Check whether the TLB operations need broadcasting on SMP systems

ARMv7 SMP hardware can handle the TLB maintenance operations
broadcasting in hardware so that the software can avoid the costly IPIs.
This patch adds the necessary checks (the MMFR3 CPUID register) to avoid
the broadcasting if already supported by the hardware.

(this patch is based on the work done by Tony Thompson @ ARM)

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm/mm/proc-v7.S

@@ -176,8 +176,8 @@ cpu_v7_name:
  */
 __v7_setup:
 #ifdef CONFIG_SMP
-	mrc	p15, 0, r0, c1, c0, 1		@ Enable SMP/nAMP mode
-	orr	r0, r0, #(0x1 << 6)
+	mrc	p15, 0, r0, c1, c0, 1		@ Enable SMP/nAMP mode and
+	orr	r0, r0, #(1 << 6) | (1 << 0)	@ TLB ops broadcasting
 	mcr	p15, 0, r0, c1, c0, 1
 #endif
 	adr	r12, __v7_setup_stack		@ the local stack

arch/arm/mm/tlb-v7.S

@@ -42,9 +42,11 @@ ENTRY(v7wbi_flush_user_tlb_range)
 	mov	r1, r1, lsl #PAGE_SHIFT
 	vma_vm_flags r2, r2			@ get vma->vm_flags
 1:
-	mcr	p15, 0, r0, c8, c6, 1		@ TLB invalidate D MVA (was 1)
-	tst	r2, #VM_EXEC			@ Executable area ?
-	mcrne	p15, 0, r0, c8, c5, 1		@ TLB invalidate I MVA (was 1)
+#ifdef CONFIG_SMP
+	mcr	p15, 0, r0, c8, c3, 1		@ TLB invalidate U MVA (shareable) 
+#else
+	mcr	p15, 0, r0, c8, c7, 1		@ TLB invalidate U MVA
+#endif
 	add	r0, r0, #PAGE_SZ
 	cmp	r0, r1
 	blo	1b
@@ -69,8 +71,11 @@ ENTRY(v7wbi_flush_kern_tlb_range)
 	mov	r0, r0, lsl #PAGE_SHIFT
 	mov	r1, r1, lsl #PAGE_SHIFT
 1:
-	mcr	p15, 0, r0, c8, c6, 1		@ TLB invalidate D MVA
-	mcr	p15, 0, r0, c8, c5, 1		@ TLB invalidate I MVA
+#ifdef CONFIG_SMP
+	mcr	p15, 0, r0, c8, c3, 1		@ TLB invalidate U MVA (shareable)
+#else
+	mcr	p15, 0, r0, c8, c7, 1		@ TLB invalidate U MVA
+#endif
 	add	r0, r0, #PAGE_SZ
 	cmp	r0, r1
 	blo	1b
@@ -87,5 +92,5 @@ ENDPROC(v7wbi_flush_kern_tlb_range)
 ENTRY(v7wbi_tlb_fns)
 	.long	v7wbi_flush_user_tlb_range
 	.long	v7wbi_flush_kern_tlb_range
-	.long	v6wbi_tlb_flags
+	.long	v7wbi_tlb_flags
 	.size	v7wbi_tlb_fns, . - v7wbi_tlb_fns