[PATCH 4/4] x86: OLPC: add OLPC device-tree support

Andres Salomon
2010-06-29T02:01:07Z

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@queued.net>
---
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
+
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
+
+#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))
+
+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
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@davemloft.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>
+#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)
help
This option adds a device-tree directory under /proc which contains
an image of the device tree that the kernel copies from Open
--
1.5.6.5