, int nr_args, const void **args, int nr_res,
> diff --git a/arch/x86/kernel/olpc_prom.c b/arch/x86/kernel/olpc_prom.c
> new file mode 100644
> index 0000000..e2ecaf2
> --- /dev/null
> +++ b/arch/x86/kernel/olpc_prom.c
> @@ -0,0 +1,152 @@
> +/*
> + * olpc_prom.c: OLPC-specific OFW device tree support code.
> + *
> + * 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
> + *
> + *  Adapted for sparc by David S. Miller davem@davemloft.net
> + *  Adapted for x86/OLPC by Andres Salomon <dilinger@queued.net>
> + *
> + *      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.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/errno.h>
> +#include <linux/slab.h>
> +#include <linux/of.h>
> +#include <linux/of_pdt.h>
> +#include <asm/olpc_ofw.h>
> +
> +static phandle __init olpc_prom_getsibling(phandle node)
> +{
> +	const void *args[] = { (void *)node };
> +	void *res[] = { &node };
> +
> +	if (node == -1)
> +		return 0;
> +
> +	if (olpc_ofw("peer", args, res) || node == -1)
> +		return 0;
> +
> +	return node;
> +}
> +
> +static phandle __init olpc_prom_getchild(phandle node)
> +{
> +	const void *args[] = { (void *)node };
> +	void *res[] = { &node };
> +
> +	if (node == -1)
> +		return 0;
> +
> +	if (olpc_ofw("child", args, res) || node == -1) {
> +		pr_err("PROM: %s: fetching child failed!\n", __func__);
> +		return 0;
> +	}
> +
> +	return node;
> +}
> +
> +static int __init olpc_prom_getproplen(phandle node, const char *prop)
> +{
> +	const void *args[] = { (void *)node, prop };
> +	int len;
> +	void *res[] = { &len };
> +
> +	if (node == -1)
> +		return -1;
> +
> +	if (olpc_ofw("getproplen", args, res)) {
> +		pr_err("PROM: %s: getproplen failed!\n", __func__);
> +		return -1;
> +	}
> +
> +	return len;
> +}
> +
> +static int __init olpc_prom_getproperty(phandle node, const char *prop,
> +		char *buf, int bufsize)
> +{
> +	int plen;
> +
> +	plen = olpc_prom_getproplen(node, prop);
> +	if (plen > bufsize || plen < 1)
> +		return -1;
> +	else {
> +		const void *args[] = { (void *)node, prop, buf, (void *)plen };
> +		void *res[] = { &plen };
> +
> +		if (olpc_ofw("getprop", args, res)) {
> +			pr_err("PROM: %s: getprop failed!\n", __func__);
> +			return -1;
> +		}
> +	}
> +
> +	return plen;
> +}
> +
> +static int __init olpc_prom_nextprop(phandle node, char *prev, char *buf)
> +{
> +	const void *args[] = { (void *)node, prev, buf };
> +	int success;
> +	void *res[] = { &success };
> +
> +	buf[0] = '\0';
> +
> +	if (node == -1)
> +		return -1;
> +
> +	if (olpc_ofw("nextprop", args, res) || success != 1)
> +		return -1;
> +
> +	return 0;
> +}
> +
> +static int __init olpc_prom_pkg2path(phandle node, char *buf,
> +		const int buflen, int *len)
> +{
> +	const void *args[] = { (void *)node, buf, (void *)buflen };
> +	void *res[] = { len };
> +
> +	if (node == -1)
> +		return -1;
> +
> +	if (olpc_ofw("package-to-path", args, res) || *len < 1)
> +		return -1;
> +
> +	return 0;
> +}
> +
> +void * __init prom_early_alloc(unsigned long size)
> +{
> +	/* this is called late enough that we can alloc normally */
> +	return kzalloc(size, GFP_KERNEL);
> +}
> +
> +static struct of_pdt_ops prom_olpc_ops __initdata = {
> +	.nextprop = olpc_prom_nextprop,
> +	.getproplen = olpc_prom_getproplen,
> +	.getproperty = olpc_prom_getproperty,
> +	.getchild = olpc_prom_getchild,
> +	.getsibling = olpc_prom_getsibling,
> +	.pkg2path = olpc_prom_pkg2path,
> +};
> +
> +void __init olpc_prom_build_devicetree(void)
> +{
> +	phandle root;
> +
> +	root = olpc_prom_getsibling(0);
> +	if (root < 0) {
> +		pr_err("PROM: unable to get root node from OFW!\n");
> +		return;
> +	}
> +	of_pdt_build_devicetree(root, &prom_olpc_ops);
> +}
> diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
> index 28295d0..07e3daa 100644
> --- a/drivers/of/pdt.c
> +++ b/drivers/of/pdt.c
> @@ -29,6 +29,8 @@ static struct of_pdt_ops *of_pdt_prom_ops __initdata;
>  void __initdata (*of_pdt_build_more)(struct device_node *dp,
>  		struct device_node ***nextp);
>  
> +void __initdata (*of_pdt_init_devicetree)(void);
> +
>  #if defined(CONFIG_SPARC)
>  unsigned int of_pdt_unique_id __initdata;
>  
> diff --git a/fs/proc/proc_devtree.c b/fs/proc/proc_devtree.c
> index d9396a4..9779039 100644
> --- a/fs/proc/proc_devtree.c
> +++ b/fs/proc/proc_devtree.c
> @@ -11,6 +11,7 @@
>  #include <linux/stat.h>
>  #include <linux/string.h>
>  #include <linux/of.h>
> +#include <linux/of_pdt.h>
>  #include <linux/module.h>
>  #include <linux/slab.h>
>  #include <asm/prom.h>
> @@ -228,6 +229,9 @@ void __init proc_device_tree_init(void)
>  {
>  	struct device_node *root;
>  
> +	if (of_pdt_init_devicetree)
> +		of_pdt_init_devicetree();
> +
>  	proc_device_tree = proc_mkdir("device-tree", NULL);
>  	if (proc_device_tree == NULL)
>  		return;
> diff --git a/include/linux/of_pdt.h b/include/linux/of_pdt.h
> index c65a18a..5b29aef 100644
> --- a/include/linux/of_pdt.h
> +++ b/include/linux/of_pdt.h
> @@ -38,6 +38,7 @@ extern void *prom_early_alloc(unsigned long size);
>  
>  /* for building the device tree */
>  extern void of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops);
> +extern void (*of_pdt_init_devicetree)(void);
>  
>  extern void (*of_pdt_build_more)(struct device_node *dp,
>  		struct device_node ***nextp);
> -- 
> 1.5.6.5
> 
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Grant Likely - Oct. 20, 2010, 6:56 p.m.
On Sun, Oct 10, 2010 at 10:13 PM, Grant Likely
<grant.likely@secretlab.ca> wrote:
> On Sun, Oct 10, 2010 at 02:06:26AM -0700, Andres Salomon wrote:
>>
>> Make use of PROC_DEVICETREE to export the tree, and sparc's PROMTREE code to
>> call into OLPC's Open Firmware to build the tree.
>>
>> Signed-off-by: Andres Salomon <dilinger@queued.net>
>
> Holding off on this one until I hear from the x86 maintainers [cc'd].

