x86/apic: Move online masking to core code

All implementations of apic->cpu_mask_to_apicid_and() mask out the offline
cpus. The callsite already has a mask available, which has the offline CPUs
removed. Use that and remove the extra bits.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235446.560868224@linutronix.de

arch/x86/kernel/apic/apic.c

@@ -2205,19 +2205,12 @@ int default_cpu_mask_to_apicid_and(const struct cpumask *cpumask,
 				   const struct cpumask *andmask,
 				   unsigned int *apicid)
 {
-	unsigned int cpu;
+	unsigned int cpu = cpumask_first_and(cpumask, andmask);
 
-	for_each_cpu_and(cpu, cpumask, andmask) {
-		if (cpumask_test_cpu(cpu, cpu_online_mask))
-			break;
-	}
-
-	if (likely(cpu < nr_cpu_ids)) {
+	if (cpu >= nr_cpu_ids)
+		return -EINVAL;
 	*apicid = per_cpu(x86_cpu_to_apicid, cpu);
 	return 0;
-	}
-
-	return -EINVAL;
 }
 
 int flat_cpu_mask_to_apicid_and(const struct cpumask *cpumask,
@@ -2226,14 +2219,12 @@ int flat_cpu_mask_to_apicid_and(const struct cpumask *cpumask,
 {
 	unsigned long cpu_mask = cpumask_bits(cpumask)[0] &
 				 cpumask_bits(andmask)[0] &
-				 cpumask_bits(cpu_online_mask)[0] &
 				 APIC_ALL_CPUS;
 
-	if (likely(cpu_mask)) {
+	if (!cpu_mask)
+		return -EINVAL;
 	*apicid = (unsigned int)cpu_mask;
 	return 0;
-	}
-	return -EINVAL;
 }
 
 /*

arch/x86/kernel/apic/vector.c

@@ -221,8 +221,11 @@ static int __assign_irq_vector(int irq, struct apic_chip_data *d,
 	 * Cache destination APIC IDs into cfg->dest_apicid. This cannot fail
 	 * as we already established, that mask & d->domain & cpu_online_mask
 	 * is not empty.
+	 *
+	 * vector_searchmask is a subset of d->domain and has the offline
+	 * cpus masked out.
 	 */
-	BUG_ON(apic->cpu_mask_to_apicid_and(mask, d->domain,
+	BUG_ON(apic->cpu_mask_to_apicid_and(mask, vector_searchmask,
 					    &d->cfg.dest_apicid));
 	return 0;
 }

arch/x86/kernel/apic/x2apic_cluster.c

@@ -108,31 +108,24 @@ x2apic_cpu_mask_to_apicid_and(const struct cpumask *cpumask,
 			      const struct cpumask *andmask,
 			      unsigned int *apicid)
 {
+	unsigned int cpu;
 	u32 dest = 0;
 	u16 cluster;
-	int i;
 
-	for_each_cpu_and(i, cpumask, andmask) {
-		if (!cpumask_test_cpu(i, cpu_online_mask))
-			continue;
-		dest = per_cpu(x86_cpu_to_logical_apicid, i);
-		cluster = x2apic_cluster(i);
-		break;
-	}
-
-	if (!dest)
+	cpu = cpumask_first_and(cpumask, andmask);
+	if (cpu >= nr_cpu_ids)
 		return -EINVAL;
 
-	for_each_cpu_and(i, cpumask, andmask) {
-		if (!cpumask_test_cpu(i, cpu_online_mask))
-			continue;
-		if (cluster != x2apic_cluster(i))
+	dest = per_cpu(x86_cpu_to_logical_apicid, cpu);
+	cluster = x2apic_cluster(cpu);
+
+	for_each_cpu_and(cpu, cpumask, andmask) {
+		if (cluster != x2apic_cluster(cpu))
 			continue;
-		dest |= per_cpu(x86_cpu_to_logical_apicid, i);
+		dest |= per_cpu(x86_cpu_to_logical_apicid, cpu);
 	}
 
 	*apicid = dest;
-
 	return 0;
 }