[ARM] nommu: manage the CP15 things

All the current CP15 access codes in ARM arch can be categorized and
conditioned by the defines as follows:

     Related operation	Safe condition
  a. any CP15 access	!CPU_CP15
  b. alignment trap	CPU_CP15_MMU
  c. D-cache(C-bit)	CPU_CP15
  d. I-cache		CPU_CP15 && !( CPU_ARM610 || CPU_ARM710 ||
				CPU_ARM720 || CPU_ARM740 ||
				CPU_XSCALE || CPU_XSC3 )
  e. alternate vector	CPU_CP15 && !CPU_ARM740
  f. TTB		CPU_CP15_MMU
  g. Domain		CPU_CP15_MMU
  h. FSR/FAR		CPU_CP15_MMU

For example, alternate vector is supported if and only if
"CPU_CP15 && !CPU_ARM740" is satisfied.

Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/head-nommu.S

@@ -9,7 +9,6 @@
  * published by the Free Software Foundation.
  *
  *  Common kernel startup code (non-paged MM)
- *    for 32-bit CPUs which has a process ID register(CP15).
  *
  */
 #include <linux/linkage.h>
@@ -40,7 +39,11 @@
 ENTRY(stext)
 	msr	cpsr_c, #PSR_F_BIT | PSR_I_BIT | SVC_MODE @ ensure svc mode
 						@ and irqs disabled
+#ifndef CONFIG_CPU_CP15
+	ldr	r9, =CONFIG_PROCESSOR_ID
+#else
 	mrc	p15, 0, r9, c0, c0		@ get processor id
+#endif
 	bl	__lookup_processor_type		@ r5=procinfo r9=cpuid
 	movs	r10, r5				@ invalid processor (r5=0)?
 	beq	__error_p				@ yes, error 'p'
@@ -58,6 +61,7 @@ ENTRY(stext)
  */
 	.type	__after_proc_init, %function
 __after_proc_init:
+#ifdef CONFIG_CPU_CP15
 	mrc	p15, 0, r0, c1, c0, 0		@ read control reg
 #ifdef CONFIG_ALIGNMENT_TRAP
 	orr	r0, r0, #CR_A
@@ -74,6 +78,7 @@ __after_proc_init:
 	bic	r0, r0, #CR_I
 #endif
 	mcr	p15, 0, r0, c1, c0, 0		@ write control reg
+#endif /* CONFIG_CPU_CP15 */
 
 	mov	pc, r13				@ clear the BSS and jump
 						@ to start_kernel