Oops, and it appears that patch breaks the build on other
architectures when CONFIG_OF is enabled and CONFIG_PROMTREE is not due
to how of_pdt_init_devicetree is defined.

g.

>
> g.
>
>> ---
>>  arch/x86/Kconfig                |    2 +
>>  arch/x86/include/asm/olpc_ofw.h |    4 +
>>  arch/x86/include/asm/prom.h     |    1 +
>>  arch/x86/kernel/Makefile        |    1 +
>>  arch/x86/kernel/olpc_ofw.c      |    8 ++
>>  arch/x86/kernel/olpc_prom.c     |  152 +++++++++++++++++++++++++++++++++++++++
>>  drivers/of/pdt.c                |    2 +
>>  fs/proc/proc_devtree.c          |    4 +
>>  include/linux/of_pdt.h          |    1 +
>>  9 files changed, 175 insertions(+), 0 deletions(-)
>>  create mode 100644 arch/x86/include/asm/prom.h
>>  create mode 100644 arch/x86/kernel/olpc_prom.c
>>
>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>> index cea0cd9..7d4ef72 100644
>> --- a/arch/x86/Kconfig
>> +++ b/arch/x86/Kconfig
>> @@ -2069,6 +2069,8 @@ config OLPC_OPENFIRMWARE
>>       bool "Support for OLPC's Open Firmware"
>>       depends on !X86_64 && !X86_PAE
>>       default y if OLPC
>> +     select OF
>> +     select OF_PROMTREE
>>       help
>>         This option adds support for the implementation of Open Firmware
>>         that is used on the OLPC XO-1 Children's Machine.
>> diff --git a/arch/x86/include/asm/olpc_ofw.h b/arch/x86/include/asm/olpc_ofw.h
>> index 08fde47..13075df 100644
>> --- a/arch/x86/include/asm/olpc_ofw.h
>> +++ b/arch/x86/include/asm/olpc_ofw.h
>> @@ -28,4 +28,8 @@ static inline void setup_olpc_ofw_pgd(void) { }
>>
>>  #endif /* !CONFIG_OLPC_OPENFIRMWARE */
>>
>> +#ifdef CONFIG_PROC_DEVICETREE
>> +extern void olpc_prom_build_devicetree(void);
>> +#endif /* CONFIG_PROC_DEVICETREE */
>> +
>>  #endif /* _ASM_X86_OLPC_OFW_H */
>> diff --git a/arch/x86/include/asm/prom.h b/arch/x86/include/asm/prom.h
>> new file mode 100644
>> index 0000000..b4ec95f
>> --- /dev/null
>> +++ b/arch/x86/include/asm/prom.h
>> @@ -0,0 +1 @@
>> +/* dummy prom.h; here to make linux/of.h's #includes happy */
>> diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
>> index fedf32a..ced0c9a 100644
>> --- a/arch/x86/kernel/Makefile
>> +++ b/arch/x86/kernel/Makefile
>> @@ -107,6 +107,7 @@ scx200-y                  += scx200_32.o
>>
>>  obj-$(CONFIG_OLPC)           += olpc.o
>>  obj-$(CONFIG_OLPC_OPENFIRMWARE)      += olpc_ofw.o
>> +obj-$(CONFIG_PROC_DEVICETREE)        += olpc_prom.o
>>  obj-$(CONFIG_X86_MRST)               += mrst.o
>>
>>  microcode-y                          := microcode_core.o
>> diff --git a/arch/x86/kernel/olpc_ofw.c b/arch/x86/kernel/olpc_ofw.c
>> index 3218aa7..6c4d243 100644
>> --- a/arch/x86/kernel/olpc_ofw.c
>> +++ b/arch/x86/kernel/olpc_ofw.c
>> @@ -1,5 +1,7 @@
>>  #include <linux/kernel.h>
>>  #include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_pdt.h>
>>  #include <linux/init.h>
>>  #include <asm/page.h>
>>  #include <asm/setup.h>
>> @@ -38,6 +40,12 @@ void __init setup_olpc_ofw_pgd(void)
>>       /* implicit optimization barrier here due to uninline function return */
>>
>>       early_iounmap(base, sizeof(olpc_ofw_pgd) * PTRS_PER_PGD);
>> +
>> +#ifdef CONFIG_PROC_DEVICETREE
>> +     /* OFW set up succesfully; use it for the device tree */
>> +     of_pdt_init_devicetree = olpc_prom_build_devicetree;
>> +#endif
>> +
>>  }
>>
>>  int __olpc_ofw(const char *name, int nr_args, const void **args, int nr_res,
>> diff --git a/arch/x86/kernel/olpc_prom.c b/arch/x86/kernel/olpc_prom.c
>> new file mode 100644
>> index 0000000..e2ecaf2
>> --- /dev/null
>> +++ b/arch/x86/kernel/olpc_prom.c
>> @@ -0,0 +1,152 @@
>> +/*
>> + * olpc_prom.c: OLPC-specific OFW device tree support code.
>> + *
>> + * 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
>> + *
>> + *  Adapted for sparc by David S. Miller davem@davemloft.net
>> + *  Adapted for x86/OLPC by Andres Salomon <dilinger@queued.net>
>> + *
>> + *      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.
>> + */
>> +
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/errno.h>
>> +#include <linux/slab.h>
>> +#include <linux/of.h>
>> +#include <linux/of_pdt.h>
>> +#include <asm/olpc_ofw.h>
>> +
>> +static phandle __init olpc_prom_getsibling(phandle node)
>> +{
>> +     const void *args[] = { (void *)node };
>> +     void *res[] = { &node };
>> +
>> +     if (node == -1)
>> +             return 0;
>> +
>> +     if (olpc_ofw("peer", args, res) || node == -1)
>> +             return 0;
>> +
>> +     return node;
>> +}
>> +
>> +static phandle __init olpc_prom_getchild(phandle node)
>> +{
>> +     const void *args[] = { (void *)node };
>> +     void *res[] = { &node };
>> +
>> +     if (node == -1)
>> +             return 0;
>> +
>> +     if (olpc_ofw("child", args, res) || node == -1) {
