MIPS: Loongson: Add a machtype kernel command line argument

The difference between some loongson-based machines is very small, so, if
there is no necessary to add new kernel config options to cope with this
difference, it will be better to share the same kernel image file between
them, benefit from this, the linux distribution developers only have a need
to compile the kernel one time.

This machtype kernel command line argument will be used later to share the
same kernel image file between two different machines(menglong & yeeloong)
made by lemote.

Thanks very much to Zhang Le for cleaning up the machtype implementation.
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Documentation/kernel-parameters.txt

@@ -1286,6 +1286,10 @@ and is between 256 and 4096 characters. It is defined in the file
 			(machvec) in a generic kernel.
 			Example: machvec=hpzx1_swiotlb
 
+	machtype=	[Loongson] Share the same kernel image file between different
+			 yeeloong laptop.
+			Example: machtype=lemote-yeeloong-2f-7inch
+
 	max_addr=nn[KMG]	[KNL,BOOT,ia64] All physical memory greater
 			than or equal to this physical address is ignored.
 

arch/mips/include/asm/bootinfo.h

@@ -7,6 +7,7 @@
  * Copyright (C) 1995, 1996 Andreas Busse
  * Copyright (C) 1995, 1996 Stoned Elipot
  * Copyright (C) 1995, 1996 Paul M. Antoine.
+ * Copyright (C) 2009       Zhang Le
  */
 #ifndef _ASM_BOOTINFO_H
 #define _ASM_BOOTINFO_H
@@ -57,6 +58,17 @@
 #define	MACH_MIKROTIK_RB532	0	/* Mikrotik RouterBoard 532 	*/
 #define MACH_MIKROTIK_RB532A	1	/* Mikrotik RouterBoard 532A 	*/
 
+/*
+ * Valid machtype for Loongson family
+ */
+#define MACH_LOONGSON_UNKNOWN  0
+#define MACH_LEMOTE_FL2E       1
+#define MACH_LEMOTE_FL2F       2
+#define MACH_LEMOTE_ML2F7      3
+#define MACH_LEMOTE_YL2F89     4
+#define MACH_DEXXON_GDIUM2F10  5
+#define MACH_LOONGSON_END      6
+
 #define CL_SIZE			COMMAND_LINE_SIZE
 
 extern char *system_type;

arch/mips/include/asm/mach-loongson/machine.h

@@ -15,7 +15,7 @@
 
 #define LOONGSON_UART_BASE (BONITO_PCIIO_BASE + 0x3f8)
 
-#define LOONGSON_MACHNAME "lemote-fuloong-2e-box"
+#define LOONGSON_MACHTYPE MACH_LEMOTE_FL2E
 
 #endif
 

arch/mips/loongson/common/Makefile

@@ -3,7 +3,7 @@
 #
 
 obj-y += setup.o init.o cmdline.o env.o time.o reset.o irq.o \
-    pci.o bonito-irq.o mem.o
+    pci.o bonito-irq.o mem.o machtype.o
 
 #
 # Early printk support

arch/mips/loongson/common/machtype.c

@@ -2,16 +2,49 @@
  * Copyright (C) 2009 Lemote Inc. & Insititute of Computing Technology
  * Author: Wu Zhangjin, wuzj@lemote.com
  *
+ * Copyright (c) 2009 Zhang Le <r0bertz@gentoo.org>
+ *
  * 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/errno.h>
+#include <asm/bootinfo.h>
 
+#include <loongson.h>
 #include <machine.h>
 
+static const char *system_types[] = {
+	[MACH_LOONGSON_UNKNOWN]         "unknown loongson machine",
+	[MACH_LEMOTE_FL2E]              "lemote-fuloong-2e-box",
+	[MACH_LEMOTE_FL2F]              "lemote-fuloong-2f-box",
+	[MACH_LEMOTE_ML2F7]             "lemote-mengloong-2f-7inches",
+	[MACH_LEMOTE_YL2F89]            "lemote-yeeloong-2f-8.9inches",
+	[MACH_DEXXON_GDIUM2F10]         "dexxon-gidum-2f-10inches",
+	[MACH_LOONGSON_END]             NULL,
+};
+
 const char *get_system_type(void)
 {
-	return LOONGSON_MACHNAME;
+	if (mips_machtype == MACH_UNKNOWN)
+		mips_machtype = LOONGSON_MACHTYPE;
+
+	return system_types[mips_machtype];
 }
 
+static __init int machtype_setup(char *str)
+{
+	int machtype = MACH_LEMOTE_FL2E;
+
+	if (!str)
+		return -EINVAL;
+
+	for (; system_types[machtype]; machtype++)
+		if (strstr(system_types[machtype], str)) {
+			mips_machtype = machtype;
+			break;
+		}
+	return 0;
+}
+__setup("machtype=", machtype_setup);

arch/mips/loongson/fuloong-2e/Makefile

@@ -2,6 +2,6 @@
 # Makefile for Lemote Fuloong2e mini-PC board.
 #
 
-obj-y += irq.o reset.o machtype.o
+obj-y += irq.o reset.o
 
 EXTRA_CFLAGS += -Werror