ARM: proc-arm94*.S: fix setup function

Both ARM946 and ARM940 setup functions were corrupting r1 and r2,
which is not permissible - these are used to carry the machine ID
and boot data into the kernel, and must be preserved.

The code responsible for this was the same in both files: they were
using the registers to generate a protection region register value.

Fix this by turning this process into a macro, and using that macro
in both these files with an alternative register allocation.  r0,
r3 and r7 can be used for temporary values here.

Reported-by: Alex Dumitrache <broscutamaker@gmail.com>
Tested-by: Georg Hofstetter <g3gg0.de@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/proc-arm940.S b/arch/arm/mm/proc-arm940.S
index e5212d4..c42cdd3 100644
--- a/arch/arm/mm/proc-arm940.S
+++ b/arch/arm/mm/proc-arm940.S
@@ -297,26 +297,16 @@
 	mcr	p15, 0, r0, c6,	c0, 1
 
 	ldr	r0, =(CONFIG_DRAM_BASE & 0xFFFFF000) @ base[31:12] of RAM
-	ldr	r1, =(CONFIG_DRAM_SIZE >> 12)	@ size of RAM (must be >= 4KB)
-	mov	r2, #10				@ 11 is the minimum (4KB)
-1:	add	r2, r2, #1			@ area size *= 2
-	mov	r1, r1, lsr #1
-	bne	1b				@ count not zero r-shift
-	orr	r0, r0, r2, lsl #1		@ the area register value
-	orr	r0, r0, #1			@ set enable bit
-	mcr	p15, 0, r0, c6,	c1, 0		@ set area 1, RAM
-	mcr	p15, 0, r0, c6,	c1, 1
+	ldr	r7, =CONFIG_DRAM_SIZE >> 12	@ size of RAM (must be >= 4KB)
+	pr_val	r3, r0, r7, #1
+	mcr	p15, 0, r3, c6,	c1, 0		@ set area 1, RAM
+	mcr	p15, 0, r3, c6,	c1, 1
 
 	ldr	r0, =(CONFIG_FLASH_MEM_BASE & 0xFFFFF000) @ base[31:12] of FLASH
-	ldr	r1, =(CONFIG_FLASH_SIZE >> 12)	@ size of FLASH (must be >= 4KB)
-	mov	r2, #10				@ 11 is the minimum (4KB)
-1:	add	r2, r2, #1			@ area size *= 2
-	mov	r1, r1, lsr #1
-	bne	1b				@ count not zero r-shift
-	orr	r0, r0, r2, lsl #1		@ the area register value
-	orr	r0, r0, #1			@ set enable bit
-	mcr	p15, 0, r0, c6,	c2, 0		@ set area 2, ROM/FLASH
-	mcr	p15, 0, r0, c6,	c2, 1
+	ldr	r7, =CONFIG_FLASH_SIZE		@ size of FLASH (must be >= 4KB)
+	pr_val	r3, r0, r6, #1
+	mcr	p15, 0, r3, c6,	c2, 0		@ set area 2, ROM/FLASH
+	mcr	p15, 0, r3, c6,	c2, 1
 
 	mov	r0, #0x06
 	mcr	p15, 0, r0, c2, c0, 0		@ Region 1&2 cacheable