>> +             pr_err("PROM: %s: fetching child failed!\n", __func__);
>> +             return 0;
>> +     }
>> +
>> +     return node;
>> +}
>> +
>> +static int __init olpc_prom_getproplen(phandle node, const char *prop)
>> +{
>> +     const void *args[] = { (void *)node, prop };
>> +     int len;
>> +     void *res[] = { &len };
>> +
>> +     if (node == -1)
>> +             return -1;
>> +
>> +     if (olpc_ofw("getproplen", args, res)) {
>> +             pr_err("PROM: %s: getproplen failed!\n", __func__);
>> +             return -1;
>> +     }
>> +
>> +     return len;
>> +}
>> +
>> +static int __init olpc_prom_getproperty(phandle node, const char *prop,
>> +             char *buf, int bufsize)
>> +{
>> +     int plen;
>> +
>> +     plen = olpc_prom_getproplen(node, prop);
>> +     if (plen > bufsize || plen < 1)
>> +             return -1;
>> +     else {
>> +             const void *args[] = { (void *)node, prop, buf, (void *)plen };
>> +             void *res[] = { &plen };
>> +
>> +             if (olpc_ofw("getprop", args, res)) {
>> +                     pr_err("PROM: %s: getprop failed!\n", __func__);
>> +                     return -1;
>> +             }
>> +     }
>> +
>> +     return plen;
>> +}
>> +
>> +static int __init olpc_prom_nextprop(phandle node, char *prev, char *buf)
>> +{
>> +     const void *args[] = { (void *)node, prev, buf };
>> +     int success;
>> +     void *res[] = { &success };
>> +
>> +     buf[0] = '\0';
>> +
>> +     if (node == -1)
>> +             return -1;
>> +
>> +     if (olpc_ofw("nextprop", args, res) || success != 1)
>> +             return -1;
>> +
>> +     return 0;
>> +}
>> +
>> +static int __init olpc_prom_pkg2path(phandle node, char *buf,
>> +             const int buflen, int *len)
>> +{
>> +     const void *args[] = { (void *)node, buf, (void *)buflen };
>> +     void *res[] = { len };
>> +
>> +     if (node == -1)
>> +             return -1;
>> +
>> +     if (olpc_ofw("package-to-path", args, res) || *len < 1)
>> +             return -1;
>> +
>> +     return 0;
>> +}
>> +
>> +void * __init prom_early_alloc(unsigned long size)
>> +{
>> +     /* this is called late enough that we can alloc normally */
>> +     return kzalloc(size, GFP_KERNEL);
>> +}
>> +
>> +static struct of_pdt_ops prom_olpc_ops __initdata = {
>> +     .nextprop = olpc_prom_nextprop,
>> +     .getproplen = olpc_prom_getproplen,
>> +     .getproperty = olpc_prom_getproperty,
>> +     .getchild = olpc_prom_getchild,
>> +     .getsibling = olpc_prom_getsibling,
>> +     .pkg2path = olpc_prom_pkg2path,
>> +};
>> +
>> +void __init olpc_prom_build_devicetree(void)
>> +{
>> +     phandle root;
>> +
>> +     root = olpc_prom_getsibling(0);
>> +     if (root < 0) {
>> +             pr_err("PROM: unable to get root node from OFW!\n");
>> +             return;
>> +     }
>> +     of_pdt_build_devicetree(root, &prom_olpc_ops);
>> +}
>> diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
>> index 28295d0..07e3daa 100644
>> --- a/drivers/of/pdt.c
>> +++ b/drivers/of/pdt.c
>> @@ -29,6 +29,8 @@ static struct of_pdt_ops *of_pdt_prom_ops __initdata;
>>  void __initdata (*of_pdt_build_more)(struct device_node *dp,
>>               struct device_node ***nextp);
>>
>> +void __initdata (*of_pdt_init_devicetree)(void);
>> +
>>  #if defined(CONFIG_SPARC)
>>  unsigned int of_pdt_unique_id __initdata;
>>
>> diff --git a/fs/proc/proc_devtree.c b/fs/proc/proc_devtree.c
>> index d9396a4..9779039 100644
>> --- a/fs/proc/proc_devtree.c
>> +++ b/fs/proc/proc_devtree.c
>> @@ -11,6 +11,7 @@
>>  #include <linux/stat.h>
>>  #include <linux/string.h>
>>  #include <linux/of.h>
>> +#include <linux/of_pdt.h>
>>  #include <linux/module.h>
>>  #include <linux/slab.h>
>>  #include <asm/prom.h>
>> @@ -228,6 +229,9 @@ void __init proc_device_tree_init(void)
>>  {
>>       struct device_node *root;
>>
>> +     if (of_pdt_init_devicetree)
>> +             of_pdt_init_devicetree();
>> +
>>       proc_device_tree = proc_mkdir("device-tree", NULL);
>>       if (proc_device_tree == NULL)
>>               return;
>> diff --git a/include/linux/of_pdt.h b/include/linux/of_pdt.h
>> index c65a18a..5b29aef 100644
>> --- a/include/linux/of_pdt.h
>> +++ b/include/linux/of_pdt.h
>> @@ -38,6 +38,7 @@ extern void *prom_early_alloc(unsigned long size);
>>
>>  /* for building the device tree */
>>  extern void of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops);
>> +extern void (*of_pdt_init_devicetree)(void);
>>
>>  extern void (*of_pdt_build_more)(struct device_node *dp,
>>               struct device_node ***nextp);
>> --
>> 1.5.6.5
>>
>
Andres Salomon - Oct. 21, 2010, 9:17 p.m.
On Wed, 20 Oct 2010 12:56:21 -0600
Grant Likely <grant.likely@secretlab.ca> wrote:

