IB/hfi1: Create common functions for affinity CPU mask operations

CPU masks are used to keep track of affinity assignments for IRQs
and processes. Operations performed on these affinity CPU masks are
duplicated throughout the code.

Create common functions for affinity CPU mask operations to remove
duplicate code.

Reviewed-by: Michael J. Ruhl <[e-mail]>
Signed-off-by: Sebastian Sanchez <[e-mail]>
Signed-off-by: Dennis Dalessandro <[e-mail]>
Signed-off-by: Doug Ledford <[e-mail]>

drivers/infiniband/hw/hfi1/affinity.c

···
 	set->gen = 0;
 }
 
+/* Increment generation of CPU set if needed */
+static void _cpu_mask_set_gen_inc(struct cpu_mask_set *set)
+{
+	if (cpumask_equal(&set->mask, &set->used)) {
+		/*
+		 * We've used up all the CPUs, bump up the generation
+		 * and reset the 'used' map
+		 */
+		set->gen++;
+		cpumask_clear(&set->used);
+	}
+}
+
+static void _cpu_mask_set_gen_dec(struct cpu_mask_set *set)
+{
+	if (cpumask_empty(&set->used) && set->gen) {
+		set->gen--;
+		cpumask_copy(&set->used, &set->mask);
+	}
+}
+
+/* Get the first CPU from the list of unused CPUs in a CPU set data structure */
+static int cpu_mask_set_get_first(struct cpu_mask_set *set, cpumask_var_t diff)
+{
+	int cpu;
+
+	if (!diff || !set)
+		return -EINVAL;
+
+	_cpu_mask_set_gen_inc(set);
+
+	/* Find out CPUs left in CPU mask */
+	cpumask_andnot(diff, &set->mask, &set->used);
+
+	cpu = cpumask_first(diff);
+	if (cpu >= nr_cpu_ids) /* empty */
+		cpu = -EINVAL;
+	else
+		cpumask_set_cpu(cpu, &set->used);
+
+	return cpu;
+}
+
+static void cpu_mask_set_put(struct cpu_mask_set *set, int cpu)
+{
+	if (!set)
+		return;
+
+	cpumask_clear_cpu(cpu, &set->used);
+	_cpu_mask_set_gen_dec(set);
+}
+
 /* Initialize non-HT cpu cores mask */
 void init_real_cpu_mask(void)
 {
···
 		if (!zalloc_cpumask_var(&diff, GFP_KERNEL))
 			return -ENOMEM;
 
-		if (cpumask_equal(&set->mask, &set->used)) {
-			/*
-			 * We've used up all the CPUs, bump up the generation
-			 * and reset the 'used' map
-			 */
-			set->gen++;
-			cpumask_clear(&set->used);
+		cpu = cpu_mask_set_get_first(set, diff);
+		if (cpu < 0) {
+			free_cpumask_var(diff);
+			dd_dev_err(dd, "Failure to obtain CPU for IRQ\n");
+			return cpu;
 		}
-		cpumask_andnot(diff, &set->mask, &set->used);
-		cpu = cpumask_first(diff);
-		cpumask_set_cpu(cpu, &set->used);
 
 		free_cpumask_var(diff);
 	}
···
 
 	if (set) {
 		cpumask_andnot(&set->used, &set->used, &msix->mask);
-		if (cpumask_empty(&set->used) && set->gen) {
-			set->gen--;
-			cpumask_copy(&set->used, &set->mask);
-		}
+		_cpu_mask_set_gen_dec(set);
 	}
 
 	irq_set_affinity_hint(msix->irq, NULL);
···
 	 * If we've used all available HW threads, clear the mask and start
 	 * overloading.
 	 */
-	if (cpumask_equal(&set->mask, &set->used)) {
-		set->gen++;
-		cpumask_clear(&set->used);
-	}
+	_cpu_mask_set_gen_inc(set);
 
 	/*
 	 * If NUMA node has CPUs used by interrupt handlers, include them in the
···
 		return;
 
 	mutex_lock(&affinity->lock);
-	cpumask_clear_cpu(cpu, &set->used);
+	cpu_mask_set_put(set, cpu);
 	hfi1_cdbg(PROC, "Returning CPU %d for future process assignment", cpu);
-	if (cpumask_empty(&set->used) && set->gen) {
-		set->gen--;
-		cpumask_copy(&set->used, &set->mask);
-	}
 	mutex_unlock(&affinity->lock);
 }