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

From: Grant Likely
Date: Mon Oct 11 2010 - 00:13:20 EST

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@xxxxxxxxxx>

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@xxxxxxxxxxxxx
> + * Adapted for x86/OLPC by Andres Salomon <dilinger@xxxxxxxxxx>
> + *
> + * 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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