> On Sun, Oct 10, 2010 at 10:13 PM, Grant Likely
> <grant.likely@secretlab.ca> wrote:
> > On Sun, Oct 10, 2010 at 02:06:26AM -0700, Andres Salomon wrote:
> >>
> >> Make use of PROC_DEVICETREE to export the tree, and sparc's
> >> PROMTREE code to call into OLPC's Open Firmware to build the tree.
> >>
> >> Signed-off-by: Andres Salomon <dilinger@queued.net>
> >
> > Holding off on this one until I hear from the x86 maintainers
> > [cc'd].
> 
> Oops, and it appears that patch breaks the build on other
> architectures when CONFIG_OF is enabled and CONFIG_PROMTREE is not due
> to how of_pdt_init_devicetree is defined.
> 
> g.
> 

D'oh.  Do you have any preferences for what we should be using here?
Generic OF hook?  PDT-specific hook?  Forget the hook and just call
a PDT function?  I'm leaning towards that last option.


> >
> > g.
> >
> >> ---
> >>  arch/x86/Kconfig                |    2 +
> >>  arch/x86/include/asm/olpc_ofw.h |    4 +
> >>  arch/x86/include/asm/prom.h     |    1 +
> >>  arch/x86/kernel/Makefile        |    1 +
> >>  arch/x86/kernel/olpc_ofw.c      |    8 ++
> >>  arch/x86/kernel/olpc_prom.c     |  152
> >> +++++++++++++++++++++++++++++++++++++++ drivers/of/pdt.c
> >>      |    2 + fs/proc/proc_devtree.c          |    4 +
> >>  include/linux/of_pdt.h          |    1 +
> >>  9 files changed, 175 insertions(+), 0 deletions(-)
> >>  create mode 100644 arch/x86/include/asm/prom.h
> >>  create mode 100644 arch/x86/kernel/olpc_prom.c
> >>
> >> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> >> index cea0cd9..7d4ef72 100644
> >> --- a/arch/x86/Kconfig
> >> +++ b/arch/x86/Kconfig
> >> @@ -2069,6 +2069,8 @@ config OLPC_OPENFIRMWARE
> >>       bool "Support for OLPC's Open Firmware"
> >>       depends on !X86_64 && !X86_PAE
> >>       default y if OLPC
> >> +     select OF
> >> +     select OF_PROMTREE
> >>       help
> >>         This option adds support for the implementation of Open
> >> Firmware that is used on the OLPC XO-1 Children's Machine.
> >> diff --git a/arch/x86/include/asm/olpc_ofw.h
> >> b/arch/x86/include/asm/olpc_ofw.h index 08fde47..13075df 100644
> >> --- a/arch/x86/include/asm/olpc_ofw.h
> >> +++ b/arch/x86/include/asm/olpc_ofw.h
> >> @@ -28,4 +28,8 @@ static inline void setup_olpc_ofw_pgd(void) { }
> >>
> >>  #endif /* !CONFIG_OLPC_OPENFIRMWARE */
> >>
> >> +#ifdef CONFIG_PROC_DEVICETREE
> >> +extern void olpc_prom_build_devicetree(void);
> >> +#endif /* CONFIG_PROC_DEVICETREE */
> >> +
> >>  #endif /* _ASM_X86_OLPC_OFW_H */
> >> diff --git a/arch/x86/include/asm/prom.h
> >> b/arch/x86/include/asm/prom.h new file mode 100644
> >> index 0000000..b4ec95f
> >> --- /dev/null
> >> +++ b/arch/x86/include/asm/prom.h
> >> @@ -0,0 +1 @@
> >> +/* dummy prom.h; here to make linux/of.h's #includes happy */
> >> diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
> >> index fedf32a..ced0c9a 100644
> >> --- a/arch/x86/kernel/Makefile
> >> +++ b/arch/x86/kernel/Makefile
> >> @@ -107,6 +107,7 @@ scx200-y                  += scx200_32.o
> >>
> >>  obj-$(CONFIG_OLPC)           += olpc.o
> >>  obj-$(CONFIG_OLPC_OPENFIRMWARE)      += olpc_ofw.o
> >> +obj-$(CONFIG_PROC_DEVICETREE)        += olpc_prom.o
> >>  obj-$(CONFIG_X86_MRST)               += mrst.o
> >>
> >>  microcode-y                          := microcode_core.o
> >> diff --git a/arch/x86/kernel/olpc_ofw.c
> >> b/arch/x86/kernel/olpc_ofw.c index 3218aa7..6c4d243 100644
> >> --- a/arch/x86/kernel/olpc_ofw.c
> >> +++ b/arch/x86/kernel/olpc_ofw.c
> >> @@ -1,5 +1,7 @@
> >>  #include <linux/kernel.h>
> >>  #include <linux/module.h>
