ARM: 6944/1: mm: allow ASID 0 to be allocated to tasks

Now that ASID 0 is no longer used as a reserved value, allow it to be
allocated to tasks.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/context.c

@@ -94,7 +94,7 @@ static void reset_context(void *info)
 		return;
 
 	smp_rmb();
-	asid = cpu_last_asid + cpu + 1;
+	asid = cpu_last_asid + cpu;
 
 	flush_context();
 	set_mm_context(mm, asid);
@@ -144,13 +144,13 @@ void __new_context(struct mm_struct *mm)
 	 * to start a new version and flush the TLB.
 	 */
 	if (unlikely((asid & ~ASID_MASK) == 0)) {
-		asid = cpu_last_asid + smp_processor_id() + 1;
+		asid = cpu_last_asid + smp_processor_id();
 		flush_context();
 #ifdef CONFIG_SMP
 		smp_wmb();
 		smp_call_function(reset_context, NULL, 1);
 #endif
-		cpu_last_asid += NR_CPUS;
+		cpu_last_asid += NR_CPUS - 1;
 	}
 
 	set_mm_context(mm, asid);