MIPS: Add generic support for multiple machines within a single kernel

This patch adds a generic solution to support multiple machines based on
a given SoC within a single kernel image. It is implemented already for
several other architectures but MIPS has no generic support for that yet.

[Ralf: This competes with DT but DT is a much more complex solution and this
code has been used by OpenWRT for a long time so for now DT is a bad reason
to stop the merge but longer term this should be migrated to DT.]

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: kaloz@openwrt.org
Cc: Luis R. Rodriguez <lrodriguez@atheros.com>
Cc: Cliff Holden <Cliff.Holden@Atheros.com>
Patchwork: https://patchwork.linux-mips.org/patch/1814/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 54 insertions, 0 deletions

diff --git a/arch/mips/include/asm/mips_machine.h b/arch/mips/include/asm/mips_machine.h
new file mode 100644
index 00000000000..363bb352c7f
--- /dev/null
+++ b/arch/mips/include/asm/mips_machine.h
@@ -0,0 +1,54 @@
+/*
+ *  Copyright (C) 2008-2010 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  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 __ASM_MIPS_MACHINE_H
+#define __ASM_MIPS_MACHINE_H
+
+#include <linux/init.h>
+#include <linux/stddef.h>
+
+#include <asm/bootinfo.h>
+
+struct mips_machine {
+	unsigned long		mach_type;
+	const char		*mach_id;
+	const char		*mach_name;
+	void			(*mach_setup)(void);
+};
+
+#define MIPS_MACHINE(_type, _id, _name, _setup)			\
+static const char machine_name_##_type[] __initconst		\
+			__aligned(1) = _name;			\
+static const char machine_id_##_type[] __initconst		\
+			__aligned(1) = _id;			\
+static struct mips_machine machine_##_type			\
+		__used __section(.mips.machines.init) =		\
+{								\
+	.mach_type	= _type,				\
+	.mach_id	= machine_id_##_type,			\
+	.mach_name	= machine_name_##_type,			\
+	.mach_setup	= _setup,				\
+};
+
+extern long __mips_machines_start;
+extern long __mips_machines_end;
+
+#ifdef CONFIG_MIPS_MACHINE
+int  mips_machtype_setup(char *id) __init;
+void mips_machine_setup(void) __init;
+void mips_set_machine_name(const char *name) __init;
+char *mips_get_machine_name(void);
+#else
+static inline int mips_machtype_setup(char *id) { return 1; }
+static inline void mips_machine_setup(void) { }
+static inline void mips_set_machine_name(const char *name) { }
+static inline char *mips_get_machine_name(void) { return NULL; }
+#endif /* CONFIG_MIPS_MACHINE */
+
+#endif /* __ASM_MIPS_MACHINE_H */