[ARM] 5222/1: Allow configuring user:kernel split via Kconfig

This patch adds a config option (CONFIG_VMSPLIT_*) to allow choosing
between 3:1, 2:2 and 1:3 user:kernel memory splits.

Tested-by: Riku Voipio <[e-mail]>
Signed-off-by: Lennert Buytenhek <[e-mail]>
Signed-off-by: Russell King <[e-mail]>

arch/arm/Kconfig

···
 	select PLAT_IOP
 	select PCI
 	select ARCH_SUPPORTS_MSI
+	select VMSPLIT_1G
 	help
 	  Support for Intel's IOP13XX (XScale) family of processors.
 
···
 	  <http://www.linuxdoc.org/docs.html#howto>.
 
 	  If you don't know what to do here, say N.
+
+choice
+	prompt "Memory split"
+	default VMSPLIT_3G
+	help
+	  Select the desired split between kernel and user memory.
+
+	  If you are not absolutely sure what you are doing, leave this
+	  option alone!
+
+	config VMSPLIT_3G
+		bool "3G/1G user/kernel split"
+	config VMSPLIT_2G
+		bool "2G/2G user/kernel split"
+	config VMSPLIT_1G
+		bool "1G/3G user/kernel split"
+endchoice
+
+config PAGE_OFFSET
+	hex
+	default 0x40000000 if VMSPLIT_1G
+	default 0x80000000 if VMSPLIT_2G
+	default 0xC0000000
 
 config NR_CPUS
 	int "Maximum number of CPUs (2-32)"

arch/arm/include/asm/memory.h

···
 #ifndef __ASM_ARM_MEMORY_H
 #define __ASM_ARM_MEMORY_H
 
+#include <linux/compiler.h>
+#include <linux/const.h>
+#include <mach/memory.h>
+#include <asm/sizes.h>
+
 /*
  * Allow for constants defined here to be used from assembly code
  * by prepending the UL suffix only with actual C code compilation.
  */
-#ifndef __ASSEMBLY__
-#define UL(x) (x##UL)
-#else
-#define UL(x) (x)
-#endif
-
-#include <linux/compiler.h>
-#include <mach/memory.h>
-#include <asm/sizes.h>
+#define UL(x) _AC(x, UL)
 
 #ifdef CONFIG_MMU
 
-#ifndef TASK_SIZE
 /*
+ * PAGE_OFFSET - the virtual address of the start of the kernel image
  * TASK_SIZE - the maximum size of a user space task.
  * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area
  */
-#define TASK_SIZE		UL(0xbf000000)
-#define TASK_UNMAPPED_BASE	UL(0x40000000)
-#endif
+#define PAGE_OFFSET		UL(CONFIG_PAGE_OFFSET)
+#define TASK_SIZE		(UL(CONFIG_PAGE_OFFSET) - UL(0x01000000))
+#define TASK_UNMAPPED_BASE	(UL(CONFIG_PAGE_OFFSET) / 3)
 
 /*
  * The maximum size of a 26-bit user space task.
  */
 #define TASK_SIZE_26		UL(0x04000000)
-
-/*
- * Page offset: 3GB
- */
-#ifndef PAGE_OFFSET
-#define PAGE_OFFSET		UL(0xc0000000)
-#endif
 
 /*
  * The module space lives between the addresses given by TASK_SIZE

arch/arm/mach-footbridge/include/mach/memory.h

···
 
 #endif
 
-/* Task size and page offset at 3GB */
-#define TASK_SIZE		UL(0xbf000000)
-#define PAGE_OFFSET		UL(0xc0000000)
-
 /*
  * Cache flushing area.
  */
···
  * Physical DRAM offset.
  */
 #define PHYS_OFFSET		UL(0x00000000)
-
-/*
- * This decides where the kernel will search for a free chunk of vm
- * space during mmap's.
- */
-#define TASK_UNMAPPED_BASE ((TASK_SIZE + 0x01000000) / 3)
 
 #define FLUSH_BASE_PHYS		0x50000000
 

arch/arm/mach-iop13xx/include/mach/memory.h

···
  * Physical DRAM offset.
  */
 #define PHYS_OFFSET	UL(0x00000000)
-#define TASK_SIZE  	UL(0x3f000000)
-#define PAGE_OFFSET	UL(0x40000000)
-#define TASK_UNMAPPED_BASE ((TASK_SIZE + 0x01000000) / 3)
 
 #ifndef __ASSEMBLY__