> >> +#include <linux/of.h>
> >> +#include <linux/of_pdt.h>
> >>  #include <linux/init.h>
> >>  #include <asm/page.h>
> >>  #include <asm/setup.h>
> >> @@ -38,6 +40,12 @@ void __init setup_olpc_ofw_pgd(void)
> >>       /* implicit optimization barrier here due to uninline
> >> function return */
> >>
> >>       early_iounmap(base, sizeof(olpc_ofw_pgd) * PTRS_PER_PGD);
> >> +
> >> +#ifdef CONFIG_PROC_DEVICETREE
> >> +     /* OFW set up succesfully; use it for the device tree */
> >> +     of_pdt_init_devicetree = olpc_prom_build_devicetree;
> >> +#endif
> >> +
> >>  }
> >>
> >>  int __olpc_ofw(const char *name, int nr_args, const void **args,
> >> int nr_res, diff --git a/arch/x86/kernel/olpc_prom.c
> >> b/arch/x86/kernel/olpc_prom.c new file mode 100644
> >> index 0000000..e2ecaf2
> >> --- /dev/null
> >> +++ b/arch/x86/kernel/olpc_prom.c
> >> @@ -0,0 +1,152 @@
> >> +/*
> >> + * olpc_prom.c: OLPC-specific OFW device tree support code.
> >> + *
> >> + * 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
> >> + *
> >> + *  Adapted for sparc by David S. Miller davem@davemloft.net
> >> + *  Adapted for x86/OLPC by Andres Salomon <dilinger@queued.net>
> >> + *
> >> + *      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.
> >> + */
> >> +
> >> +#include <linux/kernel.h>
> >> +#include <linux/module.h>
> >> +#include <linux/errno.h>
> >> +#include <linux/slab.h>
> >> +#include <linux/of.h>
> >> +#include <linux/of_pdt.h>
> >> +#include <asm/olpc_ofw.h>
> >> +
> >> +static phandle __init olpc_prom_getsibling(phandle node)
> >> +{
> >> +     const void *args[] = { (void *)node };
> >> +     void *res[] = { &node };
> >> +
> >> +     if (node == -1)
> >> +             return 0;
> >> +
> >> +     if (olpc_ofw("peer", args, res) || node == -1)
> >> +             return 0;
> >> +
> >> +     return node;
> >> +}
> >> +
> >> +static phandle __init olpc_prom_getchild(phandle node)
> >> +{
> >> +     const void *args[] = { (void *)node };
> >> +     void *res[] = { &node };
> >> +
> >> +     if (node == -1)
> >> +             return 0;
> >> +
> >> +     if (olpc_ofw("child", args, res) || node == -1) {
> >> +             pr_err("PROM: %s: fetching child failed!\n",
> >> __func__);
> >> +             return 0;
> >> +     }
> >> +
> >> +     return node;
> >> +}
> >> +
> >> +static int __init olpc_prom_getproplen(phandle node, const char
> >> *prop) +{
> >> +     const void *args[] = { (void *)node, prop };
> >> +     int len;
> >> +     void *res[] = { &len };
> >> +
> >> +     if (node == -1)
> >> +             return -1;
> >> +
> >> +     if (olpc_ofw("getproplen", args, res)) {
> >> +             pr_err("PROM: %s: getproplen failed!\n", __func__);
> >> +             return -1;
> >> +     }
> >> +
> >> +     return len;
> >> +}
> >> +
> >> +static int __init olpc_prom_getproperty(phandle node, const char
> >> *prop,
> >> +             char *buf, int bufsize)
> >> +{
> >> +     int plen;
> >> +
> >> +     plen = olpc_prom_getproplen(node, prop);
> >> +     if (plen > bufsize || plen < 1)
> >> +             return -1;
> >> +     else {
> >> +             const void *args[] = { (void *)node, prop, buf,
> >> (void *)plen };
> >> +             void *res[] = { &plen };
> >> +
> >> +             if (olpc_ofw("getprop", args, res)) {
> >> +                     pr_err("PROM: %s: getprop failed!\n",
> >> __func__);
> >> +                     return -1;
> >> +             }
> >> +     }
> >> +
> >> +     return plen;
> >> +}
> >> +
> >> +static int __init olpc_prom_nextprop(phandle node, char *prev,
> >> char *buf) +{
