Re: [PATCH 4/4] x86: OLPC: add OLPC device-tree support
From: Grant Likely
Date: Tue Jun 29 2010 - 04:13:10 EST
Hi Andres, comments below....
On Mon, Jun 28, 2010 at 7:00 PM, Andres Salomon <dilinger@xxxxxxxxxx> 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.
>
> (Yes, I know this leaks memory by simply using kmalloc)
>
> Signed-off-by: Andres Salomon <dilinger@xxxxxxxxxx>
> ---
> arch/x86/Kconfig | 5 ++
> arch/x86/include/asm/olpc_prom.h | 42 +++++++++++
> arch/x86/include/asm/prom.h | 5 ++
> arch/x86/kernel/Makefile | 1 +
> arch/x86/kernel/olpc_ofw.c | 13 ++++
> arch/x86/kernel/olpc_prom.c | 148 ++++++++++++++++++++++++++++++++++++++
> fs/proc/Kconfig | 2 +-
> 7 files changed, 215 insertions(+), 1 deletions(-)
> create mode 100644 arch/x86/include/asm/olpc_prom.h
> 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 71c194d..7aea004 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -2071,6 +2071,11 @@ config OLPC_OPENFIRMWARE
> that is used on the OLPC XO-1 Children's Machine.
> If unsure, say N here.
>
> +config OF
> + def_bool y
> + depends on OLPC_OPENFIRMWARE
> + select OF_PROMTREE
> +
This hunk will need to be respun on top of Stephen's CONFIG_OF change.
It's currently in my test-devicetree branch on
git://git.secretlab.ca/git/linux-2.6
> endif # X86_32
>
> config K8_NB
> diff --git a/arch/x86/include/asm/olpc_prom.h b/arch/x86/include/asm/olpc_prom.h
> new file mode 100644
> index 0000000..96cdcee
> --- /dev/null
> +++ b/arch/x86/include/asm/olpc_prom.h
> @@ -0,0 +1,42 @@
> +#include <linux/of.h> /* linux/of.h gets to determine #include ordering */
> +/*
> + * Definitions for talking to the Open Firmware PROM on
> + * Power Macintosh computers.
> + *
> + * Copyright (C) 1996-2005 Paul Mackerras.
> + *
> + * Updates for PPC64 by Peter Bergner & David Engebretsen, IBM Corp.
> + * Updates for SPARC by David S. Miller
> + * Updates for x86/OLPC by Andres Salomon
> + *
> + * 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.
> + */
> +
> +#ifndef _X86_PROM_OLPC_H
> +#define _X86_PROM_OLPC_H
> +#ifdef __KERNEL__
> +
> +#define OF_ROOT_NODE_ADDR_CELLS_DEFAULT 2
> +#define OF_ROOT_NODE_SIZE_CELLS_DEFAULT 1
Do you really need to override these from the default?
> +#define of_compat_cmp(s1, s2, l) strncmp((s1), (s2), (l))
> +#define of_prop_cmp(s1, s2) strcasecmp((s1), (s2))
> +#define of_node_cmp(s1, s2) strcmp((s1), (s2))
Ditto here?
> +extern void prom_build_devicetree(void);
> +
> +extern void *prom_early_alloc(unsigned long size);
> +
> +extern char *prom_firstprop(phandle node, char *buf);
> +extern char *prom_nextprop(phandle node, const char *prev, char *buf);
> +extern int prom_getproplen(phandle node, const char *prop);
> +extern int prom_getproperty(phandle node, const char *prop,
> + char *buffer, int bufsize);
> +extern phandle prom_getchild(phandle node);
> +extern phandle prom_getsibling(phandle node);
> +
> +#endif /* __KERNEL__ */
> +#endif /* _X86_PROM_OLPC_H */
> diff --git a/arch/x86/include/asm/prom.h b/arch/x86/include/asm/prom.h
> new file mode 100644
> index 0000000..7b561b2
> --- /dev/null
> +++ b/arch/x86/include/asm/prom.h
> @@ -0,0 +1,5 @@
> +#ifdef CONFIG_OLPC_OPENFIRMWARE
> +# include <asm/olpc_prom.h>
> +#else
> +# error "No OFW prom defined for x86!"
> +#endif
Personally, I wouldn't bother with the header file redirection.
> diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
> index 0925676..3d7e535 100644
> --- a/arch/x86/kernel/Makefile
> +++ b/arch/x86/kernel/Makefile
> @@ -105,6 +105,7 @@ 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 3e13a4b..8838edb 100644
> --- a/arch/x86/kernel/olpc_ofw.c
> +++ b/arch/x86/kernel/olpc_ofw.c
> @@ -6,6 +6,7 @@
> #include <asm/io.h>
> #include <asm/pgtable.h>
> #include <asm/olpc_ofw.h>
> +#include <asm/prom.h>
>
> /* address of OFW callback interface; will be NULL if OFW isn't found */
> static int (*olpc_ofw_cif)(int *);
> @@ -103,3 +104,15 @@ void __init olpc_ofw_detect(void)
> (unsigned long)olpc_ofw_cif, (-start) >> 20);
> reserve_top_address(-start);
> }
> +
> +#ifdef CONFIG_PROC_DEVICETREE
> +static int __init olpc_ofw_build_devicetree(void)
> +{
> + /* initialize the device-tree that proc uses */
> + if (olpc_ofw_cif)
> + prom_build_devicetree();
> +
> + return 0;
> +}
> +arch_initcall(olpc_ofw_build_devicetree);
> +#endif /* CONFIG_PROC_DEVICETREE */
> diff --git a/arch/x86/kernel/olpc_prom.c b/arch/x86/kernel/olpc_prom.c
> new file mode 100644
> index 0000000..1128f3f
> --- /dev/null
> +++ b/arch/x86/kernel/olpc_prom.c
> @@ -0,0 +1,148 @@
> +/*
> + * 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
> + *
> + * 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>
> +#include <asm/prom.h>
> +
> +phandle prom_getsibling(phandle node)
> +{
> + const void *args[] = { (void *)node };
> + void *res[] = { &node };
> +
> + if (node == -1)
> + return -1;
> +
> + if (olpc_ofw("peer", args, res) || node == -1)
> + return -1;
> +
> + return node;
> +}
> +
> +phandle 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) {
> + printk(KERN_ERR "PROM: %s: fetching child failed!\n", __func__);
> + return 0;
> + }
> +
> + return node;
> +}
> +
> +int prom_getproplen(phandle node, const char *prop)
> +{
> + const void *args[] = { (void *)node, prop };
> + int len;
> + void *res[] = { &len };
> +
> + if (node == -1)
> + return 0;
> +
> + if (olpc_ofw("getproplen", args, res)) {
> + printk(KERN_ERR "PROM: %s: getproplen failed!\n", __func__);
> + return 0;
> + }
> +
> + return len;
> +}
> +
> +int prom_getproperty(phandle node, const char *prop, char *buf,
> + int bufsize)
> +{
> + int plen;
> +
> + plen = 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)) {
> + printk(KERN_ERR "PROM: %s: getprop failed!\n", __func__);
> + return -1;
> + }
> + //((unsigned char *)buf)[plen] = '\0';
> + }
> +
> + return 0;
> +}
> +
> +char *prom_firstprop(phandle node, char *buf)
> +{
> + buf[0] = '\0';
> +
> + if (node == -1)
> + return NULL;
> +
> + return prom_nextprop(node, "", buf);
> +}
> +
> +char *prom_nextprop(phandle node, const char *prev, char *buf)
> +{
> + const void *args[] = { (void *)node, prev, buf };
> + int success;
> + void *res[] = { &success };
> +
> + buf[0] = '\0';
> +
> + if (node == -1)
> + return NULL;
> +
> + if (olpc_ofw("nextprop", args, res) || success != 1) {
> + printk(KERN_ERR "PROM: %s: nextprop failed!\n", __func__);
> + return NULL;
> + }
> +
> + return buf;
> +}
> +
> +void * __init prom_early_alloc(unsigned long size)
> +{
> + /* unlike SPARC, we don't bother keeping track of prom memory */
> + return kzalloc(size, GFP_KERNEL);
> +}
> +
> +void __init prom_build_devicetree(void)
> +{
> + struct device_node **nextp;
> + phandle root;
> +
> + root = prom_getsibling(0);
> + if (root < 0) {
> + printk(KERN_ERR "PROM: unable to get root node from OFW!\n");
> + return;
> + }
> +
> + allnodes = prom_create_node(root, NULL);
> + allnodes->full_name = "/";
> +
> + nextp = &allnodes->allnext;
> + allnodes->child = prom_build_tree(allnodes,
> + prom_getchild(allnodes->phandle), &nextp);
> +}
> diff --git a/fs/proc/Kconfig b/fs/proc/Kconfig
> index 858a859..86f67ce 100644
> --- a/fs/proc/Kconfig
> +++ b/fs/proc/Kconfig
> @@ -41,7 +41,7 @@ config PROC_VMCORE
>
> config PROC_DEVICETREE
> bool "Support for device tree in /proc"
> - depends on PROC_FS && (PPC || MICROBLAZE)
> + depends on PROC_FS && (PPC || MICROBLAZE || OLPC_OPENFIRMWARE)
This change should no longer be necessary with the way I've modified patch 3/4.
Cheers,
g.
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