[PATCH v3 2/6] arm/dt: Allow CONFIG_OF on ARM

Grant Likely
2011-02-12T08:14:37Z

From: Jeremy Kerr <jeremy.kerr@canonical.com>

Add some basic empty infrastructure for DT support on ARM.

v3: - moved cmd_line export and initrd setup to this patch to make the
series bisectable.
- switched to alloc_bootmem_align() for allocation when
unflattening the device tree. memblock_alloc() was not the
right interface.

Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---
arch/arm/Kconfig | 7 ++++++
arch/arm/include/asm/prom.h | 25 ++++++++++++++++++++++
arch/arm/include/asm/setup.h | 3 +++
arch/arm/kernel/Makefile | 1 +
arch/arm/kernel/devtree.c | 47 ++++++++++++++++++++++++++++++++++++++++++
arch/arm/kernel/setup.c | 4 ++--
arch/arm/mm/init.c | 9 ++++++++
7 files changed, 94 insertions(+), 2 deletions(-)
create mode 100644 arch/arm/include/asm/prom.h
create mode 100644 arch/arm/kernel/devtree.c

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 5cff165..d8a330f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1586,6 +1586,13 @@ endmenu

menu "Boot options"

+config USE_OF
+ bool "Flattened Device Tree support"
+ select OF
+ select OF_EARLY_FLATTREE
+ help
+ Include support for flattened device tree machine descriptions.
+
# Compressed boot loader in ROM. Yes, we really want to ask about
# TEXT and BSS so we preserve their values in the config files.
config ZBOOT_ROM_TEXT
diff --git a/arch/arm/include/asm/prom.h b/arch/arm/include/asm/prom.h
new file mode 100644
index 0000000..8f1037f
--- /dev/null
+++ b/arch/arm/include/asm/prom.h
@@ -0,0 +1,25 @@
+/*
+ * arch/arm/include/asm/prom.h
+ *
+ * Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#ifndef __ASMARM_PROM_H
+#define __ASMARM_PROM_H
+
+#ifdef CONFIG_OF
+
+#include <asm/setup.h>
+#include <asm/irq.h>
+
+static inline void irq_dispose_mapping(unsigned int virq)
+{
+ return;
+}
+
+#endif /* CONFIG_OF */
+#endif /* ASMARM_PROM_H */
diff --git a/arch/arm/include/asm/setup.h b/arch/arm/include/asm/setup.h
index f1e5a9b..1cec82a 100644
--- a/arch/arm/include/asm/setup.h
+++ b/arch/arm/include/asm/setup.h
@@ -221,6 +221,9 @@ extern struct meminfo meminfo;
#define bank_phys_end(bank) ((bank)->start + (bank)->size)
#define bank_phys_size(bank) (bank)->size

+extern int arm_add_memory(unsigned long start, unsigned long size);
+extern char cmd_line[COMMAND_LINE_SIZE];
+
#endif /* __KERNEL__ */

#endif
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 185ee82..8df05fd 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_ARM_THUMBEE) += thumbee.o
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_ARM_UNWIND) += unwind.o
obj-$(CONFIG_HAVE_TCM) += tcm.o
+obj-$(CONFIG_OF) += devtree.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
obj-$(CONFIG_SWP_EMULATE) += swp_emulate.o
CFLAGS_swp_emulate.o := -Wa,-march=armv7-a
diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
new file mode 100644
index 0000000..75e3df8
--- /dev/null
+++ b/arch/arm/kernel/devtree.c
@@ -0,0 +1,47 @@
+/*
+ * linux/arch/arm/kernel/devtree.c
+ *
+ * Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+
+#include <asm/setup.h>
+#include <asm/page.h>
+
+void __init early_init_dt_add_memory_arch(u64 base, u64 size)
+{
+ arm_add_memory(base, size);
+}
+
+void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
+{
+ return alloc_bootmem_align(size, align);
+}
+
+/**
+ * irq_create_of_mapping - Hook to resolve OF irq specifier into a Linux irq#
+ *
+ * Currently the mapping mechanism is trivial; simple flat hwirq numbers are
+ * mapped 1:1 onto Linux irq numbers. Cascaded irq controllers are not
+ * supported.
+ */
+unsigned int irq_create_of_mapping(struct device_node *controller,
+ const u32 *intspec, unsigned int intsize)
+{
+ return intspec[0];
+}
+EXPORT_SYMBOL_GPL(irq_create_of_mapping);
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 78678b0..0c692c7 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -125,7 +125,7 @@ EXPORT_SYMBOL(elf_platform);

static const char *cpu_name;
static const char *machine_name;
-static char __initdata cmd_line[COMMAND_LINE_SIZE];
+char cmd_line[COMMAND_LINE_SIZE];
struct machine_desc *machine_desc __initdata;

static char default_command_line[COMMAND_LINE_SIZE] __initdata = CONFIG_CMDLINE;
@@ -480,7 +480,7 @@ static struct machine_desc * __init setup_machine(unsigned int nr)
return list;
}

-static int __init arm_add_memory(unsigned long start, unsigned long size)
+int __init arm_add_memory(unsigned long start, unsigned long size)
{
struct membank *bank = &meminfo.bank[meminfo.nr_banks];

diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index cddd684..a2ba1d1 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -15,6 +15,7 @@
#include <linux/mman.h>
#include <linux/nodemask.h>
#include <linux/initrd.h>
+#include <linux/of_fdt.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/memblock.h>
@@ -71,6 +72,14 @@ static int __init parse_tag_initrd2(const struct tag *tag)

__tagtable(ATAG_INITRD2, parse_tag_initrd2);

+#ifdef CONFIG_OF_FLATTREE
+void __init early_init_dt_setup_initrd_arch(unsigned long start, unsigned long end)
+{
+ phys_initrd_start = start;
+ phys_initrd_size = end - start + 1;
+}
+#endif /* CONFIG_OF_FLATTREE */
+
/*
* This keeps memory configuration data used by a couple memory
* initialization functions, as well as show_mem() for the skipping