> >> +     const void *args[] = { (void *)node, prev, buf };
> >> +     int success;
> >> +     void *res[] = { &success };
> >> +
> >> +     buf[0] = '\0';
> >> +
> >> +     if (node == -1)
> >> +             return -1;
> >> +
> >> +     if (olpc_ofw("nextprop", args, res) || success != 1)
> >> +             return -1;
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +static int __init olpc_prom_pkg2path(phandle node, char *buf,
> >> +             const int buflen, int *len)
> >> +{
> >> +     const void *args[] = { (void *)node, buf, (void *)buflen };
> >> +     void *res[] = { len };
> >> +
> >> +     if (node == -1)
> >> +             return -1;
> >> +
> >> +     if (olpc_ofw("package-to-path", args, res) || *len < 1)
> >> +             return -1;
> >> +
> >> +     return 0;
> >> +}
> >> +
> >> +void * __init prom_early_alloc(unsigned long size)
> >> +{
> >> +     /* this is called late enough that we can alloc normally */
> >> +     return kzalloc(size, GFP_KERNEL);
> >> +}
> >> +
> >> +static struct of_pdt_ops prom_olpc_ops __initdata = {
> >> +     .nextprop = olpc_prom_nextprop,
> >> +     .getproplen = olpc_prom_getproplen,
> >> +     .getproperty = olpc_prom_getproperty,
> >> +     .getchild = olpc_prom_getchild,
> >> +     .getsibling = olpc_prom_getsibling,
> >> +     .pkg2path = olpc_prom_pkg2path,
> >> +};
> >> +
> >> +void __init olpc_prom_build_devicetree(void)
> >> +{
> >> +     phandle root;
> >> +
> >> +     root = olpc_prom_getsibling(0);
> >> +     if (root < 0) {
> >> +             pr_err("PROM: unable to get root node from OFW!\n");
> >> +             return;
> >> +     }
> >> +     of_pdt_build_devicetree(root, &prom_olpc_ops);
> >> +}
> >> diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
> >> index 28295d0..07e3daa 100644
> >> --- a/drivers/of/pdt.c
> >> +++ b/drivers/of/pdt.c
> >> @@ -29,6 +29,8 @@ static struct of_pdt_ops *of_pdt_prom_ops
> >> __initdata; void __initdata (*of_pdt_build_more)(struct
> >> device_node *dp, struct device_node ***nextp);
> >>
> >> +void __initdata (*of_pdt_init_devicetree)(void);
> >> +
> >>  #if defined(CONFIG_SPARC)
> >>  unsigned int of_pdt_unique_id __initdata;
> >>
> >> diff --git a/fs/proc/proc_devtree.c b/fs/proc/proc_devtree.c
> >> index d9396a4..9779039 100644
> >> --- a/fs/proc/proc_devtree.c
> >> +++ b/fs/proc/proc_devtree.c
> >> @@ -11,6 +11,7 @@
> >>  #include <linux/stat.h>
> >>  #include <linux/string.h>
> >>  #include <linux/of.h>
> >> +#include <linux/of_pdt.h>
> >>  #include <linux/module.h>
> >>  #include <linux/slab.h>
> >>  #include <asm/prom.h>
> >> @@ -228,6 +229,9 @@ void __init proc_device_tree_init(void)
> >>  {
> >>       struct device_node *root;
> >>
> >> +     if (of_pdt_init_devicetree)
> >> +             of_pdt_init_devicetree();
> >> +
> >>       proc_device_tree = proc_mkdir("device-tree", NULL);
> >>       if (proc_device_tree == NULL)
> >>               return;
> >> diff --git a/include/linux/of_pdt.h b/include/linux/of_pdt.h
> >> index c65a18a..5b29aef 100644
> >> --- a/include/linux/of_pdt.h
> >> +++ b/include/linux/of_pdt.h
> >> @@ -38,6 +38,7 @@ extern void *prom_early_alloc(unsigned long
> >> size);
> >>
> >>  /* for building the device tree */
> >>  extern void of_pdt_build_devicetree(phandle root_node, struct
> >> of_pdt_ops *ops); +extern void (*of_pdt_init_devicetree)(void);
> >>
> >>  extern void (*of_pdt_build_more)(struct device_node *dp,
> >>               struct device_node ***nextp);
> >> --
> >> 1.5.6.5
> >>
> >
> 
> 
> 
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Patch

