[PATCH 9/9] x86: OLPC: add OLPC device-tree support

Andres Salomon
2010-08-30T04:05:57Z

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.

This also adds an init hook to proc_device_tree_init so that we can ensure
the device tree has been built prior to the proc_root_init stuff attempting
to populate /proc/device-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

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 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 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..fb04d8a
--- /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, const 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 9945e58..b4bd0ee 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