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index cea0cd9..7d4ef72 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2069,6 +2069,8 @@  config OLPC_OPENFIRMWARE
 	bool "Support for OLPC's Open Firmware"
 	depends on !X86_64 && !X86_PAE
 	default y if OLPC
+	select OF
+	select OF_PROMTREE
 	help
 	  This option adds support for the implementation of Open Firmware
 	  that is used on the OLPC XO-1 Children's Machine.
diff --git a/arch/x86/include/asm/olpc_ofw.h b/arch/x86/include/asm/olpc_ofw.h
index 08fde47..13075df 100644
--- a/arch/x86/include/asm/olpc_ofw.h
+++ b/arch/x86/include/asm/olpc_ofw.h
@@ -28,4 +28,8 @@  static inline void setup_olpc_ofw_pgd(void) { }
 
 #endif /* !CONFIG_OLPC_OPENFIRMWARE */
 
+#ifdef CONFIG_PROC_DEVICETREE
+extern void olpc_prom_build_devicetree(void);
+#endif /* CONFIG_PROC_DEVICETREE */
+
 #endif /* _ASM_X86_OLPC_OFW_H */
diff --git a/arch/x86/include/asm/prom.h b/arch/x86/include/asm/prom.h
new file mode 100644
index 0000000..b4ec95f
--- /dev/null
+++ b/arch/x86/include/asm/prom.h
@@ -0,0 +1 @@ 
+/* dummy prom.h; here to make linux/of.h's #includes happy */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index fedf32a..ced0c9a 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -107,6 +107,7 @@  scx200-y			+= scx200_32.o
 
 obj-$(CONFIG_OLPC)		+= olpc.o
 obj-$(CONFIG_OLPC_OPENFIRMWARE)	+= olpc_ofw.o
+obj-$(CONFIG_PROC_DEVICETREE)	+= olpc_prom.o
 obj-$(CONFIG_X86_MRST)		+= mrst.o
 
 microcode-y				:= microcode_core.o
diff --git a/arch/x86/kernel/olpc_ofw.c b/arch/x86/kernel/olpc_ofw.c
index 3218aa7..6c4d243 100644
--- a/arch/x86/kernel/olpc_ofw.c
+++ b/arch/x86/kernel/olpc_ofw.c
@@ -1,5 +1,7 @@ 
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_pdt.h>
 #include <linux/init.h>
 #include <asm/page.h>
 #include <asm/setup.h>
@@ -38,6 +40,12 @@  void __init setup_olpc_ofw_pgd(void)
 	/* implicit optimization barrier here due to uninline function return */
 
 	early_iounmap(base, sizeof(olpc_ofw_pgd) * PTRS_PER_PGD);
+
+#ifdef CONFIG_PROC_DEVICETREE
+	/* OFW set up succesfully; use it for the device tree */
+	of_pdt_init_devicetree = olpc_prom_build_devicetree;
+#endif
+
 }
 
 int __olpc_ofw(const char *name, int nr_args, const void **args, int nr_res,
diff --git a/arch/x86/kernel/olpc_prom.c b/arch/x86/kernel/olpc_prom.c
new file mode 100644
index 0000000..e2ecaf2
--- /dev/null
+++ b/arch/x86/kernel/olpc_prom.c
@@ -0,0 +1,152 @@ 
+/*
+ * olpc_prom.c: OLPC-specific OFW device tree support code.
+ *
+ * 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
+ *
+ *  Adapted for sparc by David S. Miller davem@davemloft.net
+ *  Adapted for x86/OLPC by Andres Salomon <dilinger@queued.net>
+ *
+ *      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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_pdt.h>
+#include <asm/olpc_ofw.h>
+
+static phandle __init olpc_prom_getsibling(phandle node)
+{
+	const void *args[] = { (void *)node };
+	void *res[] = { &node };
+
+	if (node == -1)
+		return 0;
+
+	if (olpc_ofw("peer", args, res) || node == -1)
+		return 0;
+
+	return node;
+}
+
+static phandle __init olpc_prom_getchild(phandle node)
+{
+	const void *args[] = { (void *)node };
+	void *res[] = { &node };
+
+	if (node == -1)
+		return 0;
+
+	if (olpc_ofw("child", args, res) || node == -1) {
+		pr_err("PROM: %s: fetching child failed!\n", __func__);
+		return 0;
+	}
+
+	return node;
+}
+
+static int __init olpc_prom_getproplen(phandle node, const char *prop)
+{
+	const void *args[] = { (void *)node, prop };
+	int len;
+	void *res[] = { &len };
+
+	if (node == -1)
+		return -1;
+
+	if (olpc_ofw("getproplen", args, res)) {
+		pr_err("PROM: %s: getproplen failed!\n", __func__);
+		return -1;
+	}
+
+	return len;
+}
+
+static int __init olpc_prom_getproperty(phandle node, const char *prop,
+		char *buf, int bufsize)
+{
+	int plen;
+
+	plen = olpc_prom_getproplen(node, prop);
+	if (plen > bufsize || plen < 1)
+		return -1;
+	else {
+		const void *args[] = { (void *)node, prop, buf, (void *)plen };
+		void *res[] = { &plen };
+
+		if (olpc_ofw("getprop", args, res)) {
+			pr_err("PROM: %s: getprop failed!\n", __func__);
+			return -1;
+		}
+	}
+
+	return plen;
+}
+
+static int __init olpc_prom_nextprop(phandle node, char *prev, char *buf)
+{
+	const void *args[] = { (void *)node, prev, buf };
+	int success;
+	void *res[] = { &success };
+
+	buf[0] = '\0';
+
+	if (node == -1)
+		return -1;
+
+	if (olpc_ofw("nextprop", args, res) || success != 1)
+		return -1;
+
+	return 0;
+}
+
+static int __init olpc_prom_pkg2path(phandle node, char *buf,
+		const int buflen, int *len)
+{
+	const void *args[] = { (void *)node, buf, (void *)buflen };
+	void *res[] = { len };
+
+	if (node == -1)
+		return -1;
+
+	if (olpc_ofw("package-to-path", args, res) || *len < 1)
+		return -1;
+
+	return 0;
+}
+
+void * __init prom_early_alloc(unsigned long size)
+{
+	/* this is called late enough that we can alloc normally */
+	return kzalloc(size, GFP_KERNEL);
+}
+
+static struct of_pdt_ops prom_olpc_ops __initdata = {
+	.nextprop = olpc_prom_nextprop,
+	.getproplen = olpc_prom_getproplen,
+	.getproperty = olpc_prom_getproperty,
+	.getchild = olpc_prom_getchild,
+	.getsibling = olpc_prom_getsibling,
+	.pkg2path = olpc_prom_pkg2path,
+};
+
+void __init olpc_prom_build_devicetree(void)
+{
+	phandle root;
+
+	root = olpc_prom_getsibling(0);
+	if (root < 0) {
+		pr_err("PROM: unable to get root node from OFW!\n");
+		return;
+	}
+	of_pdt_build_devicetree(root, &prom_olpc_ops);
+}
diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
index 28295d0..07e3daa 100644
--- a/drivers/of/pdt.c
+++ b/drivers/of/pdt.c
@@ -29,6 +29,8 @@  static struct of_pdt_ops *of_pdt_prom_ops __initdata;
 void __initdata (*of_pdt_build_more)(struct device_node *dp,
 		struct device_node ***nextp);
 
+void __initdata (*of_pdt_init_devicetree)(void);
+
 #if defined(CONFIG_SPARC)
 unsigned int of_pdt_unique_id __initdata;
 
diff --git a/fs/proc/proc_devtree.c b/fs/proc/proc_devtree.c
index d9396a4..9779039 100644
--- a/fs/proc/proc_devtree.c
+++ b/fs/proc/proc_devtree.c
@@ -11,6 +11,7 @@ 
 #include <linux/stat.h>
 #include <linux/string.h>
 #include <linux/of.h>
+#include <linux/of_pdt.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <asm/prom.h>
@@ -228,6 +229,9 @@  void __init proc_device_tree_init(void)
 {
 	struct device_node *root;
 
+	if (of_pdt_init_devicetree)
+		of_pdt_init_devicetree();
+
 	proc_device_tree = proc_mkdir("device-tree", NULL);
 	if (proc_device_tree == NULL)
 		return;
diff --git a/include/linux/of_pdt.h b/include/linux/of_pdt.h
index c65a18a..5b29aef 100644
--- a/include/linux/of_pdt.h
+++ b/include/linux/of_pdt.h
@@ -38,6 +38,7 @@  extern void *prom_early_alloc(unsigned long size);
 
 /* for building the device tree */
 extern void of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops);
+extern void (*of_pdt_init_devicetree)(void);
 
 extern void (*of_pdt_build_more)(struct device_node *dp,
 		struct device_node ***nextp);